Combination of ACY1215, a Selective Histone Deacetylase 6 (HDAC6) Inhibitor with the Bruton Tyrosine Kinase (BTK) Inhibitor, Ibrutinib, Represents a Novel Therapeutic Strategy in Mantle Cell Lymphoma (MCL)

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 1660-1660 ◽  
Author(s):  
Eva Sahakian ◽  
Jennifer Rock-Klotz ◽  
Bijal D. Shah ◽  
John Powers ◽  
Jennifer L. Cultrera ◽  
...  

Abstract Abstract 1660 Recently, we have found that HDAC6 is overexpressed in MCL cell lines and in primary human MCL cells. Knocking-down HDAC6 in MCL cells with a shRNA lentiviral system resulted in cell cycle arrest and apoptosis induction. Interestingly, MCL cells lacking HDAC6 displayed a significantly decreased STAT3 phosphorylation and abrogation of IL-10 gene transcriptional activity. ACY1215 is a novel, selective, orally bioavailable HDAC6 inhibitor. Treatment of MCL cell lines with this agent resulted in decreased cell viability and proliferation. In addition, ACY1215 inhibits IL-10 production in a dose dependent manner. Bruton tyrosine kinase (BTK) is a member of Tec family of kinases with a very distinct role in B-cell antigen receptor (BCR) signaling. The selective BTK-inhibitor PCI-32765 has shown promising pre-clinical and clinical activity in MCL. In addition to their direct anti-lymphoma effects, disruption of BTK also induces positive immunological changes such as inhibition of the immunosuppressive STAT3/IL-10 signaling pathway1. The above observations led us to determine whether the direct antitumor effects and the immunological properties of ACY1215 and PCI-32765 could be potentiated when these agents are used in combination. First, the viability of MCL cells was decreased when they were treated in vitro with either PCI-32765 or ACY1215. However, combination of these two agents resulted in a 3-fold increase in apoptosis induction, pointing to a synergistic effect of BTK and HDAC6 inhibition in MCL. The additional findings that this approach can increase the immunogenicity of MCL cells and anti-MCL immune responses has provided the proper framework for combining the selective HDAC6 inhibitor ACY1215 with BTK inhibition as a novel therapeutic strategy in MCL. Disclosures: Chen-Kiang: Bristol Myers Squibb: Consultancy; Pfizer: Research Funding. Jones:Acetylon Pharmaceuticals, Inc: Employment.

2021 ◽  
Author(s):  
Lena Weindl ◽  
Lena Weindl ◽  
Imke Atreya ◽  
Peter Dietrich ◽  
Sabine Neubeck ◽  
...  

Neuroendocrine neoplasms (NENs) represent a rare and heterogeneous group of malignancies, sharing features of both neural and endocrine cells. NENs G3 appear as a highly aggressive subset with poor prognosis and limited therapeutic options. The small-molecule inhibitor of the WEE1 tyrosine kinase, adavosertib (AZD1775), has previously demonstrated potent anti-tumor effects on various types of cancer in preclinical and clinical studies. However, the role of adavosertib in NENs G3 had remained elusive. We evaluated the effects of adavosertib on pancreatic (BON-1, QGP-1) and bronchopulmonary (NCI-H720) neuroendocrine tumor cell lines applying 2-dimensional and 3-dimensional spheroid models. We newly demonstrated that adavosertib is sufficient to reduce cell viability and proliferation in neuroendocrine cell lines with features of high-grade NENs. As underlying mechanisms, we identified adavosertib-mediated DNA-double-strand breaks and a G2/M cell cycle checkpoint abrogation leading into mitotic catastrophe and cancer cell apoptosis. Silencing of WEE1 via siRNA transfection resulted in a phenotype similar to adavosertib treatment. Together, inhibition of the WEE1 tyrosine kinase applying adavosertib on NENs G3 outlines a promising novel therapeutic strategy.


Blood ◽  
2012 ◽  
Vol 120 (9) ◽  
pp. 1877-1887 ◽  
Author(s):  
Yu-Tzu Tai ◽  
Betty Y. Chang ◽  
Sun-Young Kong ◽  
Mariateresa Fulciniti ◽  
Guang Yang ◽  
...  

Abstract Bruton tyrosine kinase (Btk) has a well-defined role in B-cell development, whereas its expression in osteoclasts (OCs) further suggests a role in osteoclastogenesis. Here we investigated effects of PCI-32765, an oral and selective Btk inhibitor, on osteoclastogenesis as well as on multiple myeloma (MM) growth within the BM microenvironment. PCI-32765 blocked RANKL/M-CSF–induced phosphorylation of Btk and downstream PLC-γ2 in OCs, resulting in diminished TRAP5b (ED50 = 17nM) and bone resorption activity. PCI-32765 also inhibited secretion of multiple cytokines and chemokines from OC and BM stromal cell cultures from both normal donors (ED50 = 0.5nM) and MM patients. It decreased SDF-1–induced migration of MM cells, and down-regulated MIP1-α/CCL3 in MM cells. It also blocked MM cell growth and survival triggered by IL-6 or coculture with BM stromal cells or OCs in vitro. Importantly, PCI-32765 treatment significantly inhibits in vivo MM cell growth (P < .03) and MM cell–induced osteolysis of implanted human bone chips in SCID mice. Moreover, PCI-32765 prevents in vitro colony formation by stem-like cells from MM patients. Together, these results delineate functional sequelae of Btk activation mediating osteolysis and growth of MM cells, supporting evaluation of PCI-32765 as a novel therapeutic in MM.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Zahra Tayarani-Najaran ◽  
Seyed Ahmad Emami ◽  
Javad Asili ◽  
Alireza Mirzaei ◽  
Seyed Hadi Mousavi

TheScutellariaspecies (Lamiaceae) is used as a source of flavonoids to treat a variety of diseases in traditional medicine. In spite of many reports about the cytotoxic and antitumor effects of some species of this genus, anticancer researches on one of the Iranian speciesS. litwinowiihave not yet been conducted.The cytotoxic properties of total methanol extract ofS. litwinowiiand its fractions were investigated on different cancer cell lines including AGS, HeLa, MCF-7, PC12 and NIH 3T3. Meanwhile, the role of apoptosis in this toxicity was explored. The cells were cultured in DMEM medium and incubated with different concentrations of herb plant extracts. Cell viability was quantitated by MTT assay. Apoptotic cells were determined using propidium iodide staining of DNA fragmentation by flow cytometry (sub-G1 peak).Scutellaria litwinowiiinhibited the growth of malignant cells in a dose-dependent manner. Among solvent fractions ofS. litwinowii, the methylene chloride fraction was found to be more toxic compared to other fractions. The IC50values of this fraction against AGS, HeLa, MCF-7 and PC12 cell lines after 24 h were determined, 121.2 ± 3.1, 40.9 ± 2.5, 115.9 ± 3.5 and 64.5 ± 3.4μg/ml, respectively.Scutellaria litwinowiiinduced a sub-G1 peak in the flow cytometry histogram of treated cells compared to control cells indicating that apoptotic cell death is involved inS. litwinowiitoxicity.Scutellaria litwinowiiexerts cytotoxic and proapototic effects in a variety of malignant cell lines and could be considered as a potential chemotherapeutic agent in cancer treatment.


2021 ◽  
Vol 3 (Supplement_6) ◽  
pp. vi6-vi6
Author(s):  
Takashi Fujii ◽  
Shun Yamamuro ◽  
Masamichi Takahashi ◽  
Akihide Kondo ◽  
Yoshitaka Narita ◽  
...  

Abstract The therapeutic outcome of glioblastomas (GBMs) is still very poor. Therefore, invention of novel therapeutic methods against GBM cases is considered urgent. The antitumor effects of naturally-derived compounds are attracting attention recently, and therapeutic efficacy of curcumin, a plant-derived compound previously used for multiple purpose, has been indicated in many cancer systems; however, clinical application of curcumin is considered difficult because of its poor bioavailability (under 1 %). Curcumin monoglucuronide (CMG), a water-soluble prodrug of curcumin recently developed for overcoming this weakness, has been demonstrated excellent antitumor effects for several malignancies in vitro and in vivo; therefore, we investigated the effects of CMG against GBM cells. CMG induced cell death of human GBM cells lines (T98G, U251MG, and U87MG) by dose dependent manner by triggering multiple forms of cell death such as apoptosis and perthanatos. Immunoblotting of CMG-treated GBM cell lysates demonstrated activation of multiple cell death signaling. Furthermore, immunodeficiency mice harboring intracerebral U87MG cell xenografts systemically treated by CMG showed significantly prolonged survival compared with control mice. These results suggest CMG would be a novel therapeutic agent against GBM cases.


2020 ◽  
Author(s):  
Fang Ren ◽  
Gong Zhang ◽  
Caiyu Li ◽  
Gailing Li ◽  
Yuan Cao ◽  
...  

Abstract Background: Hesperetin, an active compound found in citrus fruits, possesses antiproliferative effects toward several types of cancer cell lines, including cervical cancer. In this study, we explore the antitumor effects of Hesperetin on the human cervical cancer human papilloma virus (HPV)-positive (CaSki and HeLa) and HPV-negative (C-33A) cell lines and further elucidated the underlying mechanisms of this action. Methods: Cell viability and proliferation was measured by the MTT assay and 5-ethynyl-2′-deoxyuridine (EdU) incorporation assay, respectively. dUTP-fluorescein nick end-labeling (TUNEL) staining, Annexin V‑fluorescein isothiocyanate (FITC)/propidium iodide (PI) staining and flow cytometry was used to assess the degree of apoptosis. JC-1 staining assay was used to evaluate the change of mitochondrial membrane potential (ΔΨm) and Western blot assays were used to determine apoptosis-related factors at protein level. Results: Hesperetin (100, 200 and 400 μM) exhibited a significant exclusive inhibitory effect against the growth of HPV-infected CaSki and HeLa cancer cells via induction of apoptosis in a concentration-dependent manner, while it was almost not active in HPV-negative C-33A cancer cells and normal cervix epithelial H8 cells. Moreover, this antitumor effect executed by Hesperetin was associated with disruption of ΔΨm, the release of cytochrome c from mitochondria, activation of pro-apoptotic proteins (Bax, cleaved caspase-3 and caspase-9) and inhibition of anti-apoptotic proteins (Bcl-2). During this process, cleaved caspase-8 remained unchanged. In addition, Hesperetin led to a downregulation of E6 oncoprotein expression and upregulation of tumor suppressor protein p53 level. Conclusions: Collectively, these results implicated that Hesperetin can induce apoptosis of HPV‑positive cervical cancer cells via a mitochondria-mediated intrinsic signaling pathway, together with the repression of E6 and enhancement of p53 protein level, indicating Hesperetin may be considered as a potential candidate for the development of innovative anti-HPV cervical cancer agents.


2017 ◽  
Vol 11 (5) ◽  
pp. 237 ◽  
Author(s):  
Gregory W. Hosier ◽  
Naji J. Touma

Ibrutinib is a bruton tyrosine kinase (BTK) inhibitor approved for B cell malignancies. Although there are currently two clinical trials evaluating ibrutinib in combination with nivolumab (programmed cell death protein 1, PD-1, inhibitor) or everolimus (mammalian target of rapamycin, mTOR, inhibitor) for metastatic renal cell carcinoma (RCC), there are no reports of RCC (metastatic or non-metastatic) showing response to a BTK inhibitor in humans. Here we report a 22-month clinical response of biopsy-proven RCC to ibrutinib. This is unexpected, given that BTK is not wellimplicated in RCC pathophysiology. We explore a possible mechanism for the response of RCC to ibrutinib through inhibition of interleukin-2-inducible T-cell kinase (ITK) leading to enhanced antitumour immune responses.


2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi66-vi66
Author(s):  
Shabierjiang Jiapaer ◽  
Yu Dong ◽  
Tomohiro Kitabayashi ◽  
Taskuya Furuta ◽  
Hemragul Sabit ◽  
...  

Abstract BACKGROUND Glioblastoma (GBM) represents the most aggressive and frequent type of primary malignant brain tumors with a dismal clinical outcome. Though adjuvant temozolomide (TMZ) chemotherapy followed by surgical resection can extend patient`s post-operative survival, a considerable number of GBM cases are refractory to TMZ. Novel therapeutic agents that can overcome chemoresistance against TMZ are urgent. Drug repositioning is a process of identifying new indications for existing drugs and provides potential possibilities to discover new drugs. In this study, we explored novel anti-glioma agents which enhances the effect of TMZ with the strategy of drug repositioning. METHODS Drug library which contains 1300 diverse chemical compounds was screened using 2 kinds of glioma stem cell (GSC) lines to select novel therapeutic candidate. The effect of candidate drug on the proliferation of GSCs was estimated by sphere formation assay. To evaluate its efficacy against glioma cell biology, proliferation assay, matrigel invasion assay were performed. To clarify the mechanism of drug effects, we investigated target molecules by gelatin zymography and western blot. RESULTS Acyl CoA synthetase inhibitor named 2-fluoropalmitic acid (2-FPA) was selected as a novel candidate. 2-FPA suppressed proliferation of glioma cell lines by single administration and/or combination with TMZ. The sphere formation of GSCs was suppressed by combination therapy. Combination therapy enhanced TMZ effect. 2-FPA also suppressed invasion of glioma cell lines in a dose dependent manner. 2-FPA suppressed MMP-2 activity and phosphorylation of STAT3. CONCLUSION 2-FPA was identified as a novel potential therapeutic agent against GBM.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4402-4402
Author(s):  
Gunter Schuch ◽  
Ellen Schafer ◽  
Katharina Eggert ◽  
Sonja Loges ◽  
Manfred Jucker ◽  
...  

Abstract The tyrosine kinase pp60src is involved in several signal transduction pathways such as signalling of hematopoetic growth factors and cytokines. The viral form v-src was the first oncogene described and mutations of regulatory tyrosine residues in cellular src (c-src) have been linked to malignant transformation. However, no mutations in the gene of c-src have been described in leukemia so far, although some data of src mutations in solid tumors have been reported. The current study was undertaken to examine the role of src in acute myeloid leukemia (AML). Blood and bone marrow specimen of patients with newly diagnosed or recurrent AML treated at our institution were sampled. AML cell lines or CD34 positive cells of healthy donors served as positive and negative controls, respectively. RNA was isolated, and RT-PCR was performed using 4 different primer pairs spanning the coding region of c-src. Protein expression and phosphorylation was studied after protein extraction and Western blot analyses using src and phospho-src specific antibodies. The effect of src inhibitors PP1 and PP2 on leukemic cell proliferation was studied in human and murine cell lines. Mutational analyses of the coding region were performed using SSCP/heteroduplex and bi-directionally sequencing. In all 60 patients analyzed expression of c-src mRNA was detected by RT-PCR. Western blot analyses confirmed strong expression of src on the protein level and revealed a robust activation of the protein as determined by tyrosine phosphorylation. Inhibition of src phosphorylation by src-specific inhibitors PP1 and PP2 was detected by Western blot using an antibody specific for phospho-src. Incubation of leukemic cells with PP1 and PP2 caused significant inhibition of proliferation in a dose dependent manner. Mutational analyses as performed by SSCP/heteroduplex and bi-directionally sequencing revealed wildtype sequence in all cell lines and 60 clinical samples. In summary, pp60src is highly expressed and activated in cell lines and clinical samples of human AML. Moreover, phosphorylation of src is essential for leukemic cell proliferation. Mutations in the coding sequence of c-src causing constitutive activation could be excluded by mutational analyses of primary AML samples. These data suggest that pp60src plays a crucial role in AML and src inhibition by targeted therapy might offer a useful new approach in the treatment of AML.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2581-2581
Author(s):  
Roland B. Walter ◽  
Brian W. Raden ◽  
Irwin D. Bernstein ◽  
Jonathan A. Cooper

Abstract Background: CD33, the target for the anti-AML immunoconjugate, gemtuzumab ozogamicin (GO; Mylotarg™), contains two cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs). We have previously shown that these motifs control uptake of antibody-bound CD33 and GO-induced cytotoxicity. In this study, we determined which phosphorylation state favors uptake of antibody-bound CD33, identified proteins that bind to CD33 in an ITIM-dependent manner, and assessed their importance for CD33 internalization by siRNA-based gene silencing. Methods: Internalization of anti-CD33 antibodies was measured by flow cytometry in the presence or absence of the tyrosine phosphatase inhibitor, pervanadate, in human CD33+ AML cell lines (ML-1, HL-60, NB4, U937, TF-1) and CD33− Jurkat T cells infected with wild-type and mutant CD33. Pull-down experiments were performed with glutathione S-transferase (GST) proteins fused to phosphorylated cytoplasmic tails of CD33, using human myeloid cell lysates. Co-immunoprecipitations were performed with myeloid cell lines expressing HA-tagged wild-type CD33. Lentivirus-based siRNA constructs were generated for gene silencing, and expressed in human CD33+ AML cell lines. Results: Pervanadate significantly increased uptake of anti-CD33 antibodies in human AML cell lines; this effect was dependent upon the integrity of the ITIMs and was prevented by co-treatment with the Src tyrosine kinase inhibitor PP2, suggesting that Src family kinase-dependent phosphorylation of the ITIMs critically controls uptake of antibody-bound CD33, possibly by altering which proteins binds to CD33 or by facilitating binding of adaptor-proteins required for endocytosis. We identified several proteins, including the tyrosine phophatases, SHP-1 and SHP-2, and the non-receptor tyrosine kinase, Syk, which bound to phosphorylated wild-type and mutant CD33 in a manner that paralleled the endocytic properties of the corresponding CD33 protein. Since these three proteins have been implicated in endocytic processes of other cell surface proteins, we assessed their role in uptake of antibody-bound CD33 by siRNA-mediated gene silencing. Simultaneous depletion of SHP-1 and SHP-2, but not SHP-1 or SHP-2 alone, significantly increased internalization of antibody-bound CD33 in the two AML cell lines with the highest cell surface expression of CD33, whereas no effect was seen in two other cell lines with lower CD33 expression levels. In contrast, depletion of Syk, whose expression has previously been correlated to the inhibitory effect of anti-CD33 antibodies on AML cell growth, failed to affect antibody internalization in the cell lines assessed. Conclusion: These studies indicate that the phosphorylation status of the ITIMs controls uptake of antibody-bound CD33. In line with this model, SHP-1 and SHP-2, which have been shown to dephosphorylate CD33 in vitro, can affect this endocytic process. Thus, our data imply manipulation of the phosphorylation state of CD33, e.g. by activating Src family kinases or interfering with phosphatases as a novel means to increase uptake of anti-CD33 antibody-based therapeutics such as GO. Finally, the variable effect of SHP-1 and SHP-2 depletion suggests that there are significant cell-type specific differences in the response to anti-CD33 antibody ligation, for example differences in tyrosine phosphorylation levels and/or activation/recruitment or redundancies of tyrosine phosphatases.


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