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Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cell surface carbohydrates expressed on epithelial cells are thought to play an important role in tumor progression. Previously, we have shown that expression of core 2-branched O-glycans is closely correlated with vessel invasion and depth of invasion in colon and lung carcinomas. In this study, we found that expression of core 2 beta1,6-N-acetylglucosaminyltransferase-1, Core2GnT, is positively correlated with the progression of prostate cancer in human patients. Statistical analysis demonstrated that Core2GnT is an independent predictor for progressed pathological stage (pT3) and for prostate-specific antigen (PSA) relapse. To determine directly the roles of Core2GnT in prostate cancer progression, we set up an experimental tumor model using the LNCaP prostate cancer cell line. Because this line does not express Core2GnT, we established an LNCaP line stably expressing Core2GnT, LNCap-Core2GnT, by transfecting cDNA encoding Core2GnT. When mock-transfected LNCaP cells and LNCaP-Core2GnT were inoculated in the prostate of nude mice, LNCaP-Core2GnT cells produced three times heavier prostate tumors than mock-transfected LNCaP cells. Furthermore, we found that LNCaP-Core2GnT cells adhered more strongly to prostate stromal cells, type IV collagen and laminin than did LNCaP-mock cells, but LNCaP and LNCaP-Core2GnT cells grew almost at the same rate on plates coated with type IV collagen or laminin. These results indicate that Core2GnT is an extremely useful prognostic marker for prostate cancer progression. The results also suggest that acquiring Core2GnT in prostate carcinoma cells facilitates adhesion to type IV collagen and laminin, and this increased adhesion may be a cause for aggressive tumor formation by prostate cancer cells expressing Core2GnT.
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PMID:Expression of core 2 beta1,6-N-acetylglucosaminyltransferase facilitates prostate cancer progression. 1593 19

Neuroendocrine (NE) tumor cells in prostatic carcinoma (PCa) may influence tumor proliferation by a paracrine stimulus. The role of NE tumor cells is discussed controversially. This study investigates the influence of NE tumor differentiation on proliferation in PCa. Neuroendocrine differentiation, Ki-67, and Polo-like kinase 1 were studied immunohistochemically in 73 consecutive prostatectomies. Polo-like kinase 1 (PLK1) expression was also studied by Western and Northern blot analysis. Tumors were classified as high NE (HNE) and low NE differentiated (LNE), and depending on the growth pattern, with solitary and clusters of NE tumor cells. Low NE differentiated tumors were defined as less than 30 and HNE as 30 or more NE tumor cells per hot spot. Patients were followed by serum prostate-specific antigen (PSA) analysis. Neuroendocrine differentiation was present at least focally in 70% of tumors; 57% were HNE and 43% LNE. Solitary NE tumor cells were more often found in low-grade PCa, whereas clusters of NE tumor cells were more frequent in high-grade PCa. PLK1 messenger RNA and protein as well as Ki-67 were overexpressed in tumor tissue compared with tumor-free tissue. A stronger proliferation as determined by Ki-67 and PLK1 expression was present in HNE tumors compared with LNE tumors and in tumors with clusters in contrast to tumors with solitary NE tumor cells. Analysis for PSA relapse-free survival showed an earlier progression in HNE than in LNE tumors and in PCa with clusters of NE tumor cells. A significant and clustered NE differentiation in PCa may lead to an increased proliferation and earlier tumor progression, whereas few and solitary NE tumor cells have no prognostic impact.
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PMID:Influence of neuroendocrine tumor cells on proliferation in prostatic carcinoma. 1594 24

Hepatocyte activator inhibitor-1 (HAI-1) is a transmembrane serine protease inhibitor that regulates the conversion of latent to active hepatocyte growth factor (HGF). Studies supporting a role for the HGF pathway in prostate carcinogenesis prompted an analysis of HAI-1 expression in the prostate. Here we analyze the regulation of HAI-1 expression by androgen, oncogenic transformation, and cancer progression. Immunohistochemical analysis revealed that HAI-1 expression was restricted to prostate epithelium, where staining occurred primarily in basal and atrophic luminal epithelial cells. Compared to normal glands, HAI-1 expression was significantly increased in localized prostate cancer and was present in most prostate cancer metastases. HAI-1 protein expression levels were sensitive to androgen in normal epithelium but not in cancer. Although androgen did not increase HAI-1 protein expression levels in LNCaP cells, it decreased HAI-1 surface expression, consistent with previous data from our group (Martin DB, Gifford DR, Wright ME, Keller A, Yi E, Goodlett DR, Aebersold R, Nelson PS: Quantitative proteomic analysis of proteins released by neoplastic prostate epithelium. Cancer Res 2004, 64:347-355). HAI-1 overexpression in cancer was predictive of prostate-specific antigen recurrence (relative risk, 1.24). These results suggest that HAI-1 regulates the HGF Met axis on prostate epithelial cells and influences HGF mediated tumor invasion and metastasis.
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PMID:Regulation of hepatocyte activator inhibitor-1 expression by androgen and oncogenic transformation in the prostate. 1597 69

Lethal phenotypes of human prostate cancer are characterized by progression to androgen independence, although the mechanisms behind this progression remain unclear. Arsenic is a potential human prostate carcinogen that may affect tumor progression. In this study, we used a prostate cancer cell model in which an immortalized, nontumorigenic human prostate epithelial cell line (RWPE-1) had been malignantly transformed by chronic low-level arsenic to help determine whether arsenic affects prostate tumor progression. Control and CAsE-PE (chronic-arsenic-exposed human prostate epithelial) cells were continuously maintained in a complete medium [keratinocyte serum-free medium (K-SFM) with bovine pituitary extract and epidermal growth factor] or in a steroid-depleted medium (K-SFM alone). The arsenic-transformed cells showed a more rapid proliferation rate in complete medium than did control cells and also showed sustained proliferation in steroid-reduced medium. Although both control and CAsE-PE cells showed similar levels of androgen receptor (AR), androgens were less effective in stimulating cell proliferation and AR-related gene expression in CAsE-PE cells. For instance, dihydrotestosterone caused a 4.5-fold increase in prostate-specific antigen transcript in control cells but only a 1.5-fold increase in CAsE-PE cells. CAsE-PE cells also showed relatively low levels of growth stimulation by nonandrogen steroids, such as estradiol. Thus, arsenic-induced malignant transformation is associated with acquired androgen independence in human prostate cells. This acquired androgen independence was apparently not due to AR up-regulation, increased activity, or altered ligand specificity. The precise manner in which arsenic altered CAsE-PE growth and progression is undefined but may involve a bypass of AR involving direct stimulation of downstream signaling pathways.
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PMID:Acquisition of androgen independence by human prostate epithelial cells during arsenic-induced malignant transformation. 1614 Jun 17

In prostate cancer, a fine balance between cell proliferation and apoptotic death is lost, resulting in increased cellular mass and tumor progression. One approach to redress this imbalance and control this malignancy is its preventive intervention through the use of dietary natural agents. Here, we investigated the growth-inhibitory effect and associated mechanisms of Lupeol, a triterpene present in fruits and vegetables, in androgen-sensitive human prostate cancer cells. Lupeol treatment resulted in significant inhibition of cell viability in a dose-dependent manner and caused apoptotic death of prostate cancer cells. Lupeol was found to induce the cleavage of poly(ADP-ribose) polymerase protein and degradation of acinus protein with a significant increase in the expression of FADD protein. Among all death receptor targets examined, Lupeol specifically caused a significant increase in the expression of Fas receptor. The small interfering RNA-mediated silencing of the Fas gene and inhibition of caspase-6, caspase-8, and caspase-9 by their specific inhibitors confirmed that Lupeol specifically activates the Fas receptor-mediated apoptotic pathway in androgen-sensitive prostate cancer cells. The treatment of cells with a combination of anti-Fas monoclonal antibody and Lupeol resulted in higher cell death compared with the additive effect of the two compounds alone, suggesting a synergistic effect. Lupeol treatment resulted in a significant inhibition in growth of tumors with concomitant reduction in prostate-specific antigen secretion in athymic nude mice implanted with CWR22Rnu1 cells. Because early clinical prostate cancer growth is an androgen-dependent response, the results of the present study suggest that Lupeol may have a potential to be an effective agent against prostate cancer.
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PMID:A novel dietary triterpene Lupeol induces fas-mediated apoptotic death of androgen-sensitive prostate cancer cells and inhibits tumor growth in a xenograft model. 1632 71

The plasminogen activation system is involved in cancer progression and metastasis. Among other proteolytic factors, it includes the serine protease urokinase-type plasminogen activator (uPA) and its three-domain (D1D2D3) receptor uPAR (CD87), which focuses plasminogen activation to the cell surface. The function of uPAR is regulated in part through shedding of domain D1 by proteases, e.g., uPA itself or plasmin. Human tissue kallikrein 4 (hK4), which is highly expressed in prostate and ovarian tumor tissue, was previously shown to cleave and activate the pro-enzyme forms of prostate-specific antigen (PSA, tissue kallikrein hK3) and uPA. Here we demonstrate that uPAR is also a target for hK4, being cleaved in the D1-D2 linker sequence and, to a lesser extent, in its D3 juxtamembrane domain. hK4 may thus modulate the tumor-associated uPA/uPAR-system activity by either activating the pro-enzyme form of uPA or cleaving the cell surface-associated uPA receptor.
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PMID:Interplay of human tissue kallikrein 4 (hK4) with the plasminogen activation system: hK4 regulates the structure and functions of the urokinase-type plasminogen activator receptor (uPAR). 1649 55

Progression to androgen independence is the lethal end stage of prostate cancer. We used expression of androgen receptor (AR)-targeted short hairpin RNAs (shRNA) to directly test the requirement for AR in ligand-independent activation of androgen-regulated genes and hormone-independent tumor progression. Transient transfection of LNCaP human prostate cancer cells showed that AR shRNA decreased R1881 induction of the prostate-specific antigen (PSA)-luciferase reporter by 96%, whereas activation by forskolin, interleukin-6, or epidermal growth factor was inhibited 48% to 75%. Whereas the antiandrogen bicalutamide provided no further suppression, treatment with the mitogen-activated protein kinase (MAPK) inhibitor U0126 completely abrogated the residual activity, indicating a MAPK-dependent, AR-independent pathway for regulating the PSA promoter. Expression of doxycycline-inducible AR shRNA expression in LNCaP cells resulted in decreased levels of AR and PSA as well as reduced proliferation in vitro. When these cells were grown as xenografts in immunocompromised mice, induction of AR shRNA decreased serum PSA to below castration nadir levels and significantly retarded tumor growth over the entire 55-day experimental period. This is the first demonstration that, by inducibly suppressing AR expression in vivo, there is an extensive delay in progression to androgen independence as well as a dramatic inhibition of tumor growth and decrease in serum PSA, which exceeds that seen with castration alone. Based on these findings, we propose that suppressing AR expression may provide superior therapeutic benefit in reducing tumor growth rate than castration and may additionally be very effective in delaying progression to androgen independence.
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PMID:Short hairpin RNA knockdown of the androgen receptor attenuates ligand-independent activation and delays tumor progression. 1707 86

Gene products of the A disintegrin and metalloprotease (ADAM) family are critically involved in carcinogenesis and tumor progression of various solid tumors. Little is known about ADAM8 in prostate cancer. In our quest for novel diagnostic tissue markers of prostate cancer, we aimed to evaluate the expression of ADAM8 in prostate cancer and to correlate it with clinicopathological parameters. One hundred twenty-eight clinicopathologically characterized prostate cancer patients, with available follow-up data, were immunostained for ADAM8. Additionally, ADAM8 mRNA expression was quantified by real-time reverse transcription polymerase chain reaction (n = 59). ADAM8 protein expression was significantly associated with higher pT status, positive nodal status, and higher Gleason scores. Still, a significant prognostic value for the prostate-specific antigen relapse-free survival of ADAM8 could not be demonstrated. The differentiality of ADAM8 expression on protein and on mRNA level was low and partially inconclusive. Therefore, despite of its significant association with conventional parameters of an unfavorable prognosis, ADAM8 adds only limited information to the conventional histopathological assessment of prostate cancer.
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PMID:ADAM8 expression in prostate cancer is associated with parameters of unfavorable prognosis. 1710 10

Human tissue kallikreins (KLKs) are attracting increased attention due to their role as biomarkers for the screening, diagnosis, prognosis, and monitoring of various cancers including those of the prostate, ovarian, breast, testicular, and lung. Human tissue kallikrein genes represent the largest contiguous group of proteases within the human genome. Originally thought to consist of three genes, the identification of the human kallikrein locus has expanded this number to fifteen. These genes, and their encoded proteins, share a high degree of homology and are expressed in different tissues. Prostate-specific antigen (PSA), the most commonly known kallikrein, is a useful biomarker for prostate cancer. Several other kallikreins, including kallikreins 2 (KLK2) and 11 (KLK11) are emerging as complementary prostate cancer biomarkers. Along with these kallikreins, several others have been implicated in the other cancers. For example, KLK5, 6, 7, 10, 11, and 14 are emerging biomarkers for ovarian cancer. The identification of kallikrein substrates and the development of proteolytic cascade models implicate kallikrein proteins in cancer progression. This review describes the current status of kallikreins as cancer biomarkers.
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PMID:Human tissue kallikreins: the cancer biomarker family. 1727 79

Vascular endothelial growth factor (VEGF), one of the most potent angiogenic factors, is suggested to play a crucial role in tumor neovascularization and is associated with tumor progression and metastasis in prostate cancer. This study evaluated the significance of the VEGF T-460C polymorphism in the risk and the progression of prostate cancer. In a case-control experiment, 270 patients with prostate cancer and 252 male controls were investigated to assess the association of the VEGF T-460C polymorphism with the risk of prostate cancer. Prostate-specific antigen (PSA) recurrence in 95 patients who underwent radical prostatectomy and survival in 99 patients with metastases at diagnosis were analyzed to evaluate the influence of the polymorphism in cancer progression. The CC and TC genotypes of the polymorphism were associated with significantly higher rates of PSA recurrence after radical prostatectomy than the TT genotype and were independent predictors of PSA recurrence (P=0.011) in a multivariate analysis. In contrast, metastatic prostate cancer patients with the TT genotype showed significantly worse survival as compared to the CC and TC genotypes. In a multivariate analysis, the TT genotype was an independent predictor of cancer-specific survival (P=0.006). The VEGF T-460C polymorphism may have a substantial impact on both PSA recurrence after radical prostatectomy and survival in advanced prostate cancer. The molecular mechanisms of the polymorphism on the differing status in prostate cancer should be elucidated in further studies.
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PMID:Clinical implication of vascular endothelial growth factor T-460C polymorphism in the risk and progression of prostate cancer. 1791 66


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