Requirement of estrogen receptor alpha DNA-binding domain for HPV oncogene-induced cervical carcinogenesis in mice

Fibroblast Stromal Support Model for Predicting Human Papillomavirus-Associated Cancer Drug Responses

Currently, there are no specific antiviral therapeutic approaches targeting Human papillomaviruses (HPVs), which cause around 5% of all human cancers. Specific antiviral reagents are particularly needed for HPV-related oropharyngeal cancers (HPV+OPCs) whose incidence is increasing and for which there are no early diagnostic tools available. We and others have demonstrated that the estrogen receptor alpha (ERα) is overexpressed in HPV+OPCs, compared to HPV-negative cancers in this region, and that these elevated levels are associated with an improved disease outcome. Utilizing this HPV+ specific overexpression profile, we previously demonstrated that estrogen attenuates the growth and cell viability of HPV+ keratinocytes and HPV+ cancer cells in vitro. Expansion of this work in vivo failed to replicate this sensitization. The role of stromal support from the tumor microenvironment (TME) has previously been tied to both the HPV lifecycle and in vivo therapeutic responses. Our investigations revealed that in vitro co-culture with fibroblasts attenuated HPV+ specific estrogen growth responses. Continuing to monopolize on the HPV+ specific overexpression of ERα, our co-culture models then assessed the suitability of the selective estrogen receptor modulators (SERMs), raloxifene and tamoxifen, and showed growth attenuation in a variety of our models to one or both of these drugs in vitro. Utilization of these SERMs in vivo closely resembled the sensitization predicted by our co-culture models. Therefore, the in vitro fibroblast co-culture model better predicts in vivo responses. We propose that utilization of our co-culture in vitro model can accelerate cancer therapeutic drug discovery.

High rate of high-risk human papillomavirus among benign and breast cancer patients in Ethiopia

INTRODUCTION

There have been numerous studies that showed the presence of human papillomavirus (HPV) in breast cancer; nonetheless, there is ongoing debate regarding their association. Given few studies in Ethiopia, we aimed to investigate the magnitude of HPV infection in Ethiopian breast cancer patients.

METHODS

A total of 120 formalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained, and basic demographic, clinical, and histological data were collected from medical records. DNA was extracted from archived FFPE breast tissue specimens using GeneRead DNA FFPE Kit. The AnyplexTM II HPV28 Detection Kit (Seegene, Korea) was used to detect HPV by following the manufacturer's instructions. The SPSS Version 25 was used to enter and analyze data.

RESULTS

Among the 120 study participants; HPV (both high-risk and low-risk) was detected in 20.6% of breast cancer and 29.6% of non-malignant breast tumors. The most common genotype was the high-risk HPV 16 genotype. The frequency of HPV was nearly 10-fold higher in estrogen receptor-positive than ER-negative breast cancer. The percentage of HPV in the luminal (luminal A and luminal B) breast cancer subtypes was also much higher than in the non-luminal subtypes (HER-2 enriched and triple-negative breast cancer).

CONCLUSION

This study did not find a significant difference in HPV expression between breast cancer and non-malignant breast tumors; however, the higher percentage of HPV in ER-positive compared to ER-negative breast cancer warrants further attention.

HPV and Cervical Cancer: Molecular and Immunological Aspects, Epidemiology and Effect of Vaccination in Latin American Women

Cervical cancer is primarily caused by Human Papillomavirus (HPV) infection and remains a significant public health concern, particularly in Latin American regions. This comprehensive narrative review addresses the relationship between Human Papillomavirus (HPV) and cervical cancer, focusing on Latin American women. It explores molecular and immunological aspects of HPV infection, its role in cervical cancer development, and the epidemiology in this region, highlighting the prevalence and diversity of HPV genotypes. The impact of vaccination initiatives on cervical cancer rates in Latin America is critically evaluated. The advent of HPV vaccines has presented a significant tool in combating the burden of this malignancy, with notable successes observed in various countries, the latter due to their impact on immune responses. The review synthesizes current knowledge, emphasizes the importance of continued research and strategies for cervical cancer prevention, and underscores the need for ongoing efforts in this field.

Combination of Estrogen Receptor Alpha and Histological Type Helps to Predict Lymph Node Metastasis in Patients with Stage IA2 to IIA2 Cervical Cancer

Objective

This study aimed to identify a subset of patients with stage IA2 to IIA2 cervical cancer who are at low risk of lymph node metastasis (LNM) using pathological parameters including estrogen receptor alpha (ERα) and progesterone receptor (PR).

Methods

The clinical data of patients with stage IA2 to IIA2 cervical cancer who underwent radical surgery between 2014 and 2015 were retrospectively reviewed. Immunohistochemical staining was used to determine the expression of ERα and PR. A low-risk criterion for LNM was identified using logistic regression analysis, and its performance was estimated through receiver-operating characteristic curve analysis.

Results

Of 263 patients, 57 (21.7%) had pathological LNM. ERα (adjusted odds ratio [aOR], 7.582; 95% confidence interval [CI], 2.991–19.222; P < 0.001) and squamous cell carcinoma (aOR, 3.520; 95% CI, 1.887–6.568; P < 0.001) were identified as independent predictors for no LNM by multivariate logistic regression analysis, while PR had no effect on LNM. The rate of LNM was 1.4% for low-risk patients (n = 73) identified as ERα positive with squamous cell carcinoma. The 5-year disease-free survival in low-risk patients was significantly greater than in those negative for ERα and/or those with non-squamous cell carcinoma (96.9% vs 80.1%, P = 0.002).

Conclusion

ERα positivity and squamous cell carcinoma are associated with a low risk of LNM in patients with stage IA2 to IIA2 cervical cancer. Hence, those patients without a low risk of LNM could be considered for definitive chemoradiotherapy to avoid unnecessary surgery.

Vitamin A deficiency in K14E7HPV expressing transgenic mice facilitates the formation of malignant cervical lesions

Infection with high-risk human papillomavirus (HR-HPV) is the main cause of cervical cancer (CC), but viral infection alone does not guarantee the development of this malignancy. Indeed, deficiencies of dietary micronutrients could favor cervical cancer development in individuals that harbor HR-HPV infections. The status of retinoid levels, natural and synthetic derivatives of vitamin A, is important in maintaining cellular differentiation of the cervical epithelium. Moreover, many studies show a link between deficient intake of retinoids or alteration of the retinoid receptors and CC development. In spite of this, the effect of vitamin A deficiency (VAD) in presence of HR-HPV oncoproteins on cervical carcinogenesis in vivo has not been reported. Transgenic mice expressing E6 or E7 oncoproteins (K14E6 or K14E7 mice, respectively) were used to evaluate the possible role of VAD in the development of malignant cervical lesions. The survival of the mice in VAD condition was studied, and histopathological analysis and immunohistochemical detection of molecular cancer markers such as the tumor suppressor retinoic acid receptor beta (RARβ), proliferating cell nuclear antigen (PCNA), cleaved caspase 3, and the tumor suppressor protein p16^INK4A (inhibitor of CDK4) were performed. Our results show that K14E6/VAD mice showed moderate cervical dysplasia; notably, K14E7/VAD mice developed severe cervical dysplasia and cervical in situ carcinoma at an early age. VAD synergizes with HPV16E7 oncoprotein expression favoring cervical carcinogenesis in vivo.

SERMs suppresses the growth of ERα positive cervical cancer xenografts through predominant inhibition of extra-nuclear ERα expression

The role of estrogens and estrogen receptors (ER) in cervical cancer (CC) is not well established. However, epidemiological studies and abundant evidence from genetically engineered mouse models support such hypothesis. In this study, we have addressed estrogen responsiveness in a human CC cell line xenograft mouse model. We assessed the sensitivity of Ethynyl Estradiol (EE), SERMs (fulvestrant, MPP) and a non-SERM (EGCG) to competitively modulate the growth of ERα+^ve MS751 CC xenografts. We also checked the agonistic-antagonistic propensity of the above treatments to alter the histology of ovariectomised mouse uterine cervix. Chronic EE treatment encouraged the growth of ERα+^ve MS751 CC xenografts, while SERMs and EGCG significantly decreased tumor formation. SERMs were found to inhibit ERα expression, localized within cytoplasmic and membrane compartments. Conversely, ERα was not inducible and EE administration suppressed the growth of ERα-^ve HeLa CC xenografts. SERMs competitively induced atrophic features to uterine cervix, with MPP giving rise to mucinous metaplasia in the ectocervix. We have demonstrated that, estrogen sensitivity mediated through ERα has promoted CC tumorigenesis. This in turn was modulated by SERMs, predominantly through inhibition of extra-nuclear ERα expression. Though, induction of hyper-estrogenic status in the ectocervix, might underrate the utility of SERMs in ERα+^ve CC.

The vaginal and fecal microbiota of a murine cervical carcinoma model under synergistic effect of 17β-Estradiol and E7 oncogene expression

Cervical cancer is an important health issue worldwide. Many factors are related to this condition as the persistence of human papillomavirus (HPV) infection (e.g. type 16 and 18), the use of hormonal contraceptives for long periods of time, pH changes and bacterial vaginosis. The association between the microbiota and cervical human cancer is an interesting issue to be explored; given that environmental and hormonal factors may change the vaginal microbiota contributing to this condition. Our hypothesis was that changes in the microbiota diversity is associated with the development of cervical cancer. We evaluated the microbiota diversity in vaginal lavages and fecal samples at different stages of cervical cancer development in a mice model (K14HPV16E7) with type 16 E7 oncogene expression (E7), under continuous or not continuous stimulus of 17β-estradiol (E2) and compared it with a non-transgenic isogenic control (FVB) under same conditions. Our results indicate that continuous E2 administration during 6 months in the model with type 16 E7 expression causing development of cancer, is associated with significant changes in the microbiota diversity of the cervicovaginal lavages. Similar results were not observed in the same model when no E2 was administered to the mice. The FVB mice with no E7 expression which do not develop cervical cancer, did not show comparable changes in the microbiota diversity when E2 was administered during the same period. Normal evolution of the cervical epithelium and microbiota diversity were observed for the FVB mice with no E2 administration. Large changes in the microbiota diversity in fecal samples were not observed suggesting a specific organ effect of E7 expression associated to E2 on the vaginal microbiota.

WAPL induces cervical intraepithelial neoplasia modulated with estrogen signaling without HPV E6/E7

Since cervical cancer still afflicts women around the world, it is necessary to understand the underlying mechanism of cervical cancer development. Infection with HPV is essential for the development of cervical intraepithelial neoplasia (CIN). In addition, estrogen receptor signaling is implicated in the development of cervical cancer. Previously, we have isolated human wings apart-like (WAPL), which is expected to cause chromosomal instability in the process of HPV-infected precancerous lesions to cervical cancer. However, the role of WAPL in the development of CIN is still unknown. In this study, in order to elucidate the role of WAPL in the early lesion, we established WAPL overexpressing mice (WAPL Tg mice) and HPV E6/E7 knock-in (KI) mice. WAPL Tg mice developed CIN lesion without HPV E6/E7. Interestingly, in WAPL Tg mice estrogen receptor 1 (ESR1) showed reduction as compared with the wild type, but cell growth factors MYC and Cyclin D1 controlled by ESR1 expressed at high levels. These results suggested that WAPL facilitates sensitivity of ESR1 mediated by some kind of molecule, and as a result, affects the expression of MYC and Cyclin D1 in cervical cancer cells. To detect such molecules, we performed microarray analysis of the uterine cervix in WAPL Tg mice, and focused MACROD1, a co-activator of ESR1. MACROD1 expression was increased in WAPL Tg mice compared with the wild type. In addition, knockdown of WAPL induced the downregulation of MACROD1, MYC, and Cyclin D1 but not ESR1 expression. Furthermore, ESR1 sensitivity assay showed lower activity in WAPL or MACROD1 downregulated cells than control cells. These data suggested that WAPL increases ESR1 sensitivity by activating MACROD1, and induces the expression of MYC and Cyclin D1. Therefore, we concluded that WAPL not only induces chromosomal instability in cervical cancer tumorigenesis, but also plays a key role in activating estrogen receptor signaling in early tumorigenesis.

Solid fuel use for heating and risks of breast and cervical cancer mortality in China

BACKGROUND

Carcinogens released from indoor burning of solid fuels are believed to enter the bloodstream and to be metabolized in breast and cervical tissues. Little evidence exists about the relationship of solid fuel use from heating with breast and cervical cancer.

OBJECTIVES

To examine the association of solid heating fuel use with breast and cervical cancer mortality.

METHODS

This study included female participants aged 30-79 years who were enrolled in the China Kadoorie Biobank during 2004-2008 from 10 diverse regions across China. During a 10.2-year median follow-up, 177 breast cancer deaths and 113 cervical cancer deaths were documented. Multivariable Cox regression models yielded adjusted hazard ratios (HRs) for the associations of self-reported long-term heating fuel exposure with two cancer deaths. Stratified analyses were used to assess effect modification.

RESULTS

We included 236,116 participants for breast cancer analyses and 228,795 for cervical cancer analyses. Compared with non-solid fuel use, the fully adjusted HRs of cervical cancer deaths were 1.75 (0.91-3.38) for wood use, 2.23 (1.09-4.59) for mixed fuel (coal and wood) use. No evident relationship was observed for breast cancer deaths. Cervical cancer risk increased with the duration of solid fuel use (P for trend = 0.041). Elevated cervical cancer risk was observed in post-menopausal women (HR 2.01, 1.01-4.03), not in pre-menopausal women (HR 0.77, 0.56-2.31) (P for heterogeneity = 0.004); and in those aged ≥50 years (HR 2.56, 1.17-5.86), not in those aged < 50 years (HR 0.69, 0.26-1.84) (P < 0.001).

CONCLUSION

Indoor solid fuel combustion for heating may be associated with a higher risk for cervical cancer death, but not for breast cancer. The strength of the association increased with the duration of exposure and was modified by age and menopause status.

The Relationship between Estrogen-Related Signaling and Human Papillomavirus Positive Cancers

High risk-human papillomaviruses (HPVs) are known carcinogens. Numerous reports have linked the steroid hormone estrogen, and the expression of estrogen receptors (ERs), to HPV-related cancers, although the exact nature of the interactions remains to be fully elucidated. Here we will focus on estrogen signaling and describe both pro and potentially anti-cancer effects of this hormone in HPV-positive cancers. This review will summarize: (1) cell culture-related evidence, (2) animal model evidence, and (3) clinical evidence demonstrating an interaction between estrogen and HPV-positive cancers. This comprehensive review provides insights into the potential relationship between estrogen and HPV. We suggest that estrogen may provide a potential therapeutic for HPV-related cancers, however additional studies are necessary.

The multifarious roles of the chemokine CXCL14 in cancer progression and immune responses

The chemokine CXCL14 is a highly conserved, homeostatic chemokine that is constitutively expressed in skin epithelia. Responsible for immune cell recruitment and maturation, as well as impacting epithelial cell motility, CXCL14 contributes to the establishment of immune surveillance within normal epithelial layers. Furthermore, CXCL14 is critical to upregulating major histocompatibility complex class I expression on tumor cells. Given these important roles, CXCL14 is often dysregulated in several types of carcinomas including cervical, colorectal, endometrial, and head and neck cancers. Its disruption has been shown to limit critical antitumor immune regulation and is correlated to poor patient prognosis. However, other studies have found that in certain cancers, namely pancreatic and some breast cancers, overexpression of stromal CXCL14 correlates with poor patient survival due to increased invasiveness. Contributing to the ambiguity CXCL14 plays in cancer is that the native CXCL14 receptor remains uncharacterized, although several candidate receptors have been proposed. Despite the complexity of CXCL14 functions, it remains clear that this chemokine is a key regulatory factor in cancer and represents a potential target for future cancer immunotherapies.

Estrogen Attenuates the Growth of Human Papillomavirus-Positive Epithelial Cells

Human papillomaviruses cause around 5% of all human cancers, yet there are no specific antiviral therapeutic approaches available for combatting these cancers. These cancers are currently treated with standard chemoradiation therapy (CRT). Specific antiviral reagents are desperately required, particularly for HPV+HNSCC whose incidence is increasing and for which there are no diagnostic tools available for combatting this disease. Using data from The Cancer Genome Atlas (TCGA), we and others determined that the estrogen receptor alpha (ERα) is overexpressed in HPV+HNSCC and that elevated levels are associated with an improved disease outcome. This has led to the proposal that estrogen treatment could be a novel therapeutic approach for combatting HPV+cancers. Here, we demonstrate that estrogen attenuates the growth of HPV+epithelial cells using multiple mechanisms, supporting the idea that estrogen has potential as a therapeutic agent for the treatment of HPV+HNSCC.

Human papillomaviruses (HPVs) are small, double-stranded DNA viruses that are significant risk factors in the development of cancer, and HPV accounts for approximately 5% of all worldwide cancers. Recent studies using data from The Cancer Genome Atlas (TCGA) have demonstrated that elevated levels of estrogen receptor alpha (ERα) are associated with improved survival in oropharyngeal cancers, and these elevated receptor levels were linked with human papillomavirus-positive cancers (HPV+cancers). There has been a dramatic increase in HPV-related head and neck squamous cell carcinomas (HPV+HNSCCs) over the last 2 decades, and therapeutic options for this ongoing health crisis are a priority; currently, there are no antiviral therapeutics available for combatting HPV+cancers. During our TGCA studies on head and neck cancer, we had also discovered the overexpression of ERα in HPV+cancers. Here, we demonstrate that 17β-estradiol (estrogen) attenuates the growth/cell viability of HPV+cancers in vitro, but not HPV-negative cancer cells. In addition, N/Tert-1 cells (foreskin keratinocytes immortalized with human telomerase reverse transcriptase [hTERT]) containing human papillomavirus 16 (HPV16) have elevated levels of ERα and growth sensitivity after estrogen treatment compared with parental N/Tert-1 cells. Finally, we demonstrate that there are potentially two mechanisms contributing to the attenuation of HPV+ cell growth following estrogen treatment. First, estrogen represses the viral transcriptional long control region (LCR) downregulating early gene expression, including E6/E7. Second, expression of E6 and E7 by themselves sensitizes cells to estrogen. Overall, our results support the recent proposal that estrogen could be exploited therapeutically for the treatment of HPV-positive oral cancers.

IMPORTANCE Human papillomaviruses cause around 5% of all human cancers, yet there are no specific antiviral therapeutic approaches available for combatting these cancers. These cancers are currently treated with standard chemoradiation therapy (CRT). Specific antiviral reagents are desperately required, particularly for HPV+HNSCC whose incidence is increasing and for which there are no diagnostic tools available for combatting this disease. Using data from The Cancer Genome Atlas (TCGA), we and others determined that the estrogen receptor alpha (ERα) is overexpressed in HPV+HNSCC and that elevated levels are associated with an improved disease outcome. This has led to the proposal that estrogen treatment could be a novel therapeutic approach for combatting HPV+cancers. Here, we demonstrate that estrogen attenuates the growth of HPV+epithelial cells using multiple mechanisms, supporting the idea that estrogen has potential as a therapeutic agent for the treatment of HPV+HNSCC.

GPER Overexpression in Cervical Cancer Versus Premalignant Lesions: Its Activation Induces Different Forms of Cell Death

BACKGROUND

The effect of estrogen has been traditionally studied through the modulation of its alpha and beta nuclear receptors; however, the G Protein-Coupled Estrogen Receptor (GPER) has been recently involved in the pathology of numerous tumors. Although the study of GPER in cervical cancer has begun, its contribution still remains to be completely evaluated.

OBJECTIVE

The purpose of this work was to determine the expression of this receptor in different degrees of cervical lesions and whether the stimulation with its specific agonist (G-1) modulated mechanisms of cell survival or cell death in cervical cancer cells.

METHODS

Sections of 44 formalin-fixed paraffin-embedded blocks from patients were analyzed by automated immunohistochemistry. After the stimulation with G-1, proliferation was evaluated by the xCELLigence technology, the integrity of the mitochondrial membrane permeability by MitoCaptureTM fluorescence staining, apoptosis by flow cytometry, and senescence by the senescence-associated β-galactosidase kit.

RESULTS

GPER was widely expressed in cervical cancer but not in its precursor lesions. The staining was predominantly cytoplasmic, although it was also important in the nucleus of the epithelial cells. G-1 inhibited proliferation, decreased the mitochondrial permeability, and increased the percentage of apoptosis in SiHa, HeLa, and C-33A. Only in C-33A, an increase of the cells in necrosis was observed, whereas SiHa was the only cell line in which senescence was evidenced.

CONCLUSION

GPER is a receptor associated with cervical cancer that inhibits the growth and induces different mechanisms of death in cells derived from uterine cervical cancer. It suggests that GPER can be considered a pharmacological target that prevents the development of cervical carcinogenesis.

17β-estradiol and progesterone effect on human papillomavirus 16 positive cells grown as spheroid co-cultures

Human papillomavirus (HPV) is the key epidemiologic factor of cervical cancer, but additional cofactors are mandatory. Estrogen has been considered as one of those. Here, the aim was to study the effects of steroid hormones on HPV16 E6-E7, estradiol receptors ERα and ERβ, and progesterone receptor (PR) in HPV16-positive cervical carcinoma cell lines SiHa and CaSki grown as epithelial and fibroblast spheroid co-cultures. The spheroid co-cultures were exposured to 17β-estradiol or progesterone from day 7 onwards. mRNA levels of HPV16 E6-E7, ERα, ERβ and PR normalized against GAPDH were analyzed with quantitative reverse transcription-qPCR (RT-qPCR). 17β-estradiol and progesterone decreased HPV16 E6-E7 mRNA expression in CaSki and increased in SiHA co-cultures. In CaSki co-cultures, ERβ expression was blocked after 17β-estradiol exposure while in SiHa cells it slightly increased ERβ expression. PR expression was seen only in CaSki spheroids and it vanished after exposure to steroid hormones. Fibroblasts expressed all three hormone receptors as monolayers but ERβ expression decreased and ERα and PR vanished after co-culturing. Cell culturing platform changes both oncogene and hormone receptor expression in HPV16 positive cervical cancer cell lines. This needs to be considered when in vitro results are extrapolated to in vivo situations.

Why Human Papillomaviruses Activate the DNA Damage Response (DDR) and How Cellular and Viral Replication Persists in the Presence of DDR Signaling

Human papillomaviruses (HPV) require the activation of the DNA damage response (DDR) in order to undergo a successful life cycle. This activation presents a challenge for the virus and the infected cell: how does viral and host replication proceed in the presence of a DDR that ordinarily arrests replication; and how do HPV16 infected cells retain the ability to proliferate in the presence of a DDR that ordinarily arrests the cell cycle? This raises a further question: why do HPV activate the DDR? The answers to these questions are only partially understood; a full understanding could identify novel therapeutic strategies to target HPV cancers. Here, we propose that the rapid replication of an 8 kb double stranded circular genome during infection creates aberrant DNA structures that attract and activate DDR proteins. Therefore, HPV replication in the presence of an active DDR is a necessity for a successful viral life cycle in order to resolve these DNA structures on viral genomes; without an active DDR, successful replication of the viral genome would not proceed. We discuss the essential role of TopBP1 in this process and also how viral and cellular replication proceeds in HPV infected cells in the presence of DDR signals.

The G protein-coupled estrogen receptor (GPER/GPR30) may serve as a prognostic marker in early-stage cervical cancer

BACKGROUND

Estrogen signalling is transmitted via various receptors and multiple intracellular signalling pathways. Estrogen receptor alpha (ERα)-mediated transcription of target genes has been demonstrated to be closely linked to human papilloma virus (HPV)-induced carcinogenesis in case of cervical cancer. So far, the role of non-genomic estrogen signals in cervical cancer, e.g. transmitted by the G protein-coupled estrogen receptor (GPER) remains to be rather elusive. Today's knowledge on the role of GPER in cervical cancer is sparse and-to the best of our knowledge-GPER has not been investigated in context with clinicopathological parameters or prognosis of cervical cancer. Therefore, the current study investigated whether GPER is expressed in cervical cancer tissue. Further, GPER was correlated to clinicopathological parameters, tissue markers of cervical carcinogenesis and to patient overall and recurrence-free survival.

MATERIALS AND METHODS

Cervical cancer tissue was collected from 156 patients during surgery between 1993 and 2002. GPER immunostaining was performed on all the cases and correlated to clinicopathological data. More than half of all patients were diagnosed at advanced stage (FIGO II-IV 93/156; 59.6%) of disease. The large majority of patients presented with tumours of intermediate or high grade (G2-3 140/152, 92.1%). 22 cervical cancer-related deaths (22/156, 14.1%) were documented during the follow-up period.

RESULTS

GPER was detected in various subcellular staining patterns. In 129/156 (82.7%) cases GPER was expressed in the tumour cell cytoplasm (GPER^cyt). GPER immunopositivity at the cell membrane (GPER^mem) was found in 114/156 (73.1%) cases. While co-occurrence of both membrane and cytoplasmic staining (GPER^cyt + GPER^mem) was detected in the majority of tissue samples (101/156; 64.7%), only few cases (14/156, 9.0%) were classified as not expressing GPER at all. GPER^cyt was positively correlated with tumour grade. Statistical associations of GPER and both p16 and p53 were detected. Finally, immunopositivity of GPER^cyt was predictive for favourable overall as well as recurrence-free survival in cervical cancer of early stage (FIGO I).

CONCLUSION

This retrospective study reports GPER^cyt to be associated with improved overall and recurrence-free survival in early-stage cervical cancer. Further investigations are needed thus to determine whether this observation may be of clinical impact. Interestingly, Raloxifene-a GPER-activating selective estrogen receptor modulator-has recently been demonstrated to be preventive for cervical cancer relapse in mice. Whether this effect is only reliant on raloxifene blocking ERα or may also be related to activation of GPER remains to be determined.

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.

Conisation as a marker of persistent human papilloma virus infection and risk of breast cancer

BACKGROUND

Human papillomavirus (HPV) infection may increase breast cancer (BC) risk.

METHODS

To examine this, we used nationwide medical registries to identify all Danish women who underwent conisation to remove HPV-associated cervical precancerous lesions (n=87 782) from 1978 to 2013. We computed the absolute risk of BC and standardised incidence ratios (SIRs) and 95% confidence intervals (95% CIs) for breast cancer, based on national breast cancer incidence rates.

RESULTS

Conisation was associated with slightly increased BC incidence (SIR=1.1, 95% CI=1.0-1.1), and an absolute BC risk of 7.7% (95% CI=7.3-8.1%) in 35.9 years of follow-up. BC risk was elevated throughout follow-up, especially in the first 5 years (<1 year: SIR=1.2, 95% CI=0.92-1.5; 1-5 years: SIR=1.2, 95% CI=1.1-1.3; ⩾5 years: SIR=1.1, 95% CI=1.0-1.1). Women who underwent conisation and had autoimmune disease had elevated BC risk after 5 years of follow-up (SIR=1.4, 95% CI=1.0-1.8).

CONCLUSIONS

BC risk is slightly elevated in women with persistent HPV infection, possibly due to detection bias.

Murine Double-Minute 2 Homolog Single Nucleotide Polymorphisms 285 and 309 in Cervical Carcinogenesis

Background and Objective

In Caucasians, the MDM2 single nucleotide polymorphism (SNP) 285 G>C (rs117039649) neutralizes the effect of 309 T>G (rs2279744), which increases MDM2 expression and impairs the p53 pathway. In this study, we examined the distribution of these two SNPs in Polish women with squamous cell carcinoma (SCC) (n = 379), adenocarcinoma (n = 59) and other cervical tumor types (n = 18).

Methods

The polymerase chain reaction-restriction fragment length polymorphism technique and DNA sequencing were employed in our study.

Results

The P trend value calculated for the MDM2 285 G>C polymorphism was statistically significant (P_trend = 0.016) for SCC. Using logistical regression analysis adjusted for the effect of age, pregnancy, oral contraceptive use, tobacco smoking, and menopausal status, we observed that the MDM2 285 G>C SNP protected against SCC, with an adjusted odd ratio (OR) for the C carriers versus G/G genotype of 0.536 (P = 0.019). Stratified analyses of MDM2 285 G>C revealed a protective role of the C allele against SCC in women with a positive history of oral contraceptive use (age-adjusted OR 0.413, P = 0.021) and in premenopausal women (age-adjusted OR 0.362, P = 0.022). We also found that the 285GG/309GG vs 285GG/309 TT genotype increased the risk of SCC (adjusted OR 1.890, P = 0.005). However, the 285CC/309GG + 285GC/309GG versus 285GG/309GG genotype reduced the risk of SCC (adjusted OR 0.311, P = 0.004).

Conclusion

Our results demonstrate that the MDM2 285C gene variant and 285CC/309GG + 285GC/309GG genotypes protect against SCC, most likely by neutralizing the effect of the 309 T>G SNP. The 285GG/309GG genotype increases the risk of SCC possibly due to increased MDM2 expression.

Electronic supplementary material

The online version of this article (doi:10.1007/s40291-015-0153-4) contains supplementary material, which is available to authorized users.

Model systems to study the life cycle of human papillomaviruses and HPV-associated cancers

The prevalent human papillomaviruses (HPVs) infect either cutaneous or mucosal epithelium. Active Infections lead to epithelial hyperprolifeation and are usually cleared in healthy individuals within a year. Persistent infections in the anogenital tracts by certain high-risk genotypes such as HPV-16, HPV-18 and closely related types, can progress to high grade dysplasias and carcinomas in women and men, including cervical, vulva, penile and anal cancers. A significant fraction of the head and neck cancers are also caused by HPV-16. The viral oncogenes responsible for neoplastic conversion are E6 and E7 that disrupt the pathways controlled by the two major tumor suppressor genes, p53 and members of pRB family. Because HPV cannot be propagated in conventional submerged monolayer cell cultures, organotypic epithelial raft cultures that generate a stratified and differentiated epithelium have been used to study the viral life cycle. This article describes several systems to examine aspects of the viral productive phase, along with the advantages and limitations. Animal model systems of HPV carcinogenesis are also briefly described.

Human papillomavirus induced transformation in cervical and head and neck cancers

Human papillomavirus (HPV) is one of the most widely publicized and researched pathogenic DNA viruses. For decades, HPV research has focused on transforming viral activities in cervical cancer. During the past 15 years, however, HPV has also emerged as a major etiological agent in cancers of the head and neck, in particular squamous cell carcinoma. Even with significant strides achieved towards the screening and treatment of cervical cancer, and preventive vaccines, cervical cancer remains the leading cause of cancer-associated deaths for women in developing countries. Furthermore, routine screens are not available for those at risk of head and neck cancer. The current expectation is that HPV vaccination will prevent not only cervical, but also head and neck cancers. In order to determine if previous cervical cancer models for HPV infection and transformation are directly applicable to head and neck cancer, clinical and molecular disease aspects must be carefully compared. In this review, we briefly discuss the cervical and head and neck cancer literature to highlight clinical and genomic commonalities. Differences in prognosis, staging and treatment, as well as comparisons of mutational profiles, viral integration patterns, and alterations in gene expression will be addressed.