Decreased expression of miR-133a correlates with poor prognosis in colorectal cancer patients

AIM: To investigate microRNA-133a(miR-133a) expression in colorectal cancer(CRC) and its relationship with tumorigenesis and disease prognosis.METHODS: Quantitative real-time polymerase chain reaction was used to measure levels of miR-133 a in tumor samples and adjacent non-cancerous tissues from 169 patients undergoing radical resection for CRC. The associations between miR-133 a expression and patient age, sex, as well as clinicopathologic parameters, such as tumor size, differentiation, location, invasion depth, metastasis, tumor-node-metastasis(TNM) stage and overall patient survival, were analyzed by MannWhitney U and Kruskal-Wallis tests. The Kaplan-Meier method and Cox proportional hazards regression analyses were performed to estimate the prognostic factors for patient survival prediction.RESULTS: The expression of miR-133 a was significantly downregulated in CRC tissues compared with adjacent non-cancerous tissues(P < 0.05). This reduction was associated with the depth of the local invasion, poor differentiation, lymph node metastasis and advanced disease(P < 0.05). Moreover, Kaplan-Meier analysis demonstrated that patients with low miR-133 a expression had poorer overall survival(OS) than those with high miR-133 a expression(P < 0.001). Univariate analysis revealed statistically significant correlations between OS and miR-133 a level, tumor local invasion, lymph node metastasis and TNM stage(P < 0.001). Furthermore, miR-133 a levels and TNM stage were independently associated with OS(HR = 0.590, 95%CI: 0.350-0.995, P < 0.05; and HR = 6.111, 95%CI: 1.029-36.278, P < 0.05, respectively).CONCLUSION: The downregulation of miR-133 a may play an important role in the progression of CRC and can be used as an independent factor to determine CRC prognosis.

Krüppel-like factor 8 overexpression is correlated with angiogenesis and poor prognosis in gastric cancer

AIM:To investigate Krüppel-like factor 8 (KLF8) expression in gastric cancer and its relationship with angiogenesis and prognosis of gastric cancer. METHODS:One hundred and fifty-four patients with gastric cancer who underwent successful curative resection were retrospectively enrolled in the study. Fifty tumor-adjacent healthy gastric tissues (≥ 5 cm from the tumor margin) obtained during the original resection were randomly selected for comparative analysis. In situ expression of KLF8 and CD34 proteins were examined by immunohistochemistry. The intratumoral microvessel density (MVD) was determined by manually counting the immunostained CD34-positive endothelial cells in three consecutive high-magnification fields (× 200). The relationship between differential KLF8 expression and MVD was assessed using Spearman's correlation coefficient test. χ2 test was performed to evaluate the effects of differential KLF8 expression on clinicopathologic factors. Kaplan-Meier and multivariate Cox survival analyses were used to assess the prognostic value of differential KLF8 expression in gastric cancer. RESULTS:Significantly higher levels of KLF8 protein were detected in gastric cancer tissues than in the adjacent non-cancerous tissues (54.5% vs 34.0%, P < 0.05). KLF8 expression was associated with tumor size (P < 0.001), local invasion (P = 0.005), regional lymph node metastasis (P = 0.029), distant metastasis (P = 0.023), and tumor node metastasis (TNM) stage (P = 0.002), as well as the MVD (r = 0.392, P < 0.001). Patients with KLF8 positive expression had poorer overall survival (P < 0.001) and cancer-specific survival (P < 0.001) than those with negative expression. Multivariate analysis demonstrated that KLF8 expression independently affected both overall and cancer-specific survival of gastric cancer patients (P = 0.035 and 0.042, respectively). CONCLUSION:KLF8 is closely associated with gastric tumor progression, angiogenesis and poor prognosis, suggesting it may represent a novel prognostic biomarker and therapeutic target for gastric cancer.