Faculty Bibliography

Tissue microarrays (TMAs) are a valuable resource that have been used for molecular profiling and biomarker development. The high throughput and cost savings make TMAs well suited for the rapid screening of large patient populations and for use in multitissue studies. Construction and casting is time consuming and the most important step in the use of a TMA. Occasionally, improper casting of a TMA leads to failure of the block. Similarly, repeated sectioning can cause the block to become too thin to collect additional sections. Considering the increased use of TMA and their occasional failure, we developed a method to repair fractured blocks or blocks worn thin from repeated sectioning

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