Abstract: Phycocyanin (PC) is recognized as a natural food colorant in China, which can be used in the processing of many foods at low temperatures. PC is also an excellent functional pigment-protein complex. Lots of studies have reported that PC could exert a significant antitumor effect and inhibit the proliferation and migration of non-small cell lung cancer (NSCLC) cells. To get insights into the antineoplastic mechanism of phycocyanin in NSCLC cells, we performed high-throughput miRNA sequencing (miRNA-seq) to analyze the miRNA expression in A549 cells after undergoing phycocyanin treatment. The results indicated that both known and novel predicted miRNAs were sequenced successfully. Totally 136 differentially expressed miRNAs were selected by statistical analysis, including 74 up-regulated and 62 down-regulated miRNAs. Based on their expression levels, these 136 miRNAs could be clustered into 4 patterns. The quantitative real-time polymerase chain reaction (qPCR) validation results were consistent with the miRNA-seq results. Moreover, gene ontology (GO) annotation and functional enrichment analysis showed that cell proliferation related proteins such as PAK4, MAPK13 and RASSF10 were predicted as the potential novel targets of some important miRNAs, playing significant roles in the inhibitory effect of PC on NSCLC cells. Instead of traditional mRNA-seq, this study focused on investigating miRNAs involved in the inhibitory effect of PC on NSCLC cells, which will provide a theoretical foundation for the utilization of antineoplastic ingredients in functional foods and the targeted treatment of NSCLC.

Key words: phycocyanin; A549 cells; miRNA sequencing; cell proliferation; regulatory mechanism