Project description:We elucidated the functional significance and molecular mechanisms of DUSP5P1 lncRNA (dual specificity phosphatase 5 pseudogene 1) in gastric carcinogenesis. We demonstrated that gastric cancer (GC) patients with high DUSP5P1 expression had shortened survival in two independent cohorts. DUSP5P1 promoted GC cell migration and invasion in vitro and metastasis in vivo. Mechanistically, DUSP5P1 activated ARHGAP5 transcription by directly binding to the promoter of ARHGAP5 with a binding motif of TATGTG. RNA-seq revealed that ARHGAP5 activated focal adhesion and MAPK signalling pathways to promote GC metastasis. DUSP5P1 also dysregulated platinum drug resistance pathway. Consistently, DUSP5P1 overexpression in GC cells antagonized cytotoxic effect of Oxaliplatin, and shDUSP5P1 plus Oxaliplatin exerted synergistic effect on inhibiting GC metastasis in vitro and in vivo. DUSP5P1 depletion also suppressed the growth of platinum drug-resistant PDO models. In conclusion, DUSP5P1 promoted GC metastasis by directly modulating ARHGAP5 expression to activate focal adhesion and MAPK pathways, serves as therapeutic target for platinum drug resistant GC, and is an independent prognostic factor in GC.
Project description:We elucidated the functional significance and molecular mechanisms of DUSP5P1 lncRNA (dual specificity phosphatase 5 pseudogene 1) in gastric carcinogenesis. We demonstrated that gastric cancer (GC) patients with high DUSP5P1 expression had shortened survival in two independent cohorts. DUSP5P1 promoted GC cell migration and invasion in vitro and metastasis in vivo. Mechanistically, DUSP5P1 activated ARHGAP5 transcription by directly binding to the promoter of ARHGAP5 with a binding motif of TATGTG. RNA-seq revealed that ARHGAP5 activated focal adhesion and MAPK signalling pathways to promote GC metastasis. DUSP5P1 also dysregulated platinum drug resistance pathway. Consistently, DUSP5P1 overexpression in GC cells antagonized cytotoxic effect of Oxaliplatin, and shDUSP5P1 plus Oxaliplatin exerted synergistic effect on inhibiting GC metastasis in vitro and in vivo. DUSP5P1 depletion also suppressed the growth of platinum drug-resistant PDO models. In conclusion, DUSP5P1 promoted GC metastasis by directly modulating ARHGAP5 expression to activate focal adhesion and MAPK pathways, serves as therapeutic target for platinum drug resistant GC, and is an independent prognostic factor in GC.
Project description:We elucidated the functional significance and molecular mechanisms of DUSP5P1 lncRNA (dual specificity phosphatase 5 pseudogene 1) in gastric carcinogenesis. We demonstrated that gastric cancer (GC) patients with high DUSP5P1 expression had shortened survival in two independent cohorts. DUSP5P1 promoted GC cell migration and invasion in vitro and metastasis in vivo. Mechanistically, DUSP5P1 activated ARHGAP5 transcription by directly binding to the promoter of ARHGAP5 with a binding motif of TATGTG. RNA-seq revealed that ARHGAP5 activated focal adhesion and MAPK signaling pathways to promote GC metastasis. DUSP5P1 also dysregulated platinum drug resistance pathway. Consistently, DUSP5P1 overexpression in GC cells antagonized cytotoxic effect of Oxaliplatin, and shDUSP5P1 plus Oxaliplatin exerted synergistic effect on inhibiting GC metastasis in vitro and in vivo. DUSP5P1 depletion also suppressed the growth of platinum drug-resistant PDO models. In conclusion, DUSP5P1 promoted GC metastasis by directly modulating ARHGAP5 expression to activate focal adhesion and MAPK pathways, serves as therapeutic target for platinum drug resistant GC, and is an independent prognostic factor in GC.
Project description:Platinum-based chemotherapy is effective in inducing shrinkage of primary lung cancer lesions; however, it shows limited therapeutic efficacy in patients with brain metastasis (BM). In this study, we utilized a BM model of PC9 lung adenocarcinoma cells and found that the derivative brain metastatic subpopulations (PC9-BrMs) of parental cells PC9 developed obvious resistance to platinum; this suggested that the acquisition of chemo-resistance by brain metastatic cells is attributable to the intrinsic changes in the metastatic cells. Therefore, we performed an integrated profiling of metabolomics and proteomics, and described a radically altered spectrum of BM metabolism and protein expression compared with primary lung cancer cells. We identified a unique metabolite status characterized by high consumption of glutathione (GSH) for antioxidant stress response, both in BM cells and clinical serum samples.
Project description:Platinum-based chemotherapy is effective in inducing shrinkage of primary lung cancer lesions; however, it shows limited therapeutic efficacy in patients with brain metastasis (BM). In this study, we utilized a BM model of PC9 lung adenocarcinoma cells and found that the derivative brain metastatic subpopulations (PC9-BrMs) of parental cells PC9 developed obvious resistance to platinum; this suggested that the acquisition of chemo-resistance by brain metastatic cells is attributable to the intrinsic changes in the metastatic cells. Therefore, we performed an integrated profiling of metabolomics and proteomics, and described a radically altered spectrum of BM metabolism and protein expression compared with primary lung cancer cells. We identified a unique metabolite status characterized by high consumption of glutathione (GSH) for antioxidant stress response, both in BM cells and clinical serum samples.
Project description:Cullin 4B (CUL4B), a scaffold protein that assembles CRL4B ubiquitin ligase complexes, has been reported to be overexpressed in several types of solid tumors and contributes to epigenetic silencing of tumor suppressor. However, its clinical significance and the molecular mechanisms underlying its regulation in gastric cancer (GC) remain largely unknown. Here, we showed that CUL4B was elevated in GC tissues and its overexpression was positively correlated with poor prognosis and lymph node metastasis. CUL4B knockdown in GC cells decreased proliferation, mesenchymal transition and invasion in vitro, as well as tumor growth and metastasis in nude mice, and CUL4B overexpression induced the opposite results. Further studies showed that miR-101 could inhibit CUL4B expression by directly targeting its 3’-UTR and they were inversely correlated in clinical GC specimens. Notably, a positive relationship between CUL4B and HER2 was found in GC clinical specimens, GC cells and GC xenograft tumors. Through bioinformatics analysis of miRNA-seq data and target prediction, we nominated miR-125a as a direct target of CUL4B. ChIP assays demonstrated that CUL4B directly repressed miR-125a expression by physically binding to its promoter. In addition, we confirmed miR-125a is the target of HER2. Consequently, we demonstrated that CUL4B can up-regulate HER2 expression through repressing miR-125a. Most importantly, silencing of HER2 by Herceptin or siRNA partially reversed CUL4B-induced epithelial-to-mesenchymal transition (EMT), cell invasion and metastasis in vitro and in vivo. These findings define a CUL4B-miR-125a-HER2 regulatory mechanism shed light on CUL4B oncogenic mechanisms and reveals promising therapeutic targets for progressive GC. CUL4B proteins are frequently upregulated in human cancer, yet little is known about the underlying molecular mechanisms of CUL4B induced gastric cancer(GC) carcigenesis.Here, we uncover the critical role of CUL4B in gastric cancer growth and metastasis through the regulation of HER2 expression.CUL4B contributes to GC invasion and metastasis by transcriptional repression of HER2 targeting miR-125a, which provide a new insight into how CUL4B regulates GC progression and metastasis.
Project description:Purpose: Despite advances in radical surgery and chemotherapy delivery, ovarian cancer is the most lethal gynecologic malignancy. Most of these patients are treated with platinum-based chemotherapies, but there is no biomarker model to guide their responses to these therapeutic agents. We have developed and independently tested our novel multivariate molecular predictors for forecasting patients' responses to individual drugs on a cohort of 58 ovarian cancer patients. Experimental Design: We adapted and applied the previously-published COXEN algorithm to develop molecular predictors for therapeutic responses of patients' tumors based on expression signatures derived from the NCI-60 in vitro drug activities and genomic expression data. Genome-wide candidate biomarkers were first triaged by examining expression patterns of frozen and formalin-fixed paraffin embedded (FFPE) tissue samples. We then identify initial drug sensitivity biomarkers for carboplatin and paclitaxel, respectively. These biomarkers were further narrowed by examining concordant expression patterns between cell lines and a historical set of ovarian cancer patients. Multivariate predictors were obtained from the NCI-60 cell lines and refined using historical patient cohorts. To independent validate these molecular predictors, we performed genome-wide profiling on FFPE samples of 58 ovarian cancer patients obtained prior to adjuvant chemotherapy. Results: Carboplatin predictor significantly stratified platinum sensitive and resistant patients (p = 0.019) with sensitivity = 93%, specificity = 33%, PPV = 65%, and NPV = 78%. Paclitaxel predictor also significantly stratified patients' responses (p = 0.033) with sensitivity = 96%, specificity = 26%, PPV = 61%, and NPV = 86%. The combination predictor for platinum-taxane combination demonstrated a significant survival difference between the predicted responders and nonresponders with median survival of 12.9 months vs. 8.1 months (p = 0.045). Conclusions: COXEN predictors successfully stratified platinum resistance and taxane response in this retrospective cohort, especially based on their FFPE tumor samples. Accurate prediction of chemotherapeutic response, especially to platinum agents is highly clinically relevant and could alter primary management of ovarian cancer. Gene expression data from 58 stage III-IV ovarian cancer patients treated with Carboplatin and Taxol agents