Antisense to cyclin D1 inhibits vascular endothelial growth factor-stimulated growth of vascular endothelial cells: implication of tumor vascularization.

PURPOSE: Our aim was to determine the effects of cyclin D1 inhibition on tumor-associated neovascularization and endothelial cell growth. EXPERIMENTAL DESIGN: We have generated adenovirus system for antisense to cyclin D1 (AS CyD1) and evaluated in vitro and in vivo effects. Small interfering RNA against cyclin D1 was also used to analyze cyclin D1 inhibition-associated vascular endothelial growth factor (VEGF) regulation. RESULTS: The xenografts treated with adenoviral AS CyD1 showed less vessel density and displayed smaller tumor size in colon cancer cell lines HCT116 and DLD1. In vitro studies indicated that AS CyD1 decreased VEGF protein expression in DLD1 but not in HCT116. Cyclin D1 small interfering RNA caused a decrease in VEGF expression at protein and RNA levels in DLD1. A modest decrease was noted in the VEGF promoter activity, with inactivation of the STAT3 transcription factor through dephosphorylation. On the hand, the cyclin D1 inhibition plus STAT3 inhibitor markedly decreased VEGF expression in HCT116, although VEGF did not change by the STAT3 inhibitor alone. In cultures of human umbilical vein endothelial cells (HUVEC), VEGF augmented cyclin D1 expression and cell growth. AS CyD1 significantly inhibited HUVEC growth even in the presence of VEGF. AS CyD1 also significantly suppressed in vitro tube formation in VEGF-treated HUVEC and in vivo macroaneurysm formation in VEGF-treated Matrigel plug. CONCLUSIONS: Our results suggest that cyclin D1 may play a role in the maintenance of VEGF expression and that AS CyD1 could be potentially useful for targeting both cancer cells and their microenvironment of tumor vessels.

Overexpression of MT3-MMP in hepatocellular carcinoma correlates with capsular invasion.

BACKGROUND/AIMS: Extracellular matrix-degrading matrix metalloproteinases (MMPs) are invariably up-regulated in epithelial cancers and are key agonists of angiogenesis, invasion and metastasis. Recent studies have shown high levels of various MMPs, including MT1-MMP, MMP-1, MMP-2 and MMP-9, and their involvement in tumor progression in human hepatocellular carcinoma (HCC). However, the expression and role of MT3-MMP in HCC remains unclear. METHODOLOGY: We examined the immunohistochemical expression of MT3-MMP in surgically resected HCCs (n=58), hepatitis C virus (HCV) and hepatitis B virus (HBV)-related chronic hepatitis (n=34) and cirrhosis (n=24). RESULTS: MT3-MMP expression was observed in all non-cancerous liver tissues. In HCCs, 52% (30/58) of patients showed high MT3-MMP expression while the remaining 48% (28/58) of patients showed low expression. A clinicopathological survey demonstrated a significant correlation between high MT3-MMP expression and capsular invasion of carcinoma (p = 0.034) although there was no correlation between high MT3-MMP expression in HCC and overall survival or disease-free survival. CONCLUSIONS: MT3-MMP was expressed not only in chronic hepatitis and liver cirrhosis, but also in HCC, and high MT3-MMP expression correlated significantly with capsular invasion of carcinoma.

NY-ESO-1 expression and immunogenicity in malignant and benign breast tumors.

NY-ESO-1 is a cancer/testis antigen expressed in normal adult tissues solely in the testicular germ cells of normal adults and in various cancers. It induces specific humoral and cellular immunity in patients with NY-ESO-1-expressing cancer. The aim of this study was to determine the frequency of NY-ESO-1 mRNA and protein expression in malignant and benign breast tumors. NY-ESO-1 mRNA expression was detected by conventional reverse transcription-PCR and real-time PCR, and that of the protein expression by immunohistochemistry and Western blot analysis. Expression of NY-ESO-1 mRNA was detected in 37 of 88 (42%) cancer specimens, whereas that of the NY-ESO-1 protein was detected only in 1 mRNA-positive specimen. In the latter case, expression level of NY-ESO-1 mRNA relative to that in the testis was relatively high (75% of testicular expression) and to the other among breast cancer specimens. In benign breast lesions, 21 of 31 (68%) specimens expressed low levels of NY-ESO-1 mRNA. In 1 case of fibroadenoma, NY-ESO-1 mRNA was 8% of the testicular level, and protein was detected by Western blot analysis. Only 1 breast cancer patient had detectable antibody at time of surgery, which disappeared within 2 years. Tumor specimen from this patient was both NY-ESO-1 mRNA and protein positive, and NY-ESO-1-specific CD8 T cells were detected in this patient by IFN-gamma enzyme-linked immunospot assay using NY-ESO-1 recombinant adeno and vaccinia virus. A higher rate of NY-ESO-1 expression was noted in breast cancer with high histological grade and negative hormone receptor status, suggesting NY-ESO-1 as a potential tumor antigen for immunotherapy in patients with breast cancer and poor prognosis.

Methylation and expression of p16INK4 tumor suppressor gene in primary colorectal cancer tissues.

It is known that p16(INK4) tumor suppressor gene expression in colon cancer cells is repressed by methylation at the CpG island of promoter, but in vivo silencing of p16 gene is not fully understood. Some studies showed that primary colorectal cancer (CRC) tissues often overexpress the p16 protein, while others showed the high incidence of p16 methylation. The aim of this study was to clarify p16 gene regulation in vivo. We used real-time methylation-specific PCR (MSP) to examine density of p16 methylation, and immunohistochemistry, Western blot analysis to determine p16 protein expression. Methylation was detected in 5 CRC cell lines tested and 9 of 21 (42.9%) CRCs. Four of 5 CRC cell lines did not express p16 mRNA, but 6 of 9 CRCs did express p16 mRNA even with methylation. Real-time MSP showed that CRC tissues had a wide variety in methylation density (methylation index: 0.28-0.91) and that highly methylated CRC tissues displayed significantly lower p16 mRNA expression than those with no-methylation or low-methylation. Immunohistochemistry showed that the majority of CRCs (53 of 55: 96.4%) overexpressed the p16 protein. Low p16 expression was associated with lymph node metastasis (p=0.003) and large tumor size (p=0.048). Western blot in a subset of non-tumor and tumor samples showed a consistent overexpression of the p16 protein. These results showed that CRC tissues displayed variable methylation density, which may be characteristics of p16 gene methylation in vivo. Our data suggest that a low p16 expression due to methylation may contribute to tumor enlargement and expansion of CRC.

NY-ESO-1 expression and immunogenicity in esophageal cancer.

PURPOSE: Although NY-ESO-1 was isolated from an esophageal carcinoma patient, its expression in this type of cancer and its immunogenicity in esophageal cancer patients have not yet been fully elucidated. We report here the frequency of NY-ESO-1 mRNA and protein expression in esophageal cancer and the presence of NY-ESO-1-specific immune response in patients. EXPERIMENTAL DESIGN: One hundred twenty three esophageal squamous cell carcinoma specimens were analyzed for the expression of NY-ESO-1 mRNA by conventional and real-time reverse transcription-PCR and the expression of protein by immunohistochemistry and Western blot. Sera and peripheral blood lymphocytes from 51 patients were analyzed for the NY-ESO-1 antibody production by enzyme-linked immunosorbent assay and NY-ESO-1 T cell response by enzyme-linked immunospot assay. Survival analyses were also performed. RESULTS: NY-ESO-1 mRNA was expressed in 41 of 123 (33%) esophageal squamous cell carcinoma specimens, and its expression was found at higher frequency in well-differentiated and moderately differentiated type of cancer. No mRNA copy was detected in any of the adjacent normal tissues. Twenty-one of 24 (87.5%) NY-ESO-1 mRNA-positive tumors were stained positively by immunohistochemistry. Correlation between the level of NY-ESO-1 mRNA expression and the degree of immunohistochemistry positivity was observed. Antibody production was observed in 2 patients with tumors that showed protein expression. Furthermore, a CD8 T-cell response against NY-ESO-1 was observed in 1 of the 2 seropositive patients. CONCLUSIONS: The high expression frequency of NY-ESO-1 mRNA and protein indicates NY-ESO-1 as a feasible vaccine target in esophageal cancer.

Quantitative molecular diagnosis of peritoneal lavage fluid for prediction of peritoneal recurrence in gastric cancer.

We developed a quantitative multiple-marker RT-PCR assay for sensitive detection of free cancer cells in the peritoneal cavity and examined the significance of this molecular diagnostic technique for detection and prediction of peritoneal dissemination in patients with gastric cancer. Preoperative peritoneal lavage fluid samples obtained from 129 patients with gastric cancer were subjected to RT-PCR assay with primers specific for carcinoembryonic antigen (CEA) and cytokeratin-20 (CK-20), and conventional cytological examination with Papanicolaou staining. The multi-marker RT-PCR assay was positive in 59 of 129 (46%) gastric cancer patients, whereas conventional cytology was positive in only 9 of 129 (7%) patients. Thirty-two of 129 (22%) patients suffered disease recurrence after surgery. Twenty-one of these patients were confirmed to have had peritoneal recurrence. Although conventional cytology was positive on peritoneal washes in only 9 patients, the RT-PCR assay was positive in 20 of these 21 patients. Furthermore, in cases with negative cytology, patients with PCR-positive findings in peritoneal lavage fluid had a significantly poorer prognosis than those with negative PCR, mainly because of peritoneal recurrence. Our results suggest that the multiplex RT-PCR assay for CEA and CK-20 was highly sensitive for detection and might be useful for prediction of peritoneal dissemination in gastric cancer.

Real-time rapid reverse transcriptase-polymerase chain reaction for intraoperative diagnosis of lymph node micrometastasis: clinical application for cervical lymph node dissection in esophageal cancers.

BACKGROUND: New molecular techniques have been designed to detect cancer micrometastases that are otherwise missed by conventional histologic examination. The aim of this study was to establish a sensitive and rapid genetic assay to detect lymph node micrometastasis and to assess its usefulness clinically for cervical lymphadenectomy in esophageal cancer. We have recently shown that metastasis in the lymph node chain along the recurrent laryngeal nerves (rec LNs) is a predictor of cervical node metastasis in esophageal cancer. In our retrospective study, the positive rate of cervical lymph node metastasis with rec LNs metastasis was 51.6%, and the rate without rec LNs metastasis was 11.6%. There was a significant difference in both positive rates (P =.0002). METHODS: Rec LNs obtained from 50 patients with esophageal cancer were assessed prospectively by intraoperative histopathologic examination (HE) and genetic analysis. The latter involved a real-time quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) system with multiple markers, carcinoembryonic antigen, squamous cell carcinoma, and melanoma antigen-3, whose messenger RNAs are highly and frequently expressed in esophageal cancers. Cervical lymphadenectomy was subsequently performed in a subset of these patients. RESULTS: Ten of 50 patients (20%) were scored as node positive by HE, and 24 patients (48%) were scored positive by genetic diagnosis, including 9 HE-positive cases. Genetic diagnosis of rec LNs accurately predicted all 9 cases with cervical lymph node metastasis and 2 cases with cervical lymph node recurrence, whereas HE missed 2 cases with cervical lymph node metastasis and 2 cases with cervical lymph node recurrence. CONCLUSIONS: Our real-time rapid RT-PCR assay can improve the sensitivity of HE for detection of lymph node metastasis and might be potentially useful for intraoperative genetic diagnosis for subsequent cervical lymphadenectomy in esophageal cancer surgery.

Assessment of stanniocalcin-1 as a prognostic marker in human esophageal squamous cell carcinoma.

Stanniocalcin-1 (STC1) is a secreted glycoprotein hormone and highly expressed in various types of human malignancies. Although evidence points to the role of STC1 in human cancers, the clinical significance of STC1 expression in esophageal cancer has not been well established. Quantitative reverse transcriptase-polymerase chain reaction and immunohistochemistry were performed to assess the expression of STC1 in the cancer cell line TE8 and esophageal cancer tissues from 229 esophageal squamous cell carcinomas (ESCC). Surgically-resected tissue sections were immunostained for potential regulators of STC1 expression, hypoxia-inducible factor-1α (HIF-1α) and p53. Marked increase in STC1 mRNA and protein expression was noted in TE8 cells cultured under hypoxic conditions. Overexpression of STC1 mRNA was noted in ESCC tumors compared to normal counterparts. Positive immunohistochemical staining for STC1 protein was observed in 38.9% of patients, and correlated significantly with advanced pT status (p=0.019), poor prognosis [overall survival (p<0.0006) and disease-free survival (p<0.0002) of ESCC patients who had undergone curative surgery]. Positive staining for HIF-1α and p53 proteins in ESCC did not correlate with STC1 expression. The results showed marked induction of STC1 expression under hypoxia in cultured cells and in esophageal cancer cells and that overexpression of STC1 was an independent prognostic factor in patients with esophageal cancer who had undergone curative surgery. STC1 is a potentially useful biomarker for ESCC treatment.

Parthenolide, an NF-κB inhibitor, suppresses tumor growth and enhances response to chemotherapy in gastric cancer.

AIM: This study evaluated the sesquiterpene lactone parthenolide, an inhibitor of transcription factor nuclear factor-kappaB (NF-κB), in the treatment of gastric cancer in vitro and in vivo. MATERIALS AND METHODS: In vitro, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was performed to evaluate the effect of parthenolide on growth inhibition and chemosensitization to antitumor drugs of three gastric cancer cell lines (MKN-28, MKN-45 and MKN-74). Microarray analysis was performed to identify genes which were up- or down-regulated on the treatment of parthenolide. The isobologram analysis was introduced to evaluate the synergic effect of parthenolide on antitumor drugs. In vivo, the effect of parthenolide was investigated in a mouse peritoneal dissemination model with and without chemotherapy. RESULTS: Parthenolide significantly inhibited cell growth in three gastric cancer cell lines. The phosphorylation of NF-κB was down-regulated by the treatment of parthenolide. The synergic effect of parthenolide was confirmed in combination with paclitaxel and cisplatin. In the peritoneal dissemination model, parthenolide significantly suppressed the disseminated nodules as a single agent and also enhanced chemosensitivity to paclitaxel. Furthermore, the combined therapy of parthenolide and paclitaxel significantly contributed to prolonging the survival duration. CONCLUSION: The NF-κB inhibitor, parthenolide, may enhance chemosensitivity to paclitaxel in the treatment of patients with gastric cancer.

Gene therapy using ets-1 transcription factor decoy for peritoneal dissemination of gastric cancer.

The ets-1 transcription factor plays an important role in cell proliferation, differentiation, apoptosis and tissue remodeling. Aberrant ets-1 expression correlates with aggressive tumor behavior and poorer prognosis in patients with various malignancies. This study evaluated the efficacy of double-stranded decoy oligonucleotides targeting ets-1-binding cis elements for the suppression of ets-1 in treatment of a peritoneal dissemination model of gastric cancer. In vitro, MTT assay was performed to evaluate the effect of the ets-1 decoy on cell growth. Electrophoretic mobility shift assay (EMSA) was performed to determine ets-1 activity. In vivo, the effect of the ets-1 decoy was investigated in the peritoneal dissemination nude mice model. Disseminated nodules were analyzed immunohistochemically. Ets-1 decoy, but not scrambled decoy, significantly inhibited cell growth in 2 gastric cancer cell lines, which showed overexpression of ets-1 protein by inhibiting the binding activity of ets-1. In the peritoneal dissemination model, the ets-1 decoy significantly suppressed the disseminated nodules, and tended to prolong the survival rate. PCNA index, microvessel density and VEGF expression were also reduced in peritoneal tumors treated with ets-1 decoy. Intraperitoneal injection of ets-1 decoy inhibited peritoneal dissemination of gastric cancer in a nude mice model. The results indicate that the decoy strategy for ets-1 offers a promising therapy for patients with incurable peritoneal dissemination of gastric cancer, most of which show overexpression of ets-1 protein.

A prospective trial for avoiding cervical lymph node dissection for thoracic esophageal cancers, based on intra-operative genetic diagnosis of micrometastasis in recurrent laryngeal nerve chain nodes.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate the usefulness of intra-operative genetic diagnosis of RN node micrometastasis in the decision-making of 3FL for thoracic esophageal cancers. METHODS: Eighty-nine patients with middle and lower thoracic esophageal cancer were enrolled in a prospective study, in which 3FL was performed when RN node metastasis was revealed by intra-operative histological examination and/or genetic analysis using real-time RT-PCR assay. For other cases, 2FL was performed. RESULTS: Of the 89 patients, 3FL was performed for 33 patients and 2FL for 56 patients. In the 3FL group, RN node metastasis was both histologically and genetically positive in 19 patients, histologically negative and genetically positive in 11, and histologically positive and genetically negative in 3, with cervical node metastasis being detected in 7, 3, and 0 patients, respectively. In the 2FL group, only one patient had cervical node recurrence during the follow-up period. The post-operative survival in this study was equivalent to that of the historical controls (3-year survival rates 63.9% vs. 52.3%, P = 0.1513) of 66 3FL patients when 3FL was the first choice for thoracic esophageal cancers. CONCLUSIONS: Intra-operative histological and genetic diagnosis of RN node metastasis may help avoid unnecessary cervical node resection. A Phase III trial should be done.

Overexpression of beta 1,4N-acetylgalactosaminyl- transferase mRNA as a molecular marker for various types of cancers.

OBJECTIVE: To determine GalNAcT mRNA expression in human carcinoma cell lines and primary tumor tissues. Assessment of the potential use of GalNAcT mRNA as a molecular marker for detection of metastatic cancer cells in the peripheral blood of patients with hepatocellular carcinoma. METHODS/RESULTS: We investigated GalNAcT mRNA expression in various human cancer cell lines and primary cancer tissues using RT-PCR assay for GalNAcT mRNA. The expression of GalNAcT mRNA was detected in 25 of 26 cancer cell lines tested and in the majority of primary tumors from different organs: 8 of 10 colon cancers, 9 of 9 breast cancers, 11 of 12 esophageal cancers, 14 of 14 gastric cancers, 4 of 18 pancreatic cancers, 6 of 12 biliary tract cancers, 17 of 18 hepatocellular carcinomas and 13 of 14 lung cancers. Semi-quantitative analysis with duplex RT-PCR showed that the amount of the GalNAcT mRNA was enhanced in cancer tissues as compared to the surrounding cancer-free tissues. Blood specimens of 5 of 14 patients with hepatocellular carcinoma were positive for GalNAcT mRNA, all of whom developed recurrent disease in less than 24 months. Peripheral blood samples of 30 normal subjects were negative for GalNAcT mRNA. CONCLUSION: Our results suggest that the RT-PCR assay for GalNAcT mRNA could be a potentially useful molecular marker for detecting cancer dissemination in blood circulation of patients with malignancy.

Application of molecular diagnosis for detection of peritoneal micrometastasis and evaluation of preoperative chemotherapy in advanced gastric carcinoma.

BACKGROUND: In advanced gastric cancer, peritoneal recurrence is the main cause of death after curative surgical resection. The aim of this report was to describe a novel approach for quantitative genetic diagnosis using peritoneal lavage for the identification of patients at high risk for peritoneal recurrence and for evaluation of the clinical response to intraperitoneal chemotherapy in advanced gastric cancer. METHODS: Nineteen patients with advanced gastric cancer who underwent staging laparoscopy and intraperitoneal chemotherapy before surgical resection or systemic chemotherapy between June 1999 and September 2001 were enrolled in this study. All peritoneal lavage specimens, collected at both staging laparoscopy and gastrectomy, were subjected to real-time quantitative genetic diagnosis. RESULTS: The reverse transcriptase polymerase chain reaction (RT-PCR) values decreased in 8 cases, stabilized as negative in 5, and increased in 6 during therapy. Patients whose RT-PCR values diminished and were ultimately negative survived except for one, and all but one patient whose values increased during treatment died of recurrence. CONCLUSIONS: Quantitative evaluation of genetic changes can provide accurate, useful information on the effects of preoperative intra-abdominal chemotherapy and overall prognosis for patients with advanced gastric cancer.

JTE-522, a cyclooxygenase-2 inhibitor, is an effective chemopreventive agent against rat experimental liver fibrosis1.

BACKGROUND & AIMS: The aim of this study was to assess the effects of cyclooxygenase (COX)-2 inhibition on rat experimental liver fibrogenesis. METHODS: We investigated the inhibitory effects of a selective COX-2 inhibitor, JTE-522, on liver fibrosis induced by a choline-deficient, l-amino acid-defined diet (CDAA). Inhibitory effect was also tested in a second model of thioacetamide (TAA)-induced liver fibrosis. RESULTS: CDAA induced liver fibrosis and preneoplastic foci at 12 weeks and cirrhosis at 36 weeks. Hepatocellular carcinoma was noted in 13 of 15 rats (87%). JTE-522 significantly inhibited fibrosis and development of preneoplastic lesions in a dose-dependent manner and completely inhibited generation of cirrhosis and hepatocellular carcinoma at both low and high doses (10 and 30 mg/kg body wt/day, respectively). JTE-522 administrated only from 12 weeks to 36 weeks also prevented cirrhosis and formation of hepatocellular carcinoma. JTE-522 itself did not cause local or systemic gross or histopathologic changes at 36 weeks. Mechanistic studies indicated that the CDAA model displayed up-regulation of several biomarkers, including COX-2, arachidonate metabolite (prostaglandin E(2)), serum aspartate aminotransferase, and c-myc expression. The model also showed an increased proportion of activated hepatic stellate cells, proliferating cell nuclear antigen index, and CD45-positive inflammatory cells in the liver. JTE-522 effectively diminished these changes. JTE-522 exhibited similar antifibrosis effects in the TAA model. CONCLUSIONS: Our results suggest that COX-2 is involved in CDAA- and TAA-induced liver fibrosis. Our data also indicate that JTE-522 is a potent chemopreventive agent of rat liver fibrosis with low toxicity.

Hepatic expression of ANG2 RNA in metastatic colorectal cancer.

We examined the RNA content of the gene encoding angiopoietin (Ang)-2, a modifier of angiogenesis, in hepatic metastases of colorectal cancer (CRC) to explore the role of this protein in neovascularization of metastatic foci. Metastatic CRC exhibited notable blood flow and tumor vessel formation at tumor frontiers. Reverse-transcription polymerase chain reaction assays indicated that the ANG2 RNA content was greater in metastatic CRC than in primary CRC. Investigation of metastatic foci using laser capture microdissection revealed that the RNA content of ANG2, but not ANG1, increased from the bordering liver region to the periphery of the metastatic disease, and also from the periphery to the intermediate portion of the metastatic lesion; immunohistochemical analysis confirmed that there was a corresponding gradual increase in Ang-2 protein expression. Tie-2, a receptor for angiopoietins, was preferentially expressed in the bordering liver region rather than in metastatic CRC. Vascular endothelial growth factor (VEGF) also exhibited an expression pattern similar to that of Ang-2, and there was a significant correlation between the RNA content of ANG2 and that of VEGF in dissected samples (P =.002). Western blot analysis suggested that expression of Ang-1, Ang-2, Tie-2, and VEGF may be regulated at a transcriptional level. The increase in ANG2 RNA content from the peripheral portion of the tumor to the intermediate portion, coinciding with the decrease in recruitment of periendothelial supporting cells around the vascular endothelial cells, suggests that Ang-2 may play a role in the immaturity of tumor vessels. In conclusion, the current study suggests that Ang-2 and VEGF may cooperate to enhance the formation of new blood vessels in metastases of CRC to the liver.