ALBERT

Description: Imatinib mesylate (IM) could reverse marrow angiogenesis and decrease the plasma level of vascular endothelial growth factor (VEGF) in chronic myeloid leukemia (CML) patients. The current study investigated the impact of 4 VEGF (VEGFA) and 3 VEGF receptor (VEGFR2) gene polymorphisms on the outcomes of 228 CML patients following IM therapy (male:female 96:132; median age at start of IM, 55 years-old; chronic phase: accelerated phase: blastic crisis, 205/17/2). The DNAs from blood samples were genotyped using MALDI-TOF-based method. VEGFA genotypes such as -2578C〉A (rs699947), -460T〉C (rs833061), +405G〉C (rs2010963) and +936 C〉T (rs3025039) loci, and VEGFR2 genotypes including rs1531289, rs1870377 and rs2305948 were analyzed. In single marker analyses, strong correlations were noted between complete cytogenetic response (CCyR) and VEGFR2 genotypes (rs1531289 and rs1870377), treatment failure and VEGFR2 genotype (rs1870377), dose escalation and VEGFR2 genotype (rs1870377), complete molecular response (CMoR) and VEGFA genotype (rs3025039), progression to advanced disease stage and VEGFA genotypes (rs699947 and rs833061). Three haplotypes of VEGFR2 gene were generated as follows: GT (46.1%), AT (27.9%) and GA (25.7%). Haplotype analyses showed good correlations between VEGFR2 haplotype and CCyR, treatment failure, and dose escalation of IM. Multivariate analyses confirmed strong correlations of VEGFR2 polymorphisms (especially rs1531289, rs1870377 or VEGFR2 haplotype) with CCyR, treatment failure, dose escalation and of VEGFA genotype (rs699947) with progression to advanced disease stage. The VEGFR2 genotypes and haplotype correlate well with cytogenetic response, treatment failure and dose escalation of IM therapy in CML patients, while VEGFA genotype correlates with progression to advanced disease stage.

Description: Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder, characterized by the presence of BCR/ABL fusion gene. It is unclear which cellular events drive BCR/ABL gene translocation or initiate leukemogenesis in CML. Bcl-2 promotes survival of hematopoietic stem cells. Accordingly, apoptosis-related pathway may involve in the leukemogenesis of CML. In the current study, we evaluated 80 single nucleotide polymorphism (SNP) markers involved in the pathways of apoptosis (n = 30), angiogenesis (n = 7), myeloid cell growth (n = 14), xenobiotic metabolism (n = 13), WT1 signaling (n = 7), interferon signaling (n = 4), and others (n = 5) in 170 CML patients and 182 healthy controls. In a single-marker analysis, the following SNPs were identified including VEGFA, BCL2, CASP7, JAK3, CSF3, and HOCT1. In the multivariate logistic model with these SNPs and covariates, only BCL2 (rs1801018) was significantly associated with the susceptibility to CML (P = .05; odds ratio [OR] 2.16 [1.00-4.68]). In haplotype analyses, haplotype block of BCL2 consistently showed significant association with the susceptibility to CML. Risk allele analysis showed that a greater number of risk alleles from BCL2 SNP correlated to increasing risk of CML (overall P = .1, OR 1.84 [1.06-3.22] for 3-4 risk alleles vs 0-1 risk alleles). The current study indicated that BCL2 SNP seemed to be associated with increasing susceptibility to CML.

Description: Background: Imatinib resistance (IR) is a well known cause of treatment failure in chronic myeloid leukemia (CML) patients being treated with imatinib mesylate (IM). Several cellular and genetic mechanisms of IR have been proposed including amplification and overexpression of the BCR-ABL gene, the presence of specific point mutations and MDR1 gene overexpression. Methods: We investigated the impact of 16 single nucleotide polymorphisms (SNPs) in 5 genes potentially associated with pharmacogenetics of IM (ABCB1, multidrug resistance 1; ABCG2, breast-cancer resistance protein; CYP3A5, cytochrome P450 3A5; HOCT1, human organic cation transporter 1; AGP1, alpha-1-acid glycoprotein-1, plasma protein binding to IM). The major endpoints included: response to IM: cytogenetic (CyR) or molecular response (MoR); resistance to IM: loss of response (LOR), treatment-failure (including primary resistance or LOR); progression to accelerated phase (AP) or blast crisis (BC), or death; and need for IM dose escalation to overcome resistance or LOR. The DNAs from peripheral blood samples were genotyped using the Sequenom MassARRAY system based on MALDI-TOF technique. The study population included 229 patients whose clinical outcomes following IM therapy were evaluated from January 2000 to January 2007 (male:female 96:133; median age at start of IM, 53 years-old; white:non-white 170:59; chronic phase:AP:BC, 199:23:3). Results: The frequencies of genotypes in 16 SNPs are summarized in Table 1. The GG allele in ABCG2 (rs2231137), AA allele in CYP3A5 (rs776746) and advanced stage were significantly associated with poor response to IM, while GG allele at HOCT1 (rs683369) and advanced stage correlated with high rate of LOR or treatment failure. The CC allele in ABCG2 (rs2231142) was also identified as an independent predictor of more frequent need for IM dose escalation. The results of multivariate analyses are summarized in Table 2. Conclusion: Using a novel, multiple candidate gene approach based on the pharmacogenetics of Imatinib mesylate, we identified several SNP candidates in patients with CML that are potential predictors of clinical response to IM (rs2231137, ABCG2 or rs776746, CYP3A5), resistance to IM (rs683369, HOCT1) and need for IM dose escalation (rs2231142, ABCG2). Further studies are warranted to validate the role of these SNPs in the early identification of individuals with CML who may not respond optimally to standard IM therapy. Table 1. The genotype frequency and clinical significance in 16 SNPs Table 2. Multivariate regression model based on Cox's proportional hazard model for each-point

Description: Genetic variants in the candidate genes of the apoptosis pathway and susceptibility to chronic myeloid leukemia Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder, characterized by the presence of BCR/ABL fusion gene. It is unclear which cellular events drive BCR/ABL gene translocation or initiate leukemogenesis in CML. Bcl-2 promotes survival of hematopoietic stem cells. Accordingly, apoptosis–related pathway may involve in the leukemogenesis of CML. In the current study, we evaluated 80 SNP markers (Table 1) involved in the pathways of apoptosis (n=31; BCL2, BAX, BCL2L2, BCL6, BCL2L11, BIRC5, CASP1, CASP3, CASP7, CASP8, CASP9, CASP10, FAS, FASL, APAF1, TNFR2, PDCD1, GZMB), angiogenesis (n=7; VEGFA, VEGFR2), myeloid cell growth (n=13; FLT2, CSF3, CSF2, JAK3, IL1A, IL1B, IL1R), xenobiotic metabolism (n=13; ABCB1, ABCG2, CYP3A5, HOCT1), WT1 signaling (n=7), interferon signaling (n=4; IFNG, IFNGR1, IFNGR2) and others (n=5; GNB3, ULK3, ORM, PTK2) in 170 CML patients and 182 healthy controls with European ancestry. In a single marker analysis, following SNPs were identified including VEGFA, BCL2, CASP7, JAK3, CSF3 and HOCT1. In the multivariate logistic model with these 7 SNPs and covariates, only BCL2 (rs1801018) was significantly associated with the susceptibility to CML (p=0.05; adj-OR 2.16, [1.00–4.68]). In haplotype analyses, haplotype block of BCL2 consistently showed significant association with the susceptibility to CML. Risk allele analysis showed that a greater number of risk alleles from BCL2 SNP correlated to increasing risk of CML (overall p=0.1, OR 1.84, [1.06–3.22] for 3–4 risk alleles vs. 0–1 risk alleles). The current study indicated that BCL2 SNP seemed to be associated with increasing susceptibility to CML. Table 1. Summary of 80 candidate gene single nucleotide polymorphisms Gene SNP ID Apoptosis pathway (n=30) BCL2 rs1801018, rs2279115 BAX rs11667351 BCL2L2 rs7042474 BCL6 rs1056932, rs11545363 BCL2L11 rs6746608, rs12613243 BIRC5 rs9904341, rs2071214 CASP1 rs580253 CASP3 rs1049253 CASP7 rs7922608 CASP8 rs1045485, rs3769818, rs3834129 CASP9 rs4645981 CASP10 rs13010627, rs13006529 FASL rs763110 FAS rs2234767, rs1800682, rs3218619, rs3218612, rs2234978 APAF1 rs1439123, rs2288713 TNFR2 rs1061622 PDCD1 rs2227981 GZMB rs7144366 Angiogenesis (n=7) VEGFA rs699947, rs833061, rs2010963, rs3025039 VEGFR2 rs1531289, rs1870377, rs2305948 Myeloid Growth (n=14) FLT3 rs35602083 CSF3 rs25645, rs1042658 CSF2 rs25882 JAK3 rs3008, rs3212713 JAK3 IL1A rs17561, rs1800587 IL1A IL1B rs1143634, rs1143633, rs1143627, rs16944 IL1R rs2228139, rs315952 WT1 signaling (n=7) WT1 rs1799937, rs2234591, rs2234590, rs2301254, rs2301252, rs2301250, rs6508 Xenobiotic metabolism (n=13) ABCB1 rs1045642, rs2032582, rs1128503 ABCG2 rs2231142, rs2231137 CYP3A5 rs776746, rs28383469, rs28383468 HOCT1 rs1867351, rs12208357, rs683369, rs2282143, rs628031 Interferon signaling (n=4) IFNG rs1861494, rs2069705 IFNGR1 rs3799488 IFNGR2 rs9808753 Others (n=5) GNB3 rs5443 ULK3 rs2290573 ORM rs1126724, rs3182041 PTK2 rs4554515

Description: Indoleamine 2,3-dioxygenase-1 (IDO1; IDO) mediates oxidative cleavage of tryptophan, an amino acid essential for cell proliferation and survival. IDO1 inhibition is proposed to have therapeutic potential in immunodeficiency-associated abnormalities, including cancer. Here, we describe INCB024360, a novel IDO1 inhibitor, and investigate its roles in regulating various immune cells and therapeutic potential as an anticancer agent. In cellular assays, INCB024360 selectively inhibits human IDO1 with IC50 values of approximately 10nM, demonstrating little activity against other related enzymes such as IDO2 or tryptophan 2,3-dioxygenase (TDO). In coculture systems of human allogeneic lymphocytes with dendritic cells (DCs) or tumor cells, INCB024360 inhibition of IDO1 promotes T and natural killer (NK)–cell growth, increases IFN-γ production, and reduces conversion to regulatory T (Treg)–like cells. IDO1 induction triggers DC apoptosis, whereas INCB024360 reverses this and increases the number of CD86high DCs, potentially representing a novel mechanism by which IDO1 inhibition activates T cells. Furthermore, IDO1 regulation differs in DCs versus tumor cells. Consistent with its effects in vitro, administration of INCB024360 to tumor-bearing mice significantly inhibits tumor growth in a lymphocyte-dependent manner. Analysis of plasma kynurenine/tryptophan levels in patients with cancer affirms that the IDO pathway is activated in multiple tumor types. Collectively, the data suggest that selective inhibition of IDO1 may represent an attractive cancer therapeutic strategy via up-regulation of cellular immunity.