Endocytosis is one of the major ways cells communicate with their environment. This process is frequently hijacked by pathogens. Endocytosis also participates in the oncogenic transformation. Here, we review the approaches to inhibit endocytosis, discuss chemical inhibitors of this process, and discuss potential clinical applications of the endocytosis inhibitors.

Novel pyridine-thiazole hybrid molecules were synthesized and subjected to physico-chemical characterization and screening of their cytotoxic action towards a panel of cell lines derived from different types of tumors (carcinomas of colon, breast, and lung, glioblastoma and leukemia), and normal human keratinocytes, for comparison. High antiproliferative activity of the 3-(2-fluorophenyl)-1-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-propenone 3 and 4-(2-{1-(2-fluorophenyl)-3-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-3-oxopropylsulfanyl}-acetylamino)-benzoic acid ethyl ester 4 was revealed. The IC₅₀ of the compound 3 in HL-60 cells of the acute human promyelocytic leukemia was 0.57 µM, while in the pseudo-normal human cell lines, the IC₅₀ of this compound was >50 µM, which suggests that the compounds 3 and 4 might be perspective anticancer agents. The detected selectivity of the derivatives 3 and 4 for cancer cell lines inspired us to study the mechanisms of their cytotoxic action. It was shown that preincubation of tumor cells with Fluzaparib (inhibitor of PARP1) reduced the cytotoxic activity of the derivatives 3 and 4 by more than twice. The ability of these compounds to affect DNA nativity and cause changes in nucleus morphology allows for the suggestion that the mechanism of action of the novel pyridine-thiazole derivatives might be related to inducing the genetic instability in tumor cells.

Anticancer screening of several novel thienopyrimidines has been performed. The thienopyrimidine derivatives were synthesized from available starting materials according to the convenient synthetic procedures using a one-pot solvent-free reaction which gave a wide access to thienopyrimidine-derivative production. The synthesized compounds were preselected via molecular docking to be tested for their anticancer activity in NCI 60 cell lines. It was observed that some compounds showed remarkable anticancer activity. It was found that the most active compound among thieno[2,3-d]pyrimidine-4(3H)-ones is 2-(benzylamino)-5,6-dimethylthieno[2,3-d]pyrimidin-4(3H)-one, which possesses cytotoxic activity on almost all cancer cell lines with mean growth 51.01%, where the most sensitive was the melanoma cell line MDA-MB-435 with GP (Growth Percent) = −31.02%. The patterns of structure–activity that are important for further optimization of the structure and the creation of more selective and active anticancer agents were proposed.

The development of novel efficient substances for anticancer chemotherapy is an important problem of medicinal chemistry. Aim. To evaluate the level of cytotoxic action of novel thiazole derivatives towards tumor cell lines of different origin. Methods. Four N acylated 2-amino-5-benzyl-1,3-thiazoles (5a-d) were synthesized by reaction of 2-amino-5-R-benzyl-1,3-thiazoles with acid chlorides in the presence of triethylamine in the dioxane medium. Anticancer screening of the synthesized thiazoles was performed by the MTT assay. Results. Thiazole derivatives were shown to exert antineoplastic activity towards different types of tumor cells. The anti-glioma and anti-melanoma selectivity of these derivatives action was demonstrated. The compound 5a was found to be the most toxic for human glioblastoma U251 cells and human melanoma WM793 cells. At the same time, the created compounds possessed low toxicity towards pseudo-normal cells. Conclusion. The novel thiazole derivative 5a was the most toxic against human glioblastoma and melanoma cells. K e y w o r d s: thiazole derivatives, 2-amino-5-benzyl-1,3-thiazoles, anticancer activity, leukemia, glioblastoma, melanoma.