The oncogenic potential of human papillomaviruses: a review on the role of host genetics and environmental cofactors

Unraveling molecular mechanisms of Head and neck cancer

Malignancies that develop from mucosal epithelium of the upper aerodigestive tract are known as head and neck squamous cell carcinomas (HNSCC). Heterogeneity, late stage diagnosis and high recurrence rate are big hurdles in head and neck treatment regimen. Presently, the biomarkers available for diagnosis and prognosis of HNSCC are based on smoking as the major risk habit. This review shed light on the differential environment of HNSCC in smokeless tobacco consuming Indian patients. Frequent mutation in genes involved in DNA repair pathway (p53), cell proliferation (PIK3CA, HRAS) and cell death (CASP8, FADD) are common in western population. On the contrary, the genes involved in metastasis (MMPs, YAP1), lymphocyte proliferation (TNFRSF4, CD80), cell-cell adhesion (DCC, EDNRB), miRNA processing (DROSHA) and inflammatory responses (TLR9, IL-9) are mutated in Indian HNSCC patients. Gene ontology enrichment analysis highlighted that responses to chemical stimulus, immune pathways and stress pathways are highly enriched in Indian patients.

Immunogenicity of a Two-Dose Human Papillomavirus Vaccine Schedule in HIV-Infected Adolescents with Immune Reconstitution

HIV-infected patients are at increased risk of human papillomavirus (HPV) acquisition and HPV-associated diseases. This study set out to determine whether a two-dose (2D) HPV vaccination schedule was sufficient in HIV-infected adolescents with immune reconstitution (IR) following antiretroviral treatment. Participants aged 9–15 years who had CD4 cell counts > 500 cells/mm³ and HIV-1 RNA < 40 copies/mL for at least one year were assigned to the 2D schedule, while older participants or those without IR received a three-dose (3D) schedule. Antibodies to HPV-16 and -18 were measured using a pseudovirion-based neutralization assay. A total of 96 subjects were enrolled; 31.3% and 68.7% received the 2D and 3D schedule, respectively. Of these, 66.7% and 57.6% of the 2D and 3D participants, respectively, were male. The seroconversion rates for HPV-16 and HPV-18 were 100% in all cases, except for HPV-18 in males who received the 3D schedule (97.4%). In males, the anti-HPV-16 geometric mean titers (GMTs) were 6859.3 (95% confidence interval, 4394.3–10,707.1) and 7011.1 (4648.8–10,573.9) in the 2D and 3D groups (p = 0.946), respectively, and the anti-HPV-18 GMTs were 2039.3 (1432.2–2903.8) and 2859.8 (1810.0–4518.4) in the 2D and 3D (p = 0.313) groups, respectively. In females, the anti-HPV-16 GMTs were 15,758.7 (8868.0–28,003.4) and 26,241.6 (16,972.7–40,572.3) in the 2D and 3D groups (p = 0.197), respectively, and the anti-HPV-18 GMTs were 5971.4 (3026.8–11,780.6) and 9993.1 (5950.8–16,781.1) in the 2D and 3D groups (p = 0.271), respectively. In summary, a 2D schedule is as immunogenic in young adolescents with IR as a 3D schedule in older subjects and those without IR.

The prevalence of human leucocyte antigen and human papillomavirus DNA in penile intraepithelial neoplasia in England 2011-2012

BACKGROUND

The pathogenesis of penile intraepithelial neoplasia (PeIN) is unclear but human papillomavirus (HPV) infection and polymorphisms in human leucocyte antigen (HLA).

OBJECTIVES

To examine the prevalence of HPV DNA and HLA in PeIN.

METHODS

Adult Caucasian men with a clinical and histological diagnosis of PeIN, that is, Bowenoid papulosis (BP), Bowen's disease of penis (BDP) and erythroplasia of Queyrat (EQ) were selected and phenotyped from the clinical records. DNA was extracted from blood and paraffin-embedded sections for HLA and HPV typing, respectively. Human leucocyte antigen allele frequencies were compared with those derived from the UK-based Caucasian population.

RESULTS

Seventy-two cases of PeIN (20 BP, 34 BDP and 18 EQ) were studied. Human papillomavirus DNA was identified in 65/72 (90.2%) PeIN; Alphapapillomavirus types were detected in 62/72 (85%) followed by Betapapillomavirus types in 9/72 (12.5%) and cutaneous types in 7/72 (9.7%); HPV16 was the most prevalent genotype at 35/72 (48.6%) followed by HPV33 at 7/72 (9.7%); multiple infections were seen in 18/72 (25%) PeIN. HLA-C*15 (Bonferroni corrected p = 0.049) confers susceptibility to PeIN, whereas HLA-DQA1*01 (corrected p = 0.02) protects against PeIN. HPV16-associated PeIN cases showed no statistically significant association with HLA genotype after multiple corrections.

CONCLUSION

Human papillomavirus is involved in the pathogenesis of PeIN. Immunogenotype may play a role in the pathogenesis of PeIN.

Immunogenetics and human papillomavirus (HPV) in male genital lichen sclerosus (MGLSc)

BackgroundThe pathogenesis of male genital lichen sclerosus (MGLSc) is controversial. Incriminated factors include infection with human papillomavirus (HPV) and autoimmunity (e.g. Human Leukocyte Antigen [HLA]). To address the roles of HLA and HPV in MGLSc we studied adult Caucasian males with a clinical and histological diagnosis of MGLSc. The men in the study attended two specialised Male Genital Dermatoses Clinics between July 2011 and September 2012 and were selected and phenotyped from the clinical records. DNA was extracted from blood and paraffin-embedded biopsy sections, for HLA and HPV typing, respectively. HLA allele frequencies were compared with those derived from the UK-based Caucasian population. Eighty-eight cases of MGLSc were identified. HPV DNA was detected in 33/88 (37.5%) cases of MGLSc. HPV16 was the most prevalent type found: 11/88 (12.5%) MGLSc. No statistically significant HLA associations were established but HLA-B*35, -B*51, -C*15, -DRB1*04, -DRB1*10 (predisposition) and -DQA1*01 (protection) were revealed as alleles of interest. HPV16-associated MGLSc cases showed no statistically significant association with HLA genotype. The relationship between HPV and MGLSc suggests a passenger effect rather than a pathogenic role. HLA is not associated with MGLSc nor co-existent HPV16.

Detecting Ureaplasma urealyticum among HIV-infected women with or without human papillomavirus using real-time PCR with the ANYPLEX™ II STI-7 assay system

Objectives

Human immunodeficiency virus (HIV) infections increase the chances of women contracting human papillomavirus (HPV), the prime causative agent of cervical cancer. Additionally, Ureaplasma urealyticum is the most frequent pathogen prevailing in sexually transmitted diseases in HIV-infected women. The aim of this study was to determine the presence of U. urealyticum among HIV-infected women with or without HPV in Ghana.

Methods

DNA samples were extracted from cervico-vaginal swabs obtained from 96 HIV-infected women attending the Kumasi South Hospital. U. urealyticum in the DNA samples was detected by real-time PCR with the Anyplex™ II STI-7 detection assay. Microsoft Excel was used to analyze the data, and the Chi-square test was used to determine associations and dependence among the variables.

Results

Among the study population, 93.75% (90/96) were positive for at least one pathogen.In total, 36.5% (35/96) of the women were infected by U. urealyticum, with 30.21% (29/96) being co-infected with HPV. There was no significant association (95% CI, p > 0.05) between U. urealyticum and HPV status among the HIV-infected women.

Conclusion

U. urealyticum and HPV are highly pathogenic, and their prevalence in this study reiterates the need for their routine screening in HIV-infected patients.

New Insights in the Pathogenesis of HPV Infection and the Associated Carcinogenic Processes: The Role of Chronic Inflammation and Oxidative Stress

Human papillomavirus (HPV) is a small double-stranded DNA virus with tropism for epithelial cells. To this date, over 150 genotypes are known and are classified into two major groups, low-risk and high-risk strains, depending on the ability of the virus to induce malignant transformation. The host's immunity plays a central role in the course of the infection; therefore, it may not be clinically manifest or may produce various benign or malignant lesions. The pathogenic mechanisms are complex and incompletely elucidated. Recent research suggests the role of chronic inflammation and oxidative stress (OS) in the pathogenesis of HPV infection and the associated carcinogenic processes. Chronic inflammation induces OS, which in turn promotes the perpetuation of the inflammatory process resulting in the release of numerous molecules which cause cell damage. Reactive oxygen species exert a harmful effect on proteins, lipids, and nucleic acids. Viral oncogenes E5, E6, and E7 are involved in the development of chronic inflammation through various mechanisms. In addition, HPV may interfere with redox homeostasis of host cells, inducing OS which may be involved in the persistence of the infection and play a certain role in viral integration and promotion of carcinogenesis. Knowledge regarding the interplay between chronic inflammation and OS in the pathogenesis of HPV infection and HPV-induced carcinogenesis has important consequences on the development of new therapeutic strategies.

Upregulation of PIR gene expression induced by human papillomavirus E6 and E7 in epithelial oral and cervical cells

The hallmark of high-risk human papillomavirus (HR-HPV)-related carcinogenesis is E6 and E7 oncogene overexpression. The aim of this work was to characterize epithelial oral and cervical cancer cells that express HR-HPV E6 and E7 oncoproteins. Transcriptomic assay using DNA microarrays revealed that PIR gene expression was detected in oral cells in an HR-HPV E6/E7-dependent manner. In addition, PIR was overexpressed in HPV-positive SiHa and Ca Ski cells, whereas it was undetectable in HPV-negative C33A cells. The PIR expression was dependent on functional HR-HPV E6 and E7 oncoproteins even though the E7 oncoprotein had higher activity to induce PIR overexpression in comparison with E6. In addition, using an siRNA for PIR silencing in oral cells ectopically expressing HR-HPV E6/E7, there was a significant increase in E-cadherin transcripts and a decrease in Vimentin, Slug, Zeb and Snail transcripts, suggesting that HR-HPV-induced PIR overexpression is involved in epithelial–mesenchymal transition. Furthermore, migration of PIR-silenced cells was significantly decreased. Finally, using inhibitors of some specific pathways, it was found that EGFR/ERK and PI3 K/AKT signalling pathways are important for E7-mediated PIR overexpression. It can be concluded that PIR gene expression is highly dependent on the expression of HR-HPV oncoproteins and is important for EMT regulation.

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.

Viral Interplay with the Host Sumoylation System

Viruses have evolved elaborate means to regulate diverse cellular pathways in order to create a cellular environment that facilitates viral survival and reproduction. This includes enhancing viral macromolecular synthesis and assembly, as well as preventing antiviral responses, including intrinsic, innate, and adaptive immunity. There are numerous mechanisms by which viruses mediate their effects on the host cell, and this includes targeting various cellular post-translational modification systems, including sumoylation. The wide-ranging impact of sumoylation on cellular processes such as transcriptional regulation, apoptosis, stress response, and cell cycle control makes it an attractive target for viral dysregulation. To date, proteins from both RNA and DNA virus families have been shown to be modified by SUMO conjugation, and this modification appears critical for viral protein function. More interestingly, members of the several viral families have been shown to modulate sumoylation, including papillomaviruses, adenoviruses, herpesviruses, orthomyxoviruses, filoviruses, and picornaviruses. This chapter will focus on mechanisms by which sumoylation both impacts human viruses and is used by viruses to promote viral infection and disease.

Oncogenic Role of Tumor Viruses in Humans

Viruses are the intracellular pathogens that reproduce only in the living cell and manipulate the cellular machinery to produce more viruses. Viral replications can affect cellular genes of the host in multiple cancerous ways. Approximately, 20% of all human oncogenesis is caused by cancer-causing viruses known as oncoviruses. Viral infection causes chronic inflammation leading to cell death, uncontrollable proliferation, and modulated expression of some of the regulatory proteins. Oncogenesis is a multistep phenomenon in which normal host cells are transformed into cancerous cells on the basis of host genetic variability. Oncogenic viruses encode genes that cause viral replication and transformation of the host cells to produce viral proteins and protein complexes. The phenomenon from basic viral infection to tumorigenesis is lengthy due to the involvement of factors like immunity complications, cellular mutations, and exposure to other cancerous agents. The viruses that are involved in human cancer development are Hepatitis B virus (HBV), Hepatitis C virus (HCV), Epstein-Barr virus (EBV), Human papilloma virus (HPV), Kaposi's sarcoma herpes virus (KSHV), and Human T lymphotrophic virus 1 (HTLV-1). This review article summarizes advanced knowledge related to human oncogenic viruses and the molecular mechanisms that lead to tumorigenesis in humans.

Phase II studies to select the formulation of a multivalent HPV L1 virus-like particle (VLP) vaccine

Our objective was to develop a multivalent prophylactic HPV vaccine that protects against infection and disease caused by HPV16/18 (oncogenic types in existing prophylactic vaccines) plus additional oncogenic types by conducting 3 Phase II studies comparing the immunogenicity (i.e., anti-HPV6/11/16/18 geometric mean titers [GMT]) and safety of 7 vaccine candidates with the licensed quadrivalent HPV6/11/16/18 vaccine (qHPV vaccine) in young women ages 16-26. In the first study (Study 1), subjects received one of 3 dose formulations of an 8-valent HPV6/11/16/18/31/45/52/58 vaccine or qHPV vaccine (control). In Study 2, subjects received one of 3 dose formulations (termed low-, mid-, and high-dose formulations, respectively) of a 9-valent HPV6/11/16/18/31/33/45/52/58 vaccine (9vHPV vaccine) or qHPV vaccine (control). In Study 3, subjects concomitantly received qHPV vaccine plus 5-valent HPV31/33/45/52/58 or qHPV vaccine plus placebo (control). All vaccines were administered at day 1/month 2/month 6. In studies 1 and 3, anti-HPV6/11/16/18 GMTs at month 7 were non-inferior in the experimental arms compared with the control arm; however, there was a trend for lower antibody responses for all 4 HPV types. In Study 2, this immune interference was overcome with the mid- and high-dose formulations of the 9vHPV vaccine by increasing antigen and adjuvant doses. In all 3 studies, all vaccine candidates were strongly immunogenic with respect to HPV31/33/45/52/58 and were well tolerated. Based on the totality of the results, the middle dose formulation of the 9vHPV vaccine was selected for Phase III evaluation. Each 0.5mL dose contains 30μg/40μg/60μg/40μg/20μg/20μg/20μg/20μg/20μg of HPV6/11/16/18/31/33/45/52/58 virus-like particles, and 500μg of amorphous aluminum hydroxyphosphate sulfate adjuvant.ClinicalTrials.gov numbers NCT00260039, NCT00543543, and NCT00551187.

HLA Immunogenotype Determines Persistent Human Papillomavirus Virus Infection in HIV-Infected Patients Receiving Antiretroviral Treatment

A proportion of human immunodeficiency virus (HIV)-infected patients develop persistent, stigmatizing human papillomavirus (HPV)-related cutaneous and genital warts and anogenital (pre)cancer. This is the first study to investigate immunogenetic variations that might account for HPV susceptibility and the largest to date to categorize the HPV types associated with cutaneous warts in HIV-positive patients. The HLA class I and II allele distribution was analyzed in 49 antiretroviral (ART)-treated HIV-positive patients with persistent warts, 42 noninfected controls, and 46 HIV-positive controls. The allele HLA-B*44 was more frequently identified in HIV-positive patients with warts (P = .004); a susceptible haplotype (HLA-B*44, HLA-C*05; P = .001) and protective genes (HLA-DQB1*06; P = .03) may also contribute. Cutaneous wart biopsy specimens from HIV-positive patients harbored common wart types HPV27/57, the unusual wart type HPV7, and an excess of Betapapillomavirus types (P = .002), compared with wart specimens from noninfected controls. These findings suggest that HLA testing might assist in stratifying those patients in whom vaccination should be recommended.

Different effects of H2O2 treatment on cervical squamous carcinoma cells and adenocarcinoma cells

INTRODUCTION

This study aims to compare the antioxidant abilities of cervical squamous carcinoma cells and cervical adenocarcinoma cells and to study the related mechanisms.

MATERIAL AND METHODS

Cervical squamous carcinoma and adenocarcinoma cells were treated with H2O2. Cell proliferation was determined with the MTT assay. The reactive oxygen species (ROS) level was detected by the 2',7'-dichlorofluorescein-diacetate (DCFH-DA) method. The 5,5'-dithiobis-2-nitrobenzoic acid (DTNB) method was performed to measure intracellular concentrations of reduced glutathione (GSH) and oxidized glutathione (GSSG). The nitrite formation method, the molybdate colorimetric method, and the DTNB colorimetric method were used to determine activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), respectively.

RESULTS

Compared with untreated control cells, cell proliferation of cervical squamous carcinoma cells and cervical adenocarcinoma cells was significantly inhibited by H2O2 treatment (p < 0.05). Reactive oxygen species levels and GSSG levels were significantly increased (p < 0.01), whereas GSH levels were significantly decreased (p < 0.05 or 0.01) in both cells after H2O2 treatment. Thus the ratio of GSH/GSSG was significantly decreased by H2O2 treatment in both cells (p < 0.01). In addition, H2O2 treatment significantly increased activities of SOD, CAT, and GPx in both cells (p < 0.05 or 0.01). Furthermore, the above-mentioned changes induced by H2O2 treatment were more dramatic in cervical squamous carcinoma cells.

CONCLUSIONS

The antioxidant ability of cervical squamous carcinoma cells is lower than that of cervical adenocarcinoma cells, which may be related to the increased ROS levels in cervical squamous carcinoma cells induced by H2O2 treatments.

Human papillomavirus vaccination in HIV-infected women: need for increased coverage

Human immunodeficiency virus (HIV)-infected women carry a significant burden on human papillomavirus (HPV) infection and associated diseases. As HIV-infected individuals are living longer, the prevalence of HPV infection is rising and HPV-associated cytological abnormalities remain high despite successful treatments of HIV infection. Several HPV vaccines are currently available and recommended for adolescents and adults up to age 26. The vaccines are safe, immunogenic and effective in preventing diseases due to HPV types included in the vaccines, particularly among persons without prior HPV exposure. This review summarizes available data on the use of the HPV vaccines among HIV-infected women. The immunogenicity and safety of the vaccines are highlighted and in particular, barriers to vaccination among HIV-infected women are discussed.

Immunology and Immunotherapy of Head and Neck Cancer

The immune system plays a key role in the development, establishment, and progression of head and neck squamous cell carcinoma (HNSCC). A greater understanding of the dysregulation and evasion of the immune system in the evolution and progression of HNSCC provides the basis for improved therapies and outcomes for patients. HNSCC cells evade the host immune system through manipulation of their own immunogenicity, production of immunosuppressive mediators, and promotion of immunomodulatory cell types. Through the tumor's influence on the microenvironment, the immune system can be exploited to promote metastasis, angiogenesis, and growth. This article provides a brief overview of key components of the immune infiltrating cells in the tumor microenvironment, reviewing immunological principles related to head and neck cancer, including the concept of cancer immunosurveillance and immune escape. Current immunotherapeutic strategies and emerging results from ongoing clinical trials are presented.

Functional implications of mitochondrial reactive oxygen species generated by oncogenic viruses

Between 15-20% of human cancers are associated with infection by oncogenic viruses. Oncogenic viruses, including HPV, HBV, HCV and HTLV-1, target mitochondria to influence cell proliferation and survival. Oncogenic viral gene products also trigger the production of reactive oxygen species which can elicit oxidative DNA damage and potentiate oncogenic host signaling pathways. Viral oncogenes may also subvert mitochondria quality control mechanisms such as mitophagy and metabolic adaptation pathways to promote virus replication. Here, we will review recent progress on viral regulation of mitophagy and metabolic adaptation and their roles in viral oncogenesis.

Concomitant anal and cervical human papillomavirusV infections and intraepithelial neoplasia in HIV-infected and uninfected women

OBJECTIVE

To assess factors associated with concomitant anal and cervical human papillomavirus (HPV) infections in HIV-infected and at-risk women.

DESIGN

A study nested within the Women's Interagency HIV Study (WIHS), a multicenter longitudinal study of HIV-1 infection in women conducted in six centers within the United States.

METHODS

Four hundred and seventy HIV-infected and 185 HIV-uninfected WIHS participants were interviewed and examined with anal and cervical cytology testing. Exfoliated cervical and anal specimens were assessed for HPV using PCR and type-specific HPV testing. Women with abnormal cytologic results had colposcopy or anoscopy-guided biopsy of visible lesions. Logistic regression analyses were performed and odds ratios (ORs) measured the association for concomitant anal and cervical HPV infection.

RESULTS

One hundred and sixty-three (42%) HIV-infected women had detectable anal and cervical HPV infection compared with 12 (8%) of the HIV-uninfected women (P  <  0.001). HIV-infected women were more likely to have the same human papillomavirus (HPV) genotype in the anus and cervix than HIV-uninfected women (18 vs. 3%, P  < 0.001). This was true for both oncogenic (9 vs. 2%, P  =  0.003) and nononcogenic (12 vs. 1%, P < 0.001) HPV types. In multivariable analysis, the strongest factor associated with both oncogenic and nononcogenic concomitant HPV infection was being HIV-infected (OR = 4.6 and OR  = 16.9, respectively). In multivariable analysis of HIV-infected women, CD4 cell count of less than 200 was the strongest factor associated with concomitant oncogenic (OR  = 4.2) and nononcogenic (OR  =  16.5) HPV infection.

CONCLUSION

HIV-infected women, particularly those women with low CD4 cell counts, may be good candidates for HPV screening and monitoring for both cervical and anal disease.

Merkel cell polyomavirus-positive Merkel cell carcinoma cells do not require expression of the viral small T antigen

Increasing evidence suggests that Merkel cell carcinoma (MCC) is caused by the Merkel cell polyomavirus (MCV). The viral sequence encodes for two potential oncoproteins, i.e., the small T antigen (sT) and the large T antigen (LT). Indeed, sT has recently been shown to bear transforming activity. Here, we confirm this observation by demonstrating focus formation upon expression of MCV sT in NIH3T3 fibroblasts. On the other hand, however, we provide evidence that established MCC cells do not require sT for growth and survival. Silencing of sT protein expression by two different sT-specific short hairpin RNAs (shRNAs) leads to variable degrees of growth retardation in MCV-positive MCC cell lines. However, these effects are not sT specific, as proliferation of MCV-negative cell lines is similarly affected by these sT shRNAs. Furthermore, ectopic expression of shRNA-insensitive sT does not revert the growth inhibition implicated by sT silencing. Finally, the unambiguous and specific growth inhibition induced by means of an shRNA targeting both T antigens, can be completely rescued by ectopic expression of LT alone, thus demonstrating a dispensable role of sT. Altogether, our results indicate that MCV LT is more relevant in maintaining the proliferation and survival of established MCC cell lines.

Adult recurrent respirator papillomatosis: a new therapeutic approach with pegylated interferon alpha 2a (Peg-IFNα-2a) and GM-CSF

OBJECTIVE

To determine a new therapeutic approach using granulocyte monocyte-colony-stimulating factor (GM-CSF) and pegylated interferon alpha 2a (Peg-IFNα-2a) as adjuvant therapy in patients with adult recurrent respiratory papillomatosis.

STUDY DESIGN

Descriptive observational clinical trial.

SETTING

Departments of Otolaryngology and Immunology.

METHODS

Fourteen patients with adult recurrent respiratory papillomatosis were examined regarding medical history and number of operations before and after treatment. Voice disorder and glottal stop were evaluated using the Voice-Related Quality-of-Life instrument. Papilloma staging was determined using the Coltera/Derkay diagram. The patients received Peg-IFNα-2a at 180 mcg weekly for 6 months. In the third month, the patients began GM-CSF treatment at 400 mcg weekly for 2 months. The patients were observed for 12 months after treatment ended.

RESULTS

Eleven patients met the study criteria; 3 patients had tracheotomies before treatment, and they were decannulated after treatment. Before treatment, the scale of voice quality ranged from 34 to 45 points (mean, 38.31). After treatment, the range was 12 to 35 points (mean, 21.09; P < .001). Prior to therapy, the glottal stop ranged from 50% to 90% (average, 62.27%). After therapy, the range decreased to 0% to 15% (mean, 4.63%; P < .001). The number of surgical interventions decreased. Two patients each had 1 surgical intervention after treatment began.

CONCLUSION

A new adjuvant treatment based on immunogenetic mechanisms against human laryngeal papilloma virus, with expectations of reducing disease aggressiveness and the number of operations, avoids the risks of surgery.

IMPLICATION FOR PRACTICE

Peg-IFNα-2a and GM-CSF is an adjuvant therapy for treating adult recurrent respiratory papillomatosis.

Epidermoid cancer of the anal canal

Anal canal cancer is a rare cancer with incidence that continues to rise. This has been in large part due to increased prevalence of immunosuppressed conditions such as organ transplantation and human immunodeficiency virus along with transmission of the human papillomavirus. Identification of high-risk groups and close monitoring of these groups can help to detect earlier stages of cancer. Chemoradiation therapy remains the mainstay of treatment with excellent outcomes. Surgery for anal canal carcinoma remains as a salvage technique for failed chemoradiation or recurrent disease.

Immunosuppressive tumor microenvironment in cervical cancer patients

Cervical cancer is caused by Human papillomavirus (HPV) in virtually all cases. These HPV-induced cancers express the viral oncogenes E6 and E7 and are therefore potentially recognized by the immune system. Despite the abundant presence of these foreign antigens, the immune system is unable to cope with the tumor. Due to the constant immunological pressure, cervical cancers can evolve different immune evasion strategies, which will be described in the current review. Several approaches for immunotherapy of cervical cancer are currently under development, which aim at inducing strong HPV-specific immunity. Besides the reinforcement of potent anti-tumor immune responses, immunotherapy could also enhance HPV-specific T regulatory cells. Supplementary strategies that neutralize an immunosuppressive milieu may have great potential. These strategies are discussed as well.

Exploiting the therapeutic potential of microRNAs in viral diseases: expectations and limitations

New therapeutic approaches are urgently needed for serious diseases, including cancer, cardiovascular diseases, viral infections, and others. A recent direction in drug development is the utilization of nucleic acidbased therapeutic molecules, such as antisense oligonucleotides, ribozymes, short interfering RNA (siRNA), and microRNA (miRNA). miRNAs are endogenous, short, non-coding RNA molecules. Some viruses encode their own miRNAs, which play pivotal roles in viral replication and immune evasion strategies. Conversely, viruses that do not encode miRNAs may manipulate host cell miRNAs for the benefits of their replication. miRNAs have therefore become attractive tools for the study of viral pathogenesis. Lately, novel therapeutic strategies based on miRNA technology for the treatment of viral diseases have been progressing rapidly. Although this new generation of molecular therapy is promising, there are still several challenges to face, such as targeting delivery to specific tissues, avoiding off-target effects of miRNAs, reducing the toxicity of the drugs, and overcoming mutations and drug resistance. In this article, we review the current knowledge of the role and therapeutic potential of miRNAs in viral diseases, and discuss the limitations of these therapies, as well as strategies to overcome them to provide safe and effective clinical applications of these new therapeutics.

IGF1 mRNA isoform expression in the cervix of HPV-positive women with pre-cancerous and cancer lesions

Human papillomavirus (HPV) plays a crucial role in cervical cancer etiology. However, not all HPV-infected women develop cancer, indicating that additional cellular factors facilitate carcinogenesis. The aim of this study was to analyze the expression profile of insulin-like growth factor 1 (IGF1) isoforms in the context of FOX2, SP1 and IGF1 receptor (IGF1R) expression during HPV-dependent cervical carcinogenesis. One hundred and nine epithelial tissue samples from women with pre-cancerous and cancer lesions of the cervix were analyzed. HPV DNA was identified by PCR, and real-time PCR was used to quantify the expression levels of the analyzed genes. All IGF1 mRNA splicing isoforms were up-regulated in pre-cancerous cells, and a shift in the balance towards mitogenic IGF1Eb was observed in the cancer samples. IGF1 expression was controlled mainly by the P1 promoter, and an increase in P2 usage was observed in the cancer. Correlations between IGF1 mRNA splicing isoforms and the FOX2 splicing factor, as well as P1/P2 activity and SP1 transcription factor expression levels were detected. No correlation was observed between the expression of IGF1 and its receptor IGF1R. Our results suggest that IGF1, in particular its splicing profile, may be an additional prognostic factor in cervical carcinogenesis.