Effects of CKMT1 on radiosensitivity of nasopharyngeal carcinoma cells

Radioresistance is an important factor for unsatisfactory prognosis in Nasopharyngeal carcinoma (NPC) patients. Ubiquitous mitochondrial creatine kinase (CKMT1) is always associated with malignancy in a variety of cancers. However, its significance in NPC progression and radiosensitivity remains unclear. The present study focused on investigating the effects of CKMT1 on NPC cell radiosensitivity.

CKMT1 was overexpressed in NPC cell line CNE-1 or knocked out in CNE-2. Biological changes were detected after cells exposing to different doses of X-ray to determine the role of CKMT1 on NPC cell radiosensitivity.

CKMT1 promotes proliferation and migration in NPC cell lines CNE-1 and CNE-2. Overexpression of CKMT1 in CNE-1 cells enhanced colony formation rates, reduced G2/M phase cell cycle arrest, lowered apoptosis rate and c-PARP level, and elevated STAT3 phosphorylation level after radiation treatment. While knocking out CKMT1 using the CRISPR/Cas9 system in CNE-2 cells lowered colony formation rates, increased G2/M phase cell cycle arrest, apoptosis rates, and c-PARP levels, and decreased STAT3 phosphorylation in response to radiation treatment.

NPC cells with higher CKMT1 exhibited lower radiosensitivity through promoting phosphorylation of STAT3. Our findings suggest that CKMT1 may be an alternative radiotherapeutic target in NPC therapy.