Detection of gemcitabine-resistant genes expression in lung cancer cell lines using real-time PCR

Objective: To explore the molecular mechanism of gemcitabine-resistance, the relative mRNA expression of five genes related to gemcitabine-resistance was detected in six lung cancer cell lines. Methods: The total RNA was extracted from six lung cancer cell lines GLC-82, NCI-H460, A549, 95-C, 95-D and QG56. Then the cDNA was amplified by real-time quantitative PCR method to quantify the gene expression of RRM1, PTEN, ERCC1, dCK and CDA. The cytotoxicity of gem- citabine to cell lines was tested by MTT method. Results: Among the detected six lung cancer cell lines, the mRNA level of RRM1, PTEN and ERCC1 in lung squamous cell line QG56 was highest, and the IC50 of gemcitabine to QG56 cell line was also highest. Conclusion: The mRNA expression of RRM1, PTEN and ERCC1 was correlated, and the high expression of RRM1 was related to gemcitabine resistance of lung cancer.

LncRNA AFAP1-AS1 exhibits oncogenic characteristics and promotes gemcitabine-resistance of cervical cancer cells through miR-7-5p/EGFR axis

Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted therapy.In our study,the role of long non-coding RNA(lncRNA)AFAP1-AS1 in gemcitabine resistance and related mechanisms were explored in cervical cancer cells.Methods:Gemcitabine-resistant cervical cancer cell lines HT-3-Gem and SW756-Gem were constructed using the gemcitabine concentration gradient method.The overall survival rates and recurrence-free survival rates were evaluated by Kaplan-Meier analysis.The interaction was verified through a Dual-luciferase reporter gene assay and a Biotinylated RNA pull-down assay.Cell proliferation ability was assessed through methyl-thiazolyl-tetrazolium(MTT),soft agar,and colony formation experiments.Cell cycle and apoptosis were detected byflow cytometry.Results:Up-regulation of AFAP1-AS1 in cervical cancer predicted a poor prognosis.Besides,patients in the gemcitabine-resistance group had higher levels of AFAP1-AS1 than the gemcitabine-sensitive group.AFAP1-AS1 promoted tumor growth and induced gemcitabine tolerance of cervical cancer cells.In addition,AFAP1-AS1 mediated epidermal growth factor receptor(EGFR)expression by serving as a molecular sponge for microRNA-7a-5p(miR-7-5p).This present study also proved that the knockdown of EGFR or overexpression of miR-7a-5p abolished the accelerative role of AFAP1-AS1 overexpression in cancer progression and gemcitabine tolerance.Conclusions:In general,the AFAP1-AS1/miR-7-5p/EGFR axis was tightly related to the progression and gemcitabine tolerance of cervical cancer,providing potential targets for the management of cervical cancer.