Conformational SERS Classification of K‐Ras Point Mutations for Cancer Diagnostics

Abstract

Point mutations in Ras oncogenes are routinely screened for diagnostics and treatment of tumors (especially in colorectal cancer). Here, we develop an optical approach based on direct SERS coupled with chemometrics for the study of the specific conformations that single-point mutations impose on a relatively large fragment of the K-Ras gene (141 nucleobases). Results obtained offer the unambiguous classification of different mutations providing a potentially useful insight for diagnostics and treatment of cancer in a sensitive, fast, direct and inexpensive manner.

Surface Enhanced Raman Spectroscopy for DNA Biosensors—How Far Are We?

“…Detecting small differences in PCR amplicon melting (dissociation) curves enables differentiation the melting plots and detection mutation in the amplified DNA molecules. Then, wild-type and heterozygous samples can be easily differentiated in the melting plots [28,29].…”

“…Label-free (without using Raman reporters) DNA detection is much easier in terms of the preparation of the sample process, although the SERS signal of the DNA (or moieties modifying the DNA) is much weaker than when a Raman reporter is used. However, there are interesting examples of DNA detection in a direct way [29][30][31][32][33][34][35][36][37][38]. Usually, the SERS signal depends on the quantity of DNA strands in the sample and the content of specific bases in the DNA chain, sometimes even with a one base difference sensitivity-see Figure 1.…”

Optofluidic device for the quantification of circulating tumor cells in breast cancer

“…These biomaterials include cell-free nucleic acids, proteins, vesicles as well as circulating tumour cells (CTCs) that underwent epithelial to mesenchymal transition, and whose distribution and concentration are correlated with prognosis and metastasis 5 . The analysis of tumour material obtained by liquid biopsies requires highly sensitive assays, which are only emerging within the past few years 3, 4, 6–8 , with CTCs and circulating-tumor nucleic acids as the most investigated targets 9 . Currently, most of liquid biopsy approaches for CTCs are based on the use of the epithelial cell adhesion molecule (EpCAM) antibodies to capture the CTCs and their subsequent characterization with immunostaining or retro-transcription polymerase chain reaction 10–13 .…”

Cancer characterization and diagnosis with SERS-encoded particles

“…In fact, there is a strong interest in the development of highly sensitive nanotechnological methodologies that would shift medical diagnosis (Howes et al 2014) to the next level of the state of the art in biomedical diagnostics , pathogen detection or gene identification (Morla-Folch 2016;Morla-Folch et al 2017). Among them, optical systems are ideally suited for fast and accurate classification of tumor cells and tissues, early detection of intraepithelial or intraductal diseases, including most cancers, and to assess tumor margins and response to therapy.…”