结直肠组织中脂类的拉曼光谱研究

利用共聚焦显微拉曼光谱系统，检测了结直肠癌组织及邻近正常组织的拉曼光谱234例，从分子水平探讨结直肠癌变的原因。实验结果表明：在900～2 100 cm-1频移范围内，与正常组织比较，归属于结直肠癌组织中脂类伸缩振动的1 067和1 133 cm-1 拉曼峰强度相对较弱，扭转振动的1 299 cm-1与CH面内变形振动的1 264 cm-1拉曼峰的强度比值减少，应用SPSS16.0统计学软件进行平均值计算与比较，正常组织中的1 299和1 264 cm-1的强度比值平均值为3.17，癌变组织的为1.33; 二者的分界值为1.96，以此判别结直肠癌组织和正常组织符合率为94%。研究表明，结直肠癌组织中脂类的链内纵向有序性下降，不饱和度增加。可推测结直肠癌组织中脂类的能量储存增加是引起这些变化的原因，而这些变化将导致细胞膜的流动性增强，从而改变细胞膜的物质运输、能量传递和信号传导，终将引起DNA 结构的变化。因此，脂类的能量分布变化可能是导致细胞癌变的原因之一。

Micro-Raman Spectra for Lipids in Colorectal Tissue

Confocal Raman microscopy system was used to investigate the etiology of colorectal cancer at the molecular level A total of two hundred and thirty four micro-Raman spectra were measured from thirty nine patients for surgically resected colorectal cancer specimens and adjacent normal tissues in the region 900-2 100 cm~(-1).Two bands at 1 064 and 1 134 cm~(-1) whicb are attributed to the all-trans bond stretching vibrations of the C-C lipid skeleton decreased in colorectal cancer tissue samples.The ratio of the Raman band intensity at 1 299 cm~(-1) assigned to in-phase CH_2 twisting vibrations of lipids to that at 1 264 cm~(-1) from CH in-plane deformation was different for colorectal cancerous and normal tissues.The mean values of the (I_(1 299)/I_(1 264)) were 3.17 for normal tissues and 1.33 for cancer tissues using the software function of "Compare Means".Further,the scatter plots were used for grouping the ratio of Raman intensity at 1 299 to 1 264 cm~(-1) according to tissue pathologic types by graph of the SPSS16.00 software.The decision lines (I_(1 299)/I_(1 264)=1.96) separates between cancer and normal tissue with a coincidence rate of 94% (188/200) according to the histological results by graph.The results show that the differences between cancer and normal tissue spectra appear to arise from a decrease in the degree of the longitudinal order and an increase in the degree of unsaturation of lipid,which causes the fluidity of lipid to increases when normal cells are transformed into cancerous cells.