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:Differential expression of microRNA expression in tamoxifen-sensitive MCF-7 versus tamoxifen-resistant LY2 human breast cancer cells
Project description:Resistance to tamoxifen is a major challenge in the treatment of estrogen receptor positive breast cancer. Acquired resistance to drug involves multilayered genetic and epigenetic regulation . The oncogene EZH2 plays significant role in the development of resistance against tamoxifen, widely used in the treatment of breast cancer. Inhibition of EZH2 has proven to reverse the tamoxifen resistance breast cancer cells back to the sensitive state. The molecular mechanism through which EZH2 inhibition triggers its effects are not known.This study was conducted to understand the global change in proteome profile of tamoxifen resistant MCF-7 breast cancer cells as a result of effect of EZH2 knockdown. Label Free Quantitative proteomics revealed a large number of proteins altered in acquired tamoxifen resistant cells compared to the sensitive cells. A total of 286 proteins were identified with normalized RT for each m/z out of which 86 proteins were upregulated by more than 1.3 fold and 98 proteins were down regulated by more than 1.3 fold in MCF-7 tamoxifen resistant breast cancer cells in comparison to the sensitive breast cancer cells. Upon EZH2 knockdown in tamoxifen resistant cells, a total of 115 proteins were found to be altered with 20 proteins upregulated by more than 1.3 fold and 49 proteins down regulated by more than 1.3 fold. Among the top upregulated proteins were L-lactate dehydrogenase A chain, Alpha and Gamma-enolase, Calreticulin, heat shock protein HSP-90-beta, Alpha-actinin-4, Elongation factor 1-alpha, Vimentin, Protein S100A6, Putative protein FAM10A5, Heterogeneous nuclear ribonucleoprotein A1 and Keratin 1. In addition, 15 proteins were found to be down regulated in EZH2si transfected tamoxifen sensitive cells which otherwise were highlyup regulated in resistant cells in the presence of normal level of EZH2. This indicates a possible regulation of these molecules by EZH2 leading to loss of resistance. Our data unveils important molecular players downstream to EZH2 knockdown leading to regain of sensitivity to tamoxifen in acquired tamoxifen resistance.Thus, EZH2 seems to exert its effects through regulation of metabolism, epithelial to mesenchymal transition and protein synthesis & folding. Hence, targeting EZH2 or the molecules down the cascade might be helpful in reacquiring sensitivity to tamoxifen intamoxifen-resistant cells.
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.