Endocrine Abstracts

Introduction: Adrenocortical tumors consist in frequent benign adenomas (ACA) and rare highly malignant carcinomas (ACC). BIRC7/livin gene, a member of the inhibitors of apoptosis family, plays an important role in tumorigenesis in a variety of malignancies. Different studies demonstrated that BIRC7 overexpression represent a risk factor for cancer development and progression. The aim of our study was to evaluate the expression of BIRC7 in normal adrenals and adrenocortical tumors.

Methods: BIRC7 mRNA expression was detected by quantitative real-time RT-PCR analysis in fresh-frozen tissue samples (24 ACC, 18 ACA, and 17 normal adrenal). The correlation between BIRC7 levels and several clinical parameters was also investigated.

Result: BIRC7 mRNA expression was similar between adenomas and normal adrenals. However it was significantly increased in malignant adrenocortical tumors (P<0.005 vs both ACA and normal adrenal). No significant difference was found between cortisol-secreting and non cortisol-secreting tumors. In the ACC group, we did not observe any significant correlation between BIRC7 levels and clinical risk factors, such as age, tumor size, Weiss score, ENSAT tumor stage, Ki67-index and number of metastasis at diagnosis.

Conclusion: To our knowledge, this is the first study that investigates the BIRC7/livin expression in normal adrenal and adrenocortical tumors. We demonstrate that BIRC7 is specifically over-expressed in ACC. As previously reported for different tumor types, these findings open a new prospective for the use of BIRC7 as a potential therapeutic target in ACC.