m6A mRNA Methylation Regulates LKB1 to Promote Autophagy of Hepatoblastoma Cells through Upregulated Phosphorylation of AMPK

Abstract

The N6-methyladenosine (m6A) 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.

Exploration of Potential Biomarkers and Immune Landscape for Hepatoblastoma: Evidence from Machine Learning Algorithm

“…With the development of high-throughput sequencing technology, more and more aberrantly expressed mRNAs have been identi ed in HB [5][6][7]. Moreover, the elevated N6-methyladenosine alteration in HB represents a carcinogenic pathway [8]. Several studies have also found that various genes, such as zinc nger antisense 1 [9] and TUG1 [10], are involved in proliferation, apoptosis, and glutaminolysis.…”

Roles of RNA Modifications in Diverse Cellular Functions

“…Furthermore, one study found that WTAP could regulate autophagy by mediating the phosphorylation of the positive autophagy regulator, AMPK, in HCC cells ( Li G. et al, 2021 ). Mechanistically, WTAP decreased the mRNA stability of Lkb1 , the kinase upstream of AMPK which regulates AMPK phosphorylation, in an m 6 A-dependent manner ( Li G. et al, 2021 ). Subsequently, knockdown of Wtap resulted in increased autophagy ( Li G. et al, 2021 ).…”

“…Mechanistically, WTAP decreased the mRNA stability of Lkb1 , the kinase upstream of AMPK which regulates AMPK phosphorylation, in an m 6 A-dependent manner ( Li G. et al, 2021 ). Subsequently, knockdown of Wtap resulted in increased autophagy ( Li G. et al, 2021 ).…”

Role of WTAP in Cancer: From Mechanisms to the Therapeutic Potential

“…In addition, WTAP knockdown led to a G2/M phase block in hepatocellular carcinoma via the ETS1-p21/p27 axis, promoting apoptosis in tumor cells [ 53 ]. WTAP knockdown inhibited hepatocellular carcinoma growth and metastasis in hepatocellular carcinoma by promoting autophagosome production [ 105 ]. Further mechanistic studies revealed that liver kinase B1 (LKB1), the upstream kinase of Adenosine 5′-monophosphate activated protein kinas (AMPK), is regulated by WTAP and mediates AMPK phosphorylation in an m 6 A-dependent manner, thereby promoting hepatocellular carcinoma autophagy [ 105 , 106 , 107 ].…”