Expression of protooncogene c-kit and its ligand stem cell factor (SCF) in gastric carcinoma cell lines.
We examined 13 human gastric carcinoma cell lines for the expression of both c-kit and stem cell factor (SCF). Expression of mRNAs was detected by both Northern blot analysis and reverse transcriptase-polymerase chain reaction (RT-PCR), and expression of translated proteins was detected by western blotting. Using RT-PCR we confirmed the expression of c-kit in five (ECC12, TMK1, MKN7, GCIY, and HGC27) cell lines. Northern blot analysis showed coexpression of both c-kit and SCF in ECC12 and expression of SCF in five other (MKN74, MKN1 OKAJIMA, KATOIII, and TMK1) cell lines. SCF stimulated both tyrosine phosphorylation of c-kit and growth of ECC12, whereas it did not stimulate those of GCIY. The sizes of c-kit transcript and protein in GCIY were slightly smaller than those of the reported ones, suggesting the presence of a biologically inactive truncated form of c-kit in GCIY. The present study suggests that c-kit/SCF system might play an important role in the carcinogenesis and tumor growth of ECC12 and that the truncated form of c-kit in GCIY might not be associated with malignant transformation.
Hassan
S
S
Department of Medicine, Kobe University School of Medicine, Japan.
Kinoshita
Y
Y
Kawanami
C
C
Kishi
K
K
Matsushima
Y
Y
Ohashi
A
A
Funasaka
Y
Y
Okada
A
A
Maekawa
T
T
He-Yao
W
W
Chiba
T
T
D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D006801:Humans; D008024:Ligands; D019009:Proto-Oncogene Proteins c-kit / Q000032:analysis*; D012333:RNA, Messenger / Q000032:analysis; D019089:Stem Cell Factor / Q000032:analysis*; D013274:Stomach Neoplasms / Q000235:genetics*
D008024:Ligands; D012333:RNA, Messenger; D019089:Stem Cell Factor; D019009:Proto-Oncogene Proteins c-kit