Publications by authors named "Sajida Piperdi"

23 Publications

  • Page 1 of 1

Down-regulation of Skp2 expression inhibits invasion and lung metastasis in osteosarcoma.

Sci Rep 2018 09 24;8(1):14294. Epub 2018 Sep 24.

Department of Orthopedic Surgery, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY, USA.

Osteosarcoma (OS), the most common primary cancer of bone, exhibits a high propensity for local invasion and distant metastasis. This study sought to elucidate the role of S phase kinase-associated protein (Skp2) in osteosarcoma invasion and metastasis and to explore flavokawain A (FKA), a natural chalcone from kava extract, as a potential Skp2 targeting agent for preventing osteosarcoma progression. Skp2 was found to be overexpressed in multiple osteosarcoma cell lines, including 5 standard and 8 primary patient-derived cell lines. Patients whose tumors expressed high levels of Skp2 sustained a significantly worse metastasis-free (p = 0.0095) and overall survival (p = 0.0013) than those with low Skp2. Skp2 knockdown markedly reduced in vitro cellular invasion and in vivo lung metastasis in an orthotopic mouse model of osteosarcoma. Similar to Skp2 knockdown, treatment with FKA also reduced Skp2 expression in osteosarcoma cell lines and blocked the invasion of osteosarcoma cells in vitro and lung metastasis in vivo. Together, our findings suggest that Skp2 is a promising therapeutic target in osteosarcoma, and that FKA may be an effective Skp2-targeted therapy to reduce osteosarcoma metastasis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41598-018-32428-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6155331PMC
September 2018

Detection of circulating tumor DNA in patients with osteosarcoma.

Oncotarget 2018 Feb 18;9(16):12695-12704. Epub 2018 Jan 18.

Division of Hematology/Oncology, Children's Hospital at Montefiore, Bronx, NY, USA.

Identification and quantification of somatic alterations in plasma-derived, circulating tumor DNA (ctDNA) is gaining traction as a non-invasive and cost effective method of disease monitoring in cancer patients, particularly to evaluate response to treatment and monitor for disease recurrence. To our knowledge, genetic analysis of ctDNA in osteosarcoma has not yet been studied. To determine whether somatic alterations can be detected in ctDNA and perhaps applied to patient management in this disease, we collected germline, tumor, and serial plasma samples from pediatric, adolescent, and young adult patients with osteosarcoma and used targeted Next Generation Sequencing (NGS) to identify somatic single nucleotide variants (SNV), insertions and deletions (INDELS), and structural variants (SV) in 7 genes commonly mutated in osteosarcoma. We demonstrate that patient-specific somatic alterations identified through comparison of tumor-germline pairs can be detected and quantified in cell-free DNA of osteosarcoma patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/oncotarget.24268DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5849166PMC
February 2018

CD49b inhibits osteogenic differentiation and plays an important role in osteosarcoma progression.

Oncotarget 2017 Oct 23;8(50):87848-87859. Epub 2017 Sep 23.

Department of Pediatrics, Children's Cancer Hospital, The University of Texas MD Anderson Cancer Center, Houston, TX, USA.

Osteosarcoma is a cancer whose cell of origin lies in the differentiation pathway between the mesenchymal stem cell (MSC) and the osteoblast (OB). In this study, we sought to determine if surface markers associated with osteoblastic differentiation are involved in osteosarcoma progression. cDNA expression arrays were performed on MSCs and osteoblasts to identify differentially expressed genes. The specificity of candidate genes for osteoblast differentiation was assessed through time course experiments in differentiation media with confirmation utilizing CD49b transfected MSCs. In addition, CD49b was transfected into osteosarcoma cell lines to determine its impact on cell proliferation, motility, and invasion. Finally, the expression of CD49b was assessed in osteosarcoma patient samples and correlated with survival outcomes. cDNA expression arrays identified a list of genes differentially expressed between MSCs and osteoblasts with a subset of those genes encoding cell surface proteins. Three genes were selected for further analysis, based on qPCR validation, but only CD49b was selective for osteoblastic differentiation. Forced expression of CD49b in MSCs led to delayed osteoblastic differentiation. Down-regulation of CD49b expression in osteosarcoma cell lines resulted in inhibition of their migration and invasion capacity. CD49b expression in osteosarcoma patients was associated with presence of metastases and inferior 5 year overall survival (31.4% vs. 57.4%, p=0.03). Surface proteins involved in osteosarcoma cell differentiation, such as CD49b, have the potential to serve as prognostic biomarkers, and may lead to the identification of new therapeutic targets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/oncotarget.21254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5675677PMC
October 2017

Genetically transforming human osteoblasts to sarcoma: development of an osteosarcoma model.

Genes Cancer 2017 Jan;8(1-2):484-494

Department of Pediatrics, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, NY, USA.

Osteosarcoma is the most common primary malignant bone tumor in children and young adults. Although histologically defined by the presence of malignant osteoid, the tumor possesses lineage multipotency suggesting it could be derived from a cell anywhere on the differentiation pathway between a mesenchymal stem cell (MSC) and a mature osteoblast. To determine if preosteoblasts (pOB) could be the cell of origin differentiated MSCs were transformed with defined genetic elements. MSCs and pOB differentiated from the same MSCs were serially transformed with the oncogenes hTERT, SV40 large T antigen and H-Ras. Assays were performed to determine their tumorigenic properties, differentiation capacity and histologic appearance. When subcutaneously implanted in immunocompromised mice, cell lines derived from transformed MSC and pOB formed tumors in 4 weeks. In contrast to the transformed MSC, the pOB tumors demonstrated a histological appearance characteristic of osteosarcoma. The cell lines derived from the transformed pOB only had osteogenic and chondrogenic differentiation potential, but not adipogenic ones. However, the transformed MSC cells and standard osteosarcoma cell lines maintained their tri-lineage differentiation capacity. The inability of the transformed pOB cell line to undergo adipogenic differentiation, may suggest that osteosarcoma is derived from a cell intermediate in differentiation between an MSC and a pOB, with partial commitment to the osteoblastic lineage.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/genesandcancer.133DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5396624PMC
January 2017

The effect of bone morphogenetic protein-2 on osteosarcoma metastasis.

PLoS One 2017 6;12(3):e0173322. Epub 2017 Mar 6.

Division of Pediatric Hematology/Oncology and Blood & Marrow Cell Transplantation, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx New York, United States of America.

Purpose: Bone Morphogenetic Protein-2 (BMP-2) may offer the potential to enhance allograft-host osseous union in limb-salvage surgery following osteosarcoma resection. However, there is concern regarding the effect of locally applied BMP-2 on tumor recurrence and metastasis. The purpose of this project was to evaluate the effect of exogenous BMP-2 on osteosarcoma migration and invasion across a panel of tumor cell lines in vitro and to characterize the effect of BMP-2 on pulmonary osteosarcoma metastasis within a xenograft model.

Experimental Design: The effect of BMP-2 on in vitro tumor growth and development was assessed across multiple standard and patient-derived xenograft osteosarcoma cell lines. Tumor migration capacity, invasion, and cell proliferation were characterized. In addition, the effect on metastasis was measured using a xenograft model following tail-vein injection. The effect of exogenous BMP-2 on the development of metastases was measured following both single and multiple BMP-2 administrations.

Results: There was no significant difference in migration capacity, invasion, or cell proliferation between the BMP-2 treated and the untreated osteosarcoma cell lines. There was no significant difference in pulmonary metastases between either the single-dose or multi-dose BMP-2 treated animals and the untreated control animals.

Conclusions: In the model systems tested, the addition of BMP-2 does not increase osteosarcoma proliferation, migration, invasion, or metastasis to the lungs.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0173322PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5338793PMC
August 2017

Targeted therapy of osteosarcoma with radiolabeled monoclonal antibody to an insulin-like growth factor-2 receptor (IGF2R).

Nucl Med Biol 2016 Dec 30;43(12):812-817. Epub 2016 Jul 30.

Albert Einstein College of Medicine, Bronx, NY, USA; Department of Radiology, Nuclear Medicine, Montefiore Medical Center, Bronx, NY, USA; Department of Microbiology and Immunology, Albert Einstein College of Medicine, Bronx, NY, USA.

Introduction: Osteosarcoma overall survival has plateaued around 70%, without meaningful improvements in over 30years. Outcomes for patients with overt metastatic disease at presentation or who relapse are dismal. In this study we investigated a novel osteosarcoma therapy utilizing radioimmunotherapy (RIT) targeted to IGF2R, which is widely expressed in OS.

Methods: Binding efficiency of the Rhenium-188(Re)-labeled IGF2R-specific monoclonal antibody (mAb) to IGF2R on OS17 OS cells was assessed with Scatchard plot analysis. Biodistribution studies were performed in heterotopic murine osteosarcoma xenografts. Tumor growth was compared over a 24-day period post-treatment between mice randomized to receive Re-labeled IGF2R-specific murine mAb MEM-238 (Re-MEM-238) or one of three controls: Re-labeled isotype control mAb, unlabeled MEM-238, or no treatment.

Results: Results demonstrate that the radioimmunoconjugate had a high binding constant to IGF2R. Both Re-MEM-238 and the isotype control had similar initial distribution in normal tissue. After 48h Re-MEM-238 exhibited a 1.8 fold selective uptake within tumor compared to the isotype control (p=0.057). Over 24days, the tumor growth ratio was suppressed in animals treated with RIT compared to unlabeled and untreated controls (p=0.005) as demonstrated by a 38% reduction of IGF2R expressing osteosarcoma cells in the RIT group (p=0.002).

Conclusions: In conclusion, given the lack of new effective therapies in osteosarcoma, additional investigation into this target is warranted.

Advances In Knowledge: High expression of IGF2R on osteosarcoma tumors, paired with the specificity and in vivo anti-cancer activity of Re-labeled IGF2R-specific mAb suggests that IGF2R may represent a novel therapeutic target in the treatment of osteosarcoma.

Implications For Patient Care: This targeted approach offers the benefits of being independent of a specific pathway, a resistance mechanism, and/or an inherent biologic tumor trait and therefore is relevant to all OS tumors that express IGF2R.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.nucmedbio.2016.07.008DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5118104PMC
December 2016

HHLA2, a member of the B7 family, is expressed in human osteosarcoma and is associated with metastases and worse survival.

Sci Rep 2016 08 17;6:31154. Epub 2016 Aug 17.

Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.

Over the past four decades there have been minimal improvements in outcomes for patients with osteosarcoma. New targets and novel therapies are needed to improve outcomes for these patients. We sought to evaluate the prevalence and clinical significance of the newest immune checkpoint, HHLA2, in osteosarcoma. HHLA2 protein expression was evaluated in primary tumor specimens and metastatic disease using an osteosarcoma tumor microarray (TMA) (n = 62). The association of HHLA2 with the presence of tumor infiltrating lymphocytes (TILs) and five-year-event-free-survival were examined. HHLA2 was expressed in 68% of osteosarcoma tumors. HHLA2 was expressed in almost all metastatic disease specimens and was more prevalent than in primary specimens without known metastases (93% vs 53%, p = 0.02). TILs were present in 75% of all osteosarcoma specimens. Patients whose tumors were ≥25% or ≥50% HHLA2 positive had significantly worse five-year event-free-survival (33% vs 64%, p = 0.03 and 14% vs 59%, p = 0.02). Overall, we have shown that HHLA2 is expressed in the majority of osteosarcoma tumors and its expression is associated with metastatic disease and poorer survival. Along with previously reported findings that HHLA2 is a T cell co-inhibitor, these results suggest that HHLA2 may be a novel immunosuppressive mechanism within the osteosarcoma tumor microenvironment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep31154DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4987662PMC
August 2016

Immune infiltration and PD-L1 expression in the tumor microenvironment are prognostic in osteosarcoma.

Sci Rep 2016 07 26;6:30093. Epub 2016 Jul 26.

Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA.

Osteosarcoma patient survival has remained stagnant for 30 years. Novel therapeutic approaches are needed to improve outcomes. We examined the expression of Programmed Death Ligand 1 (PD-L1) and defined the tumor immune microenvironment to assess the prognostic utility in osteosarcoma. PD-L1 expression in osteosarcoma was examined in two patient cohorts using immunohistochemistry (IHC) (n = 48, n = 59) and expression was validated using quantitative real time PCR (n = 21) and western blotting (n = 9). IHC was used to determine the presence of tumor infiltrating lymphocytes and antigen-presenting cells (APCs) in the tumor. Expression of PD-L1 was correlated with immune cell infiltration and event-free-survival (EFS). The 25% of primary osteosarcoma tumors that express PD-L1 were more likely to contain cells that express PD-1 than PD-L1 negative tumors (91.7% vs 47.2%, p = 0.002). Expression of PD-L1 was significantly associated with the presence of T cells, dendritic cells, and natural killer cells. Although all immune cell types examined were present in osteosarcoma samples, only infiltration by dendritic cells (28.3% vs. 83.9%, p = 0.001) and macrophages (45.5% vs. 84.4%, p = 0.031) were associated with worse five-year-EFS. PD-L1 expression was significantly associated with poorer five-year-EFS (25.0%. vs. 69.4%, p = 0.014). Further studies in osteosarcoma are needed to determine if targeting the PD-L1:PD-1 axis improves survival.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/srep30093DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4960483PMC
July 2016

A RUNX2-Mediated Epigenetic Regulation of the Survival of p53 Defective Cancer Cells.

PLoS Genet 2016 Feb 29;12(2):e1005884. Epub 2016 Feb 29.

Cancer and Stem Cell Epigenetics Section, Laboratory of Cancer Biology and Genetics, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, United States of America.

The inactivation of p53 creates a major challenge for inducing apoptosis in cancer cells. An attractive strategy is to identify and subsequently target the survival signals in p53 defective cancer cells. Here we uncover a RUNX2-mediated survival signal in p53 defective cancer cells. The inhibition of this signal induces apoptosis in cancer cells but not non-transformed cells. Using the CRISPR technology, we demonstrate that p53 loss enhances the apoptosis caused by RUNX2 knockdown. Mechanistically, RUNX2 provides the survival signal partially through inducing MYC transcription. Cancer cells have high levels of activating histone marks on the MYC locus and concomitant high MYC expression. RUNX2 knockdown decreases the levels of these histone modifications and the recruitment of the Menin/MLL1 (mixed lineage leukemia 1) complex to the MYC locus. Two inhibitors of the Menin/MLL1 complex induce apoptosis in p53 defective cancer cells. Together, we identify a RUNX2-mediated epigenetic mechanism of the survival of p53 defective cancer cells and provide a proof-of-principle that the inhibition of this epigenetic axis is a promising strategy to kill p53 defective cancer cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1371/journal.pgen.1005884DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4771715PMC
February 2016

Transcriptional Profiling Identifies the Signaling Axes of IGF and Transforming Growth Factor-b as Involved in the Pathogenesis of Osteosarcoma.

Clin Orthop Relat Res 2016 Jan;474(1):178-89

Background: Osteosarcoma is the most common primary bone tumor in adolescents associated with skeletal development. The molecular pathogenesis of osteosarcoma has not been completely determined, although many molecular alterations have been found in human osteosarcomas and cell lines.

Questions/purposes: We questioned whether (1) we could identify gene expression in osteosarcoma specimens that differs from normal osteoblasts and mesenchymal stem cells and (2) this would provide clues to the molecular pathogenesis of osteosarcoma?

Methods: The whole-genome transcriptional profiles of osteosarcomas, including two primary biopsy specimens, two cell lines, two xenografts derived from patient specimens, and one from normal osteoblasts and from mesenchymal stem cells, respectively, were quantitatively measured using serial analysis of gene expression. A statistical enrichment was performed, which selects the common genes altered in each of the osteosarcomas compared with each of the normal counterparts independently.

Results: Sixty (92%) of 65 total genes that were at least twofold downregulated in osteosarcoma compared with osteoblasts and mesenchymal stem cells, could be classified in four categories: (1) seven genes in the insulin–like growth factor (IGF) signaling axis, including three of the IGF-binding proteins (IGFBP) and three of the IGFBPrelated proteins (IGFBPrP); (2) eight genes in the transforming growth factor-b (TGF-b)/bone morphogenetic protein (BMP) signaling cascade; (3) 39 genes encoding cytoskeleton and extracellular matrix proteins that are regulated by TGF-b/BMPs; and (4) six genes involved in cell cycle regulation, including tumor suppressors TP63 and p21.

Conclusions: Based on these transcriptional profiles, a coordinated theme of clustered gene deregulation in osteosarcoma has emerged. Cell proliferation driven by the IGF axes during bone growth is unrestrained owing to downregulation of IGFBPs and cell cycle regulators. Tumor cells may be maintained in an undifferentiated state secondary to impaired TGF-b/BMP signaling. This wellpreserved pattern suggests that the alterations in the signaling axes of IGF-1 and TGF-b, in concert with cell cycle regulators, may be an important pathogenic basis of osteosarcoma. CLINIC RELEVANCE: This study provides a possible molecular basis of pathogenesis of osteosarcoma. This may help to develop new therapeutic targets and strategy for this disease. Preclinical and subsequently clinical testing of inhibitors of the IGF-1 and TGF pathways would be warranted.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11999-015-4578-1DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4686509PMC
January 2016

Targeting Glycoprotein NMB With Antibody-Drug Conjugate, Glembatumumab Vedotin, for the Treatment of Osteosarcoma.

Pediatr Blood Cancer 2016 Jan 25;63(1):32-8. Epub 2015 Aug 25.

Division of Pediatric Hematology/Oncology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York.

Background: Cure rates for children and young adults with osteosarcoma have remained stagnant over the past three decades. Targeting glycoprotein non-metastatic b (GPNMB) with the antibody-drug conjugate glembatumumab vedotin has improved outcomes for patients with melanoma and breast cancer. The potential utility of targeting GPNMB in osteosarcoma was explored.

Methods: GPNMB protein expression was evaluated by immunohistochemistry in human osteosarcoma tumor samples and by enzyme-linked immunosorbent assay (ELISA) in osteosarcoma cell lines. mRNA expression was measured by quantitative PCR in primary osteosarcoma samples and cell lines. Surface GPNMB expression was evaluated by flow cytometry and correlated with in vitro and in vivo cytotoxicity of glembatumumab vedotin.

Results: Sixty seven human osteosarcoma samples were evaluated by immunohistochemistry, including 12 samples from initial biopsy, 38 samples from definitive surgery, and 17 from the time of disease recurrence. GPNMB was expressed in 92.5% (62/67) of osteosarcoma samples. All primary osteosarcoma samples expressed high levels of GPNMB mRNA. Glembatumumab induced cytotoxic effects in 74% (14/19) of osteosarcoma cell lines, and GPNMB protein levels correlated with glembatumumab in vitro cytotoxicity (r = -0.46, P = 0.04). All osteosarcoma cell lines demonstrated surface GPNMB expression.

Conclusions: GPNMB is expressed in osteosarcoma and targeting GPNMB with the antibody-drug conjugate glembatumumab vedotin demonstrates osteosarcoma cytotoxic activity. Clinical trials are indicated to assess the efficacy of targeting GPNMB in patients with osteosarcoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/pbc.25688DOI Listing
January 2016

Ganglioside GD2 expression is maintained upon recurrence in patients with osteosarcoma.

Clin Sarcoma Res 2015 24;5(1). Epub 2015 Jan 24.

Division of Pediatric Hematology/Oncology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, 3415 Bainbridge Ave, Rosenthal Pavilion, Room 300, Bronx, NY 10467 USA ; Department of Pediatrics and Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY USA.

Background: Osteosarcoma is the most common primary malignant bone tumor in children and young adults. Ganglioside GD2 has been previously found on the cell surface in various tumor types, including osteosarcomas.

Findings: In this study, forty-nine additional osteosarcoma samples from 14 individual patients were assessed for GD2 expression via immunohistochemistry, of which 47 samples were found to express GD2. In matched samples from patients, GD2 expression seen at initial biopsy was found to persist in 100% of tissues taken at recurrence.

Conclusions: GD2 expression was found to persist upon recurrence. These results suggest a phase 2 trial in children with recurrent osteosarcoma should provide an appropriate read out on the efficacy of anti-GD2 antibody.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13569-014-0020-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4311500PMC
February 2015

Development of a Model System to Evaluate Local Recurrence in Osteosarcoma and Assessment of the Effects of Bone Morphogenetic Protein-2.

Clin Cancer Res 2015 Jul 3;21(13):3003-12. Epub 2014 Dec 3.

Department of Pediatrics, Montefiore Medical Center and The Children's Hospital at Montefiore, Bronx, New York. Albert Einstein College of Medicine, Bronx, New York. Department of Molecular Pharmocology, Albert Einstein College of Medicine, Bronx, New York.

Purpose: It is increasingly relevant to better define what constitutes an adequate surgical margin in an effort to improve reconstructive longevity and functional outcomes following osteosarcoma surgery. In addition, nonunion remains a challenging problem in some patients following allograft reconstruction. Bone morphogenetic protein-2 (BMP-2) could enhance osseous union, but has been historically avoided due to concerns that it may promote tumor recurrence.

Experimental Design: An orthotopic xenograft murine model was utilized to describe the natural temporal course of osteosarcoma growth. Tumors were treated either with surgery alone, surgery and single-agent chemotherapy, or surgery and dual-agent chemotherapy to assess the relationship between surgical margin and local recurrence. The effect of BMP-2 on local recurrence was similarly assessed.

Results: Osteosarcoma tumor growth was categorized into reproducible phases. Margins greater than 997 μm resulted in local control following surgery alone. Margins greater than 36 μm resulted in local control following surgery and single-agent chemotherapy. Margins greater than 12 μm resulted in local control following surgery and dual-agent chemotherapy. The application of exogenous BMP-2 does not confer an increased risk of local recurrence.

Conclusions: This model reliably reproduces the clinical, radiographic, and surgical conditions encountered in human osteosarcoma. It successfully incorporates relevant chemotherapy, further paralleling the human experience. Surgical margins required to achieve local control in osteosarcoma can be reduced using single-agent chemotherapy and further decreased using dual-agent chemotherapy. The application of BMP-2 does not increase local recurrence in this model.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1078-0432.CCR-14-0986DOI Listing
July 2015

Insulin-like growth factor 1 receptor and response to anti-IGF1R antibody therapy in osteosarcoma.

PLoS One 2014 29;9(8):e106249. Epub 2014 Aug 29.

Division of Pediatric Hematology/Oncology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York, United States of America; Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York, United States of America.

Background: Survival outcomes for patients with osteosarcoma (OS) have remained stagnant over the past three decades. Insulin-like growth factor 1 receptor (IGF1R) is over-expressed in a number of malignancies, and anti-IGF1R antibodies have and are currently being studied in clinical trials. Understanding the molecular aberrations which result in increased tumor response to anti-IGF1R therapy could allow for the selection of patients most likely to benefit from IGF1R targeted therapy.

Methods: IGF1R mRNA expression was assessed by RT PCR in OS patient primary tumors, cell lines, and xenograft tumors. IGF1R copy number was assessed by 3 approaches: PCR, FISH, and dot blot analysis. Exons 1-20 of IGF1R were sequenced in xenograft tumors and 87 primary OS tumors, and surface expression of IGF1R was assessed by flow cytometry. Levels of mRNA and protein expression, copy number, and mutation status were compared with tumor response to anti-IGF1R antibody therapy in 4 OS xenograft models.

Results: IGF1R mRNA is expressed in OS. Primary patient samples and xenograft samples had higher mRNA expression and copy number compared with corresponding cell lines. IGF1R mRNA expression, cell surface expression, copy number, and mutation status were not associated with tumor responsiveness to anti-IGF1R antibody therapy.

Conclusions: IGF1R is expressed in OS, however, no clear molecular markers predict response to IGF1R antibody-mediated therapy. Additional pre-clinical studies assessing potential predictive biomarkers and investigating targetable molecular pathways critical to the proliferation of OS cells are needed.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0106249PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4149550PMC
November 2015

HER-2 expression is not prognostic in osteosarcoma; a Children's Oncology Group prospective biology study.

Pediatr Blood Cancer 2014 Sep 22;61(9):1558-64. Epub 2014 Apr 22.

Department of Pediatrics, The Children's Hospital at Montefiore and the Albert Einstein College of Medicine, Bronx, New York.

Background: Since the initial reports of human epidermal growth factor receptor 2 (HER-2) expression as being prognostic in osteosarcoma, numerous small studies varying in the interpretation of the immunohistochemical (IHC) staining patterns have produced conflicting results. The Children's Oncology Group therefore embarked on a prospective biology study in a larger sample of patients to define in osteosarcoma the prognostic value of HER-2 expression using the methodology employed in the initial North American study describing an association between HER-2 expression and outcome.

Procedure: The analytic patient population was comprised of 149 patients with newly diagnosed osteosarcoma, 135 with localized disease and 14 with metastatic disease, all of whom had follow up clinical data. Paraffin embedded material from the diagnostic biopsy was stained with CB11 antibody and scored by two independent observers. Correlation of HER-2 IHC score and demographic variables was analyzed using a Fisher's exact test and correlation with survival using a Kaplan-Meier analysis.

Results: No association was found with HER-2 status and any of the demographic variables tested including the presence or absence of metastatic disease at diagnosis. No association was found between HER-2 status and either event free survival or overall survival in the patients with localized disease.

Conclusion: HER-2 expression is not prognostic in osteosarcoma in the context of this large prospective study. HER-2 expression cannot be used as a basis for stratification of therapy. Identification of potential prognostic factors should occur in the context of large multi-institutional biology studies.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/pbc.25074DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4288578PMC
September 2014

Ganglioside GD2 as a therapeutic target for antibody-mediated therapy in patients with osteosarcoma.

Cancer 2014 Feb 25;120(4):548-54. Epub 2013 Oct 25.

Division of Pediatric Hematology/Oncology, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York.

Background: Survival outcomes for patients with osteosarcoma have remained stagnant over the past 30 years. Targeting of ganglioside GD2, a glycosphingolipid on the cell surface of some tumors, with immunotherapy has resulted in improved outcomes for patients with neuroblastoma. In the current study, the expression pattern of GD2 was examined in osteosarcoma.

Methods: Immunohistochemistry was performed on osteosarcoma samples from patients at the time of initial biopsy, definitive surgery, and disease recurrence. The intensity and location of staining were scored. Cell-based enzyme-linked immunoadsorbent assay was performed on osteosarcoma cell lines to quantitate the level of GD2 expression.

Results: Forty-four osteosarcoma samples were evaluated by immunohistochemistry, including 8 samples from the initial biopsy, 28 samples from the definitive surgery, and 8 samples from the time of disease recurrence. GD2 was expressed on all 44 osteosarcoma samples. Osteosarcoma tissue obtained at the time of disease recurrence demonstrated a higher intensity of staining compared with samples obtained at initial biopsy and definitive surgery (P = .016). The majority of osteosarcoma cell lines expressed GD2 at higher levels than the neuroblastoma cell line BE(2)-C.

Conclusions: Ganglioside GD2 is highly expressed on osteosarcomas. Clinical trials are needed to assess the efficacy of targeting GD2 in patients with osteosarcoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cncr.28461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3946333PMC
February 2014

β-Catenin Does Not Confer Tumorigenicity When Introduced into Partially Transformed Human Mesenchymal Stem Cells.

Sarcoma 2012 18;2012:164803. Epub 2012 Oct 18.

The Department of Pediatrics, Albert Einstein College of Medicine, Yeshiva University, Bronx, NY 10461, USA.

Although osteosarcoma is the most common primary malignant bone tumor in children and adolescents, its cell of origin and the genetic alterations are unclear. Previous studies have shown that serially introducing hTERT, SV40 large TAg, and H-Ras transforms human mesenchymal stem cells into two distinct sarcomas cell populations, but they do not form osteoid. In this study, β-catenin was introduced into mesenchymal stem cells already containing hTERT and SV40 large TAg to analyze if this resulted in a model which more closely recapitulated osteosarcoma. Results. Regardless of the level of induced β-catenin expression in the stable transfectants, there were no marked differences induced in their phenotype or invasion and migration capacity. Perhaps more importantly, none of them formed tumors when injected into immunocompromised mice. Moreover, the resulting transformed cells could be induced to osteogenic and chondrogenic differentiation but not to adipogenic differentiation. Conclusions. β-catenin, although fostering osteogenic differentiation, does not induce the malignant features and tumorigenicity conveyed by oncogenic H-RAS when introduced into partly transformed mesenchymal stem cells. This may have implications for the role of β-catenin in osteosarcoma pathogenesis. It also may suggest that adipogenesis is an earlier branch point than osteogenesis and chondrogenesis in normal mesenchymal differentiation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2012/164803DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3483784PMC
November 2012

Cell surface receptor expression patterns in osteosarcoma.

Cancer 2012 Feb 12;118(3):740-9. Epub 2011 Jul 12.

Department of Orthopaedic Surgery, Montefiore Medical Center and The Children's Hospital at Montefiore, Bronx, New York 10467, USA.

Background: Although the presence of numerous cell signaling receptors in osteosarcoma is known, their simultaneous characterization has not been performed to date. The current study sought to characterize and quantify the expression of cell surface receptors across a variety of osteosarcoma cell lines.

Methods: Standard (n = 4) and patient-derived (n = 10) osteosarcoma cell lines were cultured and labeled with antibodies to epidermal growth factor receptor, human epidermal growth factor receptor (HER)-2, HER-3, HER-4, insulin-like growth factor 1 receptor (IGF-1R), IGF-2R, insulin receptor (IR), vascular endothelial growth factor receptor (VEGFR)-1, VEGFR-2, VEGFR-3, c-Met, fibroblast growth factor receptor (FGFR)-2, FGFR-3, and platelet-derived growth factor receptor (PDGFR)-β. Cell surface examination was performed using flow cytometry, and the geometric fluorescent mean for each receptor was calculated and compared against a positive control.

Results: Significant overexpression of IGF-2R was shown in all cell lines, with an average geometric mean above the upper expression quartile. A variable expression pattern was seen for c-Met, PDGFR-β, IR, IGFR-1, HER-2, and VEGFR-3 with expression values for the remaining receptors mainly in the lower quartile. An apparent association between the expression of IGF-1R and HER-2 and between the expression of PDGFR-β and IR was demonstrated.

Conclusion: IGF-2R was consistently overexpressed on the cell surface across all tested osteosarcoma cell lines. Substantial, although variable, expression of c-Met, HER-2, IGF-1R, VEGFR-3, IR, and PDGFR-β was demonstrated as well, suggesting that these receptors may contribute to osteosarcoma aggressiveness and biological heterogeneity and may serve as potential targets within a subset of tumors. Associated receptor expression may provide new insight into common regulatory factors or pathways. Targeting either common factors or targeting multiple specific receptors may have therapeutic relevance.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cncr.26339DOI Listing
February 2012

Preclinical activity of palifosfamide lysine (ZIO-201) in pediatric sarcomas including oxazaphosphorine-resistant osteosarcoma.

Cancer Chemother Pharmacol 2009 Sep 18;64(4):733-40. Epub 2009 Feb 18.

Department of Pediatric Hematology/Oncology, Phoenix Childrens Hospital, Phoenix, AZ 85003, USA.

Purpose: Oxazaphosphorines, such as ifosfamide (IFA), are frequently used in the treatment of pediatric sarcomas. They are pro-drugs and undergo hepatic metabolism into the active moiety and potentially toxic by-products such as acrolein and chloracetaldehyde, which may cause hemorrhagic cystitis and encephalopathy, respectively. In addition, resistance to oxazaphosphorines can be mediated by overexpression of enzymes involved in their catabolism. Isophosphoramide mustard (IPM, palifosfamide) is the active moiety of IFA. In the current study, the activity of palifosfamide lysine (ZIO-201), a stable form of palifosfamide, was evaluated in a panel of sarcoma cell lines and tumor xenografts including oxazaphosphorine-resistant xenografts.

Methods: The cytotoxic effect of palifosfamide lysine was studied in osteosarcoma (OS), Ewing's sarcoma (ES) and rhabdomyosarcoma (RMS) cell lines using the MTT assay. In vivo, the maximum tolerated dose (MTD) of palifosfamide lysine was determined in SCID mice based on a 3-day intravenous (IV) administration schedule. The effect on tumor growth and event-free survival was assessed at the MTD in all three sarcoma xenografts. In OS, cyclophosphamide (CPA)-resistant and -sensitive xenografts (OS31 and OS33, respectively) were evaluated for palifosfamide lysine activity. ALDH1A1 and ALDH3A1 gene expression data for the OS xenografts were mined from the Pediatric Preclinical Testing Program gene expression data. ALDH3A1 enzyme levels were compared between the CPA-resistant and -sensitive xenografts.

Results: Palifosfamide lysine was cytotoxic against all the cell lines tested with the IC(50) ranging from 0.5 to 1.5 microg/ml except for OS222, which had an IC(50) of 7 microg/ml. The IV MTD of palifosfamide lysine in mice was 100 mg/kg per day for three consecutive days. Tumor growth inhibition was seen in both OS31 and OS33 xenografts and the RMS xenograft resulting in a significant difference in event-free survival between the control and the treated groups. Differential gene expression of ALDH3A1 but not ALDH1A1 was noted in the OS31 xenograft. This was confirmed by RT-PCR and the ALDH3A1 enzyme assay. ALDH3A1 enzyme activity was measured at 100 mIU/mg of protein in OS31 xenograft but no significant activity was seen in the OS33 xenograft.

Conclusions: We conclude that palifosfamide lysine has broad activity in a panel of sarcoma cell lines. It inhibits tumor growth in OS and RMS xenografts. Furthermore, it is active against the CPA-resistant, ALDH3A1 overexpressing, OS xenograft suggesting that it might have the potential of overcoming this resistance mechanism against oxazaphosphorines and may be an active agent in resistant/relapsed sarcomas in patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00280-008-0922-4DOI Listing
September 2009

Activation of the RAF/mitogen-activated protein/extracellular signal-regulated kinase kinase/extracellular signal-regulated kinase pathway mediates apoptosis induced by chelerythrine in osteosarcoma.

Clin Cancer Res 2008 Oct;14(20):6396-404

Department of Pediatrics and Molecular Pharmacology, The Albert Einstein College of Medicine, The Children's Hospital at Montefiore, Bronx, New York 10467, USA.

Purpose: Chelerythrine, a widely used broad-range protein kinase C inhibitor, induces apoptosis in many cell types. In this study, the mechanism of chelerythrine-induced apoptosis in osteosarcoma was investigated.

Experimental Design: Signaling pathways activated by chelerythrine in osteosarcoma were detected by Western blots. Impacts of RAF/mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) kinase (MEK)/ERK MAPK on apoptosis and cell survival were studied using genetic approaches and pharmacologic pathway-specific inhibitors.

Results: Osteosarcoma cells underwent apoptosis rapidly after treatment with chelerythrine. Three parallel MAPKs pathways, including the ERKs, c-Jun NH(2) kinases, and p38, were activated by chelerythrine in a dose-dependent and time-dependent fashion. For the ERKs, the activation was evident at the earliest time point tested (2 minutes) and sustained for >4 hours. Introduction of a dominant-negative H-RAS mutant (17N) partially attenuated ERK activation and delayed the onset of apoptosis induced by chelerythrine. The ERK activation and apoptotic effects of chelerythrine were greatly abrogated by the pharmaceutical inhibitors of MEK, but not by those of c-Jun NH(2) kinase or p38. Moreover, osteosarcoma cells were sensitized to chelerythrine by transient transfection with wild-type MEK1 or constitutively active MEK1 and became resistant with dominant-negative MEK1. Other protein kinase C inhibitors, including GF109203X or Gö6976, did not cause ERK activation or apoptosis in the same timeframe tested.

Conclusion: In osteosarcoma, chelerythrine-induced apoptosis is mediated through activation of the RAF/MEK/ERK pathway. These findings suggest that activating the ERK MAPK, as opposed to inhibiting it, may be a therapeutic strategy in osteosarcoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1158/1078-0432.CCR-07-5113DOI Listing
October 2008

Platelet-derived growth factor receptor as a prognostic marker and a therapeutic target for imatinib mesylate therapy in osteosarcoma.

Cancer 2008 May;112(10):2119-29

Orthopedic Surgery Service, Memorial Sloan-Kettering Cancer Center, Weil Medical College of Cornell University, New York, New York, USA.

The purpose of this review was to determine whether imatinib mesylate (STI571, Gleevec) has a role in the treatment of osteosarcoma. The expression of platelet-derived growth factor (PDGF) receptor and its ligand was examined in a panel of surgical specimens obtained from 54 osteosarcoma patients, and then the expression was compared with prognosis. The effects of imatinib mesylate on growth and molecular events in 10 patient-derived osteosarcoma cell cultures were investigated. Immunohistochemical studies demonstrated frequent expression of PDGF-AA (80.4%) and PDGF-alpha receptor (79.6%) and their correlation with inferior event-free survival (P < .05). PDGF-B-B and PDGF-beta-receptor expressions were also frequent (75.4% and 86%, respectively); however, statistically significant inferior event-free survival was not demonstrated (P = .15). In vitro studies demonstrated that imatinib mesylate had a variable cytotoxic effect on various osteosarcoma primary cultures, with an IC(50) of 5.6 microM to 9.5 microM, and blocked the PDGF-induced intracellular signal transduction as well as inhibition of downstream Akt phosphorylation. Mitogen-activated protein kinase (MAPK) was constitutively activated despite PDGF stimulation and imatinib mesylate treatment in 7 of 10 osteosarcoma cultures, perhaps explaining uncontrolled proliferation and relative unresponsiveness to imatinib. Imatinib mesylate could not be viewed as having a role as a single agent at current conventional doses for the treatment of osteosarcoma. These findings predicted activity in osteosarcoma clinical trials and suggested that in vitro model systems predict clinical behavior and that PDGF and its receptor expression could potentially be used for determining prognosis of osteosarcoma.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/cncr.23437DOI Listing
May 2008

Monoclonal antibodies to Mycobacterium tuberculosis CDC 1551 reveal subcellular localization of MPT51.

Tuberculosis (Edinb) 2007 Nov 19;87(6):489-97. Epub 2007 Sep 19.

Division of Pediatric Infectious Diseases, Department of Pediatrics, Albert Einstein College of Medicine, Bronx, NY 10461, USA.

Mycobacterium tuberculosis CDC 1551, a highly immunogenic outbreak strain, previously reported to have unique surface distribution of capsular polysaccharide, was used to generate novel monoclonal antibodies (mabs) to surface mycobacterial targets. Two immunoglobulin G1 (IgG1) mAbs, 16a1 and 16a6 were generated. The mAbs originated from the same B cell, bound strongly to whole cell M. tuberculosis CDC1551 and to its cell wall, membrane and cytosol fractions recognizing a 90kDa protein. Immunoprecipitation using mAb 16a1 isolated a protein with amino acid peptide sequences matching MPT51 from the cytosol. This immunogenic protein of unknown function was previously reported only in culture filtrates of M. tuberculosis. Our findings suggest for the first time that this protein is found within the M. tuberculosis cell.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.tube.2007.07.005DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2475595PMC
November 2007

Antigenic evidence of prevalence and diversity of Mycobacterium tuberculosis arabinomannan.

J Clin Microbiol 2004 Jul;42(7):3225-31

Department of Pediatrics, Children's Hospital at Montefiore, Albert Einstein College of Medicine, Golding Bldg., Room 702, 1300 Morris Park Ave., Bronx, NY 10461, USA.

Arabinomannan (AM) is a polysaccharide of the mycobacterial capsule. The capsular polysaccharides of various microorganisms are diverse, and this diversity is important for classification of organisms into serotypes and vaccine development. In the present study we examined the prevalence and diversity of AM among Mycobacterium tuberculosis strains using four AM-binding monoclonal antibodies (MAbs). One of these MAbs, MAb 9d8, is known to bind to AM specifically. By whole-cell enzyme-linked immunosorbent assay (ELISA), the AM recognized by MAb 9d8 was detected on the surfaces of 9 of 11 strains, while 2 strains showed no reactivity with MAb 9d8. However, the AM recognized by MAb 9d8 was found in the culture supernatants of all 11 M. tuberculosis strains tested, as demonstrated by capture ELISA. Other AM-binding MAbs reacted both with the surfaces and with the culture supernatants of all 11 strains. Mice immunized with an experimental AM-recombinant Pseudomonas aeruginosa exoprotein A (rEPA) conjugate vaccine had an increased antibody response to AM and a moderate reduction in the numbers of CFU in their organs 7 days after challenge. Our results indicate that AM was detected in all M. tuberculosis strains tested, with differences in epitope distributions of certain strains. In addition, our results suggest that an experimental AM-rEPA vaccine has a moderate effect on the numbers of CFU in organs early after infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/JCM.42.7.3225-3231.2004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC446310PMC
July 2004