Hormone therapy resistance in prostate cancer tied to amino acids

What happened: hormone therapy resistance in prostate cancer meets metabolism

A Weill Cornell Medicine team reports a metabolic route that may help explain hormone therapy resistance in prostate cancer: tumors can rewire amino acid metabolism to keep cholesterol production running when hormone signaling is blocked.

In their preclinical study in Nature Metabolism, investigators found that a compound called propionyl-CoA—made during normal energy metabolism from the breakdown of the amino acids isoleucine and valine—acts as a signal that switches on cholesterol production, helping prostate cancer cells adapt to hormone-deprived conditions created by treatment.

• Key metabolic signal: propionyl-CoA (and the related metabolite propionylcarnitine)
• Key pathway outcome: sustained cholesterol production that supports androgen (male hormone) signaling
• Clinical problem addressed: diminished response to androgen receptor–blocking therapy as tumors adapt

What the evidence shows about hormone therapy resistance in prostate cancer

The evidence comes from a preclinical study that combines laboratory models with observations from human prostate tumors, so it explains a plausible mechanism but does not yet prove that changing diet or metabolism will improve outcomes in people.

Researchers identified elevated levels of propionylcarnitine in more aggressive human prostate tumors, then traced a mechanism in which propionyl-CoA promotes “propionylation” of SREBP2, stabilizing this protein and keeping cholesterol-producing genes switched on even when conditions would normally suppress cholesterol production.

• Mechanism described: propionyl-CoA → propionylation of SREBP2 → SREBP2 stays active → cholesterol genes remain on
• Why cholesterol matters here: cancer cells can use excess cholesterol to produce androgens that activate the androgen receptor
• Therapy context named in the report: drugs like enzalutamide are designed to block androgen receptor signaling, but increased male sex hormone production can help tumors keep that signaling going

How hormone therapy resistance in prostate cancer may rise during treatment

The study reports that propionyl-CoA levels rose when prostate cancer cells were deprived of male hormones in laboratory models, suggesting the pathway may be activated as a survival strategy under hormone-deprived treatment conditions.

In mouse models, restricting isoleucine and valine slowed tumor growth and reduced metastases of prostate cancer cells to the lungs, while boosting propionyl-CoA promoted tumor growth and increased lung colonization—results that align with the idea that this amino-acid–to-cholesterol signaling route can support more aggressive behavior under pressure from therapy.

• Treatment-linked signal shift observed: higher propionyl-CoA under male-hormone deprivation (lab models)
• Directional findings in mice: isoleucine/valine restriction slowed growth and reduced lung metastases; higher propionyl-CoA did the opposite
• Stated clinical implication: potential targets for new drugs or, pending clinical testing, controlled dietary strategies

Practical context for metabolic health: amino acids, obesity, diabetes, and unknowns

The report highlights that the amino acids involved—i.e., the branched-chain amino acids isoleucine and valine—are essential and are abundant in protein-rich foods such as meat, fish, and dairy, which puts a familiar nutrition topic in the frame of cancer metabolism.

At the same time, the researchers note that propionyl-CoA may come from sources beyond diet, and they flag open questions relevant to metabolic health: obesity and diabetes have been associated with altered circulating levels of branched-chain amino acids, and aging or cancer-associated cachexia can involve substantial muscle loss, but whether these systemic changes increase propionyl-CoA production within tumors remains unknown.

• Diet connection mentioned: isoleucine and valine are essential amino acids and common in protein-rich foods
• Metabolic-health overlap noted: obesity and diabetes linked to altered circulating branched-chain amino acids (association, not causation in this report)
• Clinical relevance still being tested: investigators frame dietary approaches as “pending clinical testing”

Limitations and what to watch next in hormone therapy resistance in prostate cancer

This is a preclinical report, so its strongest claims are about mechanism and effects in laboratory and mouse models, not proven benefits of interventions in people with prostate cancer.

The authors emphasize next steps rather than prescriptions: determining whether drugs or carefully controlled dietary strategies can make existing treatments work better, while also accounting for other potential sources of propionyl-CoA and the uncertainty about how whole-body metabolic states translate into tumor-level propionyl-CoA.

• Applies most directly to: the studied models and the tumor-metabolite associations described in human samples
• Not yet established: whether changing isoleucine/valine intake in humans affects tumor propionyl-CoA, cholesterol signaling, or therapy response
• Next-step focus stated: new drug targets and clinically tested, controlled dietary strategies