Abstract
To determine the effect of cell density on vascular endothelial growth factor (VEGF) expression and the mechanism of this effect, four human colon cancer cell lines were grown as sparse or confluent monolayers or as spheroids. VEGF mRNA increased >2-fold in cells grown as confluent monolayers or spheroids compared with cells grown as sparse monolayers. Semiquantitative reverse transcription-PCR demonstrated a 2-fold increase in the larger VEGF mRNA isoform (189 bp) in confluent cells. Sparse cells grown in conditioned medium from confluent cells demonstrated a >2-fold increase in VEGF mRNA. These data suggest that VEGF expression may be regulated by an unidentified soluble factor.
Footnotes
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↵1 This work was supported in part by NIH T-32 Grant CA09599 (to A. N. K.), NIH/National Cancer Institute Grant R29 CA67952 (to R. R.), the Sid Richardson Foundation (to R. R.), and American Cancer Society Career Development Award 94-21 (to L. M. E.).
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↵2 To whom requests for reprints should be addressed, at Department of Surgical Oncology, Box 106, University of Texas M. D. Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, TX 77030. Phone: (713) 792-6926; Fax: (713) 792-0722.
- Received May 20, 1996.
- Accepted July 16, 1996.
- ©1996 American Association for Cancer Research.
Volume 56, Issue 17
