title: Reduction of human chorionic gonadotropin beta subunit expression by modified U1 snRNA caused apoptosis in cervical cancer cells.
abstract: BACKGROUND
  Secretion of human chorionic gonadotropin, especially its beta subunit by malignant trophoblastic tumors and varieties of tumors of different origin is now well documented; however the role of hCG in tumorogenesis is still unknown.
  
  
  RESULTS
  This study documents the molecular presence of human chorionic gonadotropin beta subunit in uterine cervix cancer tissues and investigates a novel technique to reduce hCGbeta levels based on expression of a modified U1 snRNA as a method to study the hormone's role in biology of human cervical cancer cells cultured in vitro. The property of U1 snRNA to block the accumulation of specific RNA transcript when it binds to its donor sequence within the 3' terminal exon was used. The first 10 nucleotides of the human U1 snRNA gene, which normally binds to the 5'ss in pre-mRNA were replaced by a sequence complementary to a 10-nt segment in the terminal exon of the hCGbeta mRNA. Three different 5' end-mutated U1 snRNA expression plasmids were tested, each targeting a different sequence in the hCGbeta mRNA, and we found each one blocked the expression of hCGbeta in HeLa cells, a cervix carcinoma cell line, as shown by immunohistochemistry and qRT-PCR. Reduction of hCGbeta levels resulted in a significantly increased apoptosis rate with almost 90% of cells transfected with modified anti-hCGbeta U1 snRNAs showing morphological changes characteristic of the apoptotic process.
  
  
  CONCLUSIONS
  These data suggest that human chorionic gonadotropin beta subunit may act as a tumor growth-stimulating factor.
authors.affiliation: Department of Cell Biology, University of Medical Sciences, Rokietnicka 5D, Poznan, Poland. ajanko@amp.edu.pl
authors.forename: Anna
authors.initials: A
authors.lastname: Jankowska
authors.forename: Samuel I
authors.initials: SI
authors.lastname: Gunderson
authors.forename: Miroslaw
authors.initials: M
authors.lastname: Andrusiewicz
authors.forename: Beata
authors.initials: B
authors.lastname: Burczynska
authors.forename: Anna
authors.initials: A
authors.lastname: Szczerba
authors.forename: Artur
authors.initials: A
authors.lastname: Jarmolowski
authors.forename: Ewa
authors.initials: E
authors.lastname: Nowak-Markwitz
authors.forename: Jerzy B
authors.initials: JB
authors.lastname: Warchol
mesh_terms: D017209:Apoptosis; D002453:Cell Cycle; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D020868:Gene Silencing; D006367:HeLa Cells; D006801:Humans; D007150:Immunohistochemistry; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012342:RNA, Small Nuclear / Q000378:metabolism*; D014162:Transfection; D002583:Uterine Cervical Neoplasms / Q000235:genetics / Q000473:pathology*
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D012333:RNA, Messenger; D012342:RNA, Small Nuclear; C405483:U1 small nuclear RNA