Biology subjects

Djiane, A.

Publications and source records attributed to Djiane, A..

8 recordsLinked to original sources

bioRxiv2026

Furan fatty acid supplementation protects against muscle atrophy during cancer cachexia

Background: Cachexia is a multifactorial syndrome frequently observed in cancer patients, characterized by progressive weight loss, muscle atrophy, and systemic inflammation. We recently demonstrated that supplementation with FuFA-F2, a naturally occurring lipid found in various foods, increases muscle mass in different metabolic contexts. Here, we investigated whether FuFA-F2 supplementation could prevent tumor-induced muscle wasting and preserve skeletal muscle integrity during cancer cachexia. Methods: In vitro, C2C12 myotubes were exposed to TNF and IFN{gamma} to mimic cachectic conditions, and the effects of FuFA-F2 on myotube morphology were assessed. In vivo, cancer cachexia was induced by subcutaneous injection of C26 adenocarcinoma cells into male CD2F1 mice. Three groups were compared: non-grafted control mice, untreated C26 tumor-bearing mice, and C26 tumor-bearing mice orally supplemented with FuFA-F2 (13 mg/kg/day) for 14 days. Results: In C2C12 myotubes, TNF and IFN{gamma} exposure reduced myotube area by 17% (p < 0.05), whereas FuFA-F2 treatment prevented this atrophy and restored myotube area to control levels (p < 0.05). In vivo, FuFA-F2 supplementation prevented muscle wasting in C26 tumor-bearing mice without affecting tumor growth or the loss of white adipose tissue. After 14 days, hindlimb muscle weight was reduced by 22% in C26 mice compared with controls (0.706 vs. 0.903 g, p < 0.05), whereas muscle weight in FuFA-F2-treated mice (0.835 g) was not significantly different from controls. Consistently, spontaneous wheel activity was markedly reduced in C26 mice during the final four days (-79%; 3.4 vs. 16.5 km, p < 0.05), whereas FuFA-F2-treated mice maintained activity levels closer to those of controls (11.2 km). RNA-seq analysis revealed extensive transcriptional reprogramming of skeletal muscle in response to C26 tumor growth, with 5,465 differentially expressed genes (DEGs; 32% of detected genes) between Control and C26 mice. Notably, FuFA-F2 substantially attenuated this response, with only 366 DEGs (2%) between Control and C26 + FuFA-F2 mice, and principal component analysis (PCA) showed a transcriptomic profile closer to controls. Tumor-induced alterations involved pathways related to proteostasis, inflammation, and tissue remodeling, which were largely prevented or attenuated by FuFA-F2. Consistent with these findings, FuFA-F2 prevented the induction of Myostatin, Activin A, MAFbx and MuRF1, and attenuated muscle fibrosis and local inflammation. Conclusions: These findings demonstrate that FuFA-F2 preserves skeletal muscle mass and function in the C26 model of cancer cachexia, despite ongoing tumor progression. FuFA-F2 markedly attenuates tumor-induced transcriptional reprogramming and associated catabolic, inflammatory and fibrotic responses, supporting its potential as a therapeutic strategy to preserve skeletal muscle during cancer cachexia.

cancer biology↗

bioRxiv2025

E(spl)m4 Directly Antagonizes Traf4 to Inhibit JNK Signaling in Drosophila

TRAF proteins are adaptor proteins that participate in signal transduction downstream of the Toll or TNF receptors and could elicit E3-Ubiquitin Ligase activity. They have been implicated in multiple processes during signal transduction, inflammation, and morphogenesis. In Drosophila, Traf4 has been implicated in the regulation of JNK signaling and cell death as well as Adherens Junctions regulation. Using overexpression approaches, we show here that Traf4 promotes JNK and caspase activation, as well as junctional E-Cadherin/ {beta}-Catenin depletion, resulting in epithelial cell delamination. Using biochemical, modelling, and functional genetics approaches, we further show that the Bearded-type small protein E(spl)m4 binds to Traf4, and inhibits its downstream signaling towards JNK activation and cell delamination, without affecting the effects of Traf4 on Adherens Junctions. Thus, this study identifies an endogenous peptide inhibiting Traf4 signaling, potentially by blocking Traf4 trimerization.

developmental biology↗

bioRxiv2025

Tumour-derived Ilp8 and Upd3 control intestinal progenitor cells depletion during cachexia in Drosophila larvae

In animals, tumour development triggers systemic effects, impacting the physiology of distant organs. In Drosophila larvae, wing disc neoplastic tumours result in developmental delay and organ wasting reminiscent of cachexia. This paraneoplastic syndrome affects many organs, but its effects on the intestine, a key organ in the regulation of nutrient and energy homeostasis, remain understudied. We describe here that neoplastic tumours also affect the development of the larval midgut, leading to altered cell type numbers, with a depletion of the stem-cell-like Adult Midgut Precursors (AMPs), and a disorganisation of the niche cells which enter precocious differentiation. Importantly, these intestinal cell type alterations are initiated before the onset of reduced food intake, and of muscle and adipose tissue atrophies, and thus represent a new paraneoplastic phenotype. Screening for mediators, we show that tumour derived Ilp8 and Upd3 control AMPs number and niche specification respectively.

developmental biology↗

bioRxiv2024

MDM2 stabilization of Notch intracellular domain upon DNA damage plays a major role in non-small cell lung carcinoma response to platinum chemotherapy

Despite major advances in lung cancer clinical management, majority of patients suffering non-small cell lung carcinoma (NSCLC) are treated in first line with platinum in combination with immune checkpoint inhibitors. Although platinum compounds normally display an initial therapeutic effect, relapse constitutes a major challenge in the clinical management of NSCLC patients. Therefore, it is fundamental to understand the relapse underlying mechanisms to find new therapeutic opportunities to improve patients survival. Here, we found that different DNA damage inducers increase the protein levels of Notch Intracellular Domain (NICD), i.e., the active form of NOTCH1. Mechanistically, we unveiled that upon platinum treatment, there was a concomitant increase of MDM2 together with NICD, and we also observed an MDM2-mediated ubiquitination and stabilization of NICD. Of note, using patient-derived xenografts displaying intrinsic carboplatin resistance, we demonstrated that the combination of carboplatin with MDM2 and NICD inhibitors increased survival and reduced tumor growth compared with carboplatin in monotherapy. Moreover, in patients with NSCLC who received platinum chemotherapy, MDM2 expression level in the tumor was correlated with poor progression-free survival, further validating MDM2 key role in the response to platinum compounds. Our findings open a therapeutic opportunity for NSCLC patients, the main lung cancer subtype of the leading cause of death by cancer worldwide.

cancer biology↗

bioRxiv2023

Fat body glycolysis defects inhibit mTOR and promote distant muscle disorganization through TNF-α/egr and ImpL2 signaling in Drosophila larvae

The fat body in Drosophila larvae serves as a reserve tissue and participates, through its endocrine function, in the regulation of organismal growth and homeostasis. To better understand its role in growth coordination, we induced severe fat body atrophy by knocking down in adipose cells several key enzymes of the glycolytic pathway. Our results show that impairing the last steps of glycolysis led to a drastic shrinkage in adipose cell size and lipid droplets content, and a downregulation of the mTOR pathway. Strikingly, fat body atrophy resulted in the distant disorganization of body wall muscles and the release of muscle-specific proteins in the hemolymph. Molecularly we showed that REPTOR activity was required for fat body atrophy downstream of glycolysis inhibition, and that the effect of fat body atrophy on muscles did not require upd3 secretion, but depended the production of egr/TNF- and of the insulin pathway inhibitor ImpL2.

physiology↗

bioRxiv2023

The Hippo pathway terminal effector TAZ/WWTR1 mediates oxaliplatin sensitivity in HCT116 colon cancer cells

YAP and TAZ, the Hippo pathway terminal transcriptional activators, are frequently upregulated in cancers. In tumor cells, they have been mainly associated with increased tumorigenesis controlling different aspects from cell cycle regulation, stemness, or resistance to chemotherapies. In fewer cases, they have also been shown to oppose cancer progression, including by promoting cell death through the action of the P73/YAP transcriptional complex, in particular after chemotherapeutic drug exposure. Using several colorectal cancer cell lines, we show here that oxaliplatin treatment led to a dramatic core Hippo pathway down-regulation and nuclear accumulation of TAZ. We further show that TAZ was required for the increased sensitivity of HCT116 cells to oxaliplatin, an effect that appeared independent of P73, but which required the nuclear relocalization of TAZ. Accordingly, Verteporfin and CA3, two drugs affecting the activity of YAP and TAZ, showed an antagonistic with oxaliplatin in co-treatments. Our results support thus an early action of TAZ to sensitize cells to oxaliplatin, consistent with a model in which nuclear TAZ in the context of DNA damage and P53 activity pushes cells towards apoptosis.

cancer biology↗

bioRxiv2020

MAGI1 inhibits the AMOTL2/p38 stress pathway and prevents luminal breast tumorigenesis

Alterations to cell polarization or to intercellular junctions are often associated with epithelial cancer progression, including breast cancers (BCa). We show here that the loss of the junctional scaffold protein MAGI1 is associated with bad prognosis in luminal BCa, and promotes tumorigenesis. E-cadherin and the actin binding scaffold AMOTL2 accumulate in MAGI1 deficient cells which are subjected to increased stiffness. These alterations are associated with low YAP activity, the terminal Hippo-pathway effector, but with an elevated ROCK and p38 Stress Activated Protein Kinase activities. Blocking ROCK prevented p38 activation, suggesting that MAGI1 limits p38 activity in part through releasing actin strength. Importantly, the increased tumorigenicity of MAGI1 deficient cells is rescued in the absence of AMOTL2 or after inhibition of p38, demonstrating that MAGI1 acts as a tumor-suppressor in luminal BCa by inhibiting an AMOTL2/p38 stress pathway.

cancer biology↗

bioRxiv2020

Loss of epithelial polarity redirects Notch signaling and triggers a Xrp1 response during neoplastic growth in Drosophila

Aggressive neoplastic growth can be initiated by a limited number of genetic alterations, such as the well-established cooperation between loss of cell architecture and hyperactive signaling pathways. However, our understanding of how these different alterations interact and influence each other remains very incomplete. Using Drosophila paradigms of imaginal wing disc epithelial growth, we have monitored the changes in Notch pathway activity according to the polarity status of cells (scrib mutant). We show that the scrib mutation impacts the direct transcriptional output of the Notch pathway, without altering the global distribution of Su(H), the Notch dedicated transcription factor. The Notch-dependent neoplasms require however, the action of a group of transcription factors, similar to those previously identified for Ras/scrib neoplasm (namely AP-1, Stat92E, Ftz-F1, and bZIP factors), further suggesting the importance of this transcription factor network during neoplastic growth. Finally our work highlights some Notch/scrib specificities, in particular the role of the PAR domain containing bZIP transcription factor and Notch direct target Pdp1 for neoplastic growth.

developmental biology↗