Inducing apoptosis and upregulation of Bax and Fas ligand expression by allicin in hepatocellular carcinoma in Balb/c nude mice

Many health benefits have been ascribed to allicin, including vasorelaxant activities. However, the molecular mechanisms underlying these effects remain unknown. To apply allicin in clinical anti-HCC treatment, different doses of allicin and Adriamycin （ADM） were led into transplanted tumor model established by injecting HCC BEL7402 cells into subcutaneous tissue of nude mice. Treatment with allicin and ADM resulted in tumor regression with inducing of Bax and Fas ligand （FasL） mRNA.

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.

Modulation of NRF2 and UGT1A expression by epigallocatechin-3-gallate in colon cancer cells and BALB/c mice

Background Green tea is an important source of flavonoids in human diets and epidemiological data correlate green tea consumption with a reduced cancer risk. Given its complicated properties at effective concentrations, we put epigallocatechin-3-gallate （EGCG） that previously reported on its anti-proliferative activities against several cancer cell lines on our research agenda to further examine the mechanism of its chemopreventive potential. Methods RNA interference （RNAi） expression vector pSilencer 3.1-H1 was used to construct recombinant nuclear factor erythroid 2 related factor 2 （Nrf2）-targeting RNAi plasmids. EGCG （5 μg/ml） was added into the culture fluid of cells before and after transfection. RT-PCR and Western blotting were used to detect the expression of uridine 5＇-diphosphate-glucuronosyltransferase （UGT）IA in cells. Forty male BALB/c mice were assigned to four groups： a normal unexposed control and three groups treated with varying doses of EGCG. Four weeks later, the mice were sacrificed, and their colon tissues were subjected to mRNA and protein expression of Nrf2 and UGT1A via RT-PCR and Western blotting analysis. Results EGCG up-regulated the expression of Nrf2 and increased the level of UGT1A in cells. The blockade of Nrf2 activity via RNA intervention largely attenuated the induction of UGT1A expression by EGCG. In mice, the mRNA and protein levels of Nrf2 and UGT1A detected by RT-PCR and Western blotting increased （both P 〈 0.05 compared with the control）. This increase in Nrf2 expression also had a positive correlation with an increased UGT1A expression. Conclusions EGCG mediated its effect in part by inducing the NRF2 signaling pathway and increasing UGT1A expression. Both in vitro and in vivo studies demonstrated the role of NRF2 and UGT1A expression in the potential use of EGCG as a possible chemopreventive agent and supported further study of EGCG for cancer treatment.

Down-regulation of human leukocyte antigens class I on peripheral T lymphocytes and NK cells from subjects in region of high-incidence gastrointestinal tumor

Background Many types of human tumors can suppress the immune system to enhance their survival. Loss or down-regulation of human leukocyte antigens （HLA） class I on tumors is considered to be a major mechanism of tumor immune escape. Our previous studies found that HLA class I on peripheral-blood mononuclear cells was significantly lower in gastric cancer patients. The present study made an analysis of HLA class I expression on peripheral-blood T lymphocytes and NK cells from subjects of Lijiadian village, a village with high-incidence gastrointestinal tumor. Methods A total of 181 villagers from Lijiadian village and 153 normal controls from the Department of Health Examination Center were enrolled in this study. Using a multi-tumor markers detection system, these villagers were divided into two groups： high-risk group （tumor markers positive group） and low-risk group （tumor markers negative group）. The percentage of T lymphocytes and NK cells and levels of HLA class I on their surface were determined in these subjects by flow cytometry. Results Percentages of T lymphocytes and NK cells in peripheral-blood mononuclear cells did not vary with age. The expression level of HLA class I on peripheral T lymphocytes and NK cells was not affected by age or gender, but was significantly down-regulated in Lijiadian villagers （P 〈0.05）, with the low-risk group, there was a significant reduction of cells （P 〈0.05） in the high-risk group. especially on the surface of NK cells （P 〈0.01）. Compared HLA class I on peripheral T lymphocytes （P 〈0.05） and NK Conclusions HLA class I on peripheral T lymphocytes and NK cells may be involved in tumorigenesis and development of gastrointestinal tumor, and understanding their changes in expression may provide new insights into the mechanism of tumor immunity.