Biology subjects

Sigala, S.

Publications and source records attributed to Sigala, S..

5 recordsLinked to original sources

bioRxiv2026

A multilayered in silico analysis links UHRF1, DNA methylation and developmental chromatin memory to lineage-dependent prognosis in gastric, renal and adrenal cancers

Aberrant DNA methylation is a hallmark of cancer, but its clinical interpretation remains debated. UHRF1, a key epigenetic adaptor for DNA methylation maintenance and chromatin bivalency regulation in embryonic stem cells, is frequently overexpressed yet shows context-dependent prognostic behaviour. By integrating bulk and single-cell transcriptomics, CpG-resolution methylation, developmental chromatin states, immune profiling and clinical outcomes across gastric (STAD), clear-cell renal (KIRC) and adrenal (ACC) carcinomas, we identified a four-class UHRF1-embryonic morphogenesis (UHRF1-EM) framework resolving this paradox. This axis revealed an inverse prognostic pattern: whilst across all three tumours EM-low and EM-high states mark better or worse prognosis, respectively, UHRF1-high levels associate with favourable outcome in STAD (UH-EML), and unfavourable in KIRC and ACC (UH-EMH). The classification proved reproducible and independently prognostic after adjustment for stage and molecular subtypes, outperforming existing classifiers and exceeding pathological stage in KIRC and ACC. Multivariable models incorporating UHRF1-EM yielded uniformly positive {Delta}C-indices. Hypermethylation associated with the UHRF1-EM axis was enriched at ESC bivalent developmental loci (EM and oncofoetal genes), but not at housekeeping cell-cycle sites. In STAD, this pattern was related to oncofoetal gene downregulation and best prognosis, whereas in KIRC and ACC it matched with gene-body/enhancer methylation, higher EM expression, immunosuppressive microenvironments and worst prognosis. Together, these findings establish the UHRF1-EM axis as a clinically robust molecular classifier and support a mechanistic model in which tumour-specific epigenetic engagement of developmental loci may contribute to the prognostic inversion, providing a foundation for further mechanistic experimental validation.

cancer biology↗

bioRxiv2026

Updating ACC preclinical models: characterization of two new patient-derived cell lines

AdrenoCortical Carcinoma (ACC) is an aggressive, rare and heterogenous malignancy, that requires diverse preclinical models. For this reason, the development of new cell lines is pivotal. Here we describe the development and characterization of two of them, SMAC-2 and SMAC-3, established from surgical specimens of ACC patients. The characterization included their mutational profiling, the evaluation of steroidogenic enzymes expression, secretory activity and the expression of steroid hormone receptors. The proliferative ability of these cells within a zebrafish embryos xenograft was also evaluated. SMAC-2 originated from a metastatic EDP-M-treated ACC in a female patient with Cushing syndrome and hyperandrogenism, while SMAC-3 derived from a male patient with a mitotane-treated local recurrence, with no sign of hypercortisolism. TP53 was mutated in both lines. SMAC-2 cells were characterized by a pathogenic alteration on CTTNB1 gene and a deletion of CDKN2A gene, while SMAC-3 on MSH2 gene. Basal hormonal status analysis showed a cell model-specific fingerprint either in the hormonal secretion and gene and protein expression of steroid hormone receptors. SMAC-2 secreted high levels of cortisol. SMAC-3 secreted low basal level of cortisol. Mitotane displayed in both cell lines a low potency. Under the experimental conditions used, the xenografted area did not increase for both cell models. Experiments were carried out to study the stability of the two cell lines. SMAC-2 and SMAC-3 display unique molecular and functional features, expanding the repertoire of experimental ACC models and representing valuable tools for preclinical research alongside established cell lines.

pharmacology and toxicology↗

bioRxiv2024

Dlk1 is a novel adrenocortical stem/progenitor cell marker that predicts malignancy in adrenocortical carcinoma

Disruption of processes involved in tissue development and homeostatic self-renewal is increasingly implicated in cancer initiation, progression, and recurrence. The adrenal cortex is a dynamic tissue that undergoes life-long turnover. Here, using genetic fate mapping and murine adrenocortical carcinoma (ACC) models, we have identified a population of adrenocortical stem cells that express delta-like non-canonical Notch ligand 1 (DLK1). These cells are active during development, near dormant postnatally but are re-expressed in ACC. In a study of over 200 human ACC samples, we have shown DLK1 expression is ubiquitous and is an independent prognostic marker of recurrence-free survival. Paradoxically, despite its progenitor role, spatial transcriptomic analysis has identified DLK1 expressing cell populations to have increased steroidogenic potential in human ACC, a finding also observed in four human and one murine ACC cell lines. Finally, the cleavable DLK1 ectodomain is measurable in patients serum and can discriminate between ACC and other adrenal pathologies with high sensitivity and specificity to aid in diagnosis and follow-up of ACC patients. These data demonstrate a prognostic role for DLK1 in ACC, detail its hierarchical expression in homeostasis and oncogenic transformation and propose a role for its use as a biomarker in this malignancy. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=160 SRC="FIGDIR/small/609117v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@12aba74org.highwire.dtl.DTLVardef@374daaorg.highwire.dtl.DTLVardef@cbdc37org.highwire.dtl.DTLVardef@1e6aeac_HPS_FORMAT_FIGEXP M_FIG C_FIG Statement of significanceThis study presents DLK1 as a novel biomarker in ACC with opportunities for use in the diagnosis, prognosis and longitudinal follow up of patients. DLK1, a marker of adrenocortical stem cells, is re-expressed in ACC, is measurable in patients serum and is associated with increased malignancy.

cancer biology↗

bioRxiv2023

The super-enhancer landscape reflects molecular subgroups of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare cancer of the adrenal gland with generally very unfavourable outcome. Two molecular subgroups, C1A and C1B, have been previously identified with a significant association with patient survival. In this work, we study chromatin state organization characterized by histone modifications using ChIP-sequencing in adult ACC. We describe the super-enhancer landscape of ACC, characterized by H3K27ac, and identify super-enhancer regulated genes that play a significant role in tumorigenesis. We show that the super-enhancer landscape reflects differences between the molecular sub-groups C1A and C1B and identify networks of master transcription factors mirroring these differences. Additionally, we study the effects of molecules THZ1 and JQ1 previously reported to affect super-enhancer-driven gene expression in ACC cell lines. Our results reveal that the landscape of histone modifications in ACC is linked to its molecular subgroups and thus provide the groundwork for future analysis of epigenetic reprogramming in ACC.

cancer biology↗

bioRxiv2022

Innovative multidimensional models in a high-throughput-format for different cell types of endocrine origin

The adrenal gland provides an important function by integrating neuronal, immune, vascular, metabolic and endocrine signals under a common organ capsule. It is the central organ of the stress response system and has been implicated in numerous stress-related disorders. While for other diseases, regeneration of healthy organ tissue has been aimed at such approaches are lacking for endocrine diseases - with the exception of type-I-diabetes. Moreover, tumor formation is very common, however, appropriate high-throughput applications reflecting the high heterogeneity and furthermore relevant 3D-structures in vitro are still widely lacking. Recently, we have initiated the development of standardized multidimensional models of a variety of endocrine cell/tissue sources in a new multiwell-format. Firstly, we confirmed common applicability for pancreatic pseudo-islets. Next, we translated applicability for spheroid establishment to adrenocortical cell lines as well as patient material to establish spheroids from malignant, but also benign adrenal tumors. We aimed furthermore at the development of bovine derived adrenal organoids and were able to establish steroidogenic active organoids containing both, cells of cortical and medullary origin. Overall, we hope to open new avenues for basic research, endocrine cancer and adrenal tissue-replacement-therapies as we demonstrate potential for innovative mechanistic insights and personalized medicine in endocrine (tumor)-biology.

cancer biology↗