Significant Changes in D2-like Dopamine Gene Receptors Expression Associated with Non- Small -Cell Lung Cancer: Could it be of Potential Use in the Design of Future Therapeutic Strategies?

Introduction: The alterations in the expression of five different dopamine receptor genes (DRD1- DRD5) associated with certain diseases of the immune and nervous systems have previously been reported, and play multiple roles in various disorders such as cancer. This study focused on the relationship between changes in dopamine receptor gene expression and non - small - cell lung cancer. Methods: Peripheral blood were obtained from 30 non-small cell lung cancer (NSCLC) patients and normal individuals. Total cellular RNA was extracted from peripheral blood mononuclear cells (PBMC) and cDNA was synthesized. Real - Time PCR was carried out using primer pairs specific for the five dopamine gene receptors mRNA and β-actin ( as internal control). Finally the specificities of the obtained PCR products for the respective dopamine receptors fragments were confirmed by sequencing. Results: Statistical analysis using SPSS software showed significant difference (P-value<0.05) in DRD2, DRD3 and DRD4 expression in NSCLC patients with comparison to normal individuals. The expression of these genes in the patient group was lower than those in the healthy controls, however, DRD1 and DRD5 genes did not show any significant changes. Conclusions: It can be concluded that there is a quantitative significant difference of D2-like dopamine receptor genes expression in non- small -cell lung cancer that is not the same in all kind of receptor genes. On the other hand such significant differences and profiles could contribute to diagnosis, treatment, survey and monitoring of non- small- cell lung cancer. In addition, it could be of potential use in the design of future therapeutic strategies.