INTRODUCTION: Peroxisome proliferator-activated receptors (PPARs) are members of the steroid/thyroid nuclear receptor superfamily. They are involved in many processes important for cell and tissue homeostasis and contribute to various pathologic processes; they are key regulators not only in atherosclerosis and diabetes, but also in inflammation and in cancer. MATERIALS AND METHODS: PPAR immunocytochemical expression was analyzed in seven human bladder tumour cell lines (TCCSUP, RT112, VMCUB1, 639V, T24, RT4, SG65), which were also injected in nude mice to assess their tumorigenicity and metastatic ability. RESULTS: PPARa expression was moderate (1.84-5.38% of positive cells) in all cell lines except for SG 65 (11.53%). PPARb/d expression was weak (1.5-3.18%) in RT112, TCCSUP, T24, 639V and greater (5.9-7.77%) in VMCUB1, RT4, SG65. PPARg expression was low (2.19-3.61%) in not tumourigenic cells (TCCSUP, RT112); it was the highest (10.06-14.54%) in cells causing tumours resembling human papillary superficial bladder cancers (639V, VMCUB1); it was high (5.8-7.99%) in cells causing tumours resembling human papillary invasive bladder cancers (RT4, T24); it was the lowest (0.73%) in SG65 cells, which induced tumours resembling human solid invasive bladder cancers. CONCLUSION: These results, confirmed by western blotting, indicate a negative association between PPARg expression and malignancy in bladder cancer cells. Experiments in progress suggest that this negative association may be probably explained by the proapoptotic action of the natural PPARg ligand prostaglandin J2 and by its interaction with some angiogenic factors.
Expression of peroxisome proliferator-activated receptors in human bladder cancer cell lines and correlation with tumorigenicity and malignancy
CALZA, Roberta;
2002
Abstract
INTRODUCTION: Peroxisome proliferator-activated receptors (PPARs) are members of the steroid/thyroid nuclear receptor superfamily. They are involved in many processes important for cell and tissue homeostasis and contribute to various pathologic processes; they are key regulators not only in atherosclerosis and diabetes, but also in inflammation and in cancer. MATERIALS AND METHODS: PPAR immunocytochemical expression was analyzed in seven human bladder tumour cell lines (TCCSUP, RT112, VMCUB1, 639V, T24, RT4, SG65), which were also injected in nude mice to assess their tumorigenicity and metastatic ability. RESULTS: PPARa expression was moderate (1.84-5.38% of positive cells) in all cell lines except for SG 65 (11.53%). PPARb/d expression was weak (1.5-3.18%) in RT112, TCCSUP, T24, 639V and greater (5.9-7.77%) in VMCUB1, RT4, SG65. PPARg expression was low (2.19-3.61%) in not tumourigenic cells (TCCSUP, RT112); it was the highest (10.06-14.54%) in cells causing tumours resembling human papillary superficial bladder cancers (639V, VMCUB1); it was high (5.8-7.99%) in cells causing tumours resembling human papillary invasive bladder cancers (RT4, T24); it was the lowest (0.73%) in SG65 cells, which induced tumours resembling human solid invasive bladder cancers. CONCLUSION: These results, confirmed by western blotting, indicate a negative association between PPARg expression and malignancy in bladder cancer cells. Experiments in progress suggest that this negative association may be probably explained by the proapoptotic action of the natural PPARg ligand prostaglandin J2 and by its interaction with some angiogenic factors.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
