Immunohistochemical Staining of Precursor Forms of Prostate-specific Antigen (proPSA) in Metastatic Prostate Cancer

Frequency of metastasis to the gastrointestinal tract determined by endoscopy in a community-based gastroenterology practice

Metastasis to the gastrointestinal tract is rare. We performed a retrospective analysis to identify patients with metastatic disease to the gastrointestinal tract using two databases containing pathology results from all endoscopic procedures conducted by nearly 200 gastroenterologists in a community setting over a 14-year period. Forty-nine patients were diagnosed with metastasis to the gastrointestinal tract by endoscopy during the study period. Most were women (71%). The most common metastases to the gastrointestinal tract identified by endoscopy were breast cancers (n = 18), followed by melanomas (n = 12), ovarian cancers (n = 7), kidney cancers (n = 5), prostate cancers (n = 2), lung cancer (n = 1), and pancreatic cancer (n = 1). Three patients had unknown primary sites. Among women, the three leading known primary tumor sites were breast, ovary, and melanoma. Among men, the three leading primary tumor sites were melanoma, kidney, and prostate. The stomach was the most common portion of the gastrointestinal tract involved by metastases. Most affected women and were most frequently encountered in the stomach.

Prostatic adenocarcinoma presenting with metastases to the testis and epididymis: A case report

Few cases of testicular metastases from prostate carcinoma have been reported, and asymptomatic metastases of prostate carcinoma to both the testis and epididymis are extremely rare. The current study presents the case of a 69-year-old male with testicular and epididymal metastases from prostate carcinoma. The patient was admitted to The First Hospital of Shijiazhuang with a 2-year history of lower urinary tract symptoms. Digital rectal examination revealed an enlarged multinodular prostate, and the serum prostate-specific antigen (PSA) level was >100 ng/ml. Magnetic resonance imaging showed prostate carcinoma with seminal vesicle involvement. A prostate biopsy showed prostate gland adenocarcinoma. The Gleason score was 3+3. The immunohistochemistry results were as follows: Prostatic acid phosphatase (+++), PSA (+++), P504s (+++), p63 (-) and cytokeratin 34βE12 (-), with a Ki-67 of ~5%. The patient was treated with a bilateral orchiectomy. The testicular pathology showed that the right testis and epididymis were invaded with metastatic adenocarcinoma. The left testis and epididymis were normal. The patient was treated with conventional flutamide endocrine therapy. At present the patient remains in a stable condition after 24 months of follow-up.

Metastatic carcinoma of unknown primary: diagnostic approach using immunohistochemistry

Carcinoma of unknown primary origin (CUP) is one of the 10 most prevalent malignancies. CUP patients in whom a site of origin can be ascribed have better outcomes than those in which the primary tumor remains unidentified. Among the tools available to pathologists in approaching these lesions, immunohistochemistry is a reliable, inexpensive, and widely available resource. New markers continue to emerge, which, in combination with other historically useful antibodies, allow rapid and accurate identification of primary site in an increasing number of cases. This review discusses the approach to the diagnosis of CUP using immunohistochemistry and outlines some of the most useful markers with a particular focus on the utility of lineage-restricted transcription factors, including CDX2, NKX3-1, PAX8, SATB2, TTF-1, and SF1.

PSA affects prostate cancer cell invasion in vitro and induces an osteoblastic phenotype in bone in vivo

BACKGROUND

Patients with advanced prostate cancer frequently have a poor prognosis as a result of metastasis and present with high serum PSA levels. There is evidence suggesting that the serine protease activity of PSA could be involved in the invasion and metastasis of prostate cancer. In this study, we determined the effects of PSA and its precursor, pro-PSA, on invasion and the type of bone metastasis.

METHODS

We stably transfected prostate adenocarcinoma cells, human DU-145 and rat MatLyLu, with either the full-length prepro-PSA sequence or pre-PSA DNA, to generate subclones of cells that secrete pro-PSA or free PSA, respectively. Secretion of PSA was measured by western blot analysis and enzyme-linked immunosorbent assay (ELISA). The invasive and migratory properties of the cells were determined using a basement membrane extract and were compared with corresponding empty vector control cells. Twelve days after injection of PSA-secreting MatLyLu cells into the femora of nude mice, bone tumor burden and histomorphometry were determined using a stereological technique.

RESULTS

The transfected cells secreted 0.15-2.23 ng PSA/10(6) cells/day. Pro-PSA-secreting subclones increased invasion and migration by 24-263%. Conversely, the PSA-secreting subclones significantly reduced both invasion and migration by 59-70%. The divergent effects on invasion and migration observed in pro-PSA- and PSA-secreting subclones indicate that different forms of PSA may have different functions. Intrafemoral injections with PSA-secreting MatLyLu cells resulted in an increase in osteoblastic parameters when compared with non-PSA-secreting subclones as measured by bone histomorphometry. Concomitantly, a decrease in osteoclasts and eroded surface was observed.

CONCLUSIONS

Our in vitro data suggest that PSA, dependent on the predominant form secreted, may decrease or increase invasive properties of prostate cancer cells. The in vivo results indicate that PSA in the bone microenvironment may contribute to the osteoblastic phenotype of bone metastasis frequently observed in prostate cancer.

Immunohistochemical staining of radixin and moesin in prostatic adenocarcinoma

BACKGROUND

Some members of the Protein 4.1 superfamily are believed to be involved in cell proliferation and growth, or in the regulation of these processes. While the expression levels of two members of this family, radixin and moesin, have been studied in many tumor types, to our knowledge they have not been investigated in prostate cancer.

METHODS

Tissue microarrays were immunohistochemically stained for either radixin or moesin, with the staining intensities subsequently quantified and statistically analyzed using One-Way ANOVA or nonparametric equivalent with subsequent Student-Newman-Keuls tests for multiple comparisons. There were 11 cases of normal donor prostates (NDP), 14 cases of benign prostatic hyperplasia (BPH), 23 cases of high-grade prostatic intraepithelial neoplasia (HGPIN), 88 cases of prostatic adenocarcinoma (PCa), and 25 cases of normal tissue adjacent to adenocarcinoma (NAC) analyzed in the microarrays.

RESULTS

NDP, BPH, and HGPIN had higher absolute staining scores for radixin than PCa and NAC, but with a significant difference observed between only HGPIN and PCa (p = < 0.001) and HGPIN and NAC (p = 0.001). In the moesin-stained specimens, PCa, NAC, HGPIN, and BPH all received absolute higher staining scores than NDP, but the differences were not significant. Stage 4 moesin-stained PCa had a significantly reduced staining intensity compared to Stage 2 (p = 0.003).

CONCLUSIONS

To our knowledge, these studies represent the first reports on the expression profiles of radixin and moesin in prostatic adenocarcinoma. The current study has shown that there were statistically significant differences observed between HGPIN and PCa and HGPIN and NAC in terms of radixin expression. The differences in the moesin profiles by tissue type were not statistically significant. Additional larger studies with these markers may further elucidate their potential roles in prostatic neoplasia progression.

The role of tissue microarrays in prostate cancer biomarker discovery

Tissue microarrays (TMAs) offer the potential to rapidly translate genomics and basic science research findings to practical clinical application. This is particularly true in the field of cancer biomarker research, where TMAs can be used for candidate biomarker validation and association with patient clinical, pathologic, and outcomes parameters. In this review, we examine the effect of TMA use on prostate cancer biomarker research, focusing on the types of TMAs that have been used, and the biomarkers that have been examined. The results demonstrate that TMAs have been very effective in screening candidate biomarkers for subsequent, extended evaluation in large patient populations. In addition, the use of TMAs in multiple biomarker series allows for the statistical analysis of sets of biomarkers as diagnostic or prognostic tests. The processes used here can be applied to any tumor type to improve patient diagnosis, prognosis, and treatment response prediction.

Immunohistochemical differentiation of high-grade prostate carcinoma from urothelial carcinoma

The histologic distinction between high-grade prostate cancer and infiltrating high-grade urothelial cancer may be difficult, and has significant implications because each disease may be treated very differently (ie, hormone therapy for prostate cancer and chemotherapy for urothelial cancer). Immunohistochemistry of novel and established prostatic and urothelial markers using tissue microarrays (TMAs) were studied. Prostatic markers studied included: prostate-specific antigen (PSA), prostein (P501s), prostate-specific membrane antigen (PSMA), NKX3.1 (an androgen-related tumor suppressor gene), and proPSA (pPSA) (precursor form of PSA). "Urothelial markers" included high molecular weight cytokeratin (HMWCK), p63, thrombomodulin, and S100P (placental S100). TMAs contained 38 poorly differentiated prostate cancers [Gleason score 8 (n=2), Gleason score 9 (n=18), Gleason score 10 (n=18)] and 35 high-grade invasive urothelial carcinomas from radical prostatectomy and cystectomy specimens, respectively. Each case had 2 to 8 tissue spots (0.6-mm diameter). If all spots for a case showed negative staining, the case was called negative. The sensitivities for labeling prostate cancers were PSA (97.4%), P501S (100%), PSMA (92.1%), NKX3.1 (94.7%), and pPSA (94.7%). Because of PSA's high sensitivity on the TMA, we chose 41 additional poorly differentiated primary (N=36) and metastatic (N=5) prostate carcinomas which showed variable PSA staining at the time of diagnosis and performed immunohistochemistry on routine tissue sections. Compared to PSA, which on average showed 18.8% of cells with moderate to strong positivity, cases stained for P501S, PSMA, and NKX3.1 had on average 42.5%, 53.7%, 52.9% immunoreactivity, respectively. All prostatic markers showed excellent specificity. HMWCK, p63, thrombomodulin, and S100P showed lower sensitivities in labeling high-grade invasive urothelial cancer in the TMAs with 91.4%, 82.9%, 68.6%, and 71.4% staining, respectively. These urothelial markers were relatively specific with only a few prostate cancers showing scattered (<or=2%) weak-moderate positive cells. In summary, PSA can be used as the first screening marker for differentiating high-grade prostate adenocarcinoma from high-grade urothelial carcinoma. Immunohistochemistry for P501S, PSMA, NKX3.1, and pPSA are useful when high-grade prostate cancer is suspected based on the morphology or clinical findings, yet shows negative or equivocal PSA staining. HMWCK and p63 are superior to the novel markers thrombomodulin and S100P.

Free PSA forms in prostatic tissue and sera of prostate cancer patients: Analysis by 2-DE and western blotting of immunopurified samples

OBJECTIVE

The isoform pattern of free prostate-specific antigen (fPSA) from sera of patients with prostate cancer (PCa) and no evidence of prostate cancer (NPCa), cancerous and non-cancerous tissues and seminal plasma, have been compared, above all regarding the degree of sialylation, with the aim to show a better discrimination of PCa and NPCa.

DESIGN AND METHODS

The samples have been immunopurified and analyzed by two dimensional gel electrophoresis and western blotting. It was investigated which patterns were obtained when looking for the fPSA and the (-5/-7)proPSA (precursor form) before and after desialylation.

RESULTS

The fPSA sialylation and the proPSA pattern in cancerous and non-cancerous prostate tissues were similar to each other and only slightly different from PCa and NPCa sera. The different fPSA isoforms observed could not be due solely to differences in the degree of sialylation, because different fPSA and (-5/-7)proPSA precursor isoforms were still present after complete desialylation.

CONCLUSIONS

Although slight differences in the fPSA and (-5/-7) proPSA glycosylation and isoform pattern were observed, they were not large enough to be considered to improve PCa diagnosis.