scholarly journals Akt/p27kip1 Pathway Is Not Involved in Human Insulinoma Tumorigenesis

2018 ◽  
Vol 2018 ◽  
pp. 1-5
Author(s):  
Adriana Graciela Díaz ◽  
Andrea Paes de Lima ◽  
Paula Garibaldi ◽  
Maria de los Milagros Rubio ◽  
Florencia García ◽  
...  
Keyword(s):  
Normal Tissue ◽  
Islet Cells ◽  
Polyclonal Antibodies ◽  
Akt Pathway ◽  
Cyclin D ◽  
Predominant Form ◽  
Human Insulinoma ◽  
Paraffin Tissue ◽  
Intracellular Pathway ◽  
Low Rate

Insulinomas are pancreatic neuroendocrine tumors (pNET), usually benign. Akt/p27kip1 is an intracellular pathway overexpressed in many pNET. There are no data regarding its expression in human insulinomas. We aimed to investigate the expression of Akt and p27kip1 in 24 human insulinomas and to compare them to their expression in normal surrounding islets. Staining was performed on embedded paraffin tissue using polyclonal antibodies against total Akt, p-Akt, p27kip1, and pp27kip1. p-Akt was the predominant form in insulinomas; they presented lower Akt and p-Akt expression than normal islets in 83.3% and 87.5% of tumors, respectively. p27kip1 and pp27kip1 were mainly cytoplasmic in both insulinomas and normal tissue. Cytoplasmic pp27kip1 staining was higher in insulinomas and surprisingly nearly half of the insulinomas also presented nuclear p27kip1 (p=0.029). No differences were observed in the subcellular localization of p27kip1 and activation of Akt between benign and malignant insulinomas. The low expression of Akt seen in insulinomas might explain the usual benign behavior of this type of pNET. Cytoplasmic p27kip1 in both insulinomas and normal islet cells could reflect the low rate of replication of beta cells, while nuclear p27kip1 would seem to indicate stabilization and nuclear anchoring of the cyclin D-Cdk4 complex. Our data seem to suggest that the Akt pathway is not involved in human insulinoma tumorigenesis.

Immunohistochemical localization of the 1,25(OH)2D3 receptor and calbindin D28k in human and rat pancreas

1994 ◽  
Vol 267 (3) ◽  
pp. E356-E360 ◽  
Author(s):  
J. A. Johnson ◽  
J. P. Grande ◽  
P. C. Roche ◽  
R. Kumar
Keyword(s):  
Beta Cells ◽  
Pancreatic Beta Cells ◽  
Biochemical Characterization ◽  
Islet Cells ◽  
Polyclonal Antibodies ◽  
Pancreatic Tissue ◽  
Exocrine Pancreatic Function ◽  
Pancreatic Islet Cell ◽  
Rat Pancreas ◽  
Calbindin D28k

1,25-Dihydroxyvitamin D3 [1,25(OH)2D3] is required for normal glucose-stimulated insulin release from pancreatic beta-cells. Biochemical characterization techniques have demonstrated the presence of the 1,25(OH)2D3 receptor (VDR) in homogenates of whole pancreas. Autoradiographic studies using radiolabeled 1,25(OH)2D3 suggest that the VDR is localized to beta-cells but are inconclusive. We used immunohistochemical techniques to stain serial sections from both human and rat pancreas with polyclonal antibodies to human VDR, chick calbindin D28k, insulin, glucagon, and somatostatin. VDR was present in the islet cells and also at low levels in acinar cells of the human and rat pancreas. Calbindin D28k was distributed in a manner similar to the VDR in pancreatic islets but was not present in acini. These results show for the first time that VDR and calbindin D28k are present in human pancreatic tissue. VDR and calbindin D28k are focally distributed throughout pancreatic islet cell types in humans and rats; VDR is also present in the exocrine pancreas. These findings suggest that 1,25(OH)2D3 may influence both endocrine and exocrine pancreatic function.

Silver Staining of Pancreatic Islets as Revealed by Electron Microscopy

1967 ◽  
Vol 25 ◽  
pp. 44-45
Author(s):  
Kazuaki Misugi ◽  
Nobuko Misugi ◽  
Hiroshi Yamada
Keyword(s):  
Pancreatic Islet ◽  
Silver Staining ◽  
Islet Cells ◽  
Severe Hypoglycemia ◽  
Granular Cell ◽  
Electron Microscopic Level ◽  
Staining Reaction ◽  
Electron Microscopic ◽  
Pancreatic Islet Cell ◽  
D Cell

The authors had described the fine structure of a type of pancreatic islet cell, which appeared different from typical alpha and beta cells, and tentatively considered that this third type of granular cell probably represents the D cell (Figure 1).Since silver staining has been widely used to differentiate different types of pancreatic islet cells by light microscopy, an attempt to examine this staining reaction at the electron microscopic level was made.Material and Method: Surgically removed specimens from three infants who suffered from severe hypoglycemia were used. The specimens were fixed and preserved in 20% neutral formalin. Frozen sections, 30 to 40 micron thick, were prepared and they were stained by Bielschowsky's method as modified by Suzuki (2). The stained sections were examined under a microscope and islet tissues were isolated. They were fixed in 1% osmium tetroxide in phosphate buffer for one hour and embedded in Epon 812 following dehydration through a series of alcohols and propylene oxide.

Cardiac myocytes cultured on a basement membrane extract of the ehs tumor

1986 ◽  
Vol 44 ◽  
pp. 270-271
Author(s):  
L. Terracio ◽  
A. Dewey ◽  
K. Rubin ◽  
T.K. Borg
Keyword(s):  
Extracellular Matrix ◽  
Basement Membrane ◽  
Cardiac Myocytes ◽  
Normal Tissue ◽  
Cell Spreading ◽  
Collagen Iv ◽  
Basement Membrane Extract ◽  
Membrane Extract ◽  
Growth Development ◽  
Multicellular Organisms

The recognition and interaction of cells with the extracellular matrix (ECM) effects the normal physiology as well as the pathology of all multicellular organisms. These interactions have been shown to influence the growth, development, and maintenance of normal tissue function. In previous studies, we have shown that neonatal cardiac myocytes specifically interacts with a variety of ECM components including fibronectin, laminin, and collagens I, III and IV. Culturing neonatal myocytes on laminin and collagen IV induces an increased rate of both cell spreading and sarcomerogenesis.

Immunocytochemical methodology for the localization of neuronal antigens at the ultrastructural level

1990 ◽  
Vol 48 (3) ◽  
pp. 876-877
Author(s):  
Jorge Pecci Saavedra ◽  
Mark Connaughton ◽  
Juan José López ◽  
Alicia Brusco
Keyword(s):  
Spinal Cord ◽  
Substantia Nigra ◽  
Polyclonal Antibodies ◽  
Ultrastructural Level ◽  
Point Of View ◽  
Nerve Tissue ◽  
Tissue Fixation ◽  
Optimal Conditions ◽  
Interpeduncular Nucleus ◽  
Technical Point

The use of antibodies as labels for the localization of specific molecules in the nervous systan has been extensively applied in recent years. Both monoand polyclonal antibodies or antisera have been employed. The knowledge of the organization of neuronal connectivities, gliovascular relationships, glioneuronal relationships and other features of nerve tissue has greatly increased.A number of areas of the nervous systan have been analyzed in our laboratory, including the nuclei of the raphe system, the reticular formation, interpeduncular nucleus, substantia nigra, caudate nucleus, putamen, pallidum, spinal cord, pineal gland and others.From a technical point of view, a number of variables needed to be taken into account in order to obtain reliable and reproducible results. The design of the optimal conditions of tissue fixation, embedding, sectioning, dilution of antibodies, and adaptation of Sternberger PAP technique were sane of the parameters taken into account to optimize the results. It is critical that each step of the technique be defined for each particular case.

192: Tubularized Urethral Replacement: What is the Maximum Distance for Normal Tissue Regeneration?

2004 ◽  
Vol 171 (4S) ◽  
pp. 51-51
Author(s):  
Roger E. De Filippo ◽  
Hans G. Pohl ◽  
James J. Yoo ◽  
Anthony Atala
Keyword(s):  
Tissue Regeneration ◽  
Normal Tissue ◽  
Maximum Distance

Transcriptome analysis of pediatric cALL versus normal tissue reveals a novel signature of the malignant phenotype

2009 ◽  
Vol 221 (03) ◽  
Author(s):  
GHS Richter ◽  
UE Hattenhorst ◽  
B Beinvogl ◽  
D Schenk ◽  
MS Staege ◽  
...  
Keyword(s):  
Transcriptome Analysis ◽  
Normal Tissue ◽  
Malignant Phenotype
Sign in / Sign up

Export Citation Format

Share Document