scholarly journals Identification of Hsp90 inhibitors as potential drugs for the treatment of TSC1/TSC2 deficient cancer

2021 ◽  
Author(s):  
Evelyn M. Mrozek ◽  
Vineeta Bajaj ◽  
Yanan Guo ◽  
Izabela Malinowska ◽  
Jianming Zhang ◽  
...  

Inactivating mutations in either TSC1 or TSC2 cause Tuberous Sclerosis Complex, an autosomal dominant disorder, characterized by multi-system tumor and hamartoma development. Mutation and loss of function of TSC1 and/or TSC2 also occur in a variety of sporadic cancers, and rapamycin and related drugs show highly variable treatment benefit in patients with such cancers. The TSC1 and TSC2 proteins function in a complex that inhibits mTORC1, a key regulator of cell growth, which acts to enhance anabolic biosynthetic pathways. In this study, we identified and validated five cancer cell lines with TSC1 or TSC2 mutations and performed a kinase inhibitor drug screen with 197 compounds. The five cell lines were sensitive to several mTOR inhibitors, and cell cycle kinase and HSP90 kinase inhibitors. The IC50 for Torin1 and INK128, both mTOR kinase inhibitors, was significantly increased in three TSC2 null cell lines in which TSC2 expression was restored.  Rapamycin was significantly more effective than either INK128 or ganetespib (an HSP90 inhibitor) in reducing the growth of TSC2 null SNU-398 cells in a xenograft model. Combination ganetespib-rapamycin showed no significant enhancement of growth suppression over rapamycin. Hence, although HSP90 inhibitors show strong inhibition of TSC1/TSC2 null cell line growth in vitro, ganetespib showed little benefit at standard dosage in vivo. In contrast, rapamycin which showed very modest growth inhibition in vitro was the best agent for in vivo treatment, but did not cause tumor regression, only growth delay.

PLoS ONE ◽  
2021 ◽  
Vol 16 (4) ◽  
pp. e0248380
Author(s):  
Evelyn M. Mrozek ◽  
Vineeta Bajaj ◽  
Yanan Guo ◽  
Izabela A. Malinowska ◽  
Jianming Zhang ◽  
...  

Inactivating mutations in either TSC1 or TSC2 cause Tuberous Sclerosis Complex, an autosomal dominant disorder, characterized by multi-system tumor and hamartoma development. Mutation and loss of function of TSC1 and/or TSC2 also occur in a variety of sporadic cancers, and rapamycin and related drugs show highly variable treatment benefit in patients with such cancers. The TSC1 and TSC2 proteins function in a complex that inhibits mTORC1, a key regulator of cell growth, which acts to enhance anabolic biosynthetic pathways. In this study, we identified and validated five cancer cell lines with TSC1 or TSC2 mutations and performed a kinase inhibitor drug screen with 197 compounds. The five cell lines were sensitive to several mTOR inhibitors, and cell cycle kinase and HSP90 kinase inhibitors. The IC50 for Torin1 and INK128, both mTOR kinase inhibitors, was significantly increased in three TSC2 null cell lines in which TSC2 expression was restored. Rapamycin was significantly more effective than either INK128 or ganetespib (an HSP90 inhibitor) in reducing the growth of TSC2 null SNU-398 cells in a xenograft model. Combination ganetespib-rapamycin showed no significant enhancement of growth suppression over rapamycin. Hence, although HSP90 inhibitors show strong inhibition of TSC1/TSC2 null cell line growth in vitro, ganetespib showed little benefit at standard dosage in vivo. In contrast, rapamycin which showed very modest growth inhibition in vitro was the best agent for in vivo treatment, but did not cause tumor regression, only growth delay.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1716-1716 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Teru Hideshima ◽  
Robert J. Lutz ◽  
Sonia Vallet ◽  
Samantha Pozzi ◽  
...  

Abstract CD138 is expressed on differentiated plasma cells and is involved in the development and/or proliferation of multiple myeloma (MM), for which it is a primary diagnostic marker. In this study, we report that immunoconjugates comprised of the murine/human chimeric CD138-specific monoclonal antibody nBT062 conjugated with highly cytotoxic maytansinoid derivatives (nBT062-SMCC-DM1, nBT062-SPDB-DM4 and nBT062-SPP-DM1) showed cytotoxic activity against CD138-positive MM cells both in vitro and in vivo. These agents demonstrated cytotoxicity against OPM1 and RPMI8226 (CD138-positive MM cell lines) in a dose and time-dependent fashion and were also cytotoxic against primary tumor cells from MM patients. Minimal cytotoxicity was noted in CD138-negative cell lines and no activity was observed against peripheral blood mononuclear cells from healthy volunteers, suggesting that CD138-targeting is important for immunoconjugate-mediated cytotoxicity. Examination of the mechanism of action whereby these immunoconjugates induced cytotoxicity in MM cells demonstrated that treatment triggered G2/M cell cycle arrest, followed by apoptosis associated with cleavage of PARP and caspase-3, -8 and -9. Neither interleukin-6 nor insulin-like growth factor-I could overcome the apoptotic effect of these agents. The level of soluble (s)CD138 in the BM plasma from 15 MM patients was evaluated to determine the potential impact of sCD138 on immunoconjugate function. The sCD138 level in BM plasma was found to be significantly lower than that present in MM cell culture supernatants where potent in vitro cytotoxicity was observed, suggesting that sCD138 levels in MM patient BM plasma would not interfere with immunoconjugate activity. Because adhesion to bone marrow stromal cells (BMSCs) triggers cell adhesion mediated drug resistance to conventional therapies, we next examined the effects of the conjugates on MM cell growth in the context of BMSC. Co-culture of MM cells with BMSCs, which protects against dexamethasoneinduced death, had no impact on the cytotoxicity of the immunoconjugates. The in vivo efficacy of these immunoconjugates was also evaluated in SCID mice bearing established CD138-positive MM xenografts and in a SCID-human bone xenograft model of myeloma. Significant tumor growth delay or regressions were observed at immunoconjugate concentrations that were well tolerated in all models tested. The ability of these agents to mediate bystander killing of proximal CD138-negative cells was also evaluated. While nBT062-SPDB-DM4 was inactive against CD138-negative Namalwa cells cultured alone, significant killing of these CD138-negative cells by nBT062-SPDB-DM4 was observed when mixed with CD138-positive OPM2 cells. This bystander killing may contribute to the eradication of MM tumors by disrupting the tumor microenvironment and/or killing CD138-negative MM tumor cells, such as the putative CD138 negative myeloma stem cells. These studies demonstrate strong evidence of in vitro and in vivo selective cytotoxicity of these immunoconjugates and provide the preclinical framework supporting evaluation of nBT062-based immunoconjugates in clinical trials to improve patient outcome in MM.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 793-793 ◽  
Author(s):  
Amie S. Corbin ◽  
Shadmehr Demehri ◽  
Ian J. Griswold ◽  
Chester A. Metcalf ◽  
William C. Shakespeare ◽  
...  

Abstract Oncogenic mutations of the KIT receptor tyrosine kinase have been identified in several malignancies including gastrointestinal stromal tumors (GIST), systemic mastocytosis (SM), seminomas/dysgerminomas and acute myelogenous leukemia (AML). Mutations in the regulatory juxtamembrane domain are common in GIST, while mutations in the activation loop of the kinase (most commonly D816V) occur predominantly in SM and at low frequency in AML. Several ATP-competitive kinase inhibitors, including imatinib, are effective against juxtamembrane KIT mutants, however, the D816V mutant is largely resistant to inhibition. We analyzed the sensitivities of cell lines expressing wild type KIT, juxtamembrane mutant KIT (V560G) and activation loop mutant KIT (D816V,F,Y and murine D814Y) to a potent Src/Abl kinase inhibitor, AP23464, and analogs. IC50 values for inhibition of cellular KIT phosphorylation by AP23464 were 5–11 nM for activation loop mutants, 70 nM for the juxtamembrane mutant and 85 nM for wild type KIT. Consistent with this, IC50 values in cell proliferation assays were 3–20 nM for activation loop mutants and 100 nM for wild type KIT and the juxtmembrane mutant. In activation loop mutant-expressing cell lines, AP23464, at concentrations ≤50 nM, induced apoptosis, arrested the cell cycle in G0/G1 and down-regulated phosphorylation of Akt and STAT3, signaling pathways critical for the transforming capacity of mutant KIT. In contrast, 500 nM AP23464 was required to induce equivalent effects in wild-type KIT and juxtamembrane mutant-expressing cell lines. These data demonstrate that activation loop KIT mutants are considerably more sensitive to inhibition by AP23464 than wild type or juxtamembrane mutant KIT. Non-specific toxicity in parental cells occurred only at concentrations above 2 μM. Additionally, at concentrations below 100 nM, AP23464 did not inhibit formation of granulocyte/macrophage and erythrocyte colonies from normal bone marrow, suggesting that therapeutic drug levels would not impact normal hematopoiesis. We also examined in vivo target inhibition in a mouse model. Mice were subcutaneously injected with D814Y-expressing (D816V homologous) murine mastocytoma cells. Once tumors were established, compound was administered three-times daily by oral gavage. One hour post treatment we observed >90% inhibition of KIT phosphorylation in tumor tissue. Following a three-day treatment regimen, there was a statistically significant difference in tumor size compared to controls. Thus, AP23464 analogs effectively target D816-mutant KIT both in vitro and in vivo and inhibit activation loop KIT mutants more potently than the wild type protein. These data provide evidence that this class of kinase inhibitors may have therapeutic potential for D816V-expressing malignancies such as SM or AML.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yuichi Sawaguchi ◽  
Ryuta Yamazaki ◽  
Yukiko Nishiyama ◽  
Masayuki Mae ◽  
Atsuhiro Abe ◽  
...  

Pim kinases are overexpressed in various types of hematological malignancies and solid carcinomas, and promote cell proliferation and survival. Here in this study, we investigated the preclinical profile of novel pan-Pim kinase inhibitors with imidazopyridazine and thiazolidinedione structure. Imidazopyridazine-thiazolidinediones inhibited activities of Pim kinases with IC50 values of tens to hundreds nanomolar. With YPC-21440 and/or YPC-21817, which exhibited especially high inhibitory activities against Pim kinases, we investigated in vitro and in vivo activities of imidazopyridazine-thiazolidinediones. In silico analysis of binding mode of YPC-21440 and Pim kinases revealed that it directly bound to ATP-binding pockets of Pim kinases. In the kinase panel tested, YPC-21440 and YPC-21817 were highly specific to Pim kinases. These compounds exerted antiproliferative activities against various cancer cell lines derived from hematological malignancies and solid carcinomas. Furthermore, they suppressed phosphorylation of Pim kinase substrates, arrested cell cycle at the G1 phase, and induced apoptosis in cultured cancer cells. In tumor xenograft models, YPC-21440 methanesulfonate and YPC-21817 methanesulfonate exerted antitumor activities. Furthermore, pharmacodynamic analysis with a xenograft model suggested that YPC-21817 methanesulfonate inhibited Pim kinases in tumors. In conclusion, our data revealed that imidazopyridazine-thiazolidinediones are novel Pim kinases inhibitors, effective on various types of cancer cell lines both in vitro and in vivo.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hu Lei ◽  
Han-Zhang Xu ◽  
Hui-Zhuang Shan ◽  
Meng Liu ◽  
Ying Lu ◽  
...  

AbstractIdentifying novel drug targets to overcome resistance to tyrosine kinase inhibitors (TKIs) and eradicating leukemia stem/progenitor cells are required for the treatment of chronic myelogenous leukemia (CML). Here, we show that ubiquitin-specific peptidase 47 (USP47) is a potential target to overcome TKI resistance. Functional analysis shows that USP47 knockdown represses proliferation of CML cells sensitive or resistant to imatinib in vitro and in vivo. The knockout of Usp47 significantly inhibits BCR-ABL and BCR-ABLT315I-induced CML in mice with the reduction of Lin−Sca1+c-Kit+ CML stem/progenitor cells. Mechanistic studies show that stabilizing Y-box binding protein 1 contributes to USP47-mediated DNA damage repair in CML cells. Inhibiting USP47 by P22077 exerts cytotoxicity to CML cells with or without TKI resistance in vitro and in vivo. Moreover, P22077 eliminates leukemia stem/progenitor cells in CML mice. Together, targeting USP47 is a promising strategy to overcome TKI resistance and eradicate leukemia stem/progenitor cells in CML.


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3487
Author(s):  
Yu-Ling Lu ◽  
Ming-Hsien Wu ◽  
Yi-Yin Lee ◽  
Ting-Chao Chou ◽  
Richard J. Wong ◽  
...  

Differentiated thyroid cancer (DTC) patients are usually known for their excellent prognoses. However, some patients with DTC develop refractory disease and require novel therapies with different therapeutic mechanisms. Targeting Wee1 with adavosertib has emerged as a novel strategy for cancer therapy. We determined the effects of adavosertib in four DTC cell lines. Adavosertib induces cell growth inhibition in a dose-dependent fashion. Cell cycle analyses revealed that cells were accumulated in the G2/M phase and apoptosis was induced by adavosertib in the four DTC tumor cell lines. The sensitivity of adavosertib correlated with baseline Wee1 expression. In vivo studies showed that adavosertib significantly inhibited the xenograft growth of papillary and follicular thyroid cancer tumor models. Adavosertib therapy, combined with dabrafenib and trametinib, had strong synergism in vitro, and revealed robust tumor growth suppression in vivo in a xenograft model of papillary thyroid cancer harboring mutant BRAFV600E, without appreciable toxicity. Furthermore, combination of adavosertib with lenvatinib was more effective than either agent alone in a xenograft model of follicular thyroid cancer. These results show that adavosertib has the potential in treating DTC.


2020 ◽  
Vol 15 (1) ◽  
pp. 871-883
Author(s):  
Jinshan Zhang ◽  
Dan Rao ◽  
Haibo Ma ◽  
Defeng Kong ◽  
Xiaoming Xu ◽  
...  

AbstractBackgroundOsteosarcoma is a common primary malignant bone cancer. Long noncoding RNA small nucleolar RNA host gene 15 (SNHG15) has been reported to play an oncogenic role in many cancers. Nevertheless, the role of SNHG15 in the doxorubicin (DXR) resistance of osteosarcoma cells has not been fully addressed.MethodsCell Counting Kit-8 assay was conducted to measure the half-maximal inhibitory concentration value of DXR in osteosarcoma cells. Western blotting was carried out to examine the levels of autophagy-related proteins and GDNF family receptor alpha-1 (GFRA1). Quantitative reverse transcription-polymerase chain reaction was performed to determine the levels of SNHG15, miR-381-3p, and GFRA1. The proliferation of osteosarcoma cells was measured by MTT assay. The binding sites between miR-381-3p and SNHG15 or GFRA1 were predicted by Starbase bioinformatics software, and the interaction was confirmed by dual-luciferase reporter assay. Murine xenograft model was established to validate the function of SNHG15 in vivo.ResultsAutophagy inhibitor 3-methyladenine sensitized DXR-resistant osteosarcoma cell lines to DXR. SNHG15 was upregulated in DXR-resistant osteosarcoma tissues and cell lines. SNHG15 knockdown inhibited the proliferation, DXR resistance, and autophagy of osteosarcoma cells. MiR-381-3p was a direct target of SNHG15, and GFRA1 bound to miR-381-3p in osteosarcoma cells. SNHG15 contributed to DXR resistance through the miR-381-3p/GFRA1 axis in vitro. SNHG15 depletion contributed to the inhibitory effect of DXR on osteosarcoma tumor growth through the miR-381-3p/GFRA1 axis in vivo.ConclusionsSNHG15 enhanced the DXR resistance of osteosarcoma cells through elevating the autophagy via targeting the miR-381-3p/GFRA1 axis. Restoration of miR-381-3p expression might be an underlying therapeutic strategy to overcome the DXR resistance of osteosarcoma.


2019 ◽  
Author(s):  
Yusuke Tarumoto ◽  
Shan Lin ◽  
Jinhua Wang ◽  
Joseph P. Milazzo ◽  
Yali Xu ◽  
...  

AbstractLineage-defining transcription factors (TFs) are compelling targets for leukemia therapy, yet they are among the most challenging proteins to modulate directly with small molecules. We previously used CRISPR screening to identify a Salt-Inducible Kinase 3 (SIK3) requirement for the growth of acute myeloid leukemia (AML) cell lines that overexpress the lineage TF MEF2C. In this context, SIK3 maintains MEF2C function by directly phosphorylating histone deacetylase 4 (HDAC4), a repressive cofactor of MEF2C. Here, we evaluated whether inhibition of SIK3 with the tool compound YKL-05-099 can suppress MEF2C function and attenuate disease progression in animal models of AML. Genetic targeting of SIK3 or MEF2C selectively suppressed the growth of transformed hematopoietic cells underin vitroandin vivoconditions. Similar phenotypes were obtained when exposing cells to YKL-05-099, which caused cell cycle arrest and apoptosis in MEF2C-expressing AML cell lines. An epigenomic analysis revealed that YKL-05-099 rapidly suppressed MEF2C function by altering the phosphorylation state and nuclear localization of HDAC4. Using a gatekeeper allele ofSIK3, we found that the anti-proliferative effects of YKL-05-099 occurred through on-target inhibition of SIK3 kinase activity. Based on these findings, we treated two different mouse models of MLL-AF9 AML with YKL-05-099, which attenuated disease progressionin vivoand extended animal survival at well-tolerated doses. These findings validate SIK3 as a therapeutic target in MEF2C-positive AML and provide a rationale for developing drug-like inhibitors of SIK3 for definitive pre-clinical investigation and for studies in human patients with leukemia.Key PointsAML cells are uniquely sensitive to genetic or chemical inhibition of Salt-Inducible Kinase 3in vitroandin vivo.A SIK inhibitor YKL-05-099 suppresses MEF2C function and AMLin vivo.


2019 ◽  
Vol 116 (34) ◽  
pp. 16981-16986 ◽  
Author(s):  
Claudio Scuoppo ◽  
Jiguang Wang ◽  
Mirjana Persaud ◽  
Sandeep K. Mittan ◽  
Katia Basso ◽  
...  

To repurpose compounds for diffuse large B cell lymphoma (DLBCL), we screened a library of drugs and other targeted compounds approved by the US Food and Drug Administration on 9 cell lines and validated the results on a panel of 32 genetically characterized DLBCL cell lines. Dasatinib, a multikinase inhibitor, was effective against 50% of DLBCL cell lines, as well as against in vivo xenografts. Dasatinib was more broadly active than the Bruton kinase inhibitor ibrutinib and overcame ibrutinib resistance. Tumors exhibiting dasatinib resistance were commonly characterized by activation of the PI3K pathway and loss of PTEN expression as a specific biomarker. PI3K suppression by mTORC2 inhibition synergized with dasatinib and abolished resistance in vitro and in vivo. These results provide a proof of concept for the repurposing approach in DLBCL, and point to dasatinib as an attractive strategy for further clinical development in lymphomas.


Cancers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1550 ◽  
Author(s):  
Tomomi Sanomachi ◽  
Shuhei Suzuki ◽  
Keita Togashi ◽  
Asuka Sugai ◽  
Shizuka Seino ◽  
...  

Spironolactone, a classical diuretic drug, is used to treat tumor-associated complications in cancer patients. Spironolactone was recently reported to exert anti-cancer effects by suppressing DNA damage repair. However, it currently remains unclear whether spironolactone exerts combinational effects with non-DNA-damaging anti-cancer drugs, such as gemcitabine and epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). Using the cancer cells of lung cancer, pancreatic cancer, and glioblastoma, the combinational effects of spironolactone with gemcitabine and osimertinib, a third-generation EGFR-TKI, were examined in vitro with cell viability assays. To elucidate the underlying mechanisms, we investigated alterations induced in survivin, an anti-apoptotic protein, by spironolactone as well as the chemosensitization effects of the suppression of survivin by YM155, an inhibitor of survivin, and siRNA. We also examined the combinational effects in a mouse xenograft model. The results obtained revealed that spironolactone augmented cell death and the suppression of cell growth by gemcitabine and osimertinib. Spironolactone also reduced the expression of survivin in these cells, and the pharmacological and genetic suppression of survivin sensitized cells to gemcitabine and osimertinib. This combination also significantly suppressed tumor growth without apparent adverse effects in vivo. In conclusion, spironolactone is a safe candidate drug that exerts anti-cancer effects in combination with non-DNA-damaging drugs, such as gemcitabine and osimertinib, most likely through the suppression of survivin.


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