Immunocytochemical studies on the nuclear ubiquitous casein and cyclin-dependent kinases substrate following 5-aminolevulinicacid-mediated photodynamic therapy on MCF-7 cells

SummaryBackgroundRecent data indicates that nuclear ubiquitous casein and cyclin-dependent kinases substrate (NUCKS) may play role in tumor growth. In present study authors examined whether photodynamic therapy with 5-aminolevulinic acid (5-ALA) induces NUCKS expression in breast cancer cell line, MCF-7.MethodsIn the experiment concentration of 5-ALA was 6.5 mM. Excitation wavelength was 630 ± 20 nm, total light dose of light 5 or 10 J/cm2 and irradiance 60 mW/cm2 was used. Cells were collected at established time points and Western blot and immunocytochemical studies were performed using antibody against NUCKS.ResultsStudies proved strong cytotoxic effects in cells following PDT with 6.5 mM of precursor and 10 J/cm2. Western blot analysis revealed the strongest expression of NUCKS at 7 h after PDT. At next time points, 18 and 24 h, expression of NUCKS decreased and became similar to that of control group. Further immunocytochemical studies showed very strong expression of NUCKS following PDT with 5-ALA and light irradiation of 5 J/cm2. Early, at 0 h, that expression was predominantly seen in nuclei, while at 7 h expression of NUCKS was observed in disseminated manner within entire cells in both nuclei and cytoplasm, with prevalence of cytoplasmic staining.ConclusionsAuthors suggest that NUCKS is involved in cellular responses following PDT, and since parallel induction of NUCKS and proapoptotic marker Bax and inhibition of anti-apoptotic Bcl-2 was observed, this protein might also be involved in induction of apoptosis following PDT.