Interleukine 6 contribution to cellular proliferation and senescence in pituitary tumours

SABATINO M E; GENOVESE D M; GRONDONA E; SOSA L DEL V.; PEREZ P; GUTIÉRREZ, S; TORRES, A I; DE PAUL, A L

Mar del Plata

Congreso; Annual Meeting Argentine Society for Biochemistry and Molecular Biology LI Reunión Annual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.; 2015

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular.

Pituitary tumors are mostly benign, suggesting the participation of intrinsic mechanisms as cellular senescence, a program with anti-tumorigenic potential. In previous studies we showed evidence of cellular senescence in experimental pituitary tumors development. Inflammatory secretome, in particular IL-6 cytokine, regulates cellular senescence. In this study we evaluated IL-6 contribution in cellular proliferation and senescence of normal and tumoral pituitaries. Primary cultures from normal or 40 days-estrogenized Wistar male rats were treated with IL-6 or with LPS alone or after BFA (secretion inhibitor) or BAY (NF-kB blocker) incubation. The proportion of SA-b-gal (senescence) or Ki67 (proliferation) positive cells was evaluated. Exogenous IL-6 decreased normal and tumoral cell proliferation while increased senescent cells number only under tumoral setting. Also, LPS, exclusively through its secreted factors, raised the senescent cells proportion in normal and tumoral conditions and also induced tumoral cell proliferation. The NF-kB blockage by BAY alone or in combination with LPS increased cellular senescence and showed a dual role toward proliferation control in tumoral cells. These data suggest that IL-6 might play a relevant role in the pituitary tumor growth control, and NF-kB may act as a key regulator between pituitary cell proliferation and senescence in tunorigenesis