Genetic Instability in Peripheral Lymphocytes as Biological Marker for Non-Small Cell Lung Cancer Patients in the South Indian State of Andhra Pradesh

Independent and Interactive Effect of CYPs and GSTs Genetic Variants and Tobacco Smoking on the Risk of Non-Small Cell Lung Carcinoma

BACKGROUND

CYP and GST gene families detoxify tobacco carcinogens and have been linked to the risk of non-small cell lung carcinoma (NSCLC).

AIM

Independent and combined effects of CYP and GST genetic variations and smoking on the risk of non-small cell lung carcinoma (NSCLC) and its sub-histological types.

METHODS

We modelled an epistatic interaction via the effects of particular genotypes in two genes as OR (odds ratio), OR1, and OR2, a combination of both genotypes were characterized as OR_combine. In contrast, the two ORs' epistatic interaction for the individual genotypes has been represented as OR_interaction = OR_combine/(OR1 × OR2).

RESULTS

The variant genotypes of CYP2A6 (OR:4.2, p <0.001), GSTT1 (OR:3.9, p <0.001), and GSTM1 (OR: 4.5, p <0.001) were showed a significant risk with NSCLC. GSTM1 (del.)/CYP2A6 (variant) genotype was associated with a higher risk of NSCLC (OR:12.5, p <0.001). GSTM1 (del.)/CYP2A6 (Ser/Pro+Pro/Pro) and GSTM1 (del.)/CYP2A13 (CT+TT) interacted redundantly (OR_intraction = 0.66 and 0.64). A co-suppressive interaction was observed between GSTT1 (del.)/CYP2A6 (Ser/Pro+Pro/Pro) (OR_intraction = 0.41). Simultaneously, both GSTT1/GSTM1 del. genotype was associated with a significantly higher risk to NSCLC. In contrast, GSTT1 del./GSTM1 del. genotype interaction displayed a co-suppressive effect (OR_intraction = 0.15). CYP1A1(TC+CC)/CYP2A13(CT+TT)mutually interacted synergistically (OR_intraction = 1.27).CYP1A1 (TC+CC)/GSTP1 (Val/Val+Ile/Val) genotype demonstrated an additive (OR_intraction = 1) effect. GSTP1(Val/Val+Ile/Val) interacts with GSTT1 (del.) genotype exerted a suppressive effect (OR_intraction = 0.69). CYP2A6 in smokers increased risk by 4.2 (p = 0.001) to 5.6 fold (p <0.001), while GSTM1 and GSTT1 were independent of smoking.

CONCLUSION

Epistatic interactions revealed that CYPs/GSTs might follow a web of the interactions to modify the risk of NSCLC.

Genetic damage in lymphocytes of lung cancer patients is correlated to the composition of the respiratory tract microbiome

Recent findings indicate that the microbiome may have significant impact on the development of lung cancer by its effects on inflammation, dysbiosis or genome damage. The aim of this study was to compare the sputum microbiome of lung cancer (LC) patients with the chromosomal aberration (CA) and micronuclei (MN) frequency in peripheral blood lymphocytes. In the study, the taxonomic composition of the sputum microbiome of 66 men with untreated LC were compared with 62 control subjects with respect to CA and MN frequency and centromere fluorescence in situ hybridisation analysis. Results showed a significant increase in CA (4.11 ± 2.48% versus 2.08 ± 1.18%) and MN (1.53 ± 0.67% versus 0.87 ± 0.49%) frequencies, respectively, in LC patients as compared to control subjects. The higher frequency of centromeric positive MN of LC patients was mainly due to aneuploidy. A significant increase in Streptococcus, Bacillus, Gemella and Haemophilus in LC patients was detected, in comparison to the control subjects while 18 bacterial genera were significantly reduced, which indicates a decrease in the beta diversity in the microbiome of LC patients. Although, the CA frequency in LC patients is significantly associated with an increased presence of the genera Bacteroides, Lachnoanaerobaculum, Porphyromonas, Mycoplasma and Fusobacterium in their sputum, and a decrease for the genus Granulicatella after application of false discovery rate correction, significance was not any more present. The decrease of MN frequency of LC patients is significantly associated with an increase in Megasphaera genera and Selenomonas bovis. In conclusion, a significant difference in beta diversity of microbiome between LC and control subjects and association between the sputum microbiome composition and genome damage of LC patients was detected, thus supporting previous studies suggesting an etiological connection between the airway microbiome and LC.

Genomic instability in chronic obstructive pulmonary disease and lung cancer: A systematic review and meta-analysis of studies using the micronucleus assay

Respiratory tissues are highly susceptible to diseases due to the constant exposure to physical and chemical airborne pollutants. Chronic obstructive pulmonary disease (COPD) and lung cancer are among the most common causes of serious illness and death worldwide. The inflammatory environment associated with these respiratory diseases has long been accepted as the major player in the development of airway abnormalities. The presence and relevance of DNA damage and genomic instability makes the micronucleus assay a suitable candidate to quantitatively estimate these early pathogenetic events. A systematic review and meta-analysis were planned to determine underlying common mechanisms that can explain the relationships between COPD and lung cancer. A total of 17 studies from Jan 1999 to Dec 2019 comparing micronucleus frequency in patients affected by respiratory diseases vs healthy controls were analysed. Our results confirmed the presence of significant association between MN frequency and the diseases investigated, and suggested a circle of events linking inflammation induced oxidative stress to the risk of disease through genomic instability and hypoxia. Therefore, using non-invasive, robust and cost effective genomic instability assays such as the micronucleus assay, would allow us to capture unique phenotypic and biological changes that would allow the identification of subjects at high risk of developing lung diseases and improve early detection strategies.

The Clinical Study of Urokinase-Type Plasminogen Activator and Vascular Endothelial Growth Factor in Gastric Cancer

The aim of this study is to explore the expression and significance of urokinase-type plasminogen activator (u-PA) and vascular endothelial growth factor (VEGF) in gastric cancer, providing a novel insight for the diagnosis and treatment of gastric cancer. The gastric cancer specimens, which were excised from 87 patients and confirmed during July, 2012-July, 2014, were selected as observation group, and the normal tissue next to the tumor (more than 5 cm from the edge of the tumor) from 45 patients were randomly selected as control. u-PA and VEGF were detected by immunohistochemistry for the analysis of the correlation of u-PA and VEGF in two groups. The positive rates of u-PA and VEGF in gastric cancer tissue were 81.61 and 79.31 %, respectively, which were 6.67 and 8.89 % in the control group, respectively. The positive rates in the observation group were obviously higher than those in the control group, and the difference was statistically significant (P < 0.05). Among the 87 gastric cancer tissue samples from the observation group, the positive rates of u-PA and VEGF in the gastric cancer with poor differentiation, lymphatic metastasis, invasion up to serosal layer, and TNM stage III + IV were obviously higher than those in the gastric cancer with high differentiation, non-lymphatic metastasis, invasion not up to the serosal layer, and TNM stage I + II, and the difference was statistically significant (P < 0.05). Among the 87 gastric cancer tissue samples from the observation group, u-PA and VEGF were found to be positive in 60 cases and negative in 7 cases. By comparing the two groups, u-PA and VEGF were positively correlated in gastric cancer tissue (P < 0.05). u-PA and VEGF were highly expressed in gastric cancer tissue, which could be used as the molecular biological indicators to predict the invasion and metastasis potential of gastric cancer. The combination of two factors plays a guiding role in early diagnosis and treatment of gastric cancer.

Psychological interventions to improve the quality of life in Indian lung cancer patients: A neglected area

The incidence of lung cancer is very high and evidence suggests that patients experience imbalanced emotional capabilities due to less survival rate compared to other cancers. Direct and indirect psychological interventions are mandatory to improve the outcome of lung cancer treatment. Although such interventions are being practiced in developed nations, the effects of psychological interventions on the treatment outcome in the Indian context are lacking. Since there is a definite correlation between treatment outcome and psychological issues, it is high time that clinicians in developing countries including India adopt practices to enhance the quality of life of lung cancer patients.

Association of CYP1A1, GSTM1 and GSTT1 gene polymorphisms with risk of non-small cell lung cancer in Andhra Pradesh region of South India

BACKGROUND

Lung cancer is one of the most preventable causes of death globally both in developed and developing countries. Although it is well established that smokers develop lung cancer, there are some smokers who are free from the disease risk. The predisposition to lung cancer is attributed to genetic polymorphisms in xenobiotic metabolizing genes. Reports on assessment of xenobiotic metabolizing genes like Cytochrome P 450 1A1 (CYP1A1), Glutathione -S -transferase M1 (GSTM1) and T1 (GSTT1) polymorphisms from India are meagre, and reports from Andhra Pradesh are lacking.

METHODS AND RESULTS

Assessment of polymorphisms in CYP1A1, GSTM1 and GSTT1 in NSCLC patients and healthy individuals specific to population of Andhra Pradesh, a South Indian state was attempted by multiplex PCR and RFLP, and this is the first study which tried to correlate oxidative stress with the polymorphisms in xenobiotic metabolizing genes. Results showed that CYP1A1 m1 'CC' genotype was significantly associated with lung cancer susceptibility with a 2.3-fold risk, CYP1A1 m2 'AG' gene polymorphisms with 8.8-fold risk and GSTT1 (-/-) genotype demonstrated a twofold risk of disease susceptibility.

CONCLUSIONS

A combined role of genetic polymorphisms and smoking status can be attributed for the cause of lung cancer. Further, the association between oxidative stress and genetic polymorphisms showed a correlation between GSTT1 and super oxide dismutase activity; CYP1A1 m1, m2 and GSTT1 with glutathione peroxidase activity; CYP1A1 m1 and GSTM1 with melondialdehyde levels; and CYP1A1 m1 and GSTT1 with 8-oxo-7,8-dihydro-2'-deoxyguanosine. A higher risk of lung cancer seems to be associated with combined gene polymorphisms of phase I and phase II enzymes than that ascribed to single gene polymorphism.

Association of TNFα-308, IFNγ+874, and IL10-1082 gene polymorphisms and the risk of non-small cell lung cancer in the population of the South Indian state of Telangana

BACKGROUND

Cytokine-mediated inflammation is important in the pathogenesis of non-small cell lung cancer (NSCLC). Genetic polymorphisms in cytokine genes and their association with lung cancer in the Indian population have not been reported.

METHODS

For the first time, we analyzed genetic polymorphisms of TNFα ^-308, IFNγ ⁺⁸⁷⁴, and IL10 ^-1082 genes in 246 NSCLC patients and 250 healthy controls in the South Indian population from Telangana using ARMS PCR.

RESULTS

IFNγ⁺⁸⁷⁴ A/T and IL10^-1082 G/G gene polymorphisms were found to be significantly associated with NSCLC with 1.56- and 1.68-fold disease risk, respectively. There was no association between the risk of NSCLC and TNFα^-308 polymorphism. Gene polymorphisms stratified according to smoking revealed that IFNγ⁺⁸⁷⁴ A/T polymorphisms in smokers increased the disease risk by 2.91 fold. IL10^-1082 G/G polymorphisms showed 2-fold increased risk among patients who were smokers when compared to the controls. However, there was no association between TNFα^-308, IFNγ⁺⁸⁷⁴, and IL10^-1082 gene polymorphism and the stage of the NSCLC patients. The overall risk associated with the combination of these polymorphisms indicated that the TNFα^-308 G/A + IFNγ⁺⁸⁷⁴ A/T + IL10^-1082 G/G genotype increased the risk by 1.5 fold.

CONCLUSIONS

The results of our study indicate an association between cytokine gene polymorphisms and the risk of NSCLC in an Indian population.