The aim of the present work was to detect the effect of human mesenchymal stem cells (MSCs) on HepG2 cells (hepatocellular carcinoma cell line) by applying RT-PCR technique, to detect gene expression of the following genes: BCL2, PCNA, Survivin, β-Catenin, VEGF and Telomerase. The cultured cells were divided into 3 groups: HepG2 cells as control, HepG2 cells treated with MSC conditioned medium and HepG2 cells treated with co-culture conditioned medium. Results showed that BCL2, PCNA, Survivin, β-Catenin, VEGF and Telomerase gene expression was detected in HepG2 cells.Addition of MSC conditioned medium decreased expression of BCL2, PCNA and β-Catenin. However, no further suppression was observed with BCL2, PCNA and β-Catenin with addition of co-culture conditioned medium. Addition of co-culture conditioned medium decreased expression of survivin and telomerase.The above mentioned results suggest that MSCs could affect HepG2 cells in culture. Further in vivo studies are recommended to evaluate the role of stem cells in liver malignancy.