Gene therapy for endocrine diseases represents an exciting new type of molecular intervention that may be a curative one. Endocrine disorders that might be treated by gene therapy include monogenic diseases, such as GH deficiency and hypothalamic diabetes insipidus, and multifactorial diseases, such as diabetes mellitus, obesity and cancer. Premises seem promising for endocrine tumours, but many combined approaches of cell and gene therapy are foreseeable also for other endocrine disorders. This review outlines the principles of gene therapy, describes the endocrine disorders that might take advantage of gene transfer approaches, as well as the gene therapy interventions that have already been attempted, their major limitations and the problems that remain to be solved.
L Barzon, R Bonaguro, G Palu and M Boscaro
L Barzon, F Fallo, N Sonino and M Boscaro
L Barzon, F Fallo, N Sonino and M Boscaro
OBJECTIVE: The natural course of adrenal incidentalomas, especially those with subclinical autonomous glucocorticoid production, i.e. subclinical Cushing's syndrome, and the risk that such conditions will evolve towards overt Cushing's syndrome are unknown. DESIGN: Longitudinal follow-up evaluation of a series of 284 consecutive patients with adrenal incidentaloma. METHODS AND RESULTS: Out of 284 consecutive patients with adrenal incidentaloma studied at our Institution in the last 15 years, 98 patients (23 with subclinical hypercortisolism) underwent surgery. Of 130 non-operated patients with a follow-up of at least 1 year, eight had subclinical hypercortisolism at diagnosis. We describe in detail four patients who developed overt Cushing's syndrome after 1-3 years of follow-up. Only one of these patients had subclinical hypercortisolism at first diagnosis. Estimated cumulative risk for a non-secreting adrenal incidentaloma to develop subclinical hyperfunction was 3.8% after 1 year and 6.6% after 5 years. For patients with masses with subclinical autonomous glucocorticoid overproduction, estimated cumulative risk to develop overt Cushing's syndrome was 12.5% after 1 year. CONCLUSIONS: In patients with adrenal incidentalomas the risk of progression towards overt Cushing's syndrome is not low, at variance with previous reports. A careful biochemical and hormonal follow-up is advisable in all patients who do not need surgery at first presentation.
L Barzon, N Sonino, F Fallo, G Palu and M Boscaro
Clinically silent adrenal masses discovered by imaging studies performed for unrelated reasons, i.e. adrenal incidentalomas, have become a rather common finding in clinical practice. However, only limited studies of incidence, prevalence, and natural history of adrenal incidentalomas are available. A comprehensive review of the literature shows the prevalence of adrenal incidentalomas to be 2.3% at autopsy and 0.5-2% at abdominal computed tomography scan. Most lesions are adrenocortical adenomas at histology, whereas the prevalence of adrenocortical carcinomas is relatively low. The risk of malignancy over time for masses defined as benign at diagnosis is estimated at about 1/1000, even though 5-25% of masses increase in size during follow-up. Hyperfunction develops in about 1.7% of cases and the risk is higher in patients with lesions larger than 3 cm. Cortisol hypersecretion is the most likely disorder that may ensue, and it remains subclinical in about two-thirds of cases. The lack of controlled studies precludes making specific management recommendations. Large perspective controlled studies to define the epidemiology, natural history, and possible associated morbidity of adrenal incidentalomas and their impact on the quality of life of patients are needed.
F Fallo, C Betterle, S Budano, M Lupia, M Boscaro and N Sonino
OBJECTIVE: To evaluate by echocardiography the cardiac structure and function in patients with primary adrenocortical insufficiency. DESIGN AND METHODS: Two-dimensionally guided M-mode echocardiograms and spectral Doppler studies were performed in seven consecutive patients with newly diagnosed autoimmune primary adrenal failure before and 4-8 months after an adequate regimen of steroid substitution. Echocardiographic parameters were also studied in ten healthy controls. RESULTS: In the cases with untreated Addison's disease, both left ventricular end-systolic and end-diastolic dimensions were significantly reduced in comparison with those in controls (P<0.01). Four patients had echocardiographic signs of mitral valve prolapse (MVP) at the anterior leaflet, with no evidence of mitral regurgitation by Doppler echocardiography. Systolic clicks characteristic of MVP were present on auscultation in two of these cases. Left ventricular chamber size normalized, i.e. significantly increased (P<0.01), and both echocardiographic and physical signs of MVP resolved after steroid substitution in all patients. All other echocardiographic indices were normal before and after treatment. CONCLUSIONS: Patients with untreated Addison's disease have cardiac abnormalities which regress after steroid substitution. A valvular-ventricular disproportion due to the hypovolemic state could explain these findings.
L Barzon, M Chilosi, F Fallo, G Martignoni, L Montagna, G Palu and M Boscaro
OBJECTIVE: To evaluate the roles of the CDKN1C (P57KIP2) gene, which encodes for the cyclin-dependent kinase inhibitor CDNC, and the TP53 tumor suppressor gene in adrenal tumorigenesis, as a means of investigating the molecular basis of sporadic adrenal tumors, which is unknown. DESIGN: Screening for the presence CDKN1C and TP53 mutations and analyzing the expression pattern of CDNC, P53 and its downstream effector CDN1 (P21WAF1/CIP1) in a series of 79 sporadic adrenal tumors. METHODS: Single-strand conformation polymorphism and sequencing were used for mutation analysis of CDKN1C and TP53 in blood and adrenal tissue samples. In a subgroup of 48 tissues, CDKN1C expression was evaluated by RT-PCR and immunohistochemistry. Immunohistochemical analysis of P53 and CDN1 was performed. RESULTS: No somatic mutations of CDKN1C were found in the tumors analyzed, in spite of low/absent CDNC expression in adrenocortical adenomas and carcinomas. Mutations in the TP53 gene were present in 70% of adrenocortical carcinomas, associated with abnormal P53 and CDN1 expression, but not in benign neoplasms. In the normal adrenal cortex, CDNC expression was strictly nuclear and confined to the cortical zone (i.e. zona glomerulosa and reticularis), with no staining in the medulla. CONCLUSIONS: Mutations in the TP53 gene are frequent in adrenocortical carcinomas and might be used as a marker of malignancy. In the normal adrenal cortex, the zone-specific pattern of expression of CDNC suggests a role in adrenal differentiation.
F Fallo, A Scarda, N Sonino, A Paoletta, M Boscaro, C Pagano, G Federspil and R Vettor
OBJECTIVE: Glucocorticoids were found to inhibit adiponectin gene expression and secretion both in vitro and in animal models. We evaluated first the acute effect of i.v. glucocorticoids on adiponectin in normal subjects and secondly plasma adiponectin levels in a series of patients with Cushing's syndrome compared with controls. DESIGN AND METHODS: Hydrocortisone (25 mg) was administered i.v. to five healthy volunteers, with blood samples taken at -15, 0, 30, 60, 120 and 180 min. Twenty-one patients with Cushing's syndrome were divided in two groups: one with 11 obese and the other with 10 non-obese Cushing's patients. Each group was compared with controls that were matched for sex, age, body mass index, waist circumference, glucose, insulin, lipid levels and blood pressure. RESULTS: In normal subjects, hydrocortisone produced a decrease in adiponectin at 30 and 60 min, compared with placebo (P<0.05). Adiponectin was lower in non-obese Cushing's patients than in non-obese controls (P<0.004). In contrast, there was no difference in adiponectin levels in obese Cushing's patients and in obese controls. Adiponectin was inversely correlated (P<0.05) with homeostasis model assessment index in both obese and non-obese Cushing's patients; in non-obese Cushing's patients only, adiponectin was inversely correlated with urinary cortisol (P<0.05). CONCLUSIONS: Glucocorticoids inhibit adiponectin in man, as shown by both exogenous administration to healthy subjects and endogenous cortisol hyperproduction. Similar levels of adiponectin in obese Cushing's patients and their obese controls indicate that obesity per se may act as a predominant factor in masking the relationship between adiponectin and cortisol.
L Barzon, P Zucchetta, M Boscaro, MC Marzola, F Bui and F Fallo
OBJECTIVE: Adrenocortical scintigraphy has demonstrated clinical utility in the morpho-functional characterization of adrenal tumors. The aim of this study was to identify possible relationships between the scintigraphic pattern and endocrine and/or morphological data in a series of adrenocortical carcinomas. DESIGN AND METHODS: Twenty-one patients with adrenocortical carcinoma (11 nonfunctioning and 10 hormone-secreting) were investigated with 75Se-methyl-nor-cholesterol scintigraphy. Clinical, hormonal, radiological, and pathological data were analyzed. RESULTS: The adrenal mass showed no radiocholesterol uptake in 18 cases (11 nonfunctioning and 7 functioning lesions). Contralateral normal adrenal gland was visualized in all patients with nonfunctioning tumors, whereas classic bilateral nonvisualization was observed in the 7 cases with hyperfunctioning masses. Three patients with cortisol-producing carcinomas showed radiotracer uptake by the mass, without visualization of the contralateral gland. At histology, the tumors were shown to be undifferentiated adrenocortical carcinomas; they had an aggressive clinical behavior. CONCLUSIONS: Radiocholesterol scintigraphy has an important role in diagnosing adrenocortical carcinomas, which typically are not visualized. However, 30% of hypersecreting adrenocortical carcinomas show an atypical increased tracer uptake, not predictive of the biochemical and histological features of the tumor.
N Sonino, C Navarrini, C Ruini, F Fallo, M Boscaro and GA Fava
OBJECTIVE: Little is known about the relationship between recent life events and onset of hyperprolactinemia, despite the well-known effect of acute psychological stress on prolactin levels in healthy subjects. Recent life events in patients with hyperprolactinemia compared with healthy controls were investigated. DESIGN: Case-control study. METHODS: Fifty-two consecutive patients with hyperprolactinemia (45 females/7 males; mean age 34.9+/-10.1 years, range 18-60 years) and 52 healthy subjects matched for socio-demographic variables were studied. Nineteen patients (18 females/1 male) had no pituitary tumor and were diagnosed as suffering from idiopathic hyperprolactinemia. Patients with additional pathology or with high prolactin due to medications were excluded. All patients were interviewed by Paykel Interview for Recent Life Events while on remission after surgery or pharmacological treatment. The time period considered was the year preceding the first signs of hyperprolactinemia, and the year before interview for controls. RESULTS: Patients with hyperprolactinemia reported significantly more life events than control subjects (P<0.001). The same significant difference compared with controls applied to patients with (n=16) and without (n=36) depression. All categories of events (except events that were likely to be under the subject's control) were significantly more frequent. There were no significant differences between patients with prolactinoma (n=33) and those with idiopathic hyperprolactinemia (n=19). CONCLUSIONS: Within the complexity of phenomena implicated in the pathogenesis of hyperprolactinemia, our findings emphasize a potential role of emotional stress in either prolactin-secreting pituitary tumors or idiopathic hyperprolactinemia. Appraisal of life stress may have implications in clinical assessment (e.g. functional hyperprolactinemia) and decisions (e.g. termination of long-term pharmacological treatment).
L Barzon, R Bonaguro, I Castagliuolo, M Chilosi, E Franchin, C Del Vecchio, I Giaretta, M Boscaro and G Palu
OBJECTIVE AND DESIGN: Based on our clinical experience with combined gene therapy of glioblastoma, we developed a retroviral vector expressing two therapeutic genes (i.e. thymidine kinase of herpes simplex virus, HSV-TK, and interleukin-2, IL-2) and evaluated its efficiency in vitro and in vivo. METHODS: Expression of therapeutic genes in transduced thyroid carcinoma cells was analyzed by real-time RT-PCR. Ganciclovir sensitivity of infected cells was assessed in vitro in thyroid carcinoma cell lines and in vivo in nude mice bearing xenografted thyroid cancers. The combined effect of IL-2/HSV-TK was compared with the effect of IL-2 alone. RESULTS: Expression of therapeutic genes was higher in differentiated than in anaplastic thyroid carcinoma cells. Ganciclovir treatment led to dose- and time-dependent killing of transduced cells in vitro. A bystander effect was demonstrated by using mixtures of infected and non-infected cells. In vivo studies showed a significant reduction of growth and the presence of an inflammatory infiltrate in transduced thyroid tumors expressing IL-2 alone, as compared with non-infected tumors. By using the retroviral vector expressing IL-2/HSV-TK, treatment with ganciclovir led to complete eradication of anaplastic tumors and a >80% reduction of the size of differentiated thyroid carcinomas. Histological analysis of tumor specimens showed extensive necrosis and inflammatory cell infiltrates. The combination of IL-2/HSV-TK plus ganciclovir was significantly more efficient than IL-2 alone in eradicating tumor masses. The bystander effect was also obtained in vivo. CONCLUSIONS: These findings demonstrate the feasibility and efficiency of a combined immunomodulating and suicide gene therapy approach for thyroid carcinomas.