AIM: To investigate the genotype frequencies of MLH1 promoter polymorphism -93G>A and to determine whether it could play any role in modulating familial and sporadic CRC susceptibility risk.
METHODS: A case-control study comprising of 104 histopathologically confirmed CRC patients as cases (52 sporadic CRC and 52 Lynch syndrome patients) and 104 normal healthy individuals as controls was undertaken. DNA was extracted from peripheral blood and the polymorphism was genotyped employing PCR-RFLP methods. The genotypes were categorized into homozygous wild type, heterozygous and homozygous variants. The risk association between these polymorphisms and CRC susceptibility risk was calculated using binary logistic regression analysis and deriving odds ratios (ORs).
RESULTS: When risk association was investigated for all CRC patients as a single group, the heterozygous (G/A) genotype showed a significantly higher risk for CRC susceptibility with an OR of 2.273, (95%CI: 1.133-4.558 and p-value=0.021). When analyzed specifically for the 2 types of CRC, the heterozygous (G/A) genotype showed significantly higher risk for sporadic CRC susceptibility with and OR of 3.714, (95%CI: 1.416-9.740 and p-value=0.008). Despite high OR value was observed for Lynch syndrome (OR: 1.600, 95%CI: 0.715-3.581), the risk was not statistically significant (P=0.253).
CONCLUSION: Our results suggest an influence of MLH1 promoter polymorphism -93G>A in modulating susceptibility risk in Malaysian CRC patients, especially those with sporadic disease.
METHODS: Various techniques including qRT-PCR, western blotting, and immunohistochemistry assays were utilized to examine gene expression patterns. Functional assays such as wound-healing assay, transwell invasion assay, 5-Ethynyl-2'-deoxyuridine assay, and metabolic assays were conducted to assess the impact of CEP55 on the behaviors of TNBC cells. CD163-positive macrophages were quantified by flow cytometry. The chromatin immunoprecipitation assay and dual-luciferase reporter assay were performed to assess the association of SPI1 with CEP55. A xenograft mouse model experiment was used to analyze the impact of SPI1 on tumor development in vivo.
RESULTS: CEP55 and SPI1 expression levels were significantly upregulated in TNBC tissues and cells. The depletion of CEP55 led to decreased TNBC cell migration, invasion, proliferation, glucose metabolism, and M2 macrophage polarization, indicating its crucial role in promoting TNBC progression. Moreover, SPI1 transcriptionally activated CEP55 in TNBC cells, and its overexpression was associated with accelerated tumor growth in vivo. Further, CEP55 overexpression relieved SPI1 silencing-induced inhibitory effects on TNBC cell migration, invasion, proliferation, glucose metabolism, and M2 macrophage polarization.
CONCLUSION: SPI1-mediated transcriptional activation of CEP55 plays a key role in enhancing TNBC cell migration, invasion, proliferation, glucose metabolism, and M2 macrophage polarization. These insights provide valuable information for potential targeted therapies to combat TNBC progression by modulating the SPI1-CEP55 axis.
MATERIALS AND METHODS: Atrial arrhythmogenesis was investigated in Langendorff-perfused young (3-4 month) and aged (>12 month), wild type (WT) and peroxisome proliferator activated receptor-γ coactivator-1β deficient (Pgc-1β-/-) murine hearts modeling age-dependent chronic mitochondrial dysfunction during regular pacing and programmed electrical stimulation (PES).
RESULTS AND DISCUSSION: The Pgc-1β-/- genotype was associated with a pro-arrhythmic phenotype progressing with age. Young and aged Pgc-1β-/- hearts showed compromised maximum action potential (AP) depolarization rates, (dV/dt)max, prolonged AP latencies reflecting slowed action potential (AP) conduction, similar effective refractory periods and baseline action potential durations (APD90) but shortened APD90 in APs in response to extrasystolic stimuli at short stimulation intervals. Electrical properties of APs triggering arrhythmia were similar in WT and Pgc-1β-/- hearts. Pgc-1β-/- hearts showed accelerated age-dependent fibrotic change relative to WT, with young Pgc-1β-/- hearts displaying similar fibrotic change as aged WT, and aged Pgc-1β-/- hearts the greatest fibrotic change. Mitochondrial deficits thus result in an arrhythmic substrate, through slowed AP conduction and altered repolarisation characteristics, arising from alterations in electrophysiological properties and accelerated structural change.
AIMS: The aim of this study was to analyze the mutations in genes involved in CRC including MLH1, MSH2, KRAS, and APC genes.
METHODS: A total of 76 patients were recruited. We used the polymerase chain reaction-denaturing high-performance liquid chromatography for the detection of mutations in the mismatch repair (MMR) and APC genes and the PCR single-strand conformation polymorphism for screening of the KRAS gene mutations.
RESULTS: We identified 17 types of missense mutations in 38 out of 76 patients in our patients. Nine mutations were identified in the APC gene, five mutations were detected in the KRAS gene, and two mutations were identified in the MSH2 gene. Only one mutation was identified in MLH1. Out of these 17 mutations, eight mutations (47 %) were predicted to be pathogenic. Seven patients were identified with multiple mutations (3: MSH2 and KRAS, 1: KRAS and APC, 1: MLH1 and APC, 2: APC and APC).
CONCLUSIONS: We have established the PCR-DHPLC and PCR-SSCP for screening of mutations in CRC patients. This study has given a snapshot of the spectrum of mutations in the four genes that were analyzed. Mutation screening in patients and their family members will help in the early detection of CRC and hence will reduce mortality due to CRC.