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Cancer Letters Nov 2023Rigosertib (RGS) is a benzyl styryl sulfone which exhibits impressive cytotoxicity in cancer cells. However, its modulating effect on tumor immune microenvironment...
Rigosertib (RGS) is a benzyl styryl sulfone which exhibits impressive cytotoxicity in cancer cells. However, its modulating effect on tumor immune microenvironment remains elusive. In our experiments, compared with immunodeficient mouse model, increased tumor growth arrest and robust anti-tumor immunity were observed in RGS-treated colorectal cancer (CRC) isograft tumors in immunocompetent mice. Intriguingly, RGS markedly down-regulated programmed cell death ligand 1 (PD-L1) expression in both vivo and in vitro. Meanwhile, RGS increased autophagic vacuole number in CRC cells as seen by transmission electron microscopy and immunofluorescence. Moreover, increased LC3-II level and tandem-mRFP- GFP- LC3 labeled vacuole accumulation demonstrated RGS-induced autophagic flux. Mechanistically, it is the activation of AMP-activated protein kinase-UNC-51-like kinase 1 (AMPK-ULK1) axis, rather than the canonical mTOR signaling pathway, that plays a pivotal role in RGS-induced autophagy. AMPK-ULK1 dependent autophagy inhibition, by either short interfering RNA or chemical inhibitors, blocked RGS-induced PD-L1 degradation. Finally, RGS exhibited synergistic anti-tumor activity with cytotoxic T-lymphocyte-associated protein 4 monoclonal antibody in the CRC isograft model. Furthermore, apart from the immunomodulatory effect, we also confirmed the direct cytotoxicity of RGS in inducing mitochondria-related apoptosis. Altogether, considering its PD-L1 inhibitory and cytotoxic effects, RGS could be a promising drug for CRC therapy.
Topics: Animals; Mice; AMP-Activated Protein Kinases; Autophagy; B7-H1 Antigen; Colorectal Neoplasms; Sulfones; Tumor Microenvironment
PubMed: 37805162
DOI: 10.1016/j.canlet.2023.216422 -
Expert Review of Anticancer Therapy Aug 2016Hypomethylating agents (HMAs) are the standard of care for patients with higher-risk myelodysplastic syndromes (MDS), but patients who relapse or are refractory have a... (Review)
Review
INTRODUCTION
Hypomethylating agents (HMAs) are the standard of care for patients with higher-risk myelodysplastic syndromes (MDS), but patients who relapse or are refractory have a poor prognosis with an estimated survival of 4-6 months. Rigosertib, a Ras mimetic that inhibits the phophoinositide 3-kinase and polo-like kinase pathways, has been tested in patients with higher-risk MDS following treatment with HMAs, where there are no approved second-line therapies.
AREAS COVERED
This review will provide an overview of rigosertib, including safety and efficacy demonstrated in clinical trials. Expert commentary: There is an urgent need for new treatment options for patients who have failed or progressed on HMAs. Rigosertib is currently undergoing testing as a single agent in certain subsets of higher-risk MDS patients as well as in combination with azacitidine, where preliminary data show efficacy in patients with de novo MDS as well as HMA failures.
Topics: Azacitidine; Disease Progression; Drug Therapy, Combination; Glycine; Humans; Myelodysplastic Syndromes; Prognosis; Sulfones; Survival Rate; Treatment Outcome
PubMed: 27400247
DOI: 10.1080/14737140.2016.1209413 -
Molecular Cell Jul 2020We recently used CRISPRi/a-based chemical-genetic screens and cell biological, biochemical, and structural assays to determine that rigosertib, an anti-cancer agent in...
We recently used CRISPRi/a-based chemical-genetic screens and cell biological, biochemical, and structural assays to determine that rigosertib, an anti-cancer agent in phase III clinical trials, kills cancer cells by destabilizing microtubules. Reddy and co-workers (Baker et al., 2020, this issue of Molecular Cell) suggest that a contaminating degradation product in commercial formulations of rigosertib is responsible for the microtubule-destabilizing activity. Here, we demonstrate that cells treated with pharmaceutical-grade rigosertib (>99.9% purity) or commercially obtained rigosertib have qualitatively indistinguishable phenotypes across multiple assays. The two formulations have indistinguishable chemical-genetic interactions with genes that modulate microtubule stability, both destabilize microtubules in cells and in vitro, and expression of a rationally designed tubulin mutant with a mutation in the rigosertib binding site (L240F TUBB) allows cells to proliferate in the presence of either formulation. Importantly, the specificity of the L240F TUBB mutant for microtubule-destabilizing agents has been confirmed independently. Thus, rigosertib kills cancer cells by destabilizing microtubules, in agreement with our original findings.
Topics: Antineoplastic Agents; Cell Proliferation; Cells, Cultured; Crystallography, X-Ray; Drug Contamination; Glycine; Humans; Microtubules; Mutation; Neoplasms; Pharmaceutical Preparations; Protein Conformation; Sulfones; Tubulin
PubMed: 32619469
DOI: 10.1016/j.molcel.2020.06.008 -
Immunity, Inflammation and Disease Sep 2021Here, by using the lipopolysaccharide (LPS)-induced mice sepsis model, we treated septic wild-type (WT) mice or MEK1 mice with rigosertib to evaluate its prospective...
BACKGROUND
Here, by using the lipopolysaccharide (LPS)-induced mice sepsis model, we treated septic wild-type (WT) mice or MEK1 mice with rigosertib to evaluate its prospective effects on sepsis.
METHODS
We also generated macrophages derived from bone marrow from WT or MEK1 mice. These macrophages were pretreated with rigosertib and then induced with LPS or poly I:C.
RESULTS
Rigosertib suppressed LPS or poly I:C-induced expression of inflammatory cytokines (tumor necrosis factor-alpha [TNF-α] and interleukin-6 [IL-6], and IL-23) in WT bone marrow-derived macrophages while failed to affect the upregulation of TNF-α and IL-6 in LPS-treated bone marrow-derived macrophages from MEK1 mice. Rigosertib promoted survival rate, ameliorated lung injury, and reduced inflammatory cytokine levels in serum of WT septic mice.
CONCLUSION
In contrast, the effects of rigosertib on sepsis were abrogated in septic MEK1 mice, which had inducible constitutive activation of MEK1 signaling. Rigosertib alleviated LPS-induced sepsis inhibits MEK1/ERK signaling pathway.
Topics: Animals; Glycine; Lipopolysaccharides; MAP Kinase Signaling System; Mice; Sepsis; Sulfones
PubMed: 34061465
DOI: 10.1002/iid3.458 -
International Journal of Molecular... Dec 2021Rigosertib is multi-kinase inhibitor that could represent an interesting therapeutic option for non-resectable patients with cholangiocarcinoma, a very aggressive...
Rigosertib is multi-kinase inhibitor that could represent an interesting therapeutic option for non-resectable patients with cholangiocarcinoma, a very aggressive hepatic cancer with limited effective treatments. The Western blotting technique was used to evaluate alterations in the expression of proteins involved in the regulation of the cell cycle of cholangiocarcinoma EGI-1 cells. Our results show an increase in EMI1 and Cyclin B protein levels after Rigosertib treatment. Moreover, the phosphorylation of CDK1 is significantly reduced by Rigosertib, while PLK1 expression increased after 24 h of treatment and decreased after 48 h. Finally, we evaluated the role of p53. Its levels increase after Rig treatment, and, as shown in the cell viability experiment with the p53 inhibitor Pifithrin, its activity is necessary for the effects of Rigosertib against the cell viability of EGI-1 cells. In conclusion, we hypothesized the mechanism of the action of Rigosertib against cholangiocarcinoma EGI-1 cells, highlighting the importance of proteins involved in the regulation of cell cycles. The CDK1-Cyclin B complex and p53 play an important role, explaining the Block in the G2/M phase of the cell cycle and the effect on cell viability.
Topics: CDC2 Protein Kinase; Cell Cycle Proteins; Cell Division; Cholangiocarcinoma; Cyclin B; G2 Phase; Glycine; Humans; Phosphorylation; Protein Kinase Inhibitors; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Signal Transduction; Sulfones; Tumor Cells, Cultured; Tumor Suppressor Protein p53; Polo-Like Kinase 1
PubMed: 35008638
DOI: 10.3390/ijms23010213 -
Molecular Cancer Therapeutics Feb 2021Relapsed pediatric rhabdomyosarcomas (RMS) and neuroblastomas (NBs) have a poor prognosis despite multimodality therapy. In addition, the current standard of care for...
Relapsed pediatric rhabdomyosarcomas (RMS) and neuroblastomas (NBs) have a poor prognosis despite multimodality therapy. In addition, the current standard of care for these cancers includes vinca alkaloids that have severe toxicity profiles, further underscoring the need for novel therapies for these malignancies. Here, we show that the small-molecule rigosertib inhibits the growth of RMS and NB cell lines by arresting cells in mitosis, which leads to cell death. Our data indicate that rigosertib, like the vinca alkaloids, exerts its effects mainly by interfering with mitotic spindle assembly. Although rigosertib has the ability to inhibit oncogenic RAS signaling, we provide evidence that rigosertib does not induce cell death through inhibition of the RAS pathway in RAS-mutated RMS and NB cells. However, the combination of rigosertib and the MEK inhibitor trametinib, which has efficacy in RAS-mutated tumors, synergistically inhibits the growth of an RMS cell line, suggesting a new avenue for combination therapy. Importantly, rigosertib treatment delays tumor growth and prolongs survival in a xenograft model of RMS. In conclusion, rigosertib, through its impact on the mitotic spindle, represents a potential therapeutic for RMS.
Topics: Apoptosis; Glycine; Humans; Neuroblastoma; Rhabdomyosarcoma; Spindle Apparatus; Sulfones
PubMed: 33158997
DOI: 10.1158/1535-7163.MCT-20-0525 -
Translational Oncology Aug 2021High-risk neuroblastoma has a poor prognosis despite intense treatment, demonstrating the need for new therapeutic strategies. Here we evaluated the effects of...
High-risk neuroblastoma has a poor prognosis despite intense treatment, demonstrating the need for new therapeutic strategies. Here we evaluated the effects of rigosertib (ON-01910.Na) in preclinical models of high-risk neuroblastoma. Among several hundred cancer cell lines representing 24 tumor types, neuroblastoma was the most sensitive to rigosertib. Treatment of MYCN-amplified neuroblastoma organoids resulted in organoid disintegration, decreased cell viability, and increased apoptotic cell death. Neuroblastoma response to rigosertib involved G2M cell cycle arrest and decreased phosphorylation of AKT (Ser473) and ERK1/2 (Thr202/Tyr204). Rigosertib delayed tumor growth and prolonged survival of mice carrying neuroblastoma MYCN-amplified PDX tumors (median survival: 31 days, treated; 22 days, vehicle) accompanied with increased apoptosis in treated tumors. We further identified vincristine and rigosertib as a potential promising drug combination treatment. Our results show that rigosertib might be a useful therapeutic agent for MYCN-amplified neuroblastomas, especially in combination with existing agents.
PubMed: 34118691
DOI: 10.1016/j.tranon.2021.101149 -
Pharmaceutics Apr 2023Rigosertib (ON-01910.Na) is a small-molecule member of the novel synthetic benzyl-styryl-sulfonate family. It is currently in phase III clinical trials for several... (Review)
Review
Rigosertib (ON-01910.Na) is a small-molecule member of the novel synthetic benzyl-styryl-sulfonate family. It is currently in phase III clinical trials for several myelodysplastic syndromes and leukemias and is therefore close to clinical translation. The clinical progress of rigosertib has been hampered by a lack of understanding of its mechanism of action, as it is currently considered a multi-target inhibitor. Rigosertib was first described as an inhibitor of the mitotic master regulator Polo-like kinase 1 (Plk1). However, in recent years, some studies have shown that rigosertib may also interact with the PI3K/Akt pathway, act as a Ras-Raf binding mimetic (altering the Ras signaling pathway), as a microtubule destabilizing agent, or as an activator of a stress-induced phospho-regulatory circuit that ultimately hyperphosphorylates and inactivates Ras signaling effectors. Understanding the mechanism of action of rigosertib has potential clinical implications worth exploring, as it may help to tailor cancer therapies and improve patient outcomes.
PubMed: 37111716
DOI: 10.3390/pharmaceutics15041232 -
Molecular Cell Jul 2020Rigosertib is a styryl benzyl sulfone that inhibits growth of tumor cells and acts as a RAS mimetic by binding to Ras binding domains of RAS effectors. A recent study...
Rigosertib is a styryl benzyl sulfone that inhibits growth of tumor cells and acts as a RAS mimetic by binding to Ras binding domains of RAS effectors. A recent study attributed rigosertib's mechanism of action to microtubule binding. In that study, rigosertib was obtained from a commercial vendor. We compared the purity of clinical-grade and commercially sourced rigosertib and found that commercially sourced rigosertib contains approximately 5% ON01500, a potent inhibitor of tubulin polymerization. Clinical-grade rigosertib, which is free of this impurity, does not exhibit tubulin-binding activity. Cell lines expressing mutant β-tubulin have also been reported to be resistant to rigosertib. However, our study showed that these cells failed to proliferate in the presence of rigosertib at concentrations that are lethal to wild-type cells. Rigosertib induced a senescence-like phenotype in the small percentage of surviving cells, which could be incorrectly scored as resistant using short-term cultures.
Topics: Antineoplastic Agents; Cell Proliferation; Drug Contamination; Drug Resistance, Neoplasm; Glycine; Humans; Lung Neoplasms; Mutation; Sulfones; Tubulin; Tumor Cells, Cultured
PubMed: 32619468
DOI: 10.1016/j.molcel.2020.05.024 -
Annals of Hematology Sep 2019Rigosertib is a novel multi-kinase inhibitor, which has clinical activity towards leukemic progenitor cells of patients with high-risk myelodysplastic syndromes (MDS)...
Rigosertib is a novel multi-kinase inhibitor, which has clinical activity towards leukemic progenitor cells of patients with high-risk myelodysplastic syndromes (MDS) after failure or progression on hypomethylating agents. Since the bone marrow microenvironment plays an important role in MDS pathogenesis, we investigated the impact of rigosertib on cellular compartments within the osteo-hematopoietic niche. Healthy C57BL/6J mice treated with rigosertib for 3 weeks showed a mild suppression of hematopoiesis (hemoglobin and red blood cells, both - 16%, p < 0.01; white blood cells, - 34%, p < 0.05; platelets, - 38%, p < 0.05), whereas there was no difference in the number of hematopoietic stem cells in the bone marrow. Trabecular bone mass of the spine was reduced by rigosertib (- 16%, p = 0.05). This was accompanied by a lower trabecular number and thickness (- 6% and - 10%, respectively, p < 0.05), partly explained by the increase in osteoclast number and surface (p < 0.01). Milder effects of rigosertib on bone mass were detected in an MDS mouse model system (NHD13). However, rigosertib did not further aggravate MDS-associated cytopenia in NHD13 mice. Finally, we tested the effects of rigosertib on human mesenchymal stromal cells (MSC) in vitro and demonstrated reduced cell viability at nanomolar concentrations. Deterioration of the hematopoietic supportive capacity of MDS-MSC after rigosertib pretreatment demonstrated by decreased number of colony-forming units, especially in the monocytic lineage, further supports the idea of disturbed crosstalk within the osteo-hematopoietic niche mediated by rigosertib. Thus, rigosertib exerts inhibitory effects on the stromal components of the osteo-hematopoietic niche which may explain the dissociation between anti-leukemic activity and the absence of hematological improvement.
Topics: Animals; Glycine; Hematopoiesis; Hematopoietic Stem Cells; Mesenchymal Stem Cells; Mice; Mice, Transgenic; Myelodysplastic Syndromes; Stem Cell Niche; Sulfones
PubMed: 31312928
DOI: 10.1007/s00277-019-03756-1