Circular RNA PLEC acts as a sponge of microRNA-198 to promote gastric carcinoma cell resistance to paclitaxel and tumorigenesis

Gastric carcinoma (GC) is one of the most frequent types of malignancy worldwide. Resistance to paclitaxel (PTX) has become an obstacle to the prognosis of GC, and the underlying mechanism is not clear. A previous study identified GC-related circRNAs via microarray analysis and bioinformatics analysis, and we discovered that circPLEC (hsa_circ_104722) was markedly upregulated in GC tissues and cells. The molecular mechanism of circPLEC in PTX-resistant GC cells still needs to be explored. In the present study, qRT-PCR demonstrated that circPLEC was upregulated in PTX-resistant GC tissues and cells, indicating that circPLEC boosts the PTX resistance of GC. circPLEC downregulation weakened GC resistance to PTX and tumorigenesis, migration and invasion and promoted the apoptosis of PTX-resistant GC cells. MiR-198 inhibitor reversed the effect of circPLEC downreguAlation in PTX-resistant GC cells, and MUC19 downregulation weakened GC resistance to PTX and tumorigenesis and improved the apoptosis of PTX-resistant GC cells. In summary, circPLEC acts as a sponge of miR-198 to promote the PTX resistance and tumorigenesis of GC cells by regulating MUC19 expression.