scholarly journals A long non-coding RNA in the let-7 complex acting as a potent and specific death effector of cancer cells

2021 ◽  
Author(s):  
Tosca Birbaumer ◽  
Tommy Beat Schlumpf ◽  
Makiko Seimiya ◽  
Yanrui Jiang ◽  
Renato Paro
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Ectopic Expression ◽  
Specific Cell ◽  
Rna Molecules ◽  
Non Coding Rna ◽  
Evolutionarily Conserved ◽  
Death Effector

The let-7 complex in Drosophila encodes three evolutionarily conserved microRNAs: miR-100, let-7, and miR-125. These act as heterochronic genes in regulating developmental timing in response to the steroid hormone ecdysone and play important roles in cell differentiation. Here we identify two additional long non-coding RNAs in the let-7 complex, we named let-A and let-B. Both are transcribed in the large first intron of the primary RNA encoding the microRNAs. We show these RNAs to be sequentially expressed in early pupal stages in response to ecdysone signaling, albeit exhibiting a different expression pattern compared to the microRNA let-7. Surprisingly, ectopic expression of let-A in Drosophila cancer cells induces rapid cell death. Dead cells further release RNA molecules in the medium that is becoming toxic to other cancer cells. In vivo grown tumors lose their tumorigenicity after being incubated in the let-A induced medium. Moreover, feeding flies carrying transplanted tumor cells with such induced medium leads to reduced growth of tumors in a subset of hosts. Our results uncover a new lncRNA which can act as a potent and specific cell death effector for Drosophila tumor cells.

scholarly journals Branched-chain amino acid aminotransferase 2 regulates ferroptotic cell death in cancer cells

2020 ◽  
Author(s):  
Kang Wang ◽  
Zhengyang Zhang ◽  
Hsiang-i Tsai ◽  
Yanfang Liu ◽  
Jie Gao ◽  
...  
Keyword(s):  
Cell Death ◽  
Amino Acid ◽  
Cancer Cells ◽  
Ectopic Expression ◽  
Branched Chain Amino Acid ◽  
Pancreatic Cancer Cells ◽  
Key Enzyme ◽  
Branched Chain

Abstract Ferroptosis, a form of iron-dependent cell death driven by cellular metabolism and iron-dependent lipid peroxidation, has been implicated as a tumor-suppressor function for cancer therapy. Recent advance revealed that the sensitivity to ferroptosis is tightly linked to numerous biological processes, including metabolism of amino acid and the biosynthesis of glutathione. Here, by using a high-throughput CRISPR/Cas9-based genetic screen in HepG2 hepatocellular carcinoma cells to search for metabolic proteins inhibiting ferroptosis, we identified a branched-chain amino acid aminotransferase 2 (BCAT2) as a novel suppressor of ferroptosis. Mechanistically, ferroptosis inducers (erastin, sorafenib, and sulfasalazine) activated AMPK/SREBP1 signaling pathway through iron-dependent ferritinophagy, which in turn inhibited BCAT2 transcription. We further confirmed that BCAT2 as the key enzyme mediating the metabolism of sulfur amino acid, regulated intracellular glutamate level, whose activation by ectopic expression specifically antagonize system Xc– inhibition and protected liver and pancreatic cancer cells from ferroptosis in vitro and in vivo. On the contrary, direct inhibition of BCAT2 by RNA interference, or indirect inhibition by blocking system Xc– activity, triggers ferroptosis. Finally, our results demonstrate the synergistic effect of sorafenib and sulfasalazine in downregulating BCAT2 expression and dictating ferroptotic death, where BCAT2 can also be used to predict the responsiveness of cancer cells to ferroptosis-inducing therapies. Collectively, these findings identify a novel role of BCAT2 in ferroptosis, suggesting a potential therapeutic strategy for overcoming sorafenib resistance.

scholarly journals Dual-Function Anti-CD47mAbs Induce Tumor Cell Death and Promote Phagocytosis Resulting in Enhanced in Vivo Efficacy

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 991-991
Author(s):  
Pamela T. Manning ◽  
Benjamin J. Capoccia ◽  
Michael P. Rettig ◽  
Ronald R. Hiebsch ◽  
Robert W. Karr ◽  
...  
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Tumor Burden ◽  
Dual Function ◽  
Employment Equity ◽  
Hematologic Cancer ◽  
Equity Ownership

Abstract Recent success in immunomodulation of cancer has targeted immune checkpoints such as CTLA-4, PD-1 and PDL-1 to enhance adaptive immunity by stimulating production of tumor-selective, cytotoxic T cells. Anti-CD47mAbs enhance innate immunity by increasing the phagocytosis of tumor cells by macrophages leading to processing and presentation of tumor antigens to prime the adaptive T cell response. Many cancers, including hematologic cancers, up-regulate the expression of CD47 presumably to avoid immune destruction. Increased CD47 expression protects cancer cells from phagocytosis by sending a “don't eat me” signal to macrophages via SIRPalpha, an inhibitory receptor that prevents phagocytosis of CD47-bearing cells. CD47mAbs that block the CD47/SIRPalpha interaction (“blocking-only” mAbs) enhance phagocytosis of cancer cells in vitro. We have identified two CD47mAbs, Vx-1000 and Vx-1004, both of which block the CD47/SIRPalpha interaction and promote phagocytosis of tumor cells by macrophages equally well. However, Vx-1004 also has the unique property of killing cancer cells, but not normal blood cells, via a direct, cell-autonomous, cytotoxic mechanism. Therefore, Vx-1004 is a dual-function antibody. Vx-1004 selectively kills a variety of hematologic cancer cells in vitro, while Vx-1000, the blocking-only mAb, does not as assessed by annexin V staining and flow cytometry (Figure 1). In dose-response studies, cell death in leukemia cells was induced in 2 hrs by <1 ug="" vx-1004="" whereas="" normal="" peripheral="" blood="" mononuclear="" cells="" are="" resistant="" to="" the="" induction="" of="" cell="" death="" by="" following="" incubation="" with="" 10="" for="" 24="" hrs="" both="" these="" cd47mabs="" bind="" many="" species="" cd47="" including="" mouse="" and="" human="" p=""> To determine if the tumor-toxic activity of Vx-1004 confers enhanced efficacy in vivo compared to Vx-1000, we compared them in two mouse hematologic cancer models: murine acute promyelocytic leukemia (APL) and B cell lymphoma (BCL). Briefly, 1x106 GFP-labeled C57BL/6 APL cells were injected IV into wild-type C57BL/6 mice that were then treated IP with 0.4 mg/kg of either Vx-1000 or Vx-1004 on the day of tumor injection and on days 3 and 6 following tumor injection, a very low dose and limited dosing regimen. On day 25, the blood of these mice was analyzed for the number of circulating APL cells. As shown in Figure 2, Vx-1000 did not significantly reduce tumor burden compared to the control group. In contrast, Vx-1004 significantly reduced tumor burden compared to controls, demonstrating greater efficacy of the dual-function CD47mAb. In addition, enhanced efficacy of Vx-1004 compared to Vx-1000 was demonstrated in BCL (Figure 3). In this model, NSG mice were injected with 1x106 murine A20 lymphoma cells subcutaneously and then treated with 0.4mg/kg/day of the CD47mAbs IP for the first five days following tumor injection. In this model, Vx-1000 also failed to inhibit tumor growth compared to controls while Vx-1004 significantly reduced tumor burden at 35 days compared to both the control and Vx-1000 groups, nearly four weeks after treatment was stopped. These data demonstrate increased anti-cancer efficacy with a dual-function CD47mAb that not only blocks the CD47/SIRPalpha interaction to increase phagocytosis of cancer cells, but also selectively kills cancer cells. These studies indicate that dual-function CD47mAbs may have better anti-tumor activity in vivo and support their use in human clinical trials. Figure 1 Figure 1. Disclosures Manning: Corvus Pharmaceutical: Employment, Equity Ownership. Capoccia:Corvus Pharmaceutical: Employment, Equity Ownership. Hiebsch:Corvus Pharmaceutical: Employment, Equity Ownership. Karr:Corvus Pharmaceutical: Employment, Equity Ownership. Frazier:Corvus Pharmaceutical: Consultancy, Equity Ownership.

scholarly journals Inducing oncolytic cell death in human cancer cells by the long non-coding RNA let-A

2021 ◽  
Author(s):  
Tosca Birbaumer ◽  
Tommy Beat Schlumpf ◽  
Makiko Seimiya ◽  
Yanrui Jiang ◽  
Renato Paro
Keyword(s):  
Cell Death ◽  
Cancer Cells ◽  
Cell Lines ◽  
Human Cancer ◽  
Ectopic Expression ◽  
In Vitro Transcription ◽  
Human Cancer Cell Lines ◽  
Human Cancer Cells ◽  
Non Coding Rna

Long non-coding (lnc) RNAs contain functional elements that play important regulatory roles in a variety of processes during development, normal physiology, as well as disease. We recently discovered a new lncRNA, we named let-A, expressed from the evolutionary conserved let-7-Complex locus in Drosophila. This RNA induces cell death in Drosophila cancer cells. Here we show that ectopic expression of Drosophila let-A is also exerting an oncolytic toxicity in several human cancer cell lines, but shows almost no effect in more differentiated or cell lines derived from normal tissue. We demonstrate that let-A RNA prepared by in vitro transcription and provided in the growth medium is sufficient to induce cell death both in human and Drosophila cancer cells. The activity of in vitro transcribed let-A is most efficient in its full length, but requires prior modification/processing to become active. let-A induces a reduction of nucleolar size in treated cells. We show exo/endocytosis and Toll signaling pathway to be necessary for let-A-induced toxicity. Our findings indicate let-A exhibits an evolutionary conserved anti-cancer function, making it a promising molecule for tumor treatments.

750 Malat1 lncRNA controls metastatic reactivation of dormant breast cancer by immune evasion

2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A799-A799
Author(s):  
Dhiraj Kumar ◽  
Sreeharsha Gurrapu ◽  
Hyunho Han ◽  
Yan Wang ◽  
Seongyeon Bae ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Single Cell ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Immune Evasion ◽  
Breast Cancer Cells ◽  
Metastatic Potential ◽  
Rna Seq

BackgroundLong non-coding RNAs (lncRNAs) are involved in various biological processes and diseases. Malat1 (metastasis-associated lung adenocarcinoma transcript 1), also known as Neat2, is one of the most abundant and highly conserved nuclear lncRNAs. Several studies have shown that the expression of lncRNA Malat1 is associated with metastasis and serving as a predictive marker for various tumor progression. Metastatic relapse often develops years after primary tumor removal as a result of disseminated tumor cells undergoing a period of latency in the target organ.1–4 However, the correlation of tumor intrinsic lncRNA in regulation of tumor dormancy and immune evasion is largely unknown.MethodsUsing an in vivo screening platform for the isolation of genetic entities involved in either dormancy or reactivation of breast cancer tumor cells, we have identified Malat1 as a positive mediator of metastatic reactivation. To functionally uncover the role of Malat1 in metastatic reactivation, we have developed a knock out (KO) model by using paired gRNA CRISPR-Cas9 deletion approach in metastatic breast and other cancer types, including lung, colon and melanoma. As proof of concept we also used inducible knockdown system under in vivo models. To delineate the immune micro-environment, we have used 10X genomics single cell RNA-seq, ChIRP-seq, multi-color flowcytometry, RNA-FISH and immunofluorescence.ResultsOur results reveal that the deletion of Malat1 abrogates the tumorigenic and metastatic potential of these tumors and supports long-term survival without affecting their ploidy, proliferation, and nuclear speckles formation. In contrast, overexpression of Malat1 leads to metastatic reactivation of dormant breast cancer cells. Moreover, the loss of Malat1 in metastatic cells induces dormancy features and inhibits cancer stemness. Our RNA-seq and ChIRP-seq data indicate that Malat1 KO downregulates several immune evasion and stemness associated genes. Strikingly, Malat1 KO cells exhibit metastatic outgrowth when injected in T cells defective mice. Our single-cell RNA-seq cluster analysis and multi-color flow cytometry data show a greater proportion of T cells and reduce Neutrophils infiltration in KO mice which indicate that the immune microenvironment playing an important role in Malat1-dependent immune evasion. Mechanistically, loss of Malat1 is associated with reduced expression of Serpinb6b, which protects the tumor cells from cytotoxic killing by the T cells. Indeed, overexpression of Serpinb6b rescued the metastatic potential of Malat1 KO cells by protecting against cytotoxic T cells.ConclusionsCollectively, our data indicate that targeting this novel cancer-cell-initiated domino effect within the immune system represents a new strategy to inhibit tumor metastatic reactivation.Trial RegistrationN/AEthics ApprovalFor all the animal studies in the present study, the study protocols were approved by the Institutional Animal Care and Use Committee(IACUC) of UT MD Anderson Cancer Center.ConsentN/AReferencesArun G, Diermeier S, Akerman M, et al., Differentiation of mammary tumors and reduction in metastasis upon Malat1 lncRNA loss. Genes Dev 2016 Jan 1;30(1):34–51.Filippo G. Giancotti, mechanisms governing metastatic dormancy and reactivation. Cell 2013 Nov 7;155(4):750–764.Gao H, Chakraborty G, Lee-Lim AP, et al., The BMP inhibitor Coco reactivates breast cancer cells at lung metastatic sites. Cell 2012b;150:764–779.Gao H, Chakraborty G, Lee-Lim AP, et al., Forward genetic screens in mice uncover mediators and suppressors of metastatic reactivation. Proc Natl Acad Sci U S A 2014 Nov 18; 111(46): 16532–16537.

scholarly journals Tumor cytotoxicity and immunogenicity of a novel V-jet neon plasma source compared to the kINPen

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Lea Miebach ◽  
Eric Freund ◽  
Stefan Horn ◽  
Felix Niessner ◽  
Sanjeev Kumar Sagwal ◽  
...  
Keyword(s):  
Cell Death ◽  
Dendritic Cells ◽  
Cancer Cells ◽  
Treatment Time ◽  
Plasma Source ◽  
In Vivo Model ◽  
Antitumor Effects ◽  
Plasma Device

AbstractRecent research indicated the potential of cold physical plasma in cancer therapy. The plethora of plasma-derived reactive oxygen and nitrogen species (ROS/RNS) mediate diverse antitumor effects after eliciting oxidative stress in cancer cells. We aimed at exploiting this principle using a newly designed dual-jet neon plasma source (Vjet) to treat colorectal cancer cells. A treatment time-dependent ROS/RNS generation induced oxidation, growth retardation, and cell death within 3D tumor spheroids were found. In TUM-CAM, a semi in vivo model, the Vjet markedly reduced vascularized tumors' growth, but an increase of tumor cell immunogenicity or uptake by dendritic cells was not observed. By comparison, the argon-driven single jet kINPen, known to mediate anticancer effects in vitro, in vivo, and in patients, generated less ROS/RNS and terminal cell death in spheroids. In the TUM-CAM model, however, the kINPen was equivalently effective and induced a stronger expression of immunogenic cancer cell death (ICD) markers, leading to increased phagocytosis of kINPen but not Vjet plasma-treated tumor cells by dendritic cells. Moreover, the Vjet was characterized according to the requirements of the DIN-SPEC 91315. Our results highlight the plasma device-specific action on cancer cells for evaluating optimal discharges for plasma cancer treatment.

932 Targeting the 19S Proteasomal Subunit, Rpt4, in Colon Cancer Cells Induces Cell Death and Reduces Cellular Proliferation In Vitro and In Vivo

2013 ◽  
Vol 144 (5) ◽  
pp. S-166-S-167
Author(s):  
Karen Boland ◽  
Caoimhin Concannon ◽  
Niamh McCawley ◽  
Elaine W. Kay ◽  
Deborah McNamara ◽  
...  
Keyword(s):  
Colon Cancer ◽  
Cell Death ◽  
Cancer Cells ◽  
Cellular Proliferation ◽  
Colon Cancer Cells ◽  
Proliferation In Vitro

scholarly journals Apoptosis and in vivo models to study the molecules related to this phenomenon

2010 ◽  
Vol 8 (4) ◽  
pp. 495-497 ◽  
Author(s):  
Adriana Luchs ◽  
Claudia Pantaleão
Keyword(s):  
Cell Death ◽  
B Cell ◽  
Ectopic Expression ◽  
B Cell Lymphoma ◽  
Murine Models ◽  
In Vivo Models ◽  
Large B Cell Lymphoma ◽  
Pathological Conditions ◽  
Pharmacological Targets

ABSTRACT Apoptosis or programmed cell death is a physiological process, essential for eliminating cells in excess or that are no longer necessary to the organism, acting on tissue homeostasis, although the phenomenon is also involved in pathological conditions. Apoptosis promotes activation of biochemical pathways inside cells called caspase pathway, of the proteins responsible for the cleavage of several cell substrates, leading to cell death. Antiapoptotic members of the Bcl-2 family (B cell CLL/lymphoma 2), that belong to the intrinsic route of the activation of caspases, such as Bcl-xL (extra-large B-cell lymphoma) and Bcl-w (Bcl-2-like 2), act predominantly to prevent that pro-apoptotic members, such as Bax (Bcl-2-associated X protein) and Bak (Bcl-2 relative bak) lead to cell death. Antiapoptotic molecules are considered potentially oncogenic. Murine models are known to be valuable systems for the experimental analysis of oncogenes in vivo, and for the identification of pharmacological targets for cancer and to assess antitumor therapies. Given the importance of tumorigenesis studies on the immune responses to cancer and the possibility of investigating the participation of antiapoptotic molecules in tumor progression in vivo, the development of new models may be platforms for studies on tumorigenesis, immune antitumor responses, investigation of the ectopic expression of antiapoptotic molecules and immunotherapies for tumors.

scholarly journals Exosomes containing miRNAs targeting HER2 synthesis and engineered to adhere to HER2 on tumor cells surface exhibit enhanced antitumor activity

2020 ◽  
Author(s):  
Lei Wang ◽  
Xusha Zhou ◽  
Weixuan Zou ◽  
Yinglin Wu ◽  
Jing Zhao ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Epidermal Growth Factor Receptor ◽  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Growth Factor Receptor ◽  
Wide Range ◽  
Epidermal Growth

Abstract Background: Exosomes are small, cellular membrane-derived vesicles with a diameter of 50-150 nm. Exosomes are considered ideal drug delivery systems with a wide range of applications in various diseases, including cancer. However, nonspecific delivery of therapeutic agents by exosomes in vivo remains challenging. H uman epidermal growth factor receptor 2 (HER2) is an epidermal growth factor receptor tyrosine kinase, and its overexpression is usually associated with cell survival and tumor progression in various cancers. In this study, we aim to develop novel exosomes with dual HER2-targeting ability as a nanoparticle delivery vehicle to enhance antitumor efficacy in vivo . Results: Here, we report the generation of two kinds of exosomes carrying miRNAs designed to block HER2 synthesis and consequently kill tumor cells. 293-miR-HER2 exosomes package and deliver designed miRNAs to cells to block HER2 synthesis. These exosomes kill cancer cells dependent on HER2 for survival but do not affect cells that lack HER2 or that are engineered to express HER2 but are not dependent on it for survival. In contrast, 293-miR-XS-HER2 exosomes carry an additional peptide, which enables them to adhere to HER2 on the surface of cancer cells. Consequently, these exosomes preferentially enter and kill cells with surface expression of HER2. 293-miR-XS-HER2 exosomes are significantly more effective than the 293-miR-HER2 exosomes in shrinking HER2-positive tumors implanted in mice. Conclusions: Collectively, as novel antitumor drug delivery vehicles, HER2 dual-targeting exosomes exhibit increased target-specific delivery efficiency and can be further utilized to develop new nanoparticle-based targeted therapies.

Synergy of nanodiamond-doxorubicin conjugates and PD-L1 blockade effectively turns tumor associated macrophages against tumor cells

2021 ◽  
Author(s):  
Huazhen Xu ◽  
Tongfei Li ◽  
Chao Wang ◽  
Yan Ma ◽  
Yan Liu ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Tumor Cell ◽  
Cancer Cells ◽  
Tumor Cells ◽  
Lung Cancer Cells ◽  
Dependent Manner ◽  
Tumor Associated Macrophages ◽  
M1 Type

Abstract Background: Tumor-associated macrophages (TAM) are the most abundant stromal cells in the tumor microenvironment. Turning the TAM against their host tumor cells is an intriguing therapeutic strategy particularly attractive for patients with immunologically “cold” tumors. This concept was mechanistically demonstrated on in vitro human and murine lung cancer cells and their corresponding TAM models through combinatorial use of nanodiamond-doxorubicin conjugates (Nano-DOX) and a PD-L1 blocking agent BMS-1. Nano-DOX are an agent previously proved to be able to stimulate tumor cells’ immunogenicity and thereby reactivate the TAM into the anti-tumor M1 phenotype. Results: Nano-DOX were first shown to stimulate the tumor cells and the TAM to release the cytokine HMGB1 which, regardless of its source, acted through the RAGE/NF-κB pathway to induce PD-L1 in the tumor cells and PD-L1/PD-1 in the TAM. Interestingly, Nano-DOX also induced NF-κB-dependent RAGE expression in the tumor cells and thus reinforced HMGB1’s action thereon. Then, BMS-1 was shown to enhance Nano-DOX-stimulated M1-type activation of TAM both by blocking Nano-DOX-induced PD-L1 in the TAM and by blocking tumor cell PD-L1 ligation with TAM PD-1. The TAM with enhanced M1-type repolarization both killed the tumor cells and suppressed their growth. BMS-1 could also potentiate Nano-DOX’s action to suppress tumor cell growth via blocking of Nano-DOX-induced PD-L1 therein. Finally, Nano-DOX and BMS-1 achieved synergistic therapeutic efficacy against in vivo tumor grafts in a TAM-dependent manner. Conclusions: PD-L1/PD-1 upregulation mediated by autocrine and paracrine activation of the HMGB1/RAGE/NF-κB signaling is a key response of lung cancer cells and their TAM to stress, which can be induced by Nano-DOX. Blockade of Nano-DOX-induced PD-L1, both in the cancer cells and the TAM, achieves enhanced activation of TAM-mediated anti-tumor response.

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