title: Decreased expression of connective tissue growth factor in non-small cell lung cancer is associated with clinicopathological variables and can be restored by epigenetic modifiers.
abstract: OBJECTIVE
  Recent studies indicated undisputed contribution of connective tissue growth factor (CTGF) in the development of many cancers, including non-small cell lung cancer (NSCLC). However, the functional role and regulation of CTGF expression during tumorigenesis remain elusive. Our goal was to determine CTGF transcript and protein levels in tumoral and matched control tissues from 98 NSCLC patients, to correlate the results with clinicopathological features and to investigate whether the CTGF expression can be epigenetically regulated in NSCLC.
  
  
  METHODS
  We used quantitative PCR, Western blotting and immunohistochemistry to evaluate CTGF expression in lung cancerous and histopathologically unchanged tissues. We tested the impact of 5-Aza-2'-deoxycytidine (5-dAzaC) and trichostatin A (TSA) on CTGF transcript and protein levels in NSCLC cells (A549, Calu-1). DNA methylation status of the CTGF regulatory region was evaluated by bisulfite sequencing. The influence of 5-dAzaC and TSA on NSCLC cells viability and proliferation was monitored by the trypan blue assay.
  
  
  RESULTS
  We found significantly decreased levels of CTGF mRNA and protein (both p < 0.0000001) in cancerous tissues of NSCLC patients. Down-regulation of CTGF occurred regardless of gender in all histological subtypes of NSCLC. Moreover, we showed that 5-dAzaC and TSA were able to restore CTGF mRNA and protein contents in NSCLC cells. However, no methylation within CTGF regulatory region was detected. Both compounds significantly reduced NSCLC cells proliferation.
  
  
  CONCLUSIONS
  Decreased expression of CTGF is a common feature in NSCLC; however, it can be restored by the chromatin-modifying agents such as 5-dAzaC or TSA and consequently restrain cancer development.
authors.affiliation: Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, Święcickiego 6 Street, 60-781, Poznan, Poland. hdrzewiecka@ump.edu.pl.
authors.forename: Hanna
authors.initials: H
authors.lastname: Drzewiecka
authors.affiliation: Department of Thoracic Surgery, Poznan University of Medical Sciences, Szamarzewskiego 62 Street, 60-569, Poznan, Poland.
authors.forename: Bartłomiej
authors.initials: B
authors.lastname: Gałęcki
authors.affiliation: Department of Clinical Pathomorphology, Poznan University of Medical Sciences, Przybyszewskiego 49 Street, 60-355, Poznan, Poland.
authors.forename: Donata
authors.initials: D
authors.lastname: Jarmołowska-Jurczyszyn
authors.affiliation: Department of Clinical Pathomorphology, Poznan University of Medical Sciences, Przybyszewskiego 49 Street, 60-355, Poznan, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Kluk
authors.affiliation: Department of Thoracic Surgery, Poznan University of Medical Sciences, Szamarzewskiego 62 Street, 60-569, Poznan, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Dyszkiewicz
authors.affiliation: Department of Biochemistry and Molecular Biology, Poznan University of Medical Sciences, Święcickiego 6 Street, 60-781, Poznan, Poland.
authors.forename: Paweł P
authors.initials: PP
authors.lastname: Jagodziński
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001374:Azacitidine / Q000031:analogs & derivatives* / Q000494:pharmacology; D014408:Biomarkers, Tumor / Q000235:genetics; D002289:Carcinoma, Non-Small-Cell Lung / Q000235:genetics* / Q000473:pathology; D055513:Connective Tissue Growth Factor / Q000235:genetics* / Q000378:metabolism; D019175:DNA Methylation / Q000187:drug effects; D000077209:Decitabine; D015536:Down-Regulation / Q000187:drug effects / Q000235:genetics; D044127:Epigenesis, Genetic / Q000187:drug effects*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006367:HeLa Cells; D056572:Histone Deacetylase Inhibitors / Q000494:pharmacology*; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D008175:Lung Neoplasms / Q000235:genetics* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D011401:Promoter Regions, Genetic / Q000187:drug effects; D014407:Tumor Cells, Cultured
chemical_list: D014408:Biomarkers, Tumor; C526317:CCN2 protein, human; D056572:Histone Deacetylase Inhibitors; D006877:Hydroxamic Acids; D055513:Connective Tissue Growth Factor; C012589:trichostatin A; D000077209:Decitabine; D001374:Azacitidine
keywords: 5-Aza-2′-deoxycytidine (5-dAzaC); Clinicopathological features; Connective tissue growth factor (CTGF); Epigenetic regulation; Non-small cell lung cancer (NSCLC); Trichostatin A (TSA)