Low density lipoprotein receptor (LDLR)-targeted lipid nanoparticles for the delivery of sorafenib and Dihydroartemisinin in liver cancers.

AIMS: Liver cancer is one of the leading causes of cancer mortality worldwide. Inspired by the biological structure and function of low-density lipoprotein (LDL), in this study, an ApopB-100 based targeted lipid nanoparticles was synthesized to improve the therapeutic efficacy in liver cancer treatment. MAIN METHODS: The biological composition of ApopB is similar to LDL which can effectively increase the targeting efficiency of nanoparticles in LDL receptor (LDLR)-overexpressed liver tumors. KEYFINDINGS: We have demonstrated that the co-administration of sorafenib (SRF) and Dihydroartemisinin (DHA) could exhibit synergistic anticancer effect in HepG2 liver cancer cells. DHA produced excessive cellular reactive oxygen species (ROS) and induced greater apoptosis of cancer cells. LDL-based SRF/DHA-loaded lipid nanoparticles (LD-SDN) showed remarkable decrease in the cell viability compared to that of either of single drug treated cancer cells. Combination of SRF+DHA resulted in predominant SubG1 proportion of cells. LD-SDN exhibited the highest SubG1 (%) of cells compared to that of any of the individual drugs. Most importantly, robust antitumor response and delayed tumor growth was observed for LD-SDN treated xenograft tumor model. Ki67 proliferation index of LD-SDN (22.1 ± 5.6%) is significantly lesser compared to that of either control (86.2 ± 6.9%) or SRF (75.4 ± 4.89%) or DHA (69.4 ± 6.9%). SIGNIFICANCES: These data provide strong evidence that LDL-mimetic lipid nanoformulations could be utilized as a biocompatible and tumor targeted platform for the delivery of multiple anticancer drugs in cancer treatment.

Norcantharidin enhances ABT-737-induced apoptosis in hepatocellular carcinoma cells by transcriptional repression of Mcl-1.

Small-molecule cell-permeable Bcl-2/Bcl-xL antagonist ABT-737 has recently emerged as a novel cancer therapeutic agent because it potently induces apoptosis in certain cancer cells. However, since ABT-737 binds to Mcl-1 with low affinity, ABT-737-mediated apoptosis signaling is inhibited in hepatocellular carcinoma (HCC) cells and other solid cancer cells due to the elevated expression of Mcl-1. Accordingly, strategies that target Mcl-1 are explored for overcoming ABT-737-resistance. In this study, we reported that Norcantharidin (NCTD), a small-molecule anticancer drug derived from Chinese traditional medicine blister beetle (Mylabris), induced transcriptional repression of Mcl-1 and considerably enhanced ABT-737-triggered cell viability inhibition and apoptosis in multiple HCC cell lines. Moreover, we observed that the enhancement of ABT-737-mediated apoptosis by NCTD was associated with activation of mitochondrial apoptosis signaling pathway, which involved cytosolic release of cytochrome c, cleavage of caspase-9 and caspase-3. Additionally, knockdown of Bax/Bak, the key effectors permeabilizing mitochondrial outer membrane significantly attenuated the enhancement, indicating mitochondrial apoptosis pathway played an essential role in the execution of the apoptosis. Finally, knockdown of Mcl-1 substantially potentiated ABT-737-mediated apoptotic cell death, confirming the potency of Mcl-1 repression by NCTD in enhancing ABT-737-induced apoptosis. These results therefore suggest that combination treatment with NCTD can overcome ABT-737 resistance and enhance ABT-737 therapeutic efficacy in treating human HCC.

siRNA-targeted COL8A1 inhibits proliferation, reduces invasion and enhances sensitivity to D-limonence treatment in hepatocarcinoma cells.

The COL8A1 (collagen type VIII, alpha-1) gene, which encodes the alpha 1 chain of collagen, type VIII, may modulate migration, proliferation and adherence of various cells. Only very sparse information exists on COL8A1 expression in hepatocarcinoma. To investigate the possible role of COL8A1 in the mouse hepatocarcinoma cell line Hca-F with highly metastatic potential in the lymph nodes, we used an RNA interference (RNAi) approach to silence COL8A1 expression. The results showed that a small interfering RNA (siRNA) targeted against COL8A1 significantly impeded Hca-F cells proliferation and colony formation in soft agar. This reduction of COL8A1 expression also led to the decreased invasion of Hca-F cells dramatically in vitro. Furthermore, the downregulation of COL8A1 expression also sensitized cells to the action of D-limonene. These data together provide insights into the function of COL8A1 and suggest that COL8A1 might represent a new potential target for gene therapy in hepatocarcinoma.