School of Life Sciences, Jiangsu University, Zhenjiang 212013, China.
Department of Clinical Laboratory Medicine, Shanghai Tenth People's Hospital of Tongji University, Shanghai 200072, China.
Genes (Basel). 2021 Oct 30;12(11):1747. doi: 10.3390/genes12111747.
The N6-methyladenosine (mA) RNA modification can regulate autophagy to modulate the growth and development of tumors, but the mechanism of m6A modification for the regulation of autophagy in hepatocellular carcinoma cells (HCC) remains unclear. In the study, the knockdown of the Wilms' tumor 1-associating protein (WTAP) was made in HCC to study the correlation between m6A modification and autophagy. A fluorescent confocal microscopy analysis showed that the knockdown of WTAP could facilitate the autophagy of HCC. A Western blot analysis showed that the level of p-AMPK was decreased in WTAP-knockdown HCC cells. Additionally, LKB1, the upstream kinase of AMPK, was regulated by WTAP and it could mediate the phosphorylation of AMPK in an m6A-dependent manner. Further studies revealed that the knockdown of WTAP could reduce the level of LKB1 mRNA with m6A. This could result in the increased stability of LKB1 mRNA to promote its expression. The knockdown of WTAP could upregulate the level of autophagy and inhibit HCC proliferation. However, the overexpression of WTAP could resist autophagic cell death.
N6-甲基腺苷(m6A) RNA 修饰可以调控自噬来调节肿瘤的生长和发育，但 m6A 修饰调节肝癌细胞(HCC)自噬的机制尚不清楚。在这项研究中，敲低肝癌中的 Wilms 瘤 1 相关蛋白(WTAP)，以研究 m6A 修饰与自噬之间的相关性。荧光共聚焦显微镜分析表明，WTAP 的敲低可以促进 HCC 的自噬。Western blot 分析表明，WTAP 敲低的 HCC 细胞中 p-AMPK 的水平降低。此外，LKB1，AMPK 的上游激酶，受 WTAP 调节，并可以以 m6A 依赖的方式介导 AMPK 的磷酸化。进一步的研究表明，WTAP 的敲低可以降低 m6A 修饰的 LKB1 mRNA 水平。这可能导致 LKB1 mRNA 的稳定性增加，从而促进其表达。WTAP 的敲低可以上调自噬水平并抑制 HCC 增殖。然而，WTAP 的过表达可以抵抗自噬性细胞死亡。
