title: A novel placental like alkaline phosphatase promoter driven transcriptional silencing combined with single chain variable fragment antibody based virosomal delivery for neoplastic cell targeting [corrected].
abstract: BACKGROUND
  Placental like alkaline phosphatase (PLAP), an oncofetal antigen, is highly expressed in germ cell, cervical, ovarian and several other tumour types but minimally in normal tissues [corrected]. The expression of a PLAP promoter based transcriptional unit following antigen mediated cell specific delivery is a possible approach for tumour targeting.
  
  
  METHODS
  PLAP promoter alone or in combination with NFκB DNA response elements was used for expressing shRNA targeting the long control region (LCR) of human papillomavirus (HPV)-16 oncogenes E6 and E7 via transcriptional gene silencing in PLAP expressing cervical cancer cell lines, SiHa and CaSki. This was packaged in a Sendai virus envelope incorporating a single chain variable fragment antibody (scFv) for antibody mediated targeting. Specificity and efficacy of the shRNA was assessed by studying the heterochromatization, down regulation of the HPV-16 E6/E7 genes and subsequent effects on their targets and cell growth properties.
  
  
  RESULTS
  Reduction of HPV-16 E6 and E7 expression by TGS led to the activation of the previously suppressed target genes of p53 (PUMA and NOXA) and Rb (cyclins A2 and E). Cell death was seen only in PLAP expressing HPV-16 infected SiHa and CaSki cells but not in the HPV-18 integrated HeLa and non-PLAP CHO cells. There was reduction in the enhancer associated transcripts of the long control region (LCR) of HPV-16 E6/E7 genes. Also, an increase in the enrichment of dimethylated histone three lysine nine (H3K9Me2) and trimethylated histone three lysine twenty-seven (H3K27Me3) was observed by ChIP assay, which decreased upon trichostatin A treatment, indicating a possible mechanism for the heterochromatization of the target LCR region.
  
  
  CONCLUSIONS
  A combination of novel PLAP promoter and antibody based specificities has the potential for being developed as a possible therapeutic strategy for PLAP positive neoplasia.
authors.affiliation: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India. imranaiims@yahoo.com.
authors.forename: Imran
authors.initials: I
authors.lastname: Khan
authors.affiliation: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India. khalid_aiims@hotmail.com.|National Brain Research Centre, Manesar, Gurgaon, Haryana, 122051, India. khalid_aiims@hotmail.com.
authors.forename: Mohammad Khalid
authors.initials: MK
authors.lastname: Zakaria
authors.affiliation: National Brain Research Centre, Manesar, Gurgaon, Haryana, 122051, India. mraj03@gmail.com.
authors.forename: Mukesh
authors.initials: M
authors.lastname: Kumar
authors.affiliation: Department of Biochemistry, University of Delhi, South Campus, Benito Juarez Road, New Delhi, 110021, India. pmani27@gmail.com.
authors.forename: Prashant
authors.initials: P
authors.lastname: Mani
authors.affiliation: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India. parthoaiims@hotmail.com.
authors.forename: Parthaprasad
authors.initials: P
authors.lastname: Chattopadhyay
authors.affiliation: Department of Biochemistry, University of Delhi, South Campus, Benito Juarez Road, New Delhi, 110021, India. dpsarkar59@gmail.com.
authors.forename: Debi P
authors.initials: DP
authors.lastname: Sarkar
authors.affiliation: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, 110029, India. sub_sinha@hotmail.com.|National Brain Research Centre, Manesar, Gurgaon, Haryana, 122051, India. sub_sinha@hotmail.com.
authors.forename: Subrata
authors.initials: S
authors.lastname: Sinha
mesh_terms: D000469:Alkaline Phosphatase / Q000235:genetics*; D017209:Apoptosis; D020169:Caspases / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019175:DNA Methylation / Q000235:genetics; D050687:E2F1 Transcription Factor / Q000378:metabolism; D004742:Enhancer Elements, Genetic / Q000235:genetics; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D018014:Gene Transfer Techniques; D052162:Human papillomavirus 16 / Q000378:metabolism; D006801:Humans; D007527:Isoenzymes / Q000235:genetics*; D007700:Kinetics; D009369:Neoplasms / Q000378:metabolism*; D009856:Oncogene Proteins, Viral / Q000378:metabolism; D050725:Papillomavirus E7 Proteins / Q000235:genetics; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D057127:Single-Chain Antibodies / Q000378:metabolism*; D014158:Transcription, Genetic; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism; D022701:Virosomes / Q000378:metabolism*
chemical_list: D050687:E2F1 Transcription Factor; C068651:E6 protein, Human papillomavirus type 16; D007527:Isoenzymes; D009856:Oncogene Proteins, Viral; D050725:Papillomavirus E7 Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D012097:Repressor Proteins; D057127:Single-Chain Antibodies; D016159:Tumor Suppressor Protein p53; D022701:Virosomes; C055791:germ-cell AP isoenzyme; D000469:Alkaline Phosphatase; D020169:Caspases