TP 53

TP53 Mutation Test

Mutations of p53 are estimated to occur in up to half of all human cancers

Diagomet DNA tests is designed to detect TP53 mutations in patient samples.

Diagomet DNA test can help guide doctors decide on the appropriate course of treatment.

Purpose of the Test

TP53 mutational status can have prognostic value and reveal information about a patient's response to chemotherapy and radiation.

Background

TP53 is a tumor suppressor gene that codes for the TP53 protein, a critical component for normal cell function. It responds to stresses such as DNA damage, in order to promote growth arrest, apoptosis, and DNA repair. TP53 gene is found mutated in approximately 50% of all cancers with 98% of the mutations occurring in exons 5-8. Mutated TP53 is associated with aggressive biological behavior, poor prognosis, and altered response to therapy. Since functional TP53 proteins are often required for cell death, therapies that induce cell death, such as chemotherapy and gamma irradiation, may not be suitable for treating the patient's cancer. Further, germline alterations in TP53 gene increases cancer risk to 50% by age 40 and as high as 90% by age 80. The TP53 gene can be screened for the presence of any mutations that will affect potential cancer risk and response to therapy.

Test Method

Tumor DNA will be used for PCR amplification and sequencing of the coding TP53 exons that contain hotspot mutations.

Sample Requirements

We require 1 slide stained with hematoxylin-and-eosin and 10 unstained, nonbaked slides with 10- thick sections of FFPE tumor tissue. The tumor section should contain at least 70% tumor content as verified by a qualified pathologist. Pathology report and a scanned copy of the slides used to assess tumor content should accompany specimen in order for testing to be performed. We can also accept fresh frozen tumor sample. However, we require that the tumor is sectioned and a pathology report be generated that includes an assessment of tumor content - Please call +91-484-2413399/97 or email askus@medgenome.com if you have questions.

References

1. Harris CC, Hollstein M (1993) Clinical implications of the p53 tumor-suppressor gene. N. EngI. J. Med., 329: 1318-1327.

2. Levine A, Momand J, Finlay C (1991) The p53 tumour suppressor gene. Nature 351: 453-456.

3. Callahan R (1992) p53 mutations, another breast cancer prognostic factor. J. Natl Cancer Inst. 84: 826-827.

4. Frebourgh T, Kassel J, Lam KT, et al. (1992) Germ-line mutations of the p53 tumor suppressor gene in patients with high risk for cancer inactivate the p53 protein. PNAS 89(14): 6413-6417.

5. Glazko GV, Koonin EV, Rogozin IB (2004) Mutation hotspots in the p53 gene in tumors of different origin: correlation with evolutionary conservation and signs of positive selection. Biochim Biophys Acta 1679(2): 95-106.