Novel interaction of 14-3-3ζ/δ and HO-1 in prostate cancer

LAGE VICKERS, SOFIA; BIZZOTO, JUAN; SANCHIS, PABLO A; COTIGNOLA JAVIER; VAZQUEZ ELBA; GUERON GERALDINE

Congreso; Reunión Anual de la Sociedad Argentina de Investigación Clínica 2019; 2019

Proteomic signatures of primary prostate cancer (PCa) and associatedmetastases may aid in the identification of key player proteins involved inprogression. We have previously showed that heme-oxygenase 1 (HO-1),encoded by the gene HMOX-1, the rate-limiting enzyme in heme degradation,has a strong anti-tumoral effect in PCa. In an effort to identify HO-1 molecularpartners which might collaborate with its biological function, we undertook anin-depth mass spectrometry-based proteomics study to find HO-1 interactors.We constructed a recombinant GSTHO-1 protein. PC3 cells were transientlytransfected with GSTHO-1 or the respective control and treated with thestressor agent H 2 O 2 . Immunoprecipitated protein complexes were subjected toLC-ESI MS/MS. The proteomics analysis of HO-1 interacting factors revealeda list of 44 proteins including 14-3-3ζ/δ, a protein encoded by YWHAZ, anandrogen-responsive gene that activates proliferation, cell survival, andandrogen receptor transcriptional activity. These results were validated by co-immunoprecipitation analysis. Immunofluorescence assays provided evidencethat HO-1 and 14-3-3ζ/δ co-localize in the cell nuclei under H 2 O 2 treatment.Bioinformatics analysis were performed to investigate the clinical relevance ofthese two proteins using public database repositories. The Ross-Adams(GSE70769) dataset showed a negative correlation between HMOX-1 andYWHAZ expression (r=-0.3286; p˂0.0001). When analyzing the ratioYWHAZ/HMOX-1 in patients with PCa, the relapse free survival increasedalmost 4 times when the ratio was ˂ 1.466 (HR=3.76; p= 0.00023), i.e. whenHMOX-1 expression increased. Moreover, high expression of HMOX-1increased relapse free survival in patients with high YWHAZ expression(HR=0.4; p=0.025). In summary, our results, may cast a new light on PCatreatment highlighting a multifaceted role for HO-1 in inhibiting 14-3-3ζ/δfunction.