M. C. Zatelli

Prognostic significance of the Ki-67 labeling index in growth hormone-secreting pituitary adenomas.

CONTEXTnKi-67 is a marker of proliferation activity associated with invasiveness and prognosis in human tumors.nnnOBJECTIVEnThe aim of the study was to evaluate the Ki-67 index prognostic relevance in a group of acromegalic patients who underwent transsphenoidal surgery for a GH-secreting pituitary adenoma.nnnMATERIAL AND METHODSnWe selected 68 consecutive acromegalic patients referred to our hospital during a 5-yr period. The Ki-67 index was determined by immunohistochemistry on tissue samples obtained from each adenoma after surgery. Those patients who were not completely cured after surgery began medical therapy with somatostatin analogs (SSAs). Periodical pituitary magnetic resonance imaging and hormonal evaluation were performed during the follow-up.nnnRESULTSnTwenty-eight of 68 patients were cured after surgery (41%). Among the 40 patients treated with SSAs, 13 were considered uncontrolled. Pituitary magnetic resonance imaging showed residual/recurrent disease in 25 of 68 patients after 6 months. No correlation was found between Ki-67 index and age, tumor size, GH, or IGF-I plasma levels. Tumors described as having cavernous sinus invasion had a higher mean Ki-67 index as compared with noninvasive tumors (P < 0.01). The Ki-67 index was significantly lower in tumors in patients cured after surgery as compared with patients considered not cured (P < 0.01) and in tumors in patients controlled by SSA therapy as compared with patients considered as uncontrolled (P < 0.05).nnnCONCLUSIONnThe Ki-67 labeling index may predict clinical outcome in postsurgical management of acromegalic patients. We suggest routine Ki-67 evaluation in GH-secreting pituitary adenomas.

Growth hormone receptor blockade inhibits growth hormone-induced chemoresistance by restoring cytotoxic-induced apoptosis in breast cancer cells independently of estrogen receptor expression.

CONTEXTnGH and IGF-I play a role in breast cancer (BC) development. We previously demonstrated that GH protects the estrogen receptor (ER) positive BC-derived MCF7 cell line toward the cytotoxic effects of doxorubicin (D), independently of IGF-I. This issue may be important in ER negative BC cells that are more aggressive and more likely to develop chemoresistance.nnnAIM OF THE STUDYnThe aim of this study was to evaluate whether GH may impact chemoresistance phenotype of ER-negative BC-derived MDA-MB-231 cell line and investigate the possible mechanisms implicated in the protective action of GH toward the cytotoxic effects of D in both ER-positive and ER-negative BC-derived cell lines.nnnRESULTSnGH protects ER-negative MDA-MB-231 cells from the cytotoxic effects of D and GH receptor antagonist pegvisomant reduces GH-induced DNA synthesis also in these cells. In both MDA-MB-231 and MCF7 cells, GH does not revert D-induced G2/M accumulation but significantly reduces basal and D-induced apoptosis, an effect blocked by pegvisomant. Glutathione S-transferase activity is not implicated in the protective effects of GH, whereas D-induced apoptosis depends on c-Jun N terminal kinase (JNK) activation. GH reduces both basal and D-stimulated JNK transcriptional activity and phosphorylation.nnnCONCLUSIONSnIn human BC cell lines, GH directly promotes resistance to apoptosis induced by chemotherapeutic drugs independently of ER expression by modulating JNK, further broadening the concept that GH excess may hamper cytotoxic BC treatment. These findings support the hypothesis that blocking GH receptor may be viewed as a potential new therapeutic approach to overcome chemoresistance, especially in ER-negative BC.

Acute administration of human galanin in normal subjects reduces the potentiating effect of pyridostigmine-induced cholinergic enhancement on release of norepinephrine and pancreatic polypeptide.

The neuropeptide galanin (GAL) is widely distributed in the central and peripheral nervous systems where it often coexists with catecholamines and acetylcholine. Recently we have reported that human GAL (hGAL) in man depresses the release of norepinephrine (NE) and the responses to both assumption of upright posture and insulin-induced hypoglycemia. To gain an insight into the action of hGAL on sympathetic nervous system activity in man, we investigated the effects of a 60-min infusion (80 pmol/kg/min) of hGAL or saline on the release of NE, epinephrine (E) and pancreatic polypeptide (PP) induced by an acetylcholinesterase inhibitor, pyridostigmine bromide (PD), in nine healthy volunteers. PD (120 mg orally) induced a significant rise in plasma concentrations of NE (1.6 +/- 0.04 vs. 1.08 +/- 0.06 nmol/l), E (0.34 +/ 0.05 vs. 0.12 +/- 0.04 nmol/l) and PP (178.06 +/- 33 vs. 37.57 +/- 7.35 pmol/l), whilst it significantly reduced heart rate (HR; 61 +/- 2 vs. 71 +/- 4 beats/min). Changes in plasma levels of PP were determined as an indirect measure of amplification of endogenous cholinergic activity produced by PD. Administration of hGAL blunted the release of NE and PP evoked by PD. The mean (+/- SEM) area under the curve produced by PD of NE (50.05 +/- 3.97 nmol/l.90 min) and PP (8,692.87 +/- 1,724 pmol/l.90 min) was significantly (p < 0.001) reduced by hGAL infusion (2.65 +/- 1.57 nmol/l.90 min and 248.1 +/- 148 pmol/l.90 min, for NE and PP, respectively). hGAL failed to affect significantly the E release evoked by PD. hGAL was able to enhance HR significantly (104 +/- 5 vs. 69 +/- 3 beats/min), and completely prevented the PD-induced slowing of HR. Both PD and hGAL did not alter supine systolic and diastolic blood pressure. We conclude that hGAL significantly reduces the release of NE and PP stimulated by PD-induced enhancement of cholinergic activity. These findings are consistent with a functional interrelationship between GAL and the cholinergic system in man, and may suggest the participation of a cholinergic pathway in the galaninergic modulation of the autonomic nervous system.

Unexpected Activation of Pituitary-Adrenal Axis in Healthy Young and Elderly Subjects during Somatostatin Infusion

In this study we explored, in man, the effect of acute attenuation of growth hormone (GH) release induced by somatostatin (SRIH) on ACTH and cortisol plasma levels. Sixteen young (8 women, aged 23–32 years, and 8 men, aged 18–27 years) and 14 elderly (8 women, aged 65–82 years, and 6 men, aged 65–70 years) healthy subjects volunteered to participate in this investigation. Each subject was tested on two separate occasions by: (1) a 90-min i.v. infusion of SRIH given in 50 ml 0.9% saline delivered at a rate of 9 µg/kg/h, and (2) a 90-min i.v. infusion of isovolumetric amounts of 0.9% saline. Plasma GH, ACTH, cortisol and glucose concentrations were determined prior and up to 180 min after SRIH or saline infusion. SRIH induced a significant (p < 0.05) decrease in plasma GH levels from basal values of 0.6 ± 0.15 and 0.5 ± 0.15 µg/l to nadir values 0.25 ± 0.1 and 0.2 ± 0.1 µg/l in young and elderly subjects, respectively. The administration of SRIH was associated with a clear-cut increase in plasma ACTH levels both in young (peak, 10.6 ± 1.6 pmol/l; AUC, 558.6 ± 147.5 pmol/l/h) and in elderly (peak, 21.3 ± 5.6 pmol/l; AUC, 841.9 ± 153.8 pmol/l/h) subjects with a significant (p < 0.01) difference as compared to saline infusion. Consistent with these results, SRIH infusion resulted in an unequivocal rise in plasma cortisol levels both in young (peak, 394.8 ± 36.4 nmol/l; AUC, 18,591.62 ± 1,372.45 nmol/l/h) and in elderly (peak, 585.6 ± 51.5 nmol/l; AUC, 24,871.05 ± 1,837.03 nmol/l/h) subjects. The ACTH and cortisol responses to SRIH were significantly (p < 0.05 and p < 0.01) higher in elderly than in young subjects. No sex-related differences occurred in the SRIH-induced activation of hypothalamic-pituitary-adrenocortical (HPA) axis. We conclude that (1) infusion of SRIH, at a dose that inhibited basal GH secretion, was associated with an activation of HPA axis, and (2) this response was higher in elderly individuals compared with younger adults. The reason for this novel and unexpected SRIH effect is presently unclear; however, the latter may be mediated, at least in part, by some central nervous system ACTH-releasing mechanisms activated by SRIH-induced decrease in GH secretion.

Rare diseases in clinical endocrinology: a taxonomic classification system

PurposeRare endocrine–metabolic diseases (REMD) represent an important area in the field of medicine and pharmacology. The rare diseases of interest to endocrinologists involve all fields of endocrinology, including rare diseases of the pituitary, thyroid and adrenal glands, paraganglia, ovary and testis, disorders of bone and mineral metabolism, energy and lipid metabolism, water metabolism, and syndromes with possible involvement of multiple endocrine glands, and neuroendocrine tumors. Taking advantage of the constitution of a study group on REMD within the Italian Society of Endocrinology, consisting of basic and clinical scientists, a document on the taxonomy of REMD has been produced.Methods and resultsThis document has been designed to include mainly REMD manifesting or persisting into adulthood. The taxonomy of REMD of the adult comprises a total of 166 main disorders, 338 including all variants and subtypes, described into 11 tables.ConclusionsThis report provides a complete taxonomy to classify REMD of the adult. In the future, the creation of registries of rare endocrine diseases to collect data on cohorts of patients and the development of common and standardized diagnostic and therapeutic pathways for each rare endocrine disease is advisable. This will help planning and performing intervention studies in larger groups of patients to prove the efficacy, effectiveness, and safety of a specific treatment.

Cerebral aneurysm and acromegaly: A case report

Few cases are reported concerning the association between cerebral aneurysms and acromegaly, and this is the first case report documenting an increase in diameter of a cerebral aneurysm in persistent acromegaly. Persistently elevated GH plasma levels might promote an increase in diameter of cerebral aneurysms. An accurate follow-up in acromegalic patients is important, especially concerning the cerebrovascular system. Establishing the effectiveness and usefulness of this strategy will require future prospective studies.

How to improve effectiveness of pegvisomant treatment in acromegalic patients

PurposePegvisomant (PEGV) treatment in acromegaly patients resistant to somatostatin analogues is less effective in the real life than in clinical trials. This is a multicenter, observational, retrospective, longitudinal study. The aim was to detect characteristics which improve long-term PEGV effectiveness.Methods87 acromegalic patients treated with PEGV have been enrolled in seven referral Italian centres. PEGV was administered for up to 4xa0years, at doses up titrated until IGF-1 normalization or toxa0≥xa030xa0mg/day. The rate of patients who reached IGF-1 normalization at last visit has been calculated.ResultsIGF-1 was normalized in 75.9% of patients after 1xa0year and in 89.6% at last visit. Disease control was associated with lower baseline GH, IGF-1 and IGF-1 xULN and was more frequent when baseline IGF-1 wasxa0<xa02.7xa0×xa0ULN (pxa0<xa00.02). PEGV dose was dependent on baseline IGF-1xa0>xa02.7xa0×xa0ULN (pxa0<xa00.05) and dosesxa0>xa01.0xa0mg/BMI/day were administered more frequently when baseline IGF-1 wasxa0>xa02.0xa0×xa0ULN (pxa0=xa00.03). PEGV resistance was associated with higher BMI (pxa0=xa00.006) and was more frequent when BMI wasxa0>xa030xa0kg/m2 (pxa0=xa00.07). There were no significant differences between patients treated with monotherapy or combined treatment. IGF-1 normalization, PEGV dose and rate of associated treatment were similar between males and females. PEGV effectiveness was independent from previous management. Diabetic patients needed higher doses of PEGV than non-diabetic ones.ConclusionsPEGV effectiveness improves when up titration is appropriate. Higher PEGV doses at start and a more rapid up-titration are necessary in patients with obesity and/or IGF-1xa0>xa02.7xa0×xa0ULN.

Isolated R171Q amino acid change in MEN1 gene: polymorphism or mutation?

The change of amino acid arginine to glutamine at position 171 (R171Q) in exon 3 of MEN1 gene occurs in the general population with a frequency ranging from 1·4% to 5%, and has been occasionally reported in MEN1 carriers and in tissues from sporadic MEN1 endocrine tumours. 1–3 It is unclear whether an isolated R171Q amino acid change represents a polymorphism and/or it has a role in tumourigenesis. Recently, Balogh et al . 4 reported the R171Q amino acid change in germline DNA of six out of 32 subjects with MEN1 or MEN1-related states. Specifically, the R171Q amino acid change was associated with three novel MEN1 gene mutations (L301R, C354X and G28A) in two familial and one sporadic MEN1 cases, and was found to be the only MEN1 gene alteration in other three subjects with sporadic MEN1-related state. We report a case of a 46-year-old woman who came to our observation for recurrent primary hyperparathyroidism (PHPT). Three years before she underwent surgery for a parathyroid adenoma, a nonfunctioning pancreatic neuroendocrine tumour and a nonfunctioning adrenocortical adenoma. A MEN1 syndrome was diagnosed, but neither DNA analysis in the patient nor clinical investigations in the patient’s relatives were available. Thus, studying family history in depth, we found that a few years earlier the patient’s sister had undergone surgery for both a prolactin-secreting pituitary adenoma and PHPT due to parathyroid adenoma. The patient’s father died for liver cirrhosis when he was 46 years old and during his life was affected by recurrent gastric ulcerations requiring gastrectomy. A patient’s paternal aunt died for a cerebral mass, referred as a probable pituitary tumour causing amenorrhoea and blindness. We performed the MEN1 germline gene analysis by direct DNA sequencing, as previously described, 5 in the proband, in the two sisters and in their brother. In all cases sequence analysis revealed an isolated G > A transition at codon 171 of exon 3, resulting in the replacement of arginine (CGG) with glutamine (CAG). Clinical investigation of the brother was negative for MEN1 features. The same gene alteration was also demonstrated in her brother’s daughter, who had no clinical signs of disease. The R171Q amino acid change was found in an unrelated MEN1 proband (affected by a parathyroid adenoma and an ACTH-secreting pituitary adenoma) from a different family, in her two sons (one with PHPT and a nonfunctioning pituitary adenoma) and in the father, not clinically affected. The relationship between the two MEN1 families studied was excluded by the study of genealogic trees. Unfortunately, no tumour tissue from any of our patients was available to analyse the possible somatic loss of wild-type allele, in accordance with the Knudson two-hit hypothesis. As controls, a panel of 50 healthy Italian subjects, that is, 100 alleles, from the same geographical area was then screened, and the R171Q amino acid change in the MEN1 gene was not detected. Written informed consent for genetic testing was obtained from all patients and control subjects. More than 400 germline and somatic mutations have been identified in sporadic, familial MEN1 and MEN1-related states. 1–3

Thyroid nodule recurrence following lobo-isthmectomy: incidence, patient’s characteristics, and risk factors

PurposeThis study was aimed at assessing the incidence and timing of thyroid nodules recurrence, defined as appearance of new benign or malignant nodules in contralateral lobe in patients with benign thyroid nodules or thyroid microcarcinoma treated with lobo-isthmectomy. Patient’s characteristics and risk factors associated with this phenomenon were also investigated.MethodsA retrospective study was performed by evaluating 413 patients undergoing lobo-isthmectomy with a minimum follow-up of 1xa0year. Clinical characteristics, surgical interventions and complications, histological diagnosis, and thyroid function at last follow-up were collected.ResultsSingle or multiple thyroid nodule recurrence equally occurred in 80 patients (23%) with a median time to relapse of ~u20095xa0years (range 0.3–34.5xa0years) after lobo-isthmectomy. Recurrence was significantly associated with younger age (<u200946 years) and number of pregnancies in women. Development of hypothyroidism was not rare either (~u200910%) and appeared in 3–19xa0months; a preoperative TSH level >u20092.43xa0mIU/L was associated with the need of l-thyroxin replacement therapy after surgery. The most frequent surgical complication was transient hypoparathyroidism (4.6%), while the rate of permanent hypoparathyroidism significantly increased in patients submitted to completion thyroidectomy (5.3%).ConclusionsThyroid nodules recurrence following lobo-isthmectomy is not a rare event and occurs within 5xa0years after surgery, more frequently in younger patients with family history of nodular goiter and in women with multiple pregnancies. Pre-surgical TSH levels may predict the development of post-surgical hypothyroidism, possibly improving the management of patients addressed to surgery.

OR12,70 Role of GH-IGF-I excess on periodontal tissues

implicated in the protective action of GH towards the cytotoxic effects of D in the BC cell line, MCF7. We therefore investigated the combined effects of GH and D on MCF7 cell cycle, apoptosis and glutathione-S transferase (GST) activity. We found that GH is not capable of reverting the accumulation of MCF7 cells in G2/M phase of the cell cycle induced by D. On the contrary, GH significantly reduced both basal and D-induced MCF7 cell apoptosis, an effect nearly completely blocked by Peg. We therefore explored whether the anti-apoptotic effect of GH was mediated by GST activation, which protects DNA against damage by anticancer drugs, correlating with the drug resistance phenotype. However, we found that GH treatment significantly reduces GST activity in MCF7 cells, similarly to D. Moreover, Peg alone was also capable of reducing GST activity, possibly indicating a greater susceptibility of Peg-treated cells to DNA damage. These data altogether indicate that GH directly induces resistance to chemotherapic drugs by protecting the cells from apoptosis with a mechanism that does not involve GST. Our data further support the hypothesis that GH excess might hamper BC treatment, possibly resulting in an increased mortality.