Prevention of STAT3-related pathway in SK-N-SH cells by natural product astaxanthin.

PURPOSE: Neuroblastoma (NB) is the most common solid malignancy in children. Despite current intensive treatment, the long-term event-free survival rate is less than 50% in these patients. Thus, patients with NB urgently need more valid treatment strategies. Previous research has shown that STAT3 may be an effective target in high-risk NB patients. However, there are no effective inhibitors in clinical evaluation with low toxicity and few side effects. Astaxanthin is a safe and natural anticancer product. In this study, we investigated whether astaxanthin could exert antitumor effects in the SK-N-SH neuroblastoma cancer cell line. METHOD: MTT and colony formation assays were used to determine the effect of astaxanthin on the proliferation and colony formation of SK-N-SH cells. Flow cytometry assays were used to detect the apoptosis of SK-N-SH cells. The migration and invasion ability of SK-N-SH cells were detected by migration and invasion assays. Western blot and RT-PCR were used to detect the protein and mRNA levels. Animal experiments were carried out and cell apoptosis in tissues were assessed using a TUNEL assay. RESULT: We confirmed that astaxanthin repressed proliferation, clone formation ability, migration and invasion and induced apoptosis in SK-N-SH cells through the STAT3 pathway. Furthermore, the highest inhibitory effect was observed when astaxanthin was combined with si-STAT3. The reason for this may be that the combination of astaxanthin and si-STAT3 can lower STAT3 expression further than astaxanthin or si-STAT3 alone. CONCLUSION: Astaxanthin can exert anti-tumor effect on SK-N-SH cells. The inhibitory effect was the higher when astaxanthin was combined with si-STAT3.

Mannose inhibits the growth of prostate cancer through a mitochondrial mechanism.

The limited treatment options for advanced prostate cancer (PCa) lead to the urgent need to discover new anticancer drugs. Mannose, an isomer of glucose, has been reported to have an anticancer effect on various tumors. However, the anticancer effect of mannose in PCa remains unclear. In this study, we demonstrated that mannose inhibits the proliferation and promotes the apoptosis of PCa cells in vitro, and mannose was observed to have an anticancer effect in mice without harming their health. Accumulation of intracellular mannose simultaneously decreased the mitochondrial membrane potential, increased mitochondrial and cellular reactive oxygen species (ROS) levels, and reduced adenosine triphosphate (ATP) production in PCa cells. Mannose treatment of PCa cells induced changes in mitochondrial morphology, caused dysregulated expression of the fission protein, such as fission, mitochondrial 1 (FIS1), and enhanced the expression of proapoptotic factors, such as BCL2-associated X (Bax) and BCL2-antagonist/killer 1 (Bak). Furthermore, lower expression of mannose phosphate isomerase (MPI), the key enzyme in mannose metabolism, indicated poorer prognosis in PCa patients, and downregulation of MPI expression in PCa cells enhanced the anticancer effect of mannose. This study reveals the anticancer effect of mannose in PCa and its clinical significance in PCa patients.

Survey and Evaluation of Spacecraft-Associated Aluminum-Degrading Microbes and Their Rapid Identification Methods.

Aluminum corrosion has become a major obstacle in spacecraft construction given that aluminum is used extensively throughout the construction process. Despite its many attributes in strength and durability, aluminum is susceptible to corrosion, in particular, corrosion due to microbial contamination. Scientists have encountered a number of problems with microbial aluminum corrosion within spacecraft components. Here, we summarize recent findings with regard to the phenomenon of microbiologically influenced corrosion (MIC) on space stations in the context of microbial strains isolated from the Mir space station (Mir) and the International Space Station (ISS). Given that strains found on spacecraft are of terrestrial origin, an understanding of the contribution of Al-corrosive microbes to corrosion and related risks to space travel and astronaut health is essential for implementation of prevention strategies. Accordingly, an efficient rapid identification method of microbes with the capability to degrade aluminum is proposed. In particular, onboard implementation of a matrix-assisted laser desorption/ionization-time of flight mass spectrometer (MALDI-TOF MS) is addressed. The use of a MALDI-TOF MS on board spacecraft will be crucial to future successes in space travel given that traditional methods of identifying corrosive species are far more time-consuming. Identification of microbes by way of a MALDI-TOF MS may also aid in the study of microbial corrosion and be a valuable asset for MIC prevention.

The Impacts of Simulated Microgravity on Rat Brain Depended on Durations and Regions.

OBJECTIVE: To explore the dynamic impacts of simulated microgravity (SM) on different vital brain regions of rats. METHODS: Microgravity was simulated for 7 and 21 days, respectively, using the tail-suspension rat model. Histomorphology, oxidative stress, inflammatory cytokines and the expression of some key proteins were determined in hippocampus, cerebral cortex and striatum. RESULTS: 21-day SM decreased brain derived neurotrophic factor and induced neuron atrophy in the cerebral cortex. Strong oxidative stress was triggered at day 7 and the oxidative status returned to physiological level at day 21. Inflammatory cytokines were gradually suppressed and in striatum, the suppression was regulated partially through c-Jun/c-Fos. CONCLUSION: The results revealed that the significant impacts of SM on rat brain tissue depended on durations and regions, which might help to understand the health risk and to prevent brain damage for astronauts in space travel.

TRIB1 induces macrophages to M2 phenotype by inhibiting IKB-zeta in prostate cancer.

Immunotherapy has made great breakthroughs in the field of cancer. However, the immunotherapeutic effect of prostate cancer is unsatisfactory. We found that the expression of TRIB1 was significantly correlated with the infiltration of CD163+ macrophages in prostate cancer. This study focused on the effects of TRIB1 on macrophage polarization in the immune microenvironment of prostate cancer. RNA sequencing analysis demonstrated that TRIB1 has significant effects on the regulation of the nuclear factor (NF)-κB signaling pathway and downstream cytokines. Flow cytometry and enzyme-linked immunosorbent assay were used to examine THP-1 cells cultured in conditioned medium from prostate cancer cells overexpressing TRIB1 and showed that overexpression of TRIB1 promoted the secretion of CXCL2 and interleukin (IL)8 by PC3 cells, which increased the secretion of IL12 by THP-1 cells as well as the expression of CD163 on THP-1 cells. IKB-zeta, regulated by TRIB1, was expressed in PC3 cells but was barely detectable in DU145 cells. The reductions in CXCL2 and IL8 by the inhibition of TRIB1 were rescued by the deletion of IKB-zeta. Here we showed that TRIB1 promoted the secretion of cytokines from prostate cancer cells and induced the differentiation of monocytes/macrophages into M2 macrophages.

[Effect of androgen receptor on IgG expression, proliferation and migration of prostate cancer cells in vitro].

OBJECTIVE: To investigate the effect of androgen receptor (AR) on IgG protein expression and the proliferation and migration of prostate cancer cells. METHODS: Western blotting was used to detect the expression of AR protein and IgG in androgen-dependent prostate cancer LNCap cells and castration-resistant prostate cancer PC-3 cells. In AR-overexpressing cells (PC-3-AR cells) established by transfecting PC-3 with AR gene (pCDNA3.1) and LNCap cells with small interfering RNA-mediated AR silencing (LNCap-siAR cells) were analyzed for expressions of AR protein and IgG with Western blotting; the expression of IgG mRNA was detected by Q-PCR, and the cell proliferation and migration were assessed with MTT assay and wound healing assay, respectively. RESULTS: Compared with PC-3 cells, LNCap cells expressed a higher level of AR protein and a lower level of IgG (P<0.05). PC-3-AR cells showed attenuated proliferation and migration with a lowered expression of IgG (P<0.01), while LNCap-siAR cells showed enhanced proliferation and migration with increased expression of IgG (P<0.01). CONCLUSION: The expression of AR is inversely correlated with IgG and is associated with the proliferation and migration of prostate cancer cells in vitro.

Six new C-21 steroidal glycosides from Dregea sinensis Hemsl.

Six new C-21 steroidal glycosides (1-6) were separated from the root of Dregea sinensis Hemsl. and their structures were elucidated using extensive nuclear magnetic resonance, mass spectrometry, and infrared spectral analyses. Isolated compounds were evaluated for antitumor activity, which showed that compound 3 had moderate activity in Jurkat cells (IC50 19.54 ± 0.91 µM), and compounds 1-4 had significant effects against IL-2R and TNFR2 (IC50 1.518 ± 0.06 µM to 5.9 ± 0.07 µM).

Formation of a salsolinol-like compound, the neurotoxin, 1-acetyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, in a cellular model of hyperglycemia and a rat model of diabetes.

There are statistical data indicating that diabetes is a risk factor for Parkinson's disease (PD). Methylglyoxal (MG), a biologically reactive byproduct of glucose metabolism, the levels of which have been shown to be increase in diabetes, reacts with dopamine to form 1-acetyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline (ADTIQ); this formation may provide further insight into the connection between PD and diabetes. In this study, we investigated the role of ADTIQ in these two diseases to determine in an aim to enhance our understanding of the link between PD and diabetes. To this end, a cell model of hyperglycemia and a rat model of diabetes were established. In the cell model of hyperglycemia, compared with the control group, the elevated glucose levels promoted free hydroxyl radical formation (p<0.01). An ADTIQ assay was successfully developed and ADTIQ levels were detected and quantified. The levels of its precursors, MG and dopamine (DA), were determined in both the cell model of hyperglycemia and the rat model of diabetes. The proteins related to glucose metabolism were also assayed. Compared with the control group, ADTIQ and MG levels were significantly elevated not only in the cell model of hyperglycemia, but also in the brains of rats with diabetes (p<0.01). Seven key enzymes from the glycolytic pathway were found to be significantly more abundant in the brains of rats with diabetes. Moreover, it was found that adenosine triphosphate (ATP) synthase and superoxide dismutase (SOD) expression levels were markedly decreased in the rats with diabetes compared with the control group. Therefore, ADTIQ expression levels were found to be elevated under hyperglycemic conditions. The results reported herein demonstrate that ADTIQ, which is derived from MG, the levels of which are increased in diabetes, may serve as a neurotoxin to dopaminergic neurons, eventually leading to PD.

Dragon's blood dropping pills have protective effects on focal cerebral ischemia rats model.

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis (Lour.) S.C.Chen (Yunnan, China). As a traditional Chinese medicinal herb, it has great traditional medicinal value and is used for wound healing and to stop bleeding. Its main biological activity comes from phenolic compounds. In this study, phenolic compounds were made into dropping pills and their protective effects were examined by establishing focal cerebral ischemia rats model used method of Middle Cerebral Artery Occlusion (MCAO), and by investigating indexes of neurological scores, infarct volume, cerebral index, cerebral water content and oxidation stress. Compared to model group, high, middle and low groups of Dragon's blood dropping pills could improve the neurological function significantly (p<0.01) and reduce cerebral infarct volume of focal cerebral ischemia rats remarkably (p<0.05-0.01). Meanwhile, each group could alleviate cerebral water content and cerebral index (p<0.05-0.01) and regulate oxidative stress of focal cerebral ischemia rats obviously (p<0.05-0.01). Activities of middle group corresponded with that treated with positive control drug. The results obtained here showed that Dragon's blood dropping pills had protective effects on focal cerebral ischemia rats.

Dragon's blood may have radioprotective effects in radiation-induced rat brain injury.

Dragon's blood is a bright red resin obtained from Dracaena cochinchinensis. It is a traditional medicinal that is used for wound healing and to stop bleeding. Its main biological activity appears to be from phenolic compounds found in Dragon's blood. In this study, the radioprotective effects of Dragon's blood were examined after whole brain irradiation of rats with either 100 MeV/u Carbon (12)C(6+) heavy ions or (60)Co γ-rays. The amounts of radiation-induced oxidative stress, inflammatory cytokines and apoptosis in irradiated rat brains were compared with and without Dragon's blood treatment. Compared to the "irradiation only" control group, the Dragon's blood treatment group significantly decreased malondialdehyde and hydrogen peroxide levels, and increased superoxide dismutase activity and glutathione levels induced by oxidative stress in radiation exposed rats (P < 0.05). Dragon's blood also significantly reduced radiation-induced inflammatory cytokines of tumor necrosis factor-α, interferon-γ and interleukin-6 levels (P < 0.05) and inhibited hippocampal neuronal apoptosis in (60)Co γ-ray irradiated rats. Furthermore, Dragon's blood significantly increased expression of brain-derived neurophic factor and inhibited the expression of pro-apoptotic caspase 3 (P < 0.05-0.01). Finally, Dragon's blood significantly inhibited expression of the AP-1 transcription factor family members c-fos and c-jun proteins (P < 0.05-0.01). The results obtained here suggest that Dragon's blood has radioprotective properties in rat brains after both heavy ions and (60)Co γ-ray exposure.

Fluorescent quantum dot-labeled aptamer bioprobes specifically targeting mouse liver cancer cells.

Fluorophore-labeled bioprobes are the key for fluorescent-labeled imaging technology. In the present work, mouse liver hepatoma cell line BNL 1ME A.7R.1 (MEAR)-specific ssDNA aptamer TLS9a was used to fabricate quantum dot-labeled aptamer bioprobe (QD-Apt), which was obtained by conjugating streptavidin-modified quantum dots (SA-QDs) with biotin-derived aptamer via the interaction between biotin and streptavidin. The QD-Apt was of monodispersity and excellent fluorescence properties. When the optimum ratio of SA-QDs to aptamer, which is 1:16, was used in the preparation of the QD-Apt, the resultant QD-Apt was of satisfactory bioactivity. They could specifically recognize MEAR cells and could not recognize BNL cells and Hela cells. Particularly, the growth and viability of QD-Apt bound MEAR cells were not affected by QD-Apt within 84 h compared to control cells, indicating that the probe was biocompatible and suitable for live cell imaging.

A strategy for precise and large scale identification of core fucosylated glycoproteins.

Core fucosylation (CF) patterns of some glycoproteins are more sensitive and specific than evaluation of their total respective protein levels for diagnosis of many diseases, such as cancers. Global profiling and quantitative characterization of CF glycoproteins may reveal potent biomarkers for clinical applications. However, current techniques are unable to reveal CF glycoproteins precisely on a large scale. Here we developed a robust strategy that integrates molecular weight cutoff, neutral loss-dependent MS(3), database-independent candidate spectrum filtering, and optimization to effectively identify CF glycoproteins. The rationale for spectrum treatment was innovatively based on computation of the mass distribution in spectra of CF glycopeptides. The efficacy of this strategy was demonstrated by implementation for plasma from healthy subjects and subjects with hepatocellular carcinoma. Over 100 CF glycoproteins and CF sites were identified, and over 10,000 mass spectra of CF glycopeptide were found. The scale of identification results indicates great progress for finding biomarkers with a particular and attractive prospect, and the candidate spectra will be a useful resource for the improvement of database searching methods for glycopeptides.

Iron contributes to the formation of catechol isoquinolines and oxidative toxicity induced by overdose dopamine in dopaminergic SH-SY5Y cells.

OBJECTIVE: The selective loss of dopaminergic neurons in Parkinson's disease is suspected to correlate with the increase of cellular iron, which may be involved in the pathogenesis of PD by promotion of oxidative stress. This research investigated dopamine-induced oxidative stress toxicity contributed by iron and the production of dopamine-derived neurotoxins in dopaminergic SH-SY5Y cells. METHODS: After the SH-SY5Y cells were pre-incubated with dopamine and Fe2+ for 24 h, the cell viability, hydroxyl radical, melondialdehyde, cell apoptosis, and catechol isoquinolines were measured by lactate dehydrogenase assay, salicylic acid trapping method, thiobarbuteric acid assay, Hoechst 33258 staining and HPLC-electrochemical detection (HPLC-ECD), respectively. RESULTS: (1) Optimal dopamine (150 micromol/L) and Fe2+ (40 or 80 micromol/L) significantly increased the concentrations of hydroxy radicals and melondialdehyde in SH-SY5Y cells. (2) Induction with dopamine alone or dopamine and Fe2+ (dopamine/Fe2+) caused cell apoptosis. (3) Compared with untreated cells, the catechol isoquinolines, salsolinol and N-methyl-salsolinol in dopamine/Fe2+-induced cells were detected in increasing amounts. CONCLUSION: Due to dopamine/Fe2+-induced oxidative stress similar to the state in the parkinsonian substantia nigra neurons, dopamine and Fe2+ impaired SH-SY5Y cells could be used as the cell oxidative stress model of Parkinson's disease. The catechol isoquinolines detected in cells may be involved in the pathogenesis of Parkinson's disease as potential neurotoxins.

Quantum dot-labeled aptamer nanoprobes specifically targeting glioma cells.

Two new techniques, aptamer-based specific recognition and quantum dot (QD)-based fluorescence labeling, are becoming increasingly important in biosensing. In this study, these two techniques have been coupled together to construct a new kind of fluorescent QD-labeled aptamer (QD-Apt) nanoprobe by conjugating GBI-10 aptamer to the QD surface. GBI-10 is a single-stranded DNA (ssDNA) aptamer for tenascin-C, which distributes on the surface of glioma cells as a dominant extracellular matrix protein. The QD-Apt nanoprobe can recognize the tenascin-C on the human glioma cell surface, which will be helpful for the development of new convenient and sensitive in vitro diagnostic assays for glioma. The QD-Apt nanoprobe has particular features such as strong fluorescence, stability, monodispersity and uniformity. In addition, this probe preparation method is universal, so it is expected to provide a new type of stable nanoprobe for high-throughput and fast biosensing detection and bioimaging. New methods for real-time and dynamic tracking and imaging can be accordingly developed.