Publications by authors named "Zong-Chao Liu"

32 Publications

Proteomic profiling identifies signatures associated with progression of precancerous gastric lesions and risk of early gastric cancer.

EBioMedicine 2021 Nov 21;74:103714. Epub 2021 Nov 21.

State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences (Beijing), Beijing Institute of Lifeomics, Beijing 102206, China. Electronic address:

Background: Molecular features underlining the multistage progression of gastric lesions and development of early gastric cancer (GC) are poorly understood, restricting the ability to GC prevention and management.

Methods: We portrayed proteomic landscape and explored proteomic signatures associated with progression of gastric lesions and risk of early GC. Tissue proteomic profiling was conducted for a total of 324 subjects. A case-control study was performed in the discovery stage (n=169) based on populations from Linqu, a known high-risk area for GC in China. We then conducted two-stage validation, including a cohort study from Linqu (n = 56), with prospective follow-up for progression of gastric lesions (280-473 days), and an independent case-control study from Beijing (n = 99).

Findings: There was a clear distinction in proteomic features for precancerous gastric lesions and GC. We derived four molecular subtypes of gastric lesions and identified subtype-S4 with the highest progression risk. We found 104 positively-associated and 113 inversely-associated proteins for early GC, with APOA1BP, PGC, HPX and DDT associated with the risk of gastric lesion progression. Integrating these proteomic signatures, the ability to predict progression of gastric lesions was significantly strengthened (areas-under-the-curve=0.88 (95%CI: 0.78-0.99) vs. 0.56 (0.36-0.76), Delong's P = 0.002). Immunohistochemistry assays and examination at mRNA level validated the findings for four proteins.

Interpretation: We defined proteomic signatures for progression of gastric lesions and risk of early GC, which may have translational significance for identifying particularly high-risk population and detecting GC at an early stage, improving potential for targeted GC prevention.

Funding: The funders are listed in the Acknowledgement.
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http://dx.doi.org/10.1016/j.ebiom.2021.103714DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8617343PMC
November 2021

Dynamic protein expression of NF-κB following rat intracerebral hemorrhage and its association with apoptosis.

Exp Ther Med 2018 Nov 10;16(5):3903-3908. Epub 2018 Sep 10.

Department of Neurology, Affiliated Hospital of Qingdao University, Qingdao, Shandong 266000, P.R. China.

The aim of the present study was to evaluate the dynamic protein expression of nuclear factor (NF)-κB and apoptosis in the cerebral tissue surrounding hematoma following intracerebral hemorrhage (ICH) in rats. A total of 80 healthy male Wistar rats were divided into a sham-surgery group and an ICH group. The ICH model was established by injecting autogenous non-heparin anticoagulant arterial blood into the caudate putamen. NF-κB levels were assessed by immunohistochemistry at different time points subsequent to surgery, and apoptosis condition was investigated by terminal deoxynucleotidyl-transferase-mediated dUTP nick end labeling. Different levels of NF-κB were expressed in the cerebral tissue around the ICH at each time point in the ICH group. NF-κB protein expression was detected at 3 h following hemorrhage, mainly in the cytoplasm. Following 6 h, NF-κB was identified in the nucleus. Its expression peaked at 72 h following hemorrhage, and persisted for 5 days. Apoptosis was observed 6 h following hemorrhage, and had increased significantly by 12 h. The rate of apoptosis continued to rise from 72-120 h following hemorrhage. Correlation analysis revealed a significant positive correlation between NF-κB expression and apoptosis (r=0.753; P<0.01). The enhancement of NF-κB expression and apoptosis around ICH, and the significant positive correlation between NF-κB expression and apoptosis, indicates that NF-κB activation may enhance cerebral apoptosis in rats following ICH.
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http://dx.doi.org/10.3892/etm.2018.6715DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176140PMC
November 2018

[Mechanism of Duhuo Jisheng decotion in delaying degeneration of nucleus pulposus cells in human intervertebral disc].

Zhongguo Zhong Yao Za Zhi 2018 Jul;43(13):2764-2769

Department of Orthopedic Surgery, Affiliated Hospital of Traditional Chinese Medicine of Southwest Medical University, Luzhou 646000, China.

This paper aimed to investigate the role of Duhuo Jisheng decotion (DHJSD) in delaying human disc degeneration and its possible molecular mechanism. The intervertebral disc specimens were divided into normal and degenerated groups according to Pfirrmann classfication. The expressions of TNF-α, IL-1β, MMP-3 and MMP-13 in intervertebral disc tissue were detected by Western blot and PCR. Then degenerated human primary NPCs were cultured in vitro, the viability of NPCs treated with stromal cell-derived factor-1 (SDF-1,10 μg·L⁻¹)and various concentrations of DHJSD was assessed by the CCK-8 assay, and the appropriate concentration was screened. The experiment was divided into three groups, control group, SDF-1 group and DHJSD plus SDF-1 group. The levels of TNF-α, IL-1β, Agg, coIⅡ, MMP-3 and MMP-13 were detected. The levels of CXCR4, NF-κB major groups P65 phosphorylation (p-P65) and nuclear translocation, after treated with CXCR4 siRNA and NF-κB inhibitor (BAY11-7082) were measured by Western blot and immunofluorescence. At the same time, the expression of cell inflammatory factors and extracellular matrix were also measured. The expressions of TNF-α, IL-1β, MMP-3 and MMP-13 in the degenerated intervertebral disc tissue were significantly increased. In vitro study, the results of CCK-8 indicated that the viability of NPCs was significantly increased when DHJSD concentration was 300 mg·L⁻¹. After the experiment was divided into three groups, compared with SDF-1 group, the expressions of TNF-α, IL-1β, MMP-3 and MMP-13 in DHJSD group were significantly decreased, but the expressions of Agg, coIⅡ were significantly increased. When CXCR4-siRNA was transfected into NPCs, SDF-1 increased expressions of CXCR4 and p-P65 and inhibited nuclear translocation of P65, whose effect was suppressed by CXCR4-siRNA and DHJSD. In addition, when BAY11-7082 was used to treat NPCs, the expression of TNF-α, IL-1β, MMP-3 and MMP-13 were significantly decreased. DHJSD could inhibit the production of inflammatory factors and promote the synthesis of extracellular matrix. The potential mechanism may be related to the SDF-1/CXCR4/NF-κB signaling pathway.
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http://dx.doi.org/10.19540/j.cnki.cjcmm.20180503.001DOI Listing
July 2018

Duhuo Jisheng Decoction inhibits SDF-1-induced inflammation and matrix degradation in human degenerative nucleus pulposus cells in vitro through the CXCR4/NF-κB pathway.

Acta Pharmacol Sin 2018 Jun 24;39(6):912-922. Epub 2018 May 24.

Center for Phenomics of Traditional Chinese Medicine, Southwest Medical University, Luzhou 646000, China.

Lower back pain (LBP) is the most common disease in orthopedic clinics world-wide. A classic Fangji of traditional Chinese medicine, Duhuo Jisheng Decoction (DHJSD), has been proven clinically effective for LBP but its therapeutic mechanisms remain unclear. We hypothesized that DHJSD might relieve LBP through inhibiting the exaggerated proinflammatory cytokines and extracellular matrix (ECM) degradation. Thus, we studied the effects of DHJSD on stromal cell-derived factor-1 (SDF-1)-induced inflammation and ECM degradation in human nucleus pulposus cells (hNPCs). The primary hNPCs were isolated from either degenerated human intervertebral disc (HID) of LBP patients or normal HID of lumbar vertebral fracture patients, and cultured in vitro. The cells were treated with SDF-1 (10 ng/mL) and subsequently with different concentrations (100-500 μg/mL) of DHJSD for 24 h, respectively. We found that application of DHJSD significantly antagonized the SDF-1-induced production of proinflammatory cytokines and reduction of aggrecan and type II collagen in the hNPCs. DHJSD also markedly reduced the SDF-1-induced increase of CXCR4 and p-p65 and inhibited the nuclear translocation of p65 in the hNPCs. DHJSD, CXCR4-siRNA, and NF-κB inhibitor (BAY11-7082) caused the same inhibition of exaggerated proinflammatory cytokines in the SDF-1-treated hNPCs. These results provided compelling evidence that DHJSD may inhibit the generation of proinflammatory mediators and ECM degradation of HID through an orchestrated targeting at multiple molecules in the SDF-1/CXCR4/NF-κB pathway, thus offered novel mechanistic insights into the clinical effectiveness of DHJSD on LBP.
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http://dx.doi.org/10.1038/aps.2018.36DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6256264PMC
June 2018

Alteration of mitochondrial function and ultrastructure in the hippocampus of pilocarpine-treated rat.

Epilepsy Res 2014 Feb 3;108(2):162-70. Epub 2013 Dec 3.

Department of Neurology, The Affiliated Hospital of Medical College, Qingdao University, Qingdao 266000, China.

Present studies were carried out to decipher seizure-dependent changes in mitochondrial function and ultrastructure in rat hippocampus after status epilepticus (SE) induced by pilocarpine (PILO). Discernible mitochondrial ultrastructural damage was observed in the hippocampus. Enzyme assay revealed cytochrome oxidase (COX) activity significantly increased 3h after SE, decreased 7 d and 45 d after SE, whereas succinate dehydrogenase (SDH) activity displayed no significant changes. Quantitative real-time PCR and Western blotting showed that COX III (mitochondrial-encoded) mRNA and protein level were significantly increased at 3h, decreased to the control level on 7d and dropped significantly on 45 d; the corresponding expression of COX IV were not changed by PILO at any time tested. The results were also supported by immunohistochemistry. Thus, our results demonstrate that dysfunction of mitochondrial complex IV respiratory enzyme and mitochondrial ultrastructural damage in the hippocampus are associated with prolonged seizure during experimental temporal lobe epilepsy and mitochondria are more vulnerable to epileptic damage.
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http://dx.doi.org/10.1016/j.eplepsyres.2013.11.016DOI Listing
February 2014

Houttuyninum, an active constituent of Chinese herbal medicine, inhibits phosphorylation of HER2/neu receptor tyrosine kinase and the tumor growth of HER2/neu-overexpressing cancer cells.

Life Sci 2012 May 13;90(19-20):770-5. Epub 2012 Apr 13.

State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-sen University, Guangzhou 510060, PR China.

Aims: The overexpression of HER2/neu receptor plays a key role in tumorigenesis and tumor progression. Small molecules targeting HER2/neu have therapeutic value in cancers that overexpress HER2. In this present study, the effect of houttuyninum, a component in the Chinese herbal medicine Houttuynia cordata Thunb, on HER2/neu tyrosine phosphorylation and its in vivo antitumour activity was investigated.

Main Methods: The phosphorylation and expression of proteins were determined by Western blot analysis. The MTT assay was employed to examine the inhibition of cell proliferation in vitro. Xenografts were established in nude mice for evaluating the antitumour activity of houttuyninum in vivo.

Key Findings: Houttuyninum inhibited phosphorylation of HER2 in a dose-dependent manner with an IC50 of 5.52 μg/ml without reducing HER2/neu protein expression in MDA-MB-453 cells. Houttuyninum also inhibited the activation of ERK1/2 and AKT, downstream molecules in the HER2/neu-mediated signal transduction pathway. In contrast, tyrosine phosphorylation of EGFR was unaffected when the concentration of houttuyninum was increased to 40 μg/ml in both A431 cells and MDA-MB-468 cells. Additionally, houttuyninum preferentially inhibited the growth of MDA-MB-453 cells that overexpressed HER2/neu; the MDA-MB-468 cells that overexpress EGFR remained unaffected. Administration of houttuyninum in vivo resulted in a significant reduction of phosphorylated HER2 levels and in tumor volumes of the BT474 and N87 xenografts, which both overexpress HER2/neu.

Significance: Our findings showed that houttuyninum can inhibit the HER2/neu signalling pathway and the tumor growth of cancer cells that overexpress HER2/neu. This drug may provide therapeutic value in the treatment of cancers that involve overexpression of HER2/neu.
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http://dx.doi.org/10.1016/j.lfs.2012.03.035DOI Listing
May 2012

SYUNZ-16, a newly synthesized alkannin derivative, induces tumor cells apoptosis and suppresses tumor growth through inhibition of PKB/AKT kinase activity and blockade of AKT/FOXO signal pathway.

Int J Cancer 2010 Jul;127(1):220-9

The State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-Sen University, Guangzhou, China.

Alkannin is the major bioactive compound of Arnebia euchroma roots, which is used in many therapeutic remedies in Chinese traditional medicine. SYUNZ-16 is a new derivative of alkannin. In this study, anticancer effects of SYUNZ-16 on human lung adenocarcinoma cell line GLC-82 and human hepatocarcinoma cell line Hep3B were tested in vitro. The results showed SYUNZ-16 could obviously inhibit the proliferation of these cancer cell lines via induction of apoptosis, with the evidence of increasing AnnexinV-positive cells and cleaved caspase-3 and PARP fragments. More importantly, we found that SYUNZ-16 could inhibit AKT activity in cell-free system. Treatment of cancer cells with SYUNZ-16 decreased the phosphorylation of AKT. Additionally, SYUNZ-16 partially attenuated the phosphorylation levels of FKHR and FKHRL1 in a dose-dependent and time-dependent fashion, and led to an increase in the nuclear accumulation of exogenous FKHR, and upregulated the mRNA expression of Bim and TRADD in cancer cells. Further study showed that constitutively activated AKT1 transfection could reduce apoptosis induction mediated by SYUNZ-16. The in vivo experiments showed that SYUNZ-16 had inhibitory effects on S-180 sarcoma implanted to mice. And in GLC-82 xenograft models, SYUNZ-16 at 20 mg/kg/qod remarkably inhibited the tumor growth with the T/C value of 45.3%. Taken together, SYUNZ-16 might be a potent inhibitor of AKT signaling pathway in tumor cells. These data provide evidence for the development of SYUNZ-16 as a potential antitumor drug candidate for further research and development.
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http://dx.doi.org/10.1002/ijc.25032DOI Listing
July 2010

Synergistic cytotoxicity of Bcl-xL inhibitor, gossypol and chemotherapeutic agents in non-Hodgkin's lymphoma cells.

Cancer Biol Ther 2008 Jan 8;7(1):51-60. Epub 2007 Oct 8.

State Key Laboratory of Oncology in Southern China, Cancer Center, Sun Yat-sen University, Guangzhou, China.

Anti-apoptotic proteins Bcl-2 and Bcl-xL are overexpressed in 80% of non Hodgkin's lymphoma cells and are thought to play an important role in the resistance of lymphoma cells to current chemotherapeutic agents. Gossypol, an orally-active polyphenolic aldehyde derived from the cotton plant, has been known to have potential anti-neoplastic activity. Recently, gossypol was found to bind to the BH3 binding groove of Bcl-xL and with lesser affinity to Bcl-2. The present study was conducted to determine whether gossypol increases the sensitivity of non-Hodgkin's lymphoma cells to the actions of chemotherapeutic agents by potentiating treatment-induced apoptosis. The interactions observed between gossypol and chemotherapeutic drugs were analyzed using the median effect principle (CalcuSyn analysis). Our data showed that treatment of Ramos cells with gossypol not only induced cell arrest on the G(0)/G(1) phase, but also augmented apoptosis and growth inhibition induced by etoposide (VP-16), doxorubicin hydrochloride (ADM), vincristine (VCR), and paclitaxel (taxol). However, when gossypol was combined with cisplatin (DDP) an antagonistic effect was observed. Gossypol-induced cell cycle arrest was accompanied by decreased expression of cyclin D1 in Ramos cells. In addition, the peroxisome proliferator-activated receptor (PARP) pathway is, at least in part, involved in the gossypol-induced apoptosis when combined with VP-16. These data indicate that single-agent gossypol is effective in inhibiting growth of non-Hodgkin's lymphoma cells in vitro and combination studies with certain secondary chemotherapeutic agents further demonstrate it's synergistic cytotoxicity. These findings support future preclinical and clinical studies of gossypol in the treatment of non-Hodgkin's lymphoma.
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http://dx.doi.org/10.4161/cbt.7.1.5128DOI Listing
January 2008

Rhabdastrellic acid-A inhibited PI3K/Akt pathway and induced apoptosis in human leukemia HL-60 cells.

Cell Biol Int 2008 Jan 1;32(1):48-54. Epub 2007 Sep 1.

State Key Laboratory of Oncology in South China, Cancer Center, Sun Yat-sen University, 651 Dongfeng Road East, Guangzhou 510060, PR China.

Increasing evidence suggests that aberrant activation of PI3K/Akt is involved in many human cancers, and that inhibition of the PI3K/Akt pathway might be a promising strategy for cancer treatment. Our investigation indicates that Rhabdastrellic acid-A, an isomalabaricane triterpenoid isolated from the sponge, Rhabdastrella globostellata, inhibits proliferation of HL-60 cells with an IC(50) value of 0.68mug/ml, and induces apoptosis. Rhabdastrellic acid-A also induces cleavage of the death substrate poly (ADP-ribose) polymerase (PARP) and caspase-3. Pretreatment of HL-60 cells with the caspase-3 specific inhibitor, DEVD-CHO, prevents Rhabdastrellic acid-A-induced DNA fragmentation and PARP cleavage. Activated PI3K and Akt significantly decreases after treatment with Rhabdastrellic acid-A in HL-60 cells. Expression levels of protein bcl-2, bax remain unchanged in response to Rhabdastrellic acid-A treatment in HL-60 cells. These results suggest that Rhabdastrellic acid-A inhibits PI3K/Akt pathway and induces caspase-3 dependent-apoptosis in HL-60 human leukemia cells.
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http://dx.doi.org/10.1016/j.cellbi.2007.08.009DOI Listing
January 2008

[Apoptosis of human leukemia HL-60 cells induced by rhabdastrellic acid-A and its mechanisms].

Ai Zheng 2007 Aug;26(8):809-14

State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, 510060, PR China.

Background & Objective: Rhabdastrellic acid-A is an isomalabaricane triterpenoid isolated from the sponge Rhabdastrella globostellata from South China Sea. Our previous study indicated that rhabdastrellic acid-A can inhibit the proliferation of many types of tumor cells with minor toxicity. This study was to investigate the apoptosis of human leukemia HL-60 cells induced by rhabdastrellic acid-A and its possible mechanisms.

Methods: Inhibitory effect of rhabdastrellic acid-A on the proliferation of HL-60 cells was evaluated by MTT assay. DNA fragmentation was analyzed by agarose electrophoresis. Cell morphology was observed under fluorescent microscope. The protein levels of Caspase-3, poly(ADP-ribose) polymerase (PARP), P73, Bcl-2 and Bax were analyzed by Western blot. The expression profile of apoptosis-related genes was analyzed by gene microarray. Reverse transcription-polymerase chain reaction (RT-PCR) was conducted to confirm some altered genes identified by gene microarray.

Results: Rhabdastrellic acid-A inhibited the proliferation of HL-60 cells and the 50% inhibition concentration (IC50) was (0.64+/-0.21) microg/ml. When treated with 1 microg/ml rhabdastrellic acid-A for 36 h, condensation of nuclear chromatin of HL-60 cells was observed under fluorescent microscope and DNA fragmentation was observed by agarose electrophoresis. Also, rhabdastrellic acid-A induced cleavage of PARP and Caspase-3. The mRNA levels of 44 genes, including p73, JunD, TNFAIP3 and GADD45A, were up-regulated and the mRNA levels of 16 genes, including MAP2K5 and IGF2R, were down-regulated. The results were further confirmed by RT-PCR. The protein level of P73 was up-regulated after rhabdastrellic acid-A treatment.

Conclusion: Rhabdastrellic acid-A could induce the apoptosis of HL-60 cells which may be related to the up-regulation of apoptosis-related genes such as p73 and JunD, and the down-regulation of MAP2K5 and IGF2R.
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August 2007

Apoptosis induced by DNA primase inhibitor 3,3'-diethyl-9-methylthia-carbocyanine iodide in human leukemia HL-60 cells.

Yao Xue Xue Bao 2006 Oct;41(10):978-84

State Key Laboratory of Oncology in Southern China, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.

Aim: To investigate apoptosis induced by 3,3'-diethyl-9-methylthia-carbocyanine iodide (DMTCCI), an inhibitor of DNA primase found in our previous study, and the mechanism of DMTCCI in human myelogenous leukemia HL-60 cells.

Methods: HL-60 cells were cultured in RPMI-1640 medium and treated with different concentrations of DMTCCI. MTT assay was used to detect growth inhibition. Flow cytometry and DNA ladders were used to detect apoptosis. Western blotting was used to observe the expression of survivin, Bcl-xL, Bad, Bax, Bcl-2, caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity was measured by ApoAlert Caspase-3 Assay Kit.

Results: DMTCCI inhibited proliferation of human leukemia HL-60 cells with IC50 value of 0.24 micromol x L(-1). The results of flow cytometry and DNA ladders showed that DMTCCI could induce apoptosis of HL-60 cells. The expression levels of protein survivin and Bcl-xL were down-regulated, Bad and Bax were up-regulated, while Bcl-2 protein had no change in response to DMTCCI treatment in HL-60 cells. Treatment of HL-60 cells with DMTCCI induced the proteolytic cleavage of caspase-9, caspase-3, caspase-6, PARP, DFF45 and lamin B protein. Caspase-3 activity apparently increased at 3 h and reached a peak at 12 h after exposure to 1 micromol x L(-1) of DMTCCI in HL-60 cells.

Conclusion: DMTCCI inhibited proliferation and induced apoptosis of human leukemia HL-60 cells. Bcl-2 family proteins, survivin and caspases family proteins might play a role in the apoptosis process induced by DMTCCI.
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October 2006

[Inducement effect of Meisoindigo on apoptosis of leukemia cell line HL-60 and its mechanism].

Ai Zheng 2005 Dec;24(12):1464-8

State Key Laboratory of Oncology in Southern China, Guangzhou, Guangdong 510060, P. R. China.

Background & Objective: Meisoindigo is a powerful drug used in treating chronic myeloid leukemia (CML), but little is known about the mechanisms. This study was to investigate the inducement effect of meisoindigo on apoptosis of myelocytic leukemia cell line HL-60, and explore the possible mechanisms.

Methods: After treatment of meisoindigo, the proliferation of HL-60 cells was detected by trypan blue exclusion assay, and DNA fragmentation by agarose electrophoresis; cell morphology was observed under fluorescent microscope. Cell apoptosis and the expression of Fas were detected by flow cytometry. The expression of Caspase-3, Caspase-8, Caspase-9, PARP, Bcl-2, Bax and the concentration of cytochrome c in cytosol were analyzed by Western blot.

Results: Meisoindigo inhibited proliferation and induced apoptosis in HL-60 cells. When treated with 20 micromol/L meisoindigo for 12-48 h, the proliferation of HL-60 cells was significantly inhibited. When treated for 1 h, the apoptosis rate of HL-60 cells was (3.70+/-0.56)%; the apoptosis rate was significantly higher in HL-60 cells treated for 3, 6, and 12 h than in control cells [(19.80+/-1.13)%, (29.20+/-2.69)%, and (47.05+/-7.70)% vs. (2.65+/-0.78)%, P<0.05]. When treated with meisoindigo for 3 h, typical changes of apoptosis, such as chromatin condensation and DNA ladder, were detected in HL-60 cells. The positive rate of Fas was significantly higher in cells treated with 20 micromol/L meisoindigo for 1 h than in control cells [(21.30+/-1.27)% vs. (9.35+/-0.21)%, P<0.05]. Meisoindigo activated Caspase-3, Caspase-8, Caspase-9 and PARP, down-regulated the expression of Bcl-2, up-regulated the expression of Bax and the concentration of cytochrome c. Furthermore, pretreatment of caspase-3 inhibitor z-DEVD-fmk partially reversed the inhibitory effect of meisoindigo on cell proliferation, and decreased cell apoptosis; when treated with meisoindigo for 5 h, the apoptosis rate was significantly higher in pretreated cells than in cells without pretreatment [(29.8+/-5.4)% vs. (16.5+/-5.5)%, P<0.05]; when treated with meisoindigo for 12 h, the alive cell number was significantly lower in pretreated cells than in cells without pretreatment [(1.80+/-0.14) x 10(5)/ml vs. (3.57+/-0.18) x 10(5)/ml, P<0.05].

Conclusion: Meisoindigo induces apoptosis of HL-60 cells which may relate to regulation of caspases pathway and bcl-2 family proteins.
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December 2005

[Antitumor effect and mechanism of shikonin derivative SYUNZ-7].

Ai Zheng 2005 Dec;24(12):1453-8

State Key Laboratory of Oncology in Southern China, Guangzhou, Guangdong 510060, P. R. China.

Background & Objective: Natural shikonin compounds and their derivatives have cytotoxicity and antitumor effects. This study was to explore in vitro and in vivo antitumor effects of SYUNZ-7 [2 or 3, 11-bis(phenylsulfanyl)-6-isohexenylnaphthazarin] and the mechanisms.

Methods: In vitro antiproliferation effects of SYUNZ-7 on human lung adenocarcinoma cell line GLC-82, human nasopharyngeal cancer cell line CNE2, human oral cavity cancer cell line KB, human gastric cancer cell line MGC-803 and human hepatocellular cancer cell line HepG2 were tested by MTT assay. In vivo antitumor effect of SYUNZ-7 was tested using ascitic cancer EAC xenograft in mice and CNE2 xenograft in nude mice models. Cell apoptosis and cell cycle distribution were assessed by flow cytometry. The in vivo effect of SYUNZ-7 on angiogenesis was detected by immunohistochemistry.

Results: The 50% inhibitory concentrations (IC(50)) of SYUNZ-7 to GLC-82, CNE2, KB, MGC-803, and HepG2 cells were (2.18+/-0.04) microg/ml, (4.17+/-0.09) microg/ml, (5.41+/-0.10) microg/ml, (6.41+/-0.14) microg/ml, and (9.99+/-0.21) microg/ml, respectively. Under the treatment of 1, 2, 4, and 8 mg/kg of SYUNZ-7, the inhibitory rates of EAC xenografts in mice were (40.5+/-0.14)%, (50.9+/-2.3)%, (61.7+/-1.8)%, and (65.6+/-7.4)%, respectively (P<0.01). Under the treatment of 1, 2, and 4 mg/kg of SYUNZ-7, the inhibitory rates of CNE2 xenografts in nude mice were 24.7%, 38.3%, and 41.2%, respectively (P<0.05). SYUNZ-7 induced apoptosis of CNE2 cells in time- and concentration-dependent manners, and blocked the transition of CNE2 cells from S to G(2)/M phase. SYUNZ-7 also inhibited the angiogenesis of CNE2 xenografts in nude mice in a concentration-dependent manner.

Conclusion: SYUNZ-7 has strong in vivo and in vitro antitumor effects which are related to inducing cell apoptosis, blocking cell cycle, and inhibiting angiogenesis of tumor.
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December 2005

[Antitumor and anti-angiogenic effects of manumycin on human hepatocellular carcinoma HepG2 xenografts in nude mice].

Ai Zheng 2005 Aug;24(8):935-9

Skate Key Laboratory of Oncology in Southern China, Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, P. R. China.

Background & Objective: Farnesyl-transferase inhibitor manumycin has in vitro and in vivo antitumor effects on pancreatic cancer, colon cancer, and anaplastic thyroid carcinoma. Our previous experiments showed that manumycin could inhibit proliferation pathway and survival pathway in human hepatocellular carcinoma HepG2 cells in vitro. This study was to examine the antitumor and anti-angiogenic effects of manumycin on HepG2 xenografts in nude mice.

Methods: The xenografts derived from HepG2 cells were established in BALB/C nude mice. Inoculated mice were randomly divided into normal saline (NS) group, positive control (cyclophosphamide, CTX, 25 mg/kg) group, negative control (0.1% Me2SO, 20 ml/kg) group, low dose munumycin (2.5 mg/kg) group, and high dose munumycin (5 mg/kg) group. Tumor volume was measured in nude mice bearing xenografts. Microvessel density (MVD) was observed by immunohistochemistry. Protein levels of vascular endothelial growth factor (VEGF) and b-fibroblast growth factor (b-FGF) were determined by Western blot; mRNA level of VEGF was analyzed using reverse transcription-polymerase chain reaction (RT-PCR).

Results: The mean tumor volume ratio of nude mice xenograft (V/V(0)) was significantly lower in low dose manumycin group and high dose manumycin group than in negative control group (0.68+/-0.09 and 0.59+/-0.04 vs. 1.38+/-0.21, P < 0.01). MVD was significantly lower in manumycin-treated groups than in control group (P < 0.01). Manumycin significantly down-regulated protein level of VEGF in HepG2 cells and HepG2 xenografts, and mRNA level of VEGF in HepG2 xenografts, but didn't affect protein level of b-FGF.

Conclusions: Manumycin could inhibit the growth of human hepatocellular carcinoma HepG2 xenografts in nude mice. The down-regulation of VEGF expression and the inhibition of angiogenesis might play a key role in the anti-neoplastic effect of manumycin.
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August 2005

The molecular mechanisms involved in the cytotoxicity of alkannin derivatives.

Eur J Med Chem 2005 Dec 29;40(12):1341-5. Epub 2005 Jun 29.

School of Chemistry and Chemical Engineering, Sun Yat-Sen University, Guangzhou 510275, China.

In order to better understand the molecular aspects of the cytotoxic action mechanisms, the cytotoxicity of alkannin derivatives, 1-10, on five human tumor cell lines were examined and their standard redox potentials in aprotic medium were tested by means of cyclic voltammetry. It was suggested that the oxidative potential is closely related to the cytotoxicity. The more negative the oxidative potential of the hydroquinones, the higher cytotoxicity of these derivatives. The results of the compounds 5, 7, 9 and 10 with bad leaving groups, have higher cytotoxic action is not agreed with the bioreductive alkylation mechanism of quinones. It indicates that the molecular mechanism involving cytotoxicity of alkannin derivatives may favor the mechanism of production of reactive oxygen.
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http://dx.doi.org/10.1016/j.ejmech.2005.05.004DOI Listing
December 2005

[Radioprotective effect of aloe polysaccharides on three non-tumor cell lines].

Ai Zheng 2005 Apr;24(4):438-42

School of Pharmacy, Guangzhou University of Traditional Chinese Medicine, Guangzhou, Guangdong, 510405, P. R. China.

Background & Objective: Our previous study showed that aloe polysaccharides (AP) could evidently decrease the mortality of irradiated mice mainly through increasing the amount of hemocytes and ameliorating immune function of mice. Whether AP can protect the cells in vitro from irradiation damage is unknown. This study was to explore radioprotective effect of AP on 3 non-tumor cell lines, and its effect on cell cycle.

Methods: MTT assay was used to detect cytotoxicities of AP to normal human liver cell line Chang Liver (C. Liver), normal human embryo kidney cell line 293, and normal human umbilicus vein endothelial cell line ECV304. The 3 cell lines were treated with AP before or after irradiation. After 7-10 days normal culture, survival rate of cells was calculated by clone formation assay. Cell cycle was analyzed by flow cytometry (FCM) at different time points after irradiation.

Results: 293 cells were treated with AP at different time points before and after x-ray irradiation. Survival rate of 293 cells treated with AP 30 min before x-ray irradiation was the highest (64.2%) among all groups. Evident dosage-effect relationship of AP appeared in concentration range of 12.5-50 microg/ml. After treatment of 50 microg/ml of AP, survival rates of 293, ECV304, and C. Liver cells increased from 41.5%, 46.5%, and 40.9% to 49.4%, 72.1%, and 89.1%, respectively. Irradiation caused a distinct G(2)/M block and decreased G(0)/G(1) phase population in 293 and C. Liver cells. In C. Liver cells, pretreatment of 50 mug/ml of AP increased G(0)/G(1) phase population from 31.8% to 43.8%, decreased G(2)/M phase population from 38.5% to 13.8% 6 h after irradiation; and decreased G(2)/M phase population from 22.9% to 8.7% 24 h after irradiation. In 293 cells, the same pretreatment increased G(0)/G(1) phase population from 30.1% to 45.9% 6 h after irradiation, and from 40.4% to 45.2% 24 h after irradiation accompanied by decrease of G(2)/M population from 59.6% to 54.1%.

Conclusions: AP has radioprotective effect on non-tumor cells. This effect might relate to alleviating of cell cycle turbulence.
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April 2005

Blockade of vascular endothelial growth factor receptor signal pathway and antitumor activity of ON-III (2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone), a component from Chinese herbal medicine.

Mol Pharmacol 2005 May 9;67(5):1444-50. Epub 2005 Feb 9.

Department of Experimental Research, Cancer Center, Sun Yat-sen University, Guangzhou, China.

Antiangiogenesis is a promising strategy of cancer treatment. Vascular endothelial growth factor receptor [fetal liver kinase/kinase-inserting domain-containing receptor (KDR)] is a tyrosine kinase receptor and has been strongly implicated in tumor angiogenesis. In this study, we report that 2',4'-dihydroxy-6'-methoxy-3',5'-dimethylchalcone (ON-III), extracted from the dried flower Cleistocalyx operculatus, used in traditional Chinese medicine, reversibly inhibited KDR tyrosine kinase phosphorylation, but epidermal growth factor receptor tyrosine kinase phosphorylation was unaffected under the same concentrations of ON-III. ON-III also inhibited mitogen-activated protein kinase (MAPK) and AKT activation of KDR signal transduction in downstream molecules without reduced total MAPK and AKT. The results in vitro showed that ON-III inhibited growth of human vascular endothelial HDMEC cells in the presence of VEGF preferentially, compared with epidermal growth factor. Systemic administration of ON-III at nontoxic doses in nude mice resulted in inhibition of subcutaneous tumor growth of human hepatocarcinoma Bel7402 and lung cancer GLC-82 xenografts. The tumor vessel density decreased, as determined by immunohistochemical staining, for CD31 after ON-III treatment. These results indicated that ON-III inhibited KDR tyrosine kinase, shut down KDR-mediated signal transduction, and inhibited tumor growth of human xenografts in vivo.
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http://dx.doi.org/10.1124/mol.104.009894DOI Listing
May 2005

The tumor suppressor p33ING1b enhances taxol-induced apoptosis by p53-dependent pathway in human osteosarcoma U2OS cells.

Cancer Biol Ther 2005 Jan 15;4(1):39-47. Epub 2005 Jan 15.

Department of Orthopedic Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.

p33ING1b can stimulate cell cycle arrest, DNA repair, apoptosis and chemosensitivity. The actions of p33ING1b involve p53-dependent and p53-independent mechanisms. To investigate if the p33ING1b isoform is involved in the chemosensitivity of osteosarcoma cells, p33ING1b was overexpressed in p53+/+ U2OS cells or p53-mutant MG63 cells, and then cell growth arrest and apoptosis were assessed after treatment with taxol. The results showed that p33ING1b markedly increased taxol-induced growth inhibition and apoptosis in p53+/+ U2OS cells, but not in p53-mutant MG63 cells. Moreover, ectopic expression of p33ING1b could obviously upregulate p53, p21WAF1 and bax protein levels and activate caspase-3 in taxol-treated U2OS cells. Taken together, our data demonstrate that p33ING1b enhances taxol-induced apoptosis through p53-dependent pathway in human osteosarcoma cells. p33ING1b may be an important marker and/or therapeutic target in the prevention and treatment of osteosarcoma.
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http://dx.doi.org/10.4161/cbt.4.1.1372DOI Listing
January 2005

Aloe polysaccharides mediated radioprotective effect through the inhibition of apoptosis.

J Radiat Res 2004 Sep;45(3):447-54

Department of Pharmacology, Guangzhou University of Traditional Chinese Medicine School of Pharmaceutical Science, Guangzhou, P. R. China.

Polysaccharides from aloe are always considered an effective radioprotector on irradiation-induced skin damage. The aim of this study was to determine if aloe polysaccharides (AP) have radioprotective effects on normal human cells in vitro and mouse survival in vivo and to explore the mechanism. Pretreatment with 50 microg/ml AP could improve the surviving fraction at 2 Gy (SF2) of three normal cell lines 293, ECV304, and C. liver from 41.5%, 46.5%, and 40.9% to 49.4%, 72.1%, and 89.1%, respectively. AP could also reduce the apoptotic rate of C. liver cells from 9.5% and 43.0% to 2.2% and 10.9% 48 h and 72 h after 2 Gy irradiation, respectively. Western blot analysis showed that pretreatment with AP could block the upregulation of pro-apoptotic p53, Bax, and Bad and the downregulation of Bcl-2 by irradiation. AP could lower thymocyte apoptosis of mice in vivo after 6 Gy irradiation and abrogate the cell cycle perturbation. Fifty mg/kg of AP treatment for 30 min before 7.5 Gy irradiation provided the best radioprotective effect and improved the 30-day survival rate of mice to 86.0%, from 10.0%. AP exerted radioprotective effects in vitro and in vivo through an inhibition of apoptosis.
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http://dx.doi.org/10.1269/jrr.45.447DOI Listing
September 2004

Synthesis and cytotoxicity study of alkannin derivatives.

Eur J Med Chem 2004 Sep;39(9):755-64

School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou 510080, China.

Alkannin derivatives (3-19) were prepared through the reaction of beta,beta-dimethylacrylalkannin (1), the most abundant isohexenylnaphthazarin isolated from the roots of Arnebia euchroma, with different types of nucleophiles such as amines and thiols in the absence or presence of a reducing agent. The cytotoxicities of 1-8, 10-14 and 19 against four human carcinoma cell line (GLC-82, CNE2, Bel-7402, K-562) were found to be markedly higher than that of the naturally occurring beta,beta-dimethylacrylalkannin (1) and acetylalkannin (2). This study also shed light on the understanding of the biological activities in terms of the chemical reactivity of alkannins.
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http://dx.doi.org/10.1016/j.ejmech.2004.05.004DOI Listing
September 2004

[p33(ING1b) enhances chemosensitivity of osteosarcoma cell U2OS to etoposide].

Ai Zheng 2004 Jun;23(6):640-4

Institute of Orthopedic Oncology, Department of Orthopedic Surgery, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, PR China.

Background & Objective: As a new tumor suppressor gene, ING1 shared many biological functions with p53, such as cell cycle arrest, DNA repair, apoptosis, and chemosensitivity. The aim of this study was to investigate the effect of p33(ING1b) on chemosensitivity of osteosarcoma cells and its mechanism.

Methods: p33(ING1b) was overexpressed in osteosarcoma cell line U2OS through transient transfection. After transfection, U2OS cells were treated with etoposide for 24 hours, then cell growth inhibitory rates were detected by trypan blue exclusion assay, and apoptosis was assessed using flow cytometry analysis and fluorescent microscopy. Furthermore, the protein expression of p53, p21(WAF1), MDM2 and Bax were determined by Western blot analysis.

Results: After transient transfection with p33(ING1b) vector for 24 hours, U2OS cells were treated with 20 microg/ml VP-16 for 24 hours. The results showed that the cell growth inhibitory rates strongly increased [(63.1+/-5.1)%], and etoposide- induced apoptosis was increased(62.7%). Ectopic overexpression of p33(ING1b) increased the protein expression of p53 and strongly enhanced the expression of endogenous p21(WAF1) and Bax. Moreover, after transfection and treatment with 20 microg/ml VP-16, the protein expression of p53, p21(WAF1), and Bax strongly increased compared with other groups. The protein expression of MDM2 showed no significant difference.

Conclusion: These observations suggest that p33(ING1b) up-regulates p53 protein, and cooperate with p53 in stimulating expression of p21(WAF1) and Bax gene, thus to enhance etoposide-induced apoptosis via p53-dependent pathways.
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June 2004

Inhibition of DNA primase and induction of apoptosis by 3,3'-diethyl-9-methylthia-carbocyanine iodide in hepatocellular carcinoma BEL-7402 cells.

World J Gastroenterol 2004 Feb;10(4):514-20

Cancer Hospital, Cancer Center, Sun Yat-sen University, Guangzhou 510060, Guangdong Province, China.

Aim: To evaluate the effects of 3,3'-diethyl-9-methylthia-carbocyanine iodide (DMTCCI) on DNA primase activity and on apoptosis of human hepatocellular carcinoma BEL-7402 cells.

Methods: DNA primase assay was used to investigate DNA primase activity. MTT assay was applied to determine cell proliferation. Flow cytometric analysis, transmission electron microscopy, DNA fragmentation assay were performed to detect DMTCCI-induced apoptosis. Expression levels of p53, Bcl-2, Bcl-xL, Bad, Bax, survivin, Caspase-3 and poly (ADP-ribose) polymerase (PARP) were evaluated by immunoblot analysis. Caspase-3 activity was assessed with ApoAlert Caspase-3 colorimetric assay kit.

Results: DMTCCI had inhibitory effects on eukaryotic DNA primase activity with IC(50) value of 162.2 nmol/L. It also inhibited proliferation of human hepatocellular carcinoma BEL-7402 cells with IC(50) value of 2.09 micromol/L. Furthermore, DMTCCI-induced BEL-7402 cell apoptosis was confirmed by DNA fragmentation (DNA ladders and sub-G1 formation) and transmission electron microscopy (apoptotic bodies formation). During the induction of apoptosis, expression of Bcl-2, Bcl-xL and survivin was decreased, and that of p53, Bad and Bax was increased. Caspase-3 was activated and poly (ADP-ribose) polymerase (PARP) was cleaved in BEL-7402 cells treated with DMTCCI.

Conclusion: The present data suggest that DMTCCI has inhibitory effects on eukaryotic DNA primase and can induce apoptosis of BEL-7402 cells. The modulation of expression of p53 and Bcl-2 family proteins, and activation of Caspase-3 might be involved in the induction of apoptosis.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4716971PMC
http://dx.doi.org/10.3748/wjg.v10.i4.514DOI Listing
February 2004

Manumycin induces apoptosis in human hepatocellular carcinoma HepG2 cells.

Int J Mol Med 2003 Dec;12(6):955-9

Cancer Institute, Cancer Center, Sun Yat-sen University, 651 DongFeng Road East, Guangzhou 510060, China.

Farnesyltransferase inhibitors (FTIs) were developed to prevent Ras processing and thus to be effective agents for the treatment of cancers harbouring mutated ras. In the present study, HepG2 cells underwent internucleosomal DNA fragmentation after treatment with farnesyltransferase inhibitor manumycin (20 microM) for 12 h. Flow cytometric analysis showed that HepG2 cells were accumulated in the G2/M phase of the cell cycle and the number of apoptotic sub-G1 fraction of cells was increased after treatment with manumycin in a time-dependent manner. During the induction of apoptosis, expression of p53 and p21WAF1 was upregulated, phosphorylation of IkappaB-alpha was blocked, caspase substrates poly(ADP-ribose) polymerase (PARP) and lamin B were cleaved, and Bcl-2 and Bax protein expression remained unchanged. These results indicated that manumycin induced apoptosis in HepG2 cells. The induction of apoptosis by manumycin involved the upregulation of p53 and p21WAF1, the activation of caspases, and the inhibition of nuclear factor-kappaB (NF-kappaB) pathway. However, Bcl-2 and Bax are not associated with manumycin-mediated apoptosis.
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December 2003

[SUCI02 inhibits HER-2/neu receptor tyrosine kinase phosphorylation and growth of HER-2/neu-overexpressing breast cancer cells].

Ai Zheng 2003 Aug;22(8):790-4

Cancer Institute,Cancer Center, Sun Yat-sen University, Guangzhou, Guangdong, 510060, PR China.

Background & Objective: Overexpression of HER-2/neu receptor plays a key role in tumorigenesis,progression,prognosis and chemosensitivity of tumors. We found that SUCI02[N-(4-ethoyphenol)-2-hydroxy- acid amide] could inhibit HER2/neu phosphorylation through comprehensive screening. The aim of this study was to examine the effect of SUCI02 on HER-2/neu-overexpressing cancer cell growth.

Methods: Western blot analysis and immunoprecipitation was used to examine the changes of HER-2/neu receptor tyrosine kinase phosphorylation and protein level. MTT assay was employed to determine the growth inhibition of SUCI02 on the tumor cells.

Results: SUCI02 reversibly inhibited tyrosine phosphorylation of HER-2/neu in a dose-dependent manner with half maximal inhibition at a concentration of 4.34 microg/ml without reduced HER-2/neu receptor protein expression. Activation of MAPK and AKT, which were downstream molecules of HER-2/neu-mediated signal transduction pathway, was inhibited after being exposure to SUCI02. In contrast, tyrosine phosphorylation of EGFR was relatively unaffected at the concentrations of SUCI02 up to 40 microg/ml. SUCI02 inhibited cell proliferation of HER-2/neu- overexpressing MDA-MB-453m1 more potent than that of EGFR-overexpressing MDA-MB-468.Their IC(50) values were 1.33 microg/ml and 11.3 microg/ml,respectively.

Conclusion: SUCI02 can inhibit tyrosine phosphorylation of HER-2/neu receptor,cell proliferation of HER-2/neu-overexpressing breast cancer cells preferentially and shut down downstream HER-2/neu signal transduction.
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August 2003

Manumycin inhibits cell proliferation and the Ras signal transduction pathway in human hepatocellular carcinoma cells.

Int J Mol Med 2003 Jun;11(6):767-71

Cancer Institute, Cancer Center, Sun Yat-sen University, Guangzhou 510060, China.

Manumycin was reported to have inhibitory effect on farnesyltransferase by competing with the farnesyl pyrophosphate substrate. It exhibited different antiproliferative activity in human hepatocellular carcinoma HepG2 cells, primary cultured human cardiac muscle cells and human liver cells (CLC). HepG2 cells overexpressing ras gene were more sensitive to manumycin than the other cells. The difference might be related to Ras protein levels in these cell lines. Manumycin reduced the amount of functional ras localized at the cytoplasmic membrane, resulting in blocked C-raf-1 assocation with Ras. Manumycin inhibited ERK1/2 phosphorylation in HepG2 cells without reduced expression of ERK1/2 protein. The levels of protein MKP-1 were significantly up-regulated. Our study also demonstrated that manumycin inhibited p85/PI3K and Akt phosphorylation without reduced expression of p85/PI3K and Akt, and interfered with the association of p85/PI3K and Ras. These findings indicated that manumycin interfered with Ras membrane localization, shut down the downstream pathways of Ras and inhibited cell proliferation in HepG2 cells.
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June 2003

Ceramide induces cell cycle arrest and upregulates p27kip in nasopharyngeal carcinoma cells.

Cancer Lett 2003 Apr;193(2):149-54

Cancer Institute, Cancer Center, Sun Yat-sen University, 651 DongFeng Road East, Guangzhou 510060, China.

Ceramide mediates differentiation, growth arrest, apoptosis, proliferation, cytokine biosynthesis and secretion, and a variety of other cellular functions. However, little is known regarding ceramide signaling linked to the cell cycle. In the present study, the effect of ceramide on cell cycle in nasopharyngeal carcinoma cell line CNE2 was investigated. The results showed that ceramide inhibited cell proliferation and induced cell cycle arrest in G1 phase in CNE2 cells. Exposure of CNE2 cells to ceramide resulted in a dose-dependent up-regulation of the cyclin-dependent kinase inhibitor p27 and a decrease of phospho-Akt without reduced expression of total AKT protein. The activation of phosphatidylinositol-3-kinase (PI3K) and the protein expression of PTEN were unaffected following ceramide treatment. We concluded that ceramide induced cell cycle arrest in G1 phase in CNE2 cells and p27 up-regulation was involved in this process. In addition, up-regulation of p27 resulting from ceramide treatment may be due to the interruption of Akt, but decrease of phospho-Akt is independent of PI3K function or PTEN protein expression.
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http://dx.doi.org/10.1016/s0304-3835(03)00050-8DOI Listing
April 2003

[Tyrosine kinase receptor-mediated signal transduction and cancer treatment].

Yao Xue Xue Bao 2002 Mar;37(3):229-34

Cancer Center, Sun Yat-sen University of Medical Sciences, Guangzhou 510060, China.

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March 2002

[Tea polyphenol inhibit on growth of human nasopharyngeal carcinoma cell and xenograft in nude mice].

Ai Zheng 2002 Apr;21(4):392-4

Cancer Institute, Cancer Center, Sun Yet-sen University, Guangzhou 510060, P. R. China.

Background And Objective: It was reported that tea polyphenol(TP) possess preventive and anticancer effects on various human cancers. However the report about TP against human nasopharyngeal carcinoma(NPC) was very rare. Our previous studies have also suggested that TP has antiproliferative effect and may induce apoptosis in human NPC cell. In order to further explore the antitumor effect, the authors investigated the growth inhibition effect of TP on various human NPC cell lines and xenograft tumors of human NPC in nude mice.

Method: Antiproliferative effect of TP against seven human NPC cell lines was tested by MTT method. Antitumor effect of TP was determined using the xenografts models of human NPC cell (CNE2) in nude mice.

Results: The fifty percent inhibition concentration (IC50) of TP against NPC cell lines (NPC/HK1, CNE1, CNE2, HNE1, HNE2, SUNE1, and Fadu cells) were calculated to be 55.83, 98.43, 119.21, 127.74, 158.07, 160.72, and 163.59 micrograms/ml, respectively. Average inhibitory rates of TP against xenograft tumors of human NPC in nude mice were 12.7% (P > 0.05), under the dosage of 5 mg.(kg..d)-1, ig x 18 d. Under the dosages of 10 mg.(kg..d)-1, ig x 18 d and 20 mg.(kg..d)-1, ig x 18 average inhibitory rates were 31.0% and 38.5%, (P < 0.01), respectively.

Conclusion: The results indicated that TP possessed different antiproliferative effect on seven human NPC cell lines in vitro and on xenograft tumor of human NPC in nude mice.
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April 2002

[Antitumor effect of anuoning].

Ai Zheng 2002 Apr;21(4):379-82

Cancer Institute, Cancer Center, Sun Yet-sen University, Guangzhou 510060, P. R. China.

Background & Objective: The authors' previous studies have demonstrated that anuoning bullatacin and squamocin have anticancer activity in vitro. Squamocin could induce apoptosis of HL-60 cells. The purpose of this paper was to investigate cytotoxicity and antitumor effect of anuoning.

Methods: MTT assay was used to examine the growth inhibition of anuoning on human colon carcinoma cell line (HT-29), human nasopharyngeal carcinoma cell line (SUNE1, CNE2), human liver carcinoma (bel-7402), human breast adenocarcinoma cell line (MCF-7) and human lung adenocarcinoma cell line (GLC-82). The models of mice S-180 sarcoma and HepS were used for in vivo antitumor test.

Results: The IC50 of anuoning on CNE2, bel-7402, HT-29, SUNE1 cell were 0.044, 0.068, 0.446, and 1.617 micrograms/ml, respectively. The IC50 of anuoning on MCF-7 cell and GLC-82 cell were 1.857 and 3.481 micrograms/ml, respectively. Under the doses of 15, 30, and 60 micrograms/kg, i.p., qd x 10 d, the average tumor inhibitory rates of anuoning to mice tumor HepS were 36.9%, 51.8%, and 57.9%, respectively (P < 0.05). Under the same concentration, the average tumor inhibitory rates of anuoning on mice S-180 sarcoma were 43.0%, 52.1%, and 61.0%, respectively (P < 0.05).

Conclusions: The results indicate that the anuoning possess cell growth inhibition activity to various human tumor cells in vitro and antitumor effect in vivo.
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April 2002

[Correlation between inhibitory effect of Manumycin on human hepatoma cancer cell HepG2 and Ras signal transduction pathway].

Ai Zheng 2002 Apr;21(4):364-8

Cancer Institute, Sun Yat-sen University, Guangzhou 510060, P. R. China.

Background And Objective: Treatment with anti-cancer agents has failed to achieve satisfactory results in hepatocellular carcinoma. In the process of hepatocarcinogenesis, Ras has been shown to play an important role. Ras requires a farnesyl moiety for activation. It has been found that farnesyltransferase inhibitor Manumycin inhibits farnesyl protein transferase, which catalyzes farnesylation. This study was designed to investigate the antitumor effect of Manumycin in human hepatoma cell line HepG2 and try to clarify its influence on Ras pathway.

Methods: The growth inhibitory effect of farnesyltransferase inhibitor Manumycin on human hepatoma cell line HepG2 was observed by using [3H]thymidine incorporation assay. The relative protein expressions of pan-Ras, N-Ras, ERK1/2, AKT, and MKP-1 affected by Manumycin were determined by using Western blot analysis.

Results: Manumycin(5, 10, 20, 40, and 80 mumol/L) significantly inhibited cell growth of human hepatoma cell line HepG2 with IC50 value of (17.1 +/- 2.6) mumol/L. Manumycin could inhibit both pan-Ras and N-Ras in human hepatoma HepG2 cells, but its inhibitory effect on pan-Ras of cell membrane was much stronger. Phospho-MAPK and phospho-AKT decreased significantly after treatment of HepG2 cells with Manumycin, while total MAPK and AKT were hardly affected. After treatment with 10 nmol/L wortmannin for 1 h, which had potent inhibitory effect on phosphorylation of AKT, Manumycin had stronger inhibitory effect on phosphorylation of AKT as compared to treatment without wortmannin, eventhough AKT protein levels were still unaffected. Furthermore, the expression of MKP-1 was elevated through manumycin treatment in a concentration-dependent manner.

Conclusion: Manumycin may significantly inhibit the growth of human hepatoma cell line HepG2, which was related to its inhibition on the combination of Ras and cell membrane and increasing the expression of MKP-1, accordingly inhibiting activation of ERK1/2 and AKT. These results suggest that Manumycin antagonizes the growth of HepG2 via the suppression of ras farnesylation blocking the function of oncogenic ras against and could be a potential new anti-cancer agents human cancer, including hepatocellular carcinoma.
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April 2002
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