RESUMEN
The involvement of peroxisome proliferator-activated receptors (PPARs) in the cancer cell elimination through apoptosis is a generally accepted fact. However, some reports indicate that the activation of PPARgamma is directly responsible for carcinogenesis. Caco-2 cells, a human adenocarcinoma cells, were used as a model of colon cancer. Cell cultures (5 x 10(6) cell per dish) were pretreated for 24 h with PPAR gamma agonists ciglitazone (CI, 1 x 10(-6)M) and retinoic acid (RA, 1 x 10(-6)M) and part of the cultures were subsequently subjected to gamma-radiation (photons) with therapeutic dose of 2,5 Gy. Total cellular RNA and proteins (cytoplasmic and nuclear) were isolated 24h after cultures irradiation or 48 h after stimulation in the non irradiated part of experiment to preserve the equal growth time for all samples. gamma-Irradiation of the cells abolished nuclear translocation of PPARgamma under its agonists treatment and preserved PPARgamma in the cytoplasmic pool. But it did not affect the HSP 70 expression in response to ciglitazone and retinoic acid. Moreover, combined gamma-irradiation and CI/RA treatment of the cells changed the equilibrium between Bax and Bcl-2 mRNA to anti apoptotic state with increased expression of Bcl-2 and almost abolished expression of Bax. In conclusion, this paper provides an evidence for the anti-apoptotic action of PPARgamma agonists used along with the gamma-radiation. Moreover, it shows that the up-regulated HSP70, in response to PPARgamma agonists in gamma-irradiated cultures promotes cell survival.
Asunto(s)
Apoptosis , Neoplasias del Colon/patología , Rayos gamma , PPAR gamma/agonistas , Tiazolidinedionas/farmacología , Tretinoina/farmacología , Western Blotting , Células CACO-2 , Regulación Neoplásica de la Expresión Génica , Proteínas HSP70 de Choque Térmico/biosíntesis , Humanos , PPAR gamma/fisiología , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas c-bcl-2/genética , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores Citoplasmáticos y Nucleares/agonistas , Receptores Citoplasmáticos y Nucleares/genética , Receptores Citoplasmáticos y Nucleares/metabolismo , Proteína X Asociada a bcl-2/genética , Proteína X Asociada a bcl-2/metabolismoRESUMEN
The coexistence of three histologically different tumors (Carcinosarcoma corporis uteri, Leiomyosarcoma, Adenocarcinoma endometrial) in a giant tumor of the uterus in 58-year old patient is presented. Operative treatment relied on total hysterectomy was applied. An unusual and rare coincidence of three tumors push us to present the case and to discuss the coexistence of genital tract tumors and diagnosis and treatment of giant pelvis minor tumors.
