scholarly journals Morphological characteristics of pituitary adenomas in the phenocopy of multiple endocrine neoplasia type 1

2021 ◽  
Vol 67 (6) ◽  
pp. 50-58
Author(s):  
D. A. Trukhina ◽  
E. O. Mamedova ◽  
A. M. Lapshina ◽  
E. V. Vasilyev ◽  
A. N. Tiulpakov ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Endocrine Glands ◽  
Cytoplasmic Expression ◽  
Men1 Gene ◽  
Men 1 ◽  
Endocrine Neoplasia ◽  
Endocrine Neoplasia Type

BACKGROUND: Multiple endocrine neoplasia type 1 (MEN 1) is a rare autosomal dominant disorder caused by mutations in the MEN1 gene, which encodes the menin protein. If a patient has the MEN 1 phenotype in the absence of mutations in the MEN1 gene, the condition is classified as a phenocopy of this syndrome. Although significant progress has been made in understanding the function of menin, its role in the oncogenesis of the endocrine glands is still being elucidated. Due to its key role in physiological and pathological processes, the assessment of the menin expression can provide valuable information.AIM: to determine whether there are any differences in the expression of menin in the pituitary adenomas (PA) in patients with phenocopy of MEN 1 (phMEN 1) and genetically confirmed MEN 1 (gMEN 1) compared with their sporadic forms.MATERIALS AND METHODS: immunohistochemical assessment of the menin expression was carried out in PA of patients with gMEN 1, phMEN 1 and sporadic acromegaly (SA), surgically treated in 2008–2020. IHC was performed using antibodies to menin, PRL, GH, ACTH, FSH, TSH, Pit-1, T-box, ERA on previously prepared histological section.RESULTS: The study included 35 samples of PA: gMEN 1 — 9 samples, phMEN 1 — 12 (somatotropinomas + PHPT); CA — 14  samples. The patients were comparable by gender, adenoma size, and drug intake. The gMEN  1 group differed from phMEN 1 and SA by age (p = 0.0005). In patients with gMEN 1, the expression of menin varied from no staining (5/9) to intense cytoplasm staining. Cytoplasmic expression of menin was mainly present (11/12) in the phMEN 1. In the SA group, there was no staining in 1 case; nuclear expression was detected in 6/14 cases. The phMEN  1 group showed significantly higher cytoplasmic expression of menin than the gMEN  1 group (p = 0.006). The gMEN 1 group also differed from the SA group (p = 0.012). There were no statistically significant differences between the phMEN 1 and SA groups (p = 0.049).CONCLUSION: It was revealed that the menin expression, in general, is retained in phMEN 1 and SA groups, although with different localization in the cell structure (nucleus and / or cytoplasm). At the same time, the expression of menin varies greatly in patients with gMEN 1. According to the data obtained, it can be assumed that the pathogenesis of PA in phMEN 1 and SA may have similarities; however, there could be factors contributing to the appearance of several tumors of the endocrine glands in one person with phMEN 1. To understand this process, it is necessary to further study the genes associated with MEN 1, epigenetic factors, signaling pathways in which menin is involved.

scholarly journals Differences in Menin Expression in Pituitary Adenomas in Multiple Endocrine Neoplasia Type 1, Its Phenocopies and Sporadic Acromegaly

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A535-A536
Author(s):  
Diana A Dimitrova ◽  
Elizaveta O Mamedova ◽  
Anastasia M Lapshina ◽  
Vilen N Azizyan ◽  
Andrey Y Grigoriev ◽  
...  
Keyword(s):  
Pituitary Adenomas ◽  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Cytoplasmic Expression ◽  
Men 1 ◽  
Endocrine Neoplasia ◽  
Group 3 ◽  
Group 2 ◽  
Group 1

Abstract Introduction: Multiple endocrine neoplasia type 1 syndrome (MEN 1) is caused by mutations in MEN1 gene, encoding menin protein. A combination of pituitary adenomas (PA) and primary hyperparathyroidism (PHPT) in patients without MEN1 mutations is defined as MEN 1 phenocopy. The aim of the study is to find if there are any differences in menin expression in PA of patients with genetically confirmed MEN 1, MEN 1 phenocopies and sporadic acromegaly. Materials and Methods: Formalin-fixed paraffin-embedded PA tissues were obtained from 9 genetically confirmed MEN 1 patients (group 1), 12 patients with MEN 1 phenocopies (a combination of PA and PHPT) (group 2) and 14 patients with sporadic acromegaly (group 3). The integrity of the tissues was tested by immunohistochemistry (IHC) using antibodies against the nuclear protein Pit-1. MEN1 mutations were confirmed or excluded by Sanger sequencing or by NGS (NextSeq550, Illumina, USA). Expression of menin was assessed using IHC (Anti-Menin antibody — ChIP Grade, Abcam, UK). Results: The distribution of PA by the type of secretion in group 1 was: 3 — ACTH-secreting, 2 — PRL-secreting, 2 — GH+PRL, 1 — TSH+PRL, 1 — ACTH+PRL, 1 — silent gonadotroph adenoma. All 12 PA from group 2 were GH-secreting. All 14 PA in group 3 were GH-secreting without mixed secretion. The median age at the moment of transsphenoidal surgery in group 1 was 35 years [27; 47], in group 2 — 59 years [56; 65], in group 3 — 56 years [53; 62]. There were 2 men and 7 women in group 1; 2 men and 10 women in group 2; 4 men and 10 women in group 3. In group 1 patients did not receive somatostation analogues (SSA), 7 patients received cabergoline. In group 2 seven patients received SSA, in group 3 — 4 patients received SSA, 2 patients received cabergoline. The results of menin staining were (negative staining/positive cytoplasmic staining/positive nuclear staining): group 1 — 4/4/0; group 2 — 0/11/1; group 3 — 1/7/6. Phenocopy group showed significantly more cytoplasmic expression of menin than in MEN 1 group (p<0.008). MEN 1 group also differed from sporadic acromegaly group by nuclear expression of menin (p<0.015). No statistical significance between sporadic and phenocopy groups was found (p=0.07). Although there were no differences among these groups, the group 2 showed weak nuclear expression only in one case, while in group 3 the menin staining was present both in the nucleus and cytoplasm in equal proportions. Conclusion: Menin expression is generally preserved in PA in MEN 1 phenocopies and sporadic acromegaly, though with different pattern of nuclear and cytoplasmic expression, while its expression varies in PA in MEN 1. These findings suggest that pathogenesis of PA in MEN 1 phenocopies and sporadic acromegaly may have similarities. The mechanisms of co-occurrence of PA and PHPT in MEN 1 phenocopies are poorly understood and epigenetic modifications downstream menin interacting pathways could play a role.

Multiple endocrine neoplasia type 1

2011 ◽  
pp. 945-950
Author(s):  
R.V. Thakker
Keyword(s):  
Family History ◽  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Endocrine Glands ◽  
Men 1 ◽  
Men 2 ◽  
Endocrine Neoplasia ◽  
Endocrine Neoplasia Type

Multiple endocrine neoplasia (1, 2) is characterized by the occurrence of tumours involving two or more endocrine glands within a single patient. The disorder has previously been referred to as multiple endocrine adenopathy (MEA) or the pluriglandular syndrome. However, glandular hyperplasia and malignancy may also occur in some patients and the term multiple endocrine neoplasia (MEN) is now preferred. There are two major forms of multiple endocrine neoplasia, referred to as type 1 and type 2, and each form is characterized by the development of tumours within specific endocrine glands (Table 6.11.1). Thus, the combined occurrence of tumours of the parathyroid glands, the pancreatic islet cells, and the anterior pituitary is characteristic of multiple endocrine neoplasia type 1 (MEN 1), which is also referred to as Wermer’s syndrome. However, in multiple endocrine neoplasia type 2 (MEN 2), which is also called Sipple’s syndrome, medullary thyroid carcinoma (MTC) occurs in association with phaeochromocytoma, and three clinical variants, referred to as MEN 2a, MEN 2b and MTC-only, are recognized (Table 6.11.1). Although MEN 1 and MEN 2 usually occur as distinct and separate syndromes as outlined above, some patients occasionally may develop tumours that are associated with both MEN 1 and MEN 2. For example, patients suffering from islet cell tumours of the pancreas and phaeochromocytomas or from acromegaly and phaeochromocytoma have been described, and these patients may represent ‘overlap’ syndromes. All these forms of MEN may either be inherited as autosomal dominant syndromes or they may occur sporadically, i.e. without a family history. However, this distinction between sporadic and familial cases may sometimes be difficult as in some sporadic cases the family history may be absent because the parent with the disease may have died before developing symptoms. In this chapter, the main clinical features and molecular genetics of the MEN 1 syndrome will be discussed.

scholarly journals Absence of Germ-Line Mutations of the Multiple Endocrine Neoplasia Type 1 (MEN1) Gene in Familial Pituitary Adenoma in Contrast to MEN1 in Japanese1

1998 ◽  
Vol 83 (3) ◽  
pp. 960-965
Author(s):  
Chisato Tanaka ◽  
Katsuhiko Yoshimoto ◽  
Shozo Yamada ◽  
Hiroshi Nishioka ◽  
Setsuko Ii ◽  
...  
Keyword(s):  
Pituitary Adenoma ◽  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Germ Line ◽  
Men1 Gene ◽  
Men 1 ◽  
Endocrine Neoplasia ◽  
Endocrine Neoplasia Type ◽  
Germ Line Mutations

Germ-line mutations of the MEN1 gene were analyzed in five cases of familial and four cases of sporadic multiple endocrine neoplasia type 1 (MEN-1), six cases in three independent pedigrees of familial pituitary adenoma without MEN-1, and three cases of familial isolated primary hyperparathyroidism (FIHP) in Japanese. Eight different types of germ-line mutations in all nine cases of MEN-1 were distributed in exons 2, 3, 7, and 10 and intron 7 of the MEN1 gene. Loss of heterozygosity (LOH) on 11q13 was detected in all nine tumors of these cases with microsatellite analysis. No germ-line mutation of the MEN1 gene was detected in three pedigrees of familial pituitary adenoma and three cases of FIHP. LOH on 11q13 was detected in two cases in one pedigree of familial pituitary adenoma, and one of them showed a heterozygous somatic mutation of the MEN1 gene. No LOH on 11q13 was detected in three cases of FIHP. Based on these, we conclude that the loss of function of menin is etiological for familial or sporadic MEN-1, but not for FIHP or most familial pituitary adenoma without MEN-1.

scholarly journals Role of miR-24 in Multiple Endocrine Neoplasia Type 1: A Potential Target for Molecular Therapy

2021 ◽  
Vol 22 (14) ◽  
pp. 7352
Author(s):  
Francesca Marini ◽  
Maria Luisa Brandi
Keyword(s):  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Current Knowledge ◽  
Neuroendocrine Cells ◽  
Molecular Therapy ◽  
Multiple Cancer ◽  
Men1 Gene ◽  
Endocrine Neoplasia ◽  
Endocrine Neoplasia Type

Multiple endocrine neoplasia type 1 (MEN1) is a rare autosomal dominant inherited multiple cancer syndrome of neuroendocrine tissues. Tumors are caused by an inherited germinal heterozygote inactivating mutation of the MEN1 tumor suppressor gene, followed by a somatic loss of heterozygosity (LOH) of the MEN1 gene in target neuroendocrine cells, mainly at parathyroids, pancreas islets, and anterior pituitary. Over 1,500 different germline and somatic mutations of the MEN1 gene have been identified, but the syndrome is completely missing a direct genotype-phenotype correlation, thus supporting the hypothesis that exogenous and endogenous factors, other than MEN1 specific mutation, are involved in MEN1 tumorigenesis and definition of individual clinical phenotype. Epigenetic factors, such as microRNAs (miRNAs), are strongly suspected to have a role in MEN1 tumor initiation and development. Recently, a direct autoregulatory network between miR-24, MEN1 mRNA, and menin was demonstrated in parathyroids and endocrine pancreas, showing a miR-24-induced silencing of menin expression that could have a key role in initiation of tumors in MEN1-target neuroendocrine cells. Here, we review the current knowledge on the post-transcriptional regulation of MEN1 and menin expression by miR-24, and its possible direct role in MEN1 syndrome, describing the possibility and the potential approaches to target and silence this miRNA, to permit the correct expression of the wild type menin, and thereby prevent the development of cancers in the target tissues.

scholarly journals Germline MEN1 mutations in sixteen Japanese families with multiple endocrine neoplasia type 1 (MEN1)

1999 ◽  
pp. 475-480 ◽  
Author(s):  
N Hai ◽  
N Aoki ◽  
A Matsuda ◽  
T Mori ◽  
S Kosugi
Keyword(s):  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Family Members ◽  
Premature Stop Codon ◽  
Germline Mutations ◽  
Endocrine Tumors ◽  
Men1 Gene ◽  
Endocrine Neoplasia ◽  
Endocrine Neoplasia Type

OBJECTIVE: Multiple endocrine neoplasia type 1 (MEN1) is a syndrome of endocrine tumors involving the parathyroids, anterior pituitary and enteropancreatic neuroendocrine tissues, and is inherited in an autosomal dominant manner. Recently, the gene responsible for this syndrome, MEN1, was positionally cloned in 11q13. We aimed to assess the significance of MEN1 gene diagnostics in families with MEN1. DESIGN: Sixteen probands of familial MEN1 and their 40 family members were subjected to the study. METHODS: Full-length sequencing of the open reading frame and exon-intron boundaries in the MEN1 gene was performed with probands of familial MEN1. Family members were examined for the identified mutation in the proband. RESULTS: We identified heterozygous germline mutations of the MEN1 gene in all of 16 Japanese MEN1 families examined, achieving the highest detectability of MEN1 mutations in familial MEN1 among studies that examined more than 10 families. Eleven kinds of the identified MEN1 germline mutations were novel. More than half were nonsense or frameshift mutations resulting in a premature stop codon (9/15; 60%), and no mutation hot spots or no apparent genotype-phenotype relationships were observed, in support of the results of other studies. We identified 40 mutant MEN1 gene carriers and 16 non-carriers in the course of the present study in those families. CONCLUSIONS: Analysis of the germline mutations in the MEN1 gene, providing significantly useful clinical information to probands and family members of MEN1, should be considered as a standard procedure and categorized as belonging to Group 1 cancer predisposition testing by the American Society of Clinical Oncology.

scholarly journals Multiple endocrine neoplasia type 1 (MEN1) gene mutations in a subset of patients with sporadic and familial primary hyperparathyroidism target the coding sequence but spare the promoter region

2000 ◽  
Vol 166 (1) ◽  
pp. 1-9 ◽  
Author(s):  
W Karges ◽  
K Jostarndt ◽  
S Maier ◽  
A Flemming ◽  
M Weitz ◽  
...  
Keyword(s):  
Multiple Endocrine Neoplasia ◽  
Multiple Endocrine Neoplasia Type ◽  
Germ Line ◽  
Single Strand Conformational Polymorphism ◽  
Coding Sequence ◽  
Men1 Gene ◽  
Endocrine Neoplasia ◽  
Endocrine Neoplasia Type ◽  
Germ Line Mutations

Germ line mutations of the multiple endocrine neoplasia type 1 (MEN1) tumour suppressor gene cause MEN1, a rare familial tumour syndrome associated with parathyroid hyperplasia, adenoma and hyperparathyroidism (HP). Here we investigated the role of the MEN1 gene in isolated sporadic and familial HP. Using RT-PCR single-strand conformational polymorphism screening, somatic (but not germ line) mutations of the MEN1 coding sequence were identified in 6 of 31 (19.3%) adenomas from patients with sporadic primary HP, but none in patients (n=16) with secondary HP due to chronic renal failure. MEN1 mutations were accompanied by a loss of heterozygosity (LOH) for the MEN1 locus on chromosome 11q13 in the adenomas as detected by microsatellite analysis. No DNA sequence divergence within the 5' region of the MEN1 gene, containing the putative MEN1 promoter, was detectable in HP adenomas. Clinical characteristics were not different in HP patients with or without MEN1 mutation. Heterozygous MEN1 gene polymorphisms were identified in 9.6% and 25% of patients with primary and secondary HP respectively. In a large kindred with familial isolated familial HP, MEN1 germ line mutation 249 del4 and LOH was associated with the HP phenotype and a predisposition to non-endocrine malignancies. We suggest that the bi-allelic somatic loss of MEN1 wild-type gene expression is involved in the pathogenesis of a clinically yet undefined subset of sporadic primary HP adenomas. MEN1 genotyping may further help define the familial hyperparathyroidism-MEN1 disease complex, but it seems dispensable in sporadic primary HP.

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