Vitamin D status in Chinese pregnant women and their newborns in Beijing and their relationships to birth size.

OBJECTIVE: To evaluate the prevalence of vitamin D deficiency in pregnant women and their newborns in Beijing, China and the influence of vitamin D deficiency on birth size. DESIGN: A cross-sectional study. SETTING: Data were collected from pregnant women who delivered during April to May 2010 at 306 Hospital of PLA in Beijing, China. SUBJECTS: Participants in the study were seventy healthy nulliparous pregnant women with singleton pregnancies who delivered healthy babies at full term and their newborns. RESULTS: Severe vitamin D deficiency (25-hydroxyvitamin D (25(OH)D) < 25 nmol/l) was detected in 54·5 % of mothers and 46·6 % of newborns. Neither mothers nor newborns had serum 25(OH)D concentrations that reached the normal level (>75 nmol/l). The concentration of 25(OH)D in mothers was positively correlated with that in cord blood (r = 0·89, P < 0·001). Newborns of mothers with severe vitamin D deficiency had lower birth length and birth weight. The head circumference and birth weight were lower in vitamin D-deficient newborns. CONCLUSIONS: The study indicates that pregnant women and neonates residing in Beijing are at high risk of vitamin D deficiency. Neonatal 25(OH)D concentrations are dependently related to maternal 25(OH)D levels. Maternal and neonatal vitamin D status influences newborn size.

p53 regulates Stat3 phosphorylation and DNA binding activity in human prostate cancer cells expressing constitutively active Stat3.

Constitutive activation of the signal transducer and activator of transcription 3 (Stat3) and mutation of the p53 are both commonly detected in human prostate cancer cells. We sought to investigate whether there is functional regulation of Stat3 by wild-type (wt) p53. Our results demonstrate that expression of wt p53 but not mutant p53 significantly reduced tyrosine phosphorylation of Stat3 and inhibited Stat3 DNA binding activity in both DU145 and Tsu prostate cancer cell lines that express constitutively active Stat3. Expression of the p53 downstream target, p21(WAF-1), did not have any inhibitory effect on Stat3 phosphorylation. Wt p53 but not p21(WAF-1) induced dramatic apoptosis in these prostate cancer cells. Expression of wt p53 did not cause a reduction of phosphorylation-independent Stat3 protein and reduction of phosphorylation of three unrelated protein kinases, ERK1, ERK2 (ERK1/2), and AKT. Interestingly, p53-dependent apoptosis occurred in the presence of high levels of phosphorylated AKT and ERK1/2 in both DU145 and Tsu prostate cancer cells. Further, we evaluated a series of established human prostate, breast, and ovarian cancer cell lines and found that all cancer cell lines expressing constitutively active Stat3, only harbor mutated or deleted p53. One implication of these results is that the anti-proliferative activities of p53 may not be compatible with the constitutive Stat3 signal in cancer cells.