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Aim: The impaired function of tubular mitochondria is critical in diabetic kidney disease (DKD) progression. RUNX3 is down‐regulated in DKD models. We intend to explore the effects of RUNX3 on mitochondrial dysfunction and renal tubule injury in DKD and related mechanisms. Methods: The development of diabetes models involved injecting mice with streptozotocin while treating HK‐2 cells with high glucose (HG). By using immunohistochemical techniques, the renal localizations of RUNX3 were identified. Levels of adenosine triphosphate (ATP), mitochondrial membrane potential, and biochemical index were detected by appropriate kits. Reactive oxygen species (ROS) generation was assessed with dihydroethidium and MitoSOX Red staining. Apoptosis was assessed by flow cytometry and TUNEL. RUNX3 ubiquitination was measured. Results: RUNX3 was mainly present in renal tubules. Overexpressing RUNX3 increased Mfn2, Mfn1, ATP levels, and mitochondrial membrane potential, reduced Drp1 and ROS levels and cell apoptosis, as well as Cyt‐C release into the cytoplasm. RUNX3 overexpression displayed a reduction in urinary albumin to creatinine ratio, Hemoglobin A1c, serum creatinine, and blood urea nitrogen. Overexpressing TLR4 attenuated the inhibitory effect of RUNX3 overexpression on mitochondrial dysfunction and cell apoptosis. HG promoted RUNX3 ubiquitination and SMURF2 expression. RUNX3 knockdown cancelled the inhibitory effect of SMURF2 on mitochondrial dysfunction and cell apoptosis. Conclusion: SMURF2 interference inhibits RUNX3 ubiquitination and TLR4/NF‐κB signalling pathway, thereby alleviating renal tubule injury. [ABSTRACT FROM AUTHOR]

Long noncoding RNA MIR17HG was involved with the progression of non‐small‐cell lung cancer (NSCLC), but specific mechanisms of MIR17HG‐mediated immune escape of NSCLC cells were still unknown. The present study investigated the function of MIR17HG on regulatory T cell (Treg)‐mediated immune escape and the underlying mechanisms in NSCLC. Expression of MIR17HG and miR‐17‐5p in NSCLC tissue samples were detected using quantitative real‐time PCR (qRT‐PCR). A549 and H1299 cells were transfected with sh‐MIR17HG, miR‐17‐5p inhibitor, or sh‐MIR17HG + miR‐17‐5p inhibitor, followed by cocultured with Tregs. Cell proliferation was measured using 5‐ethynyl‐20‐deoxyuridine (Edu) staining assay and cell counting kit‐8 (CCK‐8) assay. Flow cytometry was used for determining positive numbers of FOXP3+CD4+/CD25+/CD8+ Tregs. Through subcutaneous injection with transfected A549 cells, a xenograft nude mouse model was established. Weights and volumes of xenograft tumors were evaluated. Additionally, the expressions of immune‐related factors including transforming growth factor beta (TGF‐β), vascular endothelial growth factor A (VEGF‐A), interleukin‐10 (IL‐10), IL‐4, and interferon‐gamma (IFN‐γ) in cultured cells, were evaluated by enzyme‐linked immunosorbent assay and western blot analysis. Then, miR‐17‐5p was decreased and MIR17HG was enhanced in both NSCLC tissues and cell lines. MIR17HG knockdown significantly suppressed cell proliferation, tumorigenicity, and immune capacity of Tregs in A549 and H1299 cells, whereas sh‐MIR17HG significantly reduced expression levels of VEGF‐A, TGF‐β, IL‐4, and IL‐10 but promoted the IFN‐γ level in vitro and in vivo. Moreover, downregulation of miR‐17‐5p significantly reversed the effects of sh‐MIR17HG. Additionally, we identified that runt‐ related transcription factor 3 (RUNX3) was a target of miR‐17‐5p, and sh‐MIR17HG and miR‐17‐5p mimics downregulated RUNX3 expression. In conclusion, downregulation of MIR17HG suppresses tumorigenicity and Treg‐mediated immune escape in NSCLC through downregulating the miR‐17‐5p/RUNX3 axis, indicating that this axis contains potential biomarkers for NSCLC. [ABSTRACT FROM AUTHOR]

Multiple sclerosis (MS) is a common and devastating chronic inflammatory disease of the CNS. CD4+ T cells are assumed to be the first to cross the blood–central nervous system (CNS) barrier and trigger local inflammation. Here, we explored how pathogenicity‐associated effector programs define CD4+ T cell subsets with brain‐homing ability in MS. Runx3‐ and Eomes‐, but not T‐bet‐expressing CD4+ memory cells were diminished in the blood of MS patients. This decline reversed following natalizumab treatment and was supported by a Runx3+Eomes+T‐bet− enrichment in cerebrospinal fluid samples of treatment‐naïve MS patients. This transcription factor profile was associated with high granzyme K (GZMK) and CCR5 levels and was most prominent in Th17.1 cells (CCR6+CXCR3+CCR4−/dim). Previously published CD28− CD4 T cells were characterized by a Runx3+Eomes−T‐bet+ phenotype that coincided with intermediate CCR5 and a higher granzyme B (GZMB) and perforin expression, indicating the presence of two separate subsets. Under steady‐state conditions, granzyme Khigh Th17.1 cells spontaneously passed the blood–brain barrier in vitro. This was only found for other subsets including CD28− cells when using inflamed barriers. Altogether, CD4+ T cells contain small fractions with separate pathogenic features, of which Th17.1 seems to breach the blood–brain barrier as a possible early event in MS. [ABSTRACT FROM AUTHOR]

Breast cancer (BC) ranks as the most prevalent gynecologic tumor globally. Abnormal expression of miRNAs is concerned with the development of cancers such as BC. However, little is known about the role of miR‐600 in BC. This work aimed to explore the role of miR‐600 in the malignant progression and sorafenib sensitivity of BC cells. Expression and interaction of miR‐600/EZH2/RUNX3 were analyzed by bioinformatics. qRT‐PCR was utilized to assay RNA expression of miR‐600 and mRNA expression of EZH2/RUNX3. The binding relationship between miR‐600 and EZH2 was tested by dual luciferase assay and RNA immunoprecipitation (RIP). The effects of miR‐600/EZH2/RUNX3 axis on the malignant behavior and sorafenib sensitivity of BC cells were detected by CCK‐8 and colony formation assay. Low expression of miR‐600 and RUNX3 in BC was found by bioinformatics and molecular assays. High expression of EZH2 in BC was negatively correlated with RUVX3. Dual luciferase assay and RIP demonstrated that MiR‐600 could bind to EZH2. Cell assays displayed that miR‐600 knockdown could foster the malignant progression of BC cells and reduce the sensitivity of BC cells to sorafenib. EZH2 knockdown or RUNX3 overexpression could offset the effect of miR‐600 inhibitor on the malignant behavior and sorafenib sensitivity of BC cells. MiR‐600 can hinder the malignant behavior of BC cells and foster sensitivity of BC cells to sorafenib via EZH2/RUNX3 axis, exhibiting the miR‐600/EZH2/RUNX3 axis as a feasible therapeutic target for BC patients. [ABSTRACT FROM AUTHOR]

Long‐term abuse of methamphetamine (MA) can cause lung toxicity. Intercellular communication between macrophages and alveolar epithelial cells (AECs) is critical for maintaining lung homeostasis. Microvesicles (MVs) are an important medium of intercellular communication. However, the mechanism of macrophage MVs (MMVs) in MA‐induced chronic lung injury remains unclear. This study aimed to investigate if MA can augment the activity of MMVs and if circ_YTHDF2 is a key factor in MMV‐mediated macrophage–AEC communication, and to explore the mechanism of MMV‐derived circ_YTHDF2 in MA‐induced chronic lung injury. MA elevated peak velocity of the pulmonary artery and pulmonary artery accelerate time, reduced the number of alveolar sacs, thickened the alveolar septum, and accelerated the release of MMVs and the uptake of MMVs by AECs. Circ_YTHDF2 was downregulated in lung and MMVs induced by MA. The immune factors in MMVs were increased by si‐circ_YTHDF. Circ_YTHDF2 knockdown in MMVs induced inflammation and remodelling in the internalised AECs by MMVs, which was reversed by circ_YTHDF2 overexpression in MMVs. Circ_YTHDF2 bound specifically to and sponged miRNA‐145‐5p. Runt‐related transcription factor 3 (RUNX3) was identified as potential target of miR‐145‐5p. RUNX3 targeted zinc finger E‐box‐binding homeobox 1 (ZEB1)‐related inflammation and EMT of AECs. In vivo, circ_YTHDF2 overexpression‐MMVs attenuated MA‐induced lung inflammation and remodelling by the circ_YTHDF2–miRNA‐145‐5p–RUNX3 axis. Therefore, MA abuse can induce pulmonary dysfunction and alveolus injury. The immunoactivity of MMVs is regulated by circ_YTHDF2. Circ_YTHDF2 in MMVs is the key to communication between macrophages and AECs. Circ_YTHDF2 sponges miR‐145‐5p targeting RUNX3 to participate in ZEB1‐related inflammation and remodelling of AECs. MMV‐derived circ_YTHDF2 would be an important therapeutic target for MA‐induced chronic lung injury. Key points: Methamphetamine (MA) abuse induces pulmonary dysfunction and alveoli injury.The immunoactivity of macrophage microvesicles (MMVs) is regulated by circ_YTHDF2.Circ_YTHDF2 in MMVs is the key to MMV‐mediated intercellular communication between macrophages and alveolar epithelial cells.Circ_YTHDF2 sponges miR‐145‐5p targeting runt‐related transcription factor 3 (RUNX3) to participate in zinc finger E‐box‐binding homeobox 1 (ZEB1)‐related inflammation and remodelling.MMV‐derived circ_YTHDF2 would be an important therapeutic target for MA‐induced chronic lung injury. [ABSTRACT FROM AUTHOR]

Background: Cancer‐associated fibroblasts (CAFs) are a major stromal component of human breast cancers and often promote tumor proliferation, progression and malignancy. We previously established an experimental CAF (exp‐CAF) cell line equipped with a potent tumor‐promoting ability. It was generated through prolonged incubation of immortalized human mammary fibroblasts with human breast cancer cells in a tumor xenograft mouse model. Results: Herein, we found that the exp‐CAFs highly express Runt‐related transcription factor 3 (RUNX3), while counterpart fibroblasts do not. In breast cancer patients, the proportion of RUNX3‐positive stromal fibroblast‐like cells tends to be higher in cancerous regions than in non‐cancerous regions. These findings suggest an association of RUNX3 with CAF characteristics in human breast cancers. To investigate the functional role of RUNX3 in CAFs, the exp‐CAFs with or without shRNA‐directed knockdown of RUNX3 were implanted with breast cancer cells subcutaneously in immunodeficient mice. Comparison of the resulting xenograft tumors revealed that tumor growth was significantly attenuated when RUNX3 expression was suppressed in the fibroblasts. Consistently, Ki‐67 and CD31 immunohistochemical staining of the tumor sections indicated reduction of cancer cell proliferation and microvessel formation in the tumors formed with the RUNX3‐suppressed exp‐CAFs. Conclusion: These results suggest that increased RUNX3 expression could contribute to the tumor‐promoting ability of CAFs through mediating cancer cell growth and neoangiogenesis in human breast tumors. [ABSTRACT FROM AUTHOR]

Objectives: Runx3, a member of the Runx family of transcription factors, has been studied as a tumour suppressor and key player of organ development. In a previous study, we reported differentiation failure and excessive angiogenesis in the liver of Runx3 knock‐out (KO) mice. Here, we examined a function of the Runx3 in liver, especially in iron metabolism. Methods: We performed histological and immunohistological analyses of the Runx3 KO mouse liver. RNA‐sequencing analyses were performed on primary hepatocytes isolated from Runx3 conditional KO (cKO) mice. The effect of Runx3 knock‐down (KD) was also investigated using siRNA‐mediated KD in functional human hepatocytes and human hepatocellular carcinoma cells. Result: We observed an iron‐overloaded liver with decreased expression of hepcidin in Runx3 KO mice. Expression of BMP6, a regulator of hepcidin transcription, and activity of the BMP pathway were decreased in the liver tissue of Runx3 KO mice. Transcriptome analysis on primary hepatocytes isolated from Runx3 cKO mice also revealed that iron‐induced increase in BMP6 was mediated by Runx3. Similar results were observed in Runx3 knock‐down experiments using HepaRG cells and HepG2 cells. Finally, we showed that Runx3 enhanced the activity of the BMP6 promoter by responding to iron stimuli in the hepatocytes. Conclusion: In conclusion, we suggest that Runx3 plays important roles in iron metabolism of the liver through regulation of BMP signalling. [ABSTRACT FROM AUTHOR]

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. Prognosis is often unfavorable. In this study, the effects of microRNA‐802 (miR‐802) on HCC progression were assessed in vivo and in vitro. miR‐802 was found to be significantly upregulated in HCC tumor tissue compared to paired adjacent nontumor tissue. In vitro, transfection with a miR‐802 mimic accelerated SMMC‐7721 cellular proliferation, increased accumulation of the cell‐cycle S‐phase cell populations, as well as cell migration. In vivo injection of a miR‐802 agomir promoted HCC proliferation in nude mice. Targets of miR‐802 were predicted by miRWalk, miRanda, RNA22, and Targetscan. By luciferase reporter assay RUNX3 was identified as a direct target of miR‐802. As judged by western blot analysis, RUNX3 was upregulated when miR‐802 was inhibited. These data demonstrate increased miR‐802 expression in patients with HCC and that miR‐802 overexpression promotes tumor cell growth, in a RUNX3‐dependent manner. [ABSTRACT FROM AUTHOR]

The histone demethylase Jumonji domain‐containing 1A (JMJD1A) is overexpressed in multiple cancers and promotes cancer progression. However, the role and mechanism of JMJD1A in gastric cancer (GC) remains poorly understood. Here, we found that JMJD1A could suppress GC cell proliferation and xenograft tumor growth. Using RNA sequencing, we identified runt‐related transcription factor 3 (RUNX3) as a novel target gene of JMJD1A. Mechanistically, we identified that JMJD1A upregulated RUNX3 through co–activating Ets‐1 and reducing the H3K9me1/2 levels at the RUNX3 promoter in GC cells. Functionally, JMJD1A inhibits the growth of GC cells in vivo, which is partially dependent on RUNX3. Moreover, JMJD1A expression was decreased in GC and low expression of JMJD1A was correlated with an aggressive phenotype and a poor prognosis in patients with GC. Importantly, JMJD1A expression was positively associated with RUNX3 expression in GC samples. These studies indicated that JMJD1A upregulates RUNX3 expression via co–activation of transcription factor Ets‐1 to inhibit proliferation of GC cells. Our findings provide new insight into the mechanism by which JMJD1A regulates RUNX3 transcription and suggest that JMJD1A and/or RUNX3 may be used as a therapeutic intervention for GC. [ABSTRACT FROM AUTHOR]

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy and is refractory to available treatments. Delineating the regulatory mechanisms of metabolic reprogramming, a key event in pancreatic cancer progression, may identify candidate targets with potential therapeutic significance. We hypothesized that inflammatory signaling pathways regulate metabolic adaptations in pancreatic cancer. Metabolic profiling of tumors from PDAC patients with a high‐ (>median, n = 31) and low‐NOS2 (inducible nitric oxide synthase;

Finding out the driver gene critical for the maintenance of breast cancer stem cells (BrCSCs) is important for designing a new strategy to eradicate these cells to improve patient's prognosis. Here, in our study, we revealed that PIM1, an oncogenic serine‐threonine kinase and a well‐proven contributor to the tumorigenesis of breast cancer, was involved in BrCSCs regulation and promised to be a new target for eradicating BrCSCs. In brief, PIM1 could enhance the stem cell–like traits of breast cancer cells by promoting the phosphorylation and cytoplasmic localization of RUNX3. The nuclear dislocation of RUNX3 disabled this tumour suppressor and led to breast cancer cells gaining stem cell–like traits. Inhibition of PIM1 significantly induced the nuclear retention of RUNX3, recovered its transcriptional function and attenuated the stem cell–like properties of breast cancer cells. Those findings deepened our understanding of PIM1's oncogenic effect, underlining the significance of PIM1 in designing a new strategy aimed at BrCSCs. [ABSTRACT FROM AUTHOR]

Neuropathic pain correlates with a lesion or other dysfunction in the nervous system. Sphingosine‐1‐phosphate receptor 2 (S1P2) is expressed in the central nervous system and modulates synaptic plasticity. The present study aimed to investigate the role of S1P2 in neuropathic pain caused by chronic constriction injury (CCI). Sprague‐Dawley rats were allocated into eight groups (n = 15 for each group): sham, CCI, CCI + green fluorescent protein, CCI + S1P2, CCI + Ctrl‐short hairpin RNA (shRNA), CCI + S1P2 shRNA, CCI + S1P2 + CYM‐5442, and CCI + S1P2 shRNA + CYM‐5442. The CCI model was established via sciatic nerve ligation. S1P2 was overexpressed or knocked down by intrathecal injection of adeno‐associated virus‐S1P2 (AAV‐S1P2) or AAV‐S1P2 shRNA. The S1P1 agonist, CYM‐5442 (1 mg/kg), was injected intraperitoneally after surgery. S1P2 expression, pain thresholds, apoptosis signaling, inflammation, and oxidative stress in rats were then examined. We found that sciatic nerve injury downregulated S1P2 expression in the spinal cords of rats. S1P2 overexpression enhanced pain thresholds. In contrast, S1P2 knockdown decreased pain thresholds in rats exposed to CCI. CCI and S1P2 silencing increased secretion of interleukin‐1β (IL‐1β), IL‐6, and CCL2, whereas S1P2 overexpression decreased. S1P2 impeded CCI‐induced reactive oxygen species (ROS) production and runt‐related transcription factors 3 (RUNX3) downregulation, and S1P2 knockdown had the opposite effect. S1P2 overexpression suppressed Bax and active caspase 3 expression and promoted Bcl‐2 expression, whereas loss of S1P2 reversed their expression. Additionally, S1P1 activation counteracted the effect of S1P2 on pain sensitivity. In conclusion, S1P2 is downregulated in CCI rats and may help modulate neuropathic pain via the ROS/RUNX3 pathway. [ABSTRACT FROM AUTHOR]

Circular RNAs (circRNAs), a novel class of non‐coding RNAs, have emerged as indispensable modulators in human malignancies. Aberrant cellular senescence is a phenotype observed in various cancers. The association of circRNAs with cellular senescence in tumors is yet to determined. Here, we investigated the role of circLARP4 in cellular senescence and cell proliferation in hepatocellular carcinoma (HCC). Downregulated circLARP4 level was observed in HCC tissues and cell lines. Low expression level of circLARP4 independently predicted poor survival outcome. Gain‐of‐function and loss‐of‐function assays demonstrated that circLARP4 suppressed HCC cell proliferation, mediated cell cycle arrest and induced senescence in vitro. Levels of p53 and p21, 2 key regulatory molecules in cellular senescence, were increased in circLARP4‐overexpressed HCC cells and decreased in circLARP4‐silenced HCC cells. In vivo experiments further confirmed the tumor‐suppressing activity of circLARP4. Further mechanistic studies showed that circLARP4 dampened HCC progression by sponging miR‐761, thereby promoting the expression level of RUNX3 and activating the downstream p53/p21 signaling. Our study revealed the role of circLARP4/miR‐761/RUNX3/p53/p21 signaling in HCC progression, providing a potential survival predictor and therapeutic candidate for HCC. circLARP4 is downregulated in hepatocellular carcinoma. circLARP4 suppresses hepatocellular carcinoma cell proliferation, mediates cell cycle arrest and induces senescence. circLARP4 dampens hepatocellular carcinoma progression by sponging miR‐761, thereby promoting the expression of RUNX3 and activating the downstream p53/p21 signaling. [ABSTRACT FROM AUTHOR]

Although 13cRA is involved in the regulation of cellular proliferation and differentiation, its physiological roles in chondrocyte proliferation and differentiation still remain unknown. Here, we showed that 13cRA could induce the proliferation of sika deer antler chondrocytes and expression of Ccnd3 and Cdk6. Administration of 13cRA to antler chondrocytes resulted in an obvious increase in the expression of chondrocyte marker Col II and hypertrophic chondrocyte marker Col X. Silencing of Crabp2 expression by specific siRNA could prevent the 13cRA-induced up-regulation of Col X, whereas overexpression of Crabp2 showed the opposite effects. Further study found that Crabp2 mediated the regulation of 13cRA on the expression of Runx3 which was highly expressed in the antler cartilage and inhibited the differentiation of antler chondrocytes. Moreover, attenuation of Runx3 expression greatly raised 13cRA-induced chondrocyte differentiation. Simultaneously, 13cRA could stimulate the expression of Cyp26a1 and Cyp26b1 in the antler chondrocytes. Inhibition of Cyp26a1 and/or Cyp26b1 reinforced the effects of 13cRA on the expression of Col X and Runx3, while overexpression of Cyp26b1 rendered the antler chondrocytes hyposensitive to 13cRA. Collectively, 13cRA may play an important role in the differentiation of antler chondrocytes through targeting Runx3. Crabp2 enhances the effects of 13cRA on chondrocyte differentiation, while Cyp26a1 and Cyp26b1 weaken the sensitivity of antler chondrocytes to 13cRA. [ABSTRACT FROM AUTHOR]

Laryngeal squamous cell carcinoma (LSCC) is a highly aggressive malignant cancer and accounts for 1% to 2% of all malignancies diagnosed worldwide. Runt-related transcription factor 3 (RUNX3), an important tumor suppressor, is known to related to lymph node metastasis and the development of LSCC. However, the biological roles and potential mechanisms RUNX3 expression was not well understood. In this study, we reported that the RUNX3 was significantly downregulated and highly methylated in LSCC compared with their matched normal. The enforced expression of RUNX3 inhibited LSCC cell migration, invasion, and proliferation, whereas the inhibition of RUNX3 did the opposite. We identified that RUNX3 was regulated by miR-148a-3p and found that the expression level of miR-148-3p was significantly decreased and positively related with the expression of RUNX3 in LSCC. We also identified that DNA methyltransferase enzyme DNA (cytosine-5-)-methyltransferase 1 (DNMT1) was targeted by miR-148a-3p in LSCC. The knockdown of DNMT1 promoted the expression of RUNX3 and inhibited migration, invasion, and proliferation in LSCC cells. In summary, our study demonstrated that miR-148a-3p may regulate RUNX3 expression through the modulation of DNMT1-dependent DNA methylation in LSCC, providing a novel target and a potential therapeutic pathway against LSCC. LSCC is a highly aggressive malignant cancer and accounts for 1% to 2% of all malignancies diagnosed worldwide. In this study, we reported that RUNX3, an important tumor suppressor, was significantly downregulated and highly methylated in LSCC compared with their matched normal. The overexpression of RUNX3 inhibited LSCC cell migration, invasion, and proliferation, whereas the inhibition of RUNX3 did the opposite. Moreover, RUNX3 was regulated by miR-148a-3p, which targeted DNA methyltransferase enzyme DNMT1 in LSCC cells. Therefore, miR-148a-3p may regulate RUNX3 expression through the modulation of DNMT1-dependent DNA methylation in LSCC, providing a novel target and a potential therapeutic pathway against LSCC. [ABSTRACT FROM AUTHOR]

Background Preoperative chemoradiation combined with surgery has been of focus recently in order to improve prognosis in esophageal squamous cell carcinoma ( ESCC) patients. Finding biological markers that may assist in predicting the therapeutic effect of chemoradiation may benefit the treatment effect. In this study, the role of RUNX3 in the formation of cisplatin resistance in ESCC was examined. Methods The study enrolled 103 stage IIa-IIIb ESCC patients who had undergone esophagectomy. RUNX3 expression in ESCC tissue was detected. Results A higher expression of RUNX3 in ESCC patients correlated with a more sensitive response to cisplatin-based chemotherapy. A consistently lower expression of RUNX3 was found in the ESCC tissues of patients who agreed to perioperative chemotherapy compared with patients who had undergone no preoperative treatment. A lower RUNX3 expression in cisplatin-resistant ESCC cell lines, Eca109 and TE-1, was observed compared with parental cell lines. Heterologous RUNX3 expression significantly suppressed cisplatin resistance in Eca109 and TE-1, both in vitro and vivo. Meanwhile, heterologous RUNX3 expression could inhibit growth and induce apoptosis in cisplatin resistant Eca109 and TE-1 cell lines in vitro. Remarkable inhibition of the Akt pathway was observed in heterologous RUNX3 expression in Eca109 and TE-1. Silencing Akt1 could reverse cisplatin resistance in Eca109 and TE-1. Conclusion Our results confirmed that a loss of RUNX3 in ESCC may contribute to cisplatin-resistance. RUNX3 could reverse cisplatin resistance via suppression of the Akt pathway in ESCC patients. [ABSTRACT FROM AUTHOR]

Micro RNAs are increasingly reported as tumour suppressors that regulate gene expression after transcription. Our results demonstrated that miR-4295 is overexpression in glioma tissues and its level is significantly correlated with clinical stage. We also found that miR-4295 inhibited the cell G0/G1 arrest and apoptosis leading to promoted cell proliferation and activity. The murine modelling study revealed that female nude mice injected with U87/anti-miR-4295 exhibit subcutaneous tumours in the right groin. Compared with anti- NC, the tumour volume was significantly decreased in anti-miR-4295 treatment group. Furthermore, we confirmed miR-4295 mediates the expression of RUNX3 by targeting its 3′untranslation region. In addition, N-myc protein also could bind to the promoter of pri-miR-4295 and inhibit the expression of RUNX3 in glioma cells. These results validate a pathogenetic role of a miR-4295 in gliomas and establish a potentially regulatory and signalling pathway involving N-myc/miR-4295/ RUNX3 in gliomas. [ABSTRACT FROM AUTHOR]

Accumulating data reveal that microRNAs are involved in gastric carcinogenesis. To date, no information was reported about the function and regulatory mechanism of miR-532-5p in human gastric cancer (GC). Thus, our study aims to determine the role and regulation of miR-532-5p in GC. Here, we found that transient and stable overexpression of miR-532-5p dramatically increased the potential of colony formation and migration of GC cells, decreased the percentage of cells in G1 phase and cell apoptosis in vitro, and increased the weight of mice lungs and number of lung xenografts in vivo. Gain-of-function, loss-of-function and luciferase activity assays demonstrated that miR-532-5p negatively regulated the expression of RUNX3 and its targets directly. We also found that miR-532-5p level was negatively correlated with RUNX3 gene expression in various GC cell lines. Our results indicate that miR-532-5p functions as an oncogenic miRNA by promoting cell growth, migration and invasion in human GC cells. [ABSTRACT FROM AUTHOR]

Non-small cell lung cancer ( NSCLC) frequently metastasizes to bone, which is associated with significant morbidity and a dismal prognosis. RUNX3 functions as a tumour suppressor in lung cancer and loss of expression occurs more frequently in invasive lung adenocarcinoma than in pre-invasive lesions. Here, we show that RUNX3 and RUNX3-regulated chemokines are linked to NSCLC-mediated bone resorption. Notably, the receptor activator of nuclear factor- κB ligand ( RANKL)/osteoprotegerin ( OPG) ratio, an index of osteoclastogenic stimulation, was significantly increased in human osteoblastic cells treated with conditioned media derived from RUNX3-knockdown NSCLC cells. We aimed to identify RUNX3-regulated factors that modify the osteoblastic RANKL/ OPG ratio and found that RUNX3 knockdown led to CCL5 up-regulation and down-regulation of CCL19 and CXCL11 in NSCLC cells. Tumour size was noticeably increased and more severe osteolytic lesions were induced in the calvaria and tibiae of mice that received RUNX3-knockdown cells. In response to RUNX3 knockdown, serum and tissue levels of CCL5 increased, whereas CCL19 and CXCL11 decreased. Furthermore, CCL5 increased the proliferation, migration, and invasion of lung cancer cells in a dose-dependent manner; however, CCL19 and CXCL11 did not show any significant effects. The RANKL/ OPG ratio in osteoblastic cells was increased by CCL5 but reduced by CCL19 and CXCL11. CCL5 promoted osteoclast differentiation, but CCL19 and CXCL11 reduced osteoclastogenesis in RANKL-treated bone marrow macrophages. These findings suggest that RUNX3 and related chemokines are useful markers for the prediction and/or treatment of NSCLC-induced bone destruction. © 2015 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland. [ABSTRACT FROM AUTHOR]

Correlative and functional studies support the involvement of the RUNX gene family in haematological malignancies. To elucidate the role of epigenetics in RUNX inactivation, we evaluated promoter DNA methylation of RUNX1, 2, and 3 in 23 leukaemia cell lines and samples from acute myeloid leukaemia ( AML), acute lymphocytic leukaemia ( ALL) and myelodysplatic syndromes ( MDS) patients. RUNX1 and RUNX2 gene promoters were mostly unmethylated in cell lines and clinical samples. Hypermethylation of RUNX3 was frequent among cell lines (74%) and highly variable among patient samples, with clear association to cytogenetic status. High frequency of RUNX3 hypermethylation (85% of the 20 studied cases) was found in AML patients with inv(16)(p13.1q22) compared to other AML subtypes (31% of the other 49 cases). RUNX3 hypermethylation was also frequent in ALL (100% of the six cases) but low in MDS (21%). In support of a functional role, hypermethylation of RUNX3 was correlated with low levels of protein, and treatment of cell lines with the DNA demethylating agent, decitabine, resulted in mRNA re-expression. Furthermore, relapse-free survival of non-inv(16)(p13.1q22) AML patients without RUNX3 methylation was significantly better ( P = 0·016) than that of methylated cases. These results suggest that RUNX3 silencing is an important event in inv(16)(p13.1q22) leukaemias. [ABSTRACT FROM AUTHOR]

RUNX3 is a tumor suppressor for a variety of cancers. RUNX3 suppresses the canonical Wnt signaling pathway by binding to the TCF4/β-catenin complex, resulting in the inhibition of binding of the complex to the Wnt target gene promoter. Here, we confirmed that RUNX3 suppressed Wnt signaling activity in several gastric cancer cell lines; however, we found that RUNX3 increased the Wnt signaling activity in Kato III and SNU668 gastric cancer cells. Notably, RUNX3 expression increased the ratio of the Wnt signaling-high population in the Kato III cells. although the maximum Wnt activation level of individual cells was similar to that in the control. As found previously, RUNX3 also binds to TCF4 and β-catenin in Kato III cells, suggesting that these molecules form a ternary complex. Moreover, the Ch IP analyses revealed that TCF4, β-catenin and RUNX3 bind the promoter region of the Wnt target genes, Axin2 and c- Myc, and the occupancy of TCF4 and β-catenin in these promoter regions is increased by the RUNX3 expression. These results suggest that RUNX3 stabilizes the TCF4/β-catenin complex on the Wnt target gene promoter in Kato III cells, leading to activation of Wnt signaling. Although RUNX3 increased the Wnt signaling activity, its expression resulted in suppression of tumorigenesis of Kato III cells, indicating that RUNX3 plays a tumor-suppressing role in Kato III cells through a Wnt-independent mechanism. These results indicate that RUNX3 can either suppress or activate the Wnt signaling pathway through its binding to the TCF4/β-catenin complex by cell context-dependent mechanisms. [ABSTRACT FROM AUTHOR]

Highlights: [•] miR-106b is significantly up-regulated in laryngeal carcinoma. [•] miR-106b as an oncogene can regulate laryngeal carcinoma cell line growth and invasion through directly targeting RUNX3. [•] We propose a model whereby one miRNA targets two genes in laryngeal carcinoma. [ABSTRACT FROM AUTHOR]

CD4+ helper T cells are essential for immune responses and differentiate in the thymus from CD4+ CD8+ 'double-positive' ( DP) thymocytes. The transcription factor Runx3 inhibits CD4+ T-cell differentiation by repressing Cd4 gene expression; accordingly, Runx3 is not expressed in DP thymocytes or developing CD4+ T cells. The transcription factor Thpok is upregulated in CD4-differentiating thymocytes and required to repress Runx3. However, how Runx3 is controlled at early stages of CD4+ T-cell differentiation, before the onset of Thpok expression, remains unknown. Here we show that Gata3, a transcription factor preferentially and transiently upregulated by CD4+ T-cell precursors, represses Runx3 and binds the Runx3 locus in vivo. Accordingly, we show that high-level Gata3 expression and expression of Runx3 are mutually exclusive. Furthermore, whereas Runx3 represses Cd4, we show that Gata3 promotes Cd4 expression in Thpok-deficient thymocytes. Thus, in addition to its previously documented role in promoting CD4-lineage gene-expression, Gata3 represses CD8-lineage gene expression. These findings identify Gata3 as a critical pivot of CD4- CD8 lineage differentiation. [ABSTRACT FROM AUTHOR]

BACKGROUND: Helicobacter pylori has been recognized as a definite carcinogen for gastric cancer (GC); however, the pathogenesis of H. pylori infection remains unclear. Runt-related transcription factor 3 ( RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to GC. However, in H. pylori infection-associated GC, the role of RUNX3 has not been studied. METHODS: The authors used real-time methylation-specific polymerase chain reaction analysis to determine methylation status of the RUNX3 promoter in a spectrum of gastric lesions, including 220 samples of chronic atrophic gastritis, 196 samples of intestinal metaplasia, 134 samples of gastric adenoma, 102 samples of dysplasia, and 202 samples of GC with paired noncancerous mucosa tissues and corresponding blood specimens. The association of abnormal methylation with precancerous gastric lesions was evaluated along with the association between RUNX3 methylation and H. pylori infection, and the concordance of methylation levels was investigated between serum and tissues. RESULTS: The results indicated that increasing RUNX3 promoter methylation was correlated with distinct stages of GC progression. GC tissues had the highest methylation proportion (75.2%) compared with precancerous gastric lesions, including chronic atrophic gastritis (15.9%), intestinal metaplasia (36.7%), gastric adenoma (41.8%), and dysplasia (54.9%). H. pylori infection, a major risk factor for GC, contributed to the inactivation of RUNX3 in gastric epithelial cells through promoter hypermethylation. The levels of RUNX3 methylation in serum were in significant concordance with the methylation levels observed in GC tissues ( P = .887). CONCLUSIONS: The current findings supported RUNX3 methylation as a risk factors for the carcinogenesis of chronic atrophic gastritis with H. pylori infection and indicated that circulating RUNX3 methylation is a valuable biomarker for the detection of early GC. Cancer 2012. © 2012 American Cancer Society. [ABSTRACT FROM AUTHOR]

To identify prognostic markers in nonmuscle invasive bladder cancer (NMIBC), the combined effect of RUNX3 and MGC17624 for predicting NMIBC progression was assessed. RUNX3 promoter methylation was examined using methylation specific-polymerase chain reaction (MS-PCR). MGC17624 mRNA expression was evaluated by real-time PCR. Patients were divided into three groups according to the status of the two genes and the prognostic effects of these markers were evaluated. The median follow-up period was 57.8 months (range, 9.1-189.7). The mRNA expression level of MGC17624 was significantly lower in patients with positive RUNX3 methylation than in those with negative methylation ( p = 0.047). Kaplan-Meier estimates showed significant differences in time-to-progression between the genetic combination predictors (log-rank test; p < 0.001). Patients with a poor predictive combination were at a significantly higher risk for progression [Hazard ratio (HR), 22.579] than patients with a good predictive combination in multivariate Cox regression analysis. In the subgroup analysis, a poor predictive combination accurately estimated progression in patients with intravesical therapy (HR, 20.081) and in those who experienced recurrence (HR, 54.233). Assessment of the status of RUNX3 and MGC17624 in combination was identified as a reliable method for predicting NMIBC progression. [ABSTRACT FROM AUTHOR]

Oral Diseases (2011) 17, 794-800 Objectives: Recent studies indicate various molecular abnormalities in oral squamous cell carcinomas ( OSCC), including DNA methylation of tumor-associated genes. Although promoter hypermethylation of Wnt pathway antagonists RUNX3 ( Runt-related transcription factor 3) and Wnt inhibitory factor 1 ( WIF1) has been identified as a common event in a number of carcinomas, methylation status and the role of RUNX3 as a possible tumor suppressor in oral and head and neck cancer are yet controversial. The aim of our study is to determine the occurrence of RUNX3 and WIF1 genes hypermethylation and correlation with tumor and host-related factors and prognosis in tongue carcinomas. Material and Methods: In 76 patients with tongue carcinoma, RUNX3 and WIF1 genes promoter hypermethylation analysis was assessed by nested methylation-specific PCR method. Results: Hypermethylation of WIF1 and RUNX3 genes promoters was observed in 35% and 25% of carcinomas, respectively. RUNX3 gene promoter hypermethylation was significantly associated with lymph node involvement ( P = 0.013) and tumor stage ( P = 0.006), but not with the overall survival. Occurrence of RUNX3 and WIF1 genes comethylation was associated with nodal status ( P = 0.058) and tumor stage ( P = 0.055). Conclusions: Our findings indicate that RUNX3 and WIF1 are frequently aberrantly methylated and that RUNX3 promoter methylation could be considered as a potential prognostic marker in tongue carcinoma. [ABSTRACT FROM AUTHOR]

BACKGROUND: RUNX3 is a tumor suppressor that plays important roles in cell proliferation, apoptosis, and metastasis. The authors investigated the role of RUNX3 in melanoma pathogenesis and analyzed the prognostic impact of RUNX3 expression in a large series of melanoma patients. METHODS: Two sets of tissue microarrays were constructed, including 440 cases of melanomas (202 for the training set and 238 for the validation set) and 88 cases of nevi (25 normal nevi and 63 dysplastic nevi). RUNX3 expression was evaluated by immunohistochemistry. RESULTS: Positive RUNX3 expression was observed in 56%, 54%, 33%, and 24% of the biopsies in normal nevi, dysplastic nevi, primary melanoma, and melanoma metastases, respectively. Significant differences for positive nuclear RUNX3 staining were observed between dysplastic nevi and primary melanomas (P = .002, chi-square test), between dysplastic nevi and melanoma metastases (P < .001, chi-square test), and between primary melanoma and melanoma metastases (P = .045, chi-square test). Loss of RUNX3 expression was correlated with a worse 5-year survival of melanoma patients in both training and validation sets. Furthermore, loss of RUNX3 expression was also correlated with a poor 5-year disease-specific survival in primary melanoma (P = .001) and metastatic melanoma patients (P = .008). Multivariate Cox regression analysis revealed that positive RUNX3 expression is an independent prognostic factor to predict melanoma patient outcome. CONCLUSIONS: Our findings indicate that RUNX3 plays an important role in melanoma pathogenesis and may serve as a promising prognostic marker for melanoma. [ABSTRACT FROM AUTHOR]

Subramaniam M M, Chan J Y, Omar M F M, Ito K, Ito Y, Yeoh K G, Salto-Tellez M & Putti T C (2010) Histopathology 57, 555-563 Lack of RUNX3 inactivation in columnar cell lesions of breast Aims: Ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) exhibit frequent RUNX3 inactivation by promoter hypermethylation and protein mislocalization. The aim of this study was to analyse columnar cell lesions (CCLs) to further characterize RUNX3 involvement in breast carcinogenesis. Methods and results: RUNX3 expression and methylation was analysed by immunohistochemistry and methylation-specific polymerase chain reaction (PCR), respectively, in 75 CCLs. Our previously reported DCIS and IDC data were also included. Consistent with terminal duct lobular units (TDLUs) (73 of 75, 97%), active nuclear RUNX3 protein was observed in 73 of 75 (97%) CCLs [columnar cell change, 46 of 48 (96%); columnar cell hyperplasia, 12 of 12 (100%) and flat epithelial atypia, 15 of 15 (100%). In contrast to matched TDLUs from cancer specimens [four of 40 (10%)] and CCLs, significantly inactivated RUNX3 expression was detected in DCIS [17 of 20 (85%)] and IDC [18 of 20 (90%)] (all P < 0.001). RUNX3 methylation was more frequent in DCIS [15 of 20 (75%)] and IDC [16 of 20 (80%)] than CCLs [(none of 20 (0%)] and matched TDLUs [one of 10 (10%)] from cancer patients (all P < 0.001). Conclusions: RUNX3 inactivation occurs specifically in DCIS and IDC cells. In addition, RUNX3 inactivation may not be a common association between CCLs and breast carcinomas. [ABSTRACT FROM AUTHOR]

Background and Aims: Runx family transcription factors are integral components of transforming growth factor-β signaling pathways and have been implicated in cell cycle regulation, differentiation, apoptosis, and malignant transformation. The silencing of tumor suppressor genes by aberrant hypermethylation occurs frequently in human cancer. It has been noted previously that Runx3 is regarded as an important tumor suppressor gene. Methods: Reverse transcription polymerase chain reaction was used to measure Runx3 and the DNA methyltransferase 1 (Dnmt1) messenger RNA (mRNA) expression level of paired samples of primary gastric cancer and corresponding non-cancerous gastric mucosae, which were obtained from surgically resected specimens of 70 patients. Western blot was used to detect the expression of Runx3 at protein levels. The promoter methylation status was measured by using methylation-specific polymerase chain reaction. We used Annexin V-FITC/PI assay to detect cell apoptosis, and the cell cycle was also analyzed. In order to examine the cell cycle and/or apoptosis, we determined p27 and caspase 3 expression by immunohistological analysis. Results: Our results demonstrate a loss or substantial decrease of Runx3 expression in 70 cases of gastric tumors as compared with that in normal gastric mucosa (0.5749 ± 0.3580 vs 1.7252 ± 0.4085, P < 0.05). The protein levels of the Runx3 gene were significantly lower in gastric cancers than those in adjacent normal tissues. The hypermethylation of Runx3 was involved in 50% (28/56) of gastric cancer tissues, which had reduced Runx3 mRNA expression. The differences of the Dnmt1 mRNA level were significant between the methylated and unmethylated Runx3 cancerous groups. Runx3 methylation was significantly correlated with increased Dnmt1 ( r = 0.64, P < 0.01). Enforced restoration of Runx3 expression led to the induction of cell apoptosis and upregulation of p27 and caspase3 expression in vitro. Conclusions: Our results suggest that a decrease of Runx3 expression by DNA hypermethylation is frequently associated with the evolution of gastric cancer. Runx3 was an independent prognostic factor and a potential therapeutic target for gastric cancer. [ABSTRACT FROM AUTHOR]

Gastric cancer is the top lethal cancer in Asia. As the majority of cases present with advanced disease, conventional therapies (surgery, chemotherapy, and radiotherapy) have limited efficacy to reduce mortality. Emerging modalities provide promise to combat this malignancy. Target-protein-based cancer therapy has become available in clinical practice. Numerous molecules have been shown potential to target specific pathways for tumor cell growth. Cyclooxygenase-2 (COX-2) is overexpressed in and correlated with gastric cancer, and knockdown of COX-2 or administration of COX-2 inhibitors suppresses tumor formation in models of gastric cancer. Induction of apoptosis, reduction of angiogenesis, and blocking of potassium ion channels may present new mechanisms of COX-2 inhibition. Runt-related transcription factor 3 ( RUNX3) is a candidate tumor suppressor gene whose deficiency is causally related to gastric cancer. RUNX3 is downregulated in metastatic gastric cancer. RUNX3 activation inhibits angiogenesis in xenograft tumors in nude mice. Tumor microenvironment modulation also provides a powerful tool to inhibit cancer development and progress; details of the potential roles of angiopoietins are discussed in this review. Osteopontin is a secreted protein involved in stress response, inflammation, wound healing, and immune response. Inhibition of osteopontin by RNA interfering technique suppressed tumorigenesis as well as angiogenesis in gastric cancer. Immunotherapy remains another important choice of adjuvant therapy for cancer. A tumor-specific antigen MG7-Ag has been identified with great potential for inducing immune response in gastric cancer. Using HLA-A-matched allogeneic gastric cancer cells to induce tumor-specific cytotoxic T lymphocytes appeared to be an alternative option of immunotherapy for gastric cancer. [ABSTRACT FROM AUTHOR]

The important role of CD8+ T cells in controlling HIV-1 infection through the innate as well as the adaptive immune system is well established. In addition to the major histocompatibility complex (MHC)-dependent cytotoxic activity of CD8+ T cells, they produce soluble factors that suppress HIV-1 replication in an MHC-independent manner. Several of those factors have been identified, including β-chemokines, Rantes, MIP-1α, MIP-1β, and MDC. We previously identified that prothymosin alpha (ProTα) in the conditioned medium of HVS transformed CD8+ T cells was a potent inhibitor of HIV-1 replication following proviral integration. In this report we further characterize the anti-HIV-1 activity of ProTα by demonstrating its target-cell specificity, distinction from additional inhibitors of HIV-1 transcription in CD8+ T cell supernatants, as well as the differential regulation of host cell antiviral genes that could impact HIV-1 replication. These genes include a number of transcription factors as well IFN-α-inducible genes including PKR, IRF1, and Rantes, in the absence of induction of IFN-α. These data suggest that the anti-HIV-1 activity of ProTα is mediated through the modulation of a number of genes that have been reported to suppress HIV-1 replication including the dysregulation of transcription factors and the induction of PKR and Rantes mRNA. [ABSTRACT FROM AUTHOR]

A case of adenocarcinoma with chief cell differentiation, a novel entity in the stomach, is presented. An 82-year-old woman who had undergone distal gastrectomy, was scheduled for upper gastrointestinal endoscopy to clarify mechanical ileus. A protruding tumor 16 × 14 × 9 mm in size was found in the cardia of the remnant stomach. Histological examination indicated a well-differentiated tubular adenocarcinoma composed of basophilic columnar or cuboidal cells with occasional coarse eosinophilic granules. Immunohistochemical analysis revealed strong expression of pepsinogens I and II and Runt-related transcription factor gene 3 (RUNX3), characteristic for chief cells, and MUC6 typical for mucous neck cells. However, the tumor cells were negative for the proton pump alpha subunit, a marker for parietal cells. Cdx2 and defensin-5 were not present, confirming the lack of an intestinal phenotype. The cancer cells shared characteristics of a chief cell and a mucous neck cell, resembling an ancestor of these two cell types, so-called ‘primitive chief cell’ in fundic gland. In line with these data, the cancer was diagnosed as an adenocarcinoma with chief cell differentiation. [ABSTRACT FROM AUTHOR]

The runt family transcriptional regulator, Runx3, is upregulated during the differentiation of CD8 single-positive thymocytes and is expressed in peripheral CD8+ T cells. Mice carrying targeted deletions in Runx3 have severe defects in the development and activation of CD8+ T cells, resulting in decreased CD8+ T-cell numbers, aberrant coexpression of CD4, and failure to expand CD8+ effector cells after activation in vivo or in vitro. Expression of each of the three vertebrate runt family members, including Runx3, is controlled by two promoters that generate proteins with alternative N-terminal sequences. The longer N-terminal region of Runx3, expressed from the distal promoter, is highly conserved among family members and across species. We show that transcripts from the distal Runx3 promoter are selectively expressed in mature CD8+ T cells and are upregulated upon activation. We show that the N-terminal region encoded by these transcripts carries an independent transcriptional activation domain. This domain can activate transcription in isolation, and contributes to the increased transcriptional activity observed with this isoform as compared to those expressed from the ancestral, proximal promoter. Together, these data suggest an important role for the additional N-terminal Runx3 activation domain in CD8+ T-cell function. [ABSTRACT FROM AUTHOR]

Silencing of the RUNX3 gene by hypermethylation of its promoter CpG island plays a major role in gastric carcinogenesis. To quantitatively evaluate RUNX3 methylation, a fiber-type DNA microarray was used on which methylated and unmethylated sequence probes were mounted. After bisulfite modification, a part of the RUNX3 promoter CpG island, at which methylation is critical for gene silencing, was amplified by polymerase chain reaction using a Cy5 end-labeled primer. Methylation rates (MR) were calculated as the ratio of the fluorescence intensity of a methylated sequence probe to the total fluorescence intensity of methylated and unmethylated probes. Five gastric cancer cell lines were analyzed, as well as 26 primary gastric cancers and their corresponding non-neoplastic gastric epithelia. MR in four of the cancer cell lines that lost RUNX3 mRNA ranged from 99.0% to 99.7% (mean, 99.4%), whereas MR in the remaining cell line that expressed RUNX3 mRNA was 0.6%. In primary gastric cancers and their corresponding non-neoplastic gastric epithelia, MR ranged from 0.2% to 76.5% (mean, 22.7%) and from 0.7% to 25.1% (mean, 5.5%). Ten (38.5%) of the 26 gastric cancers and none of their corresponding non-neoplastic gastric epithelia had MR >30%. Most of the samples with MR >10% tested methylation-positive by conventional methylation-specific polymerase chain reaction (MSP). This microarray-based methylation assay is a promising method for the quantitative assessment of gene methylation. [ABSTRACT FROM AUTHOR]

Runx3 is a transcription factor expressed by gastric epithelial cells. In the Runx3−/– mouse, gastric epithelia exhibited hyperplasia, and epithelial apoptosis was suppressed. By analyzing growth of the epithelial cells in primary culture, we found that Runx3−/– gastric epithelial cells are less sensitive to the growth-inhibitory and apoptosis-inducing activities of TGF-β, suggesting that Runx3 is a major growth regulator of gastric epithelial cells by regulating their response to TGF-β. We also found that Runx3 plays an important role in the control of gastric epithelial differentiation. When subcutaneously implanted into nude mice, Runx3−/– gastric epithelial cells formed tumors in which some cells differentiated into intestinal-type cells. Clonal analysis showed that gastric epithelial cells transdifferentiate into intestinal-type cells in the tumor. Considering that gastric epithelial differentiation is very stable, and that intestinal-type cells never differentiate in the mouse stomach, it is remarkable that gastric epithelial cells transdifferentiate into intestinal-type cells. We conclude that Runx3 is deeply involved in the control of both growth and differentiation of gastric epithelial cells. The role of Runx3 in the specification of gastric epithelial cells is discussed. [ABSTRACT FROM AUTHOR]

Mori T, Nomoto S, Koshikawa K, Fujii T, Sakai M, Nishikawa Y, Inoue S, Takeda S, Kaneko T, Nakao A. Decreased expression and frequent allelic inactivation of the RUNX3 gene at 1p36 in human hepatocellular carcinoma.Liver International 2005: 25: 380–388.© Blackwell Munksgaard 2005Alteration in transforming growth factor-β signaling pathway is one of the main causes of hepatocellular carcinoma (HCC). The human runt-related transcription factor 3 gene (RUNX3) is an important component of this pathway. RUNX3 locus 1p36 is commonly deleted in a variety of human cancers, including HCC. Therefore, we examined genetic and epigenetic alterations of RUNX3 in human HCC.Five HCC cell lines and 41 patients with HCC were investigated in this study. We examined the expression of RUNX3 mRNA, methylation status of RUNX3 promoter region, loss of heterozygosity (LOH) at 1p36, and mutation analysis. These results were compared with clinicopathological data.Promoter hypermethylation was detected in four (80%) of five HCC cell lines and 31 (75.6%) of 41 HCC tissues, confirmed by sequence of bisulfite-treated DNA. LOH was detected in 14 (37.8%) of 37 HCC. By comparison with clinicopathological data, hypermethylation was more common in hepatitis C virus antibody and formation of capsule-positive cases, and decrease of expression was correlated strongly with advanced stage and LOH-detected cases.Hypermethylation and LOH appear to be common mechanisms for inactivation of RUNX3 in HCC. Therefore, RUNX3 may be an important tumor suppressor gene related to hepatocarcinogenesis. [ABSTRACT FROM AUTHOR]

Human runt-related transcription factor gene 3 (RUNX3) is considered as a possible candidate of tumour suppressor gene in human gastric carcinoma.To investigate the RUNX3 protein expression in human gastric mucosa and carcinoma, we generated a polyclonal antibody, AS251, which recognized amino acid sequences from 251 to 266 of human RUNX3. The AS251 antibody was immunoreactive with only RUNX3 protein, but not with RUNX1 and RUNX2. The AS251-antibody was available for Western blotting and immunohistochemistry using paraffin-embedded specimens.Western-blot analysis revealed that three (MKN-1, -7 and -45) of six human gastric carcinoma cell lines variably expressed RUNX3 protein, consistent with the expression pattern ofRUNX3mRNA reported previously by Liet al. (Cell2002;109:113–24). Immunohistochemistry disclosed RUNX3 protein in most chief cells and a few gastrin-containing G cells in normal mucosa, but not in intestinal metaplasia and carcinoma cells.These data suggest that RUNX3 may play a physiologic role in chief cells and G cells in gastric mucosa, and that suppression of RUNX3 expression in intestinal metaplasia and carcinoma of human stomach may be implicated in gastric carcinogenesis.Eur J Clin Invest 2004; 34 (9): 605 –612 [ABSTRACT FROM AUTHOR]