Tetsuro Nishihira

A Prospective Randomized Trial of Extended Cervical and Superior Mediastinal Lymphadenectomy for Carcinoma of the Thoracic Esophagus

BACKGROUND Recurrence of thoracic esophageal carcinoma in the cervical and superior mediastinal lymph nodes occurs frequently and contributes to a poor prognosis. Extensive lymphadenectomy has been advocated. Findings in support of this to date, however, have been based on a comparison with historical controls. We herein report a prospective randomized trial of extended and conventional lymphadenectomy. METHODS Cases of thoracic esophageal carcinoma meeting criteria predictive of complete resection were randomized into conventional and extended cervical and superior mediastinal lymphadenectomy groups. RESULTS In the extended and conventional lymphadenectomy groups, respectively, mean operative time was 487 +/- 47 and 396 +/- 43 minutes, blood loss was 850 +/- 429 and 576 +/- 261 mL, node count was 82 +/- 22 and 43 +/- 15, hospital deaths occurred in 3% and 7%, 2-year survival was 83.3% and 64.8%, 5-year survival was 66.2% and 48.0%, and recurrence rate was 19.9% and 24.1%. CONCLUSION Extended lymphadenectomy may prevent recurrence and prolong survival after resection of thoracic esophageal carcinoma.

Molecular and cellular features of esophageal cancer cells

More than 70 cell lines were established from esophageal cancer, including 15 TE-series cell lines established by the authors. This article reviews molecular and cellular features of esophageal cancer cells from studies using these cell lines as well as primary tumors. The subjects reviewed include primary cultures of normal epithelium of the esophagus and of esophageal tumors, their growth and differentiation properties, chromosomal aberrations, protein kinase C, growth factors and their receptors, oncogenes, and tumor-suppressor genes. Lesions of genetic loci in esophageal cancer include the absence of mutations inras genes in primary tumors, amplification and overexpression of the c-erbB gene, co-amplification ofhst-1 andint-2 genes, mutations, and allelic loss of tumor suppressor genes, p53, Rb, APC, and MCC. Future clinical improvement will be achieved on the basis of the understanding of molecular and cellular features of esophageal cancer cells.

Basaloid-squamous carcinoma of the esophagus : A clinicopathologic, DNA ploidy, and immunohistochemical study of seven cases

Basaloid-squamous carcinoma (BSC) of the esophagus is a rare but interesting neoplasm that occurs primarily in the upper aerodigestive tract. In this study, we reviewed 371 cases of esophageal malignancies and detected seven cases (1.9%) of BSC. The clinicopathologic features, light and electron microscopic findings, and immunohistochemical localization of various differentiation-related antigens, including cytokeratin (CK) subtypes, p53, and epidermal growth factor receptor (EGFR), were examined. DNA ploidy was also determined in an effort to characterize the biologic features of these tumors. The tumors were classified as stage I (n = 1), IIB (n = 3), III (n = 2) or IV (n = 1). Six patients had lymph node metastasis, in four the metastatic carcinoma exhibited basaloid components. Histologically, all the tumors displayed a biphasic pattern of basaloid and squamous components. The former predominated in three cases, the latter in four cases. All the tumors contained solid growth of basaloid cells with microcystic patterns and stromal hyalinosis as well as palisading of cells. Ultrastructurally, markedly replicated basement membrane was observed. Immunohistochemistry revealed staining with only CK 14 and CK 19 antibodies in the periphery of the basaloid tumor nests. These antibodies were also positive in the basal layer of normal esophagus. Diffuse immunoreactivity for EGFR was demonstrated in all the tumors. Five tumors displayed p53 nuclear immunoreactivity. All of the basaloid components demonstrated aneuploidy by DNA image cytometry. We conclude that BSC is a distinct type of esophageal carcinoma that should be differentiated from the usual types of esophageal carcinoma and may be associated with aggressive biologic behavior.

Expression of p53 in human esophageal carcinoma: an immunohistochemical study with correlation to proliferating cell nuclear antigen expression.

Immunolocalization of the nuclear protein p53 tumor suppressor gene product is considered to be one of the best methods of detecting a mutated form of p53. We have studied p53 immunohistochemically by using monoclonal antibody pAb1801 in 15 cases of esophageal squamous cell carcinoma. Immunoreactive p53 was observed in the nuclei of tumor cells in 4% paraformaldehyde-fixed, frozen sections (12 of 15) and paraffin-embedded sections (11 of 15), but not in routinely processed (10% formalin-fixed) specimens. p53 expression was closely correlated with the malignant phenotype, including dysplasia. p53 was not observed in histologically normal mucosa, except in three cases in which scattered immunoreactivity was observed in parabasal and basal cells. Immunostaining of ki67 and proliferating cellular nuclear antigen on adjacent tissue sections revealed that p53 expression was strongly correlated with ki67 and proliferating cellular nuclear antigen in carcinoma and dysplastic cells, but not in normal mucosa, suggesting involvement of the mutated form of p53 in the cell cycle of malignant cells. Immunohistochemical patterns of p53 were not related significantly to clinicopathologic parameters in the cases examined. Therefore, p53 expression was strongly associated with the proliferation of carcinoma cells but not with that of normal cells in esophageal carcinoma.

Mistaken identity of widely used esophageal adenocarcinoma cell line TE-7

Cancer of the esophagus is the seventh leading cause of cancer death worldwide. Esophageal carcinoma cell lines are useful models to study the biological and genetic alterations in these tumors. An important prerequisite of cell line research is the authenticity of the used cell lines because the mistaken identity of a cell line may lead to invalid conclusions. Estimates indicate that up to 36% of the cell lines are of a different origin or species than supposed. The TE series, established in late 1970s and early 1980s by Nishihira et al. in Japan, is one of the first esophageal cancer cell line series that was used throughout the world. Fourteen TE cell lines were derived from human esophageal squamous cell carcinomas and one, TE-7, was derived from a primary esophageal adenocarcinoma. In numerous studies, this TE-7 cell line was used as a model for esophageal adenocarcinoma because it is one of the few esophageal adenocarcinoma cell lines existing. We investigated the authenticity of the esophageal adenocarcinoma cell line TE-7 by xenografting, short tandem repeat profiling, mutation analyses, and array-comparative genomic hybridization and showed that cell line TE-7 shared the same genotype as the esophageal squamous cell carcinoma cell lines TE-2, TE-3, TE-12, and TE-13. In addition, for more than a decade, independent TE-7 cultures from Japan, United States, United Kingdom, France, and the Netherlands had the same genotype. Examination of the TE-7 cell line xenograft revealed the histology of a squamous cell carcinoma. We conclude that the TE-7 cell line, used in several laboratories throughout the world, is not an adenocarcinoma, but a squamous cell carcinoma cell line. Furthermore, the cell lines TE-2, TE-3, TE-7, TE-12, and TE-13 should be regarded as one single squamous cell carcinoma cell line.

AMPLIFICATION OF THE hst-1 GENE IN HUMAN ESOPHAGEAL CARCINOMAS

The hst‐1 gene, previously designated as the hst gene, and seven other oncogenes were examined for possible structural changes in esophageal, gastric and colorectal carcinomas by Southern blot hybridization. The hst‐1 gene was amplified in eight (42.1%) of the nineteen esophageal squamous cell carcinomas and in all four metastatic tumors of lymph nodes. The degree of amplification ranged from two to eight times. Coamplification of the hst‐1 and c‐erbB‐1 gene was found in one case of esophageal carcinoma. However, no amplification of the hst‐1 gene was detected in gastric and colorectal carcinomas.

The protooncogene product, PEBP2β/CBFβ, is mainly located in the cytoplasm and has an affinity with cytoskeletal structures

The Pebpb2/Cbfb gene encodes the non-DNA binding β subunit of the heterodimeric transcription factor, PEBP2/CBF, and has been implicated in a subtype of human acute myeloid leukemia, as well as being indispensable for the development of definitive hematopoiesis in the murine fetal liver. By examining a subcellular localization of the PEBP2β/CBFβ protein in tissue culture cells, we could reveal an additional aspect of the protein other than to be a subunit of a transcription factor. Immunoblot and immunocytochemical staining showed that PEBP2β/CBFβ was mostly present in the cytoplasm. This PEBP2β/CBFβ was free from its DNA-binding partner, the α subunit of PEBP2/CBF, as judged by the electrophoretic mobility shift assays. Furthermore, a significant amount of PEBP2β/CBFβ was retained in the cytoskeleton preparation after detergent extraction of the cells and was found by double immunofluorescence to colocalize with the F-actin on stress fibers and the vinculin in membrane processes. Thus, the present study extends PEBP2β/CBFβ to be a cytoskeleton-affinitive as well as nuclear protein. The implications of these results are discussed.

An immunohistochemical analysis for cancer of the esophagus using monoclonal antibodies specific for modified nucleosides

Background. Modified nucleosides such as 1‐methyladenosine and pseudouridine exist as minute components of transfer ribonucleic acid (tRNA) and are excreted in the urine in large amounts in the presence of malignancy. Although use of these modified nucleosides as tumor markers has long been studied and many reports have detailed their relationship with malignant tumors and the urinary excretion of various modified nucleosides, there have been no reports on modified nucleosides in esophageal carcinoma.

Expression of glutathione S‐transferase‐π messenger rna in human esophageal cancers

The expression of human glutathione S‐transferase‐π (GST‐π) in resected primary esophageal tumors and in matching normal esophageal mucosa from 25 patients undergoing radical surgery was measured by RNA blot hybridization. The RNA transcript levels of GST‐π in the tumor tissues were higher than those in normal tissues in 20 of 25 cases (80%). The mean GST‐π mRNA value in the tumor tissues (n = 25) was significantly (P < 0.01) elevated as compared with that in background mucosa (n = 29), and in ten of 25 tumors (40%) the level of GST‐π mRNA exceeded the mean normal tissue value by two standard deviations (normal mean value + 2 × SD). The results obtained from the current experiment thus suggests that GST‐π might be a useful marker for human esophageal cancer. No correlation between GST‐π mRNA level and clinical stage or histologic characteristics was apparent.

Association between elevated plasma granulocyte colony-stimulating factor and the degree of surgical stress in patients undergoing gastrointestinal surgery

To characterize the changes in perioperative plasma granulocyte colony-stimulating factor (G-CSF) and analyze the effect of surgical stress on its kinetics, 41 patients undergoing gastrointestinal surgery with varying degrees of surgical stress were examined. The plasma levels of G-CSF significantly increased immediately after the operation, probably in response to surgical injury. This elevation was much higher in the 15 esophagectomy patients, at 883±300 pg/ml on postoperative day (POD) O, than in the 14 gastrectomy patients, with a value of 233±151 on POD O, (P<0.01) or in the 12 cholecystectomy patients, with a value of 64±41 on POD 1 (P<0.01). These findings led us to conclude that G-CSF levels increase significantly in the immediate postoperative period and are most likely associated with the degree of surgical stress. In addition, we studied the priming effect of G-CSF on polymorphonuclear leukocytes (PMNs). G-CSF enhanced PMN superoxide anion (O−2) production and luminol-dependent chemiluminescence (CL) induced by opsonized zymosan in a dose-dependent manner. A significant enhancement was seen in the G-CSF level (1 ng/ml) which was almost the same as the maximum G-CSF level in the esophagectomy patients. Furthermore, postoperative PMN activation occurred after the elevation of plasma G-CSF. Thus, we propose that elevated G-CSF may act as one of the mediators which activate PMN function postoperatively.