Irregular arrangement of collecting venules (IRAC) provides a critical endoscopic insight in Helicobacter pylori-induced gastritis: A secondary publication

The aim of this study was to evaluate the significance of an endoscopic atrophic border and irregular arrangement of collecting venules (IRAC) in the diagnosis of Helicobacter pylori (H. pylori)-induced gastritis. Upper gastrointestinal tract endoscopy was performed on 723 patients, who were screened them for H. pylori infection. Any patients who had undergone H. pylori eradication therapy were excluded from the study. The endoscopic atrophic border and IRAC in each patient were assessed. The H. pylori status was determined in the patients by combination of a serological test and/or histopathological examination. The H. pylori infection rates were 95.4% (455/477) in the group with an endoscopic atrophic border and 22.3% (55/246) in the group without an endoscopic atrophic border. In the diagnostic validity check, presence of an endoscopic atrophic border had a sensitivity of 89.2% and a specificity of 89.7%. Furthermore, the H. pylori infection rates were 95.5% (506/530) in the IRAC group and 2.1% (4/193) in the regular arrangement of collecting venules (RAC) group. In the diagnostic validity check, IRAC had a sensitivity of 99.2% and a specificity of 88.7%. In conclusion, the presence of an endoscopic atrophic border and IRAC are highly indicative of an H. pylori-infected gastric mucosa.

Laminin-5 is a biomarker of invasiveness in cervical adenocarcinoma

BACKGROUND

Glandular lesions are often problematic for diagnostic cervical pathology. The survival of patients with adenocarcinoma is significantly poorer than that of patient with squamous cell carcinoma. One reason for this increased risk is the aggressive invasiveness of adenocarcinoma. Therefore additional biomarkers, to supplement morphological diagnosis of adenocarcinoma, are necessary. We have assessed the diagnostic utility of Laminin-5 (Laminin γ2 chain): Lam-5 in the diagnosis of the invasiveness of cervical adenocarcinoma and related glandular lesions.

METHODS

Lam-5 immunohistochemistry was performed on archival specimens from 8 patients with uterine leiomyoma as a negative control group, 6 patients with endocervical gland hyperplasia, 6 patients with adenocarcinoma in situ, 6 patients with microinvasive adenocarcinoma and 24 patients with invasive adenocarcinoma.

RESULTS

The expression of Lam-5 was not detected in normal mucosa, but was seen along the basement membrane in endocervical gland hyperplasia and adenocarcinoma in situ and was observed in the cytoplasm of tumor cells in microinvasive and invasive adenocarcinoma.

CONCLUSION

We conclude that Lam-5 is a useful biomarker in the evaluation of invasiveness in cervical adenocarcinoma.

VIRTUAL SLIDES

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/7316562925827381.

An assessment of the diagnostic criteria for sessile serrated adenoma/polyps: SSA/Ps using image processing software analysis for Ki67 immunohistochemistry

Background

Serrated polyps belong to a heterogeneous group of lesions that are generally characterized morphologically. This type of lesion is thought to be the precursor of sporadic carcinomas with microsatellite instability, and probably also the precursor for CpG island-methylated microsatellite-stable carcinomas. For practical purposes, according to the 2010 WHO classification, the diagnostic criteria for sessile serrated adenomas/polyps (SSA/Ps) was established by the research project “Potential of Cancerization of Colorectal Serrated Lesions” led by the Japanese Society for Cancer of the Colon and Rectum. The aim of this study was to evaluate the validity of the morphologic characteristics established in Japan by using immunohistochemical staining for Ki-67.

Methods

To calculate the target cells, 2 contiguous crypts which could be detected from the bottom of the crypt to the surface of the colorectal epithelium were selected. To validate the proliferative activity, we evaluated the percentage and the asymmetrical staining pattern of Ki67 positive cells in each individual crypt. To examine the immunoreactivity of Ki67, computer-assisted cytometrical analysis was performed.

Results

SSA/Ps had a higher proliferative activity as compared to hyperplastic polyps (HPs) based on the difference in incidence of Ki67 positive cells, and the former also exhibited a significantly higher asymmetric distribution of these cells as compared to HPs, even in lesions with a diameter <10 mm.

Conclusion

We conclude that assessment of the pathological findings of SSA/Ps, including crypt dilation, irregularly branching crypts, and horizontally arranged basal crypts (inverted T- and/or L-shaped crypts) is appropriate to show a significantly higher proliferative activity as compared to HPs. Further, the use of two-dimensional image analysis software is an objective and reproducible method for this type of histological examination.

Virtual slides

The virtual slides for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6718091416698112

Clinicopathological features of serrated adenocarcinoma defined by Mäkinen in dukes' B colorectal carcinoma

OBJECTIVE

Serrated adenocarcinoma (SAC), proposed as a new pathologic type, arises predominantly in the right side of the colon and has a poorer prognosis than conventional colorectal carcinoma. The prognosis of colorectal carcinoma is variable in Dukes' B, so the aim of this study was to determine whether or not SAC has a poor prognosis in Dukes' B.

METHODS

The study group comprised 64 patients who underwent surgery for colorectal carcinoma. We undertook a statistical analysis of the association of SAC and non-SAC with sex, age, histologic type, depth of tumor, location of tumor, venous invasion and lymphatic invasion.

RESULTS

SACs were encountered in 17.5% of cases (n = 11). SAC had a less favorable 5-year survival than non-SAC (p = 0.0396 log-rank, Kaplan-Meier). The factors that achieved statistical significance in the univariate analysis were subsequently included in a multivariate analysis and we found that SAC was an independent factor (p = 0.027).

CONCLUSIONS

SAC has a poor prognosis and is not affected by other factors confirming that SAC is an independently less favorable prognostic factor.

DMBT1 is a novel gene induced by IL-22 in ulcerative colitis

BACKGROUND

Interleukin (IL)-22 is a recently identified cytokine that is suggested to play pivotal roles in various inflammatory diseases. Although the IL-22 receptor 1 (IL-22R1) is restrictively expressed in epithelial cells in the colon, the role of IL-22 in colonic diseases still remains unclear. In this study microarray analyses revealed that deleted in malignant brain tumors 1 (DMBT1) is a novel upregulated gene in IL-22-stimulated colon cancer cells. Therefore, we investigated the involvement of DMBT1 and IL-22 in ulcerative colitis (UC) tissues and examined the mechanism regulating the expression of DMBT1 in response to IL-22 stimulation.

METHODS

Changes of gene expression in IL-22-stimulated SW403 cells were investigated by microarray analyses. The effects of IL-22 on DMBT1 expression were examined in SW403 cells using a small interfering RNA (si)RNA for STAT3 or inhibitors for MEK, PI3K, and nuclear factor kappa B (NF-κB). The element responsible for IL-22-induced DMBT1 promoter activation was determined by a promoter deletion and electrophoretic mobility shift assay (EMSA). Expression of IL-22, IL-22R1, and DMBT1 in UC tissues was analyzed by real-time reverse-transcription polymerase chain reaction (RT-PCR) and immunohistochemistry.

RESULTS

IL-22 treatment enhanced the expression of DMBT1 through STAT3 tyrosine phosphorylation and NF-κB activation in colon cancer cells. The IL-22-responsive element was located between -187 and -179 in the DMBT1 promoter region. In the UC mucosa the levels of DMBT1 and IL-22 mRNA expression were significantly enhanced and positively correlated, the numbers of IL-22-positive lymphocytes were increased, and the expression of IL-22R1 and DMBT1 was enhanced in the inflamed epithelium.

CONCLUSIONS

The IL-22/DMBT1 axis may play a pivotal role in the pathophysiology of UC.

Immunohistochemical analysis of REG Iα expression in ulcerative colitis-associated neoplastic lesions

BACKGROUND AND AIMS

The regenerating gene (REG)Iα has been identified by microarray analysis as a gene that is distinctly overexpressed in ulcerative colitis (UC), and its protein product is suggested to play a pivotal role in the development of UC-associated carcinoma. In the present study, we investigated the significance of REG Iα expression as a diagnostic marker of UC-associated neoplasia.

METHODS

Tissue samples were obtained from colectomy specimens from 31 patients with long-standing UC (mean disease duration 17.2 years, range 5-29). The lesions were evaluated according to the International Classification for Dysplasia in Inflammatory Bowel Diseases, and the sections were examined using immunohistochemistry for REG Iα and p53.

RESULTS

In the 'regenerating atypia' group, REG Iα immunoreactivity was restricted to the lower third of the UC mucosa (grade 1). Lesions classified as 'indefinite for dysplasia' also showed predominantly basal-type staining for REG Iα. However, in 'low-grade dysplasia' and 'high-grade dysplasia' lesions, the localization of REG Iα immunoreactivity expanded to the middle (grade 2) and upper (grade 3) third of the UC mucosa, respectively. The REG Iα immunostaining pattern differed significantly (p < 0.0001) between non-neoplastic and neoplastic lesions, and was significantly (p < 0.0001) associated with p53 overexpression.

CONCLUSIONS

Immunohistochemical analysis of REG Iα expression is useful for differential diagnosis of non-neoplastic and neoplastic lesions in UC tissues.

Ectopic gastric mucosa and pancreatic ducts in the rectum

A 68-year-old woman with fecal occult blood was referred to Dokkyo Medical School Hospital. Colonoscopy demonstrated a flat lesion in the rectum, and endoscopic mucosal resection of the lesion was performed. Histologic examination revealed that it contained ectopic gastric mucosa, which had a gastric foveolar and glandular mucinous phenotype, as demonstrated by immunohistochemistry. Moreover, the lesion also contained CA19-9- and CK7-positive pancreatic duct-like components in the submucosal layer. The present case is the first report to describe ectopic gastric mucosa and pancreatic ducts concurrently arising in the rectum.

GROα promotes invasion of colorectal cancer cells

Growth-regulated oncogene α (GROα) is a chemokine that plays a role not only in inflammation, but also in tumorigenesis. Accumulating data suggest that GROα is involved in tumor development and invasion in various malignancies, such as melanoma and bladder cancer. However, the pathophysiological role of GROα in human colorectal cancers (CRCs) is still unknown. We examined the expression of GROα and its pathophysiological significance in human CRCs and investigated whether GROα promotes the invasive potential of colon cancer cells. Specimens of 62 primary CRCs were examined immunohistochemically for GROα, and the relationship between GROα expression and clinicopathological features was investigated. The mRNA expression of GROα and its receptor CXCR2 was examined in ten colon cancer cell lines using RT-PCR. The effect of GROα protein on invasive potential was investigated in DLD-1 and LoVo cells using a Matrigel invasion chamber assay. Forty-nine (79%) of the 62 CRCs showed positive immunoreactivity for GROα. GROα expression was significantly associated with tumor size, tumor stage, depth of invasion, LN metastasis and patient survival (P=0.021, P<0.0001, P=0.0033, P<0.0001, P=0.039, respectively). Expression of CXCR2 mRNA was detectable in all ten colon cancer cell lines examined, whereas expression of GROα mRNA was detectable in six. Treatment with GROα protein significantly increased the number of invasive cells. In conclusion, GROα may play a pivotal role in the invasion of human CRCs.

Detection of desmoplastic reaction in biopsy specimens is useful for predicting the depth of invasion of early colorectal cancer: a Japanese collaborative study

BACKGROUND

We have previously demonstrated a relationship between the depth of submucosal invasion (SM depth) and the frequency of lymph node metastasis in resected submucosal invasive colorectal cancers (SICRCs). Here, we assessed the desmoplastic reaction (DR) in pretreatment biopsy specimens of SICRC to predict the SM depth.

METHODS

A total of 359 patients with SICRCs, who had undergone surgical or endoscopic mucosal resection, were enrolled. The SM depth of the SICRC lesions was evaluated according to the procedure established by the Japanese Society for Cancer of the Colon and Rectum, and the patients' corresponding pretreatment biopsy specimens were examined histologically to evaluate the prevalence of DR.

RESULTS

For pedunculated SICRCs, the prevalence of DR in pretreatment biopsy specimens was significantly higher in moderately differentiated than in well-differentiated adenocarcinomas, but was not significantly related to SM depth. For nonpedunculated SICRCs, the prevalence of DR in pretreatment biopsy specimens was significantly related to histological type, tumor size, and SM depth. When non-pedunculated SICRCs were further divided using a specific cutoff value of 1000 μm for SM depth, the DR positivity rate in pretreatment biopsy specimens was significantly higher in SICRCs with an SM depth of ≥1000 μm (termed "SM massive CRCs") than in cases where the SM depth was <1000 μm (termed "SM slight CRCs").

CONCLUSIONS

Detection of DR in pretreatment biopsy specimens is useful for the prediction of SM depth in nonpedunculated SICRCs, and may be useful for the selection of such cases that would be treatable by endoscopic mucosal resection and endoscopic submucosal dissection (EMR/ESD).

Expression of β-catenin and REG Iα in relation to cell proliferative ability in salivary gland tumors

β-catenin and its target gene products have been thought to play pivotal roles in the progression of various neoplasias. In the present study, we examined the expression of β-catenin and regenerating gene (REG) Iα in salivary gland tumors and investigated its relationship to their cell proliferative ability. Nineteen patients with pleomorphic adenoma (PA) and 17 patients with malignant salivary gland tumors, including 7 adenoid cystic carcinomas, 7 mucoepidermoid carcinomas and 3 polymorphous low-grade adenocarcinomas, were enrolled. The specimens that had been surgically resected from these patients were examined using immunohistochemistry for β-catenin, REG Iα and Ki67. The relationships between clinicopathological features and β-catenin or REG Iα expression were then analyzed. β-catenin immunoreactivity was positive in 14 PAs (73.3%) and 14 malignant salivary gland tumors (82.4%). Four (28.6%) of the 14 β-catenin-positive PAs showed clear β-catenin immunoreactivity at the plasma membrane (membrane type), while 10 (71.4%) showed diffuse immunoreactivity in the cytoplasm and nucleus but not at the plasma membrane (non-membrane type). Twelve (85.9%) of the 14 malignant salivary gland tumors showed non-membrane-type β-catenin expression. Six (31.6%) of the 19 PAs and 10 (58.8%) of the 17 malignant salivary gland tumors were positive for REG Iα expression. PAs with non-membrane-type β-catenin expression showed a significantly higher Ki67 labeling index than PAs with negative or membrane-type expression. Additionally, PAs that were REG Iα-positive showed a significantly higher Ki67 labeling index than those that were negative. Non-membrane-type β-catenin expression was related to REG Iα positivity in PA lesions. β-catenin and its associated REG Iα protein may play a role as growth-promoting factors in the development of salivary gland tumors.

Abstract 3597: Association between the ABCG2 polymorphisms and the gefitinib-induced side effects in Japanese patients with non-small cell lung cancer

ABCG2 is a half-size ATP-binding cassette transporter implicated in cellular gefitinib transport. Reportedly, the c.421C&gt;A ABCG2 gene variant was associated with gefitinib-induced diarrhea in Caucasian patients with non-small cell lung cancer. c.421C&gt;A ABCG2, resulting in p.Q141K substitution, is more prevalent in Asian populations. Therefore, the putative relationship between gefitinib-induced adverse effects and this functional polymorphism was investigated in 75 Japanese patients with non-small cell lung cancer treated with gefitinib 250 mg/d orally, and the results were correlated with treatment-related adverse effects. c.376 C&gt;T, resulting in truncated, non-functional ABCG2, was also investigated. Forty one (54.7%) patients harbored 376T or 421A ABCG2 on at least one allele, while the remaining 34 (45.3%) were wild type for ABCG2. No significant group differences were observed in frequency of gefitinib-related diarrhea or other adverse effects. Next, DLD-1 colon cancer cells expressing wild-type (DLD-1/WT) or 141K mutant ABCG2 (DLD-1/Q141K) were established for investigation of in-vitro cell sensitivity to the ABCG2-substrate drugs, gefitinib and SN-38. ABCG2 expression was much lower in DLD-1/Q141K cells than in DLD-1/WT cells, despite similar ABCG2 mRNA levels. DLD-1/WT cells acquired more resistance to SN-38 than did DLD-1/Q141K cells, but neither cell line acquired gefitinib resistance compared with parental cells. In-vitro data also suggested that ABCG2 has only a limited role in toxicity of gefitinib, but not SN-38, in colon-derived cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3597.

Involvement of the IL-22/REG Ialpha axis in ulcerative colitis

The Regenerating gene (REG) Ialpha protein, a trophic and/or anti-apoptotic factor, is important in the pathophysiology of gastrointestinal inflammation. Interleukin (IL)-22 is a recently identified cytokine that is suggested to have pivotal roles in inflammatory bowel diseases. We therefore investigated the involvement of the IL-22/REG Ialpha axis and examined the mechanism of regulation of REG Ialpha expression by IL-22 stimulation in ulcerative colitis (UC) mucosa. Expression of IL-22, IL-22 receptor 1 (IL-22R1), and REG Ialpha in UC mucosa was analyzed by real-time RT-PCR and immunohistochemistry. The effects of IL-22 on REG Ialpha protein expression were examined using a small-interfering RNA for STAT3, an MAPK inhibitor or a PI3K inhibitor. The element responsible for IL-22-induced REG Ialpha promoter activation was determined by a promoter deletion and electrophoretic mobility shift assay. The expression of IL-22 was enhanced in infiltrating inflammatory cells, and that of IL-22R1 and REG Ialpha was concurrently enhanced in the inflamed epithelium in UC mucosa. The levels of REG Ialpha and IL-22 mRNA expression were strongly correlated, and the distributions of REG Ialpha- and IL-22R1-positive epithelial cells were very similar. IL-22 simulation enhanced the expression of REG Ialpha protein through STAT3 tyrosine phosphorylation in colon cancer cells. The IL-22-responsive element was located between -142 and -134 in the REG Ialpha promoter region. REG Ialpha protein may have a pathophysiological role as a biological mediator for immune cell-derived IL-22 in the UC mucosa.

Impact of functional ABCG2 polymorphisms on the adverse effects of gefitinib in Japanese patients with non-small-cell lung cancer

PURPOSE

ABCG2 is a half-size ATP-binding cassette transporter implicated in cellular gefitinib transport. Reportedly, the c.421C > A ABCG2 gene polymorphism was associated with gefitinib-induced diarrhea in Caucasian patients with non-small-cell lung cancer. Since c.421C > A ABCG2, resulting in p.Q141K substitution, is more prevalent in Asian populations, the putative relationship between gefitinib-induced adverse effects and this functional polymorphism was investigated in Japanese patients. c.376C > T, resulting in truncated, non-functional ABCG2, was also investigated.

METHODS

ABCG2 gene polymorphisms were evaluated in 75 patients with non-small-cell lung cancer treated with gefitinib 250 mg/day orally, and results were correlated with treatment-related adverse effects.

RESULTS

Forty (53.3%) patients harbored c.421A ABCG2 on at least one allele, while the remaining 35 (46.7%) were wild type for c.421C > A. No significant group difference was observed in frequency of gefitinib-related diarrhea or other adverse effects. In addition, the only one patient homozygous for the c.421A allele in this study was not affected with gefitinib-induced diarrhea or interstitial lung disease. Two patients (2.7%) were found to harbor the c.376T allele heterozygously. One of the two patients harbored both the c.376T and the c.421A genotypes on distinct alleles. Gefitinib-related interstitial lung disease and severe diarrhea were noted in neither of the two patients.

CONCLUSIONS

In this Japanese population, we did not find an evident association between ABCG2 polymorphisms, c.376C > T and c.421C > A, and susceptibility to gefitinib-induced adverse effects.

Involvement of REG Ialpha protein in the regeneration of ductal epithelial cells in the minor salivary glands of patients with Sjögren's syndrome

The regenerating gene (Reg) was originally isolated from regenerating rat pancreatic islets and revealed recently to constitute a multi-gene family in humans. REG Ialpha protein is known to be overexpressed not only in various human inflammatory diseases but also in various experimental models of inflammation in animal tissues. However, its involvement in pathophysiology of the minor salivary gland (MSG) is not clear. We investigated REG Ialpha expression in the MSG of patients with primary Sjögren's syndrome (SS) and assessed its role in ductal epithelial cell proliferation in such tissues. Lip biopsy specimens were obtained from 40 patients with primary SS and examined using immunohistochemistry for REG Ialpha protein, Ki67 and single-strand DNA (ssDNA). The relationships among clinicopathological factors and expression of REG Ialpha protein, Ki67 and ssDNA in the MSG were then analysed. REG Ialpha protein was expressed rarely in ductal epithelial cells of the normal MSG but was apparently overexpressed in those of patients with SS. The labelling indices for both Ki67 and ssDNA in the ductal cells of the MSGs were significantly higher in SS patients than in controls. Moreover, these labelling indices were significantly higher in REG Ialpha-positive than in negative SS patients. REG Ialpha protein may play a role in the regeneration of ductal epithelial cells in the MSGs of patients with SS.

Inhibitory effects of the cyclooxygenase-2 inhibitor, etodolac, on colitis-associated tumorigenesis in p53-deficient mice treated with dextran sulfate sodium

Non-steroidal anti-inflammatory drugs (NSAIDs) and cyclooxygenase-2 (COX-2) inhibitors are representative agents for the chemoprevention of sporadic colorectal neoplasia. However, few reports have described the chemopreventive effects of such agents on colitis-associated tumorigenesis. To clarify whether treatment with the COX-2 inhibitor may reduce the risk of colitis-associated neoplasia, we investigated the effect of one such agent, etodolac, on tumorigenesis in the colitis-associated neoplasia model using p53-deficient mice treated with dextran sulfate sodium (DSS). The p53-/- mice were divided into four groups: i) treatment with DSS + etodolac, then after two cycles of DSS, the mice were given distilled water for 84 days. In addition, etodolac was administered three times a week at a dose of 10 mg/kg body weight throughout the experiment. ii) Treatment with two cycles of DSS only, followed by distilled water for 84 days. iii) Treatment with etodolac alone. iv) Distilled water alone was administered to the control group. The incidence of mice with neoplasia was 82.4% in the DSS + etodolac group and 100% in the DSS-alone group. No neoplasia was observed in the etodolac-alone and control groups. The mean (+/- SEM) number of total neoplasias per mouse was 1.29+/-0.2 in the DSS + etodolac group and 3.0+/-0.52 in the DSS-alone group, the inter-group difference being significant (p<0.01). There was no significant difference in the inflammation score between these two groups. These results showed that treatment with etodolac significantly reduced the occurrence of neoplasia, suggesting that this COX-2 inhibitor has chemopreventive activity against colitis-associated tumorigenesis.

The CD155/poliovirus receptor enhances the proliferation of ras-mutated cells

Stimulation of the CD155/poliovirus receptor, which localizes in the cell-matrix and at cell-cell junctions, inhibits cell adhesion and enhances cell migration. Necl-5, a mouse homolog of CD155, is implicated in the formation of adherence junctions. Recently, Necl-5 has also been found to enhance cell proliferation via the stimulation of serum and platelet-derived growth factor through the Ras-Raf-MEK-ERK signaling pathway. In our present study, we find that CD155 significantly enhances the serum-induced cell proliferation of NIH3T3 cells which have been transformed by an oncogenic Ras (V12Ras-NIH3T3), but not the parental cells. CD155 expression in V12Ras-NIH3T3 cells is also found to upregulate cyclin D2, downregulate p27(Kip1) and shorten the G0/G1 phase of the cell cycle. An inhibitor of focal adhesion kinase does not reduce this CD155-mediated enhancement of V12Ras-NIH3T3 cell proliferation. The expression of CD155DeltaCP, which lacks the cytoplasmic region including the immunoreceptor tyrosine-based inhibitory motif (ITIM), has a reduced ability to enhance the serum responsiveness of V12Ras-NIH3T3 cells, suggesting that the ITIM might be required for this effect of CD155. In addition, the overexpression of exogenous CD155 enhances the serum responsiveness of HT1080 cells, which harbor a mutant N-ras gene. On the other hand, siRNA-induced knockdown of endogenous CD155 and/or CD155DeltaCP expression significantly repress the serum responsiveness of DLD-1 cells, which express endogenous CD155 and harbor a mutant K-ras gene, suggesting that this mutant may function in a dominant negative manner. Taken together, our present data suggest that CD155, at least in part, enhances the proliferation of ras-mutated cells.

REG Ialpha protein mediates an anti-apoptotic effect of STAT3 signaling in gastric cancer cells

Signal transducer and activator of transcription 3 (STAT3) signaling plays roles in inflammation-associated carcinogenesis. Regenerating gene (REG) Ialpha protein, an interleukin (IL)-6-inducible gene, is suggested to be involved in the gastritis-gastric cancer sequence. We investigated the involvement of IL-6/STAT3 signaling in REG Ialpha protein expression and examined whether REG Ialpha protein mediates an anti-apoptotic effect of STAT3 signaling in gastric cancer cells. The effects of IL-6/STAT3 signaling on REG Ialpha protein expression were examined using a STAT3 small interfering RNA system in gastric cancer cells. The element responsible for IL-6-induced REG Ialpha promoter activation was determined by a promoter deletion assay. The anti-apoptotic effects of STAT3 signaling and its induced REG Ialpha protein were examined by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphatase nick-end labeling and caspase assay in vitro. Human gastric cancer specimens were analyzed by immunohistochemistry for phosphorylated signal transducer and activator of transcription 3 (p-STAT3) and REG Ialpha protein. IL-6 treatment enhanced the expression of REG Ialpha protein through STAT3 activation in gastric cancer cells. The IL-6-responsive element was determined to lie in the sequence from -142 to -134 of the REG Ialpha promoter region. REG Ialpha protein mediated the anti-apoptotic effects of STAT3 signaling in gastric cancer cells by enhancing Akt activation, Bad phosphorylation and Bcl-xL expression. The expression of REG Ialpha protein was significantly correlated with that of p-STAT3 in gastric cancer tissues. REG Ialpha protein may play a pivotal role in anti-apoptosis in gastric tumorigenesis under STAT3 activation.

Cecal adenocarcinoma with prominent rhabdoid feature: report of a case with immunohistochemical, ultrastructural, and molecular analyses

Colorectal adenocarcinoma with rhabdoid phenotype is extremely rare, and only 1 case of adenocarcinoma showing rhabdoid dedifferentiation has been reported. The authors present another case of cecal adenocarcinoma with prominent rhabdoid feature in a 66-year-old man. The 13-cm sized tumor consisted mainly of rhabdoid cells and partly of adenocarcinoma, and transition from adenocarcinoma to rhabdoid areas was noted. Ultrastructural analysis revealed intracytoplasmic aggregates of intermediate filaments in the rhabdoid cells. Adenocarcinoma cells were diffusely immunoreactive to cytokeratin 7 and AE1/3, but occasionally positive for vimentin. The rhabdoid cells were negative for cytokeratin 7, weakly/focally immunoreactive to AE1/3, and diffusely positive for vimentin. These results suggested that the rhabdoid cells were dedifferentiated adenocarcinoma. Analysis of the rhabdoid cells with molecular techniques is also presented.

Ectopic hepatocellular carcinoma arising from pancreas: A case report and review of the literature

A 56-year-old man was found to have a pancreatic tail tumor. His blood chemistry showed no infection with hepatitis B or C virus and no elevations of tumor markers or pancreatic hormones. Abdominal ultrasound showed an encapsulated, rather heterogeneous, hypoechoic tumor, 6.5 cm in maximum diameter, with a beak sign. Helical dynamic CT revealed an irregularly enhanced tumor with pooling of contrast medium in the delayed phase. Abdominal angiography showed a hypervascular tumor. With a tentative diagnosis of non-functional islet-cell tumor, the patient underwent resection of the pancreatic body and tail with splenectomy. The contour of the liver and its surface were normal. In microscopic examination, tumor cells arranged in a trabecular pattern with focal bile pigment resembling hepatocellular carcinoma (HCC). Immunohistochemically, these tumor cells were positivefor HEPPAR-1, CAM5.2, cytokeratin 18 and COX-2, but negative for MUC-1, and cytokeratins 7, 20 and 8. These results supported a diagnosis of HCC without any adenocarcinoma component. The patient is currently doing well without any signs of recurrence in either the remaining pancreas or liver three years after surgery. We report the rare case with ectopic HCC in the pancreas with a review of the literature.