Invasion of cancerous cells into healthy tissues, known as metastasis, is often what defines a cancer as 'aggressive'. Cells move around their local microenvironment using pseudopodia, tiny 'feet' that probe into new territory like outstretched toes in the darkness, pulling a cell in one direction once they find firm footing. Some of these breast cancer cells (highlighted in green) have developed invadopodia – spikes which allow them to gradually hack through collagen fibres (purple) that surround and support blood vessels (red – also pictured on the right), ultimately using the bloodstream to travel much further. The relationship between a tumour’s microenvironment and metastasis is complex, involving communication between many different types of cells in the local environment, such as white blood cells (highlighted in white). Tackling this complexity in the future may require novel approaches, such as mathematical algorithms designed to predict a specific tumour’s vital next steps.
Written by John Ankers