Cathepsin B expression is similar in African-American and Caucasian prostate cancer patients.

BACKGROUND: Increased incidence and mortality of prostate cancer (PCa) suggest that U.S. African-American men have more invasive cancer than Caucasian men. Invasive PCa requires several proteases, including the cysteine protease cathepsin B (CB), for degradation of basement membrane and extracellular matrix proteins prior to cancer cell migration across biological compartments. Our objective was to determine whether CB immunostaining patterns, in relation to clinical data, could distinguish invasive PCa in African-American and Caucasian patients. PATIENTS AND METHODS: Fifty Gleason score 6/7 PCa cases were selected for similar clinical data with benign prostatic hyperplasia (BPH) samples as controls. Immunostainings were imaged directly from microscope slides to a computer using a digital camera. Data were quantified using Metamorph software, analyzed using the two-sample t-test and confirmed by multiple regression. RESULTS: Ratios of CB to its endogenous inhibitor stefin A (SA) immunostainings were greater in PCa than BPH, but were not significantly different in PCa of either race. The African-American patients did not show increased CB immunostaining, indicating that the contribution of this protease to invasiveness was similar in both races. CONCLUSION: When veterans received equal medical care at the Minneapolis Veterans Affairs Medical Center, African-American patients did not show increased PCa invasiveness. Our conclusion is supported by analysis of post-surgery serum total PSA levels and cancer cell invasion to margins/capsules, seminal vesicles and/or lymph nodes. Invasiveness of PCa does not appear to be race-dependent. The previous conclusion of race-based differences in PCa requires re-evaluation with respect to the role of proteases (such as CB, matrix metalloproteinase) in invasion and metastasis of cancer cells.

Prediction of immune surveillance responsive metastatic prostate cancer in pelvic lymph node and emergence of surveillance unresponsive/resistant metastatic cells.

BACKGROUND: Immune cells (lymphocytes and macrophages) provide the microenvironment for immune surveillance of metastatic prostate cancer (PCa) cells in pelvic lymph nodes. We have hypothesized that degeneration and/or apoptosis of metastatic PCa cells in pelvic lymph nodes can distinguish between aggressive and non-aggressive metastatic disease in patients. Our objective was to define the relationship between metastatic cell lysis and the presence of immune cells. MATERIALS AND METHODS: We studied archival primary PCa (n=38) and cancer-positive regional pelvic nodes (n=32) from the same patients undergoing radical retropubic prostatectomy at the Minneapolis Veterans Affairs Medical Center. RESULTS: Using morphological and immunohistochemical features of immune and metastatic cancer cells, we have identified progression of metastasis in the nodal compartments. Nodal parenchyma contained small, intermediate and large metastatic nodules/tumors. Immune surveillance occurred primarily in small tumors and surveillance was either absent or greatly reduced in intermediate and large tumors in nodes. Metastatic nodules/cells were lysed or became apoptotic when under immune-surveillance, as indicated by pyknotic nuclei and cytoplasm, the latter still had remnants of prostate specific antigen (PSA) staining. Metastatic cells without surveillance did not exhibit morphological features of cell degeneration (lysis) or apoptosis. Metastatic cells under immune-surveillance had an inverse relationship with those without immune-surveillance. This relationship differed from node to node and patient to patient. CONCLUSION: We have shown that at least two populations of metastatic cells were present in the nodes; the first group of cells was under immune surveillance, as indicated by limited to wide-spread cell lysis/apoptosis, and the second group did not exhibit morphological evidence of cell lysis indicating emergence of surveillance-unresponsive (resistant) metastatic cells. These criteria can be used to distinguish metastatic cancer that is expected to be responsive to immunotherapy from that which would show little or no benefit from such treatment. Enhancement of immune surveillance and other treatments can be used to treat surveillance-unresponsive (resistant) disease to improve survival of patients.

Increased aggressiveness of human prostate PC-3 tumor cells expressing cell surface localized membrane type-1 matrix metalloproteinase (MT1-MMP).

Membrane type-1 matrix metalloproteinase (MT1-MMP) is a multidomain transmembrane endopeptidase with a major role in physiological and pathological processes through proteolysis of extracellular matrix and other pericellular proteins. We examined cell surface function of MT1-MMP in PC-3 human prostate tumor cells selected for metastasis in nude mice (PC-3-LN4), or transfected with the full-length wild-type (WT) MT1-MMP or with the mutant form lacking the cytoplasmic tail (Delta C-MT1-MMP). Enhanced cell surface MT1-MMP was determined by fluorescence-activated cell sorting analysis and evidenced mechanistically by increased activation of proMMP-2 and invasion into type-I collagen gels. PC-3 cells overexpressing MT1-MMP grew faster than mock-transfected control cells subcutaneously in nude mice. MT1-MMP localized in caveolae, as judged by immunofluorescence microscopy and sucrose-gradient, detergent-resistant cell fractionation. Delta C-MT1-MMP was strongly associated with caveolae, whereas the WT form was present in both caveolae and noncaveolae fractions. The role of plasma membrane MT1-MMP was supported by localization of MT1-MMP by immunofluorescence microscopy at the cell surface of tumor cells in primary prostate cancers. Increased plasma membrane localization of MT1-MMP, either in caveolae or in other lipid raft structures, is a mechanism to localize this proteinase in contact with extracellular matrix and other pericellular proteins, the cleavage of which can facilitate prostate cancer cell invasion and metastasis.

Outcomes of a Hepatitis C screening program at a large urban VA medical center.

GOALS: To determine the outcomes of implementing clinical care guidelines for Hepatitis C screening, evaluation, and treatment in a large urban Veterans Affairs Medical Center. BACKGROUND: Little information exists regarding the actual outcomes of institutional screening programs for Hepatitis C. STUDY: Retrospective review of all patients tested for Hepatitis C at the Minneapolis Veterans Affairs Medical Center from January 1, 2000 to December 31, 2001. Logistic regression was used to determine factors related to successful referral and treatment. RESULTS: During this period 36,422 unique patients were screened for Hepatitis C virus (HCV) risk factors, resulting in 12,485 HCV enzyme-linked immunoassay antibody tests. HCV antibodies were positive in 681 (5.4%) patients and 520 (4.2%) were HCV-RNA-positive. Of HCV-RNA-positive patients, 430 (83%) were referred, 382 (73%) attended the Hepatitis clinic, and 232 (44.6%) received liver biopsies. Patients referred had significantly fewer comorbidities, known marital status, and greater prior clinic attendance than those not referred. Overall, 124 patients with established fibrosis received antiviral therapy (32% of patients attending clinic or 24% of viremic cohort). White race, fewer major medical problems, and age less than 60 years predicted antiviral treatment. Sustained virologic response occurred in 46 (37%) of treated patients (9% of the viremic cohort). Patients with a sustained virologic response include 17 patients with stage 3 to 4 fibrosis. CONCLUSIONS: This screening and referral program resulted in 73% of HCV-RNA-positive patients attending a specialty Hepatitis C clinic and 24% of those most likely to benefit received antiviral therapy. Measures to increase referral, engagement in care, and antiviral treatment are needed.

Spectrum of disease in U.S. veteran patients with hepatitis C.

OBJECTIVE: Hepatitis C virus (HCV) infection is more prevalent in U.S. veterans attending Veterans Affairs Medical Centers than in the general population. The purpose of this study was to examine the risk factors, psychiatric and substance abuse conditions, and severity of liver disease in veterans with HCV. METHODS: The medical records and liver biopsies of 206 consecutive patients with HCV attending a multidisciplinary medical/psychiatric chronic hepatitis clinic and who met eligibility criteria for interferon alpha-2b therapy were reviewed. RESULTS: The mean age was 46.5+/-6.8 yr and 77% were Vietnam-era veterans. Risk factors included i.v. drug use (64%), blood transfusion (15%), and cocaine use (9%), and were unknown in 12%. The average estimated duration of disease was 24+/-7.6 yr. A history of alcohol abuse or dependence was identified in 80% of patients. Psychiatric illnesses were present in 60%, the most common being depression and posttraumatic stress disorder. Overall, 89% of patients had documented psychiatric and/or substance abuse diagnoses. Severe fibrosis (stages 3-4) was present in 32% and severe inflammation (grades 2-3) was present in 71% of biopsies. Psychiatric and substance abuse diagnoses did not correlate with severity of liver disease. A total of 145 patients (71%) were prescribed interferon-based treatment. The overall virological sustained response rates were 16% after interferon monotherapy and 28% after interferon/ribavirin therapy. Reasons for not receiving interferon therapy included minimal fibrosis on liver biopsy (37 patients [18%]), worsening medical conditions (nine [4%]), and worsening psychiatric and substance abuse problems (14 [7%]). CONCLUSIONS: Advanced fibrosis is common in this cohort of veteran patients with chronic hepatitis C, and the overwhelming majority of these patients have psychiatric and/or substance abuse diagnoses. Despite these comorbidities, the majority received interferon therapies in the context of a multidisciplinary clinic. These data emphasize the importance of hepatitis C care that includes linkage of medical care and psychiatric services.

Prediction of pelvic lymph node metastasis by the ratio of cathepsin B to stefin A in patients with prostate carcinoma.

BACKGROUND: Pathologic grade and/or histologic score, extraprostatic extension indicated by invasion of the prostatic capsule, margin, and/or seminal vesicles by prostate cancer cells, serum total prostate-specific antigen (PSA), free PSA, complexed PSA levels and/or their ratios, regional pelvic lymph node metastases, and clinical staging have been used to diagnose and monitor the treatment of prostate carcinoma (PC) patients. The Gleason grading system is also used to grade/score a patient's stage of disease, with lower to higher scores indicating progression of PC. However, Gleason's system cannot be used to distinguish biologically aggressive PCs within a single Gleason score. Our objective was to identify subpopulations (or clones) of aggressive prostate cancers within an individual Gleason score by utilizing biological molecule(s) that also facilitate cancer cell invasion to prostatic stroma and metastasis to the lymph nodes. MATERIALS AND METHODS: Specimens were collected from 97 patients with PC and from 8 patients with benign prostatic hyperplasia. These patients had not been treated with hormonal and/or chemotherapeutic agents before undergoing a prostatectomy at the Minneapolis Veterans Affairs Medical Center. Formalin-fixed, paraffin or paraplast-embedded prostate tissue sections were stained with hematoxylin and eosin for pathologic diagnosis and adjacent sections were stained for for immunohistochemical study. We also collected data on age, race, extraprostatic extension, margin status, seminal vesicle, and lymph node invasion by cancer cells, clinical stage at prostatectomy, and mortality/survival data, including the available presurgery and postsurgery serum total PSA and prostatic acid phosphatase concentrations in patients. Immunohistochemical localization of mouse or rabbit anti-cathepsin B (CB) antibody IgG and mouse antihuman stefin (cystatin) A IgG was quantified using a computer-based image analysis system equipped with Metamorph software. RESULTS: CB and stefin A identified aggressive and less aggressive clones of PCs within an individual Gleason score. Tumors with a Gleason Score of 6 that are similar histologically and morphologically were heterogeneous with respect to the ratios of CB to stefin A (CB > stefin A, CB = stefin A, and CB < stefin A). We also found a significant positive association (P = 0.0066) between ratios of CB and stefin A (CB > stefin A) and the incidence of pelvic lymph node metastases, but not with ratios of CB less than stefin A and/or ratios of CB equal to stefin A. Patients with Gleason 7 PCs had a higher incidence of positive lymph nodes than those with Gleason Score 6 tumors. Our data indicated that mortality rates increased in patients when the ratios of CB were greater than stefin A. CONCLUSIONS: PC within an individual Gleason score is a heterogeneous tumor that contains clones or subpopulations of aggressive and less aggressive tumors that can be defined by the ratios of CB to stefin A. PC with an aggressive clone can be identified when the ratio of CB is greater than that of stefin A. Less aggressive clones are identified when the ratio of CB is less than that of stefin A or when the ratio of CB is equal to that of stefin A. The ratios of CB to stefin A can be used in the differential diagnosis and treatment of patients with PC. This is the first report to identify phenotypes of aggressive and less aggressive PCs within a Gleason score.