miR-451a suppresses the development of breast cancer via targeted inhibition of CCND2.

Extensive research has indicated that miRNAs are crucial for the occurrence and progression of cancers. miR-451a, involved in breast cancer (BC), is one of the miRNAs. This study focused on the mechanism by which miR-451a regulates BC. The levels of miR-451a in BC tissues and cell lines were examined using quantitative real-time polymerase chain reaction (qRT-PCR). Kaplan‒Meier analysis showed that this was intimately related to the patient's overall survival rate. Functional experiments revealed the negative effects of miR-451a on the abilities of BC cells to multiply (tested by Cell Counting Kit-8), migrate (tested by wound healing assay), and invade (tested by Transwell assay) and its positive effects on apoptosis (tested by flow cytometry). Western blotting indicated that the expression of tumor-related proteins was affected by miR-451a. Moreover, in vivo experiments suggested that tumor growth was clearly restrained by an miR-451a agonist in a xenograft tumor model. Bioinformatic analysis indicated that miR-451a directly targeted Cyclin D2 (CCND2), as demonstrated by the luciferase reporter assay. An opposite change in the level of CCND2 and miR-451a in BC was indicated by qRT-PCR, western blotting, and immunohistochemistry. Subsequently, functional experiments and western blotting analysis confirmed that CCND2 accelerated BC progression, which was regulated by miR-451a. Cumulatively, research on miR-451a may be valuable for BC treatment.

MiR-646 suppresses proliferation and metastasis of non-small cell lung cancer by repressing FGF2 and CCND2.

MicroRNA-646 (miR-646) has been implicated in several other cancers; however, its functional mechanism in non-small cell lung cancer (NSCLC) remains unclear. In this study, we observed the downregulation of miR-646 expression in NSCLC tissues and cell lines. Low-level expression of miR-646 was associated with metastasis and stage of NSCLCs. Functional assays showed that overexpression of miR-646 could suppress NSCLC cell proliferation, clonogenicity, invasion, and inhibit epithelial-mesenchymal transition (EMT), whereas decreased miR-646 expression showed the opposite effects. Importantly, miR-646 overexpression attenuated in vivo tumor growth and metastasis in nude mice models. Mechanically, miR-646 directly targeted and suppressed fibroblast growth factor 2 (FGF2) and cyclin D2 (CCND2) expression. Reintroduction of FGF2 and CCND2 attenuated miR-646-mediated suppression of proliferation and invasion in NSCLC. Collectively, these results demonstrate that miR-646 acts as a tumor suppressor in NSCLC by targeting FGF2 and CCND2, and may serve as a therapeutic target for patients with NSCLC.

Hypermethylation of CCND2 in Lung and Breast Cancer Is a Potential Biomarker and Drug Target.

Lung and breast cancer are the leading causes of mortality in women worldwide. The discovery of molecular alterations that underlie these two cancers and corresponding drugs has contributed to precision medicine. We found that CCND2 is a common target in lung and breast cancer. Hypermethylation of the CCND2 gene was reported previously; however, no comprehensive study has investigated the clinical significance of CCND2 alterations and its applications and drug discovery. Genome-wide methylation and quantitative methylation-specific real-time polymerase chain reaction (PCR) showed CCND2 promoter hypermethylation in Taiwanese breast cancer patients. As compared with paired normal tissues and healthy individuals, CCND2 promoter hypermethylation was detected in 40.9% of breast tumors and 44.4% of plasma circulating cell-free DNA of patients. The western cohort of The Cancer Genome Atlas also demonstrated CCND2 promoter hypermethylation in female lung cancer, lung adenocarcinoma, and breast cancer patients and that CCND2 promoter hypermethylation is an independent poor prognostic factor. The cell model assay indicated that CCND2 expression inhibited cancer cell growth and migration ability. The demethylating agent antroquinonol D upregulated CCND2 expression, caused cell cycle arrest, and inhibited cancer cell growth and migration ability. In conclusion, hypermethylation of CCND2 is a potential diagnostic, prognostic marker and drug target, and it is induced by antroquinonol D.

LncRNA HOTAIR Regulates CCND1 and CCND2 Expression by Sponging miR-206 in Ovarian Cancer.

BACKGROUND/AIMS: The long noncoding RNA homeobox (HOX) transcript antisense intergenic RNA (HOTAIR) has been demonstrated to be a vital modulator in the proliferation and metastasis of ovarian cancer cells, but its potential molecular mechanism remains to be elucidated. In the current study, we aimed to uncover the biological role of lncRNA HOTAIR and its underlying regulatory mechanism in the progression and metastasis of ovarian cancer. METHODS: HOTAIR expression was detected by quantitative RT-PCR (qRT-PCR) and northern blotting. The SKOV3 ovarian cancer cell line was chosen for the subsequent assays. In addition, the molecular mRNA and protein expression levels were examined by qRT-PCR and western blotting. The competitive endogenous RNA (ceRNA) mechanism was validated by bioinformatics analysis and a dual luciferase reporter gene assay. RESULTS: HOTAIR expression was significantly higher in ovarian carcinoma tissues and cell lines than in the control counterparts. Both CCND1 and CCND2 were downstream targets of miR-206. The inhibition of HOTAIR elevated the expression of miR-206 and inhibited the expression of CCND1 and CCND2. Moreover, CCND1 and CCND2 were highly expressed in ovarian cancer tissues, and their expression was positively correlated with HOTAIR expression. Finally, the functional assays indicated that the anticancer effects of miR-206 could be rescued by the simultaneous overexpression of either CCND1 or CCND2 in ovarian cancer. CONCLUSION: HOTAIR enhanced CCND1 and CCND2 expression by negatively modulating miR-206 expression and stimulating the proliferation, cell cycle progression, migration and invasion of ovarian cancer cells.

MiR-373-3p enhances the chemosensitivity of gemcitabine through cell cycle pathway by targeting CCND2 in pancreatic carcinoma cells.

OBJECTIVE: This study aimed to detect the expression of miR-373-3p and CCND2 in gemcitabine-resistance pancreatic carcinoma (PC) cells, investigate the relationship between miR-373-3p and CCND2, and explore their effects on PC propagation, migration, invasion and apoptosis. METHODS: R software was applied for analyzing differentially expressed genes (DEGs) in cell samples. The potential biological pathway was determined by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, based on R software. The gemcitabine-resistance PC cells were screened out using MTT assay, and they were applied in the next experiments. MiR-373-3p and CCND2 expression in GEM-PANC-1 cells were measured by qRT-PCR. After transfection, the expression of CCND2 protein was examined via western blot assay. Cells viability and apoptosis were confirmed by MTT proliferation assay and Flow cytometry, whereas cells migration and invasion were analyzed by transwell assay. The targeting relationship between miR-373-3p and CCND2 was identified by dual-luciferase reporter assay. RESULTS: MiR-373-3p was found to be low expressed in GEM-PANC-1 cells while CCND2 was highly expressed in GEM-PANC-1 cells. MiR-373-3p negatively regulated CCND2 expression through KEGG_Cell_Cycle_Signaling_Pathway. The targeted relationship between miR-373-3p and CCND2 could be verified using dual luciferase reporter assay. MTT proliferation assay, transwell assay and Annexin V assay demonstrated that miR-373-3p suppressed GEM-PANC-1 cells propagation and invasion and promoted cell apoptosis, while CCND2 showed totally reverse effects compared with miR-373-3p. All the results suggested that miR-373-3p could enhance the chemosensitivity of GEM-PANC-1 cells by regulating CCND2. CONCLUSION: MiR-373-3p inhibited cell propagation, migration and invasion and boosted apoptosis in gemcitabine resistance pancreatic carcinoma cells by targeting CCND2.

Expression of Flk-1 and Cyclin D2 mRNA in the Myocardium of Rats with Doxorubicin-Induced Cardiomyopathy and after Treatment with Betulonic Acid Amide.

The expression of VEGFR2 (Flk-1, according to immunohistochemistry) and of cyclin D2 mRNA (according to real-time PCR) in the myocardium of rats is studied in doxorubicin-induced cardiomyopathy and in response to betulonic acid amide. Doxorubicin alone and in combination with betulonic acid amide causes after 3 days a manifest reduction of cyclin D2 mRNA expression (by 38 and 63%, respectively), while injection of betulonic acid amide alone causes a 23-fold increase of cyclin D2 mRNA expression. An increase of cyclin D2 mRNA expression has been detected in all experimental groups after 14 days of experiment, the most pronounced in response to betulonic acid amide (63 times). The expression of Flk-1 in cardiomyocytes increases significantly in response to both chemical agents starting from day 3 of experiment. These results indicate that doxorubicin and betulonic acid amide induce cytoprotective reactions in the myocardium, first at the intracellular, then at the cellular levels.

miR-124 functions as a tumor suppressor in the endometrial carcinoma cell line HEC-1B partly by suppressing STAT3.

MicroRNAs (miRNAs) play an important role in the development and progression of endometrial carcinoma (EC). Recently, several studies have shown that microRNA-124 (miR-124) is downregulated in various cancers, which can affect tumor initiation and maintenance. However, the effects of miR-124 on EC are largely unknown. In this study, we identified the under-expression of miR-124 in 35 paired EC tissues and adjacent normal tissues. Further, functional experiments found that ectopic expression of miR-124 markedly suppressed cell proliferation, migration, and invasion of EC cells. It also induced cell apoptosis and G1-phase cell cycle arrest. Moreover, we identified signal transducer and activator of transcription 3 (STAT3) as a direct target of miR-124, and over expression of miR-124 not only induced changes in STAT3 expression but also altered expression of its target genes, cyclin D2 and matrix metalloproteinase 2, in the human endometrial carcinoma cell line HEC-1B. In addition to targeting STAT3 directly, we found that miR-124 suppresses phosphorylation of STAT3 through targeting IL-6R indirectly. Restored STAT3 expression through treatment with IL-6 cytokine partly abolished miR-124-mediated cell cycle arrest and apoptosis induction. These results combined with the tumorigenetic role of STAT3 in HEC-1B cells suggest that the antitumor effects of miR-124 are achieved, at least partly, through down regulation of STAT3 mRNA and its downstream target genes. Therefore, inhibition of constitutively activated STAT3 by ectopic expression of miR-124 in EC may provide a novel therapeutic strategy for the treatment of EC.

Sulfuretin-induced miR-30C selectively downregulates cyclin D1 and D2 and triggers cell death in human cancer cell lines.

Sulfuretin (3',4',6'-trihydroxyaurone), one of the key flavonoids isolated from Rhus verniciflua, is known to suppress inflammation and oxidative stress. However, the anti-cancer properties of sulfuretin as well as its mechanism of action remain poorly understood. Here, we show that the expression of miR-30C is markedly enhanced in sulfuretin-stimulated cells, consequently promoting apoptosis and cell cycle arrest in human cancer cell lines. The transient transfection of pre-miR-30C resulted in greater than 70% growth inhibition in PC-3 cells and provided strong evidence that miR-30C selectively suppresses the expression of cyclin D1 and D2, but not cyclin D3. Target validation analysis revealed that 3'-UTR of cyclin D2 is a direct target of miR-30C, whereas suppression by miR-30C of cyclin D1 may occur through indirect mRNA regulation. In addition, silencing miR-30C expression partially reversed sulfuretin-induced cell death. Taken together, our data suggest that miR-30C, a tumor suppressor miRNA, contributes to anti-cancer properties of sulfuretin by negatively regulating cyclin D1 and D2, providing important implications of sulfuretin and miR-30C for the therapeutic intervention of human cancers.

Human forkhead L2 represses key genes in granulosa cell differentiation including aromatase, P450scc, and cyclin D2.

FOXL2 is expressed in granulosa cells (GC) of small and medium ovarian follicles, functions as a repressor of the human steroidogenic acute regulatory gene, a marker of a GC differentiation, and its mutation is associated with premature ovarian failure (POF) in women with blepharophimosis-ptosis-epicanthus inversus syndrome (BPES), type I. We now report that FOXL2 also represses the transcription of aromatase, P450scc, and cyclin D2, three other key genes involved in GC proliferation, differentiation, and steroidogenesis, and that a FOXL2 mutation found in patients with BPES type I, also fails to repress aromatase transcription, further supporting a role for FOXL2 in follicle maturation.