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: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.
Project description:RNA sequencing technology has been carried out in order to evaluate mRNA expression changes after manipulation of miR-26a in both MCF-7 and MDA-MB-231 breast cancer cell lines. To evaluate the entire set of genes modulated by miR-26a in breast cancer, we performed RNA-seq after ectopic manipulation of this miRNA. We over-expressed miR-26a in MCF-7 epithelial cancer cell lines and also reduced its activity by stably transfecting MDA-MB-231 mesenchymal-like cancer cell lines with a specific sponge vector. GO terms and pathway enriched analysis of the transcripts that significantly change upon miR-26 ectopic manipulation implicates miR-26ab in cell cycle, apoptosis, cell spreading and cell adhesion in breast cancer
Project description:To reveal the potential regulation target genes of miR-26a and miR-23a/b clusters in articular chondrocytes, we performed a multi-omics analysis of LC-MSMS and RNA-seq using cultured chondrocytes samples, which were primarily isolated from 3-week-old wild-type, miR-26a -/- (with or without miR-26a mimic transfection afterwards) or miR-23a/b cluster flox/flox;Col2a1-cre mice. For LC-MSMS, protein from TRIZOL reagent was extracted, nanoLC-MSMS was performed. An expression list was made to further explore the regulation targets of miR-26a and miR-23a/b clusters.
Project description:HER2-positive (HER2+) breast cancer patients that do not respond to targeted treatment have a poor prognosis. The effects of targeted treatment on endogenous microRNA (miRNA) expression levels are unclear. We report that responsive HER2+ breast cancer cell lines had a higher number of miRNAs with altered expression after treatment with trastuzumab and lapatinib compared to poorly responsive cell lines. To evaluate whether miRNAs can sensitize HER2+ cells to treatment, we performed a high-throughput screen of 1626 miRNA mimics and inhibitors in combination with trastuzumab and lapatinib in HER2+ breast cancer cells. We identified eight miRNA mimics sensitizing cells to targeted treatment, miR-101-5p, mir-518a-5p, miR-19b-2-5p, miR-1237-3p, miR-29a-3p, miR-29c-3p, miR-106a-5p, and miR-744-3p. A higher expression of miR-101-5p predicted better prognosis in patients with HER2+ breast cancer (OS: p=0.0392; BCSS: p=0.0125), supporting the tumor-suppressing role of this miRNA. In conclusion, we have identified miRNAs that sensitize HER2+ breast cancer cells to targeted therapy. This indicates the potential of combining targeted drugs with miRNAs to improve current treatments for HER2+ breast cancers.
Project description:In this work, we showed that the re-expression of miR-26a in DU-145 prostate cancer cells restored the tumor suppressor activity of miR-26a. To discover the genes and pathways elicited by miR-26a re-expression, we used the miRNA pull out assay to capture and the Next Generation Sequencing to identify the miR-26a targets. Data showed that: i) miR-26a captured both non-coding and coding RNAs; ii) 46% of transcripts were putative miR-26a targets according to target prediction algorithms; iii) 21 pathways were significantly enriched and the “Pathway in Cancer” was among those comprising the largest number of genes, including BIRC5 that we experimentally validated. Accordingly, the detection of cell proliferation-related events showed that miR-26a exerted its tumor suppressor activity at several levels, by decreasing the survival, impairing the migration of tumor cells and by inducing both apoptosis and cell cycle block. In conclusion, we showed that the collection of miR-26a interacting transcripts (miR-26a/targetome) represented a fruitful platform to decipher the miR-26a-dependent gene expression networks. In perspective the availability of miRNA-specific and tumor-specific targetomes will allow the discovery of new druggable tumor genes and pathways.
Project description:RNA sequencing technology has been carried out in order to evaluate mRNA expression changes after manipulation of miR-26a in both MCF-7 and MDA-MB-231 breast cancer cell lines.
Project description:Breast cancer is the most common cancer among women. Among them, human epidermal growth factor receptor-positive (HER2+) breast cancer is more malignant. Fortunately, many anti-HER2 drugs are currently used in clinical treatments to increase patient survival. However, some HER2+ patients (~15%) still develop drug resistance after receiving trastuzumab treatment, leading to treatment failure. Using CCLE and METABRIC database analyses, we found that fibroblast growth factor receptor 4 (FGFR4) mRNA was highly detected in tumors from HER2+ breast cancer patients (P<0.001) and was associated with poorer survival in breast cancer patients. Through retrospective immunohistochemical staining analysis, we detected higher expression of FGFR4 protein in breast cancer tissues collected from patients who were resistant to trastuzumab therapy compared with breast cancer patients who responded to treatment. An FGFR4 inhibitor (FGF401) effectively inhibits tumor growth in trastuzumab-insensitive patient-derived xenograft (PDX) tumor-bearing mice. For molecular mechanism studies, we demonstrated that HER2/FGFR4 protein complexes were detected on the cell membrane of the tumor tissues in these trastuzumab-insensitive PDX tumor tissues. After trastuzumab treatment in these drug-resistant breast cancer cells, FGFR4 translocates and enters the nucleus. However, trastuzumab-induced nuclear translocation of FGFR4/HER2-intracellular domain protein complex in trastuzumab-resistant cancer cells is blocked by FGF401 treatment. We believe that FGFR4 overexpression and complex formation with HER2 can serve as molecular markers to assist clinicians in identifying trastuzumab-resistant tumors. Our results suggest that FGF401 combined with trastuzumab as adjuvant therapy for patients with trastuzumab-resistant breast cancer may be a potential new treatment strategy.
Project description:Human breast cancer SKBr-3 cells selected with trastuzumab for 6 month compared with parental SKBr-3 cells; Goal was to screen for microRNAs involved in development of trastuzumab resistance. Human breast cancer SKBr-3 cells were continuously cultured in the presence ofM-BM- 5M-BM-5g/ml trastuzumab for 6 months, and the resulting alive cells were regarded as trastuzumab-resistant. Total RNAs were prepared from these cells and cells cultured in parallel in control media, and were subjected to hybridization on the miRCURY LNA Array (Exiqon, version 11.0).
Project description:Some HER2 positive breast cancer patients are refractory to trastuzumab therapy. MicroRNAs have been used to predict therapeutic effects for various cancers, and our study suggests that the serum-based miRNA signature can effectively distinguish HER2+ MBC patients who are sensitive to trastuzumab from those are resistant.