Richard F. Jones

Evaluation of prostatitis in autopsied prostates--is chronic inflammation more associated with benign prostatic hyperplasia or cancer?

PURPOSE Chronic inflammation is associated with prostate cancer and benign prostatic hyperplasia. However, the prevalence of chronic inflammation in malignant and benign glands has not been compared. We evaluated the association of inflammation, benign prostatic hyperplasia and cancer in autopsied prostates. MATERIALS AND METHODS We prospectively analyzed 167 autopsied prostates. Pathological analysis identified each focus of cancer, benign prostatic hyperplasia nodules and areas of acute or chronic inflammation. Any cancer focus or benign prostatic hyperplasia nodule involved directly with inflammation was recorded. The association of the prevalence of prostate cancer, benign prostatic hyperplasia and inflammation was statistically assessed. RESULTS Inflammation was present in 113 (67.6%) of 167 cases. Chronic inflammation was identified in 88 (53%), acute inflammation in 6 (4%), and chronic inflammation and acute inflammation in 19 (11%) glands. In the majority of cases inflammation was present in the transitional zone. A total of 93 glands (56%) were involved with benign prostatic hyperplasia and 49 (29%) with cancer. Of the glands harboring benign prostatic hyperplasia 75% were also involved with chronic inflammation compared to only 50% of those without benign prostatic hyperplasia (p <0.01). Comparatively the glands with or without any evidence of cancer were similarly involved with chronic inflammation (55% vs 58%, p >0.1). Of the 27 glands involved with cancer and benign prostatic hyperplasia, chronic inflammation was more associated with benign prostatic hyperplasia than cancer (p = 0.006). Acute inflammation was not significantly associated with either benign prostatic hyperplasia or cancer. CONCLUSIONS Chronic inflammation was a common finding in autopsied prostates. It appeared to be directly associated with the presence of benign prostatic hyperplasia but not with cancer.

Heterocyclic amines and genotype of N-acetyltransferases as risk factors for prostate cancer.

A variety of carcinogenic heterocyclic amines are produced during the cooking of meat at high temperatures. These carcinogens are metabolized by N-acetyltransferases (NAT), which are polymorphic in the population. This study examined associations between prostate cancer (PCa) and the consumption of different kinds of meat, heterocyclic amine intake and NAT genotypes. PCa patients and controls were recruited in the Syracuse, NY area. Levels of meat and heterocyclic amine intakes were determined from validated surveys and NAT genotypes were determined by the sequences of PCR-amplified DNA from buccal swabs. A total of 152 cases and 161 controls were eligible for analysis. There was an association between PCa and history of PCa in the first-degree blood relatives (OR=4.59, 95% CI 2.21–9.70), and family history of bladder cancer (P<0.02). However, there was no association with the history of other cancers. There was no association between PCa and either 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) intake, or NAT1 and NAT2 genotypes. However, there was a trend of association with MeIQx and with rapid NAT2 and NAT1*10 in combination with PhIP. A new NAT1 allele with a frequency of one out of 544 chromosomes was found in the Caucasian subjects.

Pathological Characteristics of Prostate Cancer in Elderly Men

PURPOSE Recent guidelines recommend that men older than 75 years should not be screened for prostate cancer. However, increased life expectancy and the development of less invasive treatments have led to an interest in characterizing prostate cancer in elderly men. We determined how prostate cancer pathological characteristics differ in men older vs younger than 70 years. MATERIALS AND METHODS We studied differences in prostate cancer pathological characteristics in autopsied glands from men 70 years old or older and compared findings to those in men younger than 70 years. All men died of causes unrelated to prostate cancer. Prostates were whole mounted at 4 mm intervals. Histological analysis was done to identify and characterize each cancer focus observed. Tumor volume was measured by computerized planimetry. Cancer was defined as clinically significant or insignificant based on established histological characteristics. RESULTS Of 211 prostates evaluated 74 were from men 70 years old or older. We identified cancer in 33 men (45%) in this age group vs in 26 of 137 (19%) younger than 70 years (p <0.001). Men older than 70 years had significantly larger cancer and more clinically significant cancer (64% vs 23%, p <0.005). Older men had more advanced stage cancer and greater Gleason scores (p <0.001). CONCLUSIONS In an autopsy study of men with no history of prostate cancer those older than 70 years were more likely to have larger and higher grade prostate cancer than younger men.

Immunotherapy for Lung Metastases of Murine Renal Cell Carcinoma: Synergy Between Radiation and Cytokine-producing Tumor Vaccines

We investigated the combination therapy of local radiation of lung metastasis and vaccination with autologous tumor cells that produced interleukin (IL)-2, interferon-gamma (IFN-gamma), and granulocyte-macrophage colony-stimulating factor (GM-CSF) using the mouse Renca pulmonary metastasis model. Wild-type Renca (W/Renca) were transfected with pEF-BOS vector incorporating cDNAs for IL-2, IFN-gamma, or GM-CSF to express these cytokines. W/Renca, IL-2-producing Renca (Renca/IL-2), and IFN-gamma-producing Renca (Renca/IFN-gamma) produced subcutaneous tumor at the injection site in eight of eight, one of eight, and two of eight mice, respectively. No tumors were found in the GM-CSF-producing Renca (Renca/GM-CSF) group (zero of eight). Renca/IFN-gamma produced subcutaneous (s.c.) tumors in all Balb/c nude mice, but Renca/IL-2 and Renca/GM-CSF did not. To test the elicitation of antitumor activity, Balb/c mice were injected intravenously with 1 x 10(5) W/Renca on day 0, vaccinated, s.c., with 1 x 10(6) cells each of 5,000 rad preirradiated Renca/IL-2, Renca/IFN-gamma, and Renca/GM-CSF or 3 x 10(6) cells of preirradiated W/Renca on days 1, 7, and 14, and radiated with 300 rad to both lungs on day 5. The animals were killed on day 21 and tumor nodules in the lungs were enumerated. Neither local irradiation alone nor the combination of lung radiation and multiple vaccination with irradiated W/Renca significantly reduced the number of lung tumors. In contrast, the combination of lung radiation and the multiple vaccinations with cytokine-producing Renca cells significantly reduced the number of lung tumors. This regimen was more effective than the multiple vaccinations with cytokine-producing Renca cells alone. These studies demonstrate the efficacy of vaccination with autologous tumor cells expressing these cytokines and sensitization of the tumor target with radiation.

Diagnostic accuracy of extended biopsies for the staging of microfocal prostate cancers in autopsy specimen

Clinically insignificant prostate cancers may be predicted when biopsies show a microfocal cancer (MiFC). However, at least one-third of MiFC are underestimated by biopsies. The aim of this study was to evaluate the staging accuracy of different biopsy regimen showing a MiFC. We performed 18 biopsy cores on 164 autopsy prostates. Six cores were taken from the mid-peripheral zone (MPZ), 6 from the lateral PZ (LPZ) and 6 from the central zone (CZ). We tested seven different biopsy regimens by distinguishing the MPZ, LPZ or CZ biopsies either separately or associated with each other. Of the cancers detected by biopsies, we selected those showing a MiFC and compared our findings with whole mount analysis. The positive predictive value of a MiFC referred to how often, when needle biopsies showed a MiFC, there was a clinically insignificant cancer on whole mount prostate analysis. We found that the positive predictive value of a MiFC on 6 or 12 biopsy cores was similar irrespective of biopsy location (P≈1). On MPZ, MPZ plus LPZ and all 18 biopsies, it was 40, 70 and 87%, respectively (P<0.1). Tumor volume of cancers showing a MiFC on MPZ biopsies was significantly higher than those showing a MiFC on MPZ plus LPZ, or all 18 biopsies (P<0.05). These results show that performing additional cores in case of MiFC on sextant biopsies may help differentiating significant from insignificant cancers.

Induction of Antibodies against Prostate-Specific Membrane Antigen (PSMA) by Vaccination with a PSMA DNA Vector

Abstract Introduction and Objectives: Prostate-specific membrane antigen (PSMA) is a 750 amino acid surface protein expressed primarily in prostate epithelium, and is upregulated 10-fold in prostate cancer. It is therefore an attractive target for immunotherapy. However, most reported antibodies to PSMA apparently recognize epitopes in the residue 43–570 region of the extracellular domain, and upon binding are rapidly removed from the cell surface by internalization. This would potentially limit their ability to mediate Fc-dependent cytoxicity. In this study, we constructed a DNA expression vector, pV/TM–PSMc, in which this region was deleted from full-length PSMA cDNA. Mice were vaccinated with pV/TM–PSMc DNA to determine whether humoral responses directed against PSMA-positive human prostate cancer cells could be induced by this C-terminal region. Methods: Polymerase chain reaction (PCR)-based techniques were used to delete codons 50–570 from the coding region of human PSMA cDNA, thereby joining the C-terminal end (PSMc) to the N-terminal cytoplasmic/transmembrane domain (TM). This truncated product, TM–PSMc, was cloned into the vector pNGVL3 (pV). The resulting vector, pV/TM–PSMc, was confirmed by DNA sequencing, and by expression studies using reverse transcriptase (RT)–PCR for transcripts and immunohistochemical (IHC) staining with the PSMA monoclonal antibody (mAb) 7E11.C5. BALB/c mice were injected in the tibialis anterior muscle four times, at biweekly intervals, with 100μg vector DNA per injection. One week after the last injection, blood was drawn for serum preparation. The serum was assayed for antibodies against PSMA by IHC staining of LNCaP, a PSMA-positive human prostate cancer line. Expression in vaccinated muscle cells was determined by RT–PCR assay for TM–PSMc transcripts. Results: NIH3T3 cells transfected with pV/TM–PSMc stained positively by IHC reaction with mAb 7E11.C5. 48h after one intramuscular (i.m.) injection of mice with 100μg pV/TM–PSMc vector DNA, TM–PSMc transcripts were detectable in muscle RNA by RT–PCR analysis. Anti-serum from pV/TM–PSMc-DNA vaccinated mice, at a dilution of 1:20, intensely IHC-stained both live and fixed LNCaP cells. Conclusions: These results demonstrate that anti-PSMA humoral responses were induced by i.m. injection of mice with pV/TM–PSMc DNA. Antibodies in the anti-serum were directed against extracellular epitopes of native PSMA expressed by human prostate cancer cells. Vaccination with DNA expression vectors such as pV/TM–PSMc may provide an immunotherapeutic approach for the treatment of prostate cancer.

Clinical trials of immunotherapy for advanced prostate cancer

There is a lack of effective therapeutic regimens for advanced hormone-refractory prostate cancer (HRPC). Recent combination regimens of chemotherapy have improved management of HRPC. Neither systemic chemotherapy nor radiation regimens have significantly improved survival. Conventional systemic cytokine therapy has had limited efficacy in the treatment of advanced prostate cancer patients and its toxicity is severe. Combinations of multiple biological response modifiers for treatment of this disease also have limited efficacy. Results from phase II trials have shown that the combination of interferon-alpha and interleukin-2 therapy and the infusion of dendritic cells primed with peptides of prostate specific membrane antigen are promising. The former showed 31% response using the National Prostatic Cancer Project criteria, and the latter showed 27% of objective partial response with a reduction of >50% prostate specific antigen level. The toxicity of these two regimens was tolerated by patients. New approaches with tumor vaccines in conjunction with cytokine gene therapy have also been investigated. The clinical responses of these trials have been limited but promising. Immunotherapy may become an effective modality of prostate cancer treatment in the future.

Differential gene expression in human prostate cancer cells adapted to growth in bone in Beige mice

OBJECTIVE A metastasis model was used to identify genes potentially related to the growth of human prostate cancer in the bone. Injection of the human prostate cancer line PC3 into the femurs of Beige mice induced tumors that ruptured the femurs in 4 to 6 weeks. MATERIALS AND METHODS The subline PC3a was cultured in vitro from one of these PC3 bone tumors. PC3a cells were reinjected into femurs, and the subline PC3b was then cultured from a resulting PC3a tumor. Likewise, PC3c was derived from a PC3b bone tumor. The PC3 tumors were osteolytic, invasive and metastatic. RESULTS Analysis of gene expression in these PC3 sublines by differential-display RT-PCR identified two groups of transcripts whose steady state levels differed substantially from the original PC3 line. One group of transcripts increased with progressive adaptation to tumor formation in bone. The second group showed the reverse pattern. They progressively diminished in subsequent sublines, and were virtually absent in PC3b and PC3c. Two in this group were fibroblast growth factor receptor-2 and caveolin-1. They were strongly expressed in non-malignant prostate tissue. CONCLUSION These two downregulated genes, which have been reported to play a role in the development of androgen independence and malignant progression, may reflect molecular changes in growth regulation of PC3 cells during readaptation to an intra-osseal environment.