L1 cell adhesion molecule overexpression in hepatocellular carcinoma associates with advanced tumor progression and poor patient survival

ABSTRACT: OBJECTIVE: L1 cell adhesion molecule (L1CAM), as a member of the immunoglobulin superfamily, has recently been observed in a variety of human malignancies. However, no data of L1CAM are available for hepatocellular carcinoma (HCC). The aim of this study was to investigate the expression of L1CAM in HCC and determine its correlation with tumor progression and prognosis. METHODS: One-hundred and thirty HCC patients who had undergone curative liver resection were selected and immunohistochemistry, Western blotting, and quantitative real time polymerase chain reaction (Q-PCR) were performed to analyze L1CAM expression in the respective tumors. RESULTS: Immunohistochemistry, Western blotting, and Q-PCR consistently confirmed the overexpression of L1CAM in HCC tissues compared with their adjacent nonneoplastic tissues at both protein and gene level (both P <0.01). Additionally, the high expression of L1CAM was significantly associated with advanced tumor stage (P = 0.02) and advanced tumor grade (P = 0.03), respectively. Moreover, HCC patients with high L1CAM expression were significantly associated with lower 5-year overall survival (P <0.01) and lower 5-year disease-free survival (P <0.01), respectively. The Cox proportional hazards model further showed that L1CAM over-expression was an independent poor prognostic factor for both 5-year disease-free survival (P = 0.02) and 5-year overall survival (P = 0.008) in HCC. CONCLUSION: Our data suggest for the first time that L1CAM expression in HCC was significantly correlated with the advanced tumor progression and was an independent poor prognostic factor for both overall survival and disease-free survival in patients with HCC.Virtual slidesThe virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1970024872761542.     

NGAL and NGALR overexpression in human hepatocellular carcinoma toward a molecular prognostic classification

Aim: Neutrophil gelatinase-associated lipocalin (NGAL) and its cell surface receptor, NGALR, have been implicated in tumorigenesis and tumor progression of various human malignant neoplasms. In particularly, it has been demonstrated that NGAL is overexpressed in hepatocellular carcinoma (HCC) tissues and closely associated with the proliferation and invasion of HCC cells. The aim of this study was to investigate the clinical significance of NGAL and NGALR in HCC. Methods: Expression of NGAL and NGALR was evaluated by immunohistochemistry in tumor tissues from 138 patients who underwent curative resection of HCC. The association of NGAL or NGALR expression with the clinicopathologic features was analyzed. Univariate and multivariate analyses were performed to evaluate the prognostic value of NGAL and/or NGALR expression for HCC patients. Results: The expression levels of NGAL and NGALR were both up-regulated in HCC tissues, and to be associated with vascular invasion (both P=0.03), TNM stage (both P=0.004), and tumor recurrence (both P<0.001). A positive correlation between expression of the two markers was also observed (r=0.89; P<0.001). Additionally, survival analysis showed that high expression of NGAL or NGALR was significantly associated with poor prognosis for patients with HCC (both P=0.003). Patients with high expression of both NGAL and NGALR had a shorter overall survival (P<0.001) than those with low expression of both. Furthermore, multivariate analysis showed both NGAL and NGALR were independent predictors of overall survival. Conclusion: Our data demonstrate for the first time that the up-regulations of NGAL and NGALR expression in HCC were both significantly correlated with unfavorable clinicopathologic features and independent poor prognostic factor for overall survival in patients. These findings suggest that NGAL and NGALR expression might be served as novel prognostic factors and potential therapeutic targets in HCC.     

eEF1A1 Overexpression Enhances Tumor Progression and Indicates Poor Prognosis in Hepatocellular Carcinoma

Liver is a major contributor of protein production physiologically. The aberrant state of protein synthesis leads to tumor progression. Eukaryotic elongation factor 1 alpha 1 (eEF1A1) is a major member of the eukaryotic elongation factor family that regulates protein synthesis. Although eEF1A1 plays an essential role in controlling the cell fate, its clinical significance in tumor development and progression has not been reported. Here, we aimed to uncover the expression and prognostic significance of eEF1A1 in hepatocellular carcinoma (HCC). Our data indicated that eEF1A1 expression was elevated in HCC cell lines and clinical samples at both the mRNA and protein levels. Immunohistochemistry revealed that eEF1A1 expression was upregulated in HCC samples compared with corresponding non-tumorous tissues. In 50 HCC cases with portal vein embolus, higher eEF1A1 immunoreactivity was detected in tumor metastases compared with the primary lesions. Kaplan–Meier analysis indicated that increased eEF1A1 expression was closely associated with unfavorable post-surgical overall and disease-free survival in 453 HCC patients. Moreover, multivariate analysis indicated eEF1A1 as an independent predictor for overall and disease-free survival. Collectively, our study suggests eEF1A1 as a novel prognostic biomarker and potential therapeutic target for HCC patients.     

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, Spearman''s 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.     

Upregulation of microRNA-372 associates with tumor progression and prognosis in hepatocellular carcinoma

MicroRNA-372 (miR-372) has been demonstrated to play a crucial role in cellular proliferation and apoptosis of cancer cells. However, its effects in hepatocellular carcinoma (HCC) have not been explored. The aim of this study was to investigate the clinical significance of miR-372 in human HCC. Quantitative RT-PCR was performed to detect miR-372 expression in HCC clinical samples and cell lines. Then, Kaplan–Meier and Cox proportional regression analyses were performed to determine the association of miR-372 expression with survival of HCC patients. Moreover, the effects of miR-372 on tumorigenicity of HCC cell lines were evaluated by in vitro assays. miR-372 expression in HCC tissues was significantly higher than in the corresponding normal adjacent liver tissues (P < 0.001). There was a correlation between miR-372 upregulation and advanced TNM stage of HCC patients (P = 0.02). In addition, HCC patients with higher miR-372 expression had significantly poorer recurrence-free survival (P = 0.006) and overall survival (P = 0.001). Multivariate analysis revealed that high miR-372 expression was an independent predictor of poor prognosis (for recurrence-free survival: Hazard Ratio [HR] 6.826, P = 0.01; for overall survival: HR 9.533, P = 0.008). Moreover, in vitro assays demonstrated that the ectopic expression of miR-372 may significantly promote the cellular proliferation, invasion, and migration of HCC cell lines. Our findings showed that miR-372 may serve as a potent prognostic marker for tumor recurrence and survival of HCC patients. Furthermore, miR-372 has been identified as a promoter for tumorigenicity of HCC cells, suggesting that it might be a prospective therapeutic target for HCC.     

Association of PD-L1 and HIF-1α Coexpression with Poor Prognosis in Hepatocellular Carcinoma

OBJECTIVE: To investigate the correlation between the expression of PD-L1 and HIF-1α in hepatocellular carcinoma (HCC) tissue and further analyze the association with clinical parameters and the prognostic value of coexpression in HCC patients. METHODS: We assessed the expression of PD-L1 and HIF-1α by immunohistochemistry in tumor tissue from 90 HCC patients who underwent curative hepatectomy. The results were validated in an independent cohort of additional 90 HCC patients. RESULTS: PD-L1 and HIF-1α exhibited in tumor tissue high expression rates of 41.11% (37/90) and 43.33% (43/90), respectively, and their expressions were positively correlated (r = 0.563, P < .01). High expression of PD-L1 was significantly associated with low albumin levels (P < .05); high expression of HIF-1α was significantly correlated with high alpha-fetoprotein (AFP) levels and low albumin levels (P < .05); high expression of both PD-L1 and HIF-1α was also significantly associated with high AFP levels and low albumin levels (P < .05). High expression of PD-L1, HIF-1α, as well as both PD-L1 and HIF-1 α was respectively significantly associated with worse overall survival (OS) and disease-free survival (DFS) (P < .05). Patients with co-overexpression of PD-L1 and HIF-1α had the worst prognosis compared with other groups. Additionally, multivariate Cox regression models suggested that high expression of PD-L1, HIF-1α, as well as both PD-L1 and HIF-1α was an independent prognostic factor for OS and DFS (P < .05). Furthermore, the positive correlation and prognostic values of PD-L1 and HIF-1α were validated in an independent data set. CONCLUSION: We demonstrated that HCC patients with co-overexpression of PD-L1 and HIF-1α in tumor tissue had a significantly higher risk of recurrence or metastasis and death compared with others. Therefore, more frequent follow-up is needed for patients with co-overexpression of PD-L1 and HIF-1α. At the same time, a combinational therapy with HIF-1α inhibitors in conjunction with PD-L1 blockade may be beneficial for HCC patients with co-overexpression in the future.     

Positive Expression of Programmed Death Ligand 1 in Peritumoral Liver Tissue is Associated with Poor Survival after Curative Resection of Hepatocellular Carcinoma

BACKGROUND: Recurrence or metastasis of hepatocellular carcinoma (HCC) is mainly intrahepatic after curative resection, demonstrating that the peritumoral environment is important but often neglected. Programmed death ligand 1 (PD-L1) in intratumoral liver tissues is a poor prognosis factor whose impact is removed after curative resection. However, PD-L1 expression remains in the peritumoral liver tissues and its distribution and prognostic value are still not clear. METHODS: We assessed the expression of PD-L1 by immunohistochemistry in peritumoral liver tissues from 90 HCC patients who underwent curative hepatectomy. The results were validated in an independent cohort of additional 90 HCC patients. RESULTS: We found PD-L1 positive expression in 31.11% (28/90) of peritumoral tissues. Peritumoral PD-L1 expression was associated with a significantly worse overall survival (OS) (P = .000) and disease-free survival (DFS) (P = .001) compared to the negative expression group. Additionally, peritumoral PD-L1 positivity significantly correlated with vascular invasion and a lower albumin level (≤35 g/L). Univariate and multivariate Cox regression models both revealed peritumoral PD-L1 as an independent prognostic factor for OS (HR = 2.853, P = .002) and DFS (HR = 2.362, P = .003). The prognostic value of PD-L1 positivity was validated in the independent data set. CONCLUSIONS: Our data suggest PD-L1 expression in peritumoral hepatocytes is an independent prognostic factor for OS and DFS. This implies that future anti-cancer therapy should target not only residual tumor cells but also the “soil” for promoting tumor growth. Peritumoral PD-L1 could be a good target for adjuvant therapy after hepatectomy.     

STEAP3 promotes cancer cell proliferation by facilitating nuclear trafficking of EGFR to enhance RAC1-ERK-STAT3 signaling in hepatocellular carcinoma

STEAP3 (Six-transmembrane epithelial antigen of the prostate 3, TSAP6, dudulin-2) has been reported to be involved in tumor progression in human malignancies. Nevertheless, how it participates in the progression of human cancers, especially HCC, is still unknown. In the present study, we found that STEAP3 was aberrantly overexpressed in the nuclei of HCC cells. In a large cohort of clinical HCC tissues, high expression level of nuclear STEAP3 was positively associated with tumor differentiation and poor prognosis (p < 0.001), and it was an independent prognostic factor for HCC patients. In HCC cell lines, nuclear expression of STEAP3 significantly promoted HCC cells proliferation by promoting stemness phenotype and cell cycle progression via RAC1-ERK-STAT3 and RAC1-JNK-STAT6 signaling axes. Through upregulating the expression and nuclear trafficking of EGFR, STEAP3 participated in regulating EGFR-mediated STAT3 transactivity in a manner of positive feedback. In summary, our findings support that nuclear expression of STEAP3 plays a critical oncogenic role in the progression of HCC via modulation on EGFR and intracellular signaling, and it could be a candidate for prognostic marker and therapeutic target in HCC.Subject terms: Oncogenes, Tumour biomarkers     

S100P Expression Is a Novel Prognostic Factor in Hepatocellular Carcinoma and Predicts Survival in Patients with High Tumor Stage or Early Recurrent Tumors

The calcium-binding protein S100P is expressed in a variety of human cancer cells and is important in cancer cell growth and invasion. Using differential display, we found S100P is overexpressed in human hepatocellular carcinoma (HCC). We examined the expression of 305 unifocal, primary HCC tumors using immunohistochemistry. The S100P protein was expressed in 173 of the 305 (56.7%) HCC tumors. The expression of S100P correlated with female sex (P = 0.0162), high serum α-fetoprotein level (P = 0.0001), high tumor grade (P = 0.0029), high tumor stage (P = 0.0319), the presence of the p53 mutation (P = 0.0032), and the absence of the β-catenin mutation (P = 0.0489). Patients with HCC tumors that expressed S100P were more likely to have early tumor recurrence (ETR) (P = 0.0189) and lower 5-year survival (P = 0.0023). The multivariate analysis confirmed that S100P expression was an independent prognostic factor in HCC. The combinatorial analysis showed an additive unfavorable prognostic interaction between S100P expression and the p53 mutation. In contrast, the β-catenin mutation was associated with better prognosis in both S100P-positive and -negative HCCs. Furthermore, S100P expression was a predictor of survival in HCC patients with high tumor stage or ETR (P = 0.0026 and P = 0.0002, respectively). Our study indicates the expression of the S100P protein is a novel independent predictor for poor prognosis in HCC, and it is also an unfavorable prognostic predictor in HCC patients with high tumor stage or ETR.     

Decreased Expression of TMEM173 Predicts Poor Prognosis in Patients with Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is one of the most lethal cancer types, and chronic infection with Hepatitis B Virus (HBV) is identified as the strongest risk factor for HCC. Transmembrane Protein 173 (TMEM173) is a pattern recognition receptor which functions as a major regulator of the innate immune response to viral and bacterial infections. However, the prognostic value of TMEM173 in HCC remains elusive. Thus, we aimed to evaluate the potential prognostic significance of TMEM173 expression in HCC patients following curative resection. Immunohistochemistry was used to detect TMEM173 expression in 96 HCC patients. We found that TMEM173 protein expression was remarkably decreased in tumor tissues compared to non-tumor tissues, and that TMEM173 staining intensity was inversely correlated with tumor size, tumor invasion TNM stage and overall survival (OS) in HCC patients. Multivariate analysis supported TMEM173 as an independent prognostic factor, and identified that combining TMEM173 expression with TNM stage showed better prognostic efficiency for OS in HCC patients. In summary, TMEM173 was discovered having an independent prognostic value and may serve as a potential immunotherapeutic target for HCC.     

Identification of LZAP as a new candidate tumor suppressor in hepatocellular carcinoma

Background

LZAP was isolated as a binding protein of the Cdk5 activator p35. LZAP has been highly conserved during evolution and has been shown to function as a tumor suppressor in various cancers. This study aimed to investigate LZAP expression and its prognostic value in hepatocellular carcinoma (HCC). Meanwhile, the function of LZAP in hepatocarcinogenesis was further investigated in cell culture models and mouse models.

Methods

Real-time quantitative PCR, western blot and immunohistochemistry were used to explore LZAP expression in HCC cell lines and primary HCC clinical specimens. The functions of LZAP in the proliferation, colony formation, cell cycle, migration, invasion and apoptosis of HCC cell lines were also analyzed by infecting cells with an adenovirus containing full-length LZAP. The effect of LZAP on tumorigenicity in nude mice was also investigated.

Results

LZAP expression was significantly decreased in the tumor tissues and HCC cell lines. Clinicopathological analysis showed that LZAP expression was significantly correlated with tumor size, histopathological classification and serum α-fetoprotein (AFP). The Kaplan–Meier survival curves revealed that decreasing LZAP expression was associated with poor prognosis in HCC patients. LZAP expression was an independent prognostic marker of overall HCC patient survival in a multivariate analysis. The re-introduction of LZAP expression in the HepG2 and sk-Hep1 HCC cell lines significantly inhibited proliferation and colony formation in the HCC cells and induced G1 phase arrest and apoptosis of the HCC cells in vitro. Restoring LZAP expression in the HCC cell lines also inhibited migration and invasion. In addition, experiments with a mouse model revealed that LZAP overexpression could suppress HCC tumorigenicity in vivo.

Conclusions

Our data suggest that LZAP may play an important role in HCC progression and could be a potential molecular therapy target for HCC.     

Down-regulated expression of the protein-tyrosine phosphatase 1B (PTP1B) is associated with aggressive clinicopathologic features and poor prognosis in hepatocellular carcinoma

The protein-tyrosine phosphatase 1B (PTP1B) is a classical non-transmembrane protein tyrosine phosphatase that plays a key role in metabolic signaling and can exert both tumor suppressing and tumor promoting effects in different cancers depending on the substrate involved and the cellular context. However, the expression level and function of PTP1B in hepatocellular carcinoma (HCC) remain unclear. In this study, PTP1B expression was detected by immunohistochemistry in normal liver tissue (n=16) and hepatocellular carcinoma (n=169). The correlations between PTP1B expression level and clinicopathologic features and patient survival were also analyzed. One hundred and eleven of 169 HCC patients (65.7%) had negative or low PTP1B expression in tumorous tissues, whereas normal tissues always expressed strong PTP1B. Decreased PTP1B expression was significantly associated with aggressive clinicopathologic features and poor prognosis. Immunohistochemistry also showed that low PTP1B expression level was correlated with high percentage of OV6(+) tumor-initiating cells (T-ICs) and high frequency of nuclear β-Catenin expression in HCC specimens. Our findings demonstrate for the first time that the loss of inhibitory effect of PTP1B may contribute to progression and invasion of HCC through activation of Wnt/β-Catenin signaling and expansion of liver T-ICs. PTP1B may serve as a valuable prognostic biomarker and potential therapeutic target in HCC.     

Autophagic Protein Beclin 1 Serves as an Independent Positive Prognostic Biomarker for Non-Small Cell Lung Cancer

Beclin 1, a key regulator of autophagy, has been found to be aberrantly expressed in a variety of human malignancies. Herein, we employed immunohistochemistry (IHC) to detect the protein expression of Beclin 1 in non-small cell lung cancer (NSCLC) and paired normal adjacent lung tissues, and analyzed its clinicopathological/prognostic significance in NSCLC. Receiver operating characteristic (ROC) curve analysis was utilized to determine a cutoff point (>2 VS. ≤2) for Beclin 1 expression in a training set (n = 105). For validation, the ROC-derived cutoff value was subjected to analysis of the association of Beclin 1 with patients’ clinical characteristics and outcome in a testing set (n = 111) and the overall patient cohort (n = 216). Our data showed that Beclin 1 was significantly lower in NSCLC tissues compared with the adjacent normal tissues, negatively associating with tumor recurrence rate (65.8% VS 32.3%; p < 0.001). In the testing set and the overall patient cohort, low expression of Beclin 1 showed significantly inferior overall survival (OS) (p < 0.001) and progression-free survival (PFS) (p < 0.001) compared to high expression of Beclin 1. In the testing set and the overall patient cohort, the median duration of OS for patients with high and low expression of Beclin 1 was 108 VS. 24.5 months (p < 0.001) and 108 VS. 28 months (p < 0.001), respectively. Furthermore, low expression of Beclin 1 was also a poor prognostic factor within each stage of NSCLC patients. Multivariate analysis identified that Beclin 1 was an independent prognostic factor for NSCLC. Our findings in the present study provided evidence that Beclin 1 may thus emerge as an independent prognostic biomarker in this tumor entity in the future.     

Increased Expression of CAP2 Indicates Poor Prognosis in Hepatocellular Carcinoma

CAP2 has been suggested as a potential diagnostic biomarker for early hepatocellular carcinoma (HCC). However, its prognostic significance in HCC remains unclear. Here, we show that CAP2 expression is much higher in HCC tissues than that in paracarcinoma tissues, at both mRNA and protein levels. Data of immunohistochemistry (IHC) revealed that CAP2 was markedly up-regulated in 77.3% of HCC cases. High CAP2 expression, defined by the median score of IHC, was present in 53.3% of the patients. Kaplan-Meier analysis indicated that high CAP2 expression was associated with poor overall survival (P < .0001), disease-free survival (P = .013) and recurrence probability (P = .004) in a training cohort of 312 HCC patients. The prognostic implication of CAP2 in HCC was further confirmed in a validation cohort of 208 HCC patients and by stratified survival analysis. Multiple Cox regression analysis indicated CAP2 as an independent predictor for overall survival (hazard ratio (HR) = 1.615, 95% confidence interval: 1.345-1.938, P < .001). Collectively, we conclude that CAP2 is increased in HCC and is a novel unfavorable biomarker for prognostic prediction for patients with this deadly disease.     

Characterization of bridging integrator 1 (BIN1) as a potential tumor suppressor and prognostic marker in hepatocellular carcinoma

It has been shown that bridging integrator 1 (BIN1) can interact with c-myelocytomatosis (c-Myc) oncoprotein in cancer. However, the role of BIN1 in hepatocellular carcinoma (HCC) is not clear. In the present study, we investigated the expression and prognostic role of BIN1 in primary HCC and evaluated the function of BIN1 in hepatocarcinogenesis. Using real-time polymerase chain reaction and Western blot analysis, we found significantly decreased expression of BIN1 in primary HCC tumor tissues (n = 42) compared with adjacent normal tissues and in HCC cell lines. Immunohistochemistry analysis also found decreased BIN1 expression in HCC tumor tissues (n = 117). In clinicopathological analysis, loss of BIN1 expression correlated significantly (P < 0.05) with differentiation scores and tumor size. Importantly, decreased expression of BIN1 in tumors was found to be closely associated with a poor prognosis, and we conclude that BIN1 was an independent prognostic factor in a multivariate analysis. In mechanistic studies, restoring BIN1 expression in BIN1-null HCC cells significantly inhibited cell proliferation and colony formation and induced apoptosis of HCC cells. Furthermore, we found that BIN1 overexpression could significantly suppress the motility and invasion of HCC cells in vitro. Our results indicate that BIN1 may function as a potential tumor suppressor and serve as a novel prognostic marker in HCC patients. The BIN1 molecule might play an important role in tumor growth, cell motility and invasion. Modulation of BIN1 expression may lead to clinical applications of this critical molecule in the control of hepatocellular carcinoma as well as in early and effective diagnosis of this aggressive tumor.     

LIN28 Is Involved in Glioma Carcinogenesis and Predicts Outcomes of Glioblastoma Multiforme Patients

LIN28, an evolutionarily conversed RNA binding protein which can bind to the terminal loops of let-7 family microRNA precursors and block their processing to maturation, is highly expressed in several subsets of tumors that carry poor prognoses, such as ovarian carcinoma, hepatocellular carcinoma, colon carcinoma and germ cell carcinoma. However, there has been no study on the expression of LIN28 in glioma tissues or their importance as a prognostic predictor of glioma patients. This study aimed to examine the expression of LIN28 in glioma and correlate the results to patient outcome. We found that LIN28 expression was significantly higher in the group of patients with a poor prognosis compared to patients with a good prognosis by gene microarray. Log-rank analysis showed patients with higher LIN28 expression level in tumor had a shorter progression-free survival and overall survival times compared to those with lower LIN28 expression level. Similar results were also obtained from the tissue microarray analysis. Univariate and multivariate analyses showed high LIN28 expression was an independent prognostic factor for a shorter progression-free survival and overall survival in GBM patients. Furthermore in vitro experiments showed that down-regulation of LIN28 in U251 and U373 cells caused cell cycle arrest in the G1 phase, delayed cell proliferation, increased apoptosis, and resulted in fewer colonies compared to controls. Summarily, our data provides a potential target for cancer therapy as an approach to overcome the poor options currently available for GBM patients.     

Dyskerin overexpression in human hepatocellular carcinoma is associated with advanced clinical stage and poor patient prognosis

Background

Dyskerin (encoded by the DKC1 gene) is an essential nucleolar protein involved in cell proliferation, where it is required for the pseudo-uridylation of ribosomal RNA (rRNA) molecules and the stabilization of the telomerase RNA component. Dyskerin expression has been reported to predict poor survival in some cancer patients. The aim of the present study was to analyze the expression of dyskerin in hepatocellular carcinoma (HCC) and to determine its correlation with clinicopathologic features, including the survival of patients with HCC.

Methodology/Principal Findings

Dyskerin protein expression was detected by immunohistochemistry in paraffin sections of 252 HCC cases and 80 noncancerous liver tissues. The correlation was analyzed between dyskerin expression levels and clinicopathologic variables and prognosis. Dyskerin protein was significantly overexpressed in HCC tissues when compared to noncancerous liver tissue. Dyskerin overexpression was positively correlated with the hepatitis B surface antigen status, serum alpha-fetoprotein, and advanced clinical stage in HCC patients. A survival analysis indicated that HCC patients with higher dyskerin expression had a significantly shorter overall survival and 5-year survival time when compared to those with low expression. A multivariate analysis suggested that dyskerin overexpression was an independent factor for prognosis (hazard risk, 2.912; P = 0.007). Expression of DKC1 mRNA was measured by quantitative RT-PCR in 80 HCC and 50 non-cancerous tissues. The relationship between DKC1, TERT, MKI67, and MYC mRNA expression in HCC tissues was also evaluated. DKC1 mRNA was significantly overexpressed in HCC tissues and showed a significant correlation with MKI67 and MYC mRNA but a weak correlation with TERT mRNA.

Conclusions/Significance

Dyskerin overexpression in HCC patients was correlated with MYC and MKI67 expression and showed a possible involvement in the tumorigenic process. Dyskerin overexpression may be an unfavorable prognostic factor in patients with HCC.