[Digoxin inhibits migration and invasion of human gastric carcinoma MKN45 cells through down-regulation of AEG-1].

This study was designed to investigate the effect of digoxin on migration and invasion of human gastric carcinoma MKN45 cells and its possible mechanism. MKN45 cells were treated with different concentrations of digoxin for 24 h. The shRNA-AEG-1 plasmid was transfected into MKN45 cells via lipofectamine to block the expression of astrocyte elevated gene-1 (AEG-1). Western blot was used to analyze the protein levels of matrix metalloproteinase-9 (MMP-9), E-cadherin and AEG-1. The result showed that digoxin reduced the abilities of migration and invasion (P < 0.05), up-regulated the protein level of E-cadherin (P < 0.05), and down-regulated the protein levels of MMP-9 and AEG-1 (P < 0.05) in MKN45 cells in a dose-dependent manner. Compared with shControl group, shAGE-1 group showed inhibited cellular migration and invasion, higher expression level of E-cadherin, and lower expression levels of MMP-9 and AEG-1. These results suggest that digoxin suppresses the migration and invasion of human gastric carcinoma MKN45 cells in a dose-dependent manner through inhibiting the expression of AEG-1, and then resulting in the up-regulation of the protein expression of E-cadherin and the down-regulation of the protein expression of MMP-9.

In vivo and in vitro induction of the apoptotic effects of oxysophoridine on colorectal cancer cells via the Bcl-2/Bax/caspase-3 signaling pathway.

Oxysophoridine (OSR) is a major active alkaloid extracted from Sophoraalopecuroides L. The aim of the present study was to investigate the induction of the apoptotic effects of OSR on colorectal cancer cells in vivo and in vitro. The results of the MTT and colony formation assays demonstrated that the proliferation of HCT116 cells was inhibited by OSR in vitro. The characteristics of cellular apoptosis in OSR-treated HCT116 cells were analyzed by Hoechst 33258 staining. It was also observed that the expression of caspase-3, B-cell lymphoma-2 (Bcl-2) associated X protein (Bax) and cytochrome c increased significantly upon OSR treatment. However, the expression of Bcl-2 and poly ADP-ribose polymerase-1 (PARP-1) was downregulated in OSR-treated cells compared with untreated cells. The in vivo experiments identified that OSR significantly inhibited the growth of the transplanted mouse CT26 tumor tissue, upregulated the expression of caspase-3, Bax and cytochrome c and downregulated the expression of Bcl-2 and PARP-1, as detected by reverse transcription-quantitative polymerase chain reaction and western blotting. It may be concluded that OSR significantly induced apoptotic effects on colorectal cancer cells in vivo and in vitro, and that its mechanism may be associated with the Bcl-2/Bax/caspase-3 signaling pathway.

[Reversal of resistance to adriamycin in human breast cancer cell line MCF-7/ADM by silencing AEG-1 gene and its mechanism].

The aim of this study was to investigate the effects of AEG-1 gene silencing on the chemoresistance of human breast cancer cell line MCF-7/ADM and its possible mechanism. MCF-7/ADM cells were incubated in the medium containing adriamycin (ADM). The recombinant pLKO.1-shAEG-1 plasmid was constructed to silence AEG-1 expression in human breast cancer MCF-7/ADM cells. MTT assay was employed to detect the anti-tumor effect of ADM on MCF-7/ADM cells, and IC50 value of ADM was calculated according to MTT. Flow cytometry was used to determine the apoptosis. Western blot was used to analyze the expression levels of AEG-1, p-Akt, p-MDM2, p-Bad, p53 and MDR1. The result showed MCF-7/ADM had a significantly higher expression level of AEG-1 compared with that of MCF-7 (P < 0.05), however, the expression of AEG-1 was decreased after AEG-1 gene silencing. The IC50 value of ADM in shAEG-1 group was significantly lower than that in shcontrol group. AEG-1 gene silencing induced cell apoptosis and enhanced the pro-apoptotic effect of ADM on MCF-7/ADM cells. After AEG-1 gene silencing, the phosphorylation of Akt, MDM2 and Bad was inhibited (P < 0.05), the protein levels of p53 and MDR1 were up-regulated (P < 0.05) and down-regulated (P < 0.05) respectively, compared with control. In conclusion, the results suggest that AEG-1 gene silencing can reverse the ADM resistance in human breast cancer cell line MCF-7/ADM by means of inducing apoptosis and down-regulating the protein level of MDR1.

IGFBP-rP1 induces p21 expression through a p53-independent pathway, leading to cellular senescence of MCF-7 breast cancer cells.

OBJECTIVES: Insulin-like growth factor-binding protein (IGFBP)-related protein 1 (IGFBP-rP1), a member of the IGFBP super family, was identified as a potent tumor suppressor in several carcinomas. IGFBP-rP1 was down-regulated in primary breast cancer tissues and several breast cancer cell lines but overexpressed in senescent human mammary epithelial cells (HMECs), suggesting that IGFBP-rP1 might be a tumor suppressor in breast cancer and the tumor suppressor role of IGFBP-rP1 might be associated with cellular senescence. The aim of the study was to observe the effect of IGFBP-rP1 on cellular senescence and the molecular events mediating this biological effect in MCF-7 breast cancer cells. METHODS: DNA fragment-encoding IGFBP-rP1 was cloned in-frame N-terminally to EGFP gene to generate IGFBP-rP1-EGFP fusion protein expression plasmid (pEGFP-IGFBP-rP1). The plasmid pEGFP-IGFBP-rP1 was then transfected into MCF-7 cells, and the proliferation, cell cycle distribution, cellular senescence, and cell cycle-related protein expression of MCF-7 cells were examined by trypan blue exclusion, flow cytometry, senescence-associated galactosidase (SA-ß-gal) staining, and Western blot analysis, respectively. Two shRNA plasmid vectors against p21 or p53 gene were constructed and stably transfected into the MCF-7 cells to determine the involvement of p21 or p53 in cellular senescence induced by IGFBP-rP1. RESULTS: Transfection of IGFBP-rP1 or addition of condition medium (CM) from IGFBP-rP1-transfected cells in MCF-7 cells caused induction of a variety of senescent phenotypes, such as decrease in cell proliferation, increase in G0/G1 cell cycle arrest cells, change in cell morphology, and increase in senescence-associated galactosidase (SA-ß-gal) activity. IGFBP-rP1-induced growth arrest is associated with enhanced expression of the cyclin-dependent kinase inhibitor p21 and dephosphorylation of the retinoblastoma protein (pRB). Cell proliferation block and cellular senescence induction in response to IGFBP-rP1 were partially reversed by p21 knockdown in MCF-7 cells. Knockdown of p53 in MCF-7 cells did not influence the growth inhibition, cellular senescence, and p21 expression of the cells in response to IGFBP-rP1 transfection. CONCLUSIONS: Results from this study suggest that cellular senescence induced by IGFBP-rP1 is mediated at least in part by p21 enhanced expression, which regulated through the p53-independent pathway. IGFBP-rP1 might be one of the key molecules that trigger cellular senescence in breast cancer. Restoration of IGFBP-rP1 function might have therapeutic significance in breast cancer.

[Study of human papillomavirus in biopsy tissue specimens of esophageal carcinomas in Linzhou city].

OBJECTIVE: To investigate the prevalence of human papillomavirus (HPV), particularly of high-risk HPV in biopsy tissue specimens of esophageal carcinomas in Linzhou city. METHODS: General nested primer sets were used to detected the whole HPV genotypes, following by HPV16 and 18 type specific PCR for the HPV16 and 18 detection respectively. RESULTS: All 18 biopsy samples were HPV positive, and HPV 16 was detected in 13 of the 18 samples, HPV 18 was detected in 4 of the 18 samples. CONCLUSION: The high rate of HPV in the esophageal carcinoma samples suggested that HPV infection may be an important etiologic factor in the development of esophageal cancer in Linzhou city.

[Clinical observation on drug-separated moxibustion at Shenque (CV 8) for treatment of infantile autumn diarrhea].

OBJECTIVE: To observe therapeutic effect of drug-separated moxibustion at Shenque (CV 8) for treatment of infantile autumn diarrhea. METHODS: One hundred and thirty-six cases were randomly divided into an obser vation group and a control group, 68 cases in each group. The observation group were treated with drug-separated moxibustion at Shenque (CV 8) and the control group with oral administration of Smecta. The mean diarrhea-stopping time, the negative conversion rate of Human Rotavirus antigen in stool after treatment for 72 h, and the markedly-effective rate and the total effective rate were observed after treatment for 6 days in the twO groups. RESULTS: The markedly-effective rate and the total effective rate were 79.4% and 94.1% in the observation group and 35.3% and 75.0% in the control group, respectively, with very significantly or significantly difference between the two groups (P < 0.01 or P < 0.05); the mean diarrhea-stopping time in the observation group was shorter than that in the control group (P < 0.01); the negative conversion rate of Human Rotavirus antigen in stool after treatment for 72 h was 88.2%0 in the observation group and 69.1% in the control group with a very significantly difference between the two groups (P < 0.01). CONCLUSION: Drug-separated moxibustion at Shenque (CV 8) has a significant therapeutic effect on infantile autumn diarrhea, helps negative conversion of Human Rotavirus antigen in stool and shortens duration of disease.