Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0178874 (tumor progression)
 40,807 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Androgen suppression is the routine approach to the treatment of advanced prostate cancer. Using intermittent androgen suppression by taking the advantage of the reversible action of medical castration results in the maintenance of apoptotic potential. The experiments in the androgen-dependent androgen-dependent Shionogi carcinoma tumor model as well as clinical experience in a group of men with prostate malignancy are presented in this report. These consecutive cycles of androgen withdrawal and replacement afford an improved quality of life when the patient is off therapy. It is possible to reduce toxicity, cost of treatment and to delay tumor progression. Whether survival is affected in a beneficial or adverse way still remains to be studied.
 ...
PMID:[Theoretical considerations and initial clinical results of intermittent hormone treatment of patients with advanced prostatic carcinoma]. 748 55

Androgen deprivation displays the mean therapy of advanced stage prostatic cancer. The development of hormone-resistant disease leads to a fatal tumor progression. High-dose fosfestrol (diethylstilbestrol disphosphate) has been suggested to circumvent hormone resistance and to induce a direct cytotoxic effect. Twenty-one patients with hormone-refractory prostate cancer were enrolled in a phase I trial of continuous infusion of high, daily escalating dose of fosfestrol. Fosfestrol was given in a 3.5 hr infusion in 0.9% normal saline at a starting dose of 1.5 g/d. The dose was increased daily in the same patient according to the following schedule: 1.5, 1.8, 2.4, 3.0, 3.6, 3.9, 4.5, 5.1 and 5.7 g/d. The duration of the infusion was prolonged to 7 or 10.5 hr, if a major side effect occurred. There was neither hematological nor cardiovascular toxicity. The main dose-limiting toxicities were nausea/vomiting in 17 patients, edema in 2 patients, and more than 5% weight gain in 3 patients. The planned maximal dose was reached in 10 patients during a 3.5 hr infusion, and in 3 additional patients, after infusion prolongation. Seven patients experienced a subjective improvement: Prostatic acid phosphatase and prostatic specific antigen decreased in 4 out of 11 and in 7 out of 12 patients, respectively. The suggested dose to phase II trial is 4 g/d in 3.5 hr infusion for a duration of up to 10 days.
 ...
PMID:Phase I trial of high-dose fosfestrol in hormone-refractory adenocarcinoma of the prostate. 750 21

Bone scans, serum tissue-specific polypeptide antigen (TPS), prostate specific antigen (PSA), and neuron-specific enolase (NSE) were assessed in a total of 80 hormonally treated prostate cancer patients. Thirty-nine patients were free of osseous lesions; in 8 subjects, 3 or fewer scintigraphic hot spots were found; in 29 patients, more than 3 bone lesions were recorded. In 3 patients, a partial contribution of endocrine cell cancer structures was found, while in one patient, a homogeneous small cell carcinoma was detected at autopsy. Measurement of the serum PSA test showed a clear-cut rise from stage D0 subjects to stage D2 patients, with a small number of bone lesions (> or = 3). However, a relative decrease in the mean PSA level was measured with further progression in a number of hot spots in bone (> 3). Androgen threshold that is critical for the induction of the PSA (and PAP) expression seems to differ markedly in various cell subpopulations that arise during adenocarcinoma dedifferentiation. This fact explains not only the rise in serum PSA in the majority of progressive and previously castrated subjects after an initial period of hormonal responsiveness, but also a relative decline of androgen-dependent PSA expression with further tumor progression. Localized disease was accompanied with normal or just slightly elevated TPS concentration. In metastatic tumors, serum TPS values revealed a steady increase with the progression in bone. These data seem to reflect not only an increase in tumor proliferation rate with progressively transformed genome, but also the rise in the number of proliferating cells. The presence of nonepithelial transformed tumor structures, such as small cell cancer within a bulk of adenocarcinoma, reduces or normalizes numerical serotests values of both TPS and PSA even during tumor progression. The extent of such decline depends upon the bulk of the endocrine component. The assessment of the above parameters, especially when associated with elevated plasma NSE concentrations, may help in distinguishing an advanced adenocarcinoma with and without elements of malignant neuroendocrine structures. The proposed approach, modified by applying corresponding organ-specific markers, may be checked for its possible general use in staging protocols of various heterogeneous tumors.
 ...
PMID:A more objective staging of advanced prostate cancer--routine recognition of malignant endocrine structures: the assessment of serum TPS, PSA, and NSE values. 750 85

Androgen deprivation displays the mean therapy of advanced stage prostatic cancer, independently of palliative radiotherapy. The evolution to hormone-resistance status leads to a fatal tumor progression. High-dose fosfestrol (diethylstilbestrol diphosphate) has been suggested to circumvent hormone-resistance and to induce a direct cytotoxic effect. Sixteen patients with hormone-resistant prostate cancer were treated by continuous infusion of high-dose fosfestrol according to two schedules: 10 patients were included in a phase I trial of a daily escalating dose from 1.5 g/d to 4.5 g/d for 7 to 10 days. Six other patients were uniformly treated by 4 g/d for 3.5 h for 5 days. Between each course, patients received orally 300 mg/d fosfestrol and 200 mg/d salicylic acid. The mean age was 65 years (range 51-75). Mean number of courses was two (extremes 1-7). Toxicities: reversible weight gain was observed in five patients. One patient presented a pulmonary edema which was resolved immediately after diuretics. One patient and 9 patients respectively experienced grade III and II (OMS) nausea and vomiting. Transient perineal pruritus occurred in 5 patients. Responses: 15 patients were evaluable (one early death occurred on day 3 from tumor progression complicated by an intravascular coagulation disease). There were four objective stabilizations (NPCP criteria) lasting 2 m, 2 m, 5 m and 10 m respectively. Subjective improvement of pain was observed in five other patients. There was more than 50% reduction of PSA in eight patients. High-dose fosfestrol seems to have some objective activity with moderate toxicity and warrants further investigation.
 ...
PMID:[High dose fosfestrol in phase I-II trial for the treatment of hormone-resistant prostatic adenocarcinoma]. 817 77

Androgen deprivation therapy for advanced prostate cancer is often effective, but not curative. Molecular pathways mediating the therapeutic response and those contributing to the subsequent hormone-refractory cell growth remain poorly understood. Here, cDNA microarray analysis of human CWR22 prostate cancer xenografts during the course of androgen deprivation therapy revealed distinct global gene expression profiles in primary, regressing and recurrent tumors. Elucidation of the genes involved in the transition between these states implicated specific molecular mechanisms in therapy failure and tumor progression. First, we identified a set of androgen-responsive genes whose expression decreased during the therapy response, but was then systematically restored in the recurrent tumors. In addition, altered expression of genes that encode known targets of rapamycin or that converge on the PI3K/AKT/FRAP pathway was observed in the recurrent tumors. Further suggestion for the involvement of these genes in hormone-refractory prostate cancer came from the observation that cells established from the recurrent xenografts were strongly inhibited in vitro by rapamycin. The results of this functional genomic analysis suggest that the combined effect of re-expression of androgen-responsive genes as well as the activation of rapamycin-sensitive signaling may drive prostate cancer progression, and contribute to the failure of androgen-deprivation therapy.
 ...
PMID:Failure of hormone therapy in prostate cancer involves systematic restoration of androgen responsive genes and activation of rapamycin sensitive signaling. 1170 6

TGF beta can promote and/or suppress prostate tumor growth through multiple and opposing actions. Alterations of its expression, secretion, regulation or of the sensitivity of target cells can lead to a favorable environment for tumor development. To gain a better insight in TGF beta function during cancer progression, we have used different cultured human prostate cells: preneoplastic PNT2 cells, the androgen-dependent LNCaP and the androgen-independent PC3 and DU145 prostate cancer cell lines. We have studied by specific ELISA assays in conditioned media (CM), the secretion of TGF beta 1 and TGF beta 2 in basal conditions and after hormonal treatment (DHT or E2) and the expression of TGF beta 1 mRNA by Northern blot. We have also compared the effect of fibroblast CM on TGF beta secretion by the different cell types. Compared to PNT2 cells, cancer cell lines secrete lower levels of active TGF beta which are not increased in the presence of fibroblast CM. LNCaP cells respond to androgen or estrogen treatment by a 10-fold increase of active TGF beta secretion while PC3 and DU145 are unresponsive. In conclusion, prostate cancer cell lines have lost part of their ability to secrete and activate TGF beta, and to regulate this secretion through stromal-epithelial interactions. Androgen-sensitive cancer cells may compensate this loss by hormonal regulation.
 ...
PMID:Alterations of expression and regulation of transforming growth factor beta in human cancer prostate cell lines. 1258 36

Within the human prostate epithelium four cell populations are discriminated by their expression of keratins (K). While basal cells co-localize K5 and K14 combined with low levels of K18 (K5(++)/14(++)/18(+)), luminal cells highly express K18 (K18(++)). In addition, two intermediate subpopulations are characterized either by basal K5(++)/18(+)- or luminal K5(+)/18(++)- expression. The entire prostate epithelium is putatively derived from a basal stem cell population. They give rise to intermediate cells that transiently proliferate and mature towards differentiated luminal epithelium. Within prostate carcinoma luminal exocrine, neuro-endocrine and intermediate cells are distinguished. Intermediate cells have been postulated as progenitors for prostate carcinogenesis and targets for androgen-independent tumor progression. Androgen-independency is associated with an enrichment of intermediate cells and over-expression of peptide growth factor receptors. Targeting intermediate cells by inhibition of their peptide growth factor receptors, therefore, offers novel treatment modalities for prostate cancer.
 ...
PMID:Epithelial cell differentiation in the human prostate epithelium: implications for the pathogenesis and therapy of prostate cancer. 1285 May 22

Lethal phenotypes of human prostate cancer are characterized by progression to androgen-independence and metastasis. For want of a clinically relevant animal model, mechanisms behind this progression remain unclear. Our study used an in vivo model of androgen-sensitive LNCaP human prostate cancer cell xenografts in male SCID mice to study the cellular and molecular biology of tumor progression. Primary tumors were established orthotopically, and the mice were then surgically castrated to withdraw androgens. Five generations of androgen-independent tumors were developed using castrated host mice. Tumor samples were used to determine expressions of cellular and molecular markers. Androgen-independent tumors had increased proliferation and decreased apoptosis compared to androgen-sensitive tumors, outcomes associated with elevated expression of p53, p21/waf1, bcl-2, bax and the bcl-2/bax ratio. Blood vessel growth in androgen-independent tumor was associated with increased expression of vascular endothelial growth factor. Overexpression of androgen receptor mRNA and reduced expression of androgen receptor protein in androgen-independent tumors suggest that the androgen receptor signaling pathway may play an important role in the progression of human prostate cancer to androgen-independence. The in vivo orthotopic LNCaP tumor model described in our study mimics the clinical course of human prostate cancer progression. As such, it can be used as a model for defining the molecular mechanisms of prostate cancer progression to androgen-independence and for evaluating the effect of preventive or therapeutic regimens for androgen-independent human prostate cancer.
 ...
PMID:Progression to androgen-independent LNCaP human prostate tumors: cellular and molecular alterations. 1517 Jun 60

Heat shock protein 27 (Hsp27) is a chaperone implicated as an independent predictor of clinical outcome in prostate cancer. Our aim was to characterize changes in Hsp27 after androgen withdrawal and during androgen-independent progression in prostate xenografts and human prostate cancer to assess the functional significance of these changes using antisense inhibition of Hsp27. A tissue microarray was used to measure changes in Hsp27 protein expression in 232 specimens from hormone naive and posthormone-treated cancers. Hsp27 expression was low or absent in untreated human prostate cancers but increased beginning 4 weeks after androgen-ablation to become uniformly highly expressed in androgen-independent tumors. Androgen-independent human prostate cancer PC-3 cells express higher levels of Hsp27 mRNA in vitro and in vivo, compared with androgen-sensitive LNCaP cells. Phosphorothioate Hsp27 antisense oligonucleotides (ASOs) and small interference RNA potently inhibit Hsp27 expression, with increased caspase-3 cleavage and PC3 cell apoptosis and 87% decreased PC3 cell growth. Hsp27 ASO and small interference RNA also enhanced paclitaxel chemosensitivity in vitro, whereas in vivo, systemic administration of Hsp27 ASO in athymic mice decreased PC-3 tumor progression and also significantly enhanced paclitaxel chemosensitivity. These findings suggest that increased levels of Hsp27 after androgen withdrawal provide a cytoprotective role during development of androgen independence and that ASO-induced silencing can enhance apoptosis and delay tumor progression.
 ...
PMID:Heat shock protein 27 increases after androgen ablation and plays a cytoprotective role in hormone-refractory prostate cancer. 1537 73

Cell adhesion receptors, including the integrin-type collagen receptors (alpha1beta1, alpha2beta1, alpha10beta1 and alpha11beta1) participate in cancer progression and invasion. Quantitative RT-PCR indicated that all 4 receptors are abundantly expressed in sarcoma-derived cell lines, whereas most carcinoma-derived cells express alpha1beta1 and alpha2beta1 only. This was surprising because alpha11beta1 has been connected previously to the progression of lung adenocarcinomas. To test the hypothesis that alpha11 expression may not persist in cultured cancer cells we analyzed fresh tissue samples of 104 total prostatectomies, keeping in mind that prostate cancer cell lines showed negligible alpha11 mRNA levels. In prostate alpha2 expression was significantly lower in poorly differentiated carcinomas when compared to benign lesions (p = 0.0331). In immunohistochemistry the protein levels of alpha2 integrin decreased significantly (p = 0.0001) and the protein levels of alpha11 subunit increased significantly (p = 0.029) with the increasing grade of carcinoma. Thus alpha11beta1 may replace alpha2beta1 during tumor progression. Our observations support the idea that alpha11beta1 may be expressed in tumors but the corresponding cell lines may lose the expression of this integrin. Previous studies have shown that in cell culture androgen receptor (AR) controls alpha2beta1 expression. We measured AR mRNA levels and the number of AR positive nuclei in the prostate samples and the results showed a significant correlation between alpha2beta1 and AR. Androgen receptors may control the mechanisms regulating integrin expression in prostate.
 ...
PMID:Regulation of prostate cell collagen receptors by malignant transformation. 1615 94


1 2 3 4 Next >>