Researchers have developed a method for using Raman microscopy to detect tumor resistance in cancer cells in-vitro without the use of antibodies or markers. This could allow researchers to detect the possibility of resistance before drugs pass the preclinical phase. The findings are published in Scientific Reports.
The research was performed by scientists at the RUB Department of Biophysics, in collaboration with the RUB Department of Molecular GI-Oncology. They used the drugs erlotinib and osimertinib (trade names: Tarceva and Tagrisso), which have been approved for lung cancer therapy for their analysis. Both drugs are susceptible to patient resistance as protein changes can occur in cancer cells to evade the drugs’ effects.
To study resistance effects, proteins in cancer cell lines were mutated to simulate the protein changes that occur in drug resistant patients. Raman microscopy was used to generate a spectroscopic fingerprint of the cells’ molecular compositions and compare spectra before and after the drug treatment to analyze the chemical processes triggered by the drug.
In the mutated cells the drugs were ineffective, while the drugs were observed to be effective in non-mutated cancer cells. These results matched the clinical observations in patients who have developed resistance, demonstrating the effectiveness of this method for detecting resistance.
Unlike conventional methods, such as Western blot and high throughput screening assays based on fluorescence, Raman microscopy can measure protein changes directly rather than the response of a single tagged protein. This gives researchers a more wholistic picture of what is occurring and could help avoid the possibility of obtaining descriptive results when analyzing single signal transduction pathways.