Selective Cytotoxicity and Changes in Protein Expression of T24 Bladder Carcinoma Permanent Cell Line after Treatment with Hemocyanins

Abstract

Background: Some molluscan hemocyanins (Hcs) have significant immunological and antitumor potential, enabling their application in oncology. The antitumor activity of Hcs from marine snails Rapana venosa (RvH), giant keyhole limpet Megathura crenulata (KLH) and garden snails Helix lucorum (HlH), as well as their different derivatives, were studied in vitro on a permanent T24 cell line of bladder cancer and normal urothelial cell line HL 10/29 compared to doxorubicin. Methods: The antiproliferative activity of the tested Hcs was determined using WST-1 assay and BrdU ELISA assay. Morphological changes in both urothelial cell lines were confirmed by fluorescence microscopy. The proteomic analysis of a cell line of bladder cancer before and after treatment with functional unit (FU) βc-HlH-h using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and mass spectrometry revealed differences in the expression of some proteins. Results: Studies prove that the T24 tumor cell line is dose- and time-dependent, sensitive to the action of the tested isoforms and the glycosylated FU of these hemocyanins. Selective inhibition of T24 cell growth was observed after incubation with structural subunits (βc-HlH, RvHI and RvHII) and FUs (βc-HlH-h and RvHII-e). Fluorescent microphotographs did not show apoptotic or necrotic alterations in the normal urothelial cell line HL 10/29. The FU βc-HlH-h demonstrated the highest antiproliferative effect (similarly to doxorubicin), in which predominantly apoptotic and less late apoptotic or necrotic changes in the tumor cells were observed. Several down- and up-regulated proteins identified by proteome analysis may be associated with the apoptosis pathway. Conclusions: The present study illustrated the selectivity of the cytotoxic effect of Hcs against the Т24 cancer cell line. This is the first report of protein expression in T24 human bladder cancer cells under the influence of FU βc-HlH-h. That is probably due to the specific oligosaccharide structures rich in methylated hexoses exposed on the surface of βc-HlH-h.