UBE2S enhances the ubiquitination of p53 and exerts oncogenic activities in hepatocellular carcinoma.

Ubiquitin-conjugating enzyme E2S (UBE2S) plays pivotal roles in the progression of human cancers. However, its clinical significance and role in hepatocellular carcinoma (HCC) remain unknown. Here, we show that UBE2S is upregulated in HCC and exhibits oncogenic activities via enhancing the ubiquitination of p53. Increased expression of UBE2S was significantly correlated with higher serum AFP level, higher pathological grade, advanced TNM stage, larger tumor size, vascular invasion and unfavorable patient survivals in two independent cohorts containing a total of 845 patients with HCC. Multivariate analyses by cox regression model suggested UBE2S as an independent factor for overall survival. In vitro experiments demonstrated that UBE2S overexpression promoted, whereas UBE2S knockdown suppressed cell proliferation and migration via modulation of p53 signaling pathway. Ectopic expression of UBE2S upregulated the expression of p53 and its downstream effectors, such as p21 and Cyclin D1. Mechanistically, UBE2S enhanced the ubiquitination of p53 protein to facilitate its degradation in HCC cells. Re-expression of p53 partially attenuated the UBE2S-promoted malignant phenotypes. Collectively, our study provides compelling evidence that UBE2S is a potential prognostic factor and functions as an oncogene in HCC.

BLZF1 expression is of prognostic significance in hepatocellular carcinoma.

BLZF1, a member of b-ZIP family, has been implicated in epigenetic regulation and Wnt/ß-catenin signaling. Its expression and clinical significance in human cancers remain largely unknown. In this study, we showed that BLZF1 expression was reduced in hepatocellular carcinoma (HCC) tissues, compared to the paracarcinoma tissues, at both mRNA and protein levels. Results of immunohistochemistry revealed that BLZF1 was presented in both nuclear and cytoplasm. Decreased expression of nuclear and cytosolic BLZF1 in HCC was depicted in 68.2% and 79.2% of the 634 cases. Nuclear BLZF1 expression was significantly associated with tumor multiplicity (P = 0.048) and tumor capsule (P = 0.028), while cytosolic BLZF1 expression was correlated with serum AFP level (P = 0.017), tumor differentiation (P = 0.001) and tumor capsule (P = 0.003). Kaplan-Meier analysis indicated both nuclear and cytosolic BLZF1 expression was associated with poor overall survival. Low nuclear BLZF1 also indicated unfavorable disease-free survival and high tendency of tumor recurrence. Furthermore, multiple Cox regression analysis revealed nuclear BLZF1 as an independent factor for overall survival (Hazard Ratio (HR) = 0.827, 95% confident interval (95%CI): 0.697-0.980, P = 0.029). The prognostic value of BLZF1 was further confirmed by stratified analyses. Collectively, our data suggest BLZF1 is a novel unfavorable biomarker for prognosis of patients with HCC.

Prognostic factors of regression and relapse of complex atypical hyperplasia and well-differentiated endometrioid carcinoma with conservative treatment.

OBJECTIVE: To evaluate possible prognostic factors regarding regression and relapse of complex atypical hyperplasia (CAH) and well-differentiated endometrioid adenocarcinoma (WDC) treated with conservative treatment. METHODS: The retrospective study reviewed clinicopathologic, treatment, regression and relapse data from patients diagnosed with CAH or WDC who were treated with conservative treatment at 4 institutions. Potential factor evaluation was performed. SPSS 16 was used for statistical analyses. RESULTS: Eighty-eight patients were included (51 had WDC, and 37 had CAH). Regression was evaluated in 88 patients, with a median follow-up of 61 (range 15-95) months. Seventy-seven (87.5%) patients regressed, and 11 (12.5%) had persistent or progressive disease. Univariate and multivariate analyses showed no factors associated with regression. Relapse was evaluated in 71 patients, with median follow-up of 54 (range 8-86) months. Twenty-five/71 (35.2%) patients experienced relapse. On univariate analysis, body mass index (BMI) 30 or higher (p=0.001), WCD at initial biopsy (p=0.017) and positive expression of post-treatment ki67 (p=0.033) were associated to a higher relapse probability. However, only BMI 30 or higher was significant on multivariate analysis (p=0.012). The Kaplan-Meier analysis revealed a higher relapse probability in the patients with BMI 30 or higher (p=0.001). CONCLUSION: Obesity seems to be a risk factor for relapse of CAH or WDC with conservative treatment.

Nucleoporin 93 mediates ß-catenin nuclear import to promote hepatocellular carcinoma progression and metastasis.

Nuclear pore complex (NPC) embedded in the nuclear envelope, is the only channel for macromolecule nucleocytoplasmic transportation and has important biological functions. However, the deregulation of specific nucleoporins (Nups) and NPC-Nup-based mechanisms and their function in tumour progression remain poorly understood. Here, we aimed to identify the Nups that contribute to HCC progression and metastasis in 729 primary hepatocellular carcinoma (HCC) cases using molecular, cytological, and biochemical techniques. Our results revealed elevated Nup93 expression in HCC tissues, especially in cases with metastasis, and was linked to worse prognosis. Furthermore, Nup93 knockdown suppressed HCC cell metastasis and proliferation, while Nup93 overexpression promoted these activities. We observed that Nup93 promotes HCC metastasis and proliferation by regulating ß-catenin translocation. In addition, we found that Nup93 interacted with ß-catenin directly, independent of importin. Furthermore, LEF1 and ß-catenin facilitated the Nup93-mediated metastasis and proliferation in HCC via a positive feedback loop. Thus, our findings provide novel insights into the mechanisms underlying the Nup93-induced promotion of HCC metastasis and suggest potential therapeutic targets in the LEF1-Nup93-ß-catenin pathway for HCC therapeutics.

An E2F1/DDX11/EZH2 Positive Feedback Loop Promotes Cell Proliferation in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) accounts for one of the leading causes of cancer-related death, and is attributed to the dysregulation of genes involved in genome stability. DDX11, a DNA helicase, has been implicated in rare genetic disease and human cancers. Yet, its clinical value, biological function, and the underlying mechanism in HCC progression are not fully understood. Here, we show that DDX11 is upregulated in HCC and exhibits oncogenic activity via EZH2/p21 signaling. High expression of DDX11 is significantly correlated with poor outcomes of HCC patients in two independent cohorts. DDX11 overexpression increases HCC cell viabilities and colony formation, whereas DDX11 knockdown arrests cells at G1 phase without alteration of p53 expression. Ectopic expression of DDX11 reduces, while depletion of DDX11 induces the expression of p21. Treatment of p21 siRNA markedly attenuates the cell growth suppression caused by DDX11 silence. Further studies reveal that DDX11 interacts with EZH2 in HCC cells to protect it from ubiquitination-mediated protein degradation, consequently resulting in the downregulation of p21. In addition, E2F1 is identified as one of the upstream regulators of DDX11, and forms a positive feedback loop with EZH2 to upregulate DDX11 and facilitate cell proliferation. Collectively, our data suggest DDX11 as a promising prognostic factor and an oncogene in HCC via a E2F1/DDX11/EZH2 positive feedback loop.

PRMT6 promotes endometrial cancer via AKT/mTOR signaling and indicates poor prognosis.

Arginine methylation plays essential roles in post-transcriptional modification and signal transduction. Dysregulation of protein arginine methyltransferases (PRMTs) has been reported in human cancers, yet the expression and biological function of PRMT6 in endometrial cancer (EMC) remains unclear. Here, we show that PRMT6 is upregulated in EMC and exhibits oncogenic activities via activation of AKT/mTOR pathway. The expression of PRMT6 in EMC is much higher than that in the adjacent nontumorous tissues. Elevated PRMT6 expression is significantly associated with higher histological tumor grade and unfavorable prognosis in two independent cohorts consisting of a total of 564 patients with EMC. In vitro data demonstrate that PRMT6 expression was identified as a downstream target of miR-372-3p. Ectopic expression of miR-372-3p downregulates PRMT6. Overexpression of PRMT6 promotes EMC cell proliferation and migration, whereas knockdown of PRMT6 leads to opposite phenotypes. Mechanistically, PRMT6 induces the phosphorylation of AKT and mTOR in EMC cells. Inhibition of AKT/mTOR signaling by MK2206 or rapamycin attenuates the PRMT6-mediated EMC progression. In clinical samples, high expression of PRMT6 was correlated to low expression of miR-372-3p and high expression of phosphorylated AKT. Collectively, our findings suggest PRMT6 may function as an oncogene to promote tumor progression, and be of prognostic value to predict disease-free survival of patients with EMC. The newly identified miR-372-3p/PRMT6/AKT/mTOR axis represents a new promising target for EMC management.

ESCO2 inhibits tumor metastasis via transcriptionally repressing MMP2 in colorectal cancer.

BACKGROUND: Establishment of cohesion 1 homolog 2 (ESCO2) plays important roles in the regulation of cohesion and genomic stability and has been implicated in human cancers. Yet, its clinical significance and biological function in colorectal cancer (CRC) are unknown. METHODS: The expression of ESCO2 was examined by quantitative real-time PCR, Western blot, and immunohistochemistry. The role of ESCO2 in the tumor metastasis of CRC and the related mechanisms were investigated using in vitro and in vivo models. RESULTS: In this study, we show that low expression of ESCO2 in CRC was closely correlated with lymphatic and distant metastasis. Patients with low ESCO2 expression experienced shorter overall survival and disease-free survival in two independent cohorts containing a total of 587 CRC cases. ESCO2 overexpression suppressed, whereas ESCO2 knockdown promoted cell migration in vitro and tumor metastasis in vivo via modulation of epithelial-mesenchymal transition (EMT) process. Mechanistically, ESCO2 inhibited the transcriptional activity of MMP2 promoter to downregulate its expression. Reexpression of MMP2 partially attenuated the ESCO2-mediated malignant phenotypes. CONCLUSION: Collectively, our data suggest that ESCO2 serves as a potential prognostic factor and exerts antimetastatic activity in CRC.

CBX1 Indicates Poor Outcomes and Exerts Oncogenic Activity in Hepatocellular Carcinoma.

Dysregulation of chromobox proteins contributes to the progression of human diseases. CBX1 has been implicated in epigenetic control of chromatin structure and gene expression, but its role in human cancers remains largely unknown. Here we show that CBX1 exhibits oncogenic activities in hepatocellular carcinoma (HCC) and indicates poor outcomes. The expression of CBX1 was noticeably increased, at both mRNA and protein levels, in HCC tissues and cell lines, compared with the nontumorous ones. High CBX1 expression was significantly associated with larger tumor size, poor tumor differentiation and tumor vascular invasion. Patients with elevated expression of CBX1 were frequently accompanied with unfavorable overall and disease-free survivals in two independent cohorts consisting of 648 HCC cases. The prognostic value of CBX1 was further confirmed by stratified survival analyses. Multivariate cox regression model suggested CBX1 as an independent factor for overall survival (hazard ratio = 1.735, 95% confident interval: 1.342-2.244, P < .001). In vitro data demonstrated that CBX1 overexpression promoted cell proliferation and migration, whereas the knockdown of CBX1 resulted in the opposite phenotypes. Mechanistically, CBX1 interacted with transcription factor HMGA2 to activate the Wnt/ß-Catenin signaling pathway. Suppression of ß-Catenin by siRNA or specific inhibitor XAV-939 markedly attenuated CBX1-mediated cell growth. Collectively, our findings indicate that CBX1 functions as an oncogene and may serve as a potential prognostic biomarker in HCC.

miR-107-mediated decrease of HMGCS2 indicates poor outcomes and promotes cell migration in hepatocellular carcinoma.

Mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase (HMGCS2) has been implicated in human cancers, but its role and clinical significance in hepatocellular carcinoma (HCC) remain unknown. Here, we show that HMGCS2 is downregulated and exhibits antimetastatic potential in HCC. Low expression of HMGCS2 was associated with poor tumor differentiation, vascular invasion and worse overall and disease-free survivals in two independent cohorts consisting of 743 cases. In vitro data demonstrated HMGCS2 overexpression suppressed, whereas HMGCS2 silence promoted HCC cell migration via Epithelial-Mesenchymal Transition (EMT) process and the activation of ERK/c-Jun signaling pathway. Inhibition of ERK phosphorylation by PD098059 markedly attenuated the malignant phenotypes mediated by HMGCS2 siRNA. Furthermore, miR-107 was identified as an upstream regulator of HMGCS2 via directly targeting the 3'-UTR of HMGCS2 mRNA. Collectively, our findings suggest HMGCS2 serve as a promising prognostic biomarker and exert anti-tumor activity towards HCC, and therefore provide a potential target for HCC clinical intervention.

[High expression of nucleophosmin/B23 in hepatocellular carcinoma].

OBJECTIVE: To study the expression of nucleophosmin/B23 (B23) in tumor cells of hepatocellular carcinoma (HCC) and its clinicopathologic significance. METHODS: Mouse monoclonal antibodies against B23 were raised by recombinant protein and hybridoma technology. Immunohistochemical study for B23 was performed on 103 cases of HCC, 12 cases of focal nodular hyperplasia and 17 cases of native liver tissue adjacent to hepatic hemangioma. Fresh specimens from 10 cases of HCC and the adjacent liver tissue were also collected for reverse transcriptase-polymerase chain reaction (RT-PCR) and Western blot analysis. The expression of B23 was analyzed and compared with that of proliferative cell nuclear antigen (PCNA) in these specimens. RESULTS: RT-PCR and Western blot analysis showed that B23 expression in HCC was higher than that in adjacent liver tissue. Statistically significant difference in expressions of B23 and PCNA were also noted in the four groups studied (P < 0.01). B23 and PCNA expressions in HCC were higher than those in the other three groups (P < 0.01). There was also a statistically significant correlation between B23 and PCNA expressions amongst the four groups (r = 0.4769, P < 0.01). Besides, B23 expression in HCC correlated with pathologic tumor grading, serum alpha-fetal protein levels and cirrhotic status (P < 0.05). CONCLUSIONS: B23 expression in HCC was significantly higher than that in liver tissues with non-malignant diseases. B23 may be used as a marker for neoplastic changes in liver cells and thus has potential clinicopathologic application.

HEY2, a target of miR-137, indicates poor outcomes and promotes cell proliferation and migration in hepatocellular carcinoma.

HEY2, a bHLH transcription factor, has been implicated in the progression of human cancers. Here, we showed that HEY2 expression was markedly increased in HCC, compared with the adjacent nontumorous tissues. High HEY2 expression was closely correlated with tumor multiplicity, tumor differentiation and TNM stage. Kaplan-Meier analyses revealed that HEY2 expression was significantly associated with poor overall and disease-free survival in a training cohort of 361 patients with HCC. The prognostic implication of HEY2 was validated in another cohort of 169 HCC patients. Multivariate Cox regression model indicated HEY2 as an independent factor for overall survival in HCC (Hazard ratio = 1.645, 95% confident interval: 1.309-2.067, P<0.001). We also demonstrated that HEY2 expression was inhibited by miR-137. In clinical samples, HEY2 expression was reversely associated to miR-137 expression. Furthermore, overexpression of HEY2 increased cell viabilities, colony formation and cell migration, whereas knockdown of HEY2 resulted in the opposite phenotypes. Collectively, our data suggest HEY2 as a promising biomarker for unfavorable outcomes and a novel therapeutic target for the clinical management of HCC.