Augustin Nzitakera, Jean Bosco Surwumwe, Ella Larissa Ndoricyimpaye, Schifra Uwamungu, Delphine Uwamariya, Felix Manirakiza, Marie Claire Ndayisaba, Gervais Ntakirutimana, Benoit Seminega, Vincent Dusabejambo, Eric Rutaganda, Placide Kamali, François Ngabonziza, Rei Ishikawa, Belson Rugwizangoga, Yuji Iwashita, Hidetaka Yamada, Kimio Yoshimura, Haruhiko Sugimura, Kazuya Shinmura
{"title":"The spectrum of TP53 mutations in Rwandan patients with gastric cancer.","authors":"Augustin Nzitakera, Jean Bosco Surwumwe, Ella Larissa Ndoricyimpaye, Schifra Uwamungu, Delphine Uwamariya, Felix Manirakiza, Marie Claire Ndayisaba, Gervais Ntakirutimana, Benoit Seminega, Vincent Dusabejambo, Eric Rutaganda, Placide Kamali, François Ngabonziza, Rei Ishikawa, Belson Rugwizangoga, Yuji Iwashita, Hidetaka Yamada, Kimio Yoshimura, Haruhiko Sugimura, Kazuya Shinmura","doi":"10.1186/s41021-024-00302-y","DOIUrl":null,"url":null,"abstract":"<p><strong>Background: </strong>Gastric cancer is the sixth most frequently diagnosed cancer and third in causing cancer-related death globally. The most frequently mutated gene in human cancers is TP53, which plays a pivotal role in cancer initiation and progression. In Africa, particularly in Rwanda, data on TP53 mutations are lacking. Therefore, this study intended to obtain TP53 mutation status in Rwandan patients with gastric cancer.</p><p><strong>Results: </strong>Formalin-fixed paraffin-embedded tissue blocks of 95 Rwandan patients with histopathologically proven gastric carcinoma were obtained from the University Teaching Hospital of Kigali. After DNA extraction, all coding regions of the TP53 gene and the exon-intron boundary region of TP53 were sequenced using the Sanger sequencing. Mutated TP53 were observed in 24 (25.3%) of the 95 cases, and a total of 29 mutations were identified. These TP53 mutations were distributed between exon 4 and 8 and most of them were missense mutations (19/29; 65.5%). Immunohistochemical analysis for TP53 revealed that most of the TP53 missense mutations were associated with TP53 protein accumulation. Among the 29 mutations, one was novel (c.459_477delCGGCACCCGCGTCCGCGCC). This 19-bp deletion mutation in exon 5 caused the production of truncated TP53 protein (p.G154Wfs*10). Regarding the spectrum of TP53 mutations, G:C > A:T at CpG sites was the most prevalent (10/29; 34.5%) and G:C > T:A was the second most prevalent (7/29; 24.1%). Interestingly, when the mutation spectrum of TP53 was compared to three previous TP53 mutational studies on non-Rwandan patients with gastric cancer, G:C > T:A mutations were significantly more frequent in this study than in our previous study (p = 0.013), the TCGA database (p = 0.017), and a previous study on patients from Hong Kong (p = 0.006). Even after correcting for false discovery, statistical significance was observed.</p><p><strong>Conclusions: </strong>Our results suggested that TP53 G:C > T:A transversion mutation in Rwandan patients with gastric cancer is more frequent than in non-Rwandan patients with gastric cancer, indicating at an alternative etiological and carcinogenic progression of gastric cancer in Rwanda.</p>","PeriodicalId":12709,"journal":{"name":"Genes and Environment","volume":"46 1","pages":"8"},"PeriodicalIF":2.7000,"publicationDate":"2024-03-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10921722/pdf/","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Genes and Environment","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1186/s41021-024-00302-y","RegionNum":4,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
引用次数: 0
Abstract
Background: Gastric cancer is the sixth most frequently diagnosed cancer and third in causing cancer-related death globally. The most frequently mutated gene in human cancers is TP53, which plays a pivotal role in cancer initiation and progression. In Africa, particularly in Rwanda, data on TP53 mutations are lacking. Therefore, this study intended to obtain TP53 mutation status in Rwandan patients with gastric cancer.
Results: Formalin-fixed paraffin-embedded tissue blocks of 95 Rwandan patients with histopathologically proven gastric carcinoma were obtained from the University Teaching Hospital of Kigali. After DNA extraction, all coding regions of the TP53 gene and the exon-intron boundary region of TP53 were sequenced using the Sanger sequencing. Mutated TP53 were observed in 24 (25.3%) of the 95 cases, and a total of 29 mutations were identified. These TP53 mutations were distributed between exon 4 and 8 and most of them were missense mutations (19/29; 65.5%). Immunohistochemical analysis for TP53 revealed that most of the TP53 missense mutations were associated with TP53 protein accumulation. Among the 29 mutations, one was novel (c.459_477delCGGCACCCGCGTCCGCGCC). This 19-bp deletion mutation in exon 5 caused the production of truncated TP53 protein (p.G154Wfs*10). Regarding the spectrum of TP53 mutations, G:C > A:T at CpG sites was the most prevalent (10/29; 34.5%) and G:C > T:A was the second most prevalent (7/29; 24.1%). Interestingly, when the mutation spectrum of TP53 was compared to three previous TP53 mutational studies on non-Rwandan patients with gastric cancer, G:C > T:A mutations were significantly more frequent in this study than in our previous study (p = 0.013), the TCGA database (p = 0.017), and a previous study on patients from Hong Kong (p = 0.006). Even after correcting for false discovery, statistical significance was observed.
Conclusions: Our results suggested that TP53 G:C > T:A transversion mutation in Rwandan patients with gastric cancer is more frequent than in non-Rwandan patients with gastric cancer, indicating at an alternative etiological and carcinogenic progression of gastric cancer in Rwanda.
期刊介绍:
Genes and Environment is an open access, peer-reviewed journal that aims to accelerate communications among global scientists working in the field of genes and environment. The journal publishes articles across a broad range of topics including environmental mutagenesis and carcinogenesis, environmental genomics and epigenetics, molecular epidemiology, genetic toxicology and regulatory sciences.
Topics published in the journal include, but are not limited to, mutagenesis and anti-mutagenesis in bacteria; genotoxicity in mammalian somatic cells; genotoxicity in germ cells; replication and repair; DNA damage; metabolic activation and inactivation; water and air pollution; ROS, NO and photoactivation; pharmaceuticals and anticancer agents; radiation; endocrine disrupters; indirect mutagenesis; threshold; new techniques for environmental mutagenesis studies; DNA methylation (enzymatic); structure activity relationship; chemoprevention of cancer; regulatory science. Genetic toxicology including risk evaluation for human health, validation studies on testing methods and subjects of guidelines for regulation of chemicals are also within its scope.