Two studies from the Universidade de São Paulo's Biomedical Sciences Institute, published in the same issue of Communications Biology, have assigned surprising new functions to a pair of well-known proteins. The first concerns STIP1, a stress-inducible protein that links molecular chaperones to their client proteins and helps maintain the cell's protein balance. Working with genetically modified mice, the researchers found that reducing STIP1 in embryonic stem cells caused loss of pluripotency, heightened vulnerability to stress and genetic instability, while increasing it had the opposite, protective effect.
The second study examined Maspin, a protein long described in the literature as a tumour suppressor. The team showed that it binds to the cytoskeletal structures that give cells their shape and stability, and that depleting it in epithelial cells made them lose contact with one another and deform. Maspin also regulates the growth of the filaments that organise the cell interior, placing it at the heart of tissue architecture.
Both findings carry translational weight. STIP1's role in preserving stem cell identity makes it a candidate lever for regenerative medicine, while the Maspin work, rooted in breast cancer research, suggests the protein can act as either protector or promoter of cancer depending on cellular context, complicating a two-decade-old label. Supported by 19 FAPESP grants and scholarships, the studies exemplify the patient cell biology that underpins future therapies.