M249 melanoma cells: Vemurafenib and Selumetinib resistant through BRAF double minutes vs. parental
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ABSTRACT: CGH profiling of M249 melanoma cell line treated with step-wise increasing Vemurafenib and Selumetinib to develop resistance (VSR). The resistance mechanims was through BRAF amplification in double minute (DM) format. The control cell line is untreated M249.
Project description:The BRAFV600E mutant melanoma cell line M14 responds to the BRAF inhibitor vemurafenib, however, the differences in response between individual cells are underlying resistance. To highlight the underlying mechanisms, we performed treatment of M14 cells with vemurafenib, followed by Drop-seq. We were able to clearly distinguish cells that were treated with the drug from untreated cells, and we discovered different cell populations within the treated cells, likely reflecting heterogeneity of drug resistant cells. We were able to identify specific biomarkers, as preferentially expressed genes, for each cell population. The results of our study will address preexisting and acquired drug resistance that limits clinical usefulness of targeted strategies.
Project description:BRAF targeted drug vemurafenib have shown very good clinical benefit in melanoma patient containing BRAF V600E mutation. However, resistance always occurs in patient. Early stage of the resistance development require the tumor cell adapted to the targeted drug. We are trying to study the kinetic of melanoma cell adaptation towards vemurafenib. 10 melanoma cell lines with BRAF mutation are treated with targeted therapy vemurafenib. RNA-seq samples are collected after drug treatment for different time (day3 and day21) to compare with DMSO-treated control samples for each cell line. Except innate resistant cell line M381, all other cell lines shows inhibition of proliferation. However, a small cluster of cell lines (M397, M229 and M263) shows some other unique transcriptomic change. For cell line M397, M229 and M263, we also collected the RNA-seq data for long-term (73day/90day) drug treatment condition where the cells developed resistance to vemurafenib treatment. Dedifferentiation is enriched in these unique transcriptomic change within these 3 cell lines. Similar cell state dedifferentiation phenomenon is also reported to cause resistance towards immunotherpay where the resistant de-differentiated melanoma cells are induced by TNF which is secreted by tumor-infiltrating T cells. We also treat our cultured melanoma cells with TNF and collected the treated sample for RNA-seq experiment.
Project description:Copy number analysis to compare parental colorectal cancer cell lines and their selumetinib-resistant derivatives and identify gene copy changes that might contribute to resistance
Project description:RNA sequencing analysis to compare parental colorectal cancer cell lines and their selumetinib-resistant derivatives and identify expression changes and/or mutations that might contribute to resistance
Project description:We report the application of single-molecule-based sequencing technology for high-throughput profiling of RNAs in BRAFV600E+ thyroid cancer cell lines 8505C and WRO. We generated genome-wide transcriptome maps of 8505C and WRO cells after vemurafenib, BRAF inhibitor, treatment. In addition, we generated genome-wide transcriptome maps of clonally selected vemurafenib-resistant 8505C and WRO cells with or without vemurafenib treatment. Negative control treatment was 0.1% of dimethy solfoxide (DMSO), the diluent used to resuspend vemurafenib. The treatment regine of vemurafenib was 2 µM concentration for 24 hours. We find that both inducible response to BRAFi and acquired BRAFi resistance in thyroid cancer cells showed significant activation of the JAK/STAT pathway. Our study demonstrates that the JAK/STAT-signaling pathway is activated as thyroid cancer cells develop resistance to BRAFi and that this pathway is a potential target for anticancer activity and to overcome drug resistance that commonly develops to treatment with BRAFi in thyroid cancer and potentially in other malignancies.
Project description:Vemurafenib is a BRAF inhibitor with specificity for the most common BRAF mutant encountered in melanomas (BRAFV600E). Vemurafenib suppresses the proliferation of BRAF mutant human melanoma cells by suppressing downstream activation of the MEK/ERK mitogen activated protein kinases. We used microarrays to examine the transcriptional response of a vemurafenib-sensitive BRAFV600E human melanoma cell line (A375) to vemurafenib in order to further delineate the mechanisms by which BRAFV600E drives cell proliferation and energy metabolism in human melanoma.
Project description:Here, we investigate gene expression response of the BRAFV600E mutant cell line COLO205 to the MEK inhibitor selumetinib / AZD6244 / ARRY-142886. Although selumetinib causes long term G1 arrest, we observe cells stochastically entering the cell cycle without re-activation of ERK and initiation of a normal proliferative gene expression programme. Genes encoding DNA replication and repair factors are downregulated during G1 arrest, but many of these are transiently induced when cells escaping arrest enter S and G2. Nonetheless, mRNAs encoding key DNA replication factors including the MCM replicative helicase complex, PCNA and TIPIN remain at very low abundance.
Project description:Here, we investigate gene expression response of the BRAFV600E mutant cell line COLO205 to the MEK inhibitor selumetinib / AZD6244 / ARRY-142886. Although selumetinib causes long term G1 arrest, we observe cells stochastically entering the cell cycle without re-activation of ERK and initiation of a normal proliferative gene expression programme. Genes encoding DNA replication and repair factors are downregulated during G1 arrest, but many of these are transiently induced when cells escaping arrest enter S and G2. Nonetheless, mRNAs encoding key DNA replication factors including the MCM replicative helicase complex, PCNA and TIPIN remain at very low abundance.