Expression of HMB3, ASH1 and CLCA2 Gene among Carcinoma Lung Patients by Real Time Polymerase Chain Reaction (RT-QPCR) Assay
Background: Lung cancer is diagnosed by clinical examination for chest findings, any peripheral lymphadenopathy, radiological imaging chest x-ray, CECT scan, and histopathology, or biopsy. The tissue collection process is an invasive procedure and limited by sensitivity and specificity. Immunohistochemistry and molecular testing are being developed for the identification of subtype and tissue of origin as the lung. IN the present study we identified gene expression in carcinoma lung patients.
Methodology: 30 patients of diagnosed cases of Non-small cell and small cell lung cancer were included in the study and underwent complete tumor evaluation. Pathological type was diagnosed as lung adenocarcinoma, squamous cell carcinoma and small cell carcinoma. Additionally, twenty 29-52 (mean – 38.5 years) years healthy volunteers were selected as the control group. RNA isolated from peripheral blood mononuclear cells was quantified, prepared for cDNA synthesis and analyzed for expression of HMB3,ASH1 and CLCA2 gene.
Results: Expression of gene markers
a) The relative expression of HMGB3 was found to be significantly reduced by 1.75 relative to controls.
b) The relative expression of CLCA2 was increased by 1.5 relative to controls.
c) Relative expression of ASH1 was increased by 1.52 relative to controls.
Correlation with staging:
a) HMGB3 expression was significantly reduced in stage IV of the lung cancer relative to controls. However, no significant difference was obtained for stage III
b) CLCA2 expression was increased in both the stages of the lung cancer relative to controls
c) ASH1 expression was increased in both the stages of the lung cancer relative to controls but more in stage IV.
Correlation with histopathological subtype
a) HMGB3 expression was reduced in all subtypes of lung cancer relative to controls. However, it was significant in small cell lung cancer.
b) CLCA2 expression was increased in non-small cell lung cancer relative to controls. However, it was reduced in small cell lung cancer
c) ASH1 expression was increased in non-small cell lung cancer relative to controls
No significant correlation was observed between age and expression of HMGB3 and CLCA2 genes (r=-0.19, p>0.05). No association was obtained with smoking status or gender of patients.
Conclusion: All the three genes had variable expression in lung cancer patients and these genes can be considered for identification of circulating tumor cells in lung cancer patients.
Acknowledgment: This study has been supported by the Department of Science and Technology New Delhi under WOS-A Project (SR/WOS-A/LS-605/2016(G)
Keywords - Reference Gene, Carcinoma Lung, Gene Expression, Circulating Tumor Cells