通过测试胃粘膜正常上皮细胞、高、中、低和未分化胃癌细胞基因组DNA的表面增强拉曼光谱, 分析各自特征性谱峰。结果表明: 正常和高分化细胞基因组DNA在1 060 cm-1被抑制, 只在1 010 cm-1被激活, 但后者的谱峰更强且出现“红移”, 其DNA链结构出现不稳定; 中、低、未分化细胞基因组DNA中以上两种振动模式都被激活, 说明它们的DNA链出现了断裂, 且呈现渐强的趋势。同时也说明了脱氧核糖基在恶性程度越高的细胞基因组DNA中带正电趋势越强。1 100-1 670 cm-1谱带属于dC, dG, dA, dT的综合振动叠加, 恶性程度越高的癌细胞中更多的模式被激活。可见, 分化越低的胃癌细胞基因组DNA具有更多的振动模式被激活, 与正常的差异更明显, 并且DNA链整体带正电的趋势也可能越强, 提示可能有更多的氧化反应发生。

利用激光拉曼光谱对顺铂诱导的胃癌细胞凋亡进行分析， 胃癌细胞SGC7901经10 μg·mL-1顺铂处理24, 48, 72 h后， 一部分用于荧光染色， 另一部分用扫描方式收集细胞的拉曼光谱。 光谱结果依次经背景扣除、 平滑、 归一化、 基线校正、 峰拟合等方法预处理。 荧光染色结果显示对照组细胞核染色均匀， 而药物处理72 h后， 核碎裂， 呈致密浓染。 拉曼光谱结果显示顺铂处理24, 48, 72 h后， 与核酸及蛋白质相关的峰均有降低， 其中783, 1 002, 1 343　cm-1峰72 h后依次降低为初始值的52%， 64%， 76%， 表明顺铂能够诱导胃癌细胞凋亡， 凋亡细胞内核酸和蛋白质含量降低。 以上结果说明， 拉曼光谱能提供生物细胞内物质变化的丰富信息， 是实时检测细胞凋亡过程的有效手段。

To study the efficacy and side effects of antitumor drug by the method of Raman spectroscopy, the cancerous (SGC-7901) and normal (GES-1) gastric cells were treated with 0, 25-, 100-, and 200-mg/L 5-fluorouracil (5-Fu) for 24 h, respectively, then Raman spectra of cells were recorded. The excitation wavelength was 514.5 nm and the Raman spectra in the region of 500-1800 cm-1 were recorded. For the gastric cancer cells, as the concentration of 5-Fu increases, the band at 1094 cm-1 attributed to the symmetric stretching vibration mode of PO^(2)_(-) in the DNA backbone gradually decreases, and the intensity ratio of the band at 1315 cm-1 to that at 1340 cm-1 (I1315/I1340) shows the ascending trend, and the ratio of the band area at 1655 cm-1 to that at 1450 cm-1 (A1655/A1450) shows the slight ascending trend. For the normal gastric cells, these peaks also appear changes, however, the changes are weaker than those for the cancer cells. In SGC-7901 cells, 5-Fu can interfere with the DNA synthesis and result in the reduction of the DNA content. Besides, it can affect the unsaturation degree of the hydrocarbon chains and alter the external environment of guanine and adenine residues in cancer cells. The changes of Raman spectra for normal gastric cells reveal the side effect of 5-Fu.