Analysis of anti-cancer drug response in single cell assay microfluidic platform : Case study with lung cancer cell line

Abstract

Cancer is by far one of the leading cause of death. In conventional chemotherapy, first- or second-line drug is treated. However, it only benefits limited subpopulation of patients. To overcome the limitations, personalized medicine has been highlighted. One of the keys that brings to the personalized medicine is to understand the samples heterogeneity. Cancer cells are known to have heterogeneity depending on the internal signal system and secretory proteins of each cancer patients. Consequently, the characteristics of tumor quite differs from patients to patients, and it even varies in one tumor tissue. In order to reveal the tumors’ heterogeneity, single cell analysis has been employed. For effective therapy, several molecules in cancer cells should be analyzed simultaneously at single cell level. Many studies have shown the limitation in single cell analysis, such as low efficiency, only measures small amount of molecules or it detects only intracellular proteins or secretion molecules. Here, a developed high-throughput single cell assay microfluidic platform was used to analyze drug responses of lung cancer cell line. The single cell assay microfluidic platform consists of i) micro-chambers (# of chambers = 1,360) for manipulating single cancer cells, ii) micro pneumatic pumps for rapid single cancer cell lysis, and iii) barcode sensors of ten different secretory and intracellular proteins to analyze whether the given drug combination is effective or not. The combinatorial targeted therapy generated in this thesis is the combination of four drug containing pathway inhibitors (Osimertinib, LY294002, Ruxolitinib, and Selumetinib) treated on lung cancer cell line (H1975). Based on the single cell analysis conducted by mean fold change and correlation coefficient, it was found that the drug combination of Osimertinib and Ruxolitinib in certain ratio was the most effective combination and EGFR inhibitor with JAK inhibitor was the key factor to downregulate the cell proliferation. In addition, comparing Z score in non-drug treated group of single cancer cell, it was found that even in a same lung cancer cell line heterogeneity did exist. As the same manner as above, further analysis of OR drug treated group was organized. It was shown that p-STAT and M-CSF1 was the most down regulated protein compared to control group showing each -37.84 and -36.63 as a result. In addition, the standard deviation of p-STAT showed lower value (-6.80) compared to the control group while M-CSF1 shown higher (1.29) standard deviation compared to the control group. Which implies, due to the heterogeneity, even in down regulated proteins the tendency differs cell to cell.This demonstrates the developed single cell assay platform has the ability to show the heterogeneity of the lung cancer cell line (H1975) and by analyzing the single cell proteomics assay the device has the ability for personalized therapy.