Correlation between miR-222 and uterine cancer and its prognostic value

miR‑222 induces apoptosis in human intervertebral disc nucleus pulposus cells by targeting Bcl‑2

Intervertebral disc degeneration (IDD) is characterized by abnormal induction of apoptosis in intervertebral disc nucleus pulposus (NP) cells. Previous studies indicated that miR-222 was upregulated in patients with rheumatoid arthritis. However, the effects of miR-222 in IDD remain unclear. The present study aimed to demonstrate the role of miR-222 in NP cells. The levels of miR-222 in patients with IDD were measured by reverse transcription-quantitative PCR. Cell Counting Kit-8 and western blotting assays were used to detect cell proliferation and apoptosis-associated protein levels, respectively. In addition, luciferase reporter assays were performed to validate the predicted target genes of miR-222. miR-222 was significantly upregulated in patients with IDD. Overexpression of miR-222 inhibited cell proliferation and induced cell apoptosis. Moreover, overexpression of miR-222 resulted in an upregulation in the levels of Bax and cleaved caspase 3, and a downregulation in the levels of Bcl-2 in NP cells. The luciferase reporter assays demonstrated that Bcl-2 is a target of miR-222. Furthermore, overexpression of miR-222 increased the levels of cytochrome c, apoptotic protease activating factor-1 and cleaved caspase 9 in NP cells. Conversely, downregulation of miR-222 could promote the proliferation of NP cells. The present data demonstrated that miR-222 induced apoptosis in NP cells by directly targeting Bcl-2. Therefore, miR-222 may act as a potential therapeutic target for the treatment of IDD.

Knockdown of miR-222 inhibits inflammation and the apoptosis of LPS-stimulated human intervertebral disc nucleus pulposus cells

It has been demonstrated that miR‑222 is upregulated in human intervertebral disc (IVD) degeneration tissues; however, the underlying mechanisms remain unclear. In this study, we aimed to elucidate the mechanisms of action of miR‑222 in IVD tissues. Nucleus pulposus (NP) cells were treated with lipopolysaccharide (LPS) to simulate IVD degeneration. The expression level of miR‑222 was detected by reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR) in cells and tissues. Cell apoptosis was analyzed by flow cytometry. Additionally, western blot analysis was used to determine the levels of Toll‑like receptor 4 (TLR4), Iκβ‑alpha (IκBα) and p65. Interleukin (IL)‑1β, tumor necrosis factor‑α (TNF‑α) and IL‑6 protein expression levels were determined by enzyme‑linked immunosorbent assay (ELISA). The target gene of miR‑222 was determined by TargetScan7.2 and dual luciferase reporter gene analysis. Western blot analysis and RT‑qPCR were used to determine the mRNA and protein levels of tissue inhibitor of metalloproteinase 3 (TIMP3). The mRNA expression level of miR‑222 was found to be increased in IVD tissues and in LPS‑stimulated cells, and its expression was positively associated with the clinical MRI grade. In vitro, apoptosis was promoted/inhibited by miR‑222 mimics/inhibitors. Transfection with miR‑222 mimics/inhibitors significantly increased/decreased the production of TNF‑α, IL‑1β and IL‑6 and suppressed/enhanced collagen II and aggrecan expression. The protein levels of TLR4, p‑IκΒα and p‑p65 were upregulated/downregulated by transfection with the mimics/inhibitors. In addition, it was demonstrated that TIMP3 was a direct target gene of miR‑222, and was negatively regulated by miR‑222 in NP cells. The silencing of TIMP3 reversed the inhibitory effects of miR‑222 inhibitor on cell apoptosis, which was induced by LPS. Thus, on the whole, the findings of this study demonstrate that miR‑222 functions as a promoter of IVD development, partly via the regulation of TIMP3.

MicroRNAs in Female Malignancies

MicroRNAs (miRNAs) are endogenous 22-nucleotide RNAs that can play a fundamental regulatory role in the gene expression of various organisms. Current research suggests that miRNAs can assume pivotal roles in carcinogenesis. In this article, through bioinformatics mining and computational analysis, we determine a single miRNA commonly involved in the development of breast, cervical, endometrial, ovarian, and vulvar cancer, whereas we underline the existence of 7 more miRNAs common in all examined malignancies with the exception of vulvar cancer. Furthermore, we identify their target genes and encoded biological functions. We also analyze common biological processes on which all of the identified miRNAs act and we suggest a potential mechanism of action. In addition, we analyze exclusive miRNAs among the examined malignancies and bioinformatically explore their functionality. Collectively, our data can be employed in in vitro assays as a stepping stone in the identification of a universal machinery that is derailed in female malignancies, whereas exclusive miRNAs may be employed as putative targets for future chemotherapeutic agents or cancer-specific biomarkers.