scholarly journals CDK7 inhibition suppresses aberrant hedgehog pathway and overcomes resistance to smoothened antagonists

2019 ◽  
Vol 116 (26) ◽  
pp. 12986-12995 ◽  
Author(s):  
Fang Liu ◽  
Wenyan Jiang ◽  
Yi Sui ◽  
Wei Meng ◽  
Linjun Hou ◽  
...  

The aberrant hedgehog (Hh) pathway plays important roles in multiple cancer types, therefore serving as a promising drug target. Current clinically available hedgehog-targeted drugs act mostly by antagonizing the upstream component smoothened; however, both primary and acquired resistance to FDA-approved smoothened inhibitor (SMOi) drugs have been described. We have recently demonstrated that the BET inhibitor effectively suppresses SMOi-resistant Hh-driven cancers through antagonizing transcription of GLI1 and GLI2, the core transcriptional factors of Hh pathway, suggesting epigenetic or transcriptional targeted therapy represents an anti-Hh therapeutic strategy that can overcome SMOi resistance. Here we performed an unbiased screening of epigenetic or transcriptional targeted small molecules to test their inhibitory effects on GLI1 and GLI2 transcription or cell viability of Hh-driven tumor lines. THZ1, a covalent inhibitor of cyclin-dependent kinase 7 (CDK7), is identified as the top hit in our screening. We then confirmed that antagonizing CDK7 by either small-molecule inhibitors or the CRISPR-Cas9 approach causes substantial suppression of GLI1 and GLI2 transcription, resulting in effective inhibition of Hh-driven cancers in vitro and in vivo. More importantly, antagonizing CDK7 retains inhibitory activity against Hh-driven cancers with almost all so-far described primary or acquired SMOi resistance. Furthermore, we reveal a synergy between CDK7 inhibition and BET inhibition on antagonizing aberrant Hh pathway and Hh-driven cancers that are either responsive or resistant to SMOi. Our results illustrate transcriptional inhibition through targeting CDK7 as a promising therapeutic strategy for treating Hh-driven cancers, especially those with primary or acquired resistance to SMOi drugs.

2014 ◽  
Vol 21 (3) ◽  
pp. R183-R194 ◽  
Author(s):  
Yevgeniya Kushchayeva ◽  
Kirk Jensen ◽  
Kenneth D Burman ◽  
Vasyl Vasko

Repositioning of established non-cancer pharmacotherapeutic agents with well-known activity and side-effect profiles is a promising avenue for the development of new treatment modalities for multiple cancer types. We have analyzed some of the medications with mechanism of action that may have relevance to thyroid cancer (TC). Experimentalin vitroandin vivoevidences, as well as results of clinical studies, have indicated that molecular targets for medications currently available for the treatment of mood disorders, sexually transmitted diseases, metabolic disorders, and diabetes may be active and relevant in TC. For instance, the derivatives of cannabis and an anti-diabetic agent, metformin, both are able to inhibit ERK, which is commonly activated in TC cells. We present here several examples of well-known medications that have the potential to become new therapeutics for patients with TC. Repositioning of established medications for the treatment of TC could broaden the scope of current therapeutic strategies. These diverse treatment choices could allow physicians to provide an individualized approach to optimize treatment for patients with TC.


Author(s):  
Fugen Shangguan ◽  
Hongfei Zhou ◽  
Nengfang Ma ◽  
Shanshan Wu ◽  
Huimin Huang ◽  
...  

Cannabidiol (CBD), a phytochemical derived from Cannabis sativa L., has been demonstrated to exhibit promising anti-tumor properties in multiple cancer types. However, the effects of CBD on hepatocellular carcinoma (HCC) cells remain unknown. We have shown that CBD effectively suppresses HCC cell growth in vivo and in vitro, and induced HCC cell pyroptosis in a caspase-3/GSDME-dependent manner. We further demonstrated that accumulation of integrative stress response (ISR) and mitochondrial stress may contribute to the initiation of pyroptotic signaling by CBD. Simultaneously, CBD can repress aerobic glycolysis through modulation of the ATF4–IGFBP1–Akt axis, due to the depletion of ATP and crucial intermediate metabolites. Collectively, these observations indicate that CBD could be considered as a potential compound for HCC therapy.


2020 ◽  
Vol 10 ◽  
Author(s):  
Zhiheng Li ◽  
Su Lin Lim ◽  
Yanfang Tao ◽  
Xiaolu Li ◽  
Yi Xie ◽  
...  

Neuroblastoma (NB) is one of the most common solid tumors in childhood. To date, targeting MYCN, a well-established driver gene in high-risk neuroblastoma, is still challenging. In recent years, inhibition of bromodomain and extra terminal (BET) proteins shows great potential in multiple of Myc-driven tumors. ARV-825 is a novel BET inhibitor using proteolysis-targeting chimera (PROTAC) technology which degrades target proteins by the proteasome. In this study, we investigated the effect of ARV-825 in neuroblastoma in vitro and in vivo. Our results showed that ARV-825 treatment robustly induced proliferative suppression, cell cycle arrest, and apoptosis in NB cells. Moreover, ARV-825 efficiently depleted BET protein expression, subsequently repressing the expression of MYCN or c-Myc. In the NB xenograft model, ARV-825 profoundly reduced tumor growth and led to the downregulation of BRD4 and MYCN expression in mice. Taken together, these findings provide evidence that PROTAC BET inhibitor is an efficient way to achieve MYCN/c-Myc manipulation, and ARV-825 can be used as a potential therapeutic strategy for the treatment of neuroblastoma.


eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Christopher J Giuliano ◽  
Ann Lin ◽  
Joan C Smith ◽  
Ann C Palladino ◽  
Jason M Sheltzer

The Maternal Embryonic Leucine Zipper Kinase (MELK) has been identified as a promising therapeutic target in multiple cancer types. MELK over-expression is associated with aggressive disease, and MELK has been implicated in numerous cancer-related processes, including chemotherapy resistance, stem cell renewal, and tumor growth. Previously, we established that triple-negative breast cancer cell lines harboring CRISPR/Cas9-induced null mutations in MELK proliferate at wild-type levels in vitro (<xref ref-type="bibr" rid="bib34">Lin et al., 2017</xref>). Here, we generate several additional knockout clones of MELK and demonstrate that across cancer types, cells lacking MELK exhibit wild-type growth in vitro, under environmental stress, in the presence of cytotoxic chemotherapies, and in vivo. By combining our MELK-knockout clones with a recently described, highly specific MELK inhibitor, we further demonstrate that the acute inhibition of MELK results in no specific anti-proliferative phenotype. Analysis of gene expression data from cohorts of cancer patients identifies MELK expression as a correlate of tumor mitotic activity, explaining its association with poor clinical prognosis. In total, our results demonstrate the power of CRISPR/Cas9-based genetic approaches to investigate cancer drug targets, and call into question the rationale for treating patients with anti-MELK monotherapies.


2020 ◽  
Vol 26 ◽  
Author(s):  
Maryam Dashtiahangar ◽  
Leila Rahbarnia ◽  
Safar Farajnia ◽  
Arash Salmaninejad ◽  
Arezoo Gowhari Shabgah ◽  
...  

: The development of recombinant immunotoxins (RITs) as a novel therapeutic strategy has made a revolution in the treatment of cancer. RITs are resulting from the fusion of antibodies to toxin proteins for targeting and eliminating cancerous cells by inhibiting protein synthesis. Despite indisputable outcomes of RITs regarding inhibiting multiple cancer types, high immunogenicity has been known as the main obstacle in the clinical use of RITs. Various strategies have been proposed to overcome these limitations, including immunosuppressive therapy, humanization of the antibody fragment moiety, generation of immunotoxins originated from endogenous human cytotoxic enzymes, and modification of the toxin moiety to escape the immune system. This paper devoted to reviewing recent advances in the design of immunotoxins with lower immunogenicity.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yi Xin She ◽  
Qing Yang Yu ◽  
Xiao Xiao Tang

AbstractInterleukins, a group of cytokines participating in inflammation and immune response, are proved to be involved in the formation and development of pulmonary fibrosis. In this article, we reviewed the relationship between interleukins and pulmonary fibrosis from the clinical, animal, as well as cellular levels, and discussed the underlying mechanisms in vivo and in vitro. Despite the effects of interleukin-targeted treatment on experimental pulmonary fibrosis, clinical applications are lacking and unsatisfactory. We conclude that intervening in one type of interleukins with similar functions in IPF may not be enough to stop the development of fibrosis as it involves a complex network of regulation mechanisms. Intervening interleukins combined with other existing therapy or targeting interleukins affecting multiple cells/with different functions at the same time may be one of the future directions. Furthermore, the intervention time is critical as some interleukins play different roles at different stages. Further elucidation on these aspects would provide new perspectives on both the pathogenesis mechanism, as well as the therapeutic strategy and drug development.


2021 ◽  
Vol 7 (2) ◽  
pp. 113
Author(s):  
Anne-Laure Bidaud ◽  
Patrick Schwarz ◽  
Guillaume Herbreteau ◽  
Eric Dannaoui

Systemic fungal infections are associated with high mortality rates despite adequate treatment. Moreover, acquired resistance to antifungals is increasing, which further complicates the therapeutic management. One strategy to overcome antifungal resistance is to use antifungal combinations. In vitro, several techniques are used to assess drug interactions, such as the broth microdilution checkerboard, agar-diffusion methods, and time-kill curves. Currently, the most widely used technique is the checkerboard method. The aim of all these techniques is to determine if the interaction between antifungal agents is synergistic, indifferent, or antagonistic. However, the interpretation of the results remains difficult. Several methods of analysis can be used, based on different theories. The most commonly used method is the calculation of the fractional inhibitory concentration index. Determination of the usefulness of combination treatments in patients needs well-conducted clinical trials, which are difficult. It is therefore important to study antifungal combinations in vivo, in experimental animal models of fungal infections. Although mammalian models have mostly been used, new alternative animal models in invertebrates look promising. To evaluate the antifungal efficacy, the most commonly used criteria are the mortality rate and the fungal load in the target organs.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Zetao Chen ◽  
Yihong Chen ◽  
Yan Li ◽  
Weidong Lian ◽  
Kehong Zheng ◽  
...  

AbstractGlioma is one of the most lethal cancers with highly vascularized networks and growing evidences have identified glioma stem cells (GSCs) to account for excessive angiogenesis in glioma. Aberrant expression of paired-related homeobox1 (Prrx1) has been functionally associated with cancer stem cells including GSCs. In this study, Prrx1 was found to be markedly upregulated in glioma specimens and elevated Prrx1 expression was inversely correlated with prognosis of glioma patients. Prrx1 potentiated stemness acquisition in non-stem tumor cells (NSTCs) and stemness maintenance in GSCs, accompanied with increased expression of stemness markers such as SOX2. Prrx1 also promoted glioma angiogenesis by upregulating proangiogenic factors such as VEGF. Consistently, silencing Prrx1 markedly inhibited glioma proliferation, stemness, and angiogenesis in vivo. Using a combination of subcellular proteomics and in vitro analyses, we revealed that Prrx1 directly bound to the promoter regions of TGF-β1 gene, upregulated TGF-β1 expression, and ultimately activated the TGF-β/smad pathway. Silencing TGF-β1 mitigated the malignant behaviors induced by Prrx1. Activation of this pathway cooperates with Prrx1 to upregulate the expression of stemness-related genes and proangiogenic factors. In summary, our findings revealed that Prrx1/TGF-β/smad signal axis exerted a critical role in glioma stemness and angiogeneis. Disrupting the function of this signal axis might represent a new therapeutic strategy in glioma patients.


Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3470
Author(s):  
Aubrey L. Miller ◽  
Patrick L. Garcia ◽  
Samuel C. Fehling ◽  
Tracy L. Gamblin ◽  
Rebecca B. Vance ◽  
...  

Gemcitabine is used to treat pancreatic cancer (PC), but is not curative. We sought to determine whether gemcitabine + a BET bromodomain inhibitor was superior to gemcitabine, and identify proteins that may contribute to the efficacy of this combination. This study was based on observations that cell cycle dysregulation and DNA damage augment the efficacy of gemcitabine. BET inhibitors arrest cells in G1 and allow increases in DNA damage, likely due to inhibition of expression of DNA repair proteins Ku80 and RAD51. BET inhibitors (JQ1 or I-BET762) + gemcitabine were synergistic in vitro, in Panc1, MiaPaCa2 and Su86 PC cell lines. JQ1 + gemcitabine was more effective in vivo than either drug alone in patient-derived xenograft models (P < 0.01). Increases in the apoptosis marker cleaved caspase 3 and DNA damage marker γH2AX paralleled antitumor efficacy. Notably, RNA-seq data showed that JQ1 + gemcitabine selectively inhibited HMGCS2 and APOC1 ~6-fold, compared to controls. These proteins contribute to cholesterol biosynthesis and lipid metabolism, and their overexpression supports tumor cell proliferation. IPA data indicated that JQ1 + gemcitabine selectively inhibited the LXR/RXR activation pathway, suggesting the hypothesis that this inhibition may contribute to the observed in vivo efficacy of JQ1 + gemcitabine.


Leukemia ◽  
2021 ◽  
Author(s):  
Kinan Alhallak ◽  
Jennifer Sun ◽  
Katherine Wasden ◽  
Nicole Guenthner ◽  
Julie O’Neal ◽  
...  

AbstractT-cell-based immunotherapy, such as CAR-T cells and bispecific T-cell engagers (BiTEs), has shown promising clinical outcomes in many cancers; however, these therapies have significant limitations, such as poor pharmacokinetics and the ability to target only one antigen on the cancer cells. In multiclonal diseases, these therapies confer the development of antigen-less clones, causing tumor escape and relapse. In this study, we developed nanoparticle-based bispecific T-cell engagers (nanoBiTEs), which are liposomes decorated with anti-CD3 monoclonal antibodies (mAbs) targeting T cells, and mAbs targeting the cancer antigen. We also developed a nanoparticle that targets multiple cancer antigens by conjugating multiple mAbs against multiple cancer antigens for T-cell engagement (nanoMuTEs). NanoBiTEs and nanoMuTEs have a long half-life of about 60 h, which enables once-a-week administration instead of continuous infusion, while maintaining efficacy in vitro and in vivo. NanoMuTEs targeting multiple cancer antigens showed greater efficacy in myeloma cells in vitro and in vivo, compared to nanoBiTEs targeting only one cancer antigen. Unlike nanoBiTEs, treatment with nanoMuTEs did not cause downregulation (or loss) of a single antigen, and prevented the development of antigen-less tumor escape. Our nanoparticle-based immuno-engaging technology provides a solution for the major limitations of current immunotherapy technologies.


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