Identifying STRN3-RARA as a new fusion gene for acute promyelocytic leukemia.

Here we report a new fusion gene, STRN3-RARA, in acute promyelocytic leukemia (APL). It cooperates with UTX deficiency to drive full-blown APL in mice. Although STRN3-RARA leukemia quickly relapses after all-trans retinoic acid treatment, it can be restrained by cepharanthine.

Time-dependent risk of fracture in adults with type 2 diabetes receiving anti-diabetic drug: A one-stage network meta-analysis.

AIMS: To assess the time-dependent risk of fracture in adults with type 2 diabetes receiving anti-diabetic drugs. MATERIALS AND METHODS: We searched MEDLINE, EMBASE, and Cochrane Library up to 18 November 2021, for randomized controlled trials (RCTs) and propensity-score-matched non-randomized studies (NRSs) comparing all anti-diabetic drugs with standard treatment or with each other on fracture in adults with type 2 diabetes. The study performed a one-stage network meta-analysis using discrete-time hazard regression with reconstructed individual time-to-event data. RESULTS: This network meta-analysis involved seven RCTs (65,051 adults with type 2 diabetes) with a median follow-up of 36 months and three propensity-score-based NRSs (17,954 participants) with a median follow-up of 27.3 months. Among anti-diabetic drugs, thiazolidinediones increased the overall hazard of fracture by 42% (95% credible interval [CrI], 3%-97%) and almost tripled the risk after 4 years (hazard ratio [HR], 2.74; 95% CrI, 1.53-4.80). Credible subgroup analysis suggested that thiazolidinediones increased the hazard of fracture only in females (HR, 2.19; 95% CrI, 1.26-3.74) but not among males (HR, 0.81; 95% CrI, 0.45-1.40). Moderate certainty evidence established that thiazolidinediones increase 92 fractures in five years per 1000 female patients. We did not find the risk of fractures with other anti-diabetic drugs including metformin, sulfonylureas, sodium-glucose cotransporter-2 (SGLT2) inhibitors, and dipeptidyl peptidase-4 (DPP-4) inhibitors. CONCLUSIONS: Long-term use of thiazolidinediones elevates the risk of fracture among females with type 2 diabetes. There is no evidence eliciting fracture risk associated with other anti-diabetic drugs.

Structure of TBC1D23 N-terminus reveals a novel role for rhodanese domain.

Members of the Tre2-Bub2-Cdc16 (TBC) family often function to regulate membrane trafficking and to control signaling transductions pathways. As a member of the TBC family, TBC1D23 is critical for endosome-to-Golgi cargo trafficking by serving as a bridge between Golgi-bound golgin-97/245 and the WASH/FAM21 complex on endosomal vesicles. However, the exact mechanisms by which TBC1D23 regulates cargo transport are poorly understood. Here, we present the crystal structure of the N-terminus of TBC1D23 (D23N), which consists of both the TBC and rhodanese domains. We show that the rhodanese domain is unlikely to be an active sulfurtransferase or phosphatase, despite containing a putative catalytic site. Instead, it packs against the TBC domain and forms part of the platform to interact with golgin-97/245. Using the zebrafish model, we show that impacting golgin-97/245-binding, but not the putative catalytic site, impairs neuronal growth and brain development. Altogether, our studies provide structural and functional insights into an essential protein that is required for organelle-specific trafficking and brain development.

Prognostic value and biological function of LRRN4 in colorectal cancer.

BACKGROUND: Several nervous and nerve-related biomarkers have been detected in colorectal cancer (CRC) and can contribute to the progression of CRC. However, the role of leucine-rich repeat neuronal 4 (LRRN4), a recently identified neurogenic marker, in CRC remains unclear. METHODS: We examined the expression and clinical outcomes of LRRN4 in CRC from TCGA-COREAD mRNA-sequencing datasets and immunohistochemistry in a Chinese cohort. Furthermore, colony formation, flow cytometry, wound healing assays and mouse xenograft models were used to investigate the biological significance of LRRN4 in CRC cell lines with LRRN4 knockdown or overexpression in vitro and in vivo. In addition, weighted coexpression network analysis, DAVID and western blot analysis were used to explore the potential molecular mechanism. RESULTS: We provide the first evidence that LRRN4 expression, at both the mRNA and protein levels, was remarkably high in CRC compared to controls and positively correlated with the clinical outcome of CRC patients. Specifically, LRRN4 was an independent prognostic factor for progression-free survival and overall survival in CRC patients. Further functional experiments showed that LRRN4 promoted cell proliferation, cell DNA synthesis and cell migration and inhibited apoptosis. Knockdown of LRRN4 can correspondingly decrease these effects in vitro and can significantly suppress the growth of xenografts. Several biological functions and signaling pathways were regulated by LRRN4, including proteoglycans in cancer, glutamatergic synapse, Ras, MAPK and PI3K. LRRN4 knockdown resulted in downregulation of Akt, p-Akt, ERK1/2 and p-ERK1/2, the downstream of the Ras/MAPK signaling pathway, overexpression of LRRN4 leaded to the upregulation of these proteins. CONCLUSIONS: Our results suggest that LRRN4 could be a biological and molecular determinant to stratify CRC patients into distinct risk categories, and mechanistically, this is likely attributable to LRRN4 regulating several malignant phenotypes of neoplastic cells via RAS/MAPK signal pathways.

Structural and functional studies of TBC1D23 C-terminal domain provide a link between endosomal trafficking and PCH.

Pontocerebellar hypoplasia (PCH) is a group of neurological disorders that affect the development of the brain, in particular, the pons and cerebellum. Homozygous mutations of TBC1D23 have been found recently to lead to PCH; however, the underlying molecular mechanisms remain unclear. Here, we show that the crystal structure of the TBC1D23 C-terminal domain adopts a Pleckstrin homology domain fold and selectively binds to phosphoinositides, in particular, PtdIns(4)P, through one surface while binding FAM21 via the opposite surface. Mutation of key residues of TBC1D23 or FAM21 selectively disrupts the endosomal vesicular trafficking toward the Trans-Golgi Network. Finally, using the zebrafish model, we show that PCH patient-derived mutants, impacting either phosphoinositide binding or FAM21 binding, lead to abnormal neuronal growth and brain development. Taken together, our data provide a molecular basis for the interaction between TBC1D23 and FAM21, and suggest a plausible role for PtdIns(4)P in the TBC1D23-mediating endosome-to-TGN trafficking pathway. Defects in this trafficking pathway are, at least partially, responsible for the pathogenesis of certain types of PCH.

[Establishment of 14-Color Panel for Determining Leukocyte Subsets in Human Peripheral Blood with Flow Cytometry].

OBJECTIVE: To establish a 14-color flow cytometry protocol for the examination of leukocyte subsets in human peripheral blood. METHODS: We used cell membrane surface antibodies CD45, CD3, CD4, CD8, CD19, CD56, CD16, CD14, CD25, CD127, HLA-DR, CD123, CD11c and nucleus staining dye DAPI to establish a 14-color flow cytometry assay to determine the major cell subsets in human peripheral blood. We collected peripheral blood specimens from healthy volunteers to test for antibody titers and optimal photomultiplier tube (PMT) voltage, and to conduct single-color staining and fluorescence minus one control staining. After determining the test method and test conditions, the peripheral blood samples of 18 healthy volunteers were analyzed. RESULTS: According to the cell classification and staining index, optimal antibody mass concentrations selected were as follows: CD25 and CD127 at 8.0 µg/mL, CD45, CD3, CD14 and CD123 at 4.0 µg/mL, CD8, CD19, CD56, CD16, HLA-DR and CD11c at 2.0 µg/mL, CD4 at 1.0 µg/mL and DAPI at 0.1 µg/mL. The detection voltages for CD45, CD3, CD4, CD8, CD19, CD56, CD16, CD14, CD25, CD127, HLA-DR, CD123, CD11c and DAPI were 450 V, 410 V, 400 V, 550 V, 405 V, 500 V, 520 V, 550 V, 550 V, 400 V, 450 V, 400 V, 580 V, and 300 V, respectively. The appropriate fluorescence compensation was determined by single-color staining and fluorescence minus one controls. The 14-color flow cytometry panel was established to analyze the main subsets of leukocytes in human peripheral blood, and peripheral blood samples from 18 healthy adults were examined, obtaining the percentages of each subset of peripheral blood leukocytes and the immunophenotypes of the main subsets. CONCLUSION: We established a 14-color panel for determining leukocyte subsets in human peripheral blood by flow cytometry, which produced stable and reliable results and was easy to operate.

Computational flow cytometric analysis to detect epidermal subpopulations in human skin.

BACKGROUND: The detection and dissection of epidermal subgroups could lead to an improved understanding of skin homeostasis and wound healing. Flow cytometric analysis provides an effective method to detect the surface markers of epidermal cells while producing high-dimensional data files. METHODS: A 9-color flow cytometric panel was optimized to reveal the heterogeneous subgroups in the epidermis of human skin. The subsets of epidermal cells were characterized using automated methods based on dimensional reduction approaches (viSNE) and clustering with Spanning-tree Progression Analysis of Density-normalized Events (SPADE). RESULTS: The manual analysis revealed differences in epidermal distribution between body sites based on a series biaxial gating starting with the expression of CD49f and CD29. The computational analysis divided the whole epidermal cell population into 25 clusters according to the surface marker phenotype with SPADE. This automatic analysis delineated the differences between body sites. The consistency of the results was confirmed with PhenoGraph. CONCLUSION: A multicolor flow cytometry panel with a streamlined computational analysis pipeline is a feasible approach to delineate the heterogeneity of the epidermis in human skin.

MicroRNA-184 Modulates Human Central Nervous System Lymphoma Cells Growth and Invasion by Targeting iASPP.

Central nervous system lymphoma (CNSL) remains a diagnostical and therapeutical challenge. MiRNAs post-transcriptionally regulate expression of targeted mRNAs through binding to their 3' UTR to inhibit their translation or promote their degradation. Oncoprotein inhibitory member of the ASPP family (iASPP), a key inhibitor of tumor suppressor p53, has been reported to play oncogenic role in cancers. Our present study was aimed to determine whether the miR-184/iASPP axis is involved in the proliferation and invasion of CNSL. A reduced level of miR-184 was observed in CNSL tissues. Exogenous miR-184 inhibited cell survival and invasion, as well as the tumor volumes, while miR-184 inhibition could reverse this process. The RNA and protein levels of iASPP were significantly inhibited by miR-184, and the 3' UTR of iASPP was shown to be a target of miR-184. The expression of iASPP was up-regulated in CNSL tissues, compared to that of the normal brain tissues. The inhibition of iASPP by shRNA iASPP significantly repressed CNSL cells' proliferation and invasion, and reduced the volume of the tumor. Besides, iASPP overexpression could partly restore the suppressive effect of miR-184 on CNSL cell proliferation and invasive capability. We also revealed that miR-184/iASPP axis regulated the proliferation and invasion via PI3K/Akt signaling pathway, which presents a novel potential therapy for intervention of CNSL. Taken together, our findings revealed the detailed role of the miR-184/iASPP axis in CNSL and this axis might modulate the proliferation and invasion of CNSL via regulating the PI3K/Akt signaling pathway. J. Cell. Biochem. 118: 2645-2653, 2017. © 2017 Wiley Periodicals, Inc.

Endothelium originated from colorectal cancer stem cells constitute cancer blood vessels.

Tumor growth depends on the formation of blood vessels that provide the supply of nutrients and oxygen. Previous data have shown that glioblastoma stem cells are able to give rise to vascular cells to constitute the functional vessels in tumor tissues. However, which kinds of vascular cells are generated from glioblastoma stem cells is largely debated. In addition, there is little evidence showing that the stem cells from other kinds of tumors can produce vascular cells to constitute the functional blood vessels in tumor tissues. Here we show that cancer stem cells of human colorectal carcinomas (CoCSC) can give rise to vascular endothelial cells and compose the vasculatures in cancer tissues. The human-cell-specific nuclear antigen NuMA+ vascular endothelial cells were detected in the blood vessels in xenografts derived from CoCSC. NuMA+ endothelial cells incorporated into functional blood vessels. Our data indicate that the cancer stem cells derived from human colorectal carcinomas have the capacity to generate functional blood vessels and provide a new mechanism for tumor vasculogenesis in carcinoma.

Stat3-Efemp2a modulates the fibrillar matrix for cohesive movement of prechordal plate progenitors.

Recently, emerging evidence has shown that Stat3 controls tumor cell migration and invasion. However, the molecular mechanisms by which Stat3 controls the cell movement remain largely unknown. Embryonic gastrula progenitors display coordinated and orientated migration, called collective cell migration. Collective cell migration is the simultaneous movement of multiple cells and is universally involved in physiological and pathological programs. Stat3 activity is required for the migration of gastrula progenitors, but it does not affect cell specification, thus suggesting that gastrula movements are an excellent model to provide insight into Stat3 control of cell migration in vivo. In this study, we reveal a novel mechanism by which Stat3 modulates extracellular matrix (ECM) assembly to control the coherence of collective migration of prechordal plate progenitors during zebrafish embryonic gastrulation. We show that Stat3 regulates the expression of Efemp2a in the prechordal plate progenitors that migrate anteriorly during gastrulation. Alteration of Stat3-Efemp2a signaling activity disrupted the configuration of fibronectin (FN) and laminin (LM) matrices, resulting in defective coherence of prechordal plate progenitor movements in zebrafish embryos. We demonstrate that Efemp2a acts as a downstream effector of Stat3 to promote ECM configuration for coherent collective cell migrations in vivo.

Cell-Derived Microparticles in Patients with Type 2 Diabetes Mellitus: a Systematic Review and Meta-Analysis.

BACKGROUND/AIMS: The aim of this study was to assess the association between circulating cell-derived microparticles (MPs) and type 2 diabetes mellitus (T2DM). METHODS: A literature search was performed systematically in PubMed and Embase to identify available case-control or cross-sectional studies that compared different types of cell-derived MPs in patients with T2DM and non-diabetic controls. Pooled standardized mean differences (SMDs) of each MP type were pooled using meta-analysis. RESULTS: Forty-eight studies involving 2,460 patients with T2DM and 1,880 non-diabetic controls were included for systematic review and 34 of which were included for quantitative study by meta-analysis. In the overall analysis, the levels of circulating total MPs (TMPs), platelet-derived MPs (PMPs), monocyte-derived MPs (MMPs) and endothelium-derived MPs (EMPs) were significantly higher in T2DM patients than those in controls (TMPs: SMD, 0.64; 95%CI, 0.12∼1.15; P=0.02; PMPs: SMD, 1.19; 95%CI, 0.88∼1.50; P <0.00001; MMPs: SMD, 0.92; 95%CI, 0.66∼1.17; P <0.00001; EMPs: SMD, 0.73; 95%CI, 0.50∼0.96; P <0.00001). Meanwhile, no significant difference was shown in leukocyte-derived MPs (LMPs) level between diabetic and non-diabetic groups (SMD, 0.37; 95%CI, -0.15∼0.89; P=0.17). CONCLUSIONS: The counts of TMPs, PMPs, MMPs and EMPs elevated in patients with T2DM. And cell-derived MPs may play a role in the pathogenesis of T2DM.

Tanshinone IIA inhibits acute promyelocytic leukemia cell proliferation and induces their apoptosis in vivo.

Tanshinone IIA (TanIIA) is a traditional Chinese agent and has been widely used for treatment of cardiovascular diseases. Our previous study has shown that TanIIA can induce the differentiation of acute promyelocytic leukemia (APL) cells by increasing C/EBPß expression and induce APL cell apoptosis in vitro. In this study, we evaluated the activity of TanIIA against APL in vivo. We found that treatment with TanIIA prevented APL-mediated reduction in body weights. Treatment with TanIIA inhibited the proliferation of APL cells and triggered APL cell apoptosis and differentiation in vivo. Treatment with TanIIA significantly prolonged the survival of APL-bearing mice. Our data indicate that TanIIA has potent anti-APL activity with little adverse effect.

[Using 9-color Flow Cytometry Immunophenotyping to Detect Activation and Apoptosis of Human TCR Vß Lymphocyte Subpopulations in Peripheral Blood Samples].

OBJECTIVE: To establish an assay using 9-color flow cytometry immunophenotyping to detect activation and apoptosis of human TCR Vß lymphocyte subpopulations in peripheral blood samples. METHODS: We used 5 antibodies (CD3, CD4, CD8, CD95, CD69), phospholipids binding proteins Annexin V, TCR Vß Repertoire Kit and nucleus dye DAPI to establish a 9-color flow cytometry assay. Peripheral blood samples were taken from eight healthy people for test of antibodies and determination of optimal PMT and staining method (single-stained vs stained with all but one antibody). RESULTS: Appropriate detecting voltage, antibody concentration and compensation methods were determined. The distribution of TCR Vß subgroup in our samples was consistent with the TCR Vß Repertoire Kit instruction and other published literature. CONCLUSION: We have established a effective easy using 9-color flow cytometry immunophenotyping to detect human TCR Vß lymphocyte subpopulations in peripheral blood samples.

ENC1-like integrates the retinoic acid/FGF signaling pathways to modulate ciliogenesis of Kupffer's Vesicle during zebrafish embryonic development.

The left-right asymmetry is an essential feature shared by vertebrates. Cilia-driven counterclockwise flow in the mammalian node structure leads to the left-right asymmetric distribution of signals and subsequent asymmetric patterning. Although several signaling pathways have been identified in the specification of node ciliated cells, little is known about the direct downstream effectors of these signaling pathways. Here, we showed that zebrafish Ectoderm-Neural Cortex1-like (enc1l) is expressed in the Kupffer's Vesicle (KV), an equivalent structure of the mammalian node in zebrafish, and is necessary for KV ciliogenesis. Loss-of-function of enc1l increased the number and decreased the length of KV cilia. The enc1l expression in the KV region was specifically regulated by retinoic acid (RA), FGF, and Wnt signaling pathways. In addition, knocking down enc1l or ectopic enc1l expression was able to rescue the KV cilium defects caused by alteration of RA and FGF signaling, but not Wnt signaling. Taken together, these data indicate thatEnc1l is a direct downstream effector of RA and FGF signaling pathways and modulates KV ciliogenesis in the zebrafish embryo.

Genetic insights into across pancreatitis types: the causal influence of immunoglobulin G N-glycosylation variants on disease risk.

Background: While a few case-control studies indicated a possible correlation of IgG N-glycosylation patterns with pancreatitis, their restricted sample sizes and methodologies prevented conclusive insights into causality or distinguishing traits across pancreatitis types. Method: We conducted a two-sample Mendelian Randomization (MR) analysis to investigate the causal relationship between 77 IgG N-glycosylation traits and various types of pancreatitis, including acute pancreatitis (AP), chronic pancreatitis (CP), alcohol acute pancreatitis (AAP), and alcohol chronic pancreatitis (ACP). This analysis utilized summary-level data from genome-wide association studies (GWAS), employing methods such as IVW, MR-Egger, and weighted median. To ensure the robustness of our findings, several sensitivity analyses, including Cochran's Q statistic, leave-one-out, MR-Egger intercept, and MR-PRESSO global test were conducted. Result: Our study uncovered the causal relationship between specific IgG N-glycosylation traits and various types of pancreatitis. Notably, an increase in genetically predicted IGP7 levels was associated with a decreased risk of developing AP. For CP, our data suggested a protective effect associated with higher levels of both IGP7 and IGP31, contrasting with increased levels of IGP27 and IGP65, which were linked to a heightened risk. Moreover, in the case of AAP, elevated IGP31 levels were causatively associated with a lower incidence, while higher IGP26 levels correlated with an increased risk for ACP. Conclusion: This study establishes causal relationship between specific IgG N-glycosylation patterns and varying risks of different pancreatitis forms, underscoring their potential as predictive biomarkers. These findings necessitate further exploration into the underlying mechanisms, promising to inform more personalized diagnostic and therapeutic strategies in pancreatitis management.

Colorectal cancer cells secreting DKK4 transform fibroblasts to promote tumour metastasis.

Wnt/ß-catenin signalling is aberrantly activated in most colorectal cancer (CRC) and is one key driver involved in the initiation and progression of CRC. However, mutations of APC gene in CRC patients retain certain activity of APC protein with decreased ß-catenin signalling and DKK4 expression significantly upregulates and represses Wnt/ß-catenin signalling in human CRC tissues, suggesting that a precisely modulated activation of the Wnt/ß-catenin pathway is essential for CRC formation and progression. The underlying reasons why a specifically reduced degree, not a fully activating degree, of ß-catenin signalling in CRC are unclear. Here, we showed that a soluble extracellular inhibitor of Wnt/ß-catenin signalling, DKK4, is an independent factor for poor outcomes in CRC patients. DKK4 secreted from CRC cells inactivates ß-catenin in fibroblasts to induce the formation of stress fibre-containing fibroblasts and myofibroblasts in culture conditions and in mouse CRC xenograft tissues, resulting in restricted expansion in tumour masses at primary sites and enhanced CRC metastasis in mouse models. Reduced ß-catenin activity by a chemical inhibitor MSAB promoted the CRC metastasis. Our findings demonstrate why reduced ß-catenin activity is needed for CRC progression and provide a mechanism by which interactions between CRC cells and stromal cells affect disease promotion.

Nuclear factor kappa B signaling initiates early differentiation of neural stem cells.

Inflammatory mediators, many of which activate the signaling of nuclear factor kappa B (NFκB), have received increasing attention in the field of neurogenesis. NFκB signaling regulates neurite outgrowth and neural plasticity as well as the proliferation/apoptosis and terminal differentiation of neural stem cells (NSCs). Early neurogenesis from NSCs produces identical progeny through symmetric division and committed daughter cells through asymmetric division. Here, we show that NFκB signaling is required for NSC initial differentiation. The canonical IKKß/IκBα/p65 pathway is activated during the initial stages of neural differentiation induced by treatment with TNFα or withdrawal of epidermal growth factor/basic fibroblast growth factor. NSC-specific inhibition of NFκB in transgenic mice causes an accumulation of Nestin(+) /Sox2(+) /glial fibrillary acidic protein(+) NSCs. Inhibition of NFκB signaling in vitro blocks differentiation and asymmetric division and maintains NSCs in an undifferentiated state. The induction of initial differentiation and asymmetry by NFκB signaling occurs through the inhibition of C/EBPß expression. Our data reveal a novel function of NFκB signaling in early neurogenesis and provide insight into the molecular mechanisms underlying neurodevelopmental disorders and neurodegenerative diseases.

Adipogenic and osteogenic differentiation of Lin(-)CD271(+)Sca-1(+) adipose-derived stem cells.

Adipose-derived stem cells (ASCs) have been defined as cells that undergo sustained in vitro growth and have multilineage differentiation potential. However, the identity and purification of ASCs has proved elusive due to the lack of specific markers and poor understanding of their physiological roles. Here, we prospectively isolated and identified a restricted homogeneous subpopulation of ASCs (Lin(-)CD271(+)Sca-1(+)) from mouse adipose tissues on the basis of cell-surface markers. Individual ASCs generated colony-forming unit-fibroblast at a high frequency and could differentiate into adipocytes, osteoblasts, and chondrocytes in vitro. Expansion of ASCs in a large quantity was feasible in medium supplemented with fibroblast growth factor-2 and leukemia inhibitory factor, without loss of adipogenic and osteogenic differentiation capacity. Moreover, we found that the transplanted ASCs can differentiate into adipocytes in adipogenic microenvironment in vivo and osteoblasts in osteogenic microenvironment in vivo. Thus we proved that Lin, CD271, and Sca-1 could be used as the specific markers to purify ASCs from adipose tissue. The method we established to identify ASCs as defined in vivo entities will help develop ASCs transplantation as a new therapeutic strategy for bone regeneration and adipose tissue regeneration in clinic.

Individualized leukemia cell-population profiles in common B-cell acute lymphoblastic leukemia patients.

Immunophenotype is critical for diagnosing common B-cell acute lymphoblastic leukemia (common ALL) and detecting minimal residual disease. We developed a protocol to explore the immunophenotypic profiles of common ALL based on the expression levels of the antigens associated with B lymphoid development, including IL-7Rα (CD127), cytoplasmic CD79a (cCD79a), CD19, VpreB (CD179a), and sIgM, which are successive and essential for progression of B cells along their developmental pathway. Analysis of the immunophenotypes of 48 common ALL cases showed that the immunophenotypic patterns were highly heterogeneous, with the leukemic cell population differing from case to case. Through the comprehensive analysis of immunophenotypic patterns, the profiles of patient-specific composite leukemia cell populations could provide detailed information helpful for the diagnosis, therapeutic monitoring, and individualized therapies for common ALL.

[Effect of cyclooxygenase-2 inhibitor on CD4+ CD25+ regulatory T cells in mouse hepatocellular carcinoma].

OBJECTIVE: To investigate the effect of celecoxib on regulatory T cells (Treg) in mouse hepatocellular carcinoma (HCC). METHODS: Total of 40 mice was divided into two subgroups, normal animal groups include control and celecoxib group, HCC groups include control and celecoxib group. 30 mg/kg of celecoxib were given daily for 24 days for celecoxib groups. All mice were sacrificed after 24 days treatment and the removed tumor weight were measured. By detecting CD4 and CD25 with flow cytometry, the level of Treg in peripheral blood was determined. The expressions of Forkhead/winged helix transcription factor-3 (Foxp3) protein in the tumor infiltrating lymphocytes (TILs) and cyclooxygenase-2 (COX-2) protein in tumor tissue were measured by immunohistochemistry techniques. RESULTS: The mean weight of tumor in celecoxib group is much lower than that of control group [(0.82 +/- 0.30) g vs. (1.41 +/- 0.63) g, P < 0.05]. The percentage of Treg in total CD4+ T cells isolated from the peripheral blood of HCC animals in control group was higher than that of normal control group [(4.26 +/- 0.89)% vs. (3.01 +/- 0.65)%, P < 0.05]. After treatment with celecoxib, the percentage of Treg was decreased [(3.04 +/- 0.74)% vs. (4.26 +/- 0.89)%, P < 0.053 and the percentage of Foxp3 positive cell in TILs was also decreased [(8.87 +/- 3.72)% vs. (30.78 +/- 9.26)%, P < or = 0.05]. The tumor tissue COX-2 protein expression in celecoxib group was lower than in that of control group [IOD (2.90 +/- 1.030) vs. (6.63 +/- 2.279), P < 0.01)] and the changing of COX-2 in tumor tissue was according to Treg in the peripheral blood. CONCLUSION: Treg cells are increased in the peripheral blood of HCC mice and COX-2 inhibitor could decrease the percentage of Treg cell in the peripheral blood or TILs.