Sub-terahertz vibrational spectroscopy for microRNA based diagnostic of ovarian cancer

Abstract

The purpose of this research is to introduce and validate novel sub-THz resonance spectroscopy combined with molecular dynamics (MD) computation as a promising approach for optical analysis and potential quantification of molecular biomarkers in ovarian (OC) cancer cells. The ability of sub-THz spectroscopy to identify and quantify biological molecules is demonstrated by interrogation of resonance features caused by atomic vibrations within biological molecules in cancer and normal samples. In vitro human cell cultures of two ovarian cancer subtypes, SK-OV-3 human epithelial and ES-2 human clear cell carcinoma, were characterized in comparison with a normal nontransformed cell line (FT131-human fallopian tube epithelial cell line). A dramatic difference between the THz absorption spectra of cancer and normal cells and cell free samples is observed with much higher absorption intensity and a strong absorption peak at frequency of ~13 cm−1 dominating the spectra from cancer samples. Comparison of experimental spectra with MD predictions of spectroscopic signatures of microRNA molecules from the miR-200 family, known to be overexpressed in ovarian cancer, suggests an origin for this pronounced spectral peak. The rest of the cancer samples’ signature is in part similar to the signatures of normal cells and represents contributions from proteins and nucleic acid polymer molecules. Even though ovarian cancer is utilized for this proof of concept, the sub-THz spectroscopy method is very general and can be as well applied to other cancer types.