Secretory Transactivating Transcription-apoptin fusion protein induces apoptosis in hepatocellular carcinoma HepG2 cells.

Abstract

AIM:

To determine whether SP-TAT-apoptin induces apoptosis and also maintains its tumor cell specificity.

METHODS:

In this study, we designed a secretory protein by adding a secretory signal peptide (SP) to the N terminus of Transactivating Transcription (TAT)-apoptin (SP-TAT-apoptin), to test the hypothesis that it gains an additive bystander effect as an anti-cancer therapy. We used an artificial human secretory SP whose amino acid sequence and corresponding cDNA sequence were generated by the SP hidden Markov model.

RESULTS:

In human liver carcinoma HepG2 cells, SP-TAT-apoptin expression showed a diffuse pattern in the early phase after transfection. After 48 h, however, it translocated into the nuclear compartment and caused massive apoptotic cell death, as determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and annexin-V binding assay. SP-TAT-apoptin did not, however, cause any cell death in non-malignant human umbilical vein endothelial cells (HUVECs). Most importantly, the conditioned medium from Chinese hamster ovary (CHO) cells transfected with SP-TAT-apoptin also induced significant cell death in HepG2 cells, but not in HUVECs.

CONCLUSION:

The data demonstrated that SP-TAT-apoptin induces apoptosis only in malignant cells, and its secretory property might greatly increase its potency once it is delivered in vivo for cancer therapy.

• Authors: Su-Xia Han, Jin-Lu Ma, Yi Lv, Chen Huang, Hai-Hua Liang, Kang-Min Duan
• Journal: World journal of gastroenterology (World J Gastroenterol) Vol. 14 Issue 23 Pg. 3642-9 (Jun 21 2008) ISSN: 1007-9327 [Print] United States
• PMID: 18595131 (Publication Type: Journal Article)

Chemical References

• Capsid Proteins
• Culture Media, Conditioned
• Gene Products, tat
• Protein Sorting Signals
• Recombinant Fusion Proteins

Topics

• Animals
• Apoptosis
• CHO Cells
• Capsid Proteins (genetics, metabolism)
• Carcinoma, Hepatocellular (genetics, metabolism, pathology, therapy)
• Cell Line, Tumor
• Cell Nucleus (metabolism, pathology)
• Cricetinae
• Cricetulus
• Culture Media, Conditioned (metabolism)
• Endothelial Cells (metabolism)
• Gene Products, tat (genetics, metabolism)
• Genetic Therapy (methods)
• Humans
• Liver Neoplasms (genetics, metabolism, pathology)
• Protein Sorting Signals (genetics)
• Recombinant Fusion Proteins (metabolism)
• Time Factors
• Transfection