METTL14-mediated N6-methyladenosine modification of ITGB4 mRNA inhibits metastasis of clear cell renal cell carcinoma

Abstract

Background Integrin β4 (ITGB4) participates in tumorigenesis and progression of several malignancies, but its role and related mechanisms in clear cell renal cell carcinoma (ccRCC) remain unclear. Methods Quantitative real-time PCR (qRT-PCR), western blot and immunohistochemistry were used to detect mRNA and protein levels of relevant genes. Biological functions of ITGB4 and methyltransferase-like 14 (METTL14) were determined by in vitro and in vivo experiments. The levels of N6-methyladenosine (m6A) in ccRCC tissues and adjacent normal tissues were calculated via total RNA m6A quantification assay. The m6A modification of ITGB4 was demonstrated via m6A RNA immunoprecipitation (MeRIP), RIP and luciferase reporter assays. Results ITGB4 was significantly overexpressed in ccRCC tissues and high level of ITGB4 predicted poor prognosis as well as metastasis. Functionally, ITGB4 stimulated ccRCC cell migration and invasion in vitro and metastasis in vivo with epithelial–mesenchymal transition (EMT) strengthened. Mechanically, the total levels of m6A were reduced in ccRCC tissues. METTL14, a favorable factor for ccRCC patients’ prognosis, facilitated m6A modification on ITGB4 3′UTR and subsequently accelerated ITGB4 mRNA degradation, leading to its declined expression. Furthermore, the METTL14-mediated inhibition of ITGB4 expression was dependent on the YTH domain family protein 2 (YTHDF2), which acted as an m6A reader to bind to ITGB4 mRNA and to promote its decay. In addition, we demonstrated that knockdown of METTL14 promoted ccRCC cell migration, invasiveness and metastasis as well as stimulating the EMT process and the PI3K/AKT signal by overexpressing ITGB4. Conclusion Our study reveals that METTL14 inhibits ITGB4 expression via m6A modification to attenuate metastasis and EMT of ccRCC cells, suggesting the METTL14/ITGB4 axis as a potential prognostic biomarker and therapeutic target for ccRCC.

FTO Inhibits Epithelial Ovarian Cancer Progression by Destabilising SNAI1 mRNA through IGF2BP2

“…METTL3 regulates β-catenin protein expression and membrane localisation in cervical, lung, and liver cancers, thereby promoting cell migration, invasion, and EMT [ 48 ]. Knockdown of METTL14 promotes ITGB4 expression via m6A-YTHDF2, stimulates EMT, and promotes migration, invasion, and metastasis in renal clear cell carcinoma cells [ 49 ]. In breast cancer cells, FTO deletion induces EMT by increasing m6A levels and altering the 3′-terminal processing of key mRNAs along the Wnt signalling cascade [ 50 ].…”

METTL14-dependent m 6 A modification of circUGGT2 drives gastric cancer progression by sponging miR-186-3p and upregulating MAP3K9

“…Increasing evidence indicates that METTL14 plays an anti-oncogenic role by m 6 A modi cation of mRNAs [39,40], miRNAs [41,42] or lncRNAs [43,44], and m 6 A modi cation of circRNAs also takes a part in cancer progression [37,38]. Our previous study authenticated that METTL14-mediated m 6 A modi cation of circORC5 inhibits GC progression [15].…”

The emerging roles and mechanism of N6-methyladenosine (m6A) modifications in urologic tumours progression

“…Studies of m 6 A readers in RCC have mainly focused on the YTHDF1, YTHDF2, YTHDC1, and IGF2BPs. Several aspects of the role and mechanism of YTHDF1, YTHDF2, YTHDC1, and IGF2BPs in RCC have been explained in the previous sections ( Ying et al, 2021 ; Shen et al, 2022a ; Xu et al, 2022a ; Shen et al, 2022b ; Chen et al, 2022 ; Liu et al, 2022c ; Liu et al, 2022d ; Zhang et al, 2022 ). Recent studies have reported that YTHDF1-3 could act as tumour markers in RCC.…”

“…Most studies have demonstrated that lower METTL14 expression in RCC tissues is negatively associated with a poor prognosis. METTL14 can act as a tumour suppressor ( Zhang et al, 2021b ; Shen et al, 2022a ; Liu et al, 2022c ; Liu et al, 2022d ; Zhang et al, 2022 ). However, some researchers have opposite conclusions ( Chen et al, 2022 ).…”

“…Nonetheless, the underlying mechanisms in RCC remain unclear. Liu et al ( Liu et al, 2022d ) reported that significant overexpression of ITGB4 in RCC tissues and metastases, together with poor prognosis, is associated with high levels of ITGB4. Further investigations revealed that a METTL14-mediated modification of m 6 A negatively regulates ITGB4 expression.…”