Adeno-associated virus-mediated expression of apolipoprotein (a) kringles suppresses hepatocellular carcinoma growth in mice

Abstract

Hepatocellular carcinoma (HCC) constitutes more than 90% of all primary liver cancers. HCC is a hypervascular tumor that develops from dedifferentiation of small avascular HCC and is therefore a good target for anti-angiogenic gene therapy. Recent studies have identified apolipoprotein(a) [apo(a)] kringles LK68 and LK8 (LKs) as having a potential antiangiogenic and anti-tumor activity, and the current study evaluates the therapeutic potential of gene therapy with recombinant adeno-associated virus carrying genes encoding LKs (rAAV-LK) in the treatment of hypervascular HCC. We generated rAAV-LK to obtain persistent transgene expression in vivo, which is essential for anti-angiogenic therapy. The rAAV-produced LKs substantially inhibited proliferation and migration of human umbilical vein endothelial cells (HUVECs) in vitro, validating their anti-angiogenic potential. Intramuscular administration of rAAV-LK gave 60% to 84% suppression (P < .05) of tumor growth in mice bearing subcutaneously transplanted HCC derived from Huh-7 and Hep3B cells, respectively. Histological and immunohistochemical analyses of HCC tumor sections showed that a single administration of rAAV-LK gave rise to persistent expression of LKs that inhibited tumor angiogenesis and triggered tumor apoptosis, and, thus, significantly suppressed tumor growth. The administration of rAAV-LK provided a significant survival benefit (P < .05), and 3 of 10 rAAV-LK-treated mice were still alive without visible tumors and without clinical symptoms 188 days after treatment. In conclusion, rAAV-LK is a potential candidate for anti-angiogenic gene therapy in the treatment of HCC.

Low Lipoprotein(a) Concentration Is Associated with Cancer and All-Cause Deaths: A Population-Based Cohort Study (The JMS Cohort Study)

“…A recombinant protein (LK68) of LPA Kringle type IV and V experimentally suppressed tumor growth and capillary density within tumors in mice [11]. Gene therapy inducing an LK68 recombinant gene suppressed the tumor growth of transplanted hepatocellular carcinoma in mice [12] and liver metastasis and peritoneal dissemination in a murine colon cancer model [13], [14]. Tumor growth and angiogenesis were also suppressed in apo(a)-transgenic mice [15].…”

Tumor Anti-angiogenic Gene Therapy with Microencapsulated Recombinant CHO Cells

“…These methods are primarily the in vivo direct injection of the viral vectors. The viral vectors that have been used include adenovirus, 31 adeno-associated virus 29,43 and retrovirus, 41 and each method has its own advantages and limitations. Microencapsulation of recombinant cells represents a novel alternative non-viral approach to gene therapy in which therapeutic protein is sustainedly and long-term delivered by microencapsulated recombinant cells.…”

Human Apolipoprotein(a) Kringle V Inhibits Ischemia-Induced Retinal Neovascularization via Suppression of Fibronectin-Mediated Angiogenesis

“…We previously reported that rhLK8 exerted an antiangiogenic effect and that the recombinant adeno-associated virus–carrying gene encoding kringle domain V suppressed the growth of hepatocellular carcinoma in mice via inhibition of tumor angiogenesis (10,26). In this study, rhLK8 also effectively inhibited tube formation and migration of HUVECs in a dose-dependent manner at the concentrations administered without definite cellular and retinal toxicities.…”