RNA demethylase ALKBH5 prevents pancreatic cancer progression by posttranscriptional activation of PER1 in an m6A-YTHDF2-dependent manner
Authors: Rong Wan
Wenqin Xiao
Weiliang Jiang
Kai Li
Yun Feng
Yinshi Huang
Yangyang Hu
Xingya Guo
Qin Pan
Journal: Molecular cancer (2020)
Discipline: MOLECULAR BIOLOGY & GENETICS
Keywords: ALKBH5; PER1; Pancreatic cancer; m6A.
Affiliations: Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Road, Shanghai, 200080, People's Republic of China., Department of Gastroenterology, Xinhua Hospital, Shanghai Jiaotong University School of Medicine, No. 1665, Kongjiang Road, Shanghai, 200092, People's Republic of China. ., Department of Gastroenterology, Shanghai General Hospital, Shanghai Jiaotong University School of Medicine, No. 100, Haining Road, Shanghai, 200080, People's Republic of China. .

Abstract:  Background: N6-methyladenosine (m6A) is the most abundant reversible methylation modification of eukaryotic mRNA, and it plays vital roles in tumourigenesis. This study aimed to explore the role of the m6A demethylase ALKBH5 in pancreatic cancer (PC). Methods: The expression of ALKBH5 and its clinicopathological impact were evaluated in PC cohorts. The effects of ALKBH5 on the biological characteristics of PC cells were investigated on the basis of gain-of-function and loss-of-function analyses. Subcutaneous and orthotopic models further uncovered the role of ALKBH5 in tumour growth. mRNA and m6A sequencing and assays of m6A methylated RNA immunoprecipitation-qPCR (MeRIP-qPCR) were performed to identify the targeted effect of ALKBH5 on PER1. P53-binding sites in the ALKBH5 promoter were investigated by ChIP and luciferase assays to reveal the interplay between ALKBH5 and PER1-activated ATM-CHK2-P53/CDC25C signalling. Results: ALKBH5 loss characterized the occurrence and poor clinicopathological manifestations in patients with PC. Overexpression of ALKBH5 reduced tumoural proliferative, migrative, invasive activities in vitro and ameliorated tumour growth in vivo, whereas ALKBH5 knockdown facilitated PC progression. Mechanistically, ALKBH5 posttranscriptionally activated PER1 by m6A demethylation in an m6A-YTHDF2-dependent manner. PER1 upregulation led to the reactivation of ATM-CHK2-P53/CDC25C signalling, which inhibited cell growth. P53-induced activation of ALKBH5 transcription acted as a feedback loop regulating the m6A modifications in PC. Conclusion: ALKBH5 serves as a PC suppressor by regulating the posttranscriptional activation of PER1 through m6A abolishment, which may highlight a demethylation-based approach for PC diagnosis and therapy. 

Retracted: No

PubPeer comments:
 Fig. 3k and 3l have an overlap while these 2 figures were described differently ![file] , 
 Figs. 4a and 4d contain several dissected tumors having strange shadows, making them look like floating. those are indicated by red arrows. ![file] , 
 #1 Dear Tulipa Fosteriana, Thank you so much for your attention to our manuscript. According to your concern, we have carefully checked the original data of this project and found that the transwell assay images in Fig. 3l were misapplied during the preparation of submission. However, this correction will have no influence on the interpretation of the entire results and conclusions in this project. We have Corrected the misuse of this imageuff08see belowuff09 and sent the detail information of corrigendum to editorial office. We apologize for the careless mistake and we really appreciate your great helps. Thank you for your kindly reminder. ![file] #2 Dear Tulipa Fosteriana, Thank you so much for your attention to our manuscript. According to your concern, We have carefully checked these questionable pictures you mentioned in fig 4a and fig 4d, and we think strange shadows you mentioned may be caused by uneven light and camera angles. Thank you again for your kindly reminder. ,