Synergistic antitumoral activity and induction of apoptosis by novel pan Bcl-2 proteins inhibitor apogossypolone with adriamycin in human hepatocellular carcinoma.

Abstract

AIM:

To investigate the in vitro and in vivo activities and related mechanism of apogossypolone (ApoG2) alone or in combination with adriamycin (ADM) against human hepatocellular carcinoma (HCC).

METHODS:

The IC50 of ApoG2 in vitro was tested by WST assay, and the synergistic effect was analyzed using the CalcuSyn method. Cell apoptosis was determined using 4',6-diamidino-2- phenylindole staining and flow cytometric analysis. Western blotting was used to determine the expression of apoptosis-related proteins. In vivo activity was evaluated in the xenograft model in nude mice, and apoptosis in tumor tissues was determined by terminal deoxynucleotidyl transferase-mediated digoxigenin-dUTP nick-end labeling (TUNEL) assay.

RESULTS:

The IC50 of ApoG2 in HCC cells was 17.28-30.63 micromol/L. When ApoG2 was combined with ADM, increased cytotoxicity and apoptosis were observed in SMMC-7721 cells compared to treatment with ApoG2 alone. The Western blotting results indicated that the ApoG2 induced apoptosis in SMMC-7721 cells by downregulating anti-apoptotic proteins Bcl-2, Mcl-1, and Bcl-XL, up-regulating pro-apoptotic protein Noxa, and promoting the activities of caspases-9 and -3. The tumor growth of xenograft SMMC-7721 was inhibited in nude mice when ApoG2 was administered orally without causing damage to the normal tissues. The in vivo study also indicated an increasing anti-tumoral effect when ApoG2 at 100 or 200 mg/kg dosages were used together with ADM at 5.5 mg/kg, with relative tumor proliferation rate (T/C) values of 0.456 and 0.323, respectively. Apoptosis induced in vivo by ApoG2 alone or combined with ADM was confirmed by TUNEL assay in tumor tissues.

CONCLUSION:

ApoG2 is a potential non-toxic target agent that induces apoptosis by upregulating Noxa, while inhibiting anti-apoptotic proteins and promoting the effect of chemotherapy agent ADM in HCC.

• Authors: Jin-xia Mi, Guang-feng Wang, Heng-bang Wang, Xiao-qing Sun, Xin-yan Ni, Xiong-wen Zhang, Jia-ming Tang, Da-jun Yang
• Journal: Acta pharmacologica Sinica (Acta Pharmacol Sin) Vol. 29 Issue 12 Pg. 1467-77 (Dec 2008) ISSN: 1745-7254 [Electronic] United States
• PMID: 19026166 (Publication Type: Journal Article)

Chemical References

• Antibiotics, Antineoplastic
• PMAIP1 protein, human
• Proto-Oncogene Proteins c-bcl-2
• apogossypolone
• Doxorubicin
• Gossypol

Topics

• Animals
• Antibiotics, Antineoplastic (pharmacology, therapeutic use)
• Apoptosis (drug effects)
• Carcinoma, Hepatocellular (drug therapy, pathology, physiopathology)
• Cell Line, Tumor
• Dose-Response Relationship, Drug
• Doxorubicin (pharmacology, therapeutic use)
• Drug Therapy, Combination
• Gossypol (analogs & derivatives, pharmacology, therapeutic use)
• Humans
• In Situ Nick-End Labeling
• Liver Neoplasms (drug therapy, pathology, physiopathology)
• Mice
• Mice, Nude
• Molecular Structure
• Neoplasm Transplantation
• Proto-Oncogene Proteins c-bcl-2 (antagonists & inhibitors, genetics, metabolism)
• Transplantation, Heterologous