PURPOSE To determine the nature and potential pharmacologic reversibility of deficient TP53 expression and function in head and neck squamous cell carcinomas (HNSCC) with wild-type TP53, previously associated with decreased sensitivity to cisplatin therapy. EXPERIMENTAL DESIGN TP53 genotype, mRNA and protein expression, TP53-induced p21 expression, and TP53 DNA-binding and reporter gene funct...

BACKGROUND Non-melanoma skin cancers are one of the most common human malignancies accounting for 2-3% of tumors in the US and represent a significant health burden. Epidemiology studies have implicated Tp53 mutations triggered by UV exposure, and human papilloma virus (HPV) infection to be significant causes of non-melanoma skin cancer. However, the relationship between Tp53 and cutaneous HPV ...

A number of TP53-MDM2 inhibitors are currently under investigation as therapeutic agents in a variety of clinical trials in patients with TP53 wild type tumors. Not all wild type TP53 tumors are sensitive to such inhibitors. In an attempt to improve selection of patients with TP53 wild type tumors, an mRNA expression signature based on 13 TP53 transcriptional target genes was recently developed...

BACKGROUND Tumour suppressor genes such as TP53, BRCA1 and RAD51 are involved in DNA repair and their malfunctions result in genomic instability and cancer. Wild type (WT) TP53 binds to BRCA1and RAD51 in vivo and in vitro. However, mutated TP53 in tumours can interfere with WT TP53 function. We studied how mutation of TP53 in MDA-MB-468 cell line could affect its binding capacity and interfere ...

TP53 mutations occur in half of all human tumours. Mutagen-induced or spontaneous TP53 mutagenesis can be studied in vitro using the human TP53 knock-in (Hupki) mouse embryo fibroblast (HUF) immortalisation assay (HIMA). TP53 mutations arise in up to 30% of mutagen-treated, immortalised HUFs; however, mutants are not identified until TP53 sequence analysis following immortalisation (2-5 months)...

Recent reports have indicated that KRAS and TP53 mutations predict response to therapy in colorectal cancer. However, little is known about the relationship between these two common genetic alterations. Micro-RNAs (miRNAs), a class of noncoding RNA implicated in cellular processes, have been increasingly linked to KRAS and TP53. We hypothesized that lethal-7a (let-7a) miRNA regulates KRAS throu...

It has been demonstrated that tumor protein p53 (TP53) mutation in maxillary squamous cell carcinoma, is more treatment-resistant compared with the carcinoma without TP53 mutation. However, the association between TP53 mutation and treatment resistance remains unclear. As a first step in understanding the biological differences between tumors with and without TP53 mutation, a comprehensive gene...

UNLABELLED Defects in the tumor suppressor gene TP53 are known to be important in chronic lymphocytic leukemia (CLL) and TP53 inactivation is associated with a particularly aggressive form of the disease. The single nucleotide polymorphism in the TP53 gene at codon 72 (rs1042522), results in amino acid substitution influencing apoptotic potential of TP53 protein. The aim of the study was to eva...

Loss of TP53 function may contribute to 5-fluorouracil (5-FU) resistance in colorectal cancer since TP53-deficient cells may be unable to undergo apoptosis in response to 5-FU-induced DNA damage. 5-FU treatment of TP53-deficient cells would provide useful information on the apoptotic response to drug-induced DNA damage in the absence of TP53 and its transcriptional targets. We investigated apop...