Yi-Fei Mu

MicroRNA-187 inhibits tumor growth and invasion by directly targeting CD276 in colorectal cancer.

Aberrantly expressed microRNAs contribute to the initiation and progression of human cancers. However, the underlying functions of microRNA-187 (miR-187) in colorectal cancer (CRC) remain largely unexplored. Here, we demonstrated that miR-187 was significantly down-regulated in CRC tissues and cell lines compared to their normal counterparts. By Kaplan-Meier analysis, we revealed that decreased miR-187 expression was closely associated with shorter overall survival and relapse-free survival of patients with CRC. By gain- and loss-of-function studies, we showed that miR-187 remarkably suppressed CRC cell proliferation, migration, invasion, and promoted cell apoptosis. Furthermore, bioinformatics analysis and luciferase reporter assay identified that CD276 was the direct functional target of miR-187 in CRC. Genetic silencing of CD276 recapitulated similar phenotype as observed in over-expression of miR-187, and restoration of CD276 completely rescued the inhibitory effect of miR-187 in CRC cells. Taken together, our study implied the essential roles of miR-187 in suppressing CRC progression, and a novel link between miR-187 and CD276 in CRC.

The clinical impact of ICOS signal in colorectal cancer patients.

ABSTRACT The inducible T-cell co-stimulator (ICOS) belongs to the B7-CD28 immunoglobulin superfamily, which is currently the subject of intense study due to great successes gained in treatment of different malignancies by disrupting their family members. However, the role of ICOS played in colorectal cancer (CRC) remains poorly understood. A tissue microarray (n = 310) was stained with the ICOS specific antibody and ICOS expression is decreased in patients with either lymphatic or distant metastasis and inversely associated with CEA level and TNM stage of CRC patients. Importantly, high ICOS expression is significantly correlated with overall survival (OS) of CRC patients (n = 230, p < 0.001), and ICOS expression is also proved to be an independent prognostic factor by multivariate analysis. Surgical excised CRC specimens (n = 26) were enzymatically digested to get the tumor-infiltrating leukocytes and ICOS is mainly expressed on CD4+ T cells and its ligand ICOSL is detected on macrophages and tumor cells. ICOS expression level is associated with increased cytotoxic T lymphocyte antigen (CTLA)-4 (p < 0.001) and programmed death (PD-1) (p = 0.005) expression on T cells and more infiltrated CD8+ T cells (p < 0.001). Interestingly, ICOS+CD4+ cells isolated from tumor tissues have high T-bet and interferon (IFN)γ expression, the characteristics of Th1 cells, compared to ICOS−CD4+ cells. In addition, the correlation between the percentage of ICOS+CD4+ T cells in tumor tissue and peripheral blood was detected. Conclusively, expression of ICOS is associated with improved survival in CRC and percentage of ICOS+CD4+ cells acting as Th1 cells in either primary tumor tissue or peripheral blood may be a clinical biomarker for good prognosis of CRC patients.

High expression of Rab3D predicts poor prognosis and associates with tumor progression in colorectal cancer.

Rab3D belongs to Rab protein family. Previous reports showed that the expression of Rab3D was dysregulated in various types of cancer. Rab3D belongsRab3D belongs. However, little is known about the role of Rab3D in carcinogenesis and progression of colorectal cancer (CRC). Here, we first evaluated the expression of Rab3D in 32 fresh CRC and matched normal tissues and found Rab3D was dramatically increased in CRC tissues compared to normal tissues (p<0.001). Furthermore, immunochemistry was used to investigate Rab3D expression in 300CRC tissue specimens. The expression of Rab3D significantly positively correlated with the tumor size (p=0.041), CEA level (p=0.007), tumor classification (p=0.030), lymphatic metastasis (p<0.001), distant metastasis (p=0.013) and clinical stage (p=0.003). We also demonstrated that overall survival is poor in CRC patients with high expression of Rab3D (p<0.001). Finally, we showed that Rab3D activated Akt/GSK3β/Snail pathway and induced EMT process in colorectal cancer cells. In conclusion, this study establishes increased Rab3D expression is associated with invasiveness of CRC cells, and Rab3D expression status may serve as a reliable prognostic biomarker in CRC patients.

ATAD2 Overexpression Identifies Colorectal Cancer Patients with Poor Prognosis and Drives Proliferation of Cancer Cells

ATPase family AAA domain-containing 2 (ATAD2) has been identified as a critical modulator involved in cell proliferation and invasion. The purpose of this study was to explore the expression of ATAD2 in CRC tissues as well as its relationship with degree of malignancy. Data containing three independent investigations from Oncomine database demonstrated that ATAD2 is overexpressed in CRC compared with normal tissue, and similar result was also found in 32 pairs of CRC tissues by qPCR. The protein expression of ATAD2 was examined in six CRC cell lines and 300 CRC specimens. The results showed that high expression of ATAD2 was significantly correlated with tumor size (P < 0.001), serum CEA (P = 0.012), lymph node metastasis (P = 0.018), liver metastasis (P = 0.025), and clinical stage (P = 0.004). Kaplan-Meier method suggested that higher ATAD2 protein expression significantly associated with the overall survival (OS) of CRC patients (P < 0.001) and was an independent predictor of poor OS. Functional studies showed that suppression of ATAD2 expression with siRNA could significantly inhibit the growth in SW480 and HCT116 cells. These results indicated that ATAD2 could serve as a prognostic marker and a therapeutic target for CRC.

Elevated expression of ECT2 predicts unfavorable prognosis in patients with colorectal cancer.

Epithelial cell transforming sequence 2 (ECT2) is a well-studied guanine nucleotide exchange factor for the Rho family GTPase, which has been demonstrated as an oncogene in many types of human cancers. However, little is known about the prognostic value of ECT2 in colorectal cancer (CRC). In current study, we investigated the expression pattern and underlying clinical significance of ECT2 in CRC. ECT2 expression was detected in 345 CRC specimens by immunohistochemistry, and its correlation with clinicopathologic parameters and prognosis of CRC patients were analyzed. Data from Oncomine database and real-time PCR demonstrated that ECT2 expression was elevated in CRC compared with normal tissues. Among the clinical parameters analyzed, high expression level of ECT2 significantly associated with tumor size (P=0.020), serum CEA levels (P = 0.000) and TNM stage (P=0.027). Kaplan-Meier survival analysis showed that patients with high ECT2 expression had a remarkably shorter overall survival. Cox regression analysis revealed that ECT2 expression level was a significant and independent prognostic factor for overall survival rate of CRC patients. These data suggested that ECT2 is an unfavorable biomarker of prognosis in CRC and that ECT2 may be a potential therapeutic candidate for CRC treatment.

Prognostic value of regulator of G-protein signaling 6 in colorectal cancer.

Reprogrammed metabolism is a hallmark of cancer cells. Regulator of G-protein signaling 6 (RGS6), which is frequently down-regulated in multiple human malignancies, has been demonstrated to play a critical function in energy metabolism, cell apoptosis and tumorigenesis. However, limited knowledge is known about the expression pattern and prognostic value of RGS6 in colorectal cancer (CRC). In this study, we first observed that RGS6 mRNA and protein is commonly downregulated in 32 paired CRC tissues compared with their normal counterparts. Furthermore, by a large scale of immunohistochemical analysis in a tissue microarray containing 310 cases of CRC specimens, we demonstrated that the protein expression of RGS6 expression is downregulated in 40.97% (127/310) samples and detected that decreasing RGS6 expression is closely correlated with enhanced tumor size, CEA level, T classification, TNM stage, and easier lymphatic and distant metastasis. Meanwhile, Kaplan-Meier survival analysis showed that CRC patients with a lower RGS6 expression have a poorer clinical outcome than those with a higher RGS6 expression. Multivariate Cox regression analysis revealed that RGS6, lymphatic metastasis and distant metastasis are the independent prognostic factors for overall survival rate of CRC patients. Taken together, our studies reveal the prognostic value of RGS6 in CRC and support that RGS6 may act as a molecular target for CRC treatment.

The role of MRP1 in the multidrug resistance of colorectal cancer

The role of multidrug resistance associated protein 1 (MRP1) in the multidrug resistance (MDR) of colorectal cancer (CRC) remains unclear. The present study aimed to investigate the effect of MRP1 in MDR CRC and its therapeutic potential for the treatment of patients with this disease. The human MDR CRC cell lines HCT-8 and Colo205 were established through stable exposure to 5-florouracil (5-FU) over a 5-month period. MRP1 was knocked-down in MDR CRC cells through the transfection of short hairpin RNA targeting MRP1 (shMRP1). Western blotting was performed to assess the efficiency of this silencing. MTT and apoptosis assays were conducted to detect cell viability and apoptosis, respectively. Compared with their parental cells, HCT-8/5-FU and Colo205/5-FU cells were 23.1 and 15.8 times more resistant to 5-FU, and 17.2 and 20.9 times more resistant oxaliplatin, respectively. The knockdown of MRP1 resulted in the attenuation of the MDR phenotype through the induction of apoptosis. The shMRP1-transfected Colo205/5-FU cells were injected subcutaneously into the right scapular region of BALB/c nude mice and tumor size was measured for 15 days post-injection. This in vivo experiment demonstrated that MRP1 knockdown inhibited tumor growth. On the 9, 12 and 15th day post-injection, tumor volume in the shMRP1-transfected Colo205/5-FU cell-injected group was significantly lower compared with that in the Colo205/5-FU cell-injected group (day 9, 2.1±0.8 vs. 6.9±1.9 mm3, P=0.009; day 12, 3.1±1.4 vs. 14.3±4.0 mm3, P=0.008; day 15, 4.8±2.7 vs. 21.3±3.4 mm3; all P<0.001). These results demonstrate that MRP1 serves a role in the MDR phenotype of CRC through inhibiting apoptosis and may serve as a potential therapeutic target for inhibition, which would increase the efficacy of other chemotherapeutic agents in the treatment of CRC.

Plastic wound protectors decreased surgical site infections following laparoscopic-assisted colectomy for colorectal cancer: A retrospective cohort study

Abstract Laparoscopic surgery is widespread and safe for the management of patients with colorectal cancer (CRC). Although the use of standard surgical techniques can prevent perioperative wound infections, surgical site infections (SSIs) remain an unresolved complication in laparoscopic-assisted colectomy. The present study investigated the ability of plastic wound protectors applied to the extraction incision during the externalized portion of the procedure to reduce the rate of infection in laparoscopic-assisted colectomy. We completed a retrospective review of the medical records of patients who underwent nonemergent laparoscopic-assisted between January 2015 and June 2016. Outcomes for patients with and without the use of a wound protector were compared. A total of 109 patients were included in this study. There was 1 patient in the wound protector group (n = 57) and 7 in the nonwound protector group (n = 52) who developed a wound infection at the colon extraction site (P = .02). Furthermore, the average postoperative hospital stay in the wound protector group was shorter compared to the nonwound protector group (7.47 ± 0.24 vs 8.73 ± 0.54 days, P = .03). In conclusion, this study indicates that the use of a plastic wound protector during laparoscope-assisted colectomy does reduce postoperative wound infection rates, and the wound protectors are beneficial for specimen extraction and digestive tract reconstruction.

Odontogenic ameloblast-associated protein (ODAM) inhibits human colorectal cancer growth by promoting PTEN elevation and inactivating PI3K/AKT signaling

Odontogenic ameloblast-associated protein (ODAM), an acidic matricellular protein, has been implicated in several epithelial neoplasms. However, its biological functions and molecular mechanisms in cancer progression, particular colorectal carcinoma (CRC), remain unknown. Here we demonstrated that ODAM was significantly down-regulated in CRC tissues compared with their normal counterparts. Then, we established that ODAM expression level was closely correlated with CRC development and patient prognosis. The abnormal expression of ODAM dramatically affected CRC cell growth in vitro and in vivo. We further revealed that the inhibitory effects of ODAM on CRC cell growth were associated with PTEN elevation and PI3K/AKT signaling inactivation. Furthermore, we determined that silencing of PTEN expression yielded recovery of AKT activity in ODAM-expressing CRC cells. Our study suggests matricellular protein ODAM may serve as a novel prognostic marker and act as a CRC growth suppressor.