News & Views

Studies of stem cell behaviour during regeneration have largely focused on understanding how cells make the choice between self-renewal and differentiation. It remains unclear whether cells undergo smooth transitions during differentiation or pause at selective intermediate states. Three studies now explore this question in lung regeneration.

Cellular plasticity allows tumours to adapt to and overcome therapeutic challenges. A recent study uncovered the gene regulatory networks that govern cell states and phenotype switching in melanoma, opening up possibilities to therapeutically target cell states or phenotypic plasticity to render melanoma cells more vulnerable to treatment.

In this issue of Nature Cell Biology, Mercier et al. show that acute changes in membrane tension may be a physiological trigger for ESCRT assembly, which drives membrane scission, luminal vesicle budding, and a wide array of other membrane remodelling events throughout the cell.

There is increasing appreciation that many proteins self-aggregate in cells to form functional subcompartments, some of which exist as a separate liquid phase. A study now identifies the biophysical properties of AKAP95 protein condensates as critical for supporting cancer cell proliferation and RNA splicing.

Secretory proteins undergo multiple rounds of co- and post-translational quality control checks inside the cell, but how their integrity is maintained outside the cell is an emerging topic. A study establishes a model system to investigate how the extracellular proteome is protected and integrates its findings into existing immune pathways.

Cellular senescence has been widely recognised for decades as a stable arrest of cell proliferation. A recent study identifies senescence establishment and maintenance as a dynamic and reversible process regulated by (in)activation of a predetermined enhancer landscape controlled by the pioneer transcription factor AP-1.

Stem cells tightly link their metabolism to cell fate decisions; however, how cancers co-opt and bypass metabolic pathways for growth advantage remains unclear. New evidence in this issue highlights how cancer stem cells avoid epigenetically driven differentiation by shutting down endogenous serine synthesis and becoming serine auxotrophs.

The transcription factor oestrogen receptor alpha (ERα) has long been targeted for therapeutic benefit in cancer, but drug resistance can emerge through a multitude of mechanisms. A study now reveals how the ERα cistrome can become reprogrammed to confer resistance to tamoxifen in breast cancer.

CRISPR base editors can induce single-base-pair changes in the genome, although they are often inefficient. A study now shows that fusion of the DNA-binding domain of RAD51 to base editors enhances both the efficiency and the targeting range of optimized enzymes. These ‘hyper-editors’ offer effective tools for disease modeling and gene therapy.

Pluripotent cells generate all types of cells in the body and have largely been classified dichotomously into two types: naïve and primed. Arguing against a binary classification system, a study now discovers a unique transition state between naïve and primed pluripotency and describes the signals that control this transition.

Active transport along microtubules by molecular motors is a crucial cellular process that is disrupted in human diseases. Single-molecule studies from three independent groups reveal a new molecular mechanism for how cells control the activity of the complex microtubule motor cytoplasmic dynein via the neurodevelopmental protein LIS1.

Post-translational histone modifications are important regulators of nuclear reprogramming. A study now reveals that histone lysine demethylase KDM4A-mediated H3K9me3 demethylation in mammalian oocytes is essential for zygotic genome activation and preimplantation development.

YAP and TAZ, paralogous mammalian genes, act as the key transcriptional effectors of the Hippo pathway. Two recent reports show that both YAP and TAZ form liquid–liquid phase-separated bodies that promote gene transcription by engaging in super-enhancers.

Piwi proteins are aberrantly induced in human tumours, but their function in cancer has been poorly understood. A study now shows that in the absence of piRNA loading, human PIWIL1 promotes pancreatic cancer metastasis by acting as a co-activator of the anaphase-promoting complex/cyclosome (APC/C) to degrade the cell-adhesion protein Pinin.

The lack of endogenous reporter lines is a bottleneck in the study of subcellular dynamics in human adult stem cell (ASC)-derived organoids. An approach using CRISPR–Cas9-mediated homology-independent organoid transgenesis (CRISPR–HOT) in ASC-derived organoids now narrows the gap between basic research and translational studies in human organoids.

Misfolded proteins in the endoplasmic reticulum (ER) are returned to the cytosol and destroyed by a process known as ER-associated degradation (ERAD). Hrd1 has been implicated as the channel that mediates the transport of ERAD substrates to the cytosol. A study demonstrates that Hrd1 is gated by autoubiquitination and a soluble ERAD substrate.

Gene editing holds promise for the treatment of cancers that are driven by well-characterised molecular alterations. A study now provides a proof of concept for the feasibility of in vivo gene editing to correct TERT mutations in glioblastoma, providing a platform for the direct manipulation of genetic alterations to reduce tumour growth.

Understanding the metabolic rewiring of pancreatic ductal adenocarcinoma is an emerging strategy for identifying cancer-associated liabilities and improving treatment. A new study now elucidates the function of the transaminase BCAT2 in the early stages of tumor development, providing insights that could stimulate novel therapeutic strategies.

The ribosome decodes messenger RNAs and constructs proteins based on the genetic blueprint. Ribosomes also associate with non-coding RNAs, such as PIWI-interacting RNA (piRNA) precursors, during the meiotic pachytene stage. Intriguingly, the ribosome mediates pachytene piRNA biogenesis by guiding endonucleolytic cleavage of piRNA precursors.

A mechanism of secretory autophagy explains aspects of the packaging of proteins and RNA into extracellular vesicles and paves the way to a better understanding of their biological roles and medical applications.