Sonic Hedgehog Protein Purification and Identification: A Potential Biomarker for Pancreatic Cancer
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Authors
Cantú, Esperanza Felicidad
Issue Date
2011
Type
Thesis
Language
en_US
Keywords
Alternative Title
Abstract
New insights into the molecular biology of pancreatic cancer may help to improve
patient survival. Sonic hedgehog (Shh) protein is misexpressed and may maintain tumor
growth in pancreatic cancer. The digestive system served as a model to study Hedgehog
(Hh) signaling, and it was found that Shh might be secreted from the stomach into the
blood. Shh can be secreted from basolateral membranes of parietal cells into the
mesenchymal tissue, which contains blood capillaries. Shh transport through the blood
suggests that Shh could be traveling from the stomach to the pancreas, possibly
maintaining cancer cells. The aims of this study were to identify plasma Shh, and
determine a correlation between plasma Shh concentration and pancreatic cancer. It was
hypothesized that because Shh is upregulated in pancreatic cancer tissue, plasma Shh
concentration might reflect the same trend. Shh was identified in blood plasma using a
Human Shh ELISA. To purify the plasma and identify Shh protein via SDS-PAGE, fast
protein liquid chromatography, agarose bead immunoprecipitation, and heparin affinity
chromatography were employed. Pancreatic cancer patients had significantly lower
plasma Shh concentration in comparison to healthy patients. Moreover, Shh plasma
concentration as a biomarker yielded a 95.9% negative predictive value. This indicates a
high probability that screening Shh plasma concentration would correctly diagnose
patients without pancreatic cancer. Mass spectrometry analysis of an SDS-PAGE gel
displaying a 19-kDa-protein band revealed that Shh could not be detected; however, it is
possible that another Hh protein could be detected. The study should be repeated with
different fractions of the blood obtained through FPLC, and with age-matched controls to
eliminate the superficial result that age predicts pancreatic cancer.
Description
v, 40 p.
Citation
Publisher
Kalamazoo College
License
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