Project description:Infection with high-risk human papillomavirus (HPV), for example, with types 16 and 18, is closely associated with cervical cancer development, which continues to threaten women's health globally. Although HPV oncogenes have been recognized as the main cause of transformation of normal cervical epithelial cells, non-coding RNA could also be involved in the initiation and promotion of cervical cancer development. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a well-documented long non-coding RNA (lncRNA), has been previously reported to exert roles in HPV-positive cervical cancer; however, the detailed underlying mechanism has yet to be investigated. In the present study, high expression levels of MALAT1 in HPV-Positive Cervical Cancer cells were confirmed, and silencing MALAT1 resulted in decreased rates of cell proliferation, migration, and invasion, both in vitro and in a zebrafish xenograft tumor model. Moreover, the results obtained showed that silencing MALAT1 led to down-regulation of the N6-methyladenosine (m6A) demethylase ALKBH5 via regulating miR-141-3p expression, which caused a decrease in the expression levels of matrix metalloproteinase 2 (MMP2) and MMP9 expression, thereby suppressing cell migration and invasion. Taken together, the results obtained have suggested that the MALAT-ALKBH5 signaling axis may be activated in HPV-positive cervical cancer cells, which could contribute to cell proliferation and metastasis through the regulation of key genes, such as MMP2 or MMP9. The findings of the present study should both help to improve our understanding of the underlying tumorigenic mechanisms of HPV-positive cervical cancer and be of further use in the development of potential therapeutic drugs.
Project description:Cervical cancer is a Human Papilloma virus-related disease, which is on the rise in a number of countries, globally. Two essential oncogenes, E6 and E7, drive cell transformation and cancer development. These two oncoproteins target two of the most important tumour suppressors, p53 and pRB, for degradation through the ubiquitin ligase pathway, thus, blocking apoptosis activation and deregulation of cell cycle. This pathway can be exploited for anticancer therapeutic interventions, and Human Immunodeficiency Virus Protease Inhibitors (HIV-PIs) have attracted a lot of attention for this anticancer drug development. HIV-PIs have proven effective in treating HPV-positive cervical cancers and shown to restore impaired or deregulated p53 in HPV-associated cervical cancers by inhibiting the 26S proteasome. This review will evaluate the role players, such as HPV oncoproteins involved cervical cancer development and how they are targeted in HIV protease inhibitors-induced p53 restoration in cervical cancer. This review also covers the therapeutic potential of HIV protease inhibitors and molecular mechanisms behind the HIV protease inhibitors-induced p53-dependent anticancer activities against cervical cancer.
Project description:The clinical significance of co-infections with high-risk (HR) and low-risk (LR) human papillomavirus (HPV) in the etiology of cervical cancer is debated, as prospective evidence on this issue is limited. However, the question is of increasing relevance in relation to HPV-based cancer prevention. In two population-based nested case-control studies among women participating in cervical screening with baseline normal smears, we collected 4659 smears from women who later developed cancer in situ (CIS; n = 524) or squamous cervical cancer (SCC; n = 378) and individually matched control subjects who remained free of disease during study follow-up. The median follow-up until diagnosis was 6.4 to 7.8 years. All smears were tested for HPV. We used conditional logistic regression models with two-way interaction terms to estimate relative risks (RRs) for CIS and SCC, respectively. All statistical tests were two-sided. Compared with women who were infected with HRHPV only, women who were also infected with LRHPV had a lower risk for SCC (RR = 0.2, 95% confidence interval [CI] = 0.04 to 0.99, P = .049). This interaction was not shown for CIS (RR = 1.1, 95% CI = 0.4 to 3.6). Women who were positive for both HRHPV and LRHPV had, on average, a 4.8 year longer time to diagnosis of SCC than women who were positive for HRHPV only (P = .006). Results were highly robust in sensitivity analyses. Co-infection with LRHPV is associated with a lower risk of future invasive disease and longer time to diagnosis than infection with HRHPV alone. We propose that co-infection with LRHPV interferes with the rate of progression to invasive cervical cancer.
Project description:We conducted a critical appraisal of published Phase 2 and 3 efficacy trials in relation to the prevention of cervical cancer in women. Our analysis shows the trials themselves generated significant uncertainties undermining claims of efficacy in these data. There were 12 randomised control trials (RCTs) of Cervarix and Gardasil. The trial populations did not reflect vaccination target groups due to differences in age and restrictive trial inclusion criteria. The use of composite and distant surrogate outcomes makes it impossible to determine effects on clinically significant outcomes. It is still uncertain whether human papillomavirus (HPV) vaccination prevents cervical cancer as trials were not designed to detect this outcome, which takes decades to develop. Although there is evidence that vaccination prevents cervical intraepithelial neoplasia grade 1 (CIN1) this is not a clinically important outcome (no treatment is given). Trials used composite surrogate outcomes which included CIN1. High efficacy against CIN1+ (CIN1, 2, 3 and adenocarcinoma in situ (AIS)) does not necessarily mean high efficacy against CIN3+ (CIN3 and AIS), which occurs much less frequently. There are too few data to clearly conclude that HPV vaccine prevents CIN3+. CIN in general is likely to have been overdiagnosed in the trials because cervical cytology was conducted at intervals of 6-12 months rather than at the normal screening interval of 36 months. This means that the trials may have overestimated the efficacy of the vaccine as some of the lesions would have regressed spontaneously. Many trials diagnosed persistent infection on the basis of frequent testing at short intervals, i.e. less than six months. There is uncertainty as to whether detected infections would clear or persist and lead to cervical changes.
Project description:► An HPV 11 positive ICC was detected. ► Infection by other HR types was ruled out. ► The same genotype was found in a metastatic lesion.
Project description:Every year, approximately 470,000 new cases of cervical cancer are diagnosed and approximately 230,000 women worldwide die of the disease, with the majority (approximately 80%) of these cases and deaths occurring in developing countries. Human papillomaviruses (HPVs) are the etiological agents in nearly all cases (99.7%) of cervical cancer, and the HPV E6 protein is one of two viral oncoproteins that is expressed in virtually all HPV-positive cancers. E6 hijacks a cellular ubiquitin ligase, E6AP, resulting in the ubiquitylation and degradation of the p53 tumor suppressor, as well as several other cellular proteins. While the recent introduction of prophylactic vaccines against specific HPV types offers great promise for prevention of cervical cancer, there remains a need for therapeutics. Biochemical characterization of E6 and E6AP has suggested approaches for interfering with the activities of these proteins that could be useful for this purpose. PUBLICATION HISTORY : Republished from Current BioData's Targeted Proteins database (TPdb; http://www.targetedproteinsdb.com).
Project description:Epigenetic modulation is an important mechanism of miRNA dysregulation in cervical cancer. In this study, we firstly studied how this mechanism contributes to miR-375 downregulation in cervical cancer cells. Then, we further studied the association between miR-375 and MALAT1 (metastasis associated lung adenocarcinoma transcript 1) in epithelial mesenchymal transition (EMT) of the cancer cells. HPV-16 positive SiHa and CaSki cells were used as in vitro model. Our data showed that HPV-16 E6 positively modulated DNMT1 expression in both SiHa and CaSki cells. Knockdown of DNMT1 partly restored miR-375 levels in the cells. The following methylation-specific PCR (MSP) assay and qRT-PCR analysis showed that methylation was common in the promoter region of miR-375 in both SiHa and CaSki cells and demethylation partly restored miR-375 levels in the cells. Therefore, we infer that miR-375 is downregulated partly due to promoter hypermethylation mediated by DNMT1 in HPV-16 positive cervical cancer cells. Our bioinformatics analysis showed that MALAT1 has three putative binding sites with miR-375 and the following dual luciferase assay confirmed two of them. QRT-PCR analysis showed that miR-375 overexpression significantly reduced MALAT1 expression, while MALAT1 overexpression reversely suppressed miR-375 levels. Therefore, we infer that there is a reciprocal regulation between miR-375 and MALAT1 in the cells. In SiHa cells, miR-375 overexpression or MALAT1 siRNA partly restored E-cadherin expression, significantly reduced N-cadherin and also reduced invasion capacity of SiHa cells. Therefore, these results suggest that miR-375 and MALAT1 form a functional axis modulating EMT in cervical cancer.
Project description:Purpose:Colon cancer (CC) is a leading cause of cancer-related deaths worldwide. This study aimed to clarify the effect of long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on CC progression and the potential mechanism. Methods:CC cell lines HCT116 and HT29 were selected for functional analysis. The expression of MALAT1, microRNA (miR)-101-3p, and stanniocalcin 1 (STC1) in CC tissues and cells were measured by quantitative reverse transcription PCR (qRT-PCR). Cell proliferation, apoptosis, migration and invasion were measured by Cell Counting Kit-8 (CCK-8), ?flow cytometry, wound scratch and ?transwell assay, respectively. The target relationships (MALAT1 and miR-101-3p, miR-101-3p and STC1) were validated by dual-luciferase reporter and RNA pull-down assay. Results:The expression of MALAT1 was elevated in CC tissues compared with adjacent normal tissues and was associated with lymph node metastasis, depth of invasion and tumor-node-metastasis (TNM) stage. Up-regulation of MALAT1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of CC cells; while MALAT1 knockdown exhibited opposite results. MiR-101-3p was a target of MALAT1, which was negatively regulated by MALAT1. Silencing of miR-101-3p reverses the anti-tumor effect of MALAT1 knockdown on CC cells. STC1 was a target of miR-101-3p, which was negatively regulated by miR-101-3p. Silencing of STC1 reverses the tumor promoting effects of MALAT1 up-regulation and miR-101-3p down-regulation on CC cells. Conclusion:MALAT1 may function as an oncogene in CC progression by affecting the miR-101-3p/STC1 axis, providing a hopeful therapeutic option for CC.
Project description:BackgroundCervical cancer is the 4th highest cause of female reproductive tract malignancies. Multiple loci have been identified as important determinant factors for tumor susceptibility. In this report, we aimed to explore the roles of gene polymorphisms affecting x-ray repair cross complementing 1 (XRCC1), the tumor protein p53 (TP53), and fibroblast growth factor receptor 3 (FGFR3) in the context of susceptibility to cervical cancer. Additionally, we assessed the impact of single nucleotide polymorphism-single nucleotide polymorphism (SNP-SNP) interaction of these three genes in the context of cervical cancer risk in Chinese women.MethodsA case-control study consisted of 340 women located in Chongqing. Of these women, 121 were diagnosed with cervical cancer, 118 served as healthy controls, and 101 were specifically recruited elderly patients above the age of 80 who showed no history of cervical cancer. Three SNPs (XRCC1 rs25487, TP53 rs1042522, and FGFR3 rs121913483) were examined using mutation analysis of mismatch amplification PCR (MAMA-PCR) on samples obtained from peripheral blood.ResultsOur results indicated that females from southwestern China all exhibited a wild-type phenotype at FGFR3 rs121913483. We also observed that the rs25487 mutation was significantly increased within the cervical cancer population. A 2-locus SNP-SNP interaction pattern (rs25487 and rs1042522) was significantly associated with cervical cancer risk (cases vs. negative controls: OR = 4.63, 95% CI = 1.83-11.75; cases vs. elderly group: OR = 17.61, 95% CI = 4.34-71.50).ConclusionsThis is the first study to identify a novel interaction between the XRCC1 and TP53 genes that is highly associated with susceptibility to cervical cancer risk in a female population in southwestern China.
Project description:Host genetic variability modifies the risk of cervical cancer in women infected with oncogenic human papillomavirus (HPV). Studies have reported an association of the TP53 codon 72 arginine and cervical cancer, but the results are inconsistent. We examined the association of this single nucleotide polymorphism (SNP) in women with cervical cancer and cervical intraepithelial neoplasia grade 3, using a family-based association test. We further explored SNPs in two genes that regulate p53 stability: MDM2 (SNP309) and NQO1 (SNP609, SNP465). We also examined the relationship between host genotype and tumor HPV type. We genotyped 577 patients and their biological parents and/or siblings, using PCR-RFLP or Taqman assays. HPVs were typed by sequence-based methods. The transmission/disequilibrium test was used to detect disease-susceptibility alleles. The arginine peptide of TP53 codon 72 was overtransmitted in Caucasian families (P = 0.043), and the significance of this finding was enhanced in a subgroup of women infected with HPV16- and/or HPV18-related HPVs (P = 0.026). Allele C of NQO1 SNP609 was also overtransmitted in all cases (P = 0.026). We found no association between MDM2 SNP309 or NQO1 SNP465 and cervical cancer. Our results indicate that functional polymorphisms in TP53 codon 72 and NQO1 SNP609 associate with the risk of cervical cancer especially in women infected with type 16- and/or type 18-related HPVs.