Project description:The attainment of drug resistance in gastric cancer (GC) is a problematic issue. Although many studies have shown that cancer stem cells (CSCs) play an important role in the acquisition of drug resistance, there is no clinically available biomarker for predicting oxaliplatin (L-OHP) resistance in relation to CSCs. Organoid technology, a novel 3D cell culture system, allows harboring of patient-derived cancer cells containing abundant CSCs using niche factors in a dish. In this study, we established L-OHP-resistant gastric cancer organoids (GCOs) and evaluated their gene expression profile using microarray analysis. We validated the upregulated genes in the L-OHP-resistant GCOs compared to their parental GCOs to find a gene responsible for L-OHP resistance by qRT-PCR, immunohistochemistry, in vitro, and in vivo experiments. We found myoferlin (MYOF) to be a candidate gene through microarray analysis. The results from cell viability assays and qRT-PCR showed that high expression of MYOF correlated significantly with the IC50 of L-OHP in GCOs. Immunohistochemistry of MYOF in GC tissue samples revealed that high expression of MYOF was significantly associated with poor prognosis, T grade, N grade, and lymphatic invasion, and showed MYOF to be an independent prognostic indicator, especially in the GC patients treated with platinum-based chemotherapy. The knockdown of MYOF repressed L-OHP resistance, cell growth, stem cell features, migration, invasion, and in vivo tumor growth. Our results suggest that MYOF is highly involved in L-OHP resistance and tumor progression in GC. MYOF could be a promising biomarker and therapeutic target for L-OHP-resistant GC cases.
Project description:Copy number profiling of MKN45T 5-FU resistant gastric cancer cell lines and its parental cell line MKN45. We hypothesized that a detailed fine-scale survey of genomic CNAs might reveal the mechanism for acquired resistant to 5-FU in gastric cancer.
Project description:One of the first-line chemotherapy regimes for gastric cancer is a combination treatment of epirubicin, cisplatin, and 5-fluorouracil (ECF). Chemoresistance remains the major obstacle to achieving successful results from gastric cancer treatment. Understanding acquired or pre-existing resistance to anticancer drugs is essential to the development of a therapeutic modality for gastric cancer. In this study, we established ECF-resistant (ECF-R) gastric cancer cell lines. We found that nerve injury–induced protein 2 (Ninjurin2, NINJ2) functioned as a biomarker for ECF-R in both gastric cancer cells. We also investigated the NINJ2 binding molecule and downstream pathway using both LC-MS/MS and phospho-antibody arrays.
Project description:To understand the molecular basis of the acquisition of 5-FU resistance in gastric cancer stem cells, we established 5-FU-resistant gastric cancer organoids. We used microarrays to detail the global program of gene expression underlying 5-FU resistance and maintenance of stem cell properties in gastric cancer.
Project description:Cisplatin-resistant gastric cancer (GC) occurs in patients with GC treated with cisplatin-based chemotherapy, which results in disease progression and early recurrence during the treatment. To understand the initiation and developmental mechanism underlying cisplatin-resistant GC, we developed cisplatin resistant SGC7901 cells (SGC7901/DDP) from the parental cells (SGC7901/S) by continuous exposure to increasing concentrations of cisplatin and subjected these two cell lines to RNA sequencing analysis.
Project description:The study was undertaken to identify microRNAs differently expressed by intestinal type of gastric cancer using miRNA microarray. The miRNA expression in the intestinal type of gastric cancer depending on H. pylori infection suggest that different gastric cancer pathogenesis could be exist between H. pylori-positive and -negative gastric cancer.