Evaluation of Reference Genes for Normalizing RT-qPCR and Analysis of the Expression Patterns of WRKY1 Transcription Factor and Rhynchophylline Biosynthesis-Related Genes in Uncaria rhynchophylla.

Uncaria rhynchophylla (Miq.) Miq. ex Havil, a traditional medicinal herb, is enriched with several pharmacologically active terpenoid indole alkaloids (TIAs). At present, no method has been reported that can comprehensively select and evaluate the appropriate reference genes for gene expression analysis, especially the transcription factors and key enzyme genes involved in the biosynthesis pathway of TIAs in U. rhynchophylla. Reverse transcription quantitative PCR (RT-qPCR) is currently the most common method for detecting gene expression levels due to its high sensitivity, specificity, reproducibility, and ease of use. However, this methodology is dependent on selecting an optimal reference gene to accurately normalize the RT-qPCR results. Ten candidate reference genes, which are homologues of genes used in other plant species and are common reference genes, were used to evaluate the expression stability under three stress-related experimental treatments (methyl jasmonate, ethylene, and low temperature) using multiple stability analysis methodologies. The results showed that, among the candidate reference genes, S-adenosylmethionine decarboxylase (SAM) exhibited a higher expression stability under the experimental conditions tested. Using SAM as a reference gene, the expression profiles of 14 genes for key TIA enzymes and a WRKY1 transcription factor were examined under three experimental stress treatments that affect the accumulation of TIAs in U. rhynchophylla. The expression pattern of WRKY1 was similar to that of tryptophan decarboxylase (TDC) under ETH treatment. This research is the first to report the stability of reference genes in U. rhynchophylla and provides an important foundation for future gene expression analyses in U. rhynchophylla. The RT-qPCR results indicate that the expression of WRKY1 is similar to that of TDC under ETH treatment. It may coordinate the expression of TDC, providing a possible method to enhance alkaloid production in the future through synthetic biology.

Optimization of Isolation and Transformation of Protoplasts from Uncaria rhynchophylla and Its Application to Transient Gene Expression Analysis.

Protoplast-based engineering has become an important tool for basic plant molecular biology research and developing genome-edited crops. Uncaria rhynchophylla is a traditional Chinese medicinal plant with a variety of pharmaceutically important indole alkaloids. In this study, an optimized protocol for U. rhynchophylla protoplast isolation, purification, and transient gene expression was developed. The best protoplast separation protocol was found to be 0.8 M D-mannitol, 1.25% Cellulase R-10, and 0.6% Macerozyme R-10 enzymolysis for 5 h at 26 °C in the dark with constant oscillation at 40 rpm/min. The protoplast yield was as high as 1.5 × 107 protoplasts/g fresh weight, and the survival rate of protoplasts was greater than 90%. Furthermore, polyethylene glycol (PEG)-mediated transient transformation of U. rhynchophylla protoplasts was investigated by optimizing different crucial factors affecting transfection efficiency, including plasmid DNA amount, PEG concentration, and transfection duration. The U. rhynchophylla protoplast transfection rate was highest (71%) when protoplasts were transfected overnight at 24 °C with the 40 µg of plasmid DNA for 40 min in a solution containing 40% PEG. This highly efficient protoplast-based transient expression system was used for subcellular localization of transcription factor UrWRKY37. Finally, a dual-luciferase assay was used to detect a transcription factor promoter interaction by co-expressing UrWRKY37 with a UrTDC-promoter reporter plasmid. Taken together, our optimized protocols provide a foundation for future molecular studies of gene function and expression in U. rhynchophylla.

Tumor microenvironment: a prospective target of natural alkaloids for cancer treatment.

Malignant tumor has become one of the major diseases that seriously endangers human health. Numerous studies have demonstrated that tumor microenvironment (TME) is closely associated with patient prognosis. Tumor growth and progression are strongly dependent on its surrounding tumor microenvironment, because the optimal conditions originated from stromal elements are required for cancer cell proliferation, invasion, metastasis and drug resistance. The tumor microenvironment is an environment rich in immune/inflammatory cells and accompanied by a continuous, gradient of hypoxia and pH. Overcoming immunosuppressive environment and boosting anti-tumor immunity may be the key to the prevention and treatment of cancer. Most traditional Chinese medicine have been proved to have good anti-tumor activity, and they have the advantages of better therapeutic effect and few side effects in the treatment of malignant tumors. An increasing number of studies are giving evidence that alkaloids extracted from traditional Chinese medicine possess a significant anticancer efficiency via regulating a variety of tumor-related genes, pathways and other mechanisms. This paper reviews the anti-tumor effect of alkaloids targeting tumor microenvironment, and further reveals its anti-tumor mechanism through the effects of alkaloids on different components in tumor microenvironment.

Anticancer activities of TCM and their active components against tumor metastasis.

Traditional Chinese Medicine (TCM) has the characteristics of multiple targets, slight side effects and good therapeutic effects. Good anti-tumor effects are shown by Traditional Chinese Medicine prescription, Chinese patent medicine, single Traditional Chinese Medicine and Traditional Chinese medicine monomer compound. Clinically, TCM prolonged the survival time of patients and improved the life quality of patients, due to less side effects. Cancer metastasis is a complex process involving numerous steps, multiple genes and their products. During the process of tumor metastasis, firstly, cancer cell increases its proliferative capacity by reducing autophagy and apoptosis, and then the cancer cell capacity is stimulated by increasing the ability of tumors to absorb nutrients from the outside through angiogenesis. Both of the two steps can increase tumor migration and invasion. Finally, the purpose of tumor metastasis is achieved. By inhibiting autophagy and apoptosis of tumor cells, angiogenesis and EMT outside the tumor can inhibit the invasion and migration of cancer, and consequently achieve the purpose of inhibiting tumor metastasis. This review explores the research achievements of Traditional Chinese Medicine on breast cancer, lung cancer, hepatic carcinoma, colorectal cancer, gastric cancer and other cancer metastasis in the past five years, summarizes the development direction of TCM on cancer metastasis research in the past five years and makes a prospect for the future.

Hyperprins A and B, Two Complex Meroterpenoids from Hypericum przewalskii.

Hyperprins A (1) and B (2), two polyprenylated acylphloroglucinol related meroterpenoids with undescribed carbon skeletons, were isolated from Hypericum przewalskii. Compound 1 possesses a new 6/6/6/6/5/5 hexacyclic system with an unprecedented tetracyclo[10.3.1.03,8.08,12]hexadecane motif. Compound 2 features a unique 6/8/6/6 tetracyclic scaffold. Their structures were determined by spectroscopic data, chemical method, and X-ray crystallography. Compound 1 showed antiproliferation activity against the MV-4-11 cell line, and the p-bromobenzoate derivative of 2 displayed PTP1B inhibition.

Sophoridine Inhibits Human Colorectal Cancer Progression via Targeting MAPKAPK2.

Radian Sophorae flavescentis is a traditional Chinese medicine commonly used to treat cancer in China. However, its active components and underlying mechanism remain ambiguous. In this study, we have screened the pharmacokinetic parameters of the main chemical constituents of Radian Sophorae flavescentis by Traditional Chinese Medicine Systems Pharmacology (TCMSP) Database and Analysis Platform and have found that Sophoridine is one of the best antitumor active ingredients. We have found that MAPKAPK2 is a potential target for Sophoridine by the PharmMapper and KEGG databXase analysis. Moreover, we have found that Sophoridine selectively inactivates phospho-MAPKAPK2 (Thr222) and directly binds into the ATP site of MAPKAPK2 by molecular docking. Furthermore, we have found out a direct binding between MAPKAPK2 and Sophoridine by cellular thermal shift assay and drug affinity responsive targets stability assay. The inhibition effects are further confirmed by Western blot: Sophoridine significantly decreases phospho-MAPKAPK2 (Thr222) in a time-dependent manner, but there is no obvious change in its total expression in colorectal cancer cells. Clinical studies have shown that a higher level of MAPKAPK2 is associated with a poorer percent survival rate (prognosis). Furthermore, a higher level of MAPKAPK2 is positively associated with the enrichment of downregulation of apoptosis and autophagy by gene set enrichment analysis, as well as upregulation of proliferation and cell-cycle arrest. Taken together, our results suggest that the MAPKAPK2 plays a key role in Sophoridine-inhibited growth and invasion in colorectal cancers. IMPLICATIONS: These studies show that Sophoridine may be a promising therapeutic strategy that blocks tumorigenesis in colorectal cancers.