title: Upregulation and secretion of kallikrein-related peptidase 6 (KLK6) in gastric cancer.
abstract: KLK6 encoding kallikrein-related peptidase 6, a trypsin-like serine protease, has been shown to be upregulated in several cancers, although the tumorigenic role of KLK6 has not been elucidated. In this study, KLK6 was identified as a highly upregulated gene in gastric cancer; therefore, the possibility that KLK6 might be a suitable candidate tumor marker was examined. RT-PCR and immunohistochemical analysis showed overexpression of KLK6 in gastric cancer tissues compared to nontumor regions. Sera from gastric cancer patients had a 1.7-fold increase in KLK6 (373.1 μg/L, P = 0.048) compared to healthy individuals (214.2 μg/L), although there was no significant difference among patients with various tumor stages. Cellular invasiveness decreased by 45% in cells transfected with KLK6-specific small interfering RNA. Exogenous overexpression of KLK6 led to decreased activity of the E-cadherin promoter. This study shows that KLK6 is significantly upregulated and secreted in gastric cancer tissues and sera, suggesting that KLK6 might be used as a potential biomarker and therapeutic target for gastric cancer.
authors.affiliation: Medical Genomics Research Center, Korea Research Institute of Bioscience and Biotechnology, 125 Gwahak-ro, Yuseong-gu, Daejeon 305-806, Republic of Korea.
authors.forename: Jin Ju
authors.initials: JJ
authors.lastname: Kim
authors.forename: Jong-Tae
authors.initials: JT
authors.lastname: Kim
authors.forename: Hyo Ran
authors.initials: HR
authors.lastname: Yoon
authors.forename: Min Ah
authors.initials: MA
authors.lastname: Kang
authors.forename: Joo Heon
authors.initials: JH
authors.lastname: Kim
authors.forename: Young-Ha
authors.initials: YH
authors.lastname: Lee
authors.forename: Jae Wha
authors.initials: JW
authors.lastname: Kim
authors.forename: Seon-Jin
authors.initials: SJ
authors.lastname: Lee
authors.forename: Eun Young
authors.initials: EY
authors.lastname: Song
authors.forename: Pyung Keun
authors.initials: PK
authors.lastname: Myung
authors.forename: Hee Gu
authors.initials: HG
authors.lastname: Lee
mesh_terms: D015820:Cadherins / Q000235:genetics; D045744:Cell Line, Tumor; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007610:Kallikreins / Q000235:genetics* / Q000378:metabolism*; D009361:Neoplasm Invasiveness / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D013274:Stomach Neoplasms / Q000201:enzymology* / Q000235:genetics*; D015533:Transcriptional Activation; D015854:Up-Regulation / Q000235:genetics
chemical_list: D015820:Cadherins; D012333:RNA, Messenger; C103551:KLK6 protein, human; D007610:Kallikreins