[Selected mechanisms inducing resistance to immunotherapy in patients with ovarian cancer].

Recently, the intensive development of immunotherapies in the treatment of malignant tumors has been observed. The investigated treatment approaches including specific monoclonal antibodies, adoptive therapy and also anticancer vaccinations. The implementation of immunotherapy seems to be promising in treatment of the most malignant and fatal tumors including ovarian cancer. However, current findings have shown only a nonsignificant improvement of patients' survival. The possible cause of failure may be immunotherapy barriers that are a result of low immunogenicity level of ovarian cancer cells, mutation variability, and also the presence of a specific, immunosuppressive tumor microenvironment, which stimulates the cancer progression. The review presents the selected mechanisms of tumor resistance to immunological therapy. In order to project effective treatment approaches, it is necessary to understand both, mechanisms leading to the correct response for the treatment and causing therapeutic failures, resulting from resistance to therapy.

[The meaning of PD-1/PD-L1 pathway in ovarian cancer pathogenesis].

Ovarian cancer is a serious diagnostic and clinical issue. It belongs to the group of cancers with the highest mortality rate, that is why new, effective methods of therapy have been sought after. In recent years, researchers have been paying attention to the use of immunothetapy in the treatment of ovarian cancer. Currently, the numer of studies with the use of PD-1/PD-L1 pathway inhibitors is increasing. It has been reported that PD-1 receptor and its ligand are expressed on tumor cells and immunology system cells in patients with ovarian cancer. Increased expression of PD-1/PD-L1 is one of the inhibition mechanisms of the anti-tumor response by induction of peripheral tolerance. That seems why blocking PD-1/PD-L1 may be so important. A significant role in activation of programmed death cell-1 is attributed to tumor microenvironment (TME). In this review we have described the meaning of PD-1/PD-L1 pathway in ovarian cancer pathogenesis and current results of clinical trials using PD-1/PD-L1 inhibitors. Numerous clinical trials are focused on the effectiveness of immunotherapies as both monotherapy and combination therapy. The promising results of initial research phases are the basis for taking action on a larger scale. Perhaps this will allow in the future to use inhibitors of the PD-1/PD-L1 pathway in the treatment of ovarian cancer.

Enhancement of photo-bactericidal effect of tetrasulfonated hydroxyaluminum phthalocyanine on Pseudomonas aeruginosa.

At the present time, photodynamic inactivation (PDI) is receiving considerable interest for its potential as an antimicrobial therapy. The results of our study indicate that enhancement of the phototoxic effect on Pseudomonas aeruginosa can be achieved by combination of tetrasulfonated hydroxyaluminum phthalocyanine (AlPcS4) and bimetallic gold/silver nanoparticles (Au/Ag-NPs) synthesized by the cell-free filtrate of Aureobasidium pullulans. The bimetallic nanoparticles were characterized by a number of techniques including UV-vis, XPS, TEM, and SEM-EDS to be 14 ± 3 nm spherical particles coated with proteins. The effect of diode lasers with the peak-power wavelength ʎ = 650 nm (output power of 10 and 40 mW; radiation intensity of 26 and 105 mW/cm2) in combination with the AlPcS4 and the bimetallic nanoparticles mixture on the viability of P. aeruginosa rods was shown. Particularly high efficiency of killing bacterial cells was obtained for the light intensity of 105 mW/cm2, after 20, 30, and 40 min of irradiation corresponding to 126, 189, and 252 J/cm2 energy fluences. For AlPcS4+Au/Ag-NPs treatment, the viable count reduction were equal to 99.90, 99.96, and 99.975%, respectively. These results were significantly better than those accomplished for irradiated separated assays of AlPcS4 and Au/Ag-NPs.