Pathological vessel invasion is a well-known prognostic factor in early-stage, non-small cell lung cancer and preoperative predicting vessel invasion may enable us to improve prognosis by additional interventions. We evaluated the importance of vessel invasion as a prognostic factor in clinical stage IA non-small cell lung cancer and predictive performance of simple diameter-based computed tomography image analysis for vessel invasion.
The study design was retrospective, and we reviewed 398 patients who underwent surgical resection of clinical stage IA non-small cell lung cancer from 1999 to 2009. The prognostic factors for recurrence-free survival were examined by univariate and multivariate analyses. Additionally, we analyzed preoperative high-resolution computed tomography images of patients with adenocarcinoma. The greatest diameter of the tumor in the lung window and the length of the consolidation part of L in the mediastinal window were measured. Then the ratio (mediastinal window/lung window) was calculated, and the correlation between the ratio (mediastinal window/lung window) and vessel invasion was analyzed by receiver operating characteristic analysis.
Sixty-eight recurrences occurred. Multivariate analysis revealed that vessel invasion, high preoperative serum carcinoembryonic antigen, and history of other malignancy were independent prognostic factors; their hazard ratios were 2.98, 2.45, and 1.98, respectively. The receiver operating characteristic analysis showed that the area under the curve was 0.75. When we set the cut-off value of the ratio (mediastinal window/lung window) at 0.67, the sensitivity and specificity were 75% and 72%, respectively.
Vessel invasion had the greatest impact on recurrence in clinical stage IA non-small cell lung cancer. Our simple computed tomography image analysis showed good predictive performance for vessel invasion.
Lung cancer; Diagnosis; Pathology; Computed tomography
Unicentric Castleman's disease is a rare, benign lymphoproliferative disorder that is curable with surgical resection. However, significant bleeding often occurs during surgery because of tumor hypervascularity. We herein present a case of hyaline-vascular-type mediastinal unicentric Castleman's disease, successfully resected using video-assisted thoracoscopic surgery with preoperative embolization. In the present case, tumor hypervascularity and feeding vessels were revealed by computed tomography (CT), which led us to perform preoperative angiography and embolization to the tumor feeding arteries to reduce intraoperative bleeding. Castleman's disease should be considered in the differential diagnosis of hypervascular mediastinal tumors. Tumor vascularity should be assessed prior to surgery, and preoperative embolization should be considered.
To evaluate the postmortem changes of the heart wall on postmortem (PM) computed tomography (CT) in comparison with those on ante mortem CT (AMCT), and in comparison with the pathological findings, obtained in the same patients.
Materials and Methods
We studied 57 consecutive patients who had undergone AMCT, PMCT, and pathological autopsy in our tertiary care hospital between April 2009 and December 2010. PMCT was performed within 20 hours after death, followed by pathological autopsy. The cardiac chambers were measured at five sites on both AMCT and PMCT by two board-certified radiologists who were not provided with clinical information. The differences in heart wall thickness between AMCT with and without contrast medium, between AMCT and PMCT, and between PMCT and pathological anatomy were evaluated statistically. Confounding factors of postmortem change such as gender, presence of arteriosclerosis, the organ related to cause of death, age, and elapsed time since death were examined statistically.
No significant differences were observed on AMCT in comparison of contrasted and non-contrasted images. The heart wall was significantly thicker on PMCT than on AMCT (p < 0.0001) at all five measurement sites. The heart wall was significantly thicker on PMCT than on pathology specimens when measured in accordance with pathological standard mensuration. However, no significant difference was observed between PMCT measurements and those of pathology specimens at any site when the papillary muscles and epicardial fat were included. No significant association was found between postmortem change in heart wall thickness and gender, presence of arteriosclerosis, the organ related to cause of death, age, or elapsed time since death.
This is the first longitudinal study to confirm greater thickness of heart wall on postmortem images compared with ante mortem images, in the same patients. Furthermore, the postmortem changes on CT were supported by the pathological findings.
A 53-year-old man was suspected of having an esophageal neoplasm. An endoscopic examination including Lugol chromoendoscopy suggested an esophageal squamous cell neoplasm limited to the lamina propria. A targeted biopsy showed atypical squamous cells, and an endoscopic submucosal dissection was performed 22 days after the previous endoscopy. Although a single 40 mm unstained area was observed by preoperative Lugol chromoendoscopy, intraoperative endoscopy revealed a 25 mm iodine-unstained area, with small unstained areas scattered on the oral side. We included the small unstained areas in the extent of the resection through assessment by preoperative endoscopy. Histopathologically, the tumor extent appeared to coincide with the preoperative assessment. Tumor cells were found in the basal-parabasal layers of the mucosa, in which small unstained areas were scattered, although the superficial layers exhibited well-differentiated cells containing glycogen in the cytoplasm. Although Lugol chromoendoscopy, which can induce chemical esophagitis, is widely used, re-epithelialization after mucosal damage by preoperative iodine staining may complicate the intraoperative demarcation of tumors.
Lugol chromoendoscopy; Esophageal squamous cell neoplasm; Re-epithelialization
It has been suggested that ubiquitin-conjugating enzyme E2C (UBE2C, also known as UBCH10) represents a promising cancer biomarker. However, the clinicopathological or prognostic significance as well as the functions of UBE2C in bladder cancer are largely unknown. To investigate the significance of UBE2C expression in bladder cancer, immunohistochemical analysis was performed using a tissue microarray. UBE2C positivity was observed in 51 of 82 (62%) bladder urothelial carcinoma cases treated with radical cystectomy. In contrast, UBE2C was negative in all of the non-neoplastic urothelium examined. UBE2C positivity was significantly associated with higher tumor stage (p=0.0061) and presence of lymphovascular invasion (p=0.0045). In addition, UBE2C positivity was significantly associated with shorter cancer-specific survival after cystectomy (log rank p=0.0017; multivariate hazard ratio, 2.49; 95% confidence interval, 1.09-5.71). Small interfering RNA-mediated suppression of UBE2C in UM-UC-3 bladder cancer cells inhibited cell proliferation in vitro. Taken together, our results suggest that UBE2C is a novel prognostic biomarker as well as a potential therapeutic target in bladder cancer.
Cell cycle; immunohistochemistry; pathology; prognosis; urinary tract
We report here a 47-year-old male with the diagnosis of high-grade B-cell lymphoma and hemophagocytosis accompanying disseminated intravascular coagulation (DIC). Lymphoma-associated hemophagocytic syndrome (LAHS) is a life-threatening disorder, and LAHS secondary to B-cell lymphoma is relatively rare compared to that secondary to T- or NK/T-cell lymphoma in Western countries. T- or NK/T-cell LAHS is sometimes combined with DIC, which makes patients’ outcomes even worse, but few reports of B-cell LAHS accompanying DIC has been published so far. We successfully treated a patient with this condition with recombinant thrombomodulin (rTM), a novel agent for DIC. We believe that rTM is a therapeutic option in cases with B-cell LAHS accompanying DIC.
B-cell lymphoma; lymphoma-associated hemophagocytic syndrome; disseminated intravascular coagulation; recombinant thrombomodulin
Here, we show that overexpression of fer tyrosine kinase (FER), a non-receptor tyrosine kinase, predicts poor postoperative outcome and might be involved in cancer-cell survival in non-small cell lung cancer (NSCLC). Systematic screening using in silico analyses and quantitative RT-PCR revealed that FER was overexpressed in about 10% of NSCLC patients. Evaluation of FER expression using immunohistochemistry (IHC) on tissue microarrays was consistent with the mRNA level detected using quantitative RT-PCR. In analyses of 135 NSCLC patients who had undergone potential curative resection, we found that FER overexpression detected using IHC had no association with clinicopathological features such as age, sex, smoking history, histological type, disease stage, T factor, N factor, adjuvant chemotherapy history, or EGFR mutation, but was correlated with poor postoperative survival periods. A multivariate Cox regression analysis showed that this prognostic impact was independent of other clinicopathological features. In functional analyses of FER in vitro, FER exhibited a transforming activity, suggesting that it possesses oncogenic functions. We also found that human lung cancer NCI-H661 cells, which exhibited FER-outlier expression, were led to apoptosis by the knockdown of FER using RNA interference. FER overexpression might serve as a prognostic biomarker and be involved in cancer-cell survival in NSCLC.
Non-small cell lung cancer; FER overexpression; prognostic factor
Metastatic seminoma can potentially be confused with lymphoma in a lymph node biopsy. Here, we report a case in which the immunohistochemistry of CD10 was a pitfall in the differential diagnosis of a metastatic seminoma, and further present a brief study of CD10 expression in a seminoma series. A 67-year-old man, who had a history of lobectomy of the lung due to squamous cell carcinoma 2 years prior, showed lymphadenopathy of the neck and the paraaorta on follow-up study by fluorodeoxyglucose-positron emission computer tomography scan. The biopsy of the cervical node demonstrated infiltration of large atypical cells. The results of the screening immunohistochemistry were CD20(-), CD3(-), CD10(+), CD30(-), AE1/AE3(-), and placental alkaline phosphatase(-), providing the impression of CD10-positive lymphoma. However, the following studies revealed germ cell characteristics [OCT3/4(+), SALL4(+), and CLDN6(+)], confirming the diagnosis of seminoma. We further evaluated CD10 expression in a series of seminomas (n=16). Strong positivity was observed in 14 cases; partial and weak positivity, in 2 cases. These findings should be considered in the differential diagnosis of seminoma.
Testicular seminoma; CD10; PLAP; OCT3/4
Merkel cell polyomavirus (MCPyV) has recently been identified in Merkel cell carcinoma (MCC), an aggressive cancer that occurs in sun-exposed skin. Conventional technologies, such as polymerase chain reaction (PCR) and immunohistochemistry, have produced conflicting results for MCPyV infections in non-MCC tumors. Therefore, we performed quantitative analyses of the MCPyV copy number in various skin tumor tissues, including MCC (n = 9) and other sun exposure-related skin tumors (basal cell carcinoma [BCC, n = 45], actinic keratosis [AK, n = 52], Bowen’s disease [n = 34], seborrheic keratosis [n = 5], primary cutaneous anaplastic large-cell lymphoma [n = 5], malignant melanoma [n = 5], and melanocytic nevus [n = 6]). In a conventional PCR analysis, MCPyV DNA was detected in MCC (9 cases; 100%), BCC (1 case; 2%), and AK (3 cases; 6%). We then used digital PCR technology to estimate the absolute viral copy number per haploid human genome in these tissues. The viral copy number per haploid genome was estimated to be around 1 in most MCC tissues, and there were marked differences between the MCC (0.119–42.8) and AK (0.02–0.07) groups. PCR-positive BCC tissue showed a similar viral load as MCC tissue (0.662). Immunohistochemistry with a monoclonal antibody against the MCPyV T antigen (CM2B4) demonstrated positive nuclear localization in most of the high-viral-load tumor groups (8 of 9 MCC and 1 BCC), but not in the low-viral-load or PCR-negative tumor groups. These results demonstrated that MCPyV infection is possibly involved in a minority of sun-exposed skin tumors, including BCC and AK, and that these tumors display different modes of infection.
Gelatinous drop-like corneal dystrophy (GDLD), also known as familial subepithelial corneal amyloidosis, is an autosomal recessive disorder that causes progressive corneal opacity due to accumulation of amyloid fibrils in the corneal stroma. Genetic analyses have revealed that a mutation in membrane component chromosome 1 surface marker 1 gene is responsible for GDLD. However, the mechanism of amyloid formation in the corneal stroma remains unclear. The present study attempted to reveal the role of advanced glycation end products (AGE) and d-amino acids in amyloid formation in GDLD.
Informed consent was obtained from five patients with GDLD, three patients with bullous keratopathy and three patients with interstitial keratitis and all the specimens were analysed. Localisation of amyloid fibrils was analysed using Congo-red and thioflavin T staining. In addition, the localisation of AGE (Nɛ-carboxy(methyl)-l-lysine, pyrraline and pentosidine) and d-β-aspartic acid-containing proteins, a major form of d-amino acid-containing proteins, was analysed immunohistochemically.
In all GDLD specimens, strong immunoreactivity to AGE and d-β-aspartic acid-containing proteins was detected in the subepithelial amyloid-rich region. In contrast, amyloid fibrils, AGE, or d-amino acid-containing proteins were slightly detected in the corneal stroma of patients with bullous keratopathy and interstitial keratitis.
Abnormally accumulated proteins rich in AGE and d-β-aspartic acid co-localise in the amyloid lesions in GDLD. These results indicate that non-enzymatic post-translational modifications of proteins, including AGE formation and isomerisation of aspartyl residues, will be the cause as well as the result of amyloid fibril formations in GDLD.
Advanced glycation end products; biochemistry; cornead-amino acids; d-β-aspartic acid; familial subepithelial corneal amyloidosis; GDLD; gelatinous drop-like corneal dystrophy; M1S1; Nɛ-(carboxy)methyl-l-lysin; optics and refraction; pathology; pentosidine; physiology; pyrraline; treatment surgery; tumour-associated calcium signal transducer 2 (TACSTD2)
Ovarian clear cell carcinoma (CCC) is a unique type of ovarian cancer characterized by distinct clinicopathological and molecular features. CCC is considered to be a highly malignant disease because it is resistant to conventional chemotherapy, and, when presented at advanced stages, has a dismal overall survival. Identifying and characterizing biomarkers associated with its malignant behavior is fundamental toward elucidating the mechanisms underlying its aggressive phenotype. In this study, we performed immunohistochemical analysis on 89 CCCs to assess their expression of Rsf-1 (HBXAP), a chromatin remodeling gene frequently amplified and overexpressed in several types of human cancer. We found that 73 (82%) of 89 CCCs expressed Rsf-1 and most importantly, there was a statistically significant correlation between Rsf-1 immunostaining intensity and two disease parameters: advanced stage (p= 0.008) and status of retroperitoneal lymph node metastasis (p= 0.023). However, there was no correlation between Rsf-1 expression and patient age, peritoneal tumor dissemination, or overall survival. In conclusion, a higher expression level of Rsf-1 is associated with advanced clinical stage and lymph node metastasis in CCC. Our data suggest that Rsf-1 participates in tumor progression in CCC, and indicates that the contribution of Rsf-1 to disease aggressiveness deserves further study.
DBC1/KIAA1967 (deleted in breast cancer 1) is a putative tumor-suppressor gene cloned from breast cancer specimens and is reported to regulate p53-dependent apoptosis through its specific inhibition of SIRT1 deacetylase. Although SIRT1 plays a pivotal role in carcinogenesis by regulating cellular proliferation, survival and death, its role in breast cancer remains controversial. Therefore, we aimed to investigate the expression status and clinicopathological significance of DBC1 and SIRT1 in breast cancer tissues. We evaluated the expression of DBC1 and SIRT1 in breast core-needle biopsy specimens from 48 primary breast cancer patients between 2005 and 2008. These patients were treated with primary systemic chemotherapy and subsequent surgical resection of the lesions. Immunohistochemical expression scores of DBC1 and SIRT1 were evaluated, and the relationship between their expression levels and clinicopathological features of breast cancer was analyzed. The expression was observed exclusively in the nuclei of normal and neoplastic ductal cells. In breast biopsy specimens, positive expression of DBC1 and SIRT1 was noted in 85 and 98% of patients, respectively. Expression of DBC1 was significantly associated with the tumor nuclear grade (P=0.019). DBC1 and SIRT1 expression was inversely correlated with HER2 expression (P=0.026 and 0.003, respectively). Lower expression of DBC1 and SIRT1 indicated a tendency for a favorable pathological response to chemotherapy, although this was not statistically significant. Our results reveal that the expression of DBC1 and SIRT1 in breast tissues is associated with tumor characteristics.
DBC1; SIRT1; breast cancer; nuclear grade; HER2
Matricellular proteins, including periostin, are important for tissue regeneration.
Methods and Findings
Presently we investigated the function of periostin in cutaneous wound healing by using periostin-deficient (−/−) mice. Periostin mRNA was expressed in both the epidermis and hair follicles, and periostin protein was located at the basement membrane in the hair follicles together with fibronectin and laminin γ2. Periostin was associated with laminin γ2, and this association enhanced the proteolytic cleavage of the laminin γ2 long form to produce its short form. To address the role of periostin in wound healing, we employed a wound healing model using WT and periostin−/− mice and the scratch wound assay in vitro. We found that the wound closure was delayed in the periostin−/− mice coupled with a delay in re-epithelialization and with reduced proliferation of keratinocytes. Furthermore, keratinocyte proliferation was enhanced in periostin-overexpressing HaCaT cells along with up-regulation of phosphorylated NF-κB.
These results indicate that periostin was essential for keratinocyte proliferation for re-epithelialization during cutaneous wound healing.
Background: Gastric cancer (GC) is a major cancer, sometimes associated with Epstein-Barr virus (EBV). Some transcriptional factors (TFs) are specific to the digestive tract and related to the character of the tumors. Methods: We studied three TFs, SOX2, CDX2, and hepatocyte nuclear factor 4 alpha-promoter 1 (HNF4aP1) in GC. First, 255 tumors including 31 EBV-associated GC were immunohistochemically examined using tissue arrays and compared TF type and mucin phenotype. We classified them into 4 TF types: N-TF type as SOX2-/HNF4aP1- tumor, G: SOX2+/HNF4aP1-, GI: SOX2+/HNF4aP1+, and I: SOX2-/HNF4aP1+. Next, 915 GCs were intensely investigated and compared with their clinicopathological factors.Results: In the first study, 255 GCs were classified into N-TF 44%, G-TF 31%, GI-TF 3%, and I-TF 2%. The TF type did not strictly accord with the mucin phenotype, classified by MUC2/5AC/6/CD10 expression. EBV status was the only factor related to both the TF and mucin phenotype classifications (P<0.0001, <0.0001). TF classification is related to more factors including tumor stage, than mucin phenotype classification. The second study using 915 GCs revealed that N-TF gradually increased and I-TF decreased as GC invaded deeper. TF classification was not related to nodal involvement in each tumor stage. HNF4aP1 and CDX2 were independent factors for early stage tumor in logistic regression analysis. Conclusions: EBV-associated GC is a discriminating group in both TF and mucin phenotype. TF classification, especially the absence of HNF4aP1 and CDX2, is related to tumor invasion. TF classification is a useful marker to study the carcinogenesis of GC further.
Gastric cancer; transcriptional factor; Epstein-Barr virus; SOX2; HNF4a
We report an extremely rare case of small intestinal cancer metastasized to the urinary bladder, presenting a urologic symptom. A 41-year-old man first presented with nausea, vomiting and abdominal pain. Based on the clinical diagnosis of jejunal cancer, he underwent a partial resection of the jejunum with lymph node dissection. The pathological diagnosis was moderately differentiated adenocarcinoma of the jejunum, pT4N0. Seventeen months after surgery, he presented with a gross hematuria. Computed tomographic scan showed wall thickening of the posterior wall of the urinary bladder. No tumor was found in other organs or lymph nodes. Based on histological and immunohistochemical analysis, the diagnosis of urinary bladder metastasis from jejunal adenocarcinoma was made. This is the first report of urinary bladder metastasis from small intestinal cancer. Although very rare, the possibility of metastatic small intestinal cancer should be considered in differential diagnosis in patients with adenocarcinoma involving the urinary bladder.
Adenocarcinoma; Immunohistochemistry; Metastasis; Small intestinal cancer; Urinary bladder
A unique case of prostatic stromal sarcoma (PSS) that recurred in the pelvic cavity with massive high‐grade prostatic intraepithelial neoplasia is described. A 52‐year‐old man who presented with urinary retention underwent a radical cystoprostatectomy. Tumour tissues of the prostate showed an admixture of hyperplastic glands and markedly cellular stroma of spindle cells arranged in a fascicular pattern, and the tumour was diagnosed as PSS. 66 months after the operation, CT scans revealed three recurrent tumours around the bilateral obturator and left fore iliopsoas. The recurrent tumours were biphasic neoplasms, as before, but the epithelial component had grown prominent and manifested overt atypia in a manner resembling high‐grade prostatic intraepithelial neoplasia. Our findings suggest that not only the stromal component but also and the epithelial components of PSS may have malignant potential.
Recent genome-wide analysis has demonstrated that somatic mutations in ARID1A (BAF250) are the most common molecular genetic changes in ovarian clear cell carcinoma (OCCC). ARID1A mutations, which occur in approximately half of OCCC cases, lead to deletion of the encoded protein and inactivation of the putative tumor suppressor. In this study, we determined the significance of loss of ARID1A immunoreactivity with respect to several clinicopathological features in a total of 149 OCCCs. First, we demonstrated that ARID1A immunohistochemistry showed concordance with the mutational status in 91% of cases with 100% sensitivity and 66% specificity. Specifically, among 12 OCCC cases for which ARIDA mutational status was known, ARIDIA immunoreactivity was undetectable in all 9 cases harboring ARID1A mutations and was undetectable in one of 3 cases with wild-type ARID1A. With respect to the entire cohort, ARID1A immunoreactivity was undetectable in 88 (59%) of 149 OCCCs. There was no significant difference between ARID1A negative and positive cases in terms of histopathologic features, age, clinical stage, or overall survival. In conclusion, this study provides further evidence that mutations in ARID1A resulted in loss of ARID1A protein expression in OCCC, although no significant differences between ARID1A positive and negative cases were observed with respect to any clinicopathological features examined.
ovarian; ARID1A; pathology
We investigated the possibility of using a pharmacologic agent to modulate viral gene expression in order to target radiotherapy to tumor tissue. In a murine xenograft model, we had previously shown targeting of [125I]2'-fluoro-2'-deoxy-beta-D-5-iodouracilarabinofuranoside ([125I]FIAU) to tumors engineered to express the Epstein-Barr virus (EBV)-thymidine kinase (TK). Here we extend those results to targeting of a therapeutic radiopharmaceutical [131I]FIAU to slow or stop tumor growth or to achieve tumor regression. These outcomes were achieved in xenografts with tumors that constitutively expressed the EBV-TK, as well as with naturally-infected EBV tumor cell lines. Burkitt's lymphoma and gastric carcinoma required activation of viral gene expression by pretreatment with bortezomib. Marked changes in tumor growth could also be achieved in naturally-infected Kaposi's sarcoma herpesvirus (KSHV) tumors following bortezomib activation. Bortezomib-induced enzyme-targeted radiation (BETR) therapy illustrates the possibility of pharmacologically modulating tumor gene expression to effect targeted radiotherapy.
Acute myocardial infarction (AMI) is a common and lethal heart disease, and the recruitment of fibroblastic cells to the infarct region is essential for the cardiac healing process. Although stiffness of the extracellular matrix in the infarct myocardium is associated with cardiac healing, the molecular mechanism of cardiac healing is not fully understood. We show that periostin, which is a matricellular protein, is important for the cardiac healing process after AMI. The expression of periostin protein was abundant in the infarct border of human and mouse hearts with AMI. We generated periostin−/− mice and found no morphologically abnormal cardiomyocyte phenotypes; however, after AMI, cardiac healing was impaired in these mice, resulting in cardiac rupture as a consequence of reduced myocardial stiffness caused by a reduced number of α smooth muscle actin–positive cells, impaired collagen fibril formation, and decreased phosphorylation of FAK. These phenotypes were rescued by gene transfer of a spliced form of periostin. Moreover, the inhibition of FAK or αv-integrin, which blocked the periostin-promoted cell migration, revealed that αv-integrin, FAK, and Akt are involved in periostin signaling. Our novel findings show the effects of periostin on recruitment of activated fibroblasts through FAK-integrin signaling and on their collagen fibril formation specific to healing after AMI.
Epstein-Barr virus (EBV)-associated gastric carcinoma (GC) is the monoclonal growth of EBV-infected epithelial cells, and the entity was recognized only recently. EBV-associated GC is distributed worldwide and more than 90,000 patients are estimated to develop GC annually in association with EBV (10% of total GC). EBV-associated GC occurs in two forms in terms of the histological features, i.e., lymphoepithelioma-like GC and ordinary type of GC. Both share characteristic clinicopathological features, such as the preferential occurrence as multiple cancer and remnant stomach cancer. While the expression of EBV-latent genes is restricted to several in the infected cells (Latency I), EBV-associated GC shows gastric cell phenotype, resistance to apoptosis, and the production of immunomodulator molecules. Recently, global and non-random CpG island methylation of the promoter region of many cancer-related genes has been demonstrated with their decreased expression, such as p16 INK4A, p73 and E-cadherin. This abnormality is accompanied by methylation of the EBV genome itself, suggesting a process of virus-driven hypermethylation in the development of neoplastic cells. Further studies are necessary to determine the precise sequence of EBV infection, methylation, transformation and selection of the predominant clone within the stomach mucosa. Future studies are also desirable for the target and strategy of therapy, such as initiating viral replication or reversing the DNA methylation of cellular genes.
Epstein-Barr virus; gastric cancer; DNA methylation; viral oncogenesis; histology; chronic inflammation
The KT tumor is a transplantable strain of a human Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC), established in severe combined immunodeficiency (SCID) mice, with which the cytokine expression of EBVaGC can be investigated without interference from the infiltrating lymphocytes. As a part of a high-density oligonucleotide array (GeneChip) analysis of EBVaGC, the interleukin-1β (IL-1β) gene was the only cytokine gene that showed markedly higher expression in the KT tumor cells than in two tumor strains of EBV-negative GC. The results were confirmed by Northern blotting, Western blotting, and enzyme-linked immunosorbent assay. Furthermore, we demonstrated a positive signal for IL-1β mRNA in the carcinoma cells of a surgically resected EBVaGC, but not in EBV-negative GC, by in situ hybridization. In vitro, IL-1β increased the cell growth of a GC cell line, TMK1. Thus, IL-1β may act as an autocrine growth factor in EBVaGC.
PPARγ is a ligand-activated transcription factor and functions as a heterodimer with a retinoid X receptor (RXR). Supraphysiological activation of PPARγ by thiazolidinediones can reduce insulin resistance and hyperglycemia in type 2 diabetes, but these drugs can also cause weight gain. Quite unexpectedly, a moderate reduction of PPARγ activity observed in heterozygous PPARγ-deficient mice or the Pro12Ala polymorphism in human PPARγ, has been shown to prevent insulin resistance and obesity induced by a high-fat diet. In this study, we investigated whether functional antagonism toward PPARγ/RXR could be used to treat obesity and type 2 diabetes. We show herein that an RXR antagonist and a PPARγ antagonist decrease triglyceride (TG) content in white adipose tissue, skeletal muscle, and liver. These inhibitors potentiated leptin’s effects and increased fatty acid combustion and energy dissipation, thereby ameliorating HF diet-induced obesity and insulin resistance. Paradoxically, treatment of heterozygous PPARγ-deficient mice with an RXR antagonist or a PPARγ antagonist depletes white adipose tissue and markedly decreases leptin levels and energy dissipation, which increases TG content in skeletal muscle and the liver, thereby leading to the re-emergence of insulin resistance. Our data suggested that appropriate functional antagonism of PPARγ/RXR may be a logical approach to protection against obesity and related diseases such as type 2 diabetes.
A transplantable human Epstein-Barr virus-associated gastric carcinoma (EBVaGC), designated KT, was propagated in severe combined immunodeficiency (SCID) mice for 12 passages. Mucin and cytokeratin expression and the Alu sequence in tumor DNA confirmed that the KT tumor was derived from human epithelial tissue. The identity of clonal EBV in the original and KT tumors was demonstrated by terminal repeat analysis of EBV DNA. The pattern of latency gene expression of EBV was the same in both tumors. EBER1 was presented similarly in tumor cell nuclei by in situ hybridization. Reverse transcription-PCR analysis also demonstrated Q-promoter-driven EBNA1 expression but not BZLF1, EBNA2, or LMP1 expression. Thus, the transplantable human EBVaGC KT retains the original EBV with the same latency gene expression and can serve as a model for this unique type of gastric carcinoma.