Purpose: Selecting patients according to key genetic characteristics may help to tailor chemotherapy and optimize the treatment in non^small cell lung cancer (NSCLC). Polymorphisms at the xeroderma pigmentosum group D (XPD), excision repair cross-complementing 1 (ERCC1), and cytidine deaminase (CDA) genes have been associated with alterations in enzymatic activity and may change sensitivity to the widely used cisplatin-gemcitabine regimen. Gln polymorphisms and response, clinical benefit, toxicity, time to progression (TTP), and overall survival (OS) was estimated using Pearson's m 2 tests, the Kaplan-Meier method, the log-rank test, and the Cox proportional hazards model. Results: The CDA Lys 27 Lys polymorphism significantly correlated with better clinical benefit (P = 0.04) and grade z3 neutropenia and thrombocytopenia, as well as with longer TTP and OS (P = 0.006 and P = 0.002, respectively), whereas no significant associations were found among ERCC1 and XPD polymorphisms and both response and clinical outcome. Finally, the enzymatic activity assay showed a significant lower mean in subjects harboring the CDA Lys 27 Lys polymorphism. Conclusions: Our data suggested the role of CDA Lys 27 Lys polymorphism as a possible predictive marker of activity, toxicity,TTP, and OS in advanced NSCLC patients treated with cisplatin and gemcitabine. These results may be explained by the lower enzymatic activity associated with the Lys 27 Lys CDA and offer a potential new tool for treatment optimization. Lung cancer is the leading cause of cancer-related deaths inWestern countries. Non -small cell lung cancer (NSCLC) accounts for >85% of primary lung cancers and approximately two thirds of NSCLC patients are diagnosed at an advanced stage (1).Pooled data from older randomized trials of cisplatin-based chemotherapy versus best supportive care showed that cisplatin-based chemotherapy was associated with a modest improvement in overall survival (OS; ref. 2). In more recent randomized trials, new cytotoxic drugs such as paclitaxel, docetaxel, vinorelbine, or gemcitabine in combination with a platinum compound have shown an absolute 15% to 20% improvement of survival in favor of chemotherapy versus best supportive care. In particular, the 1-year survival rate for best supportive care was 11% to 17% versus 30% to 35% for chemotherapy, which prolonged median survival by 3 to 4 months (3). However, none of the last-generation doublets was shown to be superior to the others and they all seemed to have reached the therapeutic plateau, with objective response rates of 30% to 40%, median survival time of 8 to 10 months, and 1-year survival rate of 30% to 40% (4). Indeed, a four-arm randomized phase III trial showed no substantial differences in response rate, time to progression (TTP), and OS among paclitaxel (24-hour infusion) -cisplatin, docetaxel-cisplatin, paclitaxel-carboplatin, and gemcitabine-cisplatin combination (4). Therefore, the cisplatin-gemcitabine combination is one of the standard regimens for the treatment of ...
Because the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor erlotinib and the multitargeted antifolate pemetrexed are registered in the treatment of second-line nonsmall-cell lung cancer (NSCLC), empirical combinations of these drugs are being tested. This study investigated molecular mechanisms underlying their combination in six NSCLC cell lines. Cells were characterized by heterogeneous expression of pemetrexed determinants, including thymidylate synthase (TS) and dihydrofolate reductase (DHFR), and mutations potentially affecting chemosensitivity. Pharmacological interaction was studied using the combination index (CI) method, whereas cell cycle, apoptosis induction, and EGFR, extracellular signalregulated kinases 1 and 2, and Akt phosphorylation were studied by flow cytometry, fluorescence microscopy, and enzyme-linked immunosorbent assays. Reverse-transcriptase polymerase chain reaction (RT-PCR), Western blot, and activity assays were performed to assess whether erlotinib influenced TS. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium assays demonstrated that EGFR and k-Ras mutations were related to erlotinib sensitivity, whereas TS and DHFR expression were related to pemetrexed sensitivity. Synergistic cytotoxicity was found in all cells, most pronounced with pemetrexed ϩ erlotinib (24 h) 3 erlotinib (48 h) sequence (CI, 0.09 -0.40), which was associated with a significant induction of apoptosis. Pemetrexed increased EGFR phosphorylation and reduced Akt phosphorylation, which was additionally reduced by drug combination (Ϫ70.6% in H1650). Erlotinib significantly reduced TS expression and activity, possibly via E2F-1 reduction, as detected by RT-PCR and Western blot, and the combination decreased TS in situ activity in all cells. Erlotinib and pemetrexed showed a strong synergism in NSCLC cells, regardless of their genetic characteristics. Induction of apoptosis, modulation of EGFR and Akt phosphorylation, and changes in the expression of critical genes involved in pemetrexed activity contribute to this synergistic interaction and support the clinical investigation of these markers.Non-small-cell lung cancer (NSCLC) is the leading cause of cancer-related deaths in the Western world. Chemotherapy represents the backbone of treatment of advanced NSCLC, which represents more than 50% of cases diagnosed. Article, publication date, and citation information can be found at http://molpharm.aspetjournals.org. doi:10.1124/mol.107.042382.ABBREVIATIONS: NSCLC, non-small-cell lung cancer; 5-FU, 5-fluorouracil; AI, apoptotic index; BCRP, breast cancer resistance protein; CI, combination index; DHFR, dihydrofolate reductase; EGFR, epidermal growth factor receptor; FA, fraction affected; FPGS, folyl-polyglutamate synthetase; GARFT, glycinamide ribonucleotide formyltransferase; MRPs, multidrug-related protein; PI3K, phosphatidylinositide 3-kinase; RFC, reduced folate carrier; TKI, tyrosine-kinase inhibitor; TS, thymidylate synthase; LY294002, (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one ...
Purpose: Standard treatments have modest effect against pancreatic cancer, and current research focuses on agents targeting molecular pathways involved in tumor growth and angiogenesis. This study investigated the interactions between ZD6474, an inhibitor of tyrosine kinase activities of vascular endothelial growth factor receptor-2 and epidermal growth factor receptor (EGFR), gemcitabine, and ionizing radiation in human pancreatic cancer cells and analyzed the molecular mechanisms underlying this combination. Experimental Design: ZD6474, ionizing radiation, and gemcitabine, alone or in combination, were given in vitro to MIA PaCa-2, PANC-1, and Capan-1cells and in vivo to MIA PaCa-2 tumor xenografts. The effects of treatments were studied by the evaluation of cytotoxicity, apoptosis, cell cycle, EGFR and Akt phosphorylation, modulation of gene expression of enzymes related to gemcitabine activity (deoxycytidine kinase and ribonucleotide reductase), as well as vascular endothelial growth factor immunohistochemistry and microvessel count. Results: In vitro, ZD6474 dose dependently inhibited cell growth, induced apoptosis, and synergistically enhanced the cytotoxic activity of gemcitabine and ionizing radiation. Moreover, ZD6474 inhibited phosphorylation of EGFR and Akt and triggered cell apoptosis. PCR analysis showed that ZD6474 increased the ratio between gene expression of deoxycytidine kinase and ribonucleotide reductase. In vivo, ZD6474 showed significant antitumor activity alone and in combination with radiotherapy and gemcitabine, and the combination of all three modalities enhanced MIA PaCA-2 tumor growth inhibition compared with gemcitabine alone. Conclusions: ZD6474 decreases EGFR and Akt phosphorylation, enhances apoptosis, favorably modulates gene expression in cancer cells, and acts synergistically with gemcitabine and radiotherapy to inhibit tumor growth. These findings support the investigation of this combination in the clinical setting.Pancreatic cancer is a highly malignant illness that has steadily increased in incidence over recent decades, and it is now the fourth leading cause of death from cancer in the Western world. Despite this, there has been little improvement in prognosis over the past 20 years (1). Due to the delay of clinical symptoms, pancreatic cancer is usually detected at an advanced stage, and survival ranges between 4 and 6 months after diagnosis. Moreover, because of its aggressive biological behavior, this malignancy has a grim prognosis even following surgical resection, and the 5-year survival for all stages of the disease remains below 4% (2). Therefore, pancreatic cancer represents a clinical challenge and novel therapeutic approaches are warranted.Several studies showed that pancreatic cancer is characterized by dysregulation of molecular mechanisms involved in cell proliferation, invasiveness, and angiogenesis (3). Epidermal growth factor receptor (EGFR) is a key driver of cell proliferation, and
Aminoalkohole des Typs (II) werden aus den Estern (I) nach bekannten Verfahren (→ Säurechlorid → Aldehyde → Cyanhydrine → Aminoalkohole) synthetisiert.
We first reported that the most relevant genes involved in gemcitabine metabolism are expressed in ovarian carcinoma, and might be associated with more aggressive histotypes. The assessment of the expression levels of RRM2 as marker of clinical outcome deserves further investigation in a larger series of ovarian cancer patients.
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