Jiewei Chen

GNA13 as a prognostic factor and mediator of gastric cancer progression

Guanine nucleotide binding protein (G protein), alpha 13 (GNA13) has been implicated as an oncogenic protein in several human cancers. In this study, GNA13 was characterized for its role in gastric cancer (GC) progression and underlying molecular mechanisms. The expression dynamics of GNA13 were examined by immunohistochemistry (IHC) in two independent cohorts of GC samples. A series of in-vivo and in-vitro assays was performed to elucidate the function of GNA13 in GC and its underlying mechanisms. In both two cohorts of GC samples, we observed that GNA13 was markedly overexpressed in GC tissues and associated closely with aggressive magnitude of GC progression and poor patients survival. Further study showed that upregulation of GNA13 expression increased the proliferation and tumorigenicity of GC cells in vitro and in vivo, by promoting cell growth rate, colony formation, and tumor formation in nude mice. By contrast, knockdown of GNA13 effectively suppressed the proliferation and tumorigenicity of GC cells in vitro and in vivo. Our results also demonstrated that the molecular mechanisms of the effect of GNA13 in GC included promotion of G1/S cell cycle transition through upregulation of c-Myc, activation of AKT and ERK activity, suppression of FOXO1 activity, upregulation of cyclin-dependent kinase (CDK) regulator cyclin D1 and downregulation of CDK inhibitor p21Cip1 and p27Kip1. Our present study illustrated that GNA13 has an important role in promoting proliferation and tumorigenicity of GC, and may represent a novel prognostic biomarker and therapeutic target for this disease.

α4 contributes to bladder urothelial carcinoma cell invasion and/or metastasis via regulation of E-cadherin and is a predictor of outcome in bladder urothelial carcinoma patients

AIMnα4 is upregulated in several types of human cancer and possesses an oncogenic role. However, the abnormalities of α4 and its underlying mechanisms in the pathogenesis of bladder urothelial carcinoma (BUC) remain unknown.nnnMETHODSnα4 expression profile was examined by reverse transcription polymerase chain reaction, western blotting and immunohistochemistry (IHC) in BUC tissues and normal urothelial bladder epithelial tissues. Short hairpin RNA (ShRNA) interfering approach was employed to suppress endogenous α4 expression in BUC cells to determine its role in tumourigenesis, invasion/metastasis and the potential mechanism.nnnRESULTSnα4 expression in BUC was significantly up-regulated at both mRNA and protein levels compared with that in normal urothelial bladder epithelial tissues. High expression of α4 was inversely correlated with poor survival of the BUC patients (P<0.05). Down-regulation of α4 in BUC EJ and T24 cells led to a G1 phase cell cycle arrest, suppressed cell growth, markedly inhibited invasive motility in vitro and metastatic potential in vivo. Moreover, down-regulation of α4 was found to increase E-cadherin expression and reduce metastasis-associated protein 1 (MTA1) expression either in transcript or protein levels. Importantly, a significant correlation between high expression of α4 and negative expression of E-cadherin in BUC cohorts was observed (P<0.001).nnnCONCLUSIONSnThese findings suggest a potential important role of α4 in control of cell migration and/or invasion via the regulation of E-cadherin expression, and the high α4 expression, as examined by IHC, is an independent molecular marker for shortened survival time of patients with BUC.

Overexpression of α-sma-positive fibroblasts (CAFs) in Nasopharyngeal Carcinoma Predicts Poor Prognosis

Purpose: The aim of this study is to investigate the differential expression of α-sma-positive fibroblasts (CAFs) in nasopharyngeal carcinomas (NPCs), nasopharyngitis, metastatic tissues of NPCs and its prognostic value in NPCs. Methods: The expression of α-sma-labeled CAFs in 85 NPCs, 32 nasopharyngitis and 12 metastatic tissues of NPCs was detected by immunohistochemical method. The relationship between CAFs and clinicopathological parameters of NPCs was analyzed. Results: The high density of CAFs in the NPCs, nasopharyngitis and metastatic tissues of NPCs group were 41.2% (35/85), 6.2% (2/32) and 83.3% (10/12), and a significant difference was showed among these three groups (P<0.05). Chi-square test showed that there was no significant correlation between the density of CAFs and gender, age, N stage, treatment (P>0.05), but closely correlated with T stage and relapse (P<0.05). Kaplan-Meier survival analysis showed that the mean overall survival of high-density and low-density CAFs was 86.8 months and 127.0 months, respectively. Correspondingly, the 5-year survival rates were 57.1% (20/35) and 90.0% (45/50), and there were inversely statistical differences between two groups (P<0.05). Cox multivariate analysis showed that the density of CAFs could be used as an independent prognostic factor for the survival of NPC patients (P<0.05). Conclusions: The density of CAFs could be closely related to the metastasis of NPCs, and also is an efficient prediction factor of poor survival in patients with NPCs.

Overexpression of LBH is associated with poor prognosis in human hepatocellular carcinoma

Purpose Limb-bud and heart (LBH) levels are correlated with adverse survival in several malignancies; however, their significance in hepatocellular carcinoma (HCC) remains unclear. The objective of this study was to determine the association between LBH status and clinical outcomes. Methods We selected 226 patients with HCC who were treated surgically between 2003 and 2010 at a single academic center. Immunohistochemistry (IHC) was used to detect the protein expression of LBH in HCC samples. Receiver operating characteristic (ROC) curve analysis, Spearman’s rank correlation, Kaplan–Meier plots, and the Cox proportional hazards regression model were used to analyze the data. Results A high expression of LBH was detected in 20 (8.8%) of 226 HCC samples. Correlation analysis demonstrated that LBH in HCC was significantly correlated with aspartate aminotransferase (AST)/alanine aminotransferase (ALT) levels and clinical stages (P<0.05). In the Kaplan–Meier analysis, the mean survival time of patients with low levels of LBH was longer than that for those with high levels of LBH (P<0.05). The 3-year overall survival rate was 20% for patients with HCC and high levels of LBH versus 67% for patients with HCC and low levels of LBH. In the multivariate analysis, AST/ALT level, clinical stage, tumor relapse, and the level of LBH were the independent prognostic factors for overall survival (P<0.05). Conclusion Overexpression of LBH might contribute to the development and progression of HCC. LBH could be a novel prognostic marker for HCC.

PRMT5 Circular RNA Promotes Metastasis of Urothelial Carcinoma of the Bladder through Sponging miR-30c to Induce Epithelial–Mesenchymal Transition

Purpose: Circular RNAs (circRNAs), a novel class of noncoding RNAs, have recently drawn lots of attention in the pathogenesis of human cancers. However, the role of circRNAs in cancer cells epithelial–mesenchymal transition (EMT) remains unclear. In this study, we aimed to identify novel circRNAs that regulate urothelial carcinoma of the bladder (UCB) cells’ EMT and explored their regulatory mechanisms and clinical significance in UCBs. Experimental Design: We first screened circRNA expression profiles using a circRNA microarray in paired UCB and normal tissues, and then studied the clinical significance of an upregulated circRNA, circPRMT5, in a large cohort of patients with UCB. We further investigated the functions and underlying mechanisms of circPRMT5 in UCB cells’ EMT. Moreover, we evaluated the regulation effect of circPRMT5 on miR-30c, and its target genes, SNAIL1 and E-cadherin, in two independent cohorts from our institute and The Cancer Genome Atlas (TCGA). Results: We demonstrated that upregulated expression of circPRMT5 was positively associated with advanced clinical stage and worse survival in patients with UCB. We further revealed that circPRMT5 promoted UCB cells EMT via sponging miR-30c. Clinical analysis from two independent UCB cohorts showed that the circPRMT5/miR-30c/SNAIL1/E-cadherin pathway was essential in supporting UCB progression. Importantly, we identified that circPRMT5 was upregulated in serum and urine exosomes from patients with UCB, and significantly correlated with tumor metastasis. Conclusions: CircPRMT5 exerts critical roles in promoting UCB cells’ EMT and/or aggressiveness and is a prognostic biomarker of the disease, suggesting that circPRMT5 may serve as an exploitable therapeutic target for patients with UCB.

CD8+ tumor-infiltrating lymphocytes as a novel prognostic biomarker in lung sarcomatoid carcinoma, a rare subtype of lung cancer

Purpose The aim of this study was to investigate the degree of infiltration of CD8+ tumor-infiltrating lymphocytes (TILs) including high and low density in lung sarcomatoid carcinoma (LSC) and their clinicopathological significance. Patients and methods The density of CD8+ TILs in paraffin-embedded tissue sections from 100 LSC patients was detected by immunohistochemical staining, and the relationship of CD8+ TILs with clinicopathological features and prognosis was analyzed. Results The chi-squared test showed that the degree of infiltration of CD8+ TILs was significantly correlated with the clinicopathological stage and T stage of LSC (P<0.05). The univariate analysis demonstrated that tumor size, clinicopathological stage, T stage, N stage, M stage, and CD8+ TILs are risk factors that affect prognosis of the patients (P<0.05). The mean overall survival (OS) of LSC patients with a high density of CD8+ TILs was 92.3 months, which was significantly higher than 31.2 months in patients with a low density of CD8+ TILs (P<0.05). Cox regression multivariate analysis confirmed that the density of CD8+ TILs was an independent prognostic factor for OS time of LSC patients (hazard ratio=0.455, P<0.05). Conclusion CD8+ TILs could be used as an effective prognostic index for LSC patients, and a high density of CD8+ TILs in tumor tissue may predict a better outcome.

Overexpression of amplified in breast cancer 1 (AIB1) gene promotes lung adenocarcinoma aggressiveness in vitro and in vivo by upregulating C-X-C motif chemokine receptor 4

BackgroundWe previously found that overexpression of the gene known as amplified in breast cancer 1 (AIB1) was associated with lymph node metastasis and poor prognosis in patients with lung adenocarcinoma. However, the role of AIB1 in that malignancy remains unknown. The present study aimed to investigate the function of AIB1 in the process of lung adenocarcinoma cell metastasis.MethodsA series of in vivo and in vitro assays were performed to elucidate the function of AIB1, while real-time PCR and Western blotting were utilized to identify the potential downstream targets of AIB1 in the process of lung adenocarcinoma metastasis. Rescue experiments and in vitro assays were performed to investigate whether the invasiveness of AIB1-induced lung adenocarcinoma was mediated by C-X-C motif chemokine receptor 4 (CXCR4).ResultsThe ectopic overexpression of AIB1 in lung adenocarcinoma cells substantially enhanced cell migration and invasive abilities in vitro and tumor metastasis in vivo, whereas the depletion of AIB1 expression substantially inhibited lung adenocarcinoma cell migration and invasion. CXCR4 was identified as a potential downstream target of AIB1 in lung adenocarcinoma. The knockdown of AIB1 greatly reduced CXCR4 gene expression at both the transcription and protein levels, whereas the knockdown of CXCR4 in cells with AIB1 ectopic overexpression diminished AIB1-induced migration and invasion in vitro and tumor metastasis in vivo. Furthermore, we found a significant positive association between the expression of AIB1 and CXCR4 in lung adenocarcinoma patients (183 cases), and the co-overexpression of AIB1 and CXCR4 predicted the poorest prognosis.ConclusionsThese findings suggest that AIB1 promotes the aggressiveness of lung adenocarcinoma in vitro and in vivo by upregulating CXCR4 and that it might be usable as a novel prognostic marker and/or therapeutic target for this disease.

CSTF2-induced shortening of the RAC1 3'UTR promotes the pathogenesis of urothelial carcinoma of the bladder.

Shortening of the 3 untranslated regions (3UTR) of mRNA is an important mechanism for oncogene activation. However, 3UTR alteration events, their pathologic functions, and underlying mechanisms in human urothelial carcinoma of the bladder (UCB) are not clear. Here, we combine RNA sequencing, bioinformatics, and clinical studies in two independent cohorts of patients with UCB to identify a novel RAC1 shorter 3UTR isoform that is frequently expressed in UCB and is critical in the tumorigenesis and acquisition of a poor prognostic phenotype in patients. Short 3UTR isoform of RAC1 substantially upregulated RAC1 expression by escaping from miRNA-targeted repression and played an essential oncogenic role in UCB pathogenesis. An important cleavage/polyadenylation factor, cleavage stimulation factor 2 (CSTF2), induced 3UTR shortening of RAC1 in UCB by mediating slow transcriptional elongation at RAC1 Cotranscriptional recruitment of CSTF2 on the GUAAU motif at proximal polyadenylation site of RAC1 attenuated the recruitment of two transcription factors AFF1 and AFF4, causing the defects in elongation. CSTF2 regulated the tumorigenic functions of the shorter RAC1 isoform in UCB cells, enhancing cell proliferation, migration, and invasion. The combination of high expression of CSTF2 and high usage of RAC1 short-3UTR isoform may be used as a powerful biomarker to predict poor prognosis in UCB. Our findings also suggest a CSTF2-regulated RAC1-3UTR shortening program as an exploitable therapeutic strategy for patients with UCB.Significance: These findings demonstrate that the short isoform of RAC1 is critical in UCB tumorigenesis and may have implications for developing new therapeutic strategies to treat this disease. Cancer Res; 78(20); 5848-62. ©2018 AACR.

EIF5A2 Contributes to the Maintenance of CD133(+) Hepatocellular Carcinoma Cells via the c‐Myc/microRNA‐29b Axis

Cancer stem cells (CSCs)/cancer‐initiating cells (CICs) are suggested responsible for driving cancer resistance to conventional therapies and for cancer recurrence and/or metastasis. CD133 is served as a key biomarker to identify and characterize this subpopulation of cells in hepatocellular carcinoma (HCC). Our previous study indicated that overexpression of eukaryotic initiation factor 5A2 (EIF5A2) promotes HCC cell metastasis and angiogenesis. In this study, we demonstrated that EIF5A2 might play a crucial role in CSCs regulation and investigated its potential molecular mechanisms. Using quantitative real‐time polymerase chain reaction assay, we observed that the expression of EIF5A2 positively correlated with CD133 levels in a cohort of cancerous and noncancerous liver tissues and cells. Next, HCC cells with high expression of EIF5A2 have a strong capacity to form undifferentiated tumor spheres in vitro and show elevated levels of stem cell‐related genes, leading to an increased ability to develop tumors when subcutaneously injected into nude mice. Furthermore, differential microRNA expression was profiling between two EIF5A2‐depleted HCC cell lines and their control one identified a decreased expression of miR‐29b in EIF5A2‐depleted cell lines. Further functional studies illustrated that downregulated miR‐29b level is responsible for EIF5A2‐maintained HCC cell stemness either in vitro or in vivo. Moreover, enforced expression of EIF5A2 in HCC cells largely enhanced the binding of c‐Myc on the promoter of miR‐29b and downregulation of miR‐29b by EIF5A2 was dependent on c‐Myc. Our findings, collectively, reveal that EIF5A2 contributes to the maintenance of CD133+ HCC cells via the c‐Myc/miR‐29b axis. Stem Cells 2018;36:180–191

p53R2 as a novel prognostic biomarker in nasopharyngeal carcinoma

Backgroundp53R2 is a target of p53 gene, which is essential for DNA repair, mitochondrial DNA synthesis, protection against oxidative stress, chromosomal instability, chronic inflammation and tumorigenesis. This study is aimed to investigate the expression of ribonucleotide reductase (RR) subunit p53R2 in nasopharyngeal carcinoma and its significance in the prognosis.MethodsThe expression levels of p53R2 in 201 patients with NPC were examined by immunohistochemical assay. The correlations of p53R2 expression and clinicopathological features of nasopharyngeal carcinoma patient were analysed by chi-square test. The Kaplan-Meier survival analysis and Cox multivariate regression model were used to analyze the prognostic significance of the patients with NPC.ResultsImmunohistochemical results showed that p53R2 was positively expressed in 92.5% (186/201) of nasopharyngeal carcinoma and the high expression rate was 38.3% (77/201). Further analysis observed that the negative correlation between expression of p53R2 and pT status had statistical significance (Pu2009<u20090.05). Kaplan-Meier survival analysis found that the mean survival time of patients with high expression of p53R2 was 143.32xa0months, while the patients with low expression level of p53R2 was 121.63xa0months (Pu2009<u20090.05). Cox regression analysis suggested that p53R2 protein expression could be used as an independent prognostic factor for nasopharyngeal carcinoma (Pu2009<u20090.05).ConclusionsThis study drew a conclusion that p53R2 could be used as a prognostic biomarker indicative of the favorable outcome for patients with nasopharyngeal carcinoma.