Establishment of a non-invasive salivary diagnostic model for TCM syndrome differentiation in breast cancer based on SELDI and bioinformatics techniques

Objective The salivary proteins of breast cancer patients of liver-qi stagnation syndrome and of liver-kidney yin deficiency syndrome were examined using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF-MS), and specific protein markers were screened out to establish a salivary protein fingerprint model for distinguishing breast cancer liver-qi stagnation and liver-kidney yin deficiency. Methods The protein patterns of 47 salivary specimens (26 cases of liver-qi stagnation of breast cancer, 21 cases of liver-kidney yin deficiency of breast cancer) were examined with SELDI-TOF-MS to establish a TCM syndrome diagnosis model for breast cancer. Results 243 protein peaks were detected in the specimens, 33 of which showed significant difference between the two groups. The liver-qi stagnation syndrome and the liver-kidney yin deficiency syndrome of breast cancer could be correctly distinguished by the diagnostic model comprised of two proteins with M/Z of 8087.575 and 3378.142 Da, respectively; 25 out of the 26 cases of liver-qi stagnation syndrome was correctly diagnosed, and all the 21 cases of liver-kidney yin deficiency were correctly excluded; the sensitivity reached 96.15% (25/26) and the specificity was 80.95%(17/21). Conclusion The salivary protein fingerprint model for TCM syndrome differentiation established with SELDI-TOF-MS provided a highly specific, sensitive new method that is worth further study and application.