Diagnostic value of dysregulated microribonucleic acids in the placenta and circulating exosomes in gestational diabetes mellitus.

AIMS/INTRODUCTION: Differentially expressed microribonucleic acids (miRNAs) in the placenta and circulating exosomes are of diagnostic value for gestational diabetes mellitus (GDM). In a cross-sectional study, we identified miRNAs expressed both in the placenta and circulating exosomes of pregnant women with GDM, and estimated their diagnostic value. MATERIALS AND METHODS: Next-generation sequencing was used to identify miRNAs in the placenta that were differentially expressed between GDM and normal glucose tolerance pregnancies. Quantitative polymerase chain reaction was used to validate the identified targets. Western blot and transmission electron microscopy were used to validate exosomes. Univariate logistic regression analysis was used to establish diagnostic models based on miRNAs expression, and the diagnostic value was estimated using the receiver operator characteristic curve. RESULTS: We identified 157 dysregulated miRNAs in the placental tissue obtained from GDM pregnancies. Of these, miRNA-125b was downregulated (P < 0.001), whereas miRNA-144 was upregulated (P < 0.001). The patterns of these two miRNAs remained the same in circulating exosomes from GDM pregnancies (all P < 0.001). miRNA-144 levels in the circulating exosomes negatively correlated with body mass index both before pregnancy (P = 0.018) and before delivery (P = 0.039), and positively correlated with blood glucose at 1 h, estimated using the oral glucose tolerance test (P = 0.044). The area under curve for the established diagnostic model was 0.898, which was higher than blood glucose levels at 0 h. CONCLUSIONS: These findings suggest that miRNA-125b and miRNA-144 are consistently dysregulated in circulating exosomes and the placenta from GDM pregnancies, and are of excellent diagnostic value for GDM.

Regulation of zinc transporters by dietary flaxseed lignan in human breast cancer xenografts.

Zinc is essential for cell growth. Previous studies have shown that zinc concentration in breast cancer tissues is higher than that in normal breast tissues. Zinc cannot passively diffuse across cell membranes and specific zinc transporter proteins are required. Two gene families have been identified involved in zinc homeostasis. ZnT transporters reduce intracellular zinc while ZIP transporters increase intracellular zinc. In this study, three human zinc transporter members: ZnT-1, ZIP2 and LIV-1 were chosen. We aimed to determine the effect of flaxseed lignan on the growth of ER-negative breast cancer cells in a nude mice model and observe the effect of flaxseed lignan on the regulation of the three zinc transporter in mRNA level. Nude mice were xenografted with human breast cancer cell line MDA-MB-231 and 6 weeks later were fed either the basal diet (BD) or BD supplemented with 10% FS and SDG for 5 weeks. The SDG levels were equivalent to the amounts in the 10% FS. RT-PCR was performed. Compared with the BD group, the tumor growth rate was significantly lower (P < 0. 05) in the FS and SDG group. ZnT-1 mRNA level in mammary tumor was increased in SDG group and decreased in FS group, but no significant difference was found. Extremely low amplification of ZIP2 from mRNA was detected, with no difference between the treatment groups. LIV-1 mRNA expression of SDG group increases compared with BD group. In FS group, it significantly increases nearly 9 times than that in BD group (P < 0. 005).

Regulation of zinc transporters by dietary zinc supplement in breast cancer.

Zinc is essential for cell growth and is a co-factor for more than 300 enzymes, representing over 50 different enzyme classes. Two gene families have been identified involved in zinc homeostasis. ZnT transporters reduce intracellular zinc while ZIP transporters increase intracellular zinc. Previous studies have shown that zinc concentration in breast cancer tissues is higher than that in normal breast tissues. However, the mechanisms involved and the relations to zinc transporters are still unknown. A series of zinc transporters are characterized in this article and several of that are emphasized in view of their unique tissue-specific expressions. Established human breast cancer in a nude mice model is used. With a dietary zinc supplement treatment, ZnT-1 mRNA expression in established human breast cancer is raised by 24%, and is nearly 2 times of that in basal diet. ZIP1, ZIP2 and LIV-1 mRNA are the same between two treatment groups. Moreover, no significant changes of these zinc transporters expressions are found between differential breast cancer cell lines in the nude mice model. This is the first report, which detects the zinc transporters expressions in established human breast cancer in nude mice model. These results lead to the constitutive expression and response to zinc in different tissues. In addition to that, ZnT-1 seems to have played an important role in zinc homeostasis, even in breast cancer.