NCBI Summary:
This gene encodes activated leukocyte cell adhesion molecule (ALCAM), also known as CD166 (cluster of differentiation 166), which is a member of a subfamily of immunoglobulin receptors with five immunoglobulin-like domains (VVC2C2C2) in the extracellular domain. This protein binds to T-cell differentiation antigene CD6, and is implicated in the processes of cell adhesion and migration. Multiple alternatively spliced transcript variants encoding different isoforms have been found. [provided by RefSeq, Aug 2011]
General function
Cell adhesion molecule
Comment
Cellular localization
Extracellular Matrix, Plasma membrane
Comment
Ovarian function
Oocyte maturation
Comment
Cumulus cell gene expression is associated with oocyte developmental quality and influenced by patient and treatment characteristics. Adriaenssens T et al. BACKGROUND Gene expression of cumulus cells (CC) could predict oocyte developmental quality. Knowledge of the genes involved in determining oocyte quality is scanty. The aim was to correlate clinical and biological characteristics during ovarian stimulation with the expression of 10 selected genes in CC. METHODS Sixty-three ICSI patients were stimulated with GnRH-agonist plus highly purified hMG (n = 35) or recombinant FSH (n = 28). Thirteen variables were analyzed: Age, BMI, duration of stimulation, serum concentrations of progesterone, 17beta-estradiol, FSH and LH on day of hCG, Ovarian Response, Oocyte Maturity, 2 pronuclei and three embryo morphology related variables: >/=7 cells, Low Fragmentation, Good Quality Embryos score. Expression of HAS2, VCAN, SDC4, ALCAM, GREM1, PTGS1, PTGS2, DUSP16, SPROUTY4 and RPS6KA2 was analyzed in pooled CC using quantitative PCR, and the relationship to the 13 variables was evaluated by multivariable analysis. RESULTS All 10 genes are expressed at oocyte retrieval, with PTGS1, SPROUTY4, DUSP16 and RPS6KA2 described in human ovary for the first time. The three variables that correlated most often with differential expression were Age, BMI and serum FSH level. Significant correlation was found with Oocyte Maturity (VCAN, P < 0.005), Low Fragmentation (RPS6KA2, P < 0.05), Embryos with >/=7 cells (ALCAM and GREM1, P < 0.05). The expression of the other genes was also correlated to oocyte developmental quality but to a less extent. SDC4, VCAN, GREM1, SPROUTY4 and RPS6KA2 showed gonadotrophin preparation-dependent expression and/or interactions (all P < 0.05). CONCLUSION The expression of ovulation related genes in CC is associated with patient and treatment characteristics, oocyte developmental potential and differs with the type of gonadotrophin used.
Expression regulated by
LH
Comment
High in microarray
Ovarian localization
Cumulus, Granulosa
Comment
Gene expression profiles of cumulus cell oocyte complexes (COCs) during ovulation reveal cumulus cells express neuronal and immune-related genes: Does this expand their role in the ovulation process
Hernandez-Gonzalez I, et al ?
Ovulation is a complex process initiated by the preovulatory LH surge, characterized by cumulus oocyte complex (COC) expansion and completed by the release of a mature oocyte. Although many ovarian genes that impact ovulation have been identified, we hypothesized that genes selectively expressed in COCs would be overlooked by approaches using whole ovary or granulosa cell samples. RNA isolated from COCs collected from preovulatory follicles of eCG-primed mice and at selected times following hCG treatment was subjected to microarray analyses and results confirmed by RT-PCR analyses, Western blotting and immunofluorescent studies. A remarkable number of genes was up-regulated in COCs including Areg, Ereg, and Btc. Several genes selectively expressed in cumulus cells compared with granulosa cells were related to neuronal (Mbp, Tnc, Nts) or immune (Alcam, Pdcd1, Cd34, Cd52 and Cxcr4) cell function. In addition to Sfrp2, other members of the Wnt/Fzd family (Sfrp4, Fdz1 and Fdz2) were expressed in COCs. Thus, there is a cumulus cell-specific, terminal differentiation process. Furthermore, immunofluorescent analyses documented that cumulus cells are highly mitotic for 4-8 h after hCG and then cease dividing in association with reduced levels of Ccnd2 mRNA. Other down-regulated genes included: Cyp19a1, Fshr, Inhb, and the oocyte factors Zp1-3 and Gja4. In summary, the vast number of matrix, neuronal and especially immune cell-related genes identified by the gene profiling data of COCs constitutes strong and novel evidence that cumulus cells possess a repertoire of immune functions that could be far greater than simply mediating an inflammatory-like response.