The loss of p53 function is a key event in tumorigenesis. Inactivation of p53 in primary tumors and cell lines is mediated by several molecular mechanisms, including deletions and rearrangements. However, generation of a p53 fusion gene has not yet been reported. Here we report a novel p53/an autosomal homolog of the fragile X mental retardation (FXR2) chimeric gene generated by an interstitial...

The dynamics of the tumor suppressor protein p53 have been previously investigated in single cells using fluorescently tagged p53. Such approach reports on the total abundance of p53 but does not provide a measure for functional p53. We used fluorescent protein-fragment complementation assay (PCA) to quantify in single cells the dynamics of p53 tetramers, the functional units of p53. We found t...

In squamous cell carcinomas (SCCs), the tumor suppressor protein p53 is frequently overexpressed. The overexpression of p53 is often due to a mutation in the p53 gene; however, increased levels of p53 protein can be observed in the tumors without p53 gene mutations. In normal human keratinocytes, p53 is a multiconformational protein. The different conformations of p53 can be identified by their...

The tumor suppressor p53 is a multi-functional protein, its functions covering cell cycle control, apoptosis, senescence, genome integrity maintenance, metabolism, cellular reprogramming and autophagy. Regulation of p53 stability is a central process in controlling these p53 functions. Multiple E3 ligases that mediate p53 degradation through the ubiquitination proteasome pathway have been well ...

Our environment contains physical, chemical and pathological agents that challenge the integrity of our DNA. In addition to DNA repair, higher multicellular organisms have evolved multiple pathways of response to damage including programmed cell death-apoptosis. The p53 protein appears to sense multiple types of DNA damage and coordinate with multiple options for cellular response. The p53 prot...

PURPOSE Markers of somatic mutation such as p16 and p53 remain controversial prognostic indicators for patients with squamous cell carcinoma of the head and neck (SCCHN). The relationship between p53 protein expression and radiation therapy is also unclear. EXPERIMENTAL DESIGN We made a prospective cohort study (n = 171) of incident cases receiving standardized therapy for SCCHN. RESULTS Pa...

Tumor suppressor p53 is a transcription factor that guards the genome stability and normal cell growth. Stresses like DNA damage, oncogenic assault will turn on p53 function which leads to cell cycle arrest for DNA repair, senescence for permanent growth arrest or apoptosis for programmed cell death. At the late stage of cancer progression, p53 is hijacked in all forms of tumors either trapped ...

p53 family proteins include p53 tumor suppressor, p63, and p73. Despite the high similarity in structure and function with p53, p63, and p73 function in tumor suppression is still controversial. Here, we show that TAp73alpha, a transcriptionally active p73 isoform, is able to synergize p53 tumor suppressor function in thyroid cancer cells. Indeed, depletion of p73 by small interfering RNA in th...

p53 is the most commonly mutated gene in human cancers. It encodes a 53 kilodalton protein with several evolutionarily conserved domains viz sequence-specific DNA binding, tetramerisation, SH3 molecule binding, C-terminal and N-terminal. Existing in the cell at a very low level and in a relatively inactive form, p53 protein is increased and activated during periods of cellular stress. Unlike ot...

in this archival analysis of genetic & protein alterations in the p53 tumor suppressor gene, we used immunohistochemical methods for detection of these alterations. the tumor series includes: 61 paraffin embedded esophageal squamous cell carcinoma from a high incidence (ethnic) & a non-high incidence regions in iran.