Citations

AbstractThe AURKA oncogene is associated with abnormal chromosome segregation and aneuploidy and predisposition to cancer. Amplification of AURKA has been detected at higher frequency in tumors from BRCA1 and BRCA2 mutation carriers than in sporadic breast tumors, suggesting that overexpression of AURKA and inactivation of BRCA1 and BRCA2 cooperate during tumor development and progression. The F31I polymorphism in AURKA has been associated with breast cancer risk in the homozygous state in prior studies. We evaluated whether the AURKA F31I polymorphism modifies breast cancer risk in BRCA1 and BRCA2 mutation carriers from the Consortium of Investigators of Modifiers of BRCA1/2. Consortium of Investigators of Modifiers of BRCA1/2 was established to provide sufficient statistical power through increased numbers of mutation carriers to identify polymorphisms that act as modifiers of cancer risk and can refine breast cancer risk estimates in BRCA1 and BRCA2 mutation carriers. A total of 4,935 BRCA1 and 2,241 BRCA2 mutation carriers and 11 individuals carrying both BRCA1 and BRCA2 mutations was genotyped for F31I. Overall, homozygosity for the 31I allele was not significantly associated with breast cancer risk in BRCA1 and BRCA2 carriers combined [hazard ratio (HR), 0.91; 95% confidence interval (95% CI), 0.77-1.06]. Similarly, no significant association was seen in BRCA1 (HR, 0.90; 95% CI, 0.75-1.08) or BRCA2 carriers (HR, 0.93; 95% CI, 0.67-1.29) or when assessing the modifying effects of either bilateral prophylactic oophorectomy or menopausal status of BRCA1 and BRCA2 carriers. In summary, the F31I polymorphism in AURKA is not associated with a modified risk of breast cancer in BRCA1 and BRCA2 carriers. (Cancer Epidemiol Biomarkers Prev 2007;16(7):1416–21)

ABSTRACT Obesity is one of the major health problems of our times. Elucidating the signaling mechanisms by which high‐fat caloric diet induces obesity is critical for the understanding of this condition and for the development of therapeutic strategies for its treatment. Here, we demonstrate a novel role for protein CD38 as a regulator of body weight during a high‐fat diet. CD38 is a ubiquitous enzyme that catalyzes the synthesis of second messengers and has been implicated in the regulation of a wide variety of signaling pathways. We report that CD38‐deficient mice are pro‐tected against high‐fat diet‐induced obesity owing to enhanced energy expenditure. In fact, calorimetric studies indicate that CD38‐deficient animals have a higher metabolic rate compared to control mice. Analysis of the mechanism revealed that this resistance to diet‐induced obesity is mediated at least in part via a NAD‐dependent activation of SIRT‐PGC1α axis, a well‐established cascade, involved in the regulation of mito‐chondrial biogenesis and energy homeostasis. Thus, together these results identify a novel pathway regulating body weight and clearly show that CD38 is a nearly obligatory component of the cellular cascade that led to diet‐induced obesity.—Barbosa, M. T. P., Soares, S. M., Novak, C. M., Sinclair, D., Levine, J. A., Aksoy, P., Chini, E. N. The enzyme CD38 (a NAD glycohydrolase, EC 3.2.2.5) is necessary for the development of diet‐induced obesity. FASEB J. 21, 3629–3639 (2007)

Purpose To compare the use of capecitabine plus oxaliplatin (CAPOX) with infusional fluorouracil (FU)/folinic acid plus oxaliplatin (FUFOX) as first-line therapy for patients with metastatic colorectal cancer (MCRC). Patients and Methods A total of 474 patients with MCRC received either CAPOX (capecitabine 1,000 mg/m2 bid, days 1 to 14 plus oxaliplatin 70 mg/m2 days 1 and 8, repeated every 22 days) ) or FUFOX (oxaliplatin 50 mg/m2 followed by leucovorin 500 mg/m2 plus FU 2,000 mg/m2 as a 22-hour infusion days 1, 8, 15, and 22, repeated every 36 days). The primary end point was progression-free survival (PFS). Secondary end points were response rate (RR), overall survival (OS), time to treatment failure, and toxicity. The study was designed to determine noninferiority for the CAPOX regimen. Results Median PFS was 7.1 months in the CAPOX arm and 8.0 months in the FUFOX arm (hazard ratio [HR], 1.17; 95% CI, 0.96 to 1.43; P = .117). Median OS was 16.8 months (CAPOX) and 18.8 months (FUFOX; HR, 1.12; 95% CI, 0.92 to 1.38; P = .26). Overall RRs were 48% for CAPOX (95% CI, 41% to 54%) and 54% for FUFOX (95% CI, 47% to 60%). Both regimens were generally well tolerated, although there was a significantly higher incidence of grade 2/3 hand-foot syndrome (HFS) in the CAPOX arm (P = .028). Conclusion CAPOX resulted in a slightly inferior efficacy than FUFOX. With respect to PFS, the best estimate of the HR of 1.17 was within the prespecified equivalence range. However, a relevant inferiority cannot be excluded. Both regimens were generally well tolerated but there was a significantly higher rate of grade 2/3 HFS in the CAPOX arm.