pRb2/p130, vascular endothelial growth factor, p27(KIP1), and proliferating cell nuclear antigen expression in hepatocellular carcinoma: their clinical significance

Heat-Shock protein A12A is a novel PCNA-binding protein and promotes hepatocellular carcinoma growth

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death. Proliferating cell nuclear antigen (PCNA) plays a pivotal role in cancer development and progression. However, the long-term dismal prognosis of HCC mandates more investigation to identify novel regulators in HCC pathogenesis. Heat-shock protein A12A (HSPA12A) encodes a novel member of the HSP70 family. Here, we report that HCC cells showed increased HSPA12A expression, and overexpression of HSPA12A promoted HCC growth and angiogenesis in mice. Gain- and loss-of-functional studies demonstrated that the proliferation of HCC HepG2 cells, as well as β-catenin expression and nuclear translocation, was promoted by HSPA12A overexpression, but in turn suppressed by HSPA12A knockdown. HSPA12A did not impact PCNA expression; however, mass spectrometry and co-immunoprecipitation immunoblotting analysis revealed that HSPA12A directly binds to PCNA and promotes its trimerization, which is an essential functional conformation of PCNA for carcinogenesis. Importantly, PCNA inhibition by PCNA-I1 reversed the HSPA12A-mediated HepG2 cell differentiation. These findings indicate that HSPA12A is a novel regulator of HCC cell proliferation and tumor growth through binding to PCNA for its trimerization. HSPA12A inhibition might represent a viable strategy for the management of HCC in humans.

Targeting Epidermal Growth Factor Receptor in Non-Small-Cell-Lung Cancer: Current State and Future Perspective

BACKGROUND

Lung cancer is one of the leading cause of cancer death worldwide, the most common histological type of lung cancer is non-small cell lung cancer (NSCLC), whose occurrence and development is closely related to the mutation and amplification of epidermal growth factor receptors (EGFR). Currently , a series of targeted drugs were developed on the inhibition of EGFR such as epidermal growth factor receptortyrosine kinase inhibitor EGFR-TKI and monoclonal antibody (McAb).

OBJECTIVE

We sought to summarizes the current drugs targeting Epidermal Growth Factor Receptor in nonsmall- cell-lung.

METHODS

We conducted a comprehensive review of the development and application of EGFR-TKI and McAb which targeted EGFR in NSCLC and compared the mechanisms of PROTAC with the traditional inhibitors.

RESULTS

The drugs targeted EGFR in NSCLC have been widely used in clinic practices. Compared to traditional chemotherapy, these drugs excel with their clear and specific targeting, better curative effects, and less toxic and side effects. However, the mechanism comes with some insurmountable weaknesses like serious toxic and other side effects, as well as proneness to producing drug resistance.

CONCLUSION

The emerging PROTAC (Proteolysis Targeting Chimera) technology has been successfully applied to selective degradation of multiple protein targets, including EGFR. It also highlights the potential and challenges of PROTAC therapy regarding future combination therapeutic options in NSCLC treatment.

The Evaluation of Angiogenesis Markers in Hepatocellular Carcinoma and Precursor Lesions in Liver Explants From a Single Institution

Hepatocellular carcinoma (HCC) is a global health problem associated with chronic liver disease. Precursor lesions are described, and the correct diagnosis of liver nodules is paramount when considering liver transplantation. We evaluated the immunohistochemical expression of vascular endothelial growth factor (VEGF) and angiopoietin-2 in HCC and precursors lesion in a single institution series of whole liver explants between 2013 and 2015, evaluating morphologic and clinical variables. The study comprised 67 patients (32.8% female) and 107 nodules. The mean age of the patients was 52.7 years (29 to 70 y). There were no significant epidemiologic differences among malignant lesions, dysplastic nodules, and regenerative nodules. Angiopoietin-2 expression was significantly more expressed in carcinoma when compared with regenerative lesions (P<0.0001). A statistically significant relationship was noted between the expression of VEGF in hepatocytes and Ang-2 expression in the small vasculature (P=0.006). VEGF expression also correlated significantly with the number of nonpaired arteries (P=0.03), although it was not useful in separating benign from malignant cases. We identified a sensitivity of 54% and a specificity of 96% using angiopoietin-2, and a sensitivity of 68.7% and a specificity of 31.2% when using VEGF for the diagnosis of HCC. There was no significant correlation between the immunohistochemical parameters and the clinical staging, the number of gross lesions, and the histologic grade in cases of HCC. Angiopoietin-2 may be a candidate biomarker in assessing liver nodules in transplant patients, and may assist in the diagnosis of difficult lesions and in small biopsies pretransplant.

Low-dose bevacizumab induces radiographic regression of vestibular schwannomas in neurofibromatosis type 2: A case report and literature review

The current case study aimed to explore the efficacy of a low-dose bevacizumab regimen in inhibiting tumor growth and minimizing adverse effects. A 55-year-old man with neurofibromatosis type 2 (NF2) suffered bilateral vestibular schwannomas (VS) measuring 5.25 and 2.54 cm³ on the left and right, respectively. His capacity for bilateral language recognition was impaired. However, the patient refused microsurgical tumor resection and gamma knife therapy. Low-dose bevacizumab regimen (3.3–2.2 mg/kg every 2–4 weeks) was administered by intravenous injection for ~1.5 years to inhibit tumor growth and avoid further deterioration of hearing. Compared with baseline measurements prior to treatment, the bilateral VS regressed to 3.59 cm³ (68%) and 2.08 cm³ (82%) on the left and right, respectively. No hearing improvement was detected; however, the patient subjectively experienced a significant hearing improvement as his ability to communicate with people and distinguish voices was restored. No adverse effects were observed. Bevacizumab provides an alternative treatment option for those who refuse surgical intervention. Given the adverse effects commonly induced by bevacizumab, the use of a low-dose regimen would appear to be promising with regard to tumor regression and hearing preservation for patients with VS in NF2. However, the minimum dose required to sustain a response to bevacizumab in NF2 patients remains unknown. Finding the minimum effective dose sufficient to sustain hearing and/or volumetric response for individual patients is required.

The clinical utility of the proliferating cell nuclear antigen expression in patients with hepatocellular carcinoma

Proliferating cell nuclear antigen (PCNA) has been suggested as a potential diagnostic biomarker for early hepatocellular carcinoma (HCC). However, its prognostic significance in HCC remains unclear. In the present study, we investigated the expression and significance of PCNA in HCC and then analyzed the role of PCNA in clinical outcomes. Our findings show that the expression intensity of PCNA is much higher in HCC tissues than that in paracarcinoma tissues and associated with AFP, albumin, tumor number, clinical grade, vascular invasion, and tumor-node-metastasis (TNM) stage (all p < 0.000). Kaplan-Meier analysis indicated that high PCNA expression was associated with poor disease-free survival (DFS) (p < 0.000) and overall survival (OS) (p < 0.000) in a training cohort of 76 HCC patients. Multiple Cox regression analysis indicated PCNA acts as an independent predictor for DFS (p = 0.002) and OS (p = 0.004) in HCC patients. Along with pathological results, our systematic review also identified the expression of PCNA was closely associated with DFS and OS (both p < 0.000). In conclusion, this study suggested that PCNA is increased in HCC patients and is indeed a novel unfavorable biomarker for prognostic prediction for patients with this deadly disease.

An improved model of predicting hepatocarcinogenic potential in rats by using gene expression data

Carcinogenicity studies using animals are expensive and time consuming. Therefore, the development of a highly accurate carcinogenicity prediction system to interpret short-term test results would be beneficial. The Ames test is popular for mutagens; however, it cannot detect non-genotoxic carcinogens. Previously, we reported a prediction system using gene expression data obtained from a short-term (28-day) study that screened candidate compounds for testing in long-term carcinogenicity studies. In this study, our system was improved by adding more gene expression data. To establish our new system, we used the data of 93 test compounds (41 hepatocarcinogens and 52 non-hepatocarcinogens). Analysis of liver gene expression data by dividing compounds into 'for training' and 'for test' categories (20 cases assigned randomly) using Support Vector Machine (SVM) identified a set of marker probe sets that could be used to predict hepatocarcinogenicity. The assigned 42 probe sets have included the cancer- or c-Myc-related genes such as Hsp90, Pink1, Hspc111, Fbx29, Hepsin, Syndecan2 and Synbindin. Compared with the older version, the improved system had a higher concordance rate with the training data and a good performance with the external test data.

Review of angiogenesis in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumor, and its vascularity is unique and greatly different from peripheral parenchyma of liver. Afferent and efferent vessels of HCC lesions come to differ as the lesion develops. The characteristic of the flow regulates the common style of metastasis. The portal tract of the HCC lesion is the first site of the intrahepatic metastasis, because cancer cells roll into the portal vein via efferent flow. On microscopic observation, HCC displays marked vascular abnormalities, arteriogenesis and capillarization. Arteriogenesis is defined as the growth of functional collateral arteries covered with smooth muscle cells from pre-existing arteries. Sinusoidal capillarization involves the transformation of fenestrated hepatic sinusoids into continuous capillaries. Several angiogenic factors have been reported, and some of them are studied as prognostic factors or target molecules of chemotherapeutic reagents. However, the mechanism of neovascularization during HCC development is still unclear. This review discusses the characteristics of angiogenesis in HCC and known angiogenic factors of HCC.

Clinical significance of expression of ZIC1 and P130 in cholangiocarcinoma

AIM: To investigate the expression of zicfamilymember1 (ZIC1) and P130 in cholangiocarcinoma and their correlation with the biological behavior of cholangiocarcinoma.

METHODS: The protein expression of ZIC1 and P130 was detected by immunohistochemistry in 43 cases of cholangiocarcinoma and 20 cases of normal bile duct tissue.

RESULTS: The positive rate of ZIC1 expression was significantly higher in cholangiocarcinoma than in normal bile duct tissue (53.49% vs 25.00%, P < 0.05). The positive rate of P130 expression in cholangiocarcinoma was significantly lower than that in normal bile duct tissue (55.81 vs 85.00%, P < 0.05). The expression of ZIC1 and P130 protein was related to pathological grade and neoplasm metastasis (both P < 0.05), but not to sex or Nevin stage (both P > 0.05). There was a negative correlation between ZIC1 and P130 expression (r = -0.360, P < 0.05) in cholangiocarcinoma. The expression of ZIC1 and P130 proteins was related to the 3-year survival rate (both P < 0.05).

CONCLUSION: The abnormal expression of ZIC1 and P130 proteins may be involved in the development and progression of cholangiocarcinoma.

CD24: a novel cancer biomarker in laryngeal squamous cell carcinoma

PURPOSE

To investigate the role of CD24 in tumor invasion and the clinical significance of its expression in laryngeal squamous cell carcinoma (LSCC).

PROCEDURES

CD24 expression was measured in Hep-2 cell lines and tumor and peritumoral tissues by quantitative real-time PCR and Western blot analysis. The role of CD24 in LSCC was investigated by CD24 depletion using small interfering RNA. Tumor tissue microarrays with samples from 102 LSCC patients were used to detect expression of CD24 and proliferating cell nuclear antigen (PCNA). Prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests.

RESULTS

CD24 was overexpressed in the LSCC cell line and in tumor tissues. Depletion of CD24 caused a notable decrease in cell proliferation, migration and invasiveness in vitro. High CD24 expression was significantly associated with T clinic stage, lymph node metastasis and tumor size (p < 0.05). Patients suffering from LSCC recurrence had higher levels of CD24 protein than those without recurrence (p < 0.0001). The proportion of patients with high PCNA expression was significantly greater among patients with CD24+ LSCC than those with CD24- LSCC (p = 0.000). Univariate and multivariate analyses revealed that CD24 was a significant predictor for overall survival.

CONCLUSIONS

Overexpression of CD24 in LSCC is associated with invasiveness, metastatic potential and high tumor proliferation status. CD24 may be a promising strategy for the future treatment of LSCC metastasis and recurrence.

HIWI is associated with prognosis in patients with hepatocellular carcinoma after curative resection

BACKGROUND

PIWI protein family was found to play an important role in stem cell self-renewal. Overexpression of HIWI, the human homolog of PIWI family proteins, was found in several solid tumors, although the role of HIWI in hepatocellular carcinoma (HCC) and its prognostic value remain unclear.

METHODS

HIWI expression was measured in stepwise metastatic HCC cell lines (HCCLM3, MHCC97H, MHCC97L, SMMC7721, and HepG2), the normal liver cell line (L02), and HCC tissue samples (n = 20). Proliferation and invasion were investigated in HCC cell lines undergoing HIWI target small interfering RNA transfection. Also explored was HIWI expression in HCC tissue microarrays (n = 168) for survival analysis.

RESULTS

Levels of HIWI protein and mRNA were up-regulated in highly metastatic HCC cell lines (HCCLM3, MHCC97H, and MHCC97L), whereas their proliferation and invasion significantly decreased after depletion of HIWI. Intratumoral HIWI expression was higher than that of peritumoral tissue (P < .001) and positively associated with proliferating cell nuclear antigen expression (P < .001). Positive expression of intratumoral HIWI was associated with larger tumor size (P = .047) and intrahepatic metastasis (P = .027) and was an independent risk factor for overall survival (P = .007) and recurrence-free survival (P = .036), particularly in patients with low serum α-fetoprotein and low Edmondson-Steiner grade.

CONCLUSIONS

HIWI may play a key role in HCC proliferation and metastasis and can be a potential prognostic factor for HCC after curative resection, particularly with well-differentiated HCC.

Vascular endothelial growth factor in the management of hepatocellular carcinoma: a review of literature

The importance of tumor angiogenesis in tumor biology is now widely accepted. Hepatocellular carcinoma (HCC) is a highly vascular tumor, and angiogenesis is believed to play a considerable role in its development and progression. The authors reviewed the role of circulating vascular endothelial growth factor (VEGF) in screening for HCC and in risk stratification and treatment monitoring. They searched the world medical literature by accessing MEDLINE and PubMed for articles on: 1) the utility of circulating VEGF for HCC screening in patients with cirrhosis; 2) the role of circulating VEGF as a predictor of the invasive potential of HCC; and 3) monitoring anti-HCC treatment effects by serial measurements of circulating VEGF. They found evidence to support a potential role for VEGF in screening and surveillance of HCC. They also found support for developing the use of VEGF in the monitoring of treatment outcomes. Several studies suggested that the circulating VEGF level may be an independent prognostic marker in HCC. Further studies are needed to determine the utility of circulating VEGF in screening of patients with cirrhosis and to determine its potential role as a prognostic and predictive biomarker in patients with HCC. Cancer 2009. (c) 2009 American Cancer Society.

SKP2 and CKS1 promote degradation of cell cycle regulators and are associated with hepatocellular carcinoma prognosis

BACKGROUND & AIMS

The cell cycle regulators P21(WAF1), P27(KIP1), P57(KIP2), P130, RASSF1A, and FOXO1 are down-regulated during hepatocellular carcinoma (HCC) pathogenesis. We investigated the role of the ubiquitin ligase subunits CKS1 and SKP2, which regulate proteasome degradation of cell cycle regulators, in HCC progression.

METHODS

Human HCC tissues from patients with better (HCCB, >3 years survival) and poorer prognosis (HCCP, <3 years survival) and HCC cell lines were analyzed.

RESULTS

The promoters of P21(WAF1), P27(KIP1), and P57(KIP2) were more frequently hypermethylated in HCCP than HCCB. Messenger RNA levels of these genes were up-regulated in samples in which these genes were not methylated; protein levels increased only in HCCB because of CKS1- and SKP2-dependent ubiquitination of these proteins in HCCP. The level of SKP2 expression correlated with rate of HCC cell proliferation and level of microvascularization of samples and was inversely correlated with apoptosis and survival. In HCCB, SKP2 activity was balanced by degradation by the ubiquitin ligase anaphase-promoting complex/cyclosome (APC/C)-CDH1 and up-regulation of SKP2 suppressor histidine triad nucleotide binding protein 1 (HINT1). In HCCP, however, SKP2 was not degraded because of down-regulation of the phosphatase CDC14B, CDK2-dependent serine phosphorylation (which inhibits interaction between CDH1 and SKP2), and HINT1 inactivation. In HCC cells, small interfering RNA knockdown of SKP2 reduced proliferation and ubiquitination of the cell cycle regulators, whereas SKP2 increased proliferation and reduced expression of cell cycle regulators.

CONCLUSIONS

Ubiquitination and proteasome degradation of P21WAF1, P27KIP1, P57KIP2, P130, RASSF1A, and FOXO1 and mechanisms that prevent degradation of SKP2 by APC/C-CDH1 contribute to HCC progression. CKS1-SKP2 ligase might be developed as a therapeutic target or diagnostic marker.

pRb2/p130 protein in relation to clinicopathological and biological variables in rectal cancers with a clinical trial of preoperative radiotherapy

BACKGROUND

pRb2/p130 plays a key role in cell proliferation and is a considerable progress about expression patterns of pRb2/p130 in number of malignancies. However, pRb2/p130 expression and its significance in rectal cancer remain unknown. The purpose of the present study was to investigate pRb2/p130 protein patterns and their correlations with clinicopathological and biological factors in rectal cancer patients with or without preoperative radiotherapy (RT).

PATIENT/METHODS

pRb2/p130 protein was examined by immunohistochemistry in 130 primary tumors, along with the corresponding 61 distant normal mucosa specimens, 85 adjacent normal mucosa specimens, 34 lymph node metastases, and 93 primary tumor biopsies from rectal cancer patients who participated in a Swedish clinical trial of preoperative RT.

RESULTS

The pRb2/p130 protein was mainly localized in the cytoplasm of tumor cells. In nonradiated cases, the lack of pRb2/p130 was related to advanced tumor-node-metastases stage, poorer differentiation, weak fibrosis, less inflammatory infiltration, higher Ki-67, and positive Cox-2 expression (p < 0.05). In radiated cases, the lack of pRb2/p130 was related to nonstaining of Cox-2 and survivin (p < 0.05). pRb2/p130 protein in primary tumors tended to be increased after RT (27% vs 16%, p = 0.07).

CONCLUSION

pRb2/p130 was mainly localized in the cytoplasm rather than in the nucleus in rectal cancer. After RT, pRb2/p130 protein seems to be increased in primary tumors, and further the relationship of the pRb2/p130 with the clinicopathological and biological variables changed compared to the nonradiated cases. However, we did not find that the pRb2/p130 was directly related to RT, tumor recurrence, and patients' survival.

CD24 is a novel predictor for poor prognosis of hepatocellular carcinoma after surgery

PURPOSE

To investigate the role of CD24 in tumor invasion and prognostic significance in hepatocellular carcinoma (HCC).

EXPERIMENTAL DESIGN

CD24 expression was measured in stepwise metastatic HCC cell lines, tumor, peritumoral tissues, and normal liver tissues by quantitative real-time PCR and Western blot. The role of CD24 in HCC was investigated by CD24 depletion using small interfering RNA. Tumor tissue microarrays of 314 HCC patients who underwent resection between 1997 and 2000 were used to detect expression of CD24, beta-catenin, and proliferating cell nuclear antigen. Prognostic significance was assessed using Kaplan-Meier survival estimates and log-rank tests.

RESULTS

CD24 was overexpressed in the highly metastatic HCC cell line and in tumor tissues of patients with recurrent HCC. Depletion of CD24 caused a notable decrease in cell proliferation, migration, and invasiveness in vitro. Univariate and multivariate analyses revealed that CD24 was a significant predictor for overall survival and relapse-free survival. CD24 expression was correlated with poor prognosis independent of alpha-fetoprotein, tumor-node-metastasis stage, and Edmondson stage. High CD24 expression was significantly associated with cytoplasmic and nuclear accumulation of beta-catenin (P = 0.023), high tumor proliferative status (P = 0.018), and diffused intrahepatic recurrence and distant metastasis (P = 0.026). Adjuvant transcatheter arterial chemoembolization after surgery reduced the rate of early recurrence (<or=1 year) in CD24(+) HCC patients (P = 0.024) but had no significant effect in CD24(-) patients (P = 0.284).

CONCLUSIONS

Overexpression of CD24 in HCC was associated with high invasiveness and metastatic potential, high tumor proliferation status, and activation of the Wnt/beta-catenin pathway. CD24 may be a novel predictor for poor prognosis of HCC patients after surgery.

Hepatocellular Carcinoma: Tumorigenesis and Prediction Markers

Hepatocellular carcinoma (HCC) is one of the most common malignancies. Although many advances have been made in the clinical study of HCC, the prognosis remains poor. Despite the discoveries in cancer biology in respect with physiological and pathological factors in relation to prognosis, HCC remains still a fatal disease due to late diagnosis. For improving the outcomes of patients with HCC, it is important to identify the factors predisposing to patient death. In recent years, based on cellular and molecular biology techniques, many tumor markers related to invasion, metastasis, recurrence and survival have been explored. However, routine biomarkers for the prediction of HCC evolution and prognosis are available in small number and less specific. These reviews focus on the recent advances in HCC tumorigenesis, revealing those biomarkers with prognosis significance or can be used for early detection.

The expression of novel gene URG4 in osteosarcoma: correlation with patients' prognosis

AIMS

Up-regulated gene 4 (URG4) is a novel gene that may be associated with the onset of tumorigenesis and cell cycle regulation. The present study examined for the first time the expression of URG4 in osteosarcoma, which is one of the most rapidly growing sarcomas, and investigated its prognostic value in both disease-free and overall survival of the patients.

METHODS

The expression of URG4 in osteosarcoma tissues was examined by immunohistochemistry in 46 patients who underwent surgical operation for osteosarcoma; the correlation of URG4 with proliferating cell nuclear antigen index (PCNA) and microvessel count (MVC) was analysed, and the prognostic value of URG4 in patients was investigated.

RESULTS

URG4 was highly expressed in 40 of 46 (86.96%) osteosarcoma specimens with cytoplasmic staining, and also increased in the specimens with recurrence (p < 0.05) and metastasis (p < 0.05). The mean disease-free survival and overall survival were 50.25 and 54.08 months for patients with over-expressed URG4, compared with 69.54 and 70.01 months for those with low expression. URG4 was also found to be highly related with PCNA, while no significant relationship was found between URG4 and MVC.

CONCLUSIONS

URG4 may play important roles in the development of osteosarcoma, and might be a useful molecular marker for predicting the prognosis of osteosarcoma.

Endocan expression correlated with poor survival in human hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second leading cause of cancer death in China. We aimed to first present the expression of endocan in HCC tissue and its correlation with the clinicopathological features and overall survival of patients with HCC after curative hepatectomy. Immunohistochemical detection of endocan, CD34, and vascular endothelial growth factor (VEGF) were performed on samples from 100 patients with HCC. Endocan protein was expressed in endothelium of HCC tissue in all specimens, but was not expressed in endothelium of pericarcinomatous liver tissue and normal liver tissue. Microvessel density (MVD) denoted by endocan (endocan-MVD) in HCC was correlated with microscopic venous invasion and VEGF expression (P < 0.05). Survival analysis showed that overall survival of patients was inversely associated with endocan-MVD (P < 0.01). Multivariate analysis showed that endocan-MVD was an independent prognostic marker for overall survival of HCC (P < 0.01). In conclusion, endocan-MVD was a significant factor to predict the prognosis of HCC patients after curative hepatectomy.

Identification of genes, including the gene encoding p27Kip1, regulated by serine 276 phosphorylation of the p65 subunit of NF-kappaB

Phosphorylation of the p65 subunit of NF-kappaB is required for its transcriptional activity. Recent reports show that phosphorylation of p65 at serine 276 regulates only a subset of genes, such as those encoding IL-6, IL-8, Gro-beta, and ICAM-1. In order to identify additional genes regulated by serine 276 phosphorylation, HepG2 hepatoma cells were infected with adenoviruses encoding either wild-type p65 or the S276A mutant of p65, followed by DNA microarray analysis. The results show that mutation of serine 276 affected the expression of several genes that encode proteins involved in cell cycle regulation, signal transduction, transcription, and metabolism. Notably, expression of S276A increased the mRNA and protein level of p27, a cell cycle inhibitory protein, which led to an increased association of p27 with cdk2, and inhibition of cdk2 activity. Furthermore, while wild-type NF-kappaB is known to increase cell proliferation in a number of different cancer cell lines, our data shows that S276A inhibited cell proliferation. Evidence is mounting that NF-kappaB plays a pivotal role in oncogenesis. Therapeutic agents that regulate the phosphorylation of serine 276 and p27 gene expression, therefore, may be useful as anti-cancer agents in the future.

Drug insight: antiangiogenic therapies for gastrointestinal cancers--focus on monoclonal antibodies

Tumor angiogenesis is strongly induced by vascular endothelial growth factor (VEGF), which is overexpressed in most human gastrointestinal cancers. VEGF overexpression is known to be associated with poor prognosis and survival in patients with various solid tumors. The humanized monoclonal anti-VEGF antibody bevacizumab (Avastin, Genentech Inc., South San Francisco, CA) is a prototypic antiangiogenic compound, and has proven therapeutic benefit combined with conventional chemotherapy-namely, significantly improved progression-free survival in patients with metastatic colorectal cancer. Bevacizumab is the only anti-VEGF antibody that has been approved by the FDA and the European Medicines Agency for the treatment of metastatic colorectal cancer. Several ongoing clinical studies are evaluating the potential of bevacizumab therapy for other gastrointestinal cancers, in combination with chemotherapy, other targeted therapies and/or radiation. Soluble chimeric receptors, tyrosine kinase inhibitors, and monoclonal antibodies against VEGF and molecular targets in the integrin and Delta-like protein 4-Notch pathways are being developed. As tumors acquire resistance to anti-VEGF therapy, further development of antiangiogenic and vascular targets and therapy is warranted.

Importance of Ezh2 polycomb protein in tumorigenesis process interfering with the pathway of growth suppressive key elements

An understanding of the mechanisms that uncover the dynamic changes in the distribution of the chromatin modifying enzymes and regulatory proteins on their target loci could provide further insight into the phenomenon of malignant transformation. Based on the current available data, it seems more and more clear that an abnormal expression of Ezh2, a member of the Polycomb group (PcG) protein, may be involved in the tumorigenesis process, in addition, different studies identify Ezh2 as a potential marker that distinguish aggressive prostate and breast cancer from indolent one. Recent investigation show that ectopic expression of Ezh2 provides proliferative advantage to primary cells through interaction with the pathways of key elements that control cell growth arrest and differentiation, like members of the retinoblastoma (Rb) family. Here, we outline how these pathways converge and we review the recent advances on the molecular mechanisms that promote cell cycle progression through deregulation of Ezh2 protein level, providing novel links between cancer progression and chromatin remodeling machineries.

Effects of oxymatrine on the expression of P21, P27, Cyclin E1 and CDK2 in human colon cancer cell line SW1116

AIM: To observe the effect of oxymatrine (OM) on the expression of P21, P27, Cyclin E1 and CDK2 in human colon cancer cell line SW1116, investigate the pathways of OM in inhibiting tumor cell proliferation, and explore its anti-tumor mechanism.

METHODS: Human colon cancer cell line SW1116 was cultured and then treated with different concentrations (2, 3, 4 g/L) of OM, respectively, for 24 and 48 hours. Flow cytometry was used to detect the cycle changes of SW1116 cells. Reverse transcription polymerase chain reaction and Western blot were performed to measure the expression of P21, P27, Cyclin E1 and CDK2 at mRNA and protein level.

RESULTS: In comparison with those in control group, the percentages of G₁/G₀-phase cells were significantly increased after treatment with 2, 3, 4 g/L OM (24 h: 67.5% ± 0.1%, 69.5% ± 1.4%, 71.0% ± 1.0% vs 58.6% ± 0.4%, P < 0.05; 48 h: 68.5% ± 0.3%, 71.9% ± 0.9%, 78.0% ± 0.4% vs 58.8% ± 0.1%, P < 0.05); the mRNA and protein expression of Cyclin E1 was down-regulated while those of P21 and P27 were up-regulated (P < 0.05); the mRNA expression of CDK2 was lowered, but the protein expression of CDK2 had no significant changes (P > 0.05).

CONCLUSION: OM may inhibit the proliferation of SW1116 cells by blocking cell cycle, down-regulating the expression of Cyclin E1 and up-regulating the expression of P21 and P27.

Prognostic molecular markers in hepatocellular carcinoma: a systematic review

Hepatocellular carcinoma (HCC) is the fifth commonest malignancy worldwide and its incidence is rising. Surgery, including transplantation, remains the only potentially curative modality for HCC, yet recurrence rates are high and long-term survival poor. The ability to predict individual recurrence risk and subsequently prognosis would help guide surgical and chemotherapeutic treatment. As understanding of hepatocarcinogenesis has increased, the myriad of genetic and molecular events that drive the hepatocarcinogenic disease process, including angiogenesis, invasion and metastasis, have been identified. This systematic review examines the evidence from published manuscripts reporting the prognostic potential of molecular biomarkers in hepatocellular carcinoma. In summary, a number of molecular biomarkers with prognostic significance have been identified in hepatocellular carcinoma. Not only might these molecules allow more accurate prediction of prognosis for patients with HCC, but they may also provide targets for potential therapeutic agents.

Liver resections for hepatocellular carcinoma in chronic liver disease: experience in an Italian centre

AIM

Liver resection (LR) and transplantation are the best options for treatment of hepatocellular carcinoma (HCC). We retrospectively analysed the experience obtained with LR for HCC in chronic liver disease patients.

METHODS

Up until May 2005, 248 patients with HCC were evaluated, and 113 resected. Of these, 97 with chronic liver disease, who underwent a total of 100 resections, form the basis of this study. Age of the patients was 65.6+/-9.2 years (range 32-81, male/female 76/21). In 77 cases there was unifocal and in 23 multinodular tumour; in 61 the size of the tumours was < or =5 cm and in 39>5 cm. Limited resections were performed in 15 cases, resections of 1-2 segments in 51, and major hepatectomies in 34.

RESULTS

Blood transfusions were required in 28 cases. Three patients died postoperatively, from liver failure and/or sepsis. Seventeen patients had nonlethal complications (mostly liver dysfunction, often with signs of amplified inflammatory response, including ARDS, without evident sources of sepsis). The 5- and 10-year survival rates were 44% and 24%, respectively. Decreased survival was significantly related to increasing number of tumour nodules and degree of liver fibrosis/presence of cirrhosis, and with the expression of markers of carcinogenesis in a sub-group who received this assessment. At 5 years the rate of liver HCC recurrence was 46%, however, death was unrelated to recurrence in 41% of non-survivors.

CONCLUSIONS

Surgery for HCC achieves acceptable early and long-term results. However, the patterns affecting perioperative outcome must be better understood, and the high recurrence rate warrants further trials to assess preventive treatments after LR.

Involvement of RB gene family in tumor angiogenesis

Angiogenesis, the development of new blood vessels from pre-existing vessels, represents a fundamental step in tumor progression and metastatization. The induction of vasculature is required for growth of the tumor mass, to ensure an adequate supply of oxygen and metabolites to the tumor beyond a critical size. Tumor angiogenesis is a highly regulated process that is controlled physiologically by the tumor microenvironment and genetically by alteration of several oncogenes or tumor suppressor genes. We will focus on recent demonstrations regarding the involvement of the retinoblastoma family proteins (phosphorylated retinoblastoma (pRb), p107 and pRb2/p130) at different levels of the angiogenic process. pRb and its homologs can regulate the expression of pro- and antiangiogenic factors, such as the vascular endothelial growth factor, through an E2F-dependent mechanism. Moreover, pRb is able to modulate also the transcriptional activity of several angiogenesis-related factors like HIF-1, Id2 and Oct-1. pRb2/p130 is required for both differentiation and mobilization of bone marrow-derived endothelial cell precursors and endothelial sprouting from neighboring vessels. The involvement of the pRb pathway in the angiogenesis process has also been demonstrated by different cellular models expressing viral oncoproteins, like human papilloma virus. Moreover, some natural and synthetic compounds demonstrate their antiangiogenetic activity with a mechanism of action involving pRb. Finally, the possible prognostic value of immunohistochemical evaluation of pRb and/or pRb2/p130 expression can represent a useful tool for the characterization of the angiogenic phenotype of specific tumor histotypes.

RB family members as predictive and prognostic factors in human cancer

The retinoblastoma family members--pRb, pRb2/p130 and p107--are tumor suppressor genes involved in controlling four major cellular processes: growth arrest, apoptosis, differentiation and angiogenesis. Molecular genetic studies have identified abnormalities of these tumor suppressor genes in a large proportion of human cancers. These genetic alterations have emerged as significant factors in the pathogenesis and progression of many types of tumors and are therefore likely to provide relevant information to assess risk in cancer patients. There is a pressing clinical need to identify prognostic and predictive factors for patients with cancer, because there is an undeniable importance in being able to determine which patients will have a favorable outcome without further therapy (prognostic factor) and which will need some additional treatment (predictive factor). This review examines the predictive and/or prognostic role of each retinoblastoma family member in human cancer.

Immunohistochemical evaluation of pRb2/p130, VEGF, EZH2, p53, p16, p21waf-1, p27, and PCNA in Barrett's esophagus

Control of the G1/S-phase transition as well as angiogenic switch are two of the most studied mechanisms in cancer. The current study examined the correlation between the immunohistochemical expression of pRb2/p130, VEGF, EZH2, p53, p16, p21waf-1, p27, and PCNA in Barrett's esophagus (BE). Overall, p53 showed a much higher expression in BE patients (up to 50%) than in controls (1-10%) (P < 0.005). Also p21 showed a downregulation in BE when compared to normal esophagus (70% of cells vs. 65%), but the difference did not show any statistical significance (P = 0.45). pRb2/p130 was detected in 80% of cells in normal controls, but showed positive in only 20% of cells in BE biopsies. Additionally, Rb2/p130 expression was inversely correlated to that of VEGF, EZH2, and PCNA (P < 0.0001, P = 0.0032, P < 0.001, respectively). p27 stained more intensely and in a widespread manner (70%) cells in normal esophageal tissues but about only 30% in BE samples (P < 0.001). Lastly, in accordance with other reports, we also found p16 expressed by immunohistochemistry at high levels in normal controls and at low levels in BE (P < 0.001). In conclusion, p16, p21, p27, and p53 staining confirmed previously published data. Interestingly, pRb2/p130 expression was found significantly decreased in metaplastic epithelium compared to normal controls and showed significant inverse correlation with the expression of other markers, such as VEGF, EZH2, and PCNA. These data, taken together, indicate that these molecular events occurring in Barrett's metaplasia (BM) may represent one of the many steps taking place during esophageal malignant progression such as impairment of cell-cycle control, altered differentiation, and unbalanced angiogenesis.

Mechanisms and markers of carcinogenesis and neoplastic progression

Neoplastic transformation evolves over a period of time involving the progression of the cellular immunophenotype (IP) from normal to hyperplastic to dysplastic, and finally, to fully malignant IPs. Superimposed on these changes is the interaction of the initiated cell with its microenvironment, whereby the neoplastically transformed cells, through the regulation or dysregulation of cytoskeletal, integrin, protease and adhesion molecules, develop a novel manner of relation with their surrounding microenvironment. Studies of the neuroendocrine-immune network revealed that the hormonal and cytokine milieu plays an important role impacting the growth and dedifferentiation capabilities of neoplastic cells. This is further affected by the tumour cells themselves determining the constitution of this hormonal microenvironment, allowing the most aggressive and invasive of neoplastically transformed cell clones to promote their own growth and dissemination. The elucidation of the steps of the progression of cancer from premalignant to metastatic and invasive forms is of utmost importance in the differential diagnosis of neoplasms and in the establishment of more efficacious therapeutic regimens. These regimens will certainly begin to take on a more individualised form. The functional characterisation of various human malignancies as to the neoplastically transformed cells' IP, the bases of their interaction with tissue stromal elements, and the molecules involved in the humoral microenvironment of the particular stage of tumour will certainly allow for the better diagnosis, staging, prognostication and treatment of cancers in the future. This paper reviews carcinogenesis from nutritional, genetic and molecular, and humoral aspects, and discusses the importance of tumour markers in the diagnosis and therapeutic management of human cancer.

Angiogenesis and antiangiogenic therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular tumor characterized by neovascularization, which plays an important role in the growth and progression of HCC. Angiogenesis provides a target for novel prognostic and therapeutic approaches to HCC. Assessment of microvessel density using immunohistochemical staining for specific endothelial cell markers such as CD34 has been shown to provide prognostic information independent of conventional pathological parameters in HCC patients. Recent studies have unveiled the important angiogenic factors involved in the regulation of angiogenesis in HCC, although the exact molecular pathways are far from clear. Current data suggest that vascular endothelial growth factor (VEGF) plays a critical role in angiogenesis of HCC. Tumor expression of VEGF has been shown to correlate with tumor invasiveness and prognosis in patients with HCC. VEGF is an important molecular target for antiangiogenic therapy. Studies in animal models have demonstrated the efficacy of antiangiogenic agents such as anti-VEGF antibody and antagonists of VEGF receptors in suppressing hepatocarcinogenesis and growth of HCC. Antiangiogenic therapy has already entered clinical trials in HCC patients and holds the promise of providing an effective novel treatment for HCC, which is of great clinical significance because there is no existing effective systemic therapy for HCC.

Silibinin efficacy against human hepatocellular carcinoma

PURPOSE

Hepatocellular carcinoma (HCC) is one of the most common recurrent malignancies, for which, currently, there is no effective therapy. Considering the antihepatotoxic activity of silibinin, a widely used drug and supplement for various liver disorders, together with its strong preventive and anticancer efficacy against various epithelial cancers, we investigated the efficacy of silibin against human HCC cells.

EXPERIMENTAL DESIGN

Silibinin effects were examined on growth, cytotoxicity, apoptosis, and cell cycle progression in two different HCC cell lines, HepG2 (hepatitis B virus negative; p53 intact) and Hep3B (hepatitis B virus positive; p53 mutated). At molecular level, cell cycle effects of silibinin were assessed by immunoblotting and in-bead kinase assays.

RESULTS

Silibinin strongly inhibited growth of both HepG2 and Hep3B cells with a relatively stronger cytotoxicity in Hep3B cells, which was associated with apoptosis induction. Silibinin also caused G1 arrest in HepG2 and both G1 and G2-M arrests in Hep3B cells. Mechanistic studies revealed that silibinin induces Kip1/p27 but decreases cyclin D1, cyclin D3, cyclin E, cyclin-dependent kinase (CDK)-2, and CDK4 levels in both cell lines. In Hep3B cells, silibinin also reduced the protein levels of G2-M regulators. Furthermore, silibinin strongly inhibited CDK2, CDK4, and CDC2 kinase activity in these HCC cells.

CONCLUSION

Together, these results for the first time identify the biological efficacy of silibinin against HCC cells, suggesting the importance of conducting further investigations in preclinical HCC models, especially on in vivo efficacy, to support the clinical usefulness of silibinin against hepatocellular carcinoma in addition to its known clinical efficacy as an antihepatotoxic agent.

Endogenous stimulators and inhibitors of angiogenesis in gastrointestinal cancers: basic science to clinical application

Progression of cancer is dependent on acquisition of vascular networks within the tumor. Tumor angiogenesis is dependent on up-regulation of angiogenesis stimulators to overcome the endogenous anti-angiogenic barrier. Such disruption of angiogenesis balance to favor neovascularization is a key step for progression of tumor growth and metastasis. In this regard, the vascular basement membrane and the extracellular matrix have been found to be rich sources of angiogenesis stimulators and inhibitors that become bioavailable on proteolysis of the matrix by tumor microenvironment-related enzymes. In this review the subgroup of endogenous angiogenesis stimulators and inhibitors is discussed, and their mechanism of action during tumor angiogenesis is evaluated. The role in regulating tumor growth and the possibility of using them as prognostic markers for human gastrointestinal cancers is discussed. Furthermore, we specifically address the role of vascular endothelial growth factor in human gastrointestinal cancers and discuss the development and use of bevacizumab (Avastin; anti-vascular endothelial growth factor antibody [Genentech, CA]) in the treatment of colorectal and other gastrointestinal cancers.

Expression of cell cycle-regulated proteins pRB2/p130, p107, E2F4, p27, and pCNA in salivary gland tumors: prognostic and diagnostic implications

The retinoblastoma family consists of the tumor suppressor nuclear phosphoprotein pRb/p105 and related proteins p107 and pRb2/p130. Recent immunohistochemical studies of the retinoblastoma family of proteins in lung and endometrial cancer and choroidal melanomas show a tight inverse correlation between the histologic grading in the most aggressive tumor types and pRb2/p130 expression. This led us to investigate the role of pRb2/p130 in salivary tumors. We studied the expression of pRb2/p130, p107, E2F4, p27, and PcNA by immunohistochemistry in a panel of 44 salivary gland tumors. We found a direct correlation between the cytoplasmic expression of pRb2/p130 and tumor grading and the presence of metastasis that was highly statistically significant (P < 0.001). Additionally, increased cytoplasmic pRb2/p130 expression was significantly correlated with a decreased probability of survival (P < 0.001). Interestingly, p107 nuclear expression showed a strong direct correlation when compared with the same variables. pRb2/p130 showed the highest percentage of undetectable nuclear levels in the specimens examined and the tightest inverse correlation (P < 0.0001) with both the histologic grading and pCNA expression in malignant salivary tumors. Additionally, E2F4 showed an identical localization pattern as to that of pRb2/p130. These data suggests an important role for pRb2/p130 in the pathogenesis and progression of certain salivary gland cancers.