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BackgroundMany studies have reported associations between estrogen receptor (ER) gene polymorphisms and postmenopausal osteoporosis (PMOP) risk and bone mineral density (BMD), but the results are controversial. The aim of the present meta-analysis is to verify the association between ERα and ERβ gene polymorphisms and osteoporosis susceptibility and BMD in postmenopausal women.MethodsPubMed, EMBASE, Web of Science, the Cochrane Library and China WeiPu Library were searched. OR and WMD with 95% CI were calculated to assess the association.ResultsOverall, no significant association was observed between ERα XbaI, ERα PvuII and PMOP susceptibility in either overall, Caucasian or Asian populations. ERα G2014A was significantly associated with a decreased risk of PMOP in Caucasian populations. There was a significant association between ERβ RsaI and PMOP risk in both overall and Asian populations. Caucasian PMOP women with ERα XbaI XX and Xx genotypes had a higher LS Z value than women with xx genotype. ERα XbaI XX genotype was associated with increased FN BMD in overall and Caucasian populations, an increased FN Z value in Asians, and a decreased FN Z value in Caucasians. There was also a significant association between ERα XbaI Xx genotype and an increased FN Z value in either Asians or Caucasians. ERα PvuII PP genotype was associated with a low LS Z value in Caucasians and a low FN BMD and Z value in Asians. Pp genotype in PMOP women was significantly correlated with low LS BMD in overall populations, a low FN Z value in either overall, Caucasian or Asian populations.ConclusionEach ERα and ERβ gene polymorphism might have different impact on PMOP risk and BMD in various ethnicities.

The overexpression of Aurora kinase A (AURKA), a member of serine/threonine kinase family, has been observed in various types of human cancers. However, the role of AURKA in osteosarcoma (OS), the most common type of primary malignancy arising from bone, has not been clarified. We used AURKA-specific lentivirus-delivered short hairpin RNA (shRNA) to significantly and sustainably silence the endogenous AURKA expression in human OS cells SAOS-2 and U2OS. We found that AURKA downregulation in OS cells prominently decreased colony formation ability in vitro and tumorigenesis ability in vivo. We further evaluated the effect of AURKA silence on cell viability by MTT assay, cell apoptosis and cell cycle by flow cytometer detection. The results showed that AURKA silence inhibited cell viability by inducing cell apoptosis and G2/M cell cycle arrest in OS cells. Taken together, our findings indicate that AURKA plays a crucial role on OS growth by inhibiting cell apoptosis and propelling cell cycle. Inhibition of AURKA by lentivirus-delivered specific shRNA showed the therapeutic potential in treatment of osteosarcoma.

A tracer experiment using the nitrogen isotope 15 N investigated the uptake and incorporation of nitrogen from sedimented cyanobacterial detritus by two species of submerged macrophytes, the native Vallisneria spiralis and the exotic Elodea nuttallii, in Lake Taihu (China). The cyanobacterium Microcystis was labeled with 15 Nammonium and dried to produce detritus, which was injected into vegetated sediments and traced to establish the fate of particulate nitrogenous material. Samples of the inoculated sediment and all parts of the plants growing therein were examined for excess 15 N after 3, 5, 9, and 22 d. Microcystis-derived nitrogen was assimilated rapidly by the plants, then translocated from the roots to the shoots and stored in different parts of the plants, where it supports growth. The ability to utilize and retain nutrients originating from sedimented cyanobacterial detritus was significantly higher in V. spiralis than in E. nuttallii. Cyanobacterial scums such as the Microcystis blooms of Lake Taihu, which drift and deposit in the sediments of the littoral zones, are an important nutrient source for macrophytes, particularly in downwind areas.