Up-Regulation of miR-21 Is Associated with Cervicitis and Human Papillomavirus Infection in Cervical Tissues

Abstract

MicroRNA-21 (miR-21) is recognized as an oncomir and shows up-regulation in many types of human malignancy. The aim of this study was to investigate the association of miR-21 expression associated with HPV infection in normal and abnormal cervical tissues. Cervical tissue samples with different cytological or histopathological grades were investigated for HPV by PCR and for miR-21 and programmed cell death, protein 4 (PDCD4) expression using quantitative real-time PCR (qRT-PCR). Laser capture microdissection (LCM) of stromal and epithelial tissues and in situ hybridization (ISH) using locked nucleic acid (LNA) probes were performed on a subset of fixed specimens. Cell line experiments were conducted on fibroblasts stimulated in culture media from HeLa cells, which were then assessed for miR-21, PDCD4, IL-6 and α-SMA expression by qRT-PCR. Twenty normal cervical cell, 12 cervicitis, 14 cervical intraepithelial neoplastic I (CIN I), 22 CIN II-III and 43 cervical squamous cell carcinoma (SCC) specimens were investigated. miR-21 levels were significantly lower in normal than in abnormal tissues. The expression of miR-21 in HPV negative normal cytology was significantly lower than in HPV positive samples in abnormal tissue and SCC. The miR-21 expression was significantly higher in HPV negative cervicitis than HPV negative normal cells. LCM and ISH data showed that miR-21 is primarily expressed in the tumor-associated stromal cell microenvironment. Fibroblasts treated with HeLa cell culture media showed up-regulated expression of miR-21, which correlated with increased expression of α-SMA and IL-6 and with down-regulation of PDCD4. These results demonstrate that miR-21 is associated with HPV infection and involved in cervical lesions as well as cervicitis and its up-regulation in tumor-stroma might be involved in the inflammation process and cervical cancer progression.

Pathogenic role of exosomes and microRNAs in HPV‐mediated inflammation and cervical cancer: A review

“…Diverse target genes have been identified for miR‐21, including programmed cell death 4 (PDCD4), phosphatase and tensin homolog (PTEN), tissue inhibitor of metalloproteinases‐3 (TIMP‐3), TNF‐α and annexin A1 (ANXA1) . miR‐21 upregulation increased IL‐6 (which is involved in inflammation and tumor development) and α‐SMA (a fibroblast marker) in HeLa‐conditioned media‐treated fibroblasts, while it significantly diminished PDCD4 expression in CC tissues . Alternative downstream targets of miR‐21 are PTEN and TIMP‐3, which have key functions as STAT3 pathway and MMP‐2/MMP‐9 negative regulators, respectively.…”

“…113,116-118 miR-21 upregulation increased IL-6 (which is involved in inflammation and tumor development) and α-SMA (a fibroblast marker) in HeLa-conditioned media-treated fibroblasts, while it significantly diminished PDCD4 expression in CC tissues. 116 Alternative downstream targets of miR-21 are PTEN and TIMP-3, which have key functions as STAT3 pathway and MMP-2/MMP-9 negative regulators, respectively. MMP-2 and MMP-9 are downstream target genes of the STAT3 pathway.…”

Multiplexed Immunosensing Platform Coupled to Hybridization Chain Reaction for Electrochemical Determination of MicroRNAs in Clinical Samples

“…In addition, it is important to remark that although the coupling of MBs with single or dual disposable electrodes has been widely described, their use with a screen‐printed carbon electrode array of eight electrodes has been reported only recently by our group . Three miRNAs, miR‐21, let‐7a and miR‐31, associated with development and progression of cervical cancer in women , were selected as target miRNAs. The results obtained, after a suitable optimization of the methodology, showed that the new HCR‐based immunosensing strategy offers in a short assay time (120 min) a sensitivity 17 and 131 times higher than that previously reported using individually modified MBs with the same capture antibody without amplification or a HCR strategy implemented on the surface of MBs , respectively.…”

miR-187 induces apoptosis of SiHa cervical carcinoma cells by downregulating Bcl-2

“…Anti-tumor strategies aim to kill cancer cells while leaving normal cells undamaged. One potential mechanism to achieve this involves inducing apoptosis by regulating the proteins that promote and inhibit this process (Bumrungthai et al, 2015;Kong et al, 2015). Bcl-2 is an extensively studied inhibitor of apoptosis, and as such, drugs targeting it have been designed.…”