Cancer of the uterine cervix and human papillomavirus infection

Human papillomaviruses (HPVs) have emerged as the principal sexually transmitted causal agents in the development of cancer of the uterine cervix in women. They also cause a variety of benign lesions, warts, intraepithelial neoplasia and anogenital, oral and pharyngeal papillomas. Presently, more than 100 HPV genotypes have been identified in humans, and about one-third of them have been sequenced. Of these, while HPV types 16 and 18 are considered to be the high-risk types, HPV 6 and 11 are the low-risk types in the development of cervical cancer. Evidence for causal role of HPV in the development of cervical neoplasia comes from the etiological and epidemiological observations together with the experimental findings of the molecular pathways elicited by HPV-transforming genes. Further evidence in favour of papillomavirus as the carcinoma virus comes from the findings of presence of HPV infections in cancers of oral, esophageal, larynx and nonmelanoma skin cancers. The oncogenic potentials of the virus have been attributed to its E6 and E7 genes. The products of these two genes stimulate cell proliferation by activating the cell-cycle-specific proteins and interfere with the functions of cellular growth-regulatory proteins, p53 and Rb. Identification and characterization of several human pathogenic HPV types warrant prevention of viral infection through vaccination or therapeutic intervention which could eventually control infection and expression of human pathogenic papillomaviruses

Selective Suppression of NF-kBp65 in Hepatitis Virus-Infected Pregnant Women Manifesting Severe Liver Damage and High Mortality

Fulminant hepatitis in Asian pregnant women is generally caused by hepatitis E virus infection, and extremely high mortality is most common in them. Decreased cell-mediated immunity is considered a major cause of death in these cases, but what exactly influences decreased immunity and high mortality specifically during pregnancy is not known. We used electrophoretic mobility shift assays, immunoblotting, and immunohistochemical analysis to study the expression and DNA binding activity of NF-kB p50 and NF-kB p65 in pregnant fulminant hepatic failure (FHF) patients and compared them with their nonpregnant counterparts. In both PBMC and postmortem liver biopsy specimens the DNA-binding activity of NF-kB was very high in samples from pregnant FHF patients compared with those from nonpregnant women as well as pregnant women with acute viral hepatitis (AVH) without FHF. Further dissection of the NF-kB complex in supershift assays demonstrated complete absence of p65 in the NF-kB complex, which is formed by homodimerization of the p50 component in pregnant FHF patients. Western blotting and immunohistochemical analysis of the expression of p50 and p65 proteins both showed higher levels of p50 expression and a complete absence or a minimal expression of p65, indicating its nonparticipation in NF-kB-dependent transactivation in pregnant FHF patients. We suggest that the exclusion of p65 from the NF-kB transactivation complex seems to be a crucial step that may cause deregulated immunity and severe liver damage, leading to the death of the patient. Our findings provide a molecular basis, for developing novel therapeutic approaches

Infection of Human Papillomavirus Type 18 and p53 Codon 72 Polymorphism in Lung Cancer Patients From India

Study objectives: Infection with specific high-risk HPV types 16 and 18 and polymorphism of p53 codon 72 has been strongly associated with the genesis of various neoplasms in humans, but such study in lung cancer is limited and the results are controversial. In India, the role of these two factors has been strongly implicated in cervical and other cancers, but the occurrence of HPV or p53 codon 72 polymorphism has not been examined in lung cancer, which is the most common cause of cancer-related death in India. Design and patients: A total of 40 tumor biopsy specimens from advanced lung cancer patients and blood samples from 40 matching control subjects were obtained for the analysis of high-risk HPV types 16 and 18 infection and p53 codon 72 polymorphism by polymerase chain reaction. Results: Only HPV type 18 was detected in 5% (2 of 40 lung cancer patients), but no other HPV could be detected. A significantly increased frequency of Arg/Arg homozygotes was observed in patients with advanced lung cancer when compared to that of control subjects (p = 0.004; odds ratio, 5.13; 95% confidence interval, 1.59 to 17.26). However, no significant correlation could be made between p53 polymorphism and different clinical stages, except for advanced stage IV patients, who showed a higher proportion of Arg/Pro heterozygous genotype. Conclusions: HPV detected in a small proportion of lung cancer patients in India demonstrated an exclusive prevalence of HPV type 18, and there was a significantly higher frequency of p53 Arg/Arg genotype when compared to that of control subjects. Observation of a shorter duration of symptoms (≤ 4 months) in as many as 78% (seven of nine stage IV patients) with Arg/Pro genotype may be an indication that lung cancer patients with the heterozygous p53 genotype are more susceptible to early progression

Infection of human papillomaviruses in cancers of different human organ sites

Clinico-epidemiological and molecular studies have established the casual link between Human Papillomavirus (HPV) infection and cervical cancer as also association of HPV infection with several other cancers. In India, cervical cancer is a leading cancer among women and almost all cases of cervical cancer show prevalence of High Risk (HR)-HPV infection. HPV has been also detected in a significant proportion of oral, esophageal, anal, vaginal, vulvar, and penile cancer and in a small percentage of lung, laryngeal, and stomach cancer in India. Due to lack of organized HPV screening program, insufficient infrastructure and trained manpower and inadequacy in cancer registries, there are not much data available on the countrywide HPV prevalence and its type distribution in different cancers in India. Forthcoming introduction of recently developed HPV vaccines in India given a new urgency to know the prevalence and distribution of various HPV types in different organ sites for the management and monitoring of vaccination program and its impact on prevalence of other cancers. This review, summarizes studies on the prevalence of HPV infection in cancers of different organ sites in India

Aberrant expression and constitutive activation of STAT3 in cervical carcinogenesis: implications in high-risk human papillomavirus infection

<p>Abstract</p> <p>Background</p> <p>Recent observations indicate potential role of transcription factor STAT3 in cervical cancer development but its role specifically with respect to HPV infection is not known. Present study has been designed to investigate expression and activation of STAT3 in cervical precancer and cancer in relation to HPV infection during cervical carcinogenesis. Established cervical cancer cell lines and prospectively-collected cervical precancer and cancer tissues were analyzed for the HPV positivity and evaluated for STAT3 expression and its phosphorylation by immunoblotting and immunohistochemistry whereas STAT3-specific DNA binding activity was examined by gel-shift assays.</p> <p>Results</p> <p>Analysis of 120 tissues from cervical precancer and cancer lesions or from normal cervix revealed differentially high levels of constitutively active STAT3 in cervical precancer and cancer lesions, whereas it was absent in normal controls. Similarly, a high level of constitutively active STAT3 expression was observed in HPV-positive cervical cancer cell lines when compared to that of HPV-negative cells. Expression and activity of STAT3 were found to change as a function of severity of cervical lesions from precancer to cancer. Expression of active pSTAT3 was specifically high in cervical precancer and cancer lesions found positive for HPV16. Interestingly, site-specific accumulation of STAT3 was observed in basal and suprabasal layers of HPV16-positive early precancer lesions which is indicative of possible involvement of STAT3 in establishment of HPV infection. In HPV16-positive cases, STAT3 expression and activity were distinctively higher in poorly-differentiated lesions with advanced histopathological grades.</p> <p>Conclusion</p> <p>We demonstrate that in the presence of HPV16, STAT3 is aberrantly-expressed and constitutively-activated in cervical cancer which increases as the lesion progresses thus indicating its potential role in progression of HPV16-mediated cervical carcinogenesis.</p

Two new novel point mutations localized upstream and downstream of the HMG box region of the SRY gene in three Indian 46,XY females with sex reversal and gonadal tumour formation

The Y chromosome-specific gene SRY is one of the key genes involved in human sex determination. The SRY gene encodes a testis-specific transcription factor that plays a key role in sexual differentiation; development in males; is located on the distal region of the short arm of the Y chromosome. Mutations in SRY gene result in XY sex reversal; pure gonadal dysgenesis. SRY expression initiates a network of gene activity that transforms the undifferentiated gonad; genital ridge into testis. Mutations in the SRY gene have been considered to account for only 0-5% of 46;XY gonadal dysgenesis cases; whereas the majority of the remaining cases may have mutation(s) in the SRY regulatory elements or other genes involved in the sex differentiation pathway. Patients both with gonadal dysgenesis; Y-chromosome presence are at high risk of developing gonadoblastoma. Using PCR; single strand conformational polymorphism (SSCP); automated DNA sequencing; we analysed the mutations in the SRY gene in three 46;XY sex reversal patients. Two patients demonstrated nucleotide substitution (A→G) within the open reading frame just outside; upstream of the conserved DNA-binding motif called the high-mobility group (HMG) box; replacing glutamine at codon 57 with arginine. Altered SSCP patterns were also observed in these patients. Histological examination of gonads in patient revealed the formation of gonadoblastoma. Patient demonstrated A→T substitution which replaces serine at codon 4 with cysteine; just outside but downstream of the HMG box. Results suggest the involvement of SRY gene in sex reversal which further supports the relationship between SRY alterations; gonadal dysgenesis and/or primary infertility

Transcription factor AP-1 in esophageal squamous cell carcinoma: Alterations in activity and expression during Human Papillomavirus infection

<p>Abstract</p> <p>Background</p> <p>Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related deaths in Jammu and Kashmir (J&K) region of India. A substantial proportion of esophageal carcinoma is associated with infection of high-risk HPV type 16 and HPV18, the oncogenic expression of which is controlled by host cell transcription factor Activator Protein-1 (AP-1). We, therefore, have investigated the role of DNA binding and expression pattern of AP-1 in esophageal cancer with or without HPV infection.</p> <p>Methods</p> <p>Seventy five histopathologically-confirmed esophageal cancer and an equal number of corresponding adjacent normal tissue biopsies from Kashmir were analyzed for HPV infection, DNA binding activity and expression of AP-1 family of proteins by PCR, gel shift assay and immunoblotting respectively.</p> <p>Results</p> <p>A high DNA binding activity and elevated expression of AP-1 proteins were observed in esophageal cancer, which differed between HPV positive (19%) and HPV negative (81%) carcinomas. While JunB, c-Fos and Fra-1 were the major contributors to AP-1 binding activity in HPV negative cases, Fra-1 was completely absent in HPV16 positive cancers. Comparison of AP-1 family proteins demonstrated high expression of JunD and c-Fos in HPV positive tumors, but interestingly, Fra-1 expression was extremely low or nil in these tumor tissues.</p> <p>Conclusion</p> <p>Differential AP-1 binding activity and expression of its specific proteins between HPV - positive and HPV - negative cases indicate that AP-1 may play an important role during HPV-induced esophageal carcinogenesis.</p

Defining the validity of classical and non-classical cellular changes indicative of low-grade squamous intraepithelial lesion encompassing human papillomavirus infection in relation to human papillomavirus deoxyribonucleic acid testing

Background: Human papillomavirus (HPV) infection as of now has been beyond doubt to be the causative agent for cervical carcinoma. Its morphological identification in Pap smear is important. Aim: To define the validity of classical and non-classical cellular changes indicative of low-grade squamous intraepithelial lesion (SIL) encompassing HPV infection in relation to positivity for ′high risk′ HPV16 as well as for ′low risk′ HPV6/11. Materials and Methods : A total of 3000 Papanicolaou smears were screened, of which 150 were reported as low grade-SIL encompassing HPV infection (LSIL-HPV). Subsequently cervical scrapes from these 150 subjects, along with equal number of normal women as controls, were collected and processed for HPV deoxy-ribonucleic acid testing by polymerase chain reaction (PCR). Results: On the basis of cytomorphological characteristics in Pap smears, HPV infection were categorized into the following two groups: Classical (koilocytic) changes (CC) encountered in 30 women and non-classical changes (NCC) encountered in 120 women. It was observed that 21 (70%) CC and 46 (38.3%) NCC of HPV infection were positive for HR-HPV16; however only 12 cases (10%) of NCC and two cases (6.6%) of CC were positive for LR-HPV 6/11. Majority (41.7%) of HPV positive cases were reported in the age group of 25 to 30 years and HPV positivity decreased with the increasing age. Conclusion: Classical cellular changes are not the only diagnostic features for HPV infection in Pap smear, non-classical diagnostic features also support the diagnosis of HPV infection and may be positive for HR-HPV16

Value of high-risk human papillomavirus 16 deoxyribonucleic acid testing with cytological entities in peri and postmenopausal women

Background: Genital human papillomavirus (HPV) infection is a sexually transmitted disease that is caused by HPV. Some types of HPV, called high-risk (HR) types may cause cell changes that sometimes lead to cervical cancer. HPV screening has been proposed for symptomatic female population; however, Pap test is the main stay in low resource setting. Aim: To detect HR HPV 16 positivity in perimenopausal and postmenopausal women and its association with cytological entities diagnosed on Pap smear. Materials and Methods: Pap smears and cervical scrapes were collected from 230 women consisting of 120 perimenopausal women approaching menopause and 110 postmenopausal women with a cervix after cessation of menstruation and processed as per routine procedure for detection of HR-HPV 16 deoxyribonucleic acid (DNA). Cytologically abnormal HPV 16 negative cases were also tested for other HR-HPV types. Results: Among the perimenopausal women 12 (10%) cases were positive for HR-HPV 16 consisting of 6 (5%) abnormal cases and 108 (90%) were HPV 16 negative consisting of 5 (4.1%) abnormal cases. However, among 110 postmenopausal women 14 (12.7%) were positive for HPV 16 DNA consisting of 6 (5.4%) abnormal cases and 96 (87.2%) were HPV 16 negative consisting of 4 (3.6%) abnormal cases. HPV 16 negative abnormal cases (9) were positive for low risk-HPV 6/11 consisting of atypical squamous cells (3) and low-grade squamous intraepithelial lesions-HPV (6). Conclusions: There is not much variation in HPV 16 positive cases in peri and postmenopausal women. By combining HPV DNA testing with Pap smear more cases having potential for pre-cancer lesions may be detected; however, HPV test cannot replace the Pap smear in low resource setting