Publications by authors named "Htoo Zarni Oo"

42 Publications

Evaluation of carbonic anhydrase IX as a potential therapeutic target in urothelial carcinoma.

Urol Oncol 2021 May 31. Epub 2021 May 31.

Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada.

Objective: Carbonic anhydrase IX (CA9) is important in the regulation of intra- and extracellular pH in solid tumors, contributing to cell growth and invasion. In urothelial carcinoma (UC), CA9 has been identified as a urinary marker for disease detection, but its biologic role is unknown. To date, differential gene expression patterns of CA9 in various molecular subtypes and potential effects of CA9 inhibition in UC cells are unknown. We aimed to investigate the function of CA9 and the effects of CA9 inhibition in invasive UC.

Methods: Immunohistochemistry was used to assess CA9 expression in a cohort of 153 patients undergoing radical cystectomy. CA9 expression was correlated with molecular subtype by analysis of the TCGA data and of our own cohort of 223 patients with invasive UC receiving neoadjuvant chemotherapy. CA9 expression was assessed in a panel of 12 UC cell lines by Western Blot and qPCR, and multiple siRNAs were used to silence CA9 in 2 cell lines. Effects of CA9 silencing on cell growth, migration, and invasion were assessed. We also used the small molecule inhibitor U-104 to inhibit CA9 in vitro and in an orthotopic xenograft model.

Results: CA9 expression was higher in cancer tissue compared to benign urothelium and was particularly highly expressed in luminal papillary and basal squamous tumors. CA9 expression did not correlate with outcome after neoadjuvant chemotherapy and/or radical cystectomy. Silencing of CA9 by siRNA diminished invasion but did not induce a consistent change of cell growth and migration. Treatment with U-104 led to cell growth reduction only at high concentrations in vitro and failed to have a significant effect on tumor growth in vivo.

Conclusions: The present study confirms over-expression of CA9 in UC and for the first time shows a correlation with molecular subtypes. However, CA9 expression showed no association with the outcome of patients with muscle invasive bladder cancer and inhibition of CA9 did not lead to a consistent inhibition of tumor growth. Based on these data, CA9 exhibits a role neither as a predictive or prognostic marker nor as a therapeutic target in invasive UC.
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http://dx.doi.org/10.1016/j.urolonc.2021.04.011DOI Listing
May 2021

Proteomic screens for suppressors of anoikis identify IL1RAP as a promising surface target in Ewing sarcoma.

Cancer Discov 2021 May 21. Epub 2021 May 21.

Michael Smith Genome Science Centre, Brtish Columbia Cancer Agency.

Cancer cells must overcome anoikis (detachment-induced death) to successfully metastasize. Using proteomic screens, we found that distinct oncoproteins upregulate IL-1 receptor accessory protein (IL1RAP) to suppress anoikis. IL1RAP is directly induced by oncogenic fusions of Ewing sarcoma (EwS), a highly metastatic childhood sarcoma. IL1RAP inactivation triggers anoikis and impedes metastatic dissemination of EwS cells. Mechanistically, IL1RAP binds the cell surface system Xc- transporter to enhance exogenous cystine uptake, thereby replenishing cysteine and the glutathione antioxidant. Under cystine depletion, IL1RAP induces cystathionine gamma lyase (CTH) to activate the transsulfuration pathway for de novo cysteine synthesis. Therefore IL1RAP maintains cyst(e)ine and glutathione pools which are vital for redox homeostasis and anoikis resistance. IL1RAP is minimally expressed in pediatric and adult normal tissues, and human anti-IL1RAP antibodies induce potent antibody-dependent cellular cytotoxicity of EwS cells. Therefore, we define IL1RAP as a new cell surface target in EwS, which is potentially exploitable for immunotherapy.
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http://dx.doi.org/10.1158/2159-8290.CD-20-1690DOI Listing
May 2021

Receptor Activator of NF Kappa B (RANK) Expression Indicates Favorable Prognosis in Patients with Muscle-invasive Bladder Cancer.

Eur Urol Focus 2021 May 4. Epub 2021 May 4.

Department of Urology, University Hospital, Tübingen, Germany; Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada; Clinical Trials Unit, Studienpraxis Urologie, Nürtingen, Germany. Electronic address:

Background: Receptor activator of NF kappa B (RANK) and its ligand have an essential role in T-cell regulation and the development of bone metastases. The role of RANK expression in muscle-invasive bladder cancer (MIBC) is unknown.

Objective: To assess the relevance of RANK expression in patients with MIBC.

Design, Setting, And Participants: Expression of RANK was assessed via immunohistochemistry of benign urothelium, MIBC tissue, and lymph node metastases from 153 patients undergoing radical cystectomy. Expression data from The Cancer Genome Atlas (TCGA) cohort were analyzed for potential associations with molecular subtypes and outcome.

Outcome Measurements And Statistical Analysis: RANK expression was correlated with clinical and pathological parameters and to individual data for the clinical course of MIBC.

Results And Limitations: Expression of RANK was significantly higher in both primary tumors (p = 0.02) and lymph node metastases (p = 0.01) compared to normal urothelium. In tumor tissue, RANK expression was significantly lower in patients with locally advanced disease and lymph node involvement compared to those with organ-confined disease (p = 0.0009) and node-negative MIBC (p = 0.0002). In univariable and multivariable analyses, high expression of RANK was associated with a longer time to recurrence (p = 0.0005 and 0.01) and better cancer-specific (p = 0.0004 and 0.007) and overall survival (p = 0.002 and 0.04). High expression of RANK was associated with better outcome for patients with luminal infiltrated tumors in the TCGA cohort.

Conclusions: RANK expression is increased in bladder cancer tissue compared to benign urothelium, with higher expression in organ-defined compared to locally advanced disease. High RANK expression indicates a favorable prognosis in MIBC. The prognostic role differs in tumors of different molecular subtypes.

Patient Summary: Expression of a protein involved in bone turnover regulation (RANK) is higher in bladder cancer tissue than in benign bladder tissue. However, high levels of RANK on tumor cells indicate favorable prognosis for patients with bladder cancer that invades the muscle layer of the bladder.
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http://dx.doi.org/10.1016/j.euf.2021.04.015DOI Listing
May 2021

Paternally Expressed Gene 10 (PEG10) Promotes Growth, Invasion, and Survival of Bladder Cancer.

Mol Cancer Ther 2020 10 26;19(10):2210-2220. Epub 2020 Aug 26.

The Vancouver Prostate Centre and Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada.

() has been associated with neuroendocrine muscle-invasive bladder cancer (MIBC), a subtype of the disease with the poorest survival. In this work, we further characterized the expression pattern of in The Cancer Genome Atlas database of 412 patients with MIBC, and found that, compared with other subtypes, mRNA level was enhanced in neuroendocrine-like MIBC and highly correlated with other neuroendocrine markers. PEG10 protein level also associated with neuroendocrine markers in a tissue microarray of 82 cases. In bladder cancer cell lines, PEG10 expression was induced in drug-resistant compared with parental cells, and knocking down of PEG10 resensitized cells to chemotherapy. Loss of PEG10 increased protein levels of cell-cycle regulators p21 and p27 and delayed G-S-phase transition, while overexpression of PEG10 enhanced cancer cell proliferation. PEG10 silencing also lowered levels of SLUG and SNAIL, leading to reduced invasion and migration. In an orthotopic bladder cancer model, systemic treatment with PEG10 antisense oligonucleotide delayed progression of T24 xenografts. In summary, elevated expression of in MIBC may contribute to the disease progression by promoting survival, proliferation, and metastasis. Targeting PEG10 is a novel potential therapeutic approach for a subset of bladder cancers.
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http://dx.doi.org/10.1158/1535-7163.MCT-19-1031DOI Listing
October 2020

An affinity chromatography and glycoproteomics workflow to profile the chondroitin sulfate proteoglycans that interact with malarial VAR2CSA in the placenta and in cancer.

Glycobiology 2020 12;30(12):989-1002

Department of Cellular and Molecular Medicine, University of California, San Diego, La Jolla, CA 92093, USA.

Chondroitin sulfate (CS) is the placental receptor for the VAR2CSA malaria protein, expressed at the surface of infected erythrocytes during Plasmodium falciparum infection. Infected cells adhere to syncytiotrophoblasts or get trapped within the intervillous space by binding to a determinant in a 4-O-sulfated CS chains. However, the exact structure of these glycan sequences remains unclear. VAR2CSA-reactive CS is also expressed by tumor cells, making it an attractive target for cancer diagnosis and therapeutics. The identities of the proteoglycans carrying these modifications in placental and cancer tissues remain poorly characterized. This information is clinically relevant since presentation of the glycan chains may be mediated by novel core proteins or by a limited subset of established proteoglycans. To address this question, VAR2CSA-binding proteoglycans were affinity-purified from the human placenta, tumor tissues and cancer cells and analyzed through a specialized glycoproteomics workflow. We show that VAR2CSA-reactive CS chains associate with a heterogenous group of proteoglycans, including novel core proteins. Additionally, this work demonstrates how affinity purification in combination with glycoproteomics analysis can facilitate the characterization of CSPGs with distinct CS epitopes. A similar workflow can be applied to investigate the interaction of CSPGs with other CS binding lectins as well.
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http://dx.doi.org/10.1093/glycob/cwaa039DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7724742PMC
December 2020

Oncofetal Chondroitin Sulfate: A Putative Therapeutic Target in Adult and Pediatric Solid Tumors.

Cells 2020 03 28;9(4). Epub 2020 Mar 28.

Department of Urologic Sciences, University of British Columbia, Vancouver, BC V5Z 1M9, Canada.

Solid tumors remain a major challenge for targeted therapeutic intervention strategies such as antibody-drug conjugates and immunotherapy. At a minimum, clear and actionable solid tumor targets have to comply with the key biological requirement of being differentially over-expressed in solid tumors and metastasis, in contrast to healthy organs. Oncofetal chondroitin sulfate is a cancer-specific secondary glycosaminoglycan modification to proteoglycans expressed in a variety of solid tumors and metastasis. Normally, this modification is found to be exclusively expressed in the placenta, where it is thought to facilitate normal placental implantation during pregnancy. Informed by this biology, oncofetal chondroitin sulfate is currently under investigation as a broad and specific target in solid tumors. Here, we discuss oncofetal chondroitin sulfate as a potential therapeutic target in childhood solid tumors in the context of current knowhow obtained over the past five years in adult cancers.
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http://dx.doi.org/10.3390/cells9040818DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7226838PMC
March 2020

Y-box binding protein-1 is crucial in acquired drug resistance development in metastatic clear-cell renal cell carcinoma.

J Exp Clin Cancer Res 2020 Feb 10;39(1):33. Epub 2020 Feb 10.

Department of Urologic Sciences, Faculty of Medicine, University of British Columbia, Level 6, 2775-Laurel St, Vancouver, BC, V5Z 1M9, Canada.

Background: Renal cell carcinoma (RCC) is a highly vascular tumor and patients with low risk metastatic RCC of clear-cell histological sub-type (mccRCC) are treated with tyrosine-kinase inhibitors (TKIs), sunitinib, as the first-line of treatment. Unfortunately, TKI resistance eventually develops, and the underlying molecular mechanism is not well understood.

Methods: RCC cell-line with metastatic clear-cell histology (Caki-1), and patient samples were analysed to identify the role of Y-box binding protein 1 (YB-1) and ATP-binding cassette sub-family B member 1 (ABCB-1) in acquired sunitinib-resistance development. Caki-1 was conditioned with increasing sunitinib doses to recapitulate acquired resistance development in clinics. Sunitinib-conditioned and wild-type Caki-1 were subjected to cell viability assay, scratch assay, chicken embryo chorioallantoic membrane engraftment and proteomics analysis. Classical biochemical assays like flow cytometry, immunofluorescent staining, immunohistochemical staining, optical coherence tomography imaging, Western Blot and RT-PCR assays were applied to determine the possible mechanism of sunitinib-resistance development and the effect of drug treatments. Publicly available data was also used to determine the role of YB-1 upregulation in ccRCC and the patients' overall survival.

Results: We demonstrate that YB-1 and ABCB-1 are upregulated in sunitinib-resistant in vitro, ex vivo, in vivo and patient samples compared to the sensitive samples. This provides evidence to a mechanism of acquired sunitinib-resistance development in mccRCC. Furthermore, our results establish that inhibiting ABCB-1 with elacridar, in addition to sunitinib, has a positive impact on reverting sunitinib-resistance development in in vitro, ex vivo and in vivo models.

Conclusion: This work proposes a targeted therapy (elacridar and sunitinib) to re-sensitize sunitinib-resistant mccRCC and, possibly, slow disease progression.
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http://dx.doi.org/10.1186/s13046-020-1527-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7011538PMC
February 2020

Cancer Cells Employ Nuclear Caspase-8 to Overcome the p53-Dependent G2/M Checkpoint through Cleavage of USP28.

Mol Cell 2020 03 22;77(5):970-984.e7. Epub 2020 Jan 22.

Experimental Dermatology, Department of Dermatology, TU-Dresden, Dresden 01307, Germany; Center for Regenerative Therapies Dresden, TU-Dresden, Dresden 01307, Germany. Electronic address:

Cytosolic caspase-8 is a mediator of death receptor signaling. While caspase-8 expression is lost in some tumors, it is increased in others, indicating a conditional pro-survival function of caspase-8 in cancer. Here, we show that tumor cells employ DNA-damage-induced nuclear caspase-8 to override the p53-dependent G2/M cell-cycle checkpoint. Caspase-8 is upregulated and localized to the nucleus in multiple human cancers, correlating with treatment resistance and poor clinical outcome. Depletion of caspase-8 causes G2/M arrest, stabilization of p53, and induction of p53-dependent intrinsic apoptosis in tumor cells. In the nucleus, caspase-8 cleaves and inactivates the ubiquitin-specific peptidase 28 (USP28), preventing USP28 from de-ubiquitinating and stabilizing wild-type p53. This results in de facto p53 protein loss, switching cell fate from apoptosis toward mitosis. In summary, our work identifies a non-canonical role of caspase-8 exploited by cancer cells to override the p53-dependent G2/M cell-cycle checkpoint.
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http://dx.doi.org/10.1016/j.molcel.2019.12.023DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7060810PMC
March 2020

Multicenter Validation of Histopathologic Tumor Regression Grade After Neoadjuvant Chemotherapy in Muscle-invasive Bladder Carcinoma.

Am J Surg Pathol 2019 12;43(12):1600-1610

Department of Urology, University of Bern, Bern.

Response classification after neoadjuvant chemotherapy in muscle-invasive bladder carcinoma is based on the TNM stage at radical cystectomy. We recently showed that histopathologic tumor regression grades (TRGs) add prognostic information to TNM. Our aim was to validate the prognostic significance of TRG in muscle-invasive bladder cancer in a multicenter setting. We enrolled 389 patients who underwent cisplatin-based chemotherapy before radical cystectomy in 8 centers between 2010 and 2016. Median follow-up was 2.2 years. TRG was determined in radical cystectomy specimens by local pathologists. Central pathology review was conducted in 20% of cases, which were randomly selected. The major response was defined as ≤pT1N0. The remaining patients were grouped into partial responders (≥ypT2N0-3 and TRG 2) and nonresponders (≥ypT2N0-3 and TRG 3). TRG was successfully determined in all cases, and interobserver agreement in central pathology review was high (κ=0.83). After combining TRG and TNM, 47%, 15%, and 38% of patients were major, partial, and nonresponders, respectively. Combination of TRG and TNM showed significant prognostic discrimination of overall survival (major responder: reference; partial responder: hazard ratio 3.5 [95% confidence interval: 1.8-6.8]; nonresponder: hazard ratio 6.1 [95% confidence interval: 3.6-10.3]). This discrimination was superior compared with TNM staging alone, supported by 2 goodness-of-fit criteria (P=0.041). TRG is a simple, reproducible histopathologic measurement of response to neoadjuvant chemotherapy in muscle-invasive bladder cancer. Integrating TRG with TNM staging resulted in significantly better prognostic stratification than TNM staging alone.
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http://dx.doi.org/10.1097/PAS.0000000000001371DOI Listing
December 2019

Androgen-regulated transcription of drives alternative splicing patterns in prostate cancer.

Elife 2019 09 3;8. Epub 2019 Sep 3.

Institute of Genetic Medicine, University of Newcastle, Newcastle, United Kingdom.

Prostate is the most frequent cancer in men. Prostate cancer progression is driven by androgen steroid hormones, and delayed by androgen deprivation therapy (ADT). Androgens control transcription by stimulating androgen receptor (AR) activity, yet also control pre-mRNA splicing through less clear mechanisms. Here we find androgens regulate splicing through AR-mediated transcriptional control of the epithelial-specific splicing regulator . Both and its close paralog are highly expressed in primary prostate cancer. Androgen stimulation induces splicing switches in many endogenous ESRP2-controlled mRNA isoforms, including splicing switches correlating with disease progression. expression in clinical prostate cancer is repressed by ADT, which may thus inadvertently dampen epithelial splice programmes. Supporting this, treatment with the AR antagonist bicalutamide (Casodex) induced mesenchymal splicing patterns of genes including and . Our data reveals a new mechanism of splicing control in prostate cancer with important implications for disease progression.
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http://dx.doi.org/10.7554/eLife.47678DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6788855PMC
September 2019

Molecular Characterization of Neuroendocrine-like Bladder Cancer.

Clin Cancer Res 2019 07 5;25(13):3908-3920. Epub 2019 Apr 5.

Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada.

Purpose: Neuroendocrine (NE) bladder carcinoma is a rare and aggressive variant. Molecular subtyping studies have found that 5% to 15% of muscle-invasive bladder cancer (MIBC) have transcriptomic patterns consistent with NE bladder cancer in the absence of NE histology. The clinical implications of this NE-like subtype have not been explored in depth.

Experimental Design: Transcriptome-wide expression profiles were generated for MIBC collected from 7 institutions and clinical-use of Decipher Bladder. Using unsupervised clustering, we generated a clustering solution on a prospective training cohort (PTC; = 175), developed single-sample classifiers to predict NE tumors, and evaluated the resultant models on a testing radical cystectomy (RC) cohort ( = 225). A random forest model was finalized and applied to 5 validation cohorts ( = 1302). Uni- and multivariable survival analyses were used to characterize clinical outcomes.

Results: In the training cohort (PTC), hierarchical clustering using an 84-gene panel showed a cluster of 8 patients (4.6%) with highly heterogeneous expression of NE markers in the absence of basal or luminal marker expression. NE-like tumors were identified in 1% to 6.6% of cases in validation cohorts. Patients with NE-like tumors had significantly worse 1-year progression-free survival (65% NE-like vs. 82% overall; = 0.046) and, after adjusting for clinical and pathologic factors, had a 6.4-fold increased risk of all-cause mortality ( = 0.001). IHC confirmed the neuronal character of these tumors.

Conclusions: A single-patient classifier was developed that identifies patients with histologic urothelial cancer harboring a NE transcriptomic profile. These tumors represent a high-risk subgroup of MIBC, which may require different treatment.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-3558DOI Listing
July 2019

BAP1 haploinsufficiency predicts a distinct immunogenic class of malignant peritoneal mesothelioma.

Genome Med 2019 02 18;11(1). Epub 2019 Feb 18.

Vancouver Prostate Centre, 2660 Oak St, Vancouver, BC, V6H 3Z6, Canada.

Background: Malignant peritoneal mesothelioma (PeM) is a rare and fatal cancer that originates from the peritoneal lining of the abdomen. Standard treatment of PeM is limited to cytoreductive surgery and/or chemotherapy, and no effective targeted therapies for PeM exist. Some immune checkpoint inhibitor studies of mesothelioma have found positivity to be associated with a worse prognosis.

Methods: To search for novel therapeutic targets for PeM, we performed a comprehensive integrative multi-omics analysis of the genome, transcriptome, and proteome of 19 treatment-naïve PeM, and in particular, we examined BAP1 mutation and copy number status and its relationship to immune checkpoint inhibitor activation.

Results: We found that PeM could be divided into tumors with an inflammatory tumor microenvironment and those without and that this distinction correlated with haploinsufficiency of BAP1. To further investigate the role of BAP1, we used our recently developed cancer driver gene prioritization algorithm, HIT'nDRIVE, and observed that PeM with BAP1 haploinsufficiency form a distinct molecular subtype characterized by distinct gene expression patterns of chromatin remodeling, DNA repair pathways, and immune checkpoint receptor activation. We demonstrate that this subtype is correlated with an inflammatory tumor microenvironment and thus is a candidate for immune checkpoint blockade therapies.

Conclusions: Our findings reveal BAP1 to be a potential, easily trackable prognostic and predictive biomarker for PeM immunotherapy that refines PeM disease classification. BAP1 stratification may improve drug response rates in ongoing phases I and II clinical trials exploring the use of immune checkpoint blockade therapies in PeM in which BAP1 status is not considered. This integrated molecular characterization provides a comprehensive foundation for improved management of a subset of PeM patients.
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http://dx.doi.org/10.1186/s13073-019-0620-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6378747PMC
February 2019

Post-translational modifications in bladder cancer: Expanding the tumor target repertoire.

Urol Oncol 2020 12 17;38(12):858-866. Epub 2018 Oct 17.

Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada; Vancouver Prostate Centre, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada. Electronic address:

Over the past decade, genomic and transcriptomic analyses have uncovered promising tumor antigens including immunotherapeutic targets in bladder cancer (BCa). Conventional tumor antigens are proteins expressed on the plasma membrane of tumor cells such as EGFR, FGFR3, and ERBB2 in BCa, which can be targeted by antibodies or similar epitope-specific binding reagents. The cellular proteome consists of ∼100,000 proteins but the expression of these proteins is rarely unique to tumor cells. Many tumor-associated proteins are post-translationally modified with phosphorylation, glycosylation, ubiquitination, or SUMOylation moieties. Although these modifications expand the complexity, they potentially offer novel targeting opportunities across tumor sub-populations. Experimental targeting of cancer-specific post-translational modifications (PTMs) has shown encouraging results in pre-clinical models of BCa, which could potentially overcome issues with inherent intra-tumor heterogeneity due to simultaneous expression on different proteins. Here, we review current knowledge on post-translational modifications in BCa and highlight recent efforts in experimental targeting strategies.
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http://dx.doi.org/10.1016/j.urolonc.2018.09.001DOI Listing
December 2020

Clinicopathological significance of RCAN2 production in gastric carcinoma.

Histopathology 2019 Feb;74(3):430-442

Department of Molecular Pathology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

Aims: Gastric cancer (GC) is one of the leading causes of cancer-related death worldwide. Genes expressed only in cancer tissue may be useful biomarkers for cancer diagnosis and therapeutics. The aims of the present study were to analyse regulator of calcineurin 2 (RCAN2) in a large number of GCs, and to investigate how these expression patterns correlate with clinicopathological parameters and various markers.

Methods And Results: An immunohistochemical analysis of RCAN2 in 207 GC tissue samples showed that 110 (53%) GCs were positive for RCAN2. RCAN2-positive GCs were more advanced in terms of TNM classification and tumour stage than RCAN2-negative GCs. Furthermore, RCAN2 was an independent prognostic classifier for GC patients. The cell growth and invasiveness of RCAN2 small interfering RNA (siRNA)-transfected GC cell lines were less than those of the negative control siRNA-transfected cell lines, whereas those of RCAN2-transfected cells were significantly increased as compared with those of empty vector-transfected cells. RCAN2 siRNA inhibits the phosphorylation of AKT and p44/p42 (ERK1/2). RCAN2 was colocalised with EGFR, nuclear β-catenin, MMP7, laminin-γ2, VEGF-A, and VEGF-C.

Conclusion: These results suggest that RCAN2 is involved in tumour progression and is an independent prognostic classifier in patients with GC.
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http://dx.doi.org/10.1111/his.13764DOI Listing
February 2019

Selective Inhibition of the Lactate Transporter MCT4 Reduces Growth of Invasive Bladder Cancer.

Mol Cancer Ther 2018 12 27;17(12):2746-2755. Epub 2018 Sep 27.

Vancouver Prostate Centre, University of British Columbia, Vancouver, Canada.

The significance of lactate transporters has been recognized in various cancer types, but their role in urothelial carcinoma remains mostly unknown. The aim of this study was to investigate the functional importance of the monocarboxylate transporter (MCT) 4 in preclinical models of urothelial carcinoma and to assess its relevance in patient tumors. The association of MCT4 expression with molecular subtypes and outcome was determined in The Cancer Genome Atlas (TCGA) cohort and two independent cohorts of patients with urothelial carcinoma. Silencing of MCT4 was performed using siRNAs in urothelial carcinoma cell lines. Effects of MCT4 inhibition on cell growth, apoptosis, and production of reactive oxygen species (ROS) were assessed. Moreover, effects on lactate efflux were determined. The effects of MCT4 silencing were assessed in an orthotopic xenograft model. MCT4 expression was higher in the basal subtype. Decreased MCT4 methylation and increased RNA and protein expression were associated with worse overall survival (OS). Inhibition of MCT4 led to a reduction in cell growth, induction of apoptosis, and an increased synthesis of ROS. MCT4 inhibition resulted in intracellular accumulation of lactate. , stable knockdown of MCT4 reduced tumor growth. The expression of MCT4 in urothelial carcinoma is associated with features of aggressive tumor biology and portends a poor prognosis. Inhibition of MCT4 results in decreased tumor growth and Targeting lactate metabolism via MCT4 therefore provides a promising therapeutic approach for invasive urothelial carcinoma, especially in the basal subtype.
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http://dx.doi.org/10.1158/1535-7163.MCT-18-0107DOI Listing
December 2018

Divergent Biological Response to Neoadjuvant Chemotherapy in Muscle-invasive Bladder Cancer.

Clin Cancer Res 2019 08 17;25(16):5082-5093. Epub 2018 Sep 17.

Department of Urologic Sciences, University of British Columbia, Vancouver, British Columbia, Canada.

Purpose: After cisplatin-based neoadjuvant chemotherapy (NAC), 60% of patients with muscle-invasive bladder cancer (MIBC) still have residual invasive disease at radical cystectomy. The NAC-induced biological alterations in these cisplatin-resistant tumors remain largely unstudied.

Experimental Design: Radical cystectomy samples were available for gene expression analysis from 133 patients with residual invasive disease after cisplatin-based NAC, of whom 116 had matched pre-NAC samples. Unsupervised consensus clustering (CC) was performed and the consensus clusters were investigated for their biological and clinical characteristics. Hematoxylin & Eosin and IHC on tissue microarrays were used to confirm tissue sampling and gene expression analysis.

Results: Established molecular subtyping models proved to be inconsistent in their classification of the post-NAC samples. Unsupervised CC revealed four distinct consensus clusters. The CC1-Basal and CC2-Luminal subtypes expressed genes consistent with a basal and a luminal phenotype, respectively, and were similar to the corresponding established pretreatment molecular subtypes. The CC3-Immune subtype had the highest immune activity, including T-cell infiltration and checkpoint molecule expression, but lacked both basal and luminal markers. The CC4-Scar-like subtype expressed genes associated with wound healing/scarring, although the proportion of tumor cell content in this subtype did not differ from the other subtypes. Patients with CC4-Scar-like tumors had the most favorable prognosis.

Conclusions: This study expands our knowledge on MIBC not responding to cisplatin by suggesting molecular subtypes to understand the biology of these tumors. Although these molecular subtypes imply consequences for adjuvant treatments, this ultimately needs to be tested in clinical trials.
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http://dx.doi.org/10.1158/1078-0432.CCR-18-1106DOI Listing
August 2019

TEM8/ANTXR1-Specific CAR T Cells as a Targeted Therapy for Triple-Negative Breast Cancer.

Cancer Res 2018 01 28;78(2):489-500. Epub 2017 Nov 28.

Department of Translational Biology and Molecular Medicine, Baylor College of Medicine, Houston, Texas.

Triple-negative breast cancer (TNBC) is an aggressive disease lacking targeted therapy. In this study, we developed a CAR T cell-based immunotherapeutic strategy to target TEM8, a marker initially defined on endothelial cells in colon tumors that was discovered recently to be upregulated in TNBC. CAR T cells were developed that upon specific recognition of TEM8 secreted immunostimulatory cytokines and killed tumor endothelial cells as well as TEM8-positive TNBC cells. Notably, the TEM8 CAR T cells targeted breast cancer stem-like cells, offsetting the formation of mammospheres relative to nontransduced T cells. Adoptive transfer of TEM8 CAR T cells induced regression of established, localized patient-derived xenograft tumors, as well as lung metastatic TNBC cell line-derived xenograft tumors, by both killing TEM8 TNBC tumor cells and targeting the tumor endothelium to block tumor neovascularization. Our findings offer a preclinical proof of concept for immunotherapeutic targeting of TEM8 as a strategy to treat TNBC. These findings offer a preclinical proof of concept for immunotherapeutic targeting of an endothelial antigen that is overexpressed in triple-negative breast cancer and the associated tumor vasculature. .
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http://dx.doi.org/10.1158/0008-5472.CAN-16-1911DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5771806PMC
January 2018

Evasion of immunosurveillance by genomic alterations of PPARγ/RXRα in bladder cancer.

Nat Commun 2017 07 24;8(1):103. Epub 2017 Jul 24.

Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada, V5Z 1M9.

Muscle-invasive bladder cancer (MIBC) is an aggressive disease with limited therapeutic options. Although immunotherapies are approved for MIBC, the majority of patients fail to respond, suggesting existence of complementary immune evasion mechanisms. Here, we report that the PPARγ/RXRα pathway constitutes a tumor-intrinsic mechanism underlying immune evasion in MIBC. Recurrent mutations in RXRα at serine 427 (S427F/Y), through conformational activation of the PPARγ/RXRα heterodimer, and focal amplification/overexpression of PPARγ converge to modulate PPARγ/RXRα-dependent transcription programs. Immune cell-infiltration is controlled by activated PPARγ/RXRα that inhibits expression/secretion of inflammatory cytokines. Clinical data sets and an in vivo tumor model indicate that PPARγ/RXRα impairs CD8 T-cell infiltration and confers partial resistance to immunotherapies. Knockdown of PPARγ or RXRα and pharmacological inhibition of PPARγ significantly increase cytokine expression suggesting therapeutic approaches to reviving immunosurveillance and sensitivity to immunotherapies. Our study reveals a class of tumor cell-intrinsic "immuno-oncogenes" that modulate the immune microenvironment of cancer.Muscle-invasive bladder cancer (MIBC) is a potentially lethal disease. Here the authors characterize diverse genetic alterations in MIBC that convergently lead to constitutive activation of PPARgamma/RXRalpha and result in immunosurveillance escape by inhibiting CD8+ T-cell recruitment.
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http://dx.doi.org/10.1038/s41467-017-00147-wDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5524640PMC
July 2017

MYCN amplified neuroblastoma requires the mRNA translation regulator eEF2 kinase to adapt to nutrient deprivation.

Cell Death Differ 2017 09 2;24(9):1564-1576. Epub 2017 Jun 2.

Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, Canada.

MYC family proteins are implicated in many human cancers, but their therapeutic targeting has proven challenging. MYCN amplification in childhood neuroblastoma (NB) is associated with aggressive disease and high mortality. Novel and effective therapeutic strategies are therefore urgently needed for these tumors. MYC-driven oncogenic transformation impairs cell survival under nutrient deprivation (ND), a characteristic stress condition within the tumor microenvironment. We recently identified eukaryotic Elongation Factor 2 Kinase (eEF2K) as a pivotal mediator of the adaptive response of tumor cells to ND. We therefore hypothesized that eEF2K facilitates the adaptation of MYCN amplified NB to ND, and that inhibiting this pathway can impair MYCN-driven NB progression. To test our hypothesis, we first analyzed publicly available genomic databases and tissue microarrays for eEF2K expression in NB, and for links between eEF2K, MYCN, and clinical outcome in NB. Effects of eEF2K inhibition were evaluated on survival of MYCN amplified versus non-amplified NB cell lines under ND. Finally, NB xenograft mouse models were used to confirm in vitro observations. Our results indicate that high eEF2K expression and activity are strongly predictive of poor outcome in NB, and correlates significantly with MYCN amplification. Inhibition of eEF2K markedly decreases survival of MYCN amplified NB cell lines in vitro under ND. Growth of MYCN amplified NB xenografts is markedly impaired by eEF2K knockdown, particularly under caloric restriction. In summary, eEF2K protects MYCN overexpressing NB cells from ND in vitro and in vivo, highlighting this kinase as a critical mediator of the adaptive response of MYCN amplified NB cells to metabolic stress.
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http://dx.doi.org/10.1038/cdd.2017.79DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5563988PMC
September 2017

An Oncofetal Glycosaminoglycan Modification Provides Therapeutic Access to Cisplatin-resistant Bladder Cancer.

Eur Urol 2017 07 10;72(1):142-150. Epub 2017 Apr 10.

Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada; Vancouver Prostate Centre, Vancouver, BC, Canada; Zymeworks Inc., Vancouver, BC, Canada. Electronic address:

Background: Although cisplatin-based neoadjuvant chemotherapy (NAC) improves survival of unselected patients with muscle-invasive bladder cancer (MIBC), only a minority responds to therapy and chemoresistance remains a major challenge in this disease setting.

Objective: To investigate the clinical significance of oncofetal chondroitin sulfate (ofCS) glycosaminoglycan chains in cisplatin-resistant MIBC and to evaluate these as targets for second-line therapy.

Design, Setting, And Participants: An ofCS-binding recombinant VAR2CSA protein derived from the malaria parasite Plasmodium falciparum (rVAR2) was used as an in situ, in vitro, and in vivo ofCS-targeting reagent in cisplatin-resistant MIBC. The ofCS expression landscape was analyzed in two independent cohorts of matched pre- and post-NAC-treated MIBC patients.

Intervention: An rVAR2 protein armed with cytotoxic hemiasterlin compounds (rVAR2 drug conjugate [VDC] 886) was evaluated as a novel therapeutic strategy in a xenograft model of cisplatin-resistant MIBC.

Outcome Measurements And Statistical Analysis: Antineoplastic effects of targeting ofCS.

Results And Limitations: In situ, ofCS was significantly overexpressed in residual tumors after NAC in two independent patient cohorts (p<0.02). Global gene-expression profiling and biochemical analysis of primary tumors and cell lines revealed syndican-1 and chondroitin sulfate proteoglycan 4 as ofCS-modified proteoglycans in MIBC. In vitro, ofCS was expressed on all MIBC cell lines tested, and VDC886 eliminated these cells in the low-nanomolar IC concentration range. In vivo, VDC886 effectively retarded growth of chemoresistant orthotopic bladder cancer xenografts and prolonged survival (p=0.005). The use of cisplatin only for the generation of chemoresistant xenografts are limitations of our animal model design.

Conclusions: Targeting ofCS provides a promising second-line treatment strategy in cisplatin-resistant MIBC.

Patient Summary: Cisplatin-resistant bladder cancer overexpresses particular sugar chains compared with chemotherapy-naïve bladder cancer. Using a recombinant protein from the malaria parasite Plasmodium falciparum, we can target these sugar chains, and our results showed a significant antitumor effect in cisplatin-resistant bladder cancer. This novel treatment paradigm provides therapeutic access to bladder cancers not responding to cisplatin.
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http://dx.doi.org/10.1016/j.eururo.2017.03.021DOI Listing
July 2017

Burkitt lymphoma expresses oncofetal chondroitin sulfate without being a reservoir for placental malaria sequestration.

Int J Cancer 2017 04 6;140(7):1597-1608. Epub 2017 Feb 6.

Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen and Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark.

Burkitt lymphoma (BL) is a malignant disease, which is frequently found in areas with holoendemic Plasmodium falciparum malaria. We have previously found that the VAR2CSA protein is present on malaria-infected erythrocytes and facilitates a highly specific binding to the placenta. ofCS is absent in other non-malignant tissues and thus VAR2CSA generally facilitates parasite sequestration and accumulation in pregnant women. In this study, we show that the specific receptor for VAR2CSA, the oncofetal chondroitin sulfate (ofCS), is likewise present in BL tissue and cell lines. We therefore explored whether ofCS in BL could act as anchor site for VAR2CSA-expressing infected erythrocytes. In contrast to the placenta, we found no evidence of in vivo sequestering of infected erythrocytes in the BL tissue. Furthermore, we found VAR2CSA-specific antibody titers in children with endemic BL to be lower than in control children from the same malaria endemic region. The abundant presence of ofCS in BL tissue and the absence of ofCS in non-malignant tissue encouraged us to examine whether recombinant VAR2CSA could be used to target BL. We confirmed the binding of VAR2CSA to BL-derived cells and showed that a VAR2CSA drug conjugate efficiently killed the BL-derived cell lines in vitro. These results identify ofCS as a novel therapeutic BL target and highlight how VAR2CSA could be used as a tool for the discovery of novel approaches for directing BL therapy.
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http://dx.doi.org/10.1002/ijc.30575DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5318225PMC
April 2017

Oncofetal Chondroitin Sulfate Glycosaminoglycans Are Key Players in Integrin Signaling and Tumor Cell Motility.

Mol Cancer Res 2016 12 21;14(12):1288-1299. Epub 2016 Sep 21.

Centre for Medical Parasitology at Department of International Health, Immunology and Microbiology, University of Copenhagen, Denmark.

Many tumors express proteoglycans modified with oncofetal chondroitin sulfate glycosaminoglycan chains (ofCS), which are normally restricted to the placenta. However, the role of ofCS in cancer is largely unknown. The function of ofCS in cancer was analyzed using the recombinant ofCS-binding VAR2CSA protein (rVAR2) derived from the malaria parasite, Plasmodium falciparum We demonstrate that ofCS plays a key role in tumor cell motility by affecting canonical integrin signaling pathways. Binding of rVAR2 to tumor cells inhibited the interaction of cells with extracellular matrix (ECM) components, which correlated with decreased phosphorylation of Src kinase. Moreover, rVAR2 binding decreased migration, invasion, and anchorage-independent growth of tumor cells in vitro Mass spectrometry of ofCS-modified proteoglycan complexes affinity purified from tumor cell lines on rVAR2 columns revealed an overrepresentation of proteins involved in cell motility and integrin signaling, such as integrin-β1 (ITGB1) and integrin-α4 (ITGA4). Saturating concentrations of rVAR2 inhibited downstream integrin signaling, which was mimicked by knockdown of the core chondroitin sulfate synthesis enzymes β-1,3-glucuronyltransferase 1 (B3GAT1) and chondroitin sulfate N-acetylgalactosaminyltransferase 1 (CSGALNACT1). The ofCS modification was highly expressed in both human and murine metastatic lesions in situ and preincubation or early intravenous treatment of tumor cells with rVAR2 inhibited seeding and spreading of tumor cells in mice. This was associated with a significant increase in survival of the animals. These data functionally link ofCS modifications with cancer cell motility and further highlights ofCS as a novel therapeutic cancer target.

Implications: The cancer-specific expression of ofCS aids in metastatic phenotypes and is a candidate target for therapy. Mol Cancer Res; 14(12); 1288-99. ©2016 AACR.
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http://dx.doi.org/10.1158/1541-7786.MCR-16-0103DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5136311PMC
December 2016

Real-time and label free determination of ligand binding-kinetics to primary cancer tissue specimens; a novel tool for the assessment of biomarker targeting.

Sens Biosensing Res 2016 Jul;9:23-30

Centre for Medical Parasitology at Department of Immunology and Microbiology, University of Copenhagen, Denmark; Department of Infectious Diseases, Copenhagen University Hospital, Copenhagen, Denmark.

In clinical oncology, diagnosis and evaluation of optimal treatment strategies are mostly based on histopathological examination combined with immunohistochemical (IHC) expression analysis of cancer-associated antigens in formalin fixed paraffin-embedded (FFPE) tissue biopsies. However, informative IHC analysis depends on both the specificity and affinity of the binding reagent, which are inherently difficult to quantify . Here we describe a label-free method that allows for the direct and real-time assessment of molecular binding kinetics on FFPE tissue specimens using quartz crystal microbalance (QCM) enabled biosensor technology. We analysed the interaction between the rVAR2 protein and its placental-like chondroitin sulfate (pl-CS) receptor in primary human placenta tissue and in breast and prostate tumour specimens . rVAR2 interacted with FFPE human placenta and cancer tissue with an affinity in the nanomolar range, and showed no detectable interaction with pl-CS negative normal tissue. We further validated the method by including analysis with the androgen receptor N-20 antibody (-AR). As the K value produced by this method is independent of the number of epitopes available, this readout offers a quantitative and unbiased readout for binding-avidity and amount of binding epitopes. In summary, this method adds a new and important dimension to classical IHC-based molecular pathology by adding information about the binding characteristics in biologically relevant conditions. This can potentially be used to select optimal biologics for diagnostic and for therapeutic applications as well as guide the development of novel high affinity binding drugs.
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http://dx.doi.org/10.1016/j.sbsr.2016.05.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4942562PMC
July 2016

Not all NOTCH Is Created Equal: The Oncogenic Role of NOTCH2 in Bladder Cancer and Its Implications for Targeted Therapy.

Clin Cancer Res 2016 06 14;22(12):2981-92. Epub 2016 Jan 14.

The Vancouver Prostate Centre, University of British Columbia, Vancouver, BC, Canada. Department of Urologic Sciences, University of British Columbia, Vancouver, BC, Canada.

Purpose: Recent molecular analyses of bladder cancer open the door to significant advances in targeted therapies. NOTCH has been identified as a tumor suppressor in bladder cancer, but prior reports have focused on NOTCH1 Here we hypothesized that NOTCH2 is an oncogene suitable for therapeutic targeting in bladder cancer.

Experimental Design: We studied genomic aberrations of NOTCH, compared survival and tumor progression according to NOTCH2 expression levels, and studied NOTCH2 function in vitro and vivo

Results: We report a high rate of NOTCH2 copy number gain in bladder cancer. High NOTCH2 expression was identified especially in the basal subtype and in mesenchymal tumors. NOTCH2 activation correlated with adverse disease parameters and worse prognosis by immunohistochemistry. Forced overexpression of the intracellular domain of NOTCH2 (N2ICD) induced cell growth and invasion by cell-cycle progression, maintenance of stemness and epithelial-to-mesenchymal transition (EMT). These effects were abrogated by silencing of CSL, indicating that the effects were mediated through the canonical NOTCH signaling pathway. In an orthotopic xenograft model, forced overexpression of N2ICD increased growth, invasion, and metastasis. To explore the potential for therapeutic targeting of NOTCH2, we first silenced the receptor with shRNA and subsequently treated with a specific inhibitory antibody. Both interventions decreased cell growth, invasion, and metastasis in vitro and in the orthotopic xenograft model.

Conclusions: We have demonstrated that NOTCH2 acts as an oncogene that promotes bladder cancer growth and metastasis through EMT, cell-cycle progression, and maintenance of stemness. Inhibition of NOTCH2 is a rational novel treatment strategy for invasive bladder cancer. Clin Cancer Res; 22(12); 2981-92. ©2016 AACR.
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http://dx.doi.org/10.1158/1078-0432.CCR-15-2360DOI Listing
June 2016

Hepatoma-derived growth factor-related protein 2 promotes DNA repair by homologous recombination.

Nucleic Acids Res 2016 Mar 31;44(5):2214-26. Epub 2015 Dec 31.

Unit of Cell Death and Metabolism, Center for Autophagy, Recycling and Metabolism, Danish Cancer Society Research Center, Strandboulevarden 49, 2100 Copenhagen, Denmark

We have recently identified lens epithelium-derived growth factor (LEDGF/p75, also known as PSIP1) as a component of the homologous recombination DNA repair machinery. Through its Pro-Trp-Trp-Pro (PWWP) domain, LEDGF/p75 binds to histone marks associated with active transcription and promotes DNA end resection by recruiting DNA endonuclease retinoblastoma-binding protein 8 (RBBP8/CtIP) to broken DNA ends. Here we show that the structurally related PWWP domain-containing protein, hepatoma-derived growth factor-related protein 2 (HDGFRP2), serves a similar function in homologous recombination repair. Its depletion compromises the survival of human U2OS osteosarcoma and HeLa cervix carcinoma cells and impairs the DNA damage-induced phosphorylation of replication protein A2 (RPA2) and the recruitment of DNA endonuclease RBBP8/CtIP to DNA double strand breaks. In contrast to LEDGF/p75, HDGFRP2 binds preferentially to histone marks characteristic for transcriptionally silent chromatin. Accordingly, HDGFRP2 is found in complex with the heterochromatin-binding chromobox homologue 1 (CBX1) and Pogo transposable element with ZNF domain (POGZ). Supporting the functionality of this complex, POGZ-depleted cells show a similar defect in DNA damage-induced RPA2 phosphorylation as HDGFRP2-depleted cells. These data suggest that HDGFRP2, possibly in complex with POGZ, recruits homologous recombination repair machinery to damaged silent genes or to active genes silenced upon DNA damage.
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http://dx.doi.org/10.1093/nar/gkv1526DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4797281PMC
March 2016

Targeting Human Cancer by a Glycosaminoglycan Binding Malaria Protein.

Cancer Cell 2015 10;28(4):500-514

Translational Genomics Research Institute (TGen), Phoenix, AZ 85004, USA.

Plasmodium falciparum engineer infected erythrocytes to present the malarial protein, VAR2CSA, which binds a distinct type chondroitin sulfate (CS) exclusively expressed in the placenta. Here, we show that the same CS modification is present on a high proportion of malignant cells and that it can be specifically targeted by recombinant VAR2CSA (rVAR2). In tumors, placental-like CS chains are linked to a limited repertoire of cancer-associated proteoglycans including CD44 and CSPG4. The rVAR2 protein localizes to tumors in vivo and rVAR2 fused to diphtheria toxin or conjugated to hemiasterlin compounds strongly inhibits in vivo tumor cell growth and metastasis. Our data demonstrate how an evolutionarily refined parasite-derived protein can be exploited to target a common, but complex, malignancy-associated glycosaminoglycan modification.
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http://dx.doi.org/10.1016/j.ccell.2015.09.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4790448PMC
October 2015

Significance of miR-148a in Colorectal Neoplasia: Downregulation of miR-148a Contributes to the Carcinogenesis and Cell Invasion of Colorectal Cancer.

Pathobiology 2015 22;82(5):233-41. Epub 2015 Sep 22.

Department of Molecular Pathology, Institute of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.

Objective: Colorectal cancer (CRC) develops through the deregulation of gene expression and the accumulation of epigenetic abnormalities, leading to tumor cell acquisition of malignant features. MicroRNAs (miRNAs) play a critical role in cancer development, where they can act as oncogenes or oncosuppressors.

Methods: miR-148a expression was measured by qRT-PCR in patients with colorectal adenoma (n = 21) and CRC (stage I-IV, n = 159) using formalin-fixed paraffin-embedded tissue samples. In situ hybridization (ISH) using an miR-148a-specific probe was also performed. To further confirm the direct effect of miR-148a on matrix metalloproteinase (MMP)7 expression in CRC, MTT and cell invasion assays using HT29 and WiDr cells were performed.

Results: miR-148a expression was found to be clearly downregulated in high-grade adenoma compared to low-grade adenoma on both qRT-PCR and ISH analysis. Downregulation of miR-148a expression was significantly correlated with advanced clinicopathological features and was an independent prognostic classifier in patients with stage III CRC. In CRC cells and tissues, miR-148a expression was inversely correlated with the expression of MMP7.

Conclusion: We showed the collaborative participation of miR-148a and MMP7 in CRC cell invasion. These results also demonstrate that the downregulation of miR-148a expression promotes CRC progression, especially carcinogenesis and cancer cell invasion.
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http://dx.doi.org/10.1159/000438826DOI Listing
July 2016

Fukutin, identified by the Escherichia coli ampicillin secretion trap (CAST) method, participates in tumor progression in gastric cancer.

Gastric Cancer 2016 Apr 30;19(2):443-452. Epub 2015 Jul 30.

Department of Molecular Pathology, Hiroshima University Institute of Biomedical and Health Sciences, 1-2-3 Kasumi, Minami-ku, Hiroshima, 734-8551, Japan.

Background: Gastric cancer (GC) is the fifth commonest malignancy worldwide and still one of the leading causes of cancer-related death. The aim of this study was to identify a novel prognostic marker or therapeutic target for GC.

Methods: We analyzed candidate genes from our previous Escherichia coli ampicillin secretion trap (CAST) libraries in detail, and focused on the FKTN gene because it was overexpressed in both GC cell line CAST libraries, MKN-1 and MKN-45.

Results: Quantitative reverse transcriptase PCR analysis of FKTN revealed that FKTN messenger RNA was overexpressed in nine of 28 (32.1 %) GC tissue samples compared with nonneoplastic gastric mucosa. Immunostaining of fukutin showed that 297 of 695 cases (42.7 %) were positive for fukutin. Fukutin-positive GC cases were significantly associated with differentiated histological features, and advanced T grade and N grade. In addition, fukutin expression was observed more frequently in the intestinal phenotype (51 %) of GC than in other phenotypes (37 %) when defined by the expression patterns of mucin 5AC, mucin 6, mucin 2, and CD10. FKTN small interfering RNA treatment decreased GC cell proliferation.

Conclusions: These results indicate that the expression of fukutin may be a key regulator for progression of GC with the intestinal mucin phenotype.
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http://dx.doi.org/10.1007/s10120-015-0511-2DOI Listing
April 2016

Targeting HER2 with T-DM1, an Antibody Cytotoxic Drug Conjugate, is Effective in HER2 Over Expressing Bladder Cancer.

J Urol 2015 Oct 3;194(4):1120-31. Epub 2015 Jun 3.

Vancouver Prostate Centre and Department of Urologic Sciences, University of British Columbia (TH, RS, HZO, WJ, IM, SA, TD, TT, NL, LF, PCB), Vancouver, British Columbia, Canada; Department of Urology, Institute of Biomedical and Health Science, Hiroshima University (TH), Hiroshima, Japan. Electronic address:

Purpose: Systemic therapy for advanced bladder cancer has not changed substantially in more than 2 decades and mortality rates remain high. The recognition of HER2 over expression in bladder cancer has made HER2 a promising therapeutic target. T-DM1, a new drug consisting of the HER2 antibody trastuzumab conjugated with a cytotoxic agent, has been shown in breast cancer to be superior to trastuzumab. We tested T-DM1 in preclinical models of bladder cancer.

Materials And Methods: We evaluated the effect of T-DM1 compared to trastuzumab in different in vitro and in vivo models of HER2 over expressing bladder cancer.

Results: RT4V6 was the highest HER2 expressing bladder cancer cell line and it showed higher growth inhibition with T-DM1 compared to trastuzumab. T-DM1 but not trastuzumab induced apoptosis of RT4V6 cells after G2/M arrest on cell cycle analysis. HER2 expression was higher in cell lines with acquired cisplatin resistance compared to the corresponding parental cell lines. Resistant cells showed higher sensitivity to T-DM1 by the induction of apoptosis. In addition, cells cultured in anchorage independent conditions increased HER2 expression compared to cells cultured in adherent conditions and T-DM1 significantly inhibited colony formation in soft agar compared to trastuzumab. In an orthotopic bladder cancer xenograft model tumor growth of cisplatin resistant RT112 was significantly inhibited by T-DM1 via the induction of apoptosis compared to treatment with control IgG or trastuzumab.

Conclusions: T-DM1 has promising antitumor effects in preclinical models of HER2 over expressing bladder cancer.
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http://dx.doi.org/10.1016/j.juro.2015.05.087DOI Listing
October 2015