Aryl hydrocarbon receptor-interacting protein (AIP) is associated with 15-20 % of familial isolated pituitary adenomas and 50-80 % of cases with AIP mutation exhibit a somatotropinoma. Herein we report clinical characteristics of a large family where AIP R304X variants have been identified. AIP mutation analysis was performed on a large (n = 52) Turkish family across six generations. Sella MRIs of 30 family members were obtained. Basal pituitary hormone levels were evaluated in 13 family members harboring an AIP mutation. Thirteen of 52 family members (25 %) were found to have a heterozygous nonsense germline R304X mutation in the AIP gene. Seven of the 13 mutation carriers (53.8 %) had current or previous history of pituitary adenoma. Of these 7 mutation carriers, all but one had somatotropinoma/somatolactotropinoma (85.7 % of the pituitary adenomas). Of the 6 acromegaly patients with AIP mutation (F/M: 3/3) the mean age at diagnosis of acromegaly was 32 ± 10.3 years while the mean age of symptom onset was 24.8 ± 9.9 years. Three of the six (50 %) acromegaly cases with AIP mutation within the family presented with a macroadenoma and none presented with gigantism. Biochemical disease control was achieved in 66.6 % (4/6) of the mutation carriers with acromegaly after a mean follow-up period of 18.6 ± 17.6 years. Common phenotypic characteristics of familial pituitary adenoma or somatotropinoma due to AIP mutation vary between families or even between individuals within a family.

Somatostatin is a natural inhibitor of growth hormone, and its analogues are clinically used for the therapy of acromegaly, gigantism, thyrotropinoma, and other carcinoid syndrome. However, natural somatostatin is limited for clinical usage because of its short half-life in vivo. Albumin fusion technology was used to construct long-acting fusion proteins, and Pichia pastoris was used as an expression system. Three fusion proteins, (somatostatin (SS)14)2-human serum albumin (HSA), (SS14)3-HSA, and HSA-(SS14)3, were constructed with different fusion copies of somatostatin-14 and fusion orientations. The expression level of (SS14)3-HSA and HSA-(SS14)3 was much lower than (SS14)2-HSA due to the additional fusion of the somatostatin-14 molecule. Matrix-assisted laser desorption ionization-time-of-flight mass spectrometry revealed that severe degradation occurred in the fermentation process. Similar to the standard of somatostatin-14, all three fusion proteins were able to inhibit growth hormone secretion in the blood, with (SS14)2-HSA being the most effective one. On the whole, (SS14)2-HSA was the most effective protein in both production level and bioactivity, and increasing the number of small protein copies fused to HSA may not be a suitable method to improve the protein bioactivity.

Acromegaly and gigantism are due to excess GH secretion, usually by a pituitary adenoma. It is an uncommon disease. Diagnosis is made by showing elevated GH and IGF-I levels in patients with a clinical picture suggesting the condition. Once excess GH is confirmed by biochemical tests, MRI of the hypothalamic-pituitary area should be performed to ascertain the source of excess GH. Transsphenoidal surgery of the pituitary adenoma is the treatment of choice. However, introduction of new drugs has changed the treatment sequence in recent years. Medical treatment with somatostatin analogues may be indicated as primary treatment in patients in whom surgery is not expected to be curative or is contraindicated. The GH receptor antagonist should be use in patients not controlled after surgery who do not adequately respond to somatostatin analogues. Radiotherapy would be indicated in patients not controlled after surgery and medical treatment or with large tumor remnants after surgery.

: A 7'3″ basketball player was noted to have 2 to 3 times thicker tissue in his hands than 6'10″ players by an endocrinologist sitting 10 rows above the player in a basketball arena. This led to the diagnosis of pituitary gigantism where the history revealed that he was 7'3″ at 15 years of age. At age 19 when the acryl enlargement was noted, a diagnostic workup revealed elevated growth hormones and insulin-like growth factor 1 (IGF-1) with a 2 × 1.3 cm pituitary tumor. His history suggested that his epiphyseal plates had closed at age 15, and because he continued to produce IGF-1, he now has acromegaly. His elevated adrenocorticotropic hormone (ACTH) before surgery suggests that he also had preclinical Cushing's disease. After pituitary transsphenoidal surgery, all acryl enlargement in hands and ligaments disappeared. His growth hormone, IGF-1 and ACTH returned to normal 2 weeks after surgery.

The somatostatin analog lanreotide Autogel has proven to be efficacious for treating acromegaly in international studies and in clinical practices around the world. However, its efficacy in Japanese patients has not been extensively evaluated. We examined the dose-response relationship and long-term efficacy and safety in Japanese patients with acromegaly or pituitary gigantism. In an open-label, parallel-group, dose-response study, 32 patients (29 with acromegaly, 3 with pituitary gigantism) received 5 injections of 60, 90, or 120 mg of lanreotide Autogel over 24 weeks. Four weeks after the first injection, 41% of patients achieved serum GH level of <2.5 ng/mL and insulin-like growth factor-I (IGF-I) level was normalized in 31%. Values at Week 24 were 53% for GH and 44% for IGF-I. Dose-dependent decreases in serum GH and IGF-I levels were observed with dose-related changes in pharmacokinetic parameters. In an open-label, long-term study, 32 patients (30 with acromegaly, 2 with pituitary gigantism) received lanreotide Autogel once every 4 weeks for a total of 13 injections. Dosing was initiated with 90 mg and adjusted according to clinical responses at Weeks 16 and/or 32. At Week 52, 47% of patients had serum GH levels of <2.5 ng/mL and 53% had normalized IGF-I level. In both studies, acromegaly symptoms improved and treatment was generally well tolerated although gastrointestinal symptoms and injection site induration were reported. In conclusion, lanreotide Autogel provided early and sustained control of elevated GH and IGF-I levels, improved acromegaly symptoms, and was well tolerated in Japanese patients with acromegaly or pituitary gigantism.

Mutations of the aryl hydrocarbon receptor interacting protein (AIP) have been associated with familial isolated pituitary adenomas predisposing to young-onset acromegaly and gigantism. The precise tumorigenic mechanism is not well understood as AIP interacts with a large number of independent proteins as well as three chaperone systems, HSP90, HSP70 and TOMM20. We have determined the structure of the TPR domain of AIP at high resolution, which has allowed a detailed analysis of how disease-associated mutations impact on the structural integrity of the TPR domain. A subset of C-terminal α-7 helix (Cα-7h) mutations, R304* (nonsense mutation), R304Q, Q307* and R325Q, a known site for AhR and PDE4A5 client-protein interaction, occur beyond those that interact with the conserved MEEVD and EDDVE sequences of HSP90 and TOMM20. These C-terminal AIP mutations appear to only disrupt client-protein binding to the Cα-7h, while chaperone binding remains unaffected, suggesting that failure of client-protein interaction with the Cα-7h is sufficient to predispose to pituitary adenoma. We have also identified a molecular switch in the AIP TPR-domain that allows recognition of both the conserved HSP90 motif, MEEVD, and the equivalent sequence (EDDVE) of TOMM20.

Growth hormone is of vital importance for normal growth and development. Individuals with growth hormone deficiency develop pituitary dwarfism with disproportionate delayed growth of skull and facial skeleton giving them a small facial appearance for their age. Both hyper and hypopituitarism have a marked effect on development of oro-facial structures including eruption and shedding patterns of teeth, thus giving an opportunity to treating dental professionals to first see the signs and symptoms of these growth disorders and correctly diagnose the serious underlying disease.

Familial GH-secreting tumors are seen in association with three separate hereditary clinical syndromes: multiple endocrine neoplasia type 1, Carney complex, and familial isolated pituitary adenomas.

Acromegaly and gigantism are due to excess GH production, usually as a result of a pituitary adenoma. The incidence of acromegaly is 5 cases per million per year and the prevalence is 60 cases per million. Clinical manifestations in each patient depend on the levels of GH and IGF-I, age, tumor size, and the delay in diagnosis. Manifestations of acromegaly are varied and include acral and soft tissue overgrowth, joint pain, diabetes mellitus, hypertension, and heart and respiratory failure. Acromegaly is a disabling disease that is associated with increased morbidity and reduced life expectancy. The diagnosis is based primarily on clinical features and confirmed by measuring GH levels after oral glucose loading and the estimation of IGF-I. It has been suggested that the rate of mortality in patients with acromegaly is correlated with the degree of control of GH. Adequately treated, the relative mortality risk can be markedly reduced towards normal.