Multivariate analysis of Raman spectroscopy of wild type and mutants p53 cancer biomarker

摘要

Most of the techniques used for medical diagnosis, apply methods of analysis to identify certain substances calledbiomarkers. These techniques generally have the disadvantages of being laborious, invasive, and dependent on thephysician’s experience. Raman spectroscopy is projected as a technique capable of identifying biomarkers in a noninvasive,simple and economical way. The analysis of the spectroscopic results by means of multivariable mathematicaltechniques would allow to eliminate the subjective interpretation of the results and therefore contribute to objective andmore reliable diagnoses.The tumor suppressor wild type p53 protein is considered a cancer biomarker. Present in the human body is activatedwhen cellular damage is detected. The p53 protein acts to protect DNA integrity: repairing the damage or inducingcellular death. When p53 do not respond correctly, the damage is not arrested, and tumor growth is developed. Mutationsin p53 are related to inactivation of the wild type and therefore the presence of tumors.In this work, Raman spectra of wild type and mutants p53 were obtained through a micro-spectrometer. The spectrawere analyzed by multivariate methods. Principal component analysis and support vector machine algorithms showedthat it is possible to discriminate between the wild and mutant type of this biomarker with an accuracy of 94%. Ramanspectra of wild type p53 at different concentrations were used to estimate the limit of the detection of this protein bymeans of partial least squares regression. The limit of detection was found as low as 0.946 μM without additionalreagents.