Researchers at the Fred Hutch Cancer Center found that a single transfer RNA controls cellular identity and therapy response, identifying a molecular driver of aggressive prostate cancer.
Prostate Cancer Faces Treatment Resistance
Prostate cancer remains a leading cause of cancer in men, often altering cellular characteristics over time. While standard therapies target the androgen receptor—a protein that fuels tumor growth—many tumors eventually transition to an androgen receptor-independent state. Once independent of this receptor, tumors become much more aggressive and less responsive to standard medical interventions.
Scientists investigated how messenger RNA translation and protein synthesis are involved when tumors acquire these treatment-resistant features. In a study utilizing prostate cancer cell lines, mouse models, and patient tumor samples, researchers examined the specific mechanics of protein construction. They tracked how biological information moves from mRNA to build proteins, uncovering a previously unrecognized vulnerability in how cancer cells adapt to therapy.
Transfer RNA serves as a central component of protein synthesis and plays important roles in the epigenetic regulation of gene expression in tumors. In addition to these duties, tRNAs participate in various cellular activities such as stress responses, signaling pathways, and cell growth, which suggests they contribute to cancer development and tumor advancement. Various conditions, including type 2 diabetes, neurodevelopmental issues, and multiple malignancies like colorectal, bladder, and breast cancer, are linked to abnormalities in tRNAs and the enzymes that modify them.
Molecule tRNA1Arg(UCU) Drives Cancer Cell Identity
Across all examined model systems, researchers observed a consistent pattern involving a specific molecule designated as tRNAArg(UCU)-1. This specific tRNA was abundant in prostate cancer cells that remained responsive to androgen treatments but diminished in treatment-resistant tumors. Further analysis of 35 prostate cancer patients linked low levels of this tRNA to earlier bone metastasis and shorter survival rates.
We found that we can shift the cell state between androgen receptor-dependent to an androgen receptor-independent state with a single tRNA.
When investigators experimentally reduced levels of this tRNA in laboratory models, resistance to androgen-receptor inhibitors increased. Conversely, restoring its activity reversed the effect, driving the cells back toward a drug-sensitive state. The molecule supports the production of SMARCC2, which forms part of a protein complex that controls access to DNA and maintains cellular identity. Meanwhile, two DNA-binding proteins, TARDBP and ZSCAN29, regulate the production of the tRNA itself.
Oncology Reconsiders Cancer Biology
The discovery challenges long-held assumptions in oncology regarding the passive nature of transfer RNAs in cellular maintenance and disease.
Researchers are currently studying whether this tRNA could serve as a biomarker or therapeutic target to guide more precise treatments for difficult-to-manage prostate cancers.
Implications Extend to Other Malignancies
Investigators view prostate cancer as an archetype for studying tRNA-dependent state changes, but the underlying mechanisms may extend far beyond a single diagnosis. Many other malignancies undergo similar cellular identity switches following treatment, creating acquired drug resistance across different tissue types.
The research team intends to apply this investigative framework to other diseases that exhibit treatment-induced alterations, explicitly noting lung and breast cancers as future candidates for study as investigators establish independent laboratories to continue the work.