Search bioRxiv⌕ Search

Biology subjects

Gastaldello, S.

Publications and source records attributed to Gastaldello, S..

3 recordsLinked to original sources

Synthetic inhibition of the SUMO pathway by targeting the SAE1 component via TAK-981 compound impairs tumor growth and chemosensitizers embryonal and alveolar rhabdomyosarcoma cell lines.

BackgroundRhabdomyosarcoma (RMS) is a highly aggressive pediatric soft tissue sarcoma with limited therapeutic options, particularly for cases resistant to conventional treatments. The SUMOylation pathway, which plays a key role in regulating cell cycle, apoptosis, and transcription, has emerged as a potential therapeutic target in RMS. Elevated levels of SUMO1 and SUMO2/3 conjugates in RMS cell lines, compared to normal human skeletal muscle cells, underscore the association between hyper-SUMOylation and aggressive cancer phenotypes. Understanding these molecular underpinnings is critical for the development of innovative and effective treatments. MethodsThe investigation encompassed transcriptomic and protein analyses to profile SUMOylation pathway components across alveolar and embryonal RMS subtypes, aiming to identify heterogeneity that could guide personalized therapy approaches. TAK-981s interactions with chemotherapeutic agents, were evaluated for synergistic effects. Additionally, its impact on radiosensitivity and key signaling pathways, such as AKT and ERK phosphorylation, was assessed to elucidate its mechanism of action. ResultsTranscriptomic and proteomic analyses revealed distinct expression profiles of SUMOylation pathway components across RMS subtypes, highlighting heterogeneity that could guide personalized therapeutic strategies. Notably, SAE1 protein was overexpressed in RMS tissues and cells, positioning it as a potential biomarker for this cancer. Its activity was effectively counteracted by TAK-981, a SUMO inhibitor that demonstrated significant therapeutic potential by suppressing RMS cell proliferation and migration and enhancing the cytotoxic effects of chemotherapeutic agents, actinomycin D and doxorubicin. However, TAK-981 did not increase radiosensitivity, suggesting its selective action through chemical inhibition mechanisms. Mechanistically, TAK-981 reduced phosphorylation of key signaling proteins, including AKT and ERK, critical for RMS cell survival. ConclusionThe findings of this study establish TAK-981 as a promising therapeutic agent for RMS. The results also provide foundational insights into the role of SUMOylation associated to the new biomarker SAE1 in RMS and its subtypes, paving the way for the development of personalized treatment strategies that leverage SUMO pathway inhibition.

cancer biology↗

Serum from patients with Idiopathic inflammatory myopathy induces skeletal muscle weakness

Idiopathic inflammatory myopathies (IIM) are a group of systemic autoimmune inflammatory disorders that primarily affect striated muscles leading to weakness and accelerated fatigue. The disseminated muscle phenotype points to systemic humoral factors as mediators of the disease. Autoantibodies are important biomarkers for disease classification; it is not known if they play a direct role in IIM disease development. This study aims to investigate if IIM patient serum or isolated IgG could directly impair contractile function in muscle. Isolated flexor digitorum brevis (FDB) muscles from healthy mice were exposed to serum (10-50%) from healthy controls or patients with recent onset IIM. Some muscles were exposed to isolated total IgG (50 or 150g/ml) from patients with IIM. Muscle force in whole muscles was measured before and after exposure to sera or IgG. Muscle force and intracellular [Ca2+] in single muscle fibers were measured after exposure to serum. FDB muscles exposed to serum from patients with IIM displayed a marked reduction in force production in both 10% and 50% serum. Moreover, single myofibers dissected from FDB muscles exposed to IIM sera displayed lower force but unaffected Ca2+ release during contractions, which indicates myofibrillar dysfunction, but not intracellular Ca2+ release, as the cause to weakness. FDB muscles exposed to total IgG from IIM patients did not display any reduction in muscle force. In conclusion IIM patient serum, but not total IgG, impairs force production in skeletal muscle fibers. As the experiments were performed in isolated muscle, our results cannot be explained by infiltrating immune cells, impaired neuronal or vascular functions. This suggests that humoral factors play a direct role in the pathogenesis of muscle weakness in recent onset IIM.

physiology↗

A unifying model to predict variable drug response for personalised medicine

Pharmacogenomics is a key component of personalized medicine. It promises a safer and more effective drug treatment by individualizing the choice of drug and dose based on an individuals genetic profile1,2. The majority of commonly prescribed drugs are metabolized by a small set of Cytochrome P450 (CYP) enzymes3. In clinical practice, genetic biomarkers are being used to categorize patients into predefined *-alleles to predict CYP450 enzyme activity and adjust drug dosages accordingly. Yet, this approach has important limitations as it leaves a large part of variability in drug response unexplained4,5. Here, we present a novel approach and introduce a continuous scale (instead of categorical) assignments to predict metabolic enzyme activity. The proposed strategy uses full gene sequencing data, a neural network model and CYP2D6 mediated tamoxifen metabolism from a prospective study of 561 breast cancer patients. The model explains 79% of the interindividual variability in CYP2D6 activity compared to 54% with the conventional approach. It is capable of assigning accurate enzyme activity to alleles containing previously uncharacterized combinations of variants and were replicated in an independent cohort of tamoxifen treated patients, a cohort of Venlafaxine users as well as in vitro functional assays using HEK cells. These results demonstrate the advantage of a continuous scale and a completely phased genotype for prediction of CYP450 enzyme activity and thereby enables more accurate prediction of individual drug response.

pharmacology and toxicology↗