Cancer Theranostic Dyes

Funding Information: This work was financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., within the scope of the projects of the Ministry of Science Technology and Higher Education: UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB and, in part, by the Jeanne and J.-Louis Lévesque foundation, Montreal, QC, Canada (J.E.v.L.). J.E.v.L. is a member of the Research Center of the CHUS (CRCHUS), Sherbrooke, QC, Canada, supported by the Fonds de la Recherche du Québec—Santé. C.R.R., A.L. and R.V. were funded by FCT/MCTES, grant numbers SFRH/BPD/124612/2016, SFRH/BD/12161/2022, and SFRH/BD/09845/2022, respectively. Publisher Copyright: © 2023 by the authors. Estradiol-BODIPY linked via an 8-carbon spacer chain and 19-nortestosterone- and testosterone-BODIPY linked via an ethynyl spacer group were evaluated for cell uptake in the breast cancer cell lines MCF-7 and MDA-MB-231 and prostate cancer cell lines PC-3 and LNCaP, as well as in normal dermal fibroblasts, using fluorescence microscopy. The highest level of internalization was observed with 11β-OMe-estradiol-BODIPY 2 and 7α-Me-19-nortestosterone-BODIPY 4 towards cells expressing their specific receptors. Blocking experiments showed changes in non-specific cell uptake in the cancer and normal cells, which likely reflect differences in the lipophilicity of the conjugates. The internalization of the conjugates was shown to be an energy-dependent process that is likely mediated by clathrin- and caveolae-endocytosis. Studies using 2D co-cultures of cancer cells and normal fibroblasts showed that the conjugates are more selective towards cancer cells. Cell viability assays showed that the conjugates are non-toxic for cancer and/or normal cells. Visible light irradiation of cells incubated with estradiol-BODIPYs 1 and 2 and 7α-Me-19-nortestosterone-BODIPY 4 induced cell death, suggesting their potential for use as PDT agents. publishersversion published