Newly Discovered Cellular Pathway Found to Fuel Production of Cancer-Driving Proteins

A previously unknown biological mechanism helps certain cancer cells selectively produce the proteins that drive tumor growth, according to a study published in Nature Cell Biology. Researchers at The University of Texas MD Anderson Cancer Center uncovered that a specific enzyme facilitates the translation of growth-promoting proteins such as KRAS, potentially offering a novel target to combat treatment resistance in common malignancies.

Understanding the Role of the METTL13 Enzyme

KRAS is among the most frequently mutated cancer genes, playing a central role in driving tumor progression across multiple forms of the disease, including numerous lung and pancreatic cancers. Although targeted therapies designed to block KRAS have improved patient outcomes, tumors frequently adapt and develop resistance over time. Many oncogenic genes generate messenger RNA rich in specific codons that serve as genetic instructions for building proteins. However, structural and metabolic barriers can make these codons difficult for the cell’s protein-building machinery to read efficiently.

Co-led by Pawel Mazur, associate professor of experimental radiation oncology at MD Anderson, along with collaborators at other institutions, the study investigated how cancer cells overcome these hurdles. The team discovered that an enzyme called METTL13 applies a small chemical tag, known as methylation, to a protein involved in the translation machinery. This modification allows cancer cells to read the mRNA codons more efficiently, conferring a distinct advantage in producing elevated amounts of proteins that support tumor survival.

Importantly, the researchers observed that METTL13 does not broadly increase the production of all cellular proteins. Instead, it selectively enhances a specific subset of proteins directly involved in cancer proliferation.

Preclinical Findings and Potential Implications for Treatment Resistance

To evaluate the functional importance of this pathway, the researchers tested the effects of reducing or removing METTL13 in laboratory models. The intervention lowered the levels of KRAS and other cancer-driving proteins, successfully slowing tumor growth across several preclinical cancer models.

Furthermore, in models of KRAS-mutant lung cancer—including tumors that had already acquired resistance to the targeted inhibitor sotorasib—the loss of METTL13 slowed tumor progression, restored sensitivity to the treatment, and significantly extended survival. The researchers also noted that patients whose tumors exhibited higher METTL13 activity generally displayed poorer responses to KRAS inhibitors, pointing to a potential clinical correlation with drug resistance.

Limitations and Future Directions

While existing therapies typically focus on inhibiting the KRAS protein after it has already been synthesized, these findings highlight a potential strategy to intervene earlier by limiting protein production at the source. Nevertheless, experts emphasize important limitations:

• All current findings are strictly preclinical and derived from laboratory and animal models.
• The identified pathways require rigorous further validation before they can be translated into human clinical applications.
• Additional research is needed to determine whether METTL13 activity levels can reliably serve as a predictive biomarker to identify which patients might benefit most from targeted therapies.

Researchers are continuing to explore the exact mechanisms by which METTL13 regulates protein synthesis and are working on the development of safe strategies to target the enzyme in future therapeutic approaches.