mRTVP-1, a novel p53 target gene with proapoptotic activities.
We identified a novel mouse gene, mRTVP-1, as a p53 target gene using differential display PCR and extensive promoter analysis. The mRTVP-1 protein has 255 amino acids and differs from the human RTVP-1 (hRTVP-1) protein by two short in-frame deletions of two and nine amino acids. RTVP-1 mRNA was induced in multiple cancer cell lines by adenovirus-mediated delivery of p53 and by gamma irradiation or doxorubicin both in the presence and in the absence of endogenous p53. Analysis of RTVP-1 expression in nontransformed and transformed cells further supported p53-independent gene regulation. Using luciferase reporter and electrophoretic mobility shift assays we identified a p53 binding site within intron 1 of the mRTVP-1 gene. Overexpression of mRTVP-1 or hRTVP-1 induced apoptosis in multiple cancer cell lines including prostate cancer cell lines 148-1PA, 178-2BMA, PC-3, TSU-Pr1, and LNCaP, a human lung cancer cell line, H1299, and two isogenic human colon cancer cell lines, HCT116 p53(+/+) and HCT116 p53(-/-), as demonstrated by annexin V positivity, phase-contrast microscopy, and in selected cases 4',6'-diamidino-2-phenylindole staining and DNA fragmentation. Deletion of the signal peptide from the N terminus of RTVP-1 reduced its apoptotic activities, suggesting that a secreted and soluble form of RTVP-1 may mediate, in part, its proapoptotic activities.
Ren
Chengzhen
C
Scott Department of Urology, Baylor College of Medicine, Houston, Texas 77030, USA.
Li
Likun
L
Goltsov
Alexei A
AA
Timme
Terry L
TL
Tahir
Salahaldin A
SA
Wang
Jianxiang
J
Garza
Laura
L
Chinault
A Craig
AC
Thompson
Timothy C
TC
D000595:Amino Acid Sequence; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000235:genetics* / Q000502:physiology; D048429:Cell Size; D004317:Doxorubicin / Q000494:pharmacology; D005720:Gamma Rays; D005796:Genes; D017930:Genes, Reporter; D006801:Humans; D008565:Membrane Proteins; D051379:Mice; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D021382:Protein Sorting Signals; D016415:Sequence Alignment; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*; D015854:Up-Regulation
D000970:Antineoplastic Agents; C094538:GLIPR1 protein, human; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D021382:Protein Sorting Signals; D016159:Tumor Suppressor Protein p53; D004317:Doxorubicin