ABSTRACT
Although the tyrosine kinase inhibitor (TKI) imatinib is often used as first-line therapy for newly diagnosed chronic myelogenous leukemia (CML), some patients fail to respond, or become intolerant to imatinib. Nilotinib is a potent and selective second-generation TKI, with confirmed efficacy and tolerability in patients with imatinib-resistant or -intolerant CML. A phase I/II study was conducted in Japanese patients with imatinib-resistant or -intolerant CML or relapsed/refractory Ph+ acute lymphoblastic leukemia. Thirty-four patients were treated with nilotinib for up to 36 months. Major cytogenetic response was achieved in 15/16 patients (93.8%) with chronic-phase CML within a median of approximately 3 months. Major molecular response was achieved in 13/16 patients (81.3%). These responses were sustained at the time of the most recent evaluation in 13 patients and 11 patients, respectively. Hematologic and cytogenetic responses were also observed in patients with advanced CML. The BCR-ABL mutation associated with the most resistance to available TKIs, T315I, was observed in three patients. Common adverse events included rash, nasopharyngitis, leukopenia, neutropenia, thrombocytopenia, nausea, headache and vomiting. Most adverse events resolved following nilotinib dose interruptions/reductions. These results support the favorable long-term efficacy and tolerability of nilotinib in Japanese patients with imatinib-resistant or -intolerant chronic-phase chronic myeloid leukemia.
Subject(s)
Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Protein Kinase Inhibitors/therapeutic use , Protein-Tyrosine Kinases/antagonists & inhibitors , Pyrimidines/therapeutic use , Adult , Aged , Aged, 80 and over , Asian People/genetics , Cytogenetic Analysis , Female , Fusion Proteins, bcr-abl/genetics , Humans , Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics , Male , Middle Aged , Mutation/drug effects , Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics , Protein Kinase Inhibitors/adverse effects , Pyrimidines/adverse effects , Young AdultABSTRACT
BACKGROUND & AIMS: The calcium channel voltage-dependent alpha2delta subunit consists of 4 genes, CACNA2D1 to CACNA2D4, of which CACNA2D2 and CACNA2D3 are located on 3p21.3 and 3p21.1, respectively. Here, we examined the relation between alpha2delta subunit gene alterations and gastric carcinogenesis. METHODS: The expression and methylation status of the alpha2delta subunit genes were analyzed by reverse transcription-polymerase chain reaction (RT-PCR) and methylation-specific PCR in gastric cancers (GCs). The effects of CACNA2D3 expression were examined by cell proliferation and adhesion assays, and they predicted target gene alterations. RESULTS: Aberrant methylation of CACNA2D1 and CACNA2D3 mostly corresponded to their expression status in GC cell lines. CACNA2D1/3 methylation was detected in 10 (12.5%) and 24 (30%) of the 80 GC cases, respectively, but no CACNA2D2 methylation was seen in 32 cases. CACNA2D3 methylation was more frequently found in diffuse type than in intestinal type (16/38 [42.1%] vs 8/42 [19.0%]; P = .025) GCs. Among the 53 patients with advanced GCs, patients with cancers showing CACNA2D3 methylation had a significantly shorter survival time than patients without this methylation (P = .003). Exogenous CACNA2D3 expression strongly inhibited cell growth and adhesion and up-regulated p21 and p27 expression in HEK-293T and NUGC4 cells. Inverse effects were seen by CACNA2D3 small interfering RNA treatment in the CACNA2D3-positive cell lines, indicating that CACNA2D3 may have tumor suppressive functions. CONCLUSIONS: Loss of CACNA2D3 expression through aberrant promoter hypermethylation may contribute to gastric carcinogenesis, and CACNA2D3 methylation is a useful prognostic marker for patients with advanced GC.
