Suppressive effect of YY1-mediated RGS22 regulation on the proliferation, migration and invasion of pancreatic ductal adenocarcinoma.

Regulator of G-protein signaling 22 (RGS22) is specifically expressed in the testis and in tumors of epithelial origin, but the expression and role of RGS22 in pancreatic cancer are unclear. In this study, 52 pairs of pancreatic ductal adenocarcinoma (PDAC) and adjacent non-neoplastic tissue samples with the corresponding clinical data were used to examine the expression of RGS22 and its relationship with PDAC prognosis. The findings showed that the expression of RGS22 was higher in the PDAC tissues than in the adjacent non-tumorous tissues and its expression was associated with the degree of blood vessel invasion. The in vitro experiments with PDAC cell lines and a normal control cell line showed that the proliferation, invasion, and metastasis of PDAC cells were suppressed by RGS22 overexpression and enhanced by RGS22 knockdown. The in vivo effect of RGS22 on PDAC xenografts was studied using subcutaneous implantation of tumor cells in BALB/cA-nu mice, and the results corroborated the in vitro findings. Analysis of the regulators of RGS22 showed that it was positively regulated by the transcription factor Yin Yang-1 (YY1). Thus, YY1-mediated RGS22 regulation suppressed the proliferation, migration, and invasion of PDAC.

Effect of the transcription factor YY1 on the development of pancreatic endocrine and exocrine tumors: a narrative review.

Pancreatic tumors are classified into endocrine and exocrine types, and the clinical manifestations in patients are nonspecific. Most patients, especially those with pancreatic ductal adenocarcinoma (PDAC), have lost the opportunity to receive for the best treatment at the time of diagnosis. Although chemotherapy and radiotherapy have shown good therapeutic results in other tumors, their therapeutic effects on pancreatic tumors are minimal. A multifunctional transcription factor, Yin-Yang 1 (YY1) regulates the transcription of a variety of important genes and plays a significant role in diverse tumors. Studies have shown that targeting YY1 can improve the survival time of patients with tumors. In this review, we focused on the mechanism by which YY1 affects the occurrence and development of pancreatic tumors. We found that a YY1 mutation is specific for insulinomas and has a role in driving the degree of malignancy. In addition, changes in the circadian network are a key causative factor of PDAC. YY1 promotes pancreatic clock progression and induces malignant changes, but YY1 seems to act as a tumor suppressor in PDAC and affects many biological behaviors, such as proliferation, migration, apoptosis and metastasis. Our review summarizes the progress in understanding the role of YY1 in pancreatic endocrine and exocrine tumors and provides a reasonable assessment of the potential for therapeutic targeting of YY1 in pancreatic tumors.

Roundabout homolog 1 inhibits proliferation via the YY1-ROBO1-CCNA2-CDK2 axis in human pancreatic cancer.

Pancreatic cancer (PC) is highly malignant and has a high mortality with a 5-year survival rate of less than 8%. As a member of the roundabout immunoglobulin superfamily of proteins, ROBO1 plays an important role in embryogenesis and organogenesis and also inhibits metastasis in PC. Our study was designed to explore whether ROBO1 has effects on the proliferation of PC and its specific mechanism. The expression of ROBO1 was higher in cancer tissues than in matched adjacent tissues by immunohistochemistry (IHC) and qRT-PCR. Low ROBO1 expression is associated with PC progression and poor prognosis. Overexpression of ROBO1 can inhibit the proliferation of PC cells in vitro, and the S phase fraction can also be induced. Further subcutaneous tumor formation in nude mice showed that ROBO1 overexpression can significantly inhibit tumor growth. YY1 was found to directly bind to the promoter region of ROBO1 to promote transcription by a luciferase reporter gene assay, a chromatin immunoprecipitation (ChIP) and an electrophoretic mobility shift assay (EMSA). Mechanistic studies showed that YY1 can inhibit the development of PC by directly regulating ROBO1 via the CCNA2/CDK2 axis. Taken together, our results suggest that ROBO1 may be involved in the development and progression of PC by regulating cell proliferation and shows that ROBO1 may be a novel and promising therapeutic target for PC.

Linc01232 promotes the metastasis of pancreatic cancer by suppressing the ubiquitin-mediated degradation of HNRNPA2B1 and activating the A-Raf-induced MAPK/ERK signaling pathway.

Pancreatic cancer (PC) is a malignant cancer with high mortality and poor prognosis. In this study, we found that Linc01232 was significantly upregulated in PC tissues and cells and higher Linc01232 expression was associated with poorer prognosis. Linc01232 overexpression promoted and Linc01232 knockdown inhibited the migration and invasion of PC cells. The results of RNA pull-down, RNA Binding Protein Immunoprecipitation (RIP) assays revealed that Linc01232 physically interacted with Heterogeneous Nuclear Ribonucleoprotein A2/B1 (HNRNPA2B1) (680-890 nt fragment with the RNA recognition motif 2 domain) to inhibit its ubiquitin-mediated degradation in PC cells. RNA sequencing was performed to obtain the transcriptional profiles regulated by Linc01232 and we further demonstrated that Linc01232 participated in the alternative splicing of A-Raf by stabilizing HNRNPA2B1 and subsequently regulated the MAPK/ERK signaling pathway. Collected, our study showed that Linc01232/HNRNPA2B1/A-Raf/MAPK axis participated in the progression of PC and provided a potential therapeutic target for PC.

The YY1/miR-548t-5p/CXCL11 signaling axis regulates cell proliferation and metastasis in human pancreatic cancer.

Pancreatic cancer (PC) is a malignant tumor with a poor prognosis and high mortality. However, the biological role of miR-548t-5p in PC has not been reported. In this study, we found that miR-548t-5p expression was significantly decreased in PC tissues compared with adjacent tissues, and that low miR-548t-5p expression was associated with malignant PC behavior. In addition, high miR-548t-5p expression inhibited the proliferation, migration, and invasion of PC cell lines. Regarding the molecular mechanism, the luciferase reporter gene, chromatin immunoprecipitation (ChIP), and functional recovery assays revealed that YY1 binds to the miR-548t-5p promoter and positively regulates the expression and function of miR-548t-5p. miR-548t-5p also directly regulates CXCL11 to inhibit its expression. A high level of CXCL11 was associated with worse Tumor Node Metastasis (TNM) staging in patients with PC, enhancing proliferation and metastasis in PC cells. Our study shows that the YY1/miR-548t-5p/CXCL11 axis plays an important role in PC and provides a new potential candidate for the treatment of PC.

Optimization of internal reference genes for qPCR in human pancreatic cancer research.

BACKGROUND: Pancreatic cancer (PC) has been becoming a common cancer with high mortality and quantitative real-time polymerase chain reaction (qPCR) is one of the best choices for researching gene expression. Internal reference genes, such as actin beta (ACTB) and glyceraldehyde-3-phosphatide hydrogenase (GAPDH) have long been used in relative quantification analysis. But evidence shows that some internal reference genes expression may vary in different tissues, cell lines and different conditions. The present study aimed to find more stable internal reference gene for qPCR experiment in PC. METHODS: Total RNA of human PC tissues were prepared using TRIZOL reagent. qPCR was performed using FastStart Universal SYBR Green Master to reflects the expression of target genes. Normfinder and geNorm were used to analyze the stability of chosen internal reference genes. RESULTS: According to the results of NormFinder and geNorm, eukaryotic translation initiation factor 2B subunit alpha (EIF2B1) and importin 8 (IPO8) were the same most stable internal reference genes in PCs and non-neoplastic tissues. In addition, EIF2B1 and IPO8 remained the most stable internal reference genes only in PCs. Using a normalization factor NF2 by geNorm as reference, the normalized GAPDH and ACTB expression levels were obviously up-regulated by 3.29- and 2.23-fold change, meanwhile ribosomal protein S17 (RPS17) were down-regulated by 0.77-fold change in PCs comparing with corresponding adjacent tissues. CONCLUSIONS: The use of the combination of EIF2B1 and IPO8 would provide more stable results in differential expression analysis and prognostic analysis of PC.

YY1 targets tubulin polymerisation-promoting protein to inhibit migration, invasion and angiogenesis in pancreatic cancer via p38/MAPK and PI3K/AKT pathways.

BACKGROUND: Pancreatic cancer (PDAC) is a highly invasive cancer with poor prognosis. Recent research has found that the transcription factor Yin Yang 1 (YY1) plays an inhibitory role in the development of pancreatic cancer. It has been reported that tubulin polymerisation-promoting protein (TPPP) plays an indispensable role in a variety of tumours, but its expression and role in pancreatic cancer have not yet been elucidated. METHODS: In this study, we performed ChIP-sequencing and found that YY1 directly binds to the promoter region of TPPP. The expression of TPPP in pancreatic cancer was detected by western blotting and immunohistochemistry. Four-week-old male BALB/c-nude mice were used to assess the effect of TPPP on pancreatic cancer. RESULTS: Immunohistochemistry revealed that TPPP was expressed at low levels in pancreatic cancer tissues, and was associated with blood vessel invasion. The results from vivo experiments have showed that TPPP could enhance the migration and invasion of pancreatic cancer. Further experiments showed that YY1 could inhibit the migration, invasion and angiogenesis of pancreatic cancer cells by downregulating TPPP via p38/MAPK and PI3K/AKT pathways. CONCLUSION: Our study demonstrates that TPPP may act as a promoter and may serve as a novel target for the treatment of pancreatic cancer.

YY1 inhibits the migration and invasion of pancreatic ductal adenocarcinoma by downregulating the FER/STAT3/MMP2 signaling pathway.

Pancreatic ductal adenocarcinoma (PDAC) has a poor prognosis and a high mortality rate. The transcription factor YY1 acts as an inhibitor of many types of tumors. We found that YY1 knockdown promoted the invasion and migration of PANC-1 and BxPC-3 cells; FER knockdown partially restored the promotion of pancreatic cancer caused by YY1 knockdown. In vivo experiments yielded the same results. According to luciferase reporter gene, electrophoretic mobility shift (EMSA) and chromatin immunoprecipitation (ChIP) assays, YY1 directly binds to the FER promoter region. Moreover, higher level FER expression results in a worse TNM stage and prognosis for patients with PDAC. Furthermore, by downregulating FER, YY1 inhibits the formation of the STAT3-MMP2 complex, thereby suppressing expression of MMP2 and ultimately inhibiting the migration and invasion of pancreatic cancer. Our study demonstrates that the YY1/FER/STAT3/MMP2 axis is associated with the progression of pancreatic cancer and may provide a new therapeutic target for the treatment of pancreatic cancer.

Effect of microRNA-208a on mitochondrial apoptosis of cardiomyocytes of neonatal rats.

OBJECTIVE: To explore the effect and mechanism of microRNA-208a (miR-208a) in the mitochondrial apoptosis of cardiomyocytes of neonatal rats. METHODS: The primary cultured cardiomyocytes of neonatal rats were added into the hypoxia incubator for the hypoxia induction. The overexpression system for miR-208a of cardiomyocytes of neonatal rats was built. The flow cytometry assay was employed to detect the incidence of apoptosis in the over-expressed miR-208a. The mitochondrial staining technique was used to detect the change in the mitochondrial morphology of over-expressed miR-208a. The bioinformatic analysis was chosen to analyze and predict the target gene of miR-208a. RESULTS: Firstly, the primary culture system of cardiomyocytes of neonatal rats was successfully built. The miR-208a was over-expressed in cardiomyocytes of neonatal rats by miR-208a Mimics. Results of flow cytometry assay showed that the over-expressed miR-208a could significantly reduce the incidence of apoptosis; while results of mitochondrial staining indicated the change in the mitochondrial morphology of over-expressed miR-208a and the mitochondrial fission process was inhibited. In conclusion, it was supposed that miR-208a could inhibit the activation of mitochondrial fission process to keep the cardiomyocytes from apoptosis. CONCLUSIONS: The over-expressed miR-208a can reduce the incidence of apoptosis in the cardiomyocytes of neonatal rats, significantly change the mitochondrial morphology and inhibit the mitochondrial fission process.

A DFT + U study of acetylene selective hydrogenation over anatase supported PdaAgb (a + b = 4) cluster.

It is well known that the addition of Ag into Pd can promote the selectivity of acetylene hydrogenation to ethylene, and early theoretical studies focus on ideal single crystal model catalysts, so it is worth studying relatively realistic catalyst models, such as metal oxide supported PdAg systems. In this work, the reaction mechanisms for acetylene selective hydrogenation on the anatase TiO2(101) supported PdaAgb (a + b = 4) cluster are studied by density functional theory calculations with a Hubbard U correction. The results show that Ag addition to the Pd4 cluster reduces the interaction between the PdAg cluster and the support, and the possible reason is that the amount of electron transfer from the TiO2 support to the PdAg cluster decreases with increasing number of Ag atoms. Consequently the adsorption energies of acetylene and ethylene would become smaller on the anatase supported PdAg cluster as compared to that on the anatase supported Pd4 cluster, and this may help to enhance the selectivity of ethylene formation. Moreover, the reaction kinetics study of acetylene hydrogenation on anatase TiO2(101) supported PdAg cluster shows that the activation energy of the hydrogenation step is higher on the PdAg cluster than that on the pure Pd4 cluster, and thus reduces its catalytic activity. Importantly, the present calculation results suggested that the selectivity of ethylene formation, which is defined as the energy difference between the adsorption energy of ethylene and the barrier for its further hydrogenation, varies with the ratio of Pd/Ag in the PdAg cluster: the Pd3Ag system shows relatively low selectivity compared to that of the pure Pd4 cluster, whereas Pd2Ag2/PdAg3 displays higher selectivity than that of the pure Pd4 cluster. Furthermore, our present results demonstrated that the anatase support plays a key role in the acetylene hydrogenation processes: on one hand, it reduces the reaction activity of acetylene hydrogenation processes compared to the Pd2Ag2/Pd(111) and Pd2Ag2 clusters; on the other hand, it enhances the selectivity of ethylene due to its lower desorption energy. It was also found that the carbon species inside the Pd2Ag2 cluster has little effect on the catalytic selectivity towards ethylene formation, whereas the hydrogenation catalytic activity is enhanced significantly. Finally the role of the Pd2Ag2-anatase interface on the catalytic properties of acetylene hydrogenation was studied, and it was found that the interface can increase the activity of acetylene hydrogenation but the selectivity is not improved.

[Effects of yijing recipe on sperm apoptosis and mitochondrial membrane potential in patients with idiopathic oligoathenoteratospermia].

OBJECTIVE: To investigate the effects of Yijing Recipe on sperm apoptosis and mitochondrial membrane potential (MMP) in patients with idiopathic oligoathenoteratospermia. METHODS: Using the self-control method, we examined sperm apoptosis and MMP in 30 patients with oligoathenoteratospermia before and after treated with Yijing Recipe. RESULTS: The rates of early sperm apoptosis (AV +/PI -) and MMP loss were significantly reduced after treatment as compared with pre-medication ([2.86 +/- 1.47]% vs [4.26 +/- 2.79]% and [21.77 +/- 13.46]% vs [41.73 +/- 20.30]%, P<0.05). No statistically significant difference was observed in the sperm death rate (PI+) before and after treatment ([34.10 +/- 16.26]% vs [30.21 +/- 13.50]%, P>0.05). CONCLUSION: Yijing Recipe can reduce early sperm apoptosis and improve MMP, which may be one of the mechanisms underlying its efficacy on oligoathenoteratospermia.