Transcriptional profiling enables molecular classification of adrenocortical tumours

OBJECTIVE

Tumours in the adrenocortex are common human tumours. Malignancy is however, rare, the yearly incidence being 0.5-2 per million inhabitants, but associated with a very aggressive behaviour. Adrenocortical tumours are often associated with altered hormone production with a variety of clinical symptoms. The aggressiveness of carcinomas together with the high frequency of adenomas calls for a deeper understanding of the underlying biological mechanisms and an improvement of the diagnostic possibilities.

METHODS

Microarray gene expression analysis was performed in tumours of adrenocortex with emphasis on malignancy as well as hormonal activity. The sample set consisted of 17 adenomas, 11 carcinomas and 4 histological normal adrenocortexes. RNA from these was hybridised according to a reference design on microarrays harbouring 29 760 human cDNA clones. Confirmation was performed with quantitative real time-PCR and western blot analysis.

RESULTS

Unsupervised clustering to reveal relationships between samples based on the entire gene expression profile resulted in two subclusters; carcinomas and non-cancer specimens. A large number of genes were accordingly found to be differentially expressed comparing carcinomas to adenomas. Among these were IGF2, FGFR1 and FGFR4 in growth factor signalling the most predominant and also the USP4, UBE2C and UFD1L in the ubiquitin-proteasome pathway. Moreover, two subgroups of carcinomas were identified with different survival outcome, suggesting that survival prediction can be made on the basis of gene expression profiles. Regarding adenomas with aldosterone overproduction, OSBP and VEGFB were among the most up-regulated genes compared with the other samples.

CONCLUSIONS

Adrenocortical carcinomas are associated with a distinct molecular signature apparent in their gene expression profiles. Differentially expressed genes were identified associated with malignancy, survival as well as hormonal activity providing a resource of candidate genes for an exploration of possible drug targets and diagnostic and prognostic markers.

Expression profiling of adrenocortical neoplasms suggests a molecular signature of malignancy

BACKGROUND

Distinguishing between adrenocortical adenomas and carcinomas is often difficult. Our aim was to investigate the differences in transcriptional profiles between benign and malignant adrenocortical neoplasms using complementary DNA microarray techniques.

METHODS

We studied 7 patients with adrenocortical carcinomas and 13 with adenomas. Histopathology was reviewed in all patients; clinical follow-up was at least 1 year. Hybridizations were performed in duplicate against RNA reference. Expression levels were analyzed in the R environment for statistical computing with the use of aroma, limma, statistics, and class packages.

RESULTS

Transcriptional profiles were homogeneous among adenomas, while carcinomas were much more heterogeneous. Hierarchical clustering and self-organizing maps could separate clearly carcinomas from adenomas. Among genes that were most significantly upregulated in carcinomas were 2 ubiquitin-related genes (USP4 and UFD1L) and several insulinlike growth factor-related genes (IGF2, IGF2R, IGFBP3 and IGFBP6). Among genes that were most significantly downregulated in carcinomas were a cytokine gene (CXCL10), several genes related to cell metabolism (RARRES2, ALDH1A1, CYBRD1 and GSTA4), and the cadherin 2 gene (CDH2).

CONCLUSIONS

Through the use of cDNA arrays, adrenocortical adenomas and carcinomas appear to be clearly distinguishable on the basis of their specific molecular signature. The biologic importance of the up- and downregulated genes is yet to be determined.

Alterations of the SDHD gene locus in midgut carcinoids, Merkel cell carcinomas, pheochromocytomas, and abdominal paragangliomas

Several types of endocrine tumors show frequent somatic deletions of the distal part of chromosome arm 11q, where the tumor-suppressor gene SDHD (succinate-ubiquinone oxidoreductase subunit D), constitutionally mutated in paragangliomas of the head and neck, is located. In this study, we screened 18 midgut carcinoids, 7 Merkel cell carcinomas, 46 adrenal pheochromocytomas (37 sporadic and 9 familial), and 7 abdominal paragangliomas for loss of heterozygosity (LOH) and/or mutations at the SDHD gene locus. LOH was detected in 5 out of 8 (62%) informative midgut carcinoids, in 9 out of 30 (30%) sporadic pheochromocytomas, in none of the familial pheochromocytomas (0%), and in 1 out of 6 (17%) abdominal paragangliomas. No sequence variants were detected in the pheochromocytomas or paragangliomas. However, two constitutional putative missense mutations, H50R and G12S, were detected in two midgut carcinoids, which were both associated with LOH of the other allele. The same sequence variants were also detected in two Merkel cell carcinomas. In addition, the S68S polymorphism was found to coexist with the G12S sequence variant in both cases. In conclusion, we show that alterations of the SDHD gene seem to be involved in the tumorigenesis of both midgut carcinoids and Merkel cell carcinomas.

Aberrations of centrosomes in adrenocortical tumors

The frequent and generalized chromosomal imbalances that are characteristic of adrenocortical carcinomas suggest that incomplete chromosome segregation often takes place in these tumors. As a step towards elucidating the mechanism behind the multiple numerical chromosomal aberrations, we have evaluated a series of 14 such tumors for centrosome abnormalities using immunohistochemical detection of the gamma-tubulin centrosome component. The proportion of cells with more than the expected number of 2 centrosomes was moderately increased in the 4 adenomas (1-7%), while a high increase was observed in the 10 carcinomas (1-19%), as compared to the normal reference tissues (0.3%) (p<0.001). Similarly, the centrosome amplification tended to be more pronounced in the carcinomas where the aberrant cells carried 3 or 4 positive signals in 9 of the 10 tumors, and 6 signals were recorded in one tumor, while in the adenomas more than 3 signals was only recorded in one of the 4 cases. The findings demonstrate that centrosome amplifications occur frequently in both adrenocortical adenomas and carcinomas, thus supporting its role in driving the tumor development as opposed to being a consequence of it. Furthermore, the more pronounced occurrence in the malignant form as well as in the larger tumors, offers one likely explanation for the increasing generalized aneuploidy observed during the tumor development, and points to new therapeutic strategies aimed at restoring normal centrosome function.

In vitro release of aldosterone and cortisol in human adrenal adenomas correlates to mRNA expression of steroidogenic enzymes for genes CYP11B2 and CYP17

Adenomas of the adrenal cortex cause different disorders depending on the main steroid synthesized and released. The aim of this research is to increase our understanding of the pathophysiology of steroidogenesis in adrenocortical disorders by comparing the release of steroids from adrenocortical adenomas in vitro with the messenger RNA (mRNA) expression of steroid synthesizing enzymes. Fourteen patients with adrenal tumors were included in the present study; nine were diagnosed with primary aldosteronism and three with Cushing's syndrome. Two patients had an adrenal tumor discovered on computed tomography (CT) during workup for an unrelated disease. Serum cortisol, plasma aldosterone, and urinary catecholamines were normal. Tissue was taken for in vitro steroid release, and aldosterone and cortisol in the medium after a 1-hour incubation were determined. Oligonucleotide probes with sequences complementary to mRNAs encoding for the steroid synthesizing enzymes 11 beta-hydroxylase (CYP11B1), 18-hydroxylase (CYP11B2), 17 alpha-hydroxylase (CYP17), and 21-hydroxylase (CYP21) were synthesized (Genset, Paris, France) and in situ hybridization was performed. Moderate expression of CYP11B2 and low expression of CYP11B1 were seen in the zona glomerulosa. The zona fasciculata of the control adrenals expressed a high signal of CYP11B1, whereas the expression of CYP11B2 was very low. There was considerable variation in aldosterone release from the aldosteronomas, whereas the tumors from the Cushing patients showed no detectable release of aldosterone. In contrast, tumors from patients with primary aldosteronism, Cushing's syndrome, and no hyperfunction all had the ability to synthesize and release cortisol in vitro. The highest cortisol release was found in tumors from patients with Cushing's syndrome, but also the nonhyperfunctioning tumors and some of the aldosteronomas released significant amounts of cortisol. The two patients with highest release of aldosterone in vitro showed the highest expression of CYP11B2 and the lowest expression of CYP11B1 and CYP17. The remaining aldosteronomas had low expression of CYP11B2, similar to the two other groups. Expression of CYP11B1 was high as expected in the Cushing adenomas, but also the two nonhyperfunctioning tumors and some of the aldosteronomas showed a moderate expression. Adenomas from Cushing's syndrome, nonhyperfunctioning adenomas, and some of the aldosterone-producing adenomas had moderate to high expression of CYP17. This paper presents new means for functional characterization of adrenocortical tumors. Diagnosis of an aldosteronoma is often difficult, and with the advent of these methods it is possible to determine the functional capacity of a tumor, once it is removed. This is of special interest if the patient remains hypertensive postoperatively, and it is not clear whether the patient indeed had a functioning tumor.

Genetic background of adrenocortical tumor development

The increasing occurrence of incidentally discovered benign adrenocortical tumors has become a clinical dilemma because of the difficulties in differentiating them from their malignant counterpart. Adrenocortical tumors are associated with familial cancer syndromes such as the Beckwith-Wiedemann syndrome, the Li-Fraumeni syndrome, the Carney complex, multiple endocrine neoplasia type 1, congenital adrenal hyperplasia, and the McCune-Albright syndrome. Genetic events are known to take place on the chromosomal and gene level in sporadic adrenocortical tumors.

Comparison of the cost-effectiveness of budesonide and sodium cromoglycate in the management of childhood asthma in everyday clinical practice

BACKGROUND

Budesonide and sodium cromoglycate are both recommended as maintenance therapy for childhood asthma.

OBJECTIVE

To compare the cost-effectiveness of these two treatment strategies in clinical practice, in an open-label, pharmacoeconomic clinical trial.

METHODS

Health economics were evaluated in 138 children, ages 5 to 11 years, with unstable asthma not previously treated with corticosteroids or cromones. The asthma was stabilized during 4 to 6 weeks with budesonide 200 to 400 microg twice daily. The children were then randomly allocated to one of the two treatment strategies aiming at maintaining asthma control for 12 months; budesonide 400 microg/day (N = 69) or sodium cromoglycate 60 mg/day (N = 69). If asthma control was judged unsatisfactory, the doses were increased or the children were switched to the alternate treatment.

RESULTS

In children continuing on the same treatment, the degree of asthma control was similar in the two groups at study end. To maintain asthma control, 42% of cromoglycate children switched to budesonide, and then experienced a 14% increase in symptom-free days. No budesonide patient had to switch therapy because of lack of asthma control. Although not statistically significant, total annual cost per patient was 24% (Swedish kronor 4195; US $487; Euro 485) lower in the budesonide than the cromoglycate group, mainly due to a lower cost for asthma medication.

CONCLUSIONS

A budesonide strategy for continued maintenance treatment, after an initial period of stabilizing treatment with budesonide, resulted in lower costs and less drug switches than did a strategy with sodium cromoglycate.

Comparative genomic hybridization identifies loss of 18q22-qter as an early and specific event in tumorigenesis of midgut carcinoids

Carcinoid tumors are rare neuroendocrine tumors occurring in the lung or in the digestive tract where they are further subclassified as foregut, midgut, or hindgut carcinoids. To gain a better understanding of the genetic basis of the different types of carcinoid tumors, we have characterized numerical imbalances in a series of midgut carcinoids, and compared the results to previous findings in carcinoids from the lung. Numerical imbalances were revealed in 16 of the 18 tumors, and the most commonly detected aberrations were losses of 18q22-qter (67%), 11q22-q23 (33%), and 16q21-qter (22%), and gain of 4p14-qter (22%). The total number of alterations found in the metastases was significantly higher than in the primary tumors, indicating the accumulation of acquired genetic changes in the tumor progression. Losses of 18q and 11q were present both in primary tumors and metastases, whereas loss of 16q and gain of 4 were only detected in metastases. Furthermore, the pattern of comparative genomic hybridization alterations varied depending on the total number of detected alterations. Taken together, the findings would suggest a progression of numerical imbalances, in which loss of 18q and 11q represent early events, and loss of 16q and gain of 4p are late events in the tumor progression of midgut carcinoids. When compared to previously published comparative genomic hybridization abnormalities in lung carcinoids, loss of 11q was found to occur in both tumor types, whereas loss of 18q and 16q and gain of 4 were not revealed in lung carcinoids. The results indicate that inactivation of a putative tumor suppressor gene in 18q22-qter represents a frequent and early event that is specific for the development of midgut carcinoids.

Insulin-like growth factor-II in endocrine pancreatic tumours. Immunohistochemical, biochemical and in situ hybridization findings

In earlier studies a high-molecular-weight (HMW) insulin-like growth factor-II (IGF-II) peptide was identified in adult human pancreas and localized to the insulin-producing B-cells. This peptide has now been investigated in neoplastic insulin cells. Forty endocrine pancreatic tumours and 17 pancreatic adenocarcinomas of ductal type were included in the study. All cases were investigated with immunohistochemical techniques using antibodies to IGF-II, insulin, pro-insulin, glucagon, somatostatin, pancreatic polypeptide, gastrin and vasoactive intestinal peptide (VIP). Frozen tissue from nine tumours and two normal pancreatic glands was extracted, gel separated, and quantified using radioimmunoassay. The tumours were also investigated by in situ hybridization. IGF-II-immunoreactive cells were found in nearly all the 18 insulin-producing tumours (16/18), in a minority of the other endocrine tumours, but not in pancreatic adenocarcinomas. All extracts from the endocrine tumours showed varying amounts of IGF-II and had different molecular-weight forms. The immunohistochemical and radioimmunoassay findings are both based on immunological binding and were further confirmed by Northern blot and in situ hybridization. These results show that IGF-II is expressed in insulin-producing tumours as well as in pancreatic tumours producing other peptides, in contrast to normal pancreatic islets where IGF-II is found exclusively in insulin-producing cells.

Chromosomal alterations in human pancreatic endocrine tumors

Comparative genomic hybridization (CGH) was used to investigate changes in DNA copy numbers in 25 paraffin-embedded samples of pancreatic endocrine tumors from 23 patients. Insulin was the dominant hormone in 12, glucagon in 7, somatostatin in 1, and pancreatic polypeptide in 2 tumors. One to 15 (mean, 8.1) changes in DNA copy numbers were observed in 22 of the 25 tumors. The most recurrent aberration, found in 68% of the tumors, involved gains in chromosome 7 with a minimal overlapping region at 7q11.2. Other frequent gains included chromosomes 19 (60%) and 14 (56%). Chromosome arm 20q was amplified in 48% of the cases with the minimal overlapping region of 20q11.1-13.1. The two most frequent DNA losses were found at 11q21-22 in 32% and at 11p13-15 in 24% of the cases. The amplified chromosomal regions contain several candidate genes that may be involved in islet cell tumorigenesis. The regions with most frequent losses are likely to contain still uncharacterized tumor suppressor genes. Wiley-Liss, Inc.

Gelatinase A, membrane type 1 matrix metalloproteinase, and extracellular matrix metalloproteinase inducer mRNA expression: correlation with invasive growth of breast cancer

Invasive breast cancer varies widely in biologic aggressiveness, from fairly indolent tumors to rapidly disseminating carcinomas. Matrix metalloproteinases have enzymatic activity and assist in tumor invasion by degrading basement membranes and extracellular matrix. The extracellular matrix metalloproteinase inducer EMMPRIN is thought to stimulate fibroblasts to produce the zymogen pro-gelatinase A. The membrane type 1-matrix metalloproteinase (MT1-MMP) is thought to assist in tumor invasion and metastasis by activating pro-gelatinase A, which shows enhanced expression in various tumors. Overexpression of gelatinase A has shown to correlate with a malignant phenotype in many tumor forms. The aim of the study was to investigate the mRNA expression pattern of MT1-MMP, gelatinase A, and EMMPRIN in breast tumors. Formalin-fixed paraffin-embedded breast tissue samples from 18 patients operated on with breast-conserving surgery for invasive breast carcinoma <20 mm between 1977 and 1985 were analyzed using the mRNA in situ hybridization technique. Most of the patients were node-negative (15/18) and underwent postoperative irradiation to the breast (16/18). The median age at diagnosis was 52 years (21-83 years). At the time of the study 11 patients were alive, 4 without recurrence; 7 patients had been operated for ipsilateral breast tumor recurrences, and 2 had distant metastases. The median follow-up was 112 months (102-193 months). Seven patients died of disseminated breast cancer; their median follow-up was 43 months (22-116 months). (35)S-labeled antisense and sense mRNA probes transcribed from linearized plasmids containing cDNA for the matrix metalloproteinases gelatinase A and MT1-MMP and the glycoprotein EMMPRIN were hybridized to 5 microm paraffin-embedded tissue sections. Several invasive carcinomas were surrounded by normal tissue and carcinoma in situ lesions. Gelatinase A, MT1-MMP, and EMMPRIN mRNA expression were detected in all of the carcinomas. The gelatinase A mRNA expression was mainly localized to stromal cells at moderate to high levels surrounding the invading carcinoma cells but was also seen in single cells at low levels in in situ lesions and in some normal glandular cells. MT1-MMP and EMMPRIN were expressed in all of the carcinomas and were mainly localized to tumor cells; but they were also seen to some extent in single cells at low levels in in situ lesions and in normal glandular cells. No differences in levels of expression for gelatinase A, MT1-MMP, or EMMPRIN were seen in patients who survived compared to patients who died from metastatic disease. The co-expression of gelatinase A, MT1-MMP, and EMMPRIN mRNA in invasive breast carcinoma supports the theory that these proteins interact and are important for the invasive phenotype in breast carcinoma. Hence EMMPRIN may be a central factor for stimulation of gelatinase A activation. Specific inhibition for individual MMP members could in the future be target-specific events in breast tumor progression. Inhibition of EMMPRIN could be such a target.

Comparative genomic hybridization reveals frequent losses of chromosomes 1p and 3q in pheochromocytomas and abdominal paragangliomas, suggesting a common genetic etiology

Pheochromocytomas and abdominal paragangliomas are rare, catecholamine-producing tumors that arise from the chromaffin cells derived from the neural crest. We used comparative genomic hybridization (CGH) to screen for copy number changes in 23 pheochromocytomas and 11 abdominal paragangliomas. The pattern of copy number changes was similar between pheochromocytomas and paragangliomas, with the most consistent finding being loss of 1cen-p31, which was detected in 28/34 tumors (82%). Losses were also found on 3q22-25 (41%), 11p (26%), 3p13-14 (24%), 4q (21%), 2q (15%), and 11q22-23 (15%), and gains were detected on 19p (26%), 19q (24%), 17q24-qter (21%), 11cen-q13 (15%), and 16p (15%). Losses of 1p and 3q were detected in the majority of tumors, whereas gains of 19p and q, 17q, and 16p were seen only in tumors with six or more CGH alterations. This progression of genetic events did not correspond with the conversion to a malignant phenotype. CGH alterations involving chromosome 11 were more frequent in the malignant tumors, compared with the benign tumors (9/12 versus 3/16). In summary, we propose that pheochromocytomas and abdominal paragangliomas, which share many clinical features, also have a common genetic origin and that the loss of 1cen-p31 represents an early and important event in tumor development.

Efficacy of once-daily versus twice-daily administration of budesonide by Turbuhaler(R) in children with stable asthma

We evaluated the efficacy of once-daily versus twice-daily treatment with budesonide, delivered by a Turbuhaler(R), in the management of children with stable asthma in a randomized, double-blind, parallel-group study involving 206 children (age 5-15 years). After a 2-week run-in period during which the children were maintained on their usual dose of budesonide (200 microg or 400 microg/day), patients were randomized to receive the same daily dose in either two daily administrations (morning and evening) or as a single dose in the morning over a period of 12 weeks. The primary efficacy variable was morning peak expiratory flow (PEF). The mean morning PEF during the run-in phase was 271 L/min in patients randomized to once-daily treatment and 264 L/min in those randomized to twice-daily treatment. The mean change from baseline to the last 2 weeks of the treatment period in the two groups was -0.3 L/min (95% confidence limits -6.6 to +6.0) and 2.5 L/min (-4.3 to +9.3). The estimated difference between the groups was -2.8 L/min, with 90% confidence limits of -10.4 + 4.5; these were close to the limits regarded as indicative of equivalence (-10 to +10), and hence the difference was not regarded as clinically relevant. Similarly, there were no significant differences between the groups in regard to secondary efficacy measures such as spirometric tests and symptom scores. Both treatments were well tolerated. We conclude that once-daily administration of budesonide by Turbuhaler(R) is as effective as twice-daily treatment in the management of stable asthma in children treated with inhaled steroids at doses of 200-400 microg/day.

No overrepresentation of congenital adrenal hyperplasia in patients with adrenocortical tumours

OBJECTIVE

The development and progression of sporadic adrenocortical tumours are poorly understood. In autopsy studies adrenocortical tumours are found in between 2 and 9% of the general population. In congenital adrenal hyperplasia (CAH), decreased production of cortisol leads to increased secretion of ACTH from the pituitary, resulting in hyperplasia of the adrenals. More than 95% of all cases of CAH are due to steroid 21-hydroxylase deficiency, resulting from mutations in the CYP21 gene. In subjects homozygous and heterozygous for CYP21 mutations, adrenocortical tumours have been found in a high frequency compared to the general population, suggesting that chronic ACTH stimulation may play a role in the development of this tumour form. In order to test whether mild undiagnosed CAH is a common predisposing factor, we screened 27 patients with sporadic adrenocortical tumours for CYP21 mutations.

DESIGN

A retrospective study.

PATIENTS

We screened 27 patients with sporadic adrenocortical tumours, representing both benign and malignant as well as hormonally active and silent lesions.

MEASUREMENTS

Mutation analyses of the CYP21 gene was performed by allele-specific PCR on high molecular weight DNA. The method used detects the nine CYP21 mutations that are responsible for 95% of all disease-causing alleles in CAH.

RESULTS

No mutations were detected in any of the 23 DNA samples that were prepared from leucocytes. In 4 cases where no leucocyte DNA was available, tumour tissue was analysed. In one of these tumours, two CYP21 mutations, V281 L and L307insT, were found in heterozygous form.

CONCLUSION

Our data indicate that mild undiagnosed congenital adrenal hyperplasia is not a common underlying factor predisposing to adrenocortical tumours, at least not in the Swedish population.

Gelatinase A and membrane-type 1 matrix metalloproteinase mRNA: expressed in adrenocortical cancers but not in adenomas

In an attempt to understand the mechanism behind the invasion and metastasis in adrenocortical cancer we performed mRNA in situ hybridization on 30 tumors for three matrix metalloproteinases (MMPs): gelatinase A, membrane type 1 matrix metalloproteinase (MT1-MMP), and collagenase-3. All are known to participate in the invasion and metastasis of other tumor forms by degrading the extracellular matrix. Thirteen of sixteen cancers, but only one of fourteen benign lesions showed expression of gelatinase A, which was localized in stromal cells. MT1-MMP is thought to assist in tumor invasion and metastasis by activating the zymogen gelatinase A. Of 14 malignant tumors analyzed, 12 showed MT1-MMP mRNA expression, which in 7 cases was detected in both neoplastic and stromal cells. The benign tumors showed MT1-MMP expression in only 3 of 11 cases, and it was restricted to tumor cells. Fourteen tumors (11 cancers, 3 adenomas) were also analyzed for collagenase-3 mRNA, but no expression was detected. In conclusion, our data show that gelatinase A mRNA is expressed in most malignant adrenocortical tumors but not in the benign tumors. Gelatinase A mRNA expression is restricted to stromal cells, whereas its activator, MT1-MMP, is expressed in both stromal and neoplastic cells. Inhibition of gelatinase A and other proteinases may in the future become important as a form of cancer treatment.

Genotyping of adrenocortical tumors: very frequent deletions of the MEN1 locus in 11q13 and of a 1-centimorgan region in 2p16

To identify chromosomal regions that may contain loci for tumor suppressor genes involved in adrenocortical tumor development, a panel of 60 tumors (39 carcinomas and 21 adenomas) were screened for loss of heterozygosity. Although the vast majority of loss of heterozygosity (LOH) were detected in the carcinomas and involved chromosomes 2, 4, 11, and 18, only few were found in the adenomas. Therefore, 2 loci that harbor the familial cancer syndromes Carney complex in 2p16 and the multiple endocrine neoplasia type 1 gene in 11q13 were further studied in 27 (13 carcinomas and 14 adenomas) of the 60 tumors. Detailed analysis of the 2p16 region mapped a minimal area of overlapping deletions to a 1-centimorgan region, which is separate from the Carney complex locus. LOH for a microsatellite marker (PYGM), very close to the MEN1 gene, was detected in all 8 informative carcinomas (100%) and in 2 of 14 adenomas. Of the 27 cases analyzed in detail, 13 cases (11 carcinomas and 2 adenomas) showed LOH on chromosome 11 and was therefore selected for MEN1 gene mutation analysis. In 6 cases a common polymorphism (Asp418Asp) was found, but no mutation was detected. In conclusion, our data indicate the existence of tumor suppressor genes at multiple chromosomal locations, whose inactivations are involved in the development of adrenocortical carcinomas. Loss of genetic material from 2p16 was strongly associated with the malignant phenotype, as it was seen in almost all carcinomas but not in any of the adenomas. LOH in 11q13 also occurred frequently in the carcinomas, but was not associated with a MEN1 mutation, suggesting the involvement of a different tumor suppressor gene on this chromosome.

Characterisation of endothelin-1-related protein in human adrenal cortex and in cortical lesions

Endothelin (ET)-1 is a 21-amino acid peptide with potent vasopressor and vasoconstrictive properties. Biochemical studies suggest that this peptide occurs in the adrenal cortex, where it appears to influence steroid hormone production and catecholamine release. Concomitant with our previous immunohistological study, we found ET-1 immunoreactive (IR) cells in human adrenal cortex and cortical neoplasms, but not in the medulla. These ET-1 IR cells were numerous in adenomas, but were seen only occasionally in some of the carcinomas. In the present study, the ET-1 IR protein was extracted from normal (n = 5) and hyperplastic (n=3) human cortex as well as from cortical adenomas (n = 10) and carcinomas (n = 5). Its molecular weight, determined by SDS-polyacrylamide gel electrophoresis and immunoblotting, was 9 kD, which is lower than that of prepro-ET-1 (21 kD), but larger than that of pre-ET-1 (4.3 kD) and ET-1 (2.5 kD). The normal cortical specimens, hyperplasias, adenomas and three of the five carcinomas all contained this distinct band. The two carcinomas lacking it were associated with Conn's syndrome. The protein may constitute a protein not previously described, but further studies are needed to determine its complete structure.

Neuroendocrine differentiation and nerves in human adrenal cortex and cortical lesions

Neuroendocrine differentiation and nerve distribution were studied in sections from human cortex (n=11) and cortical lesions (hyperplasias, n=9; adenomas, n=13; carcinomas, n=14) with four markers, namely chromogranin A(CgA), synaptophysin (SYN), neuron-specific enolase (NSE), protein gene product (PGP) 9.5 and small synaptic vesicle protein (SV)2. All but two cases expressed neuroendocrine differentiation. NSE was the most commonly occurring marker and the NSE immunoreactive cells were detected in normal cortex, mainly in zona glomerulosa, as well as in adenomas and carcinomas. SYN and PGP 9.5 immunoreactive cells were especially prominent in the carcinomas, while SV2 immunoreactive cells were seen mainly in normal cortex. The difference in distribution pattern of the neuroendocrine markers between adenomas and carcinomas was not so distinct that it can be used for histopathological diagnosis. The significance of neuroendocrine differentiation in cortex and cortical lesions is uncertain, but may reflect an involvement in special hormonal functions. No obvious relationship was found between the clinical syndromes and the degree of neuroendocrine differentiation. Three of the neuroendocrine markers also visualized nerve structures. PGP 9.5, which is regarded as the most 'general' nerve marker, visualized more nerve structures than did the other markers. Normal cortex contained most immunoreactive nerves, whereas they were less numerous in hyperplasias and sparse or even absent in the neoplasms. The nerves appeared among the parenchymal cells but were particularly prominent around vessels. The results suggest that the cortical nerves influence not only the regulation of the blood supply but also the hormonal regulation at the cellular level.

Novel splicing of an IGF2 polymorphic region in human adrenocortical carcinomas

The human IGF2 gene lies on chromosome 11p15.5 and encodes for a mitogenic peptide. IGF2 is often overexpressed in many tumours including adrenal carcinomas. In this study while screening 12 adrenocortical carcinomas for heterozygosity at the Apa I and (CA)n repeat polymorphisms we observed a novel splicing event in two samples which showed both an allelic expression imbalance and preferential splicing for one of the alleles. Further examination revealed that the splicing was not confined to one particular site. Three of such splice products were isolated and cloned. Using RNase protection analysis the presence of this splicing event was demonstrated for both adrenocortical carcinoma samples and also in a Hep3B cell line. This suggested that the event may be occurring in all the samples. The presence of this splicing was then confirmed in all 12 adrenocortical carcinoma samples by PCR. These data suggest that the splicing event may be a general feature for IGF2 transcripts.

Genetic aberrations in adrenocortical tumors detected using comparative genomic hybridization correlate with tumor size and malignancy

The differentiation between malignant and benign adrenocortical tumors is often difficult, and better markers are required. Because the genetic background of adrenocortical tumors is poorly characterized, we used comparative genomic hybridization (CGH) to screen for DNA sequence copy number changes in 8 sporadic primary adrenocortical cancers and 14 adenomas. There was a strong relationship between the number of genetic aberrations detected using CGH and both tumor size and malignancy. No alterations were seen in the smaller adenomas (< 5 cm), whereas the two largest adenomas (5 cm each) and seven of the eight cancers (7-20 cm) showed an increased number of genetic alterations. The presence of genetic aberrations detected using CGH was associated with an aneuploid DNA pattern. In the cancers, losses most often involved the chromosomal regions 2, 11q, and 17p (four of eight tumors), whereas gains took place at chromosomes 4 and 5 (four of eight tumors). In conclusion, our data indicate that genetic changes may help to define the malignant potential of adrenocortical tumors. Furthermore, the CGH results implicate several chromosomal regions that may contain genes with an important role in the development of adrenocortical cancers.

Nedocromil sodium 2% eye drops for twice-daily treatment of seasonal allergic conjunctivitis: a Swedish multicentre placebo-controlled study in children allergic to birch pollen

This was a multicentre, double-blind, randomized group comparative study in which 77 children, aged 6-16 years, received 2% nedocromil sodium eye drops and 72 received placebo, one drop into each eye twice daily. The treatment period was 4 weeks, covering the peak birch pollen season. Prior to the start of the season, patients who had attended the clinic the previous 2 years because of seasonal allergic conjunctivitis (SAC) to birch pollen, entered a one week baseline period during which symptoms were assessed, dairy cards completed, and routine sampling of blood and urine carried out. The double-blind treatment period then commenced at the onset of the birch pollen season. Patients/parents kept daily diary record cards of eye symptom severity and concomitant therapy. Conjunctivitis was mild in both treatment groups but nedocromil sodium was more effective than placebo in controlling symptoms. During the 2-3 weeks of peak pollen counts, this therapeutic effect was statistically significant for itching (P < 0.01), watering (P < 0.05) and total symptom score (P < 0.01), but was not significant for grittiness (P = 0.08) or redness (P = 0.06). Global opinions of efficacy showed no difference between treatments, due to a high placebo effect (however, the diary card data indicated a significant improvement with nedocromil sodium). We therefore conclude that nedocromil sodium 2% eye drops, administered twice daily, is an effective treatment for SAC in children.

Primary hyperparathyroidism. Low surgical morbidity supports liberal attitude to operation

OBJECTIVE

To evaluate the results of a modern surgical approach in patients with primary hyperparathyroidism.

DESIGN

Retrospective analysis.

SETTING

University hospital, tertiary care center.

PATIENTS

One hundred patients consecutively operated on for suspected primary hyperparathyroidism. Patients were available for follow-up 1 month (n = 100) and 1 year (n = 96) after surgery.

INTERVENTION

Cervical exploration. Surgical strategy was to remove enlarged parathyroid glands only and perform a biopsy on no more than one normal gland.

MAIN OUTCOME MEASURES

Surgical morbidity and normocalcemia.

RESULTS

No operative mortality or wound infection occurred in any patient. Postoperative vocal cord paralysis was recorded in two patients; both recovered fully. Two patients underwent a second operation. (One patient experienced subcutaneous bleeding and the second patient, previously operated on for toxic goiter, experienced persistent hypercalcemia and was operated on 5 days after the initial operation. A second abnormal gland was then found on the contralateral side, not initially surgically explored.) At follow-up, 97 patients were normocalcemic; three patients had hypoparathyroidism: two of these patients, with multiglandular disease, were normocalcemic and received a low dose of vitamin D (1 alpha [OH]D3), and one patient, who had had a single adenoma removed, was slightly hypocalcemic, however, asymptomatic.

CONCLUSIONS

More than 90% of patients with primary hyperparathyroidism can be operated on without complications occurring. This supports a liberal attitude to operation.