Thymosin Beta-4 Drives Endometriosis Progression Through a Circular RNA Signaling Pathway | Research

The takeaway

A circular RNA (circPIP5K1A) promotes endometriosis by sponging miR-153-3p to upregulate the peptide Thymosin beta-4 (TMSB4X), which activates TGF-β signaling to increase cell growth, migration, and invasion.

TMSB4X → TGF-β activation
Thymosin beta-4 X-linked (upregulated by circPIP5K1A sponging miR-153-3p) activates TGF-β signaling to drive endometriosis cell proliferation, migration, and invasion

What the researchers found

CircPIP5K1A was significantly elevated in endometriosis tissues and cells. Silencing circPIP5K1A suppressed proliferation, blocked cell cycle progression, increased apoptosis, and decreased migration and invasion. The mechanism: circPIP5K1A sponges miR-153-3p, relieving its suppression of TMSB4X (Thymosin beta-4 X-linked). Elevated TMSB4X then activates TGF-β signaling, promoting endometriosis progression. Inhibiting miR-153-3p reversed the effects of circPIP5K1A knockdown, confirming the regulatory axis.

Why it matters

Endometriosis affects about 190 million women worldwide and has limited treatment options beyond hormones and surgery. Identifying Thymosin beta-4 as a key driver — regulated through a specific circRNA-miRNA axis — reveals a potential new therapeutic target. If this pathway can be blocked, it could offer a novel, non-hormonal treatment approach.

The numbers in context

CircPIP5K1A high in EM; silencing reduced proliferation, migration, invasion; increased apoptosis; miR-153-3p sponging confirmed; TMSB4X upregulated; TGF-β pathway activated

How the study worked

In vitro study using endometriosis tissues and hEM15A cells. Gene/protein expression measured by RT-qPCR and Western blotting. Functional assays: CCK-8 (viability), wound healing (migration), transwell (invasion), flow cytometry (cell cycle, apoptosis). Molecular interactions confirmed by dual-luciferase reporter assay and RNA immunoprecipitation (RIP).

Who was studied

Endometriosis tissue samples and hEM15A cells studying circPIP5K1A/miR-153-3p/TMSB4X pathway

What this study cannot tell us

Entirely in vitro — no animal model or clinical validation of the circPIP5K1A/miR-153-3p/TMSB4X axis in vivo. Endometriosis involves complex hormonal, immune, and stromal interactions not captured in cell culture. The therapeutic potential of targeting this pathway remains speculative. The study used a single endometriosis cell line, limiting generalizability across endometriosis subtypes.

How to read the evidence

This is an in vitro mechanistic study using endometriosis tissue samples and cell lines. While the molecular pathway is well-validated through multiple complementary assays (luciferase, RIP, functional experiments), all work was done in cell culture without in vivo confirmation.

When this study was published

Published in 2021, this study established the circPIP5K1A/miR-153-3p/TMSB4X axis in endometriosis and remains relevant as Thymosin beta-4's role in gynecological disease continues to be explored.

The bigger picture

This study reveals a new role for Thymosin beta-4 beyond its well-known functions in wound healing and tissue repair. In endometriosis, its pro-migratory and pro-invasive properties — normally beneficial for repair — become pathological, driving disease progression. This dual nature of peptide functions illustrates how the same peptide can be therapeutic in one context and disease-promoting in another.

Questions still open

Could blocking TMSB4X expression or its downstream TGF-β signaling reduce endometriosis severity in animal models?
Is TMSB4X elevated in endometriosis lesions from patients compared to healthy peritoneum?
Would targeting the circPIP5K1A/miR-153-3p axis with RNA-based therapeutics be feasible for endometriosis treatment?

Common questions

What role does Thymosin beta-4 play in endometriosis?

Thymosin beta-4 normally helps with cell movement and tissue repair. In endometriosis, it's overproduced due to a chain of molecular events (circular RNA → microRNA suppression → Thymosin beta-4 increase), which activates the TGF-β pathway. This drives the cells to grow, migrate, and invade tissue — the key behaviors that make endometriosis progress and spread.

Could this finding lead to new treatments for endometriosis?

Potentially. If blocking Thymosin beta-4 or the circular RNA that controls it can slow endometriosis progression, it could offer a non-hormonal treatment option — important because current hormonal treatments have significant side effects and can affect fertility. However, this concept needs to be tested in animal models and then clinical trials.

Read the original research

Circular RNA PIP5K1A (circPIP5K1A) accelerates endometriosis progression by regulating the miR-153-3p/Thymosin Beta-4 X-Linked (TMSB4X) pathway.

Bioengineered, 12(1), 7104-7118

View on PubMed ↗Publisher’s paper ↗

Citation

Sun, Lin; Wei, Yan; Wang, Junli. (2021). Circular RNA PIP5K1A (circPIP5K1A) accelerates endometriosis progression by regulating the miR-153-3p/Thymosin Beta-4 X-Linked (TMSB4X) pathway.. Bioengineered, 12(1), 7104-7118. https://doi.org/10.1080/21655979.2021.1978618