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Published on: July 28, 2010
Characteristic Mutational Damages in Gastric and Colorectal Adenocarcinomas
Saule Yermekova1, Madina Orazgaliyeva2, Tatyana Goncharova3
1Department of Molecular Biology with General Chemistry and Biochemistry Course, Kazakh-Russian Medical University, Almaty, Republic of Kazakhstan.
Introduction:
Gastric and colorectal adenocarcinomas are prevalent malignancies characterized by mutations in genes such as p53, RAS, and MDM2, which play crucial roles in tumorigenesis and cancer progression. Understanding the specific mutational patterns and their implications in these cancers was essential for identifying potential therapeutic targets.
Aim:
To identify the nature of mutational disorders in the p53, p21Waf1, RAS and MDM2 genes, depending on the degree of cell differentiation by adenocarcinomas of the gastrointestinal tract.
Methods:
Genomic DNA was isolated from 200 samples of stomach tissue and 233 samples of colon and rectum adenocarcinomas. A total of 433 samples, including gastric adenocarcinomas, colon and rectum adenocarcinomas and adjacent tissues, were collected.
Results:
Genomic DNA was isolated, and mutational analysis of p53, RAS (HRAS, KRAS, NRAS), and MDM2 genes was performed using polymerase chain reaction, gel electrophoresis, and restriction enzyme analysis. The deletion of p53 exon-intron 5-6, as well as HRAS 12 and HRAS 61 mutations, were detected in 78% of poorly differentiated adenocarcinomas. The deletions of p53 exon-intron 7-9 - in 100% of moderately differentiated adenocarcinomas and 50-60% of adjacent tissues. The loss of WAF1 gene expression was registered in almost 90% of poorly differentiated adenocarcinomas and 20% of adjacent tissue samples. The KRAS and NRAS mutations in almost 63.9% of studied colon and rectal samples indicated autonomous cell growth. This explains the aggressive and metastatic growth of tumours and the ineffectiveness of growth factor inhibitors in colorectal cancer. Finding ways to influence specific substitutions in RAS genes could prevent and eliminate uncontrolled invasive tumour growth.
Conclusion:
By identifying specific gene mutations and differences in genetic markers, the study provided insights for the development of targeted diagnostic methods and personalised treatment strategies, ultimately improving the clinical outcomes in the field of oncology.
Insights
This study analyzed gene mutations in gastric and colorectal cancers, finding specific p53 and RAS alterations linked to tumor aggressiveness. These insights are crucial for developing targeted therapies and improving cancer treatment outcomes.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Gastric and colorectal adenocarcinomas are common cancers driven by mutations in genes like p53, RAS, and MDM2.
- Understanding these genetic alterations is key to identifying therapeutic targets for cancer progression.
Purpose of the Study:
- To investigate mutations in p53, p21Waf1, RAS, and MDM2 genes in gastrointestinal adenocarcinomas.
- To correlate these gene mutations with the degree of tumor cell differentiation.
Main Methods:
- Genomic DNA was extracted from 433 gastric, colon, and rectal adenocarcinoma samples and adjacent tissues.
- Mutational analysis of p53, RAS (HRAS, KRAS, NRAS), and MDM2 genes was performed using PCR, gel electrophoresis, and restriction enzyme analysis.
Main Results:
- Specific p53 deletions and HRAS mutations were found in 78% of poorly differentiated adenocarcinomas.
- Loss of WAF1 gene expression occurred in 90% of poorly differentiated tumors, and KRAS/NRAS mutations in 63.9% of colorectal samples indicated autonomous cell growth.
- These genetic alterations correlate with aggressive tumor behavior and resistance to growth factor inhibitors.
Conclusions:
- Identifying specific gene mutations and genetic markers offers insights for targeted diagnostics.
- This research supports the development of personalized treatment strategies to improve oncological outcomes.
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