Atiprimod is a novel cationic amphiphilic compound and has been shown to exert antimyeloma effects both in vitro and in mouse experiments. This study was undertaken to evaluate the therapeutic efficacy of atiprimod on mantle cell lymphoma (MCL) and elucidate the mechanism by which it induces cell apoptosis.
IntroductionMantle cell lymphoma (MCL) represents approximately 8% of all non-Hodgkin lymphomas (NHLs). It has the worst prognosis among all B-cell-derived malignancies with median survival of 3 to 4 years. [1][2][3] Although MCL has been treated with chemotherapy, radiotherapy, hematopoietic stem cell transplantation, molecular targeted therapy, and combination therapy of these treatments, no standard treatment approach has been established thus far. Novel therapeutic agents are needed in clinical trials. [4][5][6][7][8]5] decane-2-propanamine), a novel cationic amphiphilic compound, has been studied for its anticancer properties in malignancies. [9][10][11] Recent reports have suggested that atiprimod exhibits antiproliferative and antiangiogenic activities, induces apoptosis via activation of caspases-3 and -8, and inhibits phosphorylation of Akt and STAT3 in multiple myeloma (MM). 10,12 In addition, atiprimod exhibits in vivo antimyeloma effects in xenograft severe combined immunodeficient (SCID) mouse models. 10,13 These results provide a framework for clinical trials of atiprimod in MM.MCL has distinct biologic, morphologic, and immunophenotypic features in NHL. 14 MCL responds to similar agents used effectively for MM. For example, the chemotherapy regimens CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) and hyperCVAD (cyclophosphamide, vincristine, doxorubicin, decadron, cytarabine, and methotrexate) are effective in B-cell NHL, especially in MCL, 15 but their slight modifications are also effective in MM. [16][17][18][19] Bortezomib, a potent and specific proteasome inhibitor that was U. S. Food and Drug Administration-approved for relapsed MM, was also proven to be effective in MCL. 20 Thalidomide is active in MM, and thalidomide in combination with rituximab induces impressive antitumor activity in relapsed/ refractory MCL patients. 21 Revlimid, an immunomodulatory drug that produces durable clinical responses in patients with relapsed and refractory MM, 22 also is showing activity in clinical trials for treatment of NHL. Thus, we hypothesize that MCL and MM share certain biologic mechanisms in responding to various compound therapies. Atiprimod, which exhibits significant antitumor ability against MM cells by growth inhibition and apoptosis, 10 may also prove effective in MCL. In this study, we demonstrate that atiprimod not only inhibited growth and induced apoptosis of MCL cell lines SP53, MINO, Grant 519, Jeko-1, and freshly isolated patient-derived primary MCL cells in vitro, but it was also therapeutic against established human MCL in xenograft SCID mouse models. Of importance, atiprimod exhibited lower cytotoxicity against normal T cells. Furthermore, we attempted to eluc...