Immunohistochemical study of nuclear factor-κB expression in esophageal squamous cell carcinoma: prognostic significance and sensitivity to treatment with 5-FU.

Nuclear factor-κB (NF-κB) is expressed in many types of cancers. It has been suggested that the expression of NF-κB is associated with poor prognosis and resistance to chemoradiation therapies. This study evaluated the relationship between the expression of NF-κB and the prognosis and sensitivity of esophageal squamous cell carcinoma (ESCC) to chemotherapy. One hundred and nine ESCC specimens, from patients who had undergone radical esophagectomy, were divided into two groups depending on the expression of NF-κB. Surgical data and prognosis were compared between the two groups. NF-κB-positive tumors were detected in 61.5% of the cases. In 69 patients with stage II and III disease, 41 patients who were NF-κB-positive showed poor survival. The sensitivity of esophageal squamous cell carcinoma cell lines to 5-fluorouracil (5-FU) was analyzed by their NF-κB expression, and the effect of 5-FU was evaluated on the proliferation and activity of two cell lines of cultured ESCCs expressing NF-κB. ESCCs with activated NF-κB had poor sensitivity to 5-FU. These results suggest that the increased expression of NF-κB is associated with poor prognosis in patients with ESCC. NF-κB may be a target for ESCC therapy because of its selective expression in this type of cancer.

Inverse correlation between NKG2D expression on CD8+ T cells and the frequency of CD4+CD25+ regulatory T cells in patients with esophageal cancer.

Although malignant diseases are known to be associated with immune suppression, detailed mechanisms of this phenomenon are still unknown. NKG2D is an activating cell surface receptor expressed by natural killer (NK) cells and CD8+ T cells, and it has been reported that NKG2D engagement is extremely important for T cell activation. In the current study, NKG2D expression on CD8+ T cells and the frequency of CD4+ CD25+ regulatory T (Treg) cells were determined by multicolor flow cytometry to investigate one of the mechanisms responsible for immune evasion in esophageal cancer patients. NKG2D expression on CD8+ T lymphocytes in esophageal cancer patients was significantly lower than in those of normal controls. NKG2D expression in T3/T4 esophageal cancer was significantly lower than that in T1/T2 esophageal cancer. CD8+ T cells from patients with lymph node metastasis expressed significantly lower NKG2D than those without lymph node metastasis. Moreover, significantly lower NKG2D expression was observed in stage III/IV cancer in comparison with stage I/II. The frequency of CD4+CD25+ Treg cells in esophageal cancer patients was significantly higher than those in normal controls. NKG2D expression on CD8+ T cells was significantly inversely correlated with the frequency of CD4+CD25+ Treg cells in esophageal cancer patients. Our data indicates that decreased NKG2D expression on CD8+ T cells is correlated with disease severity. Decreased NKG2D expression and an increase in Treg cells may be one of the key mechanisms responsible for immune evasion in esophageal cancer.

The gene expression level of transforming growth factor-beta (TGF-beta) as a biological prognostic marker of hepatocellular carcinoma.

The question that transforming growth factor-beta (TGF-beta) provides a tumor-suppressive or a tumor promoting role is still unknown in hepatocellular carcinoma (HCC). In the present study, we quantitatively investigated the gene expression levels of TGF-beta in liver tissues from patients with HCC. We also evaluated the prognostic importance of TGF-beta gene in HCC patients. A total of 59 patients with primary HCC who underwent hepatectomy between 1993 and 2001 were enrolled. TGF-beta gene expression levels of tumors and of noncancerous livers were analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The percentage of apoptotic cells in tumor cells (apoptotic index: AI) was evaluated with immunohistochemistry. Also the expression of survivin protein (apoptosis inhibitor) in tumors was detected by immunohistochemistry. TGF-beta gene expression levels of tumors were compared with clinicopathological findings of patients. The relative expression level of TGF-beta mRNA of 59 tumor tissues did not differ from those of 8 normal liver tissues or 59 noncancerous liver tissues. The mean AI of 29 tumors with normal expression levels of TGF-beta gene (4%) was significantly higher than that of 30 tumors with low expression levels of TGF-beta gene (2.5%, p = 0.03). Thirteen out of 30 tumors (43%) with low expression level of TGF-P gene showed survivin positive, while only 4 out of 29 tumors (14%) with preserved expression of TGF-beta gene showed survivin positive. This difference was significant (p = 0.012). The overall 5-year survival rate of 29 patients with tumors with preserved TGF-beta gene prolonged to 72% compared with that of 30 patients who had tumors with suppressed TGF-beta gene (58%, p = 0.156). In HCC, TGF-beta gene may play a defensive role against tumor progression by regulating survivin protein expression and by controlling occurrence of spontaneous apoptosis in tumors.

CD8+ lymphocyte infiltration and apoptosis in hepatocellular carcinoma.

AIMS: Tumour-infiltrating lymphocytes (TILs) play a role in local anti-tumour immunity. Tumour cells may escape from immune surveillance by expressing RCAS1, a receptor-binding cancer antigen expressed on SiSo cells, which inhibits T cell growth. In this study, the correlation between the density of CD8+ TILs, tumour cell apoptosis, and tumour RCAS1 expression was investigated in hepatocellular carcinoma (HCC). METHODS: We obtained tissues from 60 patients with surgically resected HCCs. CD8+ TILS, apoptotic cancer cells, and RCAS1 expressing cancer cells were identified by immunohistochemistry. RESULTS: The density of CD8+ T cells in tumours (mean: 9.5/HPF, HPF: high power field) was significantly less than in non-cancerous hepatic lobules (17.8/HPF, p<0.001) and in relation to the progression of tumour stage. The density of CD8+ T cells in tumours positively correlated with the occurrence of tumour cell apoptosis, but did not correlate with RCAS1 protein expression. CONCLUSIONS: CD8+ TILs may play a role in the occurrence of tumour cell apoptosis in HCC, but CD8+ TILs may not be controlled by RCAS1 in HCC.

Heparanase gene expression and its correlation with spontaneous apoptosis in hepatocytes of cirrhotic liver and carcinoma.

Heparanase (hep) degrades heparan sulphate proteoglycans (HSPGs), which are the main components of the extracellular matrix. This process has been considered as the first step of tumour invasion or metastasis. However, HSPGs play an important role in signal transduction. Thus, the degradation of HSPGs by hep may suppress tumour cell growth. In the present study, we investigated the clinicopathological importance of enhanced hep mRNA expression in 48 hepatocellular carcinomas (HCCs) and in 48 non-cancerous liver samples obtained from the same patients by quantitative real-time reverse transcriptase polymerase chain reaction (RT-PCR). Spontaneous apoptosis in the hepatocytes was evaluated by immunohistochemistry. The relative hep mRNA expression levels were described as hep/glyceraldehyde-3-phosphate dehydrogenase (GAPDH) ratios. The hep mRNA levels of HCCs were significantly lower than those of non-cancerous livers (P<0.001). Hep mRNA levels decreased with increasing liver fibrosis. A significant positive correlation between hep gene expression and spontaneous apoptosis was detected. Hep expression in the tumours did not correlate with tumour differentiation or with tumour stage. However, low hep gene expression was associated with a poor disease-free survival of the patients. Thus, hep gene expression may play an important role in programmed cell death and this gene expression may be lost during the malignant transformation of hepatocytes.

survivin messenger RNA expression is a good prognostic biomarker for oesophageal carcinoma.

Oesophageal squamous cell carcinoma is one of the most malignant tumours. To identify patients with a high risk of recurrence of oesophageal squamous cell carcinoma, we investigated the prognostic significance of survivin mRNA expression in oesophageal squamous cell carcinoma, which has recently been reported to be a good marker for unfavourable prognosis in various tumours. Tumours and non-cancerous epitheliums adjacent to tumours were obtained by surgical resection from 57 patients with oesophageal squamous cell carcinoma. Expression levels of survivin and glyceraldehyde-3-phosphate dehydrogenase mRNA were analysed quantitatively by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The survivin/glyceraldehyde-3-phosphate dehydrogenase ratios of tumours were higher than those of non-cancerous tissues (P=0.0003). Tumour-survivin/glyceraldehyde-3-phosphate dehydrogenase ratio did not correlate with histologic type, lymph node metastasis, and stage of tumours. In 53 surviving patients, the 5-year survival rate of 17 patients with high survivin mRNA expressed oesophageal squamous cell carcinoma (14.1%) was significantly poorer than that of 36 with low survivin mRNA expressed oesophageal squamous cell carcinoma (46.8%, P=0.0018). In these patients, tumour-survivin mRNA expression was recognised as a good marker of cancer recurrence independently from tumour stage. These findings indicate that survivin mRNA expression in oesophageal squamous cell carcinoma may be a good biomarker for identifying patients with high risk of cancer recurrence.

Re-expression of the cadherin-catenin complex in lymph nodes with metastasis in advanced gastric cancer: the relationship with patient survival.

The cadherin-catenin complex has been recognized as an important factor associated with tumor metastasis. However, the clinical significance of the expression of adhesion molecules in lymph nodes with metastasis remains unclear. The aim of this study was to investigate the clinical significance of the re-expression of the cadherin-catenin complex in metastatic lymph nodes in patients with advanced gastric cancer. Immunohistochemical expression of E-cadherin, alpha- and beta-catenin were analyzed in 96 primary gastric cancers with serosal invasion and in 79 lymph nodes with metastasis. The expression levels of these adhesion molecules in primary tumors and lymph nodes with metastasis were compared. Ninety-four out of 96 primary tumors (98%) showed reduced expression of adhesion molecules. Out of 79 cases with lymph node metastasis, increased expression of one or more adhesion molecules in metastatic foci as compared with primary tumors was detected in 52 cases (66%). Re-expression of adhesion molecules in metastatic lymph nodes was detected in a more advanced stage. The overall 5-year survival rate of the 52 patients who had lymph nodes with metastasis with re-expression of adhesion molecules (8%) was significantly poorer than that of the 27 who had lymph nodes with metastasis without re-expression of adhesion molecules (33%, P = 0.0012). The re-expression of the cadherin-catenin complex in lymph nodes with metastasis may play an important role in the growth of cancer cells in metastatic foci. A comparison of the expression patterns of adhesion molecules between the primary tumor and metastatic lymph nodes may provide new prognostic information for patients with advanced gastric cancer.

Correlation between cathepsin D expression and p53 protein nuclear accumulation in oesophageal squamous cell carcinoma.

AIM: The lysosomal protease cathepsin D has been reported to be associated with tumour progression in malignant tumours. Expression of the gene encoding cathepsin D is known to be stimulated by oestrogen in mammary cancer cells. Recent experiments revealed that a p53 DNA binding site is located in the promoter region of the cathepsin D gene. This fact indicates that cathepsin D expression may correlate with p53 protein expression. The purpose of this study is to evaluate the expression patterns of the cathepsin D and p53 proteins in oesophageal squamous cell carcinoma (SCC). METHODS: In 154 patients with oesophageal SCC, expression of the cathepsin D and p53 proteins was measured in tumours by means of immunohistochemistry using monoclonal antibodies against cathepsin D (clone, 1C11) and p53 (clone, BP53-12). RESULTS: Cathepsin D was detected in tumour cells, although it was not found in normal oesophageal epithelium adjacent to carcinoma. High cathepsin D expression (positive tumour cells > 10%) was detected in 76 of 154 cases (49%) and high p53 nuclear expression (positive tumour cells > 50%) was detected in 70 cases (46%). High cathepsin D expression was significantly associated with invasive tumour growth (p = 0.002), poor prognosis (p = 0.049), and nuclear accumulation of p53 protein (p = 0.001). Overexpression of both p53 and cathepsin D was seen in 45 of the 154 cases (29.2%). In addition, there was a positive correlation between the cathepsin D index (percentage of cathepsin D positive tumour cells) and Ki-67 labelling index (percentage of Ki-67 positive tumour cells) in 154 oesophageal SCCs (rho = 0.257; p = 0.009). However, in multivariate survival analysis, cathepsin D expression by the tumours was not an independent prognostic factor in patients with oesophageal SCC (p = 0.236). CONCLUSIONS: The expression of cathepsin D by cancer cells may play an important role in the invasive growth of oesophageal SCC. Overexpression of both p53 and cathepsin D was seen frequently in tumours; p53 gene abnormalities may correlate with cathepsin D overexpression in oesophageal SCC.

Expression of survivin mRNA and protein in gastric cancer cell line (MKN-45) during cisplatin treatment.

Survivin is a member of the inhibitor of apoptosis protein (IAP) family. Survivin has been reported to be expressed in many cancers, but not in differentiated normal tissue. Recent studies revealed that survivin correlated with the chemo-resitance of cancer cells. In the present study, the changes in expression levels of survivin messenger RNA (mRNA) and survivin protein in a gastric cancer cell line (MKN-45) during cisplatin (CDDP) treatment were analyzed and compared with the occurrence of apoptotic cell death. Cell growth was inhibited even with a low dose CDDP (0.1 or 1 microg/ml) 1 hr treatment. However, the percentage of apoptotic cells did not change after 48 hr incubation with low dose CDDP. Only with high dose CDDP (10 microg/ml), did the percentage of apoptotic cells explosively increase between 12 and 24 hr treatment. Relative expression levels of survivin mRNA and survivin protein increased after CDDP treatment. The cell expression rates of survivin mRNA after 48 hr treatment with 0.1 and 1 microg/ml of CDDP were 2 to 6 fold higher than that of the survivin mRNA of untreated cells. Also, the relative cell expression level of survivin protein after 24 hr treatment with 0.1 or 1 microg/ml of CDDP was 3 to 6.5 fold higher than that of the survivin protein of untreated cells. These results indicate that survivin expression may correlate with the chemo-resistance of malignant cells.

Significant correlation between micrometastasis in the lymph nodes and reduced expression of E-cadherin in early gastric cancer.

BACKGROUND: E-cadherin has been recognized as an important factor associated with tumor metastasis. However, the relationship between micrometastasis in the lymph nodes and the expression of E-cadherin in the primary tumor in gastric cancer remains unclear. METHODS: Two consecutive sections of 4522 lymph nodes from 162 patients with early gastric cancer were prepared for simultaneous hematoxylin and eosin (H&E) and cytokeratin (CK) staining. Sections of primary tumors from 135 of these patients were prepared for E-cadherin immunostaining. RESULTS: The incidence of lymph node involvement was significantly increased, from 6.8% (11/162 patients) by H&E staining, to 27% (43/162 patients) by CK immunostaining (P < 0.0001). Micrometastasis in the lymph node was found in 32 of 151 (21%) patients who had no lymph node metastasis evidenced by H&E staining. Micro-lymph node metastasis was frequently found in tumors with a diameter more than 1.0 cm, of those that were poorly differentiated, deeply invaded, showed lymphatic on vascular invasion, and in those that showed reduced expression of E-cadherin. Loss of expression of E-cadherin in the primary tumor was closely correlated with micro-lymph node metastasis. Patients with tumors with micro-lymph node metastasis detected by CK immunostaining had a significantly lower 5-year survival rate (P < 0.01) than those without such metastases. CONCLUSION: Tumors more than 1.0 cm in diameter and those that exhibit poor differentiation, deep invasion (i.e., to the submucosa), lymphatic or vascular invasion, and reduced expression of E-cadherin are risk factors for lymph node metastasis in early gastric cancer. Thus, it is recommended that cancers confined to the mucosa (m-cancers) that are more than 1.0 cm in diameter should not be treated with limited surgery without lymphadenectomy.

[Immunohistochemical study of dihydropyrimidine dehydrogenase (DPD) and p53 in biopsied specimens of esophageal cancer before chemoradiotherapy].

We studied whether the immunohistochemical status of dihydropyrimidine dehydrogenase (DPD) and p53 can be used to predict the sensitivity to chemoradiotherapy (CRT) in patients with esophageal cancer. In 19 patients who did not undergo preoperative CRT, the immunoreactivity of DPD and p53 in biopsied specimens correlated well with those in surgically resected specimens (DPD: 100%, p53: 73%). Fifteen patients were treated with 5-FU (250-300 mg/body/day: day 1-5, 8-12), low-dose cisplatin (10 mg/body/day: day 1, 8) and radiotherapy (30-40 Gy). The response rate (CR + PR) for CRT in these patients was 40%. All tumors that showed CR or PR demonstrated low expression of DPD. However, all tumors with high DPD expression showed MR or NC. However, the expression of p53 did not correlate with the response rate for CRT. Therefore, the effect of CRT for esophageal cancer may be predicted by immunohistochemical examination of DPD in biopsied tumor specimens.

Thymidine phosphorylase activity in liver tissue and its correlation with multifocal occurrence of hepatocellular carcinomas.

BACKGROUND: In hepatocellular carcinoma (HCC), new tumors develop in the residual liver within a few years after hepatectomy. However, the biological risk factors of multifocal occurrence of cancers remains unclear. In this study, the thymidine phosphorylase (TP) activity, which is known as an angiogenic factor, of cancerous and non-cancerous liver tissues in HCC was analyzed to determine its suitability as a biological marker of the multifocal occurrence of HCCs. MATERIALS AND METHODS: Fresh tissues (tumor: HCC and adjacent liver tissue: N-HCC) from 63 patients with HCC and normal liver tissues (NL) from 6 patients without HCC were obtained. The TP activities of the tissues were analyzed by an enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean TP activity of 63 HCCs (136 U/mg protein) was higher than that of 63 N-HCCs (81 U/mg protein) and that of 6 NLs (47 U/mg protein, p < 0.001). Multifocal occurrence of HCCs were detected in 17 patients. In these 17 patients, the mean TP activity of HCCs (145 U/mg protein) was not different from that of HCCs from the remaining 46 patients (133 U/mg protein, p = 0.272), however the mean TP activity of N-HCCs (110 U/mg protein) was significantly higher than that of N-HCCs from the remaining 46 patients (71 U/mg protein, p = 0.038). Moreover, only a high TP activity of N-HCCs was detected as a significant risk factor of multifocal occurrence of HCCs. CONCLUSION: Patients who have tumors with high TP activity in the non-cancerous livers may have a risk of multifocal occurrence of HCCs in the residual liver.

Changes in survivin messenger RNA level during cisplatin treatment in gastric cancer.

Survivin is a member of the inhibitor of apoptosis protein (IAP) family. The expression of survivin has not been reported in differentiated normal tissues, but it has been observed in many cancerous tissues. Recent studies have revealed that survivin may correlate with the chemo-radio resistance of certain malignant cells. In the present study, the correlation between the occurrence of apoptosis and the level of expression of survivin messenger RNA (mRNA) was investigated in a gastric cancer cell line (MKN-45) and in patients with advanced gastric cancer during cisplatin (CDDP) treatment. In the gastric cancer cell line, the percentage of apoptotic cells (apoptotic index: AI) did not change after 48 h incubation with low-dose CDDP (1 microg/ml), whereas the AI explosively increased between 12 and 24 h treatment with high-dose CDDP (10 microg/ml). Relative levels of expression of survivin mRNA and survivin protein increased after low- and high-dose CDDP treatment. Survivin mRNA was not detected in normal gastric mucosas. Also, in 13 patients with advanced gastric cancer who underwent CDDP-based preoperative chemotherapy, survivin mRNA was detected in only 2 cases (15.4%). Survivin mRNA was observed in the resected tumor specimens of two cases. No significant correlation between survivin mRNA expression and the occurrence of apoptosis in resected tumors or between survivin mRNA expression and patient survival was observed. These findings indicate that survivin may play an important role for the chemoresistance of this cancer cell line. However, the clinical importance of survivin expression remains unclear in patients with gastric cancer.

The expression of thymidine phosphorylase suppresses spontaneous apoptosis of cancer cells in esophageal squamous cell carcinoma.

OBJECTIVE: Thymidine phosphorylase (TP) is an enzyme which converts thymidine to thymine. TP is expressed in a variety of human carcinomas and is known to be a potent angiogenic factor. A recent in vitro study indicated that TP is involved in the intracellular apoptotic signal transduction pathway. The aim of this study was to investigate the correlations between the expression of TP, microvessel density (MVD) and the occurrence of spontaneous apoptosis in esophageal squamous cell carcinoma (ESCC). METHODS: The expression of TP, intratumoral MVDs and percentages of apoptotic cancer cells, expressed by the apoptotic index (AI), of 155 tumors from 155 patients with ESCC were analyzed by immunohistochemistry and compared. RESULTS: Positive TP expression in cancer and stromal cells was detected in 89 (57.4%) and 104 (67.1%) cases, respectively. The mean MVD and mean AI of the 155 tumors were 288/mm(2) (range: 36-668/mm(2)) and 2.1% (range: 0-20.4%). The mean MVD of 104 tumors with TP-positive stromal cells (336/mm(2)) was higher than that of 51 tumors with TP-negative stromal cells (188/mm(2), p < 0.001). However, the mean MVD of 89 tumors with TP-positive cancer cells (293/mm(2)) did not differ from that of 66 tumors with TP-negative cancer cells (280/mm(2), p = 0.509). On the other hand, the mean AI of 89 tumors with TP-positive cancer cells (1.2%) was lower than that of 66 tumors with TP-negative cancer cells (3.4%, p < 0.001). However, the mean AI of 104 tumors with TP-positive stromal cells (1.9%) did not differ from that of 51 tumors with TP-negative stromal cells (2.6%, p = 0.058). No significant correlation between the MVDs and the AIs was observed (rho = -0.067, p = 0.409). CONCLUSION: In ESCC, TP may play an important role in tumor progression by increasing microvessels and suppressing apoptosis of cancer cells.

Prognostic factors in patients with advanced gastric cancer treated by noncurative resection: a multivariate analysis.

BACKGROUND/AIMS: The relationship between prognostic factors and survival time after noncurative gastric resection in patients with advanced gastric cancer was examined by a retrospective review of data on 364 patients. METHODOLOGY: There were 168 patients without metastasis to the liver or peritoneum (group A), 127 with peritoneal metastasis and no liver metastasis (group B), 50 with liver metastasis and no peritoneal metastasis (group C) and 19 with synchronous liver and peritoneal metastases (group D). Patients were primarily treated with the following 3 drugs: the fluorinated pyrimidines, cisplatin, and mitomycin C. RESULTS: Patients in group D had a very poor prognosis as compared with the other groups. Multivariate analysis using the Cox's proportional hazard model adjusted for sex, age, and other covariants indicated that lymph node metastasis, lymph node dissection, and fluorinated pyrimidines for group A, cisplatin for group B, and lymph node dissection for group C were independent prognostic factors. An analysis of patients excluding cases who died within 30 days after surgery revealed that lymph node dissection for group A, lymph node dissection and cisplatin for group B, and lymph node dissection for group C were independent prognostic factors. CONCLUSIONS: Treatment protocol specific for the residual disease may improve the survival of patients with advanced gastric cancer treated by noncurative resection.

Postoperative morbidity and mortality after gastrectomy for gastric carcinoma.

BACKGROUND/AIMS: Surgical technique and postoperative care for gastric cancer have significantly improved in recent years. However, whether postoperative morbidity or mortality rates after gastrectomy for gastric cancer were reduced or not in recent years was unclear. In this study, we analyzed the chronological changes of postoperative morbidity and mortality rates, and we analyzed risk factors for postoperative morbidity and mortality in patients undergoing gastrectomy for carcinomas of the stomach. METHODOLOGY: A total of 887 patients with gastric cancer were gastrectomized in our hospital between January 1985 and December 1996. The patients were divided into three groups on the basis of chronology. The first group included patients treated over the period 1985 to 1988 (n = 324); the second group, 1989 to 1992 (n = 300); and the third group, 1993 to 1996 (n = 263). Postoperative morbidity rates and mortality rates were compared among the three groups. Also, significant risk factors affecting postoperative morbidity and in-hospital mortality were analyzed by the multiple logistic regression analysis. RESULTS: Postoperative complications were detected in 95 patients (10.7%) and in-hospital mortality rate was 2.4% (21/887). Postoperative morbidity rates were 10.5%, 11%, and 10.6% in the first, second, and third groups, respectively and postoperative mortality rates were 2.5%, 2%, and 2.7%, respectively. These postoperative morbidity and mortality rates were not different between the groups (P = 0.979 and P = 0.866). The most common postoperative complication was anastomotic leakage (56/95, 58.9%). Significant risk factors affecting in-hospital mortality were Stage IV (P = 0.006) and noncurative gastric resection (P = 0.004). However, the extent of lymph node dissection, combined resection, or the existence of preoperative complications were not significant risk factors of in-hospital mortality by multiple logistic regression analysis. CONCLUSIONS: These results indicate that patients with far-advanced gastric cancer might have a high risk of postoperative mortality. In noncurative operations for patients with advanced gastric cancer, unnecessary lymph node dissection or combined resection should be avoided.

Cyclin D1 expression and retinoblastoma gene protein (pRB) expression in esophageal squamous cell carcinoma.

PURPOSE: Alterations in the cell cycle regulatory cyclin/retinoblastoma protein (pRB) pathway play a important role in tumor progression in esophageal squamous cell carcinoma (ESCC). In the present study, we evaluated the prognostic significance of the combined analysis of cyclin D1 and pRB in ESCC retrospectively. METHODS: Immunoreactivities of cyclin D1 and pRB were evaluated in 148 surgically resected ESCC by use of monoclonal antibodies. Disease-free survival of patients was compared among the four subgroups according to the phenotypes of cyclin D1 and pRB expressions. RESULTS: High immunoreactivities of pRB and cyclin D1 were detected in 64.2% and 40.5% of tumors, respectively. The loss of pRB expression and overexpression of cyclin D1 correlated with short survival. However, these factors were not detected as independently prognostic in multivariate analysis. In 107 surviving patients who underwent curative operation, co-expressed pRB and cyclin D1 (pRB+/cyclin D1 +: 29 patients) were correlated with unfavorable prognosis (disease-free 5-year survival rate: 42.7%) and high cancer recurrence rate (44.8%) compared with that of 40 patients with pRB +/cyclin D1- tumors (70.5% and 27.5%). The disease-free 5-year survival rate of patients with pRB+/cyclin D1- tumors was significantly better than that of other groups (P=0.001). However, the disease-free 5-year survival rate of 29 patients with pRB+/cyclin D1 + tumors was equivalent to that of 29 patients with pRB-/cyclin D1tumors (48.3%), and that of nine patients with pRB-/cyclin D1+ tumors (22.2%, P=0.237). CONCLUSIONS: Our results suggest that overexpression of cyclin D1 may suppress pRB function, and that combined analysis of pRB and cyclin D1 may be a useful parameter of patient prognosis in ESCC.

A partially unfolded state of equine beta-lactoglobulin at pH 8.7.

The urea-induced unfolding transition of equine beta-lactoglobulin was studied at pH 8.7 using circular dichroism (CD), ultracentrifugation, and gel filtration chromatography. The unfolding transition curves showed that at least one intermediate accumulates at moderate concentrations of urea. Furthermore, analytical ultracentrifugation experiments indicated that the intermediate forms a dimer. Thus, the urea-induced unfolding transition was measured by CD at various protein concentrations and was analyzed by a model assuming the four conformational states (the native, intermediate, dimeric intermediate, and unfolded states). The characteristics of the intermediate are markedly different from those of the intermediate previously observed at pH 4.0 or 1.5. The intermediate at pH 8.7 does not show the intense far-ultraviolet CD suggestive of the nonnative alpha-helix.

Correlation between spontaneous apoptosis and the expression of angiogenic factors in advanced gastric adenocarcinoma.

The aim of this study was to investigate whether angiogenic factors influence the occurrence of spontaneous apoptosis in advanced gastric cancer. The apoptotic indices (AIs) of 97 tumors from 97 patients with advanced gastric cancer (pT3, pN0, pM0, Stage II) were analyzed by the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end labeling (TUNEL) method. Intratumoral microvessel densities (IMVDs) of tumors stained with anti-CD34 monoclonal antibody were quantified under x 200 magnification using computer-assisted image analysis. The expressions of angiogenic factors, such as vascular endothelial growth factor (VEGF), thymidine phosphorylase (dThdPase), transforming growth factor-alpha (TGF-alpha), and p53 were analyzed immunohistochemically and compared with IMVDs and AIs. The mean IMVD of the 97 tumors was 365/mm2 (range 147-990/mm2). The mean AI of tumors was 2.1% (range 0-11.3%). A significant inverse correlation between the AIs and the IMVDs was shown (p = -0.278, P = 0.0064). The mean IMVDs of tumors with high expressions of dThdPase, TGF-alpha, or p53 were significantly higher than those of tumors with low expressions of these factors. The mean AI of tumors with high expressions of dThdPase was significantly lower than that of tumors with low expressions of dThdPase (P = 0.023). However, no significant correlations were detected between AIs and the expression levels of VEGF, TGF-alpha, or p53. In gastric cancer, dThdPase may play an important role in tumor progression by increasing microvessels and by suppressing apoptosis of cancer cells.

Clinicopathological significance of cathepsin D expression in gastric adenocarcinoma.

OBJECTIVE: An estrogen-regulated lysosomal protease, cathepsin D, has been detected in a variety of tissues. This proteinase has been described as closely associated with tumor progression and metastasis in malignant tumors. The purpose of this study was to determine the clinicopathological and prognostic significance of cathepsin D expression in gastric adenocarcinoma. METHODS: In a consecutive series of 478 patients with gastric carcinoma (median follow-up period: 93 months, range: 1-285 months), cathepsin D expression in tumors was quantitatively analyzed with immunohistochemistry using a monoclonal antibody against cathepsin D (clone: 1C11). The percentage of cathepsin-D-positive cancer cells (the CD index) was calculated. In addition, the amount of cathepsin-D-positive stromal cells was evaluated; three grades (high, intermediate, and low) were used for the classification. RESULTS: The mean CD index of 478 tumors was 12.8% (range: 0-100%, median: 8%). The mean CD index of diffuse-type gastric carcinomas (14.9%) was significantly higher than that of intestinal-type carcinomas (10.1%, p < 0.0001). Cathepsin D expression of cancer cells was significantly associated with the depth of tumor invasion in both types. The percentage of tumors with high cathepsin D expression in stromal cells was significantly higher in well-differentiated tumors (25.5%) than in moderately differentiated (12.8%) or in poorly differentiated tumors (19.1%). Cathepsin D expression of stromal cells was significantly associated with the depth of tumor invasion in the intestinal type, in contrast to the diffuse type. Highly expressed cathepsin D in cancer cells was associated with a poor prognosis in both types of carcinoma, but in stromal cells highly expressed cathepsin D was associated to a poor prognosis in the intestinal type only. CONCLUSION: These results indicate that cathepsin D expression in cancer cells may play an important role in tumor progression in diffuse-type gastric carcinoma, whereas in the intestinal type of carcinoma, cathepsin D expression in stromal cells may play an important role in tumor progression.