Combination of Nanoparticle-Delivered siRNA for Astrocyte Elevated Gene-1 (AEG-1) and All-trans Retinoic Acid (ATRA): An Effective Therapeutic Strategy for Hepatocellular Carcinoma (HCC)

Abstract

Hepatocellular carcinoma (HCC) is a fatal cancer with no effective therapy. Astrocyte elevated gene-1 (AEG-1) plays a pivotal role in hepatocarcinogenesis and inhibits retinoic acid-induced gene expression and cell death. Combination of a lentivirus expressing AEG-1 shRNA and all-trans retinoic acid (ATRA) profoundly and synergistically inhibited subcutaneous human HCC xenografts in nude mice. We now have developed liver-targeted nanoplexes by conjugating poly(amidoamine) (PAMAM) dendrimers with polyethylene glycol (PEG) and lactobionic acid (Gal) (PAMAM-PEG-Gal) which were complexed with AEG-1 siRNA (PAMAM-AEG-1si). The polymer conjugate was characterized by 1H-NMR, MALDI and mass spectrometry, and optimal nanoplex formulations were characterized for surface charge, size and morphology. Orthotopic xenografts of human HCC cell QGY-7703 expressing luciferase (QGY-luc) were established in the livers of athymic nude mice and tumor development was monitored by bioluminescence imaging (BLI). Tumor-bearing mice were treated with PAMAM-siCon, PAMAM-siCon+ATRA, PAMAM-AEG-1si and PAMAM-AEG-1si+ATRA. In the control group the tumor developed aggressively. ATRA showed little effect due to high AEG-1 levels in QGY-luc cells. PAMAM-AEG-1si showed significant reduction in tumor growth and the combination of PAMAM-AEG-1si+ATRA showed profound and synergistic inhibition so that the tumors were almost undetectable by BLI. A marked decrease in AEG-1 level was observed in tumor samples treated with PAMAM-AEG-1si. The group treated with PAMAM-AEG-1si+ATRA nanoplexes showed increased necrosis, inhibition of proliferation and increased apoptosis when compared to other groups. Liver is an ideal organ for RNAi therapy and ATRA is an approved anti-cancer agent. Our exciting observations suggest that the combinatorial approach might be an effective way to combat HCC.

Oncogenic Role of SND1 in Development and Progression of Hepatocellular Carcinoma

“…The human HCC cell line QGY-7703 was developed at Fudan University, Shanghai, obtained from Dr. Zhao-zhong Su in 2008, and cultured as described (23). Generation and characterization of QGY-7703 cells expressing luciferase (QGY-luc) have been described (24,25). Early passage (>5) cultures of QGY-7703 and QGY-luc cells were stored in liquid nitrogen and in vivo studies described in this manuscript were performed with freshly thawed culture of the cells after confirming mycoplasma-free using mycoplasma detection kit (ThermoFisher Scientific).…”

Ligand-based targeted therapy: a novel strategy for hepatocellular carcinoma

“…54 Lactobionic acid (LA), comprising gluconic acid and Gal moiety, is the common ligand for hepatoma-targeted delivery. [55][56][57] The Gal residues on drug delivery system can recognize and bind specifically to the ASGPR on the hepatoma cells, 58,59 thus they facilitate drug delivery into the cells, which are inhibited and killed by therapeutic agents in delivery vehicles. Zhong's group developed a series of Gal-directed hepatoma-targeting delivery system to enhance the accumulation of anticancer drugs into and antitumor activity toward hepatoma cells.…”

Dendrimers as Drug Nanocarriers: The Future of Gene Therapy and Targeted Therapies in Cancer

“…They have been successfully used as nucleic acid delivery systems in many in vitro and in vivo researches of which we present selected examples [107][108][109][110][111][112][113][114][115][116][117][118][119].…”

“…Researchers from Virginia Commonwealth University used nanoplexes of PAMAM dendrimer with polyethylene glycol and lactobionic acid complexed with AEG-1 siRNA against hepatocellular carcinoma (HCC), a fatal cancer with no effective therapy. Applied in the combination with all-trans retinoic acid (ATRA), the complex developed a profound and synergistic inhibition in tumor growth in human HCC xenografts model suggesting, that combinatorial approach might be an effective way to combat resistant types of cancer [117]. Liu et al used PAPMAM dendrimers as a nanoparticle delivery platform for a MDR1 gene targeting siRNA to reverse multidrug resistance (MDR) in human breast cancer MCF-7/ADR cells.…”