Publications by authors named "Pienta K"

The relation between tumor kinetics and disease progression in patients with hormone-refractory prostate cancer (HRPC) has not been well described. Biochemical recurrence of prostate cancer is characterized by detectable prostate-specific antigen (PSA) levels after treatment and occurs in approximately 30% of patients after therapy for apparent localized disease. An increase in PSA almost always occurs before clinical evidence of disease.

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Currently, approximately 30,000 men die annually of metastatic, hormone-refractory prostate cancer. Androgen blockade is palliative and is generally effective for an average of 2 to 3 years until a patient develops androgen-independent disease. Newer chemotherapeutic regimens can induce remissions in approximately 50% of patients; however, median survival for patients with androgen-independent disease is still 8 to 12 months.

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Purpose: The purpose of this study was to evaluate an 80 kDa proteolytic fragment of E-cadherin as a potential biomarker for prostate cancer progression and to identify putative proteases that are responsible for the cleavage of E-cadherin.

Experimental Design: A wide spectrum of prostate cancer tissue and serum specimens representing different stages of prostate cancer was examined for the accumulation of the 80 kDa fragment of E-cadherin. Additionally, an expression array analysis was used to identify putative proteases that may have been involved in the cleavage of E-cadherin.

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While survival periods for patients with localized prostate cancer have increased, there is still no curative therapy for metastatic disease. Using non-invasive bioluminescent imaging, we designed a comprehensive murine model to monitor tumor location and expansion. We detected micrometastases after one week that correlated by gross necropsy, autoradiography, and histopathology with organ and skeletal lesions seen clinically.

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It is well established that after metastatic cancer cells escape the primary tumour and enter the circulation, their interactions with microvascular endothelium of a target organ constitute an essential rate-limiting step in haematogenous cancer metastasis. However, the physiological and biochemical processes supporting neoplastic cell arrest and retention in the microcirculation are still poorly understood. In this study, we present experimental evidence that microvascular endothelium of metastasis-prone tissues undergoes activation in response to desialylated cancer-associated carbohydrate structures such as Thomsen-Friedenreich (TF) antigen (Galbeta1-3GalNAc) expressed on circulating glycoproteins and neoplastic cells.

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Background: The authors evaluated the combination of oral cyclophosphamide, oral prednisone, and diethylstilbestrol (DES) in patients with androgen-independent prostate carcinoma (AIPC).

Methods: Thirty-seven patients with prostate carcinoma refractory to androgen ablation who had undergone antiandrogen withdrawal (if previously treated with an antiandrogen) were enrolled in the current study. They were treated with oral cyclophosphamide 100 mg per day on Days 1-20, prednisone 10 mg per day continuously, and DES 1 mg continuously, on a 30-day cycle.

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Recent studies suggest that only endothelium-attached malignant cells are capable of giving rise to hematogenous cancer metastases. Moreover, tumor cell adhesion to microvascular endothelium could be crucial in metastasis predilection to specific organs or tissues. However, the existing in vitro and in vivo techniques do not provide for sufficient delineation of distinct stages of a dynamic multi-step intravascular adhesion process.

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Androgen deprivation therapy (ADT) is a mainstay in the treatment of prostate cancer. The ideal timing, duration and composition of ADT remains undefined. At the present time, first-line therapy consists of orchiectomy, LHRH agonists, or combined androgen blockade (CAB).

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Background: Preclinical data suggest that the combination of intravenous (i.v.) paclitaxel, carboplatin, oral etoposide, and oral estramustine (TEEC) has significant activity in patients with advanced, hormone-refractory prostate carcinoma.

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The two major theories of cancer metastasis, the seed and soil hypothesis and the mechanical trapping theory, view tumor cell adhesion to blood vessel endothelia and cancer cell aggregation as corresponding key components of the metastatic process. Here, we demonstrate in vitro, ex vivo, and in vivo that metastatic breast and prostate carcinoma cells form multicellular homotypic aggregates at the sites of their primary attachment to the endothelium. Our results suggest that metastatic cell heterotypic adhesion to the microvascular endothelium and homotypic aggregation represent two coordinated subsequent steps of the metastatic cascade mediated largely by similar molecular mechanisms, specifically by interactions of tumor-associated Thomsen-Friedenreich glycoantigen with the beta-galactoside-binding protein, galectin-3.

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Testicular cancer remains a major success story in the realm of solid tumors. There are still many remaining challenges in diagnosis, treatment, and prevention of long-term toxicity. Surgery and platinum-based chemotherapy, however, still encompass the main treatment modalities.

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Human prostate cancers (PCa) express great variability in their ability to metastasize to bone. The identification of molecules associated with aggressive phenotypes will help to define PCa subsets and will ultimately lead to better treatment strategies. The chemokine stromal-derived factor-1 (SDF-1 or CXCL12) and its receptor CXCR4 are now known to modulate the migration and survival of an increasing array of normal and malignant cell types including breast, pancreatic cancers, glioblastomas, and others.

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Prostate cancer metastasis to bone may be mediated by preferential proliferation of these cells in the bone's microenvironment. We hypothesize that this preferential proliferation is mediated by bone-associated growth factors (GFs) and cytokines. To test our hypothesis, human prostate cancer cells, derived from both soft tissue (LNCaP, DuCaP, DU145) and bone metastases (PC-3, VCaP, MDA-2a, MDA-2b), were treated with bone-associated GFs and cytokines (PDGF, IGF-1, TGF-beta, EGF, bFGF, TNF-alpha, IL-1, and IL-6) for 48 h, and their growth responses were compared.

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Background: Prostate carcinoma (PC) frequently metastasizes to bone, where it causes significant morbidity and mortality. Stromal elements in the primary and metastatic target organs are important mediators of tumor cell intravasation, chemoattraction, adhesion to target organ microvascular endothelium, extravasation, and growth at the metastatic site.

Methods: The role of stromal factors in bone metastasis was determined with a cyclic DNA microarray comparison of a bone-derived cell PC cell line with a soft tissue-derived cell PC cell line and by evaluating the effects of selected stromal components on PC cell chemotaxis, cell adhesion to human bone marrow endothelium (HBME), and PC cell growth.

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Bone metastasis is a common phenomenon in patients with advanced prostate cancer. The molecular and cellular mechanisms involved in this process are not well understood. Past reviews on this subject primarily focused on prostate tumor growth in the bone marrow and the effects this growth has on bone homeostasis (ie osteoblastic and osteolytic).

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Objectives: To identify genes important in prostate cancer metastatic to bone. Bone-specific metastasis is a common feature of prostate cancer and a significant cause of morbidity.

Methods: To identify factors involved in organ-specific metastasis, we used cDNA microarray analysis to compare a bone-derived cell line, VCaP, with a soft tissue-derived cell line, DuCaP.

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Prostate cancer is a leading cause of cancer-related death in males and is second only to lung cancer. Although effective surgical and radiation treatments exist for clinically localized prostate cancer, metastatic prostate cancer remains essentially incurable. Here we show, through gene expression profiling, that the polycomb group protein enhancer of zeste homolog 2 (EZH2) is overexpressed in hormone-refractory, metastatic prostate cancer.

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Plasma fibronectin-mediated invasion of human DU145 prostate cancer cell line was efficaciously inhibited in a rat tumor model by treatment with Ac-PHSCN-NH(2) peptide. Invasion of DU145 cells was stimulated by the PHSRN sequence of plasma fibronectin. However, PHSCN acts as a competitive inhibitor of PHSRN-mediated invasion.

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The majority of men with progressive prostate cancer develop metastases with the skeleton being the most prevalent metastatic site. Unlike many other tumors that metastasize to bone and form osteolytic lesions, prostate carcinomas form osteoblastic lesions. However, histological evaluation of these lesions reveals the presence of underlying osteoclastic activity.

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Recently, several important studies have validated prostate-specific antigen (PSA) as a reliable measure of response to chemotherapeutic treatment in advanced hormone-refractory prostate cancer. Furthermore, although chemotherapy in this setting has always been considered palliative, several analyses of recent clinical trials have demonstrated a significant association between declines in PSA values of 50% or more and prolonged survival. Mitoxantrone, in combination with prednisone, has been shown to provide significant palliation and improved quality of life.

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Using a modified version of the mRNA differential display technique, five human bladder cancer cell lines from low grade to metastatic were analyzed to identify differences in gene expression. A 316-bp cDNA (C11-300) was isolated that was not expressed in the metastatic cell line TccSuP. Sequence analysis revealed that this gene was identical to KIAA 0429, has a 5.

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Androgen deprivation therapy remains a mainstay of treatment for men with prostate cancer. New uses for hormonal therapy, including use in the adjuvant and neoadjuvant setting, are being evaluated. Prevention of the side effects of therapy has led to the development of alternative schedules and therapeutics.

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Purpose/objectives: To explore the experiences of couples living with prostate cancer, the impact of the illness on their quality of life, their ability to manage symptoms, and their suggestions for interventions that would help them to improve their daily experiences.

Design: Descriptive, qualitative.

Setting: Six focus groups were used to obtain the data; two were patient-only groups, two were spouse-caregiver groups, and two were dyad groups.

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Integrin alpha(v)beta(3) is involved in varied cell biological activities, including angiogenesis, cell adhesion, and migration on several extracellular matrix components. Although alpha(v)beta(3) is not typically expressed in epithelial cells, it is expressed in macrophages, activated leukocytes, cytokine-stimulated endothelial cells, osteoclasts, and certain invasive tumors. Interestingly, the adhesion and migration of breast cancer cells on bone matrix are mediated, in part, by alpha(v)beta(3).

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Testicular cancer remains a major success story in the realm of solid tumors. Although testicular cancer is highly treatable and curable, there are still many young men who succumb to the disease. Over the past year, important data regarding the diagnosis, treatment, and prognosis of testicular cancer have been reported.

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