Tian Li

Sun Yat-Sen University, Guangzhou, Guangdong Sheng, China

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Publications (10)21.08 Total impact

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    ABSTRACT: Background: Emerging evidence implicates the platelet-derived growth factor-D (PDGF-D) in many types of human solid tumors. We investigated whether PDGF-D plays an important role in endometrial cancer (EC) in relation to clinicopathologic phenotype, angiogenesis, and patient prognosis. Materials and Methods: We analyzed PDGF-D protein expression by Western blotting in twenty-seven human endometrial cancer tissues, and matched normal endometrial controls collected at the third Affiliated hospital of Sun Yat-sen University during 2012-2013 (n=27). Immunohistochemical staining was performed using a human PDGF-D antibody on the endometrial cancer patients collected in the same facility during January 2001 and October 2013 (n=152). Patients were followed from the time of primary surgery in 2001-2013 until death or last follow-up. We correlated the PDGF-D expression levels with clinicopathologic parameters and prognosis in human endometrial cancer patients. Results: Compared with matched normal endometrial cases, PDGF-D was up-regulated in endometrial cancer. Expression of PDGF-D protein, found in 78% of the cases, was associated with nonendometrioid histologic type (p=0.028), FIGO stage III/IV (p=0.039), >50% solid tumor growth (p=0.048), pelvic LN metastasis (p=0.035) and ER and PR negativity (p=0.04 and 0.002). PDGF-D expression was also significantly associated with expression of VEGF-A (p=0.021). In multivariate analysis, PDGF-D expression proved to be an independent prognostic factor in addition to histologic grade and FIGO stage. Patients with high expression levels of PDGF-D had a significantly poorer overall survival rate compared with patients with no expression. Conclusions: PDGF-D expression is frequently up-regulated in endometrial cancer, and is associated with aggressive features and poor prognosis.
    Asian Pacific journal of cancer prevention: APJCP 04/2014; 15(8):3741-5. · 1.50 Impact Factor
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    ABSTRACT: ABT-737 is a BH3 mimetic small molecule inhibitor that can effectively inhibit the activity of antiapoptotic Bcl-2 family proteins including Bcl2, Bcl-xL and Bcl-w, and further enhances the effect of apoptosis by activating the proapoptotic proteins (t-Bid, Bad, Bim). In this study, we demonstrate that ABT-737 improved the radiation sensitivity of cervical cancer HeLa cells and thereby provoked cell apoptosis. Our results show that ABT-737 inhibited HeLa cell proliferation and activated JNK and its downstream target c-Jun, which caused the up-regulation of Bim expression. Blockade of JNK/c-Jun signaling pathway resulted in significant down-regulation of ABT-737-induced Bim mRNA and protein expression level. Also, ABT-737 could evoke the Bim promoter activity, and enhance the radiation sensitivity of HeLa cells via JNK/c-Jun and Bim signaling pathway. Our data imply that combination of ABT-737 and conventional radiation therapy might represent a highly effective therapeutic approach for future treatment of cervical cancer.
    PLoS ONE 01/2012; 7(12):e52483. · 3.53 Impact Factor
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    ABSTRACT: Loss or mutation of the PTEN (phosphatase and tensin homologue deleted on chromosome 10) gene is associated with resistance to epidermal growth factor receptor (EGFR) inhibitors. However, the mechanism underlying remains elusive. In this study, we aimed to explore whether sensitivity to the EGFR tyrosine kinase inhibitor (TKI) is affected by PTEN status in endometrial cancer cells. PTEN siRNA and the PTEN gene were transfected into HEC-1A and Ishikawa endometrial cancer cells using lentiviral vectors. Cells were treated under various concentrations of RG14620 and rapamycin, which are EGFR and mammalian target of rapamycin (mTOR) inhibitors, respectively. The IC(50) of RG16420 was determined by using the MTT method. Cell apoptosis and the cell cycle were studied, and activation of EGFR, AKT, and p70S6 were detected by Western blot analysis. Loss of PTEN promoted cell proliferation and led to significant increases in the levels of EGFR, phospho-EGFR, AKT, phospho-AKT, and phospho-mTOR proteins. Ishikawa and HEC-1A(PTENkd) cells that displayed loss and inactivation of PTEN function were resistant to RG14620. HEC-1A and Ishikawa(PTEN) cells with intact PTEN were sensitive to RG14620. The combination of two inhibitors was more effective than both monotherapies, particularly in carcinoma cells with PTEN dysfunction. Decreased phospho-EGFR protein expression was observed in all cell lines that were sensitive to RG14620. Decreased phospho-AKT and phospho-p70S6 protein expression was observed in PTEN-intact cells that were sensitive to RG14620. PTEN loss results in resistance to EGFR TKI, which was reversed by PTEN reintroduction or mTOR inhibitor treatment. The combined treatment of EGFR TKI and the mTOR inhibitor provided a synergistic effect by promoting cell death in PTEN-deficient and PTEN-intact endometrial cancer cells, particularly in PTEN-deficient carcinoma cells with up-regulated EGFR activation.
    Molecular and Cellular Biochemistry 09/2011; 361(1-2):19-29. · 2.33 Impact Factor
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    ABSTRACT: Impairment of a cell cycle checkpoint is often associated with sensitivity to chemotherapeutic drugs. Here, we studied the correlations between the checkpoint with forkhead-associated and ring finger (CHFR) gene expression and responses to paclitaxel in endometrial cancer cells. We cultured 6 endometrial cancer cell lines exposed to paclitaxel, studied the cell cytotoxicity, cell cycle distribution, CHFR expression, and methylation status before and after a demethylation agent (5-aza) treatment. CHFR was silenced by small interfering RNA (siRNA). Then we examined tumor growth and CHFR expression with paclitaxel alone or combined with 5-aza pretreatment in vivo. We found that HEC-1B, RL-952, and AN3CA cells were sensitive to paclitaxel. Moreover, CHFR was weakly expressed in these cells, whereas paclitaxel-resistant cells (ISH, HEC-1A, and KLE) had high CHFR expression. Then we found that restored expression of CHFR by demethylation decreased the sensitivity to paclitaxel in AN3CA cells. In addition, cells with CHFR demethylation resulted in G2/M phase arrest that induced to paclitaxel resistance. These results were confirmed again in small interfering RNA-transfected HEC-1A cells. Furthermore, in nude mice model, restored expression of CHFR by demethylation inhibited tumor growth and decreased sensitivity to paclitaxel. Our data suggest that CHFR suppression regulated by hypermethylation may sensitize endometrial cancer cells to paclitaxel, and CHFR may be a promising marker to predict the response of endometrial cancer to paclitaxel.
    International Journal of Gynecological Cancer 08/2011; 21(6):996-1003. · 1.94 Impact Factor
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    ABSTRACT: Folate (FOL) mediated poly-lactide-co-glycolide-polyethylene glycol nanoparticles (FOL-PEG-PLGA NPs) bearing paclitaxel (PTX) were prepared for the effective delivery of drug to endometrial carcinoma. The average size, zeta potential and encapsulation efficiency of FOL-targeted NPs were found to be around 220 nm, -30.43 mV and 95.6%. Cellular uptake was observed. The accumulation of FOL-targeted NPs depends on dual effects of passive and active targeting. The FOL-targeted PTX NPs showed a greater cytotoxicity against HEC-1A cancer cells in vitro and in vivo, which might be induced by apoptosis. H&E staining did not showed apparent tissue damage to liver and kidney of the mice after injecting NPs intravenously. These results suggest that the novel FOL-PEG-PLGA NPs could be a potential delivery system with excellent therapeutic efficacy for targeting the drugs to cancer cells.
    Bioorganic & medicinal chemistry 07/2011; 19(13):4057-66. · 2.82 Impact Factor
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    ABSTRACT: The type-1 insulin-like growth factor receptor (IGF-1R) is over-expressed by endometrial carcinoma, level of IGF-1R has been correlated with tumor progression, and high IGF-1R expression has been found to be an important prognostic factor. In the study, we used lentivirus-mediated shRNA targeting IGF-1R to silence its expression, then assessed the effect of down-regulation of this receptor on cell growth and chemosensitivity to cisplatin. Lentivirus-mediate shRNA was designed and transfected to the endometrial carcinoma HEC-1B cell. The IGF-1R mRNA and related protein expression, cell proliferation ability, cell apoptosis, and cell cycle change were detected. Cell proliferation inhibition rates, cell apoptosis, and level of cleaved caspase-9 were measured in various concentrations of cisplatin. The mRNA and protein level of IGF-1R, and the phosphorylated protein p-Akt, p-Erk were all suppressed after transfection. Cell proliferation was inhibited in successive five days after transfection, the highest inhibition rate was 43.28 ± 3.55% on day 5. After transfection, 24.96 ± 1.05% cells were in G(2)/M phase, and cell apoptotic rate increased from 10.66 ± 0.08 to 19.92 ± 1.34%. In various concentrations of cisplatin, transfected cells proliferation was significantly inhibited which made the IC50 value drop from 21.85 uM to 10.58 uM. Incubation with different concentrations of cisplatin for 48 h, cells apoptotic rate increased to 41.92 ± 2.5, 31.13 ± 2.76, 22.21 ± 4.63%, respectively, which was accompanied with increased cleaved caspase-9 expression. Lentivirus-mediated shRNA targeting IGF-1R has the potential to develop as a clinical treatment method in advanced and chemoresistant endometrial carcinoma.
    Molecular and Cellular Biochemistry 03/2011; 353(1-2):225-33. · 2.33 Impact Factor
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    ABSTRACT: The type-1 insulin-like growth factor receptor (IGF-1R) is one member of tyrosine protein kinase receptor family. It is a causal factor for tumor initiation, development and frequently overactivated in a variety of human malignancies, including endometrial carcinoma. To investigate its possibility as a therapeutic target for endometrial carcinoma, we adopted RNA interference technology to down-regulate IGF-1R expression in endometrial carcinoma and analyzed its apoptosis inductive effect and tumorigenicity in vivo. Results showed that RNAi mediated down-regulation of IGF-1R expression in endometrial carcinoma significantly induced apoptosis, reduced downstream protein phosphorylation and decreased tumorigenicity in vivo accompanied with lower proliferation index in tumor tissue, Which implied the therapeutic potential of RNAi in the treatment of endometrial carcinoma by targeting IGF-1R and IGF-1R may be a potential therapeutic target for human endometrial carcinoma.
    International immunopharmacology 02/2011; 11(2):244-9. · 2.21 Impact Factor
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    ABSTRACT: This study was conducted to evaluate and compare molecular and cellular effects of paclitaxel in combination with epidermoid growth factor receptor (EGFR) or/and mammalian target of rapamycin( mTOR) inhibitors with two endometrial cancer lines HEC-1A and Ishikawa. Treatment was with the EGFR inhibitor RG14620, the mTOR inhibitor rapamycin, and the conventional cytotoxic drug paclitaxel, alone or in combination. The 50% inhibitory concentration (IC50) and cell viability were determined by the MTT assay. Multiple drug effect/ combination indexes (CI) analysis was applied to assess interactions between paclitaxel and the two inhibitors. Apoptosis and cell cycling were evaluated by flow cytometry analysis. Western blotting was performed to evaluate the related protein alteration in PI3K/AKT signaling pathway. RG14620, rapamycin and paclitaxel showed obvious dose-dependent growth inhibition with time. The IC50 of paclitaxel at 24 hours decreased significantly when pretreated with low doses of RG14620 and Rapamycin alone or in combination. Moreover, combination index (CI) of paclitaxel with each inhibitor was larger than 1, indicating a synergistic effect between pairs of drugs in these two cell lines. FACS analysis showed the cell apoptosis rate increased with a synergistic effect. On Western blotting, activation of PI3K/AKT pathway was detected in both two cell lines in the control case. When paclitaxel was used as a single-agent or in combinations, the protein expression of PI3K/AKT pathway totally abated, especially in HEC-1A cells, suggesting a role in chemoresistance. The combination of three drugs induced the greatest over-expression of caspase-3. Combining targeted inhibitors with cytotoxic chemotherapy appears to be a promising strategy for the effective treatment of endometrial cancer which merits further clinical investigation.
    Asian Pacific journal of cancer prevention: APJCP 01/2011; 12(11):2951-7. · 1.50 Impact Factor
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    ABSTRACT: Prior studies in different tumor models have shown that, under conditions of PTEN deficiency, the mitogen-activated protein kinase (MAPK) signaling pathway appear to play a major role in the tumor cell's proliferative and survival pathway, and that pharmacological inhibition of this pathway results in tumor growth inhibition. This study aimed to explore whether sensitivity to p38MAPK inhibitors are specifically due to status of PTEN in endometrial cancer cells. We developed a series of endometrial cancer cell lines with different PTEN expressions (Ishikawa, RL-952, HEC-1B and HEC-1A cells) or introduced the wild-type PTEN and PTEN-siRNA in four endometrial cancer cells to change its PTEN expression with a p38MAPK inhibitor, SB203580 for 2 days. Cell proliferation, cell apoptosis, and cell cycle distribution were studied, and activation of AKT, ATF-2, and p38MAPK was examined by Western blotting. In cultivated PTEN-deficient endometrial cancer cells, in addition to an activation of AKT, a phosphorylation of p38MAPK and ATF-2 was evident, while PTEN-positive endometrial cancer cells lacked AKT activation but revealed a reduced expression of p-p38MAPK and p-ATF-2. These PTEN-deficient endometrial cancer cells demonstrated an increased sensitivity to the anti-proliferative effects induced by SB203580 compared with the PTEN-positive endometrial cancer cells, which corresponded to alterations in cell cycle response and cell apoptosis. PTEN-deficient endometrial cancer cells exhibit higher p38MAPK activity, and genetic studies demonstrate that p38MAPK functions dependently of AKT. Furthermore, PTEN loss sensitizes cells to p38MAPK inhibition in endometrial carcinoma cells. These findings indicate that inhibitors of p38MAPK have the potential to be effective in the treatment of endometrial cancer patients with PTEN-deficient tumors and should be evaluated in this setting.
    Journal of Cancer Research and Clinical Oncology 07/2010; 136(7):1089-99. · 2.91 Impact Factor
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    ABSTRACT: The occurrence of uterine leiomyoma is related to the abnormal expression of some genes, but the molecular mechanism has not been clarified yet, the study screened genes related to uterine leiomyoma by comparing different genes expressed in uterine leiomyoma tissues with normal myometrium uterine tissues. To compare different genes expressed in uterine leiomyoma tissues with normal myometrium uterine tissues by fluorescent differential display reverse transcription polymerase chain reaction (FDD-RTPCR). Four sets of anchor primers and three sets of arbitrary primers, totally twelve primer combinations, were used for FDD-RTPCR amplification. Differentially expressed cDNA fragments were cloned, sequenced, and analyzed in origin. And one of differentially expressed bands was analyzed by RT-PCR. Twenty-seven cDNA fragments were isolated from uterine leiomyoma. N(568) cDNA fragment shared 96% homology with the sequence of GCRG114 gene. RT-PCR confirmed that this gene was expressed lowlier in uterine leiomyoma tissues than in normal myometrium uterine tissues. N(568) cDNA fragment is highly homologous with the sequence of GCRG114 gene, and it may be related to the development of uterine leiomyoma.
    Ai zheng = Aizheng = Chinese journal of cancer 03/2004; 23(3):292-5.