Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.7.10.1 (ERK)
95,504 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epidermal growth factor receptor (EGFR) monoclonal antibodies (mAb) are used widely to treat metastatic colorectal cancer (mCRC) patients, but it is now clear that patients harboring K-ras mutation are resistant to EGFR mAbs such as cetuximab (Erbitux) and panitumumab (Vectibix). For this reason, current recommendations for patient care involve diagnosing the K-ras mutational status of patients prior to EGFR mAb therapy. In this study, we investigated the ability of two MEK inhibitors currently in clinical trials, AS703026 and AZD6244, to address the challenge posed by the resistance of K-ras mutated colorectal cancers to EGFR mAb. AS703026 and AZD6244 were tested in various cell-based assays and tumor xenograft studies, focusing on isogenic human colorectal tumor cell lines that expressed only WT or mutant K-Ras (D-WT or D-MUT). The EGFR mAb cetuximab inhibited the Ras-ERK pathway and proliferation of D-WT cells in vitro and in vivo, but it did not inhibit proliferation of D-MUT cells in either setting. In contrast, AS703026 and AZD6244 effectively inhibited the growth of D-MUT cells in vitro and in vivo by specific inhibition of the key MEK downstream target kinase ERK. Inhibition of MEK by AS703026 or AZD6244 also suppressed cetuximab-resistant colorectal cancer cells attributed to K-ras mutation both in vitro and in vivo. Our findings offer proof-of-concept for the use of MEK inhibitors as an effective therapy in K-ras mutated CRC.
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PMID:MEK1/2 inhibitors AS703026 and AZD6244 may be potential therapies for KRAS mutated colorectal cancer that is resistant to EGFR monoclonal antibody therapy. 2111 63

The fusion gene EML4-ALK (echinoderm microtubule-associated protein-like 4 gene and the anaplastic lymphoma kinase gene) was recently identified as a novel genetic alteration in non-small cell lung cancer (NSCLC). EML4-ALK translocations correlate with specific clinical and pathological features, in particular lack of EGFR and K-ras mutations, and may be associated with resistance to EGFR tyrosine-kinase inhibitors (TKIs). Here, we report a case of a patient with a concomitant EGFR mutation and ALK translocation resistant to erlotinib. Considering this report, ALK status should be investigated in unexplained cases of EGFR-TKI-resistance of EGFR mutated NSCLCs.
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PMID:EGFR and EML4-ALK gene mutations in NSCLC: a case report of erlotinib-resistant patient with both concomitant mutations. 2116 33

In a previous study, human ZNF312b was identified as a cell proliferation-associated oncogene via the K-ras/extracellular signal-regulated kinase cascade in gastric cancer. However, the mechanism concerning its transcriptional activation remains unknown. Here, we show that DNA methylation and histone acetylation of the ZNF312b promoter function as a switch for ZNF312b transcriptional activation in gastric cancer. The transcription level of ZNF312b was increased by treatment with a demethylating agent, 5-aza-2'-deoxycytidine and the histone deacetylase inhibitor sodium butyrate, in several human cancer cell lines including gastric cancer. Consistent with these results, epigenetic analysis, such as pyrosequencing, bisulfate sequencing and methyl-specific polymerase chain reaction (MSP), showed that the expression level of ZNF312b is highly dependent on the degree of DNA methylation in gastric cancer cell lines. In addition, by ChIP assay using anti-acetyl/methyl H3K9 antibodies, histone acetylation was shown to mediate the expression of the ZNF312b gene. Interestingly, ChIP assay using the Sp1 antibody revealed that the binding of transcription factor Sp1 to the ZNF312b promoter for its transcriptional activation requires DNA demethylation and histone acetylation. Moreover, a knockdown of Sp1 resulted in a decrease in ERK-mediated proliferation via downregulation of the ZNF312b gene in gastric cancer cells. Taken together, these results suggest that the aberrant expression of ZNF312b promotes gastric tumorigenesis through epigenetic modification of its promoter region and provides a molecular mechanism for ZNF312b expression to contribute to the progression of gastric cancer.
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PMID:Human ZNF312b oncogene is regulated by Sp1 binding to its promoter region through DNA demethylation and histone acetylation in gastric cancer. 2117 Sep 90

Epigenetic therapy for solid tumors could benefit from an in vivo model that defines tumor characteristics of responsiveness and resistance to facilitate patient selection. Here we report that combining the histone deacetylase inhibitor entinostat with the demethylating agent vidaza profoundly affected growth of K-ras/p53 mutant lung adenocarcinomas engrafted orthotopically in immunocompromised nude rats by targeting and ablating pleomorphic cells that occupied up to 75% of the tumor masses. A similar reduction in tumor burden was seen with epigenetic therapy in K-ras or EGFR mutant tumors growing orthotopically. Increased expression of proapoptotic genes and the cyclin-dependent kinase inhibitor p21 was seen. Hundreds of genes were demethylated highlighted by the reexpression of polycomb-regulated genes coding for transcription factor binding proteins and the p16 gene, a key regulator of the cell cycle. Highly significant gene expression changes were seen in key regulatory pathways involved in cell cycle, DNA damage, apoptosis, and tissue remodeling. These findings show the promise for epigenetic therapy in cancer management and provide an orthotopic lung cancer model that can assess therapeutic efficacy and reprogramming of the epigenome in tumors harboring different genetic and epigenetic profiles to guide use of these drugs.
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PMID:Combination therapy with vidaza and entinostat suppresses tumor growth and reprograms the epigenome in an orthotopic lung cancer model. 2122 63

Mouse models of cancer represent powerful tools for analysing the role of genetic alterations in carcinogenesis. Using a mouse model that allows tamoxifen-inducible somatic activation (by Cre-mediated recombination) of oncogenic K-ras(G12D) in a wide range of tissues, we observed hyperplasia of squamous epithelium located in moist or frequently abraded mucosa, with the most dramatic effects in the oral mucosa. This epithelium showed a sequence of squamous hyperplasia followed by squamous papilloma with dysplasia, in which some areas progressed to early invasive squamous cell carcinoma, within 14 days of widespread oncogenic K-ras activation. The marked proliferative response of the oral mucosa to K-ras(G12D) was most evident in the basal layers of the squamous epithelium of the outer lip with hair follicles and wet mucosal surface, with these cells staining positively for pAKT and cyclin D1, showing Ras/AKT pathway activation and increased proliferation with Ki-67 and EdU positivity. The stromal cells also showed gene activation by recombination and immunopositivity for pERK indicating K-Ras/ERK pathway activation, but without Ki-67 positivity or increase in stromal proliferation. The oral neoplasms showed changes in the expression pattern of cytokeratins (CK6 and CK13), similar to those observed in human oral tumours. Sporadic activation of the K-ras(G12D) allele (due to background spontaneous recombination in occasional cells) resulted in the development of benign oral squamous papillomas only showing a mild degree of dysplasia with no invasion. In summary, we show that oral mucosa is acutely sensitive to oncogenic K-ras, as widespread expression of activated K-ras in the murine oral mucosal squamous epithelium and underlying stroma can drive the oral squamous papilloma-carcinoma sequence.
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PMID:Acute sensitivity of the oral mucosa to oncogenic K-ras. 2138 Oct 32

EGFR and c-Met are both overexpressed in lung cancer and initiate similar downstream signaling, which may be redundant. To determine how frequently ligands that initiate signaling of both pathways are found in lung cancer, we analyzed serum for hepatocyte growth factor (HGF), transforming growth factor-alpha, and amphiregulin (AREG) in lung cancer cases and tobacco-exposed controls. HGF and AREG were both significantly elevated in cases compared to controls, suggesting that both HGF/c-Met and AREG/EGFR pathways are frequently active. When both HGF and AREG are present in vitro, downstream signaling to MAPK and Akt in non-small cell lung cancer (NSCLC) cells can only be completely inhibited by targeting both pathways. To test if dual blockade of the pathways could better suppress lung tumorigenesis in an animal model than single blockade, mice transgenic for airway expression of human HGF were treated with inhibitors of both pathways alone and in combination after exposure to a tobacco carcinogen. Mean tumor number in the group using both the HGF neutralizing antibody L2G7 and the EGFR inhibitor gefitinib was significantly lower than with single agents. A higher tumor K-ras mutation rate was observed with L2G7 alone compared to controls, suggesting that agents targeting HGF may be less effective against mutated K-ras lung tumors. This was not observed with combination treatment. A small molecule c-Met inhibitor decreased formation of both K-ras wild-type and mutant tumors and showed additive anti-tumor effects when combined with gefitinib. Dual targeting of c-Met/EGFR may have clinical benefit for lung cancer.
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PMID:Targeting of Both the c-Met and EGFR Pathways Results in Additive Inhibition of Lung Tumorigenesis in Transgenic Mice. 2139 Feb 44

Lung cancer is a heterogenous group of disorders, and a difficult disease to treat. The traditional approach of surgical resection for early-stage disease, potentially followed by chemotherapy, as well chemotherapy (with or without radiation) in later stages of disease is being supplemented with a personalized approach. The personalized approach has classically been used by the oncologist based on clinical/pathological parameters such as the performance status of the patient and histology of lung cancer. As molecular mechanisms have been explored in lung cancer more recently, the personalized approach also has incorporated molecular abnormalities. In particular, EGFR, K-ras, ALK, MET, CBL, and COX2, have come to the forefront as potential biomarkers and therapeutic targets. Thus, we review the various molecular mechanisms in lung cancer and the role of novel therapeutics.
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PMID:Personalized treatment of lung cancer. 2142 Nov 17

Mutations of the AKT1 (v-akt murine thymoma viral oncogene homologue 1) gene at amino acid 17 (E17K) and in the kinase domain of the AKT2 gene have been reported in non-small cell lung cancer (NSCLC). We investigated AKT1 and AKT2 mutations (n=146 and n=124, respectively) in surgically-treated NSCLC cases. The presence or absence of AKT1 (E17K) and AKT2 kinase domain mutations was analyzed by direct sequencing. Although there were no AKT1 mutations at the N-terminal, an AKT2 mutation was detected in 1 of 124 lung cancer patients (0.8%). The sample was also analyzed for EGFR, K-ras, PIK3CA and BRAF mutations. In addition to the AKT2 missense mutation (R371H), this lung adenocarcinoma was shown to harbor an EGFR (L861Q) and a PIK3CA (E542Q) mutation. This study demonstrated that mutations in the kinase domain of AKT2 occur in a small percentage of Japanese patients with lung cancer, while E17K AKT1 mutations do not occur at all.
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PMID:AKT1 and AKT2 mutations in lung cancer in a Japanese population. 2147 66

Lung cancer is the leading cause of death from cancer in Western countries. For improved diagnosis and refined therapeutical approaches it is of major importance to understand by what mechanisms carcinoma of the lung develop. The analysis of primary lung cancer revealed specific chromosomal alterations and allelic losses of the short arm of chromosome 3. Genetic aberrations have been observed in proto-oncogenes such as H-ras, K-ras, C-myc and raf-1 as well as in the tumor suppressor genes Rb and p53. Rearrangement of rlf and elevated expression in certain lung tumors have also been reported. The development of lung cancer also involves the altered activation of genes coding for growth factors such as TGF beta 2 and certain growth factor receptor genes such as c-erbB-2, HEK2 and FGFR-4.
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PMID:Oncogenic alterations in primary human lung-tumors (review). 2160 36

The incidence of multiple primary lung adenocarcinoma (MPLA) is increasing, and it is important to distinguish MPLA from intrapulmonary metastasis (IPM) in order to determine the therapeutic strategy. However, there is no reliable method to differentiate between the two. The purpose of this study was to distinguish MPLA from IPM based on the gene status of EGFR and K-ras and the morphological Noguchi classification system. Sixty-eight tumors from 34 cases of clinical MPLA were evaluated. Of them, 11 cases (32.4%) were diagnosed as biological MPLA (bMPLA) by EGFR/K-ras mutation analyses, and 12 cases (35.3%) by morphological analysis. In all, 23 of the 34 cases (67.6%) were diagnosed as bMPLA. The remaining 11 cases were diagnosed as biological IPM (bIPM). The 5-year survival rates of bMPLA and bIPM were 90.9% and 63.6%, respectively (p=0.04). These findings suggest that the combination method including gene mutation and morphological analysis can guide treatment decisions and that there is a need for systemic chemotherapy, and surveillance monitoring.
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PMID:Detection of EGFR and K-ras mutations for diagnosis of multiple lung adenocarcinomas. 2162 14


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