Melissa Tuck

Serum and Plasma Collection

Starting with properly collected, processed, annotated, and stored human specimens is critical for successful research using unsupervised, high-throughput technologies for discovery, validation, and translation from such samples. Samples that are not reproducibly collected and managed undermine data generated in platforms, such as mass spectroscopy–based proteomic technologies. The key factors that determine quality of human biosamples are use of consistent methodologies for collection, handling, processing, and storing specimens; understanding the potential sources of bias; and thoroughly annotating the life-cycle of the specimen. These factors apply when a new biospecimen resource is being created or when previously collected or banked samples are being used. Standard operating procedures permit control of bias and ensure that high-quality biosamples result in reproducible data. Compliance with increasingly complex human subject protection regulations governing the collection, management, storage, sharing, and use of human biosamples is essential to ensure that data will be published in high-quality journals, that intellectual property is protected, and that data generated using biosamples can be used as part of submissions to governmental regulatory bodies for product approvals.

Abstract 1286: Pharmacodynamics of oral curcumin in plasma and rectal mucosa in a Phase IIa trial

Background: Curcumin, a dietary polyphenol derivative of turmeric, has potent cancer reductive activity in in vivo colon carcinogenesis models. We administered curcumin at doses of 2 g or 4 g to separate groups of 20 healthy human smokers with > 8 aberrant crypt foci (ACF). The 2 g dose showed no ACF reduction while the 4 g dose showed a 46% reduction (p Methods: Curcuminoid products were extracted from homogenized biopsy tissue and ultacentrifuged plasma and evaporated under argon. The separation was performed on a Symmetry ® C 18 column. The mobile phase used under gradient conditions was 25% acetonitrile with 74.9% containing 0.1% acetic acid (25:74.9:0.1; v/v/v; A) and 100% acetonitrile containing 0.1% acetic acid (99.9:0.1; v/v; B) The flow rate was 0.3 mL/min and injection volume for all samples was 10 µL. The lower limit of detection for curcumin from human plasma was 5 ng/mL and from human colonic mucosa was 50 ng/5mg tissue. Results: See Table below (summarized by pre and post treatment dose for plasma and mucosal concentrations) Conclusions: Native curcumin is not detectable in the majority of biopsy and plasma samples. Conjugated curcumin is detectable in all plasma samples and the majority of mucosal biopsies with a significant increase in plasma concentrations at 4g. We postulate the conjugates detected in the rectal mucosa are delivered systemically from absorption and conjugation higher in the gastrointestinal tract and may have biologic activity. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1286. doi:10.1158/1538-7445.AM2011-1286

Rectal mucosal quantitative galactose oxidase-Schiff reaction as an early detection biomarker for colorectal cancer: Comparison to fecal occult stool blood test

The galactose oxidase-Schiff (GOS) reaction detects D-galactose-β-[1,3]-N-acetyl-D-galactosamine. This is a T-antigen expressed in mucus from malignant cells and colonic mucosa adjacent to cancer but not in normal mucosa. Previous studies using a qualitative GOS assay proved to be of limited value for the detection of colorectal neoplasia. We used a newly developed quantitative GOS assay to determine its potential as an early detection biomarker for colorectal cancer. We completed a multi-center, prospective, cross-sectional cohort validation study consisting of 70 normal controls, 23 high-risk normal patients (polyp history or family history of colorectal cancer (CRC) with currently normal colonoscopy), 137 patients with adenomatous polyps, and 69 with colorectal cancers. Prior to colonoscopy, two samples of stool were collected via a rectal exam: one for FOBT, and one for GOS. The area under the ROC curve (AUC) for detecting colonic adenomas and cancer for normal colons, computed with logistic regression was 0.69 for GOS, 0.62 for FOBT, and 0.73 for GOS combined with FOBT. Adding GOS to FOBT did not significantly change the ROC of FOBT alone. GOS does not appear to be a suitable marker of colorectal neoplasia.

Abstract 2906: Curcumin reduces aberrant crypt foci (ACF) number but does not alter prostaglandin E2 (PGE2) or 5-hydroxyeicosanopentaneic acid (5-HETE) concentration in ACF or in normal human colorectal mucosa

Curcumin, a dietary polyphenol derivative of turmeric, has potent cancer preventive activity in in vivo colon carcinogenesis models. To determine whether curcumin has pharmacodynamic effects on the human colon, we administered curcumin at doses of 2 g or 4 g to separate groups of 20 healthy human smokers who had 8 or more aberrant crypt foci on screening colonoscopy. We removed 3 aberrant crypt foci and 4 flat mucosal biopsies under magnifying endoscopy prior to and after 28 days of daily curcumin dosing. We enrolled 41 subjects (66% African Americans, 27% Caucasian, mean age 55+/−6.5 years). PGE2 and 5-HETE concentrations on tissue biopsies (assayed with liquid chromatography tandem mass spectroscopy) are shown in the Table. Curcumin concentrations assayed by HPLC in the colonic mucosa were undetectable ( (Support: NCI N01-35610, F. Meyskens PI Univ California Irvine) Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2906.