scholarly journals RA190, a Proteasome Subunit ADRM1 Inhibitor, Suppresses Intrahepatic Cholangiocarcinoma by Inducing NF-KB-Mediated Cell Apoptosis

2018 ◽  
Vol 47 (3) ◽  
pp. 1152-1166 ◽  
Author(s):  
Guang-Yang Yu ◽  
Xuan Wang ◽  
Su-Su Zheng ◽  
Xiao-Mei Gao ◽  
Qing-An Jia ◽  
...  

Background/Aims: Effective drug treatment for intrahepatic cholangiocarcinoma (ICC) is currently lacking. Therefore, there is an urgent need for new targets and new drugs that can prolong patient survival. Recently targeting the ubiquitin proteasome pathway has become an attractive anti-cancer strategy. In this study, we aimed to evaluate the therapeutic effect of and identify the potential mechanisms involved in targeting the proteasome subunit ADRM1 for ICC. Methods: The expression of ADRM1 and its prognostic value in ICC was analyzed using GEO and TCGA datasets, tumor tissues, and tumor tissue arrays. The effects of RA190 on the proliferation and survival of both established ICC cell lines and primary ICC cells were examined in vitro. Annexin V/propidium iodide staining, western blotting and immunohistochemical staining were performed. The in vivo anti-tumor effect of RA190 on ICC was validated in subcutaneous xenograft and patient-derived xenograft (PDX) models. Results: ADRM1 levels were significantly higher in ICC tissues than in normal bile duct tissues. ICC patients with high ADRM1 levels had worse overall survival (hazard ratio [HR] = 2.383, 95% confidence interval [CI] =1.357 to 4.188) and recurrence-free survival (HR = 1.710, 95% CI =1.045 to 2.796). ADRM1 knockdown significantly inhibited ICC growth in vitro and in vivo. The specific inhibitor RA190 targeting ADRM1 suppressed proliferation and reduced cell vitality of ICC cell lines and primary ICC cells significantly in vitro. Furthermore, RA190 significantly inhibited the proteasome by inactivating ADRM1, and the consequent accumulation of ADRM1 substrates decreased the activating levels of NF-κB to aggravate cell apoptosis. The therapeutic benefits of RA190 treatment were further demonstrated in both subcutaneous implantation and PDX models. Conclusions: Our findings indicate that up-regulated ADRM1 was involved in ICC progression and suggest the potential clinical application of ADRM1 inhibitors (e.g., RA190 and KDT-11) for ICC treatment.

2020 ◽  
Vol 13 ◽  
pp. 175628481989543
Author(s):  
Amanda Braga Bona ◽  
Danielle Queiroz Calcagno ◽  
Helem Ferreira Ribeiro ◽  
José Augusto Pereira Carneiro Muniz ◽  
Giovanny Rebouças Pinto ◽  
...  

Background: Gastric cancer is one of the most incident types of cancer worldwide and presents high mortality rates and poor prognosis. MYC oncogene overexpression is a key event in gastric carcinogenesis and it is known that its protein positively regulates CDC25B expression which, in turn, plays an essential role in the cell division cycle progression. Menadione is a synthetic form of vitamin K that acts as a specific inhibitor of the CDC25 family of phosphatases. Methods: To better understand the menadione mechanism of action in gastric cancer, we evaluated its molecular and cellular effects in cell lines and in Sapajus apella, nonhuman primates from the new world which had gastric carcinogenesis induced by N-Methyl-N-nitrosourea. We tested CDC25B expression by western blot and RT-qPCR. In-vitro assays include proliferation, migration, invasion and flow cytometry to analyze cell cycle arrest. In in-vivo experiments, in addition to the expression analyses, we followed the preneoplastic lesions and the tumor progression by ultrasonography, endoscopy, biopsies, histopathology and immunohistochemistry. Results: Our tests demonstrated menadione reducing CDC25B expression in vivo and in vitro. It was able to reduce migration, invasion and proliferation rates, and induce cell cycle arrest in gastric cancer cell lines. Moreover, our in-vivo experiments demonstrated menadione inhibiting tumor development and progression. Conclusions: We suggest this compound may be an important ally of chemotherapeutics in the treatment of gastric cancer. In addition, CDC25B has proven to be an effective target for investigation and development of new therapeutic strategies for this malignancy.


2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Feng He ◽  
Zonghui Xiao ◽  
Hailan Yao ◽  
Sen Li ◽  
Miao Feng ◽  
...  

Abstract Background The P38 mitogen-activated protein kinase (MAPK) pathway plays an essential role in CVB3-induced diseases. We previously demonstrated microRNA-21 has potential inhibitory effect on the MAP2K3 which locates upstream of P38 MAPK and was upregulated in mouse hearts upon CVB3 infection. However, the effect and underlying mechanism of miRNA-21 on CVB3 infection remain unclear. Methods We detected continuous changes of cellular miRNA-21 and P38 MAPK proteins expression profiling post CVB3 infection in vitro within 12 h. P38 MAPK signaling was inhibited by the specific inhibitor, small interfering RNA and miRNA-21 mimic in vitro, CVB3 replication, cell apoptosis rate and proliferation were detected. Viral load in the mice heart, cardiomyocyte apoptosis rate and histological of the heart were also detected in the mice model of viral myocarditis pretreated with miRNA-21-lentivirus. Results We observed significant upregulation of miRNA-21 expression followed by suppression of the MAP2K3/P38 MAPK signaling in CVB3-infected Hela cells. The inactivation of the MAP2K3/P38 MAPK signaling by P38 MAPK specific inhibitor, small interfering RNA against MAP2K3, or miRNA-21 overexpression significantly inhibited viral progeny release from CVB3-infected cells. Mechanistically, when compared with control miRNA, miRNA-21 showed no effect on capsid protein VP1 expression and viral load within host cells, while significantly reversing CVB3-induced caspase-3 activation and cell apoptosis rate, further promoting proliferation of infected cells, which indicates the inhibitory effect of miRNA-21 on CVB3 progeny release. In the in vivo study, when compared with control miRNA, miRNA-21 pretreatment remarkably inactivated the MAP2K3/P38 MAPK signaling in mice and protected them against CVB3 infection as evidenced by significantly alleviated cell apoptosis rate, reduced viral titers, necrosis in the heart as well as by remarkably prolonged survival time. Conclusions miRNA-21 were reverse correlated with P38 MAPK activation post CVB3 infection, miRNA-21 overexpression significantly inhibited viral progeny release and decreased myocytes apoptosis rate in vitro and in vivo, suggesting that miRNA-21 may serve as a potential therapeutic agent against CVB3 infection through targeting the MAP2K3/P38 MAPK signaling.


2017 ◽  
Vol 37 (3) ◽  
Author(s):  
Xin Chen ◽  
Bo Yue ◽  
Changming Zhang ◽  
Meihao Qi ◽  
Jianhua Qiu ◽  
...  

The aim of the present study was to explore the mechanism through which miR-130a-3p affects the viability, proliferation, migration, and invasion of nasopharyngeal carcinoma (NPC). Tissue samples were collected from the hospital department. NPC cell lines were purchased to conduct the in vitro and in vivo assays. A series of biological assays including MTT, Transwell, and wound healing assays were conducted to investigate the effects of miR-130a-3p and BACH2 on NPC cells. MiR-130a-3p was down-regulated in both NPC tissues and cell lines, whereas BACH2 was up-regulated in both tissues and cell lines. MiR-130a-3p overexpression inhibited NPC cell viability, proliferation, migration, and invasion but promoted cell apoptosis. The converse was true of BACH2, the down-regulation of which could inhibit the corresponding cell abilities and promote apoptosis of NPC cells. The target relationship between miR-130a-3p and BACH2 was confirmed. The epithelial–mesenchymal transition (EMT) pathway was also influenced by miR-130a-3p down-regulation. In conclusion, miR-130a-3p could bind to BACH2, inhibit NPC cell abilities, and promote cell apoptosis.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 761-761 ◽  
Author(s):  
Shinya Kimura ◽  
Hidekazu Segawa ◽  
Junya Kuroda ◽  
Takeshi Yuasa ◽  
Taira Maekawa

Abstract Imatinib mesylate (also known as STI-571 and Gleevec) has drastically changed the treatment of Philadelphia chromosome positive (Ph+) leukemias. However, the resistance to imatinib has frequently been reported, particularly in patients with advanced-stage disease. A novel orally bioavailable inhibitor of the ABL tyrosine kinase (TK) named CNS-9 was developed from the 2-(phenylamino)pyrimidine class to overcome resistance mechanisms of imatinib. Inhibition of TK phosphorylation (IC50) on wild type (wt) BCR/ABL in 293T cell line by CNS-9 was 22nM, which was 2-log more potent than imatinib. Importantly, CNS-9 inhibited TK phosphorylation of E255K mutant BCR/ABL with IC50 of 98nM, while imatinib could not inhibit it with clinically relevant concentration. The T315I mutant BCR/ABL protein was resistant to CNS-9 and imatinib. CNS-9 also inhibited TK phosphorylation of platelet-derived growth factor receptor (PDGFR) or c-Kit pathways at the very similar observed IC50s when compared with imatinib, in spite of significant higher potency against ABL. The ability of CNS-9 in vitro to inhibit 101 TK molecules was assayed by KinaseProfilerTM (Upstate), showing also more specific inhibitory activity against ABL than imatinib. The growth of BCR/ABL-positive cell lines K562, KU812, BaF3 harboring wt BCR/ABL (BaF3/wt) and E255K (BaF3/E255K) was inhibited by CNS-9 with IC50 of 5, 3, 17, and 110nM, respectively (Table 1). Generally, CNS-9 was 20 to 30-fold more potent on the growth inhibition than imatinib in these same cell lines. We next investigated the in vivo effect on the leukemic growth inhibition of CNS-9. Nude mice were injected subcutaneously with 3x107 KU812 (wt BCR/ABL) on Day 0. CNS-9 or imatinib were orally administrated twice a day from Day 7 to Day 18. The dosages of CNS-9 and imatinib, which inhibited completely tumor growth were 20mg/kg/day and 200mg/kg/day, respectively, indicating that CNS-9 is 10-fold potent than imatinib in vivo. To examine the in vivo effect of CNS-9 against mutant BCR/ABL, BaF3/wt, BaF3/E255K or BaF3/T315I were engrafted to nude mice and treated with CNS-9 or imatinib. CNS-9 was also 10-fold potent than imatinib against BaF3/wt. Intriguingly, mice harboring BaF3/wt or BaF3/E255K showed significantly prolonged survival when treated with CNS-9. Consistent with in vitro assay, CNS-9 had no effect on T315I, and imatinib was not effective against both E255K and T315I. In conclusion, CNS-9 is substantially more inhibitory and more specifically than imatinib toward BCR/ABL-dependent cell growth both in vitro and in vivo Moreover, CNS-9 may be effective for leukemia patients whose leukemic cells harbor E255K mutant. The efficacy and safety of CNS-9 for Ph+ leukemias should be verified in early phase clinical trials. The IC50s values of leukemic cell lines for CNS-9 and imatinib CNS-9 (nM) imatinib (nM) K562 p210 wt BCR/ABL 5 130 KU812 p210 wt BCR/ABL 3 67 U937 BCR/ABL (−) >1000 >1000 BaF3 p190 wt BCR/ABL 17 360 BaF3 p190 E255K BCR/ABL 110 >1000 BaF3 p190 T315I BCR/ABL >1000 >1000


2013 ◽  
Vol 31 (15_suppl) ◽  
pp. e13545-e13545 ◽  
Author(s):  
Vladimir Konstantinovich Bozhenko ◽  
Tatyana Michailovna Kulinich ◽  
Elena Aleksandrovna Kudinova ◽  
Andrey Boldyrev ◽  
Vladimir Alekseevich Solodkij

e13545 Background: MM-D37K is a synthetic peptide which consists of p16INK4a-specific inhibitor of complex cyclin D- CDK4 and CDK6 and cell penetrating peptide (CPP) – Antp (Penetratin). We investigated in vitro and in vivo cytotoxic, cytostatic and antitumor activity of MM-D37K. The level of cyclin A, Ki67,bax, bcl-2 and pRb phosphorylation was investigated. Full range of Toxicology tests and Pharmacokinetics experiments in mice, rats and rabbits were performed. Methods: Different cell lines (Jurcat, Raji, A549, MCF-7, Hct-116, Ht-29, HEK293) were incubated with 0.1-100 mM MM-D37K for 24-48 hrs. Proliferation (MTT), DNA-content, cell cycle (flow cytometry) and mRNA level of appropriate proteins (RT PCR) were investigated. In vivo experiments were conducted on xenograft model of HCT116, A-549 at concentration 5 and 10 mg/kg of MM-D37K. Toxicology experiments were made under RF Law and included 3 types of animals. LC-MS MMD37K method of detection in plasma was developed. Results: MM-D37K prevented pRb phosphorilation and proliferation activation in all investigated cell lines. Cell cycle was blocked in G1 phase. Cytostatic effect did not depend on p16 mutation or expression. MM-D37K induced apoptosis in 20-82% of investigated cells at 40 mM with lowest level for MCF-7. LD10 for rats was 100 mg/kg and no deaths were registered for rabbits (highest dose was 50 mg/kg). Concentration of MMD-37K in plasma after 2 min and bolus i.v. injection in dose 10 mg/kg was 72.16±5.64 mcg/ml. Concentration decreased in two phases. 1st – t1/2 = 2.39±0.39 min and for 2nd t1/2=2.39±0.39 hr. Antitumor effects in xenograft model were 53% for A-549 and 67% for HCT116. Conclusions: Our results proved cytotoxic, cytostatic and antitumor effects of MM-D37K in investigated cell lines in vitro and in vivo. Toxicological and pharmacokinetics results allow us recommend for I/IIa Phase clinical trial. (Support: MetaMax Ltd., RFFI, Minpromtorg RF.)


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 266-266
Author(s):  
Shan Lin ◽  
Clement Larrue ◽  
Nastassja K. Scheidegger ◽  
Bo Kyung A. Seong ◽  
Neekesh V Dharia ◽  
...  

Abstract First-generation, large-scale functional genomic screens have revealed hundreds of potential genetic vulnerabilities in acute myeloid leukemia (AML), a devastating hematologic malignancy with poor overall survival. Because these large-scale genetic screens were primarily performed in vitro in established AML cell lines, their translational relevance has been debated. Therefore, we established a protocol for CRISPR screening in orthotopic xenograft models of human AML, including patient-derived-xenograft (PDX) models that are tractable for CRISPR-editing. We first defined experimental conditions necessary for an optimal in vivo screen via barcoding experiments. We determined that sub-lethal irradiation was necessary for improved barcode representation in bone marrow and to reduce mouse-to-mouse variation. Moreover, it was critical to combine samples from multiple mice to achieve complete in vivo library representation. Next, using the Broad DepMap and other publicly available functional genomic screen data, we identified 200 genes that were stronger dependencies in AML cell lines compared to all other cancer types screened. Using this list, we created a secondary library and performed parallel in vivo and in vitro screens using the MV4-11 and U937 cell lines and a PDX model. In vitro and in vivo hits were surprisingly well correlated, although a modest number of targets did not score well in vivo. Notably, dependencies identified across AML cell line models were strongly recapitulated in the PDX model, validating the application of AML cell lines for dependency discovery. Our in vivo screens nominated the mitochondria-localized RING-type ubiquitin E3 ligase MARCH5 as a potential therapeutic target in AML. Using CRISPR, we first validated this in vitro dependency on MARCH5 and determined that MARCH5 is a critical guardian to prevent apoptosis in AML. MARCH5 depletion activates the canonical mitochondrial apoptosis pathway in a BAX/BAK1-dependent manner. Multiple genome-wide screens revealed that a dependency on MARCH5 is strongly correlated with a dependency on MCL1, but not other anti-apoptotic BCL2-family members, across the AML cell lines in the screen. As observed with MCL1 inhibition, MARCH5 depletion sensitized AML cells to venetoclax, a BCL2-specific inhibitor FDA-approved in combination with a hypomethylating agent for the treatment of older adults with AML. Importantly, MARCH5 depletion diminished the venetoclax resistance induced by MCL1 overexpression but not that caused by BCLXL overexpression. Altogether, these results suggest that MARCH5 is required for maintaining MCL1 activity specifically. Since there are no small molecule inhibitors directed against MARCH5, we deployed a dTAG system as an approximation of pharmacological inhibition. This approach uses a hetero-bifunctional small molecule that binds the FKBP12 F36V-fused MARCH5 and the E3 ligase VHL, leading to the ubiquitination and proteasome-mediated degradation of the fusion protein. dTAG-MARCH5 cells were established via deleting endogenous MARCH5 by CRISPR and expressing exogenous FKBP-tagged MARCH5 protein. MARCH5 degradation with the dTAG molecule dTAG V-1 markedly impaired cell growth in vitro. Additionally, we demonstrated the utility of dTAG system in vivo using a PDX model. The combination treatment of dTAG V-1 and venetoclax elicited a much stronger anti-leukemic effect compared to the treatment with only venetoclax or dTAG V-1, further highlighting MARCH5 as a promising synergistic target for enhancing the efficacy of venetoclax in AML. Taken together, our in vivo screening approach, coupled with CRISPR-competent PDX models and dTAG-directed protein degradation, constitute a useful platform for prioritizing AML targets emerging from in vitro screens to serve as the starting point for therapy development. Disclosures Dharia: Genentech: Current Employment. Piccioni: Merck Research Laboratories: Current Employment. Stegmaier: Bristol Myers Squibb: Consultancy; KronosBio: Consultancy; AstraZeneca: Consultancy; Auron Therapeutics: Consultancy, Current equity holder in publicly-traded company; Novartis: Research Funding.


2014 ◽  
Vol 307 (12) ◽  
pp. C1102-C1112 ◽  
Author(s):  
L. Twyffels ◽  
A. Strickaert ◽  
M. Virreira ◽  
C. Massart ◽  
J. Van Sande ◽  
...  

Iodide is captured by thyrocytes through the Na+/I− symporter (NIS) before being released into the follicular lumen, where it is oxidized and incorporated into thyroglobulin for the production of thyroid hormones. Several reports point to pendrin as a candidate protein for iodide export from thyroid cells into the follicular lumen. Here, we show that a recently discovered Ca2+-activated anion channel, TMEM16A or anoctamin-1 (ANO1), also exports iodide from rat thyroid cell lines and from HEK 293T cells expressing human NIS and ANO1. The Ano1 mRNA is expressed in PCCl3 and FRTL-5 rat thyroid cell lines, and this expression is stimulated by thyrotropin (TSH) in rat in vivo, leading to the accumulation of the ANO1 protein at the apical membrane of thyroid follicles. Moreover, ANO1 properties, i.e., activation by intracellular calcium (i.e., by ionomycin or by ATP), low but positive affinity for pertechnetate, and nonrequirement for chloride, better fit with the iodide release characteristics of PCCl3 and FRTL-5 rat thyroid cell lines than the dissimilar properties of pendrin. Most importantly, iodide release by PCCl3 and FRTL-5 cells is efficiently blocked by T16Ainh-A01, an ANO1-specific inhibitor, and upon ANO1 knockdown by RNA interference. Finally, we show that the T16Ainh-A01 inhibitor efficiently blocks ATP-induced iodide efflux from in vitro-cultured human thyrocytes. In conclusion, our data strongly suggest that ANO1 is responsible for most of the iodide efflux across the apical membrane of thyroid cells.


2021 ◽  
Vol 11 (2) ◽  
pp. 272
Author(s):  
Eva Martínez-Pinilla ◽  
Núria Rubio-Sardón ◽  
Sandra Villar-Conde ◽  
Gemma Navarro ◽  
Eva del Valle ◽  
...  

Suitable in vivo and in vitro models are instrumental for the development of new drugs aimed at improving symptoms or progression of multiple sclerosis (MS). The cuprizone (CPZ)-induced murine model has gained momentum in recent decades, aiming to address the demyelination component of the disease. This work aims at assessing the differential cytotoxicity of CPZ in cells of different types and from different species: human oligodendroglial (HOG), human neuroblastoma (SH-SY5Y), human glioblastoma (T-98), and mouse microglial (N-9) cell lines. Moreover, the effect of CPZ was investigated in primary rat brain cells. Cell viability was assayed by oxygen rate consumption and by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide-based (MTT) method. Our results demonstrated that CPZ did not cause death in any of the assayed cell models but affected mitochondrial function and aerobic cell respiration, thus compromising cell metabolism in neural cells and neuron-glia co-cultures. In this sense, we found differential vulnerability between glial cells and neurons as is the case of the CPZ-induced mouse model of MS. In addition, our findings demonstrated that reduced viability was spontaneous reverted in a time-dependent manner by treatment discontinuation. This reversible cell-based model may help to further investigate the role of mitochondria in the disease, and study the molecular intricacies underlying the pathophysiology of the MS and other demyelinating diseases.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1867-1867
Author(s):  
Yijing Li ◽  
Yang Liu ◽  
Yuxuan Che ◽  
Joseph McIntosh ◽  
Alexa A Jordan ◽  
...  

Abstract Introduction As a rare form of non-Hodgkin's lymphoma, mantle cell lymphoma (MCL) is an aggressive subtype. This is largely due to frequent relapses after therapies including paradigm shifting therapies BTK inhibitors (BTKi), such as ibrutinib and acalabrutinib, and Bcl-2 inhibitor (Bcl-2i) venetoclax after long-term treatment in the clinic. Dysregulation of Bcl-2 and Bcl-X L, contributes to therapeutic resistance in MCL. AZD0466 is a novel and highly potent Bcl-2/X L dual inhibitor with active moiety AZD4320. Our preliminary data showed AZD4320 is potent in inhibiting cell viability of MCL cells (IC 50 = 1.6-78 nM). In this study, we assessed the combination efficacy of AZD4320/AZD0466 and acalabrutinib on preclinical MCL models. Methods Cell viability assay was performed to assess the in vitro efficacy of AZD4320 and acalabrutinib alone or in combination in a panel of ibrutinib/venetoclax-sensitive and -resistant MCL cell lines. Cell apoptosis assay was also performed to determine if AZD4320 and acalabrutinib enhanced cell death by cell apoptosis in MCL cell lines. Protein expression profiles of a panel of pro- and anti-apoptotic proteins and other relevant proteins were detected by immunoblotting. Since AZD4320 is limited in preclinical model due to physicochemical properties and dose limiting cardiovascular toxicity, AZD0466, the drug-dendrimer conjugate of AZD4320, was used for in vivo experiment. In vivo efficacy of AZD0466 (34 mg/kg, weekly, iv) and acalabrutinib (20 mg/kg, BID, oral) alone or in combination was evaluated using a Mino-venetoclax-R (Mino-R) cell xenograft model and a PDX model derived from an ibrutinib-CAR-T dual-resistant MCL patient. Results AZD4320 in combo with acalabrutinib inhibited cell proliferation synergistically in both ibrutinib/venetoclax-sensitive and -resistant cell lines (combination index = 0.17-0.93). Compared to vehicle or either single agent, the combination enhanced cell apoptosis by increasing pro-apoptotic markers cleaved caspase 3 and cleaved PARP. In the xenograft mouse model derived from venetoclax-resistant Mino-R cells, co-treatment of AZD0466 and acalabrutinib decreased tumor size significantly compared to vehicle (n = 5, p < 0.0001) or either single agent (n = 5, p = 0.0118 and 0.0070, respectively). Furthermore, in the PDX mouse model derived from a patient relapsed subsequently from ibrutinib and CAR T therapy, the combination of AZD0466 and acalabrutinib inhibited tumor growth compared to vehicle or either single agent. Acalabrutinib or AZD0466 improved survival compared with vehicle by 14 days or 32 days, respectively. Compared to Acalabrutinib or AZD0466, the combination therapy extended survival by 25 days and 7 days, respectively. All mice tolerated the treatment dose without any weight loss compared to the vehicle or either single agent group. Conclusion Compared to AZD4320/AZD0466 and acalabrutinib, combination therapy demonstrated anti-MCL synergy both in vitro and in vivo. These findings suggest that targeting Bcl-2/X L and BTK is promising to overcome multiple acquired resistance phenotypes, including CD19 CAR T-cell therapy. Disclosures Andersen: AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Cidado: AstraZeneca: Current Employment, Current equity holder in publicly-traded company. Wang: DTRM Biopharma (Cayman) Limited: Consultancy; BeiGene: Consultancy, Honoraria, Research Funding; Physicians Education Resources (PER): Honoraria; Anticancer Association: Honoraria; Janssen: Consultancy, Honoraria, Research Funding; CAHON: Honoraria; The First Afflicted Hospital of Zhejiang University: Honoraria; Epizyme: Consultancy, Honoraria; AstraZeneca: Consultancy, Honoraria, Research Funding; BGICS: Honoraria; Imedex: Honoraria; Clinical Care Options: Honoraria; Celgene: Research Funding; Genentech: Consultancy; Loxo Oncology: Consultancy, Research Funding; InnoCare: Consultancy, Research Funding; Molecular Templates: Research Funding; Lilly: Research Funding; VelosBio: Consultancy, Research Funding; BioInvent: Research Funding; Oncternal: Consultancy, Research Funding; OMI: Honoraria; Newbridge Pharmaceuticals: Honoraria; Scripps: Honoraria; Hebei Cancer Prevention Federation: Honoraria; Chinese Medical Association: Honoraria; Pharmacyclics: Consultancy, Research Funding; Juno: Consultancy, Research Funding; CStone: Consultancy; Bayer Healthcare: Consultancy; Miltenyi Biomedicine GmbH: Consultancy, Honoraria; Kite Pharma: Consultancy, Honoraria, Research Funding; Acerta Pharma: Consultancy, Honoraria, Research Funding; Dava Oncology: Honoraria; Moffit Cancer Center: Honoraria; Mumbai Hematology Group: Honoraria.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 377-377
Author(s):  
Maryam Ghalandary ◽  
Yuqiao Gao ◽  
Martin Becker ◽  
Diana Amend ◽  
Klaus H. Metzeler ◽  
...  

Abstract Background: The prognosis of patients with acute myeloid leukemia (AML) remains poor and novel therapeutic options are intensively needed. Targeted therapies specifically address molecules with essential function for AML and deciphering novel essential target genes is of utmost importance. Functional genomics via CRISPR\Cas9 technology paves the way for the systematic discovery of novel essential genes, but was so far mostly restricted to studying cell lines in vitro, lacking features of, e.g., primary tumor cells and the in vivo tumor microenvironment. To move closer to the clinical situation in patients, we used the CRISPR\Cas9 technology in patient-derived xenograft (PDX) models of AML in vivo. Methods: Primary tumor cells from seven patients with AML were transplanted into immunocompromised NSG mice and serially transplantable PDX models derived thereof. PDX models were selected which carry the AML specific mutations of interest at variant allele frequencies close to 0.5. PDX cells were lentivirally transduced to express the Cas9 protein and a sgRNA; successfully transduced PDX cells were enriched by flow cytometry gating on a recombinant fluorochrome or by puromycin. The customized sgRNA library was designed using the CLUE (www.crispr-clue.de) platform and cloned into a lentiviral vector with five different sgRNAs per target gene, plus positive and negative controls (Becker et al., Nucleic Acids Res. 2020). PDX cells were lentivirally transduced with the CRISPR/Cas9 sgRNA library, transplanted into NSG mice, grown in vivo and cells re-isolated at advanced AML disease. sgRNA distribution was measured by next generation sequencing and compared to input control using the MAGeCK pipeline. Interesting dropout hits from PDX in vivo screens were validated by fluorochrome-guided competitive in vivo experiments in the PDX models, comparing growth of PDX AML cells with knockout of the gene of interest versus control knockout in the same mouse. PDX cells were transduced with lentiviral vectors expressing a single sgRNA, using in parallel three different sgRNAs per target gene. Targeting and control sgRNAs were marked by different fluorochromes; PDX cells expressing targeting or control sgRNA were mixed at a 1:1 ratio, injected into NSG mice and PDX models competitively grown until advanced disease stage, when cell distributions was determined by flow cytometry. Human AML cell lines were studied in vitro for comparison. Results: In search for genes with essential function in AML, we cloned a small customized sgRNA library targeting 34 genes recurrently mutated in AML and tested the library in two PDX AML models in vivo. From the dropouts, we validated most interesting target genes using fluorochrome-guided competitive in vivo assays. Knockout of NPM1 abrogated in vivo growth in all PDX AML models tested, reproducing the known common essential function of NPM1. KRAS proved an essential function in PDX AML models both with and without an oncogenic mutation in KRAS, although with a stronger effect upon KRAS mutation, suggesting that patients with tumors both with and without KRAS mutation might benefit from treatment inhibiting KRAS. Surprising results were obtained for WT1 and DNMT3A. Both genes are frequently mutated in AML, but most AML cell lines tested in vitro do not show an essential function of any of the two genes, in published knockdown or knockout data, including from the Cancer Dependency Map database. On the contrary, knockout of either WT1 or DNMT3A was shown to enhance growth of AML cell lines and increase leukemogenesis in certain models. In PDX models in vivo, we found a clearly essential function for DNMT3A in all AML samples and WT1 in most samples tested and PDX in vivo results were discordant to cell line in vitro data, suggesting that cell line inherent features and/or the in vivo environment influence the function of WT1 and DNMT3A. Conclusion: We conclude that functional genomics in PDX models in vivo allows discovering essentialities hidden for cell line in vitro approaches. WT1 and DNMT3A harbor the potential to represent attractive therapeutic targets in AML under in vivo conditions, warranting further evaluation. Disclosures No relevant conflicts of interest to declare.


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