Kallikrein-Related Peptidase 14 Acts on Proteinase-Activated Receptor 2 to Induce Signaling Pathway in Colon Cancer Cells
Kallikrein-Related Peptidase 14 Acts on Proteinase-Activated Receptor 2 to Induce Signaling Pathway in Colon Cancer Cells
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DOI：
10.1016/j.ajpath.2011.07.016
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发表时间：
2011-11-01
影响因子：
6
通讯作者：
Darmoul, Dalila
中科院分区：
文献类型：
--
作者：
Gratio, Valerie;Loriot, Celine;Darmoul, Dalila
丝氨酸蛋白酶通过裂解和激活蛋白酶激活受体(PARs)参与肿瘤的生长和侵袭。最近的研究表明PAR-1和PAR-4(被凝血酶激活)和PAR-2(被胰酶激活但不被凝血酶激活)与人类结肠癌的生长有关。然而，结肠肿瘤中PARS的内源性激活剂仍不清楚。我们假设激肽释放酶相关多肽酶(KLK)家族成员KLK14是一个已知的肿瘤生物标记物，由结肠癌产生，并通过激活PARs向人结肠癌细胞发出信号。我们发现KLK14mRNA在16个人结肠癌细胞系中表达，KLK14蛋白在结肠癌细胞系中表达和分泌，KLK14(0.1mU/L)可诱导人结肠癌细胞株HT29细胞内钙离子浓度升高。KLK14诱导的钙离子通量与KLK14介导的PAR-2激活内化有关。此外，KLK14可能通过激活PAR-2诱导细胞外信号调节激酶1和2(ERK1/2)的磷酸化和HT29细胞的增殖。PAR-2裂解和激活阻断抗体显著降低KLK14诱导的ERK1/2信号转导。最后，用免疫组化方法证实了KLK14在结肠腺癌中的异位表达以及在正常肠上皮中的缺失。这些结果首次证明了KLK14在结肠癌中的异常表达及其与PAR-2受体信号转导的关系。因此，KLK14及其受体PAR-2可能是结肠肿瘤发生的治疗靶点。(Am J Pathol 2011,170：2625-2636.Doi：10.1016/j.ajpath.2011.07.016)
Serine proteinases participate in tumor growth and invasion by cleaving and activating proteinase-activated receptors (PARs). Recent studies have implicated PAR-1 and PAR-4 (activated by thrombin) and PAR-2 (activated by trypsin but not by thrombin) in human colon cancer growth. The endogenous activators of PARs in colon tumors, however, are still unknown. We hypothesize that the kallikrein-related peptidase (KLK) family member KLK14, a known tumor biomarker, is produced by colonic tumors and signals to human colon cancer cells by activating PARs. We found that i) KLK14 mRNA was present in 16 human colon cancer cell lines, ii) KLK14 protein was expressed and secreted in colon cancer cell lines, and KLK14 (0.1 mu mol/L) induced increases in intracellular calcium in HT29, a human colon cancer derived cell line. KLK14-induced calcium flux was associated with internalization of KLK14-mediated activation of PAR-2. Furthermore, KLK14 induced significant extracellular signal regulated kinases 1 and 2 (ERK1/2) phosphorylation and HT29 cell proliferation, presumably by activating PAR-2. A PAR-2 cleavage and activation blocking antibody dramatically reduced KLK14-induced ERK1/2 signaling. Finally, ectopic expression of KLK14 in human colon adenocarcinomas and its absence in normal epithelia was demonstrated by IHC analysis. These results demonstrate, for the first time, the aberrant expression of KLK14 in colon cancer and its involvement in PAR-2 receptor signaling. Thus, KLK14 and its receptor, PAR-2, may represent therapeutic targets for colon tumorigenesis. (Am J Pathol 2011, 170:2625-2636. DOI: 10.1016/j.ajpath.2011.07.016)