A common nonsense mutation in EphB2 is associated with prostate cancer risk in African American men with a positive family history.

BACKGROUND: The EphB2 gene was recently implicated as a prostate cancer (PC) tumour suppressor gene, with somatic inactivating mutations occurring in approximately 10% of sporadic tumours. We evaluated the contribution of EphB2 to inherited PC susceptibility in African Americans (AA) by screening the gene for germline polymorphisms. METHODS: Direct sequencing of the coding region of EphB2 was performed on 72 probands from the African American Hereditary Prostate Cancer Study (AAHPC). A case-control association analysis was then carried out using the AAHPC probands and an additional 183 cases of sporadic PC compared with 329 healthy AA male controls. In addition, we performed an ancestry adjusted association study where we adjusted for individual ancestry among all subjects, in order to rule out a spurious association due to population stratification. RESULTS: Ten coding sequence variants were identified, including the K1019X (3055A-->T) nonsense mutation which was present in 15.3% of the AAHPC probands but only 1.7% of 231 European American (EA) control samples. We observed that the 3055A-->T mutation significantly increased risk for prostate cancer over twofold (Fisher's two sided test, p = 0.003). The T allele was significantly more common among AAHPC probands (15.3%) than among healthy AA male controls (5.2%) (odds ratio 3.31; 95% confidence interval 1.5 to 7.4; p = 0.008). The ancestry adjusted analyses confirmed the association. CONCLUSIONS: Our data show that the K1019X mutation in the EphB2 gene differs in frequency between AA and EA, is associated with increased risk for PC in AA men with a positive family history, and may be an important genetic risk factor for prostate cancer in AA.

Is active surveillance a suitable option for African American men with prostate cancer? A systemic literature review.

BACKGROUND: Certain patients presenting with either low or very-low-risk prostate cancer (PCa) can represent a therapeutic dilemma for physicians. The oncologic outcomes of active surveillance (AS) for men with very-low-risk PCa are overall excellent. However, there are concerns about AS related to the potential for upgrading or upstaging. The African American (AA) population is under-represented in studies evaluating AS outcomes and this is particularly important because of the unique epidemiology of PCa in AA men. METHODS: A literature review through the Medline database published from 1990 until August 2015 was performed to identify studies reporting outcomes of the AA population with low-risk PCa that underwent either AS or treatment. An additional search for studies on genetic mechanisms involved in development of PCa in AA men was also performed. RESULTS: Eleven studies on pathologic results of AA men who would qualify for AS were identified and in eight of these studies AA race was found to be associated with adverse pathological outcomes such as positive surgical margins, upgrading or upstaging. The other three studies reported no significance in these parameters with respect to race. Five more studies reported outcomes of AS in AA men with different study end points. AA men were mainly found to have a higher rate of disease reclassification subsequent to active treatment. The studies on genetic mechanisms also identified different genetic alterations in the AA population. CONCLUSIONS: AA men with clinically defined low-risk PCa may have either a higher grade or volume of cancer that was not detected on routine evaluation. Therefore, AS among such patients should be approached with caution. We recommend discussing such risks with AA patients with an acknowledgement that existing favorable outcomes noted in largely Caucasian populations may not be applicable to AA patients. We propose a modified evaluation plan for AA patients that includes an early confirmatory biopsy preceded by an magnetic resonance imaging to optimally detect occult cancer foci.

Apoptosis resistance increases with metastatic potential in cells of the human LNCaP prostate carcinoma line.

The aim of this study was to determine whether stable differences in apoptosis sensitivity were selected for in nonmetastatic and metastatic variants of the LNCaP human prostate carcinoma line that had been isolated from tumors grown orthotopically in the prostate glands and regional lymph nodes of nude mice. The nonmetastatic LNCaP-Pro5 cells were significantly more sensitive to thapsigargin-induced apoptosis than were the metastatic LNCaP-LN3 cells, as measured by viability, DNA fragmentation, and interleukin 1beta-converting enzyme family-mediated cleavage of the DNA repair enzyme, poly(ADP-ribose) polymerase. Apoptosis resistance in the metastatic cells was associated with higher levels of expression of the cell death suppressor BCL-2 and lower levels of the death promoters BAX and BAK than were detected in the nonmetastatic LNCaP-Pro5 cells, whereas levels of two other BCL-2 family members (BCL-X(L) and BAD) were indistinguishable. Our data support the hypothesis that apoptosis resistance contributes to prostate cancer metastasis and that elevated expression of BCL-2 is involved.

Suppression of angiogenesis, tumorigenicity, and metastasis by human prostate cancer cells engineered to produce interferon-beta.

We determined whether the IFN-beta gene can be used to suppress angiogenesis, tumor growth, and metastasis of human prostate cancer cells growing in the prostate of nude mice. Highly metastatic PC-3M human prostate cancer cells were engineered to constitutively produce murine IFN-beta subsequent to infection with a retroviral vector containing murine IFN-beta cDNA. Parental (PC-3M-P), control vector-transduced (PC-3M-Neo), and IFN-beta-transduced (PC-3M-IFN-beta) cells were injected into the prostate (orthotopic) or subcutis (ectopic) of nude mice. PC-3M-P and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastases, whereas PC-3M-IFN-beta cells did not. PC-3M-IFN-beta cells also suppressed the tumorigenicity of bystander nontransduced prostate cancer cells. PC-3M-IFN-beta cells produced small tumors (3-5 mm in diameter) in nude mice treated with anti-asialo GM1 antibodies and in severe combined immunodeficient/Beige mice. Immunohistochemical staining revealed that PC-3M-IFN-beta tumors were homogeneously infiltrated by macrophages, whereas control tumors contained fewer macrophages at their periphery. Most tumor cells in the control tumors were stained positive by an antibody to proliferative cell nuclear antigen; very few were positively stained by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling. In sharp contrast, PC-3M-IFN-beta tumors contained fewer proliferative cell nuclear antigen-positive cells and many terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling-positive cells. Staining with antibody against CD31 showed that control tumors contained more blood vessels than PC-3M-IFN-beta tumors. PC-3M-IFN-beta cells were more sensitive to lysis mediated by natural killer cells in vitro or to cytostasis mediated by macrophages than control transduced cells. Conditioned medium from PC-3M-IFN-beta cells augmented splenic cell-mediated cytolysis to control tumor cells, which could be neutralized by antibody against IFN-beta. Collectively, the data suggest that the suppression of tumorigenicity and metastasis of PC-3M-IFN-beta cells is due to inhibition of angiogenesis and activation of host effector cells.

Blockade of NF-kappaB activity in human prostate cancer cells is associated with suppression of angiogenesis, invasion, and metastasis.

Since the NF-kappaB/relA transcription factor is constitutively activated in human prostate cancer cells, we determined whether blocking NF-kappaB/relA activity in human prostate cancer cells affected their angiogenesis, growth, and metastasis in an orthotopic nude mouse model. Highly metastatic PC-3M human prostate cancer cells were transfected with a mutated IkappaBalpha (IkappaBalphaM), which blocks NF-kappaB activity. Parental (PC-3M), control vector-transfected (PC-3M-Neo), and IkappaBalphaM-transfected (PC-3M-IkappaBalphaM) cells were injected into the prostate gland of nude mice. PC-3M and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastasis, whereas PC-3M-IkappaBalphaM cells produced slow growing tumors with low metastatic potential. NF-kappaB signaling blockade significantly inhibited in vitro and in vivo expression of three major proangiogenic molecules, VEGF, IL-8, and MMP-9, and hence decreased neoplastic angiogenesis. Inhibition of NF-kappaB activity in PC-3M cells also resulted in the downregulation of MMP-9 mRNA and collagenase activity, resulting in decreased invasion through Matrigel. Collectively, these data suggest that blockade of NF-kappaB activity in PC-3M cells inhibits angiogenesis, invasion, and metastasis.

Neoadjuvant chemotherapy and hormonal therapy followed by radical prostatectomy: feasibility and preliminary results.

PURPOSE: We assessed the feasibility and efficacy of integrating chemotherapy and androgen ablation with radical prostatectomy in patients with locally advanced prostate cancer. The neoadjuvant approach was adopted because it allows an in situ assessment of antitumoral activity. PATIENTS AND METHODS: Thirty-three patients were enrolled who met the clinical criteria of stage T1-2, Gleason score of >/= 8 or T2b-T2c, Gleason score of 7 and prostate-specific antigen (PSA) level greater than 10 ng/mL (n = 15), or clinical stage T3 (n = 18). Therapy consisted of 12 weeks of ketoconazole and doxorubicin alternating with vinblastine, estramustine, and androgen ablation followed by prostatectomy. The ability of neoadjuvant chemotherapy and hormonal therapy to induce a 20% rate of pT0 in the prostatectomy specimen as well as surgical feasibility were assessed. RESULTS: Chemotherapy complications were comparable to those reported with this regimen previously. No major intraoperative complications occurred. Postoperative complications occurred in 10 (33%) of 30 patients. One patient died at home after discharge (postoperative day 17; no autopsy was performed). Ten (33%) of the 30 patients had organ-confined disease, and 20 (70%) of 30 had extraprostatic extension; 11 (37%) of the 30 had positive lymph nodes. Only five (17%) of 30 exhibited positive surgical margins. All patients achieved an undetectable PSA level postoperatively, and 20 of the surviving 29 patients remain without disease recurrence with a median follow-up of 13 months (range, 9 to 18 months). CONCLUSION: Chemotherapy and androgen ablation followed by radical prostatectomy was feasible in patients with locally advanced prostate cancer. Although the goal of achieving a 20% rate for pT0 status was not achieved, we believe this type of integrated therapeutic strategy should be investigated further for its ability to alter the course of regionally advanced prostate cancer.

Relative expression of type IV collagenase, E-cadherin, and vascular endothelial growth factor/vascular permeability factor in prostatectomy specimens distinguishes organ-confined from pathologically advanced prostate cancers.

The tumor grade (Gleason score) in the biopsy and pretherapy prostate-specific antigen level do not accurately predict disease outcome of individual patients' prostate cancer. We used a rapid colorimetric in situ hybridization technique to evaluate the expression level of E-cadherin (which affects cell cohesion); matrix metalloproteinases (MMPs) types 2 and 9 (which affect invasion); and vascular endothelial growth factor/vascular permeability factor (which affects angiogenesis) in archival prostatectomy specimens from 40 patients. Intratumoral heterogeneity for gene expression (edge versus center versus perineural area) was more pronounced in advanced cancers than in those that were organ confined. Regardless of Gleason score, the highest expression level for E-cadherin was found in the center or perineural area of the tumors, whereas the highest expression levels for MMP-2 and MMP-9 were associated with the invasive edge. The relationship between advancing pathological stage and expression of all four metastasis-related genes was highly significant. Decreased expression of E-cadherin and increased expression of MMP-2, MMP-9, and vascular endothelial growth factor/vascular permeability factor were associated with the Gleason score of the tumors. Irrespective of serum prostate-specific antigen level or Gleason score, the ratio between expression of MMPs and E-cadherin at the invasive edge of tumors exhibited the strongest association with nonorgan-confined prostate cancer. These data suggest that the relative expression of metastasis-related genes in radical prostatectomy specimens can distinguish between organ-confined and advanced prostate cancers and provides the rationale for a prospective study correlating gene expression in pretherapy core biopsies with outcome.

Highly metastatic human prostate cancer growing within the prostate of athymic mice overexpresses vascular endothelial growth factor.

Angiogenesis is essential for tumor progression and metastasis. It is mediated by the release of angiogenic factors by the tumor or host. We analyzed the expression of angiogenic factors by the prostate cancer cell line LNCaP and two derived variants, in vitro and in vivo, to determine whether metastatic cell lines express higher levels of these factors. The production of three angiogenic factors, vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and interleukin 8 (IL-8), by LNCaP and its variants, LNCaP-LN3 (highly metastatic) and LNCaP-Pro5 (slightly metastatic), was measured by ELISA. VEGF, bFGF, and IL-8 mRNA expression was determined in vitro by Northern blot analysis. VEGF mRNA expression was determined in vivo by in situ hybridization. VEGF and flk-1 protein expression and microvessel density of LNCaP cell tumors were quantified by immunohistochemistry. In vitro, VEGF production by LNCaP-LN3 (3.15+/-0.04 pg/ml/10(3) cells) was significantly higher than those of both LNCaP (2.38+/-0.34 pg/ml/10(3) cells) and LNCaP-Pro5 (1.67+/-0.37 pg/ml/10(3) cells; P = 0.049 and 0.001, respectively). None of the three cell lines produced detectable levels of bFGF or IL-8 in vitro. In vivo, LNCaP-LN3 tumors exhibited higher levels of VEGF mRNA and protein (152.2+/-28.5 and 200.5+/-28.3) and of flk-1 protein (156.5+/-20.6) and had higher microvessel density (16.4+/-4.2) than either LNCaP tumors (89+/-17.5, 173.3+/-23.0, 124.6+/-21.6, and 12.4+/-3.5, respectively) or LNCaP-Pro5 tumors (63+/-14.7, 141.2+/-38.1, 126.1+/-20, and 5.8+/-2.2, respectively). In conclusion, metastatic human prostate cancer cells exhibited enhanced VEGF production and tumor vascularity compared with prostate cancer cells of lower metastatic potential. Thus, VEGF may play an important role in prostate cancer metastasis.

Selection of highly metastatic variants of different human prostatic carcinomas using orthotopic implantation in nude mice.

The purpose of this study was to determine whether the implantation of human prostate cancer cells into the prostates of nude mice and their subsequent growth there can be used to select variants with increasing metastatic potential. PC-3M and LNCaP cells were injected into the prostates of athymic mice. Tumors from the prostate or lymph nodes were harvested, and cells were reinjected into the prostate. This cycle was repeated three to five times to yield cell lines PC-3M-Pro4, PC-3M-LN4, LNCaP-Pro3-5, and LNCaP-LN3-4. Parental and variant cells were injected into the prostates of nude mice. PC-3M-LN4 cells produced enhanced regional lymph node and distant organ metastasis as compared to PC-3M-Pro4 or PC-3M cells. After i.v. or intracardiac inoculation, PC-3M-LN4 cells produced a higher incidence of lung metastasis and bone metastasis, respectively, than PC-3M or PC-3M-Pro4 cells. Subsequent to implantation into the prostate, LNCaP-LN3 cells produced a higher incidence of regional lymph node metastases than LNCaP-Pro5 or LNCaP cells. After intrasplenic implantation, LNCaP-LN3 cells also yielded experimental liver metastases. The metastatic LNCaP-LN3 cells exhibited clonal karyotypic abnormalities, were less sensitive to androgen (in vitro and in vivo), and produced high levels of prostate-specific antigen. Collectively, the data show that the orthotopic implantation of human prostate cancer cell lines in nude mice is a relevant model with which to study the biology of prostate cancer metastasis and to select variant cell lines with enhanced metastatic potential.

Interleukin 8 expression regulates tumorigenicity and metastases in androgen-independent prostate cancer.

Interleukin 8 (IL-8) is mitogenic and chemotactic for endothelial cells. Within a neoplasm, IL-8 is secreted by inflammatory and neoplastic cells. The highly metastatic PC-3M-LN4 cell line overexpresses IL-8 relative to the poorly metastatic PC-3P cell line. We evaluated whether IL-8 expression by human prostate cancer growing within the prostate of athymic nude mice regulates tumor angiogenesis, growth, and metastasis. PC-3P cells were transfected with the full-length sense IL-8 cDNA, whereas PC-3M-LN4 cells were transfected with the full-sequence antisense IL-8 cDNA. Control cells were transfected with the neomycin resistance gene (Neo). In vitro, sense-transfected PC-3P cells overexpressed IL-8-specific mRNA and protein, which resulted in up-regulation of matrix metalloproteinase 9 (MMP-9) mRNA, and collagenase activity, resulting in increased invasion through Matrigel. After antisense transfection of the PC-3M-LN4 cells, IL-8 and MMP-9 expression, collagenase activity, and invasion were markedly reduced relative to controls. After orthotopic implantation, the sense-transfected PC-3P cells were highly tumorigenic and metastatic, with significantly increased neovascularity and IL-8 expression compared with either PC-3P cells or controls. Antisense transfection significantly reduced the expression of IL-8 and MMP-9 and tumor-induced neovascularity, resulting in inhibition of tumorigenicity and metastasis. These results demonstrate that IL-8 expression regulates angiogenesis in prostate cancer, in part by induction of MMP-9 expression, and subsequently regulates the growth and metastasis of human prostate cancer.

A randomized, double-blind, placebo-controlled study of the effects of pomegranate extract on rising PSA levels in men following primary therapy for prostate cancer.

BACKGROUND: The primary objective of this study was to compare the effects of pomegranate juice on PSA doubling times (PSADT) in subjects with rising PSA levels after primary therapy for prostate cancer. METHODS: Double-blind, placebo-controlled multi-institutional study, evaluated the effects of pomegranate liquid extract on serum PSA levels. The primary end point of this study was change in serum PSADT. Additional secondary and exploratory objectives were to evaluate the safety of pomegranate juice and to determine the interaction of manganese superoxide dismutase (MnSOD) AA genotype and pomegranate treatment on PSADT. RESULTS: One-hundred eighty-three eligible subjects were randomly assigned to the active and placebo groups with a ratio of 2:1 (extract N=102; placebo N=64; juice N=17). The majority of adverse events were of moderate or mild grade. Median PSADT increased from 11.1 months at baseline to 15.6 months in the placebo group (P<0.001) compared with an increase from 12.9 months at baseline to 14.5 months in the extract group (P=0.13) and an increase from 12.7 at baseline to 20.3 in the juice group (P=0.004). However, none of these changes were statistically significant between the three groups (P>0.05). Placebo AA patients experienced a 1.8 month change in median PSADT from 10.9 months at baseline to 12.7 months (P=0.22), while extract patients experienced a 12 month change in median PSADT from 13.6 at baseline to 25.6 months (P=0.03). CONCLUSIONS: Compared with placebo, pomegranate extract did not significantly prolong PSADT in prostate cancer patients with rising PSA after primary therapy. A significant prolongation in PSADT was observed in both the treatment and placebo arms. Men with the MnSOD AA genotype may represent a group that is more sensitive to the antiproliferative effects of pomegranate on PSADT; however, this finding requires prospective hypothesis testing and validation.

Integrating chemohormonal therapy and surgery in known or suspected lymph node metastatic prostate cancer.

BACKGROUND: Prostate cancer persisting in the primary site after systemic therapy may contribute to emergence of resistance and progression. We previously demonstrated molecular characteristics of lethal cancer in the prostatectomy specimens of patients presenting with lymph node metastasis after chemohormonal treatment. Here we report the post-treatment outcomes of these patients and assess whether a link exists between surgery and treatment-free/cancer-free survival. METHODS: Patients with either clinically detected lymph node metastasis or primaries at high risk for nodal dissemination were treated with androgen ablation and docetaxel. Those responding with PSA concentration <1 ng ml(-1) were recommended surgery 1 year from enrollment. ADT was withheld postoperatively. The rate of survival without biochemical progression 1 year after surgery was measured to screen for efficacy. RESULTS: Forty patients were enrolled and 39 were evaluable. Three patients (7.7%) declined surgery. Of the remaining 36, 4 patients experienced disease progression during treatment and 4 more did not reach PSA <1. Twenty-six patients (67%) completed surgery, and 13 (33%) were also progression-free 1 year postoperatively (8 with undetectable PSA). With a median follow-up of 61 months, time to treatment failure was 27 months in the patients undergoing surgery. The most frequent patterns of first disease recurrence were biochemical (10 patients) and systemic (5). CONCLUSIONS: Half of the patients undergoing surgery were off treatment and progression-free 1 year following completion of all therapy. These results suggest that integration of surgery is feasible and may be superior to systemic therapy alone for selected prostate cancer patients presenting with nodal metastasis.

Prostate cancer in African-American men: outcome following radiation therapy with or without adjuvant androgen ablation.

PURPOSE: To compare the outcome of irradiated clinically localized prostate cancer in African-American and white patients. METHODS AND MATERIALS: This was a retrospective review of 1,201 men, 116 African-American and 1,085 white, with T1-T3, N0/NX, M0 prostate cancer receiving external radiation between 1987 and 1996. Pretreatment characteristics, treatment parameters, and outcome (relapse or rising prostate-specific antigen [PSA] levels, local recurrence, metastatic relapse, and survival) were compared between the groups using univariate and multivariate statistical methods. RESULTS: There were no significant differences between African-American and white patients in T-stage, Gleason score, prostatic acid phosphatase (PAP) level, and testosterone level. African-Americans had a significantly lower incidence of abnormal digital rectal findings and a proportionally higher incidence of obstructive urinary symptoms at presentation and tended to be somewhat younger. A major difference between the two groups was in the significantly higher PSA levels among African-Americans (median, 14 ng/ml) than among white patients (median, 9.5 ng/ml). This translated into a higher incidence of unfavorable disease according to our criteria (39% vs. 25%) among African-Americans and, thus, to the more frequent use of adjuvant androgen ablation and to somewhat higher radiation doses in these patients. With a median follow-up of 42 months the overall 6-year freedom from relapse for African-Americans was 63% compared to 61% for whites (p = 0.634). We found no significant differences in biochemical relapse rates between any subgroups of African-Americans and whites. Specifically, even patients who did not have androgen ablation, when stratified by PSA levels, had similar outcomes regardless of race. Likewise, local recurrence and metastasis rates were not significantly different between the two groups. CONCLUSIONS: Although African-American patients tend to have higher pretreatment PSA levels than white patients, the outcome for the disease is similar in the two groups when stratified by known pretreatment prognostic factors. Our data provide no evidence for the hypothesis that prostate cancer in African-Americans is intrinsically more virulent than in whites.

Allogeneic lymphocyte stimulation by human spleen. Identification of cells that are very effective for presenting class II HLA antigens.

Human spleen cells were fractionated by percoll density gradient centrifugation and by sorting in the FACS with mixtures of fluorescent antibodies against T cells, B cells, monocytes, and Sig-bearing cells. Cells responsible for powerful MLR stimulation were class II HLA antigen-positive and were concentrated in preparations depleted of all the markers listed above. These cells represented 1-2% of the initial spleen cells. They were remarkably more active than other HLA class II antigen-positive cells. The procedure described allows rapid enrichment for the responsible cells. It should be useful for further characterization of these cells and for performing studies on their function.

Prediction of early kidney transplant rejection by a crossmatch with donor skin.

Immunofluorescence staining of donor skin with recipient serum was performed in 25 patients undergoing kidney transplantation. Transplants were performed when cytotoxicity T cell crossmatches with long incubation and with antiglobulin enhancement were negative. In 20 patients the skin crossmatch was negative and all had an uneventful course. In 5 other recipients, the crossmatch with skin was positive and all developed severe rejection 1-8 days after transplantation. The correlation between skin crossmatch and early rejection was statistically highly significant (P less than 0.00001). Rejection in the skin-crossmatch-positive group led to graft loss in 3, and chronic rejection with poor residual function in the other 2 patients. Serum creatinine at one month was in the 2.6-5.0 mg/dl range in these two patients, while in the group with negative skin crossmatches 15 had serum creatinine levels of less than 1.6, and 5 were in the 1.6-2.5 mg/dl range. Although the nature of the skin antigen is unknown, it appears that this crossmatch procedure was highly accurate in predicting early kidney transplant rejection.

Kidney transplant recipients with long incubation-positive antiglobulin-negative T cell crossmatches.

Low-affinity, cold-reactive antibodies easily removed by washing were not detected by the antiglobulin technique but killed T lymphocytes when washing was omitted, incubation was prolonged, and cytotoxic tests were incubated at room temperature or at 4 degrees C. These antibodies were present in approximately 25% of sera from dialysis patients. Only a subset of such sera (22%) reacted with autologous lymphocytes. The majority (86%) appeared to detect non-HLA antigens. A small number (14%) detected class I HLA antigens. Two patients transplanted with antiglobulin-negative, T-warm-negative crossmatch results, but positive cytotoxicity after a 2-hr incubation without washing, rapidly lost their grafts (less than 1 month) due to rejection. Their sera contained antibodies against non-HLA alloantigens expressed on lymphocytes and platelets, but not on granulocytes or erythrocytes. Two other patients with positive autoantibody tests exhibiting similar crossmatches with the current serum were transplanted recently. Both of them retain their grafts with good function at one month. In two other cases, the recipients were unreactive against the donor in current serum but displayed an antiglobulin-negative, 2-hr cytotoxicity-positive pattern in a previously drawn serum specimen. One patient continues to have stable renal function after 10 months. The other patient lost the transplant as a result of renal artery thrombus thought not to be immunologic in origin. Work is continuing to define the specificity and determine the clinical relevance of such cold-reactive antibodies.

Recruitment experience in the first phase of the African American Hereditary Prostate Cancer (AAHPC) study.

The African American Hereditary Prostate Cancer (AAHPC) Study is an ongoing multicenter genetic linkage study organized by Howard University and the National Human Genome Research Institute (NHGRI), with support from the Office for Research on Minority Health and the National Cancer Institute. The goals of the study are to: (i) look for evidence of involvement of chromosome 1q24-25 (HPC1) in African American men with hereditary prostate cancer (HPC) and (ii) conduct a genome-wide search for other loci associated with HPC in African American men. To accomplish these goals, a network has been established including Howard University, the NHGRI, and six Collaborative Recruitment Centers (CRCs). The CRCs are responsible for the identification and enrollment of 100 African American families. To date, 43 families have been enrolled. Recruitment strategies have included mass media campaigns, physician referrals, community health-fairs/prostate cancer screenings, support groups, tumor registries, as well as visits to churches, barber shops, and universities. By far, the most productive recruitment mechanisms have been physician referrals and tumor registries, yielding a total of 35 (81%) families. Approximately 41% (n = 3400) of probands initially contacted by phone or mail expressed interest in participating; the families of 2% of these met the eligibility criteria, and 75% of those families have been enrolled in the study, indicating a 0.5% recruitment yield (ratio of participants to contacts). As the first large-scale genetic linkage study of African Americans, on a common disease, the challenges and successes of the recruitment process for the AAHPC Study should serve to inform future efforts to involve this population in similar studies.

Systemic administration of 4-amidinoindanon-1-(2'-amidino)-hydrazone, a new inhibitor of s-adenosylmethionine decarboxylase, produces cytostasis of human prostate-cancer in athymic nude-mice.

CGP 48664A, a new S-adenosylmethionine decarboxylase inhibitor, blocks the production of spermidine and spermine, two polyamines that play critical roles in cellular proliferation. Under in vitro conditions, CGP 48664A produced cytostasis of the human prostate cancer cell lines LNCaP, LNCaP-LN3, PC-3M, and PC-3M-MM2 in a dose-dependent manner. This cytostasis was reversed by the addition of exogenous polyamines to the culture medium. LNCaP-LN3 cells or PC-3M-MM2 cells were implanted into the prostate of nude mice. Daily administration of CGP 48664A significantly inhibited tumor size and serum levels of prostate-specific antigen in mice implanted with LNCaP-LN3 cells. The therapeutic effect was related to the time the treatment was initiated, the volume of disease, and the length of treatment. CGP 48664A was not effective against the fast-growing PC-3M-MM2 tumor. These data suggest that to broaden its effectiveness, CGP 48664A should be combined with other cytoreductive agents.

Genetic abnormalities specifically associated with varying metastatic potential of prostate cancer cell lines as detected by comparative genomic hybridization.

Established recently are two in vivo prostate tumor progression models in which subclones of the PC3M and LNCaP cell lines were selected for varying growth characteristics and metastatic potential after successive orthotopic implantation in the prostate of nude mice. In this study, we used comparative genomic hybridization (CGH) to compare the chromosomal abnormalities between the parental cell lines and their respective variants and to determine if specific chromosomal abnormalities can be identified that are associated with different growth properties. PC3M and its derivative cell lines PC3M-Pro4 and PC3M-LN4 shared gains of 8q22--qter, 10q21--q22, and Xq27--qter and loss of 13q33--qter. PC3M-Pro4, a derivative line that produced significantly larger tumors in the prostate, had a unique gain of 3q13. In contrast, PC3M-LN4, the derivative line that produced significantly larger metastatic tumors in the lymph nodes and had higher incidences of distant metastases, had a specific gain of 1q21--q22 and losses of 10q23--qter and 18q12--q21. In the second in vivo model, LNCaP and its derivative cell lines shared gain of 3q27--qter and loss on 13q21--qter. The derivative line that produced significantly larger tumors in the prostate, LNCaP-Pro5, had a unique gain on 13q12--q13. In comparison, LNCaP-LN3, a derivative line that had a significantly higher incidence of lymph node metastases and produced significantly larger metastatic tumors in the lymph nodes, had specific losses of 16q23--qter and 21q. Interestingly, some regions of loss (e.g., 10q23-->qter, 16q23-->qter, and 18q12-->q21) detected in the variant cell lines correlated well with abnormalities seen in clinical prostate cancer cases. Thus, our data suggest not only that these cell lines are relevant in vivo models for prostate cancer progression, but also that CGH is a valuable tool for uncovering chromosomal regions that are important for aggressive growth and metastasis of prostate cancer cells.

Deoxyribonucleic acid flow cytometry and traditional pathologic variables in invasive penile carcinoma: assessment of prognostic significance.

OBJECTIVES: The identification of reliable prognostic factors to guide the selection of patients at high risk of harboring subclinical metastases in penile cancer is important. We evaluated traditional pathologic variables and deoxyribonucleic acid (DNA) flow cytometry to determine the prognostic significance of these variables for the subsequent development of lymph node metastases. METHODS: Clinical data and pathologic specimens were retrospectively reviewed from patients treated surgically at university-affiliated hospitals from 1958 to 1987. Pathologic analysis (grade, depth of invasion, and pathologic stage) and DNA flow cytometry were performed on specimens from 46 patients with invasive penile carcinoma and complete medical records. Pathologic variables were compared with DNA flow cytometry results in patients who never developed lymph node metastasis (32 patients, median follow-up 121 months) and in those who presented with or developed proved lymph node metastases (14 patients, median follow-up 18 months). RESULTS: The distributions of diploid and nondiploid tumors were similar in patients with or without lymph node metastasis. In addition, there was no significant difference in the grade distributions of tumors with respect to lymph node status. Patients with positive nodes more commonly had tumors that invaded greater than 0.5 cm or that exhibited pathologic Stage T2 or greater (deep invasion). All 14 patients who presented with or subsequently developed metastasis had deep primary tumors. Thirteen of 36 patients with clinically negative nodes had superficially invasive tumors (pathologic Stage T1 and depth of invasion 0.5 cm or less), and none developed metastasis (median follow-up 124 months [range 58 to 240]). Tumor grade was significantly related to the likelihood of deep invasion but was not an independent prognostic factor for metastasis. CONCLUSIONS: DNA flow cytometry does not add prognostic information to that obtained by pathologic assessment in patients with invasive penile carcinoma. The presence of pathologic Stage T2 or greater or depth of invasion greater than 0.5 cm defines a group of patients at high risk of inguinal node metastasis. A novel finding was that patients with minimally invasive lesions (0.5 cm or less) and no evidence of corporal invasion (pathologic Stage T1) have little risk of inguinal node metastasis. Close observation of reliable patients meeting these criteria may be a safe alternative to prophylactic lymphadenectomy.