6 research outputs found
Evidence that human blastomere cleavage is under unique cell cycle control
To understand the molecular pathways that control early human embryo
development.
Improved methods of linear amplification of mRNAs and whole human genome
microarray analyses were utilized to characterize gene expression in
normal appearing 8-Cell human embryos, in comparison with published
microarrays of human fibroblasts and pluripotent stem cells.
Many genes involved in circadian rhythm and cell division were
over-expressed in the 8-Cells. The cell cycle checkpoints, RB and WEE1,
were silent on the 8-Cell arrays, whereas the recently described tumor
suppressor, UHRF2, was up-regulated > 10-fold, and the proto-oncogene,
MYC, and the core element of circadian rhythm, CLOCK, were elevated up
to > 50-fold on the 8-Cell arrays.
The canonical G1 and G2 cell cycle checkpoints are not active in
totipotent human blastomeres, perhaps replaced by UHRF2, MYC, and
intracellular circadian pathways, which may play important roles in
early human development
Genome-wide microarray evidence that 8-cell human blastomeres over-express cell cycle drivers and under-express checkpoints
Purpose To understand cell cycle controls in the 8-Cell human
blastomere.
Methods Data from whole human genome (43,377 elements) microarray
analyses of RNAs from normal 8-Cell human embryos were compiled with
published microarrays of RNAs from human fibroblasts, before and after
induced pluripotency, and embryonic stem cells. A sub database of 3,803
genes identified by high throughput RNA knock-down studies, plus genes
that oscillate in human cells, was analyzed.
Results Thirty-five genes over-detected at least 7-fold specifically on
the 8-Cell arrays were enriched for cell cycle drivers and for proteins
that stabilize chromosome cohesion and spindle attachment and limit DNA
and centrosome replication to once per cycle.
Conclusions These results indicate that 8-cell human blastomere cleavage
is guided by cyclic over-expression of key proteins, rather than
canonical checkpoints, leading to rapidly increasing gene copy number
and a susceptibility to chromosome and cytokinesis mishaps, well-noted
characteristics of preimplantation human embryos
Detection of RUNX2 gene expression in cumulus cells in women undergoing controlled ovarian stimulation
Abstract Background RUNX2 is a transcription factor, whose expression has been recently identified in the mouse ovary. Regulation of RUNX2 expression and its function in the human ovary have not been determined yet. The aim of the present study is the investigation of the possible correlation between RUNX2 gene expression in cumulus cells and controlled ovarian stimulation and pregnancy outcomes after ART treatment. Methods A total of 41 patients undergoing ICSI treatment for male factor infertility were enrolled into a specific ART program, during which cumulus cells were collected. The expression of RUNX2 gene in cumulus cells was examined by real-time PCR. Results Concerning RUNX2 gene expression, 12 out of 41 women were detected with RUNX2 expression, with ratios ranging from 0.84 to 1.00, while 28 out of 41 women had no expression (ratio = 0). Only 1 woman presented a weak RUNX2 gene expression (ratio = 0.52). From 8 women that proceeded to pregnancy, 7 of them did not express RUNX2 gene in cumulus cells, while one was the woman with weak gene expression that also achieved pregnancy. The group of women without RUNX2 expression presented higher number of follicles (p = 0.013), higher number of retrieved oocytes (p = 0.016), higher basal LH serum levels (p = 0.016) and higher peak estradiol levels (p = 0.013), while the number of fertilized oocytes differed marginally between the two groups (p = 0.089). Moreover, RUNX2 expression was negatively associated with LH levels (OR = 0.22, p = 0.021) and E2 levels (OR = 0.25, p = 0.026). Conclusions Consequently, based on the preliminary findings of the present pilot study a potential inhibitory mechanism of RUNX2 gene is observed in the ovary when high mRNA levels are detected, suggesting that RUNX2 could possibly be used as a candidate genetic marker in the monitoring of the outcome of an ART treatment.</p