Inhibition of p38 MAPK increases the sensitivity of 5-fluorouracil-resistant SW480 human colon cancer cells to noscapine.

A major cause of treatment failure in advanced colon cancer is resistance to chemotherapy. p38 mitogen-activated protein kinase (MAPK) has been associated with cellular apoptosis and plays an important role in multidrug resistance (MDR) in cancer cells. In the present study the effect of p38 MAPK on the sensitivity of 5-fluorouracil (5-FU)-resistant SW480 (SW480/5-FU) human colon cancer cells to noscapine was investigated. Following p38 MAPK interference, the inhibitory effect of noscapine on cell viability and proliferation was increased in the SW480/5-FU cells and there was also a decrease in the expression level of minichromosome maintenance proteins, recombinant Ki-67 and proliferating cell nuclear antigen. Inhibition of p38 MAPK also enhanced noscapine-induced G1-phase cell cycle arrest in the SW480/5-FU cells and there was also a decrease in the protein and mRNA expression level of cyclin D, cyclin E and cyclin-dependent kinase 2, and an increase in the expression level of P57. Furthermore, p38 MAPK interference increased noscapine-induced apoptosis of the SW480/5-FU cells and there was an increase in the protein and mRNA expression level of caspases-3 and 8 and Bax, and decreased Bcl-2 expression level. The sensitivity of the SW480/5-FU cells to noscapine was also increased following p38 MAPK interference, as demonstrated by MDR inhibition via decreased Akt activity and reduced protein expression level of the MDR proteins P-glycoprotein, multidrug resistance protein 1 and ATP-binding cassette G2. These observations indicated that inhibition of p38 MAPK increased the sensitivity of the SW480/5-FU cells to noscapine by suppressing proliferation, induction of cell cycle arrest and apoptosis, and reversal of MDR in the SW480/5-FU cells.

Noscapine Induces Apoptosis in Human Colon Cancer Cells by Regulating Mitochondrial Damage and Warburg Effect via PTEN/PI3K/mTOR Signaling Pathway.

BACKGROUND: Noscapine is an opium alkaloid that has recently been shown to potentiate anti-cancer therapeutic effects by inducing apoptosis in various malignant cells without any detectable toxicity. However, the mechanism by which noscapine induces apoptosis in colon cancer cells remains unclear. MATERIALS AND METHODS: In this study, we explored the anti-cancer activity of noscapine in 5-fluorouracil (5-FU)-resistant human colon cancer cell lines HT29/5-FU and LoVo/5-FU and investigated the possible underlying mechanism. The apoptosis and mitochondrial morphology of cells were detected by TUNEL assay and transmission electron microscopy (TEM). The mitochondrial membrane potential (MMP) was determined using JC-1. The mitochondrial permeability transition pore (mPTP) opening was detected by the calcein-AM/cobalt assay. The levels of glucose, lactic, and ATP in cells were evaluated by ELISA kits. Relative protein expression levels were detected by Western blot. RESULTS: We verified that PTEN was involved in noscapine-induced apoptosis in HT29/5-FU and LoVo/5-FU cells. Noscapine greatly increased mitochondrial damage by altering mitochondrial morphology, inducing mitochondrial membrane potential depolarization, and enabling mitochondrial permeability transition pore opening in HT29/5-FU and LoVo/5-FU cells. In addition, noscapine inhibited the Warburg effect by decreasing the levels of glucose, lactic acid, and ATP and inhibiting the protein expression of glucose transporter 1, lactate dehydrogenase-B, hexokinase 2, and pyruvate kinase M2 in HT29/5-FU and LoVo/5-FU cells. However, PTEN interference counteracted the effect of noscapine on mitochondrial damage and the Warburg effect in HT29/5-FU and LoVo/5-FU cells by decreasing the activation of PI3K/mTOR signaling. CONCLUSION: These results indicated that noscapine induced the apoptosis of HT29/5-FU and LoVo/5-FU human colon cancer cells by regulating mitochondria damage and the Warburg effect via PTEN, and the process is closely related to the PI3K/mTOR signaling pathway.

Noscapine inhibits migration of colon cancer SW480 cells by down-regulating Wnt3a/β-catenin signaling pathway and cadherin 17 / 中国肿瘤生物治疗杂志

@# Objective: To explore the effects of noscapine (Nos) on the expression of cadherin 17 (CDH17) in colon cancer SW480 cells and the mechanism of Nos on cell migration. Methods: SW480 cells were divided into the control group, empty vector (si-EV) group, CDH17 interference (si-CDH17) group, Nos treatment group, and CDH17 interference+Nos treatment (si-CDH17+Nos) group. Small interfering RNA (siRNA) was used to knockdown CDH17, and the selected concentration of Nos was (55.30±2.21) µg/ml (IC50). The mRNA expression of CDH17 was detected by qPCR; the apoptosis and migration abilities of SW480 cells were observed by Hoechst33258 staining and Transwell assay; the contents of VEGF, MMP2 and MMP9 in SW480 cells were measured by ELISA, and the protein expressions of CDH17, Wnt3a and β-catenin were determined by WB. Results: Compared with the control group, mRNA and protein expressions of CDH17 obviously decreased, cell apoptosis and migration significantly reduced, while the contents of VEGF, MMP2 and MMP9 as well as the protein expressions of Wnt3a and β-catenin significantly decreased in Nos treatment group, siCDH17 group and si-CDH17+Nos treatment group (all P<0.01).The effect of si-CDH17+Nos treatment was more significant than that of si-CDH17 (P<0.01). Conclusion: Nos induces apoptosis and inhibits the migration of human colon cancer SW480 cells, which may be related to the down-regulation of CDH17 expression and inhibition of the Wnt3a/β-catenin signaling pathway.

Silencing of cadherin-17 enhances apoptosis and inhibits autophagy in colorectal cancer cells.

Cadherin-17 (CDH17), a structurally unique member of the non-classical cadherin family, is associated with poor survival, cell proliferation, and metastasis in colorectal cancer. However, the role of CDH17 in the apoptosis and autophagy of colorectal cancer cells remains unclear. Here, we aimed to investigate the effect of CDH17 knockdown on autophagy and apoptosis in colorectal cancer cells. We inhibited CDH17 expression in KM12SM and KM12C colorectal cancer cells by RNA interference and found that silencing of CDH17 significantly inhibited cell viability and increased apoptosis in KM12SM and KM12C cells. In addition, silencing of CDH17 significantly increased the expression of cleaved caspase-3 and Bax and decreased the expression of Bcl-2. Concurrently, silencing of CDH17 significantly inhibited the conversion of LC3-I to LC3-II and decreased the formation of LC3+ autophagic vacuoles and the accumulation of acidic vesicular organelles, indicating that autophagy was significantly inhibited in KM12SM and KM12C cells. Additionally, treatment with the autophagy-specific activator rapamycin attenuated apoptosis in CDH17-knockdown cells and as indicated by decreased caspase-3 activity, decreased expression of cleaved caspase-3 and Bax, and increased expression of Bcl-2. In conclusion, CDH17 silencing induced apoptosis and inhibited autophagy in KM12SM and KM12C cells, and this autophagy protected the cells from apoptotic cell death.

Downregulation of liver-intestine cadherin enhances cisplatin-induced apoptosis in human gastric cancer BGC823 cells.

Gastric cancer is the fourth most common type of cancer. Liver-intestine cadherin (CDH17) has been found to be involved in the proliferation and apoptosis of gastric cancer cells. Cisplatin is one of the most widely used antineoplastic agents in the treatment of solid tumor and hematological malignancies. However, the mechanism of enhancing cisplatin-inducing effects on human gastric cancer BGC823 cells by blocking CDH17 gene, both in vitro and in vivo, remains to be clarified. In this study, we investigated the signaling pathway by which cisplatin induces apoptosis by blocking CDH17 gene in gastric cancer BGC823 cells. Our results indicate that down-expression of CDH17 gene can enhance apoptosis-inducing effects of cisplatin on human gastric cancer BGC823 cells. The expression levels of Bax and Cyt-c proteins were upregulated, but the expression levels of Bcl-2 and Bcl-xL proteins were downregulated by blocking CDH17 gene in gastric cancer BGC823 cells after treatment with cisplatin. Moreover, down-expression of CDH17 enhanced the efficacy of cisplatin-induced inhibition of tumor growth in nude mice via apoptosis induction. Down-expression of CDH17 gene can significantly improve apoptosis-inducing effects of cisplatin in vitro and in vivo, which is a new strategy to improve chemotherapeutic effects on gastric cancer.

Down-regulation of liver-intestine cadherin enhances noscapine-induced apoptosis in human colon cancer cells.

BACKGROUND: The aim of the present study was to explore the signaling pathway of noscapine which induces apoptosis by blocking liver-intestine cadherin (CDH17) gene in colon cancer SW480 cells. METHODS: Human colon cancer SW480 cells were transfected with CDH17 interference vector and treatment with 10 µmol/L noscapine. The proliferation and apoptosis of SW480 cells were detected by MTT assay and AnnexinV-FITC/PI flow cytometry kit (BD), respectively. Cell invasion were assessed by transwell assays. Apoptosis related proteins (Cyt-c, Bax, Bcl-2 and Bcl-xL) levels were evaluated by western blot. RESULTS: Compared to the noscapine group, the proliferation was decreased significantly and the apoptosis was increased significantly in SW480 cells of the siCDH17+noscapine group. Cyt-c and Bax protein levels in siCDH17+noscapine group was higher than that of the noscapine group, but Bcl-2 and Bcl-xL protein levels in siCDH17+noscapine group were lower than that of the noscapine group. Moreover, up-expression of CDH17 inhibited the efficacy of noscapine-induced apoptosis in SW480 cells. CONCLUSIONS: We inferred that down-expression of extrinsic CDH17 gene can conspicuously promote apoptosis-inducing effects of noscapine on human colon cancer SW480 cells, which is a novel strategy to improve chemotherapeutic effects on colon cancer.

[Knock-down of cadherin 17 inhibits proliferation and promote apoptosis in noscapine-resistant human SW480 colon cancer cells].

Objective To investigate the effects of cadherin 17 (CDH17) on the proliferation and apoptosis of noscapine-resistant human SW480 colon cancer cells. Methods The level of CDH17 in noscapine-resistant human SW480 colon cancer cells was knocked down by small interfering RNA (siRNA), and the silence was confirmed by Western blotting and real-time quantitative PCR. Transfected SW480 cells were treated with noscapine, and then the proliferation and cell viability of SW480 cells were measured by MTT assay and plate clone formation assay, respectively; the apoptosis of SW480 cells was detected by flow cytometry combined with annexinV-FITC/PI staining; the expressions of poly-ADP-ribose polymerase (PARP) and caspase-3 were determined by Western blotting. Results Compared with NC-siRNA group and control group, the expression levels of CDH17 protein and mRNA were down-regulated in the CDH17-siRNA-transfected SW480 cell lines. After noscapine treatment, compared with NC-siRNA and control group, the colony-forming ratio and cell viability were significantly lower in CDH17-siRNA -transfected cell lines, and the expression levels of cleaved-PARP and cleaved- caspase-3 were up-regulated in CDH17-siRNA group, and the cell apoptosis rate increased. Conclusion Knock-down of CDH17 in SW480 cells can effectively inhibit cell proliferation and promote cell apoptosis as well as improve SW480 cell sensitivity to narcotine.

Sensitive electrochemical immunosensor based on three-dimensional nanostructure gold electrode.

A sensitive electrochemical immunosensor was developed for detection of alpha-fetoprotein (AFP) based on a three-dimensional nanostructure gold electrode using a facile, rapid, "green" square-wave oxidation-reduction cycle technique. The resulting three-dimensional gold nanocomposites were characterized by scanning electron microscopy and cyclic voltammetry. A "sandwich-type" detection strategy using an electrochemical immunosensor was employed. Under optimal conditions, a good linear relationship between the current response signal and the AFP concentrations was observed in the range of 10-50 ng/mL with a detection limit of 3 pg/mL. This new immunosensor showed a fast amperometric response and high sensitivity and selectivity. It was successfully used to determine AFP in a human serum sample with a relative standard deviation of <5% (n=5). The proposed immunosensor represents a significant step toward practical application in clinical diagnosis and monitoring of prognosis.