Lentivirus-mediated inhibition of USP39 suppresses the growth of gastric cancer cells via PARP activation.

Gastric cancer (GC) is the second most common cause of cancer-associated mortality worldwide. Ubiquitin-specific peptidase 39 (USP39) has important roles in mRNA processing and has been reported to be involved in the growth of breast cancer cells. However, the roles of USP39 in GC have remained to be investigated, which was the aim of the present study. A lentivirus expressing short hairpin RNA targeting USP39 was constructed and transfected into MGC80‑3 cells. Suppression of USP39 expression significantly decreased the proliferation and colony forming ability of MGC80‑3 cells as indicated by an MTT and a clonogenic assay, respectively. In addition, flow cytometric cell cycle analysis revealed that depression of USP39 induced G2/M‑phase arrest, while an intracellular signaling array showed that the cleavage of PARP at Asp214 was increased following USP39 knockdown. These results suggested that USP39 is involved in the proliferation of GCs and may be utilized as a molecular target for GC therapy.