Mouse anti-Human CAPN9 polyclonal antibody

Calpains constitute a superfamily of Ca2+-dependent cysteine proteases, indispensable for various cellular processes. Among the 15 mammalian calpains, calpain 8/nCL-2 and calpain 9/nCL-4 are predominantly expressed in the gastrointestinal tract and are restricted to the gastric surface mucus (pit) cells in the stomach. Possible functions reported for calpain 8 are in vesicle trafficking between ER and Golgi, and calpain 9 are implicated in suppressing tumorigenesis. These highlight that calpains 8 and 9 are regulated differently from each other and from conventional calpains and, thus, have potentially important, specific functions in the gastrointestinal tract. However, there is no direct evidence implicating calpain 8 or 9 in human disease, and their properties and physiological functions are currently unknown. To address their physiological roles, we analyzed mice with mutations in the genes for these calpains, Capn8 and Capn9, Capn8(-/-) and Capn9(-/-) mice were fertile, and their gastric mucosae appeared normal. However, both mice were susceptible to gastric mucosal injury induced by ethanol administration. Moreover, the Capn8(-/-) stomach showed significant decreases in both calpains 9 and 8, and the same was true for Capn9(-/-). Consistent with this finding, in the wild-type stomach, calpains 8 and 9 formed a complex we termed "G-calpain,'' in which both were essential for activity. This is the first example of a "hybrid'' calpain complex. To address the physiological relevance of the calpain 8 proteolytic activity, we generated calpain 8: C105S "knock-in'' (Capn8(CS/CS)) mice, which expressed a proteolytically inactive, but structurally intact, calpain 8. Although, unlike the Capn8(-/-) stomach, that of the Capn8(CS/CS) mice expressed a stable and active calpain 9, the mice were susceptible to ethanol-induced gastric injury. These results provide the first evidence that both of the gastrointestinal-tract-specific calpains are essential for gastric mucosal defense, and they point to G-calpain as a potential target for gastropathies caused by external stresses.

Background: Genome-wide association studies (GWAS) have identified more than 100 genetic loci for various cancers. However, only one is for endometrial cancer. Methods: We conducted a three-stage GWAS including 8,492 endometrial cancer cases and 16,596 controls. After analyzing 585,963 single-nucleotide polymorphisms (SNP) in 832 cases and 2,682 controls (stage I) from the Shanghai Endometrial Cancer Genetics Study, we selected the top 106 SNPs for in silica replication among 1,265 cases and 5,190 controls from the Australian/British Endometrial Cancer GWAS (stage II). Nine SNPs showed results consistent in direction with stage I with P < 0.1. These nine SNPs were investigated among 459 cases and 558 controls (stage IIIa) and six SNPs showed a direction of association consistent with stages land H. These six SNPs, plus two additional SNPs selected on the basis of linkage disequilibrium and P values in stage II, were investigated among 5,936 cases and 8,166 controls from an additional 11 studies (stage IIIb). Results: SNP rs1202524, near the CAPN9 gene on chromosome 1q42.2, showed a consistent association with endometrial cancer risk across all three stages, with ORs of 1.09 [95% confidence interval (Cl), 1.03-1.16] for the A/G genotype and 1.17(95% Cl, 1.05-1.30) for the GIG genotype (P = 1.6 x 10(-4) in combined analyses of all samples). The association was stronger when limited to the endometrioid subtype, with ORs (95% Cl) of 1.11 (1.04-1.18) and 1.21 (1.08-1.35), respectively (P = 2.4 x 10(-5)). Conclusions: Chromosome 1q42.2 may host an endometrial cancer susceptibility locus. Impact: This study identified a potential genetic locus for endometrial cancer risk. Cancer Epidemiol Biomarkers Prev; 21(6); 980-7. (C) 2012 AACR.