TMED3 promotes the progression and development of lung squamous cell carcinoma by regulating EZR.

ABSTRACT

Lung squamous cell carcinoma (LUSC) has a poor clinical prognosis and lacks effective targeted therapy. The transmembrane emp24 trafficking protein 3 (TMED3) belongs to the TMED family, which is responsible for the transport of intracellular proteins. This study was to explore the clinicopathological significance and biological effects of TMED3 in LUSC. Expression of TMED3 in LUSC was detected by immunohistochemical (IHC). The loss-of-function assays were used to investigate the effects of TMED3 on proliferation, apoptosis, cell cycle, and migration of LUSC cells. The influence of TMED3 knockdown on tumor growth in vivo was evaluated by mice xenograft models. In addition, the downstream target of TMED3 was recognized by RNA sequencing and Ingenuity Pathway Analysis (IPA). Moreover, TMED3 was upregulated in LUSC tissue, which was positively correlated with pathological grade. TMED3 knockdown was involved in the regulation of LUSC cell function, such as inhibition of proliferation, reduction of colony formation, induction of apoptosis, and reduction of migration. TMED3 knockdown induced abnormalities in apoptosis-related proteins in LUSC cells. In addition, the inhibition of cell migration by TMED3 knockdown was achieved by regulating EMT. Mechanically, EZR was considered as a potential target for TMED3 to regulate the progress of LUSC. Inhibition of EZR can inhibit the progression of LUSC, and even reduce the promoting effects of TMED3 overexpression on LUSC. In conclusion, TMED3 promoted the progression and development of LUSC by EZR, which may be a novel therapeutic target for LUSC.