• BMB Reports
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• 제29권5호
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• pp.442-447
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• 1996

Mutations in codon 12, 13 and 61 of one of the three ras genes, H-ras, K-ras and N-ras, convert these genes into active oncogenes. The presence of H-ras gene mutations have important prognostic implications in various cancers. In this study, the H-ras gene mutations were investigated by two-step PCRRFLP in patients with bladder and stomach cancer. For the control experiments, T24 and SK2 cell lines were used. In a total of 36 bladder cancer patient cases, five (13.9%) mutations were found by this method. Of these, point 12 mutations were two (5.6%) cases and point 61 mutations were three (8.3%) cases. On the other hand, H-ras mutation was not found in 29 cases of stomach cancer. The results of the mutated H-ras gene confirmed by direct sequencing analysis were correlated well with PCR analysis. From the sensitivity test, the H-ras mutation was found to have about 0.2% of mutated DNA mingled in normal DNA. In conclusion, the H-ras mutation has a higher clinical Significance in bladder cancer than stomach cancer. Moreover the two-step PCR-RFLP method is sensitive, rapid and relatively simple for clinical work in detecting H-ras point mutations.

• Asian Pacific Journal of Cancer Prevention
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• 제17권6호
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• pp.2787-2793
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• 2016

Background: Urinary bladder cancer is a common malignancy in the West and ranks as the $7^{th}$ most common cancer in our region of Kashmir, India. FGFR3 mutations are frequent in superficial urothelial carcinoma (UC) differing from the RAS gene mutational pattern. The aim of this study was to analyze the frequency and association of FGFR3 and RAS gene mutations in UC cases. Materials and Methods: Paired tumor and adjacent normal tissue specimens of 65 consecutive UC patients were examined. DNA preparations were evaluated for the occurrence of FGFR3 and RAS gene mutations by PCR-SCCP and DNA sequencing. Results: Somatic point mutations of FGFR3 were identified in 32.3% (21 of 65). The pattern and distribution were significantly associated with low grade/stage (p<0.05). The overall mutations in exon 1 and 2 in all the forms of RAS genes aggregated to 21.5% and showed no association with any clinic-pathological parameters. In total, 53.8% (35 of 65) of the tumors studied had mutations in either a RAS or FGFR3 gene, but these were totally mutually exclusive in and none of the samples showed both the mutational events in mutually exclusive RAS and FGFR3. Conclusions: We conclude that RAS and FGFR3 mutations in UC are mutually exclusive and non-overlapping events which reflect activation of oncogenic pathways through different elements.

• BMB Reports
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• 제49권9호
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• pp.455-456
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• 2016

Mutations of APC and KRAS are frequently observed in human colorectal cancers (CRCs) and the Wnt/β-catenin and Ras pathways are consequently activated in a significant proportion of CRC patients. Mutations in these two genes are also known to synergistically induce progression of CRCs. Through a series of studies, we have demonstrated that inhibition of the Wnt/β-catenin signaling pathway negatively regulates Ras stability, therefore, Ras abundance is increased together with β-catenin in both mice and human CRCs harboring adenomatous polyposis coli (APC) mutations. In a recent study, we identified KY1220, a small molecule that simultaneously degrades β-catenin and Ras by inhibition of the Wnt/β-catenin pathway, and obtained its derivative KYA1797K, which has improved activity and solubility. We found that KYA1797K binds the RGS domain of axin and enhances the binding affinity of β-catenin or Ras with the β-catenin destruction complex components, leading to simultaneous destabilization of β-catenin and Ras via GSK3β activation. By using both in vitro and in vivo studies, we showed that KYA1797K suppressed the growth of CRCs harboring APC and KRAS mutations through destabilization of β-catenin and Ras. Therefore, our findings indicate that the simultaneous destabilization of β-catenin and Ras via targeting axin may serve as an effective strategy for inhibition of CRCs.

• Asian Pacific Journal of Cancer Prevention
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• 제16권8호
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• pp.3505-3508
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• 2015

Background: Ras genes are thought to play an important role in human cancer since they have been found to be activated frequently in several types of tumors including breast cancer, where the overall incidence of K-RAS oncogene activation is 0-10%. Evaluation of K-RAS gene not only for mutational frequency but also for mutation types in this downstream signaling gene pathway is necessary to determine the mechanisms of action. The present study was conducted to test the hypothesis that K-RAS activation is involved in breast cancer risk of south Indian population. Materials and Methods: A total of 70 paired pathologically confirmed tumor and non-tumor tissues from the same breast cancer patients were analysed for most common K-RAS mutations of codon 12,13 and 61 by polymerase chain reaction followed by restriction digestion and direct nucleotide sequencing method. Results: We found that a high rate of homozygous and heterozygous mutations of codon 12, but not codon 13 and 61, may influence the invasive ductal carcinoma of breast risk in this study. Conclusions: Our study indicated that only codon 12 may be involved in initiating breast carcinogenesis in India.

• Asian Pacific Journal of Cancer Prevention
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• 제17권9호
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• pp.4511-4515
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• 2016

Background: K-RAS and N-RAS gene mutations cause resistance to treatment in patients with colorectal cancer. Based on this, awareness of mutation of these genes is considered a clinically important step towards better diagnosis and appropriate treatment. Materials and Methods: Fifty paraffin-embedded blocks of colorectal cancer were obtained from Imam Reza Hospital of Birjand, Iran. Following DNA extraction, the samples were analyzed for common mutations of exons 2, 3 and 4 of KRAS and NRAS genes using real time PCR and pyrosequencing. Results: According to this study, the prevalence of mutations was respectively 28% (14 out of 50) and 2% (1 out of 50) in KRAS and NRAS genes. All the mutations were observed in patients >50 years old. Conclusions: Mutations were found in both KRAS and NRAS genes in colorectal cancers in Iranian patients. Determining the frequency of these mutations in each geographical region may be necessary to benefit from targeted cancer therapy.

• Asian Pacific Journal of Cancer Prevention
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• 제14권1호
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• pp.329-332
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• 2013

Background: The study aimed to determine the incidence of K-ras and BRAF mutations in colorectal cancers (CRCs) in Thai patients and evaluate association with clinicopathological parameters including treatment outcomes in terms of event free survival (EFS). Materials and Methods: Two-hundred colorectal cancer specimens were collected for studies of K-Ras codon 12, 13 and 61, and BRAF codon 600 by polymerase chain reaction and direct nucleotide sequencing. Results: The overall incidence of K-Ras mutations in our patients was 23%. K-ras mutation frequencies in CRC stages (AJCC) I, II, III and IV were 6.7%, 16.1%, 23.3% and 26.6%, respectively (p-value>0.05). The three most common mutation forms were G12D, G12V and G13D. K-Ras mutation status was associated with poorer EFS in stage I-III CRCs (p-value 0.03). Conclusions: The study found a lower mutation frequency of K-Ras and BRAF compared to reports involving other ethnic groups. However, K-Ras mutations did have a negative prognostic value in early-stage CRCs.

• 한국동물학회지
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• 제39권3호
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• pp.231-238
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• 1996

여러 종류의 폐암과 췌장암 세포주를 배양하여 DNA를 분리하였다. 분리한 DNA는 PCR(Polymerase Chain Reaction)로 증폭하여 염기 서열화를 시행하여 K-ras와 p53 유전자들의 돌연변이 종류. 빈도 및 가능한 관계에 대하여 조사하였다. 연구한 암세포주 중 약 81%가 종양 유전자 K-ras와 암 억제 유전자 p53 중 적어도 하나의 돌연변이를 가지고 있었으며 두 유전자 각각에 대해서는 암 세포주 중 약 54.5%에서 돌연변이가 나타났다. 발견된 돌연변이의 종류는 1개의 세포주에 발견된 넌센스 돌연변이 이외에는 모두 미스센스 돌연변이가 일어났으며 2개의 세포주에서 일어난 염기 삽입이외에는 모두 염기 치환이 일어났다. 현재까지 p53 코돈 중 ras와 동시에 돌연변이가 일어난다고 보고된 코돈 이외에도 p53 코돈 164-165과 248이 K-ras와 동시에 돌연변이가 발생하였고, p53 유전자의 돌연변이의 위치에 관계없이 K-ras 유전자에서는 exon 1. 코돈 12개에서 돌연변이가 발생하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제14권11호
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• pp.6653-6656
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• 2013

Background: The single most common proto-oncogene change in human neoplasms is a point mutation in RAS genes. A wide range of variation in frequency of KRAS mutations has been seen in hematologic malignancies. Despite this, RAS roles in leukemogenesis remain unclear. The frequency of KRAS mutations in CML has been reported to be between zero an 10%. Many attempts have been done to develop an anti-RAS drug as a therapeutic target. Materials and Methods: This cross sectional study was performed in Mashhad University of Medical Sciences, Mashhad, Iran from 2010-2012. In 78 CML patients (diagnosed according to WHO 2008 criteria) in chronic or accelerated phases, KRAS mutations in codons 12 and 13 were analyzed using a modified PCR-restriction fragment length polymorphism (RFLP) method. Results: We did not detect any KRAS mutations in this study. Conclusions: KRAS mutations are overall rare in early phase CML and might be secondary events happening late in leukemogenesis cooperating with initial genetic lesions.

• Molecules and Cells
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• 제42권6호
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• pp.441-447
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• 2019

RAS gene mutations are frequently found in one third of human cancers. Affecting approximately 1 in 1,000 newborns, germline and somatic gain-of-function mutations in the components of RAS/mitogen-activated protein kinase (RAS/MAPK) pathway has been shown to cause developmental disorders, known as RASopathies. Since RAS-MAPK pathway plays essential roles in proliferation, differentiation and migration involving developmental processes, individuals with RASopathies show abnormalities in various organ systems including central nervous system. The frequently seen neurological defects are developmental delay, macrocephaly, seizures, neurocognitive deficits, and structural malformations. Some of the defects stemmed from dysregulation of molecular and cellular processes affecting early neurodevelopmental processes. In this review, we will discuss the implications of RAS-MAPK pathway components in neurodevelopmental processes and pathogenesis of RASopathies.

• BMB Reports
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• 제36권4호
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• pp.399-402
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• 2003

Early detection of bladder cancer is particularly important since it dramatically affects the survival rates. However, neither urinary cytology nor tumor markers that are currently used are sensitive enough for the early detection of bladder cancer or recurrent disease. The ras genes are frequently mutated in cancer. In this study, we investigated the diagnostic potential of ras mutation analysis in urinary sediments of patients with bladder cancer using a single-strand conformation polymorphism analysis and polymerase chain reaction. Mutation in codon 12 of the H-ras gene was observed in 39% of the patients. Our results indicate that this approach may significantly improve diagnostic sensitivity in detecting bladder tumors.