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Proceedings of the National Academy of... Dec 2022The liver-specific microRNA, miR-122, plays an essential role in the propagation of hepatitis C virus (HCV) by binding directly to the 5'-end of its genomic RNA. Despite...
The liver-specific microRNA, miR-122, plays an essential role in the propagation of hepatitis C virus (HCV) by binding directly to the 5'-end of its genomic RNA. Despite its significance for HCV proliferation, the host factors responsible for regulating miR-122 remain largely unknown. In this study, we identified the cellular RNA-binding protein, ELAVL1/HuR (embryonic lethal-abnormal vision-like 1/human antigen R), as critically contributing to miR-122 biogenesis by strong binding to the 3'-end of miR-122. The availability of ELAVL1/HuR was highly correlated with HCV proliferation in replicon, infectious, and chronically infected patient conditions. Furthermore, by screening a kinase inhibitor library, we identified rigosertib, an anticancer agent under clinical trials, as having both miR-122-modulating and anti-HCV activities that were mediated by its ability to target polo-like kinase 1 (PLK1) and subsequently modulate ELAVL1/HuR-miR-122 signaling. The expression of PLK1 was also highly correlated with HCV proliferation and the HCV positivity of HCC patients. ELAVL1/HuR-miR-122 signaling and its mediation of PLK1-dependent HCV proliferation were demonstrated by performing various rescue experiments and utilizing an HCV mutant with low dependency on miR-122. In addition, the HCV-inhibitory effectiveness of rigosertib was validated in various HCV-relevant conditions, including replicons, infected cells, and replicon-harboring mice. Rigosertib was highly effective in inhibiting the proliferation of not only wild-type HCVs, but also sofosbuvir resistance-associated substitution-bearing HCVs. Our study identifies PLK1-ELAVL1/HuR-miR-122 signaling as a regulatory axis that is critical for HCV proliferation, and suggests that a therapeutic approach targeting this host cell signaling pathway could be useful for treating HCV and HCV-associated diseases.
Topics: Animals; Humans; Mice; Carcinoma, Hepatocellular; Cell Proliferation; ELAV-Like Protein 1; Hepacivirus; Hepatitis C; Liver Neoplasms; MicroRNAs; Signal Transduction; Polo-Like Kinase 1
PubMed: 36512502
DOI: 10.1073/pnas.2214911119 -
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 -
International Journal of Molecular... Jul 2021Cholangiocarcinoma is the first most common cancer of the biliary tract. To date, surgical resection is the only potentially curative option, but it is possible only for...
Cholangiocarcinoma is the first most common cancer of the biliary tract. To date, surgical resection is the only potentially curative option, but it is possible only for a limited percentage of patients, and in any case survival rate is quite low. Moreover, cholangiocarcinoma is often chemotherapy-resistant, and the only drug with a significant benefit for patient's survival is Gemcitabine. It is necessary to find new drugs or combination therapies to treat nonresectable cholangiocarcinoma and improve the overall survival rate of patients. In this work, we evaluate in vitro the antitumoral effects of Rigosertib, a multi-kinase inhibitor in clinical development, against cholangiocarcinoma EGI-1 cell lines. Rigosertib impairs EGI-1 cell viability in a dose- and time-dependent manner, reversibility is dose-dependent, and significant morphological and nuclear alterations occur. Moreover, Rigosertib induces the arrest of the cell cycle in the G2/M phase, increases autophagy, and inhibits proteasome, cell migration, and invasion. Lastly, Rigosertib shows to be a stronger radiosensitizer than Gemcitabine and 5-Fluorouracil. In conclusion, Rigosertib could be a potential therapeutic option, alone or in combination with radiations, for nonresectable patients with cholangiocarcinoma.
Topics: Antineoplastic Agents; Autophagy; Bile Duct Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Movement; Cholangiocarcinoma; Deoxycytidine; Fluorouracil; Glycine; Humans; Radiation-Sensitizing Agents; Sulfones; Gemcitabine
PubMed: 34360994
DOI: 10.3390/ijms22158230 -
Cellular Signalling Sep 2021The therapeutic potency of Rigosertib (RGS) in the treatment of the myelodysplastic syndrome has been investigated previously, but little is known about its mechanisms...
BACKGROUND
The therapeutic potency of Rigosertib (RGS) in the treatment of the myelodysplastic syndrome has been investigated previously, but little is known about its mechanisms of action.
METHODS
The present study integrates systems and molecular biology approaches to investigate the mechanisms of the anti-tumor effects of RGS, either alone or in combination with 5-FU in cellular and animal models of colorectal cancer (CRC).
RESULTS
The effects of RGS were more pronounced in dedifferentiated CRC cell types, compared to cell types that were epithelial-like. RGS inhibited cell proliferation and cell cycle progression in a cell-type specific manner, and that was dependent on the presence of mutations in KRAS, or its down-stream effectors. RGS increased both early and late apoptosis, by regulating the expression of p53, BAX and MDM2 in tumor model. We also found that RGS induced cell senescence in tumor tissues by increasing ROS generation, and impairing oxidant/anti-oxidant balance. RGS also inhibited angiogenesis and metastatic behavior of CRC cells, by regulating the expression of CD31, E-cadherin, and matrix metalloproteinases-2 and 9.
CONCLUSION
Our findings support the therapeutic potential of this potent RAS signaling inhibitor either alone or in combination with standard regimens for the management of patients with CRC.
Topics: Animals; Apoptosis; Cell Line, Tumor; Cell Proliferation; Colorectal Neoplasms; Glycine; Humans; Signal Transduction; Sulfones; Xenograft Model Antitumor Assays
PubMed: 34214591
DOI: 10.1016/j.cellsig.2021.110069 -
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 -
Molecular Cancer Jun 2021While immune checkpoint blockade (ICB) is the current first-line treatment for metastatic melanoma, it is effective for ~ 52% of patients and has dangerous side...
BACKGROUND
While immune checkpoint blockade (ICB) is the current first-line treatment for metastatic melanoma, it is effective for ~ 52% of patients and has dangerous side effects. The objective here was to identify the feasibility and mechanism of RAS/RAF/PI3K pathway inhibition in melanoma to sensitize tumors to ICB therapy.
METHODS
Rigosertib (RGS) is a non-ATP-competitive small molecule RAS mimetic. RGS monotherapy or in combination therapy with ICB were investigated using immunocompetent mouse models of BRAF and BRAF melanoma and analyzed in reference to patient data.
RESULTS
RGS treatment (300 mg/kg) was well tolerated in mice and resulted in ~ 50% inhibition of tumor growth as monotherapy and ~ 70% inhibition in combination with αPD1 + αCTLA4. RGS-induced tumor growth inhibition depends on CD40 upregulation in melanoma cells followed by immunogenic cell death, leading to enriched dendritic cells and activated T cells in the tumor microenvironment. The RGS-initiated tumor suppression was partially reversed by either knockdown of CD40 expression in melanoma cells or depletion of CD8 cytotoxic T cells. Treatment with either dabrafenib and trametinib or with RGS, increased CD40SOX10 melanoma cells in the tumors of melanoma patients and patient-derived xenografts. High CD40 expression level correlates with beneficial T-cell responses and better survival in a TCGA dataset from melanoma patients. Expression of CD40 by melanoma cells is associated with therapeutic response to RAF/MEK inhibition and ICB.
CONCLUSIONS
Our data support the therapeutic use of RGS + αPD1 + αCTLA4 in RAS/RAF/PI3K pathway-activated melanomas and point to the need for clinical trials of RGS + ICB for melanoma patients who do not respond to ICB alone.
TRIAL REGISTRATION
NCT01205815 (Sept 17, 2010).
Topics: Animals; Antineoplastic Agents; CD40 Antigens; Female; Glycine; Humans; Immune Checkpoint Inhibitors; Male; Melanoma; Mice; Phosphatidylinositol 3-Kinases; Protein Kinase Inhibitors; Signal Transduction; Sulfones; Xenograft Model Antitumor Assays; raf Kinases; ras Proteins
PubMed: 34092233
DOI: 10.1186/s12943-021-01366-y -
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 -
Oncology Research Sep 2021Cell cycle deregulation is involved in the pathogenesis of many cancers and is often associated with protein kinase aberrations, including the polo-like kinase 1 (PLK1)....
Cell cycle deregulation is involved in the pathogenesis of many cancers and is often associated with protein kinase aberrations, including the polo-like kinase 1 (PLK1). We used retinoblastoma, an intraocular malignancy that lacks targeted therapy, as a disease model and set out to reveal targetability of PLK1 with a small molecular inhibitor ON-01910.Na. First, transcriptomic analysis on patient retinoblastoma tissues suggested that cell cycle progression was deregulated and confirmed that PLK1 pathway was upregulated. Next, antitumor activity of ON-01910.Na was investigated in both cellular and animal levels. Cytotoxicity induced by ON-01910.Na was tumor specific and dose dependent in retinoblastoma cells, while nontumor cells were minimally affected. In three-dimensional culture, ON-01910.Na demonstrated efficient drug penetrability with multilayer cell death. Posttreatment transcriptomic findings revealed that cell cycle arrest and MAPK cascade activation were induced following PLK1 inhibition and eventually resulted in apoptotic cell death. In Balb/c nude mice, a safe threshold of 0.8 nmol intravitreal dosage of ON-01910.Na was established for intraocular safety, which was demonstrated by structural integrity and functional preservation. Furthermore, intraocular and subcutaneous xenograft were significantly reduced with ON-01910.Na treatments. For the first time, we demonstrated targetability of PLK1 in retinoblastoma by efficiently causing cell cycle arrest and apoptosis. Our study is supportive that local treatment of ON-01910.Na may be a novel, effective modality benefiting patients with PLK1-aberrant tumors.
Topics: Animals; Antineoplastic Agents; Apoptosis; Cell Cycle Checkpoints; Cell Cycle Proteins; Cell Line, Tumor; Cell Proliferation; Cell Survival; Gene Expression Profiling; Glycine; Humans; Mice; Mice, Inbred BALB C; Mice, Nude; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Retinal Neoplasms; Retinoblastoma; Sulfones; Xenograft Model Antitumor Assays; p38 Mitogen-Activated Protein Kinases; Polo-Like Kinase 1
PubMed: 33573708
DOI: 10.3727/096504021X16130322409507 -
Cells Dec 2020In cancer pharmacology, a drug candidate's therapeutic potential is typically expressed as its ability to suppress cell growth. Different methods in assessing the cell...
In cancer pharmacology, a drug candidate's therapeutic potential is typically expressed as its ability to suppress cell growth. Different methods in assessing the cell phenotype and calculating the drug effect have been established. However, inconsistencies in drug response outcomes have been reported, and it is still unclear whether and to what extent the choice of data post-processing methods is responsible for that. Studies that systematically examine these questions are rare. Here, we compare three established calculation methods on a collection of nine in vitro models of glioblastoma, exposed to a library of 231 clinical drugs. The therapeutic potential of the drugs is determined on the growth curves, using growth inhibition 50% (GI50) and point-of-departure (PoD) as the criteria. An effect is detected on 36% of the drugs when relying on GI50 and on 27% when using PoD. For the area under the curve (AUC), a threshold of 9.5 or 10 could be set to discriminate between the drugs with and without an effect. GI50, PoD, and AUC are highly correlated. The ranking of substances by different criteria varies somewhat, but the group of the top 20 substances according to one criterion typically includes 17-19 top candidates according to another. In addition to generating preclinical values with high clinical potential, we present off-target appreciation of top substance predictions by interrogating the drug response data of non-cancer cells in our calculation technology.
Topics: Antineoplastic Agents; Area Under Curve; Bortezomib; Brain Neoplasms; Cell Line, Tumor; Drug Resistance, Neoplasm; Glycine; Humans; Sulfones
PubMed: 33333810
DOI: 10.3390/cells9122689 -
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