Small-molecule inhibition of BRD4 as a new potent approach to eliminate leukemic stem- and progenitor cells in acute myeloid leukemia (AML)

Small-molecule inhibition of BRD4 as a new potent approach to eliminate leukemic stem- and progenitor cells in acute myeloid leukemia (AML)

ABSTRACT

Acute myeloid leukemia (AML) is a life-threatening stem cell disease characterized by uncontrolled proliferation and accumulation of myeloblasts. Using an advanced RNAi screen-approach in an AML mouse model we have recently identified the epigenetic ‘reader’ BRD4 as a promising target in AML. In the current study, we asked whether inhibition of BRD4 by a small-molecule inhibitor, JQ1, leads to growth-inhibition and apoptosis in primary human AML stem- and progenitor cells. Primary cell samples were obtained from 37 patients with freshly diagnosed AML (n=23) or refractory AML (n=14). BRD4 was found to be expressed at the mRNA and protein level in unfractionated AML cells as well as in highly enriched CD34+/CD38- and CD34+/CD38+ stem- and progenitor cells in all patients examined. In unfractionated leukemic cells, submicromolar concentrations of JQ1 induced major growth-inhibitory effects (IC50 0.05-0.5 µM) in most samples, including cells derived from relapsed or refractory patients. In addition, JQ1 was found to induce apoptosis in CD34+/CD38− and CD34+/CD38+ stem- and progenitor cells in all donors examined as evidenced by combined surface/Annexin-V staining. Moreover, we were able to show that JQ1 synergizes with ARA-C in inducing growth inhibition in AML cells. Together, the BRD4-targeting drug JQ1 exerts major anti-leukemic effects in a broad range of human AML subtypes, including relapsed and refractory patients and all relevant stem- and progenitor cell compartments, including CD34+/CD38- and CD34+/CD38+ AML cells. These results characterize BRD4-inhibition as a promising new therapeutic approach in AML which should be further investigated in clinical trials


oncotarget. impact factor Zoya Demidenko Dr. Zoya N. Demidenko Zoya N. Demidenko , Ph.D. is Executive Manager of the Oncotarget journal . Oncotarget publishes high-impact research papers of general interest and outstanding significance and novelty in all areas of biology and medicine: in translational, basic and clinical research including but not limited to cancer research, oncogenes, oncoproteins and tumor suppressors, signaling pathways as potential targets for therapeutic intervention, shared targets in different diseases (cancer, benign tumors, atherosclerosis, eukaryotic infections, metabolic syndrome and other age-related diseases), chemotherapy, and new therapeutic strategies. After earning her Ph.D. in molecular biology, Zoya was awarded a Fogarty post-doctoral Fellowship from the National Institutes of Health in Bethesda, MD. After successful completion of post-doctoral training, she continued her professional career at George Washington University and Albert Einstein School of Medicine . In 2005 she cofounded the startup company Oncotarget Inc. which is focused on the development of anti-aging and anti-cancer drugs. Her research interests include signal transduction, cell cycle and cellular senescence, and their pharmacological targeting. In 2009 she cofounded the publishing house Impact Journals which specializes in publishing scientific journals. In 2011 she was selected to be a Member of the National Association of Professional Women .


When people speak of today’s medicine, accuracy plays one of the most significant roles and human lives are directly dependent on it. Hence, any researches related to medicine are required to meet the highest standards. The problem nowadays is that any conclusions of researches can be shared online and used as a reference without being properly verified and validated. Mikhail (Misha) Blagosklonny of Oncotarget clearly understood this issue and decided to come up with an alternative solution. That’s how a weekly oncology-focused research journal named “Oncotarget” has been founded back in 2010. The major principle of this journal is based on Altmetric scores that are used as a quality measure. That allows both readers and authors to quality-check publications with Altmetric Article Reports that provide “real-time feedback containing data summary related to a particular publication.” Oncotarget website provides a full publications list with respective scores higher than 100 as well as reports discussed above. Mikhail (Misha) Blagosklonny proud to share his new approach and hopes it creates the required help to anyone, who has interest in oncology.
“A diagnostic autoantibody signature for primary cutaneous melanoma” has the Altmetric score of 594. This study was published back in 2018 by Oncotarget and written by several experts from Hollywood Private Hospital, Edith Cowan University, Dermatology Specialist Group, St. John of God Hospital and The University of Western Australia. The introduction of the study discusses “recent data shows that Australians are four times more likely to develop a cancer of the skin than any other type of cancer”, and shares an insight on melanoma that “is curable by surgical excision in the majority of cases, if detected at an early stage.”
The publication has got an Altmetric score of 594. Mikhail (Misha) Blagosklonny realizes that most of readers are willing to comprehend the very meaning of it. Based on the Altmetric website, the score relates to “how many people have been exposed to and engaged with a scholarly output.” Hence, the paper about melanoma, was used for citations in various news articles 69 times. In addition, it was referred to in 2 online blogs, as well as 25 Tweets on Twitter and 1 Facebook post. FOX23 of Tulsa, Oklahoma has headlined their report on July 20, 2018 as “New blood test could detect skin cancer early”, using the main content of Australia study 
Another Oncotarget’s study with a top score of 476, is “Biomarkers for early diagnosis of malignant mesothelioma: Do we need another moon-shot,”. This publication has appeared in 60 news stories, 1 online blog post and 6 Twitter posts. The majority of public may have come across a concise overview only, however those who visit Mikhail (Misha) Blagosklonny at Oncotarget, do get useful scientific facts. Oncotarget is proud to have the ability to share with online viewers this highly appreciated and top-quality information, that is trustworthy and reliable.

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