فایل ورد کامل بازدارندگی رشد سورافنیب و متاستازیس کارسینومای هپاتوسلولی با بلوک کردن STAT3

توجه : به همراه فایل word این محصول فایل پاورپوینت (PowerPoint) و اسلاید های آن به صورت هدیه ارائه خواهد شد

این مقاله، ترجمه شده یک مقاله مرجع و معتبر انگلیسی می باشد که به صورت بسیار عالی توسط متخصصین این رشته ترجمه شده است و به صورت فایل ورد (microsoft word) ارائه می گردد

متن داخلی مقاله بسیار عالی، پر محتوا و قابل درک می باشد و شما از استفاده ی آن بسیار لذت خواهید برد. ما عالی بودن این مقاله را تضمین می کنیم

فایل ورد این مقاله بسیار خوب تایپ شده و قابل کپی و ویرایش می باشد و تنظیمات آن نیز به صورت عالی انجام شده است؛ به همراه فایل ورد این مقاله یک فایل پاور پوینت نیز به شما ارئه خواهد شد که دارای یک قالب بسیار زیبا و تنظیمات نمایشی متعدد می باشد

توجه : در صورت مشاهده بهم ریختگی احتمالی در متون زیر ،دلیل ان کپی کردن این مطالب از داخل فایل می باشد و در فایل اصلی فایل ورد کامل بازدارندگی رشد سورافنیب و متاستازیس کارسینومای هپاتوسلولی با بلوک کردن STAT3،به هیچ وجه بهم ریختگی وجود ندارد

تعداد صفحات این فایل: ۲۴ صفحه

STAT3 در اغلب سلول های تومور فعال بوده و از این رو بیانگر یک هدف مولکولی جذاب است. در این مقاله، مان نشان دادیم که سورافنیب موجب مهار فسفوریلاسیون STAT3 گردید:۱- در S727 توسط مسیر تولید سیگنال MEK/ERK، ۲-در Y705 با بلوک کردن مسیر تولید سیگنال PI3K/Akt و ۳- مستقل از JAK و SHP2 موجب مهار رشد تومور HCC می شود. اگرچه برخی مطالعات حاکی از این می باشند که سورافنیب موجب مهار تولید سیکنال STAT3 در برخی سرطان ها شامل HCC می شود، تاکنون، این نخستین مطالعه ای است که به بررسی مهار فعالیت STAT3 روی بقایای فسفوریلات توسط مکانیسم های مهم میبردازد.
فسفوریلاسیون STAT3 در Y705 موجب دیمریزاسیون، انتقال هسته ای، بیوند DNA و رونوشت ژنی شد و این در حالی است که فسفوریلاسیون دیگر بقایای STAT3، S727 موجب بهبود فعالیت رونوشتی می شود. ترکیب فسفوریلاسیون تیروزین و سرین برای اکتیواسیون کامل STAT3 لازم است.ما پی بردیم که STAT3 در Y705 و S727 i  فسفوریلات شده و موجب مهار  فسفوریلاسیون هر دو سایت درمیان سلول های HCC شده و صفات مولکولی کاملا متفاوتی را نشان دادند. ۲ ساعت بعد از درمان باز دارندگی اتفاق افتاد و تا ۲۴ ساعت به طول انجامید. و این حاکی از عمل سریع سورافنیب می باشد. به علاوه،  ما به شناسایی مکانیسم های بالقوه دخیل در بلوک سازی تولید سیگنال STAT3 برداختیم.

عنوان انگلیسی:Sorafenib inhibits growth and metastasis of hepatocellular carcinoma by blocking STAT3~~en~~

INTRODUCTION Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third most frequent cause of cancerrelated death globally. Although prognosis of patients with HCC has increased in recent decades, long-term survival remains unsatisfactory because of the high rate of recurrence and metastasis[1]. Advances in treating this disease are likely to develop from a better understanding of its biology and behavior, which are affected by multiple molecular pathways controlled by transcription factors[2,3]. Signal transducer and activator of transcription 3 (STAT3) plays a critical role in transcriptional regulation of genes that are involved in tumor cell proliferation, survival and invasion[4]. Constitutive activation of STAT3 is observed in 72.4% of human HCC[5] and in a wide variety of other cancer types[6,7]. Overexpression of constitutively activated forms of STAT3 induces the formation of foci in vitro and tumors in mouse models. Moreover, inhibiting STAT3 function via RNA knockdown, peptide inhibition, and expression of dominant-negative forms in cancer cells leads to a decrease in tumor progression[8]. Our group has also reported that knockdown of STAT3 with antisense oligonucleotides inhibits tumor growth and metastasis in a mouse xenograft model of HCC[9]. In human HCC tissues, constitutive activation of STAT3 is a significant predictor of overall survival[5]. Thus, targeting of STAT3 activation may prove to be an effective approach to controlling HCC. Sorafenib (Nexavar, BAY 43-9006) is a multikinase inhibitor that has shown anti-tumor activity against a wide variety of cancers including HCC[10,11]. Sorafenib blocks tumor cell proliferation and angiogenesis by targeting the Raf/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signaling pathway and receptor tyrosine kinases (RTKs), such as vascular endothelial cell growth factor receptor (VEGFR)-2, VEGFR-3, platelet-derived growth factor receptor-, fms-like tyrosine kinase receptor-3 (FLT3), RET, and c-KIT[10,11]. Recently, sorafenib has been shown to suppress tumor growth by decreasing STAT3 phosphorylation in a group of human malignancies[12-15]. In HCC, sorafenib has also been suggested to overcome TRAIL resistance through the inhibition of STAT3[16]. However, thus far, the exact molecular mechanisms by which sorafenib inhibited STAT3 have not been fully elucidated. Here, we found that sorafenib decreased STAT3 phosphorylation at both tyrosine and serine residues (Y705 and S727), which were independent of Janus kinase 2 (JAK2) and phosphatase shatterproof 2 (SHP2) activity. We further demonstrated that inhibition of the phosphatidylinositol-3-kinase (PI3K)/Akt and MEK/ERK path-ways was responsible for Y705 and S727 dephosphorylation, respectively, by sorafenib. Consistent with these findings, sorafenib markedly inhibited STAT3 dephosphorylation, suppressed tumor growth and metastasis in an immunocompetent orthotopic rat HCC model. MATERIALS AND METHODS Reagents and cell lines Sorafenib (BAY 43-9006, Bayer Pharmaceutical Corporation) was dissolved in sterile dimethyl sulfoxide (DMSO) for in vitro experiments, and in Cremophor EL (Sigma) and 95% ethanol (50:50) for in vivo experiments. DMSO was added to cultures at 0.1% (v/v) final concentration as a vehicle control. Primary antibodies, STAT3 and phosphorylated STAT3 (p-STAT3; Y705 and S727); Akt and phosphorylated Akt (p-Akt; S473); JAK2 and phosphorylated JAK2 (p-JAK2; Y1007/1008); ERK1/2 and phosphorylated ERK1/2 (p-ERK1/2; T202/Y204); SHP2 and phosphorylated SHP2 (p-SHP2; Y580) were purchased from Cell Signaling Technology. Cyclin D1 was from Abcam. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) was purchased from Millipore. Human or rat Akt small interfering RNA (siRNA), control siRNA, were obtained from Shanghai GenePharma Co. (Shanghai, PR China). LY294002, a PI3K inhibitor, and U0126, a MEK inhibitor, were purchased from Cell Signaling Technology. Two human HCC cell lines, HCCLM3[17,18] and HepG2 (ATCC), and a rat HCC cell line, Morris hepatoma 3924A (MH) cells (German Cancer Research Center Tumor Collection)[19], were maintained in high-glucose DMEM supplemented with 10% heat-inactivated fetal bovine serum, L-glutamine, 100 units/mL penicillin, and 100 g/mL streptomycin. Cell lines were cultured at 37 in a humidified incubator in 5% CO2. MTT assay The effect of sorafenib on HCC cell growth was determined with the 3-[4,5-dimethylthiazol-2-yl]-2,5- diphenyltetrazoliumbromide (MTT) assay. Cells were seeded into 96-well flat-bottom plates (1×۱۰۳ /well) and cultured for 24, 48 or 72 h in medium supplemented with sorafenib (0, 0.05, 0.1, 1, 5, 10 or 20 mol/L; 6 wells/dose), and each experiment was repeated at least three times. After sorafenib treatment, cells were incubated with MTT (20 L/well) at 37 for 4 h, and then 200 L DMSO was added. The absorbance of individual wells was determined at 570 nm. Western blotting analysis Western blot analysis was performed as previously described[20]. Briefly, total cell lysates were prepared, and proteins were separated by SDS-PAGE, followed by transfer to polyvinylidene difluoride membranes. The membranes were washed, blocked, and incubated with the specific primary antihuman antibodies against p-STAT3-Y705 (1:1000), p-STAT3-S727 (1:1000), STAT3 (۱:۱۰۰۰), p-Akt (1:1000), Akt (1:1000), p-ERK1/2 (1:1000), ERK1/2 (1:1000), p-JAK2 (1:1000), JAK2 (1:1000), p-SHP2 (1:1000), SHP2 (1:1000), cyclin D1 (1:1000), or GAPDH (1:5000), followed by incubation with horseradish peroxidase-conjugated secondary antibodies. Proteins were detected by enhanced chemiluminescence assay (Pierce-Thermo Scientific).

$$en!!