METTL3 promotes prostate cancer progression by regulating miR-182 maturation in m6A-dependent manner.

METTL3 was known to run through the whole cycle of RNA. It relied on m6A modification in the mRNAs of cancer-related genes to regulate tumour progression. The development of prostate cancer cells could be promoted by METTL3 via hedgehog pathway. Recent studies had shown that the effect of METTL3 on non-coding RNA was mainly dependent on the modification of m6A. However, it is still unknown whether METTL3 promotes tumour development through this mechanism in prostate cancer. The expression of METTL3 in prostate cancer tissues and cells was analysed by qRT-PCR and Western blot assays. CCK-8 assay, colony formation assay, wound-healing assay and transwell assays were conducted to detect the impact of METTL3 on cell proliferation, migration and invasion. Nude mice tumour models were built to evaluate the role of METTL3 in tumorigenesis. N6-methyladenosine (m6A) RNA immunoprecipitation assay (MeRIP) and co-immunoprecipitations assays were performed to verified that METTL3 upregulated the m6A level, interacted with microprocessor protein DGCR8, recognized the m6A modification of pre-miR-182 to regulate its maturation.METTL3 was highly expressed in prostate cancer, and knockdown of METTL3 significantly inhibited cell proliferation, migration, invasion and tumorigenesis, while overexpression of METTL3 promoted cell proliferation, migration, invasion and tumorigenesis in PCa. In addition, we found that METTL3 upregulating the level of m6A, and interacted with DGCR8 to recognize the m6A modification of pre-miR-182 to regulate its splicing and maturation and promote the high expression of miRNA. Our study suggests that METTL3 could be used in targeted therapies for PCa.

Wang D ，Wang X ，Huang B ，Zhao Y ，Tu W ，Jin X ，Shao Y ，Zhu Y ，Lu G ... -  《-》

METTL3-mediated m6A modification of pri-miR-148a-3p affects prostate cancer progression by regulating TXNIP.

Prostate cancer (PCa) severely affects men's health worldwide. The mechanism of methyltransferase-like 3 (METTL3) in affecting PCa development by regulating miR-148a-3p expression via N6-methyladenosine (m6A) modification was investigated. METTL3, miR-148a-3p, and thioredoxin interacting protein (TXNIP) levels were determined using RT-qPCR and Western blotting. The m6A modification level of miR-148a-3p was observed by Me-RIP assay. Bioinformatics website predicted miR-148a-3p and TXNIP levels in PCa and their correlation, and the binding site between them was verified by dual-luciferase assay. The proliferation, migration, invasion, and apoptosis of PCa cells were examined by CCK-8 assay, Transwell assay, and flow cytometry. A transplanted tumor model was established in nude mice to observe the tumor growth ability, followed by determination of TXNIP levels in tumor tissues by immunohistochemistry. METTL3 interference restrained the proliferation, migration, and invasion and promoted apoptosis of PCa cells. METTL3 up-regulated miR-148a-3p by promoting the m6A modification of pri-miR-148a-3p in PCa cells. miR-148a-3p overexpression nullified the inhibitory actions of silencing METTL3 on PCa cell growth. miR-148a-3p facilitated PCa cell growth by silencing TXNIP. METTL3 interference inhibited tumor growth by down-regulating miR-148a-3p and up-regulating TXNIP. METTL3 promoted miR-148a-3p by mediating the m6A modification of pri-miR-148a-3p, thereby targeting TXNIP, interfering with METTL3 to inhibit the proliferation, migration and invasion of PCa cells, promote apoptosis, and inhibit tumor growth in nude mice.

Li G ，Liu J ，Wang Y ，Liu H ，Fu J ，Zhao Y ，Huang Y ... -  《-》

METTL3 promote tumor proliferation of bladder cancer by accelerating pri-miR221/222 maturation in m6A-dependent manner.

Han J ，Wang JZ ，Yang X ，Yu H ，Zhou R ，Lu HC ，Yuan WB ，Lu JC ，Zhou ZJ ，Lu Q ，Wei JF ，Yang H ... -  《Molecular Cancer》

METTL3 facilitates prostate cancer progression via inducing HOXC6 m6A modification and stabilizing its expression through IGF2BP2-dependent mechanisms.

HOXC6 (Homeobox C6) and methyltransferase-like 3 (METTL3) have been shown to be involved in the progression of prostate cancer (PCa). However, whether HOXC6 performs oncogenic effects in PCa via METTL3-mediated N6-methyladenosine (m6A) modification is not yet reported. The Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), flow cytometry, transwell, scratch, sphere formation assays were applied for cell growth, invasion, migration and stemness analyses. Glycolysis was evaluated by measuring glucose consumption, lactate generation and ATP/ADP ratio. The N6-methyladenine (m6A) modification profile was determined by RNA immunoprecipitation (Me-RIP) assay. The proteins that interact with PGK1 (phosphoglycerate kinase 1) were confirmed by Co-immunoprecipitation assay. Tumor formation experiments in mice were conducted for in vivo assay. PCa tissues and cells showed highly expressed HOXC6 and METTL3. Functionally, the silencing of HOXC6 or METTL3 suppresses PCa cell proliferation, invasion, migration, stemness, and glycolysis. Moreover, METTL3-induced HOXC6 m6A modification to stabilize its expression. In addition, the m6A reader IGF2BP2 directly recognized and bound to HOXC6 mRNA, and maintained its stability, and was involved in the regulation of HOXC6 expression by METTL3. Furthermore, IGF2BP2 knockdown impaired PCa cell proliferation, invasion, migration, stemness, and glycolysis by regulating HOXC6. Besides that HOXC6 interacted with the glycoytic enzyme PGK1 in PCa cells. In vivo assays further showed that METTL3 silencing reduced the expression of HOXC6 and PGK1, and impeded PCa growth. METTL3 promoted PCa progression by maintaining HOXC6 expression in an m6A-IGF2BP2-dependent mechanism.

He P ，Liu X ，Yu G ，Wang Y ，Wang S ，Liu J ，An Y ... -  《-》

Methyltransferase-like 3 facilitates lung cancer progression by accelerating m6A methylation-mediated primary miR-663 processing and impeding SOCS6 expression.

Lung cancer (LC) remains a threatening health issue worldwide. Methyltransferase-like protein 3 (METTL3) is imperative in carcinogenesis via m6A modification of microRNAs (miRNAs). This study estimated the effect of METTL3 in LC by regulating m6A methylation-mediated pri-miR-663 processing. miR-663 expression in 4 LC cell lines and normal HBE cells was determined using RT-qPCR. A549 and PC9 LC cells selected for in vitro studies were transfected with miR-663 mimics or inhibitor. Cell viability, migration, invasion, proliferation, and apoptosis were detected by CCK-8, Transwell, EdU, and flow cytometry assays. The downstream target genes and binding sites of miR-663 were predicted via Starbase database and validated by dual-luciferase assay. LC cells were delivered with oe-METTL3/sh-METTL3. Crosslinking between METTL3 and DGCR8 was verified by co-immunoprecipitation. Levels of m6A, miR-663, and pri-miR-663 were measured by m6A dot blot assay and RT-qPCR. m6A modification of pri-miR-663 was verified by Me-RIP assay. Finally, the effects of METTL3 in vivo were ascertained by tumor xenograft in nude mice. miR-663 was upregulated in LC cells, and miR-663 overexpression promoted cell proliferation, migration, invasion, and inhibited apoptosis, but miR-663 knockdown exerted the opposite effects. miR-663 repressed SOCS6 expression. SOCS6 overexpression annulled the promotion of miR-663 on LC cell growth. METTL3 bound to DGCR8, and METTL3 silencing elevated the levels of pri-miR-663 and m6A methylation-modified pri-miR-663, and suppressed miR-663 maturation and miR-663 expression. METTL3 facilitated tumor growth in mice through the miR-663/SOCS6 axis. METTL3 promotes LC progression by accelerating m6A methylation-mediated pri-miR-663 processing and repressing SOCS6.

Li S ，Lu X ，Zheng D ，Chen W ，Li Y ，Li F ... -  《-》