Rong Zhen Luo

High expression of H3K27me3 in human hepatocellular carcinomas correlates closely with vascular invasion and predicts worse prognosis in patients

It has been suggested that trimethylation of lysine 27 on histone H3 (H3K27me3) is a crucial epigenetic process in tumorigenesis. However, the expression dynamics of H3K27me3 and its clinicopathological/prognostic significance in hepatocellular carcinoma (HCC) are unclear. In this study, immunohistochemical analysis (IHC) was used to examine protein expression of H3K27me3 in HCC tissues from two independent cohorts and corresponding nontumorous hepatocellular tissues by tissue microarray. The optimal cutpoint of H3K27me3 expression was assessed by the X-tile program. Our results showed that the cutpoint for high expression of H3K27me3 in HCCs was determined when more than 70% of the tumor cells showed positive staining. High expression of H3K27me3 was observed in 134 of 212 (63.2%) and 76 of 126 (60.4%) of HCCs in the testing and validation cohorts, respectively. Correlation analysis demonstrated that high expression of H3K27me3 in HCCs was significantly correlated with large tumor size, multiplicity, poor differentiation, advanced clinical stage and vascular invasion (P < 0.05). In addition, high expression of H3K27me3 in HCC patients was associated closely with shortened survival time, independent of serum α-fetoprotein levels, tumor size and multiplicity, clinical stage, vascular invasion and relapse as evidenced by univariate and multivariate analysis in both cohorts (P < 0.05). In different subsets of HCC patients, H3K27me3 expression was also a prognostic indicator in patients with stage II tumors (P < 0.05). Thus, these findings provide evidence that a high expression of H3K27me3, as detected by IHC, correlates closely with vascular invasion of HCCs and is an independent molecular marker for poor prognosis in patients with HCC.

Prognostic Significance of SOX2 Expression in Nasopharyngeal Carcinoma

The significance of SOX2 in nasopharyngeal carcinoma (NPC), a tumor associated with Epstein–Barr virus (EBV), remains unclear. Here, we reported that, in the univariate analysis, SOX2 expression was correlated with a poorer distant metastasis-free survival (DMFS). The EBV-VCA/IgA titers in patients with NPC were also associated with a poorer overall survival (OS). Patients with NPC, who had both strong staining of SOX2 and high titers of EBV-VCA/IgA, had the poorest prognoses. Therefore, SOX2 or the combination of the SOX2 expression level and EBV-VCA/IgA titers could be valuable to predict distant metastasis or the prognosis of NPC.

The prognostic effect of perineural invasion in esophageal squamous cell carcinoma

BackgroundPerineural invasion (PNI) is correlated with adverse survival in several malignancies, but its significance in esophageal squamous cell carcinoma (ESCC) remains to be clearly defined. The objective of this study was to determine the association between PNI status and clinical outcomes.MethodsWe retrospectively evaluated the PNI of 433 patients with ESCC treated with surgery between 2000 and 2007 at a single academic center. The resulting data were analyzed using Spearman’s rank correlation, the Kaplan-Meier method, Cox proportional hazards regression modeling and Harrell’s concordance index (C-index).ResultsPNI was identified in 209 of the 433 (47.7%) cases of ESCC. The correlation analysis demonstrated that PNI in ESCC was significantly correlated with tumor differentiation, infiltration depth, pN classification and stage (P < 0.05). The five-year overall survival rate was 0.570 for PNI-negative tumors versus 0.326 for PNI-positive tumors. Patients with PNI-negative tumors exhibited a 1.7-fold increase in five-year recurrence-free survival compared with patients with PNI-positive tumors (0.531 v 0.305, respectively; P < 0.0001). In the subset of patients with node-negative disease, PNI was evaluated as a prognostic predictor as well (P < 0.05). In the multivariate analysis, PNI was an independent prognostic factor for overall survival (P = 0.027). The C-index estimate for the combined model (PNI, gender and pN status) was a significant improvement on the C-index estimate of the clinicopathologic model alone (0.739 v 0.706, respectively).ConclusionsPNI can function as an independent prognostic factor of outcomes in ESCC patients, and the PNI status in primary ESCC specimens should be considered for therapy stratification.

Assessment of Early Tumor Response to Cytotoxic Chemotherapy with Dynamic Contrast-Enhanced Ultrasound in Human Breast Cancer Xenografts

There is a strong need to assess early tumor response to chemotherapy in order to avoid adverse effects from unnecessary chemotherapy and allow early transition to second-line therapy. This study was to quantify tumor perfusion changes with dynamic contrast-enhanced ultrasound (CEUS) in the evaluation of early tumor response to cytotoxic chemotherapy. Sixty nude mice bearing with MCF-7 breast cancer were administrated with either adriamycin or sterile saline. CEUS was performed on days 0, 2, 4 and 6 of the treatment, in which time-signal intensity (SI) curves were obtained from the intratumoral and depth-matched liver parenchyma. Four perfusion parameters including peak enhancement (PE), area under the curve of wash-in (WiAUC), wash-in rate (WiR) and wash-in perfusion index (WiPI) were calculated from perfusion curves and normalized with respect to perfusion of adjacent liver parenchyma. Histopathological analysis was conducted to evaluate tumor perfusion, tumor cell density, microvascular density (MVD) and proliferating cell density. Significant decreases of tumor normalized perfusion parameters (i.e., nPE, nWiAUC, nWiR and nWiPI) were noticed between adriamycin-treated and control groups (P<0.01) 2 days after therapy. There were significant differences of tumor volumes between control and treated groups on day 6 (P<0.001) while there were no significant differences in tumor volume on days 0, 2 and 4 (P>0.05). Significant decreases of tumor perfusion, tumor cell density, MVD and proliferating cell density were seen in adrianycin-treated group 2 days after therapy when compared to control group (P<0.001). Dynamic CEUS for quantification of tumor perfusion could be used for early detection of cancer response to cytotoxic chemotherapy prior to notable tumor shrinkage.

Decreased expression of PTPN12 correlates with tumor recurrence and poor survival of patients with hepatocellular carcinoma.

Background Protein tyrosine phosphatase non-receptor type 12 (PTPN12), has been identified as a potent tumor suppressor in human cancers and a critical regulator of cell adhesion and migration. However, the PTPN12 expression and its prognostic significance in HCC have not been well elucidated. Methodology/Principal Findings In this study, tissue microarray-based immunohistochemistry (IHC) was investigated in an HCC cohort with adjacent liver tissues as controls. The resulting data were analyzed using receiver operating characteristic curves, Spearmans rank correlation, Kaplan-Meier plots and Cox proportional hazards regression modeling. Our results showed that decreased expression of PTPN12 was more frequently observed in HCC tissues compared to the adjacent non-tumorous liver tissues. Further correlation analyses indicated that the decreased PTPN12 expression was closely correlated with tumor recurrence (P = 0.015). Univariate analysis showed a significant association between decreased expression of PTPN12 and adverse cancer-specific survival and recurrence-free survival (P<0.001). In different subsets of overall patients, PTPN12 expression was also a prognostic indicator in patients with stage I/II or stage III/IV (P<0.05). Importantly, multivariate analysis (P<0.05) identified PTPN12 expression in HCC as an independent prognostic factor. Conclusions/Significance Our findings provide a basis for the concept that PTPN12 protein expression is frequently decreased or lost in human HCC tissues and that decreased PTPN12 expression may represent an acquired recurrence phenotype of HCC and that PTPN12 expression may act as a biomarker of prognosis for patients with HCC.

Overexpression of karyopherin 2 in human ovarian malignant germ cell tumor correlates with poor prognosis.

Background The aim of this study was to identify a biomarker useful in the diagnosis and therapy of ovarian malignant germ cell tumor (OMGCT). Methods The karyopherin 2 (KPNA2) expression in OMGCT and normal ovarian tissue was determined by standard gene microarray assays, and further validated by a quantitative RT-PCR and immunohistochemistry. The correlation between KPNA2 expression in OMGCT and certain clinicopathological features were analyzed. Expression of SALL4, a stem cell marker, was also examined in comparison with KPNA2. Results KPNA2 was found to be over-expressed by approximately eight-fold in yolk sac tumors and immature teratomas compared to normal ovarian tissue by microarray assays. Overexpression was detected in yolk sac tumors, immature teratomas, dysgerminomas, embryonal carcinomas, mature teratomas with malignant transformation and mixed ovarian germ cell tumors at both the transcription and translation levels. A positive correlation between KPNA2 and SALL4 expression at both the transcription level (R = 0.5120, P = 0.0125), and the translation level (R = 0.6636, P<0.0001), was presented. Extensive expression of KPNA2 was positively associated with pathologic type, recurrence and uncontrolled, ascitic fluid presence, suboptimal cytoreductive surgery necessity, resistance/refraction to initial chemotherapy, HCG level and SALL4 level in OMGCT patients. KPNA2 was found to be an independent factor for 5-year disease-free survival (DFS) of OMGCT (P = 0.02). The 5-year overall survival (OS) and DFS rate for KPNA2-low expression patients (88% and 79%, n = 48) were significantly higher than the OS and DFS rate for KPNA2-high expression patients (69% and 57.1%, n = 42)(P = 0.0151, P = 0.0109, respectively). The 5-year OS and DFS rate for SALL4-low expression patients (84% and 74%, n = 62) was marginally significantly higher than the high expression patients (78.6% and 71.4%, n = 28)(P = 0.0519, P = 0.0647, respectively). Conclusions KPNA2 is a potential candidate molecular marker and important prognostic marker in OMGCT patients.

Skp2 expression unfavorably impacts survival in resectable esophageal squamous cell carcinoma

BackgroundThe correlation of S-phase kinase–associated protein 2 (Skp2) with metastasis and prognosis in esophageal squamous cell carcinoma (ESCC) is controversial. The purpose of this study was to explore whether there was a correlation between the expression of Skp2 evaluated by immunohistochemistry and the clinical outcome of patients with operable ESCC, and to further determine the possible mechanism of the impact of Skp2 on survival.MethodsTissue microarrays that included 157 surgically resected ESCC specimens was successfully generated for immunohistochemical evaluation. The clinical/prognostic significance of Skp2 expression was analyzed. Kaplan-Meier analysis was used to compare the postoperative survival between groups. The prognostic impact of clinicopathologic variables and Skp2 expression was evaluated using a Cox proportional hazards model. A cell proliferation assay and a colony formation assay were performed in ESCC cell lines to determine the function of Skp2 on the progression of ESCC in vitro.ResultsSkp2 expression correlated closely with the T category (p = 0.035) and the pathological tumor-node-metastasis (TNM) stage (p = 0.027). High expression of Skp2 was associated with poor overall survival in resectable ESCC (p = 0.01). The multivariate Cox regression analysis demonstrated that pathological T category, pathological N category, cell differentiation, and negative Skp2 expression were independent factors for better overall survival. In vitro assays of ESCC cell lines demonstrated that Skp2 promoted the proliferative and colony-forming capacity of ESCCs.ConclusionsNegative Skp2 expression in primary resected ESCC is an independent factor for better survival. Skp2 may play a pro-proliferative role in ESCC cells.

HBx-mediated decrease of AIM2 contributes to hepatocellular carcinoma metastasis

Tumor metastasis is responsible for the high mortality rates in patients with hepatocellular carcinoma (HCC). Absent in melanoma 2 (AIM2) has been implicated in inflammation and carcinogenesis, although its role in HCC metastasis remains unknown. In the present study, we show that AIM2 protein expression was noticeably reduced in HCC cell lines and clinical samples. A reduction in AIM2 was closely associated with higher serum AFP levels, vascular invasion, poor tumor differentiation, an incomplete tumor capsule and unfavorable postsurgical survival odds. In vitro studies demonstrated that AIM2 expression was modulated by hepatitis B virus X protein (HBx) at transcriptional and post‐translational levels. HBx overexpression markedly blocked the expression of AIM2 at mRNA and protein levels by enhancing the stability of Enhancer of zeste homolog 2 (EZH2). Furthermore, HBx interacted with AIM2, resulting in an increase of AIM2 degradation via ubiquitination induction. Functionally, knockdown of AIM2 enhanced cell migration, formation of cell pseudopodium, wound healing and tumor metastasis, whereas reintroduction of AIM2 attenuated these functions. The loss of AIM2 induced the activation of epithelial‐mesenchymal transition (EMT). Fibronectin 1 (FN1) was found to be a downstream effector of AIM2, with its expression reversely modulated by AIM2. Silencing of FN1 significantly halted cell migration induced by AIM2 depletion. These data demonstrate that HBx‐induced loss of AIM2 is associated with poor outcomes and facilitates HCC metastasis by triggering the EMT process. The results of the present study therefore suggest that AIM2 is a potential prognostic biomarker in hepatitis B virus‐related HCC, as well as a possible therapeutic target for tumor metastasis.

The prognostic significance of lymphovascular invasion in patients with resectable gastric cancer: a large retrospective study from Southern China.

BackgroundThe focus of this study was to assess the impact of lymphovascular invasion (LVI) on both the recurrence of cancer and the long-term survival of Chinese patients with resectable gastric cancer (GC).MethodsA retrospective analysis of the clinicopathological data for 1148 GC patients who had undergone gastrectomy with regional lymphadenectomy was performed. The primary objective was to assess the correlation between LVI and post-surgery outcomes for each patient. This was done by routine H & E staining for LVI on patients’ disease-free survival (DFS) and disease-specific survival (DSS).ResultsLVI was detected in 404 (35.2%) of the 1148 GC patients. The presence of LVI was significantly correlated with the level of CA19-9, the tumor size, the Lauren classification, tumor differentiation, gastric wall invasive depth, lymph node involvement, distant metastasis and an advanced TNM stage. There was a lower DFS and DSS in the patients with LVI as compared to the patients without LVI. A multivariate analysis also identified LVI as an independent prognostic factor of both DSS and DFS.ConclusionsThe presence of LVI is a risk factor for the recurrence of cancer and an independent indicator of a poor outcome in GC patients following surgery. The LVI status should be taken into consideration when determining the best approach for the treatment of the individual.

Quantitative Assessment of Tumor Blood Flow Changes in a Murine Breast Cancer Model After Adriamycin Chemotherapy Using Contrast-Enhanced Destruction-Replenishment Sonography

The purpose of the study was to detect tumor blood flow changes after chemotherapy with contrast‐enhanced destruction‐replenishment sonography.