Protein tyrosine kinase 7 plays a tumor suppressor role by inhibiting ERK and AKT phosphorylation in lung cancer.
Protein tyrosine kinase 7 (PTK7) is a catalytically inactive receptor tyrosine kinase that is also known as colon carcinoma kinase-4 (CCK-4). Recent reports have shown that PTK7 plays an important role in carcinogenesis, and it is known to be upregulated in gastric, colon and esophageal cancer, as well as in liposarcoma. However, the role of PTK7 in lung cancer has not been investigated. The aim of the present study was to investigate the expression levels and the role of PTK7 in lung cancer. We found that PTK7 expression was downregulated at the mRNA as well as protein levels in human lung squamous cell carcinoma (LSCC). Upon investigation of the functional role of PTK7 in LSCC, we found that overexpression of PTK7 in LSCC cells resulted in inhibition of cell proliferation, invasion and migration. Furthermore, we confirmed that these phenotypic changes are associated with the inactivation of AKT and ERK. Our findings suggest that PTK7 has different oncogenic roles in organs and target tumors.
Department of Translational Research, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea.
Ji-Hee
JH
Kim
Department of Translational Research, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea.
Junhye
J
Kwon
Department of Thoracic Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea.
Hae Won
HW
Lee
Department of Thoracic Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea.
Moon Chul
MC
Kang
Department of Translational Research, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea.
Hyeon-Joon
HJ
Yoon
Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Republic of Korea.
Seung-Taek
ST
Lee
Department of Thoracic Surgery, Korea Cancer Center Hospital, Korea Institute of Radiological and Medical Sciences, Seoul 139-706, Republic of Korea.
Jong Ho
JH
Park
D063646:Carcinogenesis / Q000235:genetics; D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D015815:Cell Adhesion Molecules / Q000096:biosynthesis* / Q000235:genetics; D045744:Cell Line, Tumor; D048049:Extracellular Signal-Regulated MAP Kinases / Q000235:genetics / Q000378:metabolism*; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D051058:Oncogene Protein v-akt / Q000235:genetics* / Q000378:metabolism; D010766:Phosphorylation; D020794:Receptor Protein-Tyrosine Kinases / Q000096:biosynthesis* / Q000235:genetics
D015815:Cell Adhesion Molecules; C096905:PTK7 protein, human; D020794:Receptor Protein-Tyrosine Kinases; D051058:Oncogene Protein v-akt; D048049:Extracellular Signal-Regulated MAP Kinases