Two postdoctoral researchers in the laboratory of Shujun Liu, PhD, a member of Case CCC's Molecular Oncology Program, have uncovered new insights into how combinations of mutations in the TP53 gene influence lung cancer progression and treatment response.
Sicheng Bian, PhD, and Huiqin Bian, PhD, share co-first authorship of the study, Combined Point Mutations in a Single Allele of the TP53 Gene Potentiates the Oncogenic and Transcriptional Properties of TP53 in Lung Cancer, published in the International Journal of Biological Sciences. Their complementary expertise and collaborative leadership were central to the research, which advances understanding of how multiple mutations within a single TP53 allele can interact to change the protein's biological activity.
TP53 is among the most frequently mutated genes in human cancer. Although individual TP53 mutations have been extensively studied, the functional consequences of multiple point mutations occurring together on the same allele remain less well understood.
The researchers investigated a combined TP53 mutation configuration, termed cbTP53, involving three hotspot mutations located within and outside the protein's DNA-binding domain. Using experimental, structural, and analytical approaches, they demonstrated that these mutations produce conformational changes that alter p53's interactions with DNA and its regulation of downstream gene expression.
Their findings showed that the combined mutations enhanced cancer cell growth, altered sensitivity to therapeutic agents, and influenced inflammatory signaling pathways. The researchers also identified increased expression of inflammatory cytokines associated with changes in p53 binding to their gene promoters, suggesting a mechanism through which these mutations may influence the tumor immune microenvironment.
In vivo experiments further demonstrated increased tumor burden associated with the combined mutation configuration.
The study's significance lies in its mechanistic characterization of how mutations acting together within a single TP53 allele can produce biological effects that differ from those associated with individual mutations. The findings underscore the importance of considering mutation combinations and their allelic context when investigating TP53 function in cancer.
While additional research is needed to establish the clinical prevalence and relevance of this specific mutation configuration, the work provides a foundation for further studies of TP53-driven tumor behavior, molecular classification and potential therapeutic vulnerabilities.
Conducted with support from the National Cancer Institute, the study reflects the contributions of emerging cancer scientists.