Expression of MMP14 in invasive pituitary adenomas: relationship to invasion and angiogenesis

Pituitary adenomas (PAs) are noncancerous tumors, and about 35% of those reported to be invasive have been classified as “invasive pituitary adenomas (IPAs)”. In clinical, operative complications, total resection failures, and high relapse rates result from invasive features during the therapeutic process. Invasive mechanism is a complex process, including metalloproteases, inhibitors and tumor microenvironment factors etc. Thus, studying invasive mechanism of PAs might contribute to understanding its biological behavior. In our research, three type tissue samples of human, pituitaries, PAs, IPAs, their mRNA expression of MMP1, MMP2, MMP9, MMP14 and MMP15 were measured using real-time PCR. MMP2 and MMP14 protein levels also were measured with immunohistochemistry in same samples. We confirmed that elevated matrix metalloproteinase-14 expression correlates with invasive characteristics of IPAs. To investigate molecular mechanism of how MMP14 contributes to invasiveness, an ATT20 cell was used in this study. After transient-transfection of the MMP14-shRNA expression vector into ATT20 cells, we observed that mRNA expression of PTTG, VEGF, and TGFβ was significantly suppressed in interference groups. Meanwhile, ATT20 cells in high concentration TIMP-1 environment exhibit reduced PTTG, VEGF, and TGFβ expression accompanied with the down-regulation of MMP14. Thus, we propose that MMP14 plays an important role in tumor invasion and angiogenesis and that a novel regulatory pathway for MMP14 may exist through VEGF and PTTG. In brief, MMP14 may be a target for therapeutic treatment.     

Pituitary carcinoma with intraspinal metastasis: report of two cases and review of the literature

Pituitary carcinomas are rare malignant neoplasms with diagnostic and management challenges. Patients with pituitary carcinomas have extremely poor outcomes. In this report, the authors describe two cases of pituitary carcinomas with intraspinal metastasis (Case 1: 42-year-old man with a history of pituitary adenoma 16 years ago developed an intraspinal lesion at C4-C5; Case 2: 26-year-old women with a history of growth hormone-producing pituitary adenoma 9 years ago developed intraspinal lesion in the sacral canal). Both patients underwent spine surgery. The intraspinal lesions were confirmed as metastatic pituitary carcinomas based on the histomorphology and immunohistochemical stains. The authors reviewed the literature for the diagnosis, treatment, and prognosis of intraspinal metastasis from pituitary carcinomas.     

Histochemical Analysis of Laminin α Chains in Diethylstilbestrol-Induced Prolactinoma in Rats

Laminin, a major basement membrane component, is important in structural support and cell proliferation and differentiation. Its 19 isoforms are assemblies of α, β, and γ chains, and the α chains (α1-5) determine the isoform characteristics. Although our previous studies showed alterations in α chain expressions during anterior pituitary development, their expressions in pituitary tumors yet to be determined. The present study used a rat model of diethylstilbestrol (DES)-induced prolactinoma to examine α chain expressions during prolactinoma tumorigenesis (0–12 weeks of DES treatment) by in situ hybridization and immunohistochemistry. mRNA of α1, α3, and α4 chains was detected in control and after 4 weeks of DES treatment. These expressions were undetectable after 8 weeks of DES treatment and in prolactinoma (12 weeks of DES treatment). Immunohistochemistry showed that the α1 chain was localized in some anterior pituitary cells in control and after 4 weeks of treatment and in endothelial cells after 8 weeks of treatment. The α3 and α4 chains were expressed in endothelial cells, and immunoreactivity and the number of immunopositive cells decreased during DES treatment. These findings suggest that alteration of laminin α chains is related to abnormal cell proliferation and neovascularization during development of DES-induced prolactinoma.     

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Background: As the pituitary gland develops, signals from the hypothalamus are necessary for pituitary induction and expansion. Little is known about the control of cues that regulate early signaling between the two structures. Ligands and receptors of the Notch signaling pathway are found in both the hypothalamus and Rathke's pouch. The downstream Notch effector gene Hes1 is required for proper pituitary formation; however, these effects could be due to the action of Hes1 in the hypothalamus, Rathke's pouch, or both. To determine the contribution of hypothalamic Notch signaling to pituitary organogenesis, we used mice with loss and gain of Notch function within the developing hypothalamus. Results: We demonstrate that loss of Notch signaling by conditional deletion of Rbpj in the hypothalamus does not affect expression of Hes1 within the posterior hypothalamus or expression of Hes5. In contrast, expression of activated Notch within the hypothalamus results in ectopic Hes5 expression and increased Hes1 expression, which is sufficient to disrupt pituitary development and postnatal expansion. Conclusions: Taken together, our results indicate that Rbpj‐dependent Notch signaling within the developing hypothalamus is not necessary for pituitary development, but persistent Notch signaling and ectopic Hes5 expression in hypothalamic progenitors affects pituitary induction and expansion. Developmental Dynamics 244:921–934, 2015. © 2015 Wiley Periodicals, Inc.     

Ultrastructural Characteristics of TSH-Producing Adenomas with Special Reference to its Close Similarity to BFA-Treated Pituitary Adenoma Cells

Two of 420 patients with pituitary adenoma who underwent operation from 1989 to 1997 had thyroid stimulating hormone (TSH) producing adenoma. We investigated these TSH cell adenomas with immunohistochemical and ultrastructural methods and compared their ultrastructural features with brefeldin A (BFA, 0.5 mg/ml) treated pituitary adenoma cells. BFA-treated pituitary adenomas include a prolactin (PRL) cell adenoma, a growth hormone (GH) cell adenoma, an adrenocorticotropic hormone (ACTH) cell adenoma, a gonadotroph adenoma, and a plurihormonal adenoma. Immunohistochemical staining disclosed that one of the TSH cell adenomas produced only TSH-;bgr and that another produces both TSH-b and FSH-b. Ultrastructural analysis showed the abundance of oval-shaped dilated rough endoplasmic reticulum (rER). Within the dilated rER, the mistlike deposit or deposit along the inner margin of the rER membrane was observed. On the other hand, BFA-treated cultured pituitary adenoma cells showed the opening of the cavity of the rER cisterna and they enlarged to an oval form with time and revealed an accumulation of electron-dense deposits within the dilated rER. These ultrastructural similarities between TSH cell adenoma and BFA-treated pituitary adenoma cells indicate the functional disturbances in the secretory passage through the Golgi apparatus in TSH cell adenoma cells.     

黄色瘤样垂体炎MRI表现:病例报告及文献复习

黄色瘤样垂体炎临床上极少见.1例33岁女性患者,因头痛、视力障碍、停经入院,实验室内分泌学检查提示皮质功能减退;MRI检查表现为鞍区占位,T1WI呈等信号,T2WI为略高信号,增强后病变明显均匀强化,垂体柄增粗,视交叉被向上推压移位,左侧海绵窦受侵,肿块包绕左侧颈内动脉,冠状位上略呈“三角形”.术前诊断为垂体腺瘤,在全身麻醉下行鞍区及鞍上占位病变切除术+视神经减压术,病理检查表现为镜下见间质泡沫细胞、淋巴浆细胞、粒细胞明显增生,支持黄色瘤样垂体炎.黄色瘤样垂体炎的MRI表现有一定的特征性,其最典型的MRI特点是垂体柄增粗及由于增粗的垂体柄、侵犯海绵窦而在MRI冠状位上表现为“三角形”.分析其影像学特点有助于提高诊断的准确性及选择适宜的治疗方案.