Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04637 (p53)
 77,613 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The fluoroquinolone antibiotic, lomefloxacin, is phototoxic in human skin exposed to UVA radiation, photosensitises DNA strand breaks and pyrimidine dimers in human keratinocytes in vitro, and is phototumorigenic in mouse skin. The p53 tumour suppressor protein is activated by a variety of cellular insults including UV radiation, to become a transcription factor for downstream markers such as the cyclin-kinase inhibitor p21CIP1/WAF1 or cause caspase transactivation which cleaves poly ADP ribose polymerase (PARP) as an early step in apoptosis. We have investigated these molecular defence responses in human skin cells treated with lomefloxacin and UVA radiation in vitro. Western blots revealed that lomefloxacin photosensitised the stabilisation of p53 protein in human fibroblasts. Lomefloxacin also photosensitised p53 transcriptional activity in amelanotic melanoma cells expressing wild-type p53 and stably transfected with a construct containing a beta-galactosidase reporter gene downstream from a p53 consensus binding sequence. Neither photosensitised production of H2O2 nor the resultant DNA strand breaks, appeared to be involved in this effect. Interestingly, p21CIP1/WAFI protein was upregulated by lomefloxacin in the dark by a p53-independent mechanism. Lomefloxacin also photosensitised the degradation of nuclear PARP, suggestive of caspase mediated, early apoptotic events.
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PMID:The phototumorigenic fluoroquinolone, lomefloxacin, photosensitises p53 accumulation and transcriptional activity in human skin cells. 1119 49

Melanoma is a devastating disease frequently encountered within both veterinary and human medicine. Molecular changes linked with neoplastic transformation of melanocytes include mutations in genes that encode proteins intrinsic to the regulatory pathways of two tumor suppressor proteins (retinoblastoma protein and p53), proto-oncogene mutation to oncogenes, altered expression of epithelial cadherin and CD44 adhesion molecules, and upregulation of angiogenic factors and other growth factors. Histologic evaluation of the primary mass is the most common means of diagnosis, with cytology used more frequently to document metastasis. Melanoma's highly variable histologic and cytologic patterns can make diagnosis by either method problematic. Adherent epithelioid morphology, including signet ring forms, and nonadherent round and spindle forms are recognized, with pigmentation an inconsistent finding. The site of the tumor, the thickness of the primary tumor or depth of invasion, and the number of mitotic figures per high-power field or per millimeter are used histologically to predict biologic behavior, whereas site and degree of pleomorphism are typically used for cytologic preparations. Diagnosis of amelanotic melanoma can be aided by ancillary diagnostic techniques. Tumor cells are usually positive for vimentin, S100, neuron-specific enolase, and Melan-A, and negative for cytokeratin. Melan-A as a positive marker is not as sensitive as the others are but is likely more specific. Monoclonal antibodies to human melanosome-specific antigens 1 and 5 cross-react with canine antigens for a combined sensitivity rate of 83%. Mouse monoclonal antibody IBF9 specifically recognizes canine melanoma antigen and also has good sensitivity. Serologic markers, including cytokines, cell adhesion molecules, and melanoma-inhibitory activity, are being investigated as potential sentinels of melanoma. Currently, there is no single diagnostic technique capable of differentiating benign from malignant melanocytic neoplasms or predicting survival time.
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PMID:A comparative review of melanocytic neoplasms. 1245 Jan 97

A six-year-old brown haired goat was presented due to recurring tissue growth at the base of the right horn. The tumour recurred after repeated surgical excision and the animal was finally euthanized because of poor prognosis. Necropsy revealed a malignant, partly amelanotic melanoma originating from the right horn base with metastases in both frontal sinuses, urinary bladder, pleura, pericardium, second thoracic vertebra, kidney and mesenteric lymph nodes. Diagnosis was confirmed by histopathology and immunohistochemistry. A strong expression of p53, a suppressor of cell proliferation and activator of apoptosis, was detected in numerous tumour cells suggesting an altered protein function.
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PMID:Expression of p53 in a malignant melanoma of a goat. 2032 51

Cancer therapy is challenging for scientists because of low effectiveness of so far existing therapies (especially in case of great invasiveness and advanced tumor stage). Such need for new drug development and search for more efficient new findings in therapeutical applications is therefore still valid. There are also conducted studies on modifying so far existing drugs and their new methods of usage in oncology practice. One of them is phenothiazine and its derivatives which are used in psychiatric treatment for years. They also exhibit antiprion, antiviral, antibacterial and antiprotozoal properties. Cytotoxic activity, influence on proliferation, ability to induce apoptosis suggest also a possibility of phenothiazine derivatives usage in cancer cells termination. The aim of our the study was to evaluate the influence of two amine derivatives of phenothiazine on cancer cells in vitro. Amelanotic melanoma C-32 cell line (ATCC) and glioma SNB-19 cells (DSMZ) were used in this study and two derivatives were analyzed. In view of examined substances tumor potential toxicity cells proliferation and viability exposed to phenothiazine derivatives were established. Cell cycle regulatory genes expression (TP53 and CDKN1A), S-phase marker--H3 gene and intracellular apoptosis pathway genes (BAX, BCL-2) were analyzed using RT-QPCR method. The influence of examined derivatives on total cell oxidative status (TOS), total antioxidative status (TAS), malondialdehyde concentration (MDA) and superoxide dismutase activity (SOD) were analyzed. As a result, examined phenothiazine derivatives cytotoxic action on C-32 and SNB-19 and also cells proliferation inhibition were determined. Cell cycle regulatory genes (TP53, CDKN1A) expression and protein products of genes involved in mitochondial apoptosis pathway (BAX, BCL-2) expression are changed by the presence of phenothiazine derivatives during culturing. There were also noted small changes in redox potential in cells exposed to two mentioned phenothiazine derivatives.
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PMID:MOLECULAR EFFECTS OF AMINE DERIVATIVES OF PHENOTHIAZINE ON CANCER CELLS C-32 AND SNB-19 IN VITRO. 2666 97

Inactivation of the p53 transcription factor by mutation or other mechanisms is a frequent event in tumorigenesis. One of the major endogenous negative regulators of p53 in humans is hDM2, a ubiquitin E3 ligase that binds to p53 causing proteasomal p53 degradation. In this work, a library of organometallic iridium(III) compounds were synthesized and evaluated for their ability to disrupt the p53/hDM2 protein-protein interaction. The novel cyclometallated iridium(III) compound 1 [Ir(eppy)2(dcphen)](PF6) (where eppy = 2-(4-ethylphenyl)pyridine and dcphen = 4, 7-dichloro-1, 10-phenanthroline) blocked the interaction of p53/hDM2 in human amelanotic melanoma cells. Finally, 1 exhibited anti-proliferative activity and induced apoptosis in cancer cell lines consistent with inhibition of the p53/hDM2 interaction. Compound 1 represents the first reported organometallic p53/hDM2 protein-protein interaction inhibitor.
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PMID:Inhibition of the p53/hDM2 protein-protein interaction by cyclometallated iridium(III) compounds. 2688 10