Dual-Drug Therapy Shows ⁤Promise in Bladder Cancer Treatment

Updated Jan. 14, 2025
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A new study reveals that ⁣a protein, PIN1, plays a important role in the development of bladder cancer by stimulating cholesterol synthesis, which fuels cancer cell growth. Researchers at the Salk Institute ⁤have developed a dual-drug therapy that effectively stopped tumor ‍growth in mice.

The therapy combines sulfopin, an experimental⁢ PIN1 inhibitor, with simvastatin, a statin already used in humans‍ to lower cholesterol. The findings, ⁤published in Cancer Discovery, suggest a potential new⁤ approach to treating this common and costly cancer.

Bladder cancer ranks among the most ⁤frequently diagnosed cancers globally and⁢ poses a⁢ significant public health challenge.Current treatments are often expensive and⁣ can lead to lifelong management or rapid disease progression.

Tony Hunter,American Cancer ⁣Society professor at Salk,said identifying PIN1’s role and the mechanism driving tumor growth is exciting. He added that the effectiveness of the therapeutic combination in suppressing tumor growth in mice offers hope for future clinical trials, pending approval of a PIN1 inhibitor for clinical use.

The researchers discovered PIN1 in 1996. It acts as an enzyme that recognizes and changes the shape of proteins when phosphate is added to serine next to proline. This process, known as phosphorylation, is crucial in controlling cell proliferation, and it’s dysregulation can lead to cancer.

By comparing normal bladder cells with cancerous ones, the team found that PIN1 expression was higher in bladder cancer cells, especially in the urothelium, ⁤the lining ⁣of the urinary tract. Eliminating the PIN1 gene reduced the development and migration of cancerous cells.

Further examination revealed that without PIN1, ⁤the cholesterol synthesis pathway, mediated by the SREBP2 protein, was substantially altered, resulting in lower cholesterol levels. xue Wang, a postdoctoral researcher in Hunter’s lab, explained that cancer cells require ⁣significant cholesterol for excessive growth, and PIN1 plays a vital role in its production.

The researchers confirmed that PIN1 works with SREBP2 to ⁤boost cholesterol production. Removing PIN1 curtails the cancer’s fuel supply,⁤ while reinstating it reverses these anti-cancer effects.

The dual-drug⁣ approach, using sulfopin to inhibit PIN1 and simvastatin to block HMGCR, an enzyme in the cholesterol pathway, ⁣proved more effective then either drug alone in suppressing cancer cell proliferation and tumor growth in mice.

Hunter noted that this is highly likely just one of many roles PIN1 plays in cancers. He added that the potential to repurpose statins, already used for cardiovascular disease, in combination with othre drugs ⁢for bladder cancer therapy is promising. The team plans to investigate whether PIN1 plays⁣ a similar role in other cancers.

What’s next

Future research will focus on clinical⁢ trials to test the effectiveness of the dual-drug therapy ⁣in humans and⁣ further ⁢explore PIN1’s role in various cancer types, perhaps leading to broader treatment⁢ applications.