The SIX1/LDHA Axis Promotes Lactate Accumulation and Leads to NK Cell Dysfunction in Pancreatic Cancer.

Background: Pancreatic cancer (PC) is a malignant cancer with poor prognosis and high mortality rate. Sine oculis homeobox homolog 1 (SIX1) participates in the development of many cancers. However, the function of SIX1 in PC is not fully understood. Methods: SIX1 expression was determined using immunohistochemistry in PC tissues and cell lines. Glucose consumption, lactate production, and ATP assays were used to detect the function of SIX1. PC cells and NK cells were cocultured to study the effect of SIX1 overexpression in PC cells on NK cell function. Chromatin immunoprecipitation (ChIP) assays were used to study the relationship between SIX1 and lactate dehydrogenase A (LDHA). A series of in vitro and in vivo assays were further applied to elucidate the important role of the SIX1/LDHA axis in metabolism and NK cell dysfunction in PC. Results: SIX1 was significantly upregulated in PC tissue; SIX1 overexpression promoted the glycolysis capacity of PANC-1 and CFPAC-1 cells and resulted in NK cell dysfunction after the NK cells had been cultured with PC cells. LDHA inhibitor partially restored the promotion of PC caused by SIX1 overexpression. According to ChIP assays, SIX1 directly binds to the LDHA promoter region. Moreover, LDHA inhibitor and lactate transporter blocker treatment promoted the function of NK cells cocultured with PC cells. In vivo experiments yielded the same results. Conclusion: The SIX1/LDHA axis promotes lactate accumulation and leads to NK cell dysfunction in PC.

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.

DUOX2 As a Potential Prognostic Marker which Promotes Cell Motility and Proliferation in Pancreatic Cancer.

DUOX2 has been reported to highly express in several types of cancers. However, the prognostic significance and the biological function of DUOX2 expression with pancreatic cancer (PC) still remain unclear. The present study is aimed at investigating whether DUOX2 could act as a novel biomarker of prognosis and evaluating its effect on PC cell progression. The mRNA and protein expression of DUOX2 in PC cells and tissues were assessed by quantitative real-time PCR (RT-qPCR) and immunohistochemistry. The effect of DUOX2 expression on PC cell motility and proliferation was evaluated in vitro. The correlation between DUOX2 mRNA expression and clinicopathological features and its prognostic significance were analyzed according to the Gene Expression Profiling Interactive Analysis (GEPIA) website based on The Cancer Genome Atlas (TCGA) and the GTEx databases combined with our clinical information. According to bioinformatics analysis, we forecasted the upstream transcription factors (TFs) and microRNA (miRNA) regulatory mechanism of DUOX2 in PC. The expression of DUOX2 at transcriptional and protein level was dramatically increased in PC specimens when compared to adjacent nontumor specimens. Functionally, DUOX2 knockdown inhibited cell motility and proliferation activities. Our clinical data revealed that the patients had better postoperative overall survival (OS) with lower expression of DUOX2, which is consistent with GEPIA data. Multivariate analysis revealed that high DUOX2 expression was considered as an independent prognostic indicator for OS (P = 0.031). Based on Cistrome database, the top 5 TFs of each positively and negatively association with DUOX2 were predicted. hsa-miR-5193 and hsa-miR-1343-3p targeting DUOX2 were forecasted from TargetScan, miRDB, and DIANA-TarBase databases, which were negatively correlated with OS (P = 0.043 and P = 0.0088, respectively) and DUOX2 expression (P = 0.0093 and P = 0.0032, respectively) in PC from TCGA data. These findings suggest that DUOX2 acts as a promising predictive biomarker and an oncogene in PC, which could be a therapeutic target for PC.

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.

A novel antisense lncRNA NT5E promotes progression by modulating the expression of SYNCRIP and predicts a poor prognosis in pancreatic cancer.

A novel antisense lncRNA NT5E was identified in a previous microarray that was clearly up-regulated in pancreatic cancer (PC) tissues. However, its biological function remains unclear. Thus, we aimed to explore its function and clinical significance in PC. The lncNT5E expression was determined in PC specimens and cell lines. In vitro and in vivo studies detected the impact of lncNT5E depletion on PC cell proliferation, migration and invasion. Western blotting investigated the epithelial-mesenchymal transition (EMT) markers. The interaction between lncNT5E and the promoter region of SYNCRIP was detected by dual-luciferase reporter assay. The role of lncNT5E in modulating SYNCRIP was investigated in vitro. Our results showed that lncNT5E was significantly up-regulated in PC tissues and cell lines and associated with poor prognosis. LncNT5E depletion inhibited PC cell proliferation, migration, invasion and EMT in vitro and caused tumorigenesis arrest in vivo. Furthermore, SYNCRIP knockdown had effects similar to those of lncNT5E depletion. A significant positive relationship was observed between lncNT5E and SYNCRIP. Moreover, the dual-luciferase reporter assays indicated that lncNT5E depletion significantly inhibited SYNCRIP promoter activity. Importantly, the malignant phenotypes of lncNT5E depletion were rescued by overexpressing SYNCRIP. In conclusion, lncNT5E predicts poor prognosis and promotes PC progression by modulating SYNCRIP expression.

Microwave-Assisted Ablation Improves the Prognosis of Patients With Hepatocellular Carcinoma Undergoing Liver Resection.

OBJECTIVE: We evaluated microwave-assisted liver resection for hepatocellular carcinoma. PATIENTS AND METHODS: We enrolled 79 patients in this study, and microwave ablation was used for liver resection. Patients were randomized to group A (50.6%; n = 40), liver resection without microwave ablation, or group B (49.4%; n = 39), liver resection performed using microwave ablation. Data were analyzed for statistical significance. RESULTS: Of the participants enrolled, 60 were male, and the participant's average age was 59.32 ± 10.34 years. The mean overall tumor diameter was 4.39 (2.00) cm, and this did not differ between groups. Intraoperative blood loss in group B was significantly less than that in group A ( P < .001). No differences were reported between the 2 groups regarding surgical time ( P = .914), postoperative morbidity ( P = .718), and late postoperative complications ( P = .409). Postoperative drainage volume for group B was less than that of group A on the first ( P = .005) and third ( P = .019) day after surgery. The time of postoperative hospitalization in group B was significantly shorter than that in group A ( P < .001). Local recurrence was noted in 18.99% of cases (n = 15) in group B, which is less than that of group A ( P = 0.047), while in group B distant metastasis is less but not statistically significant ( P = 0.061). The 1-year and 3-year cumulative survival rates were 57% and 93.7%, respectively. CONCLUSIONS: The curative effects of liver resection combined with microwave ablation during operation are superior to only liver resection in the treatment of primary liver cancer.

Kinesin superfamily protein expression and its association with progression and prognosis in hepatocellular carcinoma.

OBJECTIVES: In this study, we characterized the expression of 32 other kinesin superfamily proteins (KIFs) and analyzed their association with the progression and prognosis of hepatocellular carcinoma (HCC). MATERIALS AND METHODS: The data from 295 HCC patients from The Cancer Genome Atlas were included in the study. An independent t-test was used to compare the KIF levels in HCC and adjacent tissues. Pearson's Chi-square test was used to assess the relationships of KIF expression with tumor biomarkers and clinicopathological parameters. Kaplan-Meier plots and log-rank tests were used to analyze survival, and univariate and multivariate analyses were used to identify independent prognostic factors. RESULTS: The expressions of 32 KIFs were compared between HCC and adjacent nontumor tissues. Among them, 12 KIFs showed no statistical significance, 17 KIFs were upregulated, and three KIFs were downregulated in tumor tissues. The levels of some KIFs were markedly correlated with that of biomarkers for the S phase and proliferation. KIF2A and KIFC3 expression was positively associated with biomarkers for cell invasion and migration. Some KIF overexpression was significantly associated with neoplastic pathological grade and tumor-node-metastasis staging. Furthermore, KIF2C, KIF4A, and KIF11 overexpression were significantly associated with shorter relapse-free survival times. KIF2A, KIF2C, KIF3A, KIF4B, KIF11, KIF15, KIFC1, and KIFC3 overexpression was associated with shorter overall survival (OS) times, whereas higher expression of KIF19 was associated with a longer OS time. Further multivariate analyses suggested that only KIF4B was an independent prognostic factor for HCC. CONCLUSIONS: Most overexpressions of abnormal KIFs were significantly associated with HCC progression and prognosis, indicating that KIFs could be prognostic and therapeutic biomarkers for HCC. However, it is necessary to further study the function of KIFs and their mechanisms involved in HCC.

MicroRNA-30a ameliorates hepatic fibrosis by inhibiting Beclin1-mediated autophagy.

We explored the role of microRNA-30a (miR-30a) and the mechanism involved in hepatic fibrosis. MiR-30a overexpression was achieved by miR-30a mimics transfection in hepatic stellate cells (HSCs) (HSC-T6, LX-2), and miR-30a agomir (ago-miR-30a) treatment in mice. MiR-30a levels were measured using TaqMan miRNA assay system, and the localization of miR-30a was detected by fluorescence in situ hybridization (FISH). The interaction of miR-30a and Beclin1 was confirmed by dual-luciferase reporter assay. Autophagic flux was analysed using tandem mRFP-GFP-LC3 fluorescence microscopy, electron microscopy and Western blot of LC3-II/I ratio. MiR-30a was notably down-regulated in activated HSCs and LX-2-exosomes induced by TGF-ß1; overexpression of miR-30a down-regulated extracellular matrix (ECM), such as α-SMA, TIMP-1, and Collagen I expression, and suppressed cell viability in HSCs. MiR-30a was significantly down-regulated in hepatic fibrosis mice and overexpression of miR-30a prevented BDL-induced fibrogenesis, concomitant with the down-regulation of ECM. MiR-30a inhibited HSCs autophagy and increased lipid accumulation in HSCs and in mice fibrotic hepatic tissues. MiR-30a inhibited its downstream effector of Beclin1 by direct targeting its 3'-UTR region. Moreover, Knock-down of Beclin1 by small interfering RNA (siRNA) inhibited HSC autophagy and activation in LX-2 cells. In conclusion, miR-30a is down-regulated in hepatic fibrosis models and its overexpression prevents liver fibrogenesis by directly suppressing Beclin1-mediated autophagy; therefore, miR-30a may be a new potential therapeutic target for controlling hepatic fibrosis.