Anticancer activity of oleanolic acid and its derivatives modified at A-ring and C-28 position.

Oleanolic acid (OA) is a five-ring triterpenoid compound, which is widely present in plants. Due to a wide range of pharmacological activities, oleanolic acid has attracted more and more attention. However, oleanolic acid is insoluble in water and has low bioavailability, which limits its clinical application. In this review, we focus on summarizing the anti-cancer activity and mechanism of the A ring or C-28 carboxyl modified derivatives of OA since 2015, to determine the strength of its anti-cancer effectiveness and evaluate whether it could be used as a clinical anti-cancer drug.

Synthesis and biological evaluation of resveratrol derivatives with anti-breast cancer activity.

Resveratrol is a natural phytoestrogen produced by plants to protect themselves from injury, UV irradiation, and fungal attack. The main active structure is E-resveratrol, which has many pharmacological activities. As the structure of resveratrol is similar to the natural estrogen 17ß-estradiol and the synthetic estrogen E-diethylstilbestrol, resveratrol is used in reducing the incidence of breast cancer. However, the therapeutic application of resveratrol is limited due to its low bioavailability. To improve its bioavailability and pharmacological activity, some resveratrol derivatives have been designed and synthesized by substitutions of methoxy, hydroxyl, and other functional groups or heterocyclic esterification either on the "A" or "B" ring, and double bonds were replaced by imine bonds and isometric heterocycles such as naphthyl and imidazole, or synthetic resveratrol oligomers. The structures, synthetic routes, and evaluation of the biological activities of these compounds are discussed. These are aimed at providing some references for the study of resveratrol derivatives in anti-breast cancer treatment.

Research status and prospect of ratoon rice in China under mechanically harvested condition.

The proportion and area of ratoon rice planting in China have been substantially increased, due to continuous improvement of rice breeding methods and consecutive innovation of cultivation technology, which has developed into one of rice planting modes with significant production efficiency. Combining the experience in research and practice, from the perspective of crop physiology and ecology, we reviewed the current situation and prospects of high-yielding formation and physiological mechanisms of ratoon rice. We focused on four key aspects: screening and breeding of ratoon rice cultivars and the classification; suitable stubble height for mechanically harvested ratoon rice, as well as water and fertilizer management; dry matter production and allocation in ratoon rice and the relationship with yield formation; regenerative activity and vigor of ratoon rice roots and their relationship with rhizosphere micro-ecological characteristics. As for the extending of mechanized low-cut stubbles ratoon rice technique, we should properly regulate the rhizosphere system, coordinate rhizosphere nutrient supply, germination of axillary buds, and tillering regeneration, to achieve the target of "four-high-one-low", that is high regeneration coefficient, high number of regeneration panicle, high harvest index, high yield, high quality, low-carbon and safe, aiming to improve the sustainability of ratoon rice industry.

Effects of nitrogen addition on rhizosphere soil properties in a salinized grassland.

We explored the impacts of nitrogen (N) inputs and the rhizosphere effect on the properties of rhizosphere and bulk soils in a salinized grassland in Northern Shanxi under N addition rates of 0, 1, 2, 4, 8, 16, 24 and 32 g N·m-2·a-1. The results showed that N addition significantly decreased soil pH, but significantly increased Ca2+, NO3--N and inorganic nitrogen contents in rhizosphere and bulk soil. With the increases of N addition rates, the contents of Ca2+, NO3--N, inorganic nitrogen in rhizosphere and bulk soils and total nitrogen in rhizosphere soil increased gradually, whereas the contents of Na+, K+, Mg2+, NH4+-N and amino acid in rhizosphere soil, and total nitrogen in bulk soil first increased and then decreased. Results of the principal component analysis showed that the responses of soil properties to low (≤8 g·m-2·a-1) and high nitrogen addition rates (>8 g·m-2·a-1) were significantly different. Compared with bulk soil, soil pH, the contents of organic acids and amino acids in rhizosphere soil were significantly lower by 0.71 units, 44.3% and 9.8%, respectively, while the contents of K+, Ca2+, Mg2+, NH4+-N, inorganic nitrogen, total carbon and total nitrogen in rhizosphere soil were significantly higher by 51.0%, 47.6%, 20.8%, 215.5%, 139.3%, 31.7% and 65.3%, respectively. These results indicated that rhizosphere effect on soil properties was stronger than that of nitrogen addition.

[The databases of transcription factors.].

The control of gene transcription is a critical level of gene expression regulation. The interactions between transcription factors (TF) and their DNA binding sites (TFBS) play a key role at this level. In order to decipher the molecular mechanism of the interactions of TFs with TFBSs and construct transcription regulatory network, it is necessary to systematically collect, save, and analyze the information of discovered TFs and their TFBSs. In recent years, multiple TF and TFBS-related databases have been established. These databeses significantly promoted the TF-related studies in the fields of molecular biology, bioinformatics, and system biology. This paper summarized the contents, characteristics, access, and advances of main TFs and TFBSs-related databases, including TRANSFAC, JASPAR, TFDB, TRRD, TRED, PAZAR, MAPPER and others.

[The action of TSG101 on HIV-1 budding and related inhibitors].

tsg101 gene is a newly found tumor suppressor gene whose product TSG101 has many important biological functions. Recent research of TSG101 has revealed that TSG101 aids HIV-1 budding from infected cells by attaching to Gag. HIV-1 budding is arrested in the cells with mutant TSG101 or without TSG101. So TSG101 would be a useful target for anti-HIV drug design. Now there is already some research on anti-HIV agents based on TSG101 structure. In this article the structure and function of TSG101 as well as the related inhibitors were reviewed.

Structure and Anti-HIV Activity of Betulinic Acid Analogues.

Firstly discovered in 1980s, human immunodeficiency virus (HIV) continues to affect more and more people. However, there is no effective drug available for the therapy of HIV infection. Betulinic acid existing in various medicinal herbs and fruits exhibits multiple biological effects, especially its outstanding anti-HIV activity, which has drawn the attentions of many pharmacists. Among the derivatives of betulinic acid, some compounds exhibited inhibitory activities at the nanomolar concentration, and have entered phase II clinical trials. This paper summarizes the current investigations on the anti-HIV activity of betulinic acid analogues, and provides valuable data for subsequent researches.

[Prognosis-related miRNA bioinformatics screening of lung adenocarcinoma and its clinical significance].

OBJECTIVE: To investigate the prognosis-related miRNA histological features and clinical significance of lung adenocarcinoma. METHODS: Using The Cancer Genome Atlas (TCGA) data, the miRNA expression profile data of human lung adenocarcinoma were searched for differential analysis, and the prognosis-related miRNAs were screened by Cox risk regression model. The targeted miRNAs were predicted by mirwalk analysis platform, KEGG functional enrichment analysis, and finally, predict the function of prognosis-related miRNAs. RESULTS: A total of 46 differential miRNAs in lung adenocarcinoma were screened, including 19 up-regulated and 27 down-regulated. Six prognostic-related miRNAs were screened by Cox survival analysis, namely hsa-mir-21, hsa-mir-142, hsa-mir-200a high expression, hsa-mir-101, hsa-let-7c, hsa-mir-378e low expression, hsa-mir-21 and hsa-mir-378e were associated with poor prognosis in patients with lung adenocarcinoma, and the survival time was shortened significantly (P<0.05, AUC=0.618). KEGG analysis showed that the above prognosis-related miRNA targeting regulatory genes were related with immune response pathways, miRNA and cancer pathways, metabolic pathways and so on. CONCLUSIONS: Hsa-mir-21 and hsa-mir-378e are associated with poor prognosis of lung adenocarcinoma, and may be used as a molecular marker for prognosis of lung adenocarcinoma after further clinical verification.