Carlos Pérez-Plasencia

HOTAIR Promotes the Hyperactivation of PI3K/Akt and Wnt/β-Catenin Signaling Pathways via PTEN Hypermethylation in Cervical Cancer

The mechanisms underlying the sustained activation of the PI3K/AKT and Wnt/β-catenin pathways mediated by HOTAIR in cervical cancer (CC) have not been extensively described. To address this knowledge gap in the literature, we explored the interactions between these pathways by driving HOTAIR expression levels in HeLa cells. Our findings reveal that HOTAIR is a key regulator in sustaining the activation of both signaling pathways. Specifically, altering HOTAIR expression—either by knockdown or overexpression—significantly influenced the transcriptional activity of the PI3K/AKT and Wnt/β-catenin pathways. Additionally, we discovered that HIF1α directly induces HOTAIR transcription, which in turn leads to the epigenetic silencing of the PTEN promoter via DNMT1. This process leads to the sustained activation of both pathways, highlighting a novel regulatory axis involving HOTAIR and HIF1α in cervical cancer. Our results suggest a new model in which HOTAIR sustains reciprocal activation of the PI3K/AKT and Wnt/β-catenin pathways through the HOTAIR/HIF1α axis, thereby contributing to the oncogenic phenotype of cervical cancer.

A microRNA Profile Regulates Inflammation-Related Signaling Pathways in Young Women with Locally Advanced Cervical Cancer

Cervical cancer (CC) remains among the most frequent cancers worldwide despite advances in screening and the development of vaccines against human papillomavirus (HPV), involved in virtually all cases of CC. In mid-income countries, a substantial proportion of the cases are diagnosed in advanced stages, and around 40% of them are diagnosed in women under 49 years, just below the global median age. This suggests that members of this age group share common risk factors, such as chronic inflammation. In this work, we studied samples from 46 patients below 45 years old, searching for a miRNA profile regulating cancer pathways. We found 615 differentially expressed miRNAs between tumor samples and healthy tissues. Through bioinformatic analysis, we found that several of them targeted elements of the JAK/STAT pathway and other inflammation-related pathways. We validated the interactions of miR-30a and miR-34c with JAK1 and STAT3, respectively, through dual-luciferase and expression assays in cervical carcinoma-derived cell lines. Finally, through knockdown experiments, we observed that these miRNAs decreased viability and promoted proliferation in HeLa cells. This work contributes to understanding the mechanisms through which HPV regulates inflammation, in addition to its canonical oncogenic function, and brings attention to the JAK/STAT signaling pathway as a possible diagnostic marker for CC patients younger than 45 years. To our knowledge to date, there has been no previous description of a panel of miRNAs or even ncRNAs in young women with locally advanced cervical cancer.

MiR-21 Regulates Growth and Migration of Cervical Cancer Cells by RECK Signaling Pathway

Expression of miR-21 has been found to be altered in almost all types of cancers, and it has been classified as an oncogenic microRNA. In addition, the expression of tumor suppressor gene RECK is associated with miR-21 overexpression in high-grade cervical lesions. In the present study, we analyze the role of miR-21 in RECK gene regulation in cervical cancer cells. To identify the downstream cellular target genes of upstream miR-21, we silenced endogenous miR-21 expression using siRNAs. We analyzed the expression of miR-21 and RECK, as well as functional effects on cell proliferation and migration. We found that in cervical cancer cells, there was an inverse correlation between miR-21 expression and RECK mRNA and protein expression. SiRNAs to miR-21 increased luciferase reporter activity in construct plasmids containing the RECK-3′-UTR microRNA response elements MRE21-1, MRE21-2, and MRE21-3. The role of miR-21 in cell proliferation was also analyzed, and cancer cells transfected with siRNAs exhibited a markedly reduced cell proliferation and migration. Our findings indicate that miR-21 post-transcriptionally down-regulates the expression of RECK to promote cell proliferation and cell migration inhibition in cervical cancer cell survival. Therefore, miR-21 and RECK may be potential therapeutic targets in gene therapy for cervical cancer.

High prevalence of human papillomavirus and European variants of HPV 16 infecting concomitantly to cervix and oral cavity in HIV positive women

Identify the prevalence of HPV infections in the uterine cervix and oral cavity and HPV16 variants in HIV+ women. A total of 174 HIV+ women attended an HIV+ specialized clinic in Mexico City. Cells were obtained from the oral cavity and cervix to extract DNA. Polymerase chain reaction (PCR) was used to amplify the HPV sequence with generic primers. We detected specific HPV types using the INNO-LiPA HPV Genotyping Extra II Kit (INNOGENETICS). The identification of variants was studied by sequencing the E6 gene with a Big Dye Terminator Kit and an Applied Biosystems 3500/3500xL genetic analyzer. HPV infection was very high in the uterine cervix (168/174, 96.6%) and oral cavity (161/174, 92.5%). The prevalence of HPV concurrent infections in the cervix and oral cavity was 155/174 (89.1%). We found hrHPVs to be more prevalent than low-risk HPVs (lrHPVs) in the oral cavity (90.2% versus 45.4%) and that infections simultaneously affected the cervix (94.3% versus 36.2%) and oral cavity (85.1% versus 20.1%). Surprisingly, only European variants of HPV type 16 were found in the uterine cervix of women and the oral cavity of all tested samples (52 oral cavity samples and 52 uterine cervix samples). The high prevalence of HPV, multiple infections and presence of the EP350G intravariant in both anatomical regions are strongly related to the persistence of the virus, which is fundamental for the development of cancer. Therefore, it is very important to control and monitor this high-risk population as well as implement programs for the early detection of HPV and vaccination.

microRNA Profile Associated with Positive Lymph Node Metastasis in Early-Stage Cervical Cancer

Lymph node metastasis (LNM) is an important prognostic factor in cervical cancer (CC). In early stages, the risk of LNM is approximately 3.7 to 21.7%, and the 5-year overall survival decreases from 80% to 53% when metastatic disease is identified in the lymph nodes. Few reports have analyzed the relationship between miRNA expression and the presence of LNM. The aim of this study was to identify a subset of miRNAs related to LNM in early-stage CC patients. Formalin-fixed paraffin-embedded tissue blocks were collected from patients with early-stage CC treated by radical hysterectomy with lymphadenectomy. We analyzed samples from two groups of patients—one group with LNM and the other without LNM. Global miRNA expression was identified by microarray analysis, and cluster analysis was used to determine a subset of miRNAs associated with LNM. Microarray expression profiling identified a subset of 36 differentially expressed miRNAs in the two groups (fold change (FC) ≥ 1.5 and p < 0.01). We validated the expression of seven miRNAs; miR-487b, miR-29b-2-5p, and miR-195 were underexpressed, and miR-92b-5p, miR-483-5p, miR-4534, and miR-548ac were overexpressed according to the microarray experiments. This signature exhibited prognostic value for identifying early-stage CC patients with LNM. These findings may help detect LNM that cannot be observed in imaging studies.