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Comparative analysis of KRAS codon 12, 13, 18, 61, and 117 mutations using human MCF10A isogenic cell lines.

ABSTRACT: KRAS mutations occur in one third of human cancers and cluster in several hotspots, with codons 12 and 13 being most commonly affected. It has been suggested that the position and type of amino acid exchange influence the transforming capacity of mutant KRAS proteins. We used MCF10A human mammary epithelial cells to establish isogenic cell lines that express different cancer-associated KRAS mutations (G12C, G12D, G12V, G13C, G13D, A18D, Q61H, K117N) at physiological or elevated levels, and investigated the biochemical and functional consequences of the different variants. The overall effects of low-expressing mutants were moderate compared to overexpressed variants, but allowed delineation of biological functions that were related to specific alleles rather than KRAS expression level. None of the mutations induced morphological changes, migratory abilities, or increased phosphorylation of ERK, PDK1, and AKT. KRAS-G12D, G12V, G13D, and K117N mediated EGF-independent proliferation, whereas anchorage-independent growth was primarily induced by K117N and Q61H. Both codon 13 mutations were associated with increased EGFR expression. Finally, global gene expression analysis of MCF10A-G13D versus MCF10A-G12D revealed distinct transcriptional changes. Together, we describe a useful resource for investigating the function of multiple KRAS mutations and provide insights into the differential effects of these variants in MCF10A cells.

SUBMITTER: Stolze B

PROVIDER: S-EPMC4336936 | biostudies-literature | 2015

REPOSITORIES: biostudies-literature

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Comparative analysis of KRAS codon 12, 13, 18, 61, and 117 mutations using human MCF10A isogenic cell lines.

Stolze Britta B Reinhart Stefanie S Bulllinger Lars L Fröhling Stefan S Scholl Claudia C

Scientific reports 20150223

KRAS mutations occur in one third of human cancers and cluster in several hotspots, with codons 12 and 13 being most commonly affected. It has been suggested that the position and type of amino acid exchange influence the transforming capacity of mutant KRAS proteins. We used MCF10A human mammary epithelial cells to establish isogenic cell lines that express different cancer-associated KRAS mutations (G12C, G12D, G12V, G13C, G13D, A18D, Q61H, K117N) at physiological or elevated levels, and inves ...[more]

PMID: 25705018

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Project description:BackgroundApproximately 40% of colorectal cancer (CRC) cases are linked to Kirsten rat sarcoma viral oncogene homolog (KRAS) mutations. KRAS mutations are associated with poor CRC prognosis, especially KRAS codon 12 mutation, which is associated with metastasis and poorer survival. However, the clinicopathological characteristics and prognosis of KRAS codon 13 mutation in CRC remain unclear.AimTo evaluate the clinicopathological characteristics and prognostic value of codon-specific KRAS mutations, especially in codon 13.MethodsThis retrospective, single-center, observational cohort study included patients who underwent surgery for stage I-III CRC between January 2009 and December 2019. Patients with KRAS mutation status confirmed by molecular pathology reports were included. The relationships between clinicopathological characteristics and individual codon-specific KRAS mutations were analyzed. Survival data were analyzed to identify codon-specific KRAS mutations as recurrence-related factors using the Cox proportional hazards regression model.ResultsAmong the 2203 patients, the incidence of KRAS codons 12, 13, and 61 mutations was 27.7%, 9.1%, and 1.3%, respectively. Both KARS codons 12 and 13 mutations showed a tendency to be associated with clinical characteristics, but only codon 12 was associated with pathological features, such as stage of primary tumor (T stage), lymph node involvement (N stage), vascular invasion, perineural invasion, tumor size, and microsatellite instability. KRAS codon 13 mutation showed no associations (77.2% vs 85.3%, P = 0.159), whereas codon 12 was associated with a lower 5-year recurrence-free survival rate (78.9% vs 75.5%, P = 0.025). In multivariable analysis, along with T and N stages and vascular and perineural invasion, only codon 12 (hazard ratio: 1.399; 95% confidence interval: 1.034-1.894; P = 0.030) among KRAS mutations was an independent risk factor for recurrence.ConclusionThis study provides evidence that KRAS codon 13 mutation is less likely to serve as a prognostic biomarker than codon 12 mutation for CRC in a large-scale cohort.

Project description:BackgroundKRAS mutations in codons 12 and 13 are established predictive biomarkers for anti-EGFR therapy in colorectal cancer. Previous studies suggest that KRAS codon 61 and 146 mutations may also predict resistance to anti-EGFR therapy in colorectal cancer. However, clinicopathological, molecular, and prognostic features of colorectal carcinoma with KRAS codon 61 or 146 mutation remain unclear.MethodsWe utilized a molecular pathological epidemiology database of 1267 colon and rectal cancers in the Nurse's Health Study and the Health Professionals Follow-up Study. We examined KRAS mutations in codons 12, 13, 61 and 146 (assessed by pyrosequencing), in relation to clinicopathological features, and tumor molecular markers, including BRAF and PIK3CA mutations, CpG island methylator phenotype (CIMP), LINE-1 methylation, and microsatellite instability (MSI). Survival analyses were performed in 1067 BRAF-wild-type cancers to avoid confounding by BRAF mutation. Cox proportional hazards models were used to compute mortality hazard ratio, adjusting for potential confounders, including disease stage, PIK3CA mutation, CIMP, LINE-1 hypomethylation, and MSI.ResultsKRAS codon 61 mutations were detected in 19 cases (1.5%), and codon 146 mutations in 40 cases (3.2%). Overall KRAS mutation prevalence in colorectal cancers was 40% (=505/1267). Of interest, compared to KRAS-wild-type, overall, KRAS-mutated cancers more frequently exhibited cecal location (24% vs. 12% in KRAS-wild-type; P?<?0.0001), CIMP-low (49% vs. 32% in KRAS-wild-type; P?<?0.0001), and PIK3CA mutations (24% vs. 11% in KRAS-wild-type; P?<?0.0001). These trends were evident irrespective of mutated codon, though statistical power was limited for codon 61 mutants. Neither KRAS codon 61 nor codon 146 mutation was significantly associated with clinical outcome or prognosis in univariate or multivariate analysis [colorectal cancer-specific mortality hazard ratio (HR)?=?0.81, 95% confidence interval (CI)?=?0.29-2.26 for codon 61 mutation; colorectal cancer-specific mortality HR?=?0.86, 95% CI?=?0.42-1.78 for codon 146 mutation].ConclusionsTumors with KRAS mutations in codons 61 and 146 account for an appreciable proportion (approximately 5%) of colorectal cancers, and their clinicopathological and molecular features appear generally similar to KRAS codon 12 or 13 mutated cancers. To further assess clinical utility of KRAS codon 61 and 146 testing, large-scale trials are warranted.

Project description:ImportanceCurrently, one of the most commonly available biomarkers in the treatment of patients with colorectal liver metastases (CRLM) is the Kirsten rat sarcoma viral oncogene homolog (KRAS); however, the prognostic implications of specific mutations of the KRAS gene are still not well defined.ObjectiveTo investigate the prognostic impact of specific KRAS mutations on patients undergoing liver resection for CRLM.Design, setting, and participantsThis retrospective single-center study was conducted from January 1, 2003, to December 31, 2013. Data about specific KRAS mutations for 331 patients who underwent hepatic resection for CRLM at Johns Hopkins Hospital between 2003 and 2013 were analyzed. Clinicopathological characteristics, perioperative details, and outcomes were stratified by specific KRAS mutation at codons 12 and 13.InterventionResection of CRLM.Main outcomes and measuresOverall survival (OS) and recurrence-free survival.ResultsA mutated KRAS (mtKRAS) was identified in 91 patients (27.5%). At a median follow-up of 27.4 months, recurrence was observed in 48 patients (52.7%) with mtKRAS and 130 patients (54.2%) with wild-type KRAS (wtKRAS) (P = .82). Median and 5-year survival among patients with mtKRAS was 32.4 months and 32.7%, respectively, vs 58.5 months and 46.9%, respectively, for patients with wtKRAS (P = .02). Patients with KRAS codon 12 mutations had worse OS (hazard ratio [HR], 1.54; 95% CI, 1.05-2.27; P = .03) vs those with wtKRAS, whereas a KRAS codon 13 mutation was not associated with prognosis (HR, 1.47; 95% CI, 0.83-2.62; P = .19). Among the 6 most common mutations in codons 12 and 13, only G12V (HR, 1.78; 95% CI, 1.00-3.17; P = .05) and G12S (HR, 3.33; 95% CI, 1.22-9.10; P = .02) were associated with worse OS compared with patients with wtKRAS (both P < .05). Among patients who recurred, G12V (HR, 2.96; 95% CI, 1.32-6.61; P = .01), G12C (HR, 6.74; 95% CI, 2.05-22.2; P = .002), and G12S mutations (HR, 4.91; 95% CI, 1.52-15.8; P = .01) were associated with worse OS (both P < .05).Conclusions and relevanceG12V and G12S mutations of codon 12 were independent prognostic factors of worse OS. Among patients who recurred after resection of CRLM, G12V, G12C, and G12S mutations were associated with worse OS. Information on specific KRAS mutations may help individualize therapeutic and surveillance strategies for patients with resected CRLM.

Project description:BackgroundMutations in KRAS, BRAF and PIK3CA are the most common somatic alterations found in the colorectal cancer (CRC) patients from Western countries; but their prevalence and prognostic value have not been adequately assessed in Asian patients. The aim of this study was to determine the mutation frequencies of these genes in Chinese CRC patients and to investigate their impact on prognosis.MethodsThe sequences of exon 2 of KRAS, exon 15 of BRAF and exons 9 and 20 of PIK3CA were evaluated by PCR and direct sequencing using DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissues from primary CRC tumors of 214 patients (colon/rectum: 126/88).ResultsKRAS, BRAF and PIK3CA mutations were identified in 44.9% (96/214), 4.2% (9/214) and 12.3% (26/212) CRCs, respectively. The most frequent mutations in KRAS, BRAF and PIK3CA were G12D, V600E and H1047R, respectively. All BRAF and 80.8% PIK3CA mutations were from colon cancer patients. BRAF V600E was associated with advanced TNM (P < 0.001), more distant metastases (P = 0.025), and worse overall survival (OS, P < 0.001; multivariate HR = 4.2, P = 0.004) in colon cancer patients. Compared with KRAS wt/BRAF wt CRC patients (N = 109), those with KRAS codon 13 mutations (N = 25) had significantly worse OS (P = 0.016; multivariate HR = 2.7, P = 0.011), whereas KRAS codon 12-mutated cases were not significantly associated with survival. Among the three most common KRAS mutations, G13D (N = 23) showed significant association with poor OS (P = 0.024; multivariate HR = 2.6, P = 0.016) compared with KRAS wt/BRAF wt patients.ConclusionOur findings indicate that PI3K/RAS-RAF signaling pathway genes are frequently mutated in Chinese CRC patients, but have different characteristics than found in Western patients. BRAF V600E is an independent prognostic factor for Chinese patients. Our finding that KRAS codon 13 mutations (in particular G13D) are associated with inferior survival in BRAF wild-type CRCs in Chinese patients was not reported thus far. Our data emphasizes the importance of prospective evaluation of molecular features in CRC patients, because a single mutation type may represent a distinct biologic effect and clinical implication.

Project description:Each cell comprising an intact, healthy, confluent epithelial layer ordinarily remains sedentary, firmly adherent to and caged by its neighbors, and thus defines an elemental constituent of a solid-like cellular collective [1,2]. After malignant transformation, however, the cellular collective can become fluid-like and migratory, as evidenced by collective motions that arise in characteristic swirls, strands, ducts, sheets, or clusters [3,4]. To transition from a solid-like to a fluid-like phase and thereafter to migrate collectively, it has been recently argued that cells comprising the disordered but confluent epithelial collective can undergo changes of cell shape so as to overcome geometric constraints attributable to the newly discovered phenomenon of cell jamming and the associated unjamming transition (UJT) [1,2,5-9]. Relevance of the jamming concept to carcinoma cells lines of graded degrees of invasive potential has never been investigated, however. Using classical in vitro cultures of six breast cancer model systems, here we investigate structural and dynamical signatures of cell jamming, and the relationship between them [1,2,10,11]. In order of roughly increasing invasive potential as previously reported, model systems examined included MCF10A, MCF10A.Vector; MCF10A.14-3-3ζ; MCF10.ErbB2, MCF10AT; and MCF10CA1a [12-15]. Migratory speed depended on the particular cell line. Unsurprisingly, for example, the MCF10CA1a cell line exhibited much faster migratory speed relative to the others. But unexpectedly, across different cell lines higher speeds were associated with enhanced size of cooperative cell packs in a manner reminiscent of a peloton [9]. Nevertheless, within each of the cell lines evaluated, cell shape and shape variability from cell-to-cell conformed with predicted structural signatures of cell layer unjamming [1]. Moreover, both structure and migratory dynamics were compatible with previous theoretical descriptions of the cell jamming mechanism [2,10,11,16,17]. As such, these findings demonstrate the richness of the cell jamming mechanism, which is now seen to apply across these cancer cell lines but remains poorly understood.

Dataset Information

Comparative analysis of KRAS codon 12, 13, 18, 61, and 117 mutations using human MCF10A isogenic cell lines.

Publications

Comparative analysis of KRAS codon 12, 13, 18, 61, and 117 mutations using human MCF10A isogenic cell lines.

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