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)

Elevated levels of epidermal growth factor receptor in head and neck cancer have been extensively reported, and are correlated with poor prognosis. The combination of cisplatin and 5-fluorouracil is a standard treatment regimen for head and neck cancer, with radiation representing another therapeutic option. Six head and neck cancer cell lines were used to study the cytotoxic effects of combining ZD1839 ('Iressa'), a new selective epidermal growth factor receptor tyrosine kinase inhibitor, and radiation. Two of the cell lines were also used to study the combination of ZD1839 and cisplatin/5-fluorouracil. Cytotoxic effects were assessed by the MTT test. The results indicated that ZD1839 applied before radiation gave the best effects (P=0.002); an effect that was strongest in those p53-mutated cell lines that express the highest epidermal growth factor receptor levels. The effects of ZD1839 with cisplatin and/or 5-fluorouracil were sequence dependent (P<0.003), with the best results achieved when ZD1839 was applied first. For the triple combinations, ZD1839 applied before cisplatin and 5-fluorouracil resulted in a slight synergistic effect (P=0.03), although the effect was greater when ZD1839 was applied both before and during cytotoxic drug exposure. In conclusion, ZD1839 applied before radiation and before and/or during cisplatin/5-fluorouracil may improve the efficacy of treatment for head and neck cancer.
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PMID:Sequence-dependent effects of ZD1839 ('Iressa') in combination with cytotoxic treatment in human head and neck cancer. 1187 48

Recurrent and metastatic squamous cell carcinoma of the head and neck (SCCHN) are difficult problems and likely to become more challenging as concurrent chemotherapy and radiation are more widely used. Randomized studies reported in 1992 established the combination of cisplatin and infusional 5-fluorouracil (5-FU) as the reference regimen for chemotherapy-naive, good-performance status patients. Subsequently, a randomized study of 194 patients comparing cisplatin and 5-FU to cisplatin and paclitaxel found better tolerance, better pain relief, and improved quality of life with the newer regimen, but no survival differences (medians of 9 months) were detected. Phase II studies of a platinum/taxane combination with a third drug have reported response rates of greater than 50%, including 15% complete responses. A number of non-platinum-containing regimens are active in pretreated patients. Gefitinib has shown median survival times comparable to those achieved with cisplatin and paclitaxel, and appears especially promising for patients who recur after cytotoxic chemotherapy. Newer antifolates, agents that target or restore deficient p53, and other signal transduction inhibitors are under study.
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PMID:Chemotherapy for recurrent or metastatic squamous cell carcinoma of the head and neck. 1559 59

The aim of this study was to determine the effect of ZD1839 on growth and apoptosis in SCC-15 (a human head and neck cancer cell line) lone, or in combination with cisplatin. High expression of the epidermal growth factor receptor has been implicated in the development of squamous cell carcinomas of head and neck. ZD1839 ('Iressa') is an orally active, selective epidermal growth factor receptor tyrosine kinase inhibitor that blocks signal transduction pathways implicated in proliferation and survival of cancer cells, and other host-dependent processes promoting cancer growth. Here, growth arrest was observed with 3.64 microm ZD1839. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (sMTT) viability assay revealed a significant decrease (P < 0.001) in the percentage of surviving cells upon treatment with ZD1839 and cisplatin compared with cisplatin or ZD1839 on their own. Combined therapy of 3.64 microm ZD1839 for 24 h, prior to administration of 100 microm cisplatin, significantly (P < 0.001) and additively increased the cytotoxicity effect of cisplatin. p53-independent apoptosis was seen with cisplatin treatment, a novel finding. These data support the use of ZD1839 in anti-cancer therapy, and particularly in combination therapy. Cisplatin may induce p53-independent apoptosis. Over-expression of Bcl-2 in head and neck squamous cell carcinoma tumour cell lines is unlikely to be a general mechanism to protect these cells from apoptosis.
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PMID:The effect of ZD1839 (Iressa), an epidermal growth factor receptor tyrosine kinase inhibitor, in combination with cisplatin, on apoptosis in SCC-15 cells. 1584 52

Although gefitinib, a selective inhibitor of epidermal growth factor receptor (EGFR) tyrosine kinase, has been clinically demonstrated to be effective for certain cancer cell types, the molecular mechanisms of the anti-tumor activity have not been fully elucidated. In this study, we investigated the mechanism of gefitinib-induced growth inhibition and apoptosis in HAG-1 human gallbladder adenocarcinoma cells. Treatment of gefitinib at a dose of 1 microM resulted in a significant growth inhibition, and the cell number irreversibly declined after 72-h incubation, with a progressive expansion of apoptotic cell population over 120-h. Following 2-h treatment, gefitinib significantly inhibited EGFR autophosphorylation and subsequent downstream signaling pathway through Erk and Akt, and induced accumulation of cells in the G0/G1 phase of the cell cycle at 24-h, accompanied by a concomitant increase in p21 transcript and increased expression of p27. Gefitinib did not affect the amount of total and phosphorylated p53 at serine 15, but upregulated the expression of total Bax, with subsequent increase in p18 Bax, an active form of Bax. The expression of Bcl-2 and Bad was unchanged. An increase in gefitinib-induced expression of total Bax might be due to the decreased degradation of Bax, because the level of Bax mRNA has not been altered by gefitinib treatment. Gefitinib promoted the cleavage of full-length p21 Bax into p18 Bax in mitochondrial-enriched fraction, a characteristic feature of Bax activation toward apoptosis. Moreover, blockade of Bax by using anti-Bax small interfering double stranded RNA (siRNA) significantly reduced gefitinib-induced apoptosis. Taken together, these data suggest a critical role of p18 Bax in gefitinib-induced apoptosis.
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PMID:Gefitinib, a selective EGFR tyrosine kinase inhibitor, induces apoptosis through activation of Bax in human gallbladder adenocarcinoma cells. 1622 13

Extensive treatment-related morbidities and stagnant survival rates over the past few decades for patients with squamous cell cancer of the head and neck (SCCHN) emphasize the need for novel diagnostics and therapeutics based on the molecular characteristics of the tumor. The development of an early detection test remains largely preliminary. Much attention has recently been given to saliva-based early detection assays that use accepted tumor markers such as p53 and DNA methylation. Most of these studies have focused on feasibility as opposed to prospective clinical trials. To date, early detection saliva assays have failed to yield a high enough sensitivity and specificity for broad population-based screening. The use of saliva as a noninvasive, inexpensive, and accessible diagnostic substrate remains desirable. Unlike SCCHN diagnostics, molecular-targeted therapies for SCCHN will soon be a reality, with many more compounds in the pipeline. The most promising of these drugs target the epidermal growth factor receptor (EGFR), which is known to be overexpressed in squamous cell carcinomas. Cetuximab, a monoclonal EGFR antibody, has shown efficacy in combination with radiotherapy in advanced SCCHN in a recent phase III trial and is currently being petitioned for US Food and Drug Administration approval. Likewise, erlotinib, an EGFR tyrosine kinase inhibitor, has shown favorable results in phase II trials as monotherapy and in combination with chemotherapy. Gefitinib, another EGFR tyrosine kinase inhibitor, has shown efficacy as monotherapy, in combination with chemotherapy, and with chemoradiotherapy. At least two phase III trials of gefitinib in patients with advanced SCCHN are ongoing. Such low-toxicity, tumor-specific targeting strategies will soon be available for patients with head and neck cancer. The challenge is to establish assays to determine which patients are most likely to benefit from these agents.
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PMID:Advances in molecular diagnostics and therapeutics in head and neck cancer. 1634 64

Gateways to Clinical Trials are a guide to the most recent clinical trials in current literature and congresses. The data in the following tables have been retrieved from the Clinical Trials Knowledge Area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com This issue focuses on the following selection of drugs: A-007, A6, adalimumab, adenosine triphosphate, alefacept, alemtuzumab, AllerVax Ragweed, amphora, anakinra, angiotensin-(1-7), anidulafungin, apomine, aripiprazole, atomoxetine hydrochloride, avanafil; BAL-8557, becatecarin, bevacizumab, biphasic insulin aspart, BMS-188797, bortezomib, bosentan, botulinum toxin type B, brivudine; Calcipotriol/betamethasone dipropionate, caspofungin acetate, catumaxomab, certolizumab pegol, cetuximab, CG-0070, ciclesonide, cinacalcet hydrochloride, clindamycin phosphate/benzoyl peroxide, cryptophycin 52, Cypher; Dabigatran etexilate, darapladib, darbepoetin alfa, decitabine, deferasirox, desloratadine, dexanabinol, dextromethorphan/quinidine sulfate, DMF, drotrecogin alfa (activated), duloxetine hydrochloride; E-7010, edaravone, efalizumab, emtricitabine, entecavir, eplerenone, erlotinib hydrochloride, escitalopram oxalate, estradiol valerate/dienogest, eszopiclone, exenatide, ezetimibe; Fondaparinux sodium, fulvestrant; Gefitinib, gestodene, GYKI-16084; Hyaluronic acid, hydralazine hydrochloride/isosorbide dinitrate; Imatinib mesylate, indiplon, insulin glargine; Juzen-taiho-to; Lamivudine/zidovudine/abacavir sulfate, L-arginine hydrochloride, lasofoxifene tartrate, L-BLP-25, lenalidomide, levocetirizine, levodopa/carbidopa/entacapone, lexatumumab, lidocaine/prilocaine, lubiprostone, lumiracoxib; MAb-14.18, mitoquidone; Natalizumab, neridronic acid, neuradiab; Olpadronic acid sodium salt, omalizumab; p53-DC vaccine, parathyroid hormone (human recombinant), peginterferon alfa-2a, peginterferon alfa-2b, pemetrexed disodium, perifosine, pimecrolimus, prasterone, prasugrel, PRO-2000, Pseudostat; R24, rasburicase, RHAMM R3 peptide, rilonacept, rosuvastatin calcium, rotavirus vaccine, rufinamide; Sabarubicin hydrochloride, SHL-749, sirolimus-eluting stent, SLx-2101, sodium butyrate, sorafenib, SU-6668; TachoSil, tadalafil, taxus, tegaserod maleate, telbivudine, tenofovir disoproxil fumarate, teriparatide, tetramethylpyrazine, teverelix, tiotropium bromide, tipifarnib, tirapazamine, tolvaptan, TransvaxTM hepatitis C vaccine, treprostinil sodium; Valganciclovir hydrochloride, valsartan/amlodipine, vandetanib, vardenafil hydrochloride hydrate, vatalanib succinate, veglin, voriconazole; Yttrium 90 (90Y) ibritumomab tiuxetan; Zileuton, zotarolimus, zotarolimus-eluting stent.
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PMID:Gateways to clinical trials. 1700 51

Gefitinib (Iressa, ZD1839) is a potent high-affinity competitive tyrosine kinase inhibitor aimed primarily at epidermal growth factor receptor (EGFR). Inhibitors in this class have recently been approved for clinical use in the treatment of advanced non-small cell lung cancer as monotherapy following failure of chemotherapy. We examined the efficacy of gefitinib on lung tumorigenesis in mouse models using both postinitiation and progression protocols. Gefitinib was given at a dose of 200 mg/kg body weight (i.g.) beginning either 2 or 12 weeks following carcinogen initiation. In the postinitiation protocol, gefitinib significantly inhibited both tumor multiplicity (approximately 70%) and tumor load (approximately 90%) in A/J or p53-mutant mice (P < 0.0001). Interestingly, gefitinib was also highly effective against lung carcinogenesis in the progression protocol when individual animals already have multiple preinvasive lesions in the lung. Gefitinib exhibited approximately 60% inhibition of tumor multiplicity and approximately 80% inhibition of tumor load when compared with control mice (both P < 0.0001). These data show that gefitinib is a potent chemopreventive agent in both wild-type and p53-mutant mice and that a delayed administration was still highly effective. Analyses of mutations in the EGFR and K-ras genes in lung tumors from either control or treatment groups showed no mutations in EGFR and consistent mutation in K-ras. Using an oligonucleotide array on control and gefitinib-treated lesions showed that gefitinib treatment failed to alter the activity or the expression level of EGFR. In contrast, gefitinib treatment significantly altered the expression of a series of genes involved in cell cycle, cell proliferation, cell transformation, angiogenesis, DNA synthesis, cell migration, immune responses, and apoptosis. Thus, gefitinib showed highly promising chemopreventive and chemotherapeutic activity in this mouse model of lung carcinogenesis.
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PMID:Effect of an epidermal growth factor receptor inhibitor in mouse models of lung cancer. 1718 87

5-Methyltetrahydrofolate, (R)-flurbiprofen; Ad5CMV-p53, adalimumab, alefacept, alemtuzumab, Alequel, alicaforsen sodium, almotriptan, anakinra, aprepitant, aripiprazole, armodafinil; Bevacizumab, bortezomib, bosentan; Canfosfamide hydrochloride, ciclesonide, clofarabine, Cypher; Darbepoetin alfa, diclofenac potassium, drotrecogin alfa (activated), duloxetine hydrochloride; Eel calcitonin, eletriptan, eplerenone, everolimus, ezetimibe; Frovatriptan; Gefitinib, gamma-hydroxybutyrate sodium; HKI-272, HYB-165; Ibutamoren mesylate, imatinib mesylate, interleukin-21, ixabepilone; KRN-951; L-Arginine hydrochloride, levodopa/carbidopa/entacapone; Micafungin sodium, motexafin gadolinium, mycophenolic acid sodium salt; Nesiritide; Peginterferon alfa-2a, pitavastatin calcium, pralatrexate, pregabalin, pVAX/L523S-Ad.L523S; Rasagiline mesylate, recombinant human nerve growth factor, regadenoson, rF-PSA, rimonabant, rizatriptan, rofecoxib, rosuvastatin calcium, rV-B7.1, rV-PSA; Sipuleucel-T, sirolimus-eluting stent, solifenacin succinate, sorafenib, sunitinib malate; Talactoferrin alfa, Taxus, tegaserod maleate, teriparatide, tipifarnib; Valdecoxib, vandetanib, vatalanib succinate; WT1-peptide vaccine; Xaliproden hydrochloride. (c) 2006 Prous Science. All rights reserved.
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PMID:Gateways to clinical trials. 1720 Jul 30

Oral squamous cell carcinomas (OSCCs) are characterized by a marked propensity for local invasion and dissemination to cervical lymph nodes. Overexpression of the epidermal growth factor receptor (EGFR) and high levels of certain matrix metalloproteinases (MMPs) have been implicated in the development of squamous cell carcinoma of oral cancer. ZD1839 (Iressa) is a quinazoline derivative that selectively inhibits the EGFR tyrosine kinase activity and is clinically used for cancer patients. This article attempted to determine the mechanisms underlying the effects of ZD1839 on the cellular level, and to characterize the effects of ZD1839 with regard to human OSCC cell growth and invasion/migration. The YD-10B cells represent a highly invasive human OSCC cell line, which has a frame shift p53 mutation. ZD1839 inhibited the growth of the cell line in a time- and dose-dependent manner. Cell cycle kinetic analysis demonstrated that ZD1839 induces a delay in cell cycle progression and a G1 arrest. This induction of a G1 cell cycle arrest was associated with the upregulation of cyclin-dependent kinase inhibitors (CDKI) p27(KIP1) and p21(CIP1/WAF1). The upregulation of CDKI in ZD1839 treated cell lines may be mediated by a p53-independent and hnRNPC1/C2-dependent pathway. In addition, 100 nM ZD1839 demonstrated that both MMP-2 and MMP-9 enzyme activity were decreased by approximately 25-30%. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that ZD1839 downregulated the uPAR mRNA level. These results might be associated with the reduction of MMP-2 and MMP-9 activities. The current in vitro study indicates that the inhibition of proliferation and invasion/migration in OSCC cell lines by ZD1839 results in an anticancer effect via multiple cellular and molecular mechanisms, and suggests that ZD1839 may be useful in inhibiting and/or preventing metastasis.
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PMID:The epidermal growth factor receptor tyrosine kinase inhibitor ZD1839 (Iressa) suppresses proliferation and invasion of human oral squamous carcinoma cells via p53 independent and MMP, uPAR dependent mechanism. 1740 24

Recently improved understanding of the pathogenesis of human head and neck squamous cell carcinoma (HNSCC) has led to the development of new, molecular-based therapeutic strategies, one of the more promising is the utilisation of tyrosine kinase (TK) inhibitors, targeting epidermal growth factor receptor (EGFR). In this study, we tested for gefitinib effectiveness in a broad panel of 12 newly established HNSCC cell lines, investigating its ability to reduce cell growth, to induce apoptosis and to modulate cell cycle and various EGFR pathway-related targets. Gefitinib IC50 values ranged between 0.064 and 33 microM, its capability to induce apoptosis and cell accumulation in G0/G1 phase was cell line-specific, and the main EGFR-related pathway involved in gefitinib activity was PI3K/Akt/mTor. We characterised our in vitro panel extensively, with the aim to identify predictive factors for gefitinib effectiveness; all cell lines were free of human papillomavirus infection, two were positive for Fhit expression, four expressed wild-type p53, and all of them variously expressed the other two p53 family members, p63 and p73. The comparison between the targets analysed and gefitinib effectiveness evidenced the absence of a clear relationship, excluding them as predictive factors for gefitinib efficacy. Our results confirmed the in vitro efficacy of an anti-EGFR approach, but other targets than those analysed here should be characterised in order to identify valid predictive factors for gefitinib utilisation.
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PMID:Validation of gefitinib effectiveness in a broad panel of head and neck squamous carcinoma cells. 1850 76


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