Protein expression and subcellular localization of familial acute myelogenous leukemia-related factor

Abstract

Abstract. The present study was designed to evaluate the expression and subcellular distribution of the familial acute myelogenous leukemia-related factor (FAMLF). A 14-amino acid epitope of the predicted open reading frame of the FAMLF gene was identified using bioinformatics. This polypeptide was synthesized, conjugated to keyhole limpet hemocyanin and was subsequently used to produce antibodies. The antibody titer and specificity were characterized using ELISA and western blot assays, respectively. The antibody detected FAMLF protein expression in several human leukemia cell lines, bone marrow cells derived from one acute myeloid leukemia patient and one chronic myeloid leukemia patient, but not in bone marrow cells of healthy subjects. The FAMLF/ GFP fusion protein was expressed in both the nucleus and the cytoplasm of transfected NIH3T3 cells. Our results demonstrate that the FAMLF gene is expressed in an AML patient but not in healthy controls, suggesting its association with AML. IntroductionAcute myeloid leukemia (AML) is the most common hematological malignancy in adults, with a worldwide incidence of ~3.6 cases in 100,000 individuals (National Cancer Institute. SEER Stat Fact Sheets: Acute Myeloid Leukemia; http://seer. cancer.gov/statfacts/html/amyl.html). A number of AMLrelated chromosomal abnormalities and gene mutations have been identified, and their involvement in the regulation of DNA methylation, signal transduction, energy synthesis, and cellular structure has been reported (1).The identification of new AML-related genes may provide insight into disease prognosis, treatment response, and new therapeutic regimens for patients with AML. Mutations in CCAAT enhancer binding factor α (CEBPA) have been associated with prolonged recurrence-free survival in AML patients (2). Mutations in nucleophosmin-1 (NPM1) and the internal tandem duplications in FLT3 predict positive AML prognosis (3), and mutations in several genes such as MLL-PTD, FLT3/ITD, WT1, and C-KIT predict negative AML prognosis (4-7). Thus, screening for mutations in CEBPA, NPM1, FLT3, and KIT is part of the routine workup for AML (8,9).A number of drugs targeting AML-related genes have been tested for their efficacy in treating AML, including TNF-related apoptosis inducing ligand (TRAIL) and tipifarnib, an inhibitor of farnesyltransferase (FTase), alone or in combination with other anti-leukemia drugs (10,11). Inhibitors of histone deacetylase, proteasome and Bcl-2 antisense oligonucleotides have also been used as targeted drugs in the clinical treatment of AML (12). Furthermore, inhibitors of Fms-like tyrosine kinase 2 (FLT-2), such as lestaurtinib (CEP701), tandutinib (MLN518) and PKC412 have shown benefit in treating FLT3-associated AML (13).Previously, we identified a large family with a high incidence of AML in Fujian China (14). A total of 11 family members in 4 generations were diagnosed with AML; two patients developed acute erythroleukemia (M6), one suffered from minimally differentiated acute myeloblastic leukemia (M1), one ha...

FAMLF is a target of miR-181b in Burkitt lymphoma

“…Studies have shown that FAMLF was highly expressed in acute myeloid leukemia and BL patients, NB4 acute promyelocytic leukemia cells, U937 macrophage-like cells, K562 myeloid leukemia cells, U266 myeloma cells, HL60 promyelocytic cells, CA46 lymphoma cells, and especially in Raji BL cells, while low expression was observed in unaffected individuals. FAMLF may be involved in hematopoietic neoplasms by promoting cell proliferation and preventing cell differentiation (6,7). …”

Lentivirus-mediated RNA interference targetingFAMLF-1inhibits cell growth and enhances cell differentiation of acute myeloid leukemia partially differentiated cells via inhibition of AKT and c-MYC

“…Using bioinformatics, we revealed the existence of at least three splice variants of FAMLF , named as FAMLF-1 , FAMLF-2 and FAMLF-3 , and also found miR181a1/b1 embedded in the second intronic regions of FAMLF gene family (see Figure 1 ). Furthermore, we were able to detect a doublet at 8 kDa by Western blot analysis of total protein lysate from AML patient's cell and AML cell lines [ 13 ]. The expression of FAMLF-1 was significantly higher in de novo adult AML than the control.…”