A Driver Never Works Alone-Interplay Networks of Mutant p53, MYC, RAS, and Other Universal Oncogenic Drivers in Human Cancer.

The knowledge accumulating on the occurrence and mechanisms of the activation of oncogenes in human neoplasia necessitates an increasingly detailed understanding of their systemic interactions. None of the known oncogenic drivers work in isolation from the other oncogenic pathways. The cooperation between these pathways is an indispensable element of a multistep carcinogenesis, which apart from inactivation of tumor suppressors, always includes the activation of two or more proto-oncogenes. In this review we focus on representative examples of the interaction of major oncogenic drivers with one another. The drivers are selected according to the following criteria: (1) the highest frequency of known activation in human neoplasia (by mutations or otherwise), (2) activation in a wide range of neoplasia types (universality) and (3) as a part of a distinguishable pathway, (4) being a known cause of phenotypic addiction of neoplastic cells and thus a promising therapeutic target. Each of these universal oncogenic factors-mutant p53, KRAS and CMYC proteins, telomerase ribonucleoprotein, proteasome machinery, HSP molecular chaperones, NF-κB and WNT pathways, AP-1 and YAP/TAZ transcription factors and non-coding RNAs-has a vast network of molecular interrelations and common partners. Understanding this network allows for the hunt for novel therapeutic targets and protocols to counteract drug resistance in a clinical neoplasia treatment.

Correlation of TNF-α and TGF-ß polymorphisms with protein levels in pancreatic ductal adenocarcinoma and colorectal cancer.

AIM OF THE STUDY: To determine the correlation of protein serum levels of two cytokines and their polymorphisms, which have an influence on their expression. MATERIAL AND METHODS: The study group consisted of 65 patients (33 men, 31 women) who met the criteria for inclusion and exclusion of pancreatic cancer, and 41 patients (25 men, 16 women) with colorectal cancer. The control group consisted of 100 healthy volunteers (63 men, 37 women). Detection of polymorphisms was performed using TaqMan probes, and concentration of proteins by ELISA method. RESULTS: The mean TNF-α concentration in patients with colorectal cancer was significantly higher compared to the control group, p< 0.0001. A statistically significant difference was noted when comparing both study groups, p = 0.0009. The analyses show that the occurrence of the polymorphic genotype -308AA of the TNF-α gene was not correlated with the increased concentration of the examined protein in patients with both pancreatic and colorectal cancer. It was also noted that the concentration of TGF-ß protein was significantly higher in patients with colorectal cancer than in patients with pancreatic cancer. These results also proved to be statistically significant, p = 0.0353. CONCLUSIONS: The only statistically significant effects were the correlations between patients belonging to a specific group (pancreatic cancer/colorectal cancer/control) and average protein levels. There was no effect of sex or genotype on the occurrence of elevated levels of TNF-α and TGF-ß protein control, despite their variability in particular types of cancer.

CpG promoter methylation of the ALKBH3 alkylation repair gene in breast cancer.

BACKGROUND: DNA repair of alkylation damage is defective in various cancers. This occurs through somatically acquired inactivation of the MGMT gene in various cancer types, including breast cancers. In addition to MGMT, the two E. coli AlkB homologs ALKBH2 and ALKBH3 have also been linked to direct reversal of alkylation damage. However, it is currently unknown whether ALKBH2 or ALKBH3 are found inactivated in cancer. METHODS: Methylome datasets (GSE52865, GSE20713, GSE69914), available through Omnibus, were used to determine whether ALKBH2 or ALKBH3 are found inactivated by CpG promoter methylation. TCGA dataset enabled us to then assess the impact of CpG promoter methylation on mRNA expression for both ALKBH2 and ALKBH3. DNA methylation analysis for the ALKBH3 promoter region was carried out by pyrosequencing (PyroMark Q24) in 265 primary breast tumours and 30 proximal normal breast tissue samples along with 8 breast-derived cell lines. ALKBH3 mRNA and protein expression were analysed in cell lines using RT-PCR and Western blotting, respectively. DNA alkylation damage assay was carried out in cell lines based on immunofluorescence and confocal imaging. Data on clinical parameters and survival outcomes in patients were obtained and assessed in relation to ALKBH3 promoter methylation. RESULTS: The ALKBH3 gene, but not ALKBH2, undergoes CpG promoter methylation and transcriptional silencing in breast cancer. We developed a quantitative alkylation DNA damage assay based on immunofluorescence and confocal imaging revealing higher levels of alkylation damage in association with epigenetic inactivation of the ALKBH3 gene (P = 0.029). In our cohort of 265 primary breast cancer, we found 72 cases showing aberrantly high CpG promoter methylation over the ALKBH3 promoter (27%; 72 out of 265). We further show that increasingly higher degree of ALKBH3 promoter methylation is associated with reduced breast-cancer specific survival times in patients. In this analysis, ALKBH3 promoter methylation at >20% CpG methylation was found to be statistically significantly associated with reduced survival (HR = 2.3; P = 0.012). By thresholding at the clinically relevant CpG methylation level (>20%), we find the incidence of ALKBH3 promoter methylation to be 5% (13 out of 265). CONCLUSIONS: ALKBH3 is a novel addition to the catalogue of DNA repair genes found inactivated in breast cancer. Our results underscore a link between defective alkylation repair and breast cancer which, additionally, is found in association with poor disease outcome.

Genetic Polymorphism and Messenger Ribonucleic Acid Concentrations of TNFα and TGFß Genes in Patients with Chronic Lower Limb Infections.

BACKGROUND: The number of chronic lower limb infections and their complications as venous and diabetic ulcers and chronic calf dermatitis is increasing worldwide. The clinical course and outcome in the immune responses to infection have been shown to be associated with genetic polymorphisms. The aim of study was to investigate frequencies of chosen single nucleotide polymorphisms (SNPs) in TNFα and TGFß genes in patients with chronic lower limb infections and evaluate expression of messenger ribonucleic acid (mRNA) concentrations in chronic leg ulcers. METHODS: Patients were divided into three groups: (group A) chronic venous leg ulcers, (group B) chronic post-traumatic non-healing wounds, and (group C) infected ischemic necrosis of the foot. Blood donors comprised the control group. Detection of polymorphisms was performed using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and gene expression by real-time PCR methods. RESULTS: Patients in all groups showed higher frequency of TNFα gene polymorphism -308GG and lower frequency of -308GA genotypes than controls. The mutated homozygote AA was higher in groups A and B than in controls. The TGFß74GG genotype was represented at highest values in group B. The GC genotype was found in all groups at a similar concentration lower than in controls. Genotypes TGFß29TT and TC were represented at similar concentrations as controls. Analyses showed that the presence of the polymorphic allele -308A of TNFα gene was correlated with an increased concentration of gene expression in patients with chronic leg ulcers (group A). In the case of both TGFß gene polymorphisms the presence of polymorphic allele C resulted in increased TGFß gene expression. CONCLUSIONS: Comparison of genotypes in polymorphic sites in TNFα and TGFß genes with their expression concentrations showed that the presence of polymorphic alleles could predispose to increased production of their proteins. Patients with prolonged non-healing wounds should have their genotypes studied, and in cases of mutation, long-term antibiotic and immune protein supply should be considered.