Project description:To develop gene-miRNA and pathway-miRNA networks in trastuzumab treatment, we performed a recent miRNA microarray profiling in trastuzumab treated/untreated SKBR3 and BT474 cell lines. The cells were plated at a starting density of 2 millions in 100 mm cell culture dishes and then, they were treated with 6 ug/mL trastuzumab and PBS in two replicates. Total RNA was isolated with the TRIzol reagent (Invitrogen) according to the manufacturer's instructions.
Project description:We sequenced untreated BT474 cells, BT474 cells treated for three days with trastuzumab or trastuzumab + pertuzumab, as well as two BT474-derived trastuzumab-resistant pools and two BT474-derived trastuzumab + pertuzumab resistant pools. Resistant pools were generated by culturing BT474 cells in gradually increasing doses of trastuzumab and trastuzumab + pertuzumab over the course of several months and continually maintained in drug.
Project description:Analysis of gene expression levels of HER2-positive breast cancer cells exposed to the conditioned medium from adipocytes. The hypothesis tested in the present study was that adipocytes secrete factors that induce the resistance of cancer cells to antibody-dependent cellular cytotoxicity mediated by trastuzumab. The results provide insight into the genes that may be involved in the adipocyte-induced cancer resistance to trastuzumab treatment. BT474 cells or SKBR3 cells were exposed to the conditioned medium (CM) from differentiated hMADS (#hMADS) or to the control medium for 2 h. Total RNA was extracted and analyzed. The experiment was performed in triplicate.
Project description:RNA sequencing of BT474 cells treated with trastuzumab or trastuzumab + pertuzumab and BT474-derived cells resistant to trastuzumab or trastuzumab + pertuzumab
Project description:We found that trastuzumab (herceptin) treatment significantly decreased five miRNAs and increased three others in SKBr3 cells, whereas in BT474 cells it significantly decreased two miRNAs and increased nine. The only miRNA that shared the same change in both cell lines was miRNA-194 (miR-194), which was upregulated following trastuzumab treatment.
Project description:Objective: Trastuzumab has been used for the treatment of HER2-positive breast cancer (BC). However, a subset of BC patients exhibited resistance to trastuzumab therapy. Thus, clarifying the molecular mechanism of trastuzumab treatment will be beneficial to improve the treatment of HER2-positive BC patients. In this study, we identified trastuzumab-responsive microRNAs that are involved in the therapeutic effects of trastuzumab. Methods and results: RNA samples were obtained from HER2-positive (SKBR3 and BT474) and HER2-negetive (MCF7 and MDA-MB-231) cells with and without trastuzumab treatment for 6 days. Next, we conducted a microRNA profiling analysis using these samples to screen those microRNAs that were up- or downregulated only in HER2-positive cells. This analysis identified miR-26a and miR-30b as trastuzumab-inducible microRNAs. Transfecting miR-26a and miR-30b induced cell growth suppression in the BC cells by 40% and 32%, respectively. A cell cycle analysis showed that these microRNAs induced G1 arrest in HER2-positive BC cells as trastuzumab did. An Annexin-V assay revealed that miR-26a but not miR-30b induced apoptosis in HER2-positive BC cells. Using the prediction algorithms for microRNA targets, we identified cyclin E2 (CCNE2) as a target gene of miR-30b. A luciferase-based reporter assay demonstrated that miR-30b post-transcriptionally reduced 27% (p=0.005) of the gene expression by interacting with two binding sites in the 3’-UTR of CCNE2. Conclusion: In BC cells, trastuzumab modulated the expression of a subset of microRNAs, including miR-26a and miR-30b. The upregulation of miR-30b by trastuzumab may play a biological role in trastuzumab-induced cell growth inhibition by targeting CCNE2. We obtained microRNA expression profiles of breast cancer cell lines, MCF7, MDA-MB-231, SKBR3, and BT474, with or without trastuzumab (4microgram/mL) treatment.
Project description:Genes involved in trastuzumab response were identified using transcriptomic data from cells hypersensitive to trastuzumab derived from BT474.
Project description:The intention was to detect genes that are determining trastuzumab efficiency in HER2-positive breast cancer cell lines with different resistance phenotypes. While BT474 should be sensitive to the drug treatment, HCC1954 is expected to be resistant due to a PI3K mutation. The cell line BTR50 has been derived from BT474 and was cultured to be resistant as well. Based on RNA-Seq data, we performed differential expression analyses on these breast cancer cell lines with and without trastuzumab treatment. In detail, five separate tests were performed, namely resistant cells vs. wild type, i.e. HCC1954 and BTR50 vs. BT474, respectively, and untreated vs. drug treated cells. The significant genes of the first two tests should contribute to resistance. The significant genes of the test BT474 vs. its drug treated version should contribute to the trastuzumab effect. To exclude false positives from the combined gene set (#64), we removed ten genes that were also significant in the test BTR50 vs. its drug treated version. This way we ended up with 54 genes that are very likely to determine trastuzumab efficiency in HER2-positive breast cancer cell lines. mRNA profiles of human breast cancer cell lines were generated by deep sequencing using Illumina HiSeq 2000. The cell lines BT474 and HCC1954 were analyzed with and without trastuzumab treatment. HCC1954 is known to be trastuzumab resistant. Additionally, the cell line BTR50 was generated as resistant version of BT474, and was analyzed with and without trastuzumab as well.
Project description:The intention was to detect genes that are determining trastuzumab efficiency in HER2-positive breast cancer cell lines with different resistance phenotypes. While BT474 should be sensitive to the drug treatment, HCC1954 is expected to be resistant due to a PI3K mutation. The cell line BTR50 has been derived from BT474 and was cultured to be resistant as well. Based on RNA-Seq data, we performed differential expression analyses on these breast cancer cell lines with and without trastuzumab treatment. In detail, five separate tests were performed, namely resistant cells vs. wild type, i.e. HCC1954 and BTR50 vs. BT474, respectively, and untreated vs. drug treated cells. The significant genes of the first two tests should contribute to resistance. The significant genes of the test BT474 vs. its drug treated version should contribute to the trastuzumab effect. To exclude false positives from the combined gene set (#64), we removed ten genes that were also significant in the test BTR50 vs. its drug treated version. This way we ended up with 54 genes that are very likely to determine trastuzumab efficiency in HER2-positive breast cancer cell lines.
Project description:Objective: Trastuzumab has been used for the treatment of HER2-positive breast cancer (BC). However, a subset of BC patients exhibited resistance to trastuzumab therapy. Thus, clarifying the molecular mechanism of trastuzumab treatment will be beneficial to improve the treatment of HER2-positive BC patients. In this study, we identified trastuzumab-responsive microRNAs that are involved in the therapeutic effects of trastuzumab. Methods and results: RNA samples were obtained from HER2-positive (SKBR3 and BT474) and HER2-negetive (MCF7 and MDA-MB-231) cells with and without trastuzumab treatment for 6 days. Next, we conducted a microRNA profiling analysis using these samples to screen those microRNAs that were up- or downregulated only in HER2-positive cells. This analysis identified miR-26a and miR-30b as trastuzumab-inducible microRNAs. Transfecting miR-26a and miR-30b induced cell growth suppression in the BC cells by 40% and 32%, respectively. A cell cycle analysis showed that these microRNAs induced G1 arrest in HER2-positive BC cells as trastuzumab did. An Annexin-V assay revealed that miR-26a but not miR-30b induced apoptosis in HER2-positive BC cells. Using the prediction algorithms for microRNA targets, we identified cyclin E2 (CCNE2) as a target gene of miR-30b. A luciferase-based reporter assay demonstrated that miR-30b post-transcriptionally reduced 27% (p=0.005) of the gene expression by interacting with two binding sites in the 3’-UTR of CCNE2. Conclusion: In BC cells, trastuzumab modulated the expression of a subset of microRNAs, including miR-26a and miR-30b. The upregulation of miR-30b by trastuzumab may play a biological role in trastuzumab-induced cell growth inhibition by targeting CCNE2.