Impaired autophagic degradation of lncRNA ARHGAP5-AS1 promotes chemoresistance in gastric cancer

a Heatmap visualization of differential lncRNAs expression (49 upregulated and 60 downregulated) in chemosensitive or resistant cells. b The expression of ARHGAP5-AS1 in chemosensitive or resistant SGC7901 and BGC823 cells were detected by qRT-PCR. Data were presented as the mean？±？SD, n？=？3. *p？<？0.05 (Student’s t-test). The Kaplan–Meier curve analysis on the impact of ARHGAP5-AS1 expression on overall survival (c) and progression？free survival (d). p-Value was calculated by Log Rank test. e The effect of ARHGAP5-AS1 knockdown on viability of resistant cells with or without DDP treatment for 36？h were detected using MTS assay. Experiments were all repeated three times and the representative data were shown. The asterisks indicate the statistical significance (p？<？0.05). f Resistant cells transfected with control siRNA (siNC) or ARHGAP5-AS1 siRNAs were treated with or without DDP (5？μg/mL) for 36？h and the apoptosis was measured using flow cytometry (top panel) as well as Western Blotting (bottom panel). g ARHGAP5-AS1 was knocked down in resistant cells and the intracellular concentration of doxorubicin hydrochloride (ADM) in ADM (5？μg/mL, 2？h)-incubated resistant cells before and after ARHGAP5-AS1 knockdown were assessed using flow cytometry (the raw fluorescence intensity measured using FL2 channel was shown as top panel and the normalized value was well statistical and shown as bottom panel). h The empty pcDNA3.1 vector or pcDNA3.1-ARHGAP5-AS1 was transfected into sensitive cells and relative cell viability before or after DDP treatment for 24？h were detected using MTS assay. i The apoptosis of sensitive cells with or without ARHGAP5-AS1 overexpression in the presence or absence of DDP treatment (2？μg/mL, 24？h) were measured using flow cytometry (top panel) as well as Western Blotting (bottom panel). j The intracellular concentration of ADM in sensitive cells before and after ARHGAP5-AS1 overexpression were determined as in