Magnetic Resonance-Guided Stereotaxy for Infusions to the Pig Brain.

The overall goal of this procedure is to perform stereotaxy in the pig brain with real-time magnetic resonance (MR) visualization guidance to provide precise infusions. The subject was positioned prone in the MR bore for optimal access to the top of the skull with the torso raised, the neck flexed, and the head inclined downward. Two anchor pins anchored on the bilateral zygoma held the head steady using the head holder. A magnetic resonance imaging (MRI) flex-coil was placed rostrally across the head holder so that the skull was accessible for the intervention procedure. A planning grid placed on the scalp was used to determine the appropriate entry point of the cannula. The stereotactic frame was secured and aligned iteratively through software projection until the projected radial error was less than 0.5 mm. A hand drill was used to create a burr hole for insertion of the cannula. A gadolinium-enhanced co-infusion was used to visualize the infusion of a cell suspension. Repeated T1-weighted MRI scans were registered in real time during the agent delivery process to visualize the volume of gadolinium distribution. MRI-guided stereotaxy allows for precise and controlled infusion into the pig brain, with concurrent monitoring of cannula insertion accuracy and determination of the agent volume of distribution.

Protein expression of a triad of frequently methylated genes, p73, p57Kip2, and p15, has prognostic value in adult acute lymphocytic leukemia independently of its methylation status.

PURPOSE: To study the relationship between protein expression and DNA methylation of a triad of cell-cycle regulatory genes known to be frequently methylated in adult acute lymphocytic leukemia (ALL). PATIENTS AND METHODS: Protein expression of p73, p15, and p57Kip2 was analyzed by immunohistochemistry using a tissue microarray (TMA) platform. The TMA was constructed using pretreatment bone marrow biopsy specimens from 64 adult patients with ALL. Protein expression was then correlated with DNA methylation and relevant clinical biologic characteristics. RESULTS: p73 protein expression was observed in 19 (30%) patients, cytoplasmic p15 in 19 (31%), and p57 in 40 (70%). Three patients (5%) had expression of all three proteins, 16 (29%) of two proteins, 31 (55%) of one protein, and six (11%) of zero proteins. An inverse association was observed between p73 DNA methylation and protein expression (P = .003). This effect was not observed for either p15 or p57Kip2. Expression of any of the proteins studied was not associated with any distinct biologic characteristic. By multivariate analysis, expression of p57Kip2, cytoplasmic p15, or a combination of p57Kip2 with either p15 or p73 was associated with a better overall survival (P < .001, .04, and .03 respectively). CONCLUSION: Expression of a triad of cell cycle regulatory proteins that includes p73, p15, and p57Kip2 has prognostic value in adult patients with ALL independently of the methylation status of each gene.

Clinical and biomarker correlates of androgen-independent, locally aggressive prostate cancer with limited metastatic potential.

PURPOSE: We have identified a subset of patients exhibiting extended survival with metastases from androgenindependent prostate cancer of which the principal site of progression was the tumor primary. The purpose of this study was to evaluate the expression of selected biomarkers to characterize this subset of prostate cancer patients. EXPERIMENTAL DESIGN: A 105 core tissue microarray was constructed from primary tumor samples from 16 patients, with matched lymph node metastases in 5 cases. Immunohistochemistry was used to evaluate selected biomarkers associated with prostate cancer progression. Standard statistical methodologies were used to compute the distribution of time to progression and overall survival associations between pairs of biomarkers. Hierarchical clustering was done between groups of biomarkers, and we devised new methods to assess homogeneity of biomarker expression. RESULTS: The median interval from diagnosis to salvage surgery was 65 months. The profile of biomarker expression was notable for virtual absence of neuroendocrine features, high CD10, low matrix metalloproteinase (MMP)-9, high E-cadherin expression, and high membranous beta-catenin. The mean proliferative index was 12.1 +/- 10.1%, and the mean apoptotic index was 3.48 +/- 2.22%, and there was a significant correlation between these indices. Expression of the epidermal growth factor receptor was associated with phospho-AKT and proliferative index but inversely associated with phospho-STAT3. CONCLUSIONS: The cohort of prostate cancer patients, characterized by locally aggressive disease rather than lethal metastatic progression, was associated with a distinctive biomarker signature. The biomarker profile was, in general, more consistent with low-grade prostate cancer exhibiting local growth rather than metastatic progression. Ongoing studies will establish whether this unique subset of patients can be identified prospectively.

Evidence that transfer of functional p53 protein results in increased apoptosis in prostate cancer.

PURPOSE: INGN 201 (Ad-p53) is a replication-defective adenoviral vector that encodes a wild-type p53 gene driven by the cytomegalovirus promoter. INGN 201 has been shown to have antitumoral activity against human prostate cancer cell lines. This study was undertaken to determine the safety of INGN 201 in patients with locally advanced prostate cancer, to assess transgene expression, and to evaluate antitumoral activity. EXPERIMENTAL DESIGN: Our study included patients with clinical stage T3, T1c-T2a with Gleason score 8-10 disease, or T2a-T2b with Gleason score 7 disease and a prostate-specific antigen level >10 ng/ml. INGN 201 was administered by intraprostatic injection under ultrasonographic guidance. One course of INGN 201 was defined as three separate INGN 201 administrations 2 weeks apart. Biopsies at baseline and 24 h after the first administration were assessed for p53 protein by immunohistochemical staining and for apoptosis by terminal deoxynucleotidyl transferase-mediated nick end labeling assay. RESULTS: A total of 38 courses of INGN 201 gene therapy were administered to 30 patients, of whom 26 underwent radical prostatectomy. There were no grade 3 or 4 adverse events related to INGN 201 administration. Of the 11 patients with negative baseline immunostaining for p53 protein, 10 had positive p53 immunostaining after the first administration of INGN 201, and 8 had an increase in apoptotic cells by terminal deoxynucleotidyl transferase-mediated nick end labeling staining. All 26 of the patients who underwent radical prostatectomy had significant residual viable prostate cancer, and 12 have experienced biochemical failure (median follow-up, 42 months). CONCLUSION: Intraprostatic INGN 201 gene therapy is safe and can reliably result in p53 protein production and apoptosis.

GSH depletion enhances adenoviral bax-induced apoptosis in lung cancer cells.

The utility of dominant acting proapoptotic molecules to induce cell death in cancer cells is being evaluated in preclinical studies and clinical trials. We recently developed a binary adenoviral expression system to enable the efficient gene transfer of Bax and other proapoptotic molecules. Using this system, overexpression of Bax protein in four non-small-cell lung cancer (NSCLC) cell lines, H1299, A549, H226 and H322, was evaluated. The H322 line exhibited significant resistance to Bax-induced cell death compared to the other cell lines. H322 cells had the highest level of glutathione (GSH). GSH levels were significantly decreased following buthionine sulfoximine treatment and this coincided with enhanced apoptosis induction by Ad-Bax in H322 cells. GSH depletion enhanced Bax protein translocation to mitochondrial membranes. These findings suggest that the redox status may be a determinant of Bax-mediated cell death and that manipulation of intracellular thiols may sensitize cells to apoptosis by facilitating Bax insertion into mitochondrial membranes.

TAD: a web interface and database for tissue microarrays.

Tissue microarrays are increasingly important tools that bring high-throughput technology to traditional pathology laboratories. In many cases, each spot on a tissue microarray is scored by a skilled pathologist and recorded manually. TAD consists of an Active Server Page web interface to a relational database that automates recording scores and linking them with clinical data for future interpretation. TAD is an open source application that can be installed locally.

Biomarker expression patterns that correlate with high grade features in treatment naive, organ-confined prostate cancer.

BACKGROUND: The early detection of prostate cancer has resulted in an increase in the number of patients with localized prostate cancer and has paralleled the reported reduction in prostate cancer mortality. The increased rate of detection of patients with localized prostate cancer may also increase the risk of potentially morbid therapy in a patient with indolent cancer. Defining the biomarker correlates of prostate cancer virulence will facilitate the appropriate application and development of therapy for patients with early disease. METHODS: A 255 core prostate cancer tissue microarray (TMA) from 47 prostatectomy specimens with organ confined tumor was constructed. Prostate cancer foci of transition and peripheral zone origin were represented on the TMA. Further, replicate cores of the two Gleason grades comprising the Gleason score, representative of Gleason scores 5-9, were arrayed from each prostatectomy specimen. Standard immunohistochemical techniques were used to assess expression of nine, cell death and cell cycle regulatory proteins implicated in the pathogenesis of prostate cancer (bax, bcl-2, bcl-xL, bin1, CD95, mdm2, p21, p53, and NFkappaB). RESULTS: The Spearman correlation coefficient revealed a strong correlation of bax, bin1, FAS, p65 and p21 expression with Gleason grade. Spearman correlation coefficients showed that expression of, bax and bin1, bax and MDM2, Bax and p21, and bax and p65 NFkappaB was highly associated. Other significant associations were identified between bin1 and p21, bin1 and MDM2, bin1 and p65 NFkappaB and between p21 and p65 NFkappaB. A model for predicting the biological potential of Gleason score 7 prostate cancer using multivariable logistic regression methods was developed. The findings also indicate that the profile of specific markers for Gleason grade 3 prostate cancer correlates with the overall context of the Gleason score. CONCLUSION: These data support the view that important molecular differences exist among and between the Gleason scores. Furthermore, there is significant molecular heterogeneity among prostatectomy specimens containing Gleason grade 3 cancer. This observation may have broader implications regarding the determination of risk among patients with prostate cancer that is currently considered to be of either good prognosis or unclear prognosis, i.e. Gleason score 7 tumors.

Immunohistochemical analysis of Bin1/Amphiphysin II in human tissues: diverse sites of nuclear expression and losses in prostate cancer.

The Bin1/Amphiphysin II gene encodes at least seven alternately spliced adapter proteins that have been implicated in membrane dynamics and nuclear processes. Nuclear localized Bin1 polypeptides have tumor suppressor and proapoptotic activities, suggesting that Bin1 may suppress cancer in tissues where nuclear expression may occur. One question is the extent to which human tissues express nuclear Bin1 isoforms. A secondary issue has been the need for a specific antibody that can detect all the splice isoforms expressed by the human, mouse, and rat Bin1 genes. Using a novel mouse monoclonal antibody with these characteristics, we performed an immunohistochemical analysis of Bin1 expression in a panel of normal human tissues. We also compared the expression profile of Bin1 in normal or malignant tissues derived from human prostate, where Bin1 is a candidate tumor suppressor gene. In brain, a distinct nuclear staining pattern overlapped with a cytosolic staining pattern present in certain layers of the cerebral cortex and cerebellum. Bone marrow cells displayed mainly nuclear localization whereas peripheral lymphoid cells exhibited mainly cytosolic localization. In several epithelial tissues, nuclear or nucleocytosolic staining patterns were displayed by basal cells in skin, breast, or prostate, whereas cytosolic or plasma membrane-associated staining patterns were noted in gastrointestinal cells. Interestingly, a striking gradient of expression was observed in gastrointestinal epithelia, particularly in the large intestine, with the strongest staining displayed by cells destined to undergo apoptosis at the villus tip. In prostate, Bin1 staining was frequently absent in cases of primary prostate adenocarcinoma. This study used a novel reagent to document the extent of expression of nuclear Bin1 isoforms, which exhibit cancer suppression and proapoptotic activity in human cells.