Human ST3Gal II and ST6GalNAc IV genes increase human serum-mediated cytotoxicity to xenogeneic cells.

Carbohydrate-antigens widely existed on glycoproteins and glycosphingolipids of all mammalian cells play a crucial role in self-defense and immunity. Xeno-reactive antibodies included in natural human sera play a protecting role in an acute phase-rejection of xenotransplantation. In this study, we investigated the effect of an alteration of glycosylation-pattern, caused by human sialyltransferases such as hST3Gal II or hST6GalNAc IV, on human serum mediated cytotoxicity in pig kidney PK15 cells. From LDH cytotoxicity assay, cytotoxicity to human serum was significantly increased in hST3Gal II and hST6GalNAc IV-transfected PK15 cells, as compared to the control. In the hST6Gal I-carrying cells, the cytotoxicity to human serum was rather decreased. Moreover, flow cytometry analysis revealed that an alteration of pig glycosylation-pattern by hST3Gal II or hST6GalNAc IV influences on a binding of human IgM or IgG, respectively, in pig kidney cells, regardless of Gal antigen alteration. Finally, we found that hST6GalNAc IV contributed to increase of terminal disialylated tetrasaccharide structure, disialyl T antigen, as evidenced by increase of the MAL II lectin binding capacity in the hST6GalNAc IV-transfected PK15 cells, compared with control. Therefore, our results suggest that carbohydrate antigens, such as disialyl T antigen, newly synthesized by the ST3Gal II- and ST6GalNAc IV are potentially believed to be new xeno-reactive elements.

Association between obesity and cancer risk in HIV-infected Asians.

INTRODUCTION: This study aimed to investigate the association between obesity and cancer risk as well as site-specific cancer risks in adults with HIV using a nationwide health screening database in Korea. METHODS: Of the 16,671 adults with a new diagnosis of HIV from 2004 to 2020, 456 incident cancer cases and 1,814 individually matched controls by sex, year of birth, year of HIV diagnosis, and follow-up duration (1:4 ratio) were included in this nested case-control study. The association between obesity (body mass index ≥25 kg/m 2 ) and cancer risks was estimated and presented as odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Of the 456 cancer incident cases, there were 146 AIDS-defining cancer cases and 310 non-AIDS-defining cancer cases. Compared with non-obese adults with HIV, obese adults with HIV were at higher risk of non-AIDS-defining cancer (OR = 1.478, 95% CI = 1.118-1.955). Otherwise, the overall risk of AIDS-defining cancer (OR = 0.816, 95% CI = 0.520-1.279) and each type of AIDS-defining cancer (Kaposi sarcoma and non-Hodgkin's lymphoma) were not high in obese adults with HIV. Of the specific types of non-AIDS-defining cancers, obesity was associated with an increased risk of colorectal cancer (OR = 3.090, 95% CI = 1.110-8.604) and liver, bile duct, and pancreatic cancers (OR = 2.532, 95% CI = 1.141-5.617). CONCLUSIONS: Obesity, which is one of the important health concerns in HIV management, was associated with an increased risk of non-AIDS-defining cancer but not AIDS-defining cancer.

Recovery Effects of Nephelium lappaceum var. pallens (Hiern) Leenh. Extract on Testosterone-Induced Inhibition of Hair Growth in C57BL/6 Mice and Human Follicular Dermal Papilla Cells.

Although various hair health medicines have been developed and are used today, additional safe and effective natural hair growth therapies still need to be developed. Nephelium lappaceum var. pallens (Hiern) Leenh. extract (NLE) reportedly exhibits anticancer, antidiabetic, and antioxidant effects, which could be linked to androgenic processes; however, there are no reports of its effects on testosterone (TS)-inhibited hair growth. The present study investigated the effects of NLE on TS-induced inhibition of hair growth in C57BL/6 mice and human follicular dermal papilla cells. Oral administration of NLE restored hair growth that was suppressed following subcutaneous injection of TS more effectively than finasteride, a drug used for treating hair loss. Histological analysis demonstrated that oral NLE administration increased the number and diameter of hair follicles in the dorsal skin of C57BL/6 mice. In addition, western blot and immunofluorescence assays showed that the oral NLE administration restored TS-induced suppression of cyclin D1, proliferating cell nuclear antigen, and loricrin expression in the skin cells of the mice. Finally, TS suppression of cell proliferation in human follicular dermal papilla cells was significantly reversed by NLE pretreatment. The results suggest that NLE is a promising nutraceutical for hair growth because it promotes hair growth in androgenetic alopecia-like models.

Understanding the molecular mechanisms of odorant binding and activation of the human OR52 family.

Structural and mechanistic studies on human odorant receptors (ORs), key in olfactory signaling, are challenging because of their low surface expression in heterologous cells. The recent structure of OR51E2 bound to propionate provided molecular insight into odorant recognition, but the lack of an inactive OR structure limited understanding of the activation mechanism of ORs upon odorant binding. Here, we determined the cryo-electron microscopy structures of consensus OR52 (OR52cs), a representative of the OR52 family, in the ligand-free (apo) and octanoate-bound states. The apo structure of OR52cs reveals a large opening between transmembrane helices (TMs) 5 and 6. A comparison between the apo and active structures of OR52cs demonstrates the inward and outward movements of the extracellular and intracellular segments of TM6, respectively. These results, combined with molecular dynamics simulations and signaling assays, shed light on the molecular mechanisms of odorant binding and activation of the OR52 family.

Mortality and Causes of Death among Individuals Diagnosed with Human Immunodeficiency Virus in Korea, 2004-2018: An Analysis of a Nationwide Population-Based Claims Database.

The mortality rate and causes of death among individuals diagnosed with human immunodeficiency virus (HIV) infection in Korea were described and compared to those of the general population of Korea using a nationwide population-based claims database. We included 13,919 individuals aged 20-79 years newly diagnosed with HIV between 2004 and 2018. The patients' vital status and cause of death were linked until 31 December 2019. Standardized mortality ratios (SMRs) for all-cause death and specific causes of death were calculated. By the end of 2019, 1669 (12.0%) of the 13,919 HIV-infected participants had died. The survival probabilities of HIV-infected individuals at 1, 5, 10, and 15 years after diagnosis in Korea were 96.2%, 91.6%, 85.9%, and 79.6%, respectively. The main causes of death during the study period were acquired immunodeficiency syndrome (AIDS; 59.0%), non-AIDS-defining cancer (8.2%), suicide (7.4%), cardiovascular disease (4.9%), and liver disease (2.7%). The mortality rate of men and women infected with HIV was 5.60-fold (95% CI = 5.32-5.89) and 6.18-fold (95% CI = 5.30-7.09) that of men and women in the general population, respectively. After excluding deaths due to HIV, the mortality remained significantly higher, with an SMR of 2.16 (95% CI = 1.99-3.24) in men and 3.77 (95% CI = 3.06-4.48) in women. HIV-infected individuals had a higher overall mortality than the general population, with AIDS the leading cause of mortality. Additionally, mortality due to non-AIDS-related causes was higher in HIV-infected individuals.

Socioeconomic burden of pneumonia due to multidrug-resistant Acinetobacter baumannii and Pseudomonas aeruginosa in Korea.

We aimed to estimate the socioeconomic burden of pneumonia due to multidrug-resistant Acinetobacter baumannii (MRAB) and Pseudomonas aeruginosa (MRPA). We prospectively searched for MRAB and MRPA pneumonia cases and matched them with susceptible-organism pneumonia and non-infected patients from 10 hospitals. The matching criteria were: same principal diagnosis, same surgery or intervention during hospitalisation, age, sex, and admission date within 60 days. We calculated the economic burden by using the difference in hospital costs, the difference in caregiver costs, and the sum of productivity loss from an unexpected death. We identified 108 MRAB pneumonia [MRAB-P] and 28 MRPA pneumonia [MRPA-P] cases. The estimated number of annual MRAB-P and MRPA-P cases in South Korea were 1309-2483 and 339-644, with 485-920 and 133-253 deaths, respectively. The annual socioeconomic burden of MRAB-P and MRPA-P in South Korea was $64,549,723-122,533,585 and $15,241,883-28,994,008, respectively. The results revealed that MRAB-P and MRPA-P occurred in 1648-3127 patients, resulted in 618-1173 deaths, and caused a nationwide socioeconomic burden of $79,791,606-151,527,593. Multidrug-resistant organisms (MDRO) impose a great clinical and economic burden at a national level. Therefore, controlling the spread of MDRO will be an effective measure to reduce this burden.

Amplification of immunity by engineering chicken MDA5 combined with the C terminal domain (CTD) of RIG-I.

Innate immune system is triggered by pattern recognition receptors (PRRs) recognition. Retinoic acid-inducible gene 1 (RIG-I) is a major sensor that recognizes RNA ligands. However, chickens have no homologue of RIG-I; instead, they rely on melanoma differentiation-associated protein 5 (MDA5) to recognize RNA ligands, which renders chickens susceptible to infection by influenza A viruses (IAVs). Here, we engineered the cMDA5 viral RNA sensing domain (C-terminal domain, CTD) such that it functions similarly to human RIG-I (hRIG-I) by mutating histidine 925 into phenylalanine, a key residue for hRIG-I RNA binding loop function, or by swapping the CTD of cMDA5 with that of hRIG-I or duck RIG-I (dRIG-I). The engineered cMDA5 gene was expressed in cMDA5 knockout DF-1 cells, and interferon-beta (IFN-ß) activity and expression of interferon-related genes were measured after transfection of cells with RNA ligands of hRIG-I or human MDA5 (hMDA5). We found that both mutant cMDA5 and engineered cMDA5 triggered significantly stronger interferon-mediated immune responses than wild-type cMDA5. Moreover, engineered cMDA5 reduced the IAV titer by 100-fold compared with that in control cells. Collectively, engineered cMDA5/RIG-I CTD significantly enhanced interferon-mediated immune responses, making them invaluable strategies for production of IAV-resistant chickens. KEY POINTS: • Mutant chicken MDA5 with critical residue of RIG-I (phenylalanine) enhanced immunity. • Engineered chicken MDA5 with CTD of RIG-I increased IFN-mediated immune responses. • Engineered chicken MDA5 reduced influenza A virus titers by up to 100-fold.

Structural basis of neuropeptide Y signaling through Y1 receptor.

Neuropeptide Y (NPY) is highly abundant in the brain and involved in various physiological processes related to food intake and anxiety, as well as human diseases such as obesity and cancer. However, the molecular details of the interactions between NPY and its receptors are poorly understood. Here, we report a cryo-electron microscopy structure of the NPY-bound neuropeptide Y1 receptor (Y1R) in complex with Gi1 protein. The NPY C-terminal segment forming the extended conformation binds deep into the Y1R transmembrane core, where the amidated C-terminal residue Y36 of NPY is located at the base of the ligand-binding pocket. Furthermore, the helical region and two N-terminal residues of NPY interact with Y1R extracellular loops, contributing to the high affinity of NPY for Y1R. The structural analysis of NPY-bound Y1R and mutagenesis studies provide molecular insights into the activation mechanism of Y1R upon NPY binding.

Paeoniflorin Enhances Endometrial Receptivity through Leukemia Inhibitory Factor.

Despite advances in assisted reproductive technology, treatment for deficient endometrial receptivity is a major clinical unmet need. In our previous study, the water extract of Paeonia lactiflora Pall. enhanced endometrial receptivity in vitro and in vivo via induction of leukemia inhibitory factor (LIF), an interleukin (IL)-6 family cytokine. In the present study, we found that paeoniflorin, a monoterpene glycoside, is the major active compound of P. lactiflora. Paeoniflorin significantly improved the embryo implantation rate in a murine model of mifepristone (RU486)-induced implantation failure. In addition, paeoniflorin increased the adhesion of human trophectoderm-derived JAr cells to endometrial Ishikawa cells through the expression of LIF in vitro. Moreover, using the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database of the human endometrium, we confirmed that LIF signaling is a key regulator for improving human endometrial receptivity. Therefore, these results suggest that paeoniflorin might be a potent drug candidate for the treatment of endometrial implantation failure by enhancing endometrial receptivity.

Caesalpinia sappan induces apoptotic cell death in ectopic endometrial 12Z cells through suppressing pyruvate dehydrogenase kinase 1 expression.

Endometriosis is a common gynecological disease defined as the growth of endometrial tissues outside the uterus. Although the mechanism underlying the progression of endometriosis has not been fully elucidated, cancer-like aerobic glycolysis is considered to mediate the elevated growth and resistance to apoptosis of endometriotic cells. The heartwood of Caesalpinia sappan L. (family Leguminosae) is a herbal medicinal product used to treat gynecological symptoms, including algomenorrhea and amenorrhea. The results of the present study revealed that endometriotic 12Z cells exhibited more rapid growth than normal endometrial cells (THES). The expression levels of pyruvate dehydrogenase kinase (PDK)1 and 3 and lactate production were higher in 12Z cells than in THES cells. In addition, the 12Z cells were more sensitive to the cytotoxicity of the aqueous extract of C. sappan heartwood (CS) than the THES cells. CS inhibited lactate production and phosphorylation of pyruvate dehydrogenase A by reducing the expression of PDK1. CS also increased mitochondrial reactive oxygen species (ROS) levels, decreased mitochondrial membrane potential and consequently stimulated the apoptosis of 12Z cells. CS-induced cell death was substantially inhibited by exogenous PDK1 expression. In conclusion, CS may be a novel drug candidate for treating endometriosis by inhibiting aerobic glycolysis and inducing ROS-mitochondria-mediated apoptotic cell death.

Mealworm Oil (MWO) Enhances Wound Healing Potential through the Activation of Fibroblast and Endothelial Cells.

Mealworm and mealworm oil (MWO) have been reported to affect antioxidant, anti-coagulation, anti-adipogenic and anti-inflammatory activities. However, the function of MWO in wound healing is still unclear. In this study, we found that MWO induced the migration of fibroblast cells and mRNA expressions of wound healing factors such as alpha-smooth muscle actin (α-SMA), collagen-1 (COL-1) and vascular endothelial growth factor (VEGF) in fibroblast cells. The tube formation and migration of endothelial cells were promoted through the activation of VEGF/VEGF receptor-2 (VEGFR-2)-mediated downstream signals including AKT, extracellular signal-regulated kinase (ERK) and p38 by MWO-stimulated fibroblasts for angiogenesis. Moreover, we confirmed that MWO promoted skin wound repair by collagen synthesis, re-epithelialization and angiogenesis in an in vivo excisional wound model. These results demonstrate that MWO might have potential as a therapeutic agent for the treatment of skin wounds.

Dual conformational recognition by Z-DNA binding protein is important for the B-Z transition process.

Left-handed Z-DNA is radically different from the most common right-handed B-DNA and can be stabilized by interactions with the Zα domain, which is found in a group of proteins, such as human ADAR1 and viral E3L proteins. It is well-known that most Zα domains bind to Z-DNA in a conformation-specific manner and induce rapid B-Z transition in physiological conditions. Although many structural and biochemical studies have identified the detailed interactions between the Zα domain and Z-DNA, little is known about the molecular basis of the B-Z transition process. In this study, we successfully converted the B-Z transition-defective Zα domain, vvZαE3L, into a B-Z converter by improving B-DNA binding ability, suggesting that B-DNA binding is involved in the B-Z transition. In addition, we engineered the canonical B-DNA binding protein GH5 into a Zα-like protein having both Z-DNA binding and B-Z transition activities by introducing Z-DNA interacting residues. Crystal structures of these mutants of vvZαE3L and GH5 complexed with Z-DNA confirmed the significance of conserved Z-DNA binding interactions. Altogether, our results provide molecular insight into how Zα domains obtain unusual conformational specificity and induce the B-Z transition.

Sclerostin inhibits Wnt signaling through tandem interaction with two LRP6 ectodomains.

Low-density lipoprotein receptor-related protein 6 (LRP6) is a coreceptor of the ß-catenin-dependent Wnt signaling pathway. The LRP6 ectodomain binds Wnt proteins, as well as Wnt inhibitors such as sclerostin (SOST), which negatively regulates Wnt signaling in osteocytes. Although LRP6 ectodomain 1 (E1) is known to interact with SOST, several unresolved questions remain, such as the reason why SOST binds to LRP6 E1E2 with higher affinity than to the E1 domain alone. Here, we present the crystal structure of the LRP6 E1E2-SOST complex with two interaction sites in tandem. The unexpected additional binding site was identified between the C-terminus of SOST and the LRP6 E2 domain. This interaction was confirmed by in vitro binding and cell-based signaling assays. Its functional significance was further demonstrated in vivo using Xenopus laevis embryos. Our results provide insights into the inhibitory mechanism of SOST on Wnt signaling.

Targeted Knockout of MDA5 and TLR3 in the DF-1 Chicken Fibroblast Cell Line Impairs Innate Immune Response Against RNA Ligands.

The innate immune system, which senses invading pathogens, plays a critical role as the first line of host defense. After recognition of foreign RNA ligands (e.g., RNA viruses), host cells generate an innate immune or antiviral response via the interferon-mediated signaling pathway. Retinoic acid-inducible gene I (RIG-1) acts as a major sensor that recognizes a broad range of RNA ligands in mammals; however, chickens lack a RIG-1 homolog, meaning that RNA ligands should be recognized by other cellular sensors such as melanoma differentiation-associated protein 5 (MDA5) and toll-like receptors (TLRs). However, it is unclear which of these cellular sensors compensates for the loss of RIG-1 to act as the major sensor for RNA ligands. Here, we show that chicken MDA5 (cMDA5), rather than chicken TLRs (cTLRs), plays a pivotal role in the recognition of RNA ligands, including poly I:C and influenza virus. First, we used a knockdown approach to show that both cMDA5 and cTLR3 play roles in inducing interferon-mediated innate immune responses against RNA ligands in chicken DF-1 cells. Furthermore, targeted knockout of cMDA5 or cTLR3 in chicken DF-1 cells revealed that loss of cMDA5 impaired the innate immune responses against RNA ligands; however, the responses against RNA ligands were retained after loss of cTLR3. In addition, double knockout of cMDA5 and cTLR3 in chicken DF-1 cells abolished the innate immune responses against RNA ligands, suggesting that cMDA5 is the major sensor whereas cTLR3 is a secondary sensor. Taken together, these findings provide an understanding of the functional role of cMDA5 in the recognition of RNA ligands in chicken DF-1 cells and may facilitate the development of an innate immune-deficient cell line or chicken model.

Ultraviolet Photoactivated Room Temperature NO2 Gas Sensor of ZnO Hemitubes and Nanotubes Covered with TiO2 Nanoparticles.

Prolonged exposure to NO2 can cause lung tissue inflammation, bronchiolitis fibrosa obliterans, and silo filler's disease. In recent years, nanostructured semiconducting metal oxides have been widely used to fabricate gas sensors because of their unique structure and surface-to-volume ratio compared to layered materials. In particular, the different morphologies of ZnO-based nanostructures significantly affect the detection property of NO2 gas sensors. However, because of the large interaction energy of chemisorption (1-10 eV), metal oxide-based gas sensors are typically operated above 100 °C, overcoming the energy limits to attain high sensitivity and fast reaction. High operating temperature negatively affects the reliability and durability of semiconductor-based sensors; at high temperature, the diffusion and sintering effects at the metal oxide grain boundaries are major factors causing undesirable long-term drift problems and preventing stability improvements. Therefore, we demonstrate NO2 gas sensors consisting of ZnO hemitubes (HTs) and nanotubes (NTs) covered with TiO2 nanoparticles (NPs). To operate the gas sensor at room temperature (RT), we measured the gas-sensing properties with ultraviolet illumination onto the active region of the gas sensor for photoactivation instead of conventional thermal activation by heating. The performance of these gas sensors was enhanced by the change of barrier potential at the ZnO/TiO2 interfaces, and their depletion layer was expanded by the NPs formation. The gas sensor based on ZnO HTs showed 1.2 times higher detection property than those consisting of ZnO NTs at the 25 ppm NO2 gas.

Quantitative analysis of adsorption and desorption of volatile organic compounds on reusable zeolite filters using gas chromatography.

In this study, we propose a method to quantitatively analyze the concentration of VOCs adsorbed on zeolite filters via gas chromatography (GC). The sampled VOCs from the filters with ethanol as a solution were characterized using GC to determine the concentration of the adsorbed VOCs by comparing the areas of GC peaks of the detected VOCs and ethanol. The proposed method also enabled determination of the desorption (regeneration) conditions of the zeolite filters according to heating temperature and time for various VOCs. Repeated adsorption and desorption of VOCs on zeolite filters and GC analyses allow us to evaluate the durability and reusability of the filter and could help predict the lifetime of zeolite filters in practice.

Enhancement of Endometrial Receptivity by Cnidium officinale through Expressing LIF and Integrins.

Improvement of endometrial receptivity is necessary for successful embryo implantation, and its impairment is associated with female infertility. In this study, we investigated the effect of the roots of Cnidium officinale Makino (CoM) on endometrial receptivity in both in vitro and in vivo model of embryo implantation. We found that CoM enhanced the adhesion of JAr cells to Ishikawa cells by stimulating expression of leukemia inhibitory factor (LIF) and integrins. In addition, blocking of LIFR using hLA or neutralization of integrins αV, ß3, and ß5 using antibodies significantly reduced the enhanced adhesion between JAr cell and CoM-treated Ishikawa cells, indicating that LIF and integrin play an important role in trophoblast-endometrium adhesion for embryo implantation. Furthermore, we identified that CoM significantly improved the implantation rate of blastocysts in the mouse model of RU-induced implantation failure. By collecting these results, here, we suggest that CoM has a therapeutic potential against female infertility associated with decreased endometrial receptivity.

Duration of sweep gas off trial for weaning from venovenous extracorporeal membrane oxygenation.

BACKGROUND: No data are available on the duration of time needed to assess the adequacy of lung function after stopping sweep gas for weaning of venovenous extracorporeal membrane oxygenation (ECMO). The objective of this study was to investigate changes in arterial blood gases (ABGs) during sweep gas off trials in patients receiving venovenous ECMO. METHODS: Data on patients receiving venovenous ECMO, with a weaning trial at least once, were collected prospectively from January 2012 through December 2017. Serial changes in ABGs during sweep gas off trial and clinical outcomes after weaning from venovenous ECMO were evaluated. RESULTS: Over the study period, 192 sweep gas off trials occurred in 93 patients: 115 (60%) failed and 77 (40%) were successful. During the trial, significant changes in blood gases were observed within 1 h in all patients. When serial ABGs were compared according to trial off results, there were no significant differences in the pH, PaCO2, and HCO3- trends across time points between successful and failed trials. However, PaO2 (70.6 versus 93.4 mmHg), SaO2 (91.9 versus 95.2%), and PaO2/FiO2 ratio (164.0 versus 233.4) were significantly lower in failed trials than successful trials within 1 h after stopping sweep gas. After 2 h of trial off, no significant change in blood gases was observed until the end of the trial. CONCLUSIONS: No change in blood gases was observed 2 h after stopping sweep gas in patients receiving venovenous ECMO. Based on our institutional experience, however, we suggest monitoring for 2 h or more after stopping sweep gas flow to assess if patients are ready for decannulation. The reviews of this paper are available via the supplemental material section.

6'-Sialylgalactose inhibits vascular endothelial growth factor receptor 2-mediated angiogenesis.

Angiogenesis should be precisely regulated because disordered neovascularization is involved in the aggravation of multiple diseases. The vascular endothelial growth factor (VEGF)-A/VEGF receptor 2 (VEGFR-2) axis is crucial for controlling angiogenic responses in vascular endothelial cells (ECs). Therefore, inactivating VEGFR-2 signaling may effectively suppress aberrant angiogenesis and alleviate related symptoms. In this study, we performed virtual screening, identified the synthetic disaccharide 6'-sialylgalactose (6SG) as a potent VEGFR-2-binding compound and verified its high binding affinity by Biacore assay. 6SG effectively suppressed VEGF-A-induced VEGFR-2 phosphorylation and subsequent in vitro angiogenesis in HUVECs without inducing cytotoxicity. 6SG also inhibited VEGF-A-induced extracellular-regulated kinase (ERK)/Akt activation and actin stress fiber formation in HUVECs. We demonstrated that 6SG inhibited retinal angiogenesis in a mouse model of retinopathy of prematurity and tumor angiogenesis in a xenograft mouse model. Our results suggest a potential therapeutic benefit of 6SG in inhibiting angiogenesis in proangiogenic diseases, such as retinopathy and cancer.

Machilin A Inhibits Tumor Growth and Macrophage M2 Polarization Through the Reduction of Lactic Acid.

Lactate dehydrogenase A (LDHA) is an important enzyme responsible for cancer growth and energy metabolism in various cancers via the aerobic glycolytic pathway. Here, we report that machilin A (MA), which acts as a competitive inhibitor by blocking the nicotinamide adenine dinucleotide (NAD) binding site of LDHA, suppresses growth of cancer cells and lactate production in various cancer cell types, including colon, breast, lung, and liver cancers. Furthermore, MA markedly decreased LDHA activity, lactate production, and intracellular adenosine triphosphate (ATP) levels induced by hypoxia-induced LDHA expression in cancer cells, and significantly inhibited colony formation, leading to reduced cancer cell survival. In mouse models inoculated with murine Lewis lung carcinoma, MA significantly suppressed tumor growth as observed by a reduction of tumor volume and weight; resulting from the inhibition of LDHA activity. Subsequently, the suppression of tumor-derived lactic acid in MA-treated cancer cells resulted in decrease of neovascularization through the regulation of alternatively activated macrophages (M2) polarization in macrophages. Taken together, we suggest that the reduction of lactate by MA in cancer cells directly results in a suppression of cancer cell growth. Furthermore, macrophage polarization and activation of endothelial cells for angiogenesis were indirectly regulated preventing lactate production in MA-treated cancer cells.