Background 

Bladder cancer often comes back after treatment, even when it is found early and has not yet spread into the muscle of the bladder. This is especially true for people with intermediate or high-risk bladder cancer that no longer responds to a treatment called Bacillus Calmette-Guérin (BCG). When this happens, there are few good treatment options left. Chemotherapy placed directly into the bladder does not always work well, and surgery to remove the bladder and create a new way for urine to leave the body can cause many complications. Because of these challenges, researchers are looking for safer and more effective alternatives. 

What the Study Proposes to Address 

This study explores a new idea: replacing the inner lining of the bladder, known as the urothelium, to stop the cancer from coming back. The idea comes from research in mice showing that after exposure to cancer-causing agents, a widespread pre-cancerous condition can take over most of the bladder lining. In these cases, the only way to prevent cancer from returning or growing is to completely replace that lining. To do this in humans, the researchers plan to create new bladder lining cells—called urothelial progenitor cells—from other types of cells in the body, such as fibroblasts (cells that normally make connective tissue). They will also develop ways to safely remove the damaged bladder lining and transplant the new, healthy cells in its place. 

Why This Research is Important 

If successful, this research could offer a new treatment for people whose bladder cancer keeps coming back after BCG therapy. Instead of removing the bladder entirely, doctors could one day replace only the unhealthy bladder lining with new, healthy cells. This could greatly reduce cancer recurrence and improve patients’ quality of life. By finding a way to stop bladder cancer from returning without major surgery, this study could change the future of treatment for thousands of patients. 

Final Report Summary

Scientists in this study discovered two important things about bladder cancer. First, they figured out which special “switches” in our DNA, called transcription factors, can turn normal skin-like cells (fibroblasts) into bladder stem cells. These new bladder stem cells can grow in lab dishes in 3D, like real bladder tissue, and can even turn into other types of bladder cells. Researchers hope these cells can one day help repair or replace damaged bladder tissue in future experiments using mice. 

The second discovery is that the tissue around bladder tumors, even when it looks normal under a microscope, is actually not normal at the molecular level. In people with bladder cancer, this surrounding tissue shows signs of stress and healing, similar to how the body responds to injury. Using advanced genetic testing called single-cell RNA sequencing, scientists found that this “normal-looking” tissue behaves more like the deeper, more aggressive layers of the bladder. They created a “basal score” to measure how much this change has happened. Patients with higher scores in this tissue tend to have worse outcomes. Researchers plan to test this finding further in future studies with bladder cancer patients.

None Reported as of August 2025

None Reported as of August 2025

Kris Prado, MD; Stanford University