Targeting Sphingosine-1-Phosphate Signaling in Breast Cancer

Sphingosine 1-phosphate acts as proliferative and fibrotic cue in leiomyoma cells

OBJECTIVE

To determine whether the bioactive sphingolipid sphingosine 1-phosphate (S1P) modulates cellular proliferation and synthesis of fibrotic proteins in leiomyoma differently than myometrial cells.

DESIGN

A basic science study using human leiomyoma and myometrial cells.

PATIENT(S)

Not applicable. This is an in vitro study performed on cellular models.

SETTING

Academic laboratory.

INTERVENTION(S)

Leiomyoma and myometrial cells were treated with S1P, as well as with selective antagonists for S1P-specific G protein-coupled receptors and secondarily with inhibitors of extracellular signal-regulated kinase 1/2 (ERK1/2) and ezrin.

MAIN OUTCOME MEASURE(S)

The main outcome measures included cellular proliferation and fibrogenesis. Bromodeoxyuridine Cell Proliferation Assay was employed to measure deoxyribonucleic acid synthesis and proliferation, whereas western blot analysis was used to assess the expression of the fibrotic markers N-cadherin, α-smooth muscle actin, transgelin, and collagen type I alpha 1.

RESULT(S)

Sphingosine 1-phosphate stimulates cellular proliferation of leiomyoma but not myometrial cells. The mitogenic effect elicited by S1P relies on the engagement of its specific receptor S1P2 and is mediated by ERK1/2 and ezrin activation. Furthermore, S1P exerts a profibrotic effect in a S1P-specific G protein-coupled receptor-dependent manner in leiomyoma but not myometrial cells.

CONCLUSION(S)

These results, besides extending the knowledge on the molecular mechanism underlying uterine leiomyoma development and fibrosis, demonstrate the pathogenetic role of S1P in leiomyoma and support the rationale for targeting S1P signaling pathway as innovative potential treatment.

A First-in-Human Phase I Study of BXQ-350, a First-in-Class Sphingolipid Metabolism Regulator, in Patients with Advanced/Recurrent Solid Tumors or High-Grade Gliomas

PURPOSE

BXQ-350, a nanovesicle formulation of saposin C, is an allosteric sphingolipid metabolism regulator that increases proapoptotic ceramide and decreases oncogenic sphingosine-1-phosphate levels. We conducted a first-in-human phase I study of BXQ-350.

PATIENTS AND METHODS

Adults (≥18 years old) with advanced/recurrent, treatment-refractory solid tumors or high-grade gliomas received BXQ-350 intravenously in five dose cohorts (0.7-2.4 mg/kg) in a 3+3 dose escalation and expansion design. The primary endpoints during dose escalation were dose-limiting toxicities and maximum tolerated dose; the primary objective in expansion parts was assessment of antitumor activity (RECIST v1.1/Response Assessment in Neuro-Oncology criteria).

RESULTS

Eighty-six patients were enrolled. Dose-limiting toxicities were not observed during dose escalation (n = 18), and a maximum tolerated dose was not identified. An additional 68 patients received the 2.4 mg/kg dose. Nine patients (10%) discontinued due to adverse events. The most common treatment-related adverse events were nausea (24%) and fatigue (23%). Eight patients had a progression-free survival of ≥6 months. Two of these achieved a partial response, and six had stable disease, among whom three had a reduction in ≥1 target lesion. Of those with progression-free survival of ≥6 months, seven remained on study for >12 months, five for >24 months, and after 7 years, two remained on study without disease progression.

CONCLUSIONS

BXQ-350 was well-tolerated as monotherapy at doses up to 2.4 mg/kg. It provided some lasting clinical benefit in patients with recurrent solid malignancies across several tumor types, consistent with a decreased systemic sphingosine-1-phosphate/ceramide metabolic rheostat. BXQ-350 warrants further clinical investigation alone and combined with standard of care for advanced solid tumors.

Explore the Role of the Sphingosine-1-Phosphate Signalling as a Novel Promising Therapeutic Target for the Management of Parkinson's Disease

Sphingosine-1-phosphate (S1P) is a cellular signalling molecule derived from sphingosine, which is a pro-apoptotic sphingolipid. Sphingolipids control various cellular actions like growth, homeostasis, and stress-related responses. The main sources of S1P in our body are erythrocytes. S1P controls both cellular mediators and other second messengers intracellularly. The S1P receptor also helps in inflammatory and neuroprotective effects (required to manage of Parkinson's). A large number of anti-Parkinson drugs are available, but still, there is a need for more effective and safer drugs. S1P and its receptors could be targeted as novel drugs due to their involvement in neuro-inflammation and Parkinson's. The present review effort to explore the biological role of S1P and related receptors, for their possible involvement in PD; furthermore. Overall, S1P and other related metabolizing enzymes have significant therapeutic opportunities for Parkinson's disease along with other neurological disorders.

Integrated Metabolomics and Transcriptomics Analysis of Anacardic Acid Inhibition of Breast Cancer Cell Viability

Anacardic acid (AnAc) inhibits the growth of estrogen receptor α (ERα)-positive MCF-7 breast cancer (BC) cells and MDA-MB-231 triple-negative BC (TNBC) cells, without affecting primary breast epithelial cells. RNA sequencing (seq) and network analysis of AnAc-treated MCF-7 and MDA-MB-231 cells suggested that AnAc inhibited lipid biosynthesis and increased endoplasmic reticulum stress. To investigate the impact of AnAc on cellular metabolism, a comprehensive untargeted metabolomics analysis was performed in five independent replicates of control versus AnAc-treated MCF-7 and MDA-MB-231 cells and additional TNBC cell lines: MDA-MB-468, BT-20, and HCC1806. An analysis of the global metabolome identified key metabolic differences between control and AnAc-treated within each BC cell line and between MCF-7 and the TNBC cell lines as well as metabolic diversity among the four TNBC cell lines, reflecting TNBC heterogeneity. AnAc-regulated metabolites were involved in alanine, aspartate, glutamate, and glutathione metabolism; the pentose phosphate pathway; and the citric acid cycle. Integration of the transcriptome and metabolome data for MCF-7 and MDA-MB-231 identified Signal transduction: mTORC1 downstream signaling in both cell lines and additional cell-specific pathways. Together, these data suggest that AnAc treatment differentially alters multiple pools of cellular building blocks, nutrients, and transcripts resulting in reduced BC cell viability.