[Expression and clinical significance of miR-23a and metastasis suppressor 1 in colon carcinoma].

OBJECTIVE: To investigate the expression of miR-23a and metastasis suppressor 1 (MTSS1) and their clinical significance in colon carcinoma. METHODS: A total of 92 cases of colon carcinomas were collected with both the tumor and paired normal tissue samples for the study. The miR-23a targeting MTSS1 was evaluated by luciferase reporter vector. Cell invasion potential was evaluated by trans-well invasion assay. In-situ hybridization and immunohistochemistry were used to detect miR-23a and MTSS1 expression. RESULTS: MiR-23a downregulated the expression of MTSS protein and enhanced the invasiveness of colon carcinoma. The expression rates of miR-23a and MTSS1 were 87.0% (80/92) and 17.4% (16/92) in colon carcinoma cases, respectively (P < 0.01). The up-regulation of miR-23a expression was associated with an advanced clinical stage (P = 0.029) and depth of invasion (P = 0.000). The expression of miR-23a was higher in the tumors with lymph node metastasis than those without (P = 0.041). Down-regulation of MTSS1 expression was associated with an advanced clinical stage (P = 0.027) and depth of invasion (P = 0.017). The expression of MTSS1 was lower in the tumors with lymph node metastasis than those without (P = 0.009). The expression of miR-23a had significantly negative correlation with that of MTSS1 (r = -0.594, P = 0.013). CONCLUSIONS: MiR-23a expression promotes colon carcinoma cell growth, invasion and metastasis through inhibition of MTSS gene. Both the low expression of MTSS1 and high expression of miR-23a may serve as important biological markers for the malignant phenotypes of colon cancer, such as invasion and metastasis.

Erk is involved in the differentiation induced by diallyl disulfide in the human gastric cancer cell line MGC803.

Diallyl disulfide (DADS) is a major constituent of garlic. Previously, we found that DADS both inhibited proliferation in human gastric cancer cells in vitro and in vivo, and induced G2/M arrest. In this study, we investigated whether this differentiation effect was induced by DADS in human gastric cancer MGC803 cells, and whether it was related to an alteration in ERK activity. The results showed that the growth of MGC803 cells was inhibited by DADS. Cells treated with DADS displayed a lower nucleocytoplasmic ratio and tended to form gland and intercellular conjunction structures. The ConA-mediated cell agglutination ratio and cells' ALP specific activity decreased. In MGC803 cells, dye transfer was limited to a few cells neighbouring the dye-injected cell and to a depth of 1-2 layers beneath the scrape site. However, after treatment with DADS, the LY (Lucifer Yellow) was transferred to several cells immediately neighbouring the microinjected cell and to a depth of 2-4 cell layers from the scrape site. This indicated that DADS induced differentiation in MGC803 cells. Western blot analysis revealed that although DADS did not influence the quantity of ERK1/2 protein expressed, it did decrease its phosphorylation in a concentration-dependent manner, compared with the controls. At 30 mg x L(-1), DADS inhibited the activation of ERK1/2 in 15-30 min. These results suggested that the DADS-induced differentiation of MGC803 cells involved an alteration of the ERK1/2 signaling pathway.

Differential gene and protein expression in primary gastric carcinomas and their lymph node metastases as revealed by combined cDNA microarray and tissue microarray analysis.

OBJECTIVE: To gain insight into the molecular events of lymph node metastasis of human gastric carcinoma. METHODS: The gene expression profile of five matched primary gastric carcinomas and their lymph node metastases was analyzed by complementary DNA (cDNA) microarray. Differential genes were identified in the metastatic and corresponding primary tumor pairs. Among the differentially expressed genes, carbonic anhydrase II (CAII) and insulin-like growth factor binding protein 4 (IGFBP 4) genes were detected by RT-PCR. CTTN protein expression was examined by tissue microarray. RESULTS: There was a high expression (over twofold) of 44 genes and a low expression (under twofold) of 32 genes in lymph node metastasis compared with primary gastric carcinoma, respectively. CAII mRNA was downregulated and IGFBP 4 mRNA was upregulated in paired lymph node metastases of gastric carcinomas. The overexpression of CTTN protein was related to the lymph node metastasis and the clinical stage of gastric carcinomas. CONCLUSION: This study showed that there is a low expression of genes relative to growth signal and immune response in lymph node metastases, and a high expression of genes relative to growth factor, cell cycle, cell motility and adhesion in lymph node metastases compared with primary gastric carcinomas. The expression of CTTN was related to the invasion and metastasis of gastric cancer.

[Effects of aloe gel on doxorubicin-induced extravasation injury in rats].

BACKGROUND AND OBJECTIVE: Aloe has preventive effects on some chemotherapy-induced extravasation injuries. This study was to investigate the effect and mechanism of aloe gel on doxorubicin-induced extravasation injury. METHODS: Sprague-Dawley (SD) rats were used to establish the extravasation injury model induced by doxorubicin. Thirty SD rats were randomly divided into three groups: control group, aloe gel group (1 g/L) and 50% magnesium sulfate group. The area of extravasation was measured and the degree of injury was observed. The injured tissues were resected from two randomly selected rats in each group on the 1st, 4th, 7th, 11th, and 18th day after treatments. Pathological morphology of the resected tissues was observed under an optical microscope after hematoxylin and eosin (HE) staining. The exosmosis skin and subcutaneous tissues of rats were resected five days after treatments. Then the wounds were interruptedly sutured. When sutures were removed on the 7th day after operation, the condition of primary wound healing and the healing time were recorded. Expressions of vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) in the exosmosis skin and subcutaneous tissues were detected by immunohistochemistry. RESULTS: The area and the degree of extravasation injury were smaller and less severe in the aloe gel and magnesium sulfate groups than in the control group (P<0.01). The rates of primary wound healing were significantly higher in the aloe gel (60.0%) and magnesium sulfate (66.7%) groups than in the control group (20.0%); while the healing time was significantly shorter in the aloe gel (9.6+/-1.64 d) and magnesium sulfate (9.33+/-1.40 d) groups than in the control group (12.13+/-2.06 d) (both P<0.01). Moreover, the expression levels of VEGF and EGFR were higher in the aloe gel group than in the control group. CONCLUSION: The preventive and therapeutic effects of aloe gel on doxorubicin-induced extravasation injury are satisfactory, which may be in relation to the up-regulation of VEGF and EGFR.

[Inhibitory effect of diallyl disulfide on proliferation of human colon cancer cell line SW480 in nude mice].

BACKGROUND & OBJECTIVE: Diallyl disulfide (DADS) can inhibit the proliferation of various cancer cell lines in vitro, but little is known about its in vivo antitumor effect. This study was to investigate the inhibitory effect of DADS on the proliferation of human colon cancer cell line SW480 in nude mice. METHODS: After subcutaneous transplantation of SW480 cells in the back of nude mice, 5 mice received intraperitoneal injection of DADS (30 mg/kg), and 5 received intraperitoneal injection of normal saline as control. The body weight of nude mice and tumor growth were measured. The morphology of tumor was observed under optical microscope and electron microscope. The expression of proliferating cell nuclear antigen (PCNA) was detected by immunohistochemistry and morphometric quantitative analysis. Cell cycle distribution was analyzed by flow cytometry (FCM). RESULTS: The growth of transplanted tumor was inhibited markedly by DADS; the relative tumor growth rate (T/C%) was 49.85%. In DADS group, the cellular atypia and nucleus-cytoplasm ratio were decreased, intracytoplasm cellular organs were abundant, and retrograde alters and apoptotic bodies were manifested in some cells. The protein level of PCNA was significantly lower in DADS group than in control group (149.02+/-4.26 vs. 178.86+/-7.69, P<0.05). SW480 cells in DADS group were arrested in G2/M phase; the G2/M phase proportion was significantly higher in DADS group than in control group (38.6% vs. 18.8%, P<0.01). CONCLUSION: DADS has significant inhibitory effect on the proliferation of human colon cancer SW480 cells in nude mice and can arrest cell cycle in G2/M phase.

[Diallyl trisulfide induces apoptosis of human gastric cancer cell line MGC803 through caspase-3 pathway].

BACKGROUND & OBJECTIVE: Garlic and the organosulfer compound from garlic have antitumor effects, but the mechanisms still remain unclear. This study was to investigate the changes and significance of caspase-3 activity in diallyl trisulfide (DATS)-induced apoptosis of human gastric cancer cell line MGC803. METHODS: Effects of DATS on the apoptosis of MGC803 cells and the change of activated caspase-3 were observed under a fluorescent and an electron microscopy, and detected by flow cytometry and Western blot. RESULTS: After incubation with DATS, MGC803 cells showed typical apoptotic morphologic changes, and the apoptosis rate increased significantly. DATS activated caspase-3 in a time-dependent manner: the positive rates of activated caspase-3 were 1.9%, 3.0%, 7.3%, 14.4%, and 27.6% respectively in MGC-803 cells treated with 12 mg/L DATS for 0, 4, 8, 12 and 24 h. When treated with 12 mg/L DATS for 24 h, the apoptosis rate was significantly lower in the cells with pretreatment of Ac-DEVD-CHO (a caspase-3 inhibitor) than in the cells without pretreatment (5.1% vs. 23.0%, P<0.01), indicating that Ac-DEVD-CHO efficiently attenuated DATS-induced apoptosis of MGC803 cells. Moreover, pro-caspase-3 was hydrolyzed and activated in DATS-treated MGC803 cells. CONCLUSION: DATS induces apoptosis in MGC803 cells which may be through the activation of caspase-3 pathway.

[Antitumor effect of diallyl disulfide on human gastric cancer MGC803 cells xenograft in nude mice].

BACKGROUND & OBJECTIVE: Diallyl disulfide (DADS) can inhibit growth of various cancer cell lines in vitro, but little is known about its in vivo antitumor effect. This study was designed to investigate effect of DADS on growth of human gastric carcinoma MGC803 cells xenograft in BALB/C nude mice. METHODS: MGC803 cells, with or without 1-day treatment of DADS (30 mg/L), were subcutaneously transplanted into the right axial regions of nude mice. The xenograft tumor growth in mice was observed after in vitro treatment or intraperitoneal injection of DADS. Proliferating cell nuclear antigen (PCNA) expression was detected by Western blot. RESULTS: No xenograft tumor was observed in the nude mice inoculated with DADS-treated MGC803 cells. When injected with 50, 100, and 200 mg/kg of DADS, the inhibition rate of tumor growth in the nude mice inoculated with untreated MGC803 cells were 27.8%, 66.1%, and 73.0%; the expression of PCNA was inhibited. CONCLUSION: DADS could suppress incidence of human gastric carcinoma xenograft in BALB/C nude mice, and inhibit growth of transplanted tumor.