Faculty Bibliography

OBJECTIVE: To use tissue microarray in combination with dendrogram cluster analysis to characterize some potential tumorigenic factors in association with tumor size and sex steroid hormone status in uterine leiomyomata. DESIGN: Expression analysis of 21 selected potential tumorigenic factors in 60 patients with uterine leiomyomata. SETTING: University clinical research laboratory. PATIENT(S): Hysterectomy specimens from 60 patients with uterine leiomyomata of different ages and tumor sizes. INTERVENTION(S): Tissue cores from normal myometrium and leiomyomata were examined by immunohistochemistry. MAIN OUTCOME MEASURE(S): Semiquantitative immunointensity was scored and analyzed by net gain and loss between normal myometrium and leiomyomata and integrated into dendrogram cluster tree view. RESULT(S): We found that upregulation of estrogen and progesterone receptors was reverse associated with tumor size. Upregulation of some factors (HMGA2, sex steroid receptor cofactors, proteins in insulin pathway, and CD24) were identified in a group of patients in their later forties, were associated with large fibroids, and were weakly affected by the SSH status (illustrated by endometrial phases and menopause). Downregulation of tuberin and glucocorticoid receptor was mostly isolated in a second group of women at their late reproductive age. CONCLUSION(S): Analyses of the sex steroid hormone receptors and the nonsex steroid hormone factors in leiomyomata and the matched myometrium showed different expression patterns in different tumor sizes and patients' ages. A group of patients in their late forties with the larger leiomyomata contributes largely by upregulation of nonsex steroid hormone factors. Adenomyosis is a protective factor preventing large leiomyomata

The genetic hallmark of hemangioblastomas and clear cell-renal cell carcinomas (CC-RCCs) is loss-of-function of the von Hippel-Lindau (VHL) tumor suppressor protein. VHL is required for oxygen-dependent degradation of hypoxia-inducible factor-1alpha (HIF-1alpha). In hemangioblastomas and CC-RCCs, HIF-1alpha is constitutively overexpressed leading to increased transcription of HIF-1-regulated genes, including vascular endothelial growth factor (VEGF). Because loss of VHL function is associated with increased expression of the chemokine receptor CXCR4 in CC-RCCs, we investigated the expression of HIF-1alpha, CXCR4, and its ligand stromal cell-derived factor-1alpha (SDF-1alpha) in hemangioblastomas and CC-RCCs. Immunohistochemistry revealed overexpression of both CXCR4 and SDF-1alpha within tumor cells and endothelial cells of hemangioblastomas and CC-RCCs. HIF-1alpha was detected in tumor cell nuclei of both hemangioblastomas and CC-RCCs. A specific ELISA showed that hemangioblastomas and CC-RCCs expressed SDF-1alpha protein at levels that were significantly higher than those found in normal tissue. Analysis of the VHL-null RCC line 786-0 revealed that SDF-1alpha mRNA levels were 100-fold higher than in a subclone transfected with the wild-type VHL gene. Expression of CXCR4 and SDF-1alpha mRNA was significantly decreased in HIF-1alpha-null compared with wild-type mouse embryo fibroblasts (MEFs). ELISA and Western blot studies for SDF-1alpha and CXCR4 protein expression confirmed the RNA findings in RCC lines and MEFs. These results suggest that loss-of-function of a single tumor suppressor gene can up-regulate the expression of both a ligand and its receptor, which may establish an autocrine signaling pathway with important roles in the pathogenesis of hemangioblastoma and CC-RCC

Fascin-1 is an actin-bundling protein that plays an important role in cell motility and adhesion. The level of fascin-1 is low or undetectable in normal epithelial cells. However, overexpression is reported in transformed epithelial cells and in several common types of carcinomas [Bioessays. 2002;24:359-361]. Up-regulation of fascin-1 is associated with higher grades and with aggressive tumors with poorer prognoses. We found no report on the role or the protein expression of fascin-1 in urothelial carcinomas (UCs) of the urinary bladder. In this study, we examined by immunohistochemistry the expression of fascin-1 in the normal human transitional epithelium, benign vesical lesions, and different types of UCs. We found no detectable fascin-1 in the normal transitional epithelium. There was no increase of fascin-1 expression in cystitis cystica, cystitis glandularis, nephrogenic adenoma (n = 10), inverted papilloma (n = 5), and classic exophytic papilloma (n = 4) or in adjacent transitional epithelia associated with these conditions. Patchy or diffusely weak fascin-1 expression was observed in 42% (5/12) of superficial papillary UCs (Ta), and 95% (19/20) of invasive UCs (T2 or higher) demonstrated diffuse strong staining for fascin-1. The microinvasive foci in the lamina propria of UC (T1, n = 8) were also positive for fascin-1, although they were not as strongly stained as in the deeply invasive tumors. Interestingly, the neoplastic cells in the tips of microinvasive carcinomas were distinctly positive for fascin-1. There were significant numbers of fascin-1-positive cells (>50% of the neoplastic cells) in UCs in situ (n = 10). These findings suggest an association between increased fascin-1 expression and increased invasiveness of carcinomas in the urinary bladder

Invasion into surrounding brain tissue is a fundamental feature of gliomas and the major reason for treatment failure. The process of brain invasion in gliomas is not well understood. Differences in gene expression and/or gene products between invading and noninvading glioma cells may identify potential targets for new therapies. To look for genes associated with glioma invasion, we first employed Affymetrix microarray Genechip((R)) technology to identify genes differentially expressed in migrating glioma cells in vitro and in invading glioma cells in vivo using laser capture microdissection. We observed upregulation of a variety of genes, previously reported to be linked to glioma cell migration and invasion. Remarkably, major histocompatiblity complex (MHC) class I and II genes were significantly downregulated in migrating cells in vitro and in invading cells in vivo. Decreased MHC expression was confirmed in migrating glioma cells in vitro using RT-PCR and in invading glioma cells in vivo by immunohistochemical staining of human and murine glioblastomas for beta2 microglobulin, a marker of MHC class I protein expression. To the best of our knowledge, this report is the first to describe the downregulation of MHC class I and II antigens in migrating and invading glioma cells, in vitro and in vivo, respectively. These results suggest that the very process of tumor invasion is associated with decreased expression of MHC antigens allowing glioma cells to invade the surrounding brain in a 'stealth'-like manner.Laboratory Investigation (2005) 85, 328-341, advance online publication, 31 January 2005; doi:10.1038/labinvest.3700233

Human uterine leiomyomata are the most common tumors in women of reproductive age. The pathogenesis of leiomyomata remains unknown. An animal model of Eker rats with deleted tuberous sclerosis complex gene 2 (tuberin) shows increased incidence of leiomyomata. The role of tuberin in human leiomyomata is unknown. In this study, we designed a tissue microarray with tissue cores of leiomyomata and the matched myometrium from 60 hysterectomy specimens. We examined the expression of tuberin and tuberous sclerosis complex gene 1 product hamartin, proteins of the insulin-signaling pathway, steroid receptors and some of their cofactors, and human mobility group gene A2 by immunohistochemistry. We found that nearly half of the cases displayed either reduction or loss of tuberin in leiomyomata compared with matched normal myometrium. No change of hamartin was noted. Furthermore, a significant reduction of glucocorticoid receptor was found in leiomyomata with reduced tuberin. The proteins insulin like growth factor 1, insulin-like growth factor receptor beta, AKT kinase, and phosphatidylinositol 3-kinase were upregulated. Nearly half of leiomyomata show upregulation of human mobility group gene A2, along with the steroid receptor cofactors. Our findings suggest that there are two broad groups of uterine leiomyomata. One group is associated with an alteration of tuberin and glucocorticoid receptor. The other group is associated with upregulation of human mobility group gene A2 and steroid receptor cofactors