3rd Eurasia Biochemical Approaches & Technologies, Antalya, Turkey, 4 - 07 November 2021, pp.162
Prostate cancer is the most common type of cancer in the world, followed by others such as lung,
colon, and breast cancer. According to GLOBOCAN 2018 data, prostate cancer is seen in the second
place after lung cancer in terms of cancer incidence in men all over the world. Lung cancer (59.3%)
has the highest rate of age-standardized cancer in Turkey's cancer data, followed by prostate cancer
(36.4%). While the age-standardized mortality rate was 12.9% and 12.8% in Australia and New
Zealand, respectively, it was reported to be 22.8% in Turkey.
1,2
Docetaxel is an important chemotherapeutic agent used in the treatment of many solid tumors such
as breast cancer, prostate cancer, non-small cell lung cancer, head and neck cancers, as monotherapy
or in combination with other chemotherapeutic agents.
3 Deinococcus radiodurans synthesizes
deinoxanthin, a xanthine derivative with a strong pro-oxidative effect, which it stores in the cell wall.
Deinoxanthin has an antioxidant effect as well as a pro-oxidative effect under certain conditions. In
many studies, it has been determined that deinoxanthin causes an increase in intracellular ROS due to
its pro-oxidant activity and induces apoptosis in various cancer lines.
4
In this study, the synergistic anticancer effect of deinoxanthin and docetaxel on prostate cancer, PC-3
cell line was examined. The cytotoxic activity of deinoxanthin and docetaxel against on the viability of
PC-3 separately and together was examined by MTT assay. According to the CI values of deinoxanthin
and docetaxel combinations; best agonistic effect was determined at 50 nM docetaxel-25 µM
deinoxanthin at 24 hours. Levels of BAX, BCL-2, and CASPASE-3 were determined by ELISA. When the
results are evaluated, the increase in CASPASE 3 and BAX protein levels shows that intrinsic apoptosis
is induced. In addition, the decrease in BCL2 protein level supports the induction of intrinsic apoptosis.
The results obtained by the RT-qPCR method performed to determine the BAX, CASPASE-3 and BCL2
gene expression levels were found to be correlated with the ELISA data. We also determined activity
of GR, GPx and SOD in the docetaxel and deinoxanthin-applied cells. Results may reveal that increase
in glutathione reductase, glutathione peroxidase and superoxide dismutase levels, is an indication that
the pro-oxidative effect of deinoxanthin and docetaxel drags the cell to apoptosis.