SUMMARY:Degradation of basement membrane and extracellular matrix structures are important features of the metastatic process of malignant tumors. Human heparanase degrades heparan sulfate proteoglycans, which represent the main components of basement membranes and the extracellular matrix. Because of the role of heparanase in tumor invasion and metastasis, we examined heparanase expression in primary gastric cancers and in cell lines derived from gastric cancers by immunohistochemistry and RT-PCR, respectively. Four of seven gastric cancer cell lines showed heparanase mRNA expression by RT-PCR. Heparanase protein was detected in both the cytoplasm and the nucleus of heparanase mRNA-positive cells by immunohistochemical staining. Heparanase expression was confirmed in 35 (79.5%) of 44 gastric tumor samples by immunohistochemical staining. However, no or weak heparanase expression was detected in normal gastric mucosa. In situ hybridization showed that the mRNA expression pattern of heparanase was similar to that of the protein, suggesting that increased expression of the heparanase protein at the invasive front was caused by an increase of heparanase mRNA in tumor cells. Analysis of the clinicopathologic features showed stronger heparanase expression in cases of huge growing tumors, extensive invasion to lymph vessels, and regional lymph node metastasis. In gastric cancer, patients with heparanase expression showed significantly poorer prognosis than those without such expression (p ϭ 0.006). In conclusion, our findings suggest that high expression of heparanase in gastric cancer is a strong predictor of poor survival. (Lab Invest 2003, 83:613-622).

In this study, we examined the distribution of heparanase protein in 75 esophageal squamous cell carcinomas by immunohistochemistry and analyzed the relationship between heparanase expression and clinicopathological characteristics. In situ hybridization showed that the mRNA expression pattern of heparanase was similar to that of the protein, suggesting that increased expression of the heparanase protein at the invasive front was caused by an increase of heparanase mRNA in tumor cells. Heparanase expression correlated significantly with depth of tumor invasion, lymph node metastasis, tumor node metastasis (TNM) stage and lymphatic invasion. Overexpression of heparanase in esophageal cancers was also associated with poor survival. In addition to its localization in the cytoplasm and cell membrane, heparanase was also identified in the nuclei of normal epithelial and tumor cells by immunohistochemistry. Furthermore, nuclear heparanase was detected in nuclear extract of cancer cell lines by Western blot and immunohistochemistry. Examination of the role of nuclear heparanase in cell proliferation and differentiation by double immunostaining for proliferating cell nuclear antigen (PCNA) and cytokeratin 10 (CK10) showed significant relationship between nuclear heparanase expression and differentiation (heparanase vs CK10), but not for proliferative state of esophageal cancer cells (heparanase vs PCNA). Our results suggest that cytoplasmic heparanase appears to be a useful prognostic marker in patients with esophageal cancer and that nuclear heparanase protein may play a role in differentiation. Inhibition of heparanase activity may be effective in the control of esophageal tumor invasion and metastasis.

Heparanase is a marker for poor prognosis of patients with colon cancer and could be a suitable target for antitumor therapy in colon cancer.

Immunostaining and EMSA revealed that NF-jB was activated strongly by TNF/IFN-a compared to TNF alone in a human colon adenocarcinoma cell line, RPMI4788. Although inhibition of activated NF-jB, by using an NF-jB decoy, reduced cell viability after treatment with TNF only, NF-jB decoy resulted in recovery of cell viability after TNF/IFN-a treatment. Caspase-3 activity was increased in cells induced by TNF/IFNa, while suppression of caspase-3 activity was observed in cells transfected with NF-jB decoy and then treated by TNF/ IFN-a. On the other hand, Fas expression was strongly enhanced by TNF/IFN-a, and inhibition of TNF/IFN-a-induced NF-jB activation, by using NF-jB decoy, decreased Fas expression. Cell viability and caspase-3 activity decreased in cells treated with TNF/IFN-a and anti-FasL antibody. Taken together, our findings suggest that activated NF-jB induced by the crosstalk between TNF and IFN-a is a novel proapoptotic signal acting via enhancement of Fas expression.

For the reconstruction of hypopharynx or cervical esophagus, the free jejunal graft is a very useful technique and improves the patient's quality of life.

5-fluorouracil (5-FU) is used for the treatment of stomach and colon cancer, but many tumors are resistant to this chemotherapeutic agent. 5-FU induces apoptosis of several cancer cell lines, while some chemotherapeutic agents are known to activate the transcriptional factor NF-kappaB, which strongly suppresses apoptosis in vitro. In the present study, we investigated the relationship between activation of NF-kappaB and chemoresistance to 5-FU in human stomach cancer cell lines, NUGC3 (5-FU sensitive) and NUGC3/5FU/L (5-FU resistant). Treatment with 5-FU for 9-12 h caused activation of inducible NF-kappaB in NUGC3/5FU/L cells but not in NUGC3 cells. 5-FU also resulted in an increase in the number of TUNEL-positive cells and enhanced caspase-3 activity 3- to 5-fold in NUGC3 cells but not NUGC3/5FU/L cells. Moreover we also demonstrated that the inhibition of inducible NF-kappaB activation by using a NF-kappaB decoy could induce apoptosis and reduce chemoresistance against 5-FU. Our results suggest that 5-FU chemoresistance can be overcome by inhibition of inducible NF-kappaB activation, and that the use of the NF-kappaB decoy combined with 5-FU treatment is a new molecular and gene therapeutic strategy aimed at treatment of human stomach cancers resistant to 5-FU.

. Basaloid squamous carcinoma of the esophagus is very rare. We report two cases of basaloid squamous carcinoma of the esophagus. Both tumors histologically consisted of solid cell nests with intervening fibromyxoid stroma. In some tumor nests were comprised of pseudoglandular structures containing myxoid matrix, and displayed focal immunoreactivity for laminin. Thoracic esophagectomy with lymph node dissection was followed by intrathoracic esophagogastrostomy in both patients. The patients had uneventful postoperative courses. Regular periodic follow-up showed no evidence of recurrence or metastasis in the 22-month postoperative period.

Metastasis to the breast from extramammary malignancies is rare. There are especially few reports of metastasis from esophageal cancer. We report the pathological and autopsy findings of a 44-year-old man with advanced esophageal cancer and a left breast tumor. Squamous cell carcinoma invading the mammary glands wasdemonstrated histologically. Immunostains for ER, PgR, and ErbB-2 were negative. At autopsy, metastatic lesions were found in lung, liver, diaphragm, peritoneum, spine, and mediastinal lymph nodes, with no evidence of metastasis to the skin. While metastatic breast tumors are rarely the initial sign of malignancy, it isimportant to distinguish a metastasis from primary breast cancer to avoid unnecessary conflicting treatments.