Zhang Yazhuo

The expression of TGF-β1, Smad3, phospho-Smad3 and Smad7 is correlated with the development and invasion of nonfunctioning pituitary adenomas

BackgroundTransforming growth factor β (TGF-β) signaling functions as a suppressor or a promoter in tumor development, depending on the tumor stage and type. However, the role of TGF-β signaling in nonfunctioning pituitary adenomas (NFPAs) has not been explored.MethodsTGF-β1, Smad2, phospho-Smad2 (p-Smad2), Smad3, phospho-Smad3 (p-Smad3), Smad4, and Smad7 were detected in 5 cases of normal anterior pituitaries, 29 cases of invasive NFPAs, and 21 cases of noninvasive NFPAs by real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR), Western blot, and immunohistochemical analysis.ResultsThe Smad3 and p-Smad3 protein levels gradually decreased from normal anterior pituitaries, noninvasive NFPAs, to invasive NFPAs. However, there were no significant differences in Smad2 (P = 0.122) and p-Smad2 protein levels (P = 0.101) or Smad2 mRNA level (P = 0.409). In addition, the TGF-β1 mRNA level gradually decreased while the Smad7 mRNA level gradually increased from normal anterior pituitaries, noninvasive NFPAs, to invasive NFPAs. Furthermore, proliferating cell nuclear antigen (PCNA) mRNA level was markedly increased in invasive NFPAs compared to noninvasive ones (P < 0.01), and its level was negatively correlated with Smad3 mRNA level (P < 0.01).ConclusionThe activity of TGF-β signaling may be restrained in NFPAs and is correlated with the development and invasion of NFPAs.

Protein Phosphatase 2A is Involved in the Tyrosine Hydroxylase Phosphorylation Regulated by α-Synuclein

Abstractα-Synuclein (α-Syn) plays a crucial role in the pathophysiology of Parkinson’s disease (PD), the degeneration of dopaminergic neurons. Previous studies have shown that α-Syn regulates dopamine synthesis by binding to and inhibiting tyrosine hydroxylase (TH). In neurons, protein phosphatases (PPs) play a prominent role in directing signaling toward survival or degeneration. This study was to re-evaluate whether α-Syn could regulate the tyrosine hydroxylase phosphorylation by protein phosphatase-2A (PP2A) in dopaminergic MN9D cells and cortex neurons. Our data demonstrated for the first time that α-Syn stimulates PP2A activity and reduces phosphorylation of TH through regulating the methylation of PP2A in dopaminergic MN9D cells and primary cortex neurons. Increased PP2A activity and reduced phosphorylation of PP2A at Y307 (inactive form of PP2A) were observed in α-Syn overexpression dopaminergic cells (Syn) and primary cortex neurons, and the TH phosphorylation relieved by enhancing PP2A methylation in Syn group could be abated by using PP inhibitors, okadaic acid (OKA). OKA could reduce the cell damage and cell apoptosis induced by α-Syn. Thus our findings may provide an insight into the complicated pathogenesis of PD as well as some clues to the development of novel therapeutic strategies targeting at PP2A.

Study on mirnas’ expression for the invasion of pituitary adenomas

AIM To explore the possible invasive effect of four microRNAs in invasive pituitary adenomas. MATERIAL AND METHODS Based on our previous studies, several in silico algorithms, and relative literatures, 30 Han Chinese patients with invasive pituitary adenomas and 30 with non-invasive pituitary adenomas were involved in this research. The proteins related to invasion underwent immunohistochemical staining, including basic fibroblast growth factor (FGF2), pituitary tumor transforming gene (PTTG), cyclin B1 (CCNB1), survivin, focal adhesion kinase (FAK), and microvessel density (MVD). To validate the effect of microRNAs, miR-24, miR-93, miR-126, and miR-34a were chosen as possible targets for the aforementioned proteins with four in silico algorithms. All microRNAs tests were performed using quantitative real-time polymerase chain reaction (qPCR). RESULTS In our study, FGF2, FAK, PTTG, CCNB1, and MVD were overexpressed in the invasive group compared with the non-invasive group, while an increase in the expression of survivin in the invasive group did not achieve statistical significance. This paper reviewed the literature, and four microRNAs involving invasion were selected for study: miR-24, miR-34a, miR-93, and miR-126. Under-expression of miR-24, miR-34a, and miR-93 was significant in the invasive group, while a decrease of miR-126 expression in the invasive group did not achieve statistical significance. CONCLUSION FGF2, PTTG, CCNB1, survivin, FAK, and MVD proteins of pituitary adenoma showed strong expression in invasive tumors. Furthermore, miR-24, miR-93, miR-34a, and miR-126 were under-expressed in invasive Pituitary adenomas compared with non-invasive ones. The results indicated some relationship between the miRNA and protein expression during the pituitary invasion process.AIM To explore the possible invasive effect of four microRNAs in invasive pituitary adenomas. MATERIAL AND METHODS Based on our previous studies, several in silico algorithms, and relative literatures, 30 Han Chinese patients with invasive pituitary adenomas and 30 with non-invasive pituitary adenomas were involved in this research. The proteins related to invasion underwent immunohistochemical staining, including basic fibroblast growth factor (FGF2), pituitary tumor transforming gene (PTTG), cyclin B1 (CCNB1), survivin, focal adhesion kinase (FAK), and microvessel density (MVD). To validate the effect of microRNAs, miR-24, miR-93, miR-126, and miR-34a were chosen as possible targets for the aforementioned proteins with four in silico algorithms. All microRNAs tests were performed using quantitative real-time polymerase chain reaction (qPCR). RESULTS In our study, FGF2, FAK, PTTG, CCNB1, and MVD were overexpressed in the invasive group compared with the non-invasive group, while an increase in the expression of survivin in the invasive group did not achieve statistical significance. This paper reviewed the literature, and four microRNAs involving invasion were selected for study: miR-24, miR-34a, miR-93, and miR-126. Under-expression of miR-24, miR-34a, and miR-93 was significant in the invasive group, while a decrease of miR-126 expression in the invasive group did not achieve statistical significance. CONCLUSION FGF2, PTTG, CCNB1, survivin, FAK, and MVD proteins of pituitary adenoma showed strong expression in invasive tumors. Furthermore, miR-24, miR-93, miR-34a, and miR-126 were under-expressed in invasive Pituitary adenomas compared with non-invasive ones. The results indicated some relationship between the miRNA and protein expression during the pituitary invasion process.

Aberrant expression of the sFRP and WIF1 genes in invasive non-functioning pituitary adenomas

Non-functioning pituitary adenomas (NFPAs) are the most common pituitary tumors and mainly invade the sphenoid, cavernous sinus or dura mate. Aberrant regulation of the Wnt signaling pathway plays an important role in tumorigenesis. This study was designed to investigate the relationships between secreted frizzled-related proteins (sFRPs), WIF1 genes and the invasion of NFPAs by tissue microassays (TMAs) of samples from 163 patients. Significantly weaker staining of WIF1 and sFRP4 were detected in the invasive group compared with the non-invasive group by TMAs (p = 0.002, p < 0.001). Univariate analysis showed a significant correlation between tumor invasion and low expression of WIF1 and sFRP4 (p = 0.002, p < 0.001). A similar trend was observed when analyzing the mRNA and protein levels through RT-PCR and western blot experiments. Methylation of the WIF1 promoter was significantly increased in invasive NFPAs compared with the noninvasive group (p = 0.004). The average progression free survival time in the high WIF1 group was longer than that in the low WIF1 group (p = 0.025). Furthermore, RT-PCR measured the levels of 11 miRNAs targeting WIF1 according to the Targetscan database and PubMed. The levels of miRNA-137, miRNA-374a-5p and miRNA-374b-5p in the invasive group were 0.037-fold, 0.577-fold and 0.44-fold that of the noninvasive group (p = 0.003, p = 0.049 and p = 0.047). Overexpression of miRNA-137 could inhibit the proliferation and invasion of GH3 cells through cell viability and Transwell experiments (p < 0.05). Furthermore, the WIF1 level was upregulated after overexpression of miRNA-137 compared with miRNA-137-NC (control miRNA) in GH3 cells. Our data suggest that WIF1 may be potential biomarker for the aggressiveness of NFPAs. miRNA-137 plays an important role in the Wnt signaling pathway by affecting promoter methylation of WIF1.

The role of NR2C2 in the prolactinomas

Abstract Prolactinomas are the most frequently observed pituitary adenomas. Prolactinomas invasion is a key risk factor associated with operation results, and it is highly correlated with clinical prognosis. Nuclear receptor subfamily 2 group C member 2 (NR2C2) first cloned from testis is involved in the invasion and metastasis of several human tumors. In 46 patients with prolactinamas, the expression levels of CCNB1, Notch2, and NR2C2 was determined with tissue micro-array (TMA). The association between NR2C2 levels and clinical parameters was established with univariate analysis. The levels of Notch2 and CCNB1 were analyzed by RT-PCR and western blot techniques.The average methylation levels of the NR2C2 promoter were 0.505 and 0.825 in invasive prolactinomas (IPA) and non-IPA groups, respectively (p = 0.013). Univariate analysis also showed that there is a significant relationship between high NR2C2 expression and invasion (x2 = 7.043, p = 0.008), prolactin granules (x2 = 8.712, p = 0.003), and tumor size (x2 = 4.261, p = 0.039.) With the knockdown of NR2C2, cell proliferation was inhibited. Genes related to epithelial-mesenchymal transition (EMT) induced the apoptosis in MMQ cells. In addition, the level of Notch2 and CCNB1 were down-regulated with the knockdown of NR2C2. Moreover, miR-129-5p reduced mRNA levels of NR2C2, and they inhibited cell proliferation by inducing apoptosis levels of MMQ cells. Our findings proved NR2C2 played the important role in tumorigenesis tumor invasion of prolactinomas; moreover, NR2C2 is identified as a potential target.

Detection of circulating tumor cells in patients with pituitary tumors

BackgroundCirculating tumor cells (CTCs) are tumor cells that have shed from a primary tumor and circulate in the peripheral blood. Recent experimental and clinical studies show that CTCs can be detected in early-stage disease.Case presentationWe report three cases of pituitary adenoma (PA) in which tumor cells with particles were detected in the interstitial vascular compartment by transmission electron microscopy. Tumors were completely resected. Immunohistochemical analysis showed a β-catenin score of 10.5 ± 1.5 in the three cases with CTCs compared with 2.4 ± 0.5 in 24 control adenomas. The Ki-67 labeling index was 2.1 ± 0.7 in CTCs vs. 0.2 ± 0.3 in control cases (p = 0.043), and the p53 score was 4.33 ± 1.3 vs. 0.31 ± 0.17 (p = 0.000). The E-cadherin score did not differ significantly between the two groups.ConclusionsCTCs can be detected in benign tumors such as PAs and not only in late-stage malignant tumors with apparent distant metastases. The present findings suggest that pituitary carcinomas develop from adenomas.

Malignant Transformation of Radiotherapy-Naïve Craniopharyngioma

BACKGROUND Craniopharyngioma is a rare benign intracranial neoplasm that is successfully managed with surgery or adjuvant radiotherapy. The malignant transformation of craniopharyngioma has seldom been reported. CASE DESCRIPTION A 30-year-old woman presented with a 5-month history of amenorrhea and was admitted to the hospital. She underwent surgical resection for three times and died at last. MRI revealed a new solid component of craniopharyngioma. Pathologic examination revealed malignant changes in the craniopharyngioma. In addition, We analyzed the expression of Ki-67, p53, VEGF, and MMP-9 in this malignant case after the third operation and in samples from 9 benign craniopharyngiomas. Immunohistochemical analysis showed that the Ki-67 index was higher in malignant craniopharyngiomas (50%) compared with benign craniopharyngiomas (3.0% ± 1.5%; range, 1.0%-6.0%). The p53, MMP-9, and VEGF protein levels were higher in the malignant craniopharyngioma compared with the benign craniopharyngiomas. CONCLUSIONS Patients with a high Ki-67 index and high p53, MMP-9, and VEGF protein levels and a new solid component of craniopharyngioma on MRI may benefit from aggressive treatment and close surveillance.