Simultaneous Analysis of SEPT9 Promoter Methylation Status, Micronuclei Frequency, and Folate-Related Gene Polymorphisms: The Potential for a Novel Blood-Based Colorectal Cancer Biomarker.

One challenge in colorectal cancer (CRC) is identifying novel biomarkers to be introduced in screening programs. The present study investigated the promoter methylation status of the SEPT9 gene in peripheral blood samples of subjects' positive fecal occult blood test (FOBT). In order to add new insights, we investigated the association between SEPT9 promoter methylation and micronuclei frequency, and polymorphisms in the folate-related pathway genes. SEPT9 promoter methylation, micronuclei frequency, and genotypes were evaluated on 74 individuals' FOBT positive. Individuals were subjected to a colonoscopy that provided written informed consent for study participation. SEPT9 promoter methylation status was significantly lower in the CRC group than controls (p = 0.0006). In contrast, the CaCo2 cell-line, analyzed as a tissue specific model of colon adenocarcinoma, showed a significantly higher percentage of SEPT9 promoter methylation compared to the CRC group (p < 0.0001). Linear regression analysis showed an inverse correlation between micronuclei frequency and the decrease in the methylation levels of SEPT9 promoter region among CRC patients (ß = -0.926, p = 0.0001). With regard to genotype analysis, we showed the involvement of the DHFR polymorphism (rs70991108) in SEPT9 promoter methylation level in CRC patients only. In particular, the presence of at least one 19 bp del allele significantly correlates with decreased SEPT9 promoter methylation, compared to the 19 bp ins/ins genotype (p = 0.007). While remaining aware of the strengths and limitations of the study, this represents the first evidence of a novel approach for the early detection of CRC, using SEPT9 promoter methylation, micronuclei frequency and genotypes, with the potential to improve CRC risk assessment.

Micronucleus frequency in human peripheral blood lymphocytes as a biomarker for the early detection of colorectal cancer risk.

The early detection of colorectal cancer (CRC) can significantly improve the prognosis of affected patients. The loss of genomic stability and the resulting gene alteration play an important role in the molecular pathological steps that occur early in tumorigenesis of CRC. Thus, the identification of non-invasive biomarkers, whose function may provide useful insights into critical early events in the CRC process, is of great interest. In this regard, micronucleus (MN) frequency in peripheral blood lymphocytes (PBL) has become one of the most established biomarkers for studying DNA damage in the human population. This study investigated the MN frequency in the PBL of 82 subjects (30 females and 52 males; aged 50-70 years) who were participating in a screening programme for CRC prevention. All 82 patients were positive in fecal occult blood tests and they were subsequently classified, according to colonoscopy and histological findings, as patients with CRC, patients with colon polyps or subjects without intestinal lesion, referred to as study controls. This study also examined the relationship between the plasma clastogenic activity and the frequency of micronuclei of the study population. The MN frequency was significantly higher in CRC patients than in both colon polyp patients (16.82±6.56 versus 12.23±1.88; P = 0.002) and controls (16.82±6.56 versus 8.00±1.77; P < 0.001). An increased MN frequency was detected in the lymphocytes of the polyp group in comparison to the control group, although this was lower than that observed in CRC patients (12.23±1.88 versus 8.00±1.77; P < 0.001). In the overall study population, the increase of MN frequency, which was observed in the lymphocytes of the subjects involved, was significantly associated with the clastogenic activity detected in their plasma (r = 0.594, P < 0.001). Overall, the results suggest that the MN test can become a promising biomarker for the early detection of CRC.

Neuroprotective effect of sulforaphane in 6-hydroxydopamine-lesioned mouse model of Parkinson's disease.

Parkinson's disease (PD) is characterized by the selective loss of dopaminergic nigrostriatal neurons, which leads to disabling motor disturbances. Sulforaphane (SFN), found in cruciferous vegetables, is a potent indirect antioxidant and recent advances have shown its neuroprotective activity in various experimental models of neurodegeneration. This study was undertaken to examine the effects of SFN on behavioral changes and dopaminergic neurotoxicity in mice exposed to 6-hydroxydopamine (6-OHDA). For this purpose, mice were treated with SFN (5mg/kg twice a week) for four weeks after the unilateral intrastriatal injection of 6-OHDA. The increase in 6-OHDA-induced rotations and deficits in motor coordination were ameliorated significantly by SFN treatment. In addition, SFN protected 6-OHDA-induced apoptosis via blocking DNA fragmentation and caspase-3 activation. These results were further supported by immunohistochemical findings in the substantia nigra that showed that SFN protected neurons from neurotoxic effects of 6-OHDA. The neuroprotective effect of SFN may be attributed to its ability to enhance glutathione levels and its dependent enzymes (glutathione-S-transferase and glutathione reductase) and to modulate neuronal survival pathways, such as ERK1/2, in the brain of mice. These results suggest that SFN may potentially be effective in slowing down the progression of idiopathic PD by the modulation of oxidative stress and apoptotic machinery.