scholarly journals Characterization of a Polyclonal Antibody to Human Pituitary Tumor Transforming Gene 1 (PTTG1) Protein

2001 ◽  
Vol 49 (12) ◽  
pp. 1537-1545 ◽  
Author(s):  
Sham S. Kakar ◽  
Leilei Chen ◽  
Rashmi Puri ◽  
Shawn E. Flynn ◽  
Lothar Jennes
Keyword(s):  
Molecular Weight ◽  
Recombinant Protein ◽  
Polyclonal Antibody ◽  
Pituitary Tumor ◽  
Single Band ◽  
Human Testis ◽  
Pituitary Tumor Transforming Gene ◽  
Chimeric Construct ◽  
Relative Molecular Weight ◽  
Transforming Gene

Pituitary tumor transforming gene 1 (PTTG1), recently cloned from human testis, is a potent oncogene that is expressed in most tumors. However, assessment of its potential value as a prognostic marker is dependent on the development of a suitable antibody. We have developed a rabbit polyclonal antibody, SK601, that is highly specific for the PTTG1 gene product using recombinant PTTG1 protein (24 kD) containing an N-terminal His6 tag as the immunogen. The antiserum is capable of detecting recombinant PTTG1 protein in ELISA assays at a titer of 1:100,000. Use of the antibody as the probe in Western blotting analyses revealed a single band with the anticipated relative molecular weights of 52 kD from E. coli expressing the GST-PTTG1 recombinant protein, and 56 kD from COS-7 cells transfected with the PTTG1-GFP chimeric construct. A single band with a relative molecular weight of 28 kD was observed in extract of COS-7 cells transfected with PTTG1 cDNA. The antiserum immunoprecipitated a protein of relative molecular weight of 56 kD from the extracts of COS-7 cells transfected with the PTTG1-GFP chimeric construct. Immunohistochemical analysis of COS-7 cells transfected with this construct confirmed that the antibody detected and was specific for expressing the PTTG1-GFP recombinant protein. Screening of various normal human tissues (testis, ovary, and breast) by immunohistochemistry indicated that these tissues did not exhibit staining with the exception of testis, a tissue that had previously been shown to express PTTG1 mRNA. In contrast all of the tumor tissues (testicular tumor, ovarian tumor, and breast tumor) that were assessed exhibited intense staining. The results suggest that antiserum SK601 is highly specific for the PTTG1 protein and therefore should prove useful in further analysis of the expression and interactions of this protein, including its potential application as an immunohistochemical marker of human tumors.

scholarly journals Thyroid Hormone Receptors Suppress Pituitary Tumor Transforming Gene 1 Activity in Hepatoma

2008 ◽  
Vol 68 (6) ◽  
pp. 1697-1706 ◽  
Author(s):  
Ruey-Nan Chen ◽  
Ya-Hui Huang ◽  
Chau-Ting Yeh ◽  
Chen-Hsin Liao ◽  
Kwang-Huei Lin
Keyword(s):  
Thyroid Hormone ◽  
Pituitary Tumor ◽  
Hormone Receptors ◽  
Thyroid Hormone Receptors ◽  
Pituitary Tumor Transforming Gene ◽  
Transforming Gene

scholarly journals Pituitary tumor transforming gene: a novel therapeutic target for glioma treatment

2015 ◽  
Vol 47 (6) ◽  
pp. 414-421 ◽  
Author(s):  
L. Cui ◽  
S. Xu ◽  
Z. Song ◽  
G. Zhao ◽  
X. Liu ◽  
...  
Keyword(s):  
Therapeutic Target ◽  
Pituitary Tumor ◽  
Pituitary Tumor Transforming Gene ◽  
Transforming Gene ◽  
Novel Therapeutic

scholarly journals Overexpression of pituitary tumor transforming gene 1 in HCC is associated with angiogenesis and poor prognosis

Hepatology ◽  
2006 ◽  
Vol 43 (6) ◽  
pp. 1267-1275 ◽  
Author(s):  
Tsutomu Fujii ◽  
Shuji Nomoto ◽  
Katsumi Koshikawa ◽  
Yasushi Yatabe ◽  
Osamu Teshigawara ◽  
...  
Keyword(s):  
Pituitary Tumor ◽  
Poor Prognosis ◽  
Pituitary Tumor Transforming Gene ◽  
Transforming Gene

scholarly journals Overexpressed Pituitary Tumor-Transforming Gene Causes Aneuploidy in Live Human Cells

Endocrinology ◽  
2003 ◽  
Vol 144 (11) ◽  
pp. 4991-4998 ◽  
Author(s):  
Run Yu ◽  
Wenge Lu ◽  
Jiandong Chen ◽  
Chris J. McCabe ◽  
Shlomo Melmed
Keyword(s):  
Cancer Cells ◽  
Chromosome Segregation ◽  
Pituitary Tumor ◽  
Fluorescent Protein ◽  
Human Cancer ◽  
Live Cells ◽  
Pituitary Tumor Transforming Gene ◽  
Transforming Gene

Abstract The mammalian securin, pituitary tumor-transforming gene (PTTG), is overexpressed in several tumors and transforms cells in vitro and in vivo. To test the hypothesis that PTTG overexpression causes aneuploidy, enhanced green fluorescent protein (EGFP)-tagged PTTG (PTTG-EGFP) was expressed in human H1299 cancer cells (with undetectable endogenous PTTG expression) and mitosis of individual live cells observed. Untransfected cells and cells expressing EGFP alone exhibited appropriate mitosis. PTTG-EGFP markedly prolonged prophase and metaphase, indicating that PTTG blocks progression of mitosis to anaphase. In cells that underwent apparently normal mitosis (35 of 65 cells), PTTG-EGFP was degraded about 1 min before anaphase onset. Cells that failed to degrade PTTG-EGFP exhibited asymmetrical cytokinesis without chromosome segregation (18 of 65 cells) or chromosome decondensation without cytokinesis (9 of 65 cells), resulting in appearance of a macronucleus. Fifty-one of 55 cells expressing a nondegradable mutant PTTG exhibited asymmetrical cytokinesis without chromosome segregation, and some (4 of 55) decondensed chromosomes, both resulting in macronuclear formation. During this abnormal cytokinesis, all chromosomes and spindles and both centrosomes moved to one daughter cell, suggesting potential chaos in the subsequent mitosis. In conclusion, failure of PTTG degradation or enhanced PTTG accumulation, as a consequence of overexpression, inhibits mitosis progression and chromosome segregation but does not directly affect cytokinesis, resulting in aneuploidy. These results demonstrate that PTTG induces aneuploidy in single, live, human cancer cells.

scholarly journals Murine pituitary tumor-transforming gene functions as a securin protein in insulin-secreting cells

2006 ◽  
Vol 191 (1) ◽  
pp. 45-53 ◽  
Author(s):  
Run Yu ◽  
Martha Cruz-Soto ◽  
Sergio Li Calzi ◽  
Hongxiang Hui ◽  
Shlomo Melmed
Keyword(s):  
Cell Proliferation ◽  
Pituitary Tumor ◽  
Cell Cycle Progression ◽  
Fluorescent Protein ◽  
Cell System ◽  
Β Cell ◽  
Human Pituitary ◽  
Pituitary Tumor Transforming Gene ◽  
Expression Levels ◽  
Transforming Gene

Human pituitary tumor-transforming gene 1 (PTTG1) encodes a securin protein critically important in regulating chromosome separation. Murine PTTG (mPTTG) is 66% homologous to human PTTG1 and PTTG-null (PTTG−/−) mice exhibit pancreatic β-cell hypoplasia and abnormal nuclear morphology with resultant diabetes. As we show that ductal β-cell neogenesis is intact in PTTG−/− mice, we explored mechanism for defective β-cell replication. We tested whether mPTTG exhibits securin properties in mouse insulin-secreting insulinoma MIN6 cells, using a live-cell system to monitor mitosis in cells transfected with an enhanced green fluorescent protein (EGFP)-tagged mPTTG conjugate (mPTTG-EGFP). To fulfill the criteria for securin properties, the protein should undergo degradation immediately before the metaphase-to-anaphase transition when expression levels are low, and should inhibit metaphase-to-anaphase transition when expression levels are high. EGFP itself did not undergo degradation throughout mitosis and high levels of EGFP per se did not affect normal mitosis progression (n=25). However, mPTTG-EGFP was degraded 2 min before the metaphase-to-anaphase transition when expression levels were low (n=19), and high mPTTG-EGFP levels blocked metaphase-to-anaphase transition in 13 cells. mPTTG-EGFP inhibited MIN6 cell proliferation and caused apoptosis. Immunocoprecipitation demonstrated binding of mPTTG-EGFP and separase. These results show that mPTTG exhibits properties consistent with a murine securin in insulin-secreting mouse cells and mPTTG overexpression inhibits cell proliferation, suggesting that defective β-cell proliferation observed in PTTG−/− mice is likely due to abnormal cell-cycle progression.

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