Abstract
Abstract Background: NSCLC is the most common cause of cancer-related death in the world. Platinum-based chemotherapy is the mainstay of treatment both in the adjuvant and the metastatic settings, but platinum resistance is common. A variety of mechanisms have been reported to underlie platinum-resistance. miRs are short non-coding RNA molecules, each regulating a large number of genes. We hypothesized that in platinum-resistant NSCLC cells, a small number of differentially expressed miRs modulating an abundance of gene products, activate in concert a large number of platinum-resistance mechanisms. Aim: To uncover mechanisms of platinum-resistance in NSCLC, by indentifying miRs differentially expressed in platinum resistant cells. Methods: Platinum-resistant cell lines were created by cisplatin selection of Calu6 and NCI-H23, NSCLC cell lines. RNA was hybridized to Affymetrix miR arrays, followed by TargetScan algorithm analysis. Levels of specific miRs were quantified by RT-PCR (ABI) and were modulated by miR inhibitors (Ambion). Results: Two sets of sensitive (S) and platinum-resistant (R) cell lines were created, each set consisting of a parental S line and several R sub-lines. miR array analysis was performed on the S and R lines. miRs that were significantly more abundant in each of four R lines compared to the corresponding S lines were compiled. Genes predicted to be targeted by each of those miRs with a p value < .05 were tabulated. Surprisingly, only 16 genes were common to those four gene lists, including CDK6, an important G1-S cell cycle regulator. mRNA and protein levels of CDK6 were higher in S compared to R lines, and accordingly, growth rate of R lines was slower. miR145, one of the miRs upregulated in the R lines, is predicted to target CDK6. Transfection of a miR145 inhibitor resulted in a mild increase in mRNA levels of CDK6, supporting its role as a regulator of CDK6. Conclusions: Utilizing a number of biological systems (sets of cells lines) that model the same phenotype (platinum resistance) allows for a robust analysis of the involved molecules. miR profiling of multiple systems can identify genes that are commonly regulated in different systems by different miRs. Using this approach we discovered upregulation of miRs, including miR145, resulting in downregulation of CDK6, as a potential mechanism of platinum resistance in NSCLC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 4949. doi:10.1158/1538-7445.AM2011-4949
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
