title: Retinoic acid increases expression of the calcium-binding protein S100P in human gastric cancer cells.
abstract: Retinoids mediate a wide spectrum of antitumor activities through induction of growth arrest, differentiation or apoptosis. To determine whether the effects of retinoids are mediated by specific gene activation or repression, one-day treatments of SC-M1 CL23 gastric cancer cells with vehicle alone or all-TRANS retinoic acid (tRA) (10 microM) were compared using differential display analysis. A 432-bp cDNA fragment from the tRA-treated cells was differentially amplified and its sequence analysis indicated homology with the calcium-binding protein S100P. Levels of S100P mRNA were increased 3.5-fold in SC-M1 CL23 gastric cancer cells treated with 10 microM tRA for 1 day, and the regulation was time- and concentration-dependent. Treatment with tRA (10 microM) also increased S100P mRNA levels in tRA-sensitive HtTA cells but not in inherent RA-resistant TMC-1 cells. However, the tRA-mediated increase in S100P expression was maintained in SC-M1/R cells that were established long-term in tRA-containing medium and had acquired partial RA resistance to tRA-induced growth suppression. In conclusion, tRA increases S100P expression, and the regulation remains intact in cells which develop acquired RA resistance.
authors.affiliation: Department of Internal Medicine, Tri-Service General Hospital, National Defense Medical Center, No. 161 Min-Chuan E. Road, Sec. 6, Taipei, Taiwan 114, ROC.
authors.forename: Rong-Yaun
authors.initials: RY
authors.lastname: Shyu
authors.forename: Shiang-Long
authors.initials: SL
authors.lastname: Huang
authors.forename: Shun-Yuan
authors.initials: SY
authors.lastname: Jiang
mesh_terms: D001483:Base Sequence; D015152:Blotting, Northern; D045744:Cell Line, Tumor; D017931:DNA Primers; D005470:Fluorometry; D015870:Gene Expression / Q000502:physiology*; D020869:Gene Expression Profiling; D006801:Humans; D008969:Molecular Sequence Data; D018168:Receptors, Retinoic Acid / Q000235:genetics*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism*; D017422:Sequence Analysis, DNA; D014212:Tretinoin / Q000378:metabolism*
chemical_list: D017931:DNA Primers; C437968:PLAAT4 protein, human; D018168:Receptors, Retinoic Acid; D009418:S100 Proteins; D014212:Tretinoin