Immunoassay for LMP1 in nasopharyngeal tissue based on surface-enhanced Raman scattering

Abstract

Background:Previous studies have shown that Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) is closely associated with the occurrence and development of nasopharyngeal carcinoma, and can be used as a tumor marker in screening for the disease. Here we report a new methodology based on highly specific and sensitive surface-enhanced Raman scattering (SERS) technology to detect LMP1 in nasopharyngeal tissue sections directly with no need of tedious procedures as with conventional immunohistochemistry methods. Methods: LMP1-functionalized 4-mercaptobenzoic acid (4-MBA)-labeled Au/Ag core-shell bimetallic nanoparticles were prepared first and then applied for analyzing LMP1 in formalinfixed paraffin-embedded nasopharyngeal tissue sections obtained from 34 cancer patients and 20 healthy controls. SERS spectra were acquired from a 25 × 25 spot square area on each tissue section and used to generate SERS images. Results: Data from SERS spectra and images show that this new SERS-based immunoassay detected LMP1 in formalin-fixed paraffin-embedded nasopharyngeal tissue sections with high sensitivity and specificity. The results from the new LMP1-SERS probe method are superior to those of conventional immunohistochemistry staining for LMP1, and in excellent agreement with those of in situ hybridization for EBV-encoded small RNA (EBER). Conclusion:This new SERS technique has the potential to be developed into a new clinical tool for detection and differential diagnosis of nasopharyngeal carcinoma as well as for predicting metastasis and immune-targeted treatment of nasopharyngeal carcinoma.

Surface-enhanced Raman spectroscopy of saliva proteins for the noninvasive differentiation of benign and malignant breast tumors

“…13,14 Recent reports showed that SERS has been extensively applied to a great deal of analytical systems in the research of biological molecules, from DNA, 15 RNA, 16 to whole proteins. 17,18 SERS is especially attractive for application in cancer diagnosis and evaluation utilizing human biological samples such as blood, 19 tissues, 20 cells, 21 and serum. 22 As a potential diagnostic media for disease detection, saliva offers main advantages over blood due to the easy and noninvasive sample collection, which eliminates any feelings of pain and discomfort during the process of blood collection.…”

Surface enhanced Raman spectroscopy (SERS): Potential applications for disease detection and treatment

“…[98] As with the previous examples all of the above discussed advantages of the SERS method are equally applicable to this study. [98] SORS has been previously discussed as a method for disease detection in section 2. In a subsequent study the method was investigated in specific relation to a disease process.…”

“…SERS analysis was found to considerably exceed the conventional method. [98] In total, there were 34 cancerous and 20 non-cancerous tissue samples and the SERS detection method correctly identified 33 of the cancerous samples whilst the traditional method only identified 22.…”

“…[13] Manipulation of the antibody-antigen interaction has also been exploited for the determination of nasopharyngeal cancer in tissue samples. [98] As with most of the discussed samples, antibody functionalised SERS nanotags were exposed to tissues. [98] Clinical samples were analysed and directly compared with the tissue, which had been analysed via a traditional immunohistochemical method.…”

“…[98] As with most of the discussed samples, antibody functionalised SERS nanotags were exposed to tissues. [98] Clinical samples were analysed and directly compared with the tissue, which had been analysed via a traditional immunohistochemical method. SERS analysis was found to considerably exceed the conventional method.…”