Genetic alterations in advanced HBV-related HCC with portal vein tumor thrombosis: insights from next generation DNA sequencing

Progress in research of hepatocellular carcinoma with tumor thrombus

Hepatocellular carcinoma (HCC) with tumor thrombus is a hot and difficult issue in the study of HCC, and many key issues concerning this condition are still controversial. Clinical guidelines and treatment recommendations vary widely between the East and the West, and efficacy remains unsatisfactory. In recent years, with the progress of comprehensive tumor treatment concept and the rapid development of surgical techniques, perioperative management, interventional therapy, radiotherapy, targeted therapy, and other treatment methods, the overall survival rate of HCC with tumor thrombus has been significantly extended and encouraging efficacy has been achieved. However, the core issues on how to select individualized treatment to achieve optimal treatment and how to prevent postoperative recurrence still need to be studied and discussed. This article reviews the progress in the research of hepatic carcinoma with portal vein thrombus, inferior vena cava thrombus, or bile duct thrombus.

Viral integration drives multifocal HCC during the occult HBV infection

BACKGROUND & AIMS

Although the prognosis of patients with occult hepatitis B virus (HBV) infection (OBI) is usually benign, a small portion may undergo cirrhosis and subsequently hepatocellular carcinoma (HCC). We studied the mechanism of life-long Integration of virus DNA into OBI host's genome, of which may induce hepatocyte transformation.

METHODS

We applied HBV capture sequencing on single cells from an OBI patient who, developed multiple HCC tumors and underwent liver resection in May 2013 at Tongji Hospital in China. Despite with the undetectable virus DNA in serum, we determined the pattern of viral integration in tumor cells and adjacent non-tumor cells and obtained the details of the viral arrangement in host genome, and furthermore the HBV integrated region in cancer genome.

RESULTS

HBV captured sequencing of tissues and individual cells revealed that samples from multiple tumors shared two viral integration sites that could affect three host genes, including CSMD2 on chr1 and MED30/EXT1 on chr8. Whole genome sequencing further indicated one hybrid chromosome formed by HBV integrations between chr1 and chr8 that was shared by multiple tumors. Additional 50 poorly differentiated liver tumors and the paired adjacent non-tumors were evaluated and functional studies suggested up-regulated EXT1 expression promoted HCC growth. We further observed that the most somatic mutations within the tumor cell genome were common among the multiple tumors, suggesting that HBV associated, multifocal HCC is monoclonal in origin.

CONCLUSION

Through analyzing the HBV integration sites in multifocal HCC, our data suggested that the tumor cells were monoclonal in origin and formed in the absence of active viral replication, whereas the affected host genes may subsequently contribute to carcinogenesis.

Effective combination therapy of percutaneous ethanol injection and chemotherapy based on injectable low molecular weight gels

Percutaneous ethanol injection (PEI) therapy was used in liver cancer treatment, however, the therapeutic ethanol in PEI easily flew away from injected solid tumours and hinder the treatment effect. In this paper, injectable supramolecular gels formed by self-assembly of low molecular weight gelators (LMWGs) based on glycylglycine modified phenylboronic acid were prepared to localize ethanol and load chemotherapeutic drug for in situ synergistic therapy. The mechanism, morphology and rheological property of supramolecular gels were characterized by NMR, UV, SEM, etc. The rheological study revealed that the gels were formed in situ rapidly and recovered promptly once damaged. The gels were non-toxicity to both normal 3T3 fibroblasts cells and 4T1 breast cancer cells. Doxorubicin (DOX) hydrochloride and ethanol were encapsulated in the gels for the combination of chemotherapy and PEI therapy. The in vivo anticancer activity of the DOX-loaded gels was carried out in tumour bearing mice. The injected gels were coated around tumour tissues to lock ethanol, and DOX was released sustainingly from the gels to maintain effective concentration to induce the apoptosis of tumour cells. DOX-loaded gels and the ethanol exhibited excellent therapeutic efficacy and low side effects in local cancer therapy.

Hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a heterogeneous tumor with many factors implicated in its development, with chronic infection and cirrhosis by hepatitis B virus (HBV) being the most prevalent. Cirrhosis due to metabolic syndrome, alcohol consumption, viral infection with hepatitis C virus (HCV) is also involved in its development. Treatment of HCC remains unsatisfactory. Therapeutic management for HCC includes liver transplantation, liver resection, ablation, chemoembolization, which depend on the tumor stage, liver function, and patient performance status. The involvement of different signaling pathways in the initiation and modulation of HCC development based on clinical and research data provided a strong rationale for the development of anti-cancer agents targeting key components of the pathways. The complexity of the tumor prevents the major goal of this therapeutic approach, since sorafenib, a multi-kinase inhibitor, is the only successful drug so far that belongs to the target directed therapy in advanced stage HCC.