Characteristics in Raman spectrum of serum of gastric cancer patients

Abstract

To investigate the characters of Raman spectrum in gastric cancer patients through comparing serum of functional dyspepsia patients, serum of gastric cancer patients with SGC7901 cell culture fluid, correlation with culturing time of cell line, and research the recourse of these special Raman peak. Peripheral blood samples were collected from 25 gastric cancer patients and 10 functional dyspepsia (FD) patients. Human gastric cancer cells of the line SGC7901 were cultured. The serum samples of the gastric cancer patients and of the FD patients, and the culture fluid of SGC7901 cell underwent Raman spectroscopy with 230 nm and 100 nm as the least peaks respectively. Serum of normal person, lysate, and 1604 culture fluid were used as controls. Seven reproducible Raman peaks at the wavelengths of 583, 633, 656, 674, 707, 773 and 799 nm were detected, with 230 nm as the least peak, in the serum samples of gastric cancer patients. Raman peaks at the wavelengths of 633, 656, and 674 nm were detected only in the serum samples of gastric cancer patients, and the Raman peaks at the wavelengths of 533, 707, 773, and 799 nm of the serum of gastric cancer patients (96.5 +/- 6.0, 76.9 +/- 4.7, 63.7 +/- 4.5, 285.7 +/- 18.6) were all remarkably higher than those of the serum samples of FD patients (40.3 +/- 1.8, 27.9 +/- 1.9, 22.9 +/- 1.4, 113.2 +/- 7.7, all P < 0.01). Similar condition, with 100 nm as the least peak, could detected in the Ramon peaks at the above mentioned wavelengths between the serum samples of the gastric cancer patients and the 1640 culture medium. The Raman peak of the cell culture fluid was positively correlated with the time of cell culture. The Raman peaks of the gastric cell lysate at the wavelengths of 583, 633, and 656 nm were significantly different from those of the cell culture fluid (P = 0.027, 0.029, and 0.043 respectively). The serum of gastric cancer patients has specific reproducible Raman spectrum. The cell content possibly is part of the reason of the special characters in Raman spectrum of gastric cancer serum.