Celastrol Induces Apoptosis and Autophagy via the AKT/mTOR Signaling Pathway in the Pituitary ACTH-secreting Adenoma Cells

Objective Pituitary adrenocorticotropic hormone(ACTH)-secreting adenoma is a relatively intractable endocrine adenoma that can cause a range of severe metabolic disorders and pathological changes involving multiple systems.Previous studies have shown that celastrol has antitumor effects on a variety of tumor cells via the AKT/mTOR signaling.However,whether celastrol has pronounced antitumor effects on pituitary ACTH-secreting adenoma is unclear.This study aimed to identify a new effective therapeutic drug for pituitary ACTH-secreting adenoma.Methods Mouse pituitary ACTH-secreting adenoma cells(AtT20 cells)were used as an experimental model in vitro and to establish a xenograft tumor model in mice.Cells and animals were administered doses of celastrol at various levels.The effects of celastrol on cell viability,migration,apoptosis and autophagy were then examined.Finally,the potential involvement of AKT/mTOR signaling in celastrol’s mechanism was assessed.Results Celastrol inhibited the proliferation and migration of pituitary adenoma cells in a time-and concentration-dependent manner.It blocked AtT20 cells in the G0/G1 phase,and induced apoptosis and autophagy by downregulating the AKT/mTOR signaling pathway.Similar results were obtained in mice.Conclusion Celastrol exerts potent antitumor effects on ACTH-secreting adenoma by downregulating the AKT/mTOR signaling in vitro and in vivo.

miR-200b-3p accelerates progression of pituitary adenomas by negatively regulating expression of RECK

MicroRNA(miR)-200b-3p has been associated with many tumors,but its involvement in pituitary adenoma is unclear.This study investigated the molecular mechanism underlying miR-200b-3p regulation in pituitary adenomas to provide a theoretical basis for treatment.Bioinformatics was used to analyze pituitary adenoma-related genes and screen new targets related to RECK and miRNA.As well,the relationship between miR-200b-3p and RECK protein was verified using a double-luciferase reporter gene assay.The expression of miR-200b-3p in clinical samples was analyzed by in situ hybridization.Transfection of the miR-200b-3p inhibitor and small interfering-RECK(si-RECK)was verified by qPCR.GH3 cell viability and proliferation were detected using CCK8 and EdU assays.Apoptosis was detected by flow cytometry and western blotting.Wound healing and Transwell assays were used to detect cell migration and invasion.The effects of miR-200b-3p and RECK on GH3 cells were verified using salvage experiments.miR-200b-3p was highly expressed in pituitary tumor tissue.Inhibitors of miR-200b-3p inhibited cell proliferation promoted cell apoptosis,inhibited invasion and migration,and inhibited the expression of matrix metalloproteinases.Interestingly,miR-200b-3p negatively regulated RECK.The expression of RECK in pituitary adenoma tissues was lower than that in neighboring tissues.Si-RECK rescued the function of miR-200b-3p inhibitors in the above cellular behaviors,and miR-200b-3p accelerated the development of pituitary adenoma by negatively regulating RECK expression.In summary,this study investigated the molecular mechanism by which miR-200b-3p regulates the progression of pituitary adenoma through the negative regulation of RECK.The findings provide a new target for the treatment of pituitary adenoma.

Relationship Between Histopathology and Clinical Prognosis of Invasive Pituitary Adenoma

Objective: To study the relationship between histopathology and clinical prognosis of invasive pituitary adenoma subjected to transsphenoidal surgery. Methods: The enrolled were 82 patients with invasive pituitary adenomas undergoing transsphenoidal surgery during Jan. 2000 - May 2003 in our department with full MR imaging findings, pathology data and follow-up information. The follow-up duration was 5-30 months. Results: MR imaging findings of invasive pituitary adenoma included: depression of the sellar floor, involvement of sphenoid sinus and cavernous sinus, breakthrough of diaphragma sellae, encasement of internal carotid artery, etc. Pathological examination revealed that the invasion rate of dura in sella turcica was the highest among the structures around tumor. Pituitary adenoma apoplexy was found in 20 cases (24.4%). The total removal rate for PRL-secreting adenomas was significantly lower than that for non-secreting adenomas (P<0.01), but non-, GH-, ACTH-secreting adenomas had no significant differences. The recurrence rate of PRL-secreting adenomas was higher than that of non- and GH-secreting adenomas (P<0.05). Conclusion: Among invasive pituitary adenomas, the therapeutic effects of non-and GH-secreting pituitary adenomas are better than that of PRL-secreting adenomas. Invasive biological behaviors of invasive pituitary adenomas result in radical operation failure and postoperative recurrence.

Magnetic Resonance Imaging and Biological Markers in Pituitary Adenomas with Invasion of the Cavernous Sinus Space

Objective: To investigate the predictability of MRI and the possiblebiological markers of cavernous sinus invasion of pituitary adenomas associated with fourphenomenas: angiogenesis, cell proliferation, apoptosis and matrix metalloproteinase. Methods: Weevaluated 45 patients with pituitary adenoma according to the MRI, surgical findings and theimmunohistochemistry staining of tumor tissues. Results: The results have shown that the sensitivityof MRI for predicting cavernous sinus invasion in this prospective study was 60%, its specificity85%, its positive predictive value 83.33%, negative predictive value 62.96%. 45 specimens ofpituitary adenomas were analyzed for expression of F8, VEGF, Ki-67, c-myc, Bcl-2, nm23 and MMP-9immunoreactivity using immunoperoxidase staining. MVD was assessed using F8-related antigen. Theresults have shown that MVD of invasive pituitary adenomas was significantly higher than that ofnoninvasive (P 【 0.001). There was an association between the invasion of pituitary adenomas andKi-67 LI (P = 0.039) or the expression of VEGF (P 【 0.001) and MMP-9 (P 【 0.001). But c-myc LI andBcl-2 expression have no association with invasiveness of pituitary adenomas (P = 0.061 versus P =0.201). On the other hand, there is an inverse relationship between nm23 expression and tumorinvasion (P 【 0.001). Conclusion: Parasellar extension of pituitary adenomas through the medial wallof the cavernous sinus is diagnosed at surgery, and with sensitive gadolinium-enhanced MRI, itsextent can be partly determined by radiology. Although our study has shown that MVD and theexpression of VEGF, Ki-67, nm23 and MMP-9 have associations with invasiveness of pituitary adenomas,they are lack of specificity. These markers can only provide some useful information.

Down-regulation of Leucine-rich Repeats and Immunoglobulin-like Domain Proteins (LRIG1-3) in HP75 Pituitary Adenoma Cell Line

Three human leucine-rich repeats and immunoglobulin-like domains （LRIG） genes and proteins, named LRIG1-3, has been previously characterized and it was proposed that they may act as suppressors of tumor growth. The LRIG1 protein can inhibit the growth of tumors of glial cells and the down-regulation of the LRIG1 gene may be involved in the development and progression of the tumor. Real-time reverse transcription-polymerase chain reaction （RT-PCR） is a recently developed technique for quantitative assessment of specific RNA levels. In the current study, it was demonstrated that LRIG1-3 and EGFR mRNA was detected in human pituitary adenoma cell lines and a normal pituitary sample, with differences in the expression levels. Compared to the normal pituitary samples, the expression of LRIG1-3 in HP75 cell line was lower, but the expression of EGFR in HP75 cell line was higher. The results are consistent with LRIG1-3 being tumour suppressor genes, and LRIG genes decreasing the expression of EGFR. The ratio of EGFR/LRIGl was increased at least 13-fold in HP75 cells compared with the normal pituitary cells, which was also the case for the ratio of EGFR/LRIG2 （14-fold increase in HP75） and EGFR/LRIG3 （11-fold increase in HP75）. Further studies were needed to elucidate the explicit role of LRIG genes as negative regulators of oncogenesis in human pituitary adenoma.

Study on the Expression Levels of CXCR4, CXCL12, CD44, and CD147 and Their Potential Correlation with Invasive Behaviors of Pituitary Adenomas

Objective To evaluate the factors of CXCR4, CXCL12, CD44, and CD147 as early potential diagnostic biomarkers by determining their expression levels in invasive and non-invasive pituitary adenomas. Methods Fresh pituitary adenoma specimens were collected from 35 pituitary adenoma （21 invasive and 14 non-invasive） patients who underwent surgical treatment in our Neurosurgery Department between January and April of 2009. The expression levels of CXCR4, CXCL12, CD44, and CD147 were evaluated firstly by flow cytometry, fluorescence microscopy in single cell suspensions, and then by immunohistochemical staining of paraffin tissue sections. Results Flow cytometric analyses showed that the percentage of CXCR4- and CXCL12-positive cells from invasive pituitary adenomas （IPA） was significantly higher in the single cell suspensions than that from non-invasive pituitary adenomas （nlPA） （P〈O.05）. Immunohistochemical staining revealed that CXCR4 and CXCL12 staining index scores of the invasive pituitary adenomas were significantly higher than those of the non-invasive pituitary adenomas （P〈O.05）. In contrast, neither flow cytometry nor immunohistochemical staining demonstrated significant difference between CD44 and CD147 expression levels, respectively. Conclusion Expression levels of CXCR4 and CXCL12 are correlated with the invasiveness of pituitary adenomas. Therefore, rather than CD44 and CD147, CXCR4 and CXCL12 may potentially serve as biomarkers for early detection of pituitary adenomas.

Neuroendoscopic and microscopic transsphenoidal approach for resection of nonfunctional pituitary adenomas

BACKGROUND Nonfunctional pituitary adenoma is a common type of pituitary adenoma, which can lead to headache, visual field disturbance, and cranial nerve damage due to increased tumor volume. Neuroendoscopic and microscopic transsphenoidal approaches have been widely used in the resection of nonfunctional pituitary adenomas. However, the clinical efficacy in neuroendoscopic and microscopic surgery is still controversial. AIM To explore the clinical efficacy of neuroendoscopic and microscopic transsphenoidal approach for resection of nonfunctional pituitary adenomas. METHODS We retrospectively analyzed 251 patients with nonfunctional pituitary adenomas;138 underwent neuroendoscopic surgery via transsphenoidal approach, and 113 underwent microscopic surgery via transsphenoidal approach between July 2010 and September 2015. All patients were followed up for > 6 mo. Gender, age, course of disease, tumor diameter, tumor location, and percentage of patients with headache, visual impairment, sexual dysfunction, and menstrual disorders were contrasted between the two groups to compare the difference of preoperative data. Cure rate, symptom improvement rate, recurrence rate, the postoperative hospital stay, operating time, intraoperative blood loss, and the incidence of postoperative complications were compared in order to evaluate the advantages and disadvantages of neuroendoscopic and microscopic surgery.RESULTS There was no significant difference in cure rate, symptom improvement rate, and recurrence rate between neuroendoscopy group and microscopy group (82.6% vs 85.8%, P > 0.05;90.6% vs 93.8%, P > 0.05;5.1% vs 9.7%, P > 0.05). In the neuroendoscopy group, the postoperative hospital stay was 8.4 ± 0.6 d;operating time was 167.2 ± 9.6 min;intraoperative blood loss was 83.4 ± 9.3 mL, and the rates of diabetes insipidus and electrolyte imbalance were 4.3% and 8.0%, respectively. The corresponding results in the microscopic group were 11.2 ± 0.6 d, 199.7 ± 9.3 min, 138.8 ± 13.6 mL, and 32.7% and 20.4%, respectively. There were significant differences in postoperative hospital stay, operating time, intraoperative blood loss, and the rates of diabetes insipidus and electrolyte imbalance between the two groups (P < 0.05). CONCLUSION Neuroendoscopic and microscopic transsphenoidal approaches have similar clinical efficacy for the resection of nonfunctional pituitary adenomas. Neuroendoscopic surgery reduces operating time, intraoperative bleeding, postoperative recovery, and complications.

Association of Expression of Leucine-rich Repeats and Immunoglobulin-like Domains 2 Gene with Invasiveness of Pituitary Adenoma

The Leucine-rich repeats and immunoglobulin-like domains-2（LRIG2） gene expression in pituitary adenoma and its correlation with tumor invasiveness were studied.The expression of LRIG2 mRNA and protein in human pituitary adenoma obtained surgically was detected by RT-PCR（39 cases） and immunohistochemical staining（30 cases）.It was found that LRIG2 was mostly localized at the nucleus of the pituitary adenoma cells.Its expression was significantly higher in the invasive cases than in the non-invasive cases.LRIG2 protein was positive in 14 cases out of 21 cases of invasive adenoma,but only 2 cases were positive in 9 cases of non-invasive adenoma.The positive expression rate of LRIG2 mRNA was 91.3% in invasive cases（total 23 cases） and 62.5% in non-invasive cases（total 16 cases）,respectively.LRIG2 gene is overexpressed in invasive pituitary adenoma.It may play an important role in pituitary adenoma invasiveness and further studies are necessary to elucidate the mechanism under this phenomenon.

MAGNETIC RESONANCE IMAGING CHARACTERISTICS AND SURGICAL RESULTS OF ADRENOCORTICOTROPIN-SECRETING PITUITARY ADENOMAS

Objective To evaluate magnetic resonance imaging （MRI） characteristics and surgical results of adrenocorticotropin （ACTH） -secreting pituitary adenomas. Methods MRI characteristics and relationship between MRI positive rate and surgical results of 266 patients with pathologically confn＇med Cushing＇s disease were analyzed retrospectively. All patients underwent thin-section sagittal and coronal scans of the pituitary gland before and after administration of gadolinium-diethylene triamine pentaacetic acid （Gd-DTPA） on a 1. 5 Tesla MR/scanner, and dynamic enhanced MR/was performed in 39 patients. All patients underwent transsphenoidal adenomectomy. Endocrinological examinations and assessments were performed. Results Preoperative MR/revealed normal results in 41 （ 15.4% ） cases, microadenoma in 179 （67. 3% ）, macroadenoma in 42 （ 15.8% ）, and huge adenoma in 4 （ 1.5% ）. Pituitary apoplexy was found in 13 （4.9%） cases. Positive rate of ACTH-secreting adenomas was 84.6% （225/266） on MR/scans, and that of small microadenomas was 87.2% （34/39） on dynamic enhanced MRI scans. Preoperative endocrinological tests of 199 cases supported the diagnosis of typical Cushing＇s disease, while the other 67 cases had atypical endocrinological results. The endocrinological cure rate, remission rate, and inefficacy rate were 85.7%, 7.9%, and 6. 4%, respectively. There was no difference in the initial endocrinological cure rate between the patients with positive and normal MRI results （90% vs. 87. 8%, P =0. 904）. Conclusions Enhanced coronal pituitary MR/ is helpful for preoperative localization of ACTH-secreting pituitary microadenoma. Dynamic enhanced MR/may improve detection rate of microadenoma. There is no marked difference in the surgical results for patients with preoperative MR/results indicating presence or absence of microadenoma.

Hormone Secretion by Cell Culture of Human GH-PRL Secreting Pituitary Adenomas: Effects of Bromocriptine

Dopamine agonists effectively reduce the secretion of prolactin (PRL) in the great majority of prolactinomas and reduce the bulk of the adenomas, as well as have partial therapeutic effect on some patients with acromegaly. The inhibitory effect of bromocriptine (BC), a dopamine agonist, on growth hormone (GH) and PRL secretion of dispersed cells from the pituitary adenomas of 16 cases of acromegaly, which secret GH and PRL simultaneously, were evaluated in vitro. The significant inhibitory effects of BC on PRL secretion were found in 12 cases. It was also found that PRL secretion was strongly inhibited when GH was suppressed; on the contrary, when GH secretion was not suppressed, the production of PRL was not or weakly inhibited. The exact mechanism of the effects is nuclear so far. It is necessary to investigate, at molecular level, the etiology of GH-PRL adenomas and its response to therapeutic agents.

Over-expression of LRIG1 Suppresses Biological Function of Pituitary Adenoma via Attenuation of PI3K/AKT and Ras/Raf/ERK Pathways In Vivo and In Vitro

Pituitary adenomas（PAs） are well known as a common intracranial benign tumor, and a portion of PAs are refractory to current therapeutic methods. Erb B receptors family signaling pathway regulates the expression of PAs activation associated gene. Inhibition of epidermal growth factor receptor（EGFR） can inhibit proliferation of PAs. Leucine-rich repeats and immunoglobulin-like domains protein 1（ LRIG1）, a negative mediated gene of Erb B receptors family, plays a role in many tumors. However, there are seldom researches about the functional role of LRIG1 in PAs. The aim of this study is to explore the potential effect of LRIG1 and its regulating mechanism in PAs. First, we investigated the role of LRIG1 in cell migration, invasion of PAs with transfected LRIG1 or control. Then, we explored its impact on cell proliferation and apoptosis of PAs in vivo. To study the regulating mechanism of LRIG1, we examined the expression of molecular factor of PI3K/AKT and Ras/Raf/ERK pathway using Western blotting in vitro and RT-PCR in vitro and in vivo. It was found that LRIG1 over-expression inhibited cell migration, invasion and proliferation, and promoted apoptosis of PAs in vivo and in vitro. Furthermore, LRIG1 suppressed the expression of signaling of PI3K/AKT and Ras/Raf/ERK pathways in PAs. LRIG1, as a negative mediated gene of tumor, can inhibit biological function of PAs via inhibiting PI3K/AKT and Ras/Raf/ERK pathways, and it might be a new target for gene therapy of PAs.

Factors influencing improvement of visual field after trans-sphenoidal resection of pituitary macroadenomas:a retrospective cohort study

AIM: To investigate the influencing factors of visual field improvement after trans-sphenoidal resection of pituitary macroadenomas. METHODS: This retrospective cohort study included 201 patients (366 eyes) with visual field defect induced by pituitary macroadenomas. All of them were treated with trans-sphenoidal surgery. Ophthalmologic evaluation, best -corrected visual acuity (BCVA), and visual field examination were performed before and 3mo after surgery. BCVA, visual field defect index mean deviation (MD), duration of symptoms, age, sex, and volume of tumors were compared. Expression of vascular endothelial growth factor (VEGF) and Ki-67 of tumor tissue were detected by immunohistochemical technique. RESULTS: The mean age of patients was 44.23 +/- 1.29y. Ninety -three patients were female and 108 were male. The mean tumor volume was 14.36 +/- 6.23 cm(3). The mean duration of preoperative symptoms was 11.50 +/- 0.88mo. Mean preoperative MD was -17.50 +/- 0.82 dB. Mean Preoperative visual acuity was 0.64 +/- 0.04. Postoperative visual field improved in 270 (73.77%) eyes, unchanged in 96 (26.23%) eyes. Multivariate logistic regression displayed that the factors independently influencing visual field improvement were young age (OR=1.71, 95%CI: 1.325-2.387, P=0.013), low preoperative MD absolute value (OR=1.277, 95%CI: 1.205-1.355, P<0.001), small volume of tumor (OR=1.458, 95%CI: 1.060-4.289, P<0.001), low expression of VEGF in tumor tissue (OR=1.554, 95%CI: 1.089-2.457, P=0.022), and low expression of Ki-67 in tumor tissue (OR=1.552, 95%CI: 1.161-2.847, P=0.026). CONCLUSION: After pituitary macroadenomas trans sphenoidal resection, the independent influencing factors of the visual fields recovery were low preoperative MD absolute value, young age, small volume of tumor, and expression levels of VEGF/Ki-67.

Identification of CDK6 and RHOU in Serum Exosome as Biomarkers for the Invasiveness of Non-functioning Pituitary Adenoma

Objective To explore circulating biomarkers for screening the invasiveness of non-functioning pituitary adenomas(NF-PAs).Methods The exosomal RNAs were extracted from serum of patients with invasive NF-PA(INF-PA)or noninvasive NF-PA(NNF-PA).Droplet digital PCR was adapted to detect the mRNA expression of candidate genes related to tumor progression or invasion,such as cyclin dependent kinase 6(CDK6),ras homolog family member U(RHOU),and spire type actin nucleation factor 2(SPIRE2).Student’s t-test was used to analyze the statistical difference in the mRNA expression of candidate genes between the two groups.Receiver operating characteristic(ROC)curve was used to establish a model for predicting the invasiveness of NF-PAs.The accuracy,sensitivity,specificity and precision of the model were then obtained to evaluate the diagnostic performance.Results CDK6(0.2600±0.0912 vs.0.1789±0.0628,t=3.431,P=0.0013)and RHOU mRNA expressions(0.2696±0.1118 vs.0.1788±0.0857,t=2.946,P=0.0052)were upregulated in INF-PAs patients’serum exosomes as compared to NNF-PAs.For CDK6,the area under the ROC curve(AUC)was 0.772(95%CI:0.600-0.943,P=0.005),the accuracy,sensitivity,specificity and precision were 77.27%,83.33%,75.00%and 55.56%to predict the invasiveness of NF-PAs.For RHOU,the AUC was 0.757(95%CI:0.599-0.915,P=0.007),the accuracy,sensitivity,specificity and precision were 72.73%,83.33%,68.75%and 50.00%.In addition,the mRNA levels of CDK6 and RHOU in serum exosomes were significantly positively correlated(r=0.935,P<0.001).After combination of the cut-off scores of the two genes,the accuracy,sensitivity,specificity and precision were 81.82%,83.33%,81.25%and 62.50%.Conclusions CDK6 and RHOU mRNA in serum exosomes can be used as markers for predicting invasiveness of NF-PAs.Combination of the two genes performs better in distinguishing INF-PAs from NNF-PAs.These results indicate CDK6 and RHOU play important roles in the invasiveness of NF-PAs,and the established diagnostic method is valuable for directing the clinical screening and postoperative treatment.

ELEVATED SOLUBLE EPIDERMAL GROWTH FACTOR RECEPTOR LEVEL IN PITUITARY ADENOMA AND CARCINOMA

To investigate effect of the soluble epidermal growth factor receptor (sEGFR/sErbB1) level in the periph-eral blood in development, invasiveness, apoplexy of each type of pituitary tumor. Methods The sEGFR level was determined in peripheral serum from 190 patients with pituitary diseases by enzyme linked immunosobent assay. The sEGFR levels were measured in 10 pituitary Rathke’s pouch, 18 pituitary hyperplasia, 161 pituitary adenomas including 30 microadenomas, 83 large adenomas, 48 giant adenomas, 1 pituitary carcinoma, and 28 hea-lthy controls. Results In the patients with pituitary hyperplasia, microadenoma, large adenoma, giant adenoma, and pituitary carci-noma, the sEGFR level was 188.92 ± 32.62, 209.83 ± 19.01, 333.20 ± 69.33, 405.85 ± 37.38, and 617.45 fmol/mL indepen-dently. They were all significantly higher than patients with pituitary Rathke’s pouch (156.78 ± 18.24 fmol/mL, P < 0.001) and healthy control group (159.11 ± 40.50 fmol/mL, P < 0.05). The sEGFR level in pituitary carcinoma was higher than pi-tuitary adenoma. In patients with pituitary adenoma, the sEGFR level was positive correlated to the size of pituitary adeno-mas (r = 0.998), the significant difference was observed for the sEGFR level in each group of the patients with pituitary adenomas (P < 0.001). Furthermore, in patients with pituitary ACTH-secreting microadenomas, the serum sEGFR levels in invasiveness (295.00 ± 77.80 fmol/mL) was higher than that in non-invasiveness (210.60 ± 16.4 fmol/mL, P < 0.05). In pati-ents with pituitary ACTH-secreting, PRL-secreting, GH-secreting, and non-functioning large adenomas, the serum sEGFR levels in invasiveness (407.86 ± 28.50, 399.25 ± 30.10, 386.00 ± 13.08, and 369.25 ± 36.70 fmol/mL) was higher than that in non-invasiveness (335.25 ± 63.49, 300.64 ± 47.57, 297.00 ± 61.93, and 269.30 ± 25.68 fmol/mL) respectively (P < 0.05). In patients with invasive pituitary PRL-secreting, GH-secreting, and non-functioning giant adenomas, the serum sEGFR levels not significantly different in between invasiveness (417.50 ± 35.94, 409.50 ± 69.14, and 417.50 ± 44.13 fmol/mL) and non-invasiveness (386.00 ± 49.64, 417.50 ± 44.03, and 409.51 ± 35.17 fmol/mL) (P > 0.05). In patients with pituitary large adeno-mas, the sEGFR levels in pituitary apoplexy (377.48 ± 39.18 fmol/mL) was higher than that in non-pituitary apoplexy (343.18 ± 68.17 fmol/mL, P > 0.05). Conclusions The increased level of peripheral serum sEGFR is concomitant with development, proliferous size of the adenomas in patients with pituitary adenomas. In addition, the elevated levels of serum sEGFR occur in pituitary apoplexy as clinical active tumors, and the non-invasive ACTH secreting adenomas. The sEGFR levels could be differen-tiated helpfully between pituitary adenomas and non-pituitary adenomas. These data suggest that serum sEGFR could be as a referable marker of the size and activation of proliferation in pituitary adenoma.

EFFECT OF PREOPERATIVE USE OF LONG-ACTING OCTREOTIDE ON GROWTH HORMONE SECRETING PITUITARY ADENOMA AND TRANSSPHENOIDAL SURGERY

Objective To investigate whether somatostatin analog octreotide long acting release (LAR) shrinks growth hormone (GH) secreting adenomas, and improves the results of subsequent transsphenoidal surgery. Methods Seventeen previously untreated active acromegalic patients with pituitary adenomas were treated with LAR (30 mg intramuscular injection every 28 days) for 3 months prior to transsphenoidal surgery. Clinical reaction, mean GH secretion, and tumor volume were measured under basal conditions and after LAR treatment. Results Presurgical treatment improved acromegaly symptoms and induced a significant reduction of GH under the 5 ng/mL limit in microadenoma (P < 0.05), while only 18.2% (2/11) in macroadenoma. Meanwhile, tumor shrinkage occurred in 58.8% (10/17) patients, with 1 case in the microadenoma group. All marked shrinkage (> 25%) occurred in the macroadenoma group. Statistical analysis showed tumor shrinkage caused by LAR was greater in macroadenoma group than that in microadenoma group (P < 0.05). During operation, adenoma was soft in 15 cases, with the exception of 2 cases in which the soft tumor was divided by fibrous septa, but all tumor removal was smooth. Conclusions A short term administration of preoperative LAR may induce a significant decrease in GH-secretion level and adenoma volume. Presurgical use of octreotide LAR improves surgical results especially in macroadenomas.

Simultaneous rectal neuroendocrine tumors and pituitary adenoma:A case report and review of literature

BACKGROUND Neuroendocrine tumors(NET)are rare heterogeneous tumors that arise from neuroendocrine cells throughout the body.Acromegaly,a rare and slowly progressive disorder,usually results from a growth hormone(GH)-secreting pituitary adenoma.CASE SUMMARY We herein describe a 38-year-old patient who was initially diagnosed with diabetes.During colonoscopy,two bulges were identified and subsequently removed through endoscopic submucosal dissection.Following the surgical intervention,the excised tissue samples were examined and confirmed to be grade 2 NET.^(18)F-ALF-NOTATATE positron emission tomography-computed tomography(PET/CT)and 68Ga-DOTANOC PET/CT revealed metastases in the peri-intestinal lymph nodes,prompting laparoscopic low anterior resection with total mesorectal excision.The patient later returned to the hospital because of hyperglycemia and was found to have facial changes,namely a larger nose,thicker lips,and mandibular prognathism.Laboratory tests and magnetic resonance imaging(MRI)suggested a GH-secreting pituitary adenoma.The pituitary adenoma shrunk after treatment with octreotide and was neuroendoscopically resected via a trans-sphenoidal approach.Whole-exome sequencing analysis revealed no genetic abnormalities.The patient recovered well with no evidence of recurrence during follow-up.CONCLUSION ^(18)F-ALF-NOTATE PET/CT and MRI with pathological analysis can effectively diagnose rare cases of pituitary adenomas complicated with rectal NET.

Sudden Sensorineural Hearing Loss after Pituitary Adenoma Resection-A Case Series with Literature Review

Objective Complications after transsphenoidal surgery for pituitary adenoma have been well documented in the literatures,but the occurrence of delved sudden sensorineural hearing loss(SNHL)after pituitary adenoma resection is extremely rare.In this study three cases who developed sudden SNHL 3 to 7 days after pituitary adenoma surgery without experiencing cerebrospinal fluid leak or meningitis were presented,and the possible causes of SNHL were discussed.Methods Three cases with sudden hearing loss after transsphenoidal surgery for pituitary adenoma were reviewed.The past medical history,onset of sudden hearing loss,accompanying symptoms such as headache,tinnitus,dizziness and aural fullness,and the post-operative MRI images,therapy and hearing results were reported.Results Three cases developed profound sudden SNHL on the 3rd to 7th post-operative day,all accompanied by prior headache,tinnitus and dizziness.One patient developed episodic vertigo,ear fullness accompanying with fluctuating hearing loss in the first post-operative month.Two patients had past medical history of arteriosclerosis and coronary heart disease or cerebral infarction.Two of three demonstrated obstructive hydrocephalus on MRI on the first post-operative day.Under treatment with prednisone orally,dexamethasone intratympanic mjection,neurotrophic and vasodilatation drugs for 3 to 8 months,hearing of all three improved partially.Obstructive hydrocephalus and ischemia might be responsible for the hearing loss.Conclusion Post-operative obstructive hydrocephalus and ischemia of labyrinthine arteries might lead to the delayed SNHL after transsphenoidal surgery for pituitary adenoma.

Expression of second mitochondria-derived activator of caspases, X-linked inhibitor of apoptosis protein, and caspase-3 in pituitary adenomas

Studies concerning correlations between pituitary adenomas and cell apoptosis have mainly focused on upstream apoptosis signaling, but seldom on downstream mediators. In the present study, second mitochondria-derived activator of caspases （Smac）, X-linked inhibitor of apoptosis protein （XIAP）, and caspase-3 protein were qualitatively analyzed using immunohistochemistry, and quantified by western blot. Smac, XIAP, and caspase-3 mRNA expressions were detected by reverse transcription-PCR. Results showed that XIAP protein and mRNA expressions were greater in the invasive pituitary adenoma group compared with the noninvasive pituitary adenoma group. However, Smac and caspase-3 protein and mRNA expressions were lower in the invasive pituitary adenoma group compared with the noninvasive pituitary adenoma group. In the invasive pituitary adenomas, Smac expression was positively correlated with caspase-3 protein and mRNA expression （Protein： r = 0.55, P 0.01; mRNA： r = 0.50, P 0.01）. Smac and caspase-3 expressions were negatively correlated with XIAP protein and mRNA expression （Protein： r = -0.56, -0.64, P 0.01; mRNA： r = -0.69, -0.67, P 0.01）. However, no significant differences in correlation among Smac, XIAP, and caspase-3 were detectable in noninvasive pituitary adenomas. These data indicated that high expression of XIAP and low expression of Smac and caspase-3 suppressed cell apoptosis and led to enhanced invasiveness of pituitary adenomas. Thus, Smac, XIAP, and caspase-3 may be useful markers in determining the invasive behavior of pituitary adenomas.

Expression of Neuropeptide Y in Human Pituitary Adenoma

OBJECTIVE Neuropeptide Y （NPY） acts as a neuroendocrine modulator in the anterior pituitary, and NPY mRNA and NPY-immunoreactivity have been detected in normal human anterior pituitaries. However, only a few studies of NPY expression in human pituitary adenomas have been published. Our study was conducted to determine whether or not adenomatous cells express NPY, to investigate the relationship between NPY expression and the subtypes of pituitary adenoma and to explore the clinical significance of NPY. METHODS The study included tissues from 58 patients with pituitary adenomas who underwent surgery because of their clinical diagnosis. Using a highly specific anti-NPY polyclonal antibody, immunohistochemical analysis was performed on the surgically removed pituitary adenomas. Six fresh specimens also were examined using immuno-electron microscopy. NPY was labeled with colloidal gold in order to study the distribution of NPY at the subcellular level. RESULTS The NPY expression level was significantly different among subgroups of pituitary adenomas （P〈0.05）. NPY was immuno-detected in 58.6% of all adenomas, in 91.7% of gonadotrophic adenomas and in 14.3% of prolactinomas. NPY expression was slightly lower in invasive pituitary adenomas compared to noninvasive adenomas, but the difference was not significant （t=1.81, P〉0.05）. Of particular interest was the finding that vascular endothelial cells showed positive NPY expression in some pituitary adenomas. Parts of strongly positive tumor cells were seen in channels formed without endothelial cells, but which contained some red blood cells in a formation similar to so-called vasculogenic mimicry. Immuno-electron microscopy demonstrated that 4 of the 6 fresh specimens displayed positive NPY staining with a high density of gold particles located mainly in the secretory granulas. In addition, gold particles were sparsely detected in the rough endoplasmic reticulum and cell matrix. CONCLUSION NPY exists in pituitary adenomas and its expression level was related to the types and biological characteristics of the pituitary adenomas. NPY may have a depressive effect on tumor cellular proliferation in pituitary adenomas. NPY possibly participates in modulating angiogenesis and hemodynamic changes in pituitary adenomas.

The Expression of Integrinβ1 and FAK in Pituitary Adenomas and Their Correlation with Invasiveness

The expression and possible role of integrin-focal adhesion kinase signal pathway in invasive pituitary adenomas were explored. Forty-nine human pituitary adenomas were detected for the expression of integrinβ1 （INTβ1） and focal adhesion kinase （FAK） by immunohistochemistry, and their correlation with the invasiveness of pituitary adenomas as well as between themselves was ana- lyzed. The results showed that INTβ1 was expressed in 46 cases （93.9%） and FAK in 36 cases （73.5%）, respectively, and their expression levels were highly correlated with tumor invasiveness, but not with the tumor types. It was suggested that the integrin-focal adhesion kinase signal pathway plays a role in the invasiveness of pituitary adenomas.