Potential Tumor Suppressor Promotes Cancer Growth

PHLDB3 inhibits the p53 protein to promote tumor growth.

The protein PHLDB3—–previously thought of as a potential tumor suppressor––actually promotes tumor growth, according to a study published in Nature Communications.

It has long been known that the p53 protein protects against the development of cancer by signaling cells with damaged DNA to self-destruct before they become malignant.

The growth and demise of P53 proteins are regulated by the genes MDM2 and MDMX. When the production of p53 and both genes are balanced, it allows for normal cell development. However, overproduction among either of the genes or the protein causes harm.

The results of the study showed that PHLDB3 works with MDM2 to inhibit p53 and promote tumor growth. Furthermore, the protein can cause treatment-resistance for some late-stage cancers.

“Now that we’ve identified the molecule, we could utilize it as an anti-cancer target,” said lead author Dr Hua Lu. “This target can be used to develop a drug that would hopefully, combined with chemotherapy, be more effective and less toxic.”

The investigators plan to further validate PHLDB3’s cancer-causing role in mouse models either dependently or independently of p53. Additionally, they hope to better understand the biological role of the protein in cellular signaling and normal animal development, as well as to consolidate its role in human cancer development, progression, and treatment-resistance.