Targeting the Wnt signalling pathway in cancer: Prospects and perils

The Wnt pathway, involved in cancer development and progression, has for a long time been said to be undruggable, owing to its complexity and involvement in stem cell biology. This mindset has shifted in the last few years as new research and insights into the pathway mechanisms specific to tumour cells become apparent, leading to the development of multiple compounds targeting the pathway. In this review, we introduce the Wnt pathway and its connections to cancer biology and therapy resistance. We further dive into the details of drugs that have entered clinical trials, examining their successes and side effects. We show that these drugs all have one thing in common: in order to be successful, the drugs must target tumour specific activated sub-branches of the pathway, either at the receptor level or at the nuclear transcription level.