BACKGROUND: The presence and pathophysiological role of CYP11B1 (11beta-hydroxylase) gene in the zona glomerulosa of human adrenal cortex is still controversial. METHODS: In order to specifically quantify CYP11B1, CYP11B2 (aldosterone synthase) and CYP17(17alpha-hydroxylase) mRNA levels, we developed a real-time RT-PCR assay and examined the expression in a series of adrenal tIssues, including six normal adrenals from patients adrenalectomized for renal cancer and twelve aldosterone-producing adenomas (APA) from patients with primary aldosteronism. RESULTS: CYP11B1 mRNA levels were clearly detected in normal adrenals, which comprised both zona glomerulosa and fasciculata/reticularis cells, but were also measured at a lower range (P<0.05) in APA. The levels of CYP11B2 mRNA were lower (P<0.005) in normal adrenals than in APA. CYP17 mRNAlevels were similar in normal adrenals and in APA. In patients with APA, CYP11B2 and CYP11B1 mRNA levels were not correlated either with basal aldosterone or with the change from basal aldosterone in response to posture or to dexamethasone. No correlation between CYP11B1 mRNA or CYP11B2 mRNA and the percentage of zona fasciculata-like cells was observed in APA. CONCLUSIONS: Real-time RT-PCR can be reliably used to quantify CYP11B1 and CYP11B2 mRNA levels in adrenal tIssues. Expression of CYP11B1 in hyperfunctioning zona glomerulosa suggests an additional formation of corticosterone via 11beta-hydroxylase, providing further substrate for aldosterone biosynthesis. CYP11B1 and CYP11B2 mRNA levels in APA are not related to the in vivo secretory activity of glomerulosa cells, where post-transcriptional factors might ultimately regulate aldosterone production.
F Fallo, V Pezzi, L Barzon, P Mulatero, F Veglio, N Sonino, and JM Mathis
L Barzon, G Masi, K Fincati, M Pacenti, V Pezzi, G Altavilla, F Fallo, and G Palù
Objective: Adrenocortical tumors may originate from the zona glomerulosa, zona fasciculata, or zona reticularis and be associated with syndromes due to overproduction of mineralocorticoids, glucocorticoids, or androgens respectively. We report an unusual case of recurrent adrenocortical carcinoma (ACC), which seems to contradict the paradigm of functional adrenal zonation.
Case report: A male patient presented with severe primary aldosteronism due to an ACC, which relapsed after adrenalectomy and adjuvant mitotane therapy. After removal of the tumor recurrence and eight cycles of chemotherapy with etoposide, doxorubicin and cisplatin, the patient presented again with ACC masses, but in association with overt Cushing’s syndrome and normal aldosterone levels.
Methods and results: Extensive pathologic examination showed that this shift in steroid hormone production was paralleled by an attenuation of tumor cell atypia and polymorphism, whereas gene expression profile analysis demonstrated a change in expression of adrenal steroidogenic enzymes. Moreover, cancer progression was associated with overexpression of the inhibin-α subunit, which could have contributed to the phenotypic changes.
Conclusions: This case of recurrent ACC demonstrates that adrenocortical cells can reverse their differentiation program during neoplastic progression and change their specific hormone synthesis, as a consequence of modifications in the expression profile of steroidogenic enzymes and cofactors. We hypothesize that this shift in steroid hormone secretion is a consequence of chromosome amplification induced by chemotherapy. These findings, besides opening new perspectives to study adrenocortical cell plasticity and potential, demonstrate how conventional clinical and pathologic evaluation can be combined with genomic analysis in order to dissect thoroughly the biology of cancer.
ML Panno, D Sisci, M Salerno, M Lanzino, L Mauro, EG Morrone, V Pezzi, S Palmero, E Fugassa, and S Andò
Panno ML, Sisci D, Salerno M, Lanzino M, Mauro L, Morrone EG, Pezzi V, Palmero S. Fugassa E, Andò S. Effect of triiodothyronine administration on estrogen receptor contents in peripuberal Sertoli cells. Eur J Endocrinol 1996:134:633–8. ISSN 0804–4643
The effects of thyroid hormone on androgen metabolism in peripuberal Sertoli cells through the inhibition of estradiol production have been reported previously. It was our intention to investigate further the possible role of thyroid hormone on the interaction between testicular steroids and Sertoli cells by analyzing the effects of triiodothyronine (T3) on estrogen receptor content in 2-, 3- and 4week-old euthyroid rats. Triiodothyronine treatment (3 μg/100 body wt per day) given during the last week prior to sacrifice resulted in reduced testicular growth in 2-week-old animals. Sertoli cells from all groups were cultured initially under basal conditions for the first 24 h and subsequently in the presence of testosterone and/or T3 for the additional 24 h. The in vitro addition of T3 induced a decrease of estrogen receptors (ERs) in 2- and 3-week-old animals that appeared more pronounced especially in the presence of T3 and testosterone. When T3 was tested in vivo we noticed that the decrease of ER content was even greater in all three groups under the in vitro influence of both T3 and testosterone. In 3-week-old animals a simultaneous assay of ERs in both nuclear and cytoplasmic compartments was performed. The ER concentrations in the nucleus were closely related to those of the cytoplasm. The in vivo administration of T3 was responsible for a greater decrease of ERs in the nucleus than in the cytosol. On the basis of these results, and in agreement with our previous data, we speculate that the effect of T3 in the maturational events of Sertoli cells could involve both estradiol production and ER content.
Sebastiano Andò Cattedra di Fisiopatologia Endocrina, Dipartimento di Biologia Cellulare, Università della Calabria, 87030 Arcavacata di Rende, Cosenza, Italy