Long non-coding RNA MEG3 acts as a suppressor in breast cancer by regulating miR-330/CNN1.

BACKGROUND: The current study aimed to investigate the molecular mechanism of long non-coding RNA (lncRNA) MEG3 in the development of breast cancer. METHODS: The regulating relationships among lncRNA MEG3, miRNA-330 and CNN1 were predicted by bioinformatics analysis of breast cancer samples in the Cancer Genome Atlas database. The differential expression of lncRNA MEG3, miRNA-330 and CNN1 was first validated in breast cancer tissues and cells. The effects of lncRNA MEG3 on breast cancer malignant properties were evaluated by manipulating its expression in MCF-7 and BT-474 cells. Rescue experiments, dual-luciferase assays, and RNA immunoprecipitation (RIP) experiments were further used to validate the relationships among lncRNA MEG3, miRNA-330 and CNN1. RESULTS: Bioinformatics analysis showed that lncRNA MEGs and CNN1 were significantly downregulated in breast cancer tissues, while miR-330 was upregulated. These differential expressions were further validated in our cohort of breast cancer samples. High expression levels of lncRNA MEG3 and CNN1 as well as low expression of miR-330 were significantly associated with favorable overall survival. Overexpression of lncRNA MEG3 significantly inhibited cell viability, migration and invasion, decreased cells in S stage and promoted cell apoptosis. Dual-luciferase reporter gene assay and RIP experiments showed that lncRNA MEG3 could directly bind to miR-330. Moreover, miR-330 mimics on the basis of lncRNA MEG3 overexpression ameliorated the tumor-suppressing effects of lncRNA MEG3 in breast cancer malignant properties by decreasing CNN1 expression. CONCLUSION: Our study indicated lncRNA MEG3 is a breast cancer suppressor by regulating miR-330/CNN1 axis.

Serum sex hormones correlate with pathological features of papillary thyroid cancer.

PURPOSE: Sex hormones are thought to be responsible for the unique gender differences in papillary thyroid cancer(PTC). Most previous studies on these have focused on the expression of estrogen receptors, or have been limited to animal studies. The aim of our study was to explore the relationship between serum sex hormones and the pathological features of PTC in the clinical setting, as further evidence of the role of sex hormones in PTC. METHODS: Retrospective data analysis of patients who underwent thyroid surgery at the Department of Thyroid Surgery, Nanjing Drum Tower Hospital from January 2022 to September 2022 Correlation between serum sex hormone and pathological features was analyzed in male patients and in menopausal female patients. Serum sex hormones include luteinizing hormone(LH), follicle stimulating hormone(FSH), estradiol(E2), total testosterone(TT), progesterone(P), and prolactin(PRL). Tumor pathological characteristics include the number and size of tumor, presence of extrathyroidal extension(ETE), presence of lymph node metastasis(LNM). RESULTS: Preoperative serum E2 in male patients was positively correlated with tumor size in PTC, LH was negatively correlated with LNM, while TT and P were negatively correlated with ETE. Similar findings were not observed in menopausal female patients. CONCLUSION: We observed that serum sex hormones correlate with the pathological features of PTC in male patients, for the first time in a clinical study. High serum estrogens may be a risk factor for PTC, while androgens are the opposite. This somewhat corroborates previous research and provides new variables for future PTC prediction models.

Deciphering the map of METTL14-mediated lncRNA m6A modification at the transcriptome-wide level in breast cancer.

BACKGROUND: Emerging studies have demonstrated the critical role of RNA m6A methylation in tumor progression, whereas lncRNA m6A modification profiles in breast cancer remain largely unknown. Our previous study has shown that METTL14 accelerates breast cancer migration and invasion in an m6A-dependent manner, making it critical to analyze METTL14-mediated m6A modification at a transcriptome-wide scale in breast cancer. METHODS: Here, we performed MeRIP-seq analysis in METTL14 overexpressed and control MDA-MB-231 cells. Conjoint analysis of MeRIP-seq and RNA-seq data was used to select lncRNAs with m6A methylation and differential expression. Finally, the screened lncRNA was verified by MeRIP-PCR and its function was studied via transwell assay. RESULTS: Our results determined that high expression of METLL14 results in 3996 hypermethylation peaks from 3107 transcripts, and 4100 hypomethylation peaks from 2918 transcripts. Furthermore, conjoint analysis of MeRIP-seq and RNA-seq data identified 25 lncRNAs with discrepant methylation and simultaneously discrepant expression, among which the top 10 differentially expressed LncRNAs were AC026401.3, CYTOR, LINC01943, AC084125.2, FLJ20021, LINC00472, and NORAD, MALAT1, AL161431.1, and LINC01764. Moreover, over-expressed METTL14 stimulated the m6A modification of AC084125.2, while decreasing its expression. Compared to adjacent tissues, AC084125.2 was lowly expressed in tumors and could be used as a biomarker in the diagnosis of breast cancer. Meanwhile, AC084125.2 inhibited the migration and invasion of cancer cells. CONCLUSION: In conclusion, METTL14-mediated m6A modification of lncRNAs, which might provide reference for future intervention in tumor progression.

Long non-coding RNA anti-differentiation non-coding RNA affects proliferation, invasion, and migration of breast cancer cells by targeting miR-331.

We aimed to evaluate the effects of long-chain non-coding RNA (lncRNA) anti-differentiation non-coding RNA (ANCR) on the proliferation, invasion, and migration of breast cancer cells by targeting miR-331. Forty-eight breast cancer and paracancerous tissue samples were collected. LncRNA ANCR expressions in breast cancer and adjacent tissues, human breast cancer cells and mammary epithelial cells, and miR-331 expressions in interfering cell line MDA-MB-231 (MCF-7)-shANCR, negative control MDA-MB-231 (MCF-7)-shNC and blank control MDA-MB-231 (MCF-7) were detected by real-time quantitative PCR. The correlations between lncRNA ANCR expression and clinicopathological characteristics were analyzed. Cell proliferation was detected by MTT and colony formation assays. Invasion and migration were tested by Transwell and scratch assays, respectively. The targeting relationship between ANCR and miR-331 was analyzed using the TargetScan database, and their interaction was studied using a dual-luciferase reporter assay. The expression of lncRNA ANCR in breast cancer tissue was significantly lower than that in adjacent normal tissue (p < 0.05). LncRNA ANCR was lowly expressed in various human breast cancer cell lines, being lowest in high-metastatic cell line (MDA-MB-231HM) (p < 0.05). Silencing lncRNA ANCR significantly enhanced the proliferation and invasion capacities of breast cancer cells, and promoted their tumor formation abilities in nude mice (p < 0.05). ANCR bound miR-331 targetedly, and the former negatively regulated the expression of the latter. LncRNA ANCR is lowly expressed upon breast cancer, and inhibits cell proliferation, invasion, and migration in vitro and in vivo. LncRNA ANCR exerts antitumor effects by targetedly binding miR-331 and then inhibiting its expression.