TP53 codon 72 polymorphism in radiation-associated human papillary thyroid cancer.

Area of Science:

• Genetics
• Oncology
• Radiation Epidemiology

Background:

• The TP53 gene is a critical tumor suppressor.
• Germline polymorphisms in TP53 may influence cancer susceptibility.
• Radiation exposure, like from the Chernobyl accident, is a known risk factor for thyroid cancer.

Purpose of the Study:

• To investigate the association between the TP53 codon 72 germline polymorphism and papillary thyroid cancer (PTC) risk in individuals exposed to Chernobyl radiation.
• To analyze TP53 genotype in relation to clinicopathological features of PTC in different age groups.
• To evaluate TP53 loss of heterozygosity and allele expression in tumors.

Main Methods:

• Genotyping of TP53 codon 72 polymorphism in PTC patients (pediatric/adolescent and adult) with and without Chernobyl exposure, and healthy controls.
• Analysis of TP53 loss of heterozygosity and allele expression ratio in tumor samples.
• Correlation of TP53 genotypes with clinicopathological data, including tumor stage, morphology, and lymph node status.

Main Results:

• Arg TP53 homozygotes were significantly underrepresented in adult post-Chernobyl PTC cases compared to sporadic PTC and controls.
• This underrepresentation was not observed in pediatric/adolescent post-Chernobyl PTC cases.
• No significant association was found between TP53 genotypes and tumor stage or morphology.
• Specific correlations with lymph node status were noted in certain age groups of radiation-associated PTC.

Conclusions:

• TP53 allele combinations other than Arg/Arg may contribute to PTC risk in individuals exposed to radiation during late childhood, adolescence, or young adulthood.
• The findings suggest a complex interplay between TP53 genotype, age at exposure, and radiation-induced PTC development.
• TP53 status in tumors did not show significant allelic imbalance or biased expression in heterozygous individuals.