Glutathione peroxidase 8 expression on cancer cells and cancer-associated fibroblasts facilitates lung cancer metastasis.

Lung cancer is the leading cause of cancer death worldwide, of which lung adenocarcinoma (LUAD) is the most common subtype. Metastasis is the major cause of poor prognosis and mortality for lung cancer patients, which urgently needs great efforts to be further explored. Herein, glutathione peroxidase 8 (GPX8) was identified as a novel potential pro-metastatic gene in LUAD metastatic mice models from GEO database. GPX8 was highly expressed in tumor tissues, predicting poor prognosis in LUAD patients. Knockdown of GPX8 inhibited LUAD metastasis in vitro and in vivo, while it did not obviously affect tumor growth. Knockdown of GPX8 decreased the levels of p-FAK and p-Paxillin and disturbed the distribution of focal adhesion. Furthermore, GPX8 was overexpressed in cancer-associated fibroblast (CAF) and associated with CAF infiltration in tumor microenvironment of lung cancer. GPX8 silence on fibroblasts suppressed lung cancer cell migration in the coculture system. BRD2 and RRD4 were the potential transcriptionally regulators for GPX8. Bromodomain extra-terminal inhibitor JQ1 downregulated GPX8 expression and suppressed lung cancer cell migration. Our findings indicate that highly expressed GPX8 in lung cancer cells and fibroblasts functions as a pro-metastatic factor in lung cancer. JQ1 is identified as a potential inhibitor against GPX8-mediated lung cancer metastasis.

c-MYC-mediated TRIB3/P62+ aggresomes accumulation triggers paraptosis upon the combination of everolimus and ginsenoside Rh2.

The mammalian target of rapamycin (mTOR) pathway is abnormally activated in lung cancer. However, the anti-lung cancer effect of mTOR inhibitors as monotherapy is modest. Here, we identified that ginsenoside Rh2, an active component of Panax ginseng C. A. Mey., enhanced the anti-cancer effect of the mTOR inhibitor everolimus both in vitro and in vivo. Moreover, ginsenoside Rh2 alleviated the hepatic fat accumulation caused by everolimus in xenograft nude mice models. The combination of everolimus and ginsenoside Rh2 (labeled Eve-Rh2) induced caspase-independent cell death and cytoplasmic vacuolation in lung cancer cells, indicating that Eve-Rh2 prevented tumor progression by triggering paraptosis. Eve-Rh2 up-regulated the expression of c-MYC in cancer cells as well as tumor tissues. The increased c-MYC mediated the accumulation of tribbles homolog 3 (TRIB3)/P62+ aggresomes and consequently triggered paraptosis, bypassing the classical c-MYC/MAX pathway. Our study offers a potential effective and safe strategy for the treatment of lung cancer. Moreover, we have identified a new mechanism of TRIB3/P62+ aggresomes-triggered paraptosis and revealed a unique function of c-MYC.

Myricetin inhibits interferon-γ-induced PD-L1 and IDO1 expression in lung cancer cells.

Programmed death ligand-1 (PD-L1) and indoleamine 2, 3-dioxygenase 1 (IDO1) are immune checkpoints induced by interferon-γ (IFN-γ) in the tumor microenvironment, leading to immune escape of tumors. Myricetin (MY) is a flavonoid distributed in many edible and medicinal plants. In this study, MY was identified to inhibit IFN-γ-induced PD-L1 expression in human lung cancer cells. It also reduced the expression of IDO1 and the production of kynurenine which is the product catalyzed by IDO1, while didn't show obvious effect on the expression of major histocompatibility complex-I (MHC-I), a crucial molecule for antigen presentation. In addition, the function of T cells was evaluated using a co-culture system consist of lung cancer cells and the Jurkat-PD-1 T cell line overexpressing PD-1. MY restored the survival, proliferation, CD69 expression and interleukin-2 (IL-2) secretion of Jurkat-PD-1 T cells suppressed by IFN-γ-treated lung cancer cells. Mechanistically, IFN-γ up-regulated PD-L1 and IDO1 at the transcriptional level through the JAK-STAT-IRF1 axis, which was targeted and inhibited by MY. Together, our research revealed a new mechanism of MY mediated anti-tumor activity and highlighted the potential implications of MY in tumor immunotherapy.

Identification of AHSA1 as a Potential Therapeutic Target for Breast Cancer: Bioinformatics Analysis and in vitro Studies.

BACKGROUND: Shenling Baizhu Powder (SBP), a famous Traditional Chinese Medicine (TCM) formulation, has been widely used in the adjuvant treatment of cancers, including breast cancer. This study aims to identify potential new targets for breast cancer treatment based on the network pharmacology of SBP. METHODS: By analyzing the relationship between herbs and target proteins, potential targets of multiple herbs in SBP were identified by network pharmacology analysis. Besides, by comparing the data of breast cancer tissue with normal tissue, upregulated genes in two breast cancer expression profiles were found. Thereafter, the expression level and prognosis of activator of heat shock protein 90 (HSP90) ATPase activity 1 (AHSA1) were further analyzed in breast cancer by bioinformatics analysis, and the network module of AHSA1 binding protein was constructed. Furthermore, the effect of knocking down AHSA1 on the proliferation, migration, and invasion of breast cancer cells was verified by MTT, clone formation assay, and transwell assay. RESULTS: Vascular endothelial growth factor A (VEGFA), intercellular adhesion molecule 1 (ICAM1), chemokine (C-X-C motif) ligand 8 (CXCL8), AHSA1, and serpin family E member 1 (SERPINE1) were associated with multiple herbs in SBP. AHSA1 was remarkably upregulated in breast cancer tissues and positively correlated with poor overall survival and disease metastasis- free survival. Furthermore, knockdown of AHSA1 significantly inhibited the migration and invasion in MCF-7 and MDA-MB-231 breast cancer cells but had no obvious effect on proliferation. In addition, among the proteins that bind to AHSAl, the network composed of proteasome, chaperonin, and heat shock proteins is closely connected, and these proteins are associated with poor prognosis in a variety of cancers. CONCLUSION: AHSA1 is positively correlated with breast cancer progression and might act as a novel therapeutic target for breast cancer.

Regulation of CD47 expression by interferon-gamma in cancer cells.

The anti-phagocytosis signal, CD47, prevents phagocytosis when it interacts with signal-regulatory protein alpha (SIRPα) on macrophages. Given the vital role of CD47 in immune response, further investigation on the regulation of CD47 in tumor microenvironment is needed. Herein, we identified that interferon-gamma (IFN-γ), one of the most important cytokines in the immune and inflammatory response, up-regulated CD47 expression in cancer cells and this effect could be inhibited by the JAK1/2 inhibitor ruxolitinib, as well as siRNA-mediated silencing of JAK1, STAT1, and IRF1. The IFN-γ-induced surface expression of CD47 contributed to a stronger binding affinity to SIRPα and a decrease in phagocytosis of cancer cells by macrophages. Knockdown of JAK1, STAT1, or IRF1 by siRNA reversed the decreased phagocytosis caused by IFN-γ. Besides, analysis from TCGA revealed that IFNG had a positive correlation with CD47 in various types of cancer, which was supported by the increased surface CD47 expression after IFN-γ treatment in different types of cancer cells. The discovery of IFN-γ-induced up-regulation of CD47 in cancer cells unveils another feedback inhibitory mechanism of IFN-γ, thus providing insights into cancer immunotherapy targeting CD47.

TGFß2-mediated epithelial-mesenchymal transition and NF-κB pathway activation contribute to osimertinib resistance.

Osimertinib (AZD9291) has been widely used for the treatment of EGFR mutant non-small cell lung cancer. However, resistance to osimertinib is inevitable. In this study we elucidated the molecular mechanisms of resistance in osimertinib-resistant NCI-H1975/OSIR cells. We showed that NCI-H1975/OSIR cells underwent epithelial-mesenchymal transition (EMT), which conferred sensitivity to the GPX4 inhibitor 1S, 3R-RSL3 to induce ferroptotic cell death. The EMT occurrence resulted from osimertinib-induced upregulation of TGFß2 that activated SMAD2. On the other hand, we revealed that NCI-H1975/OSIR cells were highly dependent on NF-κB pathway for survival, since treatment with the NF-κB pathway inhibitor BAY 11-7082 or genetic silence of p65 caused much greater cell death as compared with the parental NCI-H1975 cells. In NCI-H1975 cells, osimertinib activated NF-κB pathway, evidenced by the increased p65 nuclear translocation, which was abolished by knockdown of TGFß2. In the cancer genome atlas lung adenocarcinoma data, TGFB2 transcript abundance significantly correlated with EMT-associated genes and NF-κB pathway. In addition, coexistence of EMT and activation of NF-κB pathway was observed in several NCI-H1975/OSIR clones. These findings shed new light on distinct roles of TGFß2 in osimertinib-resistant cells and provide new strategies for treatment of this resistant status.

Licochalcone A inhibits interferon-gamma-induced programmed death-ligand 1 in lung cancer cells.

BACKGROUND: Programmed death-ligand 1 (PD-L1), which can be induced by interferon-gamma (IFN-γ) in the tumor microenvironment, is a critical immune checkpoint in cancer immunotherapy. Natural products which reduce IFN-γ-induced PD-L1 might be exert immunotherapy effect. Licochalcone A (LCA), a natural compound derived from the root of Glycyrrhiza inflata Batalin. (Fabaceae), was found to interfere IFN-γ-induced PD-L1. PURPOSE: The aim of this study is to further clarify the effect and the mechanism of LCA on inhibiting IFN-γ-induced PD-L1 in lung cancer cells. METHODS: The expression levels of PD-L1 were evaluated by flow cytometry, western blot and qRT-PCR. Click-iT protein synthesis assay and luciferase assay were used to identify the effect of LCA on protein synthesis. Jurkat T cell proliferation and apoptosis in the co-culture system were detected by flow cytometry. Flow cytometry was also applied to evaluate reactive oxygen species (ROS) generation. RESULTS: LCA downregulated IFN-γ-induced PD-L1 protein expression and membrane localization in human lung cancer cells, regardless of inhibiting PD-L1 mRNA level or promoting its protein degradation. LCA decreased apoptosis and proliferative inhibition of Jurkat T cells caused by IFN-γ-induced PD-L1-expressing in A549 cells in the co-culture system. Strikingly, LCA was verified as a protein synthesis inhibitor, which reduced both cap-dependent and -independent translation. LCA inhibited PD-L1 translation, likely due to inhibition of 4EBP1 phosphorylation (Ser 65) and activation of PERK-eIF2α pathway. Furthermore, LCA induced ROS generation in a time-dependent manner in lung cancer cells. N-acetyl-L-cysteine (NAC) not only revered ROS generation triggered by LCA but also restored IFN-γ-induced expression of PD-L1. Both the inhibition of 4EBP1 phosphorylation (Ser 65) and activation of PERK-eIF2α axis triggered by LCA was restored by co-treatment with NAC. CONCLUSION: LCA abrogated IFN-γ-induced PD-L1 expression via ROS generation to abolish the protein translation, indicating that LCA has the potential to be applied in cancer immunotherapy.

Phanginin R Induces Cytoprotective Autophagy via JNK/c-Jun Signaling Pathway in Non-Small Cell Lung Cancer A549 Cells.

BACKGROUND: Cassane-type diterpenoids are widely distributed in the medical plants of genus Caesalpinia. To date, plenty of cassane diterpenoids have been isolated from the genus Caesalpinia, and some of them were documented to exhibit multiple biological activities. However, the effects of these compounds on autophagy have never been reported. OBJECTIVE: To investigate the effects and mechanisms of the cassane diterpenoids including Phanginin R (PR) on autophagy in Non-Small Cell Lung Cancer (NSCLC) A549 cells. METHODS: Western blot analysis and immunofluorescence assay were performed to investigate the effects of the compounds on autophagic flux in A549 cells. The pathway inhibitor and siRNA interference were used to investigate the mechanism of PR. MTT assay was performed to detect cell viability. RESULTS: PR treatment upregulated the expression of phosphatidylethanolamine-modified microtubule-associated protein Light-Chain 3 (LC3-II) in A549 cells. Immunofluorescence assay showed that PR treatment increased the production of red-fluorescent puncta in mRFP-GFP-LC3 plasmid-transfected cells, indicating PR promoted autophagic flux in A549 cells. PR treatment activated the c-Jun N-terminal Kinase (JNK) signaling pathway while it did not affect the classical Akt/mammalian Target of Rapamycin (mTOR) pathway. Pretreatment with the JNK inhibitor SP600125 or siRNA targeting JNK or c-Jun suppressed PR-induced autophagy. In addition, cotreatment with the autophagy inhibitor Chloroquine (CQ) or inhibition of the JNK/c-Jun signaling pathway increased PR-induced cytotoxicity. CONCLUSION: PR induced cytoprotective autophagy in NSCLC A549 cells via the JNK/c-Jun signaling pathway, and autophagy inhibition could further improve the anti-cancer potential of PR.

Activation of notch 3/c-MYC/CHOP axis regulates apoptosis and promotes sensitivity of lung cancer cells to mTOR inhibitor everolimus.

The mammalian target of rapamycin (mTOR) pathway converges diverse environmental cues to support the lung cancer growth and survival. However, the mTOR-targeted mono-therapy does not achieve expected therapeutic effect. Here, we revealed that fangchinoline (FCL), an active alkaloid that purified from the traditional Chinese medicine Stephania tetrandra S. Moore, enhanced the anti-lung cancer effect of mTOR inhibitor everolimus (EVE). The combination of EVE and FCL was effective to activate Notch 3, and subsequently evoked its downstream target c-MYC. The blockage of Notch 3 signal by the molecular inhibitor of γ-secretase or siRNA of Notch 3 reduced the c-MYC expression and attenuated the combinational efficacy of EVE and FCL on cell apoptosis and proliferation. Moreover, the c-MYC could bind to the C/EBP homologous protein (CHOP) promoter and facilitate CHOP transcription. The conditional genetic deletion of CHOP reduced the apoptosis on lung cancer cells to the same degree as blockage of Notch 3/c-MYC axis, providing further evidence for that the Notch 3/c-MYC axis regulates the transcription of CHOP and finally induces apoptosis upon co-treatment of FCL and EVE in lung cancer cells. Overall, our findings, to the best of our knowledge, firstly link CHOP to Notch 3/c-MYC axis-dependent apoptosis and provide the Notch 3/c-MYC/CHOP activation as a promising strategy for mTOR-targeted combination therapy in lung cancer treatment.

Platycodin D triggers the extracellular release of programed death Ligand-1 in lung cancer cells.

Programmed death ligand-1 (PD-L1) is an important immune checkpoint for cancer immunotherapy in clinic. In this study, we reported that platycodin D, a natural product isolated from an edible and medicinal plant Platycodon grandiflorus (Jacq.) A. DC., down-regulated the protein level of PD-L1 in lung cancer cells. Flow cytometry and immunofluorescence assay showed a weaker surface PD-L1 signal in NCI-H1975 cells after the incubation with platycodin D (10 µM) for 15 min compared to the control group. Jurkat T cells showed enhancive interleukin-2 secretion when co-cultured with platycodin D-treated NCI-H1975 cells, suggesting that platycodin D-induced PD-L1 reduction increases the activation of Jurkat T cells. An augmentation of PD-L1 protein was detected in the cell culture medium from platycodin D treatment group. Chlorpromazine (60 µM) almost abolished the platycodin D-mediated PD-L1 extracellular release and restored the membrane PD-L1. Finally, hemolysis assay exhibited that platycodin D-triggered PD-L1 extracellular release was independent of the hemolytic mechanism. Taken together, our study demonstrates that platycodin D reduces the protein level of PD-L1 in lung cancer cells via triggering its release into the cell culture medium, which sheds new light for the application of natural products in cancer immunotherapy.

Establishment and Characterization of Pemetrexed-resistant NCI-H460/PMT Cells.

BACKGROUND: Pemetrexed (PMT) is a multitargeted antifolate agent that is used for treating patients with Non-Small Cell Lung Cancer (NSCLC). However, patients have presented clinical responses of drug resistance to PMT. OBJECTIVE: This study aimed to explore the underlying mechanisms of PMT resistance in NSCLC cells. METHODS: PMT-resistant NCI-H460/PMT cells were established by treating with PMT in a concentrationescalation manner. MTT assay and colony formation were performed to detect cell proliferation. Immunofluorescence was used to detect the expression of Ki-67. Transwell assay was performed to measure cell migration ability. qPCR and Western blot were used to detect the mRNA and protein expression levels of indicated genes. Small interfering RNAs (siRNA) were used to knockdown ATP binding cassette subfamily B member 1 (ABCB1) and Thymidylate Synthase (TYMS). RESULTS: This study showed that compared with the parental cells, the NCI-H460/PMT cells displayed weakened proliferation and enhanced cell mobility. In addition, the NCI-H460/PMT cells demonstrated cellular senescence, which might result in PMT resistance. The NCI-H460/PMT cells exhibited cross-resistance to other chemotherapeutics, including fluorouracil, paclitaxel, doxorubicin, etoposide and gemcitabine, possibly because of the upregulated expression of ABCB1. However, the ABCB1 knockdown by siRNA failed to eradicate PMT resistance. Moreover, TYMS, a target of PMT, was obviously upregulated in the resistant cells. The genetic silence of TYMS partially abrogated PMT resistance, suggesting that the overexpression of TYMS was a key resistant mechanism of PMT. CONCLUSION: The overexpression of TYMS was an important resistance mechanism of PMT for KRAS-mutated NCI-H460 cells. Cross-resistance to other chemotherapeutics should be considered in addressing PMT resistance.

Osimertinib (AZD9291) decreases programmed death ligand-1 in EGFR-mutated non-small cell lung cancer cells.

Osimertinib (AZD9291) is a third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) that has been approved for the treatment of EGFR-mutated non-small cell lung cancer (NSCLC). In NSCLC patients, an EGFR mutation is likely to be correlated with high levels of expression of programmed death ligand-1 (PD-L1). Here, we showed that osimertinib decreased PD-L1 expression in human EGFR mutant NSCLC cells in vitro. Osimertinib (125 nmol/L) markedly suppressed PD-L1 mRNA expression in both NCI-H1975 and HCC827 cells. Pretreatment with the N-linked glycosylation inhibitor tunicamycin, osimertinib clearly decreased the production of new PD-L1 protein probably due to a reduction in mRNA. After blocking transcription and translation processes with actinomycin D and cycloheximide, respectively, osimertinib continued to reduce the expression of PD-L1, demonstrating that osimertinib might degrade PD-L1 at the post-translational level, which was confirmed by a cycloheximide chase assay, revealing that osimertinib (125 nmol/L) decreased the half-life of PD-L1 from approximately 17.8 h and 13.8 h to 8.6 h and 4.6 h, respectively, in NCI-H1975 and HCC827 cells. Pretreatment with the proteasome inhibitors (MG-132 or bortezomib) blocked the osimertinib-induced degradation of PD-L1, but an inhibitor of autophagy (chloroquine) did not. In addition, inhibition of GSK3ß by LiCl prevented osimertinib-induced PD-L1 degradation. The results demonstrate that osimertinib reduces PD-L1 mRNA expression and induces its protein degradation, suggesting that osimertinib may reactivate the immune activity of T cells in the tumor microenvironment in EGFR-mutated NSCLC patients.

Therapeutic potential of Rhizoma Alismatis: a review on ethnomedicinal application, phytochemistry, pharmacology, and toxicology.

Rhizoma Alismatis (RA), the dried rhizome of Alisma orientale (Sam.) Juzep, is a common traditional herbal medicine named Ze Xie in Chinese. RA is an important herbal component of a number of well-known Chinese medicinal preparations. It has been used to treat various ailments, such as dysuria, edema, nephropathy, hyperlipidemia, and diabetes. A wide range of chemical compounds, mainly triterpenoids, sesquiterpenoids, and diterpenoids, have been isolated from RA; among which the protostane-type triterpenoids, termed alisols, have attracted the most attention owing to their unique chemical structures and various biological activities. The extract and active compounds of RA possess a wide spectrum of pharmacological effects (e.g., diuretic, antimetabolic disorder, hepatoprotective, immunomodulatory, antiosteoporotic, anti-inflammatory, antitumor, antibacterial, and antiviral activities). Previous toxicological evaluations indicated that the RA extracts are relatively safe and have no serious side effects within certain dose ranges. This paper reviews the up-to-date information on the ethnomedicinal application, phytochemistry, pharmacology, and toxicology of RA. This information will be useful for a better understanding of the therapeutic potential of RA.

Baicalein Induces Beclin 1- and Extracellular Signal-Regulated Kinase-Dependent Autophagy in Ovarian Cancer Cells.

Baicalein (BA), one of the major compounds isolated from the root of Scutellaria baicalensis Gerogi, exhibits various pharmacological effects, such as anti-oxidant, anti-inflammatory, and anticancer effects. In this study, we found that BA reduced cell viability and increased apoptosis in ovarian cancer cells. Treatment of cells with BA enhanced microtubule-associated protein light chain 3-II (LC3-II) expression, acidic vesicular organelle and GFP-LC3 fluorescence dot accumulation. Combined treatment with chloroquine and BA apparently reduced cell viability and increased the cleavage of poly (ADPribose) polymerase (PARP) in both HEY and A2780 ovarian cancer cell lines, indicating that BA induces a protective autophagy in these cells. Knockdown of Beclin 1 by siRNA remarkably decreased BA-induced LC3-II lipidation. In addition, we found an increase in the phosphorylation of extracellular signal-regulated kinase (ERK, Thr202/Thr204) and AKT (Ser473) after BA treatment, and inhibition of ERK activation by the pharmacological inhibitor U0126 or ERK siRNA blocked BA-induced autophagy. Taken together, these results suggest that BA induces Beclin 1- and ERK-dependent autophagy in ovarian cancer cells.

Effects of alisol B 23-acetate on ovarian cancer cells: G1 phase cell cycle arrest, apoptosis, migration and invasion inhibition.

BACKGROUND: Ovarian cancer is the first leading cause of death among gynecologic malignancies worldwide. Discovery of new chemotherapeutic drugs is still imperative for the improvement of the survival rate. PURPOSE: This study aims to investigate the anti-cancer potential of alisol B 23-acetate (AB23), a protostane-type triterpene isolated from the Alismatis Rhizoma, in the parental and paclitaxel-resistant ovarian cancer cells. METHODS: MTT assay was performed to evaluate cell viability after treatment with AB23, along with flow cytometry for apoptosis and cell cycle analysis. Western blotting was conducted to determine the relative protein level. Wound healing and transwell assays were performed to investigate the effect of AB23 on cell migration and invasion. RESULTS: AB23 obviously inhibited proliferation of the three ovarian cancer cell lines, down-regulated the protein levels of CDK4, CDK6, and cyclin D1, and blocked the cell cycle progressions in G1 phase. Meanwhile, AB23 induced accumulation of the sub-G1 phase in the three cell lines in a concentration dependent manner. The protein levels of cleaved poly ADP-ribose polymerase (PARP) and the ratio of Bax/Bcl-2 were up-regulated after treatment with AB23. Further study showed that AB23 induced endoplasmic reticulum stress through IRE1 signaling pathway and silencing of IRE1α partially enhanced AB23-induced apoptosis. Wound healing and transwell assays showed that AB23 could also suppress the migration and invasion of HEY cells. Moreover, it down-regulated the protein levels of matrix metalloproteinases MMP-2 and MMP-9. CONCLUSION: AB23 possessed anti-proliferation, anti-migration and anti-invasion activities as a single agent on ovarian cancer cells.

Red blood cell distribution width is a potential index to assess the disease activity of systemic lupus erythematosus.

BACKGROUND: General population-based investigations have revealed that red blood cell distribution width (RDW) is associated with inflammatory indexes such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP). Chronic inflammation is one of the major components of many autoimmune diseases and RDW may reflect the severity of these autoimmune diseases as well. Therefore, the objective of this study was to investigate the correlation between RDW and disease activity of systemic lupus erythematosus (SLE). METHODS: The medical records of 131 SLE patients were retrospectively analyzed. Correlations between RDW and disease activity or other inflammatory indexes were analyzed. The effect of glucocorticoid treatment for three months on RDW was estimated in 3 newly diagnosed SLE cases. RESULTS: Increased RDW was observed in SLE patients. RDW was positively correlated with serum IgM, CRP, ESR, and SLE Disease Activity Index 2000 (SLEDAI-2K). Glucocorticoid treatment decreased both SLEDAI-2K and RDW. CONCLUSION: RDW may be a useful index to estimate the disease activity of SLE.

Systematic review and meta-analysis of flow cytometry in urinary tract infection screening.

BACKGROUND: Automated urine sediment analysis of white blood cells (WBCs) and bacteria is a promising approach for urinary tract infections (UTIs) screening. However, available data on their screening efficacy is inconsistent. METHODS: English articles from Pubmed, EMBASE, and Web of Science published before December 1, 2012 were analyzed. The Quality Assessment for Studies of Diagnostic Accuracy (QUADAS) tool was used to evaluate the quality of eligible studies. Performance characteristics of WBCs and bacteria (sensitivity, specificity, and other measures of accuracy) were pooled and examined by random-effects models. RESULTS: Nineteen studies containing 22,305 samples were included. Pooled sensitivities were 0.87 (95% confidence interval [CI], 0.86-0.89) for WBCs and 0.92 (95% CI, 0.91-0.93) for bacteria. Corresponding pooled specificities were 0.67 (95% CI, 0.66-0.68) for WBCs and 0.60 (95% CI, 0.59-0.61) for bacteria. Areas under the summary receiver operating characteristics curves were 0.87 and 0.93 for WBCs and bacteria, respectively. The major limitation of eligible studies was that enrolled subjects were often not representative of clinical patient populations in which UTI would be suspected. CONCLUSIONS: WBC and bacterial measurements by the UF-100 and UF-1000i are useful indicators in UTI screening; however, the performances of these systems should be rigorously evaluated by additional studies.