Gene expression profiling demonstrates WNT/ß-catenin pathway genes alteration in Mexican patients with colorectal cancer and diabetes mellitus.

PURPOSE: Several studies have shown a strong association between diabetes mellitus (DM) and increased risk of colorectal cancer (CRC). The fundamental mechanisms that support this association are not entirely understood; however, it is believed that hyperinsulinemia and hyperglycemia may be involved. Some proposed mechanisms include upregulation of mitogenic signaling pathways like MAPK, PI3K, mTOR, and WNT, which are involved in cell proliferation, growth, and cancer cell survival. The purpose of this study was to evaluate the gene expression profile and identify differently expressed genes involved in mitogenic pathways in CRC patients with and without DM. METHODS: In this study, microarray analysis of gene expression followed by quantitative PCR (qPCR) was performed in cancer tissue from CRC patients with and without DM to identify the gene expression profiles and validate the differently expressed genes. RESULTS: Among the study groups, some differently expressed genes were identified. However, when bioinformatics clustering tools were used, a significant modulation of genes involved in the WNT pathway was evident. Therefore, we focused on genes participating in this pathway, such as WNT3A, LRP6, TCF7L2, and FRA-1. Validation of the expression levels of those genes by qPCR showed that CRC patients without type 2 diabetes mellitus (T2DM) expressed significantly more WNT3Ay LRP6, but less TCF7L2 and FRA-1 compared to controls, while in CRC patients with DM the expression levels of WNT3A, LRP6, TCF7L2, and FRA-1 were significantly higher compared to controls. CONCLUSIONS: Our results suggest that WNT/ß-catenin pathway is upregulated in patients with CRC and DM, demonstrating its importance and involvement in both pathologies.

[Use of micro RNAs in the diagnosis and prognosis of colorectal cancer (CCR)]. / Utilidad de los microARN en el diagnóstico y pronóstico del cáncer colorrectal (CCR).

The aim of this review is to present a general overview about the importance of micro RNAs (miRNAs) in colorectal carcinoma. First, we focused on the mechanisms whereby the miRNAs regulate the expression of target genes, and how an altered regulation of them is associated with several types of cancer, including colorectal carcinoma. Later, examples of some miRNAs that have been associated with cancer development and how the expression patterns of specific miRNAs can be used as potential biomarkers for prognosis, diagnosis and therapeutic outcome in colorectal carcinoma are addressed. Finally, several polymorphisms presents in the miRNAs that have been associated to risk and prognosis in colorectal carcinoma are described.

AXIN2 Polymorphisms and Their Association with Colorectal Cancer in Mexican Patients.

AIM: The aim of this study was to investigate the association of the rs2240308 and rs1133683 polymorphisms in the AXIN2 gene with colorectal cancer (CRC) in Mexican patients. MATERIALS AND METHODS: Genomic DNAs from 201 CRC patients and 100 healthy blood donors were analyzed for AXIN2 gene polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology. Statistical associations were calculated using the odds ratio (OR) test. RESULTS: The genotype distribution of the rs1133683 polymorphism C > T showed a statistical difference between the two study groups (p = 0.0019). Moreover, OR analyses demonstrated that individuals with either the C/T or T/T genotype have a decreased risk for CRC compared with individuals with the C/C genotype (OR = 0.47, 95% confidence interval [CI] = 0.25-0.86, p = 0.0134 and OR = 0.24, 95% CI = 0.10-0.57, p = 0.005, respectively). This association was also evident in a stratified analysis based on tumor-node-metastasis (TNM) stage. For the rs2240308 polymorphism C > T, the OR analysis showed a significantly increased risk for carriers of the T/T genotype (OR = 2.64, 95% CI = 1.12-6.24, p = 0.0236) and this association was also evident in the stratified analysis by TNM stage. CONCLUSION: Our results indicate the possibility that variations in the AXIN2 gene may play a significant role in promoting or preventing CRC development.

Modulation of antioxidant defense system after long term arsenic exposure in Zantedeschia aethiopica and Anemopsis californica.

Zantedeschia aethiopica (calla lily) and Anemopsis californica (yerba mansa) are plant species capable of accumulating arsenic (As) and therefore proposed as phytoremediation for removal of As from drinking water. The effects of a continuous 6 month As exposure (34±11 µg/L) from local contaminated groundwater on the antioxidant response of Z. aethiopica and A. californica were evaluated in leaves and stems of the plants bimonthly in a subsurface flow constructed wetland. As increased the activities of the antioxidant enzymes ascorbate peroxidase, glutathione reductase and catalase where higher levels were observed in Z. aethiopica than A. californica. No significant differences were detected on lipid peroxidation levels or antioxidant capacity evaluated by ORAC and DPPH assays or total phenol contents in any part of the plant, although in general the leaves of both plants showed the best antioxidant defense against the metal. In conclusion, Z. aethiopica and A. californica were able to cope to As through induction of a more sensitive enzymatic antioxidant response mechanism.