Abstract 401: CD5+CD23+ leukemic cell populations in Tcl1 transgenic mice show significantly increased proliferation and Akt phosphorylation

B-cell chronic lymphocytic leukemia (B-CLL) is the most common human leukemia. Deregulation of the T-cell leukemia/lymphoma 1 (TCL1) oncogene in mouse B-cells causes a CD5 positive leukemia similar to aggressive human B-CLLs. We recently reported that TCL1 expression in B-CLL is regulated by miR29 and miR181. To determine whether treatment with microRNAs can inhibit B-CLL in mice by targeting TCL1 we generated TCL1 transgenic mice using a construct containing 3’ and 5’ UTRs of TCL1 under B-cell specific Eμ promoter (Eμ-TCL1fl). At the age of 12-18 months these mice showed B-CLL like disease. Immunophenotyping revealed accumulation of CD5+CD23+B220+ population in spleens and lymph nodes. Our results show that CD5+CD23+ B-cell populations from Eμ-TCL1fl mice actively proliferate and display significantly increased levels of phospho-Akt. Eμ-TCL1fl mice showed immunological abnormalities similar to human B-CLL, including hypoimmunoglobulinemia, abnormal levels of cytokines, and impaired immune response. These findings revealed biochemical and immunological similarities between Tcl1 driven B-CLL in mice and human B-CLL. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 401.