Is p53 an oncogene or a Tumour suppressor?
As such, p53 has been described as “the guardian of the genome” because of its role in conserving stability by preventing genome mutation. Hence TP53 is classified as a tumor suppressor gene.
What is the function of p53?
The p53 protein is a key cell cycle regulator that manages the response to stress signals either by inducing cell growth arrest, senescence or apoptosis. The nature and intensity of stress signal, the cell type, and the cellular context dictate the final outcome.
How does p53 work as a tumor suppressor?
If the DNA can be repaired, p53 activates other genes to fix the damage. If the DNA cannot be repaired, this protein prevents the cell from dividing and signals it to undergo apoptosis. By stopping cells with mutated or damaged DNA from dividing, p53 helps prevent the development of tumors.
What does positive for p53 mean?
Tumors with positive p53 staining showed malignant features compared to negative tumors. Mutation of TP53 gene was observed in 29 (19.6%) tumors with higher age and differentiated type. In positive p53 tumors, two types could be distinguished; aberrant type and scattered type.
Is p53 always active?
Besides its primary function as a transcription factor, p53 can also promote apoptosis through direct interaction with proapoptotic and antiapoptotic proteins . The activity of p53 is always under tight control, which ensures that it is not overly abundant in nonstressed cells.
What cancers is p53 associated with?
P53 mutations associated with breast, colorectal, liver, lung, and ovarian cancers. Environ Health Perspect.
How is p53 activated?
The tumour suppressor protein p53 is stabilised and activated in response to ionising radiation. This is known to depend on the kinase ATM; recent results suggest ATM acts via the downstream kinase Chk2/hCds1, which stabilises p53 at least in part by direct phosphorylation of residue serine 20.
What type of gene is p53?
The p53 gene is a type of tumor suppressor gene.
Is p53 good or bad?
p53 Germline Mutations and Li–Fraumeni Disease. p53, famously dubbed ‘The Guardian of the Genome’, is arguably the most significant gene for cancer suppression. Somatic loss of function of p53 underpins tumor progression in most epithelial cancers and many others besides.
What happens when p53 is overexpressed?
Our research showed that was a significant inverse correlation between p53 overexpression and response to chemotherapy and a stronger association between high P53 overexpression (%) and a genetic mutation of p53 (p=0.0001). More than 50% overexpression indicated a strong probability of genetic mutation.