Medical Radiology and Radiation Safety. 2013. Vol. 58. No. 3. P. 34–38

RADIATION THERAPY

N.V. Belozor, T.V. Segeda, V.P. Starenkiy, N.A. Mitryaeva

Sfingomyelinasa for Monitoring of Chemoradioterapy Effectiveness in Cancer Treatment (Clinical and Experimental Investigation)

S.P. Grigoriev Medical Radiology Institute, National Academy of Medical Science of Ukraine, Kharkiv, Ukraine, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.

Abstract

Purpose: To substantiate experimentally and investigate the possibility to use Zn2+-dependent acid sphingomyelinase (ASMase) in monitoring of efficacy of treatment for non-small-cell lung cancer (NSCLC).

Material and methods: The results of radiation therapy (RT) with two modes of accelerated fractionation and radiosensitizing with Etoposide in 45 patient with inoperable IIIA-IIIB NSCLC against a background of determining blood serum ASMase activity in the course of the treatment. ASMase activity, ceramide (CM) amount and sphingomyelin were investigated in the blood serum of rats with transplanted Guerin’s carcinoma at combined action of high-energy photon (HEP) radiation and Etoposide. The irradiation was delivered in two fractions up to 10 Gy with linear accelerator Clinac 600 Ϯ

Results: It was determined that blood serum ASMase activity in patients with NSCLC after chemoradiation treatment increased significantly in 2.9 times and was accompanied by the tumor regression (>50 %) in 73.3 % of cases. It was shown that increased activity of ASNase in 1.9 times, 4.7 time increase of and 2.5-time reduction of SPM were observed in the blood serum of the rat’s carriers of the tumor at combined action of HEP radiation and Etoposide.

Conclusion: ASMase activity level in the course of chemoradiation therapy against a background of determining the tumor regression can be used for monitoring of efficacy of chemoradiation treatment for NSCLC. This was substantiated by the findings of clinical investigations which allowed to suggest that a mechanism associated with ASMase activation is involved in induction of accumulation of pro-apoptotic lipid CM at combined action of irradiation and Etoposide. Therefore, the possibility to use determining ASMase activity as a serous marker of apoptosis ceramide pathway to assess the efficacy of chemoradiation therapy is obvious.

Key words: nonsmall lung cancer, chemoradiotherapy, Zn2+-dependent sphingomyelinase, ceramide, apoptosis