Abnormal expression and promoter methylation of microRNAs (miRNAs) are common events during cervical carcinogenesis. Worldwide, infection by types 18 and 16 of human papillomaviruses (HPVs) is considered the major risk factor for cervical cancer development. It has been reported that expression of the miRNAs can be deregulated by specific HPV genotypes. In this study we analyzed the promoter methylation of 22 miRNAs and the expression of three miRNAs in 10 non-squamous intraepithelial lesions (Non-SIL) without HPV16 infection, and 7 Non-SIL, 16 low-grade SIL (LSIL) and 16 cervical cancer samples, all with HPV16 infection. The methylation status was determined using Human Cancer miRNA EpiTect Methyl II Signature PCR Array® and the expression of miR-124, miR-218 and miR-193b was determined by qRT-PCR using individual TaqMan assays. Comparisons of groups defined were performed using the Fisher exact test for categorical variables and Mann-Whitney test for continuous variables. A p-value of <0.05 was considered statistically significant. The methylation levels of miR-124-2, miR-218-1, miR-218-2 and miR-34b/c promoters were significantly higher in cervical cancer than in LSIL samples. The methylation levels of miR-193b promoter were significantly lower in cervical cancer than in LSIL samples. The expression of miR-124 and miR-218 was significantly lower in cervical cancer than in LSIL samples. The expression of miR-193b was significantly higher in cervical cancer than in LSIL and Non-SIL samples. Our results suggest that the abnormal promoter methylation and expression of miR-124, miR-218 and miR-193b are common events during cervical carcinogenesis.

BackgroundThe aberrant expression of miR-23b is involved in the development and progression of cancer. The aim of this study was to evaluate the potential role of methylation in the silencing of miR-23b in cervical cancer cell lines and to determine its expression in stages of malignant progression and in cervical cancer tissues HPV16-positive.MethodsThe methylation of the miR-23b promoter was determined in HeLa, SiHa, CaSki and C33A cells using a Human Cancer miRNA EpiTectMethyl II Signature PCR Array®. The cells were treated with 5-Aza-2′-deoxycytidine, and the expression of miR-23b, uPa, c-Met and Zeb1 was determined by qRT-PCR. miR-92a and GAPDH were used as controls. The expression of miR-23b was determined in cervical scrapes and biopsies of women without squamous intraepithelial lesions, with precursor lesions and with cervical cancer, all were HPV16-positive. The Fisher exact and Mann–Whitney test were used to compare the differences of the expression of miR-23b, uPa, c-Met and Zeb1 among cell groups, and the difference among patients, respectively. The association between the expression of miR-23b and cervical cancer was determined by logistic regression with a confidence level of 95 %. A value of p < 0.05 was considered statistically significant.ResultsIn C33A, HeLa and CaSki cells, methylation was associated with decreased expression of miR-23b. After treatment with 5-Aza-CdR, the expression of miR-23b increased in all cell lines and the expression of c-Met decreased in HeLa cells, while uPa and Zeb1 decreased in C33A and CaSki cells. In SiHa cells the expression of uPa, c-Met and Zeb1 increased. The expression of miR-23b decreased in relation to the increase in the severity of the lesion and was significantly lower in cervical cancer. In women with premalignant lesions HPV16-positive, decreased levels of miR-23b increased the risk of cervical cancer (OR = 36, 95 % CI = 6.7-192.6, p < 0.05).ConclusionsThe results suggest that the expression of miR-23b is regulated by the methylation of its promoter and is possible that this microRNA influence the expression of uPa, c-Met and Zeb1 in cervical cancer cells lines. In women with premalignant lesions and cervical cancer infected with HPV16, the expression level of miR-23b agree with a tumor suppressor gene.

Malignant transformation and progression in cancer is associated with the altered expression of multiple miRNAs, which are considered as post-transcriptional regulators of genes participating in various cellular processes. Although, it has been proposed that miR-23b-3p acts as a tumor suppressor in cervical cancer (CC), not all the pathways through which it alters the cellular processes have been described. The present study examines whether miR-23b-3p directly represses the c-Met expression and that consequently modifies the proliferation, migration and invasion of C33A and CaSki cells. c-Met has five microRNA response elements (MREs) for miR-23b-3p in the 3′-UTR region. The ectopic overexpression of miR-23b-3p significantly reduces c-Met expression in C33A and CaSki cells. The overexpression of miR-23b-3p reduces proliferation, migration and invasion of CaSki cells and the proliferation and invasion in C33A cells. In CaSki cells, the activation of Gab1 and Fak, downstream of c-Met, is reduced in response to the overexpression of miR-23b-3p. Together, the results in the present study indicate that miR-23b-3p is a tumor suppressor that modulates the progression of CC via posttranscriptional regulation of the c-Met oncogene. Cervical cancer (CC) is the fourth most common malignancy in women around the world, with 569,847 newly diagnosed cases and 311,365 deaths registered in 2018 1. The late detection of CC increases the risk of metastasis and death, with a third of CC patients diagnosed in the advanced stages of the disease 2. This has driven the search for progression and prognosis markers which enable the improvement of treatment scheme selection. While persistent high-risk human papillomavirus (HR HPV) infection plays a central role in the genesis of CC 3 , other factors also contribute to the origin and progression of this malignancy. Some mutations, modifications in specific and global DNA methylation, changes to the expression profiles of chromatin-modifying enzymes and the aberrant expression of microRNAs (miRNAs) are events frequently detected in CC 4,5. Regulating gene

In women, serum levels of CTSB, GKN2, LIPF, LIPFG, AZGP1, TOP2A and PGA4 are proposed as predictive markers of gastric cancer. It is unknown whether GKN1 expression varies with the sex of patients with chronic gastritis or gastric cancer. We studied 36 patients with histopathological diagnosis of chronic gastritis from the state of Guerrero, Mexico. PCR was performed for H. pylori detection and GKN1 expression was determined by RT-qPCR and western blot. GKN1 mRNA expression was significantly lower in patients with chronic follicular gastritis than in those with chronic chemical gastritis (p = 0.00071). The mRNA and protein level of expression of GKN1 were significantly lower in women with chronic follicular gastritis than in men with the same condition (p = 0.0279 and p = 0.0014, respectively); the lowest levels of GKN1 were detected in women with H. pylori-positive follicular gastritis (p = 0.0175 and p = 0.0111, respectively). Through a bioinformatic analysis, estrogen response elements were identified in the GKN1 promoter.