The prognostic influence of epigenetic changes involving multiple histones, in particular H2A and H3, is greater in early NSCLC, and evaluation of these changes may help in selecting early-stage NSCLC patients for adjuvant treatment. Our observations provide a rationale for the use of a combination of standard chemotherapy with drugs interacting with histone modifications, such as histone deacetylase inhibitors.

Gefitinib has a modest activity in second-line treatment of advanced esophageal cancer. However, the patient outcome was significantly better in female patients and in patients demonstrating high EGFR expression or SCC histology. The selection of esophageal cancer patients for future studies with EGFR-TKIs based on the level of EGFR expression in their tumors or SCC histology should be considered.

In this study, we have characterized a panel of NSCLC cell lines with differential sensitivity to gefitinib for activating mutations in egfr, pik3ca, and k-ras, and basal protein expression levels of PTEN. The egfr mutant NSCLC cell line H1650 as well as the egfr wild type cell lines H292 and A431 were highly sensitive to gefitinib treatment, indicating that other factors determine gefitinibsensitivity in egfr wild type cells. Activating k-ras mutations were specifically detected in gefitinib-resistant cells, suggesting that the occurrence of k-ras mutations is correlated with resistance to EGFR antagonists. No pik3ca mutations were detected within the panel of cell lines, and PTEN protein expression levels did not correlate with gefitinib sensitivity. Gefitinib effectively blocked Akt and Erk phosphorylation in two gefitinib-sensitive NSCLC cell lines, further supporting our previous findings that persistent activity of the PI3K/Akt and/or Ras/Erk pathways is associated with gefitinib-resistance of NSCLC cell lines. Gefitinib-resistant NSCLC cell lines, showing EGFR-independent activity of the PI3K/Akt or Ras/Erk pathways, were treated with gefitinib in combination with specific inhibitors of mTOR, P13K, Ras, and MEK. Additive cytotoxicity was observed in A549 cells co-treated with gefitinib and the MEK inhibitor U0126 or the farnesyl transferase inhibitor SCH66336 and in H460 cells treated with gefitinib and the PI3K inhibitor LY294002, but not in H460 cells treated with gefitinib and rapamycin. These data suggest that combination treatment of NSCLC cells with gefitinib and specific inhibitors of the PI3K/Akt and Ras/Erk pathways may provide a successful strategy. ' 2005 Wiley-Liss, Inc.Key words: EGFR; Erk; Akt/PKB; mTOR; SCH66336; rapamycin The EGFR II (ErbB1, HER1) is the prototypic member of the ErbB family of RTKs, which further consists of ErbB2-4 (HER2-4). The ErbB receptors share a similar protein structure, consisting of an extracellular ligand binding domain, a single transmembrane domain and an intracellular C-terminal domain with tyrosine kinase activity. Upon specific binding of EGF-like ligands to the extracellular domain, ErbB receptors dimerize, either as homodimers or as heterodimers, and undergo autophosphorylation at specific tyrosine residues within the intracellular domain. These phosphorylated tyrosines serve as docking sites for adapter molecules such as Grb2 and the p85 subunit of PI3K, which activate downstream signalling pathways. These pathways, including the Ras/MAPK and Akt/mTOR kinase cascades, in turn, regulate transcription factors and other proteins involved in cell proliferation, survival, motility and differentiation 1 (Fig. 1). Aberrantly high EGFR activity is common in several tumor types, including NSCLC, and correlates with a more aggressive disease, resistance to chemotherapy and poor patient prognosis.Monoclonal antibodies to the extracellular domain of EGFR, such as cetuximab, and EGFR tyrosine kinase inhibitors, including gefitinib and erlotinib, specifically block E...

No abstract available

Background: The presence of EGFR kinase domain mutations in a subset of NSCLC patients correlates with the response to treatment with the EGFR tyrosine kinase inhibitors gefitinib and erlotinib. Although most EGFR mutations detected are short deletions in exon 19 or the L858R point mutation in exon 21, more than 75 different EGFR kinase domain residues have been reported to be altered in NSCLC patients. The phenotypical consequences of different EGFR mutations may vary dramatically, but the majority of uncommon EGFR mutations have never been functionally evaluated.

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Epigenetic changes are currently the focus of much attention in cancer research, as there is increasing evidence supporting their role in the development and progression of cancer. 1 One particular type of epigenetic modification, the global level of methylation of histone H3, was initially shown to correlate with the survival of patients with prostate cancer. 2 We have recently extended these findings, showing that the level of histone H3 methylation also correlates with the survival of resected non small-cell lung cancer (NSCLC) patients. 3 Interestingly, overexpression of one of the enzymes responsible for catalyzing the methylation of histone H3, the SMYD3 methyltransferase, has been recently observed in colorectal, hepatocellular and breast cancers, 4 suggesting a potential role for this enzyme in human cancer. This possibility is further supported by the finding that the genotype of a variable number of tandem repeats (VNTR) polymorphism in the SMYD3 gene promoter correlates with the susceptibility to certain types of cancer in a Japanese population. 5 To evaluate a potential role of SMYD3 in NSCLC, we tested the hypothesis that the SMYD3 VNTR genotype, which can modulate the activity of the SMYD3 promoter, 5 could be related to the levels of histone H3 methylation in NSCLC samples. We also investigated the relationship between the SMYD3 VNTR genotype and the risk of NSCLC in a Caucasian population.We obtained genomic DNA from paraffin-embedded tissue sections contiguous to the sections used in our recent immunohistochemical analysis of histone H3 methylation. 3 DNA was isolated using the QIAamp DNA mini kit as described by the manufacturer (Qiagen, Venlo, The Netherlands). Genotyping of the SMYD3 VNTR polymorphism was carried out using PCR and capillary electrophoresis. A DNA fragment of the SMYD3 promoter encompassing the VNTR polymorphism was amplified by PCR using forward primer FB3 (5 0 -GGC GTCTCACGGGCTGCCGGG-3 0 ) and reverse primer FB4 (5 0 -CGGAGCCTTACGACCACCTTC-3 0 ). The FB3 primer was fluorescently labeled with FAM. PCR products were analyzed by capillary electrophoresis using the ABI PRISM TM 3100 Genetic analyzer (Applied Biosystems, Foster City, CA) and the VNTR alleles were discriminated according to the size of the PCR product (Fig. 1a). To test whether variables differed across groups, the v 2 test or Fisher exact test were used according to test condition. The ANOVA test was used to study the histone 3 methylation level according to the SMYD3 VNTR genotype.

7662 Background: Epigenetic modifications, such as methylation and/or acetylation of histones, may contribute to the development and progression of cancer. We investigated whether histone modifications influence prognosis of non-small cell lung cancer (NSCLC). Methods: We used immunohistochemistry to assess histone 3 lysine 4 dimethylation (H3K4diMe), and acetylation of histone 2A lysine 5 (H2AK5Ac), histone 2B lysine 12 (H2BK12Ac), histone 3 lysine 9 (H3K9Ac), and histone 4 lysine 8 (H4K8Ac), in resected tumor samples of 138 NSCLC patients. In addition, the genotype of a tandem repeat polymorphism in the histone 3 methyltransferase SMYD3 gene was determined using PCR and capillary electrophoresis. Data were analyzed using a recursive partitioning analysis (RPA). Results: The overall median expression of H3K4diMe, H2AK5Ac, H2BK12Ac, H3K9Ac, and H4K8Ac were 75, 10, 0, 25, and 80%, respectively. The RPA classified the patients into seven distinct prognostic groups based on TNM stage (first node), histology (second node) and histone modifications (third node). H3K4diMe (< or =85% tumor cells), H3K9Ac (< or =68% tumor cells) and H2AKAc (< or =5% tumor cells) were retained by RPA. The SMYD3 genotype was not retained by RPA. The seven groups were associated with significantly different disease- free (p<0.0001) and overall survival (p<0.0001). Interestingly, the four groups determined by stage I patients (below the first node) displayed dramatic differences in survival (median from 10 months in adenocarcinoma, H3K9Ac=68%, to 147 months in non-adenocarcinoma, H3K4diMe=85%). Conclusions: The prognostic influence of global histone modifications is greater in early stage NSCLC and it may help in the selection of early stage NSCLC patients for adjuvant treatment and provides a rationale for the use of combination of standard chemotherapy with drugs interacting with histone modifications such as histone deacetylases (HDAC) inhibitors. No significant financial relationships to disclose.