WNT7A promotes tumorigenesis of head and neck squamous cell carcinoma via activating FZD7/JAK1/STAT3 signaling / 国际口腔科学杂志·英文版

Wnt signaling are critical pathway involved in organ development, tumorigenesis, and cancer progression. WNT7A, a member of the Wnt family, remains poorly understood in terms of its role and the underlying molecular mechanisms it entails in head and neck squamous cell carcinoma (HNSCC). According to the Cancer Genome Atlas (TCGA), transcriptome sequencing data of HNSCC, the expression level of WNT7A in tumors was found to be higher than in adjacent normal tissues, which was validated using Real-time RT-PCR and immunohistochemistry. Unexpectedly, overexpression of WNT7A did not activate the canonical Wnt-β-catenin pathway in HNSCC. Instead, our findings suggested that WNT7A potentially activated the FZD7/JAK1/STAT3 signaling pathway, leading to enhanced cell proliferation, self-renewal, and resistance to apoptosis. Furthermore, in a patient-derived xenograft (PDX) tumor model, high expression of WNT7A and phosphorylated STAT3 was observed, which positively correlated with tumor progression. These findings underscore the significance of WNT7A in HNSCC progression and propose the targeting of key molecules within the FZD7/JAK1/STAT3 pathway as a promising strategy for precise treatment of HNSCC.

The anti-neoplastic activities of aloperine in HeLa cervical cancer cells are associated with inhibition of the IL-6-JAK1-STAT3 feedback loop / 中国天然药物

Cervical cancer (CC) is recognized as the most common neoplasm in the female reproductive system worldwide. The lack of chemotherapeutic agents with outstanding effectiveness and safety severely compromises the anti-cipated prognosis of patients. Aloperine (ALO) is a natural quinolizidine alkaloid with marked anti-cancer effects on multiple malignancies as well as favorable activity in relieving inflammation, allergies and infection. However, its therapeutic efficacy and underlying mechanism in CC are still unclear. In the current study, MTT assay was employed to evaluate the viability of HeLa cells exposed to ALO to preliminarily estimate the effectiveness of ALO in CC. Then, the effects of ALO on the proliferation and apoptosis of HeLa cells were further investigated by plate colony formation and flow cytometry, respectively, while the migration and invasion of ALO-treated HeLa cells were evaluated using Transwell assay. Moreover, nude mice were subcutaneously inoculated with HeLa cells to demonstrate the anti-CC properties of ALO in vivo. The molecular mechanisms underlying these effects of ALO were evaluated by Western blot and immunohistochemical analysis. This study experimentally demonstrated that ALO inhibited the proliferation of HeLa cells via G2 phase cell cycle arrest. Simultaneously, ALO promoted an increase in the percentage of apoptotic HeLa cells by increasing the Bax/Bcl-2 ratio. Additionally, the migration and invasion of HeLa cells were attenuated by ALO treatment, which was considered to result from inhibition of epithelial-to-mesenchymal transition. For molecular mechanisms, the expression and activation of the IL-6-JAK1-STAT3 feedback loop were markedly suppressed by ALO treatment. This study indicated that ALO markedly suppresses the proliferation, migration and invasion and enhances the apoptosis of HeLa cells. In addition, these prominent anti-CC properties of ALO are associated with repression of the IL-6-JAK1-STAT3 feedback loop.

The anti-proliferative and anti-inflammatory mechanisms of JAK1 inhibitor SHR0302 versus Ruxolitinib in SET2 cell line and primary cells / 中华血液学杂志

Objective: To explore the effects and molecular mechanism of the selective JAK1inhibitor SHR0302 and Ruxolitinib on myeloproliterative neoplasms (MPN) cell line SET2 and primary cells in vitro. Methods: Cell proliferation was detected by CCK8 kit. Colony forming experiment was conducted to evaluate erythroid burst colony formation unit (BFU-E) of primary cells from MPN patients. Multi-factor kits were used to detect six inflammatory cytokines. Phosphorylated proteins of Jak-Stat signaling pathway were tested by Western blot. Results: At different time points after treated with SHR0302 and Ruxolitinib, the inhibition of cell proliferation was dose dependent by both drugs (P<0.01) . The inhibitory rates of 2.5 μmol/L SHR0302 and 0.1 μmol/L Ruxolitinib on SET2 cells for 72 h were comparable, i.e. (59.94±0.60) % and (64.00±0.66) %, respectively, suggesting that the inhibitory effect of SHR0302 was weaker than that of Ruxolitinib. Similarly, both SHR0302 and Ruxolitinib inhibited BFU-E in primary marrow cells from MPN patients in a dose-dependent manner. SHR0302 1.0 μmol/L produced similar degree of inhibition compared to Ruxolitinib 0.2 μmol/L. Except IL-12, the expression of other 5 cytokines (IL-6, TNF-α, IL-1β, IL-2, IL-8) was significantly inhibited by 1.6 μmol/L SHR0302 in SET2 cells at 24 h (P<0.01) , while Ruxolitinib 1.0 μmol/L had the same effect. Several phosphorylated molecules of Jak-Stat signaling pathway were significantly inhibited by SHR0302 in SET2 cells only for 3 h. P-stat1 (Tyr701) , p-stat3 (Tyr705) were down-regulated when treated with SHR0302 1.0 μmol/L (P<0.05) , p-jak1 (tyr1022/1023) and p-stat5 (Tyr694) were inhibited at 5.0 μmol/L (P<0.05) . Ruxolitinib significantly inhibited the downstream STAT protein at 0.1 μmol/L. Again, the inhibitory effect of SHR0302 on protein expression was weaker than that of Ruxolitinib. Conclusion: SHR0302 can effectively inhibit the proliferation of MPN cell line and patients' primary cells, as well as the expression of inflammatory factors. The molecular mechanism is possibly related to the down-regulation of phosphorylated proteins of Jak-Stat signaling pathway. Overall, the anti-proliferative and anti-inflammatory effects of SHR0302 are weaker than those of Ruxolitinib.

Effect of lncRNA HULC knockdown on rat secreting pituitary adenoma GH3 cells

Pituitary adenoma is one of the most common tumors in the neuroendocrine system. This study investigated the effects of long non-coding RNAs (lncRNAs) highly up-regulated in liver cancer (HULC) on rat secreting pituitary adenoma GH3 cell viability, migration, invasion, apoptosis, and hormone secretion, as well as the underlying potential mechanisms. Cell transfection and qRT-PCR were used to change and measure the expression levels of HULC, miR-130b, and FOXM1. Cell viability, migration, invasion, and apoptosis were assessed using trypan blue staining assay, MTT assay, two-chamber transwell assay, Guava Nexin assay, and western blotting. The concentrations of prolactin (PRL) and growth hormone (GH) in culture supernatant of GH3 cells were assessed using ELISA. The targeting relationship between miR-130b and FOXM1 was verified using dual luciferase activity. Finally, the expression levels of key factors involved in PI3K/AKT/mTOR and JAK1/STAT3 pathways were evaluated using western blotting. We found that HULC was highly expressed in GH3 cells. Overexpression of HULC promoted GH3 cell viability, migration, invasion, PRL and GH secretion, as well as activated PI3K/AKT/mTOR and JAK1/STAT3 pathways. Knockdown of HULC had opposite effects and induced cell apoptosis. HULC negatively regulated the expression of miR-130b, and miR-130b participated in the effects of HULC on GH3 cells. FOXM1 was a target gene of miR-130b, which was involved in the regulation of GH3 cell viability, migration, invasion, and apoptosis, as well as PI3K/AKT/mTOR and JAK1/STAT3 pathways. In conclusion, HULC tumor-promoting roles in secreting pituitary adenoma might be via down-regulating miR-130b, up-regulating FOXM1, and activating PI3K/AKT/mTOR and JAK1/STAT3 pathways.

Immunohistochemistry of Janus Kinase 1 (JAK1) Expression in Vitiligo

BACKGROUND: Vitiligo is a chronic autoimmune disease in which the destruction of melanocytes causes white spots on the affected skin. Janus kinase (JAK) is a family of intracellular, non-receptor tyrosine kinases that transduce cytokine-mediated signals via the JAK–signal transducer and activator of transcription pathway. The aim of the present study is to explore the possible role of JAK1 in the pathogenesis of vitiligo using immunohistochemical methods. METHODS: The current study was conducted in a sample of 39 patients who presented with vitiligo and 22 healthy individuals who were age and sex matched as a control group. We used immunohistochemistry to evaluate JAK1 status (intensity and distribution) and assess the percentage of residual melanocytes using human melanoma black 45 (HMB45). RESULTS: Intense and diffuse JAK1 expression was significantly more likely to indicate vitiliginous skin compared to normal skin (p < .001). Strong and diffuse JAK1 expression was associated with short disease duration, female sex, and lower percentage of melanocytes (detected by HMB45) (p < .05). CONCLUSIONS: JAK1 may be involved in the pathogenesis of vitiligo, as indicated by intense and diffuse expression compared to control and association with lower percentage of melanocytes detected by HMB45 immunostaining.

Afatinib Reduces STAT6 Signaling of Host ARPE-19 Cells Infected with Toxoplasma gondii

Specific gene expressions of host cells by spontaneous STAT6 phosphorylation are major strategy for the survival of intracellular Toxoplasma gondii against parasiticidal events through STAT1 phosphorylation by infection provoked IFN-γ. We determined the effects of small molecules of tyrosine kinase inhibitors (TKIs) on the growth of T. gondii and on the relationship with STAT1 and STAT6 phosphorylation in ARPE-19 cells. We counted the number of T. gondii RH tachyzoites per parasitophorous vacuolar membrane (PVM) after treatment with TKIs at 12-hr intervals for 72 hr. The change of STAT6 phosphorylation was assessed via western blot and immunofluorescence assay. Among the tested TKIs, Afatinib (pan ErbB/EGFR inhibitor, 5 µM) inhibited 98.0% of the growth of T. gondii, which was comparable to pyrimethamine (5 µM) at 96.9% and followed by Erlotinib (ErbB1/EGFR inhibitor, 20 µM) at 33.8% and Sunitinib (PDGFR or c-Kit inhibitor, 10 µM) at 21.3%. In the early stage of the infection (2, 4, and 8 hr after T. gondii challenge), Afatinib inhibited the phosphorylation of STAT6 in western blot and immunofluorescence assay. Both JAK1 and JAK3, the upper hierarchical kinases of cytokine signaling, were strongly phosphorylated at 2 hr and then disappeared entirely after 4 hr. Some TKIs, especially the EGFR inhibitors, might play an important role in the inhibition of intracellular replication of T. gondii through the inhibition of the direct phosphorylation of STAT6 by T. gondii.

alpha-Lipoic Acid Inhibits Expression of IL-8 by Suppressing Activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-Infected Gastric Epithelial AGS Cells

The epithelial cytokine response, associated with reactive oxygen species (ROS), is important in Helicobacter pylori (H. pylori)-induced inflammation. H. pylori induces the production of ROS, which may be involved in the activation of mitogen-activated protein kinases (MAPK), janus kinase/signal transducers and activators of transcription (Jak/Stat), and oxidant-sensitive transcription factor, nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), and thus, expression of interleukin-8 (IL-8) in gastric epithelial cells. alpha-lipoic acid, a naturally occurring thiol compound, is a potential antioxidant. It shows beneficial effects in treatment of oxidant-associated diseases including diabetes. The present study is purposed to investigate whether alpha-lipoic acid inhibits expression of inflammatory cytokine IL-8 by suppressing activation of MAPK, Jak/Stat, and NF-kappaB in H. pylori-infected gastric epithelial cells. Gastric epithelial AGS cells were pretreated with or without alpha-lipoic acid for 2 h and infected with H. pylori in a Korean isolate (HP99) at a ratio of 300:1. IL-8 mRNA expression was analyzed by RT-PCR analysis. IL-8 levels in the medium were determined by enzyme-linked immunosorbent assay. NF-kappaB-DNA binding activity was determined by electrophoretic mobility shift assay. Phospho-specific and total forms of MAPK and Jak/Stat were assessed by Western blot analysis. ROS levels were determined using dichlorofluorescein fluorescence. As a result, H. pylori induced increases in ROS levels, mRNA, and protein levels of IL-8, as well as the activation of MAPK [extracellular signal-regulated kinase 1/2 (ERK1/2), c-Jun NH2-terminal kinase 1/2 (JNK1/2), p38], Jak/Stat (Jak1/2, Stat3), and NF-kappaB in AGS cells, which was inhibited by alpha-lipoic acid. In conclusion, alpha-lipoic acid may be beneficial for prevention and/or treatment of H. pylori infection-associated gastric inflammation.

Associations of JAK1 gene polymorphisms with allergic rhinitis in Chinese Han populations / 临床耳鼻咽喉头颈外科杂志

OBJECTIVE@#The aim of this study was to investigate the association of JAK1 polymorphisms with allergic rhinitis in China Han population.@*METHOD@#A total of 450 patients with AR and 615 healthy subjects as control were genotyped for the presence of three single nucleotide polymorphisms using polymerase chain reaction restriction fragment length polymorphism (PGR-RFLP) analysis of DNA extracted from blood samples.@*RESULT@#All control subjects were in Hardy-Weinberg equilibrium, but high frequencies of JAK1 the homozygous rs310241 CC genotype were observed in AR patients compared to controls (P < 0.05). The results also revealed that there was no association between the rest of two investigated SNPs and AR.@*CONCLUSION@#Our results suggested that JAK1 gene rs310241 CC genotype was associated with patients with AR.

Jak1/Stat3 Is an Upstream Signaling of NF-kappaB Activation in Helicobacter pylori-Induced IL-8 Production in Gastric Epithelial AGS Cells

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.

Jak1/Stat3 Is an Upstream Signaling of NF-kappaB Activation in Helicobacter pylori-Induced IL-8 Production in Gastric Epithelial AGS Cells

Helicobacter pylori (H. pylori) induces the activation of nuclear factor-kB (NF-kappaB) and cytokine expression in gastric epithelial cells. The Janus kinase/signal transducers and activators of transcription (Jak/Stat) cascade is the inflammatory signaling in various cells. The purpose of the present study is to determine whether H. pylori-induced activation of NF-kappaB and the expression of interleukin-8 (IL-8) are mediated by the activation of Jak1/Stat3 in gastric epithelial (AGS) cells. Thus, gastric epithelial AGS cells were infected with H. pylori in Korean isolates (HP99) at bacterium/cell ratio of 300:1, and the level of IL-8 in the medium was determined by enzyme-linked immonosorbent assay. Phospho-specific and total forms of Jak1/Stat3 and IkappaBalpha were assessed by Western blot analysis, and NF-kappaB activation was determined by electrophoretic mobility shift assay. The results showed that H. pylori induced the activation of Jak1/Stat3 and IL-8 production, which was inhibited by a Jak/Stat3 specific inhibitor AG490 in AGS cells in a dose-dependent manner. H. pylori-induced activation of NF-kappaB, determined by phosphorylation of IkappaBalpha and NF-kappaB-DNA binding activity, were inhibited by AG490. In conclusion, Jak1/Stat3 activation may mediate the activation of NF-kappaB and the expression of IL-8 in H. pylori-infected AGS cells. Inhibition of Jak1/Stat3 may be beneficial for the treatment of H. pylori-induced gastric inflammation, since the activation of NF-kappaB is inhibited and inflammatory cytokine expression is suppressed.

Dual role of daphnetin in suppressing HMGB1 release and HMGB1-induced inflammation in murine macrophage RAW264.7 cells and human monocytic THP-1 cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the dual role of daphnetin in suppressing high mobility group box-1 protein (HMGB1) release and blocking HMGB1-induced inflammatory response.</p><p><b>METHODS</b>Murine macrophage RAW264.7 cells were cultured in the presence of daphnetin, lipopolysaccharide (LPS), or both. HMGB1 release from the cells was determined using ELISA, and phosphorylations of JAK1/2 and of STAT1 were detected by Western blotting. Human monocytic THP-1 cells exposed to daphnetin, rhHMGB1, or both were examined for NO production using a NO detection kit, for the release of tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and prostaglandin E2 (PGE2) using ELISA, and for expressions of iNOS, COX-2 and phosphorylated p38, ERK, and JNK with Western blotting.</p><p><b>RESULTS</b>Daphnetin dose-dependently reduced the release of HMGB1 in RAW264.7 cells and suppressed rhHMGB1-induced iNOS and COX-2 expressions and release of TNF-α, IL-6, PGE2, and NO in THP-1 cells. Western blotting revealed that daphnetin significantly down-regulated the phosphorylations of JAK-STAT1 pathway in LPS-stimulated RAW264.7 cells but did not suppress the phosphorylations of MAPKs signaling pathway induced by rhHMGB1 in THP-1 cells.</p><p><b>CONCLUSION</b>Daphnetin can reduce the release of HMGB1 and suppress HMGB1-induced inflammatory response. In RAW264.7 cells, daphnetin inhibited LPS induced HMGB1 release is at least partly mediated by suppressing JAK-STAT1 signaling pathway activation.</p>

Janus Activated Kinase inhibition in Myelofibrosis.

Janus Activated Kinase (JAK) 2 plays an important role in the pathogenesis of myelofibrosis (MF). Ruxolitinib (INCB018424, Jakafi) is a potent dual JAK1 and JAK2 inhibitor. In November 2011, it became approved by the US FDA for the treatment of intermediate or high-risk MF. This review shall outline the role of Ruxolitinib in the current management of MF and its potential future.

Inhibitive effect of exogenous carbon monoxide-releasing molecules 2 on the activation of Janus kinase/signal transducer and activator of transcription pathway in sepsis / 中华烧伤杂志

<p><b>OBJECTIVE</b>To study the inhibitive effect of exogenous carbon monoxide-releasing molecules 2 (CORM-2) on the activation of Janus kinase/signal transducer and activator of transcription (JAK/STAT) pathway in sepsis.</p><p><b>METHODS</b>RAW264.7 cells were divided into normal control group, LPS group (10 mg/mL LPS, the same concentration below), LPS + inactive CORM-2 (iCORM-2) group, LPS + 50 mmol/L CORM-2 group, and LPS + 100 mmol/L CORM-2 group. TNF-alpha level in the supernatant was determined with ELISA, and the phosphorylation levels of JAK1 and JAK3 were determined with Western blot. Thirty-five male BALB/c mice were divided into normal control group, cecal ligation and puncture (CLP) group, CLP + iCORM-2 (8.0 mg/kg) group and CLP + CORM-2 group (8.0 mg/kg) according to the random number table. Mice in CLP + CORM-2 group were treated the same as mice in CLP group except for administration of CORM-2 after CLP. The plasma levels of TNF-alpha, IL-1beta, and the phosphorylation levels of JAK1, JAK3 in liver tissue were determined with ELISA 24 hours post CLP. Data were processed with t test.</p><p><b>RESULTS</b>Compared with that of normal control group [(1.9 +/- 0.3) pg/mL], the TNF-alpha level [(8.2 +/- 2.7) pg/mL, t = 2.844, P < 0.01] and phosphorylation levels of JAK1, JAK3 in LPS group increased significantly; while TNF-alpha levels in LPS + 50 mmol/L CORM-2 and LPS + 100 mmol/L CORM-2 groups decreased obviously as compared with that of LPS group [(5.7 +/- 1.4), (3.2 +/- 0.9) pg/mL, with t value respectively 2.104 and 2.363, P values all below 0.05], and it was the same with phosphorylation levels of JAK1, JAK3 in a dose-dependent manner. Compared with those of normal control group, plasma levels of TNF-alpha and IL-1beta and phosphorylation levels of JAK1, JAK3 in liver tissue significantly increased in CLP group (with t value respectively 2.916 and 2.796, and P values all below 0.05); while plasma levels of TNF-alpha and IL-1beta and the phosphorylation levels of JAK1, JAK3 in liver tissue decreased significantly in CLP + CORM-2 group (with t value respectively 2.115 and 2.398, and P values all below 0.05).</p><p><b>CONCLUSIONS</b>Exogenous CORM-2 can obviously inhibit the phosphorylation of JAKs molecules and then inhibit the activation of JAK/STAT signal pathway in sepsis, and decrease the expression of downstream cytokines to effectively prevent cascade reaction in the inflammatory response after severe infection.</p>

Study on the mechanism of arsenic trioxide inhibiting NB4 cells proliferation / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore the molecular mechanisms of arsenic trioxide (As2O3) inhibiting NB4 cells proliferation.</p><p><b>METHODS</b>The Janus kinase 1 (JAK1) protein level and its phosphorylation level in NB4 cells was detected by Western blots. NB4 cells were transfected with JAK1 siRNA or JAK1 plasmid to make JAK1 gene silenced or overexpressed. The inhibition of NB4 cells proliferation was measured by MTT assay and Trypan blue exclusion respectively. The variation of phosphorylation level of JAK1 and the cell cycle inhibitor P21 were determined by Western blots.</p><p><b>RESULTS</b>JAK1 protein was expressed stably in NB4 cells, with no phosphorylation. The phosphorylation of JAK1 was enhanced after the NB4 cells treated with As2O3. After NB4 cells transfected with JAK1 siRNA, the expression level of JAK1 was obviously lower than that of in the non-specific siRNA group and blank control group. The effect of As2O3 inhibiting NB4 cells proliferation was weaker in the JAK1 siRNA transfected group. The inhibiting rate of 4 micromol/L As2O3 on NB4 cells proliferation of JAK1 siRNA group was 49.12% being lower than that of the non-specific siRNA group (74.58%) and control group (72.33%). After NB4 cells transfected with JAK1 plasmid, the JAK1 expression level in wild-type and mutant type plasmid groups were significantly higher than those in the empty plasmid group, moreover the effect of As2O3 inhibiting proliferation was stronger in wild-type plasmid group. The inhibiting rate of 4 micromol/L As2O3 on NB4 cells proliferation of wild-type plasmid group was 69.53% being higher than that of the mutant type JAK1 plasmid group (37.26%) and the empty plasmid group (39.61%). The expression level of P21 was up-regulated after the NB4 cells treated with As2O3.</p><p><b>CONCLUSION</b>JAK1 is expressed stably in NB4 cells, but has no activity. Arsenic trioxide inhibits the proliferation of NB4 cells through activating the JAK1. P21 is up-regulated after arsenic trioxide activated the JAK1 to inhibit the proliferation of NB4 cells.</p>

Regulatory effect of resveratrol on JAK1/STAT3 signal transduction pathway in leukemia / 中国实验血液学杂志

The aim of this study was to explore the molecule mechanism of resveratrol antileukaemia. The mouse lymphocytic leukemia L1210 cells were cultured and the expressions of pJAK1 and pSTAT3 protein in L1210 cells were detected by immunohistochemistry and immunoprecipitation in vitro. The mouse model with L1210 leukemia ascites carcinoma was established and activities of singal transduction pathway molecules pJAK1 and pSTAT3 were measured by Western blot and immunohistochemistry assay in vitro. The results indicated that resveratrol could significantly inhibit the JAK1/STAT3 signal transduction pathway, down-regulate expressions of pJAK1 and pSTAT3 and reduce the phosphorylation of JAK1 and STAT3 in a dose-and time-dependent manner. It is concluded that the resveratrol can regulate signal transduction pathway and reduce the activation of JAK1/STAT3 tyrosine phosphorylation significantly, and therefore resveratrol shows chemotherapeutic potential to leukaemia.

In vitro action of leukemia inhibitory factor (LIF) on mid-secretory stage endometrial stromal cells collected from hormone-simulated, ovariectomized monkey and maintained in three-dimensional primary culture.

Leukemia inhibitory factor (LIF) is a pleiotropic cytokine that is known to play an important role in blastocyst implantation. The putative action of LIF in the regulation of uterine function has been examined using mid-secretory stage monkey endometrial stromal cells cultured on rat-tail collagen type I and treated with recombinant human LIF (rhLIF) or immunoneutralized LIF (in LIF) under serum-free condition. Long-term ovariectomized rhesus monkeys (n=8) underwent simulation of their menstrual cycles with steroid hormones and endometrial tissue samples were collected on cycle day 18; stromal cells were isolated and grown in primary culture on three-dimensional collagen matrix. Significant decline in cellular protein synthesis (P < 0.01) and cell proliferation index (P < 0.05) was observed in cells with increasing doses (0-1000 ng/ml) of rhLIF under serum-free in vitro condition. JAK1 expression in cultured cells increased (P < 0.01) in response to rhLIF as revealed from Western blot and confocal laser scanning microscopic examination, STAT1 and STAT2 expressions were unchanged, while pSTAT3 expression increased (P < 0.01) with increased concentration of rhLIF in culture medium. Autophosphorylation of JAK1 in endometrial stromal cells showed no change with increasing concentration (0.01 to 100 ng/ml) of rhLIF in vitro, but significant (P < 0.05) increase was observed with the time of exposure to rhLIF. Immunoneutralization of LIF or no addition of rhLIF to cultured cells led to significant (P < 0.01) increase in stromal cell proliferation index and significant (P < 0.01) decrease in the level of JAK1 and its autophosphorylation as compared to cells exposed to rhLIF alone. From the present set of experiments we conclude that rhLIF affects the physiological behaviour of monkey mid secretory stage endometrial stromal cells in vitro via the JAK-STAT signaling pathway.

Signaling pathways regulating self-renewal of mouse embryonic stem cells--review / 中国实验血液学杂志

Mouse embryonic stem cells (ES cells) are pluripotent in that they can give rise to almost all the cell types in vitro and in vivo. Also, they can sustain self-renewal in vitro owing to symmetrical mitosis, i.e., only the cell number increases while the daughter cells remain pluripotent. Self-renewal and pluripotency of ES cells are under stringent regulation of several signaling pathways. Activation of either JAK-STAT3 or PI3K, the downstream cascade of gp130, can maintain the self-renewal of ES cells, while phosphorylation of another gp130-related branch, SHP2-Ras-ERK, drives the differentiation. BMP2/4-mediated signaling is capable of suppressing the differentiation of ES cells in collaboration with activated JAK-STAT3 under serum free culture conditions. Other signaling such as Wnt also contributes to the self-renewal of ES cells. Generally, the network, which is composed of various signaling pathways, modulates the self-renewal and differentiation of mouse ES cells precisely. This review focuses on the role of gp130 in proliferation of mouse ES cells including inhibitory effect of JAK-STAT3 pathway activation on differentiation of mouse ES cells, maintenance effect of PI3K pathway activation on self-renewal of ES cells, promotive effect of SHP-2-Ras-ERK pathway activation on differentiation of ES cells, and influence of other signaling pathways on self-renewal of mouse ES cells, including maintenance effect of BMP combination with LIF under serum free culture conditions on self-renewal of ES cells and promotive effect of Wnt pathway activation on self-renewal of ES cells.

Gene expression profile in K562 cells treated by interferon alpha / 中国实验血液学杂志

To study the gene expression profile in K562 cells treated by IFN-alpha, so as to provide some information about the potential mechanism of IFN-alpha curing CML, the changes of gene expression were examined with the DNA array in K562 cells before and after treatment with IFN-alpha. The results showed that no gene expression difference more than 2.5 times in K562 cells was found on the first day after treatment with IFN-alpha (200 U/ml), then the genes significant expression difference increased step by step, and reached the peak on the forth day. In all examined genes, 97 genes significant expression difference were detected, 86.60% (84/97) gene of interest out of those gene were up-regulated, 13.40% (13/97) were down-regulated. In these 97 genes with significant expression difference, cell regulator protein genes accounted to 23.71% (23/97), surface receptor genes 14.43% (14/97), oncogenes and tumor suppressors 11.34% (11/97), extracellular communication proteins 9.28% (9/97), cell adhesion molecular genes 8.25% (8/97) and the other genes accounted to 32.99% (32/97). JAK1 was up-regulated to 3.78 times, JAK2 to 15.43, STAT1 and STAT2 were up-regulated to 11.98 and 8.11 times respectively, and these genes are components of JAK-STAT pathway. The number of different genes began to decrease on the fifth day. There were still 9 genes that had expression difference more than 3 times on the twenty-first day. It is concluded that when concentration of IFN-alpha was 200 U/ml, the forth day should be considered as the best time to examine change of gene expression in K562 cells treated by IFN-alpha. IFN-alpha realizes its biological functions through the JAK-STAT pathways and it may be one of the mechanisms for curing CML with IFN-alpha.

Isoproterenol-induced activation of MAPK, NFkappaB and JAK/STAT pathway in mouse myocardium / 生理学报

This study was aimed to determine the in vivo signal transduction pathway responsible for isoproterenol (ISO)-induced cardiac hypertrophy or remodeling. Mice were treated with ISO (15 mg/kg body weight) or vehicle by intraperitoneal injection (i.p.). Activation of mitogen-activted protein kinase (MAPK), NF-kappaB and JAK/STAT pathway in the left ventricular myocardium was measured by Western blot analysis. ISO significantly activated MAPK (ERK1/2 and p38) at early phase (5 min); biphasic activation of NF-kappaB was observed in our in vivo study; and ISO caused a delayed STAT3 activation (at 60 to 240 min) in mouse myocardium. Taken together, these results indicate that ISO activates these signal transduction pathways in different time course.