Inhibition of the ABL kinase activity blocks the proliferation of BCR/ABL+ leukemic cells and induces apoptosis.

The BCR/ABL fusion protein transforms myeloid stem cells. Both chronic myelogenous leukemias (CML) and a subset of acute lymphoblastic leukemias (ALL) are associated with the expression of BCR/ABL proteins. This knowledge has not yet been translated into any specific tool to control ABL driven neoplastic cells growth. CGP57148B is an ATP-competitive inhibitor of the ABL protein kinase; it has been shown to inhibit the kinase activity of ABL both in vitro and in vivo and to inhibit the growth of v-abl and bcr/abl transfectants, as well as the in vitro formation of bone marrow (BM)-derived colonies in the presence of growth factors in some CML patients. These studies were performed to investigate the activity of CGP57148B on the spontaneous proliferation of both fresh and cultured, leukemic and normal, BCR/ABL positive and negative cells, and to study its mechanism of action. Six cell lines derived from BCR/ABL+ leukemias (K562, BV173, KCL22, KU812, MC3, LAMA84), thirteen BCR/ABL negative lines, both neoplastic (KG1, SU-DHL-1, U937, Daudi, NB4, NB4.306) and derived from normal cells (PHA blasts, LAK, fibroblasts, LCL, renal epithelial cells, endothelial cells, CD34(+) cells), and 14 fresh leukemic samples were tested using a tritiated thymidine uptake assay. The in vivo phosphorylation of the BCR/ABL protein was evaluated by western blot, while apoptosis was detected by the annexin V/propidium binding test. The induction of differentiation was assayed by immunofluorescence using multiple antibodies. All six BCR/ABL+ lines showed a dose dependent inhibition of their spontaneous proliferative rate, which was not accompanied by differentiation. The treatment caused, within minutes, dephosphorylation of the BCR/ABL protein, followed in 16-24 hours by a decrease in cycling cells and induction of apoptosis. No significant inhibition of DNA synthesis was observed in any BCR/ABL negative normal or neoplastic line at concentrations </=3 microM, with the exception of fibroblasts and CD34 cells. Proliferation inhibition was observed also when using fresh samples obtained from two Ph+ ALL and 12 consecutive CML patients. Induction of apoptosis was observed in these samples too. The activity of CGP57148B can be monitored in ex vivo isolated or cultured cells using a simple and reproducible assay, without the need for exogenously added growth factors. This molecule possibly exerts its effects through the inhibition of the kinase activity of BCR/ABL and the subsequent initiation of apoptosis, without inducing cell differentiation. Some normal cells are also affected. These data support the use of CGP57148B in initial clinical studies; possible toxic effects on BM and fibroblast-derived cells will have to be closely monitored. The in vivo monitoring of patients will have to be focused on the induction of apoptosis in leukemic cells.

Gambacorti-Passerini C ，le Coutre P ，Mologni L ，Fanelli M ，Bertazzoli C ，Marchesi E ，Di Nicola M ，Biondi A ，Corneo GM ，Belotti D ，Pogliani E ，Lydon NB ... -  《BLOOD CELLS MOLECULES AND DISEASES》

Inhibition of phosphotyrosine phosphatase 1B causes resistance in BCR-ABL-positive leukemia cells to the ABL kinase inhibitor STI571.

Koyama N ，Koschmieder S ，Tyagi S ，Portero-Robles I ，Chromic J ，Myloch S ，Nürnberger H ，Rossmanith T ，Hofmann WK ，Hoelzer D ，Ottmann OG ... -  《CLINICAL CANCER RESEARCH》

Selective inhibition of cell proliferation and BCR-ABL phosphorylation in acute lymphoblastic leukemia cells expressing Mr 190,000 BCR-ABL protein by a tyrosine kinase inhibitor (CGP-57148).

Beran M ，Cao X ，Estrov Z ，Jeha S ，Jin G ，O'Brien S ，Talpaz M ，Arlinghaus RB ，Lydon NB ，Kantarjian H ... -  《CLINICAL CANCER RESEARCH》

Inhibition of Bcr-Abl kinase activity by PD180970 blocks constitutive activation of Stat5 and growth of CML cells.

Huang M ，Dorsey JF ，Epling-Burnette PK ，Nimmanapalli R ，Landowski TH ，Mora LB ，Niu G ，Sinibaldi D ，Bai F ，Kraker A ，Yu H ，Moscinski L ，Wei S ，Djeu J ，Dalton WS ，Bhalla K ，Loughran TP ，Wu J ，Jove R ... -  《ONCOGENE》

Selective induction of apoptosis in Philadelphia chromosome-positive chronic myelogenous leukemia cells by an inhibitor of BCR - ABL tyrosine kinase, CGP 57148.

Dan S ，Naito M ，Tsuruo T 《CELL DEATH AND DIFFERENTIATION》