Protein Phosphorylation
Enrique Pimentel in Handbook of Growth Factors, 2017
A major protein-tyrosine phosphatase present in the bovine brain and the human placenta is calcineurin, a calmodulin-binding protein.459,460 The major secreted isoenzyme of human prostatic acid phosphatase is also a protein-tyrosine phosphatase.461 Phosphotyrosine, but not phosphoserine or phosphothreonine, residues are specifically amplified in prostate tumor cells, and this modification is associated with repressed levels of acid phosphatase in the gland, suggesting a possible role of the enzyme in the growth of human prostatic tumors.462 There is an inverse relationship between prostatic acid phosphatase and protein-tyrosine kinase activity.463 The addition of testosterone to prostatic carcinoma cell lines, which results in decreased acid phosphatase activity, is accompanied by an increase in tyrosine kinase activity. Several different isoenzymes of acid phosphatase are present in prostatic cells, and it is not clear which form of them may interact with the cellular tyrosine kinases.
The Treatment of Advanced Prostatic Cancer with Drugs and Hormones
Nicholas Bruchovsky, James H. Goldie in Drug and Hormone Resistance in Neoplasia, 2019
One final hope is the development of new weapons with a higher and broader cell kill, or less toxicity. New drugs with different mechanisms of action are becoming less frequent, but analogues of agents such as adriamycin and cisplatin may have some advantage. A more selective approach is to develop agents which exploit cellular differences of prostatic tissue, which does not comprise a vital organ. Drugs activated by prostatic acid phosphatase can be synthesized.282 Analogues of 5α-dihydrotestosterone can irreversibly inhibit 5α-reductase.283 Alkylated steroids have been discussed earlier. All these classes are likely to require a fairly well-differentiated cellular mechanism to home onto, and therefore their utility would be in early rather than late systemic treatment.
Case 45
Simon Lloyd, Manohar Bance, Jayesh Doshi in ENT Medicine and Surgery, 2018
With the mixed hearing loss seen on the audiogram and the diffuse bilateral involvement of the calvarium seen on the CT scan, the most likely diagnosis is Paget's disease. This diagnosis can be strongly suspected from the CT appearance, with the washed out and fluffy appearance of the bone and with an apparent increase in calvarial bone volume. The CT scan may also show osteoporosis circumscripta, which are round, punched-out lesions, seen primarily in the frontal bones and occur in 10%–15% of patients. Other helpful tests are Technetium99 bone scans, which may show widespread skeletal involvement, and the biochemical markers alkaline phosphatase and urinary hydroxyproline, which are often elevated. Serum calcium is normal. Acid phosphatase may be elevated in about 20% of patients.
Coexistence of Candida albicans and Enterococcus faecalis increases biofilm virulence and periapical lesions in rats
Published in Biofouling, 2021
Qian Du, Shasha Yuan, Shuangyuan Zhao, Di Fu, Yifei Chen, Yuan Zhou, Yangpei Cao, Yuan Gao, Xin Xu, Xuedong Zhou, Jinzhi He
The maxillary samples were decalcified by 10% EDTA for 30 days. The decalcified samples were embedded in paraffin. Tissue blocks were sectioned at 5 μm. H&E staining was completed following standard protocols. Tartrate-resistant acid phosphatase (Trap) staining was carried out using the Acid Phosphatase Leukocyte kit (Sigma, St.Louis, MO). Osteoclasts were defined as multinucleated (≥ 2) Trap+ cells on the surface of alveolar bone. To identify osteoblasts, the immunohistochemical (IHC) staining was conducted with mouse monoclonal anti-osteocalcin antibody (ab13420, Abcam, at 1: 200 dilution) and anti-mouse HRP-DAB cell &tissue staining kit (CTS002, R&D). To quantify osteoclasts and osteoblasts, 6 visual fields were randomly selected for each sample, and target cells were calculated by image-pro plus (IPP, Media Cybernetics, USA).
Antitumoral Potency by Immunomodulation of Chloroform Extract from Leaves of Nitraria retusa, Tunisian Medicinal Plant, via its Major Compounds β-sitosterol and Palmitic Acid in BALB/c Mice Bearing Induced Tumor
Published in Nutrition and Cancer, 2018
Jihed Boubaker, Imene Ben Toumia, Aicha Sassi, Imen Bzouich-Mokded, Sonia Ghoul Mazgar, Fairouz Sioud, Ahmed Bedoui, Sihem Safta Skhiri, Kamel Ghedira, Leila Chekir-Ghedira
Peritoneal macrophages were obtained after intraperitoneal injection of 5 ml sterile PBS, and withdrawal of the fluid. Obtained cells were washed twice by PBS and resuspended in complete RPMI 1640; cell viability was assessed via trypan blue exclusion. One hundred µl of the cell suspension (3 106 cells / ml) were distributed in 96-well plates. The plates were incubated for 24 h at 37° C, under a humid atmosphere and at 5% CO2. The adherent cells are taken up in 20 µl Triton X-100 (1%), 10 µl of p-nitrophenyl phosphate (p-NPP) (100 mM) the acid phosphatase substrate, and 50 µl of citrate buffer (0.1 M, pH = 5). The whole is incubated at 37°C in a humid atmosphere and 5% CO2 for 30 min. The activity of acid phosphatase was determined at 405 nm (13) and the percentage of the activity is determined by the following formula: Activity (%) = 100 × (OD sample−OD control)/OD control.
Testosterone, testosterone therapy and prostate cancer
Published in The Aging Male, 2019
A. Yassin, K. AlRumaihi, R. Alzubaidi, S. Alkadhi, A. Al Ansari
The association between testosterone and prostate cancer stems from the landmark reports of Huggins and co-workers. In this initial study, it was reported that the serum marker acid phosphatase was not only dramatically reduced following castration of men with metastatic prostate cancer, but also increased by the administration of testosterone [4]; additionally, a follow-up report further highlighted the clinical benefits of castration against the administration of testosterone [5] allowing for the conclusion that testosterone administration caused “enlarged growth” of prostate cancer. In light of such evidence, castration was presented as the first effective treatment for metastatic prostate cancer and the procedure was to rapidly become common practise for advanced disease. Additional reports [6,7] further corroborated the administration of testosterone in men with prostate cancer led to rapid and poor outcomes.
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