Molecular adrenocortical tumourigenesis

Circulating E-selectin levels and insulin resistance are associated with early stages of atherosclerosis in nonfunctional adrenal incidentaloma

OBJECTIVE

To evaluate circulating E-selectin levels in patients with nonfunctional adrenal incidentaloma (NFA) in relation to insulin resistance and early atherosclerosis.

SUBJECTS AND METHODS

A total of 40 patients with NFA (mean [SD] age: 55.6 [10.7] years; 70% were females) and 35 controls (mean [SD] age: 51.5 [8.1] years; 71.4% were females) selected from age-, gender- and body mass index (BMI)- matched healthy subjects were enrolled. Serum hsCRP, lipid profile, insulin levels and the homeostasis model assessment of insulin resistance (HOMA-IR) were evaluated. High-resolution B-mode ultrasonography was performed. Serum levels of E-selectin were evaluated by enzyme-linked immunosorbent assay.

RESULTS

Patients with NFA had significantly higher values for E-selectin (14.9 (4.8) vs. 12.2 (4.1) ng/mL, p < 0.01) and CIMT (0.6 (0.1) vs. 0.5 (0.1) mm, p < 0.05) than controls. Serum E-selectin levels showed a statistically significant association with hsCRP (r = 0.751, p < 0.001), HOMA-IR (r = 0.575, p < 0.001) and CIMT (r = 0.762, p < 0.001). CIMT (Carotid intima media thickness) was increased in patients with NFA patients with NFA were more insulin resistant than controls and statistically significant relationship was found between size of tumor and HOMA-IR (r = 0.361, p < 0.001).

CONCLUSION

In conclusion, based on significantly higher values for E-selectin, CIMT and HOMA-IR in patients with NFA than controls along with significant correlation of E-selectin levels to CIMT, HOMA-IR and hs-CRP, our findings seems to indicate an increased risk of early atherosclerosis and impaired endothelial function in NFA patients, particularly in case of insulin resistance.

A Case of Oncocytic Adrenocortical Neoplasm of Borderline (Uncertain) Malignant Potential

Oncocytic neoplasms are tumors composed predominantly or exclusively of oncocytes (large polygonal cells with granular eosinophilic cytoplasm due to abnormal mitochondrial accumulation). These tumors are frequently reported in the thyroid, kidneys, and salivary glands. However, they are distinctly rare in the adrenal cortex. Oncocytic adrenocortical neoplasms (OAN) are classified regarding their biological behavior by their histological features according to the Lin-Weiss-Bisceglia system (LWB). Here, we report a case of OAN of borderline or uncertain malignant potential (BMP) with subsequently identified papillary thyroid carcinoma (PTC). A 34-year-old female with a nine-month history of fatigue presented with chest pain. A right adrenal mass was incidentally found while ruling out pulmonary embolism. A CT-guided adrenal biopsy, although not routinely indicated, was performed and interpreted as malignant with no definitive origin. Hormonal workup was unremarkable. PET-scan showed hypermetabolic adrenal mass with peak standardized uptake value of 15, suspicious of malignancy. A hypermetabolic thyroid nodule was also identified, but there was no evidence of metastatic disease. The patient underwent adrenalectomy, and the initial pathology report was interpreted as atypical pink cell tumor. A second pathology report from another laboratory favored OAN based on the morphology and immunohistochemical staining. While the histologic criteria of malignancy were not met, the large tumor size makes it compatible with BMP according to LWB criteria. A follow-up thyroid ultrasound revealed a complex thyroid nodule. A total thyroidectomy was performed, and pathology was consistent with PTC. Of interest, PTC frequently shows an increase in mitochondrial content, which is characteristic of oncocytic tumors. This case illustrates that OAN, although rare, should be considered in the differential diagnosis of adrenal masses. When OAN is identified, it should be classified regarding its biological behavior as benign or malignant using the LWB system and, eventually, the reticulin algorithm of Duregon, et al. Oncocytoma can be confirmed ultrastructurally or by immunohistochemistry. Studying the gene mutations in patients presenting with oncocytic malignancies and other tumors that demonstrate mitochondrial proliferation as PTC might help to understand the role of mitochondrial proliferation in cancer development.

Carotid Intima-Media Thickness as the Cardiometabolic Risk Indicator in Patients with Nonfunctional Adrenal Mass and Metabolic Syndrome Screening

Background

Our purpose was to show the association of adrenal incidentaloma and metabolic syndrome in consideration of the studies and to detect the increase in the carotid intima-media thickness which is regarded as the precessor of atherosclerosis.

Material/Methods

Eighty-one patients who were diagnosed with adrenal mass were included in the study. Hormonal evaluation, insulin rezistance measurement with the HOMA-IR and 1-mg DST were performed of all patients. The patients were classified as follows: mass size <3 cm (K₁) and mass size of at least 3 cm (K₂). Echocardiography and carotid intima-media thickness of the patients were measured using B-mode ultrasound. Thirty-three healthy individuals were enrolled as the control group.

Results

Mass size of 64.19% K₁, while mass size of the remainder (35.81%) K₂ was calculated. Five of the patients with adrenal mass were detected to have subclinical Cushing syndrome. The remaining 76 patients were accepted as nonfunctional. It was seen with regard to metabolic and biochemical parameters that plasma glucose (p=0.01), insulin (p=0.00) and triglyceride (p=0.012) values of all patients were significantly high compared to those of the control group. It was detected that measured heart rate (p=0.00), end-diastolic diameter (p=0.02), end-systolic diameter (p=0.014) and carotid intima-media thickness (p=0.00) values of the patients with adrenal mass were significantly higher than those of the healthy control group.

Conclusions

We found that the increased insulin resistance, increased risk of cardiovascular disease with the increase in the thickness of carotid intima-media and diastolic disfunction parameters, although the patients with adrenal incidentaloma are nonfunctional.

The insulin and igf-I pathway in endocrine glands carcinogenesis

Endocrine cancers are a heterogeneous group of diseases that may arise from endocrine cells in any gland of the endocrine system. These malignancies may show an aggressive behavior and resistance to the common anticancer therapies. The etiopathogenesis of these tumors remains mostly unknown. The normal embryological development and differentiation of several endocrine glands are regulated by specific pituitary tropins, which, in adult life, control the function and trophism of the endocrine gland. Pituitary tropins act in concert with peptide growth factors, including the insulin-like growth factors (IGFs), which are considered key regulators of cell growth, proliferation, and apoptosis. While pituitary TSH is regarded as tumor-promoting factor for metastatic thyroid cancer, the role of other pituitary hormones in endocrine cancers is uncertain. However, multiple molecular abnormalities of the IGF system frequently occur in endocrine cancers and may have a role in tumorigenesis as well as in tumor progression and resistance to therapies. Herein, we will review studies indicating a role of IGF system dysregulation in endocrine cancers and will discuss the possible implications of these findings for tumor prevention and treatment, with a major focus on cancers from the thyroid, adrenal, and ovary, which are the most extensively studied.

The use of immunohistochemical expression of SF-1 and EMA in distinguishing adrenocortical tumors from renal neoplasms

Steroidogenic factor -1 (SF-1) is an orphan member of the nuclear hormone receptor superfamily, and is considered to play an important role in the differentiation of steroidogenic tissues. In this study, we compared the immunohistochemical stains of SF-1 and epithelial membrane antigen (EMA) in non-neoplastic adrenal tissue, and adrenal and renal tumors using tissue microarrays (TMAs). The adrenal tissue array included 19 cases of normal adrenal cortex, 22 cases of adrenal adenoma, and 20 cases of adrenal cortical carcinoma. The renal tissue array included 20 cases of each of the following types of renal cell carcinoma: clear cell, papillary, and chromophobe. In addition, 20 cases of renal oncocytoma were also included in the study. SF-1 showed positive staining in all cases (100%) of normal adrenal cortex and adrenal cortical adenoma, and in 18 (90%) cases of adrenocortical carcinoma. In renal tumors, SF-1 showed negative stains in all of oncocytoma, papillary, and chromophobe renal cell carcinoma. Only 3 out of 20 cases of clear cell renal cell carcinoma showed weak positivity in approximately 10% of tumor cells. EMA stained positively in 85%, 95%, 100%, and 95% of clear cell, papillary, chromophobe renal cell carcinomas, and oncocytomas, respectively. EMA was completely negative in the adrenal TMAs. In conclusion, SF-1 and EMA may be helpful in the differentiation of adrenal tumors from renal tumors in difficult cases.

Pattern of adrenal morphology and function in patients with acromegaly

BACKGROUND

Acromegaly is well known to induce hypertrophic and hyperplastic changes in various organs and is commonly accompanied by arterial hypertension. In our study, we assess the adrenal morphology and function in a series of patients with acromegaly and possible associations with the activity of the disease and arterial hypertension.

MATERIALS AND METHODS

Sixty patients with acromegaly, admitted to two endocrinology departments in the time period 2005-2010, were studied prospectively. Basal IGF-1 and growth hormone levels after oral glucose tolerance test were used to assess the disease activity. All subjects underwent adrenal CT scan, basal adrenal hormonal investigation and evaluation with 24-h urinary free cortisol and cortisol levels following low-dose dexamethasone suppression test. In 33 acromegalics, the 'modified' saline infusion test (MSI), i.e. saline infusion after dexamethasone administration, was performed to identify autonomous aldosterone (ALD) secretion.

RESULTS

Abnormal adrenal morphology was present in 48% of our patients, and a significant association was found between the presence of arterial hypertension and adrenal morphology. Among patients with adrenal morphological changes, 55% exhibited no adrenal secretory hyperactivity, 34% autonomous cortisol, 7% ALD and 4% combined autonomous cortisol and ALD secretion, when applying recently proposed modified cut-off levels compared to widely used criteria. An increased prevalence of autonomous ALD secretion was shown among the subgroup of patients with acromegaly tested with MSI.

CONCLUSIONS

This study provides evidence of an increased prevalence of anatomic and functional adrenal alterations in patients with acromegaly; further studies will clarify the importance of evaluating these subjects with baseline hormonal investigation along with dynamic testing and modified cut-offs.

Clinically silent adrenal adenomas - their relation to the metabolic syndrome and to GNB3 C825T gene polymorphism

OBJECTIVES

Aim of the study was to assess the prevalence of C825T GNB3 gene polymorphism in patients with adrenal incidentaloma (AI) as well as its relation to the metabolic syndrome (MS) and cortisol status.

SUBJECT AND METHODS

Alltogether 82 subjects (50 patients with AI, mean age 57.9 + 15 years and 32 subjects without AI, mean age 53.8 + 6.9 years) were included in this study. Parameters of glucose and lipid metabolism, serum adiponectin and the single nucleotide polymorphism C825T in GNB3 gene using PCR-RFLP method were examined. To detect subclinical Cushing syndrome an overnight dexamethason test was performed in all patients with AI.

RESULTS

Patients with AI had signifcantly higher BMI, HOMA, triacylglycerols (p < 0.05) and significantly lower serum adiponectine (p < 0.05) than controls. There were no significant differences in metabolic parameters between group with and without subclinical Cushing syndrome (SCS). The prevalence of T allele of GNB3 gene in patients with AI was not significantly higher as compared with control group (32% vs. 47%). No significant differences in serum glucose and lipids between carriers of T and C alleles were detected. However carriers of T allele had significantly lower serum adiponectin than those with allele C (p < 0.01).

CONCLUSION

We conclude that patients with AI had significantly higher cardiovascular risk factors that is not related to the presence of SCS. Moreover patients with AI and TC or TT genotype have significantly lower serum adiponectin which may be an early symptom of metabolic syndrome in patients with AI.

Number of genomic imbalances correlates with the overall survival for adrenocortical cancer in childhood

BACKGROUND

Adrenocortical tumours (ACT) in children are rare and, if malignant, often associated with poor prognosis. Relevant cytogenetic factors for prognosis are hardly available.

PROCEDURES

We analysed 14 adrenocortical cancers (ACC) of children by comparative genomic hybridisation (CGH).

RESULTS

The total number of genomic imbalances ranged from 1 to 17 in individual tumour samples. The most common imbalances were +1q (57%), +12p (50%), +12q (50%), +1p (43%), +7q (42%), +9q (42%), +15q (42%), and -4q (57%), -11q (57%), -4p (42%), and -16q (42%). The median number of genomic changes was 5.5 (n = 8) in pT1-pT2 and 15.5 (n = 6) in pT3-pT4 tumours. The median number was 4 in the eight patients, who remain in remission more than 51 months and 15.5 in the six patients, who have died from the disease within 44 months. Moreover, all seven patients with less than 10 individual imbalances were in remission (median follow-up 72 months), while all but one patient with 10 and more individual imbalances (n = 7) have died from the disease (median survival time 30 months). Comparison of the data from children and adults revealed characteristic differences. Gain of 1p and loss of 4p, 4q and 16q are frequent in childhood and rare in adults. Inversely, loss of 1p is rare in childhood but frequent in adult ACT.

CONCLUSION

The number of CGH imbalances appeared to have a predictive value for overall survival in paediatric ACC.

Functioning adrenocortical oncocytoma: a case report and review of the literature

Adrenocortical oncocytoma is exceptionally rare. Most of these tumors are benign and nonfunctioning. We report a case of functioning adrenocortical oncocytoma located in the right adrenal gland in a 53-year-old woman who presented with Cushing's syndrome. The tumor was small, with exclusively oncocytic histologic features. A discussion of this case and a review of the literature on this entity is presented.

[Adrenocortical secretory tumors]

Adrenocortical tumors are rare and mostly non-secreting; their discovery is incidental. When secreting, they produce steroid excess and result in a clinical presentation such as the Cushing syndrome, primary aldosteronism, virilization or feminization syndrome. Such tumors are mostly sporadic but can belong to hereditary syndromes predisposing to tumors. The diagnosis of secreting adrenocortical tumors is based upon clinical presentation and biological data associated with specific biological assessments. Adrenal imaging has been considerably improved with the development of CT scan, which can be completed by MRI if necessary. Most of adrenocortical tumors are adenoma, nevertheless some of them can be malignant and the prognosis of such carcinomas is poor. Management of secreting adrenocortical tumors requires surgery in most of the cases and laparoscopic access is now widely used and provides good results in the treatment of benign tumors.

Steroidogenic acute regulatory (StAR)-directed immunotherapy protects against tumor growth of StAR-expressing Sp2-0 cells in a rodent adrenocortical carcinoma model

Adrenocortical carcinoma (ACC) is a highly malignant tumor with poor response to classical antitumor therapy. Steroidogenic acute regulatory (StAR) protein is expressed in most human ACCs. The aim of this study was to induce antitumoral T cells directed against StAR in a murine tumor model. Because a suitable syngenic adrenocortical mouse tumor model is lacking, we established a clone of the mouse myeloma Sp2-0 tumor cell line stably expressing murine StAR (Sp2-mStAR). Using repeated im injections of plasmid DNA encoding mStAR followed by infection with a recombinant vaccinia virus (rVV) expressing mStAR, we induced a cytotoxic T-cell response as measured by enzyme-linked immunospot assay. To demonstrate antitumor activity of the vaccination procedure, mice were treated as follows: group A, mice immunized with plasmids and rVV encoding mStAR receiving Sp2-mStAR cells; control group B, mice immunized with the empty plasmid and the empty rVV receiving Sp2-mStAR cells; control group C, mice immunized with the empty plasmid and rVV encoding P450 side-chain cleavage enzyme receiving Sp2-mStAR cells; and control group D, mice immunized with plasmid and rVV encoding mStAR receiving parental Sp2-0 cells. A high proportion (89-100%) of the control groups B, C, and D developed subcutaneous tumors. In contrast, immunization specific for mStAR (group A) was highly protective against tumor growth (percentage of tumor-free animals, 67%; P < 0.001 vs. controls). In summary, these results show that T-cell tolerance toward mStAR can be broken, resulting in antitumoral immunity. Thus, StAR represents a candidate target antigen for immunotherapeutic strategies against ACC.

Gene array analysis of macronodular adrenal hyperplasia confirms clinical heterogeneity and identifies several candidate genes as molecular mediators

Corticotropin (ACTH)-independent macronodular adrenal hyperplasia (AIMAH) is a heterogeneous condition in which cortisol secretion may be mediated by gastrointestinal peptide (GIP), vasopressin, catecholamines and other hormones. We studied the expression profile of AIMAH by genomic cDNA microarray analysis. Total RNA was extracted from eight tissues (three GIP-dependent) and compared to total RNA obtained from adrenal glands from 62 normal subjects. Genes had to be altered in 75% of the patients, and be up- or downregulated at a cutoff ratio of at least 2.0; 82 and 31 genes were found to be consistently up- and downregulated, respectively. Among the former were regulators of transcription, chromatin remodeling, and cell cycle and adhesion. Downregulated sequences included genes involved in immune responses and insulin signaling. Hierarchical clustering correlated with the two main AIMAH diagnostic groups: GIP-dependent and non-GIP-dependent. The genes encoding the 7B2 protein (SGNE1) and WNT1-inducible signaling pathway protein 2 (WISP2) were specifically overexpressed in the GIP-dependent AIMAH. For these, and six more genes, the data were validated by semiquantitative amplification in samples from a total of 32 patients (the original eight, six more cases of AIMAH, and 18 other adrenocortical hyperplasias and tumors) and the H295R adrenocortical cancer cell line. In conclusion, our data confirmed AIMAH's clinical heterogeneity by identifying molecularly distinct diagnostic subgroups. Several candidate genes that may be responsible for AIMAH formation and/or progression were also identified, suggesting pathways that affect the cell cycle, adhesion and transcription as possible mediators of adrenocortical hyperplasia.

Adrenocortical adenoma and carcinoma: histopathological and molecular comparative analysis

We compared histomorphological features and molecular expression profiles of adrenocortical adenomas (ACAd) and carcinomas (ACCa). A critical histopathological review (mean, 11 slides per patient) was conducted of 37 ACAd and 67 ACCa. Paraffin-embedded tissue cores of ACAd (n = 33) and ACCa (n = 38) were arrayed in triplicate on tissue microarrays. Expression profiles of p53, mdm-2, p21, Bcl-2, cyclin D1, p27, and Ki-67 were investigated by immunohistochemistry and correlated with histopathology and patient outcome using standard statistical methodology. Median follow-up period was 5 years. Tumor necrosis, atypical mitoses, and >1 mitosis per 50 high-power fields were factors that were highly specific for ACCa (P <.001). Number (0 to 4) of unfavorable markers [Ki-67 (+), p21 (+), p27 (+), mdm-2(-)] expressed was significantly associated with mitotic activity and morphologic index (i.e., number of adverse morphologic features) and highly predictive of malignancy (P <.001). Ki-67 overexpression occurred in 0 ACAd and 36% ACCa (P <.001) and was significantly associated with mitotic rate and unfavorable morphologic index (P <.001). Tumor necrosis, atypical mitoses, >5 mitoses per 50 high-power fields, sinusoidal invasion, histologic index of >5, and presence of more than two unfavorable molecular markers were associated significantly with metastasis in ACCa. Well-established histopathologic criteria and Ki-67 can specifically distinguish ACCAd from ACCa. Tumor cell proliferation (Ki-67) correlates with mitotic activity and morphologic index. Tumor morphology is a better predictor of metastatic risk in ACCa than current immunohistochemistry-detected cell cycle regulatory and proliferation-associated proteins.

Comparative genomic hybridization analysis of adrenocortical tumors

Comparative genomic hybridization (CGH) is a molecular cytogenetic technique that allows the entire genome of a tumor to be surveyed for gains and losses of DNA copy sequences. A limited number of studies reporting the use of this technique in adult adrenocortical tumors have yielded conflicting results. In this study we performed CGH analysis on 13 malignant, 18 benign, and 1 tumor of indeterminate malignant potential with the aim of identifying genetic loci consistently implicated in the development and progression of adrenocortical tumors. Tissue samples from 32 patients with histologically proven adrenocortical tumors were available for CGH analysis. CGH changes were seen in all cancers, 11 of 18 (61%) adenomas, and the 1 tumor of indeterminate malignant potential. Of the adrenal cancers, the most common gains were seen on chromosomes 5 (46%), 12 (38%), 19 (31%), and 4 (31%). Losses were most frequently seen at 1p (62%), 17p (54%), 22 (38%), 2q (31%), and 11q (31%). Of the benign adenomas, the most common change was gain of 4q (22%). Mann-Whitney analysis showed a highly significant difference between the cancer group (mean changes, 7.6) and the adenoma group (mean changes, 1.1) for the number of observed CGH changes (P < 0.01). Logistic regression analysis showed that the number of CGH changes was highly predictive of tumor type (P < 0.01). This study has identified several chromosomal loci implicated in adrenocortical tumorigenesis. Activation of a protooncogene(s) on chromosome 4 may be an early event, with progression from adenoma to carcinoma involving activation of oncogenes on chromosomes 5 and 12 and inactivation of tumor suppressor genes on chromosome arms 1p and 17p.

Hyperplasia versus adenoma in endocrine tissues: are they different?

The traditional view holds that hyperplasia of endocrine glands is secondary to oversecretion of a trophic hormone. However, in most cases, the mechanism underlying this growth is the spontaneous proliferation of benign neoplasias. Pathologists still depend on subtle morphological criteria to delineate and further classify these tumours. Owing to their variable architecture, a bewildering nomenclature has emerged for these tumours, exemplified by the many names applied to the goitrous thyroid gland: hyperplasia, adenomatous goitre, adenomatoid nodules, benign nodular thyroid disease, adenoma, etc. This article reviews the evidence suggesting that: (1) the varied types of benign neogeneration of endocrine tissue, the spectrum of which ranges from 'simple hyperplasia' to 'true adenoma', involve the same process; (2) even clonality of a growing lesion cannot distinguish hyperplasia from neoplasia; and (3) the basic processes in both cases are not different from those that cause benign tumours in other organs.