Context-dependent modification of PFKFB3 in hematopoietic stem cells promotes anaerobic glycolysis and ensures stress hematopoiesis.

Metabolic pathways are plastic and rapidly change in response to stress or perturbation. Current metabolic profiling techniques require lysis of many cells, complicating the tracking of metabolic changes over time after stress in rare cells such as hematopoietic stem cells (HSCs). Here, we aimed to identify the key metabolic enzymes that define differences in glycolytic metabolism between steady-state and stress conditions in murine HSCs and elucidate their regulatory mechanisms. Through quantitative 13C metabolic flux analysis of glucose metabolism using high-sensitivity glucose tracing and mathematical modeling, we found that HSCs activate the glycolytic rate-limiting enzyme phosphofructokinase (PFK) during proliferation and oxidative phosphorylation (OXPHOS) inhibition. Real-time measurement of ATP levels in single HSCs demonstrated that proliferative stress or OXPHOS inhibition led to accelerated glycolysis via increased activity of PFKFB3, the enzyme regulating an allosteric PFK activator, within seconds to meet ATP requirements. Furthermore, varying stresses differentially activated PFKFB3 via PRMT1-dependent methylation during proliferative stress and via AMPK-dependent phosphorylation during OXPHOS inhibition. Overexpression of Pfkfb3 induced HSC proliferation and promoted differentiated cell production, whereas inhibition or loss of Pfkfb3 suppressed them. This study reveals the flexible and multilayered regulation of HSC glycolytic metabolism to sustain hematopoiesis under stress and provides techniques to better understand the physiological metabolism of rare hematopoietic cells.

PRMT1 Sustains De Novo Fatty Acid Synthesis by Methylating PHGDH to Drive Chemoresistance in Triple-Negative Breast Cancer.

Triple-negative breast cancer (TNBC) chemoresistance hampers the ability to effectively treat patients. Identification of mechanisms driving chemoresistance can lead to strategies to improve treatment. Here, we revealed that protein arginine methyltransferase-1 (PRMT1) simultaneously methylates D-3-phosphoglycerate dehydrogenase (PHGDH), a critical enzyme in serine synthesis, and the glycolytic enzymes PFKFB3 and PKM2 in TNBC cells. 13C metabolic flux analyses showed that PRMT1-dependent methylation of these three enzymes diverts glucose toward intermediates in the serine-synthesizing and serine/glycine cleavage pathways, thereby accelerating the production of methyl donors in TNBC cells. Mechanistically, PRMT1-dependent methylation of PHGDH at R54 or R20 activated its enzymatic activity by stabilizing 3-phosphoglycerate binding and suppressing polyubiquitination. PRMT1-mediated PHGDH methylation drove chemoresistance independently of glutathione synthesis. Rather, activation of the serine synthesis pathway supplied α-ketoglutarate and citrate to increase palmitate levels through activation of fatty acid synthase (FASN). Increased palmitate induced protein S-palmitoylation of PHGDH and FASN to further enhance fatty acid synthesis in a PRMT1-dependent manner. Loss of PRMT1 or pharmacologic inhibition of FASN or protein S-palmitoyltransferase reversed chemoresistance in TNBC. Furthermore, IHC coupled with imaging MS in clinical TNBC specimens substantiated that PRMT1-mediated methylation of PHGDH, PFKFB3, and PKM2 correlates with chemoresistance and that metabolites required for methylation and fatty acid synthesis are enriched in TNBC. Together, these results suggest that enhanced de novo fatty acid synthesis mediated by coordinated protein arginine methylation and protein S-palmitoylation is a therapeutic target for overcoming chemoresistance in TNBC. SIGNIFICANCE: PRMT1 promotes chemoresistance in TNBC by methylating metabolic enzymes PFKFB3, PKM2, and PHGDH to augment de novo fatty acid synthesis, indicating that targeting this axis is a potential treatment strategy.

PTBP2 binds to a testis-specific long noncoding RNA, Tesra, and activates transcription of the Prss42/Tessp-2 gene.

Long noncoding RNAs (lncRNAs) have recently been proved to be functional in the testis. Tesra, a testis-specific lncRNA, was suggested to activate the transcription of Prss42/Tessp-2, a gene that is involved in meiotic progression, in mouse spermatocytes. To reveal the molecular mechanism underlying the activation, we searched for Tesra-binding proteins by a Ribotrap assay followed by LC-MS/MS analysis and identified polypyrimidine tract binding protein 2 (PTBP2) as a candidate. Analysis of public RNA-seq data and our qRT-PCR results indicated that Ptbp2 mRNA showed an expression pattern similar to the expression patterns of Tesra and Prss42/Tessp-2 during testis development. Moreover, PTBP2 was found to be associated with Tesra in testicular germ cells by RNA immunoprecipitation. To evaluate the effect of PTBP2 on the Prss42/Tessp-2 promoter, we established an in vitro reporter gene assay system in which Tesra expression could be induced by the Tet-on system and thereby Prss42/Tessp-2 promoter activity could be increased. In this system, the Prss42/Tessp-2 promoter activity was significantly decreased by the knockdown of PTBP2. These results suggest that PTBP2 contributes to Prss42/Tessp-2 transcriptional activation by Tesra in spermatocytes. The finding provides a precious example of a molecular mechanism of testis lncRNA functioning in spermatogenesis.

Mature mRNA processing that deletes 3' end sequences directs translational activation and embryonic development.

Eggs accumulate thousands of translationally repressed mRNAs that are translated into proteins after fertilization to direct diverse developmental processes. However, molecular mechanisms underlying the translation of stored mRNAs after fertilization remain unclear. Here, we report a previously unknown RNA processing of 3' end sequences of mature mRNAs that activates the translation of stored mRNAs. Specifically, 9 to 72 nucleotides at the 3' ends of zebrafish pou5f3 and mouse Pou5f1 mRNAs were deleted in the early stages of development. Reporter assays illustrated the effective translation of the truncated forms of mRNAs. Moreover, promotion and inhibition of the shortening of 3' ends accelerated and attenuated Pou5f3 accumulation, respectively, resulting in defective development. Identification of proteins binding to unprocessed and/or processed mRNAs revealed that mRNA shortening acts as molecular switches. Comprehensive analysis revealed that >250 mRNAs underwent this processing. Therefore, our results provide a molecular principle that triggers the translational activation and directs development.

Generation of bicistronic Dmp1-Cre knock-in mice using a self-cleaving 2A peptide.

INTRODUCTION: The conditional manipulation of genes using the Cre recombinase-locus of crossover in P1 (Cre/loxP) system is an important tool for revealing gene functions and cell lineages in vivo. The outcome of this method is dependent on the performance of Cre-driver mouse strains. In most cases, Cre knock-in mice show better specificity than randomly inserted Cre transgenic mice. However, following knock-in, the expression of the original gene replaced by Cre is lost. MATERIALS AND METHODS: We generated a new differentiated osteoblast- and osteocyte-specific Cre knock-in mouse line that carries the viral T2A sequence encoding a 2A self-cleaving peptide at the end of the coding region of the dentin matrix protein 1 (Dmp1) gene accompanied by the Cre gene. RESULTS: We confirmed that Dmp1-T2A-Cre mice showed high Cre expression in osteoblasts, osteocytes, odontoblasts, and periodontal ligament cells and that the 2A self-cleaving peptide efficiently produced both Dmp1 and Cre proteins. Furthermore, unlike the Dmp1 knockout mice, homozygous Dmp1-T2A-Cre mice showed no skeletal abnormalities. Analysis using the Cre reporter strain confirmed differentiated osteoblast- and osteocyte-specific Cre-mediated recombination in the skeleton. Furthermore, recombination was also detected in some nuclei of skeletal muscle cells, spermatocytes, and intestinal cells. CONCLUSION: 2A-Cre functions effectively in vivo, and Dmp1-T2A-Cre knock-in mice are a useful tool for studying the functioning of various genes in hard tissues.

Factors affecting the induction of uncoupling protein 1 in C2C12 myogenic cells.

Brown/beige adipocytes, which are derived from skeletal muscle/smooth muscle-lineage cells, consume excess energy as heat through the expression of mitochondrial uncoupling protein 1 (UCP1). Previous studies have shown that forced expression of PR/SET domain (PRDM)-16 or early B-cell factor (EBF)-2 induced UCP1-positive adipocytes in C2C12 myogenic cells. Here, we explored the culture conditions to induce Ucp1 expression in C2C12 cells without introducing exogenous genes. Treatment with rosiglitazone (a peroxisome proliferator-activated receptor (PPAR)-γ agonist), GW501516 (a PPARδ agonist), and bone morphogenetic protein (BMP)-7 for 8 days efficiently increased Ucp1 expression in response to treatment with forskolin, an activator of the protein kinase A pathway. BMP7 dose-dependently increased forskolin-induced Ucp1 expression in the presence of rosiglitazone and GW501516; however, GW501516 was not required for Ucp1 induction. Additionally, the structurally related proteins, BMP6 and BMP9, efficiently increased forskolin-induced Ucp1 expression in rosiglitazone-treated cells. UCP1 protein was localized in cells with lipid droplets, but adipocytes were not always positive for UCP1. Continuous treatment with BMP7 was needed for the efficient induction of Ucp1 by forskolin treatment. Significant expression of Prdm16 was not detected, irrespective of the treatment, and treatment with rosiglitazone, GW501516, and BMP7 did not affect the expression levels of Ebf2. Fibroblast growth factor receptor (Fgfr)-3 expression levels were increased by BMP9 in rosiglitazone-treated cells, and molecules that upregulate Fgfr3 transcription partly overlapped with those that stimulate Ucp1 transcription. The present results provide basic information on the practical differentiation of myogenic cells to brown adipocytes.

On-tissue polysulfide visualization by surface-enhanced Raman spectroscopy benefits patients with ovarian cancer to predict post-operative chemosensitivity.

Chemosensitivity to cisplatin derivatives varies among individual patients with intractable malignancies including ovarian cancer, while how to unlock the resistance remain unknown. Ovarian cancer tissues were collected the debulking surgery in discovery- (n = 135) and validation- (n = 47) cohorts, to be analyzed with high-throughput automated immunohistochemistry which identified cystathionine γ-lyase (CSE) as an independent marker distinguishing non-responders from responders to post-operative platinum-based chemotherapy. We aimed to identify CSE-derived metabolites responsible for chemoresistant mechanisms: gold-nanoparticle (AuN)-based surface-enhanced Raman spectroscopy (SERS) was used to enhance electromagnetic fields which enabled to visualize multiple sulfur-containing metabolites through detecting scattering light from Au-S vibration two-dimensionally. Clear cell carcinoma (CCC) who turned out less sensitive to cisplatin than serous adenocarcinoma was classified into two groups by the intensities of SERS intensities at 480 cm-1; patients with greater intensities displayed the shorter overall survival after the debulking surgery. The SERS signals were eliminated by topically applied monobromobimane that breaks sulfane-sulfur bonds of polysulfides to result in formation of sulfodibimane which was detected at 580 cm-1, manifesting the presence of polysulfides in cancer tissues. CCC-derived cancer cell lines in culture were resistant against cisplatin, but treatment with ambroxol, an expectorant degrading polysulfides, renders the cells CDDP-susceptible. Co-administration of ambroxol with cisplatin significantly suppressed growth of cancer xenografts in nude mice. Furthermore, polysulfides, but neither glutathione nor hypotaurine, attenuated cisplatin-induced disturbance of DNA supercoiling. Polysulfide detection by on-tissue SERS thus enables to predict prognosis of cisplatin-based chemotherapy. The current findings suggest polysulfide degradation as a stratagem unlocking cisplatin chemoresistance.

Narrow band imaging for thoracic endometriosis.

BACKGROUND: The thoracic cavity is the most frequent site of extrapelvic endometriosis. It exhibits a wide variety of clinical manifestations, such as chest pain, cough, and respiratory distress, and is frequently associated with pelvic endometriosis. Although histological confirmation is the gold standard for a definitive diagnosis, endoscopic identification of the affected area is often difficult. Narrow band imaging (NBI) is an imaging technique that emphasizes vascular structures and is reported to be useful in the diagnosis of pelvic endometriosis. CASE PRESENTATIONS: A 31-year-old woman and 39-year-old woman developed a recurrent right pneumothorax during their menstruation cycles. They both had no medical history suggesting pelvic endometriosis. We planned an elective video-assisted thoracoscopic surgery for the suspicion of thoracic endometriosis. In addition to white light alone, an NBI observation enhanced the microvasculature of the suspected lesions and allowed us to identify the affected area more clearly. Partial resections of the diaphragm were performed. Histopathological and immunohistochemical studies of each specimen confirmed the diagnosis of extrapelvic endometriosis. CONCLUSIONS: NBI may improve the diagnostic accuracy for thoracic endometriosis, especially in clinically suspected patients but without a history of pelvic endometriosis.

Progesterone receptor membrane associated component 1 enhances obesity progression in mice by facilitating lipid accumulation in adipocytes.

Progesterone receptor membrane associated component 1 (PGRMC1) exhibits haem-dependent dimerization on cell membrane and binds to EGF receptor and cytochromes P450 to regulate cancer proliferation and chemoresistance. However, its physiological functions remain unknown. Herein, we demonstrate that PGRMC1 is required for adipogenesis, and its expression is significantly enhanced by insulin or thiazolidine, an agonist for PPARγ. The haem-dimerized PGRMC1 interacts with low-density lipoprotein receptors (VLDL-R and LDL-R) or GLUT4 to regulate their translocation to the plasma membrane, facilitating lipid uptake and accumulation, and de-novo fatty acid synthesis in adipocytes. These events are cancelled by CO through interfering with PGRMC1 dimerization. PGRMC1 expression in mouse adipose tissues is enhanced during obesity induced by a high fat diet. Furthermore, adipose tissue-specific PGRMC1 knockout in mice dramatically suppressed high-fat-diet induced adipocyte hypertrophy. Our results indicate a pivotal role of PGRMC1 in developing obesity through its metabolic regulation of lipids and carbohydrates in adipocytes.

Biochemical, Metabolomic, and Genetic Analyses of Dephospho Coenzyme A Kinase Involved in Coenzyme A Biosynthesis in the Human Enteric Parasite Entamoeba histolytica.

Coenzyme A (CoA) is an essential cofactor for numerous cellular reactions in all living organisms. In the protozoan parasite Entamoeba histolytica, CoA is synthesized in a pathway consisting of four enzymes with dephospho-CoA kinase (DPCK) catalyzing the last step. However, the metabolic and physiological roles of E. histolytica DPCK remain elusive. In this study, we took biochemical, reverse genetic, and metabolomic approaches to elucidate role of DPCK in E. histolytica. The E. histolytica genome encodes two DPCK isotypes (EhDPCK1 and EhDPCK2). Epigenetic gene silencing of Ehdpck1 and Ehdpck2 caused significant reduction of DPCK activity, intracellular CoA concentrations, and also led to growth retardation in vitro, suggesting importance of DPCK for CoA synthesis and proliferation. Furthermore, metabolomic analysis showed that suppression of Ehdpck gene expression also caused decrease in the level of acetyl-CoA, and metabolites involved in amino acid, glycogen, hexosamine, nucleic acid metabolisms, chitin, and polyamine biosynthesis. The kinetic properties of E. histolytica and human DPCK showed remarkable differences, e.g., the Km values of E. histolytica and human DPCK were 58-114 and 5.2 µM toward dephospho-CoA and 15-20 and 192 µM for ATP, respectively. Phylogenetic analysis also supported the uniqueness of the amebic enzyme compared to the human counterpart. These biochemical, evolutionary features, and physiological importance of EhDPCKs indicate that EhDPCK represents the rational target for the development of anti-amebic agents.

Gold-nanofève surface-enhanced Raman spectroscopy visualizes hypotaurine as a robust anti-oxidant consumed in cancer survival.

Gold deposition with diagonal angle towards boehmite-based nanostructure creates random arrays of horse-bean-shaped nanostructures named gold-nanofève (GNF). GNF generates many electromagnetic hotspots as surface-enhanced Raman spectroscopy (SERS) excitation sources, and enables large-area visualization of molecular vibration fingerprints of metabolites in human cancer xenografts in livers of immunodeficient mice with sufficient sensitivity and uniformity. Differential screening of GNF-SERS signals in tumours and those in parenchyma demarcated tumour boundaries in liver tissues. Furthermore, GNF-SERS combined with quantum chemical calculation identified cysteine-derived glutathione and hypotaurine (HT) as tumour-dominant and parenchyma-dominant metabolites, respectively. CD44 knockdown in cancer diminished glutathione, but not HT in tumours. Mechanisms whereby tumours sustained HT under CD44-knockdown conditions include upregulation of PHGDH, PSAT1 and PSPH that drove glycolysis-dependent activation of serine/glycine-cleavage systems to provide one-methyl group for HT synthesis. HT was rapidly converted into taurine in cancer cells, suggesting that HT is a robust anti-oxidant for their survival under glutathione-suppressed conditions.

Characterization and validation of Entamoeba histolytica pantothenate kinase as a novel anti-amebic drug target.

The Coenzyme A (CoA), as a cofactor involved in >100 metabolic reactions, is essential to the basic biochemistry of life. Here, we investigated the CoA biosynthetic pathway of Entamoeba histolytica (E. histolytica), an enteric protozoan parasite responsible for human amebiasis. We identified four key enzymes involved in the CoA pathway: pantothenate kinase (PanK, EC 2.7.1.33), bifunctional phosphopantothenate-cysteine ligase/decarboxylase (PPCS-PPCDC), phosphopantetheine adenylyltransferase (PPAT) and dephospho-CoA kinase (DPCK). Cytosolic enzyme PanK, was selected for further biochemical, genetic, and phylogenetic characterization. Since E. histolytica PanK (EhPanK) is physiologically important and sufficiently divergent from its human orthologs, this enzyme represents an attractive target for the development of novel anti-amebic chemotherapies. Epigenetic gene silencing of PanK resulted in a significant reduction of PanK activity, intracellular CoA concentrations, and growth retardation in vitro, reinforcing the importance of this gene in E. histolytica. Furthermore, we screened the Kitasato Natural Products Library for inhibitors of recombinant EhPanK, and identified 14 such compounds. One compound demonstrated moderate inhibition of PanK activity and cell growth at a low concentration, as well as differential toxicity towards E. histolytica and human cells.

Synergistic effects of 15-deoxy Δ12,14-prostaglandin J2 on the anti-tumor activity of doxorubicin in renal cell carcinoma.

An endogenous anticancer agent, 15-deoxy -Δ12,14-prostaglandin J2 (15d-PGJ2) induces apoptosis in the chemoresistant renal cell carcinoma (RCC). Peroxisome proliferator-activated receptor-γ (PPARγ) is a nuclear receptor for 15d-PGJ2, and mediates the cytotoxicity of 15d-PGJ2 in many cancerous cells. However, 15d-PGJ2 induces apoptosis independently of PPARγ in human RCC cell line such as Caki-2. In the present study, we found that 15d-PGJ2 ameliorated the chemoresistance to one of anthracycline antibiotics, doxorubicin, in Caki-2 cells. Doxorubicin alone exhibited weak cytotoxicity at the concentrations effective for other cancer cells such as Hela cells. In addition, it did not activate caspase 3. However, the cytotoxicity of doxorubicin was increased remarkably and accompanied with the caspase- 3 activation in the presence of 15d-PGJ2. Doxorubicin alone damaged plasma membrane, and the combined application of 15d-PGJ2 with doxorubicin increased the membrane permeability slightly. PPARγ was involved in neither the anti-tumor activity nor the synergistic effect of 15d-PGJ2. 15d-PGJ2 induces apoptosis in Caki-2 cells via suppressing the phosphoinositide 3-kinase (PI3K)-Akt pathway. The effect of PI3K inhibitor on the cytotoxicity of doxorubicin was additive, but not synergistic. Although the PI3K inhibitor mimicked the cytotoxicity of 15d-PGJ2, it might not be involved in the synergism between 15d-PGJ2 and doxorubicin. In conclusion, 15d-PGJ2 enhanced the chemosensitivity of doxorubicin via the pathway independent of PPARγ and PI3K.

Rewiring of embryonic glucose metabolism via suppression of PFK-1 and aldolase during mouse chorioallantoic branching.

Adapting the energy metabolism state to changing bioenergetic demands is essential for mammalian development accompanying massive cell proliferation and cell differentiation. However, it remains unclear how developing embryos meet the changing bioenergetic demands during the chorioallantoic branching (CB) stage, when the maternal-fetal exchange of gases and nutrients is promoted. In this study, using metabolome analysis with mass-labeled glucose, we found that developing embryos redirected glucose carbon flow into the pentose phosphate pathway via suppression of the key glycolytic enzymes PFK-1 and aldolase during CB. Concomitantly, embryos exhibited an increase in lactate pool size and in the fractional contribution of glycolysis to lactate biosynthesis. Imaging mass spectrometry visualized lactate-rich tissues, such as the dorsal or posterior neural tube, somites and head mesenchyme. Furthermore, we found that the heterochronic gene Lin28a could act as a regulator of the metabolic changes observed during CB. Perturbation of glucose metabolism rewiring by suppressing Lin28a downregulation resulted in perinatal lethality. Thus, our work demonstrates that developing embryos rewire glucose metabolism following CB for normal development.

Cellular automaton simulation of the diffusive motion of bacteria and their adhesion to nanostructures on a solid surface.

The growth of a biofilm begins with the adhesion of bacteria to a solid surface. Consequently, biofilm growth can be managed by the control of bacterial adhesion. Recent experimental studies have suggested that bacterial adhesion can be controlled by modifying a solid surface using nanostructures. Computational prediction and analysis of bacterial adhesion behavior are expected to be useful for the design of effective arrangements of nanostructures for controlling bacterial adhesion. The present study developed a cellular automaton (CA) model for bacterial adhesion simulation that could describe both the diffusive motion of bacteria and dependence of their adhesion patterns on the distance between nanostructures observed in experimental studies. The diffusive motion was analyzed by the moment scaling spectrum theory, and the present model was confirmed to describe subdiffusion behavior due to obstacles. Adhesion patterns observed in experimental studies can be successfully simulated by introducing CA rules to describe a mechanism by which bacteria tend to move to increase the area of contact with nanostructures.

Cystathionine ß-synthase and PGRMC1 as CO sensors.

Heme oxygenase (HO) is a mono-oxygenase utilizing heme and molecular oxygen (O2) as substrates to generate biliverdin-IXα and carbon monoxide (CO). HO-1 is inducible under stress conditions, while HO-2 is constitutive. A balance between heme and CO was shown to regulate cell death and survival in many experimental models. However, direct molecular targets to which CO binds to regulate cellular functions remained to be fully examined. We have revealed novel roles of CO-responsive proteins, cystathionine ß-synthase (CBS) and progesterone receptor membrane component 1 (PGRMC1), in regulating cellular functions. CBS possesses a prosthetic heme that allows CO binding to inhibit the enzyme activity and to regulate H2S generation and/or protein arginine methylation. On the other hand, in response to heme accumulation in cells, PGRMC1 forms a stable dimer through stacking interactions of two protruding heme molecules. Heme-mediated PGRMC1 dimerization is necessary to interact with EGF receptor and cytochromes P450 that determine cell proliferation and xenobiotic metabolism. Furthermore, CO interferes with PGRMC1 dimerization by dissociating the heme stacking, and thus results in modulation of cell responses. This article reviews the intriguing functions of these two proteins in response to inducible and constitutive levels of CO with their pathophysiological implications.

CO-CBS-H2 S Axis: From Vascular Mediator to Cancer Regulator.

CO is a gaseous mediator generated by HO. Our previous studies revealed that CO generated from inducible HO-1 or from constitutive HO-2 modulates function of different heme proteins or enzymes through binding to their prosthetic ferrous heme to alter their structures, regulating biological function of cells and organs. Such CO-directed target macromolecules include sGC and CBS. In the liver, CO serves as a sinusoidal dilator through its action on sGC in hepatic stellate cells, while the same gas accounts for vasoconstrictor that inhibits H2S generated by CO-sensitive CBS in astrocytes. Since molecular O2 is a substrate for HO, the latter mechanism contributes to hypoxic vasodilation in neurovascular units. We have recently uncovered that stress-inducible CO in and around cancer cells suppresses CBS to result in decreased methylation of PFKFB3, the enzyme regulating PFK-1, leading to a shift of glucose biotransformation from glycolysis toward pentose phosphate pathway; such a metabolic remodeling causes chemoresistance through increasing NADPH and reduced glutathione under stress conditions for cancer cells. This article reviews the intriguing networks of CO-sensitive metabolic regulatory mechanisms in microcirculation and cancer.

Innate Response to Human Cancer Cells with or without IL-2 Receptor Common γ-Chain Function in NOD Background Mice Lacking Adaptive Immunity.

Immunodeficient hosts exhibit high acceptance of xenogeneic or neoplastic cells mainly due to lack of adaptive immunity, although it still remains to be elucidated how innate response affects the engraftment. IL-2R common γ-chain (IL-2Rγc) signaling is required for development of NK cells and a subset of dendritic cells producing IFN-γ. To better understand innate response in the absence of adaptive immunity, we examined amounts of metastatic foci in the livers after intrasplenic transfer of human colon cancer HCT116 cells into NOD/SCID versus NOD/SCID/IL-2Rγc (null) (NOG) hosts. The intravital microscopic imaging of livers in the hosts depleted of NK cells and/or macrophages revealed that IL-2Rγc function critically contributes to elimination of cancer cells without the need for NK cells and macrophages. In the absence of IL-2Rγc, macrophages play a role in the defense against tumors despite the NOD Sirpa allele, which allows human CD47 to bind to the encoded signal regulatory protein α to inhibit macrophage phagocytosis of human cells. Analogous experiments using human pancreas cancer MIA PaCa-2 cells provided findings roughly similar to those from the experiments using HCT116 cells except for lack of suppression of metastases by macrophages in NOG hosts. Administration of mouse IFN-γ to NOG hosts appeared to partially compensate lack of IL-2Rγc-dependent elimination of transferred HCT116 cells. These results provide insights into the nature of innate response in the absence of adaptive immunity, aiding in developing tumor xenograft models in experimental oncology.