In Reply to Drs. Fuks and Kolesnick; Drs. Gudkov and Gleiberman; and Hendry et al.

Abstract

To the Editor: Our initial proof-of-principle study in the mouse intestine showed that selective elevation of the (calculated) dose to the vascular endothelium had no effect on the clinically relevant endpoint of crypt stem cell survival at 3.5 days after irradiation ( 1 Schuller B.W. Binns P.J. Riley K.J. et al. Selective irradiation of the vascular endothelium has no effect on the survival of murine intestinal crypt stem cells. Proc Natl Acad Sci USA. 2006; 103: 3787-3792 Crossref PubMed Scopus (39) Google Scholar ). We next began to look for evidence of a direct effect on the vasculature: apoptosis at 4 h. These studies ( 2 Schuller B.W. Rogers A.B. Cormier K.S. et al. No significant endothelial apoptosis in the radiation-induced gastrointestinal syndrome. Int J Radiat Oncol Biol Phys. 2007; 68: 205-210 Abstract Full Text Full Text PDF PubMed Scopus (46) Google Scholar ) showed only a low level of apoptotic cells in the villus lamina propria and no dose response, even in the control arm, which used the same whole body photon irradiation conditions originally reported by Paris et al.( 3 Paris F. Fuks Z. Kang A. et al. Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice. Science. 2001; 293: 293-297 Crossref PubMed Scopus (1034) Google Scholar ). We contacted Drs. Fuks and Kolesnick of the Memorial Sloan-Kettering Cancer Center (MSKCC) in March 2006. We exchanged tissue blocks in May 2006 for the purposes of an interlaboratory comparison. On sections prepared at the Massachusetts Institute of Technology (MIT) from the MSKCC block (from the original study by Paris et al.[ 3 Paris F. Fuks Z. Kang A. et al. Endothelial apoptosis as the primary lesion initiating intestinal radiation damage in mice. Science. 2001; 293: 293-297 Crossref PubMed Scopus (1034) Google Scholar ]), our in situ DNA nick end labeling (TUNEL) staining showed only the same low level of leukocyte apoptosis in the lamina propria as in our own material. These data were communicated to Drs. Fuks and Kolesnick in May 2006. We never received any slides or images of the MSKCC staining on the MIT tissue blocks. In Regard to Schuller et al. (Int J Radiat Oncol Biol Phys 2007;68:205–210)International Journal of Radiation Oncology, Biology, PhysicsVol. 70Issue 3PreviewTo the Editor: In the article written by Schuller et al.(1), the authors assert that apoptosis does not occur in the endothelial cells in the gastrointestinal (GI) tract after whole-body irradiation, which is in direct conflict with the earlier publication of Paris et al. in 2001 in Science (2). Full-Text PDF