| OBJECTIVES:This study aims to analyze the mRNA expression level of IL-6in aldosterone-producing adenomas, cortisol producing adrenal tumors, pheochromocytomas, adipose tissues around tumors, and subcutaneous adipose tissues, so as to preliminarily investigate the relationship between adrenal tumors and IL-6secreted by adipose tissues.METHODS:1. Total RNA was extracted with TRIZOL from adipose tissues and adrenal tissues, including:1) adipose tissues:adipose tissues around aldosterone-producing adenomas (n=12), cortisol producing adrenal tumors (n=7), pheochromocytomas (n=7), and normal adrenal glands (n=6); subcutaneous adipose tissues of patients with aldosterone-producing adenomas (n=4) and persons without adrenal disease (n=4);2) adrenal tissues:aldosterone-producing adenomas (n=7), cortisol producing adrenal tumors (n=5), pheochromocytomas (n=6), normal adrenal cortexes (n=5), normal adrenal medullas (n=5).2. RT-PCR was used to analyze the mRNA expression level of IL-6, with GAPDH as the endogenous reference.3. The IL-6mRNA level of different adipose tissues around adrenal tumors and of different adrenal tumors was compared. Also the IL-6mRNA expression level of subcutaneous, periadrenal adipose tissues and of adrenal tumor from the same patient was compared. It was studied whether the IL-6expression level correlated with tumor volume, plasma aldosterone concentration (PAC), plasma renin activity (PRA), insulin resistance index etc. RESULTS:1. IL-6mRNA was expressed in adrenal tumors, adipose tissues around tumors and subcutaneous adipose tissues.2. The mRNA expression of IL-6in aldosterone-producing adenomas and adipose tissues:1) Expression in adipose tissues around adenomas was lower than adipose tissues around normal adrenal glands (0.63±0.25vs0.82±0.07, P<0.05); expression in subcutaneous adipose tissues of patients with adenomas tended to be higher than that in normal controls (1.01±0.12vs0.85±0.09, P=0.086);2) Expression in subcutaneous adipose tissues was significantly higher than that in adipose tissues around adenomas (1.01±0.12vs0.54±0.24, P<0.01);expression in adipose tissues around adenomas was higher than in adenomas (0.51±0.20vs0.38±0.17, P<0.05);3) IL-6mRNA level in aldosterone-producing adenomas was lower than that in pheochromocytomas (0.38±0.17vs0.65±0.22, P＜O.05), but had no difference with expression in cortisol-producing adrenal tumors (0.38±0.17vs0.42±0.14, P=0.621) or normal adrenal cortexes (0.38±0.17vs0.37±0.07, P=0.870).4) Expression in adipose tissues around aldosterone-producing adenomas was correlated with HOMA-IR. Expression in adipose tissues around aldosterone-producing adenomas of patients with MS tended to be higher than patients without MS (0.69±0.31vs0.46±0.13,P=0.163).3. The mRNA expression of IL-6in cortisol producing adrenal tumors and adipose tissues:1) Expression in adipose tissues around cortisol producing tumors tended to be lower than normal controls (0.62±0.24vs0.82±0.07,P=0.072);2) Expression in adipose tissues around tumors tended to be higher than in tumors (0.67±0.20vs0.47±0.08, P=0.246);3) IL-6mRNA level in cortisol producing tumors tended to be lower than pheochromocytomas (0.42±0.13vs0.65±022, P=0.077), and was similar with expression in normal adrenal cortexes (0.42±0.13vs0.37±0.07, P=0.408).4) Expression in adipose tissues around cortisol producing tumors was positively correlated with24hUFC (r=0.857, P<0.05), Expression in cortisol producing tumors was positively correlated with plasma cortisol level at8am (r=0.900, P0.05).4. The mRNA expression of1L-6in pheochromocytomas and adipose tissues:1) Expression in adipose tissues around pheochromocytomas and controls was similar (0.79±0.18vs0.82±0.07, P=0.670); Expression in adipose tissues around pheochromocytomas tended to be higher than adipose tissues around aldosterone-producing adenomas (0.79±0.18vs0.63±0.25, P=0.155) and adipose tissues around cortisol producing adrenal tumors (0.79±0.18vs0.62±0.24, P=0.155);2) Expression in adipose tissues around pheochromocytomas tended to be higher than pheochromocytomas (0.81±0.19vs0.65±0.22, P=0.115);3) Expression in pheochromocytomas was higher than normal adrenal medullas (0.65±0.22vs0.31±0.16, P＜O.05).5. For controls with normal adrenal glands, expression in subcutaneous adipose tissues was similar with periadrenal adipose tissues (0.85±0.09vs0.84±0.08, P=0.628), and expression in periadrenal adipose tissues was significantly higher than adrenal cortexes (0.82±0.07vs0.37±0.07, P<0.01)and medullas (0.82±0.07vs0.31±0.16, P<0.01).6. IL-6mRNA level in adipose tissues around adrenal tumors was positively correlated with tumor volume (r=0.419, P<0.05); expression in adrenal tumors was also positively correlated with tumor volume (r=0.542, P<0.05);expression in adipose tissues around adrenal tumors was positively correlated with that in tumors (r=0.696, P＜0.01).CONCLUSIONS:1. IL-6mRNA was expressed in aldosterone-producing adenomas, cortisol producing adrenal tumors, pheochromocytomas, adipose tissues around tumors and subcutaneous adipose tissues. Expression in adipose tissues around adrenal tumors tended to be higher than tumors, and the former was positively correlated with the later(r=0.696, P＜0.01), indicating there might be intimate relationship between adrenal tumors and adipose tissues around them.2. The mRNA expression of IL-6in adipose tissues around aldosterone-producing adenomas was lower than normal controls, and also lower than subcutaneous adipose tissues, but it was higher than adenomas. The clinical and pathophysiological significance of this result still needed further investigation.3. Both IL-6mRNA level in adipose tissues around adrenal tumors and in tumors were positively correlated with tumor volume, and IL-6mRNA in pheochromocytomas was higher than normal adrenal medullas, indicating that IL-6might have some relationship with tumorigenesis of the adrenal gland.4. Expression in adipose tissues around cortisol producing adrenal tumors was positively correlated with24hUFC; expression in cortisol producing adrenal tumors was positively correlated with plasma cortisol level at8am (P<0.05).5. Some of the above results were the first such reports, according to our search in the MEDLINE database. |
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