Targeting NQO1/GPX4-mediated ferroptosis by plumbagin suppresses in vitro and in vivo glioma growth.

BACKGROUND: Ferroptosis has attracted increasing interest in cancer therapy. Emerging evidences suggest that naturally occurring naphthoquinones exhibit potent anti-glioma effects via various mechanisms. METHODS: The anti-glioma effects of plumbagin were evaluated by in vitro and in vivo experiments. Anti-glioma mechanism of plumbagin was studied by proteomics, flow cytometry, MDA assay, western blot, and RT-PCR. Gene knockdown/overexpression, molecular docking, PharmMappper database, and coimmunoprecipitation were used to study the targets of plumbagin. RESULTS: Plumbagin showed higher blood-brain barrier penetration ability than that of lapachol and shikonin and elicited significant growth inhibitory effects in vitro and in vivo. Ferroptosis was the main mechanism of plumbagin-induced cell death. Mechanistically, plumbagin significantly downregulated the protein and mRNA levels of xCT and decreased GPX4 protein levels. NAD(P)H quinone dehydrogenase 1 (NQO1) was revealed as a plumbagin predictive target using PharmMappper database and molecular docking. Plumbagin enhanced NQO1 activity and decreased xCT expression, resulting in NQO1-dependent cell death. It also induced GPX4 degradation via the lysosome pathway and caused GPX4-dependent cell death. CONCLUSIONS: Plumbagin inhibited in vitro and in vivo glioma growth via targeting NQO1/GPX4-mediated ferroptosis, which might be developed as a novel ferroptosis inducer or anti-glioma candidate.

[Progress of marine anticancer agents targeting cellular proapoptotic molecules].

Apoptosis, a form of programmed cell death, is a critical defense mechanism against the formation and progression of cancer. In vivo, apoptosis functions to eliminate potentially deleterious cells without causing such adverse effects as inflammatory response, and to ensue scar formation. Therefore, activation of the apoptotic pathways becomes an intriguing strategy in the development of chemotherapeutic agents. Marine natural products have become an important source in the discovery of antitumor drugs now since it is more and more feasible to collect organisms from seas. Hundreds of marine compounds have been found to induce apoptosis in tumor cells in recent years and many of them have good antitumor activity. This review summarizes several such compounds, based on their effects on the apoptotic signaling pathways, and highlights the problems in the development of anti-cancer drugs from the natural products.

p38 MAPK signaling mediates mitochondrial apoptosis in cancer cells induced by oleanolic acid.

Oleanolic acid (OA) is a nutritional component widely distributed in various vegetables. Although it has been well recognized for decades that OA exerts certain anti-tumor activity by inducing mitochondria-dependent apoptosis, it is still unclear that what molecular signaling is responsible for this effect. In this study, we employed cancer cell lines, A549, BXPC-3, PANC-1 and U2OS to elucidate the molecular mechanisms underlying OA anti- tumor activity. We found that activation of MAPK pathways, including p-38 MAPK, JNK and ERK, was triggered by OA in both a dose and time-dependent fashion in all the tested cancer cells. Activation was accompanied by cleavage of caspases and PARP as well as cytochrome C release. SB203580 (p38 MAPK inhibitor), but not SP600125 (JNK inhibitor) and U0126 (ERK inhibitor), rescued the pro-apoptotic effect of OA on A549 and BXPC- 3 cells. OA induced p38 MAPK activation promoted mitochondrial translocation of Bax and Bim, and inhibited Bcl-2 function by enhancing their phosphorylation. OA can induce reactive oxygen species (ROS)-dependent ASK1 activation, and this event was indispensable for p38 MAPK-dependent apoptosis in cancer cells. In vivo, p38 MAPK knockdown A549 tumors proved resistant to the growth-inhibitory effect of OA. Collectively, we elucidated that activation of ROS/ASK1/p38 MAPK pathways is responsible for the apoptosis stimulated by OA in cancer cells. Our finding can contribute to a better understanding of molecular mechanisms underlying the antitumor activity of nutritional components.

A novel protein from Eupolyphaga sinensis inhibits adhesion, migration, and invasion of human lung cancer A549 cells.

Eupolyphaga sinensis Walker is an important insect used in Chinese traditional medicine. In this study, we purified a 72-kDa anticancer protein, designated as EPS72, from this species using ammonium sulfate precipitation, ultrafiltration, CM Sepharose Fast Flow cation exchange, Q Sepharose High Performance (HP) anion exchange, Butyl Sepharose HP hydrophobic chromatography, and Superdex 75 gel filtration chromatographic techniques. EPS72 exhibited a potent anticancer activity against the human lung cancer A549 cell line (IC50, 18.76 µg/mL). Further study showed that EPS72 could induce A549 cell detachment and apoptosis, inhibit cell adhesion to fibronectin and collagen IV, and restrain cell migration and invasion. Moreover, EPS72 significantly decreased the expression of ß1-integrin. This study suggests that EPS72 could potentially be developed as a novel anticancer therapeutic agent due to its possible antimetastatic activity.

Therapeutic effect of an injectable sustained-release sinomenine hydrochloride and sodium hyaluronate compound in a rabbit model of osteoarthritis.

BACKGROUND: While intra-articular injection of sinomenine hydrochloride has a therapeutic effect on osteoarthritis, it has a short half-life, and is thermolabile and photolabile. The aim of this research was to evaluate the sustained-release of sinomenine hydrochloride from an injectable sinomenine hydrochloride and sodium hyaluronate compound (CSSSI) and its therapeutic effect in a rabbit model of osteoarthritis following intra-articular injection. METHODS: An injectable compound consisting of 1% sodium hyaluronate and 2.5% sinomenine hydrochloride was prepared and kept as the experiment group, and 2.5% sinomenine hydrochloride was prepared and kept as the control group. The cumulative mass release was measured at different time points in each group in vitro. Sixty-five male Zelanian rabbits were randomly divided into five groups: 15 (30 knees) each for the control, sodium hyaluronate, sinomenine hydrochloride, and CSSSI groups respectively, and five (10 knees) for the modeling group. Papain was injected into both knees of each rabbit for model establishment. Subsequently, 0.2 ml of the corresponding drugs was injected into the articular cavities of the remaining experiment groups, while the control group was treated with 0.2 ml normal saline. All groups were treated once a week for 4 weeks. Seven days after the last treatment, knees were anatomized to perform pathological observations and Mankin's evaluation of the synovium. Four groups were compared using the SPSS 13.0 software package. RESULTS: In the in vitro sustained-release experiments, 90% of the drug was released in the experiment group 360 minutes following the injection. Comparison of the Mankin's evaluations of the four groups illustrated statistical discrepancies (P < 0.05). In further paired comparisons of the CSSSI group vs. modeling control/sodium hyaluronate/sinomenine hydrochloride groups, statistical significance was uniformly obtained. Moreover, sodium hyaluronate and sinomenine hydrochloride treatments showed significant improvement over the modeling control (P < 0.05), whereas sodium hyaluronate vs. sinomenine hydrochloride comparison failed to reach significance (P > 0.05). CONCLUSIONS: CSSSI has a sustained-release effect on sinomenine hydrochloride. Intra-articular injection of CSSSI was significantly better than the sole sodium hyaluronate or sinomenine hydrochloride for the treatment of osteoarthritis in a rabbit model.

Effective silencing of Sry gene with RNA interference in developing mouse embryos resulted in feminization of XY gonad.

Delivering siRNA or shRNA into the developing embryos is still a main challenge to use of RNAi in mammalian systems. Here we analyze several factors influencing RNAi-mediated silencing of Sry gene, which is a tightly controlled spatiotemporal expressed gene and only shortly expressed in developing mouse embryo gonad. A Sry gene-specific shRNAs expression vector (pSilencer4.1/Sry565) was constructed. The shRNA constructs were mixed with polyethylenimines (PEIs) to form a complex and then injected into pregnant mice though tail vein. Our results showed that Sry gene was downregulated significantly in developing embryos. Further study revealed that knocking-down of Sry expression resulted in feminization of gonad development in mouse embryos and the expression level of Sox9 and Wt1 gene was also significantly changed by downregulation of Sry. The transfection efficiency is associated with the amount of plasmid DNA injection, injection time, injection speed, and volume. Our studies suggest that transplacental RNAi could be implemented by tail vein injection of plasmid vector into pregnant mice.

[Oleanolic acid inhibits proliferation of HUVECs, and inhibits migration and tube formation via VEGF pathway].

To investigate the effects of oleanolic acid (OA) on the proliferation, migration and the formation of tube-like structure in human vascular endothelial cells (HUVECs). MTT assay, flat plate scarification, Transwell plates and matrigel-induced tube formation assay were performed to detect the effects of OA on proliferation, migration and tube formation. MTT assay showed that the inhibition rates of HUVECs treated with 60 and 100 microg x mL(-1) of OA for 24 h were 19% and 83% respectively. Treatment of HUVECs significantly inhibited the cell migration in a dose-dependent manner. The vascular indexes of HUVECs treated with 40 and 60 microg x mL(-1) OA were 33% and 20% respectively. Western blotting analysis showed that treatment of the cells with OA significantly attenuated the expression and secretion of VEGF. Additionally, VEGF could in part reverse the effects of OA on migration and tube formation of HUVECs. In conclusion, OA inhibits the proliferation, and VEGF plays an important role in OA induced decreased migration and tube formation of HUVECs.

Antitumor peptides from marine organisms.

The biodiversity of the marine environment and the associated chemical diversity constitute a practically unlimited resource of new antitumor agents in the field of the development of marine bioactive substances. In this review, the progress on studies of antitumor peptides from marine sources is provided. The biological properties and mechanisms of action of different marine peptides are described; information about their molecular diversity is also presented. Novel peptides that induce apoptosis signal pathway, affect the tubulin-microtubule equilibrium and inhibit angiogenesis are presented in association with their pharmacological properties. It is intended to provide useful information for further research in the fields of marine antitumor peptides.

Cytotoxic metabolites from the soil-derived fungus Exophiala pisciphila.

A new polyketide compound 1 and a new naturally occurring chromone derivative 2, along with two known indole alkaloids 3-4 were characterized from the ethyl acetate extract of a soil-derived fungal strain, Exophiala pisciphila PHF-9. The structures of compounds 1-4 were established by detailed spectroscopic analysis and comparison with literature data. The absolute configuration of 1 was determined by a modified Mosher's method. Compound 1 exhibited moderate cytotoxicity against A-549, Hela, PANC-28 and BEL-7402 cell lines.

[Lidamycin inhibits angiogenesis of zebrafish embryo via down-regulation of VEGF].

Lidamycin (LDM) is a potent antitumor antibiotic. Previous studies have shown that LDM could inhibit proliferation and migration in endothelial cells. In the present report, the effect of LDM on angiogenesis of zebrafish embryo was studied. The results showed that treatment of zebrafish embryos with LDM resulted in significant inhibition of angiogenesis. Morphological observation, quantitative endogenous alkaline phosphatase (EAP) assay, alkaline phosphatase staining, and transgenic zebrafish assay were performed to evaluate vascular development defects in zebrafish. The results indicated that after the zebrafish embryos were exposed to LDM, angiogenesis defects of zebrafish embryos were observed, including pericardial edema, reduced numbers of circulating red blood cells, suppression of zebrafish vessel growth, and absences of SIV (subintestinal vein). The expression of VEGF was detected by RT-PCR assay, quantitative reverse transcriptase real-time PCR (qRT-PCR) assay and Western blotting analysis. The results revealed that LDM could inhibit the expression of VEGF protein, while the expression of mRNA was not significantly affected. The study suggests that LDM could inhibit the zebrafish embryo angiogenesis by down-regulation ofVEGF expression.

[Effect of Sry silencing by siRNA on the expression of sex determining genes in mouse embryos].

In order to investigate Sry regulation network in the development of male embryo, we inhibited the Sry gene expression by RNAi and then examined expression of other sex-related genes. Six genes (Sox9, Wt1, Sf1, Dax1, Gata4 and Amh), which are suggested to be closely related to Sry regulation were studied. Two siRNA expression vectors pSilencer4.1/Sry217 and pSilencer4.1/Sry565 were constructed and injected into gestated mouse through tail vein at 9.5 day of conception (dpc). The inhibition efficiency of Sry and the expression of other six genes were examined in male embryos at 11.5 dpc by RT-PCR and Western-blot. Expressions of the other six genes were analyzed by fluorescence quantity PCR. The results indicated both the pSilencer4.1/Sry217 and pSilencer4.1/Sry565 could inhibit significantly increased after Sry silencing. In contrast, no significant changes were observed in the expression of Sf1, Amh, Gata4, Dax1 and Sox9 when silencing Sry by siRNA. Our results suggested that the Wt1 transcription was regulated by Sry, whereas the Sox9 expression is not directly regulated by Sry in the development of genital ridge.

[Chemical constituents from root of Actinidia chinensis].

OBJECTIVE: To study the chemical constituents from the root of Actinidia chinensis. METHOD: The roots of A. chinensis were extracted with 95% EtOH. The EtOH extract was suspended in H2O and extracted with petroleum ether, EtOAc and BuOH successively. The compounds were isolated with column chromatography from the EtOAc fraction, and elucidated on the basis of spectral analysis(MS, IR, 1H-NMR, 13C-NMR). RESULT: Seven compounds were isolated from the root of A. chinensis, and the structures were identified as 2alpha-hydroxyoleanolic acid (1), 2alpha-hydroxyursolic acid (2), euscaphic acid (3), 23-hydroxyursolic acid (4), 3beta-O-acetylursolic acid (5), ergosta4, 6, 8, (14), 22-tetraen-3-one (6), beta-steriol (7). CONCLUSION: All the compounds were obtained from the root of A. chinensis for the first time.

[Effect of fertilization condition on mammalian sex determination].

Selection of sex at or before conception is perhaps the most desired biotechnology of all time because many economic traits are related with sex. Sex selection by manipulating the conditions of sperm-oocytes fertilization would be one of the most practicable and widely used methods. This review summarized the progress in the effects of fertilization conditions on mammalian sex. Four main factors which possibly affected sex were described such as arginine concentration in female animal vagina, glucose in the uterus, maturational status of the oocyte at the time they encounter sperm as well as the hormone levels of both parents at the time of conception.

[Impact of reproductive hormone on mouse embryo sexes].

The effects of reproductive hormone on mouse embryo sexes were studied with in vitro fertilization (IVF), in vitro culture (IVC) and sex identification. Results showed that it had no adverse effects on embryos cleavage and development after the embryos were incubated with the fertilization media with 17beta-E2, FSH and progesterone respectively at the concentration of this study. Mice embryos sex ratios significantly deviated from 1:1(P < 0.01) and skewed in favor of males at the concentration of 17beta-E2 attained 70 pg/mL and progesterone attained 99 pg/mL in IVF culture media respectively. 0.01-0.04 IU/mL FSH had no effects on the mouse embryo sexes.