Study On FTIR Spectroscopy And Patterns Of Lung Cancer Tissue

Fourier Transform Infrared (FTIR) spectrum is an effective method for investigating substance molecular structure swiftly while keeping the specimens intact. So it can represent the characteristic of the cancer at molecular level. Some studies have demonstrated that FTIR spectra of malignant cells were different significantly from those of normal cells. Before FTIR scanning, the corresponding sample were subjected to pathohistological examination with HE stain, histochemical studies with PAS stain for glycoprotein. Then all the differences of spectra between cancerous tissues and normal tissues were analyzed by statistics using MEANS, paired T test and Logistic regression.1.pathohistological and histochemical studiesAll of the malignant tissues and normal tissues were identified via HE stain. Compared with the normal tissues, glycoprotein on the malignant tissue surface decreased distinctly.2.FTIR spectrum differences between normal tissues and malignant tissue(1) Changes of bands about nucleic acidThe average wavenumber of band of υsPO2- shifted from 1080.05 to 1084.91cm-1 and that of υasPO2- shifted form 1240.08cm-1 to 1241.39cm-1 which indicated that the degree of hydrogen band form by oxygen atom of the phosphodiester groups of nucleic acids was increased. And the relative contents of DNA in cancer cellular increase.(2) Changes of bands about proteinThe shift of band of υc-o of cell proteins from 1164.38cm-1 to 1173.60cm-1 indicated that the hydrogen band of cell protein become weaker. The band near 3310 cm-1 from the stretching modes of the hydrogen band N-H in protein molecules shifts to a lower wavenumber, which indicates that the intensity of the hydrogen bands on the NH…O-C is stronger in protein molecules of malignant lung tissues. The symmetric stretching modes of PO3- at 970cm-1 from the phosphorylated protein become stronger. The change of intensity of collagen bands indicates the increase of its relative contents.(3) Changes of bands about lipidThe average wavenumber of band of δCH2 of membrane lipids shifted from 1456.74cm-1 to 1460.71cm-1 that suggested that the conformation of the methylene chains of membrane lipids is more disordered than in normal tissues. The absorb at 2852 cm-1 and 2958 cm-1 relative to membrane lipids changed, because in lung cancer tissue the lipids decreased.(4) Changes of bands about carbohydrateIn malignant tissue, the bands of carbohydrate obviously decreased .It might be due to the lessen of glycoprotein on the surface of malignant tissue. 3.Statistics and patternThe Statistics method includes Means test, paired-samples test and Logistic regression,which shows that FTIR spectrometry can represent the characteristic of the lung cancer at the molecular level.