LRP16 is a novel gene cloned from lymphocytic cells, and its function is not known. The expression level of LRP16 mRNA was up-regulated by estrogen in breast cancer MCF-7 cells based on the computed aided serial analysis of gene expression (SAGE) analysis. In this study, we investigate the effect of 17β-estradiol (17β-E 2 ) on the expression of LRP16 mRNA and the effects of overexpression of LRP16 on the proliferation of cultured MCF-7 cells and the possible mechanisms involved. The expression level of LRP16 mRNA induced by 17β-E 2 was determined by Northern blot analysis. LRP16 promoter-controlled luciferase expression vector (pGL3-S 0 ) was co-transfected with various nuclear receptors, including estrogen receptor α and β (ERα and ERβ), glucocorticoid receptor α (GRα), androgen receptor (AR) and peroxisome-proliferator activated receptor γ and α (PPARγ and PPARα) into COS-7 cells, and the relative luciferase activity was measured using Dual-luciferase report assay systems. The effect of overexpression of LRP16 on MCF-7 proliferation was examined by the Trypan Blue exclusion method, and the cell cycle was analyzed by flow cytometry. The expression levels of cyclin E, p53 and p21 WAF1/CIP1 proteins were determined by Western blot analysis. The results showed (1) 17β-E 2 induced a five-to eightfold increase in LRP16 mRNA levels in MCF-7 cells; (2) the relative luciferase activities in the COS-7 cells co-transfected by pGL3-S 0 and ERα or AR were 7.8-fold and 11-fold respectively of those in the control cells transfected by pGL3-S 0 alone; (3) overexpression of LRP16 stimulated MCF-7 cell proliferation, and the numbers of cells in the S-phase of the cell cycle in cells transfected with LRP16 increased about 10% compared with the control cells; and (4) cyclin E levels were much higher in cells with overexpression of LRP16 than in the control cells, while the expression levels of p53 and p21 WAF1/CIP1 were not different between the two groups of cells. From these results we concluded that estrogen up-regulates the expression level of LRP16 mRNA through activation of ERα and that overexpression of LRP16 promotes MCF-7 cell proliferation probably by increasing cyclin E.

Addition of once-daily insulin detemir to patients with type 2 diabetes mellitus on OHA therapy resulted in few adverse events, significant improvements in glycaemic control, small reductions in weight and low rates of hypoglycaemia. On the basis of this study, concerns about hypoglycaemia or weight gain should not preclude initiation of basal insulin analogues in patients with poor glycaemic control on OHAs.

LRP16 gene expression is induced by 17-estradiol (E2) via estrogen receptor alpha (ER ) in MCF-7 human breast cancer cells. A previous study also demonstrated that ectopic expression of LRP16 gene promoted MCF-7 cell proliferation. To explore the mechanism of hormone-induced LRP16 gene expression, the LRP16 gene promoter region (-2600 to -24 bp upstream of the LRP16 gene translation starting site) was analyzed in the present study by using different 58-truncated constructs, and a luciferase reporter. The 58-flanking sequence of -676 to -24 bp (pGL3-S5) was found to be E2-responsive. After exchange of the fragment from -213 to -24 bp with the TK gene proximal promoter region in pGL3-S5, E2 still induced reporter gene activity in MCF-7 and HeLa cells. Sequence analysis showed that the pGL3-S6 (-676 to -214) sequence contains two motifs that may contribute to E2-induced transactivation; namely, an estrogen-responsive element (ERE) half-site/Sp1 at -246 to -227 bp and an E-box site at -225 to -219 bp. Further deletion and mutation analysis of these two motifs indicated that both the 1/2 ERE and Sp1 binding sites were required for E2 action, while E-box deletion did not affect the luciferase activity in MCF-7 and HeLa cells. The results of gel mobility shift and chromatin immunoprecipitation assays confirmed that both ER and Sp1 were required for hormone-induced transactivation, which involved both ER and Sp1 directly binding to DNA. Taken together, these findings suggest that ER and Sp1 play a role in activation of the human LRP16 gene promoter.

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The urinary albumin excretion rate and prevalence of microalbuminuria were higher in isolated-impaired glucose tolerance subjects than those in isolated-impaired fasting glycaemia subjects. At early abnormal glucose tolerance stage, the increasing post-challenge glycaemia might be a more important risk factor for urinary albumin excretion rate and microalbuminuria than increasing fasting glycaemia.