Abstract |
Fimbrins (also known as plastins) are actin-binding proteins of the cortical cytoskeleton present in all cells and conserved from yeast to mammals. We previously reported that the up-regulation of T- fimbrin, a fimbrin isoform, in association with G2 arrest following DNA damage and that a lack of T- fimbrin expression shortens the radiation-induced G2 arrest in Chinese hamster ovarian cells. In this study, we further investigated the role of T- fimbrin in DNA-damage response using a panel of human liver cancer cell lines and small interfering RNA technology. T- fimbrin was differentially expressed in human liver cancer cell lines. Colony formation assays revealed that cell lines lacking T- fimbrin expression were highly sensitive to DNA damage compared to cell lines that express T- fimbrin. Using siRNA designed to target T- fimbrin, we demonstrated that silencing endogenous T- fimbrin causes a marked increase in the cellular sensitivity to VP-16 and UV irradiation. Moreover, T- fimbrin deletion abrogated UV-mediated cell cycle checkpoint, and consequently led to increased apoptotic cell death in resistant cells. These findings suggest that the status of T- fimbrin expression may be a useful molecular marker for predicting the responsiveness of cancer cells to treatment with chemotherapeutic drugs.
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Authors | Hiroshi Ikeda, Yasushi Sasaki, Toshihisa Kobayashi, Hiromu Suzuki, Hiroaki Mita, Minoru Toyota, Fumio Itoh, Yasuhisa Shinomura, Takashi Tokino, Kohzoh Imai |
Journal | International journal of oncology
(Int J Oncol)
Vol. 27
Issue 4
Pg. 933-40
(Oct 2005)
ISSN: 1019-6439 [Print] Greece |
PMID | 16142308
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- Actins
- Antineoplastic Agents
- Antineoplastic Agents, Phytogenic
- Carcinogens
- Membrane Glycoproteins
- Microfilament Proteins
- Protein Isoforms
- RNA, Small Interfering
- plastin
- Etoposide
- Decitabine
- Azacitidine
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Topics |
- Actins
(chemistry)
- Antineoplastic Agents
(pharmacology)
- Antineoplastic Agents, Phytogenic
(pharmacology)
- Apoptosis
- Azacitidine
(analogs & derivatives, pharmacology)
- Carcinogens
(pharmacology)
- Cell Cycle
- Cell Line, Tumor
- Cell Separation
- Cytoskeleton
(metabolism)
- DNA Damage
- DNA Methylation
- Decitabine
- Etoposide
(pharmacology)
- Flow Cytometry
- G2 Phase
- Gene Expression Regulation, Neoplastic
- Gene Silencing
- Humans
- Immunoblotting
- Liver Neoplasms
(metabolism, pathology)
- Membrane Glycoproteins
(physiology)
- Microfilament Proteins
(physiology)
- Microscopy, Fluorescence
- Protein Isoforms
- RNA Interference
- RNA, Small Interfering
(metabolism)
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Transfection
- Ultraviolet Rays
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