Effect of four fluoroquinolones on the viability of bladder cancer cells in 2D and 3D cultures

Abstract

IntroductionThe anticancer properties of fluoroquinolones and the high concentrations they achieve in urine may help in bladder cancer therapy. This study aimed to analyze the properties of 4 fluoroquinolones as potential candidates for supportive treatment of bladder cancer. MethodsComparative analyses were performed on the cytotoxic effects of norfloxacin, enrofloxacin, moxifloxacin, and ofloxacin on normal and cancer urothelial cell lines. In 2D culture, the cytotoxic properties of fluoroquinolones were evaluated using MTT assay, real-time cell growth analysis, fluorescence and light microscopy, flow cytometry, and molecular analysis. In 3D culture, the properties of fluoroquinolones were tested using luminescence assays and confocal microscopy.Results and DiscussionAll tested fluoroquinolones in 2D culture decreased the viability of both tested cell lines in a dose- and timedependent manner. Lower concentrations did not influence cell morphology and cytoskeletal organization. In higher concentrations, destruction of the actin cytoskeleton and shrinkage of the nucleus was visible. Flow cytometry analysis showed cell cycle inhibition of bladder cancer cell lines in the G2/M phase. This influence was minimal in the case of normal urothelium cells. In both tested cell lines, increases in the number of late apoptotic cells were observed. Molecular analysis showed variable expression of studied genes depending on the drug and concentration. In 3D culture, tested drugs were effective only in the highest tested concentrations which was accompanied by caspase 3/7 activation and cytoskeleton degradation. This effect was hardly visible in non-cancer cell lines. According to the data, norfloxacin and enrofloxacin had the most promising properties. These two fluoroquinolones exhibited the highest cytotoxic properties against both tested cell lines. In the case of norfloxacin, almost all calculated LC values for bladder cancer cell lines were achievable in the urine. Enrofloxacin and norfloxacin can be used to support chemotherapy in bladder cancer patients.

Mechanisms of the Antineoplastic Effects of New Fluoroquinolones in 2D and 3D Human Breast and Bladder Cancer Cell Lines

“…Unlike their derivatives, CIP and NOR did not induce substantial changes in spheroid growth and morphology. This last result is in contrast with the findings of other authors, who demonstrated the antiproliferative and pro-apoptotic action of CIP on human T24 bladder cancer spheroids, by observing a reduction in spheroid size and the induction of apoptosis [ 5 ]. Nevertheless, higher concentrations of fluoroquinolones were used in that work, compared to those used in the present study.…”

“…Minor to moderate toxic effects were also observed in the fibroblast cell line WH1 [ 29 ]; however, all derivatives showed higher potency on the cancer cell lines tested, compared to the fibroblast one. Interestingly, the derivatives’ better performance was also confirmed in RT112 and MCF7 spheroids, in agreement with the evidence reported by other authors, who documented the antiproliferative effects of fluoroquinolones on this 3D model [ 5 , 48 , 49 ]. These results are exciting, considering that spheroids represent an in vitro model that resembles in vivo tumor architecture and biology, mimicking the main features of solid neoplasia such as hypoxia, nutrient gradient, and cell–cell as well as cell–microenvironment interactions.…”

“…Therefore, FQs’ solubility and bioavailability are dependent on the chemical environment in which they are found [ 4 ], i.e., they are more soluble in polar solvents when ionized; contrarily, they are more lipophilic in their neutral or zwitterionic state, allowing for them to penetrate tissues such as the prostate, kidney, and liver very well. For this reason, they are typically used to treat urinary and genital infections [ 3 , 5 ]. However, modification of their chemical structure allowed for the development of FQs active against Gram-positive infections of the respiratory tract.…”

“…Furthermore, the effects of these derivatives were also evaluated in another TNBC cell line, namely, MDA-MB453 cells, and in two bladder cancer cell lines (RT112 and 5637), all selected because of the poor therapeutic options available for this type of tumor. Furthermore, other authors have recently reported the interesting activity of FQs in bladder cancer cell lines [ 1 , 5 ].…”