首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Human glioblastoma multiforme (GBM) is one of the most malignant brain tumors, with a high mortality rate worldwide. Conventional GBM treatment is now challenged by the presence of the blood–brain barrier (BBB), drug resistance, and post-treatment adverse effects. Hence, developing bioactive compounds isolated from plant species and identifying molecular pathways in facilitating effective treatment has become crucial in GBM. Based on pharmacodynamic studies, andrographolide has sparked the interest of cancer researchers, who believe it may alleviate difficulties in GBM therapy; however, it still requires further study. Andrographolide is a bicyclic diterpene lactone derived from Andrographis paniculata (Burm.f.) Wallich ex Nees that has anticancer properties in various cancer cell lines. The present study aimed to evaluate andrographolide’s anticancer effectiveness and potential molecular pathways using a DBTRG-05MG cell line. The antiproliferative activity of andrographolide was determined using the WST-1 assay, while scratch assay and clonogenic assay were used to evaluate andrographolide’s effectiveness against the cancer cell line by examining cell migration and colony formation. Flowcytometry was also used to examine the apoptosis and cell cycle arrest induced by andrographolide. The mRNA and protein expression level involved in the ERK1/2/c-Myc/p53 signaling pathway was then assessed using qRT-PCR and Western blot. The protein–protein interaction between c-Myc and p53 was determined by a reciprocal experiment of the co-immunoprecipitation (co-IP) using DBTRG-05MG total cell lysate. Andrographolide significantly reduced the viability of DBTRG-05MG cell lines in a concentration- and time-dependent manner. In addition, scratch and clonogenic assays confirmed the effectiveness of andrographolide in reducing cell migration and colony formation of DBTRG-05MG, respectively. Andrographolide also promoted cell cycle arrest in the G2/M phase, followed by apoptosis in the DBTRG-05MG cell line, by inducing ERK1/2, c-Myc, and p53 expression at the mRNA level. Western blot results demonstrated that c-Myc overexpression also increased the production of the anti-apoptotic protein p53. Our findings revealed that c-Myc and p53 positively interact in triggering the apoptotic signaling pathway. This study successfully discovered the involvement of ERK1/2/c-Myc/p53 in the suppression of the DBTRG-05MG cell line via cell cycle arrest followed by the apoptosis signaling pathway following andrographolide treatment.  相似文献   

2.
Iridin is a natural flavonoid found in Belamcanda chinensis documented for its broad spectrum of biological activities like antioxidant, antitumor, and antiproliferative effects. In the present study, we have investigated the antitumor potential of iridin in AGS gastric cancer cells. Iridin treatment decreases AGS cell growth and promotes G2/M phase cell cycle arrest by attenuating the expression of Cdc25C, CDK1, and Cyclin B1 proteins. Iridin-treatment also triggered apoptotic cell death in AGS cells, which was verified by cleaved Caspase-3 (Cl- Caspase-3) and poly ADP-ribose polymerase (PARP) protein expression. Further apoptotic cell death was confirmed by increased apoptotic cell death fraction shown in allophycocyanin (APC)/Annexin V and propidium iodide staining. Iridin also increased the expression of extrinsic apoptotic pathway proteins like Fas, FasL, and cleaved Caspase-8 in AGS cells. On the contrary, iridin-treated AGS cells did not show variations in proteins related to an intrinsic apoptotic pathway such as Bax and Bcl-xL. Besides, Iridin showed inhibition of PI3K/AKT signaling pathways by downregulation of (p-PI3K, p-AKT) proteins in AGS cells. In conclusion, these data suggest that iridin has anticancer potential by inhibiting PI3K/AKT pathway. It could be a basis for further drug design in gastric cancer treatment.  相似文献   

3.
Lung cancer is the most commonly diagnosed malignant cancer in the world. Non-small-cell lung cancer (NSCLC) is the major category of lung cancer. Although effective therapies have been administered, for improving the NSCLC patient’s survival, the incident rate is still high. Therefore, searching for a good strategy for preventing NSCLC is urgent. Traditional Chinese medicine (TCM) are brilliant materials for cancer chemoprevention, because of their high biological safety and low cost. Bavachinin, which is an active flavanone of Proralea corylifolia L., possesses anti-inflammation, anti-angiogenesis, and anti-cancer activities. The present study’s aim was to evaluate the anti-cancer activity of bavachinin on NSCLC, and its regulating molecular mechanisms. The results exhibited that a dose-dependent decrease in the cell viability and colony formation capacity of three NSCLC cell lines, by bavachinin, were through G2/M cell cycle arrest induction. Meanwhile, the expression of the G2/M cell cycle regulators, such as cyclin B, p-cdc2Y15, p-cdc2T161, and p-wee1, was suppressed. With the dramatic up-regulation of the cyclin-dependent kinase inhibitor, p21Waf1/Cip1, the expression and association of p21Waf1/Cip1 with the cyclin B/cdc2 complex was observed. Silencing the p21Waf1/Cip1 expression significantly rescued bavachinin-induced G2/M cell accumulation. Furthermore, the expression of p21Waf1/Cip1 mRNA was up-regulated in bavachinin-treated NSCLC cells. In addition, MAPK and AKT signaling were activated in bavachinin-added NSCLC cells. Interestingly, bavachinin-induced p21Waf1/Cip1 expression was repressed after restraint p38 MAPK activation. The inhibition of p38 MAPK activation reversed bavachinin-induced p21Waf1/Cip1 mRNA expression and G2/M cell cycle arrest. Collectively, bavachinin-induced G2/M cell cycle arrest was through the p38 MAPK-mediated p21Waf1/Cip1-dependent signaling pathway in the NSCLC cells.  相似文献   

4.
Steroidal saponins are a group of compounds with complex structures and biological activities. They have anti-inflammatory, antimicrobial, fungicidal, and antitumor properties. Yamogenin is one of the spirostane saponins and occurs in Trigonella foenum-graecum, Asparagus officinalis, and Dioscorea collettii. It is a stereoisomer of diosgenin—a well-known compound whose activity and mechanisms of action in cancer cells are determined. However, the antitumor effect of yamogenin is still little known, and the mechanism of action has not been determined. In this study, we evaluated the effect of yamogenin on human ovarian cancer SKOV-3 cells in vitro by determining the cellular factors that trigger cell death. The viability of the cells was assessed with a Real-Time xCELLigence system and the cell cycle arrest with flow cytometry. The activity of initiator and executioner caspases (-8, -9, and -3/7) was estimated with luminometry and flow cytometry, respectively. The mitochondrial membrane depolarization, the level of oxidative stress, and DNA damage in the yamogenin-treated cells were also evaluated by flow cytometry. Genes expression analysis at the mRNA level was conducted with Real-Time PCR. Bid activation and chromatin condensation were estimated with fluorescent microscopy. The obtained results indicate that yamogenin has cytotoxic activity in SKOV-3 cells with an IC50 value of 23.90 ± 1.48 µg/mL and strongly inhibits the cell cycle in the sub-G1 phase. The compound also triggers cell death with a significant decrease in mitochondrial membrane potential, an increase in the level of oxidative stress (over two times higher in comparison to the control), and activation of caspase-8, -9, -3/7, as well as Bid. The results of genes expression indicate that the Tumor Necrosis Factor (TNF) Receptor Superfamily Members (TNF, TNFRSF10, TNFRSF10B, TNFRSF1B, and TNFRSF25), Fas Associated via Death Domain (FADD), and Death Effector Domain Containing 2 (DEDD2) were significantly upregulated and their relative expression was at least two times higher than in the control. Our work shows that yamogenin induces apoptosis in ovarian cancer cells, and both the extrinsic and mitochondrial—intrinsic pathways are involved in this process.  相似文献   

5.
6.
Breast cancer (BC) is one of the most common causes of death among women worldwide. Recently, interest in novel approaches for BC has increased by developing new drugs derived from natural products with reduced side effects. This study aimed to treat BC cells with harmine hydrochloride (HMH) to identify its anticancer effects and mechanisms. HMH treatment suppressed cell growth, migration, invasion, and colony formation in MCF-7 and MDA-MB-231 cells, regardless of the hormone signaling. It also reduced the phosphorylation of PI3K, AKT, and mTOR and increased FOXO3a expression. Additionally, HMH treatment increased p38 phosphorylation in MCF-7 cells and activated c-Jun N-terminal kinase (JNK) phosphorylation in MDA-MB-231 cells in a dose-dependent manner, where activated p38 and JNK increased FOXO3a expression. Activated FOXO3a increased the expression of p53, p21, and their downstream proteins, including p-cdc25, p-cdc2, and cyclin B1, to induce G2/M cell cycle arrest. Furthermore, HMH inhibited the PI3K/AKT/mTOR pathway by significantly reducing p-AKT expression in combination with LY294002, an AKT inhibitor. These results indicate that mitogen-activated protein kinases (MAPKs) and AKT/FOXO3a signaling pathways mediate the induction of cell cycle arrest following HMH treatment. Therefore, HMH could be a potential active compound for anticancer bioactivity in BC cells.  相似文献   

7.
8.
Jellyfish venom is a rich source of bioactive proteins and peptides with various biological activities including antioxidant, antimicrobial and antitumor effects. However, the anti-proliferative activity of the crude extract of Rhopilema nomadica jellyfish venom has not been examined yet. The present study aimed at the investigation of the in vitro effect of R. nomadica venom on liver cancer cells (HepG2), breast cancer cells (MDA-MB231), human normal fibroblast (HFB4), and human normal lung cells (WI-38) proliferation by using MTT assay. The apoptotic cell death in HepG2 cells was investigated using Annexin V-FITC/PI double staining-based flow cytometry analysis, western blot analysis, and DNA fragmentation assays. R. nomadica venom displayed significant dose-dependent cytotoxicity on HepG2 cells after 48 h of treatment with IC50 value of 50 μg/mL and higher toxicity (3:5-fold change) against MDA-MB231, HFB4, and WI-38 cells. R. nomadica venom showed a prominent increase of apoptosis as revealed by cell cycle arrest at G2/M phase, upregulation of p53, BAX, and caspase-3 proteins, and the down-regulation of anti-apoptotic Bcl-2 protein and DNA fragmentation. These findings suggest that R. nomadica venom induces apoptosis in hepatocellular carcinoma cells. To the best of the authors’ knowledge, this is the first scientific evidence demonstrating the induction of apoptosis and cell cycle arrest of R. nomadica jellyfish venom.  相似文献   

9.
Pterocarya tonkinesis(Franch.)Dode.(Juglandaceae)forms a typical community ofriverside season rain forest in Xishuangbanna area of Yunnan province1.The same genusplant P.stenoptera C.DC.,has long been used as a traditional Chinese herbal medicine2and P.tonkinesis,itself,is also used as a folk medicine for the treatment of certain cancersin partial area of China.However,no report had so far been seen on the chemicalconstituents and their biological activities of the title plant yet.In the …  相似文献   

10.
Rubuphenol (1), a new polyphenolic compound, was isolated together with the known ellagic acid (2) as new cell cycle inhibitors from Rubus aleaefolius Poir. Through a bioassay-guided separation procedure and the structure of 1 was elucidated by spectroscopic method. Compounds 1 and 2 inhibited the cel cycle of tsFT210 cells at the G0/G1 phase respectively with the MIC values of 14.6μM and 10.3μM.  相似文献   

11.
12.
Triple negative breast cancer (TNBC) is a breast cancer subtype characterized by the absence of estrogen receptor, progesterone receptor and human epidermal growth factor receptor 2 expression. TNBC cells respond poorly to targeted chemotherapies currently in use and the mortality rate of TNBC remains high. Therefore, it is necessary to identify new chemotherapeutic agents for TNBC. In this study, the anti-cancer effects of 7-α-hydroxyfrullanolide (7HF), derived from Grangea maderaspatana, on MCF-7, MDA-MB-231 and MDA-MB-468 breast cancer cells were assessed using MTT assay. The mode of action of 7HF in TNBC cells treated with 6, 12 and 24 µM of 7HF was determined by flow cytometry and propidium iodide (PI) staining for cell cycle analysis and annexin V/fluorescein isothiocyanate + PI staining for detecting apoptosis. The molecular mechanism of action of 7HF in TNBC cells was investigated by evaluating protein expression using proteomic techniques and western blotting. Subsequently, 7HF exhibited the strongest anti-TNBC activity toward MDA-MB-468 cells and a concomitantly weak toxicity toward normal breast cells. The molecular mechanism of action of low-dose 7HF in TNBC cells primarily involved G2/M-phase arrest through upregulation of the expression of Bub3, cyclin B1, phosphorylated Cdk1 (Tyr 15) and p53-independent p21. Contrastingly, the upregulation of PP2A-A subunit expression may have modulated the suppression of various cell survival proteins such as p-Akt (Ser 473), FoxO3a and β-catenin. The concurrent apoptotic effect of 7HF on the treated cells was mediated via both intrinsic and extrinsic modes through the upregulation of Bax and active cleaved caspase-7–9 expression and downregulation of Bcl-2 and full-length caspase-7–9 expression. Notably, the proteomic approach revealed the upregulation of the expression of pivotal protein clusters associated with G1/S-phase arrest, G2/M-phase transition and apoptosis. Thus, 7HF exhibits promising anti-TNBC activity and at a low dose, it modulates signal transduction associated with G2/M-phase arrest and apoptosis.  相似文献   

13.
The role of Kupffer cells (KCs) in liver regeneration is complicated and controversial. To investigate the distinct role of F4/80+ KCs at the different stages of the regeneration process, two-thirds partial hepatectomy (PHx) was performed in mice to induce physiological liver regeneration. In pre- or post-PHx, the clearance of KCs by intraperitoneal injection of the anti-F4/80 antibody (α-F4/80) was performed to study the distinct role of F4/80+ KCs during the regenerative process. In RNA sequencing of isolated F4/80+ KCs, the initiation phase was compared with the progression phase. Immunohistochemistry and immunofluorescence staining of Ki67, HNF-4α, CD-31, and F4/80 and Western blot of the TGF-β2 pathway were performed. Depletion of F4/80+ KCs in pre-PHx delayed the peak of hepatocyte proliferation from 48 h to 120 h, whereas depletion in post-PHx unexpectedly led to persistent inhibition of hepatocyte proliferation, indicating the distinct role of F4/80+ KCs in the initiation and progression phases of liver regeneration. F4/80+ KC depletion in post-PHx could significantly increase TGF-β2 serum levels, while TGF-βRI partially rescued the impaired proliferation of hepatocytes. Additionally, F4/80+ KC depletion in post-PHx significantly lowered the expression of oncostatin M (OSM), a key downstream mediator of interleukin-6, which is required for hepatocyte proliferation during liver regeneration. In vivo, recombinant OSM (r-OSM) treatment alleviated the inhibitory effect of α-F4/80 on the regenerative progression. Collectively, F4/80+ KCs release OSM to inhibit TGF-β2 activation, sustaining hepatocyte proliferation by releasing a proliferative brake.  相似文献   

14.
An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for simultaneous determination of aflatoxins B1, B2, G1, G2, M1 and M2 in traditional Chinese medicines (TCMs) was developed. The approach was characterized in details and a special focus was placed on the recovery rates of isolation procedure in different TCM matrices, i.e. rhizomes and roots, seeds, flowers, grasses and leaves. For this purpose, [13C17]-aflatoxinB1 was employed as the internal standard and a reliable solid phase extraction-based clean-up method was developed. The observed recovery rates of the six aflatoxins ranged from 85.6% to 117.6% in different matrices. Then, the established method was successfully applied to the determination of the six aflatoxins in various TCMs. For 30 commercial samples analyzed, 16 were contaminated with aflatoxins. The mean levels (incidence) of aflatoxins B1, B2, G1 and G2 in positive samples were 1.40 (68.8%), 1.27 (50.0%), 0.50 (43.8%) and 0.94 (43.8%) μg kg−1, respectively. Interestingly, aflatoxin M1 was detected in two samples with the maximal content of 0.70 μg kg−1. No sample was contaminated with aflatoxin M2. Meanwhile, a possible association between the contamination levels and the selected herbs was clarified in the present study.  相似文献   

15.
Medulloblastoma is a common malignant brain tumor in the pediatric age. The current therapeutics present serious collateral effects. Polyphenols α-mangostin and nordihydroguaiaretic acid (NDGA) exert potent antitumoral activity in different cancer models, although their antitumoral effects have not been described in medulloblastoma cells yet. This study aimed to examine the proapoptotic effects of these polyphenols on human medulloblastoma cells. Medulloblastoma cell line Daoy was incubated with increasing concentrations of α-mangostin or NDGA for 24 h. The cell viability was analyzed using crystal violet and trypan blue dyes. Determination of the glutathione (GSH)/glutathione disulfide (GSSG) ratio and levels of carbonylated proteins was performed to evaluate the oxidative stress. Cell cycle progression and induction of cell death by fluorochrome-couple and TUNEL assays were evaluated using flow cytometry assays. Individual treatments with α-mangostin or NDGA decreased the viability of Daoy cells in a dose-dependent manner, inducing G2/M and S-G2/M cell cycle arrest, respectively. Both polyphenols induced cell death and increased oxidative stress. Very interestingly, α-mangostin showed more potent effects than NDGA. Our results indicate that α-mangostin and NDGA exert important cytostatic and cytotoxic effects in the Daoy cell line. These data highlight the potential usefulness of these compounds as an alternative strategy in medulloblastoma treatment.  相似文献   

16.
Nigrosporins B, an anthraquinone derivative obtained from the secondary metabolites of marine fungus Nigrospora oryzae. In this study, we characterized the distinctive anti-cancer potential of Nigrosporins B in vitro and underlying molecular mechanisms in human cervical cancer Ca Ski cells for the first time. The results of MTT assay showed that Nigrosporins B significantly inhibited the proliferation of multiple tumor cells in a dose-dependent manner, especially for the Ca Ski cells with an IC50 of 1.24 µM. Nigrosporins B exerted an apoptosis induction effect on Ca Ski cells as confirmed by flow cytometry, AO/EB dual fluorescence staining, mitochondrial membrane potential analysis and western blot assay. In addition, Nigrosporins B induced obvious autophagy accompanied with the increase of autophagic vacuoles and the acceleration of autophagic flux as indicated by Cyto-ID staining, mRFP-GFP-LC3 adenovirus transfection and western blot analysis. Interestingly, the combination of Nigrosporins B with the three autophagy inhibitors all significantly enhanced the cytotoxicity of Nigrosporins B on Ca Ski cells, indicating that the autophagy induced by Nigrosporins B might protect Ca Ski cells from death. Furthermore, we found that Nigrosporins B inhibited the phosphorylation of PI3K, AKT, mTOR molecules and increased the protein expression levels of PTEN and p-AMPKα in a dose-dependent manner, suggesting that Nigrosporins B induced apoptosis and protective autophagy through the suppression of the PI3K/AKT/mTOR signaling pathway. Together, these findings revealed the anti-cervical cancer effect of Nigrosporins B and the underlying mechanism of action in Ca Ski cells, it might be as a promising alternative therapeutic agent for human cervical cancer.  相似文献   

17.
Fluoroquinolones (FQs) are synthetic broad-spectrum antimicrobial agents that have been recently repurposed to anticancer candidates. Designing new derivatives of FQs with different moieties to target DNA topoisomerases could improve their anticancer efficacy. The present study aimed to synthesize a novel ciprofloxacin derivative, examine its anticancer activity against HepG2 and A549 cancer cells, and investigate the possible molecular mechanism underlying this activity by examining its ability to inhibit the topo I/II activity and to induce the apoptotic and necro-apoptotic pathways. Molecular docking, cell viability, cell migration, colony formation, cell cycle, Annexin V, lactate dehydrogenase (LDH) release, ELISA, and western blotting assays were utilized. Molecular docking results showed that this novel ciprofloxacin derivative exerted dual topo I and topo II binding and inhibition. It significantly inhibited the proliferation of A549 and HepG2 cancer cells and decreased their cell migration and colony formation abilities. In addition, it significantly increased the % of apoptotic cells, caused cell cycle arrest at G2/M phase, and elevated the LDH release levels in both cancer cells. Furthermore, it increased the expression of cleaved caspase 3, RIPK1, RIPK3, and MLKL proteins. This novel ciprofloxacin derivative exerted substantial dual inhibition of topo I/II enzyme activities, showed antiproliferative activity, suppressed the cell migration and colony formation abilities for A549 and HepG2 cancer cells and activated the apoptotic pathway. In addition, it initiated another backup deadly pathway, necro-apoptosis, through the activation of the RIPK1/RIPK3/MLKL pathway.  相似文献   

18.
Chromolaena tacotana is a source of flavonoids with antiproliferative properties in human breast cancer cells, the most common neoplasm diagnosed in patients worldwide. Until now, the mechanisms of cell death related to the antiproliferative activity of its flavonoids have not been elucidated. In this study, a novel flavanone (3′,4′-dihydroxy-5,7-dimethoxy-flavanone) was isolated from the plant leaves and identified by nuclear magnetic resonance (NMR) and mass spectrometry (MS). This molecule selectively inhibited cell proliferation of triple-negative human breast cancer cell lines MDA-MB-231 and MCF-7 whit IC50 values of 25.3 μg/mL and 20.8 μg/mL, respectively, determined by MTT assays with a selectivity index greater than 3. Early and late pro-apoptotic characteristics were observed by annexin-V/7-AAD detection, accompanied by a high percentage of the Bcl-2 anti-apoptotic protein inactivated and the activation of effector Caspase-3 and/or 7 in breast cancer cells. It was verified the decreasing of XIAP more than Bcl-2 anti-apoptotic proteins expression, as well as the XIAP/Caspase-7 and Bcl-2/Bax complexes dissociation after flavanone treatment. Docking and molecular modeling analysis between the flavanone and the antiapoptotic protein XIAP suggests that the natural compound inhibits XIAP by binding to the BIR3 domain of XIAP. In this case, we demonstrate that the new flavanone isolated from leaves of Chomolaena tacotana has a promising and selective anti-breast cancer potential that includes the induction of intrinsic apoptosis by downregulation of the anti-apoptotic proteins XIAP and Bcl-2. New studies should deepen these findings to demonstrate its potential as an anticancer agent.  相似文献   

19.
Short-chain fatty acids (SCFAs) are important anti-inflammatory metabolites of intestinal flora. Oxidized low-density lipoprotein (ox-LDL)-induced macrophage activation is critical for the formation of atherosclerosis plaque. However, the association between SCFAs and ox-LDL-induced macrophage activation with respect to the formation of atherosclerosis plaque has not yet been elucidated. The present study investigated whether SCFAs (sodium acetate, sodium propionate, and sodium butyrate) can affect ox-LDL-induced macrophage activation and potential signaling pathways via regulation of the expression of the NLRP3/Caspase-1 pathway. Using human monocyte-macrophage (THP-1) cells as a model system, it was observed that ox-LDL not only induced cell inflammatory injury but also activated the NLRP3/Caspase-1 pathway. The exogenous supplementation of three SCFAs could significantly inhibit cell inflammatory injury induced by ox-LDL. Moreover, three SCFAs decreased the expression of IL-1β and TNF-α via the inactivation of the NLRP3/Caspase-1 pathway induced by ox-LDL. Furthermore, three SCFAs affected cellular metabolism in ox-LDL-induced macrophages, as detected by untargeted metabolomics analysis. The results of the present study indicated that three SCFAs inhibited ox-LDL-induced cell inflammatory injury by blocking the NLRP3/Caspase-1 pathway, thereby improving cellular metabolism. These findings may provide novel insights into the role of SCFA intervention in the progression of atherosclerotic plaque formation.  相似文献   

20.
Semen Sojae Preparatum (SSP) is one of the most widely used traditional Chinese medicines, and is also a functional food. However, contamination with aflatoxins may occur in the fermentation process. To evaluate its safety, an accurate and rapid LC–ESI–MS/MS analytical method was developed and validated for the simultaneous determination of AFB1, AFB2, AFG1, AFG2 and AFM1 in SSP. After a simple ultrasonic extraction of SSP samples, chromatographic separation was achieved on an Agilent Zorbax SB‐C18 column (2.1 × 50 mm, 3.5 μm) with a flow rate of 0.50 mL/min. The gradient elution program was performed using a mobile phase consisting of water and acetonitrile, both containing 0.1% formic acid. Detection of five aflatoxins was based on triple quadrupole mass spectrometry using a multiple reaction monitoring mode with an electrospray ionization source. SSP is likely to be contaminated by aflatoxins in the processes of fermentation, storage, transportation and usage, and it is necessary to strictly monitor it. Artemisia annua L. and Morus alba L. may inhibit the production and growth of AFB1‐ and AFB2‐producing fungi, which has a certain detoxification effect on contamination with aflatoxins in SSP.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号