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Updated: Oct 7, 2026
Comparative Lesions Analysis Through a Targeted Sequencing Approach
Published on: November 5, 2019
Mutational analysis of the Smad6 and Smad7 genes in hepatocellular carcinoma
1Second Department of Surgery, Gunma University Faculty of Medicine, Maebashi, Gunma 371-8511, Japan.
Abstract:
Resistance to the transforming growth factor-beta (TGF-beta) is a frequently found phenotype in human malignancies. The recent identification of Smad6 and Smad7, both anti-Smads which inhibit TGF-beta signaling, raises a possibility that constitutive activation of the anti-Smads by a somatic mutation may impair the TGF-beta signaling pathway. We tested this hypothesis by screening the entire coding sequences of these anti-Smads for mutations in 52 hepatocellular carcinoma (HCC) samples using polymerase chain reaction - single strand conformation polymorphism analysis. We detected no mutations, but found 3 single nucleotide polymorphisms (SNPs) in the Smad6 gene and 2 SNPs in the Smad7 gene. These results suggest that mutations of the Smad6 and Smad7 genes are not the main cause of the TGF-beta resistance in human HCC.
Insights
Somatic mutations in Smad6 and Smad7 are not the primary cause of transforming growth factor-beta (TGF-beta) resistance in hepatocellular carcinoma (HCC). Further research is needed to understand TGF-beta resistance mechanisms in this cancer.
Area of Science:
- Oncology
- Molecular Biology
- Genetics
Background:
- Transforming growth factor-beta (TGF-beta) resistance is common in human cancers.
- Smad6 and Smad7 are identified as anti-Smads that inhibit TGF-beta signaling.
- Somatic activation of anti-Smads via mutation could potentially impair TGF-beta signaling.
Purpose of the Study:
- To investigate the hypothesis that constitutive activation of Smad6 and Smad7 by somatic mutations contributes to TGF-beta resistance in hepatocellular carcinoma (HCC).
- To screen for mutations in the coding sequences of Smad6 and Smad7 in HCC samples.
Main Methods:
- Screening of the entire coding sequences of Smad6 and Smad7.
- Utilized polymerase chain reaction - single strand conformation polymorphism (PCR-SSCP) analysis.
- Analyzed 52 hepatocellular carcinoma (HCC) samples.
Main Results:
- No mutations were detected in the Smad6 and Smad7 genes within the studied HCC samples.
- Identified 3 single nucleotide polymorphisms (SNPs) in the Smad6 gene.
- Identified 2 single nucleotide polymorphisms (SNPs) in the Smad7 gene.
Conclusions:
- Mutations in Smad6 and Smad7 are unlikely to be the predominant cause of TGF-beta resistance in human HCC.
- The findings suggest that other mechanisms are responsible for TGF-beta resistance in this malignancy.