SP1-regulated p27/Kip1 gene expression is involved in terbinafine-induced human A431 cancer cell differentiation: an in vitro and in vivo study.
In this study, the differentiation-promoting effects of terbinafine (Lamisil), TB) were investigated in human epithelioid squamous carcinoma (A431) cells. The polyhydroxyethylmethacrylate (poly-HEMA)- and type-I collagen-coated culture plate models were adapted to harvest the TB-induced differentiated cells by agitation of the suspension medium. We demonstrated that p27/Kip1, p21/Cip1 and the keratinocyte differentiation marker, human involucrin (hINV), were induced (>25 microM) in TB-induced differentiated A431 cells. Animal studies demonstrated that administration of TB (10 mg/kg body weight) inhibited A431-xenografted tumor growth through differentiation processes as evidenced by expression of pancytokeratin in tumor tissues. Immunocytochemical staining analysis showed that p27/Kip1, but not p21/Cip1, positive-stained cells were detected in the early-differentiated cells of TB-treated tumor tissues. SP1, which regulates p27/Kip1 expression, was induced by TB (>10 microM) in A431 cells. The TB-induced promoter activity and protein expression levels of p27/Kip1 were significantly attenuated by pretreatment with mithramycin A, a SP1 specific inhibitor. We also demonstrated that TB-induced differentiated A431 cells sorted from the poly-HEMA-coated culture plates were arrested in the G1 phase. TB-induced G1 arrest in the suspension-cultured cells was attenuated by mithramycin A pretreatment. Such results suggest that SP1 plays a critical role in the p27/Kip1 gene transcriptional activation that may be subsequently involved in the TB-induced A431 cancer cell differentiation process.
Huang
Ching-Shui
CS
Department of Surgery, Cathay Medical Center, Taipei, Taiwan.
Ho
Wei-Lu
WL
Lee
Wen-Sen
WS
Sheu
Ming-Thau
MT
Wang
Ying-Jan
YJ
Tu
Shih-Hsin
SH
Chen
Rong-Jane
RJ
Chu
Jan-Show
JS
Chen
Li-Ching
LC
Lee
Chia-Hwa
CH
Tseng
How
H
Ho
Yuan-Soon
YS
Wu
Chih-Hsiung
CH
D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002453:Cell Cycle / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D045744:Cell Line, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000235:genetics*; D015870:Gene Expression / Q000187:drug effects*; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D009281:Naphthalenes / Q000494:pharmacology* / Q000627:therapeutic use; D009368:Neoplasm Transplantation; D008926:Plicamycin / Q000031:analogs & derivatives / Q000494:pharmacology; D016329:Sp1 Transcription Factor / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000502:physiology*; D000077291:Terbinafine; D023041:Xenograft Model Antitumor Assays
D000970:Antineoplastic Agents; D050759:Cyclin-Dependent Kinase Inhibitor p21; D009281:Naphthalenes; D016329:Sp1 Transcription Factor; D050760:Cyclin-Dependent Kinase Inhibitor p27; C066851:mithramycin A; D000077291:Terbinafine; D008926:Plicamycin