Upregulation of phosphatidylinositol glycan anchor biosynthesis class C is associated with unfavorable survival prognosis in patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common types of malignant tumor, and is the second highest cause of cancer-associated mortality, behind lung carcinoma. It is urgent to identify novel genes that can be used to confirm the diagnosis and prognosis of patients with HCC. The present study aimed to investigate the expression pattern of phosphatidylinositol glycan anchor biosynthesis class C (PIGC) in HCC and assess its clinical prognostic significance. Bioinformatics analyses were used to investigate PIGC mRNA expression levels in HCC and adjacent non-cancerous tissue samples. Furthermore, the present study detected the expression levels of PIGC protein in HCC and matched normal tissue samples via immunohistochemistry, and evaluated the prognostic significance of PIGC protein in HCC. The levels of PIGC mRNA and protein were found to be significantly higher in tissue from patients with HCC compared with non-cancerous liver tissue. The survival analysis showed that the expression levels of PIGC mRNA or protein were associated with the survival of patients with HCC. PIGC protein expression was significantly associated with Tumor-Node-Metastasis stage. A negative correlation between PIGC DNA methylation and mRNA expression was observed (Spearman r=−0.453). PIGC is an oncogene that is negatively regulated by DNA methylation, and high levels of PIGC mRNA or protein may predict an unfavorable prognosis in patients with HCC.     

Silencing of Hint1, a novel tumor suppressor gene,by promoter hypermethylation in hepatocellular carcinoma

The Hint1 protein, a member of the histidine triad (HIT) family, is highly conserved in diverse species and ubiquitously expressed in mammalian tissues. Previous studies in mice provided evidence that Hint1 may be haploinsufficient with respect to its function as a tumor suppressor. In the present study, we investigated the aberrant methylation of Hint1 and explored possible relationships between aberrant methylation and clinicopathological features in hepatocellular carcinoma (HCC). Hypermethylation of Hint1 was evaluated by the methylation specific PCR (MSP) method in 40 patients with HCC (tumor and paired adjacent non-tumor tissues) from Taiwan, 22 cases of normal liver tissue (14 from Taiwan and 8 from the US). HINT1 expression in tissues was detected by immunohistochemistry. The frequencies of hypermethylation of Hint1 in tumor, paired adjacent non-tumor and normal liver tissue were 55.0%, 37.5% and 9.1%, respectively. A statistically significant inverse association was found between Hint1 methylation status and expression of the HINT1 protein in tumor tissues (p = 0.003). The relationship between Hint1 methylation status and clinical features and other, previously measured biomarkers was also analyzed. p16 hypermethylation was statistically significantly associated with Hint1 methylation status (p = 0.035). There were no correlations between Hint1 methylation and hepatitis B (HBV) or hepatitis C (HCV) infection status or aflatoxin B₁ (AFB₁-) and polycyclic aromatic hydrocarbons (PAHs)-DNA adduct levels. These results suggest that promoter hypermethylation of Hint1 may play a role in hepatocarcinogenesis.     

Genome-wide DNA Methylation Profiling of Cell-Free Serum DNA in Esophageal Adenocarcinoma and Barrett Esophagus

Aberrant DNA methylation (DNAm) is a feature of most types of cancers. Genome-wide DNAm profiling has been performed successfully on tumor tissue DNA samples. However, the invasive procedure limits the utility of tumor tissue for epidemiological studies. While recent data indicate that cell-free circulating DNAm (cfDNAm) profiles reflect DNAm status in corresponding tumor tissues, no studies have examined the association of cfDNAm with cancer or precursors on a genome-wide scale. The objective of this pilot study was to evaluate the putative significance of genome-wide cfDNAm profiles in esophageal adenocarcinoma (EA) and Barrett esophagus (BE, EA precursor). We performed genome-wide DNAm profiling in EA tissue DNA (n = 8) and matched serum DNA (n = 8), in serum DNA of BE (n = 10), and in healthy controls (n = 10) using the Infinium HumanMethylation27 BeadChip that covers 27,578 CpG loci in 14,495 genes. We found that cfDNAm profiles were highly correlated to DNAm profiles in matched tumor tissue DNA (r = 0.92) in patients with EA. We selected the most differentially methylated loci to perform hierarchical clustering analysis. We found that 911 loci can discriminate perfectly between EA and control samples, 554 loci can separate EA from BE samples, and 46 loci can distinguish BE from control samples. These results suggest that genome-wide cfDNAm profiles are highly consistent with DNAm profiles detected in corresponding tumor tissues. Differential cfDNAm profiling may be a useful approach for the noninvasive screening of EA and EA premalignant lesions.     

Prognostic significance of BMP7 as an oncogene in hepatocellular carcinoma

This study aims to evaluate the association between BMP7 tissue expression and patient prognosis in hepatocellular carcinoma (HCC). The expression of BMP7 mRNA in HCC was characterized using real-time PCR and 30 pairs of fresh frozen HCC tissues and corresponding noncancerous tissues. BMP7 protein expression in HCC was confirmed using immunohistochemistry on a tissue microarray chip. Finally, BMP7 expression was correlated with conventional clinicopathological features of HCC and patient outcome. The expression of BMP7 mRNA and protein in HCC cells was much higher than in normal hepatic cells. Our results showed that the high expression of BMP7 in HCC was related to tumor size (p?<?0.001), histological differentiation (p?=?0.041), serum AFP (p?=?0.007), and tumor stage (p?<?0.001). Kaplan–Meier survival analysis showed that a high-expression level of BMP7 resulted in a significantly poor prognosis of HCC patients. Multivariate analysis revealed that BMP7 expression level was an independent prognostic parameter for the overall survival rate of HCC patients. These findings provide evidence that a high-expression level of BMP7 serves as a biomarker for poor prognosis for HCC. Thus, we speculate that BMP7 may be a potential target of antiangiogenic therapy for HCC.     

A novel prognostic biomarker SPC24 up-regulated in hepatocellular carcinoma

SPC24 is an important component of the nuclear division cycle 80 (Ndc80) kinetochore complex, which plays an essential role in the coupling of kinetochore to spindle microtubules (MTs) and the accurate segregation of chromosomes during mitosis. However, the functional role of SPC24 in hepatocellular carcinoma (HCC) remains unknown. Here, we detected the expression of SPC24 in HCC and analyzed its association with clinicopathologic features and prognosis of HCC patients. The expression of SPC24 mRNA was investigated in 212 cases of paired HCC and adjacent liver tissues by quantitative real-time PCR (qRT-PCR) and in the tissues of 20 HCC patients by semi-quantitative RT-PCR. Additionally, the expression of SPC24 protein was detected in 69 cases of HCC by immunohistochemistry (IHC) or in 2 cases of HCC tissues by Western-blotting. Furthermore, small interfering RNA (siRNA)-mediated silencing of SPC24 was employed in SMMC7721 and HepG2 human HCC cells to investigate cell proliferation, invasion and apoptosis. Survival curves were plotted using the Kaplan-Meier method, and differences in survival probability were obtained using the log-rank test. Independent predictors associated with disease-free survival (DFS) and overall survival (OS) were analyzed using the Cox proportional-hazards regression model. In this study, we showed that SPC24 was noticeably increased in HCC tissues compared to normal adjacent noncancerous tissues, at both mRNA and protein levels. High expression of SPC24 was significantly correlated with alpha-fetoprotein (AFP) (p = 0.044), median size (p = 0.030), tumor number (p = 0.019), and Barcelona-Clinic Liver Cancer (BCLC) stage (p = 0.015). Kaplan-Meier analysis showed that the DFS and OS of high SPC24 expression group was significantly shorter than that of low SPC24 expression group (p < 0.001; p = 0.001; respectively). The prognostic impact of SPC24 was further confirmed by stratified survival analysis. Importantly, multivariate analysis identified SPC24 upregualtion (p = 0.001), PVTT (p = 0.007), size of tumor > 5 cm (p < 0.001) as independent risk factors of DFS after resection, and SPC24 upregualtion (p < 0.001), PVTT (p = 0.029), size of tumor > 5 cm (p = 0.002), recurrence (p < 0.001) as independent prognostic factors for the OS of HCC patients. Additionally, siRNA-mediated silencing of SPC24 dramatically suppressed cell growth, adhesion, invasion and increased apoptosis in HCC cells. In conclusion, these results showed for the first time that SPC24 expression was significantly up-regulated in HCC, which may act as a novel prognostic biomarker for patients suffering from this deadly disease. Additionally, silence of SPC24 inhibiting HCC cell growth indicated that SPC24 may be a promising molecular target for HCC therapy.     

Role of ZIC1 methylation in hepatocellular carcinoma and its clinical significance

Hepatocellular carcinoma (HCC) is one of the most aggressive malignancies in humans, and its prognosis is generally poor even after surgery. The zinc finger of the cerebellum (ZIC1) gene is a novel tumor suppressor gene that plays a crucial role in vertebrate development. Altered expression of ZIC1 is observed in various types of human cancers. The aims of the present study were to investigate the methylation status of ZIC1 in HCC and evaluate its clinical implication. The methylation status of ZIC1 was analyzed in 132 pairs of HCC and corresponding noncancerous tissues by methylation-specific polymerase chain reaction (PCR) (MSP). The expression of ZIC1 messenger RNA (mRNA) in HCC tissues was examined by real-time PCR. Methylation frequency of ZIC1 in HCC was significantly higher than that in the corresponding noncancerous tissues (P?P?=?0.022), histological differentiation (P?=?0.033), and tumor stage (P?=?0.009). The downregulation of the ZIC1 mRNA expression in HCC was correlated with the ZIC1 methylation (P?P?mRNA and associated with poor survival in HCC. Overall, aberrant methylation is an important mechanism for ZIC1 inactivation in HCC, and ZIC1 methylation may be a promising biomarker for the diagnosis and prognosis of HCC.     

Genome-wide association study of the TP53 R249S mutation in hepatocellular carcinoma with aflatoxin B1 exposure and infection with hepatitis B virus

BackgroundExposure to dietary aflatoxin B1 (AFB1) induces DNA damage and mutation in the TP53 gene at codon 249, known as the TP53 R249S mutation, and is a major risk factor for hepatocellular carcinoma (HCC). AFB1 and the hepatitis B virus (HBV) together exert synergistic effects that promote carcinogenesis and TP53 R249S mutation in HCC.MethodsA genome-wide association study (GWAS) of whole genome exons was conducted using 485 HCC patients with chronic HBV infection. This was followed by an independent replication study conducted using 270 patients with chronic HBV infection. Immunohistochemistry was used to evaluate TP53 expression in all samples. This showed a correlation between codon 249 mutations and TP53 expression. Susceptibility variants for the TP53 R249S mutation in HCC were identified based on both the GWAS and replication study. The associations between identified variants and the expression levels of their located genes were analyzed in 20 paired independent samples.ResultsThe likelihood of positive TP53 expression was found to be higher in HCC patients with the R249S mutation both in the GWAS (P<0.001) and the replication study (P=0.006). The combined analyses showed that the TP53 R249S mutation was significantly associated with three single nucleotide polymorphisms (SNPs): ADAMTS18 rs9930984 (adjusted P=4.84×10⁻⁶), WDR49 rs75218075 (adjusted P=7.36×10⁻⁵), and SLC8A3 rs8022091 (adjusted P=0.042). The TP53 R249S mutation was found to be highly associated with the TT genotypes of rs9930984 (additive model, P=0.01; dominant model, P=6.43×10⁻⁵) and rs75218075 (additive model, P=0.002; dominant model, P=2.16×10⁻⁴). Additionally, ADAMTS18 mRNA expression was significantly higher in HCC tissue compared with its expression in paired non-tumor tissue (P=0.041), and patients carrying the TT genotype at rs9930984 showed lower ADAMTS18 expression in non-tumor tissue compared with patients carrying the GT genotype (P=0.0028). WDR49 expression was markedly lower in HCC tissue compared with paired non-tumor tissue (P=0.0011).ConclusionsTP53 expression is significantly associated with the R249S mutation in HCC. Our collective results suggest that rs9930984, rs75218075, and rs8022091 are associated with R249S mutation susceptibility in HCC patients exposed to AFB1 and HBV infection.     

DNA primase polypeptide 1 (PRIM1) involves in estrogen-induced breast cancer formation through activation of the G2/M cell cycle checkpoint

The DNA primase polypeptide 1 (PRIM1) is responsible for synthesizing small RNA primers for Okazaki fragments generated during discontinuous DNA replication. PRIM1 mRNA expression levels in breast tumor samples were detected by real-time PCR analysis. Xenografted tumor model was established to study the carcinogenic role of PRIM1 and its potential therapeutic applications. The average PRIM1 mRNA (copy number × 10³/μg) expression was 4.7-fold higher in tumors than in normal tissue (*p = 0.005, n = 254). PRIM1 was detected preferentially at a higher level (>40-fold) in poorly differentiated tumor tissues (n = 46) compared with more highly differentiated tumors tissues (n = 10) (*p = 0.005). Poor overall survival rate was correlated to the estrogen receptor positive (ER+, n = 20) patients with higher PRIM1 expression when compare to the ER− (n = 10) patients (Chi Square test, p = 0.03). Stable expression of PRIM1-siRNA in the ER+ BT-474 cells-xenograft tumors significantly reduced tumor volume in SCID mice (*p = 0.005). The anti-tumoral effects of inotilone isolated from Phellinus linteus was tested and had significant effects on the inhibition of PRIM1 protein expression in ER+ breast cancer cells. In vivo study was performed by administering inotilone (10 mg/kg, twice a week for 6 weeks), which resulted in significantly reduced BT-474-xenografted tumor growth volume compared with control (n =5 per group, *p < 0.05). This study provides evidences for the prognostic effects of PRIM1 with poor overall survival rate in the ER+ patients and will be valuable to test for therapeutic purpose.     

Decursin chemosensitizes human multiple myeloma cells through inhibition of STAT3 signaling pathway

Early detection of lung cancer provides the highest potential for saving lives. To date, no routine screening method enabling early detection is available, which is a key factor in the disease’s high mortality rate. Copy number changes and DNA methylation alterations are good indicators of carcinogenesis and cancer prognosis. In this study, we attempted to combine profiles of DNA copy number and methylation patterns in 20 paired cancerous and noncancerous tissue samples from non-small cell lung cancer (NSCLC) patients, and we detected several clinically important genes with genetic and epigenetic relationships. Using array comparative genomic hybridization (aCGH), statistically significant differences were observed across the histological subtypes for gains at 1p31.1, 3q26.1, and 3q26.31-3q29 as well as for losses at 1p21.1, 2q33.3, 2q37.3, 3p12.3, 4q35.2, and 13q34 in squamous cell carcinoma (SQ) patients, and losses at 12q24.33 were measured in adenocarcinoma (AD) patients (p < 0.05). In an analysis of DNA methylation at 1505 autosomal CpG loci that are associated with 807 cancer-related genes, we identified six and nine loci with higher and lower DNA methylation levels, respectively, in tumor tissue compared to non-tumor lung tissues from AD patients. In addition, three loci with higher and seven loci with lower DNA methylation levels were identified in tumor tissue from SQ patients compared to non-tumor lung tissue. Subsequently, we searched for regions exhibiting concomitant hypermethylation and genomic loss in both ADs and SQs. One clone representing 7p15.2 (which includes candidate genes such as HOXA9 and HOXA11) and one target ID representing HOXA9_E252_R were detected. Quantitative real-time PCR identified the potential candidate gene HOXA9 as being down-regulated in the majority of NSCLC patients. Moreover, following HOXA9 over-expression, the invasion of representative cell lines, A549 and HCC95, were significantly inhibited. Taken together, our results show that the combined profiling analysis technique is a useful tool for identifying biomarkers in lung cancer and that HOXA9 might be a potential candidate gene for the pathogenesis and diagnosis of NSCLC patients.     

Aberrant TIG1 methylation associated with its decreased expression and clinicopathological significance in hepatocellular carcinoma

Recently, it has been reported that tazarotene-induced gene 1 (TIG1) methylation was frequently detected in a variety of human cancers. However, the relationship between the TIG1 methylation and the characteristics of hepatocellular carcinoma (HCC) remains unknown. The aim of present study was to observe the promoter methylation of TIG1 in HCC tissues and assess its prognostic significance for HCC. Real-time quantitative polymerase chain reaction and methylation-specific polymerase chain reaction were used, respectively, to examine the mRNA expression and methylation status of TIG1 in 91 pairs of HCC and adjacent noncancerous tissues. The mRNA expression level of TIG1 was significantly lower in HCC tissues than in adjacent noncancerous tissues. The rate of TIG1 promoter methylation was significantly higher in HCC tissues than in adjacent noncancerous tissues (P?<?0.001). A strong correlation between downregulation and promoter methylation was found in these tumors (P?<?0.001). More importantly, TIG1 methylation status was related to tumor size (P?=?0.015), histological differentiation (P?=?0.004), and tumor stage (P?<?0.001). Kaplan–Meier survival analysis showed that TIG1 promoter hypermethylation was associated with a worse outcome in patients with HCC. Further, Cox multivariate analysis indicated that TIG1 methylation status was an independent prognostic factor for the overall survival rate of HCC patients. In conclusion, our data suggested that epigenetic silencing of TIG1 gene expression by promoter hypermethylation may play an important role in HCC.     

Expression and prognostic significance of placental growth factor in hepatocellular carcinoma and peritumoral liver tissue

Vascular endothelial growth factor‐targeted therapy is a promising treatment for hepatocellular carcinoma (HCC), but its clinical benefit is often accompanied by acquired resistance. In animal studies, antiplacental growth factor therapy is effective with less resistance. The role of placental growth factor (PlGF) in the progression of HCC is not clear. In our study, we used immunohistochemistry in tissue microarrays to investigate PlGF expression in tumor and peritumoral liver tissues from 105 patients with HCC. Intratumoral and peritumoral PlGF mRNA expression was analyzed in another cohort of 37 patients. Peritumoral PlGF expression was significantly higher than intratumoral PlGF expression (p < 0.001). Intratumoral PlGF expression was not associated with patients' overall survival (OS) or time to recurrence (TTR). However, peritumoral PlGF expression, which was associated with tumor size, presence of intrahepatic metastasis, TNM stage and Barcelona Clinic Liver Cancer stage, was an independent risk factor for OS (p = 0.026) and TTR (p = 0.041). The prognostic value of peritumoral PlGF expression was further validated in a validation cohort (n = 394). We inferred that the elevation of PlGF in peritumoral liver might be induced by hypoxia. We found that peritumoral PlGF expression was associated with hypoxia‐inducible factor‐1α (p = 0.017). PlGF expression was elevated in L02, a hepatic cell line, under hypoxic conditions in vitro. These findings indicate that high peritumoral PlGF expression is associated with tumor recurrence and survival after resection of HCC. PlGF could be a target of adjuvant therapy and deserves further investigations.     

Expression of intestinal trefoil factor (TFF-3) in hepatocellular carcinoma

Background: Trefoil peptides (TFF-1, 2, 3) are a family of protease-resistant regulatory factors that play a role in mucosal restitution, angiogenesis, apoptosis, and tumor progression. Intestinal trefoil peptide (TFF-3) expression has been demonstrated in benign hepatobiliary diseases, but there are limited data regarding its expression in HCC. Methods: Thirty consecutive cases of HCC from 1998 to 2003 were studied. Immunohistochemistry was performed on formalin-fixed paraffin-embedded blocks of HCC using polyclonal antibody to TFF-3. TFF-3 expression was classified as strong, moderate, weak, focal, and negative. Clinical data were obtained per an IRB-approved protocol. Results: Median age was 69 yr (range: 39–83 yr). Twenty- three patients were males and 7 were females. Treatments included hepatic resection (n=16), chemo-embolization (n=4), combined modality therapy (n=5) and no treatment (n=4). HCC was well differentiated in 12 (40%), moderately differentiated in 13 (43%), and poorly differentiated in 5 (17%) patients. TFF-3 expression was detected in 28/30 (93.3%) patient samples. Sixteen patients (53%) had moderate and 1 (3%) patient had strong TFF-3 expression. Tumor/normal tissue interface was assessable in 21 cases; 11 cases expressed TFF-3 at the interface. There was a strong correlation between tumor grade and TFF-3 expression, wherein poorly differentiated tumors had moderate/strong TFF-3 expression (p=0.008). There was no correlation between TFF-3 expression and survival (p=0.77). Furthermore, there was no correlation among age, disease stage, and survival. Conclusion: TFF-3 is commonly expressed in HCC and its expression correlates with tumor grade.