Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Androgen receptors are overexpressed in most primary and metastatic prostate cancers. A series of single photon emission computed tomography imaging agents (SPECT) utilizing the organometallic radioactive imaging species, fac-99mTc(OH(2))(3)(CO)(3)+, were prepared on the basis of the structure of Flutamide, a potent nonsteroidal antiandrogen prostate cancer drug. Novel bifunctional chelate-linked Flutamide analogues were prepared using a newly developed universal alkylating reagent, 2-bromo-N-[4-nitro-3-(trifluoromethyl)phenyl]-acetamide, 1. From compound 1, several ligands (i.e., cysteine 2, histidine 5, imidazole 3) were conjugated to the flutamide derivative to yield targeting ligands capable of either tridentate or monodentate coordination in a "2 + 1" complex. fac-Re(CO)(3)+ complexes were prepared and characterized with the functionalized conjugates to yield fac-Re(CO)(3)(2-amino-3-(1-(2-(4-nitro-3-(trifluoromethyl)phenylamino)-2-oxoethyl)-1H-imidazol-4-yl) propanoate), 4, fac-Re (CO)(3)(2-(S-cysteinyl)-N-[4-nitro-3-(trifluoromethyl) phenyl]-acetamide), 6, and fac-Re(CO)(3)(picolinate)(2-(1H-imidazol-1-yl)-N-[4-nitro-3-(trifluoromethyl)phenyl]-acetamide), 7. The corresponding radioactive 99mTc analogues were prepared and stability studies of the radioactive compounds were also conducted.
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PMID:Synthesis and characterization of nonsteroidal-linked M(CO)(3)+ (M = 99mTc, Re) compounds based on the androgen receptor targeting molecule flutamide. 1911 92

Previously, we reported that intratumor or systemic inoculation of a cationic 15-mer, innate immunity-like lytic peptide composed of d- and l-amino acids ([D]-K(6)L(9)) caused growth arrest of 22RV1 prostate carcinoma xenografts in a mouse model. However, despite its therapeutic potential, this peptide has significant systemic toxicity at concentrations slightly higher than the therapeutic one. Here, we used the acidic environment created by solid tumors as a trigger to activate anticancer lytic peptides by making them cationic only at low pH levels. We achieved this selectivity by substituting lysines (pKa, approximately 10.5) for histidines (pKa, approximately 6.1) in the parental peptide [D]-K(6)L(9). Histidine is protonated below pH 7. For that purpose, we replaced either three or all six lysines in the parental peptide with histidines to obtain the peptides [D]-K(3)H(3)L(9) and [D]-H(6)L(9). Interestingly, in vitro experiments showed pH-dependent activity only with [D]-H(6)L(9) mainly toward cancer cell lines. However, both peptides showed reduced systemic toxicity compared with the parental peptide. Intratumor and systemic inoculation of these peptides resulted in a significant decrease in the 22RV1 prostate cancer tumor volume and systemic secretion of prostate-specific antigen in a xenograft mice model. Moreover, histologic modifications revealed a significant reduction in new blood vessels selectively in tumor tissues after treatment with the peptides compared with the untreated tumors. The lytic mode of action of these new peptides, which makes it difficult for the cancer cells to develop resistance, and their selective and pH-dependent activity make them potential candidates for treatment of solid cancer tumors.
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PMID:Suppression of human solid tumor growth in mice by intratumor and systemic inoculation of histidine-rich and pH-dependent host defense-like lytic peptides. 1935 52

Allosteric regulation of human lipoxygenase (hLO) activity has recently been implicated in the cellular biology of prostate cancer. In the current work, we present isotope effect, pH, and substrate inhibitor data of epithelial 15-hLO-2, which probe the allosteric effects on its mechanistic behavior. The Dk(cat)/KM for 15-hLO-2, with AA and LA as substrate, is large indicating hydrogen atom abstraction is the principle rate-determining step, involving a tunneling mechanism for both substrates. For AA, there are multiple rate determining steps (RDS) at both high and low temperatures, with both diffusion and hydrogen bonding rearrangements contributing at high temperature, but only hydrogen bonding rearrangements contributing at low temperature. The observed kinetic dependency on the hydrogen bonding rearrangement is eliminated upon addition of the allosteric effector, 13-(S)-hydroxyoctadecadienoic acid (13-HODE), and no allosteric effects were seen on diffusion or hydrogen atom abstraction. The (k(cat)/KM)AA/(k(cat)/KM)LA ratio was observed to have a pH dependence, which was fit with a titration curve (pKa = 7.7), suggesting the protonation of a histidine residue, which could hydrogen bond with the carboxylate of 13-HODE. Assuming this interaction, 13-HODE was docked to the solvent exposed histidines of a 15-hLO-2 homology model and found to bind well with H627, suggesting a potential location for the allosteric site. Utilizing d31-LA as an inhibitor, it was demonstrated that the binding of d31-LA to the allosteric site changes the conformation of 15-hLO-2 such that the affinity for substrate increases. This result suggests that allosteric binding locks the enzyme into a catalytically competent state, which facilitates binding of LA and decreases the (k(cat)/KM)AA/(k(cat)/KM)LA ratio. Finally, the magnitude of the 13-HODE KD for 15-hLO-2 is over 200-fold lower than that of 13-HODE for 15-hLO-1, changing the substrate specificity of 15-hLO-2 to 1.9. This would alter the LO product distribution and increase the production of the pro-tumorigenic, 13-HODE, possibly representing a pro-tumorigenic feedback loop for 13-HODE and 15-hLO-2.
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PMID:Kinetic and structural investigations of the allosteric site in human epithelial 15-lipoxygenase-2. 1964 54

alpha-Methylacyl-coenzyme A racemase (AMACR) catalyzes the epimerization of (2R)- and (2S)-methyl branched fatty acyl-coenzyme A (CoA) thioesters. AMACR is a biomarker for prostate cancer and a putative target for the development of therapeutic agents directed against the disease. To facilitate development of AMACR inhibitors, a continuous circular dichroism (CD)-based assay has been developed. The open reading frame encoding AMACR from Mycobacterium tuberculosis (MCR) was subcloned into a pET15b vector, and the enzyme was overexpressed and purified using metal ion affinity chromatography. The rates of MCR-catalyzed epimerization of either (2R)- or (2S)-ibuprofenoyl-CoA were determined by following the change in ellipticity at 279nm in the presence of octyl-beta-d-glucopyranoside (0.2%). MCR exhibited slightly higher affinity for (2R)-ibuprofenoyl-CoA (K(m)=48+/-5microM, k(cat)=291+/-30s(-1)), but turned over (2S)-ibuprofenoyl-CoA (K(m)=86+/-6microM, k(cat)=450+/-14s(-1)) slightly faster. MCR expressed as a fusion protein bearing an N-terminal His(6)-tag had a catalytic efficiency (k(cat)/K(m)) that was reduced 22% and 47% in the 2S-->2R and 2R-->2S directions, respectively, relative to untagged enzyme. The continuous CD-based assay offers an economical and efficient alternative method to the labor-intensive, fixed-time assays currently used to measure AMACR activity.
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PMID:A continuous assay for alpha-methylacyl-coenzyme A racemase using circular dichroism. 1985 48

A 72-year-old man came to our clinic as a candidate of the donor of renal transplantation for his 44-year-old daughter. However, his serum PSA was found elevated, and he was diagnosed with stage C prostate cancer. He received neoadjuvant androgen deprivation therapy and subsequent IMRT as a definitive curative therapy. Since his PSA remained at a very low level after IMRT for three years, we performed systematic 16-site prostate biopsy, which revealed no viable prostate cancer cells. His renal function seemed to be normal and no functional difference was noted between the two kidneys. Then, his left kidney was harvested by hand-assisted retroperitoneal laparoscopic approach, and transplanted to his daughter successfully. The suitability of a donor with two potential problems-advanced age and a history of prostatic cancer-was discussed, together with a review of the literature.
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PMID:[A case of elderly donor in living kidney transplant after radical radiotherapy for prostate cancer]. 1992 48

One mechanism of prostate tumors for escape from androgen ablation therapies is mutation of the androgen receptor (AR). We investigated the unique properties of the AR L701H mutant, which is strongly stimulated by cortisol, by a systematic structure-function analysis. Most amino acid substitutions at position 701 did not affect AR activation by 5alpha-dihydrotestosterone. Further analysis of the AR Leu(701) variants showed that AR L701M and AR L701Q, like AR L701H, had changed ligand responsiveness. AR L701M was strongly activated by progesterone but not by cortisol, whereas the opposite was observed for AR L701Q and AR L701H. Next, we analyzed a panel of structurally related steroids to study which of the OH groups at positions 11beta, 17alpha, and 21, which discriminate cortisol from progesterone, underlie the differential responses to both hormones. The results showed that the 17alpha-OH group was essential for activation of AR L701H and AR L701Q, whereas its absence was important for activation of AR L701M. Modeling indicated a conserved H-bonding network involving the steroidal 17alpha-OH group, His(701) or Gln(701), and the backbone of Ser(778). This network is absent in Leu(701) and in other mutants. A hydrophobic leucine or methionine at position 701 is unfavorable for the 17alpha-OH group. Our results indicate that the specific amino acid residue at position 701, its interaction with the backbone of Ser(778), and the steroidal 17alpha-hydroxyl group of the ligand are all important for the distinct transcriptional responses to progesterone and cortisol of AR mutants, including the prostate cancer mutant L701H.
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PMID:Systematic structure-function analysis of androgen receptor Leu701 mutants explains the properties of the prostate cancer mutant L701H. 2000 93

A case of neuroendocrine (NE) differentiated prostate cancer is reported herein, which was progressed with NE differentiation during hormonal treatment in adenocarcinoma of the prostate. A 65-year-old man was admitted to our department with increased serum prostate specific antigen (PSA) (150 ng/ml). A prostate biopsy was performed and histological examinations indicated poorly differentiated adenocarcinoma with a Gleason score of 5 + 4 = 9. Further examinations showed metastases to systemic bones. The clinical stage was T3bN0M1b and hormonal therapy using leuprorelin was started. Eighteen months after hormonal therapy, the serum PSA level declined to 1.702 ng/ml. He subsequently experienced edema in his legs. Computed tomography (CT) demonstrated enlargement of the prostate and swelling of multiple pelvic lymph nodes. Immunohistochemical examination of a re-biopsy specimen revealed a neuroendocrine carcinoma. The neuron-specific enolase (NSE) level was 50.9 ng/ml. The treatment measure was changed from hormonal therapy to combination chemotherapy comprising cisplatin (CDDP) and irinotecan (CPT-11). Pelvic radiotherapy (50 Gy) was then performed. Two courses of the chemotherapy resulted in a great reduction of the tumor volume. However, he had liver metastases 3 months later. His condition worsened rapidly and he died at 8 months after definite diagnosis.
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PMID:[Neuroendocrine differentiation in adenocarcinoma of the prostate during hormonal treatment : a case report]. 2010 11

Metastases of prostate cancer to the penis and urethra are rare and often represent advanced disease. We describe a case of newly diagnosed prostatic adenocarcinoma with metastases to the corpus spongiosum, cavernosum, and the anterior urethra. A male patient, 77 years of age, initially had lower urinary tract obstruction symptoms. His prostate-specific antigen level was 5.02 ng/mL. Digital rectal examination disclosed stony hard tumors at both lobes of the prostate. Transrectal ultrasound-guided biopsy of the prostate revealed adenocarcinoma over both lobes; the Gleason score was 4 + 4 = 8. Cystoscopy showed a penile urethral tumor and biopsy disclosed metastatic adenocarcinoma of the prostate; the Gleason score was 4 + 4 = 8. The patient initially received hormone therapy. Biochemical failure developed after 15 months and rapidly progressed to a hormone-refractory stage. Docetaxel was then prescribed. The patient died in the 25(th) month after the diagnosis.
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PMID:Invasive adenocarcinoma of the prostate with urethral tumor. 2017 91

Conjugation of the cytotoxic drugs to receptor-binding peptides is an attractive approach for the targeted delivery of cytotoxic peptide conjugates to tumor cells. In an attempt to develop an efficient peptide-based radiopharmaceutical for targeting bombesin (BN) receptor-expressing tumors (i.e., breast and prostate), we have prepared by solid-phase peptide synthesis, a novel BN analog derived from the universal sequence of BN and conjugated to a widely characterized antineoplastic agent, methotrexate (MTX). MTX-BN, after radiolabeling with (99m)Tc via stannous-tartrate exchange, showed a good stability against cysteine and histidine transchelation as well as a high in vitro metabolic stability in human plasma. In vitro cell-binding and internalization on MDA-MB-231, MCF-7, T47-D breast cancer and PC-3 prostate cancer cell lines demonstrated high affinity and specificity of (99m)Tc-MTX-BN towards both human breast and prostate cancer cells (binding affinities in nanomolar range). In addition, the radioconjugate displayed a significant internalization (values ranged between 19-35%) into the tumor cells. In vivo biodistribution and clearance kinetics in Balb/c mice are characterized by an efficient clearance from the blood and excretion mainly through the renal-urinary pathway with some elimination via the hepatobiliary system. In vivo tumor uptake in nude mice bearing MDA-MB-231 cells was 2.70+/-0.44% ID/g at 1 h, whereas in nude mice with human epidermoid KB cells the accumulation in the tumor was found to be 1.48+/-0.31% ID/g at 1 h post injection. The tumor uptake was always higher than in the blood and muscle, with good tumor retention and good tumor-to-blood and tumor-to-muscle ratios. The accumulation/retention in the major organs (i.e., lungs, stomach, liver, intestines, etc.) was low to moderate (<6% ID/g) in both healthy and tumor-bearing mice. However, the uptake/retention in the kidneys was rather high (up to 11.05+/-1.80% ID/g), which is of a concern, particularly for radionuclide therapy. This initial study towards the development of a novel cytotoxic BN conjugate suggest that the combination of favorable in vitro and in vivo properties may render (99m)Tc-MTX-BN a potential candidate for the targeted imaging and eventually for radionuclide therapy (when labeled with an appropriate radionuclide) of BN receptor-positive tumors and deserves further evaluation.
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PMID:Synthesis and evaluation of a technetium-99m labeled cytotoxic bombesin peptide conjugate for targeting bombesin receptor-expressing tumors. 2034 67

We report a rare case of persistent false elevation of prostate-specific antigen (PSA) after radical prostatectomy (RP). Preoperative total PSA was 25.4 ng/ml and final pathology was Gleason score 3+5=8, pT3aN0M0. His first postoperative total PSA was 3.85 ng/ml. He received adjuvant hormone therapy for 10 months. Since PSA gradually elevated despite adjuvant hormone therapy, he underwent imaging for metastasis, confirming no evidence of prostate cancer recurrence. Moreover, total PSA was unmeasurable level in three other PSA assays.
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PMID:[Case of persistent false elevation of prostate-specific antigen after radical prostatectomy]. 2044 49


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