Blocking sex hormone signaling can paradoxically fuel prostate cancer escape, a fly model reveals.

Blocking sex hormone signaling can paradoxically fuel prostate cancer escape, a fly model reveals.

Androgen deprivation therapy — suppressing male sex hormone signaling — is a cornerstone of advanced prostate cancer treatment. The underlying assumption is that prostate cancers depend on androgen receptor (AR) signaling to survive. But this study challenges that assumption, finding that canonical AR signaling is actually deactivated in prostate cancer tissues, and that this loss tightly correlates with disease progression.

To test whether losing sex steroid signaling might actively drive cancer progression, the team used a Drosophila (fruit fly) model of prostate cancer. When they repressed the fly equivalent of sex steroid receptor signaling (the ecdysone receptor), they observed a paradox: some tumor formation decreased, but a new population of tumor cells emerged with the ability to escape the epithelium — wedging between normal tissue and the basement membrane through an altered extrusion mechanism.

The mechanism involves downregulation of an ecdysone target gene (βTub60D), which reshapes how tumor cells migrate out of normal tissue architecture. Rather than being eliminated, these cells adopted a new invasive strategy enabled by steroid deprivation. This raises a provocative question: does androgen deprivation therapy inadvertently create conditions for more aggressive tumor escape?

Key Findings

• Canonical AR signaling is deactivated in prostate cancer tissues, and its loss correlates with cancer progression — not regression.
• In a Drosophila prostate cancer model, ecdysone receptor repression reduces some extra-epithelial tumor formation but induces a new, previously suppressed tumor cell population.
• The emerging tumor cells escape the epithelium through altered basal extrusion, forming an abnormal layer between epithelium and basement membrane.
• This escape mechanism depends on downregulation of the ecdysone target gene βTub60D.
• Loss of sex steroid signaling has dual, opposing effects on tumor biology: anti-tumor in some contexts, pro-tumor in others.

Implications

These findings directly challenge the therapeutic rationale for sex steroid deprivation in prostate cancer. If deprivation therapy suppresses a pathway already deactivated in aggressive tumors while simultaneously enabling a new escape mechanism, the net effect could be counterproductive at certain disease stages. This warrants clinical examination of AR pathway activity at the time of treatment decisions. The basal extrusion mechanism also opens new angles for understanding how castration-resistant prostate cancer arises.

Caveats

This is a preprint and has not been peer-reviewed. The Drosophila model is a significant limitation — fruit fly accessory glands are not human prostates, and mechanisms may not translate directly. The clinical correlation between AR deactivation and progression is associative in human tissues, not experimentally causal. No human patient outcome data are presented. Summary is based on abstract only.

Source: bioRxiv — 2026-04-09