Aberrant maspin expression in gallbladder epithelium is associated with intestinal metaplasia in patients with cholelithiasis.

OBJECTIVE: Aberrant expression of maspin protein related to DNA hypomethylation in the promoter region is frequently observed in gallbladder carcinomas, whereas the non-tumorous gallbladder epithelium is maspin negative. We investigated maspin expression in non-tumorous gallbladder epithelium in patients with cholelithiasis. METHODS: An immunohistochemical study of maspin expression was performed in 69 patients with cholelithiasis and 30 patients with gastric cancer without cholelithiasis. RESULTS: Immunoreactivity for maspin was observed in focal and patchy regions of the gallbladder epithelium. Positive immunoreactivity for maspin was significantly associated with the presence of intestinal metaplasia in patients with cholelithiasis (p<0.05). CONCLUSION: The high incidence of aberrant maspin expression in both intestinal metaplasia and carcinoma of the gallbladder supports the assumption that intestinal metaplasia of the gallbladder may predispose to gallbladder carcinoma.

True carcinosarcoma of the esophagus.

Most esophageal carcinosarcomas are diagnosed as so-called carcinosarcoma, in which individual elements may be derived from a single common ancestor cell, and there have been a few reports describing true carcinosarcoma originating from two individual stem cells. We describe a case of esophageal carcinosarcoma exhibiting neoplastic osteoid formation. Immunoreactivity for vimentin and p53 was limited to only the sarcomatous component and was absent in the carcinomatous component. Furthermore, a point mutation in exon 7 of the p53 gene was observed only in the sarcomatous component. Both sarcoma and carcinoma cells distinctively metastasized to different lymph nodes. These observations led us to diagnose the esophageal tumor as a true carcinosarcoma.

Gene expression profiles in human gastric cancer: expression of maspin correlates with lymph node metastasis.

To seek for a candidate gene that would regulate tumour progression and metastasis in gastric cancer, we investigated gene expression profiles by using DNA microarray. Tumour tissue and adjacent normal tissue were obtained from 21 patients with gastric cancer and then examined for their gene expression profiles by the Gene Chip Human U95Av2 array, which includes 12 000 human genes and EST sequences. A total of 25 genes were upregulated and two genes were downregulated by at least four-fold in the tumour tissue. In a further analysis according to lymph node metastasis, the expressed levels of maspin, as well as carcinoembryonic antigen and nonspecific crossreacting antigen were significantly higher in tumours with lymph node metastasis than in those without it. Maspin expression in 85 gastric cancer patients was further investigated by using immunohistochemistry. Maspin expression was not observed in normal gastric epithelia without intestinal metaplasia. In contrast, maspin was expressed in 74 of 85 tumour tissues. There was a significant correlation between the incidence of maspin-positive tumour staining and lymph node metastasis. These results suggest that maspin has a potential role for tumour metastasis in gastric cancer.

A case of clinically and neuropathologically atypical corticobasal degeneration with widespread iron deposition.

A 65-year-old woman was admitted to our hospital for forgetfulness, depression and eccentric behavior that had been first noticed 2 years prior to admission. She showed memory impairment, perseveration and repeated violent actions, but no limb-kinetic apraxia. She died 12 years after the onset of symptoms. At autopsy, the unfixed brain weighed 820 g. Atrophy was circumscribed in the frontal lobe on both sides. The globus pallidus and the caudate nucleus were markedly atrophic and gold yellow in color, and the substantia nigra was strikingly pale. The cortical area showed neuronal loss and status spongiosus of the second and third cortical layers with ballooned neurons. Marked neuronal loss was observed in the dorsomedial nucleus of the thalamus, Meynert basal nucleus and substantia nigra. With Holzer stain, fibrillary gliosis was found to be severe in the frontal lobe, globus pallidus, subthalamic nucleus, hippocampus, dorsomedial nucleus of thalamus, substantia nigra, pontine tegmentum and inferior olivary nucleus. With Bielschowsky-Hirano stain, neurofibrillary tangles were observed in the cortex, hippocampus, substantia nigra, dentate nucleus, subthalamic nucleus, pontine nucleus, the inferior olivary nucleus, dorsomedial nucleus of the thalamus and, to a lesser extent, the neostriatum. Strikingly numerous argyrophilic and tau-positive threads were present in the cerebral white matter. These neuropathological findings corresponded to corticobasal degeneration, but lesions characteristic of progressive supranuclear palsy were also found. Moreover, widespread iron deposition throughout the central nervous system was the most striking finding of the present case. To our knowledge, such a case has not been reported in the literature to date.

Expression of angiogenic factors, basic fibroblast growth factor and vascular endothelial growth factor, in human biliary tract carcinoma cell lines.

In order to clarify angiogenic mechanism in biliary tract carcinoma, expressions and functions of basic fibroblast growth factor (bFGF) and its receptors (FGFR-1-4), and vascular endothelial growth factor (VEGF) and its receptors were investigated by using human biliary tract carcinoma cell lines (KMC-1, KMC-2, KMBC and KMG-C). Expression of bFGF was confirmed in KMC-1 and KMC-2, and that of FGFR-1-4 in all the cell lines except no FGFR-2 in KMC-2. Expression of VEGF was detected in all the cell lines, whereas the cell lines did not express VEGF receptors. Addition of anti-bFGF neutralizing antibody to the medium did not suppress cell proliferation, whereas exogenous bFGF with or without heparin accelerated cell proliferation in all cell lines. Addition of anti-bFGF neutralizing antibody or anti-VEGF neutralizing antibody to the co-culture of human umbilical vascular endothelial cells (HUVEC) and KMC-2 suppressed the proliferation of HUVEC. Surgically obtained cholangiocarcinoma tissues (n=7) were immunohistochemically negative to bFGF, while six of the seven were positive to VEGF. These findings suggested that human biliary tract carcinoma cells express both bFGF and VEGF not as autocrine growth factors but as angiogenic factors. On the other hand, expression of VEGF was found at a higher frequency than bFGF both in the cell lines and tissues.

Expression and function of interleukin-8 in human hepatocellular carcinoma.

Expression and functions of interleukin (IL)-8, a pro-inflammatory cytokine with angiogenesis action, was examined in 23 surgically resected hepatocellular carcinoma (HCC) specimens and 7 HCC cell lines. In all HCC tissues, IL-8 expression was confirmed with reverse-transcription polymerase chain reaction method and enzyme-linked immunosorbent assay, and immunohistochemistry showed HCC cells were the major producer of IL-8 in the tissues. Microvessel density was measured by the double immunohistochemical staining of muscular vessels in HCC tissues, but the density was not related to the level of IL-8 in the HCC tissues. On the other hand, in the co-culture of human umbilical vein endothelial cells (HUVEC) and a HCC cell line (KIM-1), IL-8 produced by KIM-1 significantly accelerated the proliferation of HUVEC. In addition, cases with a high IL-8 level in cancerous tissue had a significantly higher frequency of portal vein invasion, venous invasion and bile duct invasion (p<0.05). In the cultures of 7 HCC cell lines IL-8 secretion into culture medium increased with the treatment of IL-1beta or tumor necrosis factor-alpha. This showed IL-8 expression is regulated by inflammatory cytokines. IL-8 produced by HCC is an angiogenesis factor of HCC, but it could have a much more important role in the invasion and metastasis of HCC.

Dipyridamole stress thallium perfusion scan for evaluating myocardial involvement in systemic sclerosis.

Abstract To evaluate the usefulness of a dipyridamole stress thallium-201 (Tl-201) perfusion scan in detecting myocardial involvement in systemic sclerosis we performed Tl-201 scans, electrocardiograms (ECG), and echocardiograms (UCG) on 24 patients with systemic sclerosis (11 diffuse type, 13 limited type) sequentially selected randomly over an 8-month period, and compared the findings. Cardiac catheterization, coronary angiography (CAG), and right ventricular endomyocardial biopsy were performed as necessary. Of the 24 patients, Tl-201 scans revealed fixed defects (FDs; myocardial fibrosis) and/or reversible defects (RDs; myocardial ischemia) in nine patients, whereas ECG and UCG revealed defects in four and three patients, respectively. Biopsy specimens obtained from the three patients with FDs also showed both ECG and UCG abnormalities indicative of myocardial fibrosis despite their normal appearance with CAG. Autopsy findings on the heart of a patient who died of acute heart failure showed myocardial fibrosis predominantly in the left anteroposterior wall. This was consistent with the FDs area detected using the Tl-201 perfusion scan. In a patient with chronic heart failure, left ventriculography showed a decrease in the anterior wall motion of the left ventricle which coincided with the FDs area in the Tl-201 perfusion scan. In conclusion, dipyridamole stress Tl-201 scanning is useful for evaluating myocardial involvement in systemic sclerosis.

Chemoradiotherapy followed by surgery for thoracic esophageal cancer potentially or actually involving adjacent organs.

The objective of this study was to evaluate the therapeutic usefulness of chemoradiotherapy (CRT) followed by surgery in patients with clinically T4 (cT4) esophageal cancer involving adjacent organs such as the trachea, main bronchi, and large vessels. Thirty-seven patients with cT4 squamous cell carcinoma of the thoracic esophagus were enrolled in this study. The CRT regimen comprised cisplatin (70 mg/m2) on day 1, 5-fluorouracil (700 mg/m2) on days 1-4 and external irradiation (200 cGy/day, total 30 Gy) on either days 8-26 (sequential schedule, n=15) or days 1-19 (concurrent schedule, n022). Two courses of CRT were given. The results of CRT were complete response in nine patients, partial response in 19, no change in three (minor response in two), and progressive disease in six patients. The median response duration in all responders was 172 days (range: 56-2469, n=19). After CRT, 13 patients received surgery. In 12 of these patients, tumors were completely resected. Histopathologic examination of the resected specimen revealed a discrepancy between clinical response and histopathologic effect. The median duration of survival and the 1-, 2- and 5-year survival rates were 304 days (84-3155), 45%, 35% and 23% in all patients, respectively, 866 days (190-3155), 83%, 83% and 57% in the 13 patients whose tumors were resected, and 187 days (84--2630), 25%, 5% and 5% in the 24 patients whose tumors were not resected. Grade 3 toxicity, especially hematological reactions, was noted in 13.5% (5/37) of the patients. There was one toxicity-related death (sepsis). A good outcome may be obtained with CRT, followed by surgery when feasible. However, CRT can cause toxic reactions, and close monitoring of patients is required.

Expression of Hu-IFN-alphaR2 chain of type I interferon receptor in human hepatocellular carcinoma and non-cancerous tissues.

Type I interferon (IFN) receptor consists of two chains (Hu-IFN-alphaR1 and Hu-IFN-alphaR2), and Hu-IFN-alphaR2 takes a soluble, short, or long form (Hu-IFN-alphaR2a, Hu-IFN-alphaR2b, or Hu-IFN-alphaR2c, respectively). We examined Hu-IFN-alphaR2 expression in hepatocellular carcinoma (HCC) tissues and their corresponding non-cancerous (non-HCC) tissues. Immunohistochemically, Hu-IFN-alphaR2 expression was positive in 53 (77%) of 69 HCC tissues and in 61 (88%) of 69 non-HCC tissues. Hu-IFN-alphaR2 protein in tissue homogenates of HCC and non-HCC tissues obtained from 29 patients was measured by using ELISA kits, and the amount was 12.7+/-10.9 pg/mg protein in HCC tissue and 10.5+/-5.0 pg/mg protein in non-HCC tissue. Number of specimens in which Hu-IFN-alphaR2 level was 3 pg/mg protein or lower, or 20 pg/mg protein or higher, was one each for non-HCC, while it was 7 (24%) and 6 (21%) for HCC. RT-PCR analysis was done in 7 of the 29 HCC cases. It revealed both Hu-IFN-alphaR2a and Hu-IFN-alphaR2c were expressed in all HCC tissues and in 6 of the 7 non-HCC tissues, and Hu-IFN-alphaR2b was expressed in all HCC tissues and in 4 of the 7 non-HCC tissues. Because immunostaining intensity of Hu-IFN-alphaR2 tended to be higher in the areas with active inflammation, effects of inflammatory cytokines (IL-1alpha, IL-1beta, and TNF-alpha) on Hu-IFN-alphaR2 expression were examined on 11 HCC cell lines. As a result, TNF-alpha up-regulated Hu-IFN-alphaR2 expression in 7 of the 11 cell lines. In 3 of the 7 cell lines, up-regulation of Hu-IFN-alphaR2 on cell surface, as well as of the soluble form of Hu-IFN-alphaR2, was induced not only by TNF-alpha, but also by IL-1alpha or IL-1beta. In conclusion, both HCC and non-HCC tissues frequently express Hu-IFN-alphaR2c that is necessary for Type I IFN response. Hu-IFN-alphaR2 expression in HCC tissues is often attenuated or enhanced, and may be regulated by inflammatory cytokines.

Subsite preferences of pepstatin-insensitive carboxyl proteinases from prokaryotes: kumamolysin, a thermostable pepstatin-insensitive carboxyl proteinase.

Kumamolysin, a carboxyl proteinase from Bacillus novosp. MN-32, is characterized by its thermostability and insensitivity to aspartic proteinase inhibitors such as pepstatin, diazoacetyl-DL-norleucine methylester, and 1,2-epoxy-3-(p-nitro-phenoxy)propane. Here, its substrate specificity was elucidated using two series of synthetic chromogenic substrates: P(5)-P(4)-P(3)-P(2)-Phe*Nph (p-nitrophenylalanine: *cleavage site)-P(2)'-P(3)', in which the amino acid residues at the P(5)-P(2), P(2)' and P(3)' positions were systematically substituted. Among 74 substrates, kumamolysin was shown to hydrolyze Lys-Pro-Ile-Pro-Phe-Nph-Arg-Leu most effectively. The kinetic parameters of this peptide were K(m) = 41+/-5 microM, k(cat) = 176+/- 10 s(-1), and k(cat)/K(m) = 4.3+/-0.6 mM(-1) x s(-1). These systematic analyses revealed the following features: (i) Kumamolysin had a unique preference for the P(2) position. Kumamolysin preferentially hydrolyzed peptides having an Ala or Pro residue at the P(2) position; this was also observed for the pepstatin-insensitive carboxyl proteinase from Bacillus coagulans J-4 [J-4; Shibata et al. (1998) J. Biochem. 124, 642-647]. Other carboxyl proteinases, including Pseudomonas sp. 101 pepstatin-insensitive carboxyl proteinase (PCP) and Xanthomonas sp. T-22 pepstatin-insensitive carboxyl proteinase (XCP), preferred peptides having hydrophobic and bulky amino acid residue such as Leu at the P(2) position. (ii) Kumamolysin preferred such charged amino acid residues as Glu or Arg at the P(2)' position, suggesting that the S(2)' subsite of kumamolysin is occupied by hydrophilic residues, similar to that of PCP, XCP, and J-4. In general, the S(2)' subsite of pepstatin-sensitive carboxyl proteinases (aspartic proteinases) is hydrophobic in nature. Thus, the hydrophilic nature of the S(2)' subsite was confirmed to be a distinguishing feature of pepstatin-insensitive carboxyl proteinases from prokaryotes.

Expression and localization of vascular endothelial growth factor receptors in human hepatocellular carcinoma and non-HCC tissues.

Flt-1 (VEGF receptor-1) and KDR/Flk-1 (VEGF receptor-2) are the high-affinity receptors for the angiogenesis factor, vascular endothelial growth factor (VEGF). VEGF expression has been confirmed in human hepatocellular carcinoma (HCC), and VEGF is thought to be involved in the angiogenesis within HCC tissues. However, expressions of VEGF receptors in HCC have not been reported. We immunohistochemically examined expressions and localizations of Flt-1 and KDR in 28 surgically resected HCC tissues. In non-cancerous area, Flt-1 and KDR were mainly found in macrophages including Kupffer cells; both receptors were found in vascular endothelial cells in the portal veins and arteries within portal tracts; and KDR was also found in some sinusoidal endothelial cells. In cancerous area, Flt-1 and KDR were found in some macrophages, and also in the endothelial cells of intratumoral blood vessels. In 25 moderately and/or poorly differentiated HCCs, KDR expression in the blood space endothelial cells was clear and continuous in 20 cases, and focal in 5 cases. These results suggest that there would be an angiogenesis mechanism via VEGF/Flt-1 or VEGF/KDR in HCC, and the VEGF/KDR system would take a more important role.

Interferon alfa receptor expression and growth inhibition by interferon alfa in human liver cancer cell lines.

Type I interferon (IFN) receptor consists of two chains (Hu-IFN-alphaR1 and Hu-IFN-alphaR2), and Hu-IFN-alphaR2 takes a soluble (Hu-IFN-alphaR2a), short (Hu-IFN-alphaR2b), or long (Hu-IFN-alphaR2c) form. We examined the expression of type I IFN receptor, the growth-suppression effect of IFN-alpha, and their relationship in 13 liver cancer cell lines. With reverse-transcription polymerase chain reaction (RT-PCR) analysis, the expressions of Hu-IFN-alphaR1, Hu-IFN-alphaR2a, and Hu-IFN-alphaR2c were confirmed in all cell lines, and that of Hu-IFN-alphaR2b in 12 cell lines. All cell lines expressed mRNAs of a transcriptional activator, interferon regulatory factor (IRF)-1, and its antagonistic repressor (IRF-2). Flow cytometry revealed weak expression of Hu-IFN-alphaR2 on the cell surface in 12 cell lines. The soluble-form protein of Hu-IFN-alphaR2 was detected at varying levels in culture supernatants of all cell lines with enzyme-linked immunosorbent assay (ELISA). Cell proliferation was suppressed in proportion to the dose of human natural IFN-alpha at 96 hours of culture, but it was not clearly related to the expression of Hu-IFN-alphaR2 protein on the cell surface. Investigations on the morphology, DNA, and cell cycle presented four growth suppression patterns as a result of IFN-alpha: 1) induction of apoptosis and blockage of cell cycle at the S phase (9 cell lines); 2) blockage at the S phase (2 cell lines); 3) induction of apoptosis and blockage at the G2/M phase (1 cell line); and 4) blockage at the G1 phase (1 cell line). There was no evidence showing that changes in the expressions of Bcl-2, Bcl-xL, Bak, and Bax lead directly to IFN-alpha-mediated apoptosis. Our findings demonstrated that IFN-alpha would express growth-suppression effects at varying degrees by inducing inhibition of cell-cycle progression with or without apoptosis, regardless of the expression level of Hu-IFN-alphaR2 protein on the cell surface.

Effects of imidazoline and non-imidazoline alpha-adrenergic agents on canine platelet aggregation.

Aggregatory and antiaggregatory effects of imidazol(in)e and non-imidazol(in)e alpha-adrenergic agents on canine platelets were examined turbidimetrically in citrated platelet-rich plasma or washed platelet solution. Each alpha-adrenoceptor agonist alone did not induce aggregation, but adrenaline and noradrenaline potentiated dose-dependently aggregation stimulated by ADP, collagen or thrombin. Small potentiation of ADP- or collagen-stimulated aggregation was also observed in response to oxymetazoline. The alpha2-adrenoceptor antagonists and/or imidazol(in)e alpha-adrenergic agents inhibit dose-dependently adrenaline-potentiated aggregation, whereas alpha1-adrenoceptor antagonists, a beta-adrenoceptor antagonist and non-imidazol(in)e alpha-adrenergic agents were no or less effective in inhibiting adrenaline-potentiated aggregation. The alpha2-adrenoceptor agonists did not reduce inhibitory effect of alpha2-adrenoceptor antagonists for adrenaline-potentiated aggregation. The alpha2-adrenoceptor antagonists and/or imidazol(in)es were no or less effective in inhibiting aggregation induced by ADP or thrombin alone. These results demonstrated that alpha2-adrenoceptor-blocking agents and/or imidazol(in)e alpha-adrenergic agents inhibit effectively the adrenaline-potentiated platelet aggregation.

Infrequent frameshift mutations of polynucleotide repeats in multiple primary cancers affecting the esophagus and other organs.

Frequent frameshift mutations of simple nucleotide repeats in the protein-encoding regions, as well as replication errors (RERs) at microsatellite loci, have recently been demonstrated in gastrointestinal tumors. These genetic instabilities have been considered indicative of an increased risk of accumulating mutations in cancer-associated genes and of developing multiple cancers. We studied frameshift (or insertion/deletion) mutations of simple nucleotide repeats in five genes (TGFbeta type II receptor [TGFbetaRII], E2F4, MSH2, MSH3, and MSH6) in 23 tumors from 12 patients who had synchronous cancers of the esophagus and other organs. Genetic instability at four microsatellite loci, as well as mutations in the TP53, APC, and KRAS2 genes, were also studied. No frameshift mutations were observed in the TGFbetaRII, MSH3, and MSH6 genes. RER and a deletion mutation of BAT26 in MSH2 were present in one (1/23; 4%) gastric cancer. This tumor also carried a deletion mutation in the serine (AGC) repeat of the E2F4 gene. Mutation screening of the TP53, APC, and KRAS2 genes revealed that the synchronous cancers did not carry the same mutations. Our results suggested that genetic instability, such as insertion/deletion mutations in simple nucleotide repeats, is not significantly associated with the development of multiple primary cancers of the esophagus and other organs, and that these synchronous cancers developed independently according to their different environmental factors.

Expression of vascular endothelial growth factor in human hepatocellular carcinoma.

Vascular endothelial growth factor (VEGF) is thought to take an important role in tumor angiogenesis. The present study examined VEGF expression immunohistochemically in hepatocellular carcinomas (HCCs) in various histological grades and sizes. In HCCs that were composed of cancerous tissues of single histological grade, VEGF expression was the highest in well-differentiated HCCs, followed by moderately differentiated HCCs, and then poorly differentiated HCCs. VEGF positivity gradually decreased with the increase in tumor size. In the nodules larger than 3.0 cm, 36.8% were VEGF-negative. In HCCs consisting of cancerous tissues of two different histological grades, the expression was less intensive in the higher-grade HCC component. VEGF was not expressed in sarcomatous areas, while VEGF was expressed in the surrounding HCC tissues. The expression was also remarkable in the noncancerous tissues in which inflammatory cell infiltration was apparent. VEGF expression was also examined in six HCC cell lines. In reverse-transcription polymerase chain reaction (RT-PCR) analysis, expressions of the two secretion types (VEGF121 and VEGF165) were the highest. Thus, VEGF protein in culture supernatant was measured by using enzyme-linked immunosorbent assay (ELISA) with or without inflammatory cytokines, i.e., interleukin (IL)-1beta, interferon (IFN)-alpha, IFN-gamma, and tumor necrosis factor (TNF)-alpha; and growth factors, i.e., epidermal growth factor (EGF), platelet-derived growth factor (PDGF)-BB, basic fibroblast growth factor (bFGF), and transforming growth factor (TGF)-alpha. As a result, secretion of VEGF from the cell lines was upregulated at various degrees. Based on these findings, VEGF expression in HCC tissues was thought to be related to the histological grade. The findings also indicate that various cytokines and growth factors could cooperatively act to enhance VEGF expressions in HCC.

Tylosis esophageal cancer locus on chromosome 17q25.1 is commonly deleted in sporadic human esophageal cancer.

BACKGROUND & AIMS: Tumor-suppressor genes found in inherited cancer predisposition syndromes are also responsible for sporadic cancers of the same type. Recently, the tylosis oesophageal cancer (TOC) gene locus has been mapped to 17q25 by linkage analyses of pedigrees with focal nonepidermolytic palmoplantar keratoderma associated with a high risk of esophageal cancer development. The aim of this study was to clarify whether the TOC locus is affected in sporadic esophageal cancers. METHODS: We investigated loss of heterozygosity (LOH) on 17q in 58 sporadic esophageal squamous cell carcinomas (ESCs) using 20 microsatellite markers focusing on the TOC locus. RESULTS: LOH on 17q was observed in 37 of 52 (71%) informative cases at one or more loci, 80% (33/37) of which included the TOC locus. The smallest common deleted region was at D17S1839 within the TOC locus. CONCLUSIONS: The constructed deletion map revealed that the TOC locus is commonly deleted in sporadic ESCs, suggesting that a tumor-suppressor gene responsible for ESC is contained within this locus.

Mutations in the human homologue of the Drosophila patched gene in esophageal squamous cell carcinoma.

The human homologue (PTCH) of the Drosophila segment polarity gene patched has recently been identified as a tumor-suppressor gene for nevoid basal cell carcinoma syndrome and for sporadic basal cell carcinomas of the skin. We analyzed 30 esophageal squamous cell carcinomas (ESCC) for intrageneic mutations of the PTCH gene by polymerase chain reaction-single-strand conformation polymorphism analysis followed by DNA sequencing. We identified two somatic PTCH mutations (7%) in 30 ESCC. These were a nonsense mutation (CAG to TAG at codon 361) in exon 8 and a missense mutation (CAG to CTG, Gln to Leu at codon 816) in exon 14. These tumors exhibited loss of heterozygosity at the polymorphic site of the PTCH gene. These results indicate that inactivation of the PTCH gene via a two-hit mechanism occurs in a subset of ESCC.

[Treatment of patients with recurrent esophageal carcinoma].

From 1987 to 1997, 211 patients with thoracic esophageal carcinoma underwent radical surgery. The 5 year survival rate was 87% in pTNM stage I, 64% in stage II A, 57% in stage II B, and 31% in stage III. The survival curve was improved by postoperative chemotherapy including CDDP/5-FU as compared with surgery alone. Relapse occurred in 59 of these patients (28%). Lymphatic recurrence was recognized in 32 patients, hematogenic recurrence in 19, mixed type in 4, and intramural or local recurrence in 4 patients. In spite of through lymph node dissection, postoperative lymphatic recurrence was most frequent at the upper mediastinum and neck. Among hematogenic metastases, pulmonary and hepatic metastases were observed at equal incidences. The 1 year survival rate and median survival period of the patients with recurrent carcinoma were 36% and 191 days (26-1,122), respectively. There was no significant difference in prognosis between lymphatic and hematogenic recurrence. The prognosis for patients who underwent active therapy for recurrence (42 cases) was significantly better than for those who underwent only palliative therapy (17 cases). Resection of the site of recurrence was performed in 4 cases. The combination therapy of resection or irradiation and combined chemotherapy with CDDP and 5-FU resulted in a better prognosis (median survival period was 504 days) than irradiation alone or chemotherapy alone. In conclusion, early diagnosis and active multimodality therapy were important to improve the prognosis of recurrent esophageal carcinoma.

MAD-related genes on 18q21.1, Smad2 and Smad4, are altered infrequently in esophageal squamous cell carcinoma.

The MAD (mothers against decapentaplegic)-related genes, Smad2 (former name MADR2 or JV18-1) and Smad4 (former name DPC4), have been identified on chromosome 18q21.1. We analyzed 30 primary esophageal squamous cell carcinomas (ESCC) and 7 cell lines derived from ESCC for intragenic mutations and loss of heterozygosity (LOH) of the Smad2 and Smad4 genes. LOH was detected in 5 of 14 (35%) informative cases. However, no mutations in either gene were detected in either the primary carcinomas or the cell lines, and only a G-to-A base transition within the 3'-untranslated region of the Smad4 gene was observed in a carcinoma. There were no homozygous deletions in either of the genes in the cell lines. MAD-related genes on chromosome 18q21.1 are altered infrequently in ESCC.

A new human hepatocellular carcinoma cell line (HAK-2) forms various structures in collagen gel matrices.

We established a new human hepatocellular carcinoma (HCC) cell line, designated HAK-2, from a surgically resected HCC of a 57-yr-old Japanese man. The patient's tumor consisted of 5 different histological features in a single nodule: well-differentiated HCC with trabecular pattern; and moderately differentiated HCC with 4 different patterns (i.e., trabecular, pseudoglandular, solid, and scirrhous). Morphologically, HAK-2 cells on a plastic dish showed oval-shaped nuclei and large flat, polygonal eosinophilic cytoplasm and proliferated in a monolayered sheet with a population doubling time of 36.8 hours. Meanwhile, various structures, such as compact, trabecular, and tubular arrangements, were induced in HAK-2 cells cultured in type I collagen gel matrix. Also, HAK-2 cells in vitro underwent spontaneous apoptosis more frequently than other HCC cell lines examined. HAK-2 cells secreted various plasma proteins including albumin into the culture medium. Chromosome and flow cytometric analyses revealed that HAK-2 had many structural abnormalities with human karyotype and a single aneuploid cell population with a DNA index of 3.7, respectively. These findings suggest that HAK-2 is a new human HCC cell line representing two morphological characteristics; (1) formation of various structures in the presence of extracellular matrix and (2) frequent spontaneous apoptosis in vitro.