Nuclear expression of phosphorylated EGFR is associated with poor prognosis of patients with esophageal squamous cell carcinoma

OBJECTIVES

Although it has been reported that epidermal growth factor receptor (EGFR) is able to translocate from the plasma membrane to the nucleus, the pathophysiological role of this translocation in tumorigenicity is still unclear. In the present study, to elucidate the pathophysiological significance of EGFR translocation, we investigated the expression not only of conventional EGFR but also its phosphorylated form (pEGFR), focusing on its cellular localization in esophageal cancer tissues.

METHODS

Fifty-two specimens of esophageal squamous cell carcinoma (SCC) obtained by surgery were examined immunohistochemically for their EGFR and pEGFR immunostaining patterns. The relationships between clinicopathological parameters and EGFR or pEGFR immunostaining patterns were then analyzed.

RESULTS

In 37 (71.2%) of the 52 esophageal SCCs, EGFR immunoreactivity was clearly localized at the plasma membrane of the cancer cells, whereas pEGFR immunoreactivity was clearly localized in the nucleus in 19 (36.5%) cases. Nuclear expression of pEGFR significantly correlated with TNM stage and lymph node metastasis, and moreover was associated with a poor outcome of esophageal SCC.

CONCLUSIONS

Nuclear translocalization of pEGFR is associated with an increase in the malignant potential of esophageal SCC and may affect prognosis in patients with esophageal SCC.

Involvement of cyclooxygenase-2 and vascular endothelial growth factor in vascularization and lymph node metastasis of colorectal cancers with submucosal invasion

BACKGROUND AND AIMS

Although patients with early colorectal cancer invading the submucosa (CRC-sm) may be treated with endoscopic mucosal resection alone, they generally undergo additional surgery because of the risk of lymph node metastasis. The aims of the present study were to examine the roles of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor (VEGF) in tumor vascularization and to investigate whether COX-2 and VEGF expression and tumor vascularity are useful markers for predicting lymph node metastasis in CRC-sm.

METHODS

Twenty-seven resected specimens of CRC-sm with lymph node dissection were examined, and expression of COX-2 and VEGF was evaluated immunohistochemically and scored. Microvessel density (MVD) in CRC-sm tissues was estimated using a Macscope system after CD34 immunostaining. The relationships among clinicopathological parameters, COX-2 and VEGF expression, and MVD in CRC-sm tissues were then analyzed.

RESULTS

Scores for COX-2, VEGF and MVD were all significantly higher in patients with CRC-sm with lymphatic invasion or lymph node metastasis. COX-2 score (P < 0.0001) and VEGF score (P = 0.035) were significantly correlated with MVD in CRC-sm tissues. In addition, COX-2 score was significantly correlated with VEGF score in the CRC-sm specimens examined.

CONCLUSIONS

Both COX-2 and VEGF are involved in tumor vascularization in CRC-sm. COX-2 expression, VEGF expression, and MVD are possible markers for predicting lymph node metastasis in patients with CRC-sm, and use of COX-2 expression may be clinically practical.

Long-Term Survival After Repeat Resections of Metastases in Liver, Lung, and Stomach from Sigmoid Colon Cancer: Report of a Case

A 74-year-old female patient underwent a simultaneous colectomy and hepatectomy for sigmoid colon cancer and its hepatic metastases. Six months later she underwent a hepatectomy for recurrent hepatic metastases; then 10 months later, a pulmonary resection for pulmonary metastasis; and 24 months later, a partial gastrectomy for gastric metastasis. As of December 2005, at 7 years 6 months after the first surgery and at 4 years after the last surgery, the patient is still alive with a good quality of life and no sign of recurrence.

P16-Immunostaining Pattern as a Predictive Marker of Lymph Node Metastasis and Recurrence in Early Uterine Cervical Cancer

OBJECTIVES

We investigated the relationship between P16-immunostaining patterns and clinicopathological factors in early uterine cervix cancers and assessed whether P16-immunostaining patterns predict the prognosis of the patients with early uterine cervix cancers.

METHODS

Twenty-nine early squamous cell carcinoma (SCC) specimens of the uterus were examined using immunohistochemistry for P16 expression. The P16-immunostaining pattern was classified into two groups: the homogeneous type and the heterogeneous type. P16-immunostaining patterns were evaluated in different parts of the carcinoma in situ (CIS): the center of the tumor and the front interface of the infiltrating tumor.

RESULTS

All specimens were of the homogeneous type in CIS. The P16-immunostaining pattern was significantly of the heterogeneous type in the front interface of the infiltrating tumor with lymphatic invasion, vascular invasion, lymph node metastasis, and recurrence. Regarding the P16-immunostaining patterns in the front interface of the infiltrating tumor, the patients with the heterogeneous type showed a significantly worse prognosis than the patients with the homogeneous type.

CONCLUSIONS

The prognosis of patients with early uterine cervical SCC may be predicted by evaluating the P16-immunostaining pattern in the front interface of the infiltrating tumor.

Using the supercharge technique to additionally revascularize the gastric tube after a subtotal esophagectomy for esophageal cancer

BACKGROUND

Maintaining sufficient blood flow to the gastric tube after a subtotal esophagectomy for esophageal cancer is crucial for decreasing esophagogastric anastomotic leakage.

METHODS

After subtotal esophagectomy for esophageal cancer, the supercharge technique was performed in 21 esophageal reconstruction patients to additionally revascularize the gastric tube using the splenic artery and vein, external carotid artery, and internal jugular vein. Operative results of the supercharge group were retrospectively compared with those of the control group (patients not receiving the technique).

RESULTS

Both operation time and operative blood loss in the supercharge group were significantly longer and larger than those of the control group. However, the incidence of anastomotic leakage was significantly lower in the supercharge group than in the control group.

CONCLUSION

This practical supercharge technique reduces leakage during esophageal anastomosis.

Malignant stromal tumor, so called "gastrointestinal stromal tumor", with rhabdomyomatous differentiation occurring in the gallbladder

Gastrointestinal stromal tumors (GISTs) constitute the largest category of primary nonepithelial neoplasms of the gastrointestinal tract. It is extremely rare that this tumor occurs in the bile tract, and only a few cases have been reported. Immunohistochemically, the tumor cells revealed a phenotype similar to Cajal cells, occasionally with differentiation to smooth muscle cells or neural cells. We present a case of malignant stromal tumor similar to GISTs with rhabdomyomatous differentiation of the gallbladder in a 68-year-old woman. The resected tumor was predominantly composed of spindle cells with rhabdomyomatous differentiation. Immunohistochemical study revealed diffuse staining of tumor cells using vimentin despite negative staining for desmin or S-100. This indicated a mesenchymal origin of the cells without smooth muscle or neuronal differentiation. Myoglobin-positive cells, in which phosphotungstic acid hematoxylin staining revealed cross striations of the cytoplasm, suggested rhabdomyomatous differentiation. Diffuse positivity for KIT in the cells suggested that the pathogenesis of this tumor may resemble that of GIST. The tumor may have derived from a mesenchymal stem cell that had undergone partial rhabdomyomatous differentiation.

Analysis of K-ras mutations and expression of cyclooxygenase-2 and gastrin protein in laterally spreading tumors

BACKGROUND AND AIM

Recent advances in colonoscopic techniques have led to the increased detection of, and interest in, superficial type colorectal tumors, and a new category, the 'laterally spreading tumor (LST)', has been proposed. However, the characteristics of the genetic alterations in these LSTs have not yet been fully determined. We therefore classified LSTs as LST-granular (LST-G) or LST-non-granular (LST-NG), according to their macroscopic appearance, and examined the genetic alterations in these two tumor groups compared with those in protruded type tumors.

METHODS

We obtained a total of 62 colorectal tumors, including 26 protruded type, 17 LST-G and 19 LST-NG, from specimens resected surgically or endoscopically. We examined K-ras codon 12 mutations by using the polymerase chain reaction-restriction fragment length polymorphism method and by fluorescence direct sequencing. We also performed immunohistochemistry to analyze cyclooxygenase (COX)-2 and gastrin abnormalities.

RESULTS

The incidence of K-ras mutation was 50.0% in protruded type tumors, 76.5% in LST-G, and 26.3% in LST-NG. The frequencies of COX-2 overexpression were 73.1, 88.2, and 31.6%, respectively, and those of gastrin overexpression were 61.5, 82.4, and 26.3%, respectively. Therefore, LST-G is similar to protruded type tumors in that the incidence of K-ras mutation and the frequencies of COX-2 and gastrin overexpression are high. LST-NG differs from both of these tumor types in that the values of these three indicators are all low.

CONCLUSIONS

These results show that LST-G and LST-NG have different genetic alterations.

Tumor cell dissociation score highly correlates with lymph node metastasis in superficial esophageal carcinoma

BACKGROUND

It is still not clear which parameters are important for predicting the metastatic potential of superficial esophageal squamous cell carcinoma (SESCC). The purpose of the present paper was thus to investigate tumor cell dissociation (TCD) in SESCC as a predictive factor of lymph node metastasis.

METHODS

Thirty-three SESCC were classified into four groups based on the depth of tumor invasion. Carcinomas not invading as far as the muscularis mucosa were classified as group A; carcinomas invading to the muscularis mucosa or less than one-third of the upper submucosa were classified as group B; those invading to the middle layer of the submucosa were classified as group C; and those invading one-third of the lower submucosa were classified as group D. The TCD score was calculated by dividing the length of the TCD region by the maximal longitudinal length of the area of invasion into or beyond the lamina propria, and multiplying by 100. E-cadherin expression of the carcinomas was investigated in the TCD area and the successive area of mucosal invasive carcinoma (SAM).

RESULTS

The incidence of lymph node metastasis was 0% in group A, 10% in group B, 36.4% in group C and 57.1% in group D. The mean TCD scores (+/-SEM) of SESCC with lymph node metastasis were higher than that without (85.3 +/- 5.7, 16.3 +/- 3.9, respectively; P < 0.001). In group C, the TCD score of cases with lymph node metastases was higher than in those without lymph node metastasis (P < 0.001). E-cadherin expression was significantly reduced in the area of TCD compared with the SAM located over the TCD area (P < 0.001).

CONCLUSIONS

The TCD score is an important predictive marker for lymph node metastasis in SESCC. Clinical evaluation of TCD scores in endoscopic mucosal resection (EMR) specimens would enable accurate prediction of lymph node metastasis and extend the indication of EMR treatment for SESCC.

Methylation of the oestrogen receptor gene in non-neoplastic epithelium as a marker of colorectal neoplasia risk in longstanding and extensive ulcerative colitis

BACKGROUND

Surveillance colonoscopy is widely recommended in patients with longstanding and extensive ulcerative colitis (UC) in order to detect colorectal neoplasia at an early stage. However, it still remains questionable whether surveillance colonoscopy effectively enables early detection of UC associated neoplasia. There is a great need for sensitive markers to identify individuals at increased risk of neoplasia. The oestrogen receptor (OR) gene shows age related methylation in the colorectal epithelium and is methylated frequently in sporadic colorectal neoplasia, suggesting that OR methylation may predispose to colorectal neoplasia.

AIM

To clarify whether analysis of methylation of the OR gene in non-neoplastic epithelium can contribute to prediction of increased neoplasia risk in UC patients.

MATERIALS AND METHODS

A total of 165 non-neoplastic colorectal epithelia from 30 patients with longstanding and extensive UC, including 13 UC patients with neoplasia and 17 patients without, were evaluated. Methylation specific polymerase chain reaction was performed to determine the methylation status of the OR gene.

RESULTS

Methylation of the OR gene was detected in 54 of 70 (77.1%) non-neoplastic colorectal epithelia in UC with neoplasia but in only 23 of 95 (24.2%) without neoplasia. Methylation of the OR gene was significantly more frequent in non-neoplastic epithelium from UC with neoplasia than in chronic colitic epithelium from UC without neoplasia. Furthermore, in UC with neoplasia, the OR gene was extensively methylated in non-neoplastic epithelia throughout the colorectum compared with those in UC without neoplasia.

CONCLUSION

These results suggest that analysis of OR gene methylation may have potential as a useful marker for identifying individuals at increased risk of neoplasia among those with longstanding and extensive UC.

Evaluation of tumor cell dissociation as a predictive marker of lymph node metastasis in submucosal invasive colorectal carcinoma

PURPOSE

Tumor cell dissociation-the histologic finding of small solid carcinoma cell clusters and groups of dissociated dedifferentiated carcinoma cells at the invasive front-is related to tumor metastasis and patient prognosis. However, few previous reports have examined tumor cell dissociation in submucosal invasive colorectal carcinoma. We investigated the relation between tumor cell dissociation and lymph node metastasis in submucosal invasive colorectal carcinoma. We also examined immunohistochemical expression of E-cadherin and beta-catenin in submucosal invasive colorectal carcinoma.

METHODS

Submucosal invasive colorectal carcinoma tissue samples from 20 patients with lymph node metastasis and 100 patients without lymph node metastasis were evaluated. Sections stained with hematoxylin and eosin were evaluated for tumor cell dissociation. Immunohistochemistry was used to determine the expression and cellular distribution of E-cadherin and beta-catenin.

RESULTS

Tumor cell dissociation was more frequently identified in submucosal invasive colorectal carcinoma cases with lymph node metastasis than in those without lymph node metastasis (P = 0.0001). Decreased membranous expression of E-cadherin occurred more frequently in submucosal invasive colorectal carcinoma cases with lymph node metastasis than in those without lymph node metastasis (P = 0.025). Nuclear expression of beta-catenin tended to be present in submucosal invasive colorectal carcinoma cases with lymph node metastasis (P = 0.063). Decreased membranous expression of E-cadherin occurred more frequently in submucosal invasive colorectal carcinoma cases with tumor cell dissociation than in those without tumor cell dissociation (P = 0.0023).

CONCLUSIONS

Our results suggest that there is a relation between tumor cell dissociation and lymph node metastasis in submucosal invasive colorectal carcinoma. Tumor cell dissociation formation might be related to abnormal expression patterns of E-cadherin and beta-catenin in submucosal invasive colorectal carcinoma. Tumor cell dissociation and decreased membranous expression of E-cadherin would be important predictive markers for lymph node metastasis in submucosal invasive colorectal carcinoma.

Detection of Her2/neu, c-MYC and ZNF217 gene amplification during breast cancer progression using fluorescence in situ hybridization

The deletion of tumor suppressor genes and amplification of activating oncogenes appear to be critical events in tumorigenesis. We carried out fluorescence in situ hybridization (FISH) analysis of the breast cancer cell line MCF7 and clinically obtained cancer tissue sections on the basis of which we suggest a breast cancer development model. We selected 28 genes for FISH probes from breast cancer patients. Of the 28 genes studied, 14 were shown to be consistently amplified in the breast cancer cell line MCF7. We selected three genes from clinical tumor samples on the basis of results from MCF7 analysis. The amplification of Her2/neu or ZNF217 is closely associated with the stages of breast cancer. The frequency of amplification of Her2/neu increased notably in patients at stages later than IIB based on TNM staging, whereas the amplification of ZNF217 correlated with T2N1M0 at stage IIB and later stages. c-MYC amplification was not related to the stage. Her2/neu, ZNF217 and c-MYC were found to have a significantly increased copy number in breast cancer cells. In breast cancer progression, c-MYC amplification is an early event, while ZNF217 and Her2/neu amplification may play a role in the later stage of tumor development.

Endometrial adenosquamous carcinoma with osteoclast-like giant cells: immunohistochemistry and histogenesis. Case report

Primary extraskeletal epithelial neoplasms containing osteoclast-like giant cells (OGCs) are rare. We herein describe a case of adenosquamous carcinoma that developed in the endometrium together with non-neoplastic OGCs. The patient was a 72-year-old woman who underwent radical hysterectomy with salpingo-oophorectomy and lymph node dissection after being diagnosed with uterine cancer. Histologically, the tumor was found to be an adenosquamous carcinoma containing a large number of OGCs and mononuclear cells (MNCs) that had infiltrated into the stroma. Immunohistochemically, the OGCs and MNCs stained strongly positive for KP-1 and alpha-1-antichymotrypsin, and negative for the epithelial markers epithelial membrane antigen (EMA) and cytokeratins. These findings suggest that the OGCs and MNCs in this patient's tumor originated from monocytes/histiocytes, and most likely developed as part of the stromal reaction to the neoplasm.

Clear cell adenocarcinoma of the tongue

A firm, ulcerated tumor formed on the left side of the tongue of an elderly woman. Histopathological analysis showed that this unusual neoplasm was composed of monomorphic polygonal cells that exhibited a clear cytoplasm containing large amounts of periodic acid Schiff (PAS)-positive, diastase-digestive material. Most of the tumor cells stained immunohistochemically for Cytokeratin, high-molecular, CAM5.2, and epithelial membrane antigen (EMA), but were negative for alpha-smooth muscle actin, vimentin, glial fibrillary acid protein (GFAP), and S-100 protein. These findings supported a diagnosis of clear cell adenocarcinoma. Although patients with this type of tumor generally have a favorable prognosis, the tumor in our patient was fast-growing and contained a large number of Ki-67 positive cells, which are known to be highly proliferative. Thus, this case highlights the fact that even clear cell adenocarcinomas that are usually slow-growing should be investigated by conventional morphological techniques and their proliferative activity quantified in order to select the most appropriate treatment strategy.

Development of colonic neoplasia in p53 deficient mice with experimental colitis induced by dextran sulphate sodium

BACKGROUND

Several animal models for human ulcerative colitis (UC) associated neoplasia have been reported. However, most neoplasias developed in these models have morphological and genetic characteristics different from UC associated neoplasia.

AIMS

To establish a new colitis associated neoplasia model in p53 deficient mice by treatment with dextran sulphate sodium (DSS).

METHODS

DSS colitis was induced in homozygous p53 deficient mice (p53(-/-)-DSS), heterozygous p53 deficient mice (p53(+/-)-DSS) and wild-type mice (p53+/+-DSS) by treatment with 4% DSS. Numbers of developed neoplasias were compared among the experimental groups, and macroscopic and microscopic features of the neoplasias were analysed. Furthermore, K-ras mutation and beta-catenin expression were assessed.

RESULTS

p53(-/-)-DSS mice showed 100% incidence of neoplasias whereas the incidences in p53(+/-)-DSS and p53+/+-DSS mice were 46.2% and 13.3%, respectively. No neoplasias were observed in the control groups. The mean numbers of total neoplasias per mouse were 5.0 (p53(-/-)-DSS), 0.62 (p53(+/-)-DSS), and 0.2 (p53+/+-DSS). The number of neoplasias per mouse in the p53(-/-)-DSS group was significantly higher than that in the other DSS groups. The incidences of superficial type neoplasias were 91.7% in p53(-/-)-DSS mice, 75.0% in p53(+/-)-DSS mice, and 33.3% in p53+/+-DSS mice. The K-ras mutation was not detected in any of the neoplasias tested. Translocation of beta-catenin from the cell membrane to the cytoplasm or nucleus was observed in 19 of 23 (82.6%) neoplasias.

CONCLUSIONS

The p53(-/-)-DSS mice is an excellent animal model of UC associated neoplasia because the morphological features and molecular genetics are similar to those of UC associated neoplasia. Therefore, this model will contribute to the analysis of tumorigenesis related to human UC associated neoplasia and the development of chemopreventive agents.

Multilocular cystic renal cell carcinoma: a clinicopathological, immuno- and lectin histochemical study of nine cases

Multilocular cystic renal cell carcinoma (MCRCC) is an uncommon variant of renal neoplasm and its histogenesis is unclear. The aim of this study was to use immuno- and lectin histochemistry to delineate histochemical patterns which might indicate the histogenetic origin of MCRCC from a particular part or parts of the nephron. We present our experience with nine cases of MCRCC. Fifteen cases of renal cell carcinoma with cystic degeneration (RCC-CD) were selected for comparison with MCRCC. We carried out clinicopathological and immunohistochemical examinations of the MCRCC cases. Clinically, the prognosis of the patients was quite good, in that all nine patients are alive and without recurrence at the time of this report. The MCRCCs reacted strongly in a higher proportion of cases with the distal nephron markers, such as peanut agglutinin (PNA, 88.9%) and MUC1-core antibody (MUC1, 100%), but none reacted preferentially with proximal nephron markers such as vimentin, Leu M1 and Lotus tetragonolobus (LTA). The RCC-CD tumours reacted with vimentin (40%), Leu M1 (66.7%) and LTA (86.7%). Except for two cases, the RCC-CD tumours did not react with PNA or MUC1 core antibody. These results illustrate the different patterns of expression of MCRCC and RCC-CD and suggest that MCRCC originates from the distal nephron. Therefore, MCRCC should be differentiated from other types of renal cell carcinoma on the basis of the histogenesis of the tumour and the clinicopathological findings.

Alteration of the AT motif binding factor-1 expression in alpha-fetoprotein producing gastric cancer: is it an event for differentiation and proliferation of the tumors?

Alpha-fetoprotein producing gastric cancer (AFP-GC) rarely occurs, but it is classified as a special subtype of gastric cancer (GC). This tumor, as represented by the production of AFP, exhibits not only specific function but also different histology compared with ordinary-GC (O-GC). Clinically, it is likely to metastasize to the liver and, as a consequence, poor prognosis is recognized as one of the features. Recently, AT motif binding factor-1 (ATBF1) was identified as a modulator of AFP production by hepatocellular carcinoma, and the decreased expression of the protein was also reported in AFP-GC. However, little is known about the biological significance of the decreased expression. In this study, to clarify the biological characteristics of AFP-GC, antibody was raised against ATBF1 and immunohistochemistry was carried out. The antibody specifically recognized ATBF1, and the degree of expression could be characterized by immunohistochemistry. ATBF1 was expressed in O-GC and the area of tubular adenocarcinoma components of AFP-GC. On the other hand, the expression pattern varied in the hepatoid carcinoma components of AFP-GC, and AFP was expressed in the area without ATBF1 expression. Taken together, these results corroborated the previous reports that ATBF1 regulated AFP expression and inhibited transcription. Furthermore, in terms of differentiation induction, ATBF1 expression was decreased in the areas with little glandular formation. This may suggest that aberrant expression of ATBF1 induces the expression of various factors that are otherwise suppressed, and that this somehow determines the biological features of AFP-GC.

Extranodal diffuse follicular center lymphoma mimicking mantle cell lymphoma of the intestine

We report a case of diffuse follicular center lymphoma (FCL), which is a morphological variant of follicular lymphoma, resembling multiple lymphomatous polyposis (mantle cell lymphoma of the intestine). The patient was a 48-year-old Japanese man who was found, by colonoscopy, to have numerous small polypoid lesions along the entire large intestine. Abdominal computed tomography revealed hepatosplenomegaly and enlargement of multiple mesenteric lymph nodes. Histologically, the lesion was characterized by diffuse proliferation of small- to medium-sized lymphocytes with cleaved nuclei in the mucosa and submucosa. Immunohistochemical studies showed that the tumor cells were CD20+, CD10+, BCL-2+, CD5-, surface IgM-, and cyclin D1-. Moreover, a cytogenetic study showed a translocation at (14;18)(q32;q21). Finally, this case was diagnosed as diffuse FCL, although the tumor was mimicking mantle cell lymphoma.

Identification of genes differentially expressed in a newly isolated human metastasizing esophageal cancer cell line, T.Tn-AT1, by cDNA microarray

We isolated a metastasizing human esophageal squamous cell carcinoma (SCC) cell line, T.Tn-AT1, from a parental non-metastasizing cell line, T.Tn, by in vitro selection and by use of a nude mouse orthotopic inoculation model. Then, we compared the expression profiles of 9206 genes in T.Tn-AT1 and T.Tn by cDNA microarray analysis. The gene expression profiles of T.Tn and T.Tn-AT1 were very similar, and only 34 genes showed more than 3-fold differential expression. Among the 34 genes, 29 genes were down-regulated and only 5 genes were up-regulated in T.Tn-AT1 cells. Subsequently, we confirmed the expression levels of 14 of the 34 genes in T.Tn and T.Tn-AT1 cells by means of reverse transcription-polymerase chain reaction. The expression of 8 genes (KAL1, HPGD, NDN, REG1A, CXCR4, SPOCK, DIAPH2 and AIF1) was down-regulated and that of one gene (VNN2) was up-regulated in T.Tn-AT1 cells. These 9 genes encoded proteins associated with metastatic processes, such as adhesion, migration, inflammation, proliferation, and differentiation. Thus, these genes might regulate the metastasis of esophageal SCC, and could be predictive markers for lymph node metastasis of esophageal SCC.

Dedifferentiation and decreased expression of adhesion molecules, E-cadherin and ZO-1, in colorectal cancer are closely related to liver metastasis

Carcinoma cells with high metastatic potential often show a dedifferentiated phenotype at the primary site. In this study, a total of 48 cases (24 primary tumors of colorectal cancer (Pr-CRC) with liver metastasis, 24 without) were examined for E-cadherin and ZO-1 expression by immunohistochemical staining, and for their dedifferentiated phenotype. The expression levels of E-cadherin and ZO-1 were markedly decreased in the cancer cells of tumors with liver metastasis. Moreover, dedifferentiation of cancer cells, which was evaluated by the modified Gleason score, was also related to liver metastasis. However, none of the conventional clinicopathologic parameters of invasion, except lymph node metastasis, showed any relationship with liver metastasis. These results indicate that dedifferentiation and a decreased expression of E-cadherin and ZO-1 are closely related to liver metastasis.

Redifferentiation and ZO-1 reexpression in liver-metastasized colorectal cancer: possible association with epidermal growth factor receptor-induced tyrosine phosphorylation of ZO-1

Tubular gland structures of colorectal cancer (CRC) have been demonstrated to undergo dedifferentiation at the primary site, and then the gland structures are re-formed in the liver metastases. In this study, we examined the degree of differentiation of the gland structure of 48 cases of CRCs (24 cases with synchronous liver metastasis, 24 cases without metastasis) by the modified Gleason grading system. We also investigated the role of ZO-1, one of the tight junction proteins, in the morphological changes, i.e., dedifferentiation and redifferentiation, of CRCs at the primary site and liver metastases. Liver-metastasized CRCs (2.47+/-0.37) showed a lower score in the modified Gleason grading system than the corresponding primary tumors (3.28+/-0.36) did, i.e., the tumor cells had undergone redifferentiation at liver metastases. ZO-1 was expressed at the apical cell borders of normal colorectal epithelium, the luminal side of which has tubular gland structures. In comparison with this normal epithelium, the ZO-1 expression level was frequently reduced in primary CRC with liver metastasis (20.8%) and ZO-1 was reexpressed in liver metastasized cancers (79.2%). Furthermore, it was demonstrated by an immunoprecipitation-western blotting analysis on 5 cases of CRC with liver metastasis that ZO-1 bound to epidermal growth factor receptor (EGFR) irrespective of the phosphorylation status of EGFR, and that EGFR associated ZO-1 was highly tyrosine-phosphorylated only in the primary CRC, but was dephosphorylated in the liver-metastasized cancers. Our observations suggest that tyrosine phosphorylation of ZO-1 leads to down-regulation of the function of ZO-1 and dedifferentiation of the glands in CRCs, and these phenomena contribute to liver metastases, and redifferentiation of the glands occurs in the liver metastases.

Pathological issues of gastric and lower esophageal cancer: helicobacter pylori infection and its eradication

Gastric carcinoma is thought to develop via the actions of inducers and promoters of carcinogenesis. Tryptophan in charred fish or animal meat, ultraviolet rays, and irradiation, which damage genes of normal cells, have long been regarded as inducers of carcinoma, and agents such as alcohol, tobacco, aflatoxin, and nitrosoamine as promoters, with tobacco having both activities. The interaction between these environmental factors, principally diet, and Helicobacter pylori (Hp) is important in the genesis of gastric carcinoma. In this report, the histopathological feature of the Hp gastritis-carcinoma sequence is outlined, and the pathological characteristics of gastroesophageal reflux disease (GERD) and endoscopically negative reflux disease (ENRD) and the risk factors for lower esophageal carcinoma after Hp eradicated status in particular are discussed regarding aspects of cell cycle-associated factors. We conclude that (1) Infection with Hp increases the risk of gastric cancer in two histological phenotypes (i.e., diffuse undifferentiated type and intestinal differentiated type). Excessive cell replication and interrupting the mucus secretion mechanism may result in a large proportion of cells with genetic abnormalities. (2) Genetic alterations in gastric carcinogenesis may differ from those in colonic carcinogenesis. (3) The degree of GERD in Japanese patients is milder than that in patients from Western countries, although the incidence of GERD increases the status after successful eradication of Hp. It is also possible that accumulation of genetic abnormalities increases the number of cardiac and lower esophageal cancers. Investigation of cell cycle factors in GERD including ENRD can be expected to reveal the risk of carcinogenesis.