The role of steroid contraceptive hormones in the pathogenesis of invasive cervical cancer: a review

Cervical precancer and cancer incidence among insured women with and without HIV in South Africa

HIV infection increases the risk of developing cervical cancer; however, longitudinal studies in sub-Saharan Africa comparing cervical cancer rates between women living with HIV (WLWH) and women without HIV are scarce. To address this gap, we compared cervical precancer and cancer incidence rates between WLWH and women without HIV in South Africa using reimbursement claims data from a medical insurance scheme from January 2011 to June 2020. We used Royston-Parmar flexible parametric survival models to estimate cervical precancer and cancer incidence rates as a continuous function of age, stratified by HIV status. Our study population consisted of 518 048 women, with exclusions based on the endpoint of interest. To analyse cervical cancer incidence, we included 517 312 women, of whom 564 developed cervical cancer. WLWH had an ~3-fold higher risk of developing cervical precancer and cancer than women without HIV (adjusted hazard ratio for cervical cancer: 2.99; 95% confidence interval [CI]: 2.40-3.73). For all endpoints of interest, the estimated incidence rates were higher in WLWH than women without HIV. Cervical cancer rates among WLWH increased at early ages and peaked at 49 years (122/100 000 person-years; 95% CI: 100-147), whereas, in women without HIV, incidence rates peaked at 56 years (40/100 000 person-years; 95% CI: 36-45). Cervical precancer rates peaked in women in their 30s. Analyses of age-specific cervical cancer rates by HIV status are essential to inform the design of targeted cervical cancer prevention policies in Southern Africa and other regions with a double burden of HIV and cervical cancer.

Vaginal Microbiota Changes Caused by HPV Infection in Chinese Women

Human papillomavirus (HPV) infection is one of the most common sexually transmitted diseases. After studying 602 unvaccinated Chinese women using 16S rRNA to detect cervical-vaginal microecology, we analyzed the relationship between HPV infection and vaginal microecology including 20 HPV types. In Chinese women, L. gasseri–dominated and L. jensenii–dominated clusters were significantly absence. Microbial alpha diversity was significantly higher in HPV-infected and cervical intraepithelial neoplasia (CIN)–diagnosed groups than in healthy control group. Certain bacteria were associated with HPV infection and CIN, including Streptococcus, Prevotella, Chlamydia, Bifidobacterium, Ralstonia, and Aerococcus. With the development of disease, the proportions of community state type III (CST-III) and CST-IV-B gradually increased, whereas the proportions of CST-I and CST-IV-A gradually decreased. In addition, age was an influential factor for HPV infection. With aging, the probability of HPV infection and the proportion of CST-IV-B increase. In conclusion, our study was a large cross-sectional study that evaluated the relationship between vaginal microbiota and HPV infection, and brought essential comparable data.

Human Papillomavirus Infection in Head and Neck Squamous Cell Carcinomas: Transcriptional Triggers and Changed Disease Patterns

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of cancers. Collectively, HNSCC ranks sixth in incidence rate worldwide. Apart from classical risk factors like tobacco and alcohol, infection of human papillomavirus (HPV) is emerging as a discrete risk factor for HNSCC. HPV-positive HNSCC represent a distinct group of diseases that differ in their clinical presentation. These lesions are well-differentiated, occur at an early age, and have better prognosis. Epidemiological studies have demonstrated a specific increase in the proportions of the HPV-positive HNSCC. HPV-positive and HPV-negative HNSCC lesions display different disease progression and clinical response. For tumorigenic-transformation, HPV essentially requires a permissive cellular environment and host cell factors for induction of viral transcription. As the spectrum of host factors is independent of HPV infection at the time of viral entry, presumably entry of HPV only selects host cells that are permissive to establishment of HPV infection. Growing evidence suggest that HPV plays a more active role in a subset of HNSCC, where they are transcriptionally-active. A variety of factors provide a favorable environment for HPV to become transcriptionally-active. The most notable are the set of transcription factors that have direct binding sites on the viral genome. As HPV does not have its own transcription machinery, it is fully dependent on host transcription factors to complete the life cycle. Here, we review and evaluate the current evidence on level of a subset of host transcription factors that influence viral genome, directly or indirectly, in HNSCC. Since many of these transcription factors can independently promote carcinogenesis, the composition of HPV permissive transcription factors in a tumor can serve as a surrogate marker of a separate molecularly-distinct class of HNSCC lesions including those cases, where HPV could not get a chance to infect but may manifest better prognosis.

Human Papillomavirus Infection in Head and Neck Squamous Cell Carcinomas: Transcriptional Triggers and Changed Disease Patterns

Head and neck squamous cell carcinoma (HNSCC) is a heterogeneous group of cancers. Collectively, HNSCC ranks sixth in incidence rate worldwide. Apart from classical risk factors like tobacco and alcohol, infection of human papillomavirus (HPV) is emerging as a discrete risk factor for HNSCC. HPV-positive HNSCC represent a distinct group of diseases that differ in their clinical presentation. These lesions are well-differentiated, occur at an early age, and have better prognosis. Epidemiological studies have demonstrated a specific increase in the proportions of the HPV-positive HNSCC. HPV-positive and HPV-negative HNSCC lesions display different disease progression and clinical response. For tumorigenic-transformation, HPV essentially requires a permissive cellular environment and host cell factors for induction of viral transcription. As the spectrum of host factors is independent of HPV infection at the time of viral entry, presumably entry of HPV only selects host cells that are permissive to establishment of HPV infection. Growing evidence suggest that HPV plays a more active role in a subset of HNSCC, where they are transcriptionally-active. A variety of factors provide a favorable environment for HPV to become transcriptionally-active. The most notable are the set of transcription factors that have direct binding sites on the viral genome. As HPV does not have its own transcription machinery, it is fully dependent on host transcription factors to complete the life cycle. Here, we review and evaluate the current evidence on level of a subset of host transcription factors that influence viral genome, directly or indirectly, in HNSCC. Since many of these transcription factors can independently promote carcinogenesis, the composition of HPV permissive transcription factors in a tumor can serve as a surrogate marker of a separate molecularly-distinct class of HNSCC lesions including those cases, where HPV could not get a chance to infect but may manifest better prognosis.

Knowledge and awareness of cervical cancer in Southwestern Ethiopia is lacking: A descriptive analysis

Purpose

Cervical cancer remains the second most common cancer and cancer-related death among women in Ethiopia. This is the first study, to our knowledge, describing the demographic, and clinicopathologic characteristics of cervical cancer cases in a mainly rural, Southwestern Ethiopian population with a low literacy rate to provide data on the cervical cancer burden and help guide future prevention and intervention efforts.

Methods

A descriptive analysis of 154 cervical cancer cases at the Jimma University Teaching Hospital in Southwestern Ethiopia from January 2008 –December 2010 was performed. Demographic and clinical characteristics were obtained from patient questionnaires and cervical punch biopsies were histologically examined.

Results

Of the 154 participants with a histopathologic diagnosis of cervical cancer, 95.36% had not heard of cervical cancer and 89.6% were locally advanced at the time of diagnosis. Moreover, 86.4% of participants were illiterate, and 62% lived in a rural area.

Conclusion

A majority of the 154 women with cervical cancer studied at the Jimma University Teaching Hospital in Southwestern Ethiopia were illiterate, had not heard of cervical cancer and had advanced disease at the time of diagnosis. Given the low rates of literacy and knowledge regarding cervical cancer in this population which has been shown to correlate with a decreased odds of undergoing screening, future interventions to address the cervical cancer burden here must include an effective educational component.

Association of estradiol and HPV/HPV16 infection with the occurrence of cervical squamous cell carcinoma

The associations between human papillomavirus (HPV) infection or hormonal exposure and cervical cancer risk are well established. However, to the best of our knowledge, the association between high endogenous estradiol levels in conjunction with HPV/HPV16 infection and the risk of cervical squamous cell carcinoma remains unknown. To investigate this, the current study conducted a matched case-control study in Shanxi Province, China, in which clinical samples were obtained from 74 females with newly diagnosed uterine cervix squamous cell carcinoma and 74 matched healthy females who were selected from 582 healthy females according to age, place of residence, marital status and menopausal status. From all participants, DNA was extracted from cells obtained from a cervical smear and serum was separated from venous blood withdrawn during days 5-8 of the menstrual cycle. HPV/HPV16 DNA and estradiol expression levels in the serum were measured by general polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Significant differences were identified in the positive HPV and HPV16 DNA expression rates between patients and controls, with odds ratios (95% confidence interval) of 3.74 (1.84-7.59) and 4.04 (1.97-8.28), respectively. Expression levels of estradiol in patients were significantly higher compared with the controls (P<0.001), however, this was only identified when the HPV16 E2 or E6 oncogene status was negative. Considering 40 ng/ml as the cut-off estradiol level, 78.38% of patients exhibited high estradiol levels, which was significantly higher than the percentage of controls (P<0.001). An additive interaction pattern was revealed between estradiol expression levels and HPV/HPV16 infection. The results suggest that among the various types of HPV, HPV16 may be most likely to cause uterine cervix squamous cell carcinoma and an abnormally high level of endogenous estradiol may further increase this risk. Therefore, estradiol therapy may represent a new treatment strategy for cases of cervical cancer associated with HPV infection.

Oestrogen Receptor-α binds the FOXP3 promoter and modulates regulatory T-cell function in human cervical cancer

Oestrogen controls Foxp3 expression in regulatory T cells (Treg cells) via a mechanism thought to involve oestrogen receptor alpha (ERα), but the molecular basis and functional impact of ERα signalling in Treg cells remain unclear. We report that ERα ligand oestradiol (E2) is significantly increased in human cervical cancer (CxCa) tissues and tumour-infiltrating Treg cells (CD4+CD25hiCD127low), whereas blocking ERα with the antagonist ICI 182,780 abolishes FOXP3 expression and impairs the function of CxCa infiltrating Treg cells. Using a novel approach of co-immunoprecipitation with antibodies to E2 for capture, we identified binding of E2:ERα complexes to FOXP3 protein in CxCa-derived Treg cells. Chromatin immunoprecipitation analyses of male blood Treg cells revealed ERα occupancy at the FOXP3 promoter and conserved non-coding DNA elements 2 and 3. Accordingly, computational analyses of the enriched regions uncovered eight putative oestrogen response elements predicted to form a loop that can activate the FOXP3 promoter. Together, these data suggest that E2-mediated ERα signalling is critical for the sustenance of FOXP3 expression and Treg cell function in human CxCa via direct interaction of ERα with FOXP3 promoter. Overall, our work gives a molecular insight into ERα signalling and highlights a fundamental role of E2 in controlling human Treg cell physiology.

Investigation of RIP140 and LCoR as independent markers for poor prognosis in cervical cancer

Introduction

RIP140 (Receptor Interacting Protein) is involved in the regulation of oncogenic signaling pathways and in the development of breast and colon cancers. The aim of the study was to analyze the expression of RIP140 and its partner LCoR in cervical cancers, to decipher their relationship with histone protein modifications and to identify a potential link with patient survival.

Methods

Immunohistochemical analyses were carried out to quantify RIP140 and LCoR expression in formalin-fixed paraffin-embedded tissue sections cervical cancer samples. Correlations of RIP140 and LCoR expression with histopathological variables were determined by correlation analyses. Survival rates of patients expressing low or high levels of RIP140 and LCoR were compared by Kaplan-Meier curves.

Results

RIP140 overexpression was associated with a significantly shorter overall survival of cervical cancer patients. This effect was significant in the squamous cell carcinoma subtype but not in adenocarcinomas. RIP140 is no longer a significant negative prognosticator for cervical cancer when LCoR expression is low.

Discussion

RIP140 is an independent predictor of poor survival of patients with cervical cancer. Patients with tumors expressing low levels of both RIP140 and LCoR showed a better survival compared to patients expressing high levels of RIP140. Modulation of RIP140 and LCoR may represent a novel targeting strategy for cervical cancer prevention and therapy.

Functional association of oestrogen receptors with HPV infection in cervical carcinogenesis

Repeated parity and usage of oral contraceptives have demonstrated an increased risk of cervical cancer (CC) in HPV-infected women. These lifestyle observations raise the likelihood that oestrogens and HPV infection might act synergistically to affect cancers of the cervix. In vivo studies have indicated the requirement of oestrogens and ERα in the development of atypical squamous metaplasia followed by cervical intraepithelial neoplasia (CIN) I, II and III. CIN II and III are precancerous cervical lesions that can progress over time to CC as an invasive carcinoma. Recently, there has been evidence suggesting that ERα signalling in the tumour epithelium is a preliminary requisite during cancer initiation that is subsequently lost during tumorigenic progression. Conversely, continued expression of stromal ERα gains control over tumour maintenance. This review summarises the current information on the association between oestrogens and HPV infection in contributing to CC and the possibility of SERMs as a therapeutic option.

The Influence of Hormonal Factors on the Risk of Developing Cervical Cancer and Pre-Cancer: Results from the EPIC Cohort

BACKGROUND

In addition to HPV, high parity and hormonal contraceptives have been associated with cervical cancer (CC). However, most of the evidence comes from retrospective case-control studies. The aim of this study is to prospectively evaluate associations between hormonal factors and risk of developing cervical intraepithelial neoplasia grade 3 (CIN3)/carcinoma in situ (CIS) and invasive cervical cancer (ICC).

METHODS AND FINDINGS

We followed a cohort of 308,036 women recruited in the European Prospective Investigation into Cancer and Nutrition (EPIC) Study. At enrollment, participants completed a questionnaire and provided serum. After a 9-year median follow-up, 261 ICC and 804 CIN3/CIS cases were reported. In a nested case-control study, the sera from 609 cases and 1,218 matched controls were tested for L1 antibodies against HPV types 11,16,18,31,33,35,45,52,58, and antibodies against Chlamydia trachomatis and Human herpesvirus 2. Multivariate analyses were performed to estimate hazard ratios (HR), odds ratios (OR) and corresponding 95% confidence intervals (CI). The cohort analysis showed that number of full-term pregnancies was positively associated with CIN3/CIS risk (p-trend = 0.03). Duration of oral contraceptives use was associated with a significantly increased risk of both CIN3/CIS and ICC (HR = 1.6 and HR = 1.8 respectively for ≥ 15 years versus never use). Ever use of menopausal hormone therapy was associated with a reduced risk of ICC (HR = 0.5, 95%CI: 0.4-0.8). A non-significant reduced risk of ICC with ever use of intrauterine devices (IUD) was found in the nested case-control analysis (OR = 0.6). Analyses restricted to all cases and HPV seropositive controls yielded similar results, revealing a significant inverse association with IUD for combined CIN3/CIS and ICC (OR = 0.7).

CONCLUSIONS

Even though HPV is the necessary cause of CC, our results suggest that several hormonal factors are risk factors for cervical carcinogenesis. Adherence to current cervical cancer screening guidelines should minimize the increased risk of CC associated with these hormonal risk factors.

Epistatic Interaction of CYP1A1 and COMT Polymorphisms in Cervical Cancer

There is a clear association between the excessive and cumulative exposure to estrogens and the development of cancer in hormone-sensitive tissues, such as the cervix. We studied the association of CYP1A1 M1 (rs4646903) and COMT (rs4680) polymorphisms in 130 cervical cancer cases (c-cancer) and 179 controls. The CYP1A1 TT genotype was associated with a lower risk for c-cancer (OR = 0.39, p = 0.002). The allele C of CYP1A1 was a risk for c-cancer (OR = 2.29, p = 0.002). Women with COMT LL genotype had a higher risk of developing c-cancer (OR = 4.83, p < 0.001). For the interaction of the CYP1A1&COMT, we observed that TC&HL genotypes had a greater risk for c-cancer (OR = 6.07, p = 0.006) and TT&HL genotypes had a protection effect (OR = 0.24, p < 0.001). The CYP1A1 TT and COMT LL genotypes had higher estradiol levels in c-cancer (p < 0.001 and p = 0.037, resp.). C-cancer is associated with less production of 2-methoxy-estradiol resultant of functional polymorphisms of CYP1A1 and COMT, separately. CYP1A1 and COMT work in a metabolic sequence and their interaction could lead to an alternative pathway of estrogen metabolism with production of 16-OH-estrone that is more proliferative.

Association of Combined Tobacco Smoking and Oral Contraceptive Use With Cervical Intraepithelial Neoplasia 2 or 3 in Korean Women

Background

Cigarette smoking and oral contraceptive (OC) use have been associated with cervical neoplasia, and the combination of smoking and OC use could influence cervical carcinogenesis. We aimed to assess the joint effect of smoking and OC use on the risk of cervical intraepithelial neoplasia (CIN).

Methods

From a cohort of human papillomavirus-positive subjects recruited from 6 hospitals in Korea from March 2006 to November 2012, a total of 678 subjects (411 control, 133 CIN 1, and 134 CIN 2 or 3 cases) were selected for this study (mean age, 43 years). The risk of CIN associated with smoking and OC use on additive and multiplicative scales was estimated via multinomial logistic regression after adjustment for potential confounding factors. The relative excess risk due to interaction (RERI) and the synergy index (S) were used to evaluate the additive interaction.

Results

OC users (odds ratio [OR] 1.98; 95% confidence interval [CI], 1.07–3.69) and long-term OC use (≥20 months; OR 2.71; 95% CI, 1.11–6.59) had a higher risk of CIN 2/3, but had no association with CIN 1, compared to non-OC users. Smokers and heavy smoking (≥8 cigarettes/day) were not associated with any CIN grade. Combined smoking and OC use (OR 4.91; 95% CI, 1.68–14.4; RERI/S, 3.77/27.4; P for multiplicative interaction = 0.003) and combined heavy smoking and long-term OC use (OR 11.5; 95% CI, 1.88–70.4; RERI/S, 9.93/18.8; P for multiplicative interaction = 0.009) had a higher risk of CIN 2/3 but had no association with CIN 1 compared to combined non-smoking and non-OC use.

Conclusions

OC use and smoking acted synergistically to increase the risk of CIN 2 or 3 in Korean women.

Cancer risk among parous women following assisted reproductive technology

STUDY QUESTION

Do women who give birth after assisted reproductive technology (ART) have an increased risk of cancer compared with women who give birth without ART?

SUMMARY ANSWER

Without correction, the results indicate an increase in overall cancer risk, as well as a 50% increase in risk of CNS cancer for women giving birth after ART, however the results were not significant after correcting for multiple analyses.

WHAT IS KNOWN ALREADY

Studies regarding the effects of hormonal treatments involved with ART on subsequent cancer risk have provided inconsistent results, and it has also been suggested that infertility itself could be a contributory factor.

STUDY DESIGN, SIZE, DURATION

A population-based cohort consisting of all women registered in the Medical Birth Registry of Norway as having given birth between 1 January 1984 and 31 December 2010 was assembled (n = 812 986). Cancers were identified by linkage to the Cancer Registry of Norway. Study subjects were followed from start of first pregnancy during the observational period until the first cancer, death, emigration, or 31 December 2010.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Of the total study population (n = 806 248), 16 525 gave birth to a child following ART. Cox regression analysis computed hazard ratios (HR) and 95% confidence intervals (CI) comparing cancer risk between ART women and non-ART women; for overall cancer, and for cervical, ovarian, uterine, central nervous system (CNS), colorectal and thyroid cancers, and for malignant melanoma.

MAIN RESULTS AND THE ROLE OF CHANCE

A total of 22 282 cohort members were diagnosed with cancer, of which 338 were ART women and 21 944 non-ART women. The results showed an elevated risk in one out of seven sites for ART women. The HR for cancer of the CNS was 1.50 (95% CI 1.03- 2.18), and among those specifically subjected to IVF (without ICSI) the HR was 1.83 (95% CI 1.22-2.73). Analysis of risk of overall cancer gave an HR of 1.16 (95% CI 1.04-1.29). Among those who had delivered only one child by the end of follow-up, the HR for ovarian cancer was 2.00 (95% CI 1.08-3.65), and for those nulliparous at entry the HR was 1.80 (95% CI 1.04-3.11). However, all findings became non-significant after correcting for multiple analyses.

LIMITATIONS, REASONS FOR CAUTION

The results of elevated risk of overall cancer and CNS cancer lost significance when adjusting for multiple analyses, implying an important limitation of the study. The follow-up time was relatively short, especially for ART women. In addition, as the cohort was relatively young, there were few incident cancers, especially for some rarer cancer forms, such as uterine cancer. Risk assessments according to different causes of infertility could not be done.

WIDER IMPLICATIONS OF THE FINDINGS

In light of the findings in the present study, further studies should be made on risk of CNS and ovarian cancer, and continued monitoring of all those treated with ART is encouraged. Our findings may only be generalizable to women who give birth after ART, and the risk for women who remain nulliparous after ART remains to be assessed.

STUDY FUNDING/COMPETING INTEREST

The study was funded by the Norwegian National Advisory Unit on Women's Health. All authors claim no competing interests.

Lack of significant effects of Chlamydia trachomatis infection on cervical cancer risk in a nested case-control study in North-East Thailand

Cervical cancer continues to be an important public health problem in Thailand. While the high risk human papillomavirus (HPV) types have been established as the principle causative agent of both malignancies and the precursor lesions, cervical intraepithelial neoplasia (CIN), other factors may also be involved like other sexually transmitted diseases, as well as smoking. Chlamydia trachomatis is an obligate intracellular Gram-negative bacterium which has a tendency to cause chronic infection featuring inflammation and therefore might be expected to increase the risk of cervical cancer. In the present nested case-control study, 61 cases of cervical cancer and 288 matched controls with original serum samples were identified from the Khon Kaen Cohort, established in the North-East of Thailand, by linkage to the Khon Kaen population based cancer registry. C. trachomatis specific IgG antibodies at recruitment were measured by microimmunofluorescence and assessed for association with cervical cancer using STATA release10. No significant link was noted either with all cancers or after removal of adenocarcinomas. The results suggest no association between Chlamydia infection and cervical cancer development in North-East Thailand, but possible influencing factors must be considered in any future research on this topic.

Transcriptome analysis reveals the effect of oral contraceptive use on cervical cancer

Differentially-expressed genes (DEGs) correlated to oral contraceptives (OCs) were identified by comparing the transcriptomes of cervical cancer patients who have taken OCs and those who have not. Their biological functions and relevance to clinical manifestations were investigated further in order to gain an understanding of the pathogenesis of cervical cancer and provide potential therapeutic targets. Level 3 RNA-sequencing (seq) data for cervical squamous-cell carcinoma and endocervical adenocarcinoma and the clinical information were downloaded from The Cancer Genome Atlas. The present study analyzed the RNA‑seq data and information on OC use of 35 patients [OC users (n=18) and those who have never used OCs (n=17)]. Student's t‑test was used in order to identify DEGs and the false discovery rate (FDR) was estimated by a Beta-Uniform Mixture model, which was adopted in multiple testing corrections. A functional enrichment analysis was performed with the Database for Annotation, Visualization and Integrated Discovery tool and BioCarta. A total of 80 DEGs were identified in OC users while FDR=0.3 was set as the cut-off value. The metabolic process and human telomerase RNA gene transcription were significantly upregulated in DEGs. Furthermore, secreted LY6/PLAUR domain containing 1 was identified to be correlated to the pathological response, while the synapse defective 1 Rho GTPase homolog 2 was found to be significantly associated with the histological grade and overall survival time. In conclusion, present study shed light on the effect of OC use on the oncogenesis of the cervix and may indicate novel approaches for a targeted therapy of cervical cancer.

MDM2 polymorphism associated with the development of cervical lesions in women infected with Human papillomavirus and using of oral contraceptives

Background

The MDM2 gene is the major negative regulator of p53, a tumor suppressor protein. Single nucleotide polymorphism in promoter region of MDM2 gene leads to increased expression resulting in higher levels of MDM2 protein. This event increases the attenuation of the p53 pathway. Polymorphisms in this gene can interfere in the regulation of cellular proliferation. We evaluated whether MDM2 SNP309 (rs2278744) associated or not with the use of oral contraceptive can heighten susceptibility to development of cervical lesions in women HPV infected.

Methods

MDM2 SNP309 (rs2278744) was genotyped in a total of 287 patients using the PCR-RFLP technique. The results were analyzed by UNPHASED v.3.121 and SNPStats programs.

Results

The three groups (SIL, LSIL and HSIL) showed no significant differences in either genotype or allelic frequencies for MDM2 polymorphisms, except when HSIL was compared with LSIL (p = 0.037; OR = 1.81). Furthermore, in the analysis of contraceptives, a significant association was found between the use of contraceptives and the MDM2 variant in the development of high-grade cervical lesions for the TG genotype (p = 0.019; OR = 2.21) when HSIL was compared with control. When HSIL was compared with LSIL (p = 0.006; OR = 2.27).

Conclusion

The results of this study suggest that MDM2 SNP309 might be a good marker for assessing the progression of LSIL to HSIL. In addition, they also show that oral contraceptives alone, did not have any effect on the progression or development of cervical lesions. However, they may act synergistically with MDM2 SNP309 (rs2278744) and HPV infection in the development of cervical lesions.

NRIP enhances HPV gene expression via interaction with either GR or E2

We previously identified a gene, nuclear receptor-interaction protein (NRIP), which functions as a transcription cofactor in glucocorticoid receptor (GR) and human papillomavirus E2 (HPV E2)-driven gene expression. Here, we comprehensively evaluated the role of NRIP in HPV-16 gene expression. NRIP acts as a transcription cofactor to enhance GR-regulated HPV-16 gene expression in the presence of hormone. NRIP also can form complex with E2 that caused NRIP-induced HPV gene expression via E2-binding sites in a hormone-independent manner. Furthermore, NRIP can associate with GR and E2 to form tri-protein complex to activate HPV gene expression via GRE, not the E2-binding site, in a hormone-dependent manner. These results indicate that NRIP and GR are viral E2-binding proteins and that NRIP regulates HPV gene expression via GRE and/or E2 binding site in the HPV promoter in a hormone-dependent or independent manner, respectively.

Smoking habit, immune suppression, oral contraceptive use, and hormone replacement therapy use and cervical carcinogenesis: a review of the literature

High-risk human papillomaviruses (HPVs) are involved in the etiopathogenesis of cervical intraepithelial neoplasia (CIN) and cervical cancer. After taking HPV into account, smoking habit appears to be the most significant environmental risk factor, and the risk of this malignancy increases significantly with intensity and duration of smoking. Women with human immunodeficiency virus (HIV) infection experience a higher incidence of CIN and invasive cervical cancer. Among HIV+ women, the highly active antiretroviral therapy increases the regression rate of CIN, but the majority of these lesions do not regress to normal. As far as oral contraceptives (OCs), a systematic review of 28 studies found that, compared with never pill users, the relative risk (RR) of cervical cancer increased with increasing duration of OC use. The results were similar for squamous cell carcinoma and adenocarcinoma, and the RRs decreased after pill discontinuation. However, by weighing risks and benefits, the World Health Organization does not recommend any change in OC practice. There is no correlation between hormone replacement therapy and cervical cancer. Experimental data have shown that estradiol and progesterone can modulate the host immune response to HPV16. Prophylactic vaccination in conjunction with cervical screening is the best prevention strategy for cervical cancer.

Rate of and risks for regression of cervical intraepithelial neoplasia 2 in adolescents and young women

OBJECTIVE

To describe the natural history of cervical intraepithelial neoplasia (CIN) 2 in a prospective study of adolescents and young women, and to examine the behavioral and biologic factors associated with regression and progression.

METHODS

Adolescents and women aged 13 to 24 years who were referred for abnormal cytology and were found to have CIN 2 on histology were evaluated at 4-month intervals. Risks for regression were defined as three consecutive negative cytology and histology visits, and progression to CIN 3 was estimated using Cox proportional hazards regression models.

RESULTS

Ninety-five patients with a mean age of 20.4 years (±2.3) were entered into the analysis. Thirty-eight percent resolved by year 1, 63% resolved by year 2, and 68% resolved by year 3. Multivariable analysis found that recent Neisseria gonorrhoeae infection (hazard ratio 25.27; 95% confidence interval [CI] 3.11-205.42) and medroxyprogesterone acetate use (per month) (hazard ratio 1.02; 95% CI 1.003-1.04) were associated with regression. Factors associated with nonregression included combined hormonal contraception use (per month) (hazard ratio 0.85; 95% CI 0.75-0.97) and persistence of human papillomavirus (HPV) of any type (hazard ratio 0.40; 95% CI 0.22-0.72). Fifteen percent of patients showed progression by year 3. HPV 16/18 persistence (hazard ratio 25.27; 95% CI 2.65-241.2; P=.005) and HPV 16/18 status at last visit (hazard ratio 7.25; 95% CI 1.07-49.36; P<.05) were associated with progression Because of the small sample size, other covariates were not examined.

CONCLUSION

The high regression rate of CIN 2 supports clinical observation of this lesion in adolescents and young women.

Elevated aromatase expression correlates with cervical carcinoma progression

OBJECTIVES

We have previously demonstrated that aromatase mRNA is induced in cervical carcinomas compared to normal tissue, suggesting that in situ aromatase expression leading to elevated local estrogen production may contribute to cervical carcinogensis. Our objectives are to examine 1) whether aromatase protein and activity are induced in cervical carcinomas, 2) aromatase expression correlates with disease stage, and 3) inflammatory cytokines (e.g., IL-6 and TNFalpha) may correlate with aromatase expression.

METHODS

RNA and protein were isolated from human cervical carcinomas and normal cervical biopsies to examine aromatase expression, using real-time RT-PCR, Western blot analysis, and immunohistochemistry. Aromatase activity in tissue was measured using the tritiated water release method. IL-6 and TNFalpha expression was also examined.

RESULTS

Aromatase protein and activity levels were increased in cervical carcinomas compared to normal tissue. RNA levels correlated significantly with disease progression, with highest aromatase expression detected in stage IV tumors (p<0.001, R(2)=0.77). Aromatase promoters 1.3 and 1.4 were elevated in cervical carcinomas and in cervical cancer cells. The expression of inflammatory cytokines IL-6 and TNFalpha, known to induce aromatase, significantly correlated with aromatase expression (R(2)>0.9). TNFalpha treatment induced aromatase expression in cervical cancer cells.

CONCLUSION

Increased aromatase protein and activity in cervical carcinomas and the correlation of its expression with disease stage implicates it in cervical carcinogenesis. The correlation of IL-6 and TNFalpha expression with aromatase suggests that these inflammatory cytokines may induce aromatase expression, which is confirmed by induction of aromatase expression due to TNFalpha treatment of cervical cancer cells.

Prevalence and predictors of high-risk human papillomavirus infection in a population-based sample of women in rural Uganda

High-risk genital human papillomavirus (HPV) infection is aetiologically linked to cervical cancer; however, data on the prevalence and determinants of high-risk HPV infection in Uganda are limited. We conducted a population-based cross-sectional survey among 18-49-year-old women in rural Southwest Uganda. The primary outcome was presence or absence of high-risk HPV DNA (for genotypes 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59 or 68) in the genital secretions as determined by HPV DNA Hybrid Capture 2 assay (Digene Corp, Beltsville, MD, USA). In 314 women who participated, the prevalence of high-risk HPV was 17.2% (54/314; 95% confidence interval [CI]: 13-21). Older women had a lower proportion of high-risk HPV infection; with a 9% decrease in the odds ratio (OR) of high-risk HPV infection per year increase in age (OR = 0.91; 95% CI: 0.86, 0.96). The odds of detecting high-risk HPV infection was higher among women who were previously tested positive for HIV (OR = 12.1; 95% CI: 2.8, 52.3). In this population of rural Ugandan women, the prevalence of high-risk cervical HPV infection was high. Information on predictors of high-risk HPV infection and intention to receive a vaccine can guide future immunization initiatives for young sexually active women.

Atypical squamous cells and low squamous intraepithelial lesions in postmenopausal women: implications for management

OBJECTIVES

To determine whether the use of local Estrogen Replacement Therapy (ERT) affects the adequacy of colposcopic examination; to distinguish abnormal cervical smears secondary to hypoestrogenism from abnormal cervical smears due to true preneoplastic changes; and to suggest an effective management of atypical squamous cells of undeterminated significance (ASCUS) and low grade squamous intraepithelial lesion (L-SIL) in menopausal women.

STUDY DESIGN

Two-hundred fifty-four postmenopausal women with abnormal pap smears (L-SIL or ASCUS) underwent colposcopy and HPV DNA testing. All patients with positive colposcopy underwent punch biopsy, and all patients with positive histological findings underwent surgical treatment. Patients with negative colposcopy, both satisfactory [visible Squamo-Columnar Junction (SCJ)] and unsatisfactory, were treated with local estrogenic replacement therapy (ERT) for 3 months, and repeated colposcopy and pap smears. Patients with negative colposcopy and negative pap smears after ERT were included in a 6 months cytological and colposcopic follow-up. Patients with positive colposcopy underwent punch biopsy, if colposcopy was negative and cytology was positive, patients underwent endocervical curettage.

RESULTS

One-hundred ninety-five had a diagnosis of ASCUS and 59 a diagnosis of L-SIL. At the first colposcopy, 39 patients showed a lesion and had an appropriate treatment. One-hundred eighty-eight in the ASCUS group and 27 in the L-SIL group had a negative colposcopy and were treated with local ERT. At first colposcopic examination, 37 of the 215 negative colposcopies resulted satisfactory and 178 of the 215 resulted unsatisfactory. After local ERT, 130 of the 178 patients had a satisfactory follow-up colposcopy. After ERT, 25 patients of 215 with initial abnormal CVS and negative colposcopy, required appropriate treatment. After ERT, 190 patients of 215 showed negative colposcopy and at cytologic follow-up showed 23 ASCUS and 167 normal CVS.

CONCLUSIONS

A correct diagnosis and an efficient treatment seem to be obtained with a short-time ERT followed by a short-time cytological and colposcopic follow-up. With a single course of local ERT it may be possible to distinguish between benign CVS mimicking atrophy and true preneoplastic changes. Estrogen therapy will often cause enough ectropion of the endocervical cells so that the entire SCJ can be visualized. Moreover, it may reduce the number of endocervical curettage or loop excision or cone procedure for women with inadequate colposcopic examination.

Prevalence of cervical neoplastic lesions and Human Papilloma Virus infection in Egypt: National Cervical Cancer Screening Project

Background

Data from Egyptian studies provide widely varying estimates on the prevalence of pre-malignant and malignant cervical abnormalities and human papilloma virus (HPVs) infection. To define the prevalence and risk factors of pre-invasive and invasive cervical cancer (cacx), a community based full-scale cross sectional, household survey including 5453 women aged between 35 and 60 years was conducted.

Methods

The study period was between February 2000 and December 2002. Initially, conventional Papanicolaou (Pap) smears were evaluated using the Bethesda system (TBS), followed by colposcopic guided biopsy (CGB) for all epithelial abnormalities (EA). In a third step, HPV was tested on all EA by in-situ hybridization (ISH) using first the broad spectrum HPV probe recognizing HPVs 6, 11, 16, 18, 30, 31, 35, 45, 51 and 52 followed by subtyping with probes 6/11, 16/18 and 31/33. Lastly, unequivocal cases were immunostained for herpes simplex type-2 (HSV-2), cytomegalovirus (CMV), and human immunodeficiency virus (HIV).

Results

EA representing 7.8% (424/5453), were categorized into atypical squamous cell of undetermined significance (ASCUS) (34.4%), atypical glandular cell of undetermined significance (AGCUS) (15.3%), combined ASCUS and AGCUS (3.1%), low grade squamous intraepithelial lesions (SIL) (41.0%), high grade SIL (5.2%) and invasive lesions (1%). CGB of EA (n = 281) showed non neoplastic lesions (12.8%), atypical squamous metaplasia (ASM) (19.2%), cervical intraepithelial neoplasia I (CIN) (44.4%), CIN II (4.4%), CINIII (2.8%), endocervical lesions (5.2%), combined squamous and endocervical lesions (10.0%), invasive squamous cell carcinoma (SCC) (0.02%) and extranodal marginal zone B cell lymphoma (MZBCL) (0.02%). The overall predictive value of cytology was 87% while the predictive value for high grade lesions was 80%. On histological basis, HPVs were present in 94.3% of squamous lesions while it was difficult to be identified in endocervical ones. ISH revealed positivity for pan HPV in 65.9% of the studied biopsies (n = 217), with incorporation of the viral genome HPV 6/11, 16/18 and 31/33 in 11.1%, 33.3% and 17.1% respectively. Multiple HPVs infections were identified in 0.02%.

Conclusion

Pre-invasive high grade lesions and invasive cervical carcinoma represent 0.5% and 0.04% respectively in Egyptian women. HPV mostly 16/18 as a risk factor (p < 0.001), was frequently associated with mixed infections (p < 0.001) and bilharzial infestation (p < 0.001).

Human papillomavirus E2 protein associates with nuclear receptors to stimulate nuclear receptor- and E2-dependent transcriptional activations in human cervical carcinoma cells

Steroid hormones are proposed to act with human papillomaviruses (HPVs) as cofactors in the etiology of cervical cancer. Steroid hormone-activated nuclear receptors (NRs) are thought to bind to specific DNA sequences within transcriptional regulatory regions on the HPV DNA to either increase or suppress transcription of dependent genes. HPV-induced immortalization of epithelial cells usually requires integration of the viral DNA into the host cell genome. The integration event causes disruption of the E2 gene: the E2 protein is a transcription factor that regulates expression of the E6 and E7 oncoproteins by binding to four sites within the viral long control region (LCR). Our previous study suggested that E6 and E7 oncoproteins both directly bind to some NRs and serve as their cofactors. Here, we provide several lines of evidence demonstrating that the E2 protein is an NR coactivator through its physical interaction with NRs. In our study, the NR coactivator function of HPV E2 protein in human cervical carcinoma cells was independent of the type of E2, HPV transformation and the p53 status. Our observations also provide evidence suggesting regulatory mechanisms for the LCR involving interaction between the E2 protein and NRs in HeLa cells.

The underlying cause of cervical cancer in oral contraceptive users may be related to cervical mucus changes

Oral contraceptives (OCs) remain among the most effective reversible methods of birth control available today, providing almost 100% effectiveness with an impressively high margin of safety and other important health benefits. However, concerns have been raised about the role that the hormones in OCs might play in the pathogenesis of cervical cancer. Evidence shows that long-term use of OCs (five or more years) may be associated with an increased risk of cancer of the cervix. The mechanism of increased risk of cervical cancer in OCs users has long been debated, and remains uncertain. Our hypothesis is that scanty, thick, and highly viscous cervical mucus obtained in OCs users intimately involved in the pathogenesis of cervical cancer. Possibly, this architecture of cervical mucus may modulate and prolong the effect of carcinogenic agents, which have been carried by coitus and stored in posterior vaginal fornix, on squamocolumnar junction of cervix by not permitting them to be removed because of its highly viscous pattern. The role of cervical mucus changes by means of specific mucin protein changes on the pathophysiology of cervical cancer in OCs users should be investigated.

Human papillomavirus E7 oncoprotein dysregulates steroid receptor coactivator 1 localization and function

High-risk human papillomaviruses (HPVs) are present in virtually all cervical carcinomas. However, the majority of women infected with high-risk HPVs do not develop cervical cancer. Therefore, cofactors must contribute to the development and progression of cervical cancer. Although numerous studies have implicated steroid hormones as cofactors in the initiation and progression of cervical neoplasia, the molecular mechanisms by which they contribute to cervical carcinogenesis are currently unknown. These observations led us to investigate a newly discovered association of the high-risk HPV type 16 (HPV16) E7 oncoprotein with steroid receptor coactivator 1 (SRC-1), an essential component of steroid hormone signaling. HPV16 E7 has been previously reported to interact with p300 and p300/CBP-associated factor (PCAF), members of some SRC-1 transcriptional complexes. We demonstrate here that HPV16 E7 associates in vivo and in vitro with SRC-1 independently of p300 and PCAF. Luciferase reporter constructs under the control of either the interleukin-8 promoter or a promoter containing multimerized synthetic estrogen response elements were used to determine the effect of high- and low-risk HPV E7 expression on SRC-1-mediated transcription. In addition, histone acetyltransferase (HAT) assays were performed to determine the effect of HPV E7 on SRC-1-associated HAT activity. These experiments reveal that HPV16 E7 expression down-regulates SRC-1-mediated transcription and SRC-1-associated HAT activity. SRC-1 localization experiments show that SRC-1 is relocalized to the cytoplasm in the presence of high- and low-risk HPV E7 proteins. Our data suggest that HPV E7 proteins dysregulate hormone-dependent gene expression by association with and relocalization of SRC-1. Dysregulation of SRC-1 localization and function by HPV E7 may provide insight into the molecular mechanisms by which steroid hormones act as cofactors in the induction and progression of cervical neoplasia.

Human papillomavirus infection: biology, epidemiology, and prevention

Over the past several decades, knowledge of the biology and epidemiology of human papillomavirus (HPV) infection has increased tremendously. However, there are still many unanswered questions concerning the interaction of the virus with its host. The virus has been identified as a necessary causal agent for cervical squamous neoplasia and has been linked to the development of neoplasia in several other mucosal sites. The viral oncogenes E6 and E7 are the major players in the virus' scheme to evade the immune system and use the host cell replication machinery to survive. Many risk factors for infection with HPV have been identified; however, the focus now centers on identifying risk factors for persistence of the infection as it is likely that transient infections play a very small role in the overall development of clinical disease. Prevention measures to date have centered around screening programs, mostly for cervical cancer, including the perfection of screening techniques and inclusion of molecular testing for HPV into screening regimens. The development of prophylactic and therapeutic vaccines has also increased as primary prevention measures appear to have the best hope for long-term effects on cancer incidence.

Update on pathophysiologic mechanisms of human papillomavirus

PURPOSE OF REVIEW

The role of the human papillomavirus in the pathogenesis has been the subject of many publications in the recent literature. The physical state of the human papillomavirus and the role of chromosomal aneuploidy has been reported. This review discusses the recent pathological mechanisms described in the genesis of human papillomavirus-related disease.

RECENT FINDINGS

The mere presence of the human papillomavirus is not sufficient for the development of neoplasia. Genetic and other co-factors seem to be necessary for the expression of the invasive phenotype. The expression of human papillomavirus 16 E6-E7 oncogenes results in chromosomal aneuploidy, favouring the integration of high-risk human papillomavirus genomes into cellular chromosomes. The integration of human papillomavirus 16 may not always be required for the progression to the invasive phenotype unlike human papillomavirus 18 DNA. Such integration sites are randomly distributed over the whole genome. The genetic susceptibility of codon 98 of the fragile histadine triad has been elucidated.

SUMMARY

Various molecular mechanisms of human papillomavirus-associated neoplasia are discussed. The interaction between HIV and human papillomavirus are complex and favour the persistence and progression of cervical disease. Future research should pave the way for therapeutic vaccine development.

Human papillomavirus infection of the cervix uteri in women attending a Health Examination Center of the French social security

Since human papillomavirus (HPV) is the central causal factor in cervical cancer, understanding the epidemiology of this infection constitutes an important step towards development of strategies for prevention. Six hundred and fifty seven cervical samples were tested for HPV using PCR with consensus primers (MY09/MY11), by genotyping (restriction and sequencing analyses) and by cervical cytology, from women who attended a Health Examination Center of the French social security. Women with no cervical smear as well as women with cytological abnormalities within the last 3 years were recruited. HPV DNA was detected in 7.3% of the women (5.3% for high-risk, 2.4% for low-risk, and 0.5% for unknown risk types) including 6 (0.9%) mixed infections. Fifteen different genotypes were detected, of which genotypes 16 (22.2%), 58 (13.0%), 18 (11.1%), 30 (9.2%), and 33 (9.2%) were the most prevalent. In age group 17-25 years, we found the highest frequencies for both any (22.1%) and high-risk (14.7%) HPV, and prevalences gradually decreased with age. 5.2% of low-grade squamous intraepithelial lesion, 0.3% of high-grade squamous intraepithelial lesion, and 1.2% of atypical squamous cells of undetermined significance were found. The frequencies of high risk and all HPV types were significantly higher in squamous intraepithelial lesions than in those with normal and reactive/reparative changes (P < 0.0001). The prevalence of high-risk HPV in the atypical squamous cells of undetermined significance/low-grade squamous intraepithelial lesion group (28.6%) was significantly higher than in the normal and reactive/reparative changes groups (3.4%) (P < 0.0001). HPV detection was associated with younger age, single marital and non-pregnant status (P < 0.0001), premenopausal status (P = 0.0004), and contraception (P = 0.0008). Marital status (OR 4.5; 95% CI = 2.3-9.0) and tobacco consumption (OR 3.0; 95% CI = 1.6-5.7) were predictive independent factors of HPV infection. The French system of Health Examination Centers might be of interest for following women regularly, especially those with a low socioeconomic status.

Neoplasms of the reproductive tract: the role of hormone exposure

Cancers of the reproductive system are a major source of morbidity and mortality among women worldwide. Because the uterus, ovaries, and cervix are hormonally responsive tissues, exposure to endogenous or exogenous sex steroids can profoundly affect the carcinogenic process. Animal models developed to date provide valuable but imperfect systems in which to study neoplasms of the reproductive tract. Nonhuman primate models share the unique primate-specific endometrial physiology of humans, but rarely develop neoplasms of the reproductive tract. Therefore a surrogate marker approach is required for the study of hormonally induced cancer risk in primates. Rodents provide practical models in which tumorigenesis can be assayed in a short time and, with appropriate interpretation, can be used for assessment of risk, prevention, and therapeutic strategies. In addition to the spontaneous strain-dependent incidence of female reproductive cancers, the classical chemical and hormonal carcinogenesis models, and the use of xenograft approaches, novel genetically modified animals provide unique insights into relevant molecular mechanisms. Caveats in the use of rodent models include anatomical differences from the human reproductive tract, the greater possibility of different metabolic responses to hormonal agents than humans, strain variations in tumor type and hormonal responsiveness, and unexpected tumor phenotypes in genetically modified animals. Reported nonmammalian models are limited primarily to the study of ovarian carcinogenesis. Recent progress in the understanding of cervical carcinogenesis is encouraging. Unmet needs in this area of research include models of early events in ovarian carcinogenesis and strongly predictive models of endometrial cancer risk. Nonhuman primates remain indispensable for the study of some aspects of reproductive pathophysiology, but the best understanding of carcinogenesis in the reproductive tract requires a broad approach using complementary human, nonhuman primate, and nonprimate studies.

Combined oral contraceptives and cervical cancer

PURPOSE OF REVIEW

The issue of whether there might be an increased risk of cervical cancer associated with the use of oral contraceptives has been debated for decades. Early studies found a modest association with long-term use. A literature review was performed over the past 3 years, to establish whether there is any new evidence linking cervical cancer with the use of oral contraceptives.

RECENT FINDINGS

A new analysis from eight studies conducted by the International Agency for Research on Cancer and a systematic review of cervical cancer and the use of hormonal contraceptives are two recent major epidemiological links strongly suggesting the increased risk of cervical cancer (up to twofold), but only for women who were both long-term users (5 years or more) and who had persistent human papilloma virus infections of the cervix.

SUMMARY

These findings seem biologically plausible, but weighing the various risks and benefits, the World Health Organization does not recommend any change in oral contraceptive use or practice.

Genomic diversity of human papillomavirus-16, 18, 31, and 35 isolates in a Mexican population and relationship to European, African, and Native American variants

Cervical cancer, mainly caused by infection with human papillomaviruses (HPVs), is a major public health problem in Mexico. During a study of the prevalence of HPV types in northeastern Mexico, we identified, as expected from worldwide comparisons, HPV-16, 18, 31, and 35 as highly prevalent. It is well known that the genomes of HPV types differ geographically because of evolution linked to ethnic groups separated in prehistoric times. As HPV intra-type variation results in pathogenic differences, we analyzed genomic sequences of Mexican variants of these four HPV types. Among 112 HPV-16 samples, 14 contained European and 98 American Indian (AA) variants. This ratio is unexpected as people of European ethnicity predominate in this part of Mexico. Among 15 HPV-18 samples, 13 contained European and 2 African variants, the latter possibly due to migration of Africans to the Caribbean coast of Mexico. We constructed phylogenetic trees of HPV-31 and 35 variants, which have never been studied. Forty-six HPV-31 isolates from Mexico, Europe, Africa, and the United States (US) contained a total of 35 nucleotide exchanges in a 428-bp segment, with maximal distances between any two variants of 16 bp (3.7%), similar to those between HPV-16 variants. The HPV-31 variants formed two branches, one apparently the European, the other one an African branch. The European branch contained 13 of 29 Mexican isolates, the African branch 16 Mexican isolates. These may represent the HPV-31 variants of American Indians, as a 55% prevalence of African variants in Mexico seems incomprehensible. Twenty-seven HPV-35 samples from Mexico, Europe, Africa, and the US contained 11 mutations in a 893-bp segment with maximal distances between any two variants of only 5 mutations (0.6%), including a characteristic 16-bp insertion/deletion. These HPV-35 variants formed several phylogenetic clusters rather than two- or three-branched trees as HPV-16, 18, and 31. An HPV-35 variant typical for American Indians was not identifiable. Our research suggests type specific patterns of evolution and spread of HPV-16, 18, 31, and 35 both before and after the worldwide migrations of the last four centuries. The high prevalence of highly carcinogenic HPV-16 AA variants, and the extensive diversity of HPV-18, 31, and 35 variants with unknown pathogenic properties raise the possibility that HPV intra-type variation contributes to the high cervical cancer burden in Mexico.

Chorionic gonadotropin regulates the transcript level of VHL, p53, and HIF-2? in human granulosa lutein cells

The ovarian corpus luteum plays a critical role in reproduction being the primary source of circulating progesterone. After ovulation the corpus luteum is build by avascular granulosa lutein cells through rapid vascularization regulated by gonadotropic hormones. The present study was performed to investigate whether this process might be influenced by the human chorionic gonadotropin (hCG)-dependent expression of different tumor suppressor genes and hypoxia dependent transcription factors. RNA was isolated from cultured granulosa lutein cells, transcribed into cDNA, and the transcript level of following genes were determined: RB-1, VHL, NF-1, NF-2, Wt-1, p53, APC, and hypoxia inducible factor-1 (HIF-1), -2, and -3alpha. Additionally, the influence of hCG on the expression of VHL, p53, and HIf2alpha were investigated. We demonstrate that in human granulosa lutein cells the tumor suppressor genes RB-1, VHL, NF-1, NF-2, Wt-1, p53, and APC and the hypoxia dependent transcription factors HIF-1alpha, -2alpha, and -3alpha are expressed. In addition, we showed that hCG regulates the expression of p53, VHL, and HIF-2alpha. Our results indicate that hCG may determine the growth and development of the corpus luteum by mediating hypoxic and apoptotic pathways in human granulosa lutein cells.