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de la Serna, I. L.

Publications and source records attributed to de la Serna, I. L..

2 recordsLinked to original sources

YAP1 drives aggressive and therapy resistant state in melanoma through reprogramming the chromatin and regulating immune evasive programs

Despite promising initial results in targeting the RAF-MEK-ERK cascade, resistance to BRAF/MEK inhibitors remains a critical challenge in nearly 50% of melanoma patients. Our study demonstrates that robust YAP1 activation in metastatic melanoma correlates with poor survival and drives transcriptional programs linked to therapeutic resistance. Mechanistically, YAP1 predominantly remodels the chromatin landscape in resistant tumors by partnering with BRD4 and TEAD, creating a permissive transcriptional state that sustains oncogenic signaling. Clinical validation in biopsies from resistant melanoma confirms elevated expression of YAP1 target genes. Furthermore, pharmacological inhibition of BRD4 or TEAD reduces YAP1-driven transcription and reactivates antitumor immunity programs. TEAD specific inhibitors (and not verteporfin which is a highly non-specific inhibitor) synergize with immune checkpoint blockade in in vivo model system by promoting increased CD8 T cell infiltration and prolonged survival in the melanoma mouse model. Collectively, these findings reveal a chromatin-centric vulnerability in BRAF/MEK inhibitor-resistant melanoma and propose TEAD specific inhibitors as a promising dual strategy to overcome resistance and reinvigorate the immune response, offering a novel therapeutic avenue for patients. Resistance to BRAF and MEK inhibitors remains a major obstacle in the treatment of melanoma. Here, we show that elevated YAP1 activity in metastatic melanoma is associated with poor patient survival and drives transcriptional programs that promote therapeutic resistance. Mechanistically, YAP1 cooperates with BRD4 and TEAD to reprogram the chromatin landscape, establishing an oncogenic transcriptional state that sustains resistance. Analysis of patient-derived melanoma biopsies confirms increased expression of YAP1 target genes in resistant tumors. Targeting this epigenetic circuitry using pharmacological inhibitors of BRD4 or TEAD effectively suppresses YAP1-driven transcriptional output and restores antitumor immune activity, as evidenced by enhanced CD8 T cell infiltration and prolonged survival in resistant melanoma models. These effects are further supported by transcriptomic and chromatin accessibility analyses, which reveal reduced expression of immune-suppressive and proliferation-associated gene networks upon TEAD inhibition. Collectively, our findings identify a chromatin-centric mechanism underlying resistance to MAPK-targeted therapy and nominate TEAD inhibition as a promising dual-action strategy to both overcome resistance and re-engage antitumor immunity. This work offers a compelling therapeutic avenue for patients with drug-resistant melanoma.

cancer biology↗

Ablation of the evolutionarily acquired functions of the Atp1b4 gene in mice protects against obesity and increases metabolic capacity

The co-option of vertebrate orthologous ATP1B4 genes in placental mammals has radically altered the properties of the encoded BetaM proteins, which are genuine {beta}-subunits of Na,K-ATPases in lower vertebrates. Eutherian BetaM acquired an extended Glu-rich N-terminal domain resulting in complete loss of its ancestral function and became skeletal and cardiac muscle-specific component of the inner nuclear membrane. BetaM is expressed at the highest level during perinatal development and is implicated in gene regulation (Pestov et al., Proc Natl Acad Sci U S A. 2007). Here we report the long-term consequences of the Atp1b4 ablation on metabolic parameters in adult mice. BetaM deficient (Atp1b4-/Y) mice have significantly lower body weight and remarkably low adiposity. They exhibit lower fasting blood glucose, enhanced insulin sensitivity, and improved glucose tolerance as compared to their wild type littermates. Knockout mice display higher heat production, increased food intake, elevated oxygen consumption especially in darkness, and higher locomotor activity. The lower respiratory exchange ratio of knockout mice indicates that fat from the diet is metabolized rather than deposited as storage. These robust changes in mouse metabolic parameters induced by Atp1b4 disruption clearly demonstrate that eutherian BetaM plays an important role in the regulation of adult mouse metabolism. Ablation of Atp1b4, leading to the loss of evolutionarily acquired BetaM functions, serves as a model for a potential alternative pathway in mammalian evolution. Essentially, Atp1b4 ablation simulates a scenario where a specific stage in mammalian evolution is bypassed. Our results suggest that bypassing the co-option of Atp1b4 potentially reduces susceptibility to obesity.

evolutionary biology↗