To whit, from Mok's lab . . .
>>Haptoglobin- Subunit As Potential Serum Biomarker in Ovarian Cancer
Identification and Characterization Using Proteomic Profiling and Mass Spectrometry1
Bin Ye2, Daniel W. Cramer, Steven J. Skates, Steven P. Gygi, Vanessa Pratomo, Lanfei Fu, Nora K. Horick, Larry J. Licklider, John O. Schorge, Ross S. Berkowitz and Samuel C. Mok
Laboratory of Gynecologic Oncology, Department of Obstetrics and Gynecology and Reproductive Biology, Brigham and Women’s Hospital [B. Y., D. W. C., V. P., L. F., R. S. B., S. C. M.], Dana-Farber Cancer Institute, Dana-Farber Harvard Cancer Center [D. W. C., R. S. B., S. C. M.], Biostatistics Center, Massachusetts General Hospital [S. J. S., N. K. H.], and Department of Cell Biology [S. P. G., L. J. L.], Harvard Medical School, Boston, Massachusetts 02115, and University of Texas Southwestern Medical Center, Dallas, Texas 77030 [J. O. S.]
Purpose: The objective of this study was to identify and characterize new serum biomarkers in ovarian cancer patients using mass spectrometric protein profiling and specific immunological assays.
Experimental Design: Serum samples from 80 cancer patients and 91 healthy women were analyzed by surface enhanced laser desorption and ionization-mass spectrometry (MS) profiling. A candidate biomarker was purified by affinity chromatography, and its sequence was determined by liquid chromatography-tandem MS. An antibody was generated from the synthesized peptide for quantitative validation in the cases and controls. CA125 was determined and compared with the same set of specimens.
Results: Using surface enhanced laser desorption and ionization, we found a serum biomarker at 11700 Da, which had peak intensity significantly higher in cases (1.366) compared with controls (0.208, P = 0.002), and subsequently identified this as the chain of haptoglobin. ELISA indicated that Hp- was 2-fold higher in cancer serum compared with normal, benign tumor, and other gynecological cancers (P < 0.05) and had 64% sensitivity at 90% specificity alone and 91% sensitivity and 95% specificity if combined with CA125.
Conclusions: Haptoglobin-derived subunit is a potential marker for ovarian cancer that is complementary to CA125. MS-based protein profiling is a valuable tool for screening protein markers and useful to detect post-translational modification of tumor-associated proteins or abnormal metabolic products. However, confirmation of protein identity with specific antibodies is crucial for clinical application and functional studies. <<
From Clinical Cancer Research, Aug 9th edition
Cheers, Tuck |
