TAT-apoptin is efficiently delivered and induces apoptosis in cancer cells.
Apoptin has been described to induce apoptosis in various human cancer cell lines, but not in normal cells, thus making it an interesting candidate for the development of novel therapeutic strategies. Apoptin was generated and cloned into several mammalian expression vectors. Transfection or microinjection of apoptin cDNA resulted in its expression, initially in the cytoplasm with a filamentous pattern. Subsequently, apoptin entered the nucleus and efficiently induced apoptosis in several cancer cell lines. Nuclear localization was shown to be required for induction of apoptosis. Apoptin expression level was found to be an important determinant of the efficiency of induction of apoptosis. Surprisingly, expression of apoptin or GFP-apoptin cDNA induced apoptosis in some normal cells. When fused to the HIV-TAT protein transduction domain and delivered as a protein, TAT-apoptin was transduced efficiently (>90%) into normal and tumour cells. However, TAT-apoptin remained in the cytoplasm and did not kill normal 6689 and 1BR3 fibroblasts. In contrast TAT-apoptin migrated from the cytoplasm to the nucleus of Saos-2 and HSC-3 cancer cells resulting in apoptosis after 24 h. This study shows that apoptin is a powerful apoptosis-inducing protein with a potential for cancer therapy.
Guelen
Lars
L
Head and Neck Oncology Group, Department of Oral Medicine and Pathology, The Rayne Institute, Guy's, King's and St Thomas' School of Medicine and Dentistry, London, UK.
Paterson
Hugh
H
Gäken
Joop
J
Meyers
Michelle
M
Farzaneh
Farzin
F
Tavassoli
Mahvash
M
D021581:Active Transport, Cell Nucleus; D017209:Apoptosis; D036022:Capsid Proteins / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use*; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D015696:Gene Products, tat / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000627:therapeutic use*; D015316:Genetic Therapy / Q000379:methods*; D005822:Genetic Vectors; D049452:Green Fluorescent Proteins; D006367:HeLa Cells; D006801:Humans; D007700:Kinetics; D008164:Luminescent Proteins / Q000378:metabolism; D009369:Neoplasms / Q000188:drug therapy* / Q000378:metabolism; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism / Q000627:therapeutic use
D036022:Capsid Proteins; D015696:Gene Products, tat; D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; C091717:VP3 protein, Chicken anemia virus; D049452:Green Fluorescent Proteins