title: Induction of apoptosis in HPV16 E7 transfected human keratinocyte by ALA-mediated photodynamic therapy.
abstract: OBJECTIVE
  5-Aminolevulinic acid (ALA)-mediated photodynamic therapy (ALA-PDT) is effective for the treatment of condyloma and intraepithelial neoplasia associated with human papillomaviruses (HPV). However, the mechanism of PDT on HPV-infected host cells is not fully understood. The aim of this in vitro study was to examine ALA-PDT induced apoptosis in a high-risk HPV E7 gene transfected cell line.
  
  
  METHODS
  HPV16 E7 gene obtained from HPV16 positive human cervical carcinoma was transfected into a human keratinocyte cell line. PpIX generation and ALA-PDT-induced apoptosis and mitochondrial damage were investigated in vitro.
  
  
  RESULTS
  Fluorescence examination showed that HPV16E7 transfected cells could produce PpIX fairly quickly in the presence of 1mM ALA. Apoptosis occurred after ALA-PDT at dose levels of 4, 8, and 12 J/cm(2). Mitochondrial potential collapse occurred as early as 2 h post PDT. ALA-PDT induced a relatively weak and shorter caspase-9 activation but a strong and long lasting caspase-3 activation. However, mRNA levels of caspase-9 and -3 genes in cells treated with ALA-PDT were unchanged.
  
  
  CONCLUSIONS
  This in vitro study demonstrated that HPV16 E7 transfected keratinocytes could generate PpIX in the presence of ALA. Under light irradiation, ALA-PDT could induce mitochondrial-dependent apoptosis in HPV16 E7 transfected cells.
authors.affiliation: Department of Dermatology, Huadong Hospital, Fudan University, Shanghai, PR China.
authors.forename: Fei
authors.initials: F
authors.lastname: Miao
authors.affiliation: Department of Dermatology, Huadong Hospital, Fudan University, Shanghai, PR China.
authors.forename: Ting
authors.initials: T
authors.lastname: Lv
authors.affiliation: Department of Dermatology and Venereology, Shanghai Skin Diseases Hospital, Shanghai, PR China.
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: University of Colorado Cancer Center, Denver, CO, USA; MOE Key Laboratory of OptoElectronic Science and Technology for Medicine, Fujian Normal University, Fuzhou, PR China.
authors.forename: Zheng
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Department of Dermatology and Venereology, Shanghai Skin Diseases Hospital, Shanghai, PR China.
authors.forename: Xiuli
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Dermatology, Huadong Hospital, Fudan University, Shanghai, PR China. Electronic address: hongweiwang2005@aliyun.com.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Wang
mesh_terms: D000622:Aminolevulinic Acid / Q000008:administration & dosage; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology / Q000528:radiation effects; D002460:Cell Line; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism* / Q000473:pathology; D008027:Light; D050725:Papillomavirus E7 Proteins / Q000235:genetics / Q000378:metabolism*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000008:administration & dosage; D011524:Protoporphyrins / Q000378:metabolism*; D014162:Transfection; D016896:Treatment Outcome
chemical_list: D050725:Papillomavirus E7 Proteins; D017319:Photosensitizing Agents; D011524:Protoporphyrins; C059731:oncogene protein E7, Human papillomavirus type 16; D000622:Aminolevulinic Acid; C028025:protoporphyrin IX
keywords: ALA; Apoptosis; HPV; Keratinocyte; PDT; PpIX