Establishing of the Transplanted Animal Models for Human Lung Cancer

Lung cancer is the leading cause of cancer mortality worldwide.Even with the applications of excision, radiotherapy, chemotherapy, and gene therapy, the 5 year survival rate is only 15% in the USA. Clinically relevant laboratory animal models of the disease could greatly facilitate understanding of the pathogenesis of lung cancer, its progression, invasion and metastasis. Transplanted lung cancer models are of special interest and are widely used today. Such models are essential tools in accelerating development of new therapies for lung cancer. In this communication we will present a brief overview of the hosts, sites and pathways used to establish transplanted animal lung tumor models.

Anti-tumor effects of polybutylcyanoacrylate nanoparticles of diallyl trisulfide on orthotopic transplantation tumor model of hepatocellular carcinoma in BALB/c nude mice

Background Hepatocellular carcinoma （HCC） ranked the second among the causes of cancer mortality in China since the 1990s. Up to now, medication still plays an important role in the treatment of HCC. The therapies based on the allicin as a potential chemopreventive analog although is in its infancy at the present time, may have a significant role in the future management of HCC. Diallyl trisulfide （DATS） is a natural compound derived from garlic. In this study, we investigated the inhibitory effects of hepatic targeted polybutylcyanoacrylate nanoparticles of diallyl trisulfide （DATS-PBCA-NP） on orthotopic transplanted HepG2 hepatocellular carcinoma in nude mice. Methods DATS-PBCA-NP were detected by transmission electron microscope （TEM） and high-performance liquid chromatography （HPLC）. The orthotopic transplantation HCC models were established by implanting HCC HepG2 xenograft bits under the envelope of the mice liver. Successful models （n=29） were divided into 4 groups： normal saline （NS）, empty nanoparticles （EN）, DATS and DATS-PBCA-NP were intravenously administered to the mice respectively for 2 weeks. In vivo antitumor efficacy was evaluated by the measurement of tumor volume. Terminal deoxynucleotidyl transferase mediated dUTP nick end labeling （TUNEL） assay and protein levels of apoptosis and cell proliferation proteins by immunoblotting in tumor tissues were performed to elucidate the possible mechanism. Results DATS-PBCA-NP possessed smooth and round appearance, dispersed well, and released in vitro in accord with double phase kinetics model. DATS-PBCA-NP changed the tissue/organ distribution of DATS in vivo. The successful rate of tumor implantation was 100%. Intravenous administration of DATS-PBCA-NP significantly retarded the growth of orthotopically transplanted hepatoma in BALB/c nude mice （compared with the other three groups, all P〈0.05） without causing weight loss （P〉0.05）. TUNEL staining showed that the tumors from DATS-PBCA-NP treated mice exhibited a markedly higher apoptotic index compared with control tumors. Western blot analysis of tumor tissue revealed that the down-regulated expression of proliferation cell nuclear antigen （PCNA） and Bcl-2 proteins in DATS-PBCA-NP group, and there were no significant differences in the expression of Fas, FasL and Bax proteins among the four groups （P〉0.05）. Conclusions DATS-PBCA-NP has good prolonged release effect in vivo and hepatic-targeted activity, and significant anti,tumor effect on the orthotopic transplantation HCC model in mice in association with the suppression of proliferation and the induction of apoptosis of tumor cells. These advantages are probably due to their liver targeting characteristics and consequently bring a higher anti-tumor activity.