Xishan Wang

MicroRNA-93 suppress colorectal cancer development via Wnt/β-catenin pathway downregulating.

MicroRNA-93 (miR-93) is involved in several carcinoma progressions. It has been reported that miR-93 acts as a promoter or suppressor in different tumors. However, till now, the role of miR-93 in colon cancer is unclear. Herein, we have found that expression of miR-93 was lower in human colon cancer tissue and colorectal carcinoma cell lines compared with normal colon mucosa. Forced expression of miR-93 in colon cancer cells inhibits colon cancer invasion, migration, and proliferation. Furthermore, miR-93 may downregulate the Wnt/β-catenin pathway, which was confirmed by measuring the expression level of the β-catenin, axin, c-Myc, and cyclin-D1 in this pathway. Mothers against decapentaplegic homolog 7 (Smad7), as an essential molecular protein for nuclear accumulation of β-catenin in the canonical Wnt signaling pathway, is predicted as a putative target gene of miR-93 by the silico method and demonstrated that it may be suppressed by targeting its 3′UTR. These findings showed that miR-93 suppresses colorectal cancer development via downregulating Wnt/β-catenin, at least in part, by targeting Smad7. This study revealed that miR-93 is an important negative regulator in colon cancer and suggested that miR-93 may serve as a novel therapeutic agent that offers benefits for colon cancer treatment.

Role of MicroRNA 30a Targeting Insulin Receptor Substrate 2 in Colorectal Tumorigenesis

ABSTRACT MicroRNAs (miRNAs) are dysregulated in many types of malignant diseases, including colorectal cancer. miRNA 30a (miR-30a) is a member of the miR-30 family and has been implicated in many types of cancers. In this study, we determined the expression of miR-30a in human colon cancer tissues and cell lines. miR-30a was found to be significantly downregulated in both the tissues and cell lines. Furthermore, overexpression of miR-30a inhibited, while silencing of miR-30a promoted, cell proliferation, migration, and invasion in vitro. Consistently, stable overexpression of miR-30a suppressed the growth of colon cancer cell xenografts in vivo. Moreover, bioinformatic algorithms and luciferase reporter assays revealed that insulin receptor substrate 2 (IRS2) is a direct target of miR-30a. Further functional studies suggested that repression of IRS2 by miR-30a partially mediated the tumor suppressor effect of miR-30a. In addition, miR-30a inhibited constitutive phosphorylation of Akt by targeting IRS2. Additionally, clinicopathological analysis indicated that miR-30a has an inverse correlation with the staging in patients with colon cancer. Taken together, our study provides the first evidence that miR-30a suppressed colon cancer cell growth through inhibition of IRS2. Thus, miR-30a might serve as a promising therapeutic strategy for colon cancer treatment.

Elevated Mean Platelet Volume is Associated with Presence of Colon Cancer

BACKGROUND Colon cancer is the second most common cancer in developed countries. Activated platelets play a key role in inflammation and atherothrombosis, with mean platelet volume (MPV) is an early marker of platelet activation. The aim of the study was to clarify the relevance of MPV in patients with colon cancer. MATERIALS AND METHODS We measured MPV levels in 128 patients with colon cancer before and after surgery, and 128 controls matched for age, gender, body mass index (BMI) and smoking status. The odds ratios (ORs) and 95% confidence intervals (CIs) for colon cancer were calculated using multivariate logistic regression analyses across MPV quartiles. RESULTS Patients with colon cancer had higher MPV compared with controls. Surgical tumor resection resulted in a significant decrease in MPV levels (11.4 fL vs 10.7 fL; p<0.001). A positive correlation between MPV and tumor-nodule-metastases (TNM) stage was found. Furthermore, after adjusting for other risk factors, the ORs (95%CIs) for colon cancer according to MPV quartiles were 1.000, 2.238 (1.014-4.943), 3.410 (1.528-7.613), and 5.379 (2.372-12.198), respectively. CONCLUSIONS The findings show that patients with colon cancer have higher MPV levels compared with controls, and these are reduced after surgery. In addition, MPV was found to be independently associated with the presence of colon cancer. Further studies are warranted to assess the utility of MPV as a novel diagnostic screening tool for colon cancer.

Role of microRNA-30c Targeting ADAM19 in Colorectal Cancer

MicroRNAs (miRNAs) are deregulated in a number of cancers including colorectal cancer. MiR-30c belongs to miR-30 family, and is involved in a variety of malignant diseases. In this study, we detected the expression of miR-30c in colon cancer cell lines and clinical colon cancer specimens. MiR-30c was shown to be dramatically down-regulated both in cell lines and cancer tissues. Additionally, miR-30c could inhibit cancer cell growth, migration and invasion in vitro. Consistently, stable over-expression of miR-30c inhibited the growth and lung metastasis of colon cancer cell xenografts in vivo. Furthermore, bioinformatics algorithm and luciferase reporter assay indicated ADAM19 as a direct target of miR-30c. Of interest, further experiments demonstrated that inhibition of ADAM19 by miR-30c partially mediated the anti-tumor effect of miR-30c. Overall, our study provides the new insight that miR-30c inhibited colon cancer cells via targeting ADAM19. Thus, miR-30c might serve as a promising therapeutic strategy for colon cancer treatment.

Association Between Polymorphism of the Tumor Necrosis Factor Alpha-308 Gene Promoter and Colon Cancer in the Chinese Population

Tumor necrosis factor (TNF) is a type of cytokine that inhibits tumorigenesis. Several studies have assessed the relationship between the polymorphism of TNF-alpha 308G/A and the susceptibility to colon cancer; however, the results have been controversial. A case-control study was carried out to investigate whether TNF-alpha 308G/A gene polymorphism was associated with the risk of colon cancer in a group of 180 cases and 180 controls from Heilongjiang, China. DNA was isolated from peripheral blood, and gene polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism. Results of our study showed that colon cancer cases had a significantly higher frequency of TNF-alpha 308AA genotype (odds ratio=9.42, 95% confidence interval=1.18, 75.15; p=0.03) than controls. When stratified by the tumor location, tumor size, growth pattern, differentiation, and stage of colon cancer, no statistically significant results was observed. The present study demonstrated that TNF-alpha 308AA genotype was associated with a higher risk of colon cancer in the Chinese population. Confirmation of these findings in other populations is required.

Colorectal cancer stem cell and chemoresistant colorectal cancer cell phenotypes and increased sensitivity to Notch pathway inhibitor

Colorectal cancer stem cells (Co-CSCs) are a small subpopulation of tumor cells which have been proposed to be tumor-initiating cells in colorectal cancer (CRC) and to be implicated in resistance to standard chemotherapy. Chemoresistance is a common problem in the clinic. However, the interrelation between Co-CSCs and chemoresistant cells has yet to be elucidated. The present study investigated the Co-CSC phenotype in colonospheres and chemoresistant CRC cell lines and aimed to identify targets for therapy. Colonospheres and chemoresistant CRC cells were found to be enriched with the CSC markers CD133 and CD44, and exhibited similar phenotypes. Furthermore, it was found that Notch signaling may simultaneously regulate Co-CSCs and chemoresistant cells and may represent a novel strategy for targeting this pathway in CRC.

The role of EGFR monoclonal antibodies (MoABs) cetuximab/panitumab, and BRAF inhibitors in BRAF mutated colorectal cancer

Metastatic Colorectal Cancer (mCRC) is the third most common cancer and one of the leading causes of cancer-related death worldwide and accounting for 40% to 50% of newly diagnosed patients with high mortality rates. The 5-year overall survival (OS) is very low, which is 18 to 21 months even with the advancement of chemotherapeutic treatment. Two monoclonal antibodies (MoAbs), Cetuximab and Panitumumab, which target Epidermal Growth Factor Receptor (EGFR), have been approved more recently to treat mCRC.

Anti-colorectal cancer activity of macrostemonoside A mediated by reactive oxygen species

Macrostemonoside A (MSS.A), an active steroidal saponin from Allium macrostemon Bung has been shown to possess anti-coagulation and anti-obesity effects. However, the functional role of MSS.A on tumor growth has not been elucidated. We found that MSS.A significantly inhibited human colorectal cancer cell growth in Caco2 and SW480 cells. Incubation of SW480 cells with MSS.A for 48 h resulted in cell cycle arrest. Moreover, MSS.A dose-dependently induced apoptosis in SW480 cells as shown by increased AnnexinV positively stained cell population, caspase activation, increased pro-apoptotic and reduced anti-apoptotic Bcl-2 family protein levels. Treatment of SW480 cells with MSS.A resulted in increased reactive oxygen species (ROS) generation. However, pre-incubation of SW480 cells with antioxidant N-acetylcysteine (NAC) attenuated the ROS generation and anti-colorectal cancer activities of MSS.A. Lastly, intra-peritoneal injections of MSS.A significantly inhibited tumor formation in BALB/c nude mice carcinogenesis xenograft model by reduced tumor volume and tumor weight when treated at dosages of 10, 50 or 100mg/kg daily for 35 days compared with PBS control. Taken together, our results indicate that MSS.A suppressed colorectal cancer growth and induced cell apoptosis by inducing ROS production, and that MSS.A may have therapeutic relevance in the treatment of human colorectal cancer.

Novel irreversible EGFR tyrosine kinase inhibitor 324674 sensitizes human colon carcinoma HT29 and SW480 cells to apoptosis by blocking the EGFR pathway

BACKGROUND Epidermal growth factor receptor (EGFR) is widely expressed in multiple solid tumors including colorectal cancer by promoting cancer cell growth and proliferation. Therefore, the inhibition of EGFR activity may establish a clinical strategy of cancer therapy. METHODS In this study, using human colon adenocarcinoma HT29 and SW480 cells as research models, we compared the efficacy of four EGFR inhibitors in of EGFR-mediated pathways, including the novel irreversible inhibitor 324674, conventional reversible inhibitor AG1478, dual EGFR/HER2 inhibitor GW583340 and the pan-EGFR/ErbB2/ErbB4 inhibitor. Cell proliferation was assessed by MTT analysis, and apoptosis was evaluated by the Annexin-V binding assay. EGFR and its downstream signaling effectors were examined by western blotting analysis. RESULTS Among the four inhibitors, the irreversible EGFR inhibitor 324674 was more potent at inhibiting HT29 and SW480 cell proliferation and was able to efficiently induce apoptosis at lower concentrations. Western blotting analysis revealed that AG1478, GW583340 and pan-EGFR/ErbB2/ErbB4 inhibitors failed to suppress EGFR activation as well as the downstream mitogen-activated protein kinase (MAPK) and PI3K/AKT/mTOR (AKT) pathways. In contrast, 324674 inhibited EGFR activation and the downstream AKT signaling pathway in a dose-dependent manner. CONCLUSION Our studies indicated that the novel irreversible EGFR inhibitor 324674 may have a therapeutic application in colon cancer therapy.

Cost Comparison Between Hand-Assisted Laparoscopic Colectomy and Open Colectomy

PURPOSE Our aim was to compare the costs associated with hand-assisted laparoscopic colectomy (HALC) and open colectomy (OC). METHODS The data of patients who underwent either HALC or OC between March 2009 and August 2010 were retrospectively reviewed. The assessed short-term outcomes included operative time, blood lost, retrieved lymph nodes, conversion rates, and complications. Direct costs of operating room, nursing, intensive care, anesthesia, laboratory, pharmacy, radiology, and other costs related to initial hospitalization were compared. RESULTS Forty-two patients underwent HALC, whereas 45 underwent OC. Demographics in both groups were similar. The HALC patients had significantly shorter hospital stays and incision lengths, faster recovery of bowel function, and less blood loss (P<.001). There were no significant differences in operative time (169 minutes for HALC versus 171 minutes for OC), complication rates, or the number of retrieved lymph nodes. Although operative costs were higher for HALC (US