Analysis of the difference in SLCO1B1 and APOE gene polymorphisms between Mongolian and Han populations.

Objective: To analyze SLCO1B1 and APOE polymorphisms and their clinical significance in the Mongolian and Han populations in Ordos, Inner Mongolia. Methods: Mongolian patients (n = 200) with cardiovascular disease admitted to our hospital from January 2018 to December 2020 were selected as the Mongolian population group. Han patients (n = 200) with cardiovascular diseases admitted during the same period were selected as the Han population group. Mutations in SLCO1B1 and APOE were detected by real-time fluorescence qPCR, and the differences between the two groups were analyzed. Results: The nucleotide polymorphisms of SLCO1B1 and APOE in the Mongolian and Han populations were consistent with the Hardy-Weinberg law. There were significant differences in gender, age, BMI, hypertension, alcohol consumption, dyslipidemia and low-density lipoprotein cholesterol levels between the two groups. APOE genotypes were classified according to those related to the efficacy of statins and the risk of atherosclerosis, and there was a significant difference between the two groups. Conclusion: There were differences in SLCO1B1 and APOE polymorphisms between the Mongolian and Han populations in Ordos. These may explain the differences in the incidence of cardiovascular diseases and the lipid-lowering efficacy of statins between the two populations.

Study on the relationship between SLCO1B1 and ApoE gene polymorphisms and the risk of coronary heart disease in the Mongolian population.

Objective This study aimed to analyze the influence of SLCO1B1 and APOE gene polymorphisms on coronary heart disease in Mongolian population who living in Ordos area. Methods From January 2019 to June 2020, 200 Mongolian patients with coronary heart disease admitted to our hospital and other banner hospitals were selected as the case group. At the same time, 150 randomly selected healthy Mongolian people from medical examination centers comprised the control group. The polymorphisms of SLCO1B1 (388A>G, 521 T > C) and ApoE (388 T > C, 526 C > t) were detected by real-time polymerase chain reaction. Combined with environmental data, the effect of gene polymorphism on coronary heart disease was explored. Results Both SLCO1B1 and ApoE polymorphisms satisfied Hardy-Weinberg equilibrium. The SLCO1B1 genotype *1a/*1b showed the highest frequency in the case group, accounting for 35.0%, while The SLCO1B1 genotype *1b/*1b showed the highest frequency in the control group, accounting for 32.0%. Allele *1b was the most commonly seen allele in both the case group and control group (57.8% and 53.7%, respectively). Meanwhile, The difference in the distribution of SLCO1B1 *1a/*15 genotype between the two groups was statistically significant (P < .05). Conclusion The results showed that the SLCO1B *1a/*15 genotype, ApoE ε3 /ε3 genotype, and ε3 allele reduced the risk of coronary disease in the Mongolian population, making them protective genes against this disease, while the ApoE ε4 allele increased the risk of coronary disease, making it a coronary disease risk factor.

[Sanggenon C induces apoptosis of prostate cancer PC3 cells by activating caspase 3 and caspase 9 pathways].

OBJECTIVE: To investigate the effects of Sanggenon C in inducing apoptosis of prostate cancer PC3 cell line and explore the underlying mechanism. METHODS: The proliferation of PC3 cells treated for 24 h with 1, 5, 20, 50, and 100 µmol/L sanggenon C or treated with 20 µmol/L Sanggenon C for 0, 6, 12, 24 and 48 h was evaluated using MTT assay. Flow cytometry was performed for analysis of apoptosis of PC3 cells after exposure to sanggenon C with different treatment protocols, and the activity of caspase 3 was detected using spectrofluorometry. The inhibitory effect of sanggenon C on PC3 cells pretreated with DMSO, z-DEVD-fmk, z-LEHD-fmk or z-IETD-fmk for 1 h was detected by MTT assay. RESULTS: Sanggenon C inhibited the proliferation of PC3 cells in a dose- and time-dependent manner (P<0.05 except for 1 µmol/L group) with a 24-h IC50 of 18.76 µmol/L. Sanggenon C at 20 µmol/L caused inhibition rates of PC3 cells of 10.57%, 27.09%, 51.88%, 80.73% and 87.99% after treatment for 6, 12, 24, 48, and 72 h, respectively (P<0.05), and resulted in apoptosis rates of 7.43%, 20.91% and 37.56% at 12 h, 24 h and 48 h, respectively. Sanggenon C significantly increased caspase-3 activity in the cells, and its effect on PC3 cell proliferation was partially reversed by caspase 3 and caspase 9 inhibitors. CONCLUSION: Sanggenon C can dose-dependently induce growth inhibition and apoptosis of PC3 cells possibly by activating caspase 9 and caspase 3 pathways.

Combined therapeutic effects of bortezomib and anacardic acid on multiple myeloma cells via activation of the endoplasmic reticulum stress response.

Bortezomib (Bor), a proteasome inhibitor, has marked therapeutic effects in multiple myeloma (MM), and its synergistic effects with other anticancer agents have been widely investigated. In the present study, endoplasmic reticulum (ER) stress was the target of the treatment strategy; anacardic acid (AA) and Bor induce ER stress, resulting in apoptosis of multiple myeloma cells. AA/Bor combination therapy exhibited overt cytotoxicity in MM cells, by synergistically reducing cell growth and promoting cell death. Notably, expression levels of the stress­associated molecules binding protein, phosphorylated eukaryotic initiation factor 2α, activating transcription factor 4 (ATF4) and CCAAT­enhancer binding protein homologous protein (CHOP) were increased following treatment. AA/Bor combination therapy­induced U266 cell cytotoxicity was partially reversed by ATF4 gene silencing and slightly enhanced by CHOP knockdown. The results of the present study suggest that AA/Bor combination may be a potential therapeutic strategy for MM treatment.

A microRNA-mediated decrease in eukaryotic initiation factor 2α promotes cell survival during PS-341 treatment.

MicroRNAs (miRs) play pivotal roles in carcinogenesis and endoplasmic reticulum (ER) that performs the folding, modification and trafficking of proteins targeted to the secretory pathway. Cancer cells often endure ER stress during tumor progression but use the adaptive ER stress response to gain survival advantage. Here we report: (i) A group of miRs, including miR-30b-5p and miR-30c-5p, are upregulated by proteasome inhibitor PS-341 treatment, in HepG2 and MDA-MB-453 cells. (ii) Two representative PS-341-induced miRs: miR-30b-5p and miR-30c-5p are found to promote cell proliferation and anti-apoptosis in both tumor cells. (iii) eIF2α is confirmed as the congenerous target of miR-30b-5p and miR-30c-5p, essential to the anti-apoptotic function of these miRs. (iv) Upregulation of miR-30b-5p or miR-30c-5p, which occurs latter than the increase of phosphorylated eIF2α (p-eIF2α) in the cell under ER stress, suppresses the p-eIF2α/ATF4/CHOP pro-apoptotic pathway. (v) Inhibition of the miR-30b-5p or miR-30c-5p sensitizes the cancer cells to the cytotoxicity of proteasome inhibition. In conclusion, we unravels a new miRs-based mechanism that helps maintain intracellular proteostasis and promote cell survival during ER stress through upregulation of miR-30b-5p and miR-30c-5p which target eIF2α and thereby inhibit the p-eIF2α/ATF4/CHOP pro-apoptotic pathway, identifying miR-30b-5p and miR-30c-5p as potentially new targets for anti-cancer therapies.

Clinically used antirheumatic agent auranofin is a proteasomal deubiquitinase inhibitor and inhibits tumor growth.

Proteasomes are attractive emerging targets for anti-cancer therapies. Auranofin (Aur), a gold-containing compound clinically used to treat rheumatic arthritis, was recently approved by US Food and Drug Administration for Phase II clinical trial to treat cancer but its anti-cancer mechanism is poorly understood. Here we report that (i) Aur shows proteasome-inhibitory effect that is comparable to that of bortezomib/Velcade (Vel); (ii) different from bortezomib, Aur inhibits proteasome-associated deubiquitinases (DUBs) UCHL5 and USP14 rather than the 20S proteasome; (iii) inhibition of the proteasome-associated DUBs is required for Aur-induced cytotoxicity; and (iv) Aur selectively inhibits tumor growth in vivo and induces cytotoxicity in cancer cells from acute myeloid leukemia patients. This study provides important novel insight into understanding the proteasome-inhibiting property of metal-containing compounds. Although several DUB inhibitors were reported, this study uncovers the first drug already used in clinic that can inhibit proteasome-associated DUBs with promising anti-tumor effects.

Treatment with hydrogen molecules prevents RANKL-induced osteoclast differentiation associated with inhibition of ROS formation and inactivation of MAPK, AKT and NF-kappa B pathways in murine RAW264.7 cells.

The bone protective effects of the hydrogen molecule (H2) have been demonstrated in several osteoporosis models while the underlying molecular mechanism has remained unclear. Osteoclast differentiation is an important factor related to the pathogenesis of bone-loss related diseases. In this work, we evaluated the effects of incubation with H2 on receptor activator of NFκB ligand (RANKL)-induced osteoclast differentiation. We found that treatment with H2 prevented RANKL-induced osteoclast differentiation in RAW264.7 cells and BMMs. Treatment with H2 inhibits the ability to form resorption pits of BMMs stimulated by RANKL. Treatment with H2 reduced mRNA levels of osteoclast-specific markers including tartrate resistant acid phosphatase, calcitonin receptor, cathepsin K, metalloproteinase-9, carbonic anhydrase typeII, and vacuolar-type H(+)-ATPase. Treatment with H2 decreased intracellular reactive oxygen species (ROS) formation, suppressed NADPH oxidase activity, down-regulated Rac1 activity and Nox1 expression, reduced mitochondrial ROS formation, and enhanced nuclear factor E2-related factor 2 nuclear translocation and heme oxygenase-1 activity. In addition, treatment with H2 suppressed RANKL-induced expression of nuclear factor of activated T cells c1 and c-Fos. Furthermore, treatment with H2 suppressed NF-κB activation and reduced phosphorylation of p38, extracellular signal-regulated kinase, c-Jun-N-terminal kinase, and protein kinases B (AKT) stimulated with RANKL. In conclusion, hydrogen molecules prevented RANKL-induced osteoclast differentiation associated with inhibition of reactive oxygen species formation and inactivation of NF-κB, mitogen-activated protein kinase and AKT pathways.

Gambogic acid is a tissue-specific proteasome inhibitor in vitro and in vivo.

Gambogic acid (GA) is a natural compound derived from Chinese herbs that has been approved by the Chinese Food and Drug Administration for clinical trials in cancer patients; however, its molecular targets have not been thoroughly studied. Here, we report that GA inhibits tumor proteasome activity, with potency comparable to bortezomib but much less toxicity. First, GA acts as a prodrug and only gains proteasome-inhibitory function after being metabolized by intracellular CYP2E1. Second, GA-induced proteasome inhibition is a prerequisite for its cytotoxicity and anticancer effect without off-targets. Finally, because expression of the CYP2E1 gene is very high in tumor tissues but low in many normal tissues, GA could therefore produce tissue-specific proteasome inhibition and tumor-specific toxicity, with clinical significance for designing novel strategies for cancer treatment.

Sanggenon C decreases tumor cell viability associated with proteasome inhibition.

Several flavonoids have been reported to be proteasome inhibitors, but whether prenylated flavonoids are able to inhibit proteasome function remains unknown. We report for the first time that Sanggenon C, a natural prenylated flavonoid, inhibits tumor cellular proteasomal activity and cell viability. We found that (1) Sanggenon C inhibited tumor cell viability and induced cell cycle arrest at G0/G1 phase; (2) Sanggenon C inhibited the chymotrypsin-like activity of purified human 20S proteasome and 26S proteasome in H22 cell lysate, and Sanggenon C was able to dose-dependently accumulate ubiquitinated proteins and proteasome substrate protein p27; (3) Sanggenon C-induced proteasome inhibition occurred prior to cell death in murine H22 and P388 cell lines; (4) Sanggenon C induced death of human K562 cancer cells and primary cells isolated from leukemic patients. We conclude that Sanggenon C inhibits tumor cell viability via induction of cell cycle arrest and cell death, which is associated with its ability to inhibit the proteasome function and that proteasome inhibition by Sanggenon C at least partially contributes to the observed tumor cell growth-inhibitory activity.

Gambogic acid enhances proteasome inhibitor-induced anticancer activity.

Proteasome inhibition has emerged as a novel approach to anticancer therapy. Numerous natural compounds, such as gambogic acid, have been tested in vitro and in vivo as anticancer agents for cancer prevention and therapy. However, whether gambogic acid has chemosensitizing properties when combined with proteasome inhibitors in the treatment of malignant cells is still unknown. In an effort to investigate this effect, human leukemia K562 cells, mouse hepatocarcinoma H22 cells and H22 cell allografts were treated with gambogic acid, a proteasome inhibitor (MG132 or MG262) or the combination of both, followed by measurement of cellular viability, apoptosis induction and tumor growth inhibition. We report, for the first time, that: (i) the combination of natural product gambogic acid and the proteasome inhibitor MG132 or MG262 results in a synergistic inhibitory effect on growth of malignant cells and tumors in allograft animal models and (ii) there was no apparent systemic toxicity observed in the animals treated with the combination. Therefore, the findings presented in this study demonstrate that natural product gambogic acid is a valuable candidate to be used in combination with proteasome inhibitors, thus representing a compelling anticancer strategy.

Physiological levels of ATP negatively regulate proteasome function.

Intracellular protein degradation by the ubiquitin-proteasome system is ATP dependent, and the optimal ATP concentration to activate proteasome function in vitro is ∼100 µM. Intracellular ATP levels are generally in the low millimolar range, but ATP at a level within this range was shown to inhibit proteasome peptidase activities in vitro. Here, we report new evidence that supports a hypothesis that intracellular ATP at the physiological levels bidirectionally regulates 26S proteasome proteolytic function in the cell. First, we confirmed that ATP exerted bidirectional regulation on the 26S proteasome in vitro, with the optimal ATP concentration (between 50 and 100 µM) stimulating proteasome chymotrypsin-like activities. Second, we found that manipulating intracellular ATP levels also led to bidirectional changes in the levels of proteasome-specific protein substrates in cultured cells. Finally, measures to increase intracellular ATP enhanced, while decreasing intracellular ATP attenuated the ability of proteasome inhibition to induce cell death. These data strongly suggest that endogenous ATP within the physiological concentration range can exert a negative impact on proteasome activities, allowing the cell to rapidly upregulate proteasome activity on ATP reduction under stress conditions.

[Experimental study on effect of gastrodia in inducing the differentiation of mesenchymal stem cells into neuron-like cells].

OBJECTIVE: To investigate the effect of gastrodia in extracorporeal oriented inducing the differentiation of mesenchymal stem cells into neuron-like cells. METHODS: Mesenchymal stem cells were separated from bone marrow of rats by wall sticking method, amplifying cultured in vitro, and differentiated into neuron-like cells by oriented induction with gastrodia. The morphology of cells was observed under light microscopy, neuro-specific enolase (NSE), nestin and glial fibrillary acidic protein (GFAP) were detected by immunocytochemistry. RESULTS: Rats mesenchymal stem cells could be separated and amplified in vitro. After being induced by gastrodia for 2 hrs, most of the cells would be differentiated into meuron-like cells, revealing cytodendrite. By immunochemical staining, cells showed positive of NSE, nestin, and negative of GFAP. CONCLUSION: Rats' mesenchymal stem cells could be induced to differentiate into neuron-like cells.