Anti-SPINT2 monoclonal antibody, clone FQS7394(3)

Background: There are few blood tests for an efficient detection of hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV) infection. Methods: The abilities of quantitative analyses of 7 genes hypermethylation in serum DNA, a-fetoprotein (AFP) and prothrombin-induced vitamin K absence II (PIVKA-II), and various combinations to detect HCC were evaluated in a training cohort of 164 HCV-infected patients (108 HCCs; 56 non-HCCs). An optimal hybrid detector, built using data for 2 methylated genes (SPINT2 and SRD5A2), AFP, and PIVKA-II. achieved the most satisfactory ability to detect HCC in the training cohort. We evaluated the ability of the optimal hybrid detector to detect HCC in an independent validation cohort of 258 consecutive HCV-infected patients (112 HCCs; 146 non-HCCs) who were newly enrolled in 4 distinct institutes. Results: In the validation cohort of 258 patients, accuracy, sensitivity, and specificity of the hybrid detector for detection of HCC were 81.4%, 73.2%, and 87.7%, respectively. Notably, even when detecting HCC <= 2 cm in diameter, the hybrid detector maintained markedly high abilities (84.6% accuracy, 72.2% sensitivity, 87.7% specificity). Youden's index (sensitivity + specificity - 1) for HCC <= 2 cm was 0.60, vastly much superior to the 0.39 for AFP at a cut-off value of 20 ng/ml and the 0.28 for PIVKA-II at a cut-off value of 40 mAU/ml. Conclusions: These results show that the optimal hybrid blood detector can detect HCV-related HCC more accurately. (C) 2010 Elsevier B.V. All rights reserved.

Aberrant HGF-MET (hepatocyte growth factor-met proto-oncogene) signaling activation via interactions with surrounding stromal cells in tumor microenvironment has significant roles in malignant tumor progression. However, extracellular proteolytic regulation of HGF activation, which is influenced by the tumor microenvironment, and its consequential effects on melanoma malignancy remain uncharacterized. In this study, we identified SPINT2 (serine peptidase inhibitor Kunitz type 2), a proteolytic inhibitor of hepatocyte growth factor activator (HGFA), which has a significant role in the suppression of the HGF-MET pathway and malignant melanoma progression. SPINT2 expression is significantly lower in metastatic melanoma tissues compared with those in early-stage primary melanomas, which also corresponded with DNA methylation levels isolated from tissue samples. Treatment with the DNA-hypomethylating agent decitabine in cultured melanoma cells induced transcriptional reactivation of SPINT2, suggesting that this gene is epigenetically silenced in malignant melanomas. Furthermore, we show that ectopically expressed SPINT2 in melanoma cells inhibits the HGF-induced MET-AKT (v-Akt murine thymoma viral oncogene) signaling pathway and decreases malignant phenotype potential such as cell motility and invasive growth of melanoma cells. These results suggest that SPINT2 is associated with tumor-suppressive functions in melanoma by inhibiting an extracellular signal regulator of HGF, which is typically activated by tumor-stromal interactions. These findings indicate that epigenetic impairment of the tightly regulated cytokine-receptor communications in tumor microenvironment may contribute to malignant tumor progression.