Project description:Background. One of the major limitations associated to the platinum use is the resistance that almost invariably will progress in lung and ovarian cancers. In the current study, we sought to identify epigenetically regulated miRNAs as novel biomarkers of platinum-resistance in those tumor types. Methods. We combined transcriptomic data from miRNA and mRNA under the influence of an epigenetic reactivation treatment, followed by qRT-PCR and epigenteic validations for an accurate candidate selection in 23 human cancer cell lines. Functional analysis were performed to study their biological and therapeutic implications, that were further tested in 257 primary samples obtained from lung and ovarian tumors. Results. We identified a group of 9 miRNAs belonging to the CM19 cluster and 7 potential miRNA-targets potentially involved in resistance development, in both tumor types. Deregulation of miR-7, -132, -335 and -148a may be a common event in the development of CDDP-resistance. miR-7 presented specific methylation in the resistant subtypes and its reexpression, decreased cell viability, suggesting a possible cell sensitization to cisplatin. Our translational approach indicated that miR-7 methylation is a frequent event that may play an important role in the early establishment of NSCLC tumorigenesis, and seems to play an additional platinum-predictive role in ovarian cancer. Conclusions. miR-7 is a novel potential epigenetic biomarker tool for the selection of ovarian cancer patients with higher risk to earlier relapse and worst response to platinum-based chemotherapy. Funding. FIS (ISCIII): PI12/00386, PI13/01450, PI15/00186, and FEDER/FSE (Una manera de hacer Europa).
Project description:Background. One of the major limitations associated to the platinum use is the resistance that almost invariably will progress in lung and ovarian cancers. In the current study, we sought to identify epigenetically regulated miRNAs as novel biomarkers of platinum-resistance in those tumor types. Methods. We combined transcriptomic data from miRNA and mRNA under the influence of an epigenetic reactivation treatment, followed by qRT-PCR and epigenteic validations for an accurate candidate selection in 23 human cancer cell lines. Functional analysis were performed to study their biological and therapeutic implications, that were further tested in 257 primary samples obtained from lung and ovarian tumors. Results. We identified a group of 9 miRNAs belonging to the CM19 cluster and 7 potential miRNA-targets potentially involved in resistance development, in both tumor types. Deregulation of miR-7, -132, -335 and -148a may be a common event in the development of CDDP-resistance. miR-7 presented specific methylation in the resistant subtypes and its reexpression, decreased cell viability, suggesting a possible cell sensitization to cisplatin. Our translational approach indicated that miR-7 methylation is a frequent event that may play an important role in the early establishment of NSCLC tumorigenesis, and seems to play an additional platinum-predictive role in ovarian cancer. Conclusions. miR-7 is a novel potential epigenetic biomarker tool for the selection of ovarian cancer patients with higher risk to earlier relapse and worst response to platinum-based chemotherapy. Funding. FIS (ISCIII): PI12/00386, PI13/01450, PI15/00186, and FEDER/FSE (Una manera de hacer Europa).
Project description:This SuperSeries is composed of the following subset Series: GSE35711: Transcriptional Signatures as a Disease-Specific and Predictive Inflammatory Biomarker for Type 1 Diabetes [CF_S1S3_5Auto_20CF_10HC] GSE35712: Transcriptional Signatures as a Disease-Specific and Predictive Inflammatory Biomarker for Type 1 Diabetes [H1N1_S5_5Pre_5D0] GSE35716: Transcriptional Signatures as a Disease-Specific and Predictive Inflammatory Biomarker for Type 1 Diabetes [Pneu_S3S24_10Pneu_4HC] GSE35725: Transcriptional Signatures as a Disease-Specific and Predictive Inflammatory Biomarker for Type 1 Diabetes [T1D_114] Refer to individual Series
Project description:Oxaliplatin (oxPt) resistance in colorectal cancers (CRC) is a major unsolved problem. Consequently, predictive markers and a better understanding of resistance mechanisms are urgently needed. To investigate if the recently identified predictive miR-625-3p is functionally involved in oxPt resistance, stable and inducible models of miR-625-3p dysregulation were analyzed. Ectopic expression of miR-625-3p in CRC cells led to increased resistance towards oxPt. The mitogen-activated protein kinase (MAPK) kinase 6 (MAP2K6/MKK6) – an activator of p38 MAPK - was identified as a functional target of miR-625-3p, and, in agreement, was down-regulated in patients not responding to oxPt therapy. The miR-625-3p resistance phenotype could be reversed by anti-miR-625-3p treatment and by ectopic expression of a miR-625-3p insensitive MAP2K6 variant. Transcriptome, proteome and phosphoproteome profiles revealed inactivation of MAP2K6-p38 signaling as a possible driving force behind oxPt resistance. We conclude that miR-625-3p induces oxPt resistance by abrogating MAP2K6-p38 regulated apoptosis and cell cycle control networks.
Project description:Platinum compounds display clinical activity against a wide variety of solid tumors. However, resistance to these agents is a major limitation in cancer therapy. Reduced platinum uptake and increased platinum export are examples of resistance mechanisms that limit the extent of DNA damage. Here, we report the discovery and characterization of the role of ATP11B, a P-type ATPase membrane protein, in cisplatin resistance. ATP11B gene silencing restored the sensitivity of ovarian cancer cell lines to cisplatin in vitro. Combined therapy of cisplatin and ATP11B-siRNA significantly decreased cancer growth in mice bearing ovarian tumors derived from cisplatin-sensitive and -resistant cells. In vitro mechanistic studies on cellular platinum content and cisplatin efflux-kinetics indicated that ATP11B enhances the export of cisplatin from cells. The co-localization of ATP11B with fluorescent cisplatin and with vesicular trafficking proteins such as syntaxin-6 (STX6) and vesicular associated membrane protein 4 (VAMP4) strongly suggests that ATP11B contributes to secretory vesicular transport of cisplatin from Golgi to plasma membrane. In conclusion, silencing ATP11B expression might be a therapeutic strategy to overcome cisplatin resistance. We performed the transfection of control-siRNA and ATP11B-siRNA to both cisplatin-sensitive A2780-PAR and cisplatin-resistant A2780-CP20 cells respectively.