Immunohistochemical analysis of the expression of E-cadherin and ZEB1 in non-small cell lung cancer.

We performed an immunohistochemical analysis of the expression of zinc-finger E-box binding homeobox 1 (ZEB1), a master regulator of epithelial-mesenchymal transition (EMT), and determined its relationship with E-cadherin in 157 non-small cell lung carcinomas (93 adenocarcinomas, 36 squamous cell carcinomas, 18 large cell carcinomas, and 10 pleomorphic carcinomas). Although the expression of E-cadherin was low in the subset of adenocarcinomas (10%) and squamous cell carcinomas (11%), ZEB1 expression was only observed in one case of squamous cell carcinoma and none of the adenocarcinomas. In contrast, the low expression of E-cadherin (50% and 90%, respectively) and the positive expression of ZEB1 (11% and 50%, respectively) were more frequently observed in poorly differentiated carcinomas (large cell carcinomas and pleomorphic carcinomas). Overall, the expression of ZEB1 was inversely correlated with that of E-cadherin. Furthermore, the distribution of ZEB1-positive cancer cells was more restricted than in the area in which the expression of E-cadherin was lost, and the former was detected within the latter. We concluded that the expression of ZEB1 was not necessarily associated with the low expression of E-cadherin in lung adenocarcinomas and squamous cell carcinomas. The expression of ZEB1 correlated with an undifferentiated and/or sarcomatoid morphology that may occur in the late stage of EMT.

Lung cancer with loss of BRG1/BRM, shows epithelial mesenchymal transition phenotype and distinct histologic and genetic features.

BRG1 and BRM, two core catalytic subunits in SWI/SNF chromatin remodeling complexes, have been suggested as tumor suppressors, yet their roles in carcinogenesis are unclear. Here, we present evidence that loss of BRG1 and BRM is involved in the progression of lung adenocarcinomas. Analysis of 15 lung cancer cell lines indicated that BRG1 mutations correlated with loss of BRG1 expression and that loss of BRG1 and BRM expression was frequent in E-cadherin-low and vimentin-high cell lines. Immunohistochemical analysis of 93 primary lung adenocarcinomas showed loss of BRG1 and BRM in 11 (12%) and 16 (17%) cases, respectively. Loss of expression of BRG1 and BRM was frequent in solid predominant adenocarcinomas and tumors with low thyroid transcription factor-1 (TTF-1, master regulator of lung) and low cytokeratin7 and E-cadherin (two markers for bronchial epithelial differentiation). Loss of BRG1 was correlated with the absence of lepidic growth patterns and was mutually exclusive of epidermal growth factor receptor (EGFR) mutations. In contrast, loss of BRM was found concomitant with lepidic growth patterns and EGFR mutations. Finally, we analyzed the publicly available dataset of 442 cases and found that loss of BRG1 and BRM was frequent in E-cadherin-low, TTF-1-low, and vimentin-high cases and correlated with poor prognosis. We conclude that loss of either or both BRG1 and BRM is involved in the progression of lung adenocarcinoma into solid predominant tumors with features of epithelial mesenchymal transition and loss of the bronchial epithelial phenotype. BRG1 loss was specifically involved in the progression of EGFR wild-type, but not EGFR-mutant tumors.

Heterogeneous expression of nestin in myofibroblasts of various human tissues.

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.

Mucinous cystadenocarcinoma of the appendix invading the ascending colon with fistula formation: report of a case.

Based on colonoscopy findings, we made a preoperative diagnosis of primary mucinous cystadenocarcinoma of the appendix with features of a submucosal tumor (SMT) in the ascending colon. A 59-year-old woman who presented with right lower quadrant abdominal pain underwent colonoscopy, which revealed an SMT with three nodules covered with mucus in the ascending colon. Examination of colonoscopic biopsy specimens indicated "very" well-differentiated adenocarcinoma with mucus lakes. Abdominal computed tomography showed irregular wall thickness from the cecum to the ascending colon. The adjacent appendix had an enhanced wall and unclear border against the ascending colon. Thus, we performed right hemicolectomy, with good results. Histopathological examination revealed mucinous cystadenocarcinoma of the appendix, invading the ascending colon with fistula formation. Appendiceal tumors can manifest with a variety of colonoscopic features, and curative surgical resection should be attempted even if there is fistula formation.

Assessing the validity of a model to identify patients for lymph node biopsy.

A model to identify adult patients with malignant or granulomatous lymphadenopathy demonstrated a sensitivity/specificity of 0.97/0.91 in the reference sample by Vassilakopoulos and Pangalis. The current study tests the performance of the model in a new sample (n = 151) of patients with peripheral lymphadenopathy. Patient charts were reviewed for the biopsy diagnosis and for the 6 variables in the model (age, tenderness, size, generalized pruritus, supraclavicular lymphadenopathy, and texture). The prevalence rate of malignancy or granuloma in the validation sample was 0.26. When the cutoff point of 1 was used, as in the original description, the model's sensitivity/specificity in the validation sample was 0.97/0.56. The area under the receiver operating characteristic curve was 0.89 (95% confidence interval, 0.83-0.95), which was still statistically significant discrimination. Since the same model performs relatively poorly for the validation sample in terms of low specificity, a more accurate prediction model with better specificity would be needed in our patient population to help physicians identify those patients with peripheral lymphadenopathy who should undergo biopsy.