In Vitro Effect Of VPA Together With ATRA and Ara-C On Proliferation and Viability Of Pediatric AML Cell Line THP-1

In addition to its HDAC inhibitory property, Valproic acid is also known as anticonvulsant agent and mood stabilizer in the treatment of bipolar disorders. Due to its HDAC inhibitory activity and its safety in long-term usage, VPA is presumed to be a good candidate for cancer treatment. It is known that VPA induces apoptosis in leukemic cells, while not in normal cells. VPA is reported as an effective agent in treatment of pediatric AML in clinical studies and  is also well tolerated in children.

In this study, the in vitro effect of the combination of HDAC inhibitor VPA with Ara-C and ATRA which are used in AML therapy, is investigated on AML cells. For this purpose, the effect of VPA, Ara-C and ATRA on proliferation of AML cell line THP-1 is tested in cell culture condition. To assess the effect on cell proliferation, p21 expression was measured by RT-PCR method. The use of VPA alone, did not affect the cell viability, while increasing the expression of the p21 gene. VPA in combination with Ara-C, increased the expression of p21 gene more than the other combinations. Thus it is determined that the p21 gene expression is higher as a result of known cell cycle stops.

In this study, the understanding of how effective is VPA together with ATRA and/or Ara-C on AML cells, might be a good start for animal studies and clinical trials as a remarkable data for the development of new chemotherapeutic protocols.