Perivascular niches: critical hubs in cancer evolution.

Tumors are heterogeneous ecosystems in which cancer cells coexist within a complex tumor immune microenvironment (TIME). The malignant, stromal, and immune cell compartments establish a plethora of bidirectional cell-cell communication crosstalks that influence tumor growth and metastatic dissemination, which we are only beginning to understand. Cancer cells either co-opt or promote the formation of new blood and lymphatic vessels to cope with their need for nutrients and oxygen.

p57 acts as a transcriptional corepressor to regulate intestinal stem cell fate and proliferation.

p57 is a cyclin/CDK inhibitor and a negative regulator of cell proliferation. Here, we report that p57 regulates intestinal stem cell (ISC) fate and proliferation in a CDK-independent manner during intestinal development. In the absence of p57, intestinal crypts exhibit an increased proliferation and an amplification of transit-amplifying cells and of Hopx ISCs, which are no longer quiescent, while Lgr5 ISCs are unaffected.

A cellular hierarchy in melanoma uncouples growth and metastasis.

Although melanoma is notorious for its high degree of heterogeneity and plasticity, the origin and magnitude of cell-state diversity remains poorly understood. Equally, it is unclear whether growth and metastatic dissemination are supported by overlapping or distinct melanoma subpopulations. Here, by combining mouse genetics, single-cell and spatial transcriptomics, lineage tracing and quantitative modelling, we provide evidence of a hierarchical model of tumour growth that mirrors the cellular and molecular logic underlying the cell-fate specification and differentiation of the embryonic neural crest.