Biology subjects

Gambi, G.

Publications and source records attributed to Gambi, G..

4 recordsLinked to original sources

bioRxiv2025

TASC: A transcriptome-driven machine learning classifier to explore molecular heterogeneity and relapse-associated programs in T-cell Acute Lymphoblastic Leukemia

T-cell acute lymphoblastic leukemia is a biologically heterogeneous malignancy characterized by diverse transcriptional and genomic alterations. Recent studies have defined a set of recurrent molecular subtypes associated with distinct differentiation stages and clinical outcomes. However, no unified framework currently exists for assigning these subtypes in a standardized and accessible manner. Existing approaches often rely on mutation or fusion detection and may overlook broader transcriptional programs. The lack of a comprehensive, transcriptome-based classification tool has hampered the use of subtype-specific insights in both research and clinical settings. Here, we present a machine learning-based classifier trained on transcriptomic data to predict previously defined multi-omic subtypes of T-cell acute lymphoblastic leukemia. The model accurately assigns subtype identity across patient samples and cell lines, and provides a practical tool for standardized molecular stratification, supporting future integration into diagnostic and translational workflows, as demonstrated by its ability to reveal subtype-specific patterns of relapse.

bioinformatics↗

bioRxiv2025

Interaction of lncRNA LENT with DHX36 regulates translation and suppresses autophagy in melanoma.

The melanocyte lineage determining Microphthalmia-associated transcription factor (MITF) drives proliferation and survival of melanocytic melanoma cells through regulation of both coding genes and long non-coding RNAs (LncRNAs). Here we characterize LINC00520 (hereafter called LncRNA ENhancer of Translation, LENT) regulated by MITF and strongly expressed in melanocytic melanoma cells. LENT is essential for proliferation and survival of cultured melanocytic melanoma cells and xenograft tumours. LENT interacts with the G4 quadruplex resolvase DHX36 and both associate with the ribosome in the 80S and light polysome fractions. LENT modulates DHX36 association with a collection of mRNAs regulating their engagement with polysomes and fine-tuning their subsequent translation. These mRNAs encode proteins involved in endoplasmic reticulum (ER) and mitochondrial homeostasis as well as autophagy. Consequently, LENT silencing leads to extensive autophagy and mitophagy, compromised oxidative metabolic capacity accompanied by an accumulation and mis-localization of mitochondrial proteins leading to proteotoxic stress and apoptosis. The LENT-DHX36 axis therefore fine-tunes translation of proteins involved in ER and mitochondrial homeostasis suppressing autophagy and promoting survival and proliferation of melanoma cells.

cancer biology↗

bioRxiv2023

Super-enhancer driven expression of BAHCC1 promotes melanomacell proliferation and genome stability

Super enhancers (SE) are stretches of active enhancers ensuring high expression levels of key genes associated with cell function and survival. The identification of cancer-specific SE-driven genes and their functional characterization may prove to be a powerful means for the development of innovative therapeutic strategies. By performing epigenomic profiling in patient-derived short-term melanoma cultures, we identify a SE promoting the specific expression of BAHCC1 in a broad panel of cutaneous and uveal melanoma cells. BAHCC1 is highly expressed in metastatic melanoma, correlates with decreased patient survival and is required for tumor growth. Integrative genomics analyses reveal that BAHCC1 is a transcriptional regulator controlling expression of a subset of E2F/KLF-dependent cell cycle and DNA repair genes. BAHCC1 associates with BRG1-containing remodeling complexes at the promoters of these genes. In agreement, BAHCC1 silencing leads to decreased cell proliferation and delay in DNA repair. Consequently, BAHCC1 deficiency cooperates with PARP inhibition to induce melanoma cell death. Our study identifies a novel SE-driven gene expressed in cutaneous and uveal melanoma and demonstrates how its inhibition can be exploited as a therapeutic target, alone or in combination with DNA damage-inducing agents.

cancer biology↗

bioRxiv2019

CHD4 regulates PADI1 and PADI3 expression linking pyruvate kinase M2 citrullination to glycolysis and proliferation.

CHD3 and CHD4 are mutually exclusive ATPase subunits of the Nucleosome Remodelling and Deacetylation (NuRD) complex that regulates gene expression. CHD4 is essential for growth of multiple patient derived melanoma xenografts and for breast cancer. Here we show that CHD4 regulates expression of PADI1 (Protein Arginine Deiminase 1) and PADI3 in multiple cancer cell types modulating citrullination of three arginines of the allosterically-regulated glycolytic enzyme pyruvate kinase M2 (PKM2). Citrullination reprograms cross-talk between PKM2 ligands lowering its sensitivity to the inhibitors Tryptophan, Alanine and Phenylalanine and promoting activation by Serine. Citrullination thus bypasses normal physiological regulation by low Serine levels to promote excessive glycolysis defining a novel pathway regulating proliferation of melanoma and other cancer cells. We provide unique insight as to how conversion of arginines to citrulline impacts key interactions within PKM2 that act in concert to reprogram its activity as an additional mechanism regulating this important enzyme.

cancer biology↗