Management of oral cancer by radiotherapy has witnessed promising advances in the past few years, with patient-tailored radio fractionation regimens. Different fractionation schedules, conventional and altered regimes, have been used in curative radiotherapy. Although contribution of biological markers on radio response has been evaluated, its unique influence on various radio fractionation schemes has not been accounted so far. Our study analyses a set of proteins that previously demonstrated radio response influence for their possible prognostic value in decision-making process between the respective fractionation schemes. Expression patterns of regulatory proteins such as p53, cyclin D1, p16, Cdk4, p21, Rb, bcl-2 and PCNA were determined by immunohistochemistry utilizing monoclonal antibodies in 125 patients who received curative radiotherapy dose. Among these 125 patients, 90 (72%) received altered fractionation, whereas 35 (28%) received conventional fractionation. p53 over-expression correlated with local treatment failure among the patients treated with conventional fractionation whereas cyclin D1 over-expression and p16 underexpression were associated with local treatment failure as well as overall survival in altered fractionation treated cases. Our findings suggest that wild-type p53 status may be an important parameter for achieving high local control in those patients undergoing conventional fractionation, where as intact p16 and cyclin D1 status may be beneficial for effective local control in patients who are treated with altered fractionation. Furthermore, it can be assumed that conventional fractionation employs p53-mediated apoptosis, whereas altered fractionation activates the functional G1 cell-cycle checkpoint for tumor growth suppression.

Our previous study showed that p53 protein is accumulated in >60% of cases of oral squamous cell carcinoma (OSCC) and its overexpression is related to poor prognosis. However, the mechanism behind this is still elusive. The present study attempts to dissect p53 alterations at various levels from gene to function in tumor biopsies to understand whether molecular alterations have any relationship with the accumulation of p53 protein in OSCC. Protein-stabilizing mutations were observed in only 13.8% of the samples. Neither p53 polymorphisms nor human papillomavirus (HPV) infection (<2%) has any major role in augmented expression of p53 protein. Analysis of the p53 transcript demonstrated that alteration in the level of p53 mRNA (10%) is not the major mechanistic cause for accumulation of p53 protein, and p21 transcript status showed that the overexpressed p53 protein is functionally inactive. Immunoprecipitation studies demonstrated that the known interactors of p53, such as MDM2 and HSP70, have no significant role in stabilizing p53 and the significant presence of some unknown interactors, sequestering p53, and leading to the aberrant accumulation of p53. Our study suggests that overexpression of inactive p53 protein could be manifested as a result of sequestering from degradation by an unknown interacting protein rather than by gene or transcript level of alteration.

&lt;p&gt;Plant root systems are crucial for sustainable agriculture, as their architecture determines the efficiency of water and nutrient uptake by the plant. To date, it is not clear how root architecture characteristics determined in the laboratory relate to root characteristics in the field. In this study, we want to investigate the extent to which root architectural traits and root measures of young plants in the laboratory and mature plants in the field correlate when experimental conditions are the same. Furthermore, we want to evaluate whether the effects of different plant genotypes and soil types on root system development are similar in the laboratory and in the field.&lt;/p&gt; &lt;p&gt;Two maize genotypes, a wild type and a root hair defective mutant, were grown in loam and sand in a soil column experiment in the laboratory and in a plot experiment in the field. In the laboratory, root architecture parameters were derived from the analysis of X-ray CT images of the root systems. In the field, root architecture parameters were derived from the analysis of root window images, crown root counts and soil core data. Root architecture parameter sets obtained from laboratory and field measurements were compared. Using the RSA model CPlantBox, laboratory and field parameter sets were used to simulate root systems and calculate root measures, i.e. total root length, total root volume, convex hull volume, which could then be compared.&lt;/p&gt; &lt;p&gt;This study shall contribute to a better understanding of root trait changes during plant development. In addition, this study will shed light on the importance of equal experimental conditions to infer root systems from laboratory experiments to root systems in the field. Furthermore, we aim to investigate the importance of RSA models for extrapolating from young, laboratory-grown root systems to mature, field-grown root systems.&lt;/p&gt;