Morusinol Extracted from Morus alba Inhibits Cell Proliferation and Induces Autophagy via FOXO3a Nuclear Accumulation-Mediated Cholesterol Biosynthesis Obstruction in Colorectal Cancer.

The incidence rate of colorectal cancer (CRC) has been increasing significantly in recent years, and it is urgent to develop novel drugs that have more effects for its treatment. It has been reported that many molecules extracted from the root bark of Morus alba L. (also known as Cortex Mori) have antitumor activities. In our study, we identified morusinol as a promising anticancer agent by selecting from 30 molecules extracted from Morus alba L. We found that morusinol treatment suppressed cell proliferation and promoted apoptosis of CRC cells in vitro. Besides this, we observed that morusinol induced cytoprotective autophagy. The GO analysis of differentially expressed genes from RNA-seq data showed that morusinol affected cholesterol metabolism. Then we found that key enzyme genes in the cholesterol biosynthesis pathway as well as the sterol regulatory element binding transcription factor 2 (SREBF2) were significantly downregulated. Furthermore, additional cholesterol treatment reversed the anti-CRC effect of morusinol. Interestingly, we also found that morusinol treatment could promote forkhead box O3 (FOXO3a) nuclear accumulation, which subsequently suppressed SREBF2 transcription. Then SREBF2-controlled cholesterol biosynthesis was blocked, resulting in the suppression of cell proliferation, promotion of apoptosis, and production of autophagy. The experiments in animal models also showed that morusinol significantly impeded tumor growth in mice models. Our results suggested that morusinol may be used as a candidate anticancer drug for the treatment of CRC.

An efficient strategy for large-scale preparation of low polarity gingerols directly from ginger crude extract by high-speed countercurrent chromatography with different rotation mode.

This study presents an efficient strategy for large-scale preparation of low polarity gingerols directly from ginger crude extract by high-speed countercurrent chromatography with different rotation mode. The ultrasonic-assisted extraction conditions were optimized by response surface methodology and the results showed the major low polarity gingerols could be well enriched under the optimized extraction conditions. Then the crude extract without any pretreatment was directly separated by high-speed countercurrent chromatography with different rotation mode using n-hexane/ethyl acetate/methanol/water (6:4:6:4, v/v/v/v) as the solvent system. In about 400 min, five major gingerols including 150 mg of [6]-gingerol, 50 mg of [8]-gingerol, 20 mg of [6]-shogaol, 43 mg of [6]-dehydrogingerdione, and 40 mg of [10]-gingerol were obtained from 1.2 g of crude extract in a single run with repeated injection. Their structures were identified by 1 H-NMR spectroscopy.

Mutation of CESA1 phosphorylation site influences pectin synthesis and methylesterification with a role in seed development.

Cell wall biogenesis is required for the production of seeds of higher plants. However, little is known about regulatory mechanisms underlying cell wall biogenesis during seed formation. Here we show a role for the phosphorylation of Arabidopsis cellulose synthase 1 (AtCESA1) in modulating pectin synthesis and methylesterification in seed coat mucilage. A phosphor-null mutant of AtCESA1 on T166 (AtCESA1T166A) was constructed and introduced into a null mutant of AtCESA1 (Atcesa1-1). The resulting transgenic lines showed a slight but significant decrease in cellulose contents in mature seeds. Defects in cellulosic ray architecture along with reduced levels of non-adherent and adherent mucilage were observed on the seeds of the AtCESA1T166A mutant. Reduced mucilage pectin synthesis was also reflected by a decrease in the level of uronic acid. Meanwhile, an increase in the degree of pectin methylesterification was also observed in the seed coat mucilage of AtCESA1T166A mutant. Change in seed development was further reflected by a delayed germination and about 50% increase in the accumulation of proanthocyanidins, which is known to bind pectin and inhibit seed germination as revealed by previous studies. Taken together, the results suggest a role of AtCESA1 phosphorylation on T166 in modulating mucilage pectin synthesis and methylesterification as well as cellulose synthesis with a role in seed development.

Persulfidation-induced structural change in SnRK2.6 establishes intramolecular interaction between phosphorylation and persulfidation.

Post-translational modifications (PTMs), including phosphorylation and persulfidation, regulate the activity of SNF1-RELATED PROTEIN KINASE2.6 (SnRK2.6). Here, we report how persulfidations and phosphorylations of SnRK2.6 influence each other. The persulfidation of cysteine C131/C137 alters SnRK2.6 structure and brings the serine S175 residue closer to the aspartic acid D140 that acts as ATP-γ-phosphate proton acceptor, thereby improving the transfer efficiency of phosphate groups to S175 to enhance the phosphorylation level of S175. Interestingly, we predicted that S267 and C137 were predicted to lie in close proximity on the protein surface and found that the phosphorylation status of S267 positively regulates the persulfidation level at C137. Analyses of the responses of dephosphorylated and depersulfidated mutants to abscisic acid and the H2S-donor NaHS during stomatal closure, water loss, gas exchange, Ca2+ influx, and drought stress revealed that S175/S267-associated phosphorylation and C131/137-associated persulfidation are essential for SnRK2.6 function in vivo. In light of these findings, we propose a mechanistic model in which certain phosphorylations facilitate persulfidation, thereby changing the structure of SnRK2.6 and increasing its activity.

Exogenous salicylic acid regulates cell wall polysaccharides synthesis and pectin methylation to reduce Cd accumulation of tomato.

Cadmium (Cd) is harmful to plant growth and can be easily transferred from soil to plants. Plant cell wall plays important role in preventing Cd from entering cells. Salicylic acid (SA) mediated defense response increases plant resistance to heavy metals. In this study, all tomato seedlings were pre-treated with 100 µM SA for 3 d, then seedlings were used to analyze the role of SA in regulating plant cell wall resistance to Cd stress. The results showed that exogenous SA significantly reduced Cd accumulation in tomato plants and changed Cd distribution. By analyzing the cell wall composition, it was found cellulose, hemicellulose, pectin, and lignin were induced by SA. Interestingly, the content of Cd in pectin decreased by SA pretreatment, however it was increased in cellulose. Gene expression analysis showed SA up-regulated the expression level of lignin and cellulose synthase genes, but down-regulated the expression of pectin methylesterase related genes. In addition, SA down-regulated the activity of pectin methylesterase. These results indicated that SA pretreatment up-regulated cell wall polysaccharide synthesis and related gene expression to thicken the cell wall and block Cd from passing through. Furthermore, SA decreased pectin methylesterase activity and content to reduce cell wall Cd accumulation and change the Cd partition ratio.

Symptomatic treatment of brain metastases in renal cell carcinoma with sorafenib.

Brain metastasis is synchronous to the diagnosis of renal cell carcinoma (RCC). The prognosis of brain metastasis in RCC with the current treatment options is dismissal. Therefore, we present a case of an elderly female patient with RCC showing a partial response of brain metastasis after 18 months of 600 mg once daily sorafenib treatment who underwent right-sided nephrectomy. Further, withdrawal of sorafenib resulted in psychiatric changes along with increased metastasis lesions, which were recovered upon resuming the treatment, proposing that oral sorafenib can be used safely and efficiently for treatment of brain metastasis in advanced RCC.

Bufalin exerts antitumor effects by inducing cell cycle arrest and triggering apoptosis in pancreatic cancer cells.

As one of the most aggressive human malignancies, pancreatic cancer is a leading cause of cancer-related deaths worldwide and only about 4% of patients will live 5 years after diagnosis. Eighty to approximately eighty-five percent of patients are diagnosed with an unresectable or metastatic disease, which is correlated with poor prognosis and low survival rate. Therefore, it is tremendously significant to exploit novel chemicals to prevent and treat pancreatic cancer. Previous research and clinical studies have demonstrated that many natural products derived from traditional Chinese medicine (TCM) such as camptothecin derivatives and vinca alkaloids could be effective antitumor compounds, hinting that TCM is a promising source for developing new antitumor drugs. In this report, we investigated the effects of bufalin, a primary active ingredient of the traditional Chinese medicine Chan-Su, on pancreatic cancer cell lines PANC-1 and CFPAC-1 and studied the underlying molecular mechanism. We found that exposure to bufalin could suppress the proliferation of pancreatic cancer cells time and dose dependently. We used flow cytometry to study the effects of bufalin on apoptosis and cell cycle distribution in PANC-1 and CFPAC-1 cells. The results indicated that bufalin could significantly induce both apoptosis and G2/M cell cycle arrest in pancreatic cancer cells. With western blotting, we found that the expression level of an antiapoptotic protein heat shock protein 27 (Hsp27) and its partner molecule p-Akt was decreased upon the treatment with bufalin. Besides, bufalin activated pro-caspase-3 and pro-caspase-9 and modulated the expression level of Bcl-2 and Bax. These data suggested that bufalin may trigger apoptosis by targeting Hsp27, which could inhibit apoptosis by interfering with key apoptotic proteins. The influence on the level of cylinB1, CDK1, and p21 was also observed after bufalin treatment, and the relationship between Hsp27 and the cell cycle-related proteins mentioned above deserves much more research. In addition, our data showed that bufalin could enhance the growth inhibition effect of gemcitabine in above pancreatic cancer cells. Taken together, bufalin might be worthy of further study for its potential as a therapeutic agent for pancreatic cancer treatment.

[Inducible nitric oxide synthase gene expression in the testis of rats instilled with depleted uranium particles].

OBJECTIVE: To explore genital toxicity of depleted uranium (DU) by studying the changes of inducible nitric oxide synthase (iNOS) in the testis of rats instilled with DU particles. METHODS: Wistar rats were exposed to DU by means of different dosages of DU particles intratracheal instillation. The samples of the testis were collected 3 months later, and iNOS mRNA was determined by reverse-transcription PCR (RT-PCR). Semiquantitative analysis of the RT-PCR products was made with a transilluminator. RESULTS: iNOS mRNA was not observed in the control group. Compared with the control, there were significant increases of OD in the PCR products of all the DU groups (P < 0. 05 ); OD rose gradually from the DU 1 mg group to the DU 3 mg group, peaked in the latter, and subsided significantly in the DU 5 mg group (P < 0.05). CONCLUSION: Intratracheal instilled DU particles play a key role in iNOS mRNA expression of the rat testis. The iNOS mRNA expression will weaken when the DU dosage reaches a certain level, which may attribute to the complex of DU's chemical toxicity and radiation effects.