Chenxing Zhang1, Chenyue Zhang2, Jiamao Lin3, Haiyong Wang4. 1. Department of Allergy and Immunology, Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicine, Shanghai, China. 2. Department of Integrative Oncology, Fudan University Shanghai Cancer Center, Shanghai, China. 3. Department of Internal Medicine-Oncology, Shandong Cancer Hospital and Institute, Shandong Cancer Hospital affiliated to Shandong University, Shandong Academy of Medical Sciences, Jinan, China. 4. Department of Internal Medicine-Oncology, Shandong Cancer Hospital and Institute, Shandong Cancer Hospital affiliated to Shandong University, Shandong Academy of Medical Sciences, Jinan, Chinawanghaiyong6688@126.com.
Abstract
BACKGROUND/AIMS: An increasing number of studies have suggested that circular RNAs (circRNAs) have vital roles in carcinogenesis and tumor progression. However, the function of circRNAs in hepatocellular carcinoma (HCC) remains poorly characterized. METHODS: We investigated the levels of circRNAs in patients with HCC to identify potential diagnostic biomarkers. We examined circRNA expression profiles in liver tumors and paired non-cancerous liver tissues from three HCC patients with cancer thrombus using a circRNA microarray. Bioinformatics analysis was performed to find circRNAs with significantly altered expression levels between tumors and their paired non-tumor tissues. We confirmed our initial findings by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) curves were also applied to identify a candidate circRNA with the optimal specificity and sensitivity. Finally, X-tile software was adopted to calculate the most efficient cut-off value for hsa_circ_0091579 expression. RESULTS: Microarray analysis identified 20 unique circRNAs that were differentially expressed between tumor and non-tumor tissues (P < 0.05). The expression of these 20 circRNAs was verified by qRT-PCR. The expression of hsa_circ_16245-1 and hsa_circ_0091579 mRNA was consistent with their levels as tested by the microarray. The ROC curves showed that both hsa_circ_16245-1 and hsa_circ_0091579 had favorable specificity and sensitivity. We further confirmed that hsa_circ_0091579 was significantly upregulated in HCC and its high expression was intimately associated with a worse overall survival in patients with HCC. CONCLUSION: Hsa_circ_0091579 may play a critical role in HCC progression and serve as a potential biomarker for the prognosis of patients with HCC.
BACKGROUND/AIMS: An increasing number of studies have suggested that circular RNAs (circRNAs) have vital roles in carcinogenesis and tumor progression. However, the function of circRNAs in hepatocellular carcinoma (HCC) remains poorly characterized. METHODS: We investigated the levels of circRNAs in patients with HCC to identify potential diagnostic biomarkers. We examined circRNA expression profiles in liver tumors and paired non-cancerous liver tissues from three HCC patients with cancer thrombus using a circRNA microarray. Bioinformatics analysis was performed to find circRNAs with significantly altered expression levels between tumors and their paired non-tumor tissues. We confirmed our initial findings by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Receiver operating characteristic (ROC) curves were also applied to identify a candidate circRNA with the optimal specificity and sensitivity. Finally, X-tile software was adopted to calculate the most efficient cut-off value for hsa_circ_0091579 expression. RESULTS: Microarray analysis identified 20 unique circRNAs that were differentially expressed between tumor and non-tumor tissues (P < 0.05). The expression of these 20 circRNAs was verified by qRT-PCR. The expression of hsa_circ_16245-1 and hsa_circ_0091579 mRNA was consistent with their levels as tested by the microarray. The ROC curves showed that both hsa_circ_16245-1 and hsa_circ_0091579 had favorable specificity and sensitivity. We further confirmed that hsa_circ_0091579 was significantly upregulated in HCC and its high expression was intimately associated with a worse overall survival in patients with HCC. CONCLUSION: Hsa_circ_0091579 may play a critical role in HCC progression and serve as a potential biomarker for the prognosis of patients with HCC.