MicroRNAs (miRNAs) are endogenous, small noncoding RNAs that play important roles in various cellular functions and tumor development. Recent studies have indicated that miR-21 is one of the important miRNAs associated with tumor growth and metastasis, but the role and molecular mechanism of miR-21 in regulating tumor angiogenesis remain to be elucidated. In this study, miR-21 was overexpressed by transfecting pre-miR-21 into human prostate cancer cells and tumor angiogenesis was assayed using chicken chorioallantoic membrane (CAM). We found that overexpression of miR-21 in DU145 cells increased the expression of HIF-1α and VEGF, and induced tumor angiogenesis. AKT and extracellular regulated kinases (ERK) 1/2 are activated by miR-21. Inhibition of miR-21 by the antigomir blocked this process. Overexpression of the miR-21 target, PTEN, also inhibited tumor angiogenesis by partially inactivating AKT and ERK and decreasing the expression of HIF-1 and VEGF. The AKT and ERK inhibitors, LY294002 and U0126, suppressed HIF-1α and VEGF expression and angiogenesis. Moreover, inhibition of HIF-1α expression alone abolished miR-21-inducing tumor angiogenesis, indicating that HIF-1α is required for miR-21-upregulated angiogenesis. Therefore, we demonstrate that miR-21 induces tumor angiogenesis through targeting PTEN, leading to activate AKT and ERK1/2 signaling pathways, and thereby enhancing HIF-1α and VEGF expression; HIF-1α is a key downstream target of miR-21 in regulating tumor angiogenesis.

L-Cysteine is a nutritionally semiessential amino acid and is present mainly in the form of L-cystine in the extracellular space. With the help of a transport system, extracellular L-cystine crosses the plasma membrane and is reduced to L-cysteine within cells by thioredoxin and reduced glutathione (GSH). Intracellular L-cysteine plays an important role in cellular homeostasis as a precursor for protein synthesis, and for production of GSH, hydrogen sulfide (H(2)S), and taurine. L-Cysteine-dependent synthesis of GSH has been investigated in many pathological conditions, while the pathway for L-cysteine metabolism to form H(2)S has received little attention with regard to prevention and treatment of disease in humans. The main objective of this review is to highlight the metabolic pathways of L-cysteine catabolism to GSH, H(2)S, and taurine, with special emphasis on therapeutic and nutritional use of L-cysteine to improve the health and well-being of animals and humans.

Taken together, these results revealed that miR-124 levels in tumor tissues are associated with glioma occurrence, angiogenesis, and chemoresistance and that miR-124 may be used as a new diagnostic marker and therapeutic target for glioma in the future.

BackgroundGastric cancer (GC) is among the most commonly cancer occurred in Asian, especially in China. With its high heterogeneity and few of validated drug targets, GC remains to be one of the most under explored areas of precision medicine. In this study, we aimed to establish an in vivo patient-derived xenograft (PDX) model based on zebrafish (Danio rerio) embryos, allowing for a rapid analysis of the angiogenic and invasive potentials, as well as a fast drug sensitivity testing.MethodsTwo human gastric cancer cell lines (AGS and SGC-7901) were xenografted into zebrafish embryos, their sensitivity to 5-FU were tested both in vitro and in vivo. Fourteen human primary cells from gastric cancer tissue were xenografted into zebrafish embryos, their proliferating, angiogenic and metastatic activities were evaluated in vivo. Sensitivity to 5-FU, docetaxel, and apatinib were also tested on primary samples from four patients.ResultsSGC-7901 showed higher sensitivity to 5-FU than AGS both in vitro (6.3 ± 0.9 μM vs.10.5 ± 1.8 μM) and in vivo. Nine out of fourteen patient samples were successfully transplanted in zebrafish embryos and all showed proliferating, angiogenic and metastatic potentials in the living embryos. Four cases showed varied sensitivity to the selected three chemotherapeutic drugs.ConclusionsOur zebrafish PDX (zPDX) model is a preclinically reliable in vivo model for GC. The zPDX model is also a promising platform for the translational research and personalized treatment on GC.Electronic supplementary materialThe online version of this article (10.1186/s13046-017-0631-0) contains supplementary material, which is available to authorized users.

Apigenin, a flavonoid commonly present in the daily diet, is known for its potential anti-tumor properties. However, the effect of apigenin via oral administration on tumor growth and metastasis remains unknown. In this study we developed an orthotopic ovarian tumor model in nude mice to test the effect of apigenin oral administration, and showed that apigenin inhibited the micrometastasis of cancer cells in the animal tumor model. To understand the mechanism of apigenin in inhibiting metastasis, we found that apigenin greatly inhibited MMP-9 expression and p-AKT and p-p70S6K1 levels in the tumor tissues compared to the control group. We further demonstrated that the downregulation of MMP-9 by apigenin was mediated by the AKT/p70S6K1 pathway. These findings help to address the question with common interests to the public of whether oral uptake of flavonoids is effective in preventing cancer. Our results demonstrate for the first time that oral uptake of apigenin can inhibit tumor metastasis through MMP-9 expression using the orthotopic ovarian tumor model.