The assessment of the effects of low-intensity laser radiation on cells of tumor strain of kidney cancer PA-1

Viktoria V. Skvortsova, Grigory E. Brill, Galina A. Afanasyeva,

Alla B.BucharskayaSaratov State Medical University, Russia

PurposeThe purpose of the study was to

investigate the effects of low-intensity red laser in vitro on cells of tumor strain

of kidney cancer PA-1 and assess the tumor transplantability in rats after laser

irradiation, macro- and microscopic

Materials and methods12 white outbred male

rats weighing 200 ± 20 g were used in the

experiments. The tumor strain of kidney cancer PA-1 was obtained in

Bank of tumor strains of Oncological Centre n.a.

N.N. Blokhin.

Materials and methods

Immediately after removal of tumors from donor rat,

cancer tissue weighing 30 g was washed with

physiological saline, added to 10 ml of Hanks solution and mechanically milled.

Materials and methods

Suspension of tumor cells (2.5 ml) was exposed to laser irradiation previously, using semiconductor red laser (λ - 660 nm, output power - 24 mW) in a continuous mode during 20 min.

Materials and methods

• The suspension of tumor cells in a volume of 0.5 ml was administered to animals

subcutaneously in the midscapular region. Irradiated suspension was injected to six

rats from experimental group. • Six animals from control group received

non-irradiated tumor cell suspension.

Methods• Observations of tumor

growth and the measurement of tumor volume was performed

for 21 days

Results

Significant differences were marked on the 17th day of the experiment, when the

average tumor volume was 10,2 ± 2,8 cm3 in the experimental group, 2,26 ± 0,75 cm3

- in the control group (p<0,02).

Dynamics of tumor growth

9 11 13 15 17 19 210

5

10

15

20

25

control gr.

experimental gr.

Days

Volume, cm3

Results

On the 19th day of experiment the average tumor volume was 13,9 ± 1,6 cm3 in the experimental group, 4,03 ± 0,77 cm3

- in control (p<0,001).

Results

Finally, on the 21st day the size of transplanted tumors was 23,0 ± 3,8 cm3 in the experimental group, 10,4 ± 2,2 cm3

- in control (p<0.02).

against…

Histologically, we did reveal some differences in samples of tumors between

experimental and control groups.

experiment control

We observed cells with degenerative changes, with increased eosinophilia of the cytoplasm, hyperchroma-tic and smaller nuclei, that occupy from 40 to 70% of the area. Lumen of blood vessels occur from single to 10 in sight. experiment

Conclusion

The stimulation of tumor growth of kidney cancer PA-1

was recorded when suspension of tumor cells were previously

exposed with low-intensity laser irradiation in vitro.

Some questions without answers…

• How does biological activity of kidney cancer cells modify under the influence of laser irradiation?

• Does laser change genetic apparatus of cancer cells?• How long and unambiguous is effect

of exposure at these characteristics of the laser?

So, still a lot remains unclear in the tumor response to irradiation by low-power laser, which requires a special approach - immunogistochemical techniques, spectroflowmetric analyses, genetic marking under certain experimental conditions - broad field for researches!

Thanks for your attention!!!