Anti-CAPN1 monoclonal antibody, clone FQS4434

Remodeling of the cytoskeleton underlies various cellular processes, including those associated with metastasis. The role of the proteases and proteins involved in cytoskeletal reorganization is being actively studied. However, there are no published data on the relationship between the mRNA expression levels of calpains 1/2 (CAPN 1/2) and the proteins associated with cytoskeleton remodeling. Therefore, the purpose of our study was to establish the relationship between the mRNA expression levels of CAPN 1/2 and the proteins involved in cytoskeletal reorganization, such as cell motility markers (SNAIL VIM, and RND3) and actin-binding proteins (CFN1, PFN1, EZR, FSCN1, and CAP1) using the model of laryngeal/laryngopharyngeal squamous cell carcinoma (LC). The gene expression level was determined by reverse transcriptase real-time PCR and calculated using the 2-Delta Delta Ct method in paired tissue samples of 44 patients with LC (T1-4N0-2M0). The patients were divided into two groups: those with low and those with high CAPN 1/2 expression levels. It was found that metastasis in LC patients was associated with decreased expression levels of VIM and CAP1, and increased levels of CAPN1. A high level of CAPN2 was accompanied by a high expression level of EZR, indicating the activation of invasion processes. The results obtained need to be confirmed in further studies using a larger sample of patients and target genes. Our study is important in elucidating the mechanisms that underlie cancer progression and metastasis, a development that could subsequently open the way to a search for new prognostic and predictive markers of laryngeal/laryngopharyngeal cancer progression.

Calpains are calcium regulated proteases involved in cellular functions that include muscle proteolysis both ante- and postmortem. Here, we describe the molecular characterization of the rainbow trout catalytic subunits of the mu- and m-calpains, respectively. The cDNA sequence for Capn1 encodes a protein of 704 amino acids with a calculated molecular mass of 79.9 kDa. The amino acid sequence shows 66% and 86% identity with the mouse and zebrafish Capn1, respectively. The Capn2 cDNA codes for a protein consisting of 701 amino acid residues with a calculated molecular mass of 78.2 kDa. The protein shows 65% amino acid sequence identity with the mouse and chicken Capn2. The two isozymes of rainbow trout have the characteristic domains: I (propeptide), II (cysteine catalytic site), III (electrostatic switch), and IV (contains five EF-hands). Because starvation induces muscle wasting, the hypothesis of this study was that starvation could affect regulation of the calpain system in muscle. Starvation of rainbow trout fingerlings (15-20 g) for 3 5 days stimulated the expression of Capn1 (2.2-fold increase, P<0.01), Capn2 (6.0-fold increase, P<0.01), and calpastatins (1.6-fold increase, P<0.05) as measured by quantitative real-time RTPCR. The mRNA changes led to a 1.23-fold increase in the calpain catalytic activity. The results suggest a potential role of calpains in protein mobilization as a source of energy under fasting condition. (C) 2004 Elsevier Inc. All rights reserved.