Proteomic Applications in Cancer

Over recent years, oncology has been a key focus of proteomic technologies as applied in both expression and functional studies. Expression proteomic studies are screening for differences in protein patterns between tumor and control tissues. Functional proteomic studies are defined as the combination of readouts with proteomics data from the same sample at different points of time (under different conditions), with the aim of detecting and prioritizing certain proteins or polypeptides of functional relevance. 

As of today, expression proteomic studies are available for all common human cancers and some rare tumors. 

Lung cancers are traditionally classified into various subtypes on a histological basis. Squamous lung cancer, the most common histological sub-type, is followed by adenocarcinoma, and other histologies. These various subtypes were classified on the basis of 2D-PAGE [45] and MS profiles [46]. 

Using SELDI technology, a-defensin isoforms were found to be elevated in serum from colon cancer patients and in protein extracts from CRC [59]. This result was confirmed by expression analysis of microarray data obtained from 283 tumors and normal tissues followed by serum analysis of colon cancer patients and controls by ELISA. This study yielded a diagnostic sensitivity of 70%i and specificity of 83% for a-defensin in colon cancer [60]. Although these figures appear too low for developing a screening test, this 

The use of proteomics in prostate cancer, the most common cancer in men, was reviewed [94]. In vitro studies on prostate cell lines provided positive proof-of-principle results in the identification of novel biomarker when proteomics was utilized to query prostate tissue specimens. 2D-PAGE followed by MS was used to investigate protein profiles in voided urine after prostatic massage in patients with prostate cancer or with benign prostatic hyperplasia [95]. In this study, a potential novel cancer biomarker, calgranulin B/MRP-14, was identified. In another study, agarose 2D-gel 

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