The Tricyclic Antidepressant Amitriptyline Inhibits d-Cyclin Transactivation and Induces Myeloma Cell Apoptosis by Inhibiting Histone Deacetylases: In Vitro and In Silico Evidence

Abstract

Amitriptyline is a classic tricyclic antidepressant (TCA) and has been used to treat the depression and anxiety of patients with cancer, but its relevance to cancer cell apoptosis is not known. In the present study, we demonstrated that amitriptyline inhibited cyclin D2 transactivation and displayed potential antimyeloma activity by inhibiting histone deacetylases (HDACs). Amitriptyline markedly decreased cyclin D2 promoter-driven luciferase activity, reduced cyclin D2 expression, and arrested cells at the G 0 /G 1 phase of the cell cycle. Amitriptyline-induced apoptosis was confirmed by Annexin V staining, and cleavage of caspase-3 and poly(ADP-ribose) polymerase-1. D-Cyclin expression is reported to be epigenetically regulated by histone acetylation. Thus, we examined the effects of amitriptyline on histone 3 (H3) acetylation and demonstrated that amitriptyline increased acetylation of H3 and expression of p27 and p21. Further studies indicated that amitriptyline interfered with HDAC function by down-regulation of HDAC3, -6, -7, and -8, but not HDAC2, and by interacting with HDAC7. Molecular docking analysis and molecular dynamics simulations revealed that amitriptyline bound to HDAC7 and formed strong van der Waals interactions with five residues of HDAC7, including Phe162, His192, Phe221, Leu293, and His326, thus inhibiting HDAC activity. Therefore, we found that amitriptyline inhibited cyclin D2 transactivation and HDAC activity and could be a promising treatment for multiple myeloma.

The Antiparasitic Clioquinol Induces Apoptosis in Leukemia and Myeloma Cells by Inhibiting Histone Deacetylase Activity

“…Mononuclear cells were isolated from the samples by density centrifugation with Ficoll (Sigma). Primary cells were cultured at 37°C in complete Iscove's modified Dulbecco's medium as described previously (8,17).…”

“…Increase of Ac-H3 may result from down-regulation of the expression of HDACs and/or the inhibition of HDAC activity (8). HDACs are expressed in most cancer cells, including leukemia (35,36), lymphoma (36), and myelomas (8,36), and these enzymes are partly associated with chemosensitivity and clinical outcome (37).…”

“…HDACs are expressed in most cancer cells, including leukemia (35,36), lymphoma (36), and myelomas (8,36), and these enzymes are partly associated with chemosensitivity and clinical outcome (37). To determine the effects of CQ on the expression of HDACs, we examined HDAC1, -2, -3, -4, and -5 in CQ-treated myeloma and leukemia cells.…”

“…In recent years, accumulative evidence has suggested that inhibition of HDACs leads to the expression of tumor suppressor genes, such as p21 (7,8), p27 (8,9), and p53 (7,10), therefore inducing cell cycle arrest and cell apoptosis (1,9). HDAC inhibitors are emerging as a new class of anticancer agents for the treatment of solid and hematological malignancies (6).…”

The ubiquitin ligase HERC4 mediates c-Maf ubiquitination and delays the growth of multiple myeloma xenografts in nude mice

“…Mononuclear cells were isolated from the samples by Ficoll density centrifugation as described previously. 11 The collection and use of human bone marrow for this study were approved by the institutional review board of Soochow University in accordance with the Declaration of Helsinki.…”