Effect of lenalidomide on the human gastric cancer cell line SGC7901/vincristine Notch signaling.

Aim Of Study: To examine the function of lenalidomide (LEN) on the human multidrug resistance (MDR)-type gastric cancer line SGC7901/vincristine (VCR) via regulating Notch signaling.

Materials And Methods: Quantitative polymerase chain reaction was used for checking the genes of Notch, DNA methyltransferase (DNMT), RBP-J, Hes1/5, Deltex1, MDR/multidrug resistant protein (MRP); the cell proliferation and cell death were detected by cell counting kit-8 (CCK8) staining, Ki-67 expression, and propidium-iodide staining, and methylated DNA immunoprecipitation assay (MeDIP) was used for checking the 5 mC enrichment, indicating the DNA methylation of the Notch2 gene loci.

Results: LEN reduced the mRNA expression of Notch2 (P < 0.01) and increased the expression of the DNMT3A (P < 0.001) in SGC7901/VCR cell, suggesting the involvement of epigenetic regulation by DNMT3A on Notch2 gene expression. Consistently, Notch2 gene expression showed no obvious change between the LEN treatment and the control when the DNMT3A was knockdown using the interference of shRNA. The modulation of DNA methylation process on gene expression was then confirmed by 5 mC enrichment on Notch2 gene loci after LEN treatment. Furthermore, LEN could suppress the downstream genes in Notch2 signaling including RBP-J (P < 0.05), Hes1 (P < 0.001), and Deltex1 (P < 0.01). Due to the changes of gene expression pattern in Notch pathway, LEN showed a phenotype of cell proliferation suppression using CCK8 staining. Meanwhile, the expression of the genes associated with MDR and MRP was also significantly decreased (MDR, P < 0.01; MRP, P < 0.001) after LEN treatment. Therefore, inhibition of cell proliferation by LEN via Notch2 signaling combined with the MDR/MRP expression modulation contributes to the efficacy of LEN on the gastric cancer cell line SGC7901/VCR.

Conclusion: The data implicate that LEN would be an effective chemical for the therapy of drug-resistant human gastric cancer cell and the gastric cancer patients.