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Biology subjects

Neve, M.

Publications and source records attributed to Neve, M..

2 recordsLinked to original sources

Embryonic stem cell factors DPPA2/4 facilitate a unique chromatin state in non-small cell lung cancer

Embryonic regulators are often re-expressed in cancers, however the functional and molecular significance of this is not always understood. The epigenetic priming factors Developmental Pluripotency Associated 2 and 4 (DPPA2/4) have crucial roles in early development and are implicated in cancer pathogenesis. We reveal in non-small cell lung cancer (NSCLC), DPPA2/4 co-expression is associated with poorly differentiated tumours, impaired patient outcomes and accelerated in vivo xenograft tumour growth. Proteomic analyses reveal DPPA2/4 dimerise to enhance their protein stability and binding efficiency to nucleosomes. Our multiomic epigenomic analysis uncovered novel functions for DPPA2/4 in facilitating a unique chromatin landscape in NSCLC cells at active promoters and enhancers. These domains are simultaneously marked by active H3K4me3, PRC1 deposited H2AK119Ub but devoid of PRC2 deposited H3K27me3. This paradoxical uncoupling between the activity of the Polycomb Repressive Complexes is likely driven by H3K27ac at these regions that prevents PRC2 catalytic activity but not recruitment. Our results demonstrate how in NSCLC cells, DPPA2/4 promote a "poised for repression" chromatin state, uncoupling complex recruitment from catalytic activity. Our study highlights how aberrant re-activation of embryonic factors in cancers may take on new functions, promoting tumourigenesis.

molecular biology↗

Systematic loss of function screens identify pathway specific functional circular RNAs

Circular RNAs (circRNAs) are covalently closed single stranded RNAs that are produced by RNA back-splicing. A small number of circRNAs have been implicated as functional, however, we still lack systematic understanding of cellular processes and signalling pathways that are regulated by circRNAs. A major gap in understanding circRNA function is the ability to define pathways that are regulated by circRNAs. Here, we generated a pooled shRNA library targeting the back-splice junction of 3,354 human circRNAs that are expressed at low to high levels in humans. We used this library for loss of function proliferation screens in a panel of 18 cancer cell lines from four tissue types that harbour mutations leading to constitutive activity of defined pathways. Using this dataset, we identify context specific and non-specific circRNAs. We validated these observations with a secondary screen and uncovered a role for circRERE, a cell essential circRNA that regulates ferroptosis. Furthermore, we characterised the functional roles of pathway-specific circRNA, circSMAD2, a novel regulator of the WNT pathway and circMTO1, a regulator of MAPK signalling in a PTEN dependent manner. Our work sheds light on molecular pathways regulated by circRNAs and provides a catalogue of circRNAs with a measurable function in human cells.

genetics↗