Recently, we purified from adult murine bone marrow (BM) a population of CXCR4À very small embryonic-like (VSEL) stem cells and hypothesized that similar cells could be also present in human cord blood (CB). Here, we report that by employing a novel two-step isolation procedure -removal of erythrocytes by hypotonic lysis combined with multiparameter sorting -we could isolate from CB a population of human cells that are similar to murine BM-derived VSELs, described previously by us. These CBisolated VSELs (CB-VSEL) are very small (3-5 lm) and highly enriched in a population of CXCR4À CB mononuclear cells, possess large nuclei containing unorganized euchromatin and express nuclear embryonic transcription factors Oct-4 and Nanog and surface embryonic antigen SSEA-4. Further studies are needed to see if human CB-isolated VSELs similar to their murine BM-derived counterparts are endowed with pluripotent stem cell properties.

Variants in the CHEK2 have been found to be associated with prostate cancer risk in the United States and Finland. We sequenced CHEK2 gene in 140 Polish patients with prostate cancer and then genotyped the three detected variants in a larger series of prostate cancer cases and controls. CHEK2 truncating mutations (IVS2 ؉ 1G>A or 1100delC) were identified in 9 of 1921 controls (0.5%) and in 11 of 690 (1.6%) unselected patients with prostate cancer [odds ratio (OR) ‫؍‬ 3.4; P ‫؍‬ 0.004]. These mutations were found in 4 of 98 familial prostate cases (OR ‫؍‬ 9.0; P ‫؍‬ 0.0002). The missense variant I157T was also more frequent in men with prostate cancer (7.8%) than in controls (4.8%), but the relative risk was more modest (OR ‫؍‬ 1.7; P ‫؍‬ 0.03). I157T was identified in 16% of men with familial prostate cancer (OR ‫؍‬ 3.8; P ‫؍‬ 0.00002). Loss of the wild-type CHEK2 allele was not observed in any of prostate cancers from five men who carried CHEK2-truncating mutations. Our results provide evidence that the two truncating mutations of CHEK2 confer a moderate risk of prostate cancer in Polish men and that the missense change appears to confer a modest risk.

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BackgroundThe frequency of preterm labour has risen over the last few years. Hence, there is growing interest in the identification of markers that may facilitate prediction and prevention of premature birth complications. Here, we studied the association of the number of circulating stem cell populations with the incidence of complications typical of prematurity.MethodsThe study groups consisted of 90 preterm (23–36 weeks of gestational age) and 52 full-term (37–41 weeks) infants. Non-hematopoietic stem cells (non-HSCs; CD45-lin-CD184+), enriched in very small embryonic-like stem cells (VSELs), expressing pluripotent (Oct-4, Nanog), early neural (β-III-tubulin), and oligodendrocyte lineage (Olig-1) genes as well as hematopoietic stem cells (HSCs; CD45+lin-CD184+), and circulating stem/progenitor cells (CSPCs; CD133+CD34+; CD133-CD34+) in association with characteristics of prematurity and preterm morbidity were analyzed in cord blood (CB) and peripheral blood (PB) until the sixth week after delivery. Phenotype analysis was performed using flow cytometry methods. Clonogenic assays suitable for detection of human hematopoietic progenitor cells were also applied. The quantitative parameters were compared between groups by the Mann–Whitney test and between time points by the Friedman test. Fisher’s exact test was used for qualitative variables.ResultsWe found that the number of CB non-HSCs/VSELs is inversely associated with the birth weight of preterm infants. More notably, a high number of CB HSCs is strongly associated with a lower risk of prematurity complications including intraventricular hemorrhage, respiratory distress syndrome, infections, and anemia. The number of HSCs remains stable for the first six weeks of postnatal life. Besides, the number of CSPCs in CB is significantly higher in preterm infants than in full-term neonates (p < 0.0001) and extensively decreases in preterm babies during next six weeks after birth. Finally, the growth of burst-forming unit of erythrocytes (BFU-E) and colony-forming units of granulocyte-macrophage (CFU-GM) obtained from CB of premature neonates is higher than those obtained from CB of full-term infants and strongly correlates with the number of CB-derived CSPCs.ConclusionWe conclude that CB HSCs are markedly associated with the development of premature birth complications. Thus, HSCs ought to be considered as the potential target for further research as they may be relevant for predicting and controlling the morbidity of premature infants. Moreover, the observed levels of non-HSCs/VSELs circulating in CB are inversely associated with the birth weight of preterm infants, suggesting non-HSCs/VSELs might be involved in the maturation of fetal organism.