High expression of Cks1 in human non-small cell lung carcinomas.
Enhanced degradation of cyclin-dependent kinase (CDK) inhibitor p27(Kip1) is known to be a powerful prognostic marker in many types of human cancers. Human CDK subunit 1 (Cks1) and S-phase kinase associated protein 2 (Skp2) are components of the SCF(Skp2) complex, which acts as a ubiquitin ligase for p27(Kip1). There are no reports about the involvement of Cks1 in the pathogenesis of human cancer. Here we show high expression of Cks1 in non-small cell lung cancers (NSCLCs) using Western blotting and quantitative real-time RT-PCR. The Skp2 mRNA expression level was high in squamous cell carcinomas and was inversely related with the p27(Kip1) protein level in individual clinical samples. In contrast, Cks1 mRNA expression had no such relationship with p27(Kip1), although Cks1 mRNA was significantly elevated in adenocarcinomas. These results suggest that high expression of Skp2 and Cks1 may be involved in the pathogenesis of NSCLCs via different mechanisms.
Inui
Naoki
N
Second Department of Internal Medicine, Hamamatsu University School of Medicine, 1-20-1 Handayama, Hamamatsu, Shizuoka 431-3192, Japan.
Kitagawa
Kyoko
K
Miwa
Seiichi
S
Hattori
Takayuki
T
Chida
Kingo
K
Nakamura
Hirotoshi
H
Kitagawa
Masatoshi
M
D048868:Adaptor Proteins, Signal Transducing; D000230:Adenocarcinoma / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D002289:Carcinoma, Non-Small-Cell Lung / Q000209:etiology / Q000235:genetics* / Q000378:metabolism*; D002294:Carcinoma, Squamous Cell / Q000209:etiology / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism*; D050760:Cyclin-Dependent Kinase Inhibitor p27; D005260:Female; D015870:Gene Expression; D006801:Humans; D007150:Immunohistochemistry; D008175:Lung Neoplasms / Q000209:etiology / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012334:RNA, Neoplasm / Q000235:genetics / Q000378:metabolism; D044786:S-Phase Kinase-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics* / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; C081185:CKS1 protein, S cerevisiae; D018797:Cell Cycle Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D044786:S-Phase Kinase-Associated Proteins; D029701:Saccharomyces cerevisiae Proteins; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27