Yingzhuan Zhan

Graphene oxide/poly-l-lysine assembled layer for adhesion and electrochemical impedance detection of leukemia K562 cancercells

A novel biocompatible film assembled by combining of graphene oxide (GO) and poly-L-lysine (PLL) for adhesion and electrochemical impedance detection of leukemia K562 cells was proposed. The biocompatible film showed an improved immobilization capacity for living cells and a good biocompatibility for preserving the activity of the immobilized living cells. The immobilized K562 cells on the biocompatible film-modified electrode can be directly monitored with electrochemical impedance spectroscopy in the presence of [Fe(CN)₆]³⁻/⁴⁻ as redox probes. A highly sensitive electrochemical impedance method for the detection of leukemia K562 cancer cells was developed. Under the optimized conditions, the increased electron-transfer resistance with a good correlation to the logarithmic value of concentration of K562 cells ranging from 10² to 10⁷ cells mL⁻¹, and with the detection limit of 30 cells mL⁻¹ (S/N=3). Additionally, the proposed method was used to describe the viability of cells and to evaluate the effectiveness of antitumor drug Nilotinib on K562 cells. The obtained results of Nilotinib cytotoxicity are well agreed with those from WST-1 assays. Furthermore, the work demonstrates that a highly biocompatible film of PLL/GO assembled is also expected to be an appropriate matrix for the electrochemical investigation of adhesion, proliferation, apoptosis of other relevant mammalian cells which is not limited to adherent cells, and the study of cell-based biosensors.

A novel angiogenesis inhibitor impairs lovo cell survival via targeting against human VEGFR and its signaling pathway of phosphorylation.

Colorectal cancer represents the fourth commonest malignancy, and constitutes a major cause of significant morbidity and mortality among other diseases. However, the chemical therapy is still under development. Angiogenesis plays an important role in colon cancer development. We developed HMQ18–22 (a novel analog of taspine) with the aim to target angiogenesis. We found that HMQ18–22 significantly reduced angiogenesis of chicken chorioallantoic membrane (CAM) and mouse colon tissue, and inhibited cell migration and tube formation as well. Then, we verified the interaction between HMQ18–22 and VEGFR2 by AlphaScreen P-VEGFR assay, screened the targets on angiogenesis by VEGF Phospho Antibody Array, validated the target by western blot and RNAi in lovo cells. We found HMQ18–22 could decrease phosphorylation of VEGFR2(Tyr1214), VEGFR1(Tyr1333), Akt(Tyr326), protein kinase Cα (PKCα) (Tyr657) and phospholipase-Cγ-1 (PLCγ-1) (Tyr771). Most importantly, HMQ18–22 inhibited proliferation of lovo cell and tumor growth in a human colon tumor xenografted model of athymic mice. Compared with normal lovo cells proliferation, the inhibition on proliferation of knockdown cells (VEGFR2, VEGFR1, Akt, PKCα and PLCγ-1) by HMQ18–22 decreased. These results suggested that HMQ18–22 is a novel angiogenesis inhibitor and can be a useful therapeutic candidate for colon cancer intervention.

Potentiation of paclitaxel activity by curcumin in human breast cancer cell by modulating apoptosis and inhibiting EGFR signaling

It has been suggested that combined effect of natural products may improve the treatment effectiveness in combating proliferation of cancer cells. Here, we examined the combined anticancer activities of compounds of three natural origin including baicalein, curcumin, and resveratrol with chemotherapy drug paclitaxel respectively, which showed that combination of paclitaxel with curcumin exhibited synergistic growth inhibition and induced significant apoptosis in MCF-7 cell lines. Treatment of MCF-7 cell lines with paclitaxel and curcumin induced the apoptosis of regulatory protein Bcl-2 but decreased Bax expression. In addition, simultaneous treatment with paclitaxel and curcumin strongly inhibited paclitaxel-induced activities of EGFR signaling. Furthermore, the combination of paclitaxel and curcumin exerted increased anti-tumor efficacy on mouse models. Overall, our data described the promising therapeutic potential and underlying mechanisms of combining paclitaxel with curcumin in treating breast cancer.

Furanocoumarins-imperatorin inhibits myocardial hypertrophy both in vitro and in vivo.

The furanocoumarin imperatorin has been reported to have hypotensive effect, and we have investigated its activity on myocardial hypertrophy. Imperatorin displayed similar chromatographic retention peak to verapamil in the model of cardiac muscle/cell membrane chromatography, and could reduce in a concentration-dependent way protein content and cell size of myocytes prestimulated with angiotensin II. The ratio of heart weight to body weight (mg/g) (4.13 ± 0.06 in SHRs, 3.77 ± 0.02 with imperatorin 25 mg kg(-1)d(-1) 16 17 ig, P<0.01) was significantly lower in the imperatorin-treated SHRs. Taken together, our observations show that imperatorin exerts anti-hypertrophic effect both in vitro and in vivo.

Brucine, an effective natural compound derived from nux-vomica, induces G1 phase arrest and apoptosis in LoVo cells

Brucine is an alkaloid from nux vomica, has been shown various pharmacological actions. To study the possible anti-cancer mechanisms on LoVo cells, effects of Brucine on cell viability, cell cycle and apoptosis were investigated. The results showed that Brucine revealed strong growth inhibitory effect on LoVo cells, and caused LoVo cell shrinkage and membrane blobbing, induced cellular and DNA morphological changes. Cell cycle and apoptosis analysis documented that Brucine could change cell cycle and induce cell apoptosis. Brucine-mediated cell cycle arrest in G1 phase was associated with a marked increase of protein levels of CCND1 and decrease in CCNB1, cyclin E and CDC2. In addition, Brucine dose-dependently caused LoVo cells apoptosis evidenced by Annexin V/PI staining Brucine-induced apoptosis was mediated via up-regulation of Bax and down-regulation of Bcl-2. Furthermore, proteins Erk1/2, p38 and Akt phosphorylation were down regulated by Brucine in a dose-dependent manner. In summary, this paper indicates Brucine is effective against LoVo cells proliferation, and promotes LoVo cells death via apoptosis. These results reveal functional interplay among a series of pathway that are deregulated in cancer and suggest that their simultaneous targeting by Brucine could result in efficacious inhibition on cancer cells.

Momordica cochinchinensis Seed Extracts Suppress Migration and Invasion of Human Breast Cancer ZR-75-30 Cells Via Down-regulating MMP-2 and MMP-9

OBJECTIVE Metastases and invasion are the main reasons for oncotherapy failure. Momordica cochinchinensis (Mu Bie Zi in Chinese) had been used for a variety of purposes, and shown anti-cancer action. In this article, we focused on effects on regulation of breast cancer cell ZR-75-30 metastases and invasion by extracts of Momordica cochinchinensis seeds (ESMCs). METHODS Effect of ESMCs on ZR-75-30 human breast cancer cells proliferation were evaluated by MTT assay and on invasion and migration by wound-healing and matrigel invasion chamber assays. Expression and protease activity of two matrix metalloproteinases (MMPs), MMP-2 and MMP-9, were analyzed by Western blotting and gelatin zymography, respectively. RESULTS ESMC revealed strong growth inhibitory effects on ZR-75-30 cells, and effectively inhibited ZR-75-30 cell invasion in a dose-dependent manner. Western blot and gelatin zymography analysis showed that ESMC significantly inhibited the expression and secretion of MMP-2 and MMP-9 in ZR-75-30 cells. CONCLUSIONS ESMC has the potential to suppress the migration and invasion of ZR-75-30 cancer cells, and it might prove to of interest in the development of novel inhibitors for breast cancer.

A novel biphenyl urea derivate inhibits the invasion of breast cancer through the modulation of CXCR4

The increased migration and invasion of breast carcinoma cells are key events in the development of metastasis to the lymph nodes and distant organs. CXCR4, the receptor for stromal‐derived factor‐1, is reportedly involved in breast carcinogenesis and invasion. In this study, we investigated a novel biphenyl urea derivate, TPD7 for its ability to affect CXCR4 expression as well as function in breast cancer cells. We demonstrated that TPD7 inhibited the breast cancer proliferation and down‐regulated the CXCR4 expression on breast cancer cells both over‐expressing and low‐expressing HER2, an oncogene known to induce the chemokine receptor. Treatments with pharmacological proteasome inhibitors partial suppressed TPD7‐induced decrease in CXCR4 expression. Real‐time PCR analysis revealed that down‐regulation of CXCR4 by TPD7 also occurred at the translational level. Inhibition of CXCR4 expression by TPD7 further correlated with the suppression of SDF‐1α‐induced migration and invasion in breast tumour cells, knockdown of CXCR4 attenuated TPD7‐inhibitory effects. In addition, TPD7 treatment significantly suppressed matrix metalloproteinase (MMP)‐2 and MMP‐9 expression, the downstream targets of CXCR4, perhaps via inactivation of the ERK signaling pathway. Overall, our results showed that TPD7 exerted its anti‐invasive effect through the down‐regulation of CXCR4 expression and thus had the potential for the treatment of breast cancer.

Activity of taspine isolated from Radix et Rhizoma Leonticis against estrogen-receptor-positive breast cancer.

The aim of our study was to investigate the effect of taspine isolated from Radix et Rhizoma Leonticis on the growth of oestrogen-receptor-positive breast cancer xenografts in vivo and the possible mechanism for this action. In vivo taspine studies were conducted with ZR-75-30 human breast cancer xenografts in athymic mice, and then tumors tissue lysates were subjected to Western blotting analysis of estrogen receptor (ER) and progesterone receptor (PR), which was related to inhibition of tumor growth. For in vitro study, cell proliferation, cell cycle and apoptosis of ZR-75-30 cell treated with or without taspine were detected. ER and PR expression were detected by Western blotting, ER and PR mRNA were verified by reverse transcription polymerase chain reaction (RT-PCR). The results showed that treatment over 14 days resulted in a sustained and significant reduction in xenograft weight compared with untreated controls. Cell cycle and apoptosis analysis documented that taspine could change cell cycle and induce cell apoptosis. There was a significant decrease observed in the expression of ER and PR both in tumor tissue and cells after treatment with taspine, RT-PCR also showed a reduction in the expression of mRNA for ER and PR in the group treated with taspine. Taken together, these results suggested that taspine might serve as a promising candidate of ER antagonist in the treatment of oestrogen-independent breast cancer.

A novel tissue model for angiogenesis: evaluation of inhibitors or promoters in tissue level

A novel tissue model for angiogenesis (TMA) is established for effective evaluation of angiogenesis inhibitors or promoters in vitro. Lung tissues were cultured in fibrinogen “sandwich” structure which resembled the formation of neovessels in vivo. The cells and capillary-like structures grew from the lung tissues were identified as endothelial cells and neovessels. Both immunohistochemisty and western blot results indicated that autocrine VEGF bound to the KDR and induced KDR autophosphorylation that could induce the proliferation of endothelial cells and their migration as well as the formation of microvessels on the lung tissue edge. With addition of the TMA, the murine VEGF and cultured medium produced by A549 tumor cells apparently promoted the increase of neovessels. Sorafenib as a tumor angiogenesis inhibitor and Tongxinluo as an angiogenesis promoter were both used to evaluate the TMA performance and they exhibited a good effect on neovessels in the TMA. The model established imitated angiogenesis in vivo and could well serve as an effective method in evaluating the angiogenesis inhibitors or promoters, and could also be practical for screening small molecules that affect blood vessel formation.

A novel taspine derivative, HMQ1611, suppresses adhesion, migration and invasion of ZR-75-30 human breast cancer cells

BackgroundTaspine was screened for the first time from Radix et Rhizoma leonticis (Hong Mao Qi in Chinese) using cell membrane chromatography in our laboratory. Its anticancer and antiangiogenic properties were demonstrated, and it could serve as a lead compound in anticancer agent development. Here, we investigated the role of one of the derivatives, HMQ1611, with increased activity and solubility, on the regulation of breast cancer cell ZR-75-30 adhesion, migration and invasion.MethodsThe effect of HMQ1611 on adhesion, invasion and migration of human breast cancer cells ZR-75-30 was examined. The migration and invasive potential of ZR-75-30 cells were examined by wound-healing assays and matrigel invasion chamber assays. The adhesion to type IV collagen and laminin were evaluated by MTT assay. The expression and proteinase activity of two matrix metalloproteinases (MMPs), matrix metalloproteinases 2 (MMP-2) and matrix metalloproteinases 9 (MMP-9), were analyzed by Western blot analysis and gelatin zymography, respectively.ResultsHMQ1611 effectively inhibited ZR-75-30 cell invasion and significantly suppressed adhesion to type IV collagen and laminin-coated substrate in a dose-dependent manner. Western blot and gelatin zymography analysis showed that HMQ1611 significantly inhibited the expression and secretion of MMP-2 and MMP-9 in ZR-75-30 cells. Additionally, treatment of ZR-75-30 cells with HMQ1611 downregulated the expression of MMP-2 and MMP-9.ConclusionsHMQ1611 had potential to suppress the adhesion, migration and invasion of ZR-75-30 cancer cells, and it could serve as a potential novel therapeutic candidate for the treatment of metastatic breast cancer.