Baculovirus-based gene silencing of Humanin for the treatment of pituitary tumors

GOTTARDO FLORENCIA; PIDRE MATIAS; ZUCCATO CAMILA ; ASAD ANTONELLA; IMSEN MERCEDES; JAITA GABRIELA; CANDOLFI MARIANELA

APOPTOSIS

SPRINGER

Lugar: Berlin; Año: 2018

1360-8185

Pituitary tumors are the most common primary intracranial neoplasms. Humanin (HN) and Rattin (HNr), a rat homolog ofHN, are short peptides with a cytoprotective action. In the present study, we aimed to evaluate whether endogenous HNrplays an antiapoptotic role in pituitary tumor cells. Thus, we used RNA interference based on short-hairpin RNA (shRNA)targeted to HNr (shHNr). A plasmid including the coding sequences for shHNr and dTomato fluorescent reporter gene wasdeveloped (pUC-shHNr). Transfection of somatolactotrope GH3 cells with pUC-shHNr increased apoptosis, suggesting thatendogenous HNr plays a cytoprotective role in pituitary tumor cells. In order to evaluate the effect of blockade of endogenousHNr expression in vivo, we constructed a recombinant baculovirus (BV) encoding shHNr (BV-shHNr). In vitro, BV-shRNAwas capable of transducing more than 80% of GH3 cells and decreased HNr mRNA. Also, BV-shHNr increased apoptosisin transduced GH3 cells. Intratumor injection of BV-shHNr to nude mice bearing s.c. GH3 tumors increased the numberof apoptotic cells, delayed tumor growth and enhanced survival rate, suggesting that endogenous HNr may be involved inpituitary tumor progression. These preclinical data suggests that the silencing of HN expression could have a therapeuticimpact on the treatment of pituitary tumors.