The generation of PD-L1 and PD-L2 in cancer cells: From nuclear chromatin reorganization to extracellular presentation

The immune checkpoint blockade (ICB) targeting on PD-1/PD-L1 has shown remarkable promise in treating cancers. However, the low response rate and frequently observed severe side effects limit its broad benefits. It is partially due to less understanding of the biological regulation of PD-L1. Here, we systematically and comprehensively summarized the regulation of PD-L1 from nuclear chromatin reorganization to extracellular presentation. In PD-L1 and PD-L2 highly expressed cancer cells, a new TAD (topologically associating domain) (chr9: 5,400,000-5,600,000) around CD274 and CD273 was discovered, which includes a reported super-enhancer to drive synchronous transcription of PD-L1 and PD-L2. The re-shaped TAD allows transcription factors such as STAT3 and IRF1 recruit to PD-L1 locus in order to guide the expression of PD-L1. After transcription, the PD-L1 is tightly regulated by miRNAs and RNA-binding proteins via the long 3'UTR. At translational level, PD-L1 protein and its membrane presentation are tightly regulated by post-translational modification such as glycosylation and ubiquitination. In addition, PD-L1 can be secreted via exosome to systematically inhibit immune response. Therefore, fully dissecting the regulation of PD-L1/PD-L2 and thoroughly detecting PD-L1/PD-L2 as well as their regulatory networks will bring more insights in ICB and ICB-based combinational therapy.

Research advances in the association between activating transcription factor 3 and chronic liver diseases / 临床肝胆病杂志

Activating transcription factor 3 (ATF3) belongs to the transcription factor ATF/CREB family and is a stress-induced adaptive response gene. ATF3 is involved in the regulation of various cell activities to adapt to the changes in intracellular and extracellular environments. Recent studies have shown that ATF3 plays an important role in the development and progression of various chronic liver diseases, including nonalcoholic fatty liver disease, liver fibrosis, and liver cancer, by regulating gluconeogenesis, lipid metabolism, and immune function. This article reviews the mechanism of action of ATF3 in chronic liver diseases.

Cardiac Fibroblast-Specific Activating Transcription Factor 3 Promotes Myocardial Repair after Myocardial Infarction / 中华医学杂志(英文版)

<p><b>Background</b>Myocardial ischemia injury is one of the leading causes of death and disability worldwide. Cardiac fibroblasts (CFs) have central roles in modulating cardiac function under pathophysiological conditions. Activating transcription factor 3 (ATF3) plays a self-protective role in counteracting CF dysfunction. However, the precise function of CF-specific ATF3 during myocardial infarction (MI) injury/repair remains incompletely understood. The aim of this study was to determine whether CF-specific ATF3 affected cardiac repair after MI.</p><p><b>Methods</b>Fifteen male C57BL/6 wild-type mice were performed with MI operation to observe the expression of ATF3 at 0, 0.5, 1.0, 3.0, and 7.0 days postoperation. Model for MI was constructed in ATF3TGfl/flCol1a2-Cre+ (CF-specific ATF3 overexpression group, n = 5) and ATF3TGfl/flCol1a2-Cre- male mice (without CF-specific ATF3 overexpression group, n = 5). In addition, five mice of ATF3TGfl/flCol1a2-Cre+ and ATF3TGfl/flCol1a2-Cre- were subjected to sham MI operation. Heart function was detected by ultrasound and left ventricular remodeling was observed by Masson staining (myocardial fibrosis area was detected by blue collagen deposition area) at the 28 day after MI surgery in ATF3TGfl/flCol1a2-Cre+ and ATF3TGfl/flCol1a2-Cre- mice received sham or MI operation. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect cell proliferation/cell cycle-related gene expression in cardiac tissue. BrdU staining was used to detect fibroblast proliferation.</p><p><b>Results</b>After establishment of an MI model, we found that ATF3 proteins were increased in the heart of mice after MI surgery and dominantly expressed in CFs. Genetic overexpression of ATF3 in CFs (ATF3TGfl/flCol1a2-Cre+ group) resulted in an improvement in the heart function as indicated by increased cardiac ejection fraction (41.0% vs. 30.5%, t = 8.610, P = 0.001) and increased fractional shortening (26.8% vs. 18.1%, t = 7.173, P = 0.002), which was accompanied by a decrease in cardiac scar area (23.1% vs. 11.0%, t = 8.610, P = 0.001). qRT-PCR analysis of CFs isolated from ATF3TGfl/flCol1a2-Cre+ and ATF3TGfl/flCol1a2-Cre- ischemic hearts revealed a distinct transcriptional profile in ATF3-overexpressing CFs, displaying pro-proliferation properties. BrdU-positive cells significantly increased in ATF3-overexpressing CFs than control CFs under angiotensin II stimuli (11.5% vs. 6.8%, t = 31.599, P = 0.001) or serum stimuli (31.6% vs. 20.1%, t = 31.599, P = 0.001). The 5(6)-carboxyfluorescein N-hydroxysuccinimidyl ester assay showed that the cell numbers of the P2 and P3 generations were higher in the ATF3-overexpressing CFs at 24 h (P2: 91.6% vs. 71.8%, t = 8.465, P = 0.015) and 48 h (P3: 81.6% vs. 51.1%, t = 9.029, P = 0.012) after serum stimulation. Notably, ATF3 overexpression-induced CF proliferation was clearly increased in the heart after MI injury.</p><p><b>Conclusions</b>We identify that CF-specific ATF3 might contribute to be MI repair through upregulating the expression of cell cycle/proliferation-related genes and enhancing cell proliferation.</p>

Downregulated ATF3 expression inhibited growth of adrenocortical carcinoma cells and investigation of its mechanisms / 中华内分泌代谢杂志

Objective To investigate the effect of downregulated activating transcription factor 3 ( ATF3) expression on proliferation of adrenocortical carcinoma cells and its mechanisms. Methods Immunohistochemistry and Western blotting were used to detect the expression of ATF3 in human adrenocortical tumor tissues and cells. Adrenocortical carcinoma cells, Sw-13, and NCI-H259R cells, were transfected with siATF3 using lipidosome 2000, and expression of ATF3 mRNA was determined using RT-PCR; expression of ATF3, cleaved caspase 3, caspase 3, cleaved PARP, and PARP proteins were detected using Western blotting; cell growth inhibition rate and apoptosis rate were monitored using MTT and AnnexinV-FITC/PI, respectively. Sw-13 and NCI-H259R cells were treated with NVP-BEZ235, Perifosine, BKM120, IWP-2, PP2, KN93, Everolimus respectively followed by detected expression of ATF3 mRNA by realtime PCR. The effect of ATF3 on cell proliferation after inhibition of related signaling pathways were detected by MTT. Results The ATF3 in human adrenocortical gland tumor tissues and cells showed high expression. The levels of ATF3 mRNA and protein in Sw-13 and NCI-F259R cells transfected with siATF3 were significantly reduced. Compared with the negative control group ( NC siRNA), siATF3 transfection significantly inhibited the proliferation of Sw-13 and NCI-F259R cells ( P＜0. 05 ), and increased the apoptosis rate ( P＜0.05). Western blotting shown that the levels of cleaved caspase 3 and cleaved PARP protein in siATF3 transfected cells increased significantly; and realtime PCR results indicated that the expression of ATF3 mRNA was dramatically inhibited by PP2, KN93, and IWP-2 in NCI-F259R cells compared with control group ( DMSO ); but ATF3 significantly promoted the proliferation activity of NCI-F259R cells which treated by PP2, KN93, and IWP-2 signaling inhibitors. Conclusion High expression of ATF3 is existed in adrenocortical carcinoma cells. Downregulated ATF3 expression may inhibit cell proliferation and activate apoptosis pathway, resulting in apoptosis in Sw-13 and NCI-F259R cells, this mechanism of action is related to activating Wnt/β-catenin, CaMKI, and SRC pathway.

Role of α7nAChR in electroacupuncture-induced reduction of acute lung injury induced by endotoxin in rats: the relationship with JAK2/STAT3 signaling pathway / 中华麻醉学杂志

Objective To evaluate the role of α7 nicotinic acetylcholine receptor (α7nAChR) in electroacupuncture (EA)-induced reduction of acute lung injury (ALI) induced by endotoxin and the relationship with Janus kinase 2/signal transducers and activators of transcription 3 (JAK2/STAT3) signaling pathway in rats.Methods Sixty clean-grade healthy male Sprague-Dawley rats,aged 8 weeks,weighing 200-220 g,were divided into 6 groups (n=10 each) using a random number table method:control group (group C),endotoxin-induced ALI group (group ALI),EA at acupoints plus ALI group (group EA),specific α7nAChR antagonist α-bungarotoxin (α-BGT) plus ALI group (group BA),EA at acupoints plus α-BGT plus ALI group (group EBA),and EA at non-acupoints plus ALI group (group SEA).ALI was induced by intravenously injecting lipopolysaccharide 5 mg/kg.EA stimulation of bilateral Zusanli and Neiguan acupoints was performed (frequency of disperse-dense wave 2/15 Hz,wave length 0.2-0.5 ms,intensity 1-2 mA) once a day (time for stimulation 9:00 to 10:00,30 min per time) at 1-4 days before establishing the model in EA and EAB groups.EA was performed at the points 0.5 cm lateral to the acupoints of Zusanli and Neiguan with the same parameters of stimulation in group SEA.o-BGT 1 μg/kg was intraperitoneally injected at 30 min before establishing the model in BA and EBA groups.Rats were sacrificed at 6 h after injecting lipopolysaccharide,and lungs were removed for microscopic examination of the pathological changes which were scored and for determination of wet to dry weight ratio (W/D ratio),contents of tumor necrosis factor-alpha (TNF-α),interleukin-lbeta (IL-1β) and IL-6 (by enzyme-linked immunosorbent assay),and expression of α7nAChR,phosphorylated JAK2 (p-JAK2) and phosphorylated STAT3 (p-STAT3) (by Western blot).Results Compared with group C,the lung injury scores,W/D ratio and contents of TNF-α,IL-1β and IL-6 were significantly increased,and the expression of α7nAChR,p-JAK2 and p-STAT3 was up-regulated in the other five groups (P＜0.05).Compared with group ALI,the lung injury scores,W/D ratio and contents of TNF-α,IL-1β and IL-6 were significantly decreased,and the expression of α7nAChR,p-JAK2 and p-STAT3 was up-regulated in group EA,the lung injury scores,W/D ratio and contents of TNF-α,IL-1β and IL-6 were significantly increased,and the expression of o7nAChR,p-JAK2 and p-STAT3 was down-regulated in group BA (P＜0.05),and no significant change was found in the parameters mentioned above in group SEA (P＞0.05).Compared with group EA,the lung injury scores,W/D ratio and contents of TNF-α,IL-1β and IL-6 were significantly increased,and the expression of o7nAChR,p-JAK2 and p-STAT3 was down-regulated in group EBA (P＜0.05).Conclusion Up-regulated expression of α7nAChR activates JAK2/STAT3 signaling pathway,which is involved in EA-induced reduction of ALI in rats.

Expressions and clinical significances of ATF3 and Runx2 in breast carcinoma / 国际肿瘤学杂志

Objective To study the expressions and clinical significances of activating transcription factor 3 (ATF3) and Runt-related transcription factor 2 (Runx2) in breast carcinoma tissues.Methods The expressions of ATF3 and Runx2 were detected in 105 cases of primary breast invasive ductal carcinoma (IDC) and their matched para-tumor breast tissues by immunohistochemistry.The relationships between the two transcription factors and the clinical pathological features of IDC patients were analyzed.Results The positive expression rates of ATF3 and Runx2 in IDC group were 80.95％ (85/105) and 69.52％ (73/105) respectively,much higher than those in para-tumor breast tissues 11.43 ％ (12/105) and 8.57％ (9/105),with statistically significant differences (x2 =102.097,P =0.000;x2 =11.595,P =0.001).ATF3 and Runx2 expressions showed significant relationships with histological grade (x2 =14.623,P =0.001;x2 =24.891,P =0.000),lymph node metastasis (x2 =7.059,P =0.008;x2 =6.358,P =0.012) and pTNM stage of IDC (x2 =5.807,P =0.016;x2 =4.902,P =0.027),while both were not correlated with patients' age (x2 =0.274,P =0.601;x2 =1.554,P =0.213) and tumor size (x2 =2.476,P =0.290;x2 =5.261,P =0.072).There was a significant positive relationship between ATF3 and Runx2 in breast carcinoma (C =0.498,P =0.000).Conclusion The over-expressions of ATF3 and Runx2 may participate in the tumorigenesis,invasion,metastasis and clinical stage of breast carcinoma,which suggests that they may be key factors to evaluate malignant degree and prognosis of breast carcinoma.

Kahweol from Coffee Induces Apoptosis by Upregulating Activating Transcription Factor 3 in Human Colorectal Cancer Cells

Kahweol as a coffee-specific diterpene has been reported to induce apoptosis in human cancer cells. Although some molecular targets for kahweol-mediated apoptosis have been elucidated, the further mechanism for apoptotic effect of kahweol is not known. Activating transcription factor 3 (ATF3) has been reported to be associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which kahweol stimulates ATF3 expression and apoptosis in human colorectal cancer cells. Kahweol increased apoptosis in human colorectal cancer cells. It also increased ATF3 expression through the transcriptional activity. The responsible cis-element for ATF3 transcriptional activation by kahweol was CREB located between −147 to −85 of ATF3 promoter. ATF3 overexpression increased kahweol-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by kahweol. Inhibition of ERK1/2 and GSK3β blocked kahweol-mediated ATF3 expression. The results suggest that kahweol induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.

Effect of dexmedetomidine on JAK2/STAT3 signaling pathway in mice with endotoxin-induced acute lung injury / 中华麻醉学杂志

Objective To evaluate the effect of dexmedetomidine on janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway in mice with endotoxin-induced acute lung injury (ALI).Methods Twenty-four male C57BL/6 mice,weighing 20-25 g,were randomly divided into 3 groups (n=8 each) using a random number table:control group (group C),endotoxin-induced ALI group (group ALI),and dexmedetomidine group (group Dex).ALI was induced with lipopolysaccharide (LPS) 5 mg/kg injected intraperitoneally.Dexmedetomidine 40 μg/kg was injected intraperitoneally at 1 h after LPS injection in group Dex,while the equal volume of normal saline was given in C and ALI groups.At 6 h after LPS injection,blood samples were collected from the carotid artery to detect arterial oxygen partial pressure (PaO2).The mice were then sacrificed,and broncho-alveolar lavage fluid (BALF) was collected for determination of the concentrations of total protein,interleukin-1β (IL-1β),IL-6 and tumor necrosis factor-or (TNF-α).The lung tissues were removed for determination of wet to dry lung weight ratio (W/D ratio),and expression of phosphorylated JAK2 (p-JAK2),phosphorylated STAT3 (p-STAT3),IL-1β mRNA,IL-6 mRNA and TNF-α mRNA,and for examination of the pathological changes which were scored.Results Compared with group C,the PaO2 was significantly decreased,and W/D ratio,lung injury score,concentrations of total protein,IL-1β,IL-6 and TNF-α in BALF,and expression of IL-1β,IL-6 and TNF-α mRNA,p-JAK2 and p-STAT3 were increased in ALI and Dex groups (P＜0.05).Compared with group ALI,the PaO2 was significantly increased,and W/D ratio,lung injury score,concentrations of total protein,IL-1β,IL-6 and TNF-α in BALF,and expression of IL-1β,IL-6 and TNF-α mRNA,p-JAK2 and p-STAT3 were decreased in group Dex (P＜0.05).Conclusion The mechanism by which dexmedetomidine attenuates LPS-induced ALI is probably related to inhibition of activation of JAK2/STAT3 signaling pathway in mice.

Activating transcription factor-3 induction is involved in the anti-inflammatory action of berberine in RAW264.7 murine macrophages

Berberine is an isoquinoline alkaloid found in Rhizoma coptidis, and elicits anti-inflammatory effects through diverse mechanisms. Based on previous reports that activating transcription factor-3 (ATF-3) acts as a negative regulator of LPS signaling, the authors investigated the possible involvement of ATF-3 in the anti-inflammatory effects of berberine. It was found berberine concentration-dependently induced the expressions of ATF-3 at the mRNA and protein levels and concomitantly suppressed the LPS-induced productions of proinflammatory cytokines (TNF-α, IL-6, and IL-1β). In addition, ATF-3 knockdown abolished the inhibitory effects of berberine on LPS-induced proinflammatory cytokine production, and prevented the berberine-induced suppression of MAPK phosphorylation, but had little effect on AMPK phosphorylation. On the other hand, the effects of berberine, that is, ATF-3 induction, proinflammatory cytokine inhibition, and MAPK inactivation, were prevented by AMPK knockdown, suggesting ATF-3 induction occurs downstream of AMPK activation. The in vivo administration of berberine to mice with LPS-induced endotoxemia increased ATF-3 expression and AMPK phosphorylation in spleen and lung tissues, and concomitantly reduced the plasma and tissue levels of proinflammatory cytokines. These results suggest berberine has an anti-inflammatory effect on macrophages and that this effect is attributable, at least in part, to pathways involving AMPK activation and ATF-3 induction.

The research progress on the role of ATF3 in the malignant tumor / 中国医师杂志

Activating transcription factor 3 (ATF3) is a protein produced by the cells in the ischemic reperfusion injury,neuronal or liver damage,skin damage,viral oncogene expression or DNA damage.Recent studies have found that ATF3 plays an important role in the occurrence and development of human malignant tumors.

Naringenin-Mediated ATF3 Expression Contributes to Apoptosis in Human Colon Cancer

Naringenin (NAR) as one of the flavonoids observed in grapefruit has been reported to exhibit an anti-cancer activity. Activating transcription factor 3 (ATF3) is associated with apoptosis in human colon cancer cells. This study was performed to investigate the molecular mechanism by which NAR stimulates ATF3 expression and apoptosis in human colon cancer cells. NAR reduced the cell viability and induced an apoptosis in human colon cancer cells. ATF3 overexpression increased NAR-mediated cleaved PARP, while ATF3 knockdown attenuated the cleavage of PARP by NAR. NAR increased ATF3 expression in both protein and mRNA level, and increased the luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by NAR is located between -317 and -148 of ATF3 promoter. p38 inhibition blocked NAR-mediated ATF3 expression, its promoter activation and apoptosis. The results suggest that NAR induces apoptosis through p38-dependent ATF3 activation in human colon cancer cells.

ATF3 Mediates Anti-Cancer Activity of Trans-10, cis-12-Conjugated Linoleic Acid in Human Colon Cancer Cells

Conjugated linoleic acids (CLA) are a family of isomers of linoleic acid. CLA increases growth arrest and apoptosis of human colorectal cancer cells through an isomer-specific manner. ATF3 belongs to the ATF/CREB family of transcription factors and is associated with apoptosis in colorectal cancer. The present study was performed to investigate the molecular mechanism by which t10, c12-CLA stimulates ATF3 expression and apoptosis in human colorectal cancer cells. t10, c12-CLA increased an apoptosis in human colorectal cancer cells in dose dependent manner. t10, c12-CLA induced ATF3 mRNA and luciferase activity of ATF3 promoter in a dose-dependent manner. The responsible region for ATF3 transcriptional activation by t10, c12-CLA is located between -147 and -1850 of ATF3 promoter. mRNA stability of ATF3 was not affected by t10, c12-CLA treatment. t10, c12-CLA increases GSK3beta expression and suppresses IGF-1-stimulated phosphorylation of Akt. The knockdown of ATF3 suppressed expression of GSK3beta and NAG-1 and PARP cleavage. The results suggest that t10, c12-CLA induces apoptosis through ATF3-mediated pathway in human colorectal cancer cells.

Involvement of miR-106b in endothelial cells-mediated angiogenesis / 中华老年心脑血管病杂志

Objective To study whether miR-106b is involved in endothelial cells-mediated angio-genesis .Methods miR-106b cultured and transfected with endothelial cells was divided into miR-106b group ,blank control group and positive control group .RNA was extracted from miR-106b .The transfection efficiency was confirmed by inverse transcription .Endothelial cell tubes formed in matrigel were observed .Apoptosis of transfected miR-106b was assayed by TUNEL assay .Target genes of miR-106b were detected .Expressions of miR-106b and candidate genes were detected by RT-PCR and Western blot ,respectively .Results The number of endothe-lial cell tubes formed in matrigel was significantly less in miR-106b group than in blank control group and positive control group .The ratio of formed tubes ,signal transduction and mRNA ex-pression level were significantly lower in miR-106b group than in positive control group ( P0 .05) .Conclusion miR-106b inhibits endothelial cells-medi-ated angiogenesis by down-regulating the signal transduction and STAT 3 ,which is not directly re-lated with VEGFA .

The Role of ATF3 Expression and Calcineurin Inhibition in the Putative Cancer Stem Cell Fraction of Human Cutaneous Squamous Cell Carcinoma / 대한피부과학회지

BACKGROUND: A previous study reported that calcineurin inhibition by cyclosporin A (CsA) showed tumor-enhancing effects through the induction of the ATF3 transcription factor and the associated suppression of p53. The development and aggressiveness of cutaneous squamous cell carcinoma (SCC) may be determined by cancer stem cell populations, which have self-renewing potential. OBJECTIVE: To determine the role of ATF3 and calcineurin inhibition in the proliferation of SCC and evaluate the existence of putative SCC stem cells. METHODS: We performed real-time PCR, fluorescence activated cell sorting, and clonogenicity assays in SCC13 cells under conditions of calcineurin inhibition by CsA or ATF3 and p53 overexpression. The relationships amongst calcineurin inhibition, p53, and ATF3 were demonstrated by western blot analysis and transient transfection assays in SCC13 cells. RESULTS: In putative stem cell populations of SCC13 cells enriched in self-renewal potential, p53 expression was lower than that in differentiated SCC13 cells. CsA treatment or ATF3 overexpression caused an expansion of stem cell populations. Additionally, p53 overexpression inhibited cellular proliferation and reduced clonogenicity in SCC13 cells. CsA treatment led to a decrease in p53 expression and an increase in ATF3 in SCC13 cells on western blots. SCC13 cells with CsA and small interfering RNA against ATF3 demonstrated lower cell viability than SCC13 cells with CsA only and SCC13 cells with CsA and small interfering control RNA after 14 days. CONCLUSION: Putative cancer stem cell populations and differentiated cell populations in SCCs are positively regulated by ATF3 and p53, respectively.

Is Activating Transcription Factor 3 Up-Regulated in Patients with Hypospadias?

PURPOSE: Even though hypospadias is one of the most common congenital anomalies, the cause of hypospadias is largely unknown. With regard to molecular biology and microarray technology, it appears that hypospadias is potentially related to disrupted gene expression. Genomic analysis of hypospadiac tissue indicated a potential role for activating transcription factor 3 (ATF3) in the development of this anomaly. This study prospectively examined the expression of ATF3 in tissues from 20 children with hypospadias compared with 26 normal penile skin tissue samples from elective circumcision. MATERIALS AND METHODS: Prepucial tissue was obtained from children who underwent repair of hypospadias for comparison with tissue samples from children who underwent elective circumcision. Skin specimens were evaluated for the expression of ATF3 protein by immunohistochemical staining. RESULTS: Immunohistochemical staining for ATF3 in samples from children who underwent repair of hypospadias was significantly greater than in samples from children who underwent elective circumcision (80% vs. 11%, respectively; p<0.05). CONCLUSIONS: Our results indicate that ATF3 is up-regulated in the penile skin tissue of boys with hypospadias, which suggests a role for this transcription factor in the development of this abnormality.

Correlation of P-gp,bcl-2,STAT3 and the resistance of lymphoma cells to chemotherapeutic agents / 白血病·淋巴瘤

Objective To investigate the correlation of P-gP,bel-2,STAT3,IL-6,IL-10 and the resistance lymphoma cells to chemotherapeutic agents.Methods There were 28 patients,among them were divided into three groups:refractory lymphoma,lymphoma which is sensitive to agents and lymphodenitis.P-glycoprotein(P-gp)on lymphoma cell membrane,STAT3,bcl-2,IL-6 and IL-10 level into lymphonla cell were detected using FCM,and the correlation between them and chemotherapy efficacy were analysed. Results In refractory lymphoma patients,P-gp and hcl-2 are significant higher than that of the group which is sensitive to agents(P:0.01,P=0.039),but STAT3,IL-6 and IL-10 were not significant different between these two groups(P>o.05).P-gp is significant higher in lymphoma than in lymphodenitis(P=0.01).STAT3 in lymphoma is significant lower than that of in lymphodenitis (P=0.04).The level bcl-2,IL-6 and IL-10 between lymphoma and lymphodenitis are not significant different(P>0.05).Conclusion The expression level of bel-2 and p-gP is correlated to resistance to the chemotherapeutic agents in lymphoma cells.STAT3 play a role in lymphoma cell signal transduction,but it is not certain in lymphoma cell muhidrug resistance.

Expression of Activating Transcription Factor 3 in Ischemic Penumbra Region Following Focal Cerebral Ischemia / 대한해부학회지

It has been demonstrated that some of immediate early genes (IEGs) such as c-Jun or fos are induced immediately following neuronal injury and they play an important role in determining the fate of the injured neurons. Of IEGs, the activating transcription factor 3 (ATF3) is focused by many investigators, because they are expressed in various types of neural insults and have been known to serve a diverse function in both neuronal survival and death. However, little is known about the functional role of ATF3 in ischemic brain injury. So in this study, the authors examined the expression pattern of the activating transcription factor 3 (ATF3) following middle cerebral artery (MCA) occlusion-reperfusion injury. According to the findings obtained by triphenyltetrazolium chloride (TTC) stains, the authors have classified the infarcted area into two regions, the ischemic core region and the ischemic penumbra region. In both regions, many neurons underwent neuronal degeneration, characterized by the shrunken nuclei with eosinophilic perikaryon. The H & E stain also demonstrated the increased number of probable activated astrocytes and microglia in the ischemic brain regions and this was confirmed by GFAP- and OX42-immunohistochemistry. Immunohistochemical study for ATF3 also demonstrated the specific upregulation of ATF3 in the nuclei of neurons under ischemic injury, but not in those of the contralateral regions. Interestingly, the number of the ATF3 positive neurons in the ischemic penumbra regions outnumbered that of the ischemic core regions. Based on many reports that the neuronal death in ischemic penumbra region is caused by programed cell death rather than by necrosis which is main cause of neuronal death in ischemic core region, our results could suggest that the ATF3 is an important IEGs which determine the fate of the ischemic neurons.

Expressions of signal transducer and activators of transcription 3 (STAT3) and suppressor of cytokine signaling 3 (SOCS3) proteins in breast carcinoma and their association with biological behaviors / 肿瘤

Objective: To investigate the expressions of signal transducer and activators of transcription 3 (STAT3) and suppressor of cytokine signaling 3 (SOCS3) protein in the breast carcinoma tissue and their relationship with tumor differentiation, invasion, and metastasis. Methods: The expression of STAT3, phospho-STAT3 and SOCS3 protein were determined by tissue microarray and immunohistochemistry with EnVision system in 71 cases of archival breast carcinoma tissues and 41 cases of noncancerous tissues. The relationship between their expression and the clinical pathological parameters were analyzed. Results: (1) The positive rates of STAT3, phospho-STAT3, and SOCS3 was 78.9%, 69.0%, and 29.6%, respectively. The difference was significantly different compared with control (P0.05). The expression of SOCS3 was negatively related with the histopathologic grade and the axillary lymph node metastasis (P0.05). (3) The expression of STAT3 and phospho-STAT3 had negative correlation with the expression of SOCS3 in breast carcinoma tissues (P<0.01). Conclusion: The overexpressions of STAT3 and phospho-STAT3 and the down-regulated expression of SOCS3 closely correlated with the tumor carcinogenesis, progression, invasion, and metastasis of breast carcinoma. Detection of their expression is helpful in accessing the malignant degree and the biological behaviors of breast carcinoma.

Construction of stable expression of siRNA-STAT3 gene in Hep-2 cell line / 中国耳鼻咽喉头颈外科

OBJECTIVE To construct Hep-2 cell line with stable transfection of siRNA-STAT3 gene, and to explore the relationship between STAT3 expressionand the pathogenesis of laryngeal cancer. METHODS Specific STAT3 oligonucleotides were designed and synthesized. These oligonucleotides were annealed form the double strands DNA fragments. Then the fragments were cloned into pGPU6/GFP/Neo vector. The recombinant PGPU6/GFP/Neo-siRNA-STAT3 plasmid was confirmed by enzyme digestion and sequence analysis at the same time. Positive clones were selected out by G418 and p-STAT3 expression was identified by Western-blot analysis. The growth curve of the Hep-2 cells was drawn based on MTT assay and the growth ability of single Hep-2 cell was measured according to the plate colony formation assay respectively. RESULTS PGPU6/GFP/NEO-siRNA-STAT3 expression vector was successfully constructed. Western-blot analysis identified that p-STAT3 expression declined obviously in siRNA- STAT3 group compared with that in negative control and blank group. The growth curve explained that the Hep-2 cells of siRNA-STAT3 group began to show obvious inhibitory effect until they were inoculated in the culture plate for 3 days(P =0.001).There were pronounced inhibitory effect after 5 days(P=0.000). The results also showed time-effect relationship of the inhibition. Furthermore, the cell colony formation rate of siRNA- STAT3 group was less than the negative control and blank group(P =0.000). CONCLUSION We successfully selected out Hep-2 cell line expressed siRNA-STAT3 gene stably and efficiently in this study. Down regulation of STAT3 correlated with the inhibition of growth of Hep-2 cells.