scholarly journals Suppression of STAT3 Signaling by Δ9-Tetrahydrocannabinol (THC) Induces Trophoblast Dysfunction

2017 ◽  
Vol 42 (2) ◽  
pp. 537-550 ◽  
Author(s):  
Xinwen Chang ◽  
Yiding Bian ◽  
Qizhi He ◽  
Julei Yao ◽  
Jingping Zhu ◽  
...  

Aims: Marijuana is a widely used illicit drug and its consumption during pregnancy has been associated with adverse reproductive outcomes. The purpose of this study was to determine the effects of chronic intake of Δ9-tetrahydrocannabinol (THC), the major component of marijuana, on trophoblast function, placental development, and birth outcomes. Methods: The pathological characteristics and distribution of cannabinoid receptors in placenta were observed by immunohistochemical (IHC) staining. Cell migration in response to THC was measured by transwell assays. The levels of cannabinoid receptors and Signal Transducer and Activator of Transcription 3 (STAT3) were detected by western blot. Results: We found the placenta expressed two main cannabinoid receptors, suggesting that THC induced biological responses in placental cells. Supporting this hypothesis, we observed dramatic alterations of placental morphology in marijuana users. Using THC and inhibitors of cannabinoid receptors, we demonstrated that THC impaired trophoblast cell migration and invasion partly via cannabinoid receptors. Additionally, pregnant mice injected with THC showed adverse reproductive events including reduced number of fetuses, lower maternal and placental weights. Mechanistically, STAT3 signaling pathway was involved in the THC-induced suppression of trophoblast cell motility and pregnancy outcomes. Conclusion: Our study indicates that the STAT3 signaling pathway plays a critical role in THC-induced trophoblast dysfunction.

Author(s):  
Yang Yang ◽  
Q i Zhang ◽  
Jiakui Liang ◽  
Meiyuan Yang ◽  
Zheng Wang ◽  
...  

Abstract Signal transducing adaptor molecule 2 (STAM2) is a phosphotyrosine protein, which regulates receptor signaling and trafficking of mammalian cells. However, its role in gastric cancer (GC) remains undiscovered. In this study, we aimed to investigate the functions of STAM2 in GC. The mRNA and protein expression levels of STAM2 were measured by quantitative real-time PCR, western blot analysis, and immunohistochemistry. STAM2 was stably silenced in AGS and HGC-27 cells using small interfering RNA. The function of STAM2 in GC cells was further investigated by CCK-8 assay, EdU incorporation assay, flow cytometry, and scratch wound healing and Boyden chamber assays. Additionally, we conducted biological pathway enrichment analysis and rescue assays to explore the effects of STAM2 on JAK/STAT signaling pathway. Our results showed that STAM2 is remarkably highly expressed in GC tissues and cells, and overexpressed STAM2 is correlated with tumor size, advanced tumor node metastasis stage, and poor prognosis. In addition, STAM2 knockdown could significantly inhibit proliferation, block cell cycle, and restrain migration and invasion capabilities of GC cells. Mechanistically, we found that STAM2 knockdown effectively decreased the expressions of MMP2 and MMP9 and the phosphorylation levels of JAK2 and STAT3. Taken together, this study revealed that STAM2 knockdown could suppress malignant process by targeting the JAK2/STAT3 signaling pathway in GC.


Author(s):  
Zhongwei Zhao ◽  
Jingjing Song ◽  
Bufu Tang ◽  
Shiji Fang ◽  
Dengke Zhang ◽  
...  

Abstract Background Emerging evidence suggests that circular RNAs play critical roles in disease development especially in cancers. Previous genome-wide RNA-seq studies found that a circular RNA derived from SOD2 gene was highly upregulated in hepatocellular carcinoma (HCC), however, the role of circSOD2 in HCC remains largely unknown. Methods The expression profiling of circSOD2 and microRNA in HCC patients were assessed by Real-Time Quantitative Reverse Transcription PCR (qRT-PCR). SiRNA or CRISPR-CAS9 were used to silence gene expression. The biological function of circSOD2 in HCC was investigated using in vitro and in vivo studies including, trans-well cell migration, cell apoptosis, cell cycle, CCK8, siRNA interference, western blots, and xenograft mouse model. The underlying molecular mechanism was determined by Chromatin Immunoprecipitation quantitative real time PCR (ChIP-qPCR), bioinformatic analysis, biotin-pull down, RNA immunoprecipitation, 5-mc DNA pulldown and luciferase assays. Results In accordance with previous sequencing results, here, we demonstrated that circSOD2 was highly expressed in HCC tumor tissues compared with normal liver tissues. Mechanically, we showed that histone writer EP300 and WDR5 bind to circSOD2 promoter and trigger its promoter H3K27ac and H3K4me3 modification, respectively, which further activates circSOD2 expression. SiRNA mediated circSOD2 suppression impaired liver cancer cell growth, cell migration, prohibited cell cycle progression and in vivo tumor growth. By acting as a sponge, circSOD2 inhibits miR-502-5p expression and rescues miR-502-5p target gene DNMT3a expression. As a DNA methyltransferase, upregulated DNMA3a suppresses SOCS3 expression by increasing SOCS3 promoter DNA methylation. This event further accelerates SOCS3 downstream JAK2/STAT3 signaling pathway activation. In addition, we also found that activated STAT3 regulates circSOD2 expression in a feedback way. Conclusion The novel signaling axis circSOD2/miR-502-5p/DNMT3a/JAK2/STAT3/circSOD2 provides a better understanding of HCC tumorigenesis. The molecular mechanism underlying this signaling axis offers new prevention and treatment of HCC.


Biology ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 29
Author(s):  
Chakrabhavi Dhananjaya Mohan ◽  
Min Hee Yang ◽  
Shobith Rangappa ◽  
Arunachalam Chinnathambi ◽  
Sulaiman Ali Alharbi ◽  
...  

Hepatocellular carcinoma (HCC) is one of the leading cancers that contribute to a large number of deaths throughout the globe. The signal transducer and activator of transcription 3 (STAT3) is a tumorigenic protein that is overactivated in several human malignancies including HCC. In the present report, the effect of 3-formylchromone (3FC) on the STAT3 signaling pathway in the HCC model was investigated. 3FC downregulated the constitutive phosphorylation of STAT3 and non-receptor tyrosine kinases such as JAK1 and JAK2. It also suppressed the transportation of STAT3 to the nucleus and reduced its DNA-binding ability. Pervanadate treatment overrode the 3FC-triggered STAT3 inhibition, and the profiling of cellular phosphatase expression revealed an increase in SHP-2 levels upon 3FC treatment. The siRNA-driven deletion of SHP-2 led to reinstate STAT3 activation. 3FC downmodulated the levels of various oncogenic proteins and decreased CXCL12-driven cell migration and invasion. Interestingly, 3FC did not exhibit any substantial toxicity, whereas it significantly regressed tumor growth in an orthotopic HCC mouse model and abrogated lung metastasis. Overall, 3FC can function as a potent agent that can display antitumor activity by targeting STAT3 signaling in HCC models.


2019 ◽  
Vol 10 (10) ◽  
Author(s):  
Binlong Zhong ◽  
Deyao Shi ◽  
Fashuai Wu ◽  
Shangyu Wang ◽  
Hongzhi Hu ◽  
...  

Abstract Osteosarcoma (OS) is the most common malignant bone tumor. The prognosis of metastatic and recurrent OS patients still remains unsatisfactory. Cisplatin reveals undeniable anti-tumor effect while induces severe side effects that threatening patients’ health. Dynasore, a cell-permeable small molecule that inhibits dynamin activity, has been widely studied in endocytosis and phagocytosis. However, the anti-tumor effect of dynasore on OS has not yet been ascertained. In the present study, we suggested that dynasore inhibited cell proliferation, migration, invasion, and induced G0/G1 arrest of OS cells. Besides, dynasore repressed tumorigenesis of OS in xenograft mouse model. In addition, we demonstrated that dynasore improved the anti-tumor effect of cisplatin in vitro and in vivo without inducing nephrotoxicity and hepatotoxicity. Mechanistically, dynasore repressed the expression of CCND1, CDK4, p-Rb, and MMP-2. Furthermore, we found that dynasore exerts anti-tumor effects in OS partially via inhibiting STAT3 signaling pathway but not ERK-MAPK, PI3K-Akt or SAPK/JNK pathways. P38 MAPK pathway served as a negative regulatory mechanism in dynasore induced anti-OS effects. Taken together, our study indicated that dynasore does suppress cell proliferation, migration, and invasion via STAT3 signaling pathway, and enhances the antitumor capacity of cisplatin in OS. Our results suggest that dynasore is a novel candidate drug to inhibit the tumor growth of OS and enhance the anti-tumor effects of cisplatin.


2019 ◽  
Vol 11 ◽  
pp. 175883591987464 ◽  
Author(s):  
Hongye Jiang ◽  
Yong Li ◽  
Jie Li ◽  
Xuyu Zhang ◽  
Gang Niu ◽  
...  

Background: A review of the evidence has indicated the critical role of long noncoding RNA (lncRNA) LSINCT5 in a large number of human cancers. However, the mechanistic involvement of LSINCT5 in endometrial carcinoma (EC) is still unknown. Here the authors aim to characterize the expression status of LSINCT5 and elucidate its mechanistic relevance to EC. Methods: Relative expression of LSINCT5 and HMGA2 were quantified by a real-time polymerase chain reaction. SiRNAs were employed to specifically knockdown endogenous LSINCT5 in EC cells. Cell proliferation was measured with Cell Count Kit-8 kit (CCK-8, Dojindo, Kumamoto, Japan) and cell growth was assessed by a colony formation assay. The cell cycle was analyzed with propidium iodide (PI) staining. Apoptotic cells were determined by flow cytometry after Annexin V/PI double-staining. Cell migration was evaluated by a wound-healing assay, and cell invasion was assessed using a transwell migration assay. The protein levels of HMGA2, Wnt3a, p-β-catenin, c-myc, β-actin, and GAPDH were determined by western blot. Results: The authors observed positively correlated and aberrantly up-regulated LSINCT5 and HMGA2 in EC. LSINCT5 deficiency significantly inhibited cell proliferation, cell cycle progression, and induced apoptosis. Meanwhile, cell migration and invasion were greatly compromised by the LSINCT5 knockdown. LSINCT5 stabilized HMGA2, which subsequently stimulated activation of Wnt/β-catenin signaling and consequently contributed to the oncogenic properties of LSINCT5 in EC. Conclusions: Our data uncovered the oncogenic activities and highlighted the mechanistic contributions of the LSINCT5-HMGA2-Wnt/β-catenin signaling pathway in EC.


2020 ◽  
Vol 10 (8) ◽  
pp. 1199-1205
Author(s):  
Demao Kong ◽  
Xia Wang

Background and purpose: As a type of non-coding genetic material widely existing in eukaryotes, a growing amount of research have confirmed that it have close connection with the occurrence and progression of various malignancies. MicroRNA126 is increased in non-small-cell lung cancer, liver cancer and gastric carcinoma. The up-regulation of miR126 in cervical cancer is closely associated with the clinical staging, histological grade, depth of invasion and early metastasis of the tumor, and it is also of great value in predicting the survival prognosis of the tumor. However, there is little known about the relationship between miR126 and pancreatic carcinoma. Therefore, this study explored the miR126-mediated STAT3 signaling pathway in medicating pancreatic cancer cell multiplication, migration, cell cycle and apoptosis in vitro . Methods: PANC-1 cell (human pancreatic cancer cell line) was selected for routine resuscitation and subculture. The experiment is grouped as: blank control group (NC group), empty plasmid transfection group (miR126-NC group), miR126mimic transfection group (overexpression Group) and miR126 inhibition plasmid transfection group (low expression group); cell viability of each group for 12 h, 24 h, 48 h and 72 h was detected using MTT assay. Wound healing assay was used to evaluated the ability of cell migration. Flow cytometry was performed to analyze cell cycle. The mRNA expression of Caspase-3 was determined by reverse transcription PCR (RT-PCR). STAT3 protein was evaluated by western blot. Results: miR126 overexpression significantly increased cell proliferation at 12 h, 24 h, 48 h, and 72 h, while the cell proliferation rates of the low expression group at each time point were significantly reduced in comparision with those of the NC group and the miR126-NC group (P < 0 05). miR126 overexpression significantly induced cell migration, while miR126 low-expression significantly inhibited cell migration (P < 0 05). miR126 overexpression significantly enhanced the percentage of G2/M, while the percentage of G2/M in the low-expressed group was remarkably reduced in comparision with those of the NC group and the miR126-NC group (P < 0 05). The mRNA expression of Caspase-3 was significantly inhibited in miR126 overexpression group, while the expression of Caspase-3 mRNA in the cells with miR126 low expression was remarkably increased (P < 0 05). The protein expression of STAT3 in miR126 overexpression group was notably up-regulated, while the expression level of STAT3 protein in the low expression group was prominently down-regulated (P <0 05). Conclusion: MiR126 overexpression may induces the STAT3 signaling pathway and then regulates cell proliferation, cell migration, cell cycle arrest and cell apoptosis in pancreatic carcinoma.


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