Breast cancer related proteins are present in saliva and are modulated secondary to ductal carcinoma in situ of the breast.
OBJECTIVE
The objective of this study was to determine if protein-by-products secondary to cancer related oncogenes appear in the saliva of breast cancer patients.


METHODS
Three pooled (n = 10 subjects/pool) stimulated whole saliva specimens from women were analyzed. One pooled specimen was from healthy women, another pooled specimen from women diagnosed with a benign breast tumor and the other one pooled specimen was from women diagnosed with ductal carcinoma in situ (DCIS). Differential expression of proteins was measured by isotopically tagging proteins in the tumor groups and comparing them to the healthy control group. Experimentally, saliva from each of the pooled samples was trypsinized and the peptide digests labeled with the appropriate iTRAQ reagent. Labeled peptides from each of the digests were combined and analyzed by reverse phase (C18) capillary chromatography on an Applied Biosystems QStar LC-MS/MS mass spectrometer equipped with an LC-Packings HPLC.


RESULTS
The results of the salivary analyses in this population of patients yielded approximately 130 proteins in the saliva specimens. Forty-nine proteins were differentially expressed between the healthy control pool and the benign and cancer patient groups.


CONCLUSIONS
The study suggests that saliva is a fluid suffused with solubilized by-products of oncogenic expression and that these proteins may be modulated secondary to DCIS. Additionally, there may be salivary protein profiles that are unique to both DCIS and fibroadenoma tumors.
Streckfus
Charles F
CF
University of Texas Health Science Center-Dental Branch, Houston, Texas 77030, USA. charles.streckfus@uth.tmc.edu
Mayorga-Wark
Otilia
O
Arreola
Daniel
D
Edwards
Cynthia
C
Bigler
Lenora
L
Dubinsky
William P
WP
D001943:Breast Neoplasms / Q000378:metabolism*; D018270:Carcinoma, Ductal, Breast / Q000378:metabolism*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000378:metabolism*; D005260:Female; D018226:Fibroadenoma / Q000378:metabolism*; D006801:Humans; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000378:metabolism*; D040901:Proteomics; D012463:Saliva / Q000378:metabolism*; D012471:Salivary Proteins and Peptides / Q000378:metabolism*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D009363:Neoplasm Proteins; D012471:Salivary Proteins and Peptides