Citation: Mittal K (2006) Differences in Mitotic Activity May Explain Observed Differences in HIF-1α Response in Cancers and Stroma. PLoS Med 3(8): e370. doi:10.1371/journal.pmed.0030370
Published: August 29, 2006
Copyright: © 2006 Khush Mittal. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The author received no specific funding for this article.
Competing interests: The author has declared that no competing interests exist.
I read the paper by Chi et al. with interest. The authors found a greater hypoxia response gene expression in carcinomas than stromal cells grown in vitro, but were not sure of the underlying explanation (see Discussion in ). The underlying explanation may be the difference in mitotic activity and hence metabolic activity between these two cell types, such that hypoxia may be present within cancer cells, although the surrounding culture media may have similar oxygen levels as the stromal cultures.
The differences in mitotic activity could also explain greater hypoxia-related gene expression in clear-cell carcinoma compared with chromophobe carcinoma, normal tissue, or oncocytoma, as clear-cell carcinomas are more active mitotically. Did the authors compare the hypoxia gene expression with mitotic activity in various tumors?