A Synthetic Tissue Kallikrein Inhibitor Suppresses Cancer Cell Invasiveness

Abstract

Serine proteinases modulate the interaction of tumor cells with extracellular matrix components during extravasation and metastasis. The serine proteinase tissue kallikrein has been previously demonstrated in several human adenocarcinomas, and we presently report the localization of immunoreactive kallikrein and its mRNA in pancreatic adenocarcinoma. In addition, a synthetic peptide-based inhibitor specific for tissue kallikrein (FE999024) was used in our studies to explore a possible role for kallikrein in cancer cell invasiveness. Matrigel invasion assays were performed with a human breast-cancer cell line, MDA-MB-231, which expresses tissue kallikrein in culture. In the presence of FE999024 invasion through Matrigel was inhibited in a dose-dependent manner to a maximum of 39%. We also developed a novel ex vivo assay in which breast cancer cells are infused into the pulmonary circulation of artificially ventilated explanted rat lungs. At intervals up to 6 hours after infusion pulmonary invasion was quantified by bronchial alveolar lavage to recover human cancer cells from the airspace. Invading cells in the lung interstitium were also quantified after immunohistochemistry with a monoclonal antibody specific for human cytokeratin 18. The synthetic kallikrein inhibitor attenuates breast cancer cell invasion into the airspace by 33% when quantified by lavage recovery and up to 34% as quantified in the lung interstitium by cytokeratin 18 immunostaining. Cancer cells exploit serine proteinases to influence the local blood supply, extravasate into and out of vessels, and to migrate through tissue matrix during metastasis. The serine proteinase tissue kallikrein has been localized in human adenocarcinomas and related cell lines from a number of organs including prostate, breast, pituitary, colon, ovary, endometrium, kidney, and esophagus.

Kallikrein-related peptidases in prostate, breast, and ovarian cancers: from pathobiology to clinical relevance

“…More precisely, the inhibition of KLK1 by a synthetic peptide-based inhibitor resulted in a dose-dependent decreased invasion of MDA-MB-231 breast cancer cells (Wolf et al , 2001 ). Additionally, the use of the KLK1 inhibitor weakens the invasion of the breast cancer cells into lung interstitium of an ex vivo model.…”

“…Prostate cancer KLK1 Promotion of cell invasiveness; angiogenesis Emanueli et al, 2001;Giusti et al, 2005;Gao et al, 2010 KLK2 Tumor growth promotion; ECM degradation Deperthes et al, 1996;Takayama et al, 1997;Mikolajczyk et al, 1999;Rehault et al, 2001;Mize et al, 2008 PSA/KLK3 Tumor growth promotion; EMT-like changes; ECM degradation; angiogenesis; metastasis Webber et al, 1995;Cramer et al, 1996;Fortier et al, 1999;Sun et al, 2001;Yonou et al, 2001;Koistinen et al, 2002;Ishii et al, 2004;Pezzato et al, 2004;Romanov et al, 2004;Dallas et al, 2005;Veveris-Lowe et al, 2005;Goya et al, 2006;Nadiminty et al, 2006 KLK4 Tumor growth promotion; EMT-like changes; ECM degradation; metastasis Takayama et al, 2001;Matsumura et al, 2005;Veveris-Lowe et al, 2005;Beaufort et al, 2006;Gao et al, 2007;Klokk et al, 2007;Mize et al, 2008;Ramsay et al, 2008a;Wang et al, 2010 KLK7 EMT-like changes; promotion of cell invasiveness Mo et al, 2010 KLK14 Tumor growth promotion; ECM degradation Borgono et al, 2007b Breast cancer KLK1 Promotion of cell invasiveness; angiogenesis Emanueli et al, 2001;Wolf et al, 2001;Giusti et al, 2005 PSA/KLK3 Tumor suppressor Lai et al, 1996 KLK6 Tumor suppressor; inhibition of cells invasiveness; antiangiogenes...…”

An overview of the kallikrein gene families in humans and other species: emerging candidate tumour markers

“…More recently, hK11 was also shown to be a potential marker for ovarian and prostate cancer [103]. A synthetic hK1 inhibitor was recently found to suppress cancer cell invasiveness in human breast cancer cell lines [104].…”

Human Kallikrein 8 Protease Confers a Favorable Clinical Outcome in Non–Small Cell Lung Cancer by Suppressing Tumor Cell Invasiveness

“…It is not surprising that proteases, such as the hKs, are reported to promote tumor invasion (2)(3)(4)(5). Human kallikrein 8 (KLK8; neuropsin/ovasin) is a member of the KLK family and the hK8 protein is homologous to mouse neuropsin (6).…”