Increasing evidence highlights the role of bacteria in the physiopathology of cancer. However, the underlying molecular mechanisms remains poorly understood. Several cancer-associated bacteria have been shown to produce toxins which interfere with the host defense against tumorigenesis. Here, we show that lipopolysaccharides from Klebsiella pneumoniae and other Enterobacteria strongly inhibit the host tumor suppressor p53 pathway through a novel mechanism of p53 regulation. We found that lipopolysaccharides destabilize TP53 mRNA through a TLR4-NF-κB-mediated inhibition of the RNA-binding factor Wig-1. Importantly, we show that K. pneumoniae disables two major tumor barriers, oncogene-induced DNA damage signaling and senescence, by impairing p53 transcriptional activity upon DNA damage and oncogenic stress. Furthermore, we found an inverse correlation between the levels of TLR4 and p53 mutation in colorectal tumors. Hence, our data suggest that the repression of p53 by Enterobacteria via TLR4 alleviates the selection pressure for p53 oncogenic mutations and shapes the genomic evolution of cancer.
The aim of the study were to ( 1) investigate what physical and physiological parameters are most important for Frame Running capacity, a parasport for individuals with ambulatory difficulties, and (2) determine whether Frame Running capacity can be predicted in athletes with cerebral palsy. Design: Athletes with cerebral palsy (N = 62, Gross Motor Classification System I-V; 2/26/11/21/2) completed a 6-min Frame Running test. Before the 6-min Frame Running test, muscle thickness, passive range of motion (hip, knee, ankle), selective motor control, and spasticity (hip, knee, ankle) were measured in both legs. In total, 54 variables per individual were included. Data were analyzed using correlations, principal component analysis, orthogonal partial least square regression, and variable importance in projection analysis. Results: The mean 6-min Frame Running test distance was 789 ± 335 m and decreased with motor function severity. The orthogonal partial least square analysis revealed a modest degree of covariance in the variables analyzed and that the variance in the 6-min Frame Running test distance could be predicted with 75% accuracy based on all the variables measured. Variable importance in projection analysis indicated hip and knee extensor spasticity (negative effect), and muscle thickness (positive effect) arose as the most important factors contributing to Frame Running capacity. Conclusions: These results are an important resource to enable optimization of training regimes to improve Frame Running capacity and contribute to evidence-based and fair classification for this parasport.
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