Colorectal cancer (CRC) is one of the most common malignancies worldwide. Metastasis is the major cause of death in patients with CRC. Lycorine, the phenanthridine alkaloid most commonly found in spp of the Amaryllidaceae family, has shown promising anticancer activities with minor side effects. However, the effects and the detailed mechanism of lycorine against metastasis of CRC remains unclear. The purpose of this study was to investigate the effects of lycorine on CRC and characterize the molecular mechanisms observed in lycorine-treated CRC cells using RNA-sequencing. MTT assay, colony formation assay, acridine orange/ethidium bromide (AO/EB) staining and Annexin V-FITC/Propidium iodide (PI) staining were conducted to examine the effects of lycorine on cell proliferation and apoptosis in CRC cells. RNA sequencing, real-time PCR assays and western blot were performed. Migration and invasion abilities of lycorine-treated CRC cells were investigated by wound healing and transwell invasion assays. The mouse CRC lung metastasis model was established and was used to detect the effect of lycorine on CRC in vivo. Our results demonstrated that lycorine inhibited the proliferation and colony formation of CRC cells in a concentration-dependent manner. AO/EB staining and Annexin V-FITC/PI staining showed that lycorine induced apoptosis in a concentration-dependent manner. Lycorine also reduced lung metastasis of CRC in vivo. Moreover, transcriptomic analysis suggested that lycorine regulated the expression of 3556 genes. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway was implicated according to the differentially expressed genes (DEGs), and multiple pathways including those of mitogen-activated protein kinase (MAPK), relaxin, Ras, phosphatidylinositol 3‑kinase (PI3K)-protein kinase B (Akt) and Wnt/β-catenin were selected by functional enrichment analyses. Furthermore, based on transcriptomic analysis, we found that the tumor necrosis factor (TNF) pathway and endoplasmic reticulum stress were responsible for lycorine-induced apoptosis. These results obtained in this study demonstrated that lycorine has the potential to suppress CRC in vitro and in vivo through the lycorine-regulated multiple signaling pathways.

Two kinds of naphthalimide derivatives were synthesized and evaluated for in vitro their anti-hepatocellular carcinoma properties. Compound 3a with a fused thiazole fragment to naphthalimide skeleton inhibited cell migration of SMMC-7721 and HepG2, and further in vivo trials with two animal models confirmed that compound 3a moderately inhibited primary H22 tumor growth (52.6%) and potently interrupted lung metastasis (75.7%) without obvious systemic toxicity at the therapeutic dose. Mechanistic research revealed that compound 3a inhibited cancerous liver cell growth mostly by inducing G2/M phase arrest. Western blotting experiments corroborated that 3a could up-regulate the cell cycle related protein expression of cyclin B1, CDK1 and p21, and inhibit cell migration by elevating the E-cadherin and attenuating integrin α6 expression. Our study showed that compound 3a is a valuable lead compound worthy of further investigation.