Epstein‐Barr virus and gastric carcinomaFukayama, Masashi
doi: 10.1111/j.1440-1827.2010.02533.xpmid: 20518883
Epstein‐Barr virus (EBV) has been accepted as an infective agent causing gastric carcinoma (GC). Epstein‐Barr virus‐associated GC, comprising nearly 10% of all cases of GC, is the monoclonal growth of EBV‐infected epithelial cells, which express several EBV‐latent genes (latency I program). Sequential events in the gastric mucosa could be traced from EBV infection of the pit cells to fully developed carcinomas by EBV encoded small RNA (EBER)‐in situ hybridization. The histological features of the carcinoma consist of a lace pattern of carcinoma cells within the mucosa and the dense infiltration of lymphocytes and macrophages at the invasive site, which might be due to cytokines produced by neoplastic cells. The primary molecular abnormality in EBV‐associated GC is global and non‐random CpG island methylation in the promoter region of many cancer‐related genes. The experimental system of recombinant EBV infection using GC cell lines demonstrated that viral latent membrane protein 2A (LMP2A) is responsible for the promotion of DNA methylation. LMP2A up‐regulates cellular DNMT1 through the phosphorylation of STAT3, causing CpG methylation of a tumor suppressor gene, PTEN. DNA methylation in EBV‐infected stomach cells may be due to overdrive of the cellular defense against foreign DNA, which eventually leads to the development of EBV‐associated GC.
Diagnostic approach to pancreatic tumors with the specimens of endoscopic ultrasound‐guided fine needle aspirationHosoda, Waki; Takagi, Tadayuki; Mizuno, Nobumasa; Shimizu, Yasuhiro; Sano, Tsuyoshi; Yamao, Kenji; Yatabe, Yasushi
doi: 10.1111/j.1440-1827.2010.02527.xpmid: 20518885
Endoscopic ultrasound‐guided fine‐needle aspiration (EUS‐FNA) has enabled clinicians to histologically diagnose pancreatic tumors. However, EUS‐FNA specimens often result in tiny fragmented tissues, so auxiliary utilities are necessary. Using immunostaining of CK7, CDX2, neuroendocrine markers and KRAS mutation analysis, we examined 57 FNA cell block sections and 61 surgically‐resected specimens (25 invasive ductal carcinomas, 25 endocrine tumors, and 11 acinar cell tumors). In the majority of the matched pairs, the diagnoses between EUS‐FNA and surgical specimens were concordant using the following criteria: neuroendocrine markers negative, CK7 positive, and mutated KRAS gene for invasive ductal carcinomas; neuroendocrine markers diffusely positive, CK7 and CDX2 negative, and wild‐type KRAS gene for well‐differentiated endocrine tumors; and neuroendocrine markers no more than focal positive, CK7 and CDX2 with various staining patterns, and wild‐type KRAS gene for acinar cell carcinomas. Expression of CK7 and/or CDX2 in addition to KRAS mutations were occasionally seen in endocrine carcinomas, but not in well‐differentiated endocrine tumors, suggesting that ductal differentiation in an endocrine tumor may be a predictor of aggressive disease. The usefulness of these markers was confirmed using 13 additional pancreatic tumors, prospectively. Although minimal in selection, these markers are helpful in making diagnosis from EUS‐FNA specimens of the major pancreatic tumors.
Matrix biochemistry and cell biology of dedifferentiated chondrosarcomasDornauer, Kerstin; Söder, Stephan; Inwards, Carry Y.; Bovee, Judith. V. M. G.; Aigner, Thomas
doi: 10.1111/j.1440-1827.2010.02530.xpmid: 20518886
Dedifferentiated chondrosarcoma is an uncommon mesenchymal neoplasm comprised of two different components, low‐grade conventional chondrosarcoma and high‐grade non‐cartilaginous sarcoma. In order to gain better insight into the biology of this tumor, we investigated a large series of dedifferentiated chondrosarcomas by looking at the composition of the extracellular tumor matrix within each of the distinct histological components. Our results showed that the well‐differentiated portion of the tumors showed matrix components largely similar to conventional chondrosarcomas or enchondromas. In contrast, the high‐grade portions showed a variety of staining patterns related to the matrix being formed. Cartilage‐specific proteoglycans and collagens were consistently absent, except in areas showing a chondroblastic osteosarcoma histomorphology. Instead, the most dominant immunostaining was received for type I collagen. Type III and VI collagens were concentrated in the areas showing a fibroblastic phenotype. Our results lend further support to the notion that dedifferentiated chondrosarcoma represents transdifferentiation of a cell towards various blastic mesenchymal cell lineages, most commonly osteoblastic and fibroblastic, but occasionally chondroblastic as well. There was no difference in the clinical outcome of patients with differing high‐grade tumor types, emphasizing that grade is a more important predictor of biological behavior than the direction of tumor differentiation.
Histopathologic findings of transbronchial biopsy in usual interstitial pneumoniaShim, Hyo Sup; Park, Moo Suk; Park, In Kyu
doi: 10.1111/j.1440-1827.2010.02528.xpmid: 20518887
The role of transbronchial biopsy in diagnosis of usual interstitial pneumonia (UIP) is controversial. In this study, we retrospectively reviewed transbronchial biopsy specimens according to the similar criteria of previous studies, and evaluated whether diagnostic findings of UIP could be found in transbronchial biopsies. Thirty two patients with usual interstitial pneumonia, confirmed by surgical lung biopsy, were identified. In three cases (9.4%), there were combinations of interstitial fibrosis and fibroblast foci, and these findings were considered consistent with usual interstitial pneumonia. No patchwork fibrosis or honeycomb change was found. Diagnostic findings of usual interstitial pneumonia were not frequently manifested in transbronchial biopsy specimens in our study (3 out of 32 cases, 9.4%), compared with a previous report (9 out of 22 cases, 41%). In conclusion, it cannot be claimed that transbronchial biopsy is more useful in confirming usual interstitial pneumonia than previously recognized. The primary and main role of transbronchial biopsy in diagnosis of usual interstitial pneumonia is thought not to confirm a diagnosis, but to exclude other infiltrative diseases, such as malignancy, sarcoidosis or infections.
Heterogeneous expression of nestin in myofibroblasts of various human tissuesKishaba, Yuka; Matsubara, Daisuke; Niki, Toshiro
doi: 10.1111/j.1440-1827.2010.02532.xpmid: 20518888
In this study we explored the distribution of nestin‐positive cells in extraneural human tissues with special reference to stromal myofibroblasts. Tissue microarrays were constructed from various tissues with normal histology and tissues with fibrosing disorders. Sections were immunostained for nestin, alpha‐smooth muscle actin (alpha‐SMA), desmin, vimentin, CD34, and other stromal markers. Nestin was expressed in the myoepithelium of the breast, podocytes of the renal glomerulus, and endothelial cells of most organs. Nestin was also expressed in the stroma of several organs, including the intestine, uterine cervix, and endometrium. Nestin‐positive fibroblast‐like cells appeared in the stroma of the kidney, pancreas, lung, and skin in fibrosing conditions. With the notable exception of endometrial stromal cells, most of these nestin‐positive stromal cells were alpha‐SMA‐positive. Interestingly, we observed a concomitant appearance of nestin‐ and CD34‐positive myofibroblasts under fibrosing conditions. Further investigation showed that nestin was expressed by stromal fibroblasts in cervical squamous cell carcinoma, but not in lung adenocarcinoma, pointing to heterogeneity of cancer stroma. In conclusion, nestin was expressed in variable proportions of stromal myofibroblasts in human tissues. The differential expression of nestin may indicate phenotypic and functional heterogeneity. Nestin‐positive myofibroblast may represent a relatively immature subpopulation of cells with multipotentiality.
Detection of telomerase activity in cultured cells and tumor tissue of lung carcinoma by modified telomeric repeat amplification protocolLiu, Yan; Wu, Bing‐quan; Zhong, Hao‐hao; Xu, Mei‐lin; Fang, Wei‐gang
doi: 10.1111/j.1440-1827.2010.02529.xpmid: 20518889
Telomerase activity is found in various cell types including stem cells, neoplastic cells, and immortalized cells, suggesting a close association with their proliferation capacity. The telomeric repeat amplification protocol (TRAP) has been traditionally used to detect semi‐quantitatively the telomerase activity by polyacrylamide gel electrophoresis (PAGE), which is difficult to apply for large scale analysis because of laborious post‐PCR manipulation and potential carryover contamination. In the present study, a specific reverse primer was designed and the TRAP protocol was adapted to either PAGE or real‐time PCR assay. Using cultured cell lines, the real‐time TRAP showed a dramatic improvement in the reliability and accuracy of quantitation of telomerase activity and was able to discriminate the A549 cells from hundreds‐fold human embryonic lung cells. Using clinical samples of 60 lung cancers and 8 inflammatory lesions, the real‐time TRAP was also superior in quantitation, high‐throughput capability and standardization. Our modified real‐time TRAP should be applicable for the detection of telomerase activity for the initial screening and progression monitoring of lung cancer patients. Our approach is particularly useful when only limited clinical specimen is available, such as fine needle aspiration or other cytological specimens that may contain only a small number of tumor cells.
9p21 deletion in the diagnosis of malignant mesothelioma, using fluorescence in situ hybridization analysisTakeda, Maiko; Kasai, Takahiko; Enomoto, Yasunori; Takano, Masato; Morita, Kouhei; Kadota, Eiji; Nonomura, Akitaka
doi: 10.1111/j.1440-1827.2010.02534.xpmid: 20518890
Homozygous deletion of 9p21, the locus harboring the p16 gene, has been reported as one of the most common genetic alterations in malignant mesotheliomas (MMs). Previous studies showed that this alteration might be useful for differentiating benign from malignant mesothelial tumors in cytology and surgical specimens. Although the diagnostic utility of 9p21 homozygous deletion by fluorescence in situ hybridization (FISH) analysis has been reported only recently, it has not been well demonstrated. The purpose of this study is to evaluate the diagnostic utility of 9p21 homozygous deletion assessed by FISH in mesothelial neoplasm and hyperplasia of Japanese patients using paraffin‐embedded tissue. Simultaneously, p16 protein immunoexpression was explored as a potential diagnostic aid. FISH analysis demonstrated 9p21 deletion in 35 of 40 cases with MM (88%) (P < 0.001). In contrast, no cases of adenomatoid tumor, benign mesothelial multicystic tumor, reactive mesothelial hyperplasia or pleuritis showed 9p21 deletion (P < 0.005). 9p21 homozygous deletion correlated well with p16 protein expression in the tumor cells. Our study suggests that 9p21 homozygous deletion assessed by FISH on paraffin‐embedded tissue may be very useful for differentiating MM from reactive mesothelial proliferation.
Monolobar ductal plate malformation disease of the liverTerada, Tadashi; Moriki, Toshiaki
doi: 10.1111/j.1440-1827.2010.02535.xpmid: 20518892
We herein report a unique monolobar hepatic disease composed of Caroli's disease, peribiliary cysts, ductal plate malformations, peribiliary gland proliferation, hepatolithiasis, and portal phlebosclerosis with thrombi. A 73‐year‐old man underwent abdominal imaging, which revealed multiple segmental dilations of the left intrahepatic bile ducts. Polycystic kidney diseases were absent. Intrahepatic cholangiocarcinoma was suspected, and extended left lobectomy of the liver was preformed. Grossly, the hepatic left lobe was atrophic, and partly replaced by fibrous tissue. The intrahepatic bile ducts were dilated (Caroli's disease), and showed small calcium bilirubinate hepatoliths. Microscopically, the intrahepatic bile duct showed non‐obstructive segmental dilations (Caroli's disease), numerous peribiliary cysts, numerous ductal plate malformations, proliferation of intrahepatic peribiliary glands, and calcium bilirubinate hepatolithiasis. Portal veins showed phlebosclerosis with thrombi. Immunohistochemically, the various biliary epithelial cells were positive for cytokeratin (CK) 7, 8, 18, and 19, and for MUC6 and CD10. They were negative for MUC2 and MUC5AC. The ductal plate malformations were positive for fetal biliary antigen MUC1, but other biliary cell types were negative for MUC1. The present case resembles ‘monolobar Caroli's disease’. We believe that the present monolobular liver disease was congenital in origin.