Differences in the endometrial transcript profile during the receptive period between women who were refractory to implantation and those who achieved pregnancy.
BACKGROUND
Gene expression profiling of normal receptive endometrium has been characterized, but intrinsic defects in endometrial gene expression associated with implantation failure have not been reported.


METHODS
Women who had previously participated as recipients in oocyte donation cycles and repeatedly exhibited implantation failure (Group A, study group) or had at least one successful cycle (Group B, control group) and spontaneously fertile women (Group C, normal fertility group) were recruited. All were treated with exogenous estradiol and progesterone to induce an endometrial cycle, and an endometrial biopsy was taken on the seventh day of progesterone administration. RNA from each sample was analysed by cDNA microarrays to identify differentially expressed genes between groups.


RESULTS
63 transcripts were differentially expressed (>or=2-fold) between Groups A and B, of which 16 were subjected to real time RT-PCR. Eleven of these were significantly decreased in Group A with regard to Groups B and C. Among the dysregulated genes were MMP-7, CXCR4, PAEP and C4BPA.


CONCLUSIONS
Repeated implantation failure in some oocyte recipients is associated with an intrinsic defect in the expression of multiple genes in their endometrium. Significantly decreased levels of several transcripts in endometria without manifest abnormalities is demonstrated for the first time and shown to be associated with implantation failure.
Tapia
Alejandro
A
Departamento de Biología, Universidad de Santiago de Chile, Santiago, Chile. atapiap@gmail.com
Gangi
Lisa M
LM
Zegers-Hochschild
Fernando
F
Balmaceda
José
J
Pommer
Ricardo
R
Trejo
León
L
Pacheco
Isabel Margarita
IM
Salvatierra
Ana María
AM
Henríquez
Soledad
S
Quezada
Marisol
M
Vargas
Macarena
M
Ríos
Miguel
M
Munroe
David J
DJ
Croxatto
Horacio B
HB
Velasquez
Luis
L
D000328:Adult; D050716:Complement C4b-Binding Protein; D010064:Embryo Implantation; D004717:Endometrium / Q000378:metabolism*; D005260:Female; D020869:Gene Expression Profiling; D000071816:Glycodelin; D006023:Glycoproteins / Q000235:genetics; D006649:Histocompatibility Antigens / Q000235:genetics; D006801:Humans; D020783:Matrix Metalloproteinase 7 / Q000235:genetics; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism*; D019718:Receptors, CXCR4 / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction
C055609:C4BPA protein, human; D050716:Complement C4b-Binding Protein; D000071816:Glycodelin; D006023:Glycoproteins; D006649:Histocompatibility Antigens; C045246:PAEP protein, human; D011257:Pregnancy Proteins; D012333:RNA, Messenger; D019718:Receptors, CXCR4; C060932:MMP7 protein, human; D020783:Matrix Metalloproteinase 7