TY - JOUR
T1 - Chorionic gonadotropin synthesis by human tumor cell lines
T2 - examination of subunit accumulation, steady-state levels of mRNA, and gene structure
AU - Cosgrove, Dominic E.
AU - Campain, Julie A.
AU - Cox, G. Stanley
N1 - Funding Information:
This researchw as supportedb y grants from the National |nstituteso f Health (CA 36718)a nd the NebraskaD epartmenotf Health( 86-09).T he authors gratefullayc knowledge tgheen erougsi ftso f ChaGoa nd CBT cell lines from Ida Calvert andD r. Bruce Weintraub( NationalI nstituteso f Health),o f BeWo and JAR cell lines from Dr. R.A. Pattiilo (Medical Collegeo f Wisconsin),o f IM-9 cells from Dorothy Oleson and Dr. Donald Johnson (University of NebraskaM edical Center),o f recombinanptl asmids containingc DNAs for hCG-a and hCG.,0 subunits from Dr. John Fiddes( CaliforniaB iotechnologIyn,c .), and of LH, FSH, and TSH from Dr. JayanthaW ima-lasena( Universityo f NebraskaM edicalC enter).T he authorss incerelya ppreciatPea nt Walterf or her assis-tancei n the expertp reparatioonf this manuscripatn d her overalgl oodh umor.
PY - 1989/1/13
Y1 - 1989/1/13
N2 - A number of tumor cell lines have been examined that differentially produce human chorionic gonadotropin and the isolated α- or β-subunits. It has been demonstrated that all of the cell lines studied to date contain genes for both α- and β-subunits, indicating that differential and exclusive expression of one subunit is not the result of a particular cell line having lost the gene for the alternate subunit as a consequence of chromosome changes accompanying cell transformation. Because many of these established cell lines are aneuploid, it is also significant that no evidence was found for gene amplification in cell lines producing α-subunit at very high levels compared to those with very low level expression. Analysis of restriction endonuclease digests of tumor cell DNAs has demonstrated identical patterns for β-subunit in KpnI digests and KpnI/HinIII double digests. Polymorphisms were observed for α-subunit in EcoRI and HinIII digests, but these did not correspond with expression of the α-subunit. Significant levels of either mRNA (as determined by dot blot and Northern transfer hybridization analysis) were accompanied by corresponding elevated levels of α- and β-subunits (as determined by radioimmunoassay), suggesting that regulation of subunit production most likely occurs at a pretranslational stage. However, there were apparent differences in the relative ratio of α- and β-subunits and their cognate mRNAs among the cell lines.
AB - A number of tumor cell lines have been examined that differentially produce human chorionic gonadotropin and the isolated α- or β-subunits. It has been demonstrated that all of the cell lines studied to date contain genes for both α- and β-subunits, indicating that differential and exclusive expression of one subunit is not the result of a particular cell line having lost the gene for the alternate subunit as a consequence of chromosome changes accompanying cell transformation. Because many of these established cell lines are aneuploid, it is also significant that no evidence was found for gene amplification in cell lines producing α-subunit at very high levels compared to those with very low level expression. Analysis of restriction endonuclease digests of tumor cell DNAs has demonstrated identical patterns for β-subunit in KpnI digests and KpnI/HinIII double digests. Polymorphisms were observed for α-subunit in EcoRI and HinIII digests, but these did not correspond with expression of the α-subunit. Significant levels of either mRNA (as determined by dot blot and Northern transfer hybridization analysis) were accompanied by corresponding elevated levels of α- and β-subunits (as determined by radioimmunoassay), suggesting that regulation of subunit production most likely occurs at a pretranslational stage. However, there were apparent differences in the relative ratio of α- and β-subunits and their cognate mRNAs among the cell lines.
KW - (Human)
KW - Chorionic gonadotropin synthesis
KW - Gene structure
KW - Tumor cell-line
KW - mRNA, steady state level
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U2 - 10.1016/0167-4781(89)90128-0
DO - 10.1016/0167-4781(89)90128-0
M3 - Article
C2 - 2462449
AN - SCOPUS:0024562263
SN - 0167-4781
VL - 1007
SP - 44
EP - 54
JO - BBA - Gene Structure and Expression
JF - BBA - Gene Structure and Expression
IS - 1
ER -