Identification of PCA3 (DD3) in prostatic carcinoma by in situ hybridization.

PCA3 is a specific marker of prostatic carcinoma. However, PCA3 has been detected only at RNA level and a corresponding PCA3 protein has never been identified. The aim of this study was to develop a technique capable of detecting PCA3 RNA on histology sections and to assess the cellular location of the molecule. Forty-eight formalin-fixed paraffin-embedded blocks of prostatectomy specimens were selected for PCA3 detection by in situ hybridization by both radioactive and chromogenic methods. Of the 48 sections, 28 contained prostatic adenocarcinoma and 20 had benign tissue located distant from the tumor. Using the radioactive detection method, 26 of 28 available cases (93%) of cancers presented at least focal cytoplasmic PCA3 expression. The benign glands located in proximity of the cancer presented PCA3 expression in eight (29%) cases, whereas those situated distant to the tumor showed focal expression in 2 of 20 (10%) cases only. High-grade prostatic intraepithelial neoplasia (HGPIN) expressed PCA3 in 25 of 26 (96%) cases. With the chromogenic detection method, 22 of the 24 interpretable cases (92%) of cancers had at least focal cytoplasmic staining. Benign glands located close to neoplastic glands expressed PCA3 in 8 (33%) cases, but none of those distant to the tumor expressed the marker. HGPIN was positive in 17 of 24 (71%) cases. The sensitivity, specificity, positive predictive value and negative predictive value for the detection of cancer were 93, 79, 71 and 95% for the radioactive detective method and 92, 80, 71 and 95% for the chromogenic detection method, respectively. Our study shows that PCA3 RNA is expressed by most prostate cancers and HGPIN. Normal glands rarely express the marker, except those located in immediate proximity of neoplastic glands, suggesting the presence of precursor molecular changes.

The influence of MMP-14, TIMP-2 and MMP-2 expression on breast cancer prognosis.

INTRODUCTION: Matrix metalloproteinase (MMP)-2 is very active at degrading extracellular matrix. It is under the influence of an activator, membrane type 1 MMP (MMP-14), and the tissue inhibitor of metalloproteases (TIMP)-2. We hypothesized that the individual expression of these three markers or their balance may help to predict breast cancer prognosis. METHODS: MMP-2, MMP-14 and TIMP-2 expression has been evaluated by 35S mRNA in situ hybridization on paraffin material of 539 breast cancers without distant metastasis at diagnosis and with a median follow-up of 9.2 years. RESULTS: MMP-2 and MMP-14 mRNA was detected primarily in reactive stromal cells whereas TIMP-2 mRNA was expressed by both stromal and cancer cells. Of the three molecules, an adjusted Cox model revealed that high MMP-14 mRNA (> or = 10% cells) alone predicted a significantly shorter overall survival (p = 0.031) when adjusted for clinical factors (tumor size and number of involved lymph nodes). Prognostic significance was lost when further adjusted for Her-2/neu and urokinase-type plasminogen activator (p = 0.284). Furthermore, when all three components were analyzed together, the survival was worst for patients with high MMP-2/high MMP-14/low TIMP-2 (5 year survival = 60%) and best with low MMP-2/low MMP-14/high TIMP-2 (5 year survival = 74%), but the difference did not reach statistical significance (p = 0.3285). CONCLUSION: Of the MMP-14/TIMP-2/MMP-2 complex, MMP-14 was the factor most significantly associated with the outcome of breast cancer and was an independent factor of poor overall survival when adjusted for clinical prognostic factors, but not for certain ancillary markers.

Clozapine and dopamine D3 receptor antisense reduce cocaine- and amphetamine-regulated transcript expression in the rat nucleus accumbens shell.

Cocaine- and amphetamine-regulated transcript (CART) is a neuropeptide highly expressed in the hypothalamus and nucleus accumbens. Hypothalamic CART has been associated with food intake and body weight control, but in the nucleus accumbens the role of CART remains elusive. New generations of antipsychotic drugs show a good efficacy over psychotic symptoms but they induce an important weight gain. The mechanism underlying this unexpected side effect is still unknown. The present results show, for the first time, that acute and chronic treatment with the atypical neuroleptic clozapine, but not the conventional neuroleptic haloperidol, reduced the expression of CART mRNA in the shell of the nucleus accumbens. CART mRNA is colocalized with both dopamine D(2) and D(3) receptor transcripts in the nucleus accumbens shell. However, a dopamine D(3) receptor, but not D(2), antisense oligonucleotide administration reduced CART expression in this brain area. These results suggest that the dopamine D(3) receptor, but not the D(2), is involved in the control of CART expression in the nucleus accumbens and that it may participate in the modulation of CART mRNA levels by clozapine. The modulation of CART, an anorexigenic neuropeptide, in the dopamine mesolimbic pathway may potentially play a role in dysregulated food intake induced by some antipsychotic drugs.

The transcription factor NGFI-B (Nur77) and retinoids play a critical role in acute neuroleptic-induced extrapyramidal effect and striatal neuropeptide gene expression.

Despite extensive investigation, the cellular mechanisms responsible for neuroleptic actions remain elusive. We have previously shown that neuroleptics modulated the expression of some members of the ligand-activated transcription factors (nuclear receptors) including the nerve-growth factor inducible gene B (NGFI-B or Nur77) and retinoid X receptor (RXR) isoforms. Using genetic and pharmacological approaches, we investigated the role of NGFI-B and retinoids in acute behavioral and biochemical responses to dopamine antagonists. NGFI-B knockout (KO) mice display a profound alteration of haloperidol-induced catalepsy and striatal neuropeptide gene expression. Haloperidol-induced increase of striatal enkephalin mRNA is totally abolished in NGFI-B KO mice whereas the increase of neurotensin mRNA expression is reduced by 50%. Interestingly, catalepsy induced by raclopride, a specific dopamine D(2)/D(3) antagonist is completely abolished in NGFI-B-deficient mice whereas the cataleptic response to SCH 23390, a dopamine D(1) agonist, is preserved. Accordingly, the effects of haloperidol on striatal c-fos, Nor-1, and dynorphin mRNA expression are also preserved in NGFI-B-deficient mice. The cataleptic response and the increase of enkephalin mRNA expression induced by haloperidol can also be suppressed by administration of retinoid ligands 9-cis retinoic acid and docosahexaenoic acid. In addition, we demonstrate that haloperidol enhances colocalization of NGFI-B and RXRgamma1 isoform mRNAs, suggesting that both NGFI-B and a RXR isoform are highly coexpressed after haloperidol administration. Our data demonstrate, for the first time, that NGFI-B and retinoids are actively involved in the molecular cascade induced by neuroleptic drugs.