Affiliation:
1. Department of Biophysics and Cancer Biology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, 31-007 Krakow, Poland
2. Department of Chemistry and Biochemistry, Institute for Basic Sciences, University of Physical Education, 31-571 Krakow, Poland
Abstract
Animal tumors serve as reasonable models for human cancers. Both human and animal tumors often reveal triplet EPR signals of nitrosylhemoglobin (HbNO) as an effect of nitric oxide formation in tumor tissue, where NO is complexed by Hb. In search of factors determining the appearance of nitrosylhemoglobin (HbNO) in solid tumors, we compared the intensities of electron paramagnetic resonance (EPR) signals of various iron–nitrosyl complexes detectable in tumor tissues, in the presence and absence of excess exogenous iron(II) and diethyldithiocarbamate (DETC). Three types of murine tumors, namely, L5178Y lymphoma, amelanotic Cloudman S91 melanoma, and Ehrlich carcinoma (EC) growing in DBA/2 or Swiss mice, were used. The results were analyzed in the context of vascularization determined histochemically using antibodies to CD31. Strong HbNO EPR signals were found in melanoma, i.e., in the tumor with a vast amount of a hemorrhagic necrosis core. Strong Fe(DETC)2NO signals could be induced in poorly vascularized EC. In L5178Y, there was a correlation between both types of signals, and in addition, Fe(RS)2(NO)2 signals of non-heme iron–nitrosyl complexes could be detected. We postulate that HbNO EPR signals appear during active destruction of well-vascularized tumor tissue due to hemorrhagic necrosis. The presence of iron–nitrosyl complexes in tumor tissue is biologically meaningful and defines the evolution of complicated tumor–host interactions.
Funder
Jagiellonian University
Fund for Polish Science and Technology
NCBiR
European Union
Reference122 articles.
1. Paramagnetic resonance in phthalocyanine, haemoglobin, and other organic derivatives;Ingram;Discuss. Faraday Soc.,1955
2. Blois, M.S., Brown, H.W., Lemmon, R.M., Lindblom, R.O., and Weissbluth, M. (1961). Free Radicals in Biological Systems, Proceedings of the Symposium on Free Radicals in Biological Systems, Stanford University, USA, March 1960, Academic Press.
3. Detection and investigation of a new type of ESR signal characteristic of some tumour tissues;Emanuel;Nature,1969
4. A unique hyperfine ESR spectrum in mouse neoplasms analyzed by computer simulation;Brennan;Proc. Soc. Exp. Biol. Med.,1966
5. Electron spin resonance studies of nitrosyl haemoglobin in human liver, colon and stomach tumour tissues;Symons;Free Radic. Res.,1994