scholarly journals HRAS Gene

2020 ◽  
Author(s):  
Keyword(s):  
Hras Gene

scholarly journals Pathogenesis and characteristics of large ameloblastoma of the jaw: a report of two rare cases

2021 ◽  
Vol 49 (5) ◽  
pp. 030006052110148
Author(s):  
Xue Qiao ◽  
Xing Niu ◽  
Jiayi Liu ◽  
Lijie Chen ◽  
Yan Guo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Mesenchymal Transition ◽  
Morphological Changes ◽  
Molecular Evidence ◽  
Nucleotide Polymorphisms ◽  
Related Gene ◽  
Epithelial Tumor ◽  
Single Nucleotide ◽  
Mesenchymal Transition ◽  
Hras Gene

Ameloblastoma is a common odontogenic epithelial tumor that exhibits various biological behaviors, ranging from simple cystic expansion to aggressive solid masses characterized by local invasiveness, a high risk of recurrence, and even malignant transformation. We report on two cases of unusually large solid ameloblastomas. We detected epithelial–mesenchymal transition-related gene expression and HRAS gene single nucleotide polymorphisms, providing possible molecular evidence of mesenchymal morphological changes in ameloblastoma. The detailed analysis of the pathogenesis of these two cases of ameloblastoma may deepen our understanding of this rare disease and offer promising targets for future targeted therapy.

Genetic alterations in HRAS gene in relation to outcome and response to cetuximab in head and neck squamous cell carcinoma.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 5574-5574
Author(s):  
Theodoros Rampias ◽  
Athina Giagini ◽  
Hiroumi Matsuzaki ◽  
Valentina Bartzi ◽  
Spyros Siolos ◽  
...  
Keyword(s):  
Cell Lines ◽  
Mapk Pathway ◽  
Small Sample Size ◽  
Mutant Cell ◽  
Disease Free Survival ◽  
Genetic Alterations ◽  
Resistant Cell ◽  
Small Sample ◽  
The Impact ◽  
Hras Gene

5574 Background: Aberrant signaling through RAS/MAPK pathway is implicated in resistance to EGFR-targeted agents in cancer. Genetic alterations in Hras gene such as mutations and specific polymorphisms are associated with aggressive phenotype in several smoking-related malignancies. We sought to determine the impact of Hras genetic alterations on response to cetuximab and prognosis in HNSCC. Methods: Clinical outcome according to Hras status was investigated in a retrospective cohort of 140 HNSCC specimens. Primary endpoints were overall survival (OS) and disease-free survival (DFS) and secondary endpoint was treatment response. For statistical analysis, T-test was used for continuous data and x2 –test for categorical data. Cetuximab-resistant cell lines harboring mutant Hras (BB49, T24) were infected with lentivirus expressing shRNA targeting the Hras or a scrambled- shRNA. MTT assay was used to determine the effect of cetuximab on growth of lentivirus infected cells. Biochemical analysis involved immunoblotting for pERK1/2. Results: Mutationanalysis of tumor samples showed that 5.7% participants harbored Hras mutations and 16.42% harbored Hras polymorphisms (rs12628, rs41258054) that are associated with tumorigenesis. Patients bearing tumors with mutated Hras had inferior mean OS ( 22.13vs 35.20, p=0.02) and a non-significant trend for inferior mean DFS. Patients with tumors containing Hras genetic alterations (mutation or polymorphism) had significantly inferior mean OS (p=0.02) compared to those harboring wt Hras and trended towards inferior DFS (p=0.07). Patients had received various treatments such as surgery plus/minus RT and various chemotherapy regimens. A subgroup analysis of 38 patients treated with cetuximab-based regimens showed that wt Hras was associated with higher likelihood of attaining CR or PR to treatment of borderline significance (p=0.06) due to small sample size. Silencing of Hras in Hras-mutant cell lines restored sensitivity to cetuximab and caused a direct downregulation of pERK1/2 levels. Conclusions: Hras genetic alterations are associated with aggressive clinical course and may affect response to cetuximab in HNSCC.

Novel pathogenic variant in the HRAS gene with lethal outcome and a broad phenotypic spectrum among Polish patients with Costello syndrome

2017 ◽  
Vol 26 (2) ◽  
pp. 83-90
Author(s):  
Magdalena Pelc ◽  
Elżbieta Ciara ◽  
Aleksandra Jezela-Stanek ◽  
Monika Kugaudo ◽  
Agata Cieślikowska ◽  
...  
Keyword(s):  
Pathogenic Variant ◽  
Costello Syndrome ◽  
Lethal Outcome ◽  
Phenotypic Spectrum ◽  
Hras Gene

scholarly journals DNA polymerase beta bypasses in vitro a single d(GpG)-cisplatin adduct placed on codon 13 of the HRAS gene.

1995 ◽  
Vol 92 (12) ◽  
pp. 5356-5360 ◽  
Author(s):  
J. S. Hoffmann ◽  
M. J. Pillaire ◽  
G. Maga ◽  
V. Podust ◽  
U. Hubscher ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Dna Polymerase Beta ◽  
Polymerase Beta ◽  
Hras Gene

scholarly journals Polymerase ζ activity is linked to replication timing in humans: evidence from mutational signatures

2014 ◽  
Author(s):  
Vladimir B Seplyarskiy ◽  
Georgii A. Bazykin ◽  
Ruslan A. Soldatov
Keyword(s):  
Important Determinant ◽  
Experimental Studies ◽  
Point Mutations ◽  
Fold Increase ◽  
Replication Timing ◽  
Costello Syndrome ◽  
Mutational Signatures ◽  
Template Strand ◽  
The Mean ◽  
Hras Gene

Replication timing is an important determinant of germline mutation patterns, with a higher rate of point mutations in late replicating regions. Mechanisms underlying this association remain elusive. One of the suggested explanations is the activity of error-prone DNA polymerases in late-replicating regions. Polymerase ζ (pol ζ), an essential error-prone polymerase biased towards transversions, also has a tendency to produce dinucleotide mutations (DNMs), complex mutational events that simultaneously affect two adjacent nucleotides. Experimental studies have shown that pol ζ is strongly biased towards GC->AA/TT DNMs. Using primate divergence data, we show that the GC->AA/TT pol ζ mutational signature is the most frequent among DNMs, and its rate exceeds the mean rate of other DNM types by a factor of ~10. Unlike the overall rate of DNMs, the pol ζ signature drastically increases with the replication time in the human genome. Finally, the pol ζ signature is enriched in transcribed regions, and there is a strong prevalence of GC->TT over GC->AA DNMs on the non-template strand, indicating association with transcription. A recurrently occurring GC->TT DNM in HRAS gene causes the Costello syndrome; we find a 2-fold increase in the mutation rate, and a 2-fold decrease in the transition/transversion ratio, at distances of up to 1 kb from the DNM, suggesting a link between the Costello syndrome and pol ζ activity. This study uncovers the genomic preferences of pol ζ, shedding light on a novel cause of mutational heterogeneity along the genome.

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