RESUMO
The sialic acid-binding immunoglobulin-type lectin Siglec-15 is a promising target to cancer immunotherapy in several tumor types. The present study aimed to investigate Siglec-15 expression in gastric cancer (GC) patient tissue and to evaluate its clinical value. Siglec-15 expression was evaluated by immunohistochemistry with 71 patients. Siglec-15 staining was observed in tumor cells of 53 (74.64%) patients, with significant association with histologic classification and angiolymphatic invasion (p<0.05). Immunohistochemistry analysis also detected Siglec-15 in tumor-associated stroma cells (macrophages/myeloid cells). There was no significant association with outcomes parameters. Siglec-15 expression in well differentiated histological GC tissues and in the tumor microenvironment are potential targets to be further investigated as a novel prognostic factor for GC.
Assuntos
Imunoglobulinas/metabolismo , Proteínas de Membrana/metabolismo , Neoplasias Gástricas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Gástricas/patologiaRESUMO
Gastric cancer (GC) is the second most common cause of cancer-related deaths in the world. This study aims to investigate the differential tissue expression of ppGalNAc-T15 and to evaluate its possible association with clinical-pathological parameters and outcome of gastric adenocarcinoma patients. For these 70 patients were evaluated the expression by immunohistochemistry to ppGalNAc-T15. Our results showed that 33 (47.1%) patients were ppGalNAC-T15+ positive and 37 (52.9%) negative. Positive staining for ppGalNAc-T15 was significantly present in patients older than 60 years (P=0.0306) and submitted to total gastrectomy (P=0.0087). Also, some results remained at the limit of significance as surgical standing (P=0.0562) and histological grade (P=0.0549). Therefore, the ppGalNAc-T15 immunoreactivity can be useful to understand the prognosis of patients with gastric cancer.
Assuntos
Adenocarcinoma/enzimologia , Adenocarcinoma/patologia , Imuno-Histoquímica/métodos , N-Acetilgalactosaminiltransferases/metabolismo , Neoplasias Gástricas/enzimologia , Neoplasias Gástricas/patologia , Adenocarcinoma/cirurgia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Feminino , Gastrectomia , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Neoplasias Gástricas/cirurgia , Polipeptídeo N-AcetilgalactosaminiltransferaseRESUMO
This work describes purification of a protease from the visceral mass of the mussel Mytella charruana as well as evaluation of its ability to hydrolyze milk casein to generate antimicrobial peptides. The enzyme showed pI of 4.1 and a single polypeptide band of 83.1â¯kDa after SDS-PAGE. Sequence similarities with tropomyosin and myosin from mollusks were detected. The protease showed a trypsin-like activity with optimal temperature of 40⯰C and stability in a wide pH range (3.0-9.0). Km was 4.28⯱â¯0.34â¯mM of the synthetic substrate N-benzoyl-dl-arginyl-ρ-nitroanilide, whereas Vmax was 0.056⯱â¯0.001â¯nmolâ¯min-1. The enzyme hydrolyzed casein, and the hydrolysate inhibited the growth of Escherichia coli, Micrococcus luteus, Bacillus subtilis, and Klebsiella pneumoniae at a minimal inhibitory concentration of 5.0⯵gâ¯mL-1. In conclusion, the visceral mass of M. charruana contains a trypsin-like protease that can generate peptides from casein that have a bacteriostatic effect.
