The Imipridone ONC213 Targets α-Ketoglutarate Dehydrogenase to Induce Mitochondrial Stress and Suppress Oxidative Phosphorylation in Acute Myeloid Leukemia.

Eradication of acute myeloid leukemia (AML) is therapeutically challenging; many patients succumb to AML despite initially responding to conventional treatments. Here, we showed that the imipridone ONC213 elicits potent antileukemia activity in a subset of AML cell lines and primary patient samples, particularly in leukemia stem cells, while producing negligible toxicity in normal hematopoietic cells. ONC213 suppressed mitochondrial respiration and elevated α-ketoglutarate by suppressing α-ketoglutarate dehydrogenase (αKGDH) activity. Deletion of OGDH, which encodes αKGDH, suppressed AML fitness and impaired oxidative phosphorylation, highlighting the key role for αKGDH inhibition in ONC213-induced death. ONC213 treatment induced a unique mitochondrial stress response and suppressed de novo protein synthesis in AML cells. Additionally, ONC213 reduced the translation of MCL1, which contributed to ONC213-induced apoptosis. Importantly, a patient-derived xenograft from a relapsed AML patient was sensitive to ONC213 in vivo. Collectively, these findings support further development of ONC213 for treating AML. SIGNIFICANCE: In AML cells, ONC213 suppresses αKGDH, which induces a unique mitochondrial stress response, and reduces MCL1 to decrease oxidative phosphorylation and elicit potent antileukemia activity. See related commentary by Boët and Sarry, p. 950.

Enhancing anti-AML activity of venetoclax by isoflavone ME-344 through suppression of OXPHOS and/or purine biosynthesis in vitro.

Venetoclax (VEN), in combination with low dose cytarabine (AraC) or a hypomethylating agent, is FDA approved to treat acute myeloid leukemia (AML) in patients who are over the age of 75 or cannot tolerate standard chemotherapy. Despite high response rates to these therapies, most patients succumb to the disease due to relapse and/or drug resistance, providing an unmet clinical need for novel therapies to improve AML patient survival. ME-344 is a potent isoflavone with demonstrated inhibitory activity toward oxidative phosphorylation (OXPHOS) and clinical activity in solid tumors. Given that OXPHOS inhibition enhances VEN antileukemic activity against AML, we hypothesized that ME-344 could enhance the anti-AML activity of VEN. Here we report that ME-344 enhanced VEN to target AML cell lines and primary patient samples while sparing normal hematopoietic cells. Cooperative suppression of OXPHOS was detected in a subset of AML cell lines and primary patient samples. Metabolomics analysis revealed a significant reduction of purine biosynthesis metabolites by ME-344. Further, lometrexol, a purine biosynthesis inhibitor, synergistically enhanced VEN-induced apoptosis in AML cell lines. Interestingly, AML cells with acquired AraC resistance showed significantly increased purine biosynthesis metabolites and sensitivities to ME-344. Furthermore, synergy between ME-344 and VEN was preserved in these AraC-resistant AML cells. In vivo studies revealed significantly prolonged survival upon combination therapy of ME-344 and VEN in NSGS mice bearing parental or AraC-resistant MV4-11 leukemia compared to the vehicle control. This study demonstrates that ME-344 enhances VEN antileukemic activity against preclinical models of AML by suppressing OXPHOS and/or purine biosynthesis.

Comparison of S-ketamine and midazolam for intravenous preoperative sedative and anxiolytic effects in preschool children: study protocol for a randomized controlled clinical trial.

BACKGROUND: Preoperative anxiety management is gaining particular attention in paediatric anaesthesia. Pharmacological and non-pharmacological resorts can be implemented to address this special issue. Despite the various approaches currently used for preoperative sedation in children, the different sedative and anti-anxiety effects between the newly marketed anaesthetic, S-ketamine, and the traditional sedative, midazolam, are still unclear. METHODS: This is a patient- and assessor-blinded randomized controlled clinical trial. Participants (n = 110) will receive S-ketamine (0.5 mg/kg) or midazolam (0.08 mg/kg) intravenously administrated at a ratio of 1:1 in the anaesthesia holding area. The primary outcome of this study is the sedative effect evaluated via the change in the modified Yale preoperative anxiety scale. It will be performed at two timepoints: in the pre-anaesthetic holding area before premedication (baseline, marked as T0) and about 5 min after premedication in the operating room without the existence of their guardians (marked as T1). Our secondary objectives include the parent separation anxiety score, postoperative agitation, caregivers' and anaesthesia care providers' satisfaction, and mask compliance. DISCUSSION: This randomized controlled trial is the first study to compare the anti-anxiety effect of intravenous S-ketamine and midazolam. We will provide a new approach for the clinical management of preoperative anxiety in preschool children posted for elective surgery. TRIAL REGISTRATION: ChiCTR2300069998. Registered on 30 March 2023.

Acquired resistance to venetoclax plus azacitidine in acute myeloid leukemia: In vitro models and mechanisms.

The combination of venetoclax (VEN) and azacitidine (AZA) has become the standard of care for acute myeloid leukemia (AML) patients who are ≥ 75 years or unfit for intensive chemotherapy. Though initially promising, resistance to the combination therapy is an issue and VEN + AZA-relapsed/refractory patients have dismal outcomes. To better understand the mechanisms of resistance, we developed VEN + AZA-resistant AML cell lines, MV4-11/VEN + AZA-R and ML-2/VEN + AZA-R, which show > 300-fold persistent resistance compared to the parental lines. We demonstrate that these cells have unique metabolic profiles, including significantly increased levels of cytidine triphosphate (CTP) and deoxycytidine triphosphate (dCTP), changes in fatty acid and amino acid metabolism and increased utilization and reliance on glycolysis. Furthermore, fatty acid transporter CD36 is increased in the resistant cells compared to the parental cells. Inhibition of glycolysis with 2-Deoxy-D-glucose re-sensitized the resistant cells to VEN + AZA. In addition, the VEN + AZA-R cells have increased levels of the antiapoptotic protein Mcl-1 and decreased levels of the pro-apoptotic protein Bax. Overexpression of Mcl-1 or knockdown of Bax result in resistance to VEN + AZA. Our results provide insight into the molecular mechanisms contributing to VEN + AZA resistance and assist in the development of novel therapeutics to overcome this resistance in AML patients.

Enhancing anti-AML activity of venetoclax by isoflavone ME-344 through suppression of OXPHOS and/or purine biosynthesis.

Venetoclax (VEN), in combination with low dose cytarabine (AraC) or a hypomethylating agent, is FDA approved to treat acute myeloid leukemia (AML) in patients who are over the age of 75 or cannot tolerate standard chemotherapy. Despite high response rates to these combination therapies, most patients succumb to the disease due to relapse and/or drug resistance, providing an unmet clinical need for novel therapies to improve AML patient survival. ME-344 is a potent isoflavone with demonstrated inhibitory activity toward oxidative phosphorylation (OXPHOS) and clinical activity in solid tumors. Given that OXPHOS inhibition enhances VEN antileukemic activity against AML, we hypothesized that ME-344 could enhance the anti-AML activity of VEN. Here we report that ME-344 synergized with VEN to target AML cell lines and primary patient samples while sparing normal hematopoietic cells. Cooperative suppression of OXPHOS was detected in a subset of AML cell lines and primary patient samples. Metabolomics analysis revealed a significant reduction of purine biosynthesis metabolites by ME-344. Further, lometrexol, an inhibitor of purine biosynthesis, synergistically enhanced VEN-induced apoptosis in AML cell lines. Interestingly, AML cells with acquired resistance to AraC showed significantly increased purine biosynthesis metabolites and sensitivities to ME-344. Furthermore, synergy between ME-344 and VEN was preserved in these AraC-resistant AML cells. These results translated into significantly prolonged survival upon combination of ME-344 and VEN in NSGS mice bearing parental or AraC-resistant MV4-11 leukemia. This study demonstrates that ME-344 enhances VEN antileukemic activity against preclinical models of AML by suppressing OXPHOS and/or purine biosynthesis.

Effect of fruit on glucose control in diabetes mellitus: a meta-analysis of nineteen randomized controlled trials.

Objective: Diabetes mellitus is a worldwide health problem, and it remains unclarified whether fruit is beneficial in glycemic control. This study aimed to analyze evidence from randomized controlled trials evaluating the effect of fruit consumption on glucose control. Methods: We searched the PubMed, EMBASE, Ovid, Web of Science, and Cochrane Central Register of Controlled Trials databases from the respective database inception dates to December 30, 2022, to identify randomized controlled trials that evaluated the effects of fruit consumption on glucose control. Two researchers independently screened the studies in accordance with the inclusion and exclusion criteria, and performed the literature quality evaluation and data extraction. RevMan 5.4 software was used to perform the data analysis. Results: Nineteen randomized controlled trials with 888 participants were included. Fruit consumption significantly decreased the fasting blood glucose concentration (MD -8.38, 95% CI -12.34 to -4.43), but it showed no significant difference in the glycosylated hemoglobin (MD -0.17, 95% CI -0.51 to 0.17). Subgroup analyses further suggested that the consumption of both fresh and dried fruit decreased the fasting blood glucose concentration. Conclusions: Increasing the fruit intake reduced fasting blood glucose concentration. Therefore, we recommend that patients with diabetes eat more fruits while ensuring that their total energy intake remains unchanged.

Does pronator quadratus repair affect functional outcome following volar plate fixation of distal radius fractures? A systematic review and meta-analysis.

Introduction: The study aimed to evaluate the efficacy of pronator quadratus (PQ) repair versus no repair following volar plate fixation of distal radius fractures. Methods: A comprehensive search was performed in PubMed, CNKI, EMBASE, Web of Science, Ovid, and Cochrane Library databases. All randomized controlled trials comparing PQ repair with no repair in distal radius fractures before January 2023 were included. Two investigators independently screened eligible articles, assessed the study quality, and extracted data from included studies. Continuous variables used standardized mean difference and 95% confidence interval as efficacy statistics. The meta-analysis was performed using the Revman 5.4 software. Results: A total of 430 patients in 7 RCT studies were included in this meta-analysis, of which 218 underwent PQ repair, while 212 patients underwent no repair. The results of the meta-analysis displayed statistically significant differences in grip strength (short-term), pronation angle (short-term), and pronation strength (short- and long-term) between the two groups. No significant difference in other outcomes was found between the two treatment arms. Discussion: The repair of PQ may further increase grip strength and pronation function in the short-term and enhance long-term pronator muscle strength compared to no repair. However, due to the small number of articles included in the study, the above conclusions need to be verified by a larger sample and multi-center clinical study.

The preclinical pharmacological study of a novel intravenous anesthetic, ET-26 hydrochloride, in aged rats.

Background: ET-26 hydrochloride (ET-26HCl) is a novel analogue of etomidate approved for clinical trials. However, all results from recent studies were accomplished in young adult animals. The objective of this study was to evaluate the efficacy and safety of ET-26HCl in aged rats. Methods: Aged Sprague-Dawley rats were randomly divided into three groups (three males and three females in each group) were given dose of two-fold of median effective dose (ED50) of ET-26HCl, etomidate and propofol: the measurements of loss of the righting reflex (LORR) and cardiovascular and respiratory function after injection at the two-fold dose of the median effective dose were used for evaluation of effectiveness and safety, and the modified adrenocorticotropic hormone-stimulation experiment was used to evaluate the inhibition effect of the drugs on the synthesis of adrenal cortical hormones. Results: There was no significant difference in the onset time among propofol, etomidate and ET-26HCl. The duration of propofol (850.5 ± 77.4 s) was significantly longer than that caused by etomidate (489.8 ± 77.0 s, p = 0.007) and ET-26HCl (347.3 ± 49.0 s, p = 0.0004). No significant difference was observed in the time to stand and normal activity among drugs. A total of 66.7% of rats in the ET-26HCl group were evaluated to have mild hematuria. Then, etomidate and ET-26HCl had a milder blood pressure inhibition effect than propofol. Apnea was observed in all rats administered propofol and the duration for this side effect was 45.0 ± 9.0 s. For etomidate and ET-26HCl, no apnea was observed. No other clinical signs of side-effect were observed, and no rats died. No significant difference was observed in corticosterone concentrations between ET-26HCl and solvent group. However, rats administered etomidate had lower corticosterone concentrations than those administered ET-26HCl at 15, 30, and 60 min. Conclusions: Our results indicate ET-26HCl in aged rats is an effective sedative-hypnotic with stable myocardial and respiratory performance and also have mild adrenocortical suppression. Thus, these findings increase the potential for the clinical use of ET-26HCl in the elderly population.

Co-targeting of HDAC, PI3K, and Bcl-2 results in metabolic and transcriptional reprogramming and decreased mitochondrial function in acute myeloid leukemia.

Despite the recently approved new therapies, the clinical outcomes of acute myeloid leukemia (AML) patients remain disappointing, highlighting the need for novel therapies. Our lab has previously demonstrated the promising outlook for CUDC-907, a dual inhibitor of PI3K and HDAC, in combination with venetoclax (VEN), against AML both in vitro and in vivo at least partially through suppression of c-Myc. In this study, we further elucidated the mechanism of action of the combination in preclinical models of AML. We demonstrated that the combination significantly reduced primary AML cell engraftment in immunocompromised mice. RNA sequencing and metabolomics analyses revealed that the combination reduced the levels for mRNAs of key TCA cycle genes and metabolites in the TCA cycle, respectively. This was accompanied by a reduced oxygen consumption rate (OCR), demonstrating that the combination suppressed oxidative phosphorylation (OXPHOS). Metabolomics analyses revealed that a large number of metabolites upregulated in AraC-resistant AML cells could be downregulated by the combination. CUDC-907 synergized with VEN in inducing apoptosis in the AraC-resistant AML cells. In conclusion, the CUDC-907 and VEN combination induces metabolic and transcriptomic reprograming and suppression of OXPHOS in AML, which provides additional mechanisms underlying the synergy between the two agents.

c-Myc plays a critical role in the antileukemic activity of the Mcl-1-selective inhibitor AZD5991 in acute myeloid leukemia.

Acute myeloid leukemia (AML) is an aggressive disease with a low 5-year overall survival rate of 29.5%. Thus, more effective therapies are in need to prolong survival of AML patients. Mcl-1 is overexpressed in AML and is associated with poor prognosis, representing a promising therapeutic target. The oncoprotein c-Myc is also overexpressed in AML and is a significant prognostic factor. In addition, Mcl-1 is required for c-Myc induced AML, indicating that c-Myc-driven AML harbors a Mcl-1 dependency and co-targeting of Mcl-1 and c-Myc represents a promising strategy to eradicate AML. In this study, we investigated the role of c-Myc in the antileukemic activity of Mcl-1 selective inhibitor AZD5991 and the antileukemic activity of co-targeting of Mcl-1 and c-Myc in preclinical models of AML. We found that c-Myc protein levels negatively correlated with AZD5991 EC50s in AML cell lines and primary patient samples. AZD5991 combined with inhibition of c-Myc synergistically induced apoptosis in AML cell lines and primary patient samples, and cooperatively targeted leukemia progenitor cells. AML cells with acquired resistance to AZD5991 were resensitized to AZD5991 when c-Myc was inhibited. The combination also showed promising and synergistic antileukemic activity in vitro against AML cell lines with acquired resistance to the main chemotherapeutic drug AraC and primary AML cells derived from a patient at relapse post chemotherapy. The oncoprotein c-Myc represents a potential biomarker of AZD5991 sensitivity and inhibition of c-Myc synergistically enhances the antileukemic activity of AZD5991 against AML.

Paracrine effects of adipose-derived stem cells in cutaneous wound healing in streptozotocin-induced diabetic rats.

OBJECTIVE: The purpose of this study was to explore the paracrine effects of adipose-derived stem cells (ASCs) on cutaneous wound healing in diabetic rats. METHOD: The ASCs were isolated and identified by immunofluorescent staining. The ASCs-conditioned medium (ASCs-CM) was harvested. Cell counting kit (CCK)-8 assay, scratch experiments, western blot and quantitative polymerase chain reaction (qPCR) were performed to observe the effects of ASCs-CM on fibroblasts. A full-thickness skin wound diabetic rat model was prepared, using 34 male, Sprague Dawley rats. ASCs-CM or negative-control medium (N-CM) was injected around the wound surface. The existing wound area was measured on days 4, 8, 12 and 16 after the postoperative day, and the wound tissues were collected for immunohistochemical staining and qPCR quantitative study. RESULTS: In this experiment, the isolated cells were characterised as ASCs. The results of CCK-8 assay, cell scratch test, western blot and qPCR showed ASCs-CM could significantly promote the proliferation, migration and differentiation of fibroblasts. Simultaneously, the healing rate of full-thickness skin wounds in diabetic rats was significantly higher in the ASCs-CM group than the N-CM group on days 4, 8, 12 and 16. Immunohistochemical staining and qPCR results showed that the expression of vascular endothelial growth factor (VEGF, days 4 and 8), α-smooth muscle actin (SMA) (days 4 and 16), transforming growth factor (TGF)-ß1 (days 4, 8 and 12) were higher in the ASCs-CM group than that of the N-CM group (p<0.05). CONCLUSION: This experiment demonstrated that ASCs-CM may accelerate wound healing in diabetic rats by promoting the secretion of TGF-ß1, VEGF and the proliferation, migration and differentiation of fibroblasts.

Intraoperative vancomycin powder to reduce surgical site infections after posterior spine surgery: a systematic review and meta-analysis.

The purpose of the study was to evaluate the effect of local application of vancomycin powder (VP) to prevent surgical site infections (SSIs) after posterior spine surgery. A comprehensive search of Web of Science, EMBASE, Pubmed, Ovid, and Cochrane Library databases for articles published was performed to collect comparative studies of intrawound vancomycin in posterior spine surgery before March 2021. Two reviewers independently screened eligible articles based on the inclusion and exclusion criteria, assessed the study quality, and extracted the data. Revman 5.4 software was used for data analysis. A total of 22 articles encompassing 11 555 surgical patients were finally identified for meta-analysis. According to the information provided by the included literature, the combined odds ratio showed that topical use of VP was effective for reducing the incidence of SSIs (P< 0.00001) after posterior spine surgery without affecting its efficacy in the treatment of deep infections (P< 0.00001). However, there is no statistical significance in superficial infections. In a subgroup analysis, VP at a dose of 1, 2, and 0.5-2 g reduced the incidence of spinal SSIs. The result of another subgroup analysis suggested that local application of VP could significantly reduce the risk of SSIs, whether it was administered after posterior cervical surgery or thoracolumbar surgery. Moreover, the percentage of SSIs due to gram-positive germs (P< 0.00001) and MRSA (P< 0.0001) could reduce after intraoperative VP was used, but did not significantly reduce to gram-negative germs. The local application of VP appears to protect against SSIs, gram-positive germs, and MRSA (methicillin-resistant Staphylococcus aureus) infections after the posterior spinal operation.

Cotargeting of Bcl-2 and Mcl-1 shows promising antileukemic activity against AML cells including those with acquired cytarabine resistance.

Acute myeloid leukemia (AML) remains a clinical challenge. Venetoclax is an effective Bcl-2 selective inhibitor approved by the U.S. Food and Drug Administration (FDA) for treatment of AML in patients who are 75 years and older or who have comorbidities. However, resistance to venetoclax limits its clinical efficacy. Mcl-1 has been identified as one determinant of resistance to venetoclax treatment. In this study, we investigate the Mcl-1 inhibitor S63845 in combination with venetoclax in AML cells. We found that S63845 synergizes with venetoclax in AML cell lines and primary patient samples. Bak/Bax double knockdown and treatment with the pan-caspase inhibitor Z-VAD-FMK revealed that the combination induces intrinsic apoptosis in AML cells. Inhibition of Mcl-1 using another Mcl-1 selective inhibitor, AZD5991, also synergistically enhanced apoptosis induced by venetoclax in a caspase-dependent manner. Importantly, S63845 in combination with venetoclax can effectively combat AML cells with acquired resistance to the standard chemotherapy drug cytarabine. In light of these facts, the combined inhibition of Mcl-1 and Bcl-2 shows promise against AML cells, including relapse/refractory AML.

The combination of CUDC-907 and gilteritinib shows promising in vitro and in vivo antileukemic activity against FLT3-ITD AML.

About 25% of patients with acute myeloid leukemia (AML) harbor FMS-like tyrosine kinase 3 (FLT3) internal tandem duplication (ITD) mutations and their prognosis remains poor. Gilteritinib is a FLT3 inhibitor approved by the US FDA for use in adult FLT3-mutated relapsed or refractory AML patients. Monotherapy, while efficacious, shows short-lived responses, highlighting the need for combination therapies. Here we show that gilteritinib and CUDC-907, a dual inhibitor of PI3K and histone deacetylases, synergistically induce apoptosis in FLT3-ITD AML cell lines and primary patient samples and have striking in vivo efficacy. Upregulation of FLT3 and activation of ERK are mechanisms of resistance to gilteritinib, while activation of JAK2/STAT5 is a mechanism of resistance to CUDC-907. Gilteritinib and CUDC-907 reciprocally overcome these mechanisms of resistance. In addition, the combined treatment results in cooperative downregulation of cellular metabolites and persisting antileukemic effects. CUDC-907 plus gilteritinib shows synergistic antileukemic activity against FLT3-ITD AML in vitro and in vivo, demonstrating strong translational therapeutic potential.

Extracellular vesicles from GPNMB-modified bone marrow mesenchymal stem cells attenuate bone loss in an ovariectomized rat model.

AIMS: The efficacy of anti-osteoporotic treatments is still limited. Our study aimed to investigate the effect of extracellular vesicles (EVs) derived from bone marrow-derived MSCs (BMSCs) overexpressing glycoprotein non-melanoma clone B (GPNMB) on osteoporosis (OP). MAIN METHODS: Lentiviral vector for GPNMB overexpression or its negative control was generated and transfected into BMSCs. EVs enriched with GPNMB (GPNMB-EVs) were extracted from GPNMB-modified BMSC-conditioned medium and then identified. Cellular uptake and proliferation were analyzed using the Dil-labeled assay and CCK-8 assay, respectively. Cytochemical staining, western blot, and RT-qPCR analysis were performed to assess the effect of GPNMB-EVs on osteogenic differentiation of BMSCs in vitro. Dickkopf-1 (DKK1) as the inhibitor was applied to explore the Wnt/ß-catenin signaling pathway involved in the GPNMB-EV-induced osteogenic differentiation. In vivo experiments were conducted using an ovariectomized (OVX) rat model of postmenopausal osteoporosis, and then assessed the effect of GPNMB-EVs by micro-CT, and histological and immunohistochemical assays. KEY FINDINGS: GPNMB-EVs were taken up by BMSCs, and they noticeably promoted the proliferation of BMSCs. Additionally, GPNMB-EVs activated the Wnt/ß-catenin signaling to stimulate osteogenesis in BMSCs. In vivo examination showed that GPNMB-EVs remarkably improved trabecular bone regeneration and alleviated the osteoporotic phenotype in the OVX-induced rat model of OP. SIGNIFICANCE: EVs derived from GPNMB-modified BMSCs significantly stimulated the proliferation and osteogenic differentiation of BMSCs via the activation of Wnt/ß-catenin signaling and attenuated the bone loss in the OVX-induced rat model of OP. Our findings suggest the promising potential of GPNMB-EVs as cell-free therapy for the treatment of OP.

The HDAC and PI3K dual inhibitor CUDC-907 synergistically enhances the antileukemic activity of venetoclax in preclinical models of acute myeloid leukemia.

Venetoclax is a promising agent in the treatment of acute myeloid leukemia, though its antileukemic activity is limited to combination therapies. Mcl-1 downregulation, Bim upregulation, and DNA damage have been identified as potential ways to enhance venetoclax activity. In this study, we combine venetoclax with the dual PI3K and histone deacetylase inhibitor CUDC-907, which can downregulate Mcl-1, upregulate Bim, and induce DNA damage, as well as downregulate c-Myc. We establish that CUDC-907 and venetoclax synergistically induce apoptosis in acute myeloid leukemia cell lines and primary acute myeloid leukemia patient samples ex vivo. CUDC-907 downregulates CHK1, Wee1, RRM1, and c-Myc, which were found to play a role in venetoclax-induced apoptosis. Interestingly, we found that venetoclax treatment enhances CUDC-907-induced DNA damage potentially through inhibition of DNA repair. In vivo results show that CUDC-907 enhances venetoclax efficacy in an acute myeloid leukemia cell line derived xenograft mouse model, supporting the development of CUDC-907 in combination with venetoclax for the treatment of acute myeloid leukemia.

Targeting multiple signaling pathways: the new approach to acute myeloid leukemia therapy.

Acute myeloid leukemia (AML) is the most common form of acute leukemia in adults and the second most common form of acute leukemia in children. Despite this, very little improvement in survival rates has been achieved over the past few decades. This is partially due to the heterogeneity of AML and the need for more targeted therapeutics than the traditional cytotoxic chemotherapies that have been a mainstay in therapy for the past 50 years. In the past 20 years, research has been diversifying the approach to treating AML by investigating molecular pathways uniquely relevant to AML cell proliferation and survival. Here we review the development of novel therapeutics in targeting apoptosis, receptor tyrosine kinase (RTK) signaling, hedgehog (HH) pathway, mitochondrial function, DNA repair, and c-Myc signaling. There has been an impressive effort into better understanding the diversity of AML cell characteristics and here we highlight important preclinical studies that have supported therapeutic development and continue to promote new ways to target AML cells. In addition, we describe clinical investigations that have led to FDA approval of new targeted AML therapies and ongoing clinical trials of novel therapies targeting AML survival pathways. We also describe the complexity of targeting leukemia stem cells (LSCs) as an approach to addressing relapse and remission in AML and targetable pathways that are unique to LSC survival. This comprehensive review details what we currently understand about the signaling pathways that support AML cell survival and the exceptional ways in which we disrupt them.

Cotargeting of Mitochondrial Complex I and Bcl-2 Shows Antileukemic Activity against Acute Myeloid Leukemia Cells Reliant on Oxidative Phosphorylation.

Targeting oxidative phosphorylation (OXPHOS) is a promising strategy to improve treatment outcomes of acute myeloid leukemia (AML) patients. IACS-010759 is a mitochondrial complex I inhibitor that has demonstrated preclinical antileukemic activity and is being tested in Phase I clinical trials. However, complex I deficiency has been reported to inhibit apoptotic cell death through prevention of cytochrome c release. Thus, combining IACS-010759 with a BH3 mimetic may overcome this mechanism of resistance leading to synergistic antileukemic activity against AML. In this study, we show that IACS-010759 and venetoclax synergistically induce apoptosis in OXPHOS-reliant AML cell lines and primary patient samples and cooperatively target leukemia progenitor cells. In a relatively OXPHOS-reliant AML cell line derived xenograft mouse model, IACS-010759 treatment significantly prolonged survival, which was further enhanced by treatment with IACS-010759 in combination with venetoclax. Consistent with our hypothesis, IACS-010759 treatment indeed retained cytochrome c in mitochondria, which was completely abolished by venetoclax, resulting in Bak/Bax- and caspase-dependent apoptosis. Our preclinical data provide a rationale for further development of the combination of IACS-010759 and venetoclax for the treatment of patients with AML.

Inhibition of CDK9 by voruciclib synergistically enhances cell death induced by the Bcl-2 selective inhibitor venetoclax in preclinical models of acute myeloid leukemia.

Venetoclax, an FDA-approved Bcl-2 selective inhibitor for the treatment of chronic lymphocytic leukemia and acute myeloid leukemia (AML), is tolerated well in elderly patients with AML and has good overall response rates; however, resistance remains a concern. In this study, we show that targeting CDK9 with voruciclib in combination with venetoclax results in synergistic antileukemic activity against AML cell lines and primary patient samples. CDK9 inhibition enhances venetoclax activity through downregulation of Mcl-1 and c-Myc. However, downregulation of Mcl-1 is transient, which necessitates an intermittent treatment schedule to allow for repeated downregulation of Mcl-1. Accordingly, an every other day schedule of the CDK9 inhibitor is effective in vitro and in vivo in enhancing the efficacy of venetoclax. Our preclinical data provide a rationale for an intermittent drug administration schedule for the clinical evaluation of the combination treatment for AML.

Exchange nailing versus augmentative plating in the treatment of femoral shaft nonunion after intramedullary nailing: a meta-analysis.

With advances in the treatment of femoral shaft nonunion after intramedullary nailing, the optimal option remains controversial. This study aimed to quantitatively investigate outcomes in a comparison of exchange nailing and augmentative plating for femoral shaft nonunion after intramedullary nailing.The EMBASE, PubMed, Cochrane library and Clinical databases were systematically searched dating from their inception to March 2018. All retrospective controlled and prospective trials evaluating exchange nailing and augmentative plating for the treatment of femoral shaft nonunion after intramedullary nailing were identified. Two investigators extracted all related data independently and we used the review manager software to perform the meta-analysis.Three studies with a total of 232 patients were eligible for data extraction in our study. The meta-analysis indicated that the augmentative plating group had a lower nonunion rate, shorter time to union, less intra-operative blood loss, and shorter operative time than the exchange nailing group. While for the infection rate, there was no significant difference between augmentative plating and exchange nailing group.The available evidence has shown that augmentative plating is superior to exchange nailing for femoral shaft nonunion after intramedullary nailing. Cite this article: EFORT Open Rev 2019;4:513-518. DOI: 10.1302/2058-5241.4.180054.