Investigation On The Radiosensitive Effect Of Nimotuzumab On Nasopharyngeal Carcinoma CNE-2Cells By Raman Spectroscopy

Objectives: To initially study the radiosensitive effect of Nimotuzumab （h-R3） onnasopharyngeal carcinoma CNE-2cells by Raman spectroscopy.Methods: The method of MTT was used to analysize the50%inhibiton concentration（IC50） of nimotuzumab on cell proliferation, four concentrations of durg below20%IC50were selected to do drug radiotherapy sensitization experiment. CNE-2Cellswere divided into four groups: the control group, the h-R3group, the irradiation group,and h-R3combined with radiation group. The h-R3group were treated with h-R3atfour different concentrations, and then cultured for24h, followed by new nutrientsolution. The irradiation group received irradiation of2Gy X-ray by Eletkta-6MVand then cultured for24h, followed by new nutrient solution. The combined groupreceived h-R3at four different concentrations and cultured for24h, and thenexchanged by new nutrient solution, followed by irradiation at2Gy. Clonogenicassay was used to calculate the Survival Fraction （SF） of the above four groups after2weeks. Renishaw confocal micro-Raman spectroscopy conbined with PCA-LDA wasemployed to detect the above four groups after24h.20cells in each drugconcentration were detected.Results: It was shown that IC50was about832umol/L, thus the concentrations of25，50，100ug/ml，150ug/ml were selected to do drug radiotherapy sensitizationexperiment. By clonogenic assay, the SF2of conbined group was lower than that ofthe corresponding concentration of the h-R3group and the irradiation group （P<0.05）,and the SF2of conbined group enhanced with the increasing concentration （P<0.05bypairwise comparison）. By PCA-LDA method, the sensitivity and the specificity of theconbined group comparing with control group were higher than that of correspondingconcentration of the h-R3group and irradiation group, and this situation enhanced as the concentraion of h-R3increased. Further analysis of the the conbined groupcomparing the irradiation group by Raman Spectroscopy, we found that the trend ofdiscrimination of two groups became more and more obvious as the increase of drugconcentration by PCA scatter diagram.By LDA posterior probability diagram, thesensitivity for drug groups25ug/ml，50ug/ml，100ug/ml and150ug/ml was65.0%,75.7%,85.0%, and90.0%, respectively. The specificity for drug groups25ug/ml，50ug/ml，100ug/ml and150ug/ml was50.0%,70.0%,81.0%, and95.2%, respectively.From spectrum of bee, the intensity of758cm^-1、831cm^-1、1094cm^-1、1313cm^-1、1338cm^-1increased as the concentration of h-R3, while the intensity of1031cm^-1、1557cm^-1、1658cm^-1decreased.Conclusions: By analysis of Raman spectroscopy, the radiosensitive effect ofnimotuzumab on CNE-2cells enhanced as the increase of drug concentration, and150ug/ml group was the most significant, which was consistent with the resutls ofcolony forming assay. Raman spectroscopy technique can be employed to study theradiosensitive effect of Nimotuzumab （h-R3） on nasopharyngeal carcinoma CNE-2cells.