Genetic susceptibility to esophageal cancer due to CYP1A1 gene variant rs4646903 in tobacco addicted patients of Pashtun ethnicity: a case control study in Khyber Pakhtunkhwa province of Pakistan

Cancer incidence in Khyber Pakhtunkhwa, Pakistan, 2020

BACKGROUND

To present the population-based cancer statistics for Khyber Pakhtunkhwa (KP), Pakistan, an incidence study was conducted at the Shaukat Khanum Memorial Cancer Hospital and Research Centre (SKMCH&RC) in Lahore, Pakistan, in 2023.

METHODS

Records from various centres on new cancers diagnosed among residents of KP between January and December 2020 were gathered. Both active and passive methods of data collection were applied, and the information was saved in a central repository at SKMCH&RC. The incidence rates were computed by age group and sex and presented per 100,000 population.

RESULTS

Among children (0-14 years), the Age-Standardised Incidence Rate (ASIR) was 4.0 in girls and 6.1 in boys, and haematologic malignancies were more prevalent; in adolescents (15-19 years), the ASIR was 7.7 in females, 9.4 in males, and bone tumours, haematologic malignancies, and neurological cancers were prominent; in adult females (> / = 20 years), the ASIR was 84.9, and cancers of the breast, digestive system, and reproductive organs were predominant; and adult males, the ASIR was 73.0, and cancers of the gastrointestinal tract, lip/oral cavity/pharynx, prostate, and Non-Hodgkin Lymphoma (NHL) were common.

CONCLUSIONS

It is crucial to investigate the aetiology of these diseases at the community level because dietary elements, infectious diseases, and tobacco use all appear to be significant contributors. Prospective studies could play a key role in highlighting the factors linked to these diseases. Therefore, cancer registration must continue in conjunction with the exploration of risk factors.

Genic-intergenic polymorphisms of CYP1A genes and their clinical impact

The humancytochrome P450 1A (CYP1A) subfamily genes, CYP1A1 and CYP1A2, encoding monooxygenases are critically involved in biotransformation of key endogenous substrates (estradiol, arachidonic acid, cholesterol) and exogenous compounds (smoke constituents, carcinogens, caffeine, therapeutic drugs). This suggests their significant involvement in multiple biological pathways with a primary role of maintaining endogenous homeostasis and xenobiotic detoxification. Large interindividual variability exist in CYP1A gene expression and/or catalytic activity of the enzyme, which is primarily due to the existence of polymorphic alleles which encode them. These polymorphisms (mainly single nucleotide polymorphisms, SNPs) have been extensively studied as susceptibility factors in a spectrum of clinical phenotypes. An in-depth understanding of the effects of polymorphic CYP1A genes on the differential metabolic activity and the resulting biological pathways is needed to explain the clinical implications of CYP1A polymorphisms. The present review is intended to provide an integrated understanding of CYP1A metabolic activity with unique substrate specificity and their involvement in physiological and pathophysiological roles. The article further emphasizes on the impact of widely studied CYP1A1 and CYP1A2 SNPs and their complex interaction with non-genetic factors like smoking and caffeine intake on multiple clinical phenotypes. Finally, we attempted to discuss the alterations in metabolism/physiology concerning the polymorphic CYP1A genes, which may underlie the reported clinical associations. This knowledge may provide insights into the disease pathogenesis, risk stratification, response to therapy and potential drug targets for individuals with certain CYP1A genotypes.

Recently Top Trending Cancers in a Tertiary Cancer Hospital in Pakistan

Cancer is a leading cause of death, and its incidence is increasing, as reported in recent studies by GLOBOCAN. Cancer registry programs provide insights into currently trending tumors worldwide and aid in determining possible risk factors. This study was based on 7 years of cancer registry data recorded at NIMRA cancer hospital, Sindh, from 2015 to 2021. A total of 16,191 cancer patients were registered. In men, head and neck, lung, liver, colorectal and urinary tract cancers were most common. In women, breast cancer, head and neck cancer, gynecological tumors, esophageal cancer and colorectal cancer predominated. The overall data analysis indicated trending cancers in both sexes, including head and neck cancer (37.76%), breast cancer (13.83%), gynecological tumors (10.22%), esophageal cancer (5.18%), lung cancer (4.79%), colorectal cancer (4.27%), liver cancer (3.87%), lymphoma (3.16%), urinary tract cancer (3.11) and prostate cancer (1.53%). The mean age was 50.41 ± 11.78 years in men and 48.47 ± 11.88 years in women. Cancer prevalence has markedly increased worldwide, and is particularly alarming in developing countries. Various risk factors are involved in this increase, including the use of tobacco, areca nut, chewable tobacco, snuff or niswar. Current disease trends are substantially different from those in older studies at the institute.

Gene-gene and gene-environment interaction: an important predictor of oral cancer among smokeless tobacco users in Karachi

Objective: To determine the risk for oral cancer caused by simultaneous occurrence of more than one of the tested cytochrome P450 1A1MspI, glutathione S-transferaseM1 null gnd Glutathione S-transferasesT1 null gene polymorphisms. Method: The cross-sectional case-control study was conducted from December 2011 to October 2016 at the Ziauddin University, Karachi, in collaboration with Dow University of Health Sciences, Karachi, and comprised oral squamous cell carcinoma cases in group A and healthy tobacco habit-matched controls in group B. All investigations were done using standardised laboratory protocols. The outcomes were determined in terms of association of various combinations of cytochrome P450 1A1MspI, glutathione S-transferasesM1 null and glutathione S-transferases T1 null polymorphisms with oral cancer. Data was analysed using SPSS 20. Results: Of the 238 subjects, 140(58.8%) were in group A and 98(41.2%) were in group B. Mean ages in group A and B were 47.1±12.22 and 41.6±14.58 years, respectively. Male/Female ratio in group A was 1.88:1 while 83.4% were using tobacco. When cytochrome P450 1A1MspI homozygous (m2/m2) and glutathione S-transferasesM1 null variants occured simultaneously in an individual, an odds ratio of 12.8 (95% confidence interval: 1.20-135.5; p=0.03) among overall tobacco chewers was observed. For glutathione S-transferasesM1 not null and glutathione S-transferasesT1 null variant combination among overall tobacco users, the conferred odds ratio was 4.58 (95% confidence interval: 0.99-21.2; p=0.05). The other studied gene combinations did not reveal significant associations (p>0.05). ---Continue

Investigation into the expression levels of MAGEA6 in esophageal squamous cell carcinoma and esophageal adenocarcinoma tissues

Esophageal carcinoma (EC) is the sixth most deadly of all cancers. It is among the most malignant cancers due to its highly aggressive nature and low survival rate. The incidence of EC is high in Asia, particularly in Southern areas including China, Iran and Japan. There is a large body of evidence to suggest an association between the melanoma antigen gene (MAGE) family and the initiation of cancer; however, there is no clear evidence to suggest an association between EC and MAGE. Discovery of the chemical and physiological processes relevant to the occurrence of EC is vital for clinicians to diagnose and treat this highly aggressive cancer. The present study focused on the association of EC with the expression of MAGE family member A6 (MAGEA6) at the mRNA and protein levels using gene chip, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. The expression of MAGEA6 in human esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) tissue samples were compared with those in paracancerous tissue. The result of the gene chip assay revealed that as the generation grew, there was a significant increase in MAGEA6 transcription in the esophageal epithelial cell line, SHEE Different ESC cell lines also exhibited a significantly higher transcription of MAGEA6 compared with the HaCaT cell line, as determined via reverse transcription-quantitative PCR. An higher positive rate of MAGEA6 expression in ESCC and EAC tissues was also revealed when compared with paracancerous tissues, as determined via immunohistochemistry. The results indicated that MAGEA6 is highly transcribed and expressed in the development of EC and may therefore serve as a novel biomarker for the diagnosis or treatment of EC.

CYP1A1 and GSTP1 gene variations in breast cancer: a systematic review and case-control study

In first part of this study, a systematic review was designed to explore the involvement of CYP1A1 and GSTP1 genes in breast cancerogenesis. Based on systematic review, we designed a study to screen CYP1A1 and GSTP1 genes for mutation and their possible association with breast carcinogenesis. A total of 400 individuals were collected and analyzed by PCR-SSCP. After sequence analysis of coding region of CYP1A1 we identified eleven mutations in different exons of respective gene. Among these eleven mutations, ~3 folds increased breast cancer risk was found associated with Asp82Glu mutation (OR 2.99; 95% CI 1.26-7.09), with Ser83Thr mutation (OR 2.99; 95% CI 1.26-7.09) and with Glu86Ala mutation (OR 3.18; 95% CI 1.27-7.93) in cancer patients compared to controls. Furthermore, ~4 folds increase in breast cancer risk was found associated with Asp347Glu, Phe398Tyr and 5178delT mutations (OR 3.92; 95% CI 1.35-11.3) in patients compared to controls. The sequence analysis of GSTP1 resulted in identification of total five mutations. Among these five mutations, ~3 folds increase in breast cancer risk was observed associated with 1860G>A mutation, with 1861-1876delCAGCCCTCTGGAGTGG mutation (OR 2.70; 95% CI 1.10-6.62) and with 1861C>A mutation (OR 2.97; 95% CI 1.01-8.45) in cancer patients compared to controls. Furthermore, ~5 folds increase in breast cancer risk was associated with 1883G>T mutation (OR 4.75; 95% CI 1.46-15.3) and ~6 folds increase in breast cancer risk was found associated with Iso105Val mutation (OR 6.43; 95% CI 1.41-29.3) in cancer patients compared to controls. Our finding, based on systematic review and experimental data suggest that the polymorphic CYP1A1 and GSTP1 genes may contribute to risk of developing breast cancer.