[Effect of polychromatic visible light combined with infrared radiation on tumorigenicity of murine hepatoma cells and their sensitivity to lytic activity of natural killers].

Tumorigenicity of murine hepatoma cells (MH22a) and their sensitivity to lysis by natural killers (NKs) have been studied after exposure to polychromatic visible and infrared light (VIS-IR, 480-3400 nm, 40 mW/cm2), similar to the terrestrial solar spectrum without its minor UV component, in order to elucidate the involvement of this important environmental and physiotherapeutic factor in regulation of the anti-tumor defense system. The MH22 cells were in vitro exposed to VIS-IR light and their sensitivity to lytic activity of NKs was evaluated. We found that sensitivity of MH22a cells to lysis by NKs after exposure to VIS-IR light at a dose of 4.8 J/cm2 increased 1.5-2 times, while it did not change after exposure to a dose of 9.6 J/cm2 at all ratios (1 : 5-1 : 50) of the number of NKs (effectors) to that of hepatoma cells (targets). The increase in the sensitivity of hepatoma cells to NKs was accompanied by structural changes of cell surface: the capability of supramembraneous glycoproteins (glycocalix) to sorb the vital dye alcian blue (AB) was significantly lower as compared with the unexposed cells of control group. However, no changes in AB sorption was revealed in hepatoma cells exposed to the light at a dose 9.6 J/cm2. Tumorigenicity of photo-irradiated MH22a cells has been studied in the in vivo experiments. Light-exposed (4.8 and 9.6 J/cm2) and intact hepatoma cells were transplanted into syngenic mice C3HA. Tumor volumes 25 days after transplantation proved to be smaller after exposure to the light at both doses than in the control group (4-4.5 times and 2.5-4 times, respectively), which correlated with the increase in the sensitivity to lisys by NKs and decrease in the AB sorption only after light exposure at dose 4.8 J/cm2. Using the flow cytometry method we could show that VIS-IR light at the applied doses did not interfere with the distribution of hepatoma cells over the cycle phases and thus deceleration of the tumor growth was not associated with cytostatic effect of VIS-IR light. To evaluate effect of polychromatic light on the growth of the preformed tumors, the 5-day course of daily light exposures of tumor bearing mice C3HA was carried out in 10 days after subcutaneous transplantation of 2 x 10(5) cells of syngene hepatoma when the tumors had developed in 100% animals. Like in the case of transplantation of the light-exposed cells, irradiation of the tumor bearing mice at doses 4.8-9.6 J/cm2 resulted in deceleration of tumor growth (2.1-2.9 and 2.2 times respectively) for 4 weeks as compared with non-irradiated mice.

[Proliferation and tumorigenity of the murine hepatoma cells irradiated with polychromatic visible and infrared light].

In experiments in vitro, the effect of the polychromatic visible (VIS) light combined with polychromatic infrared light (VIS-IR, 480-3400 nm) and the effect of the entire spectrum of VIS radiation (385-750 nm) on the viability and proliferative activity of the murine hepatoma cells MH22a. In experiments in vivo, changes of tumorigenic properties of cells MH22a have been studied after the same kinds of light exposure. It was shown that irradiation of the hepatoma cells with two kinds of polychromatic light at a wide range of doses (4.8-38.4 J/cm2) did not lead to an increase in the number of dead cells for 24-72 h of cultivation and did not cause retardation of the hepatoma cell proliferation. Moreover, VIS-IR light at a dose of 4.8 J/cm2 and VIS light at a dose 38.4 J/cm2 stimulated cell proliferation in 24 h. Proliferation index increased by 1.6 and 1.4 times, respective, and the time of the cell number doubling decreased as compared with control. Studying the tumorigenic properties of irradiated tumor cells showed that, for 30 days after transplantation, of hepatoma cells in 24 h after their irradiation with VIS-IR light at a dose of 4.8 J/cm2 to syngenic mice C3HA, the tumor volume reduced significantly (2.6-4 times) of all stages of observation. The incidence of tumor formation decreased, whereas the survival of the tumor-bearing mice did not change. Transplantation of cells irradiated with the same light at a dose of 9.6 J/cm2 did not lead to significant changes of the tumor volume, the tumor formation incidence, and animal survival. The main contribution to the antitumor effect of the VIS-IR light seems to be made by the VIS component, as transplantation of cells irradiated with VIS alone light at a dose of 38.4 J/cm2 also stimulating proliferation of hepatoma cells in vitro into mice resulted in a reduction of their tumorigenic properties. However, the IR component in the combined VIS-IR radiation enhanced the antitumor effect of the VIS light; as a result, this effect was manifested after use of doses 8 times lower (4.8 J/cm2) than in the case of the VIS light alone (38.4 J/cm2). Mechanisms of the decrease of tumorigenic properties of hepatoma cells after irradiation with polychromatic light ad doses stimulating their proliferation in vitro are studied.

[The antigen of the differentiated basal disc cells of Hydra].

A new antigenic marker of the differentiated basal disk cells of Hydra was characterized. An antigen named 3G11 was revealed by monoclonal antibody in granules of the basal disk gland cells of the ectoderm. The antigen appearance during budding, regeneration and ectopic foot formation evidences for the differentiation of the body column epithelial cells into basal disk gland cells. Antigen 3G11 is species-specific: among six hydra species investigated, the antigen was observed exclusively in polyps of vulgaris group which is a special taxon of the filum Hydra. Cell and tissue localization of the antigen 3G11 was similar to that of the well-established biochemical hydra marker, foot specific peroxidase, reported formerly. However, ELISA data suggest that the molecule bearing antigen 3G11 does not possess any peroxidase activity. Thus the new hydra antigenic marker 3G11 extends the number of previously used markers of differentiation and allows to improve the technique of the basal disk differentiated tissue identification.