Increased expression of VEGF121/VEGF165-189 ratio results in a significant enhancement of human prostate tumor angiogenesis.
Vascular endothelial growth factor (VEGF) is a proangiogenic factor upregulated in many tumors. The alternative splicing of VEGF mRNA renders 3 major isoforms of 121, 165 and 189 amino-acids in humans (1 less amino-acid for each mouse VEGF isoform). We have designed isoform specific real time QRT-PCR assays to quantitate VEGF transcripts in mouse and human normal and malignant prostates. In the human normal prostate, VEGF(165) was the predominant isoform (62.8% +/- 5.2%), followed by VEGF(121) (22.5% +/- 6.3%) and VEGF(189) (p < 0.001) (14.6% +/- 2.1%). Prostate tumors showed a significant increase in the percentage of VEGF(121) and decreases in VEGF(165) (p < 0.01) and VEGF(189) (p < 0.05). However, the amount of total VEGF mRNA was similar between normal and malignant prostates. VEGF(164) was the transcript with the highest expression in the mouse normal prostate. Unlike human prostate cancer, tumors from TRAMP mice demonstrated a significant increase in total VEGF mRNA levels and in each of the VEGF isoforms, without changes in the relative isoform ratios. Morpholino phosphorodiamide antisense oligonucleotide technology was used to increase the relative amount of VEGF(121) while proportionally decreasing VEGF(165) and VEGF(189) levels in human prostate cell lines, through the modification of alternative splicing, without changing transcription levels and total amount of VEGF. The increase in the VEGF(121)/VEGF(165-189) ratio in PC3 cells resulted in a dramatic increase in prostate tumor angiogenesis in vivo. Our results underscore the importance of VEGF(121) in human prostate carcinoma and demonstrate that the relative expression of the different VEGF isoforms has an impact on prostate carcinogenesis.
Catena
Raul
R
Division of Oncology, Center for Applied Medical Research (CIMA), University of Navarra, Pio XII 55, 31008 Pamplona, Spain.
Muniz-Medina
Vanessa
V
Moralejo
Beatriz
B
Javierre
Biola
B
Best
Carolyn J M
CJ
Emmert-Buck
Michael R
MR
Green
Jeffrey E
JE
Baker
Carl C
CC
Calvo
Alfonso
A
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009025:Morpholines / Q000008:administration & dosage; D009389:Neovascularization, Pathologic / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009841:Oligonucleotides / Q000008:administration & dosage / Q000235:genetics; D011471:Prostatic Neoplasms / Q000098:blood supply* / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis* / Q000235:genetics
D009025:Morpholines; D009841:Oligonucleotides; D012333:RNA, Messenger; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A