MTHFD1L knockdown diminished cells growth in papillary thyroid cancer.

Methylenetetrahydrofolate dehydrogenase (NADP+ dependent) 1 like (MTHFD1L) is a mitochondrial enzyme involved in the synthesis of tetrahydrofolate (THF). This study aimed to investigate the effect of MTHFD1L in papillary thyroid cancer (PTC). Tumor tissues and adjacent tissues from 11 patients with PTC were collected, the expression level of MTHFD1L mRNA was detected by quantitative real-time polymerase chain reaction (qRT-PCR). The cancer genome atlas (TCGA) database was used for analysis MTHFD1L differentially expressed between tumor tissue and adjacent tissues. MTHFD1L was knocked down by a lentivirus-based system and CRISPR-Cas9. Affymetrix genechip human transcriptome array 2.0 was used to assess gene expression. Cell growth and motility were evaluated in vivo and in vitro. Cell apoptosis and cell cycle were investigated by flow cytometry assay. The expression levels of proteins were detected by western blotting. MTHFD1L mRNA and protein expression levels significantly increased in tumor tissues and CAL-62, K1 and TPC-1 cell lines. After knockdown MTHFD1L, the growth of cells were reduced while cell apoptosis was increased. In addition, tumor growth was inhibited after MTHFD1L knockdown in nude mice. Affymetrix genechip human transcriptome array 2.0 was founded that MTHFD1L knockdown can inhibit the expression levels of CCND1 and Notch2. Furthermore, we identified that MTHFD1L knockdown inhibited cells growth and induced cell apoptosis in PTC. Importantly, MTHFD1L knockdown decreased the expression levels of Notch2, Hes1 CCND1, Bcl-2, and PCNA protein, whereas the level of Bax increased. Our study suggested MTHFD1L knockdown could diminished PTC cell proliferation. MTHFD1L serves as a valuable therapeutic target.

METTL14 promotes the migration and invasion of breast cancer cells by modulating N6­methyladenosine and hsa­miR­146a­5p expression.

Breast cancer (BC) is the most frequently diagnosed cancer and the leading cause of cancer­related death among women worldwide. Evidence indicates that posttranscriptional N6­methyladenosine (m6A) modification modulates BC development. In the present study, we assessed BC and normal tissues to investigate this connection. RNA m6A levels were determined by methylation quantification assay. The effects of methyltransferase­like 14 (METTL14) gain­of­expression or co­transfection with an m6A inhibitor on cell migration and invasion abilities were determined by Transwell assays. The levels of differentially expressed (DE) miRNAs were verified by real­time quantitative PCR (RT­qPCR). Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses (KEGG) were performed to analyze potential function of target genes of the DE miRNAs. The effects of candidate miRNAs modulated by METTL14 on cell migration and invasion abilities were confirmed by Transwell assays. We demonstrated that m6A methyltransferase METTL14 was significantly upregulated in BC tissues compared with normal tissues. METTL14 gain­ and loss­of­expression regulated m6A levels in MCF­7 and MDA­MB­231 cells. The cell function assays revealed that METTL14 overexpression enhanced the migration and invasion capacities of BC cells. Moreover, treatment with the m6A inhibitor suppressed this enhanced cell migration and invasion. Additionally, aberrant expression of METTL14 reshaped the miRNA profile in BC cell lines. The remodeled DE miRNA/mRNA network was found to be most enriched in cancer pathways, and DE miRNAs were enriched in cell adhesion terms. hsa­miR­146a­5p modulated by METTL14 promoted cell migration and invasion. METTL14 modulates m6A modification and hsa­miR­146a­5p expression, thereby affecting the migration and invasion of breast cancer cells.