scholarly journals LLL12B, a small molecule STAT3 inhibitor, induces growth arrest, apoptosis, and enhances cisplatin-mediated cytotoxicity in medulloblastoma cells

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xiang Chen ◽  
Li Pan ◽  
Jia Wei ◽  
Ruijie Zhang ◽  
Xiaozhi Yang ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Small Molecule ◽  
Single Agent ◽  
Stat3 Signaling ◽  
Molecule Inhibitor ◽  
Stat3 Phosphorylation ◽  
Induced Apoptosis ◽  
Transcription 3

AbstractSignal Transducer and Activator of Transcription 3 (STAT3) is a transcription factor and an oncogene product, which plays a pivotal role in tumor progression. Therefore, targeting persistent STAT3 signaling directly is an attractive anticancer strategy. The aim of this study is to test the efficacy of a novel STAT3 small molecule inhibitor, LLL12B, in suppressing medulloblastoma cells in vitro and tumor growth in vivo. LLL12B selectively inhibited the induction of STAT3 phosphorylation by interleukin-6 but not induction of STAT1 phosphorylation by INF-γ. LLL12B also induced apoptosis in human medulloblastoma cells. In addition, LLL12B exhibited good oral bioavailability in vivo and potent suppressive activity in tumor growth of medulloblastoma cells in vivo. Besides, combining LLL12B with cisplatin showed greater inhibition of cell viability and tumorsphere formation as well as induction of apoptosis comparing to single agent treatment in medulloblastoma cells. Furthermore, LLL12B and cisplatin combination exhibited greater suppression of medulloblastoma tumor growth than monotherapy in vivo. The present study supported that LLL12B is a novel therapeutic agent for medulloblastoma and the combination of LLL12B with a chemotherapeutic agent cisplatin may be an effective approach for medulloblastoma therapy.

scholarly journals An acetyl-click screening platform identifies a small molecule inhibitor of Histone Acetyltransferase 1 (HAT1) with anti-tumor activity

2021 ◽  
Author(s):  
Joshua J Gruber ◽  
Amith Rangarajan ◽  
Tristan Chou ◽  
Benjamin S. Geller ◽  
Selene Banuelos ◽  
...  
Keyword(s):  
Tumor Growth ◽  
Small Molecule ◽  
Cancer Metabolism ◽  
Human Cancer ◽  
Small Molecule Inhibitor ◽  
Cellular Growth ◽  
Acetyl Coa ◽  
Molecule Inhibitor

HAT1 is a central regulator of chromatin synthesis that acetylates nascent histone H3:H4 tetramers in the cytoplasm. It may have a role in cancer metabolism by linking cytoplasmic production of acetyl-CoA to nuclear acetyl flux. This is because the HAT1 di-acetylation mark is not propagated in chromatin and instead is de-acetylated after nascent histone insertion into chromatin. Thus, HAT1 likely provides a nuclear source of free acetate that may be recycled to acetyl-CoA for nuclear acetylation reactions. Correspondingly, suppression of HAT1 protein expression impairs tumor growth. To ascertain whether targeting HAT1 is a viable anti-cancer treatment strategy we sought to identify small molecule inhibitors of HAT1. We developed a high-throughput HAT1 acetyl-click assay to facilitate drug discovery and enzymology. Screening of small molecules computationally predicted to bind the active site led to the discovery of multiple riboflavin analogs that inhibited HAT1 enzymatic activity by competing with acetyl-CoA binding. These hits were refined by synthesis and testing over 70 analogs, which yielded structure-activity relationships. The isoalloxazine core was required for enzymatic inhibition, whereas modifications of the ribityl sidechain improved enzymatic potency and cellular growth suppression. These efforts resulted in a lead compound (JG-2016) that suppressed growth of human cancer cells lines in vitro and impaired tumor growth in vivo. This is the first report of a small molecule inhibitor of the HAT1 enzyme complex and represents a step towards targeting this pathway for cancer therapy.

Rapid TNFR1-dependent lymphocyte depletion in vivo with a selective chemical inhibitor of IKKβ

Blood ◽  
2006 ◽  
Vol 107 (11) ◽  
pp. 4266-4273 ◽  
Author(s):  
Kumiko Nagashima ◽  
Vito G. Sasseville ◽  
Danyi Wen ◽  
Andrew Bielecki ◽  
Hua Yang ◽  
...  
Keyword(s):  
Bone Marrow ◽  
B Cells ◽  
Small Molecule ◽  
Mouse Bone Marrow ◽  
Tnf Receptor ◽  
Molecule Inhibitor ◽  
Induced Apoptosis ◽  
Potential Use

AbstractThe transcription factor NF-κB plays a central role in regulating inflammation and apoptosis, making it a compelling target for drug development. We identified a small molecule inhibitor (ML120B) that specifically inhibits IKKβ, an Ikappa-B kinase that regulates NF-κB. IKKβ and NF-κB are required in vivo for prevention of TNFα-mediated apoptosis. ML120B sensitized mouse bone marrow progenitors and granulocytes, but not mature B cells to TNFα killing in vitro, and induced apoptosis in vivo in the bone marrow and spleen within 6 hours of a single oral dose. In vivo inhibition of IKKβ with ML120B resulted in depletion of thymocytes and B cells in all stages of development in the bone marrow but did not deplete granulocytes. TNF receptor–deficient mouse thymocytes and B cells were resistant to ML120B-induced depletion in vivo. Surprisingly, surviving bone marrow granulocytes expressed TNFR1 and TNFR2 after dosing in vivo with ML120B. Our results show that inhibition of IKKβ with a small molecule in vivo leads to rapid TNF-dependent depletion of T and B cells. This observation has several implications for potential use of IKKβ inhibitors for the treatment of inflammatory disease and cancer.

scholarly journals Raloxifene inhibits pancreatic adenocarcinoma growth by interfering with ERβ and IL-6/gp130/STAT3 signaling

2020 ◽  
Author(s):  
Ioannis Pozios ◽  
Nina N. Seel ◽  
Nina A. Hering ◽  
Lisa Hartmann ◽  
Verena Liu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Tumor Growth ◽  
Therapeutic Option ◽  
Tumor Xenograft ◽  
Ductal Adenocarcinoma ◽  
Stat3 Signaling ◽  
Stat3 Phosphorylation ◽  
The Impact

Abstract Purpose Currently, the exact role of estrogen receptor (ER) signaling in pancreatic cancer is unknown. Recently, we showed that expression of phosphorylated ERβ correlates with a poor prognosis in patients with pancreatic ductal adenocarcinoma (PDAC). Here, we hypothesized that raloxifene, a FDA-approved selective ER modulator (SERM), may suppress PDAC tumor growth by interfering with ERβ signaling. To test this hypothesis, we studied the impact of raloxifene on interleukin-6/glycoprotein-130/signal transducer and activator of transcription-3 (IL-6/gp130/STAT3) signaling. Methods Human PDAC cell lines were exposed to raloxifene after which growth inhibition was assessed using a BrdU assay. ER knockdown was performed using siRNAs specific for ERα and ERβ. The effects of raloxifene on IL-6 expression and STAT3 phosphorylation in PDAC cells were assessed by ELISA and Western blotting, respectively. In addition, raloxifene was administered to an orthotopic PDAC tumor xenograft mouse model, after which tumor growth was monitored and immunohistochemistry was performed. Results Raloxifene inhibited the in vitro growth of PDAC cells, and this effect was reversed by siRNA-mediated knockdown of ERβ, but not of ERα, indicating ER isotype-specific signaling. We also found that treatment with raloxifene inhibited the release of IL-6 and suppressed the phosphorylation of STAT3Y705 in PDAC cells. In vivo, we found that orthotopic PDAC tumor growth, lymph node and liver metastases as well as Ki-67 expression were reduced in mice treated with raloxifene. Conclusions Inhibition of ERβ and the IL-6/gp130/STAT3 signaling pathway by raloxifene leads to potent reduction of PDAC growth in vitro and in vivo. Our results suggest that ERβ signaling and IL-6/gp130 interaction may serve as promising drug targets for pancreatic cancer and that raloxifene may serve as an attractive therapeutic option for PDAC patients expressing the ERβ isotype.

scholarly journals Pharmacological targeting PTK6 inhibits the JAK2/STAT3 sustained stemness and reverses chemoresistance of colorectal cancer

2021 ◽  
Vol 40 (1) ◽  
Author(s):  
Chaoqun Liu ◽  
Zhihua Pan ◽  
Qian Chen ◽  
Zetao Chen ◽  
Weiwei Liu ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Small Molecule ◽  
Nude Mice ◽  
Small Molecule Inhibitor ◽  
Loss Of Function ◽  
Pharmacological Inhibition ◽  
Stat3 Signaling ◽  
Molecule Inhibitor

Abstract Background Chemoresistance is the major cause of chemotherapy failure in patients with colorectal cancer (CRC). Protein tyrosine kinase 6 (PTK6) is aberrantly overexpressed in clinical CRC tissues undergoing chemotherapy. We studied if PTK6 contributed to the chemoresistance of CRC in human and mice. Methods We obtained tissue samples from patients with CRC and measured the expression of PTK6 by immunohistochemistry. Gain- and loss-of-function assays were performed to study the biological functions of PTK6. We constructed the FLAG-tagged wild type (WT), kinase-dead, and inhibition-defective recombinant mutants of PTK6 to study the effect phosphorylated activation of PTK6 played on CRC cell stemness and chemoresistance. We used small molecule inhibitor XMU-MP-2 to test the influence of PTK6 on sensitivity of CRC cells to 5-FU/L-OHP in both nude mouse and patient-derived xenograft (PDX) animal models. Results PTK6 is overexpressed in CRC tissues and plays a stimulatory role in the proliferation and chemoresistance of CRC cells both in vitro and in vivo. PTK6, especially the phosphorylated PTK6, can promote the stemness of CRC cells through interacting with JAK2 and phosphorylating it to activate the JAK2/STAT3 signaling. Pharmacological inhibition of PTK6 using XMU-MP-2 effectively reduces the stemness property of CRC cells and improves its chemosensitivity to 5-FU/L-OHP in both nude mice subcutaneously implanted tumor model and PDX model constructed with NOD-SCID mice. Conclusions PTK6 interacts with JAK2 and phosphorylates it to activate JAK2/STAT3 signaling to promote the stemness and chemoresistance of CRC cells. Pharmacological inhibition of PTK6 by small molecule inhibitor dramatically enhances the sensitivity to chemotherapy in nude mice and PDX models.

Phosphatidylinositol-3 Kinase Delta (PI3Kδ) Inhibitor AMG 319 Is a Potent, Selective and Orally Bioavailable Small Molecule Inhibitor That Suppresses PI3K-Mediated Signaling and Viability in Neoplastic B Cells

Blood ◽  
2011 ◽  
Vol 118 (21) ◽  
pp. 4964-4964 ◽  
Author(s):  
Angus Sinclair ◽  
Daniela Metz ◽  
Tim Cushing ◽  
Liqin Liu ◽  
Rachael Brake ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lines ◽  
Small Molecule ◽  
Single Agent ◽  
Chemotherapeutic Agents ◽  
B Cell Malignancies ◽  
Molecule Inhibitor ◽  
Human B Cell

Abstract Abstract 4964 Immune receptors such as the B cell receptor (BCR) require key signaling intermediate phosphatidylinositol-3 kinase delta (PI3Kδ) for normal immune cell survival, development and function. PI3Kδ is a class IA lipid kinase, is expressed primarily within the hematopoietic system and is composed of a catalytic subunit p110δ and a regulatory subunit p85. Recently, deregulated BCR-PI3Kδ signaling has been reported to play a role in B-cell malignancies such as chronic lymphocytic leukemia (CLL) and non-Hodgkin's lymphoma (NHL) by mediating abnormal B-cell growth and survival. Indeed, the constitutive phosphorylation of downstream signaling intermediate AKT is associated with poor prognosis in several B cell malignancies. Here, we have investigated the potential of a novel small molecule inhibitor of PI3Kδ, AMG 319, to suppress PI3K signaling in human B cell lines and assessed the subsequent effects on viability as a single agent and in combination with chemotherapeutic drugs in preclinical models. Small molecule AMG 319 is a potent and selective inhibitor of PI3Kδ with excellent preclinical pharmacokinetic (PK) properties. AMG 319 was found to potently inhibit PI3Kδ in enzyme assays (IC50 <10 nM). AMG 319 also potently suppressed the phosphorylation of AKT (pAKTS473) in primary murine splenocytes (IC50<5 nM) after BCR cross linking and demonstrated a less than 10 fold shift in human whole blood B cells using a similar BCR pAKT assay in vitro. In a cell based selectivity screen, AMG 319 was selective for PI3Kδ against other PI3K class I isoforms (200 to >5000 fold). Furthermore, AMG 319 was considered inactive at 10 μM on non-PI3K class I kinases in a broader kinome screen of 402 kinases. In preclinical PK studies, AMG 319 had low systemic clearance, T1/2 range of 2–4 hr, oral bioavailability of >45% and unbound fractions in plasma of 5–19%. Here, we have investigated the potential for AMG 319 to inhibit constitutive PI3K mediated signaling and effects on human B cell line viability. In a broad screen of >20 cell lines derived from B cell malignancies, the majority of lines were found to express PI3Kδ protein, all cells lines expressed the PI3Kα and β isoforms and variable levels of constitutive pAKTS473 were detected. AMG 319 was found to potently suppress constitutive pAKTS473 in the cell lines with IC50 in the low single to double digit nM range. Cellular viability was inhibited by AMG 319 though lines were variably sensitive to drug (range low double digit nM to μM IC50). As cell lines were variably sensitive to AMG 319 as a single agent, we examined if AMG 319 could enhance the efficacy of chemotherapeutic agents in vitro and in vivo. These studies focused on a DLBCL cell line HT which was relatively insensitive to AMG 319 as a single agent (IC50 ∼10 μM) in viability assays even though pAKTS473 was potently suppressed (IC50 ∼ 0.030 μM). Treatment with AMG 319 was found to synergize with the effects of vincristine to reduce cell viability in vitro using a 72 hr viability assay. Next we examined whether the enhanced cytotoxicity using these drugs in combination could be observed in vivo. Using the human B-cell lymphoma HT xenograft model, we found that AMG 319 in combination with vincristine enhanced tumor growth inhibition above that observed with either agent alone. Taken together, these findings suggest that the inhibition of PI3Kδ with AMG 319 may enhance the effects of chemotherapeutic agents in B cell malignancies. In conclusion, AMG 319 is a potent and selective inhibitor of PI3Kδ with excellent PK properties. AMG 319 inhibited constitutive pAKTS473, reduced the viability of B cell lines and synergized with vincristine in vitro and in vivo. The safety, PK and preliminary efficacy of AMG 319 are currently being investigated in a Phase I trial in patients with relapsed or refractory lymphoid malignancies. Disclosures: Sinclair: Amgen: Employment, Stock and Options. Metz:Amgen, Inc: Employment, Stock and Options. Cushing:Amgen, Inc: Employment, Stock and Options. Liu:Amgen, Inc: Employment, Stock and Options. Brake:Amgen, Inc: Employment, Stock and Options. Starnes:Amgen, Inc: Employment, Stock and Options. Means:Amgen, Inc: Employment, Stock and Options. Henne:Amgen, Inc: Employment, Stock and Options. Archibeque:Amgen: Employment, Stock and Options. Mattson:Amgen, Inc: Employment, Stock and Options. Drew:Amgen, Inc: Employment, Stock and Options. Busse:Amgen, Inc: Employment, Stock and Options. Wang:Amgen, Inc: Employment, Stock and Options. Al-Assaad:Amgen, Inc: Employment, Stock and Options. Molineux:Amgen: Employment, Stock and Options.

Morphine induces mesangial cell proliferation and glomerulopathy via κ-opioid receptors

2008 ◽  
Vol 294 (6) ◽  
pp. F1388-F1397 ◽  
Author(s):  
Marc L. Weber ◽  
Mariya Farooqui ◽  
Julia Nguyen ◽  
Michael Ansonoff ◽  
John E. Pintar ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Opioid Receptors ◽  
Mesangial Cell ◽  
Glomerular Volume ◽  
Specific Effects ◽  
Stat3 Signaling ◽  
Stat3 Phosphorylation ◽  
Transcription 3

Morphine sulfate (MS) stimulates mesangial cell (MC) proliferation, a process central to development of glomerular disease. The purpose of this study was to examine whether specific opioid receptors (OR) and signal transducer and activators of transcription 3 (STAT3) signaling are associated with MS-induced MC proliferation. C57Bl/6J and OR-specific knockout (KO) mice were treated for up to 6 wk with PBS, MS (0.7–2.14 mg/kg), naloxone (equimolar to MS), or MS+naloxone ( n = 6 per group). Glomerular volume and expression of PCNA, Thy1, and ED1/CD68 were analyzed in kidney sections. Cell proliferation and STAT3 phosphorylation were analyzed by bromodeoxyuridine (BrdU) ELISA and Western blot, respectively, in MCs in vitro. MS treatment led to enlarged kidneys and glomerulopathy and naloxone reversed these effects. MS treatment increased glomerular volume in both μ-OR (MOR) KO and δ-OR (DOR) KO mice, but not in κ-OR (KOR) KO mice. To ascertain that MS-induced glomerulopathy in vivo was due to MC proliferation, we further examined the OR-specific effects of MS in MCs in vitro. MS-induced MC proliferation in vitro was inhibited by KOR-specific nor-BNI, but not by DOR or MOR-specific antagonists naltrindol or CTOP, respectively. KOR-specific agonist U50488H stimulated proliferation of MCs, but DOR-specific agonist DPDPE and MOR-specific agonist DAMGO did not. MS failed to stimulate proliferation of MCs from KOR KO mice. MS and KOR agonists induced STAT3 phosphorylation, and STAT3 inhibitor blocked KOR agonist-induced MC proliferation. We show that MS stimulates glomerulopathy and MC proliferation via KOR and STAT3 signaling.

scholarly journals A Novel Small-Molecule Inhibitor of Protein Kinase D Blocks Pancreatic Cancer Growth In vitro and In vivo

2010 ◽  
Vol 9 (5) ◽  
pp. 1136-1146 ◽  
Author(s):  
Kuzhuvelil B. Harikumar ◽  
Ajaikumar B. Kunnumakkara ◽  
Nobuo Ochi ◽  
Zhimin Tong ◽  
Amit Deorukhkar ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Protein Kinase ◽  
Small Molecule ◽  
Small Molecule Inhibitor ◽  
Cancer Growth ◽  
Protein Kinase D ◽  
Molecule Inhibitor

scholarly journals P01.16 Effects of the STAT3 inhibitors on senescent tumour cells

2020 ◽  
Vol 8 (Suppl 2) ◽  
pp. A16.1-A16
Author(s):  
O Sapega ◽  
R Mikyskova ◽  
K Musilek ◽  
J Bieblova ◽  
Z Hodny ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Czech Republic ◽  
Cell Lines ◽  
Cellular Senescence ◽  
Tumour Cells ◽  
Stat3 Signaling ◽  
Stat3 Signaling Pathway ◽  
Stat3 Phosphorylation

BackgroundCellular senescence is the process of cell proliferation arrest. Premature cellular senescence can be induced by chemotherapy, irradiation and, under certain circumstances, by cytokines. Senescent cells produce a number of secreted proteins and growth factors that may either stimulate or inhibit cell proliferation. One of the major cytokines that play role in regulation of cellular senescence is IL-6. IL-6/STAT3 signaling pathway represent decisive regulatory factors in cellular senescence. The objective of this study was to compare the effects of the STAT3 inhibitors on senescent and proliferative tumour cells. Further, the therapeutic potential of the STAT3 inhibitors was evaluated using murine tumour models.Materials and MethodsIn vitro, as well as in vivo experiments were performed using TC-1 (model for HPV16-associated tumours) TRAMP-C2 (prostate cancer) cell lines. C57Bl/6NCrl mice, 7–8 weeks old, were obtained from Velaz (Prague, Czech Republic). Experimental protocols were approved by the Institutional Animal Care Committee of the Institute of Molecular Genetics (Prague, Czech Republic). STAT3 inhibitors, namely STATTIC, BP-102 (synthesised at the University of Hradec Kralove) and their derivatives were tested for their effects on tumour cells, such as cytotoxicity, ability to inhibit STAT3 phosphorylation, cell proliferation and tumour growth in syngeneic mice.ResultsWe have previously demonstrated that docetaxel-induced senescence in the TC-1 and TRAMP-C2 murine tumour cell lines, which was proved by in vitro (detection of increased p21 expression, positive beta-galactosidase staining, and the typical SASP capable to induce ‘bystander’ senescence), and in vivo experiments, using C57BL/6 mice [1]. Both TC-1 and TRAMP-C2 cells displayed elevated IL-6 secretion and activated STAT3 signaling pathway. Therefore, we tested efficacy of the STAT3 inhibitors on these cell lines. Cytotoxic and STAT3 phosphorylation inhibitory effects of the inhibitors were observed in both proliferating and senescent cells. Antitumor effects of selected inhibitors were evaluated.ConclusionsCollectively, STAT3 is an attractive target for therapeutic approaches in cancer treatment and we can assume that inhibition of the STAT3 pathway can be used for elimination of the pernicious effects of the senescent cells.ReferenceSimova J, Sapega O, Imrichova T, Stepanek I, Kyjacova L, Mikyskova R, Indrova M, Bieblova J, Bubenik J, Bartek J, et al: Tumor growth accelerated by chemotherapy-induced senescent cells is suppressed by treatment with IL-12 producing cellular vaccines. Oncotarget7: 54952–54964, 2016. This work was supported by the research grant No. NV18-05-00562 provided by the Grant Agency of the Ministry of Health of the Czech Republic.Disclosure InformationO. Sapega: None. R. Mikyskova: None. K. Musilek: None. J. Bieblova: None. Z. Hodny: None. M. Reinis: None.

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