Li Ru He

EZH2 supports ovarian carcinoma cell invasion and/or metastasis via regulation of TGF-β1 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.

High expression of EZH2 is associated with tumor aggressiveness and poor prognosis in patients with esophageal squamous cell carcinoma treated with definitive chemoradiotherapy

The enhancer of zeste homolog 2 (EZH2), a known repressor of gene transcription, has been reported to be associated with biological malignancy in several cancers. The potential oncogenic role of EZH2 and its clinical/prognostic significance, however, in esophageal squamous cell carcinoma (ESCC) are unclear. In this study, the methods of immunohistochemistry and fluorescence in‐situ hybridization were used to examine protein expression and amplification of EZH2 in 98 pretreatment biopsy specimens of ESCC who received definitive chemoradiotherapy (CRT). High expression of EZH2 and amplification of EZH2 was found in 54.1% and 12.0% of ESCCs, respectively. High EZH2 expression was significantly correlated with increased cell proliferation (p = 0.009), high histopathological grade (p = 0.002), regional (p = 0.025) and distant lymph node metastasis (p < 0.001) and lack of clinical complete response to CRT (p = 0.028). Univariate analysis revealed that high expression of EZH2 was associated with poor metastasis‐free survival (MFS) (p = 0.003), poor progression‐free survival (PFS) (p = 0.001) and poor disease‐specific survival (DSS) (p < 0.001). In multivariate analysis, high expression of EZH2, together with lack of clinical complete response, were evaluated as significant independent prognostic factors of MFS, PFS and DSS for patients with ESCC. These findings suggest that high expression of EZH2 correlates with tumor aggressiveness and adverse patient outcome in ESCC treated with definitive CRT. Evaluation of EZH2 expressions might be useful for predicting tumor response to CRT and prognosis for patients with ESCC.

β-Catenin/POU5F1/SOX2 transcription factor complex mediates IGF-I receptor signaling and predicts poor prognosis in lung adenocarcinoma.

Cancer stem-like cells (CSLC) are crucial in tumor initiation and progression; however, the underlying mechanism for the self-renewal of cancer cells remains undefined. In the study, immunohistochemical analysis of specimens freshly excised from patients with lung adenocarcinoma showed that high expression of insulin-like growth factor I receptor (IGF-IR) in lung adenocarcinoma cells was positively correlated with the expressions of cancer stem cell markers CD133 and aldehyde dehydrogenase 1 family member A1 (ALDH1A1). IGF-IR activation enhanced POU class 5 homeobox 1 (POU5F1) expression on human lung adenocarcinoma stem-like cells (LACSLC) through PI3K/AKT/GSK3β/β-catenin cascade. POU5F1 could form a novel complex with β-catenin and SOX2 to bind Nanog promoter for transcription to maintain self-renewal of LACSLCs, which was dependent on the functional IGF-IR. Genetic and pharmacologic inhibition of IGF-IR abrogated LACSLC capabilities for self-renewal and tumorigenicity in vitro. In an in vivo xenograft tumor model, knockdown of either IGF-IR or POU5F1 impeded tumorigenic potentials of LACSLCs. By analyzing pathologic specimens excised from 200 patients with lung adenocarcinoma, we found that colocalization of highly expressed IGF-IR with β-catenin and POU5F1 predicted poor prognosis. Taken together, we show that IGF-IR-mediated POU5F1 expression to form a complex with β-catenin and SOX2 is crucial for the self-renewal and oncogenic potentials of LACSLCs, and the integrative clinical detection of the expressions of IGF-IR, β-catenin, and POU5F1 is indicatory for predicting prognosis in the patients of lung adenocarcinoma.

Prognostic impact of H3K27me3 expression on locoregional progression after chemoradiotherapy in esophageal squamous cell carcinoma

BackgroundTrimethylation of lysine 27 on histone H3 (H3K27me3) by enhancer of zeste homolog 2 (EZH2) is an epigenetic mark that mediates gene silencing. EZH2 is overexpressed and correlates with poor prognosis in many cancers. However, the clinical implication of H3K27me3 in human malignancies has not been well established. We wished to ascertain whether a correlation exists between the expression of H3K27me3 and clinical outcome in a group of patients with esophageal squamous cell carcinoma (ESCC) treated with definitive chemoradiotherapy (CRT).MethodsThe method of immunohistochemistry (IHC) was utilized to examine the protein expression of H3K27me3 in 98 pretreatment biopsy specimens of ESCC and in 30 samples of normal esophageal mucosa. The clinical/prognostic significance of H3K27me3 expression was statistically analyzed.ResultsThe expression frequency and expression levels of H3K27me3 were significantly higher in ESCCs than in normal tissues. There was a positive correlation between H3K27me3 expression and WHO grade (P = 0.016), tumor size (P = 0.019), T status (P = 0.024), locoregional progression (P = 0.009) and EZH2 expression (P = 0.036). High H3K27me3 expression was associated with poor locoregional progression-free survival (LPFS) (P = 0.010) in ESCC. Further analysis demonstrated that H3K27me3 could stratify patient outcome in T2-3 (P = 0.048), N0 (P = 0.005) and M0 (P = 0.018) stages as well as in CRT effective group (P = 0.022).ConclusionsOur data suggests that H3K27me3 expression examined by IHC might be useful for stratifying LPFS for different subsets of ESCC patients treated with definitive CRT.

Intensive expression of Bmi-1 is a new independent predictor of poor outcome in patients with ovarian carcinoma

BackgroundIt has been suggested that the B-cell specific moloney leukemia virus insertion site 1 (Bmi-1) gene plays an oncogenic role in several types of human cancer, but the status of Bmi-1 amplification and expression in ovarian cancer and its clinical/prognostic significance are unclear.MethodsThe methods of immunohistochemistry and fluorescence in situ hybridization were utilized to examine protein expression and amplification of Bmi-1 in 30 normal ovaries, 30 ovarian cystadenomas, 40 borderline ovarian tumors and 179 ovarian carcinomas.ResultsIntensive expression of Bmi-1 was detected in none of the normal ovaries, 3% cystadenomas, 10% borderline tumors, and 37% ovarian carcinomas, respectively. Amplification of Bmi-1 was detected in 8% of ovarian carcinomas. In ovarian carcinomas, significant positive associations were found between intensive expression of Bmi-1 and the tumors ascending histological grade, later pT/pN/pM and FIGO stages (P < 0.05). In univariate survival analysis of the ovarian carcinoma cohorts, a significant association of intensive expression of Bmi-1 with shortened patient survival (mean 49.3 months versus 100.3 months, p < 0.001) was demonstrated. Importantly, Bmi-1 expression provided significant independent prognostic parameters in multivariate analysis (p = 0.005).ConclusionsThese findings provide evidence that intensive expression of Bmi-1 might be important in the acquisition of an invasive and/or aggressive phenotype of ovarian carcinoma, and serve as a independent biomarker for shortened survival time of patients.

Overexpression of AIB1 predicts resistance to chemoradiotherapy and poor prognosis in patients with primary esophageal squamous cell carcinoma

AIB1 (amplified in breast cancer 1) is frequently overexpressed in esophageal squamous cell carcinoma (ESCC), but the significance of AIB1 expression in chemoradiotherapy (CRT) sensitivity and its effect on prognosis are still unclear. In this study, the expression of AIB1 was examined by immunohistochemistry in 98 biopsy specimens of primary ESCC patients treated with definitive CRT. AIB1 overexpression was found in 63/98 (64.3%) of the ESCCs. There was a significant association between AIB1 overexpression and distant lymph node metastases (P = 0.011), but not regional lymph node metastases. In the M0 subgroup, overexpression of AIB1 was observed more frequently in stage T4 than in stage T2–3 (66.7%vs 38.5%, P = 0.031). In addition, AIB1 expression was the only factor that showed a significant correlation with CRT response, in which overexpression of AIB1 was observed more frequently in the CRT resistant group than in the CRT effective group (86.5%vs 50.8%, P < 0.001). Univariate analysis revealed that AIB1 overexpression was associated with poor progression‐free survival (PFS) (P < 0.001) and poor disease‐specific survival (DSS) (P <0.001). Furthermore, AIB1 expression could stratify patient survival in stages T2–3, T4, N1, and M0 (P < 0.05), as well as in the CRT effective group (P < 0.05), and AIB1 overexpression and CRT resistance were evaluated as significant independent prognostic factors for both PFS and DSS in multivariate analysis. These findings suggest that overexpression of AIB1 is a useful predictor of CRT resistance and an independent molecular marker of poor prognosis for ESCC patients. (Cancer Sci 2009; 100: 1591–1596)

Overexpression of AIB1 negatively affects survival of surgically resected non-small-cell lung cancer patients

BACKGROUND The amplified in breast cancer 1 (AIB1) gene has been considered to play an oncogenic role in human cancers, but its clinical/prognostic significance in non-small-cell lung cancer (NSCLC) is still unclear. PATIENTS AND METHODS The methods of immunohistochemistry and FISH were utilized to examine protein expression and amplification of AIB1 in 230 informative surgically resected NSCLCs and in 30 samples of normal lung tissues. RESULTS Overexpression and amplification of AIB1 were found in 48.3% and 8.2% of NSCLCs, respectively. AIB1 overexpression was associated with AIB1 gene amplification and cell proliferation but not related to estrogen receptor (ER)-alpha, ER-beta, progesterone receptor or androgen receptor status. A positive correlation between AIB1 overexpression and an ascending pathologic node stage in lung adenocarcinoma (ADC) was observed (P = 0.043). Univariate survival analysis demonstrated a significant association of AIB1 overexpression with shortened patient survival, especially for those with stage III disease (P < 0.001). Importantly, AIB1 expression was evaluated as the most significant predictor for survival in multivariate analysis (hazards ratio = 2.069, P < 0.001). CONCLUSION Overexpression of AIB1 might provide a selective advantage for lymph node metastasis of lung ADC and serve as a useful biomarker for poor prognosis for NSCLC patients.

PinX1 suppresses bladder urothelial carcinoma cell proliferation via the inhibition of telomerase activity and p16/cyclin D1 pathway

BackgroundPIN2/TRF1-interacting telomerase inhibitor1 (PinX1) was recently suggested as a putative tumor suppressor in several types of human cancer, based on its binding to and inhibition of telomerase. Moreover, loss of PinX1 has been detected in many human malignancies. However, the possible involvement of PinX1 and its clinical/prognostic significance in urothelial carcinoma of the bladder (UCB) are unclear.MethodsThe PinX1 expression profile was examined by quantitative real-time polymerase chain reaction (qRT-PCR), western blotting, and immunohistochemistry (IHC) in UCB tissues and adjacent normal urothelial bladder epithelial tissues. PinX1 was overexpressed and silenced in UCB cell lines to determine its role in tumorigenesis, development of UCB, and the possible mechanism.ResultsPinX1 expression in UCB was significantly down-regulated at both mRNA and protein level as compared with that in normal urothelial bladder epithelial tissues. PinX1 levels were inversely correlated with tumor multiplicity, advanced N classification, high proliferation index (Ki-67), and poor survival (P < 0.05). Moreover, overexpression of PinX1 in UCB cells significantly inhibited cell proliferation in vitro and in vivo, whereas silencing PinX1 dramatically enhanced cell proliferation. Overexpression of PinX1 resulted in G1/S phase arrest and cell growth/proliferation inhibition, while silencing PinX1 led to acceleration of G1/S transition, and cell growth/proliferation promotion by inhibiting/enhancing telomerase activity and via the p16/cyclin D1 pathway.ConclusionsThese findings suggest that down-regulation of PinX1 play an important role in the tumorigenesis and development of UCB and that the expression of PinX1 as detected by IHC is an independent molecular marker in patients with UCB.

Nimotuzumab promotes radiosensitivity of EGFR-overexpression esophageal squamous cell carcinoma cells by upregulating IGFBP-3

BackgroundEpidermal growth factor receptor (EGFR) is suggested to predict the radiosensitivity and/or prognosis of human esophageal squamous cell carcinoma (ESCC). The objective of this study was to investigate the efficacy of Nimotuzumab (an anti-EGFR monoclonal antibody) on ESCC radiotherapy (RT) and underlying mechanisms.MethodsNimotuzumab was administrated to 2 ESCC cell lines KYSE30 and TE-1 treated with RT. Cell growth, colony formation and apoptosis were used to measure anti-proliferation effects. The method of RNA interference was used to investigate the role of insulin-like growth factor binding protein-3 (IGFBP-3) in ESCC cells radiosensitivity treated with Nimotuzumab. In vivo effect of Nimotuzumab on ESCC radiotherapy was done using a mouse xenograft model.ResultsNimotuzumab enhanced radiation response of KYSE30 cells (with high EGFR expression) in vitro, as evidenced by increased radiation-inhibited cell growth and colony formation and radiation-mediated apoptosis. Mechanism study revealed that Nimotuzumab inhibited phosphorylated EGFR (p-EGFR) induced by EGF in KYSE30 cells. In addition, knockdown of IGFBP-3 by short hairpin RNA significantly reduced KYSE30 cells radiosensitivity (P<0.05), and even after the administration of Nimotuzumab, the RT response of IGFBP-3 silenced KYSE30 cells was not enhanced (P>0.05). In KYSE30 cell xenografts, Nimotuzumab combined with radiation led to significant tumor growth delay, compared with that of radiation alone (P=0.029), and also with IGFBP-3 up-regulation in tumor tissue.ConclusionsNimotuzumab could enhance the RT effect of ESCC cells with a functional active EGFR pathway. In particular, the increased ESCC radiosensitivity by Nimotuzumab might be dependent on the up-regulation of IGFBP-3 through EGFR-dependent pathway.

Clusterin as a predictor for chemoradiotherapy sensitivity and patient survival in esophageal squamous cell carcinoma

Clusterin (CLU) is frequently overexpressed and correlates closely with chemotherapy and radiotherapy resistance and poor prognosis in many human cancers. However, the significance of CLU expression in chemoradiotherapy (CRT) sensitivity and its effect on the prognosis of esophageal squamous cell carcinoma (ESCC) are still unknown. In the present study, we used the methods of immunohistochemistry and terminal deoxyuridine triphosphate nick‐end labeling assay to examine the expression status of CLU and apoptotic index in 110 pretreated biopsy specimens of ESCC patients treated with definitive CRT. High expression of CLU was observed in 42.7% of epithelium and 50.0% of stroma in ESCC. A significant association of high CLU stromal expression with large tumor size (P = 0.012) and locoregional progression (P = 0.001) was observed, and high epithelial expression of CLU showed a significant correlation with the lack of complete response (P = 0.028) and low apoptotic index (P = 0.001). Univariate analysis revealed that high CLU stromal expression was associated with poor locoregional progression‐free survival, distant progression‐free survival, and overall survival. Furthermore, ESCC patients with high CLU expression in both epithelium and stroma have the shortest survival time among the subgroups of different CLU expression status. In multivariate analysis, CLU stromal expression was evaluated as an independent prognostic factor for locoregional progression‐free survival, distant progression‐free survival, and overall survival. These findings suggest an important role for CLU, especially in stroma, in ESCC progression, and that high CLU epithelial expression might be a promising predictor of ESCC resistance to CRT. (Cancer Sci 2009; 100: 2354–2360)