Quantitative analysis of dsRNA and splicing variant for personalized therapy

Abstract

As the number of cancer patients increases, various problems arise in cancer patients due to many factors such as inaccurate diagnosis, inappropriate drugs, and incomplete compliance. It is important to classify cancer patients through responsiveness to anticancer drugs and early diagnosis of subtype of cancer and prediction of prognosis. This is essential in cancer research as it can facilitate the subsequent clinical management of cancer patients. To solve this problem, we applied biomarkers that can objectively measure the normal or pathological state and response to drugs. In particular, RNA transfers genetic and regulatory information and reflects the state of cells, so it is an accurate and useful biomarker. Accordingly, we intend to use RNA biomarkers with diagnostic technology that can observe early diagnosis and prognosis of cancer for customized medical technology and patient-friendly treatment. In this study, we predicted drug sensitivity by measuring double-stranded RNA (dsRNA) produced by hypodemethylating agents and investigated the role of AIMP2-DX2 produced by aberrant alternative splicing in colorectal cancer. Therefore, it suggests the possibility of accurate and effective cancer diagnosis and treatment through dsRNA and splicing variants.In chapter 2, Double stranded RNAs (dsRNAs) known as endogenous retroviruses (ERVs) are usually upregulated during cellular damage. Understanding the role of dsRNA in cell signaling is important to verify the correlation between dsRNA and cell death. In this study, we developed a new spiropyran (SP)-based indicator that can efficiently sense dsRNA molecules to reveal how dsRNA release influenced cell death. By employing amidine-conjugated spiropyran (Am-SP), we verified that treatment of DAC increased expression of dsRNA in several cancers or hematological patients, resulting in immune-induced cell death. Therefore, dsRNA will be harnessed as a potential biomarker for evaluating programmed cell death. Moreover, this detection system may contribute to personalizing drugs to patients by testing drug responsiveness.In chapter 3, In previous studies, it was reported that AIMP2-DX2 is expressed in various cancer cells, promotes cancer development and progression, and has a poor clinical prognosis. We investigated AIMP2-DX2 in colorectal cancer cells by confirming the existence of a large number of AIMP2-DX2 in colorectal cancer through analysis of PCAWG, ICGC, and TCGA databases. It was confirmed that AIMP2-DX2 differs in distribution according to cellular compartments such as the nucleus and cytoplasm, and also affects apoptosis.Through the analysis of RNA sequencing data, it was confirmed that AIMP2-DX2 particularly regulates the immune response and is also related to the clinical prognosis of colorectal cancer patients. Therefore, this study aims to investigate the function of AIMP2-DX2 expressed in colorectal cancer cells and further suggest the possibility of treatment of colorectal cancer and prediction of clinical outcomes in patients.