Human-mouse chimeric brain models constructed from iPSC-derived brain cells: Applications and challenges.

The establishment of reliable human brain models is pivotal for elucidating specific disease mechanisms and facilitating the discovery of novel therapeutic strategies for human brain disorders. Human induced pluripotent stem cell (iPSC) exhibit remarkable self-renewal capabilities and can differentiate into specialized cell types. This makes them a valuable cell source for xenogeneic or allogeneic transplantation. Human-mouse chimeric brain models constructed from iPSC-derived brain cells have emerged as valuable tools for modeling human brain diseases and exploring potential therapeutic strategies for brain disorders. Moreover, the integration and functionality of grafted stem cells has been effectively assessed using these models. Therefore, this review provides a comprehensive overview of recent progress in differentiating human iPSC into various highly specialized types of brain cells. This review evaluates the characteristics and functions of the human-mouse chimeric brain model. We highlight its potential roles in brain function and its ability to reconstruct neural circuitry in vivo. Additionally, we elucidate factors that influence the integration and differentiation of human iPSC-derived brain cells in vivo. This review further sought to provide suitable research models for cell transplantation therapy. These research models provide new insights into neuropsychiatric disorders, infectious diseases, and brain injuries, thereby advancing related clinical and academic research.

Yin Yang 1 regulates cohesin complex protein SMC3 in mouse hematopoietic stem cells.

ABSTRACT: Yin Yang 1 (YY1) and structural maintenance of chromosomes 3 (SMC3) are 2 critical chromatin structural factors that mediate long-distance enhancer-promoter interactions and promote developmentally regulated changes in chromatin architecture in hematopoietic stem/progenitor cells (HSPCs). Although YY1 has critical functions in promoting hematopoietic stem cell (HSC) self-renewal and maintaining HSC quiescence, SMC3 is required for proper myeloid lineage differentiation. However, many questions remain unanswered regarding how YY1 and SMC3 interact with each other and affect hematopoiesis. We found that YY1 physically interacts with SMC3 and cooccupies with SMC3 at a large cohort of promoters genome wide, and YY1 deficiency deregulates the genetic network governing cell metabolism. YY1 occupies the Smc3 promoter and represses SMC3 expression in HSPCs. Although deletion of 1 Smc3 allele partially restores HSC numbers and quiescence in YY1 knockout mice, Yy1-/-Smc3+/- HSCs fail to reconstitute blood after bone marrow transplant. YY1 regulates HSC metabolic pathways and maintains proper intracellular reactive oxygen species levels in HSCs, and this regulation is independent of the YY1-SMC3 axis. Our results establish a distinct YY1-SMC3 axis and its impact on HSC quiescence and metabolism.

Long-term follow up and comparison between conservative and interventional therapy in postoperative bronchopleural fistula-a cohort study.

Background: Bronchopleural fistula (BPF) is a relatively rare postoperative complication with high mortality. The management is tough and controversial. The aim of this study was to compare the short and long-term outcomes between the conservative and the interventional therapy in postoperative BPF. We also concluded our own strategy and experience of treatment in postoperative BPF. Methods: Postoperative BPF patients with malignancies, aged from 18 to 80 years old who had undergone thoracic surgery between June 2011 and June 2020, were included in this study and followed up from 20 months to 10 years. They were retrospectively reviewed and analyzed. Results: Ninety-two BPF patients were included in this study, 39 of whom underwent interventional treatment. Significant differences were found in the 28-day and the 90-day survival rates between the conservative and the interventional therapy (P=0.001, 43.40% vs. 76.92%; P=0.006, 35.85% vs. 66.67%). Simple conservative therapy was independently associated with 90-day mortality between the groups in postoperative BPF [P=0.002, hazards ratio (HR) =2.913, 95% confidence interval (CI): 1.480-5.731]. Conclusions: Postoperative BPF is notorious for its high mortality. Surgical and bronchoscopic interventions are recommendable in postoperative BPF as they guarantee better short and long-term outcomes compared with the conservative therapy.

Comparative Expedited Regulatory Programs of U.S Food & Drug Administration and Project Orbis Partners.

Project Orbis was initiated in May 2019 by the Oncology Center of Excellence to facilitate faster patient access to innovative cancer therapies by providing a framework for concurrent submissions and review of oncology products among international partners. Since its inception, Australia's Therapeutic Goods Administration (TGA), Canada's Health Canada (HC), Singapore's Health Sciences Authority (HSA), Switzerland's Swissmedic (SMC), Brazil's National Health Surveillance Agency (ANVISA), United Kingdom's Medicines and Healthcare Products Regulatory Agency (MHRA), and most recently Israel's Ministry of Health (IMoH) Medical Technologies, Health Information, Innovation and Research (MTIIR) Directorate, have joined Project Orbis. While each country has its own expedited review pathways to bring promising therapies to patients, there are some similarities and differences in pathways and timelines. FDA's fast-track designation and MHRA's marketing authorization under exceptional circumstances (MAEC) allow non-clinical and limited clinical evidence to support approval under these programs. HC's Extraordinary Use New Drug (EUND) pathway allows granting exceptional use authorization with limited clinical evidence. ANVISA, HSA, MTIIR, and TGA do not have standard pathways that allow non-clinical evidence and limited clinical evidence. While there is no definite regulatory pathway for HSA, the current framework for approval does allow flexibility in the type of data (non-clinical or clinical) required to demonstrate the benefit-risk profile of a product. HSA may register a product if the agency is satisfied that the overall benefit outweighs the risk. All Project Orbis Partner (POP) countries have similar programs to the FDA accelerated approval program except ANVISA. Although HSA and MTIIR do not have defined pathways for accelerated approval programs, there are opportunities to request accelerated approval per these agencies. All POP countries have pathways like the FDA priority review except MHRA. Priority review timelines for new drugs range from 120 to 264 calendar days (cd). Standard review timelines for new drugs range from 180 to 365 cd.

Predictive value of 3D ultrasound assessment of endometrial receptivity for PGD/PGS for transfer pregnancy outcome.

OBJECTIVE: To investigate the predictive value of three-dimensional ultrasound assessment of endometrial receptivity in PGD/PGS transplantation patients on pregnancy outcome. METHODS: 280 patients undergoing PGD/PGS transplantation were enrolled and divided into group A and group B according to the patients' pregnancy outcomes. The general conditions, endometrial receptivity indexes of the two groups were compared. Multifactorial logistic regression analysis was used to determine the factors influencing pregnancy outcome in PGD/PGS transplant patients. ROC curves were plotted to analyze the predictive value of 3D ultrasound parameters on pregnancy outcome. The results of the study were validated with patients who underwent FET transplantation, and the patients in the validation group were treated with the same 3D ultrasound examination method and treatment plan as the observation group. RESULTS: The differences in basic situations between two groups were not statistically significant (P > 0.05). The percentage of endometrial thickness, endometrial blood flow, and endometrial blood flow classification type II + II were higher in group A than in group B (P < 0.05). Multifactorial logistic regression analysis showed that endometrial thickness, endometrial blood flow and endometrial blood flow classification were influencing factors of pregnancy outcome in PGD/PGS patients. The sensitivity of predicting pregnancy outcome based on the results of transcatheter 3D ultrasound was 91.18%, the specificity was 82.35%, and the accuracy was 90.00%, which has a high predictive value. CONCLUSION: 3D ultrasound can predict pregnancy outcome by assessing the endometrial receptivity of PGD/PGS transplantation, in which endometrial thickness and endometrial blood flow have a good predictive value.

Perioperative outcomes of robotic versus laparoscopic distal gastrectomy for gastric cancer: a meta-analysis of propensity score-matched studies and randomized controlled trials.

BACKGROUND: Da Vinci robotic surgery system, a novel type of surgery, was widespread in surgical field. However, the perioperative outcomes of robotic distal gastrectomy (RDG) are still controversy, despite several observational studies and randomized controlled trials (RCT) had been reported. Therefore, we performed a meta-analysis of propensity score-matched (PSM) and RCT studies to evaluated the perioperative feasibility and safety of RDG. METHODS: Studies were systematically searched in PubMed, Web of Science, Cochrane Library, and Embase database, and screened according to the defined limitations. The quality of PSM studies and RCT studies were respectively assessed by ROBINS-I and Cochrane risk-of-bias tool. Extracted data were analyzed by Review Manager 5.4. RESULTS: 7 PSM studies and 1 RCT with a total of 2763 patients were included in this analysis. The longer operative time (MD = 31.42, 95% CI [22.88, 39.96], p < 0.00001), less blood loss (MD = - 25.89, 95% CI [- 36.18, - 15.6], p < 0.00001), more retrieved lymph nodes (MD = 3.46, 95% CI [2.94, 3.98], p < 0.00001), shorter time to first flatus (MD = - 0.08, 95% CI [- 0.13, - 0.02], p = 0.006) and liquid intake (MD = - 0.13, 95% CI [- 0.22, - 0.05], p = 0.002) were observed in RDG group compared with LDG group. There are no statistically significant in time to start soft diet, postoperative hospital stays, overall complications, complications Grade I-II, complications Grade ≥ III, anastomotic leakage, bleeding, intra-abdominal bleeding, intraluminal bleeding, ileus, abdominal infection, delayed gastric emptying and wound complications. CONCLUSIONS: RDG showed less blood loss and more retrieved lymph nodes, revealed less time to first flatus and liquid intake after operation. But the operative time was longer in RDG group than in LDG. The incidence rate of postoperative complications was comparable between RDG and LDG.

The Preventive Effect of Dexmedetomidine Against Delirium in Patients with Aortic Dissection: A Retrospective Cohort Study.

BACKGROUND: Dexmedetomidine (DEX) is often used to reduce the incidence of delirium in intensive care unit (ICU) patients. However, it was found in our clinical practice that the incidence of delirium in some patients with aortic dissection (AD) remained high even after using DEX. The aim of the present study was to clarify whether the protective effects of DEX against delirium were different between Stanford type A and B AD patients during ICU stay. METHODS: Data of patients with Stanford type A or B AD who were treated in the ICU of our hospital between 2015 and 2018 retrospectively were reviewed. They were divided into four groups: A1 group (Stanford type A AD patients using DEX), A2 group (Stanford type A AD patients without using DEX), B1 group (Stanford type B AD patients using DEX), and B2 group (Stanford type B AD patients without using DEX). Patients in A1 and B1 groups received intravenous administration of DEX within 1 h admission to the ICU and after surgery or stent implantation at a loading dose of 1 µg/kg, followed by continuous infusion of 0.2-0.7 µg/(kg·h) for >24 h. The mortality rate, delirium incidence, length of ICU stay, and drug administration were compared between the four groups. RESULTS: After intravenous administration of DEX, the delirium incidence in B1 group was reduced significantly compared with that in B2 group (2.8% vs. 17.8%, P = 0.04), while there was no significant difference between A1 and A2 group (20.8% vs. 24.3%, P = 0.7). However, DEX administration significantly reduced the use of anti-hypertensive drugs (P = 0.04) and morphine (P = 0.02) in Stanford type A AD patients. CONCLUSION: The use of DEX reduced the incidence of delirium in Stanford type B AD patients during ICU stay, therefore reducing the risk of medical accidents and risk of rupture of the aortic dissecting aneurysm. The preventive effect of DEX against delirium in Stanford type A AD patients was not obvious, and whether increasing the dosage of DEX could enhance the therapeutic efficacy in this group of patients needs to be further observed in future studies.

The relationship and optimal threshold of endometrial thickness with early clinical pregnancy in frozen embryo transfer cycles.

OBJECTIVE: To investigate the associations of endometrial thickness with pregnancy outcome in frozen embryo transfer (FET) cycles. METHODS: A retrospective cohort study was performed looking at 1627 FET cycles from the Reproductive Medicine Center of the study hospital between January 2017 and July 2018. Endometrial ultrasonographic characteristics were recorded on the embryo transfer day in FET cycles. RESULTS: A total of 1627 FET cycles were included. The endometrial thickness was independently associated with clinical pregnancy outcomes after adjusting for potential confounders (odds ratio 1.06; 95% confidence interval [CI] 1.01-1.12). A non-linear relationship was detected between endometrial thickness and pregnancy outcomes, whose point was 10.9 mm. The effect size of the left and right sides of the inflection point were 1.16 (95% CI 1.07-1.25) and 0.89 (95% CI 0.78-1.01), respectively. Subgroup analysis showed that the correlation between endometrial thickness and pregnancy outcome was consistent in all subgroups. CONCLUSION: The relationship between endometrial thickness and pregnancy outcome was non-linear and there is an inflection point. When endometrial thickness was less than 9.5 mm, it was positively related to clinical pregnancy rate. If it was beyond the inflection point, the pregnancy rate does not increase significantly.

Lentiviral CRISPR-guided RNA library screening identified Adam17 as an upstream negative regulator of Procr in mammary epithelium.

BACKGROUND: Protein C receptor (Procr) has recently been shown to mark resident adult stem cells in the mammary gland, vascular system, and pancreatic islets. More so, high Procr expression was also detected and used as indicator for subsets of triple-negative breast cancers (TNBCs). Previous study has revealed Procr as a target of Wnt/ß-catenin signaling; however, direct upstream regulatory mechanism of Procr remains unknown. To comprehend the molecular role of Procr during physiology and pathology, elucidating the upstream effectors of Procr is necessary. Here, we provide a system for screening negative regulators of Procr, which could be adapted for broad molecular analysis on membrane proteins. RESULTS: We established a screening system which combines CRISPR-Cas9 guided gene disruption with fluorescence activated cell sorting technique (FACS). CommaDß (murine epithelial cells line) was used for the initial Procr upstream effector screening using lentiviral CRISPR-gRNA library. Shortlisted genes were further validated through individual lentiviral gRNA infection followed by Procr expression evaluation. Adam17 was identified as a specific negative inhibitor of Procr expression. In addition, MDA-MB-231 cells and Hs578T cells (human breast cancer cell lines) were used to verify the conserved regulation of ADAM17 over PROCR expression. CONCLUSION: We established an efficient CRISPR-Cas9/FACS screening system, which identifies the regulators of membrane proteins. Through this system, we identified Adam17 as the negative regulator of Procr membrane expression both in mammary epithelial cells and breast cancer cells.

Risk factors for postoperative sepsis-induced cardiomyopathy in patients undergoing general thoracic surgery: a single center experience.

BACKGROUND: The current study aimed to investigate the incidence of sepsis-induced cardiomyopathy (SICM) in patients who received general thoracic surgery, along with the risk factors and management strategies for this complication. METHODS: The clinical records of 163 patients with postoperative sepsis were retrospectively reviewed. After propensity score matching, 144 patients were divided into 2 groups by stroke volume: the SICM group (n=72) and the non-SICM group (n=72). RESULTS: The overall incidence of postoperative SICM was 53.99%. Multiple logistic regression analysis showed that stroke volume and C-reactive protein were independent predictors of mortality in patients with postoperative sepsis. Statistical analysis by t-test and χ2 test indicated that mortality (P=0.000), B-type natriuretic peptide (P=0.001), left ventricular ejection fraction (P=0.000), the mitral peak velocity of early filling/early diastolic mitral annular velocity (E/e') (P=0.049), C-reactive protein (P=0.016), procalcitonin (P=0.013), serum creatinine (P=0.016), platelets (P=0.028), and lactic acid (P=0.002) were significantly associated with the occurrence of postoperative SICM. Among these parameters, B-type natriuretic peptide was identified as the best biomarker for predicting SICM by receiver operating characteristic (ROC) curve analysis. CONCLUSIONS: It is vital to improve the diagnosis and standard management of SICM. A combined strategy comprising early detection of suspected infection, adequate use of antibiotics, close monitoring, effective drainage, and supportive care may improve the outcomes of patients with postoperative SICM.

Toxoplasma gondii and Neospora caninum in farm-reared ostriches (Struthio camelus) in China.

BACKGROUND: The parasites Toxoplasma gondii (T. gondii) and Neospora caninum (N. caninum) are globally distributed; they infect warm-blooded animals, including many avian species. The aim of this study was to evaluate the presence of these parasites in ostriches from central China. In total, 402 ostrich (Struthio camelus) samples (293 hearts, 77 brains, and 32 serum) from slaughterhouses of the Henan Province and Hebei Province were collected. The heart juice (n = 283) and serum samples (n = 32) were tested for antibodies to T. gondii using the modified agglutination test (MAT). Hematoxylin and eosin (H&E) staining, immunohistochemical (IHC) staining, and the polymerase chain reaction were used to examine the cysts and DNA of T. gondii and N. caninum parasites, respectively. RESULTS: Antibodies to T. gondii were detected in 6.4% (20/315) (cut-off, 25). No cysts or DNA of T. gondii or N. caninum were observed in any of the 293 hearts and 77 brains. CONCLUSION: The results showed a low prevalence of T. gondii antibody in ostriches, compared to that in the other animals. N. caninum occurs at low to negligible frequencies in ostriches from China. This is the first report on screening ostriches in China for T. gondii antibodies.

CRISPR-Cas9-Mediated Gene Editing in Mouse Spermatogonial Stem Cells.

Precise genome editing is a powerful tool for analysis of gene function. However, in spermatogonial stem cells (SSCs), this still remains a big challenge mainly due to low efficiency and complexity of currently available gene editing techniques. The CRISPR-Cas9 system from bacteria has been applied to modifying genome in different species at a very high efficiency and specificity. Here we describe CRISPR-Cas9-mediated gene editing via nonhomologous end joining (NHEJ) or homology-directed repair (HDR) in SSCs. This protocol provides guidelines for derivation of SSCs, nucleofection of SSCs with the CRISPR-Cas9 system, transplantation of the gene-modified SSCs into the recipient testes, and production of mice using transplanted SSC-derived round spermatids.

Trivial role for NSMCE2 during in vitro proliferation and differentiation of male germline stem cells.

Spermatogenesis, starting with spermatogonial differentiation, is characterized by ongoing and dramatic alterations in composition and function of chromatin. Failure to maintain proper chromatin dynamics during spermatogenesis may lead to mutations, chromosomal aberrations or aneuploidies. When transmitted to the offspring, these can cause infertility or congenital malformations. The structural maintenance of chromosomes (SMC) 5/6 protein complex has recently been described to function in chromatin modeling and genomic integrity maintenance during spermatogonial differentiation and meiosis. Among the subunits of the SMC5/6 complex, non-SMC element 2 (NSMCE2) is an important small ubiquitin-related modifier (SUMO) ligase. NSMCE2 has been reported to be essential for mouse development, prevention of cancer and aging in adult mice and topological stress relief in human somatic cells. By using in vitro cultured primary mouse spermatogonial stem cells (SSCs), referred to as male germline stem (GS) cells, we investigated the function of NSMCE2 during spermatogonial proliferation and differentiation. We first optimized a protocol to generate genetically modified GS cell lines using CRISPR-Cas9 and generated an Nsmce2-/- GS cell line. Using this Nsmce2-/- GS cell line, we found that NSMCE2 was dispensable for proliferation, differentiation and topological stress relief in mouse GS cells. Moreover, RNA sequencing analysis demonstrated that the transcriptome was only minimally affected by the absence of NSMCE2. Only differential expression of Sgsm1 appeared highly significant, but with SGSM1 protein levels being unaffected without NSMCE2. Hence, despite the essential roles of NSMCE2 in somatic cells, chromatin integrity maintenance seems differentially regulated in the germline.

Effective tracking of bone mesenchymal stem cells in vivo by magnetic resonance imaging using melanin-based gadolinium3+ nanoparticles.

Tracking transplanted stem cells is necessary to clarify cellular properties and improve transplantation success. In this study, we designed and synthesized melanin-based gadolinium3+ (Gd3+ )-chelate nanoparticles (MNP-Gd3+ ) of ∼7 nm for stem cell tracking in vivo. MNP-Gd3+ possesses many beneficial properties, such as its high stability and sensitivity, shorter T1 relaxation time, higher cell labeling efficiency, and lower cytotoxicity compared with commercial imaging agents. We found that the T1 relaxivity (r1 ) of MNP-Gd3+ was significantly higher than that of Gd-DTPA; the nanoparticles were taken up by bone mesenchymal stem cells (BMSCs) via endocytosis and were broadly distributed in the cytoplasm. Based on an in vitro MTT assay, no cytotoxicity of labeled stem cells was observed for MNP-Gd3+ concentrations of less than 800 µg/mL. Furthermore, we tracked MNP-Gd3+ -labeled BMSCs in vivo using 3.0T MRI equipment. After intramuscular injection, MNP-Gd3+ -labeled BMSCs were detected, even after four weeks, by 3T MRI. We concluded that MNP-Gd3+ nanoparticles at appropriate concentrations can be used to effectively monitor and track BMSCs in vivo. MNP-Gd3+ nanoparticles have potential as a new positive MRI contrast agent in clinical applications. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 131-137, 2017.

Comparison of short outcomes between laparoscopic and experienced robotic gastrectomy: A meta-analysis and systematic review.

OBJECTIVE: The purpose of this meta-analysis is to compare the short-term outcomes between experienced robotic gastrectomy (RG) and laparoscopic gastrectomy (LG). MATERIALS AND METHODS: We searched the PubMed, Springer Link, Elsevier, and Embase databases for articles published in English before June 2015 using an electronic literature search and including cross-referenced articles. Three studies were eligible for the meta-analysis. The outcomes evaluated were operation time, estimated blood loss, harvested lymph nodes, complication, and postoperative hospital stay. RESULTS: Of a total of 562 patients, 165 underwent RG and 397 underwent LG. Operation time was significantly longer in the RG group [weighted mean difference (WMD): 21.49, 95% confidence interval (CI): 12.48-30.50, P< 0.00001). Estimated blood loss, harvested lymph nodes, complication, and postoperative hospital stay were similar between the two groups. CONCLUSION: Experienced RG has similar short-term outcomes to LG that is performed by sophisticated laparoscopic surgeons, except for operation time.

An Intracranial Electroencephalography (iEEG) Brain Function Mapping Tool with an Application to Epilepsy Surgery Evaluation.

OBJECTS: Before epilepsy surgeries, intracranial electroencephalography (iEEG) is often employed in function mapping and epileptogenic foci localization. Although the implanted electrodes provide crucial information for epileptogenic zone resection, a convenient clinical tool for electrode position registration and Brain Function Mapping (BFM) visualization is still lacking. In this study, we developed a BFM Tool, which facilitates electrode position registration and BFM visualization, with an application to epilepsy surgeries. METHODS: The BFM Tool mainly utilizes electrode location registration and function mapping based on pre-defined brain models from other software. In addition, the electrode node and mapping properties, such as the node size/color, edge color/thickness, mapping method, can be adjusted easily using the setting panel. Moreover, users may manually import/export location and connectivity data to generate figures for further application. The role of this software is demonstrated by a clinical study of language area localization. RESULTS: The BFM Tool helps clinical doctors and researchers visualize implanted electrodes and brain functions in an easy, quick and flexible manner. CONCLUSIONS: Our tool provides convenient electrode registration, easy brain function visualization, and has good performance. It is clinical-oriented and is easy to deploy and use. The BFM tool is suitable for epilepsy and other clinical iEEG applications.

Endogenous transmembrane protein UT2 inhibits pSTAT3 and suppresses hematological malignancy.

Regulation of STAT3 activation is critical for normal and malignant hematopoietic cell proliferation. Here, we have reported that the endogenous transmembrane protein upstream-of-mTORC2 (UT2) negatively regulates activation of STAT3. Specifically, we determined that UT2 interacts directly with GP130 and inhibits phosphorylation of STAT3 on tyrosine 705 (STAT3Y705). This reduces cytokine signaling including IL6 that is implicated in multiple myeloma and other hematopoietic malignancies. Modulation of UT2 resulted in inverse effects on animal survival in myeloma models. Samples from multiple myeloma patients also revealed a decreased copy number of UT2 and decreased expression of UT2 in genomic and transcriptomic analyses, respectively. Together, these studies identify a transmembrane protein that functions to negatively regulate cytokine signaling through GP130 and pSTAT3Y705 and is molecularly and mechanistically distinct from the suppressors of cytokine signaling (SOCS) family of genes. Moreover, this work provides evidence that perturbations of this activation-dampening molecule participate in hematologic malignancies and may serve as a key determinant of multiple myeloma pathophysiology. UT2 is a negative regulator shared across STAT3 and mTORC2 signaling cascades, functioning as a tumor suppressor in hematologic malignancies driven by those pathways.

Harnessing the apoptotic programs in cancer stem-like cells.

Elimination of malignant cells is an unmet challenge for most human cancer types even with therapies targeting specific driver mutations. Therefore, a multi-pronged strategy to alter cancer cell biology on multiple levels is increasingly recognized as essential for cancer cure. One such aspect of cancer cell biology is the relative apoptosis resistance of tumor-initiating cells. Here, we provide an overview of the mechanisms affecting the apoptotic process in tumor cells emphasizing the differences in the tumor-initiating or stem-like cells of cancer. Further, we summarize efforts to exploit these differences to design therapies targeting that important cancer cell population.

Specific bone cells produce DLL4 to generate thymus-seeding progenitors from bone marrow.

Production of the cells that ultimately populate the thymus to generate α/ß T cells has been controversial, and their molecular drivers remain undefined. Here, we report that specific deletion of bone-producing osteocalcin (Ocn)-expressing cells in vivo markedly reduces T-competent progenitors and thymus-homing receptor expression among bone marrow hematopoietic cells. Decreased intrathymic T cell precursors and decreased generation of mature T cells occurred despite normal thymic function. The Notch ligand DLL4 is abundantly expressed on bone marrow Ocn(+) cells, and selective depletion of DLL4 from these cells recapitulated the thymopoietic abnormality. These data indicate that specific mesenchymal cells in bone marrow provide key molecular drivers enforcing thymus-seeding progenitor generation and thereby directly link skeletal biology to the production of T cell-based adaptive immunity.

Targeting the Warburg effect for leukemia therapy: Magnitude matters.

Non-oxidative glucose metabolism represents a hallmark of cancer. It is now apparent that different cell states among normal stem or progenitor cells have distinct aerobic glycolysis (AG) dependencies. However, malignant cells are markedly more vulnerable to modifications of AG regardless of the differentiation state of their cell of origin.