Expression of EIF5A2 associates with poor survival of nasopharyngeal carcinoma patients treated with induction chemotherapy

BACKGROUND

Nasopharyngeal carcinoma (NPC) is a type of head-neck cancer with a distinguishable geographic and racial distribution worldwide. Increasing evidence supports that the accumulation of additional genetic and epigenetic abnormalities is important in driving the NPC tumorigenic process. In this study, we aim to investigate the association between EIF5A2 (Eukaryotic translation initiation factor 5A2) expression status and NPC clinical outcomes.

METHODS

The expression status of EIF5A2 was investigated in the NPC tissue microarray. Tissues were from 166 NPC patients staging II-IV, collected between 1999 and 2005. All patients were administered 2-3 cycles of DDP (cisplatin) + 5-Fu (5-fluorouracil) induction therapy and then treated with a uniform conventional two-dimensional radiotherapy. Cell motility assay, tumor growth assay and cytotoxicity assay were performed on the EIF5A2 overexpressed cells and control cells. siRNA was also used in the in vitro studies.

RESULTS

Positive staining of EIF5A2 was observed in 85.4 % (105/123) informative tumor cases. Multivariate analyses demonstrated that EIF5A2 was an independent prognostic marker of poor overall survival (OS) (P = 0.041), failure-free survival (FFS) (P = 0.029), and distant failure-free survival (D-FFS) (P = 0.043) in patients with locoregionally advanced NPC patients treated with cisplatin + 5-Fu chemoradiotherapy. The forced expression of EIF5A2 in NPC cells enhanced the cells' motility and growth ability. Knock-down of EIF5A2 in NPC cells decreased the cell's motility and growth ability. Our results also demonstrated that EIF5A2 overexpression induced chemoresistance of NPC cells to 5-Fu.

CONCLUSIONS

Our findings suggested that EIF5A2 expression, as examined by immunohistochemistry, could function as an independent prognostic factor of outcomes in NPC patients with cisplatin + 5-Fu chemoradiotherapy. EIF5A2 might be a novel therapeutic target for the inhibition of NPC progress.

12S-hydroxyeicosatetraenoic acid levels link to coronary artery disease in Type 2 diabetic patients

BACKGROUND

12(S)-Hydroxyeicosatetraenoic acid (12(S)-HETE) is a metabolite of arachidonic acid. 12(S)-HETE is involved in the pathogenesis of atherosclerosis and diabetes. However, the correlation between 12(S)-HETE and coronary artery disease (CAD) in the diabetic patient is unclear.

AIMS

The study investigated the relationship between 12(S)-HETE and CAD in Type 2 diabetes (T2D).

METHODS

Plasma 12(S)- HETE levels were detected by enzyme-linked immunosorbent assay in 103 healthy controls (control), 109 diabetic patients without CAD (diabetic), and 152 diabetic patients with CAD (diabetic-CAD).

RESULTS

12(S)-HETE levels were higher in both diabetic and diabetic-CAD groups compared to control and in the diabetic-CAD group compared to the diabetic group. In the multiple linear stepwise regression analysis, 12(S)-HETE levels correlated independently with CAD, systolic blood pressure, and glycated hemoglobin.

CONCLUSIONS

These results indicate that 12(S)-HETE levels are increased in diabetic patients with CAD, suggesting a role for atherosclerosis in T2D.

EZH2 supports ovarian carcinoma cell invasion and/or metastasis via regulation of TGF-beta1 and is a predictor of outcome in ovarian carcinoma patients

It was suggested that the enhancer of zeste homolog 2 (EZH2) gene is a putative candidate oncogene in several types of human cancer. The potential oncogenic role of EZH2 and its clinical/prognostic significance, however, in ovarian carcinoma are unclear. In this study, EZH2 expression was examined by immunohistochemistry (IHC) in cohorts of normal and tumorous ovarian tissues. High expression of EZH2 was examined in none of the normal ovaries, in 3% of the cystadenomas, in 23% of the borderline tumors and in 50% of the ovarian carcinomas, respectively. In the ovarian carcinomas, high expression of EZH2 was positively correlated with an ascending histological grade and/or advanced stage of the disease (P < 0.05). Moreover, high expression of EZH2 in ovarian carcinoma was determined to be a strong and an independent predictor of short overall survival (P < 0.05). In ovarian carcinoma HO-8910 and UACC-326 cell lines, EZH2 knockdown by RNA interference led to a G(1) phase cell cycle arrest, reduced cell growth/proliferation and inhibited cell migration and/or invasion in vitro. In addition, EZH2 knockdown was found to reduce transforming growth factor-beta1 (TGF-beta1) expression and increase E-cadherin expression either in the transcript or in the protein levels. Furthermore, a significant positive correlation between overexpression of EZH2 and TGF-beta1 in ovarian carcinoma tissues was observed (P < 0.001). These findings suggest a potential important role of EZH2 in the control of cell migration and/or invasion via the regulation of TGF-beta1 expression, and the high expression of EZH2, as detected by IHC, is an independent molecular marker for shortened survival time of patients with ovarian carcinoma.

The enhanced transcriptional activity of the V-val subtype of Epstein-Barr virus nuclear antigen 1 in epithelial cell lines

The Epstein-Barr virus encoded nuclear antigen 1 (EBNA1) is required for the replication and maintenance of the episomal EBV genome and for the transactivation of viral gene expression. EBNA1 has been classified into five subtypes, among which the V-val subtype was reported to be associated with nasopharyngeal carcinoma (NPC). Here we report a higher transcriptional activity of the V-val subtype of EBNA1 than for the prototype derived from B95.8 cells to transactivate FR-containing luciferase plasmid, which was mainly a consequence of the mutations in the carboxy-terminus of EBNA1. This interpretation was further supported by the finding that the variant form of EBNA1 has a higher binding affinity for the FR sequence than the prototype by electrophoretic mobility shift assays. The functional advantage of the V-val EBNA1 investigated in this study may contribute to the oncogenesis of NPC.

Curcumin induces down-regulation of EZH2 expression through the MAPK pathway in MDA-MB-435 human breast cancer cells

Curcumin, a natural compound isolated from turmeric, may inhibit cell proliferation in various tumor cells through a mechanism that is not fully understood. The enhancer of zeste homolog 2 (EZH2) gene is overexpressed in human breast cancers with poor prognosis. In this study, we observed a dose- and time-dependent down-regulation of expression of EZH2 by curcumin that correlates with decreased proliferation in the MDA-MB-435 breast cancer cell line. The curcumin treatment resulted in an accumulation of cells in the G(1) phase of the cell cycle. Further investigation revealed that curcumin-induced down-regulation of EZH2 through stimulation of three major members of the mitogen-activated protein kinase (MAPK) pathway: c-Jun NH2-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and p38 kinase. These data suggest that an underlying mechanism of the MAPK pathway mediates the down-regulation of EZH2, thus contributing to the anti-proliferative effects of curcumin against breast cancer.

Overexpression of EIF-5A2 predicts tumor recurrence and progression in pTa/pT1 urothelial carcinoma of the bladder

The authors investigated the status of abnormalities of eIF-5A2 gene in superficial (pTa/pT1) urothelial carcinoma of the bladder (UC), as well as its correlation with clinicopathologic variables and patient outcome. The methods of immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were utilized to examine protein/mRNA(messenger RNA) expression and amplification of eIF-5A2 in a cohort of pTa/pT1 UCs. Overexpression of EIF-5A2 was examined by IHC in 38/112 (33.9%) pTa/pT1 UCs. A significant association of overexpression of EIF-5A2 with shortened UC patient recurrence-free survival (P = 0.002), as well as with shortened progression-free survival (P = 0.004), was demonstrated. Importantly, multivariate Cox regression analysis revealed that EIF-5A2 expression provided a significant independent prognostic parameter either in tumor recurrence (P = 0.002) or in tumor progression (P = 0.007). FISH results demonstrated that eIF-5A2 amplification was detected in 5/59 of the informative UCs; in each of the five cases with eIF-5A2 amplification, overexpression of EIF-5A2 was observed. In the remaining 54 UCs without eIF-5A2 amplification, 16 cases were also observed to have overexpression of EIF-5A2. In 13 pairs of UC and adjacent normal tissues, eight UCs were examined and showed up-regulated eIF-5A2 mRNA by RT-PCR, while increased expression of EIF-5A2 protein was only detected in 4/8 UCs by Western blotting. These findings suggest that overexpression of EIF-5A2, as detected by IHC, may predict tumor recurrence and progression in pTa/pT1 UC patients, and the protein expression of eIF-5A2 might be regulated not only by gene amplification, but also by other molecular mechanisms.

Overexpression of EIF-5A2 is an independent predictor of outcome in patients of urothelial carcinoma of the bladder treated with radical cystectomy

BACKGROUND

Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in urothelial carcinoma of the bladder (UC) are unclear.

METHODS

In this study, the methods of reverse transcription-PCR, immunohistochemistry, and fluorescence in situ hybridization were used to examine mRNA/protein expression and amplification of eIF-5A2 in a large cohort of UCs treated with radical cystectomy.

RESULTS

Up-regulated expression of eIF-5A2 mRNA was observed in 50% (8 of 16) of UCs, when compared with adjacent normal bladder tissues. Overexpression of EIF-5A2 protein and amplification of eIF-5A2 was examined informatively in 45.3% (39 of 86) and 10.6% (5 of 47) of UCs, respectively. In univariate survival analysis of the UC cohorts, a significant association of overexpression of EIF-5A2 with shortened patient survival (mean, 38.2 months versus 52.9 months, P = 0.001, log-rank test) was shown. In different subsets of UC patients, overexpression of EIF-5A2 was also a prognostic indicator in grade 1/2 (P = 0.0009) and grade 3 (P = 0.016) tumor patients, and in pT1 (P = 0.0089), pT2 (P = 0.0354), pT3/4 (P = 0.0058), pN0 (P = 0.0039), and pN1-2 (P = 0.0093) tumor patients. Importantly, EIF-5A2 expression (P = 0.0007) together with pT stage (P = 0.0001) provided significant independent prognostic variables in multivariate analysis.

CONCLUSIONS

These findings indicate that overexpression of EIF-5A2 in UCs is coincident with acquisition of a poor prognostic phenotype, suggesting that the expression of EIF-5A2, as detected by immunohistochemistry, is an independent molecular marker for shortened survival time of UC patients treated with radical cystectomy.

Expression and amplification of eIF-5A2 in human epithelial ovarian tumors and overexpression of EIF-5A2 is a new independent predictor of outcome in patients with ovarian carcinoma

OBJECTIVES

Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in ovarian carcinoma are unclear.

METHODS

In this study, we examined expression of EIF-5A2, using immunohistochemistry, in 30 normal ovaries, 30 ovarian cystadenomas, 30 borderline ovarian tumors and 110 ovarian carcinomas. The amplification status of eIF-5A2 in each ovarian carcinoma was assessed by fluorescence in situ hybridization.

RESULTS

Overexpression of EIF-5A2 was detected in none of the normal ovaries, 7% cystadenomas, 30% borderline tumors, and 53% invasive ovarian carcinomas, respectively. Amplification of eIF-5A2 was detected in 16% of informative ovarian carcinomas. In ovarian carcinomas, significant positive associations were found between overexpression of EIF-5A2 and the tumors ascending grade, later pT/pN and FIGO stages, as well as increased positive rate of Ki-67 (p<0.05). In univariate survival analysis of the ovarian carcinoma cohorts, a significant association of overexpression of EIF-5A2 with shortened patient survival (mean 39.0 months vs 69.5 months, p<0.001) was demonstrated. Importantly, EIF-5A2 expression provided significant independent prognostic parameters in multivariate analysis (p=0.043).

CONCLUSIONS

These findings suggest that increased expression of EIF-5A2 in ovarian carcinoma may represent an acquired malignant phenotypic feature of tumor cells, and the overexpression of EIF-5A2, as detected by immunohistochemistry, is an independent molecular marker for shortened survival time of patients with ovarian carcinoma.