IR spectroscopic methods for diagnosis of oncological pathologies in human tissues (Review)

Abstract

Modern problems in the diagnosis of oncological pathologies using spectroscopic methods of analysis are considered. Fourier-transform IR spectroscopy methods are illustrated by investigation of tissues of breast, thyroid gland, stomach, kidney, lung, and skin excised during surgical intervention. IR spectra of surgical material are compared with data of histological analysis. Spectra of proteins and lipids in malignant neoplasms differ from those in benign tumors and in tissues beyond the pathological focus. Differences in protein spectra are attributed to changes in the supramolecular structure due to cleavage of intramolecular C=OH-N hydrogen bonds. Differences in IR spectra of lipids in neoplasms, when compared with those in normal tissues, are caused by changes in the structure of side chains of fatty-acid radicals appearing in malignant tumors. Spectral signatures of malignant pathology are revealed.Introduction. Timely detection of oncological pathology is of prime importance for selecting effective methods for treating oncological diseases. However, the diagnosis of malignant neoplasms is a very complicated aspect of oncology because tumors often manifest clinically as various symptoms, especially in early stages.The essence of the problem is that diagnostic methods currently used in medical practice such as visual, palpation, ultrasound, and x-ray, in addition to MRI and CT are capable in principle of detecting only a tumorous mass. The final conclusion about whether the detected pathology is benign or malignant is made based on morphological investigations. A correct diagnosis is possible only with careful adherence to procedures for obtaining and processing the material to be analyzed. Important considerations for a reliable diagnosis are subjective factors such as the special professional training and experience of the surgeon and a highly qualified pathologist.The morphological diagnosis of a tumor is established based on a whole set of signatures such as cytological characteristics, cell topography, their relationships to basal membranes, vessels, and the condition of the stroma, which acts as a mediator between neoplasms and the organism as a whole. Morphological signatures of malignancy are idiosyncratic to each organ and tissue and can vary considerably. Therefore, both clinical data and results of laboratory tests are very significant for a differential diagnosis of malignant tumors and elucidation of the factors stimulating malignant growth. Information about the tumor location, its growth rate, and the age of the patient can in several instances play a decisive role in the morphological diagnosis [1]. Nevertheless, available morphological data can in many cases be insufficient for an accurate verification of the pathological (tumor) process so that a conclusion about whether the tumor is benign or malignant is presumptuous in nature [2]. Because fundamental life processes, from single-celled organisms to man, are carried out on the molecular level, novel methods that investigate the pathology o...

Infrared spectroscopic analysis of skin tumor of mice treated with several medicinal plants

“…Both clinical and biological studies would benefit from the spectroscopic technique that could quantify the biochemical composition of specimens non destructively and with minimal sample preparation and handling [4] . It can also be used to measure the vibrational modes of the functional groups of molecules and is sensitive to molecular structure, conformation and the environment [5] .…”

Infrared spectra of thyroid tumor tissues

“…Since the underlying life processes are realized at the molecular level, a promising approach to studying thyroid cancer problems is to use methods which study organ pathology at the level of molecular structure and molecular interactions. Recently, owing to the high sensitivity and information content of IR spectroscopy methods relative to structural changes and the composition of molecules, attempts have been made to use such methods in biomedicine, in particular oncology [3][4][5][6][7]. It is assumed that IR spectroscopy methods are potentially capable of identifying signs which can be used to distinguish between a malignant tumor and other focal changes in human tissues and organs at the molecular interaction level [4].…”

“…Figure 1 shows the IR spectra for thyroid tumor fragments taken directly from malignant tumors for a highly differentiated form of cancer (curve 1), an undifferentiated form of cancer (curve 2), and a benign tumor (fibroma) (curve 3). In the spectra presented, we observe a number of intense absorption bands which, as noted in [7,[9][10][11][12], are typical for the spectra of protein forms which are the product of polycondensation of different α-amino acids: R 1 , R 2 are side groups or chains on individual amino acid residues.…”

“…The broad, intense absorption band with maximum (ν max ) close to 3300 cm -1 is due to stretching vibrations of N-H groups in peptide chains of the protein macromolecules, while the band in the spectral interval 1700-1600 cm -1 is due to stretching vibrations of the C=O groups of the peptide chains [7,[9][10][11][12]. These bands are very sensitive to very small changes in the geometry of the protein molecules, and also to the development of or changes in hydrogen bonds between peptide groups [7,9].…”

“…These bands are very sensitive to very small changes in the geometry of the protein molecules, and also to the development of or changes in hydrogen bonds between peptide groups [7,9]. The bands in the intervals 1576-1480 cm -1 and 1300-1230 cm -1 are due to interaction of C-N stretching vibrations and N-H bending vibrations within the molecules [7,[9][10][11][12]. Bands in the intervals 3000-2800 cm -1 and 1470-1300 cm -1 are due respectively to stretching and bending vibrations of methyl and methylene groups.…”