Bladder cancer is the seventh most common cancer in males worldwide, researchers said.
It can be grouped into two types: non-muscle-invasive cancers, which have a five-year survival rate of 90 per cent, and muscle-invasive cancers, which have poor prognoses.
The latter are normally treated with anti-cancer drugs such as cisplatin, but tend to become chemo-resistant and spread to organs such as the lungs and liver, as well as bone.
Researchers at the Hokkaido University in Japan, inoculated human bladder cancer cells labelled with luciferase into mice, creating a xenograft bladder cancer model.
The primary bladder xenograft gradually grew and, after 45 days, metastatic tumours were detected in the lungs, liver and bone.
By using a microarray analysis including more than 20,000 genes for the metastatic tumours, the team discovered a three- to 25-fold increase of the metabolic enzyme aldo-keto reductase 1C1 (AKR1C1) which mediates the resistance of metastatic bladder cancer cells.