TRANSCRIPTIONAL ANALYSIS OF ZINC-DEPENDENT HISTONE DEACETYLASES IN SEVERAL HUMAN CANCER CELLS.

Unlabelled: Histone deacetylases, especially zinc-dependent deacetylases HDACs, are among attractive drug targets for treating cancer in recent years.

Aim: To explore the expression level of HDACs in several human cancer cell lines and examine the possible association between their expression and the sensitivity/resistance to the selective- or pan-HDAC inhibitors.

Materials And Methods: The RNA expression of 11 HDACs isoforms was assayed in HeLa, HepG2, AV3, HEK293, A549, and K562 cells by semiquantitative reverse transcription-polymerase chain reaction. The sensitivity/resistance of these cell lines to the pan- or selective- HDAC inhibitors was estimated by MTS assay.

Results: The relative transcription of HDACs genes demonstrated that members of Class I HDAC (HDAC1, 2 and 3) and members of Class II HDAC (HDAC4, 5, 6 and 7) had slight to significant levels of expression in cell lines under study with no dominant HDAC-subtype gene transcription. pan-HDAC inhibitor demonstrated superior antitumor activity compared to HDAC isoform-selective inhibitor.

Conclusion: The absence of the dominant HDAC-subtype gene transcription in different human cancer cell lines explains the inferior efficacy of HDAC isoform-selective inhibitors as compared to pan-HDAC inhibitors.