HER4 promotes the growth and metastasis of osteosarcoma via the PI3K/AKT pathway

Osteosarcoma is the most common primary malignant bone tumor,which occurs in adolescents.As reported by our previous studies,HER4 indicates a poor prognosis of ...     

PI3K/AKT/mTOR信号通路及其在卵巢癌治疗中的应用

卵巢癌是女性生殖系统常见的恶性肿瘤,发病率居于妇科恶性肿瘤第三位,死亡率居于妇科恶性肿瘤之首。目前对卵巢癌的标准治疗包括肿瘤细胞减灭术及卡铂和紫杉醇的联合化疗。PI3K/AKT/mTOR信号通路在卵巢癌的细胞增殖、侵袭、细胞周期进展、血管生成及耐药中发挥重要作用,是卵巢癌中最常发生改变的细胞内途径。本文对PI3K/AKT/mTOR信号通路及其在卵巢癌增殖和进展中的影响、PI3K/AKT/mTOR信号通路抑制剂在卵巢癌中的治疗应用做简要综述。     

Targeting the PI3K/AKT pathway: a potential new weapon in the global fight against SARS-CoV-2?

Commentary on ''Capivasertib restricts SARS-CoV-2 cellular entry: a potential clinical application for COVID-19'' by Sun et al.     

Downregulation of FAP suppresses cell proliferation and metastasis through PTEN/PI3K/AKT and Ras-ERK signaling in oral squamous cell carcinoma

It is largely recognized that fibroblast activation protein (FAP) is expressed in cancer-associated fibroblasts (CAFs) of many human carcinomas. Furthermore, FAP was recently also reported to be expressed in carcinoma cells of the breast, stomach, pancreatic ductal adenocarcinoma, colorectum, and uterine cervix. The carcinoma cell expression pattern of FAP has been described in several types of cancers, but the role of FAP in oral squamous cell carcinoma (OSCC) is unknown. The role of endogenous FAP in epithelium-derived tumors and molecular mechanisms has also not been reported. In this study, FAP was found to be expressed in carcinoma cells of OSCC and was upregulated in OSCC tissue samples compared with benign tissue samples using immunohistochemistry. In addition, its expression level was closely correlated with overall survival of patients with OSCC. Silencing FAP inhibited the growth and metastasis of OSCC cells in vitro and in vivo. Mechanistically, knockdown of FAP inactivated PTEN/PI3K/AKT and Ras-ERK and its downstream signaling regulating proliferation, migration, and invasion in OSCC cells, as the inhibitory effects of FAP on the proliferation and metastasis could be rescued by PTEN silencing. Our study suggests that FAP acts as an oncogene and may be a potential therapeutic target for patients with OSCC.     

NEAT1通过PI3K/AKT/Bcl-2信号通路抑制骨质疏松

为探讨NEAT1在骨质疏松症中的作用以及可能的病理机制,本研究通过建立卵巢去势和鼠尾悬挂2种骨质疏松的小鼠模型,将C57BL/6分为假手术组(Sham组)、OVX组和TS组;经过PCR测定小鼠NEAT1的表达;Elisa法检测小鼠E2、ALP和TRACP水平;Western blotting检测细胞凋亡因子PI3K/AKT/Bcl-2的蛋白水平。结果显示,建模4周后,3组小鼠体重没有显著变化;与Sham组相比,OVX组和TS组小鼠的骨密度值显著降低,骨生化指标ALP和TRACR水平明显升高;OVX组小鼠的E2水平与Sham组相比明显降低;与Sham组相比,OVX组和TS组小鼠的NEAT1表达显著下调;与Sham组相比,OVX组和TS组小鼠p-AKT和Bcl-2蛋白水平明显降低。本研究结果表明,NEAT1可能通过抑制PI3K/AKT/Bcl-2细胞凋亡途径诱导骨质疏松。     

Effects of streptozotocin-induced type 1 maternal diabetes on PI3K/AKT signaling pathway in the hippocampus of rat neonates

Diabetes in pregnancy impairs hippocampus development in offspring, leading to behavioral problems and learning deficits. Phosphatidylinositol 3-kinase/protein kinase B (PKB/Akt) signaling pathway plays a pivotal role in the regulation of neuronal proliferation, survival and death. The present study was designed to examine the effects of maternal diabetes on PKB/Akt expression and phosphorylation in the developing rat hippocampus. Wistar female rats were maintained diabetic from a week before pregnancy through parturition and male offspring was killed at first postnatal day (P1). The hippocampal expression and phosphorylation level of PKB/Akt, one of the key molecules in PI3K/AKT signaling pathway, was evaluated using real-time polymerase chain reaction (PCR) and western blot analysis. We found a significant bilateral downregulation of AKT1 gene expression in the hippocampus of pups born to diabetic mothers (p?<?0.05). Interestingly, our results revealed a marked upregulation of Akt1 gene in insulin-treated group compared with other groups (p?<?0.05). The western blot analysis also showed the reduction of phosphorylation level of all AKT isoforms in both diabetic and insulin-treated groups compared with control (p?<?0.05). Moreover, the results showed a significant increase in phosphorylation level of AKT in insulin-treated group compared with the diabetic group. These results represent that diabetes during pregnancy strongly influences the regulation of PKB/AKT in the developing rat hippocampus. Furthermore, although the control of glycemia by insulin administration is not sufficient to prevent the alterations in PKB/Akt expression, it modulates the phosphorylation process, thus ultimately resulting in a situation comparable to that found in the normal condition.     

上皮性卵巢癌中TFAP2A对hTERT表达的调节及其机制研究

摘要 目的：探讨在上皮性卵巢癌中TFA2A对hTERT表达的调节和作用机制。方法：采用免疫组织化学方法检测TFAP2A和hTERT蛋白在卵巢正常、交界及上皮性卵巢癌组织中的表达,采用Western Blot和qRT-PCR技术检测hTERT在敲减TFAP2A基因的SKOV3、CAOV3细胞中的表达水平、检测hTERT在过表达TFAP2A基因的HO8910细胞中的表达水平。在干扰TFAP2A的CAOV3细胞中或过表达TFAP2A的HO8910细胞中分别加入PI3K/AKT信号通路激动剂740-YP或抑制剂LY294002,检测相关蛋白表达变化,探讨TFAP2A、hTERT与PI3K/AKT信号通路的关系。结果：TFAP2A在71.88%的上皮性卵巢癌组织中呈高表达,hTERT在78.12%的上皮性卵巢癌组织中呈高表达; 将hTERT 和TFAP2A的免疫组化评分行Pearson相关性分析,两者间相关系数r=0.78,P＜0.001。Western Blot和qRT-PCR的结果均显示,在SKOV3和CAOV3卵巢癌细胞中,敲减TFAP2A后,hTERT的表达均明显下降,而在HO8910卵巢癌细胞中,增强TFAP2A基因表达后,hTERT的表达均明显上升。在CAOV3和HO8910处理细胞中,分别使用PI3K/AKT信号通路激动剂740-YP 或阻滞剂LY294002处理后,Western Blot 检验hTERT和PI3K/AKT通路蛋白的表达,发现激动剂740-YP 或阻滞剂LY294002可以逆转敲减或过表达TFAP2A引发的PI3K/AKT通路蛋白表达下调或上调,但不能逆转hTERT蛋白表达下调或上调。结论：在卵巢肿瘤组织中,TFAP2A和hTERT在上皮性卵巢癌组织中均呈高表达,且hTERT的表达和TFAP2A成正相关,在上皮性卵巢癌细胞中TFAP2A可调节hTERT的表达,且TFAP2A对hTERT的表达的调节不经由PI3K/AKT通路。     

花生四烯酸通过COX-2酶代谢氧化失活PTEN促进结直肠癌生长

摘要 目的：本研究旨在阐明过表达COX-2的结直肠癌中花生四烯酸代谢与PTEN及其下游通路的相互关系。方法：利用过表达COX-2结直肠癌细胞系CT26和Apc ^Min/+小鼠腺瘤模型,联合花生四烯酸、COX-2抑制剂NS-398和COX-2基因敲除的干预,采用流式细胞仪检测细胞凋亡、细胞周期及活性氧的产生;Transwell和克隆形成试验观察细胞的迁移和增殖能力;Western blot和免疫组化检测PTEN及其下游相关蛋白的表达。结果：花生四烯酸通过COX-2酶代谢产生活性氧并失活PTEN抑癌基因表达,从而激活PI3K-AKT蛋白促进CT26结直肠癌细胞迁移和增殖,抑制细胞凋亡;而COX-2抑制剂NS-398阻止了花生四烯酸在CT26结直肠癌细胞中的恶性生物学行为。同时,在COX-2基因敲除Apc ^Min/+小鼠腺瘤组织中,减弱了氧化应激水平,增加了PTEN表达,抑制了PI3K-AKT磷酸化,进一步抑制腺瘤生长,提高小鼠生存率。结论：花生四烯酸通过COX-2酶代谢产生活性氧下调PTEN活性,并激活PI3K-AKT促进结直肠癌生长;COX-2抑制剂可间接促进PTEN表达,抑制结直肠癌生长,能够作为CRC的潜在治疗靶点。     

Recruitment of Grb2 and SHIP1 by the ITT-like motif of TIGIT suppresses granule polarization and cytotoxicity of NK cells

Activating and inhibitory receptors control natural killer (NK) cell activity. T-cell immunoglobulin and ITIM (immunoreceptor tyrosine-based inhibition motif) domain (TIGIT) was recently identified as a new inhibitory receptor on T and NK cells that suppressed their effector functions. TIGIT harbors the immunoreceptor tail tyrosine (ITT)-like and ITIM motifs in its cytoplasmic tail. However, how its ITT-like motif functions in TIGIT-mediated negative signaling is still unclear. Here, we show that TIGIT/PVR (poliovirus receptor) engagement disrupts granule polarization leading to loss of killing activity of NK cells. The ITT-like motif of TIGIT has a major role in its negative signaling. After TIGIT/PVR ligation, the ITT-like motif is phosphorylated at Tyr225 and binds to cytosolic adapter Grb2, which can recruit SHIP1 to prematurely terminate phosphatidylinositol 3-kinase (PI3K) and MAPK signaling, leading to downregulation of NK cell function. In support of this, Tyr225 or Asn227 mutation leads to restoration of TIGIT/PVR-mediated cytotoxicity, and SHIP1 silencing can dramatically abolish TIGIT/PVR-mediated killing inhibition.     

Caveolin-1 gene silencing promotes the activation of PI3K/AKT dependent on Erα36 and the transformation of MCF10A~(CE)

ERα36,a variant of estrogen receptor-α,acts as a dominant-negative factor in both estrogen-dependent and estrogen-independent transactivation signaling pathways,and is a key factor in the promotion,progression and prognosis of breast cancers.Caveolin-1,a 22-to 24-kD integral membrane protein,may function as a tumor suppressor in inhibiting of many growth-promoting signaling pathways.It was shown that downregulation of Caveolin-1 strengthens the interaction of ERα and Caveolin-1.In conclusion,Caveolin-1 gene silencing activated the PI3K/AKT signaling pathway in an ERα36-dependent way.Our finding may provide a promising therapeutic target of breast cancer.