Project description:Cancer stem cells (CSCs) possess self-renewal and chemoresistance activities. However, the manner in which these features are maintained remains obscure. We sought to identify cell surface protein(s) that mark self-renewing and chemoresistant gastric cancer cells using the Explorer Antibody Microarray. We identified PMP22, a target gene of the Wnt/β-catenin pathway, as the most upregulated cell surface protein in gastric cancer xenografts exposed to cisplatin (DDP). PMP22 expression was markedly upregulated in tumorspheric cells and declined with differentiation. Infecting gastric cancer cells with lentivirus expressing PMP22 shRNAs reduced proliferation, tumorsphere formation, and chemoresistance to cisplatin in vitro and in NOD/SCID mice. When combined with bortezomib, a PMP22 inhibitor, the chemotherapeutic sensitivity to cisplatin treatment was dramatically increased by inducing cell apoptosis in cultured cells and xenograft mouse models. Finally, mRNA expression levels of PMP22 were detected in 38 tumor specimens from patients who received 6 cycles of perioperative chemotherapy. A strong correlation between PMP22 level and tumor recurrence was revealed, thus showing a pivotal role of PMP22 in the clinical chemoresistance of gastric cancer. Our study is the first to show the role of PMP22 in gastric cancer stemness and chemoresistance and reveals a potential new target for the diagnosis and treatment of recurrent gastric cancer.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Because cancer stem cells already had genetic and epigenetic alterations which can affect the self-renewal, we tried to characterize genetic and epigenetic changes of the gastric cancer stem cells. To do this, we performed SNP array, MBD sequencing and RNA sequencing.
Project description:Post-treatment recurrence remains a major clinical challenge in colorectal cancer (CRC), and increasing evidence suggests that Cancer Stem Cells (CSCs) may mediate this process due to their enhanced resistance to conventional therapeutics. We hypothesized that the Pregnane-X receptor (PXR) may drive the chemoresistance of colorectal CSCs.. shRNA-mediated PXR down-regulation was used to analyze the role of PXR on self-renewal in the colorectal cancer cell Line LS174T. Expression and activity of PXR were quantified under conditions that promote Cancer Stem Cells (CSCs) enrichment. Conversely, CSC characterization was performed in cells enriched along their PXR activity level.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
