Region-wise distribution of high-risk human papillomavirus types in squamous cell carcinomas of the cervix in India

Impact of HPV strains on molecular mechanisms of cervix cancer

PURPOSE

Cervical cancer accounts for a high number of deaths worldwide. Risk factors are extensive for cervix cancer but Human papillomavirus (HPV) plays a prime role in its development. Different strains of HPV are prevalent globally, which show different grades of mortality and morbidity among women. This study is planned to evaluate the molecular mechanism of different strains of HPV infection and progression leading to cervix cancer.

METHODS

This review includes different research articles on cervix cancer progression reported from India and all over the world.

RESULTS

HPV 16 and 18 are prevalent strains using heparan sulfate-independent and dependent pathways for viral replication inside the cell. It also uses transcription mechanisms through NF-kappa B, FOXA-1, and AP-1 genes while strains like HPV-35, 45, and 52 are also predominant in India, which showed a very slow mechanism of progression due to which mortality rate is low after their infection with these strains.

CONCLUSION

HPV uses E6 and E7 proteins which activate NF-kappa B and AP-1 pathway which suppresses the tumor suppressor gene and activates cytokine production, causing inflammation and leading to a decrease in apoptosis due to Caspase-3 activation. In contrast, the E7 protein involves HOXA genes and decreases apoptotic factors due to which mortality and incidence rates are low in viruses that use E7 motifs. Some HPV strains employ the cap-dependent pathway, which is also associated with lower mortality and infection rates.

HPV genotype prevalence in Indian women with cervical disease and estimation of the potential impact of HPV vaccines on prevention of cervical cancer

PURPOSE

Human papillomavirus (HPV) causes genital and oropharyngeal cancers worldwide. There are significant gaps exist in the data on HPV genotype prevalence in this part of the country. HPV vaccination is one of the best preventive methods available currently. HPV genotyping plays an important role in the selection of appropriate vaccines and monitoring vaccine efficacy and coverage. The present study aimed to determine the HPV genotype prevalence and to estimate the potential impact of HPV vaccines on invasive cervical cancer.

MATERIALS AND METHODS

A total of 204 cervical biopsy samples collected from symptomatic women were subjected to an in-house designed and standardised nested multiplex PCR (NM-PCR) assay. The NM-PCR was designed to detect 38 Mucosal HPV types as a pooled result and genotyping of 15 HPV types. Further, the HPV genotype data was used to estimate the HPV vaccine bivalent, quadrivalent and nonavalent impact on the population using a mathematical formula.

RESULTS

Out of 204 samples 188 were subjected to HPV-nested PCR. A total of 163 (86.7%) samples were positive for at least one HPV type. Multiple genotypes were identified in 30% of samples processed. HPV-16 (85.3%) was the most frequently detected genotype followed by HPV-18 (13.5%) and HPV-33 (11.0%). Other genotypes were observed less frequently. Based on the HPV prevalence observed in the study a mathematical model estimated the efficacy of bivalent, quadrivalent and nonavalent vaccines were 76.1%, 76.7%, and 91.1% (average) respectively.

CONCLUSIONS

HPV-16 was the most prevalent (>85%) genotype detected in this study. Multiple infections observed in 30% of samples were quite high as compared to the majority of national, and global reference (15-25.4%) data. The Mathematical model showed that a nonavalent vaccine would give better protection.

Multiplex polymerase chain reaction for the detection of high-risk-human papillomavirus types in formalin-fixed paraffin-embedded cervical tissues

Detecting high-risk-human papillomavirus (HPV) types has become an integral part of the cervical cancer screening programmes. This study aimed to develop a multiplex polymerase chain reaction (PCR) for identification of HPV types 16 and 18 along with the beta globin gene in formalin-fixed and paraffin-embedded cervical biopsy specimens. A total of 59 samples from patients with cervical abnormalities were tested. HPV 16 positivity was 50% in cervical cancers and 52.9% in cervical intraepithelial neoplasia. Our multiplex PCR protocol can be used as a simple and cost-effective tool for high-risk-HPV detection in cervical cancer screening programmes.

HPV Genotypes distribution in Indian women with and without cervical carcinoma: Implication for HPV vaccination program in Odisha, Eastern India

BACKGROUND

Considering the limited cross protection offered by the current HPV vaccines, understanding the HPV genotype distribution among the different population is essential in predicting the efficacy of current vaccine and devising new vaccine strategy. The present work aimed at investigating the HPV genotypes distribution among women with and without cervical carcinoma in Odisha, Eastern India.

METHODS

A total of 607 participants have been enrolled between January 2014 and June 2016. L1-PCR, sequencing, and E6/E7 nested multiplex type- specific PCR were performed for HPV detection and genotyping. Cytological distribution of 440 cases includes invasive cervical carcinoma or ICC (n = 210), inflammatory smear (n = 162), normal cytology (n = 68). Statistical analyses were performed by using SPSS version 20.0 software and MediCal version 14.10.2(7). A p-value of ≤ 0.05 was considered statistically significant.

RESULTS

The overall prevalence of HPV infection was (359/595) 60.33%. Prevalence of HPV infection was 93.80% (197/210) in invasive cervical cancer (ICC) cases, 54.32% (88/162) in inflammatory smear and 19.11% (13/68) in normal cervical cytology. The most prevalent genotype was HPV16 (87.28%) followed by HPV18 (24.56%) and HPV 51(3.46%). The overall prevalence of single type was 76.58% and highest (78.9%) among ICC cases. The most frequent genotype combination after HPV16 + 18(9.4%) was HPV16 + 66 + 68(2.7%) which was frequently observed in inflammatory cytology. Age > 45years, parity ≥3, low socio-economic condition, rural residential area and post menopause state were significantly associated with HPV infection. Multiple infections did not have a significant association with any of the clinicopathological variables (stage, LN metastasis, cell type) except tumor size ≥ 2cm in ICC cases. The impact of 2v, 4v, and 9v vaccines in preventing cervical cancer in Odisha were 89.99, 91.65, and 92.16% respectively.

CONCLUSION

This data would help planning an appropriate strategy for disease monitoring and provides baseline data for post-vaccination surveillance in the region. The nonavalent vaccine would be significant in preventing cervical carcinoma in Odisha. Hence an effective vaccination program based on regional HPV epidemiological profile along with the cervical cancer screening is necessary to reduce the cervical cancer burden in India.

Knowledge, Awareness and Attitude on HPV, HPV Vaccine and Cervical Cancer among the College Students in India

BACKGROUND

Infection of specific high risk Human papillomaviruses (HPVs) is known to cause cervical cancer and two prophylactic vaccines have been developed against two major high risk HPV types 16 and 18 for prevention of cervical cancer. Because of societal, religious and ethical issues associated with the vaccination of adolescent girls in India together with lack of awareness about HPV and HPV vaccines, no successful HPV immunization program has been employed in India.

OBJECTIVE

To determine knowledge, awareness and attitude of college students on HPV, HPV vaccine and cervical cancer.

METHOD

A questionnaire-based survey was conducted in a total of 1580 undergraduate students between the age group 16-26 years comprising 684 girls and 876 boys.

RESULTS

Out of a total of 1580 students, girls had more knowledge about cervical cancer (82.45%, p<0.001), HPV (45.61%, p<0.001) and HPV vaccines (44%, p<0.001) when compared to those in boys. However, knowledge about the types of HPV and vaccines was poor. Interestingly, students from biology-major had more knowledge and awareness about cervical cancer (81.89%, p<0.001) and HPV (46.58%, <0.001) when compared to non-biology students. Girls from both biology and non-biology group had higher awareness compared to boys. Analysis of odds ratio (ORs) along with 95% CI showed older girls with 1.2 to 3 fold (p<0.05) higher knowledge than boys. All students agreed that girls should get vaccinated against HPV (p<0.001).

CONCLUSION

It is suggested that there is a need for educational intervention and awareness campaigns to augment HPV immunization program for control of cervical cancer in India.

Higher prevalence of human papillomavirus infection in adolescent and young adult girls belonging to different Indian tribes with varied socio-sexual lifestyle

BACKGROUND

Despite high prevalence of human papillomavirus (HPV) infection and cervical cancer in Indian women, no study has been done in tribal populations whose socio-sexual lifestyle is different. Therefore, HPV screening has been carried out in pre-adolescent, adolescent and young adult tribal girls using self-collected urine samples.

METHODS

20-35 ml self-collected midstream urine samples were obtained from a total of 2278 healthy tribal girls (9-25 years) comprising pre-adolescent, adolescent and young adults from three Indian states: Madhya Pradesh, Jharkhand and Chhattisgarh. β-globin positive 2034 samples were employed for HPV detection and genotyping.

RESULTS

The overall prevalence of HPV infection in tribal girls was 12.9% (262/2034). More than 65% (172/262) of them were infected with HR-HPV types of which HPV16 was the most predominant type (54%). Young adult girls aged 18-25 years showed a significantly higher prevalence of HPV infection (19.2%; OR = 3.36; 95% CI 2.97-6.34, P<0.001) as compared to that in adolescent (11.4%; OR = 1.82; 95% CI 1.20-2.76, P<0.01) or pre-adolescent girls (6.6%).

CONCLUSION

This is a first study showing significantly a very high prevalence of HPV infection in adolescent and young adult tribal girls possibly due to different socio-sexual behavior, indicating a serious health concern for Indian tribal women.

Human papillomavirus type distribution in invasive cervical cancers from Madhya Pradesh: implications for vaccination programs in central India

Invasive cervical carcinoma (ICC) remains a leading cause of female mortality in India. There is a paucity of data about human papillomavirus (HPV) type distribution among ICCs from Central India. Formalin-fixed, paraffin-embedded ICC specimens (n=270 patients) from Madhya Pradesh state were screened for HPV by GP5/6 primer-based polymerase chain reaction followed by cycle sequencing and NCBI BLAST search. HPV was detected in 93.3% of the tumors. Thirteen types were detected: HPV16 (73.7%), HPV18 (11.9%), HPV45 (2.2%), HPV66 (1.5%), HPV35 (1.1%), and HPV56 (0.7%). HPV31, 51, 58, 59, 67, 82 and JEB2 were each seen in 1 case (0.4%). HPV16 was more common among women less than 40 yr than 40 yr or older (P=0.006), and HPV18 was more common in women aged 40 yr or older (P=0.013). Squamous cell carcinomas were more frequently HPV-positive than adenocarcinomas (P=0.01). HPV18 was more common in adenocarcinoma than in squamous cell carcinoma (P=0.02). These data contribute to the pan-India profile of HPV-type relationship to ICC and show the potential of current vaccines to greatly relieve (by up to 85.6%) the ICC burden in Central India. The findings are also suggestive that next-generation HPV vaccines might be designed on a regional basis rather than from compounded global data.

Human papillomavirus (HPV) types 16 and 18 in liquid-based cervical cytology samples

Human papillomavirus (HPV) DNA testing is replacing cervical cytology as a primary cervical cancer screening tool. The aim of this study was to determine the frequency of occurrence of HPV types 16 and 18 in liquid-based cytology (LBC) cervical samples in our set-up. This study comprised of 302 LBC cervical samples. HPV 16 and HPV 18 were detected by polymerase chain reaction (PCR), and the results were compared between normal (n = 155), inflammatory (n = 99), squamous (n = 37) and glandular abnormalities (n = 11). Of our patient cohort, 73.8 % was ≤40 years old. We found HPV 16 DNA in 91/302 (30.1 %) cases and HPV 18 DNA in 21/302 (6.95 %). HPV types 16 and 18 were detected in 25.8 and 4.5 % cytologically normal samples, respectively. HPV 16 was positive in 29.3 % of inflammatory samples. Squamous cervical abnormalities were more often HPV positive (HPV 16 in 48.6 %; HPV 18 in 29.7 %) than glandular abnormalities (36.4 and 18.2 %, respectively). We found high-risk HPV DNA in more than one third of the tested women. A good number of these HPV-positive cases were negative in cervical cytology.

The apoptotic effect of hesperetin on human cervical cancer cells is mediated through cell cycle arrest, death receptor, and mitochondrial pathways

Hesperetin, a flavonoid from citrus fruits, has several bioactivities such as anti-inflammatory, antihypertensive, antiatherogenic effects. However, studies elucidating the role and the mechanism(s) of action of hesperetin in cervical cancer are sparse. In this study, we investigated the mechanism of the antiproliferative and apoptotic actions exerted by hesperetin on human cervical cancer SiHa cells. The viability of SiHa cells was evaluated using the MTT assay, apoptosis by acridine orange/ethidium bromide, propidium iodide, TUNEL assay, and Annexin V-Cy3, cell cycle distribution and mitochondrial transmembrane potential using flow cytometry, and apoptotic marker genes using quantitative real-time PCR. The treatment of SiHa cells with hesperetin (IC50, 650 μm) showed a marked concentration- and time-dependent inhibition of proliferation and induced the G2/M phase in a dose-dependent manner after 24 h. There was an attenuation of mitochondrial membrane potential with increased expression of caspase-3, caspase-8, caspase-9, p53, Bax, and Fas death receptor and its adaptor protein Fas-associated death domain-containing protein (FADD), indicating the participation of both death receptor- and mitochondria-related mechanisms. Furthermore, hesperetin-induced apoptosis was confirmed by TUNEL and Annexin V-Cy3. This study shows that hesperetin exhibits a potential anticancer activity against human cervical cancer cell lines in vitro through the reduction in cell viability and the induction of apoptosis. Altogether, these data sustain our contention that hesperetin has anticancer properties and merits further investigation as a potential therapeutic agent.

HPV genotyping and site of viral integration in cervical cancers in Indian women

Persistent HPV infection plays a major role in cervical cancer. This study was undertaken to identify HPV types in a cohort of Indian women with locally advanced cervical cancer as well as to determine the physical state and/or site of viral integration in the host genome. Pretreatment biopsies (n = 270) from patients were screened for HPV infection by a high throughput HPV genotyping assay based on luminex xMAP technology as well as MY09/11 PCR and SPF1/2 PCR. Overall HPV positivity was observed to be 95%, with HPV16 being most common (63%) followed by infection with HPV18. Integration status of the virus was identified using Amplification of Papillomavirus Oncogene Transcripts (APOT) assay in a subset of samples positive for HPV16 and/or HPV18 (n = 86) and with an adequate follow-up. The data was correlated with clinical outcome of the patients. Integration of the viral genome was observed in 79% of the cases and a preference for integration into the chromosomal loci 1p, 3q, 6q, 11q, 13q and 20q was seen. Clinical data revealed that the physical state of the virus (integrated or episomal) could be an important prognostic marker for cervical cancer.

Human papillomavirus infection among young adolescents in India: impact of vaccination

High-risk human papillomaviruses (HR-HPVs) are the causative agents of cervical cancer and prophylactic HPV vaccination has been recommended for adolescents but no data are available on the prevalence of HPV infection among adolescents in India. Self-collected midstream urine samples from 940 healthy school children, aged 8-17 years, from 12 different schools in and around Noida and Delhi, India, were collected for HPV detection by PCR. Of 458 girls, 15 (3.2%) were positive for HPV and 10 (66.6%) were positive for high-risk human papillomavirus (HR-HPV) type16 and 2 (13.3%) for HPV 18. Of 342 boys, 7 (2.1%) were HPV positive, of which 5 (71.4%) had HPV type 6 but interestingly, none were positive for HR-HPV types 16 or 18. Among HPV positive girls, 13 (66.6%) were >13 years and the rest were <13 years (P = 0.004), while all seven HPV positive boys were >13 years (P = 0.007). The majority of HPV positive adolescents (80-86%) belonged to the Hindu and related communities, whereas only about 14-20% belonged to the Muslim community. A significant association (P < 0.001) was observed between the parent's education and the awareness of cervical cancer, which was significantly higher among adolescent girls from India, thereby exerting an immense psychosocial impact on vaccination programs. A lower prevalence of HR-HPV infection among adolescent girls will have significant positive effect on HPV vaccination and cancer control programs in India where education and awareness should go hand in hand.

Update on available vaccines in India: report of the APPA VU 2010: I

The Asia Pacific Pediatric Association Vaccinology Update 2010 was held in Mumbai on November 13-14, 2010 to discuss the latest information on burden of infectious diseases, recent developments in vaccines and their impact on immunization practices against infectious diseases occurring in Indian children. During the conference the importance of including conjugate Haemophilus influenzae type b vaccine and anti-rabies vaccines in routine immunization was stressed. Also, the need for giving a second dose of measles mumps rubella vaccine at school entry; and the need for a two-dose varicella vaccine regimen (first dose at 12-15 months of age and a second dose at age 4-6 years) was elucidated. Information related to vaccines which have become available in India in recent years, namely, inactivated poliovirus vaccine; diphtheria, tetanus, acellular pertussis (DTaP) vaccine; conjugate pneumococcal vaccine; rotavirus vaccines; H1N1 vaccines; live attenuated hepatitis A virus vaccine; oral cholera vaccine; tetanus, reduced-dose diphtheria, acellular pertussis (Tdap) vaccine; and human papillomavirus vaccines were discussed.