On, J. | Search bioRxiv

bioRxiv2023

Lysosomal acid lipase-activity as a novel target to efficiently address triple-negative breast cancer high malignancy

Increased metabolism of neutral lipids, e.g. triglycerides and cholesterol esters, is a hallmark of malignant cancers such as triple-negative breast cancer (TNBC). Predominantly, cancer cells with a high epigenetic stem cell-associated signature increasingly utilize neutral lipids to maintain their high degree of tumor stemness, linking metabolic aberrations to epigenetically dysregulated differentiation processes. Lysosomal acid lipase (LIPA) is a central enzyme in the cellular utilization of exogenous and endogenous neutral lipids; however, the role of LIPA-activity in TNBC remains unexplored. We here show for the first time that pharmacological inhibition of LIPA, highly expressed in TNBC, reduces the expression markers of breast cancer stemness in cell culture models of TNBC. A role of LIPA in maintaining TNBC high cellular stemness was stressed by specific siRNA knock-down. Furthermore, inhibition of LIPA sensitized TNBC cells to therapy with Paclitaxel and Doxorubicin, two important chemotherapeutics in current TNBC treatment. When LIPA-activity was inhibited in a three-dinensional (3D) patient derived organoid model, we observed a significant reduction in TNBC cellular viability. Importantly, LIPA inhibition prevented tumor metastasis in a TNBC-zebrafish xenograft model in vivo. These findings introduce LIPA-activity as a novel pharmacological target in TNBC therapy to specifically address its high cancer malignancy with a potential for implementation of LIPA inhibitors into personalized treatment in the future.

cancer biology↗

bioRxiv2018

A single prophage WO gene rescues cytoplasmic incompatibility in Drosophila melanogaster

Wolbachia are maternally-inherited, intracellular bacteria at the forefront of vector control efforts to curb arbovirus transmission. In international field trials, the cytoplasmic incompatibility (CI) drive system of wMel Wolbachia is deployed to replace target vector populations, whereby a Wolbachia- induced modification of the sperm genome kills embryos. However, Wolbachia in the embryo rescue the sperm genome impairment, and therefore CI results in a strong fitness advantage for infected females that transmit the bacteria to offspring. The two genes responsible for the wMel-induced sperm modification of CI, cifA and cifB, were recently identified in the eukaryotic association module of prophage WO, but the genetic basis of rescue is unresolved. Here we use transgenic and cytological approaches to demonstrate that cifA independently rescues CI and nullifies embryonic death caused by wMel Wolbachia in Drosophila melanogaster. Discovery of cifA as the rescue gene and previously one of two CI induction genes establishes a new Two-by-One model that underpins the genetic basis of CI. Results highlight the central role of prophage WO in shaping Wolbachia phenotypes that are significant to arthropod evolution and vector control.\n\nSignificance StatementThe World Health Organization recommended pilot deployment of Wolbachia-infected mosquitoes to curb viral transmission to humans. Releases of mosquitoes are underway worldwide because Wolbachia can block replication of these pathogenic viruses and deterministically spread by a drive system termed cytoplasmic incompatibility (CI). Despite extensive research, the underlying genetic basis of CI remains only half-solved. We recently reported that two prophage WO genes recapitulate the modification component of CI in a released strain for vector control. Here we show that one of these genes underpins rescue of CI. Together, our results reveal the complete genetic basis of this selfish trait and pave the way for future studies exploring WO prophage genes as adjuncts or alternatives to current control efforts.

genetics↗