Upregulation Effect of Citrus Species on Brain-Derived Neurotrophic Factor.

Brain-derived neurotrophic factor (BDNF) is a neurotrophin that plays fundamental roles in neuronal survival and synaptic plasticity. Its upregulation in the brain can effectively prevent and treat central nervous system (CNS) diseases, including depression, Alzheimer's disease (AD), and Parkinson's disease (PD). BDNF is synthesized in various peripheral tissues as well as in the brain and can be transported from peripheral circulation into the brain through the blood-brain barrier. Therefore, foods that upregulate BDNF in peripheral tissues may be beneficial in preventing and treating these CNS diseases. Previously, we revealed that treatment with Chinpi (Citrus unshiu peel) and Citrus natsudaidai increased BDNF levels in the human renal adenocarcinoma cell line ACHN. Here, we evaluated the effects of 21 citrus cultivars on BDNF production in ACHN cells by measuring BDNF levels in the cell culture medium. We found that treatment with peels and pulps of 13 citrus varieties increased BDNF levels in ACHN cells. Treatment with Aurantium, Acrumen, and their hybrids citrus varieties showed a potent BDNF-upregulating effect but not with varieties belonging to Limonellus, Citrophorum, and Cephalocitrus. In addition, treatment with some of those Acrumen and its hybrid citrus species resulted in elevated levels of BDNF transcripts in ACHN cells. These results suggest that peels of many citrus cultivars contain ingredients with a potential BDNF-upregulating ability, which may be novel drug seeds for treating depression, AD, and PD. Furthermore, many citrus cultivars could be used as BDNF-upregulating foods.

Increasing Effect of Citrus natsudaidai on Brain-Derived Neurotrophic Factor.

The increase in brain-derived neurotrophic factor (BDNF) in the brain is beneficial for the treatment of depression, Alzheimer's disease (AD), and Parkinson's disease (PD); BDNF can cross the blood-brain barrier. Therefore, foods that elevate BDNF concentration in peripheral tissues may increase BDNF in the brain and thereby induce preventive and therapeutic effects against depression, AD, and PD. In this study, we aimed to determine whether Citrus natsudaidai extracts can increase BDNF concentration using the human kidney adenocarcinoma cell line ACHN, which has BDNF-producing and -secreting abilities. As test samples, methanol extracts of C. natsudaidai peel and pulp, and their n-hexane, ethyl acetate, n-butanol, and water fractions were prepared. The BDNF concentrations in culture medium of ACHN cells were assayed after 24 h cultivation in the presence of test samples. Compared with that of control (non-treated) cells, the BDNF concentration increased in the culture medium of ACHN cells treated with the methanol extract of C. natsudaidai peel and its hexane, butanol, and water fractions, as well as the butanol and water fractions of the pulp extract. Quantitative reverse transcription-polymerase chain reaction analysis revealed that ACHN cells treated with the butanol fractions of the peel and pulp extracts showed elevated levels of BDNF mRNA compared with those of non-treated cells. C. natsudaidai may increase BDNF concentration by acting on peripheral tissues and could be a medication for the prevention and treatment of depression, AD, and PD.

Effects of HMGA2 on the epithelial-mesenchymal transition-related genes in ACHN renal cell carcinoma cells-derived xenografts in nude mice.

BACKGROUND: The architectural transcriptional regulator high-mobility group AT-hook 2 (HMGA2) is an oncofetal protein which has been reported to be ectopically expressed in a variety of cancers. A high expression of HMGA2 in human renal cell carcinoma (RCC) is related with tumor invasiveness and poor prognosis. Recent in vitro studies have shown that HMGA2 knockdown was able to decrease cell proliferation and migration, and regulate the gene expression related to epithelial-mesenchymal transition (EMT). METHODS: To understand the HMGA2's effect in vivo, HMGA2 expression was knocked down in ACHN cells using small hairpin RNA (shRNA), then the HMGA2-deficient ACHN cells were xenografted into the BALB/c nude mice. Tumor growth was monitored and the expression of EMT-related genes was analyzed. RESULTS: HMGA2 expression was confirmed to be knocked down in the cultured and xenografted ACHN cells. The xenograft tumor of HMGA2-deficient cells demonstrated a retarded growth pattern compared with the control. The expression of E-cadherin was increased, whereas N-cadherin and Snail were decreased in the HMGA2-deficient xenograft tumors. CONCLUSIONS: In conclusion, to the best of our knowledge, for the first time, we have successfully developed an in vivo experiment using HMGA2-silencing ACHN cells to be grown as xenografts in nude mice. Our findings show that HMGA2 deficiency was sufficient to suppress the xenograft tumor growth in vivo, which support our hypothesis that HMGA2-induced renal carcinogenesis occurs at least in part through the regulation of tumor associated EMT genes.

Diosmetin Induces Apoptosis by Downregulating AKT Phosphorylation via P53 Activation in Human Renal Carcinoma ACHN Cells.

BACKGROUND: Diosmetin (DIOS) is the aglycone of the flavonoid glycoside, diosmin, derived naturally from the leaves of the legume, Olea europaea, and Acacia farnesiana. It has potent anticancer activity against multiple forms of cancers. However, the role of DIOS in renal carcinoma and its mechanism of action remain unclear. OBJECTIVE: The purpose of this study is to investigate the effect of DIOS on cell viability and apoptosis in renal carcinoma cells and explore the possible mechanism of action. METHODS: Cell viability, cytotoxicity, caspase activity, apoptosis, and expression of apoptotic related proteins were analyzed in renal carcinoma ACHN cells. RESULTS: The results showed that DIOS inhibited the cell viability, and induced cytotoxicity and apoptosis in ACHN cells. Furthermore, DIOS increased expression of p53 mRNA and proteins, and downregulated phosphorylation of the phosphoinositide 3-kinase and protein B kinase (PI3K/AKT). In addition, it was observed that the anticancer effect of DIOS was significantly enhanced by the p53 activator, but inhibited by the p53 inhibitor. CONCLUSION: Our data suggested that DIOS induced apoptosis in renal carcinoma ACHN cells by reducing AKT phosphorylation through p53 upregulation.

A comparative study of four methods of establishing orthotopic human renal cell carcinoma models in nude mice / 中国癌症杂志

Background and purpose: Renal cell carcinoma is the most common form of kidney cancer, characterized by lack of early symptoms and high malignancy. This study aimed to establish orthotopic nude mice models of human renal cell carcinoma with high success rate and good repeatability. Methods: The four types of methods which were adopted to establish the orthotopic models of renal cell carcinoma were orthotopic injection of 786-0 and ACHN cell suspensions, orthotopic injection of primary cell suspensions obtained from the subcutaneous tumor tissues, renal subcutis orthotopic implantation into renal capsule and surgical subcutis orthotopic implantation into renal fascia. To gain insights into the tumorigenicity and the growth of transplantation tumors, the imageological examination (PET/CT), histological examination (H-E staining, immunohistochemistry staining) and biochemical analysis of blood were carried out. Results: In terms of the subcutaneous transplantation of human renal cell carcinoma models in nude mice, tumorigenic rate of ACHN cells (90%) was higher than that of 786-0 cells (30%). The tumorigenic incidences of 786-0 cell suspensions orthotopic injection, ACHN cell suspensions orthotopic injection, ACHN subcutis cellular suspensions orthotopic injection, ACHN subcutis orthotopic implantation into renal capsule and renal fascia were 33%, 80%, 90%, 100% and 20%, respectively. ACHN subcutis orthotopic implantation into renal capsule was the most effective approach. Imageological and histological results accorded with poorly differentiated renal cell carcinoma. Conclusion: Four orthotopic nude mice models of human renal cell carcinoma were successfully established. Among these methods, ACHN subcutis orthotopic implantation into renal capsule is the most effective approach, which provides an ideal model for the research on biological behavior of human renal cell carcinoma and its treatment.