p53 gene mutation and human papillomavirus (HPV) infection in esophageal carcinoma from three different endemic geographic regions of India

Systematic Literature Review on the Burden of Human Papillomavirus Infection and Related Diseases in India

Human papillomavirus (HPV)-related diseases pose public health concerns for both genders, yet their understanding remains limited in India. This review outlines HPV incidence and prevalence, genotype distribution, and attribution rates across different HPV-related disease types. A comprehensive literature search was performed to identify observational studies on individuals aged 15 years and older, and a total of 3702 publications were identified. A total of 139 studies were included in this review, involving 607,425 subjects aged 15.8-82.2 years, with a gender distribution of 38.13% males and 61.86% females. The prevalence of HPV infection in the anogenital area among healthy males and females was 41.07% and between 0.4% and 41.8%, respectively. Among individuals with HPV-related diseases, HPV infection prevalence was 26.1%-100% in unhealthy cervixes and cervical lesions, 3.1%-41% in anal lesions, 71.4% in vulva and vaginal lesions, and 0%-92.3% in head and neck cancer. The review highlights the variability in HPV prevalence across genders and age groups in India, likely due to population heterogeneity and testing differences. This study highlights the need for rigorous and uniform studies in India on the HPV disease burden and the importance of gathering evidence with a special focus on males.

Detection of transcriptionally active high-risk human papillomavirus in patients with oesophageal carcinoma by real-time PCR

BACKGROUND

Oesophageal malignancies (OC) are the sixth most common cause of cancer-related mortality worldwide. Traditional risk factors for OC include smoking, alcohol consumption, and poorly controlled acid reflux; however, the trends in the last decade have pointed out the potential carcinogenic roles of infectious agents, especially Human Papillomavirus (HPV), in the development of OC. The prevalence of HPV infection in OC varies greatly worldwide, mainly due to the inconsistencies of the detection assays employed. This study attempted to establish the association between high-risk HPV and oesophageal malignancies by detecting the transcriptionally active HPV mRNA.

MATERIALS AND METHODS

In this cross-sectional study, 30 malignant oesophageal samples were subjected to real-time PCR to detect high-risk HPV-16 and 18 by targeting transcriptionally active E6/E7 genes. The positive samples were further subjected to viral load assessment.

RESULTS

Histopathological analysis of the patients showed that a moderately differentiated squamous cell carcinoma was seen in 56.2% of the cases. Of the 30 samples, 4 (13.3%) showed positive for HPV-16 E6/E7, and none showed positive for HPV-18 E6/E7. The viral load of HPV-16 E6/E7 in the positive samples was lesser than the copies present in the well-established cell line, SiHa.

CONCLUSION

The role of HPV in the etiopathogenesis of oesophageal malignancies is unclear. Based on this study and the supporting data presented, it can be said that the association of high-risk HPV infection in oesophageal cancers does exist, but whether it is clinically and etiologically significant is the question that needs to be answered. Multicenter studies from different geographical locations, employing multiple molecular methods with a larger sample size, could aid in a better understanding of the etiopathogenesis of HPV in OC.

P16 and P53 Expression in Esophageal Squamous Cell Carcinoma: A Brief Report From The Experience of South of Iran, and Review of the Literature

BACKGROUND

Iran is one of the high-risk countries for esophageal squamous cell carcinoma (ESCC). Human papillomavirus (HPV) has been reported as one of the etiologic, pathogenetic, and prognostic factors in this tumor, especially in high-risk geographic areas. Previous reports from our geographic area, that is, the South of Iran failed to show any evidence of HPV in the cases of ESCC by molecular methods.

OBJECTIVES

In this study, we evaluated P16 and P53 immunohistochemistry (IHC) expression in the cases of esophageal ESCC from Fars province in the South of Iran to find the presence of any correlation between clinicopathologic findings with P16 and P53 expression by IHC as etiologic and prognostic biomarkers. We also tried to compare the results from other geographic areas of Iran and the world.

RESULTS

P16 and P53 expression were found in 42.9% and 66.12% of ESCCs, respectively. No statistically significant correlation was found between clinicopathologic findings and P16 pr P53 expression.

CONCLUSION

Although P16 and P53 expression in ESCC in the South of Iran is significant, there is no statistically significant correlation between clinicopathologic findings and outcome in ESCC and expression of these 2 proteins to be considered as biomarkers. Results from other geographic areas of Iran and the world are also very controversial and inconsistent.

A multinational review: Oesophageal cancer in low to middle-income countries

Oesophageal cancer (OC) is an aggressive neoplasm that manifests in the gastrointestinal tract and is the result of numerous factors that can contribute to the development of the disease. These may include old age, nutritional deficiencies, oesophageal obstruction and food ingestion difficulties. Environmental factors serve a large role in increasing the risk of developing OC. Two factors that serve an increasing risk of developing OC are the use of tobacco and the consumption of alcohol. Genetic factors also exhibit a large effect on the risk of developing OC, for example, the causative genes in Black Africans differ from other races. OC is 3-4 times more common among men than women. OC has been previously reported in >450 000 individuals worldwide, and its incidence is increasing. The current review compares OC in low to middle-income countries with developed countries. The incidence of OC, particularly squamous cell carcinoma (SCC) is high in low and middle-income countries. In developed countries, the incidence of SCC is low compared with adenocarcinoma. The majority of OC cases are diagnosed in the late stages of the disease, leading to high mortality rates. The current review aimed to discuss factors that contribute to the development of this disease in different geographical areas and genetic mechanisms governing these findings. The current review also aims to discuss the preventative treatment options for the disease, and also discusses the diagnosis and surveillance in five LMICs, including South Africa, China, Tanzania, India and Brazil.

Esophageal Cancer: Associated Factors with Special Reference to the Kashmir Valley

Esophageal cancer is one of the most common cancers worldwide. It is a multifactorial disease, and no single agent has been identified so far as the sole cause of the cancer. Many factors like smoking, the consumption of alcohol, fungal-contaminated, spicy and various nitrosamine-containing food stuffs and hot beverages, nutritional deficiency of some vitamins like β-carotene, vitamin A, C and E and minerals like zinc, selenium and molybdenum, the use of opium, HPV infection and various genetic factors have been found associated with the occurrence of the disease worldwide. Wide geographic differences and substantial changes in the incidence of esophageal cancer occurring over time have been suggested. Among the risk factors in India, betel quid chewing carries a relatively high risk. High incidences in Kashmir have been associated with the consumption of hot salted tea, sun-dried, smoked foods, tobacco in the form of hukka and various genetic factors. The exact cause of esophageal squamous cell carcinoma is unknown. Much work has been carried out on the role of various environmental factors, gene mutations, and polymorphisms worldwide, including Kashmir. Although the Kashmir valley is present on the border of the ‘high risk esophageal cancer belt’ and esophageal squamous cell carcinoma represents the most commonly occurring malignancy in Kashmir, the amount of information available on various associated factors is still very little as there is a paucity of various epidemiological and molecular studies being carried out in this field.

p16 Expression as a Surrogate Marker for HPV Infection in Esophageal Squamous Cell Carcinoma can Predict Response to Neo-Adjuvant Chemotherapy

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a common cancer in the north east of India. The present study concerned the prevalence of human papilloma virus (HPV) in the ESCC in north eastern India and its impact on response to chemotherapy.

MATERIALS AND METHODS

p16 expression, a surrogate marker for HPV infection was assessed in 101 pre-treatment biopsies of locally advanced ESCC, reported from a comprehensive cancer centre in north east India, using immunohistochemistry. All patients received neo-adjuvant chemotherapy. Response was assessed clinically and histopathologically with attention to p16 expression.

RESULTS

p16 was expressed in 22% of ESCC (22 out of 101) and was more prevalent in patients who were more than 45 years of age (P=0.048). p16 positive tumors appeared more commonly in the upper 2/3 of the thoracic esophagus (18 in 22). Nine of the 22 (41%) p16 positive tumors achieved pathologic complete response following neo-adjuvant chemotherapy (P=0.008). There was a trend towards reduced mortality in this group (P=0.048). Some 9 of the 20 (45%) patients who achieved pathologic complete response were p16 positive.

CONCLUSIONS

Expression of p16 in ESCC correlates with higher rate of pathologic complete remission in patients undergoing neo adjuvant chemotherapy and could be a predictive marker for response assessment.

Development of esophageal cancer in Chaoshan region, China: association with environmental, genetic and cultural factors

Esophageal squamous cell carcinoma (ESCC) is the eighth most common cancer by incidence worldwide. Although the cancer is located at a readily recognizable and accessible site in the body, it is the sixth most common cause of cancer death. The 1- and 5-year survival rates in China are 50% and 15%, respectively. Furthermore, the cancer has distinct geographic and etiological risk factors in different locations around the world. Since ESCC is highly prevalent in the Chaoshan (Southeastern) region of China, this report will focus on a review of risk factors for the cancer in this area. From the review, it is clear that some important and traditional factors are involved, e.g. environmental mutagens, genetic predisposition. However, unique factors, e.g. the drinking of very hot tea, may play an important role. This review highlights the role of complex risk factors (environmental, genetic and cultural) which contribute to the multistage development of cancer: localized injury, inflammation, mitogenesis, mutagenesis, carcinogenesis and eventually mortality. The latter is contributed by unnecessary delay in seeking medical care which may be culturally related. The review emphasizes the need to identify causal mechanisms for the complex carcinogenic process which can provide opportunity for prevention and treatment of this potentially curable cancer.

Association between human papillomavirus (HPV) and oesophageal squamous cell carcinoma: a meta-analysis

The oncogenic potential of human papillomaviruses (HPV) is well known in the context of cervical carcinoma; however, their role in the development of oesophageal squamous cell carcinoma (OSCC) is less clear. We aimed to determine the extent of the association between HPV infection and OSCC. A comprehensive literature search found 132 studies addressing HPV and OSCC in human cases, and a meta-analysis was performed using a random-effects model. There was evidence of an increased risk of OSCC in patients with HPV infection [odds ratio (OR) 2·69, 95% confidence interval (CI) 2·05-3·54]. The prevalence of HPV in OSCC was found to be 24·8%. There was an increased risk associated with HPV-16 infection (OR 2·35, 95% CI 1·73-3·19). Subgroup analyses showed geographical variance, with Asia (OR 2·94, 95% CI 2·16-4·00), and particularly China (OR 2·85, 95% CI 2·05-3·96) being high-risk areas. Our results confirm an increase in HPV infection in OSCC cases.

Role of Human papilloma virus infection and altered methylation of specific genes in esophageal cancer

BACKGROUND

Evaluation of Human papilloma virus (HPV) and its association with promoter methylation of candidate genes, p53 and Aurora A in esophageal cancer.

MATERIALS AND METHODS

One hundred forty-one esophageal tissue samples from different pathologies were evaluated for HPV infection by PCR, while the promoter methylation status of p53 and Aurora A was assessed by methylation-specific restriction based PCR assay. Statistical analyses were performed with MedCalc and MDR software.

RESULTS

Based on endoscopy and histopathology, samples were categorized: cancers (n=56), precancers (n=7), esophagitis (n=19) and normals (n=59). HPV infection was found to be less common in cancers (19.6%), whereas its prevalence was relatively high in precancers (71.4%), esophagitis (57.8%) and normals (45.7%). p53 promoter methylation did not show any significant difference between cancer and normal tissues, whereas Aurora A promoter methylation demonstrated significant association with disease (p=0.00016, OR:5.6452, 95%CI:2.18 to 14.6) when compared to normals. Aurora A methylation and HPV infection was found in a higher percentages of precancer (66.6%), esophagitis (54.5%) and normal (45.2%) when compared to cancers (14.2%).

CONCLUSIONS

Aurora A promoter methylation is significantly associated with esophageal cancer, but the effect of HPV infection on this epigenetic alteration is not significant. However MDR analysis showed that the hypostatic effect of HPV was nullified when the cases had Aurora methylation and tobacco exposure. Further HPV sub-typing may give an insight into its reduced prevalence in esophageal cancer verses normal tissue. However, with the present data it is difficult to assign any significant role to HPV in the etiopathology of esophageal cancer.

Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer

BACKGROUND

Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.

AIM

To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.

METHODS

Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.

RESULTS

A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).

CONCLUSIONS

Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.

Human papillomavirus types 16 and 18 in esophagus squamous cell carcinoma: a meta-analysis

PURPOSE

A possible carcinogenic role of human papillomavirus (HPV) has been investigated in esophageal squamous cell carcinoma (ESCC) for nearly 30 years with mixed results. We performed a meta-analysis to assess the prevalence of "high-risk" HPV, HPV-16/18, in this disease. We also evaluated the association between infection with HPV-16/18 and ESCC risk by meta-analysis of case-control studies.

METHODS

Eligible studies published up to September 30, 2012 were retrieved via both computer searches of MEDLINE and EMBASE and manual review of references. A random-effects model was used to calculate summary prevalence and odds ratios (ORs) and corresponding 95% confidence intervals (CIs).

RESULTS

A total of 5755 cases of ESCC from 68 studies were included in this meta-analysis. Overall, 11.67% (95% CI, 7.74%-16.21%) of ESCC cases harbored HPV-16 and 1.82% (95% CI, 0.90%-2.95%) harbored HPV-18. In addition, meta-analysis of 10 case-control studies showed a significant increase in ESCC risk with HPV-16 infection (summary ORs = 3.55; 95% CIs, 2.05%-6.14%). However, this increased risk in ESCC was not made for HPV-18 infection (summary ORs = 1.25; 95% CIs, 0.46%-3.43%).

CONCLUSIONS

This meta-analysis indicated that HPV-16 and -18 can be detected in ESCC. HPV-16, but not HPV-18, is significantly associated with the risk of ESCC. However, it is early to conclude that both types of HPV are involved in esophageal carcinogenesis.

High prevalence of human papillomavirus in esophageal squamous cell carcinoma: a study in paired samples

Esophageal squamous cell carcinoma (ESCC) is one of the common cancers with a poor prognosis. Incidences of human papillomavirus (HPV) infection range from 0 to 67% in different parts of the world. It has been frequently associated with high-risk HPV genotypes 16 and 18. The present study analyzes the prevalence of HPV infection in ESCC tumor and adjoining mucosa. Fresh tissue samples were obtained from ESCC tumor (group I) and adjoining mucosa (group II). Aliquots of DNA extracts were used. There were 23 patients with paired samples, 19 (83%) were male. HPV was positive in 20/23 (87%). Mean age of HPV positive in group I was 56.63 ± 6.96 and in group II 54.31 ± 7.13 years (P > 0.05). Majority had more than one viral type. HPV52 was the most common observed in 14 (61%) males and two (9%) females. Other common viruses were HPV55, 39, and 59. Smoking had a significant association with viral positivity. p63 and p16 oncoproteins correlated with degree of tumor differentiation but not with viral status. We documented high prevalence of high-risk HPV in ESCC. Our observations support the concept of persistent infection by an oncogenic HPV in cancer development. Our study highlights importance of documenting viral genotype in a defined geographic area.

Role of human papillomaviruses in esophageal squamous cell carcinoma

Esophageal cancer (EC) is responsible for almost half a million deaths worldwide annually and has a multifactorial etiology, which may account for its geographical variation in incidence. In the last 30 years the potential of human papillomaviruses (HPV) as oncogenes or co-factors in the tumorigenic process of esophageal squamous cell carcinoma (ESCC) has been widely studied. While the etiology of HPV in cervical and certain other anogenital and aerodigestive cancers has been established, results regarding its role in EC have been largely inconclusive. A causal association can be evaluated only with a case-control study, where normal controls are compared to ESCC cases for the presence of HPV. We reviewed all studies investigating ESCC tissue for HPV DNA and identified 139 that met our inclusion criteria, of which only 22 were case-control studies. Our results support previous findings of higher levels of HPV detection in high-risk ESCC regions than in areas of low risk. In addition, we confirm that the role of HPV in ESCC remains unclear, despite an accumulation of studies on the subject. The variations in investigative technique, study design and sample types tested may account for the lack of consistency in results. There is a need for a meta-analysis of all case-control studies to date, and for large, well-designed case-control studies with adequate power to investigate the association. The potential benefits of prophylactic HPV vaccines could be evaluated if HPV is identified as an etiological factor in EC, highlighting the need for further research in this area.

Geographic origin is a significant determinant of human papillomavirus prevalence in oesophageal squamous cell carcinoma: systematic review and meta-analysis

BACKGROUND

Since the first reports in 1982 suggesting an aetiological role for human papillomavirus (HPV) in a subset of oesophageal squamous cell carcinomas (ESCC), the literature reporting HPV detection in ESCC has expanded rapidly. However no formal meta-analysis of this literature has been published yet. The objective of this study was to perform a systematic review and formal meta-analysis of the literature reporting HPV detection in ESCC.

METHODS

MEDLINE and Current Contents were searched through March 2012. The effect size was calculated as event rates and their 95% confidence interval (95% CI), with homogeneity testing using Cochran's Q and I² statistics. Meta-regression was used to test the impact of study-level covariates (HPV detection method, geographic origin of study) on effect size, and potential publication bias was estimated using funnel plot symmetry (Begg and Mazumdar rank correlation, Egger's regression, and Duval and Tweedie's trim and fill method).

RESULTS

Of the 1177 abstracts found, 152 studies were determined to be eligible for this meta-analysis. These 152 studies covered a total of 10,234 ESCC cases, analysed by different HPV detection methods in different geographic regions. Of these 10,234 cases, 3135 (30.6%) tested HPV-positive, translating to an effect size of 0.372 (95% CI 0.360-0.384; fixed effects model) and 0.290 (95% CI 0.251-0.31; random effects model). When stratified by HPV detection technique, there was a significant heterogeneity between the studies, but importantly, the between-strata summary comparison was not significant (random effects model; p = 0.440). In contrast, there was significant heterogeneity between the studies from the different geographic regions. In the maximum likelihood meta-regression, HPV detection method was not a significant study-level covariate, in contrast to the geographic origin of the study, which had a significant impact (p = 0.00005) on the summary effect size estimates. No evidence for significant publication bias was found in funnel plot symmetry testing. In the sensitivity analysis, all meta-analytic results appeared robust to all (n = 151) one-by-one study removals.

CONCLUSIONS

These meta-analysis results indicate that the reported wide variability in HPV detection rates in ESCC is not due to the HPV detection techniques, but is explained by the geographic origin of the study. These data substantiate the recently elaborated concept that ESCC might have a different aetiology in low-incidence and high-incidence geographic regions, HPV playing an important role only in the latter.

HPV-16/18 detection does not affect the prognosis of head and neck squamous cell carcinoma in younger and older patients

Recently, high-risk human papillomavirus (HPV) has emerged as a possible agent associated with head and neck squamous cell carcinoma (HNSCC) in younger patients. Therefore, the purpose of the present study was to assess the effect of age on the distribution of HPV-16/18 in HNSCC, together with the impact of the virus on patient prognosis. A longitudinal prospective study was used adjusted for age, gender, TNM staging, smoking status and alcohol consumption. HPV was detected by PCR with consensus primers. Results showed there was no difference in the frequency of HPV-16/18 positivity when younger patients were compared to the older patients. No association was found among high-risk HPV positivity, gender, smoking habit and anatomical site. High-risk HPV was associated with advanced TNM in bivariate analyses; however, it did not impact on survival. Only TNM staging was associated with risk of mortality. Our study supports the theory that age does not affect the presence of HPV-16/18 in HNSCC and has no impact on patient prognosis. The incidence of HNSCC among patients under the age of 45 years is reportedly on the increase worldwide. The factors associated with HNSCC in younger adults are not well established. Findings of this study indicate that HPV-16/18 may not play a role in HNSCC patients under the age of 45 years.

Association of cyclin D1 gene polymorphisms with risk of esophageal squamous cell carcinoma in Kashmir Valley: a high risk area

Investigation of potential association of SNPs (G870A, rs9344; G1722C, rs678653) of cyclin D1 gene (CCND1) with susceptibility to esophageal squamous cell carcinoma (ESCC) in Kashmir valley (India). The study included 302 subjects comprising 151 ESCC cases and 151 controls. PCR-RFLP and direct sequencing were employed for genotyping. The G870A polymorphism, the individuals carrying GA + AA genotype was having 2.80-fold increased risk for development of ESCC (OR 2.8, 95% CI = 1.77-4.4; P = 0.0001) compared to GG genotype. Further a significantly higher risk was observed in individuals who consume >3 cups per day of salted tea (OR = 5.1; 95% CI = 1.6-16.7; P = 0.0016) and had smoking habits (OR = 6.3; 95% CI = 2.9-13.9; P = 0.0005). We also demonstrate for the first time in CCND1 1722 locus, the CC genotype was strongly associated with increased risk of developing ESCC (OR = 2.58; 95% CI = 1.61-4.15; P = 0.0001). In addition, the frequency of polymorphic C allele was also found to be higher in cases (OR = 1.92; 95% CI = 1.37-2.69; P = 0.0002). There appears to be an influence of CCND1 G870A/G1772C genotypes on genetic susceptibility to ESCC.

Breast cancer and human papillomavirus infection: no evidence of HPV etiology of breast cancer in Indian women

Background

Two clinically relevant high-risk HPV (HR-HPV) types 16 and 18 are etiologically associated with the development of cervical carcinoma and are also reported to be present in many other carcinomas in extra-genital organ sites. Presence of HPV has been reported in breast carcinoma which is the second most common cancer in India and is showing a fast rising trend in urban population. The two early genes E6 and E7 of HPV type 16 have been shown to immortalize breast epithelial cells in vitro, but the role of HPV infection in breast carcinogenesis is highly controversial. Present study has therefore been undertaken to analyze the prevalence of HPV infection in both breast cancer tissues and blood samples from a large number of Indian women with breast cancer from different geographic regions.

Methods

The presence of all mucosal HPVs and the most common high-risk HPV types 16 and 18 DNA was detected by two different PCR methods - (i) conventional PCR assays using consensus primers (MY09/11, or GP5+/GP6+) or HPV16 E6/E7 primers and (ii) highly sensitive Real-Time PCR. A total of 228 biopsies and corresponding 142 blood samples collected prospectively from 252 patients from four different regions of India with significant socio-cultural, ethnic and demographic variations were tested.

Results

All biopsies and blood samples of breast cancer patients tested by PCR methods did not show positivity for HPV DNA sequences in conventional PCRs either by MY09/11 or by GP5+/GP6+/HPV16 E6/E7 primers. Further testing of these samples by real time PCR also failed to detect HPV DNA sequences.

Conclusions

Lack of detection of HPV DNA either in the tumor or in the blood DNA of breast cancer patients by both conventional and real time PCR does not support a role of genital HPV in the pathogenesis of breast cancer in Indian women.

Role of epoxide hydrolase 1 gene polymorphisms in esophageal cancer in a high-risk area in India

BACKGROUND AND AIM

Microsomal epoxide hydrolase 1 (EPHX1) is involved in the metabolism of environmental and tobacco carcinogens. Tobacco smoking, betel quid chewing, and alcohol consumption are the major known risk factors for esophageal cancer. The present case-control study evaluated the influence of EPHX1 genetic variations on esophageal cancer susceptibility in 142 patients and 185 healthy controls from a high-incidence region of India where tobacco use and alcohol consumption are widespread and the users of these two substances are also betel quid chewers.

METHODS

EPHX1 polymorphic alleles (exon 3, Tyr113His and exon 4, His139Arg) were genotyped by polymerase chain reaction-restriction fragment length polymorphism method and direct sequencing. The results were analyzed using logistic regression to calculate odds ratios (OR) and confidence intervals (CI).

RESULTS

Patients with exon 4 genotypes (139His/Arg, 139Arg/Arg) and the 139Arg allele were significantly associated with a risk of esophageal cancer (OR(His139Arg) 1.887, 95% CI = 1.112-3.201, P = 0.019; OR(Arg139Arg) 7.140, 95% CI = 1.276-393.953, P = 0.025 and OR(Arg) 1.83, 95% CI = 1.19-2.82, P = 0.003). The 139His/Arg genotype was a significant risk factor for esophageal cancer in tobacco chewers and betel quid chewers. Patients with the 139Arg/Arg genotype were at significantly higher risk for developing a well-differentiated and moderately-differentiated grade of tumor. In contrast, the 113His/His genotype of exon 3 was a significant protective factor for esophageal cancer in tobacco smokers (OR 0.291, 95% CI = 0.138-0.616, P = 0.001), betel quid chewers (OR 0.434, 95% CI = 0.236-0.797, P = 0.007), and alcohol users.

CONCLUSION

EPHX1 exon 4 139His/Arg, and 139Arg/Arg genotypes were associated with a higher risk of esophageal cancer in a high-risk area of India.

Vaccination against human papilloma virus (HPV): epidemiological evidence of HPV in non-genital cancers

Recently, the vaccine against human papillomavirus (HPV) was introduced in the national vaccination programmes of several countries worldwide. The established association between HPV and the progression of cervical neoplasia provides evidence of the expected protection of the vaccine against cervical cancer. During the last two decades several studies have also examined the possible involvement of HPV in non-genital cancers and have proposed the presence of HPV in oesophageal, laryngeal, oropharyngeal, lung, urothelial, breast and colon cancers. The possible involvement of HPV in these types of cancer would necessitate the introduction of the vaccine in both boys and girls. However, the role of HPV in the pathogenesis of these types of cancer has yet to be proven. Moreover, the controversial evidence of the possible impact of the vaccination against HPV in the prevention of non-genital cancers needs to be further evaluated. In this review, we present an overview of the existing epidemiological evidence regarding the detection of HPV in non-genital cancers.

Novel missense mutation in FHIT gene: interpreting the effect in HPV-mediated cervical cancer in Indian women

Human papillomavirus (HPV) is considered to be a major etiological factor but is not sufficient for the development of cervical cancer. Other host factors including altered tumor suppressor gene activities might contribute to the carcinogenic process. Fragile Histidine Triad (FHIT) has been shown to play a pivotal role in carcinogenesis. Therefore, we made an attempt to find out point mutation of FHIT gene in HPV mediated cervical cancer in Indian women. 112 cases of cervical carcinoma tissue biopsies and 38 cervical scrapes samples of normal cytology were employed for this study. Herein, we report a novel mutation identified at nucleotide position 655, at codon 98 from CAT --> CGT with ultimate replacement of amino acid Histidine by Arginine in cervical cancer cases. Molecular modeling was performed to predict the effect of this mutation in disease pathology. We predict that this change, His to Arg substitution in substrate-binding domain may generate catalytically inactive protein with loss of tumor suppressor activity.

Relationship between human papillomavirus 16 and esophageal squamous cell carcinoma in Uygur population in Xinjiang Uygur Autonomous Region

AIM: To investigate the infection rate of human papillomavirus 16 (HPV16) in Uygur patients with esophageal squamous cell carcinoma in Xinjiang.

METHODS: Eighty-two paraffin-embedded specimens of esophageal carcinoma and 80 tumor-adjacent specimens were used in the study. The presence of HPV16 in these specimens was detected by high-sensitivity polymerase chain reaction (PCR) using the type-specific E6 primers.

RESULTS: The infection rates of HPV16 in esophageal squamous cell carcinoma and tumor-adjacent tissue were 31.7% (26/82) and 12.5% (10/80), respectively, showing significant difference between the two groups. HPV16 infection was not correlated with patient's age and sex as well as pathological differentiation and clinical stage of the carcinoma (χ² = 0.301, 0.149, 2.876 and 0.105, respectively; all P > 0.05).

CONCLUSION: HPV 16 infection is possibly correlated with esophageal squamous cell carcinoma in Uygur population in Xinjiang but showed no correlation with patient's age and sex as well as pathological differentiation and clinical stage of the carcinoma.

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

Background

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.

Methods

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.

Results

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.

Conclusion

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.

Effects of ROCK inhibitor, Y-27632, on adhesion and mobility in esophageal squamous cell cancer cells

Rho-associated protein kinase (ROCK), a molecular switch, modulates cellular functions in many cancers, such as hepatocellular, breast, colon cancers, etc. However, little is known the effect of ROCK on cell adhesion and mobility in esophageal squamous cell cancer (ESCC), one of the most diagnosed cancers in China. In this study, Y-27632 was used to specifically block ROCK activity in ESCC cells. Adhesion of ESCC cells was detected by homotypic and heterotypic adhesion assay together with examination of E-cadherin expression. Motility of ESCC cells changes were examined by detection of phosphorylated cofilin and observed under confocal microscopy, respectively. We found that Y-27632 increased both heterotypic and homotypic adhesion, and the expression of E-cadherin; decreased phosphorylated cofilin resulting in actin rearrangement in ESCC cells. All these findings indicate that ROCK signaling pathway plays an important role in cell adhesion and mobility, suggesting that it may be used as a potential target for therapy of ESCC.

Aberrant promoter methylation and reduced expression of p16 gene in esophageal squamous cell carcinoma from Kashmir valley: a high-risk area

Esophageal squamous cell carcinoma (ESCC) is one of the most prevalent cancer in Jammu and Kashmir region of India and has multi-factorial etiology involving dietary habits, genetic factors, and gene environmental interactions. Inactivation of the p16 gene expression by aberrant promoter methylation plays an important role in the progression of esophageal carcinoma. In the present investigation, we have studied the role of p16 promoter methylation in 69 histopathologically confirmed ESCC tissues and compared it with corresponding normal adjacent tissues for DNA methylation in the CpG island in the p16 promoter region by methylation-specific polymerase chain reaction (MSP) and p16 protein expression by immunoblotting. The results showed loss of p16 expression in 67% (46/69) of tumor tissues compared to only 3% in control tissues (2/69). Promoter methylation was observed in 52% (36/69) of tumor tissues and it gradually increased with the increasing severity of histological grades of the cancer (P = 0.0001). Loss of p16 expression with promoter methylation was observed in 26 of 36 cases (72%). Analysis of patients dietary habits revealed a strong association between promoter methylation and high consumption of hot salted tea (P < 0.05) which is a most favourite drink commonly consumed by Kashmiri people.

Management of natural and bioterrorism induced pandemics

A recent approach for bioterrorism risk management calls for stricter regulations over biotechnology as a way to control subversion of technology that may be used to create a man-made pandemic. This approach is largely unworkable given the increasing pervasiveness of molecular techniques and tools throughout society. Emerging technology has provided the tools to design much deadlier pathogens but concomitantly the ability to respond to emerging pandemics to reduce mortality has also improved significantly in recent decades. In its historical context determining just how 'risky' biological weapons is an important consideration for decision making and resource allocation. Management should attempt to increase capacity, share resources, provide accurate infectious disease reporting, deliver information transparency and improve communications to help mitigate the magnitude of future pandemics.

Role of BCL2 (ala43thr), CCND1 (G870A) and FAS (A-670G) polymorphisms in modulating the risk of developing esophageal cancer

BACKGROUND

Perturbations in the cell cycle and apoptotic genes have been implicated in human malignancies. A study of BCL2 ala43thr, CCND1 G870A and FAS A-670G gene polymorphisms was undertaken to explore their role in influencing the susceptibility for development of esophageal cancer.

METHODS

A total of 151 patients and age and gender matched 201 controls were investigated for BCL2 ala43thr, CCND1 G870A and FAS A-670G polymorphisms by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP).

RESULTS

The ala43ala genotype of BCL2 anti-apoptotic gene was significantly associated with risk of developing esophageal cancer (OR 2.1, 95%CI=1.0-4.4, P=0.03), more so in males (OR 2.6, 95%CI=P=0.03). In CCND1 G870A polymorphism, the AA genotype was marginally associated with higher risk of esophageal cancer (OR 1.5, 95%CI=0.98-2.4, P=0.05). No significant differences in genotype frequencies of FAS A-670G polymorphism were seen between esophageal cancer patients and controls (P=0.32). Interaction of BCL2 ala43ala, CCND1 870AA and FAS -670AA genotypes did not increase the risk multiplicatively. Association with clinical characteristics showed BCL2 ala43ala genotype to be at increased risk for developing tumors in the middle third location (OR 2.3, 95%CI=1.0-5.3, P=0.03), while patients with CCND1 870AA genotypes were at higher risk for the development of cancer in the upper third location (OR 3.8, 95%CI=1.6-9, P=0.002). BCL2 ala43ala genotype did not modulate the cancer risk in tobacco users. However, patients with CCND1 870AA and FAS -670AA genotypes were associated with a significantly lower number of smoking and chewing pack-years, suggesting a dose-dependent interaction in the risk for esophageal cancer (P=0.005).

CONCLUSION

There appears to be an influence of BCL2 ala43ala and CCND1 870AA genotypes on esophageal cancer phenotype, particularly with regard to tumor location, which supports the theory of prevalence of site-specific genetic alterations. FAS A-670G was not associated with the risk of developing esophageal cancer. Gene-environment interaction analysis showed cancer susceptibility in CCND1 870AA and FAS -670AA genotype to be influenced by quantity of tobacco.

A study on p53 gene alterations in esophageal squamous cell carcinoma and their correlation to common dietary risk factors among population of the Kashmir valley

AIM

To systematically examine the extent of correlation of risk factors, such as age, consumed dietary habit and familial predisposition with somatic Tp53 molecular lesion causal to elevate carcinogenesis severity of esophageal squamous cell carcinoma (ESCC) among the Kashmiri population of Northern India.

METHODS

All cases (n = 51) and controls (n = 150) were permanent residents of the Kashmir valley. Genetic alterations were determined in exons 5-8 of Tp53 tumor suppressor gene among 45 ESCC cases histologically confirmed by PCR-SSCP analysis. Data for individual cancer cases (n = 45) and inpatient controls (n = 150) with non-cancer disease included information on family history of cancer, thirty prevailing common dietary risk factors along with patient's age group. Correlation of genetic lesion in p53 exons to animistic data from these parameters was generated by Chi-square test to all 45 histologically confirmed ESCC cases along with healthy controls.

RESULTS

Thirty-five of 45 (77.8%) histologically characterized tumor samples had analogous somatic mutation as opposed to 1 of 45 normal sample obtained from adjacent region from the same patient showed germline mutation. The SSCP analysis demonstrated that most common p53 gene alterations were found in exon 6 (77.7%), that did not correlate with the age of the individual and clinicopathological parameters but showed significant concordance (P<0.05) with familial history of cancer (CD = 58), suggesting germline predisposition at an unknown locus, and dietary habit of consuming locally grown Brassica vegetable "Hakh" (CD = 19.5), red chillies (CD = 20.2), hot salty soda tea (CD = 2.37) and local baked bread (CD = 1.1).

CONCLUSION

Our study suggests that somatic chromosomal mutations, especially in exon 6 of Tp53 gene, among esophageal cancer patients of an ethnically homogenous population of Kashmir valley are closely related to continued exposure to various common dietary risk factors, especially hot salty tea, meat, baked bread and "Hakh", that are rich in nitrosoamines and familial cancer history.

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 (< or = 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.