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Updated: Jul 13, 2026
Genome-Wide Analysis of DNA Methylation in Gastrointestinal Cancer
Published on: September 18, 2020
[Prognostic value of P16 gene methylation and P16 protein expression in gastrointestinal stromal tumor]
Jian-fang Liang1, Hui-xia Zheng, Ning Li
1Department of Pathology, The First Affiliated Hospital, Shanxi Medical Univercity, Taiyuan 030001, China. jfliang2000@yahoo.com.cn
Objective:
To study the methylation status of P16 gene promoter and the expression of P16 protein in gastrointestinal stromal tumors(GIST) and to explore the prognostic value.
Methods:
Methylation status of the P16 promoter was detected by methylation- specific polymerase chain reaction (MSP) and the expression of P16 protein by immunohistochemistry in 62 patients with GIST.
Results:
The status of P16 gene methylation and the expression of P16 protein were significantly different among the patients with different subclassification of GIST using Fletcher's scheme (P < 0.05, P < 0.01). And there were significant differences in progressive disease (PD) among various levels of P16 expression (P < 0.01). P16 gene methylation was closely related to P16 protein. P16 gene methylation accounted for 75% in the tumor tissue with less than 50% P16 positive cells, and accounted for only 10% in the tumor tissue with more than 50% P16 positive cells (P< 0.01).
Conclusion:
P16 immunohistochemical assessment can be used as a prognostic index for GIST. The patients with more than 50% fraction of cells with low P16 immunostaining have poor prognosis.
Insights
Methylation of the P16 gene and P16 protein expression are significant prognostic indicators in gastrointestinal stromal tumors (GIST). Low P16 protein expression in GIST patients indicates a poor prognosis.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Context:
- Gastrointestinal stromal tumors (GIST) are the most common mesenchymal tumors of the gastrointestinal tract.
- The P16 gene, a tumor suppressor, plays a critical role in cell cycle regulation and is frequently altered in various cancers.
- Understanding the molecular mechanisms underlying GIST progression is crucial for developing effective therapeutic strategies.
Purpose:
- To investigate the methylation status of the P16 gene promoter and P16 protein expression in GIST.
- To explore the potential of P16 gene methylation and protein expression as prognostic biomarkers for GIST patients.
Summary:
- This study analyzed P16 gene promoter methylation using methylation-specific polymerase chain reaction (MSP) and P16 protein expression via immunohistochemistry in 62 GIST patients.
- Significant differences in P16 methylation and protein expression were observed across different GIST subtypes (Fletcher's scheme).
- P16 gene methylation strongly correlated with P16 protein expression, with higher methylation levels associated with lower P16 protein positivity.
Impact:
- P16 immunohistochemical assessment can serve as a valuable prognostic index for GIST.
- GIST patients exhibiting low P16 immunostaining (less than 50% positive cells) demonstrate a poorer prognosis.
- These findings may contribute to improved risk stratification and personalized treatment approaches for GIST.