Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0001418 (adenocarcinoma)
 68,496 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

While KRAS activation is a fundamental initiating event in the aetiopathogenesis of pancreatic ductal adenocarcinoma (PDA), environmental factors influencing the occurrence and persistence of KRAS mutations remain largely unknown. The objective was to test the hypothesis that in PDA there are aetiopathogenic relationships among concentrations of some organochlorine compounds (OCs) and the mutational status of the KRAS oncogene, as well as among the latter and coffee intake. Incident cases of PDA were interviewed and had blood drawn at hospital admission (N = 103). OCs were measured by high-resolution gas chromatography with electron capture detection. Cases whose tumours harboured a KRAS mutation had higher concentrations of p,p'-dichlorodiphenyltrichloroethane (DDT), p,p'-dichlorodiphenyldichloroethene (DDE) and polychlorinated biphenyls (PCBs) 138, 153 and 180 than cases with wild-type KRAS, but differences were statistically significant only for p,p'-DDT and PCBs 138 and 153. The association between coffee intake and KRAS mutations remained significant (P-trend < 0.015) when most OCs where accounted for. When p,p'-DDT, PCB 153, coffee and alcohol intake were included in the same model, all were associated with KRAS (P = 0.042, 0.007, 0.016 and 0.025, respectively). p,p'-DDT, p,p'-DDE and PCB 138 were significantly associated with the two most prevalent KRAS mutations (Val and Asp). OCs and coffee may have independent roles in the aetiopathogenesis of PDA through modulation of KRAS activation, acquisition or persistence, plausibly through non-genotoxic or epigenetic mechanisms. Given that KRAS mutations are the most frequent abnormality of oncogenes in human cancers, and the lifelong accumulation of OCs in humans, refutation or replication of the findings is required before any implications are assessed.
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PMID:In pancreatic ductal adenocarcinoma blood concentrations of some organochlorine compounds and coffee intake are independently associated with KRAS mutations. 1979 53

Somatic KRAS mutation is an early well-known event in colorectal carcinogenesis but a complete understanding of RAS function and dysfunction in colorectal cancer is still to come. Our aim was to study the incidence of KRAS mutation; KRAS splice variants: KRAS4A and KRAS4B; and their relationships with various clinico-pathological characteristics in colorectal cancer (CRC).In this study, 285 CRC cases were analysed for KRAS mutation by direct DNA sequencing followed by immunohistochemical analysis after validation with real-time PCR assay, to study the protein expression of KRAS4A and -4B isoforms. KRAS gene mutations were seen in 80/285 CRCs (28.1%) and of the mutated cases, the majority of the mutations were seen in codon 12 (81.2%) as opposed to codon 13 (18.8%). CRCs with KRAS mutations were associated with a poor overall survival (p = 0.0009). Furthermore, KRAS mutations at codon 12 were associated with a poor overall survival of 64.4% at 5 years compared with a 5-year overall survival of 75.8% and 78.2% with codon 13 mutation and absence of KRAS mutations, respectively (p = 0.0025). KRAS4A protein expression was predominantly seen in the cytoplasm, while KRAS4B protein was nuclear. KRAS4A overexpression was significantly associated with left colon, histology subtype of adenocarcinoma, p27kip1, and cleaved caspase3 expression. Interestingly, KRAS4A overexpression was associated with a better overall survival (p = 0.0053). On the other hand, KRAS4B overexpression (33.2%) was significantly associated with larger tumour size (p = 0.0234) and inversely correlated with p27kip1 protein (p = 0.0159). Both KRAS mutation and KRAS4A were independent prognostic markers in a multivariate analysis with age, gender, stage, differentiation, and MSI status. Our results highlight the differential role of KRAS isoforms in CRC, their utility as a prognostic biomarker, and underline the importance of KRAS alterations as a potential therapeutic target for CRC.
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PMID:Prognostic significance of alterations in KRAS isoforms KRAS-4A/4B and KRAS mutations in colorectal carcinoma. 1982 59

The let-7 family of microRNAs are important regulatory molecules in lung cancer. One downstream target of let-7 is the RAS gene family, including KRAS, an important oncogene in the etiology and clinical outcome of lung adenocarcinoma. Recently, a SNP in the let-7 binding region of the KRAS 3' UTR was identified (termed LCS6). This functional polymorphism alters let-7 binding, resulting in both increased KRAS expression and decreased let-7 exposure. Further, this SNP has been reported as a risk trait for lung cancer among low-moderate smokers. Given the functionality of LCS6, we tested the hypothesis that this SNP is associated with the occurrence of KRAS mutation as well as patient survival. Here, we report there is no association between the LCS6 KRAS polymorphism and KRAS mutation. Further, we find no association between the LCS6 polymorphism and lung cancer survival. These unexpected findings imply that this newly reported KRAS-LCS6 polymorphism will have limited clinical utility for NSCLC.
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PMID:KRAS mutation, KRAS-LCS6 polymorphism, and non-small cell lung cancer. 1985 34

In colorectal cancer, BRAF and KRAS oncogenes are mutated in about 15% and 35% respectively at approximately the same stage of the adenoma-carcinoma sequence. Since these two mutations rarely coexist, further analysis to dissect their function of transformation in colon cancer is required. Caco-2 human colon adenocarcinoma cells were stably transfected with BRAF(V600E) (Caco-BR cells) or KRAS(G12V) (Caco-K cells) oncogenes. BRAF(V600E) is more efficient in transforming Caco-2 cells and altering their morphology. The dominant nature of BRAF(V600E) is evident by its ability to render Caco-2 cells tumorigenic in vivo all be it through selective extracellular signal-related kinase (ERK) 2 phosphorylation and high levels of cyclin D1. As a consequence, the cell cycle distribution of parental cells is altered and microsatellite instability is introduced. Attenuated ERK activation observed correlated with KSR downregulation by BRAF(V600E) without further implications to signaling. Highly activated ERK in case of KRAS(G12V) (Caco-K cells) leads to mild transformation causing Caco-K cells to express premature senescence-related markers and acquire growth factor-dependent viability. Interestingly, BRAF(WT)gets equally activated by upstream KRAS mutations present in colon adenocarcinoma cells such as DLD-1 and SW620. Taken together, these results suggest that the two oncogenes have different transforming capability in colon cancer, although they both use the mitogen-activated protein (MAP) kinase pathway to carry out their effect. In general, BRAF(V600E) presents greater potential in mediating tumorigenic effect as compared to KRAS(G12V) both in vivo and in vitro. These findings may have implications in personalised diagnosis and targeted therapeutics.
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PMID:BRAF(V600E) efficient transformation and induction of microsatellite instability versus KRAS(G12V) induction of senescence markers in human colon cancer cells. 1988 48

Drug treatment for human lung cancers remains unsatisfactory, despite the identification of many potential therapeutic targets (such as mutant KRAS protein) and the approval of agents that inhibit the tyrosine kinase activity of mutant epidermal growth factor receptor (EGFR). To seek new therapeutic strategies against lung tumors, the authors have screened 189,290 small molecules for their ability to retard growth of human lung adenocarcinoma cell lines, which harbor mutations in EGFR or KRAS. Four candidates that are structurally different from common tyrosine kinase inhibitors were selected for further study. The authors describe one small molecule (designated lung cancer screen-1 [LCS-1]) in detail here. Identification of the targets of LCS-1 and other growth inhibitors found in this screen may help to develop new agents for the treatment of lung adenocarcinomas, including those driven by mutant EGFR and KRAS.
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PMID:Identification and preliminary characterization of novel small molecules that inhibit growth of human lung adenocarcinoma cells. 1988 99

KRAS is an oncogene that can be activated by mutations. Patients with non-small cell lung cancer who have KRAS mutations do not respond to tyrosine kinase inhibitors; therefore, accurate detection of KRAS mutations is important for deciding therapeutic strategies. Although sequencing-related techniques have been frequently used, they are usually too complex, have low sensitivity, and are time-consuming for routine screening in clinical situations. We evaluated peptide nucleic acid (PNA)-clamp smart amplification process version 2 (SmartAmp2) as a detection method for KRAS codon 12 mutations in patient specimens compared with traditional sequencing and polymerase chain reaction-related methods. Among 172 lung adenocarcinoma samples, direct sequencing, enzyme-enriched sequencing, and PNA-enriched sequencing showed that 16 (9.3%), 26 (15.7%), and 28 (16.3%) tumors, respectively, contained KRAS mutations in codon 12. Using PNA-clamp SmartAmp2, we could identify 31 (18.0%) tumors that had KRAS mutations in codon 12 within 60 minutes, three of which were undetected by polymerase chain reaction-related methods. On the other hand, we examined 30 nonmalignant peripheral lung tissue specimens and found no mutations in any of the samples using PNA-clamp SmartAmp2. In this study, we confirmed that PNA-clamp SmartAmp2 has high sensitivity and accuracy and is suitable for the clinical diagnosis of KRAS codon 12 mutations.
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PMID:Usefulness of peptide nucleic acid (PNA)-clamp smart amplification process version 2 (SmartAmp2) for clinical diagnosis of KRAS codon 12 mutations in lung adenocarcinoma: comparison of PNA-clamp SmartAmp2 and PCR-related methods. 2000 40

Somatic mutations of phosphatase and tensin homolog deleted on chromosome ten (PTEN) in non-small cell lung cancers (NSCLCs) have been investigated in but a small number of cases. In addition, the relationship between PTEN mutations and epidermal growth factor receptor (EGFR), KRAS, and TP53 mutations has not been investigated. Therefore, we investigated the frequency of PTEN mutations in 176 surgically resected NSCLCs and analyzed the relationship between PTEN mutations and EGFR, ERBB2, KRAS, and TP53 mutations. Mutations of PTEN (exons 1-9), EGFR (exons 18-21), ERBB2 (exons 19 and 20), KRAS (exon 1), and TP53 (exons 2-11) were determined by polymerase chain reaction and direct sequencing. PTEN mutations were present in 8 (4.5%) of the 176 tumors. PTEN mutations were only found in ever-smokers and were significantly more frequent in squamous cell carcinoma than in adenocarcinoma (10.2% vs 1.7%, P=0.02). Mutations of EGFR, ERBB2, KRAS, and TP53 genes were found in 36 (20.5%), 2 (1.1%), 11 (6.3%), and 66 (37.5%) cases, respectively. Of the 8 tumors with PTEN mutations, 1 case concurrently had an EGFR mutation and 4 cases had TP53 mutations. However, PTEN mutations were not found in the tumors with KRAS mutation. Our findings indicate that PTEN mutations are relatively common in NSCLC, and thus analysis of PTEN mutations may facilitate a comprehensive understanding of the genetic alterations related to the EGFR signaling pathway.
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PMID:PTEN mutations and relationship to EGFR, ERBB2, KRAS, and TP53 mutations in non-small cell lung cancers. 2001 98

Epidemiologic studies have evaluated the association between KRAS mutations and resistance to the treatment of epidermal growth factor receptor (EGFR) tyrosine-kinase inhibitors (TKIs) in patients with non-small cell lung cancer (NSCLC). However, results were inconclusive. To derive a more precise estimation of the relationship, we performed this meta-analysis. Systematic computerized searches of the PubMed and Medline databases (up to Jun 30, 2009) were performed. A total of 22 studies were included in the final meta-analysis, consisting of 1470 NSCLC patients, of whom 231 had KRAS mutations (16%). Current or former smokers had a higher frequency of KRAS mutations than never smokers (25% versus 6%; OR=4.36; P<0.01). Mutations were more common among adenocarcinoma than other histologies (26% versus 16%; OR=1.98; P<0.01). The objective response rate (ORR) of NSCLC patients with mutant KRAS was 3% (6/210), whereas the ORR of NSCLC patients with wild-type KRAS was 26% (287/1125). The overall pooled RR for ORR was 0.29 (95% CI: 0.18-0.47; P<0.01). Subgroup analyses were conducted on the basis of ethnicity and study treatment, all the results were not materially altered and did not draw different conclusions, indicating that our results were robust. In summary, this meta-analysis suggests that KRAS mutations may represent negative predictive biomarkers for tumor response in NSCLC patients treated with EGFR-TKIs. However, due to a mutually exclusive relationship between KRAS and EGFR mutation and no difference in survival between KRAS mutant/EGFR wild-type and KRAS wild-type/EGFR wild-type NSCLC, the clinical usefulness of KRAS mutation as a selection marker for EGFR-TKIs sensitivity in NSCLC is limited.
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PMID:KRAS mutations and resistance to EGFR-TKIs treatment in patients with non-small cell lung cancer: a meta-analysis of 22 studies. 2002 59

Sixteen cases of primary oncocytic adenocarcinomas of the lung are reported. The patients were 11 women and 5 men between the ages of 47 and 81 years (median, 75 years) with symptoms of cough, chest pain, and shortness of breath. Surgical staging disclosed 14 patients (88%) with stage I disease, 1 (6%) with stage II, and 1 (6%) with stage III. Histologically, all the cases displayed prominent oncocytic features with conventional growth patterns, including acinar, papillary, and bronchioloalveolar. Immunohistochemically, the tumors displayed positive staining for keratin 7, thyroid transcription factor-1, and mitochondrial antibody. Molecular studies showed 3 (20%) of 15 tumors with EGFR mutations and 3 additional cases with KRAS mutations. Clinical follow-up of at least 24 months was obtained in all patients and showed that 5 patients had recurrences, 2 patients died of tumor, and 2 other patients died of unrelated conditions. These cases represent an unusual variant of pulmonary adenocarcinoma.
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PMID:Primary oncocytic adenocarcinomas of the lung: a clinicopathologic, immunohistochemical, and molecular biologic analysis of 16 cases. 2002 69

To recapitulate the stochastic nature of human cancer development, we have devised a strategy for generating mouse tumor models that involves stepwise genetic manipulation of embryonic stem (ES) cells and chimera generation. Tumors in the chimeric animals develop from engineered cells in the context of normal tissue. Adenocarcinomas arising in an allelic series of lung cancer models containing HER2 (also known as ERBB2), KRAS or EGFR oncogenes exhibit features of advanced malignancies. Treatment of EGFR(L858R) and KRAS(G12V) chimeric models with an EGFR inhibitor resulted in near complete tumor regression and no response to the treatment, respectively, accurately reflecting previous clinical observations. Transcriptome and immunohistochemical analyses reveal that PI3K pathway activation is unique to ERBB family tumors whereas KRAS-driven tumors show activation of the JNK/SAP pathway, suggesting points of therapeutic intervention for this difficult-to-treat tumor category.
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PMID:Chimeric mouse tumor models reveal differences in pathway activation between ERBB family- and KRAS-dependent lung adenocarcinomas. 2052 28


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