Induction of Apoptosis in Human Oral Keratinocyte by Doxorubicin.
We have previously reported that doxorubicin (DXR) showed much higher cytotoxicity against human oral squamous cell carcinoma cell lines compared to normal human mesenchymal normal oral cells (gingival fibroblast, periodontal ligament fibroblast, pulp cell), yielding high tumor-specificity. However, we unexpectedly found that doxorubicin showed potent cytotoxicity against human normal oral keratinocytes and primary gingival epithelial cells. In the present study, we investigated the reproducibility, underlining mechanisms and generality of this unexpected finding.



Viable cell number was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide method, fine cell structure by transmission electron microscopy and apoptosis induction by western blot analysis.



Doxorubicin induced keratinocyte toxicity, regardless of cell density and concentration of FBS in the culture medium. Doxorubicin induced apoptosis (characterized by the loss of cell surface microvilli, chromatin condensation, nuclear fragmentation and caspase-3 activation) in keratinocytes. A total of 11 anticancer drugs showed similar keratinocyte toxicity. Alkaline extract of the leaves of Sasa senanensis Rehder partially alleviated the DXR-induced keratinocyte cytotoxicity by promoting cell growth.



The present study suggested that oral keratinocyte toxicity is a novel adverse effect of most anticancer agents.
Division of Pharmacology, Meikai University School of Dentistry, Sakado, Japan sakagami@dent.meikai.ac.jp takaakio@daiwaseibutsu.co.jp.|Meikai Pharmaco-Medical Laboratory (MPL), Meikai University School of Dentistry, Sakado, Japan.
Hiroshi
H
Sakagami
Division of Pharmacology, Meikai University School of Dentistry, Sakado, Japan.
Noriyuki
N
Okudaira
Meikai Pharmaco-Medical Laboratory (MPL), Meikai University School of Dentistry, Sakado, Japan.
Yoshiko
Y
Masuda
Division of Anatomy, Meikai University School of Dentistry, Sakado, Japan.
Osamu
O
Amano
Division of Endodontics, Meikai University School of Dentistry, Sakado, Japan.
Satoshi
S
Yokose
Department of Electron Microscope, Meikai University, School of Dentistry, Sakado, Japan.
Yumiko
Y
Kanda
Daiwa Biological Research Institute Co, Ltd., Kanagawa, Japan.
Madoka
M
Suguro
Daiwa Biological Research Institute Co, Ltd., Kanagawa, Japan.
Takenori
T
Natori
Daiwa Biological Research Institute Co, Ltd., Kanagawa, Japan.
Hiroshi
H
Oizumi
Daiwa Biological Research Institute Co, Ltd., Kanagawa, Japan.
Takaaki
T
Oizumi
D000970:Antineoplastic Agents / Q000009:adverse effects*; D017209:Apoptosis; D053148:Caspase 3 / Q000378:metabolism; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D002843:Chromatin / Q000378:metabolism; D004317:Doxorubicin / Q000009:adverse effects*; D005347:Fibroblasts / Q000187:drug effects / Q000473:pathology; D005881:Gingiva / Q000166:cytology; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects / Q000473:pathology*; D046529:Microscopy, Electron, Transmission; D009062:Mouth Neoplasms / Q000473:pathology; D010513:Periodontal Ligament / Q000166:cytology; D010936:Plant Extracts / Q000737:chemistry; D018515:Plant Leaves / Q000737:chemistry; D031787:Sasa / Q000737:chemistry
D000970:Antineoplastic Agents; D002843:Chromatin; D010936:Plant Extracts; D004317:Doxorubicin; C505407:CASP3 protein, human; D053148:Caspase 3
Cytotoxicity; keratinocyte toxicity; mesenchymal and epithelial normal oral cells; oral carcinoma; tumor selectivity