Genomic instability of murine hepatocellular carcinomas with low and high metastatic capacities

Anti-metastasis traditional Chinese medicine monomer screening system based on perinucleolar compartment analysis in hepatocellular carcinoma cells

Hepatocellular Carcinoma (HCC) lacks effective anti-metastasis drugs. Traditional Chinese Medicine (TCM) monomers have shown anti-proliferation activity in HCC, but few of them are specifically anti-metastasis. Therefore, further clarifying the indicators of HCC metastasis and screening TCM monomers based on the indicators, will effectively guide the development of novel anti-HCC drugs. The perinucleolar compartment (PNC), existing in the nuclear of tumor cells, is closely correlated with metastasis of several tumors. In this study, we found positive correlation between higher PNC prevalence and metastasis in HCC tissue of patients. The PNC prevalence was also positively correlated with the malignancy of HCC cell lines. On this premise, we established a PNC-based screening system for anti-metastasis TCM monomers and obtained Camptothecin (CPT), Evodiamine and Isoglycyrrhizin, the three most effective TCM monomers from a TCM monomer library to reduce the PNC prevalence in Huh7 cells. The anti-metastasis effect of these TCM monomers was positively correlated with their PNC inhibitor effect. Our data further revealed that CPT reduced metastasis of Huh7 cells possibly by inhibiting Epithelial-Mesenchymal Transition by upregulating the expression of ZO-1, E-cadherin and Claudin-1. The PNC-based screening system is effective and it may provide an effective technical platform for the development of anti-metastasis drugs.

Relationship between Antiapoptotic Molecules and Metastatic Potency and the Involvement of DNA-Dependent Protein Kinase in the Chemosensitization of Metastatic Human Cancer Cells by Epidermal Growth Factor Receptor Blockade

The failure to treat metastatic cancer with multidrug resistance is a major problem for successful cancer therapy, and the molecular basis for the association of metastatic phenotype with resistance to therapy is still unclear. In this study, we revealed that various metastatic cancer cells showed consistently higher levels of antiapoptotic proteins, including Bcl-2, nuclear factor-kappaB, MDM2, DNA-dependent protein kinase (DNA-PK), and epidermal growth factor receptor (EGFR), and lower levels of proapoptotic proteins, including Bax and p53 than low metastatic parental cells. This was followed by chemo- and radioresistance in metastatic cancer cells compared with their parental cells. EGFR and DNA-PK activity, which are known to be associated with chemo- and radioresistance, were demonstrated to be mutually regulated by each other. Treatment with PKI166, an EGFR inhibitor, suppressed etoposide-induced activation of DNA-PK in A375SM metastatic melanoma cells. In addition, PKI166 enhanced markedly the chemosensitivities of metastatic cancer cell sublines to various anticancer drugs in comparison with those of low metastatic cancer cells. These results suggest that the activities of DNA-PK and EGFR, which is positively correlated with each other, may contribute to metastatic phenotype as well as therapy resistance, and the EGFR inhibitor enhances the effect of anticancer drugs against therapy-resistant metastatic cancer cells via suppression of stress responses, including activation of DNA-PK.