Expression of a TGF-beta1 inducible gene, TSC-36, causes growth inhibition in human lung cancer cell lines.
TSC-36 (TGF-beta1-stimulated clone 36) is a TGF-beta1 inducible gene whose product is an extracellular glycoprotein that contains a single follistatin module. TSC-36 is highly expressed in the lung, but its physiological function is unknown. In an attempt to elucidate it, we investigated the effect of TSC-36 on proliferation of human lung cancer cell lines. We found a correlation between expression of TSC-36 and cell growth: TSC-36 mRNA was not detected in cells derived from small cell lung cancer (SCLC) cells, a highly aggressive neoplasm, but was detected in some non-small cell lung cancer (NSCLC) cells, a moderately aggressive neoplasm. This suggested an antiproliferative function for TSC-36. To address this question, NSCLC PC-14 cells, which express very low level of TSC-36 protein, were transfected with TSC-36 cDNA and the proliferative capacity of stable transfectants was determined by measuring the doubling time, colony forming activity in soft agar and the level of incorporation of (3)H-thymidine into DNA. Under normal culture conditions, the transfected cells showed a longer doubling time, lower plating efficiency and lower rate of DNA synthesis than the parental cells and the control neo transfectant cells. These findings suggested that expression of TSC-36 caused growth inhibition in human lung cancer cells.
Sumitomo
K
K
Third Department of Internal Medicine, The University of Tokushima, 3-18-15 Kuramoto-cho, Tokushima, Japan. kenya@clin.med.tokushima-u.ac.jp
Kurisaki
A
A
Yamakawa
N
N
Tsuchida
K
K
Shimizu
E
E
Sone
S
S
Sugino
H
H
D015152:Blotting, Northern; D002289:Carcinoma, Non-Small-Cell Lung / Q000378:metabolism; D018288:Carcinoma, Small Cell / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D005434:Flow Cytometry; D038702:Follistatin-Related Proteins; D006023:Glycoproteins / Q000096:biosynthesis* / Q000235:genetics*; D006801:Humans; D008175:Lung Neoplasms / Q000378:metabolism*; D010957:Plasmids; D012333:RNA, Messenger / Q000378:metabolism; D014162:Transfection; D016212:Transforming Growth Factor beta / Q000378:metabolism*; D014407:Tumor Cells, Cultured
D038702:Follistatin-Related Proteins; D006023:Glycoproteins; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta