Project description:The taxanes, namely Paclitaxel and Docetaxel, are important and widely used cancer chemotherapy drugs in the treatment of invasive and metastatic human breast cancer. Although treatment with the taxanes is beneficial to many patients, drug-responsive tumors in patients with metastatic breast cancer often display resistance to these drugs, either initially or over time following the continued administration of chemotherapy drugs. To investigate the patterns of cross-resistance with the taxane drugs and to identify potential mechanisms of resistance, we generated a series of MDA-MB-231 taxane resistant cell lines. We then used microarrays to determine gene expression differences between sensitive, Docetaxel and Paclitaxel resistant MDA-MB-231 cells. RNA isolated from three independent passages of sensitive, Docetaxel and Paclitaxel resistant cell lines and purified using the Qiagen RNeasy Mini Kit. Total RNA was processed and hybridized to Affymetrix Genechip HU133A arrays.
Project description:The taxanes, namely Paclitaxel and Docetaxel, are important and widely used cancer chemotherapy drugs in the treatment of invasive and metastatic human breast cancer. Although treatment with the taxanes is beneficial to many patients, drug-responsive tumors in patients with metastatic breast cancer often display resistance to these drugs, either initially or over time following the continued administration of chemotherapy drugs. To investigate the patterns of cross-resistance with the taxane drugs and to identify potential mechanisms of resistance, we generated a series of MDA-MB-231 taxane resistant cell lines. We then used microarrays to determine gene expression differences between sensitive, Docetaxel and Paclitaxel resistant MDA-MB-231 cells.
Project description:SN-38 resistant breast cancer cell lies (MCF-7 and MDA-MB-231) were established by stepwise increasing the concentration of SN-38. Gene expression profiling was performed on parental (sensitive) MCF-7 and parental (sensitive) MDA-MB-231 cell lines and their respective SN-38 resistant cell lines. For each cell line we harvested RNA from three independent passages and conducted 3 arrays.
Project description:Small-molecule Smac mimetics target inhibitor of apoptosis (IAP) proteins to induce TNFα-dependent apoptosis in cancer cells and several Smac mimetics have been advanced into clinical development as a new class of anticancer drugs. However, preclinical studies have shown that only a small subset of cancer cell lines are sensitive to Smac mimetics used as single agents and these cell lines are at risk of developing drug resistance to Smac mimetics. Thus, it is important to understand the molecular mechanisms underlying intrinsic and acquired resistance of cancer cells to Smac mimetics in order to develop effective therapeutic strategies to overcome or prevent Smac mimetic resistance. We established Smac mimetic resistant sublines derived from MDA-MB-231 breast cancer cells, which exhibit exquisite sensitivity to the Smac mimetic SM-164, and used microarrays to detail the global programme of gene expression underlying SM-164 resistance in MDA-MB-231 cells and identified differentially expressed genes in SM-164-resistant and -sensitive MDA-MB-231 cells. SCID mice with MDA-MB-231 xenograft tumors were treated with 5 mg/kg of SM-164 intravenously for 5 days/week for 2 weeks. SM-164-regressed MDA-MB-231 tumors regrew after treatment ended. Tumor cells from these regrown MDA-MB-231 tumors were isolated and total RNAs were prepared for microarray analysis.
Project description:Small-molecule Smac mimetics target inhibitor of apoptosis (IAP) proteins to induce TNFα-dependent apoptosis in cancer cells and several Smac mimetics have been advanced into clinical development as a new class of anticancer drugs. However, preclinical studies have shown that only a small subset of cancer cell lines are sensitive to Smac mimetics used as single agents and these cell lines are at risk of developing drug resistance to Smac mimetics. Thus, it is important to understand the molecular mechanisms underlying intrinsic and acquired resistance of cancer cells to Smac mimetics in order to develop effective therapeutic strategies to overcome or prevent Smac mimetic resistance. We established Smac mimetic resistant sublines derived from MDA-MB-231 breast cancer cells, which exhibit exquisite sensitivity to the Smac mimetic SM-164, and used microarrays to detail the global programme of gene expression underlying SM-164 resistance in MDA-MB-231 cells and identified differentially expressed genes in SM-164-resistant and -sensitive MDA-MB-231 cells.
Project description:To investigate mechanism of inosine promotes the survival and metabolism of MDA-MB-231 cells under starvation conditions, MDA-MB-231 cells were treated with inosine and glucose for 12h under starvation conditions. We then performed gene expression profiling analysis using data obtained from RNA-seq of MDA-MB-231 cells under three different treatments(-G-Q,Inosine,Glucose).
Project description:We report the gene expression patterns in MDA-MB-231 (a line selected for low metastatic ability), MDA-MB-231-1833 (its bone-tropic metastatic derivative line), MDA-MB-231p27CK-DD (a phosphomimetic cell line), MDA-MB-231-1833shp27 (p27 knockdown cell line), MDA-MB-231-1833PF1502 (PI3K inhibitor treatment). It shows that the gene expression pattern are regulated in a p27 phosphorylation-dependent manner.
Project description:Acquired drug resistance represents a major challenge in chemo-therapy treatment for various types of cancers. We have found that the retinoid X receptorâselective agonist bexarotene (LGD1069, Targretin) was efficacious in treating chemo-resistant cancer cells. The goal of this microarray study was to understand the mechanism of bexaroteneâs role in overcoming acquired drug resistance using human breast cancer cells MDA-MB-231 as a model system and paclitaxel as model compound. After MDA-MB-231 cells were repeatedly treated with paclitaxel for 8 cycles with each cycle including a 3-day treatment with 30 nM paclitaxel and followed by a 7-day exposure to control medium, MDA cells resistant to paclitaxel were developed and their growth was no longer inhibited by paclitaxel treatment. Those MDA cells with acquired drug resistance, when treated with paclitaxel and bexarotene in combination, could regain their sensitivity and their growth were again inhibited. Therefore, RNA samples from parental MDA-MB-231 cells, paclitaxel-resistant MDA cells treated with vehicle, paclitaxel alone or in combination with bexarotene, were used for perform global gene expression profiling with Affymetrix HG-U133A gene chips. Keywords: Drug Treatment MDA-MB-231 cells were exposed to regimens on a 10-day cycle: a 3-day treatment with 30 nM paclitaxel and followed by a 7-day exposure to control medium. Paclitaxel resistant MDA-MB-231 cells (MDA-PR) were established within 8 cycles of such treatment (80 days). These MDA-PR cells were then treated with vehicle control, paclitaxel along, or the combination of 30 nM paclitaxel ( 3 days on and 7 days off) and 1 µM Targretin (10 days on) in a new 10-day cycle for 3 months. Thus, there are four treatment groups, parent MDA cells, MDA-PR, MDA-PR treated with paclitaxel, MDA-PR treated with paclitaxel and bexarotene, and each group had four biological replicates.