Enhanced expression of tumour suppressor RAR-β by DSPC nano-formulated lipo-ATRA in the lung of B16F10 cell-implanted C57BL6 mice and in A549 cells.

AIM: All Trans Retinoic acid (ATRA) is an efficient drug for leukemia, but is not efficient therapy for solid cancers. Hence we have used 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) and cholesterol lipo-ATRA to investigate its molecular therapeutic effect on lung cancer. The objective was to find whether it could enhance ATRA receptor, RAR-β expression in lung cells as it was lost in majority of cancers including lung cancer.

MATERIALS AND METHODS: The study was made in an experimental C57BL/6 mice model developed by tail vein injection of B16F10 cells and in A549 human lung cancer cells. The RAR-β protein expression was studied by Immunohistochemistry/Immunocytochemistry and the mRNA expression was studied by RT-PCR and qPCR methods.

KEY FINDINGS: Both free and lipo-ATRA treatments showed an enhancement of RAR-β protein and gene expressions, indicating its induction on RAR β. However, lipo-ATRA treatment has shown significant induction when compared with free ATRA treatment.

SIGNIFICANCE: Our results implies that the DSPC lipo-ATRA treatment might have accumulated more ATRA in to the target cells which might have resulted in the induction of its receptor RAR-β expression in a hypothesis of ligand induced receptor expression.