Geoffray, J. | Search bioRxiv

bioRxiv2024

TRPM8 channels control Golgi morphology through an AR-dependent induction of the Scd1 gene and modulation of unsaturated lipid content

Transient receptor potential melastatin 8 (TRPM8), the cold and menthol receptor is essential to thermosensation, although its roles in organs within the body are still unclear. Besides TRPM8, we previously cloned several isoforms, like 4TM-TRPM8, which can be expressed with or without TRPM8. In this study, we characterize the human TRPM8(85) in ER membranes in the vicinity of Golgi apparatus (GA) and mitochondria in prostate epithelial cells. Silencing of TRPM8(85) induces lipid droplet accumulation, GA expansion and fragmentation associated with a drop in the vesicular trafficking to plasmalemma. Furthermore, lipidomic analysis reveals a strong shift in unsaturated fatty acids (UFAs), induced by TRPM8(85) silencing and to a lesser extent silencing of TRPM8. UFAs increase is caused by the induction of {Delta}9 stearoyl desaturase (Scd1) gene. Silencing SCD1 or palmitate incubation prevent GA expansion in TRPM8(85)-silenced cells. Finally, we demonstrated that TRPM8 regulates SCD1 via the androgen receptor.

cell biology↗

bioRxiv2020

Low expression of ANT1 confers oncogenic properties to rhabdomyosarcoma tumor cells via modulating metabolism and death pathways.

Rhabdomyosarcoma (RMS) is the most frequent form of pediatric soft-tissue sarcoma. It is divided into 2 main subtypes: ERMS (embryonal) and ARMS (alveolar). Current treatments are based on chemotherapy, surgery and radiotherapy. 5-year survival rate remains of 70% since 2000, despite several clinical trials. RMS cells are thought to derive from muscle lineage precursors. During development, myogenesis is characterized by primary expansion of myoblasts, elimination of those in excess by cell death and the differentiation of the remaining ones into myotubes and myofibers. The idea that these processes could be hijacked by tumor cells to sustain their oncogenic transformation has emerged, while RMS is being considered as the Mister Hydes side of myogenesis. Thus, focusing on myogenic developmental programs could help understanding RMS molecular aetiology. Following this idea, we decided to concentrate on ANT1, which is involved in myogenesis and is the underlying cause of genetic disorders associated with muscle degeneration. ANT1 is a mitochondrial protein, which has a functional duality, as it is involved both in metabolism via regulation of ATP/ADP release from mitochondria, but also in apoptosis as part as the mitochondria Permeability Transition Pore (mPTP). By bioinformatic analysis of transcriptomic datasets, we observed that ANT1 is expressed at low levels in RMS. Using CRISPR-Cas9 technology, we showed that decreased ANT1 expression confers selective advantages to RMS cells in terms of proliferation and resistance to stress-induced death. These effects result notably from a metabolic switch. Restoration of ANT1 expression using a Tet-On system is sufficient to prime tumor cells to death and to increase their sensitivity to chemotherapies. Thus, modulation of ANT1 activity could appear as an appealing therapeutic approach in RMS management.

cancer biology↗