Publications by authors named "Huizhong Hu"

9 Publications

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Sperm-borne small RNAs improve the developmental competence of pre-implantation cloned embryos in rabbit.

Zygote 2021 Mar 9:1-6. Epub 2021 Mar 9.

Laboratory Animal Center, Xi'an Jiaotong University Health Science Center, No. 76, Yanta West Road, Xi'an, 710061, Shaanxi, China.

The low efficiency of somatic cell nuclear transfer (SCNT) greatly limits its application. Compared with the fertilized embryo, cloned embryos display abnormal epigenetic modification and other inferior developmental properties. In this study, small RNAs were isolated, and miR-34c and miR-125b were quantified by real-time PCR; results showed that these micro-RNAs were highly expressed in sperm. The test sample was divided into three groups: one was the fertilized group, one was the SCNT control group (NT-C group), and the third group consisted of SCNT embryos injected with sperm-borne small RNA (NT-T group). The level of tri-methylation of lysine 9 on histone H3 (H3K9me3) at the 8-cell stage was determined by immunofluorescence staining, and the cleavage ratio, blastocyst ratio, apoptotic cell index of the blastocyst and total cell number of blastocysts in each group were analyzed. Results showed that the H3K9me3 level was significantly higher in the NT-C group than in the fertilized group and the NT-T group. The apoptosis index of blastocysts in the NT-C group was significantly higher than that in the fertilized group and the NT-T group. The total cell number of SCNT embryos was significantly lower than that of fertilized embryos, and injecting sperm-borne small RNAs could significantly increase the total cell number of SCNT blastocysts. Our study not only demonstrates that sperm-borne small RNAs have an important role in embryo development, but also provides a new strategy for improving the efficiency of SCNT in rabbit.
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http://dx.doi.org/10.1017/S0967199420000805DOI Listing
March 2021

Targeting the Mevalonate Pathway to Overcome Acquired Anti-HER2 Treatment Resistance in Breast Cancer.

Mol Cancer Res 2019 11 16;17(11):2318-2330. Epub 2019 Aug 16.

Lester & Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas.

Despite effective strategies, resistance in HER2 breast cancer remains a challenge. While the mevalonate pathway (MVA) is suggested to promote cell growth and survival, including in HER2 models, its potential role in resistance to HER2-targeted therapy is unknown. Parental HER2 breast cancer cells and their lapatinib-resistant and lapatinib + trastuzumab-resistant derivatives were used for this study. MVA activity was found to be increased in lapatinib-resistant and lapatinib + trastuzumab-resistant cells. Specific blockade of this pathway with lipophilic but not hydrophilic statins and with the N-bisphosphonate zoledronic acid led to apoptosis and substantial growth inhibition of R cells. Inhibition was rescued by mevalonate or the intermediate metabolites farnesyl pyrophosphate or geranylgeranyl pyrophosphate, but not cholesterol. Activated Yes-associated protein (YAP)/transcriptional coactivator with PDZ-binding motif (TAZ) and mTORC1 signaling, and their downstream target gene product Survivin, were inhibited by MVA blockade, especially in the lapatinib-resistant/lapatinib + trastuzumab-resistant models. Overexpression of constitutively active YAP rescued Survivin and phosphorylated-S6 levels, despite blockade of the MVA. These results suggest that the MVA provides alternative signaling leading to cell survival and resistance by activating YAP/TAZ-mTORC1-Survivin signaling when HER2 is blocked, suggesting novel therapeutic targets. MVA inhibitors including lipophilic statins and N-bisphosphonates may circumvent resistance to anti-HER2 therapy warranting further clinical investigation. IMPLICATIONS: The MVA was found to constitute an escape mechanism of survival and growth in HER2 breast cancer models resistant to anti-HER2 therapies. MVA inhibitors such as simvastatin and zoledronic acid are potential therapeutic agents to resensitize the tumors that depend on the MVA to progress on anti-HER2 therapies.
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http://dx.doi.org/10.1158/1541-7786.MCR-19-0756DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6825570PMC
November 2019

Vanillic acid mitigates the ovalbumin (OVA)-induced asthma in rat model through prevention of airway inflammation.

Biosci Biotechnol Biochem 2019 Mar 13;83(3):531-537. Epub 2018 Nov 13.

b Department of Pediatric , Xi'An NO.3 Hospital , Xi'an , Shaanxi Province , China.

Asthma is a chronic allergic ailment affecting a considerably large population of the world. The aim of this study is to evaluate the ameliorative effects of vanillic acid against ovalbumin (OVA)-induced asthma in rat model. Asthma was induced in Sprague Dawley rats and vanillic acid was orally administered at 25 and 50 mg/kg body weight for 28 days. Rats challenged with OVA showed heavy signs of airway inflammation and remodeling similar to chronic asthma, evidenced by the increased differential cell counts and presence of inflammatory cytokines in the bronchoalveolar lavage fluid (BALF), along with elevated serum immunoglobulin levels, and the histological results. However, vanillic acid dose-dependently attenuated the manifestation of OVA-induced asthma (p < 0.05) through suppression of inflammatory mediators and modulation of immunoglobulin levels in rats. The asthma mitigating properties of vanillic acid might be due to suppression of oxidative stress and prevention of lung airway inflammation.
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http://dx.doi.org/10.1080/09168451.2018.1543015DOI Listing
March 2019

Inhibition of NLRP9b attenuates acute lung injury through suppressing inflammation, apoptosis and oxidative stress in murine and cell models.

Biochem Biophys Res Commun 2018 09 29;503(2):436-443. Epub 2018 Jun 29.

Department of Pediatric, Xi'an NO.3 Hospital, Xi'an, Shaanxi 710018, China. Electronic address:

Acute lung injury (ALI), known a severe disease along with high morbidity and mortality, is lacking of specific therapies. Inflammation, apoptosis and oxidative stress are critical pathologies that contribute to ALI. Recently, there is study indicated that NLRP9b, a NOD-like receptor (NLR) member, is critical in modulation of inflammatory response. However, the effects of NLRP9b on sepsis-associated ALI, and the underlying molecular mechanism have not been understood. In the present study, the wild type (WT) and NLRP9b-knockout (NLRP9b) mice with C57B/L6 background were subjected to a cecal ligation and puncture (CLP) for ALI murine model establishment. The findings indicated that NLRP9b improved the survival rate of CLP-induced ALI mice, and inhibited pulmonary histopathological alterations, inflammation, and apoptosis. NLRP9b reduced the activation of inhibitor of κBα/nuclear factor kappa B (IκBα/NF-κB), apoptosis-associated speck-like protein containing a Caspase-recruitment domain (ASC)/Casapse-1 and Caspase-3/poly (ADP-ribose) polymerase (PARP) signaling pathways in CLP-challenged mice with ALI. In vitro, mouse epithelial cells (MLE-12) were incubated with lipopolysaccharide (LPS) or recombinant NLRP9b caused a significant increased of pro-inflammatory cytokines or chemokine, and reactive oxygen species (ROS) generation; however, these changes were markedly alleviated by NLRP9-knockdown using its specific siRNA sequence. Pre-treatment of MLE-12 cells with ROS scavenger of N-acetylcysteine (NAC) remarkably decreased lipopolysaccharide (LPS)- and rMuNLRP9-induced production of ROS, and the secretion of inflammatory cytokines or chemokine, as well as the activity of IκBα/NF-κB, ASC/Casapse-1 and Caspase-3/PARP signaling pathways. Together, the findings here suggested that NLRP9b played an essential role in lung inflammation, apoptosis and oxidative stress of sepsis-induced ALI animal model or in LPS-induced MLE-12 cells, providing that NLRP9b inhibition might be a potential therapeutic option for ALI.
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http://dx.doi.org/10.1016/j.bbrc.2018.04.079DOI Listing
September 2018

HER2 Reactivation through Acquisition of the HER2 L755S Mutation as a Mechanism of Acquired Resistance to HER2-targeted Therapy in HER2 Breast Cancer.

Clin Cancer Res 2017 Sep 9;23(17):5123-5134. Epub 2017 May 9.

Lester & Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas.

Resistance to anti-HER2 therapies in HER2 breast cancer can occur through activation of alternative survival pathways or reactivation of the HER signaling network. Here we employed BT474 parental and treatment-resistant cell line models to investigate a mechanism by which HER2 breast cancer can reactivate the HER network under potent HER2-targeted therapies. Resistant derivatives to lapatinib (L), trastuzumab (T), or the combination (LR/TR/LTR) were developed independently from two independent estrogen receptor ER/HER2 BT474 cell lines (AZ/ATCC). Two derivatives resistant to the lapatinib-containing regimens (BT474/AZ-LR and BT474/ATCC-LTR lines) that showed HER2 reactivation at the time of resistance were subjected to massive parallel sequencing and compared with parental lines. Ectopic expression and mutant-specific siRNA interference were applied to analyze the mutation functionally. and experiments were performed to test alternative therapies for mutant HER2 inhibition. Genomic analyses revealed that the L755S mutation was the only common somatic mutation gained in the BT474/AZ-LR and BT474/ATCC-LTR lines. Ectopic expression of L755S induced acquired lapatinib resistance in the BT474/AZ, SK-BR-3, and AU565 parental cell lines. L755S-specific siRNA knockdown reversed the resistance in BT474/AZ-LR and BT474/ATCC-LTR lines. The HER1/2-irreversible inhibitors afatinib and neratinib substantially inhibited both resistant cell growth and the HER2 and downstream AKT/MAPK signaling driven by L755S and HER2 reactivation through acquisition of the L755S mutation was identified as a mechanism of acquired resistance to lapatinib-containing HER2-targeted therapy in preclinical HER2-amplified breast cancer models, which can be overcome by irreversible HER1/2 inhibitors. .
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http://dx.doi.org/10.1158/1078-0432.CCR-16-2191DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5762201PMC
September 2017

Upregulation of ER Signaling as an Adaptive Mechanism of Cell Survival in HER2-Positive Breast Tumors Treated with Anti-HER2 Therapy.

Clin Cancer Res 2015 Sep 26;21(17):3995-4003. Epub 2015 May 26.

Lester and Sue Smith Breast Center, Baylor College of Medicine, Houston, Texas. Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, Texas. Department of Medicine, Baylor College of Medicine, Houston, Texas.

Purpose: To investigate the direct effect and therapeutic consequences of epidermal growth factor receptor 2 (HER2)-targeting therapy on expression of estrogen receptor (ER) and Bcl2 in preclinical models and clinical tumor samples.

Experimental Design: Archived xenograft tumors from two preclinical models (UACC812 and MCF7/HER2-18) treated with ER and HER2-targeting therapies and also HER2+ clinical breast cancer specimens collected in a lapatinib neoadjuvant trial (baseline and week 2 posttreatment) were used. Expression levels of ER and Bcl2 were evaluated by immunohistochemistry and Western blot analysis. The effects of Bcl2 and ER inhibition, by ABT-737 and fulvestrant, respectively, were tested in parental versus lapatinib-resistant UACC812 cells in vitro.

Results: Expression of ER and Bcl2 was significantly increased in xenograft tumors with acquired resistance to anti-HER2 therapy compared with untreated tumors in both preclinical models (UACC812: ER P = 0.0014; Bcl2 P < 0.001 and MCF7/HER2-18: ER P = 0.0007; Bcl2 P = 0.0306). In the neoadjuvant clinical study, lapatinib treatment for 2 weeks was associated with parallel upregulation of ER and Bcl2 (Spearman coefficient: 0.70; P = 0.0002). Importantly, 18% of tumors originally ER-negative (ER(-)) converted to ER(+) upon anti-HER2 therapy. In ER(-)/HER2(+) MCF7/HER2-18 xenografts, ER reexpression was primarily observed in tumors responding to potent combination of anti-HER2 drugs. Estrogen deprivation added to this anti-HER2 regimen significantly delayed tumor progression (P = 0.018). In the UACC812 cells, fulvestrant, but not ABT-737, was able to completely inhibit anti-HER2-resistant growth (P < 0.0001).

Conclusions: HER2 inhibition can enhance or restore ER expression with parallel Bcl2 upregulation, representing an ER-dependent survival mechanism potentially leading to anti-HER2 resistance.
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http://dx.doi.org/10.1158/1078-0432.CCR-14-2728DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4558260PMC
September 2015

Receptor tyrosine kinase ERBB4 mediates acquired resistance to ERBB2 inhibitors in breast cancer cells.

Cell Cycle 2015 ;14(4):648-55

a Department of Pharmacology and Toxicology.

Approximately 25% of breast cancers overexpress and depend on the receptor tyrosine kinase ERBB2, one of 4 ERBB family members. Targeted therapies directed against ERBB2 have been developed and used clinically, but many patients continue to develop resistance to such therapies. Although much effort has been focused on elucidating the mechanisms of acquired resistance to ERBB2-targeted therapies, the involvement of ERBB4 remains elusive and controversial. We demonstrate that genetic ablation of ERBB4, but not ERBB1-3, led to apoptosis in lapatinib-resistant cells, suggesting that the efficacy of pan-ERBB inhibitors was, at least in part, mediated by the inhibition of ERBB4. Moreover, ERBB4 was upregulated at the protein level in ERBB2+ breast cancer cell lines selected for acquired lapatinib resistance in vitro and in MMTV-Neu mice following prolonged lapatinib treatment. Knockdown of ERBB4 caused a decrease in AKT phosphorylation in resistant cells but not in sensitive cells, suggesting that ERBB4 activated the PI3K/AKT pathway in lapatinib-resistant cells. Importantly, ERBB4 knockdown triggered apoptosis not only in lapatinib-resistant cells but also in trastuzumab-resistant cells. Our results suggest that although ERBB4 is dispensable for naïve ERBB2+ breast cancer cells, it may play a key role in the survival of ERBB2+ cancer cells after they develop resistance to ERBB2 inhibitors, lapatinib and trastuzumab.
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http://dx.doi.org/10.4161/15384101.2014.994966DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4614407PMC
December 2015

Systems analysis of drug-induced receptor tyrosine kinase reprogramming following targeted mono- and combination anti-cancer therapy.

Cells 2014 Jun 10;3(2):563-91. Epub 2014 Jun 10.

Scottish Informatics, Mathematics, Biology and Statistics Centre (SIMBIOS), Abertay University, Dundee, DD1 1HG, United Kingdom.

The receptor tyrosine kinases (RTKs) are key drivers of cancer progression and targets for drug therapy. A major challenge in anti-RTK treatment is the dependence of drug effectiveness on co-expression of multiple RTKs which defines resistance to single drug therapy. Reprogramming of the RTK network leading to alteration in RTK co-expression in response to drug intervention is a dynamic mechanism of acquired resistance to single drug therapy in many cancers. One route to overcome this resistance is combination therapy. We describe the results of a joint in silico, in vitro, and in vivo investigations on the efficacy of trastuzumab, pertuzumab and their combination to target the HER2 receptors. Computational modelling revealed that these two drugs alone and in combination differentially suppressed RTK network activation depending on RTK co-expression. Analyses of mRNA expression in SKOV3 ovarian tumour xenograft showed up-regulation of HER3 following treatment. Considering this in a computational model revealed that HER3 up-regulation reprograms RTK kinetics from HER2 homodimerisation to HER3/HER2 heterodimerisation. The results showed synergy of the trastuzumab and pertuzumab combination treatment of the HER2 overexpressing tumour can be due to an independence of the combination effect on HER3/HER2 composition when it changes due to drug-induced RTK reprogramming.
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http://dx.doi.org/10.3390/cells3020563DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4092865PMC
June 2014

Feedforward and feedback regulation of the MAPK and PI3K oscillatory circuit in breast cancer.

Cell Signal 2013 Jan 18;25(1):26-32. Epub 2012 Sep 18.

Centre for Research in Informatics and Systems Pathology (CRISP), University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU, UK.

Although the theoretical possibility of oscillations in MAPK signalling has long been described, experimental validation has proven more elusive. In this study we observed oscillations in MAPK and PI3K signalling in breast cancer cells in response to epidermal growth factor receptor-family stimulation. Using systems level analysis with a kinetic model, we demonstrate that receptor amplification, loss of transcriptional feedback, or pathway crosstalk, are responsible for oscillations in MAPK and PI3K signalling. Transcriptional profiling reveals architectural motifs likely to be responsible for feedback control of oscillations. Overexpression of the HER2 oncogene and inhibition of transcriptional feedback increase the amplitude of oscillations and provide experimental validation of the computational findings.
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http://dx.doi.org/10.1016/j.cellsig.2012.09.014DOI Listing
January 2013