Secretome modulation of tumor cells in senescence induced by gamma radiation .

AGUERO H.; LÓPEZ, L.A; SALVARREDI L.A. ; MARRA, F ; MILLAN, E

Parana, Entre Rios

Congreso; LIVReunión Anual Sociedad Argentina de Investigación en Bioquímica y Biología Molecular; 2018

SAIB

Senescence is a tumor suppression mechanism actioned by stimulus that affect cell genome integrity. However, senescence cells (SCs) promoted tumor cell growth and migration by proinflammatory factor secretion known as SASP (Senescence Associated Secretome Phenotype). Ionizing radiation exposition during radiotherapy is a stress stimulus that can induce senescence and other cell responses. By this way, autophagy, another cell response associated to stress stimulus, can inhibit senescence or alter SASP composition. Microtubule-associated protein 1A/1B-light chain 3 (LC3), is a canonical autophagy marker involved in autophagosome induction and formation. Objective: To study the effect of LC3 overexpression on secretome of tumor cells in senescence. Methodology and Results: Cell cultures of murine melanoma cell line B16F0 were grown during 48h and then exposed to different gamma radiation doses (0, 5 and 10 Gy). 72h later B galactosidase assay showed that 5 and 10Gy radiation increased the percentage of SCs (82,4 and 79,9 respectively vs control; p0,05). To evaluate the tumorigenic potential of SASP, conditioned media (CM) was obtained taking cell culture supernatant from SCs transfected or not and exposed or not to radiation (0 and 10Gy). A wound healing assay was made incubating arrested B16F0 cultures with these CMs. The assay showed that CM from irradiated cells (iCM) increased cell migration (iCM vs control; p