Fig 2: MYCL impairs cell adhesion and induces cytoskeletal remodeling in prostate adenocarcinoma cellsA. Confirmation of MYCL overexpression in C4–2B cells at both mRNA and protein levels.B. Cell proliferation assays showing comparable growth rates between control and MYCL-overexpressing prostate adenocarcinoma cells.C. Cell adhesion assays demonstrating reduced attachment of MYCL-overexpressing cells over time compared with controls. Representative phase-contrast images (bottom) illustrate altered cellular morphology and reduced adhesion in MYCL-overexpressing cells.D. Transcriptomic analysis revealing downregulation of integrin and cell-cycle associated genes.E. Heatmap of altered cytoskeletal and cell-cell adhesion genes, including Ephrin-EPH signaling, Rho-Rac GTPase signaling, focal adhesion, and extracellular matrix remodeling.F. RT-qPCR validation confirming reduced expression of integrins (ITGB1, ITGAV) and proliferation markers (KI67, AURKA), alongside increased expression of the mesenchymal marker VIM. Right: Western blot analysis showing reduced expression of CCND1 in MYCL-overexpressing cells. Statistical significance was determined using Student’s t-test; all comparisons shown were significant (P < 0.05).

Fig 3: MYCL is upregulated and MYC is downregulated in neuroendocrine prostate cancerA. Heatmap showing expression of the indicated genes in CRPC-adenocarcinoma (CRPC-Adeno) and neuroendocrine prostate cancer (CRPC-NE) patient samples from the Beltran cohort.B. Violin plots comparing expression of MYC family members (MYC, MYCL, MYCN) between CRPC-Adeno and CRPC-NE samples in the Beltran cohort.C. Heatmap of the indicated genes across patient groups from the ProAtlas dataset, including nonmalignant prostate tissue, adenocarcinoma with different Gleason score, and neuroendocrine prostate cancer.D. Box plots comparing expression of MYC family genes across nonmalignant samples, adenocarcinoma stratified by Gleason score, and NEPC in the ProAtlas dataset.E. Heatmap of selected lineage and MYC family genes across prostate cancer cell lines from the CTPC dataset.F. Box plots comparing MYC family gene expression across prostate cancer cell lines from the CTPC dataset.G. RT-qPCR validation of MYC family gene expression across representative prostate cancer cell lines.H. Western blot analysis of MYC family protein levels across prostate cancer cell lines.

Fig 4: MYCL suppresses androgen receptor signaling and promotes resistance to AR pathway inhibitionA. Gene set enrichment analysis (GSEA) showing significant suppression of the Hallmark androgen response pathway in MYCL-overexpressing C4–2B cells compared with controls.B. Heatmap of AR-regulated genes in MYCL-overexpressing cells demonstrating coordinated downregulation of AR-positive targets and relative enrichment of AR-negative target genes that are typically induced following androgen deprivation.C. RT-qPCR analysis showing reduced expression of AR and canonical AR target genes, including KLK3 and luminal epithelial differentiation markers (NKX3–1 and SPDEF), in MYCL-overexpressing cells (left), with corresponding Western blot analysis confirming reduced AR and NKX3–1 protein levels (right).D. AR-responsive luciferase reporter assay demonstrating reduced AR transcriptional activity upon co-transfection with MYCL under control conditions and following enzalutamide (ENZ) treatment.E. Cell viability assays showing altered growth responses of MYCL-overexpressing cells compared with controls. Under complete media (CM), MYCL-overexpressing cells exhibit reduced proliferation, whereas under increasing concentrations of enzalutamide, MYCL-overexpressing cells display relatively improved proliferation compared with control cells. Statistical significance was determined using Student’s t-test (P < 0.05).

Fig 5: MYCL drives neuroendocrine-like transcriptional reprogramming and suppresses MYC signalingA. Gene set enrichment analysis (GSEA) of Hallmark pathways showing enrichment of hypoxia, epithelial–mesenchymal transition, glycolysis, KRAS signaling, and apical surface pathways, with concurrent suppression of androgen response, MYC target genes, and Notch signaling in MYCL-overexpressing cells.B. GSEA of Gene Ontology biological processes revealing upregulation of differentiation-associated processes, alongside downregulation of DNA replication, DNA repair, and chromosome organization pathways upon MYCL overexpression.C. Dot plot highlighting enrichment of neuronal and axon-related gene programs, including axon guidance, neuron projection development, and nervous system processes, in MYCL-overexpressing cells.D. Heatmap of representative genes involved in axon guidance, synaptic/secretion pathways, and neuroendocrine (NE) plasticity, demonstrating coordinated upregulation of neuronal and NE-associated transcriptional modules in MYCL-overexpressing C4–2B cells compared with controls.E. RT-qPCR validation showing reduced MYC and increased ENO2 expression in MYCL-overexpressing cells (left), with corresponding Western blot analysis confirming suppression of MYC protein levels (right). Statistical significance was determined using Student’s t-test (P < 0.05).