Expression of metallothionein in seminal vesicles--an immunohistochemical study

A transcriptional signature associated with the onset of benign prostate hyperplasia in a canine model

BACKGROUND

Benign prostatic hyperplasia (BPH) represents the most frequent proliferative abnormality of the human prostate. In spite of the well-characterized architectural development of BPH, little is known about the cellular and molecular events that contribute to it.

METHODS

We have developed an animal model to evaluate the follow-up of hormone-induced BPH and the analysis of the gene expression associated with BPH. Immunohistochemistry on human patient samples validated the BPH-related molecular alterations.

RESULTS

Canine specific Affymetrix microarray analysis performed on sequential biopsies obtained from a beagle dog dynamic model characterized a number of genes altered during the onset of BPH. In addition to the genes involved in calcification, matrix remodeling, detoxification, cell movement, and mucosa protection (MGP, MMP2, TIMP2, ITIH3, GST, MT2A, SULT1A1, FKBP1B, MUC1, STRBP, TFF3), the up-regulation of TGFB3 and CLU indicated a complete adjustment of the transdifferentiation, senescence and apoptosis programs. The up-regulation of Clusterin was validated by RT-qPCR and immunohistochemistry, both in the dog dynamic model and in human samples, further confirming the suitability of the animal model for the study of the molecular alterations associated with BPH.

CONCLUSIONS

Transcriptome analysis performed on a dynamic animal model that accurately mimicked the human clinic, allowed us to characterize a gene expression pattern associated with the onset of BPH.

Incidence of neuroendocrine cells in the seminal vesicles and the prostate--an immunohistochemical study

INTRODUCTION

Prostate and seminal vesicles (sv) are both androgen-dependent male sex accessory glands. The cancer incidence in these two organs is vastly different. Neuroendocrine (NE) cells are involved in the regulation of prostate growth, differentiation and in prostate cancer carcinogenesis. Thus, knowledge of the incidence of NE cells in sv may add to our understanding of prostate cancer etiology.

METHODS

Samples of histologically confirmed normal prostate tissue and normal sv tissue from 20 men were immunostained for chromogranin A. The incidence of stained cells was evaluated semiquantitately.

RESULTS

Neuroendocrine cells were detected in all prostate specimens, but not a single stained cell was found in any of the sv specimens.

CONCLUSIONS

The lack of NE cells and, subsequently, of biogenic amines, peptides and growth factors may be a reason for the low cancer incidence in the seminal vesicles. Alternatively, the absence of NE cells can be seen as a hint that the stem cells of the prostate and sv react differently to endogenous and exogenous stimuli, and thus in the seminal vesicles, stem cells are not transformed into NE cells.

Tumor specific gene expression profiles in human leiomyosarcoma: an evaluation of intratumor heterogeneity

Leiomyosarcomas are malignant smooth muscle tumors characterized by a spectrum of histopathologic features and clinical behavior. Gene expression profiling of leiomyosarcomas may identify differential gene signatures that may allow for the clinical stratification of the tumors. Typically, surgical specimens from these tumors are large and manifest a variegated macroscopic appearance. Because of their large size at the time of diagnosis, sufficient tissue is available for regional and clonal heterogeneity assessment. However, if the gene expression profiles of samples taken from different locations in the tumors are drastically different, biologic classification on the basis of random sample analysis may not be adequate. Therefore, to assess intertumor and intratumor heterogeneity, the authors performed a gene expression study using leiomyosarcoma specimens from three excised sarcomas from an equal number of different patients. Comparisons between tumor and normal samples from the three patients as well as between carefully mapped peripheral and core specimens from the same tumor (excised from one of the patients), were performed. Analysis of the expression profiles demonstrated minimal intratumor variations compared with intertissue variations, indicating homogeneous tumor specific gene expression profiles. The authors also identified genes that are expressed differentially in tumor and normal tissue.