Inhibition of HO-1 enzymatic activity impairs head and neck cancer cell survival

MASCARO M.; ALONSO E.G.; SCHWEITZER K; FERNANDEZ CHAVEZ L; FERRONATO M.J.; IBARRA A.; COLO G.P.; GIORGI G.; CURINO A. C.; FACCHINETTI M.M.

Congreso; LXVI Reunión Anual de la Sociedad Argentina de Investigación Clínica (SAIC).; 2021

Sociedad Argentina de Investigación Clínica (SAIC).

We have previously reported that, in human HNSCC samples,hemeoxygenase-1 (HO-1) mRNA expression is up-regulated and itis associated with worst survival. We also reported an up-regulationof HO-1 protein levels and that it is localized in the cytoplasmic andnuclear compartments. Moreover, we demonstrated that pharmacological activation of HO-1 by hemin and genetic full-length HO-1(FL-HO-1) overexpression increases HN13 cells survival and cellcycle progression, suggesting a protumor role of HO-1 in HNSCC.However, whether byproducts of HO-1 enzymatic activity are involved in FL-HO-1 mediated-effects remains unknown. In this study,we aimed to elucidate if inhibition of HO-1 enzymatic activity impactson head and neck cancer cells behavior. To that end, HO-1 activitywas inhibited pharmacologically using ZnPP and an enzymaticallyinactive FL-H25A-HO1-overexpressing HN13 cell line was established. We evaluated HO-1 expression by western blot and indirectimmunofluorescence, cell viability by crystal violet, cell proliferationby manual cell counting, cell cycle progression by propidium iodidestaining and flow cytometry, and cell migration by wound healingassay. We found that 10 µM ZnPP impaired cell viability (p