Association of mRNA expression of TP53 and the TP53 codon 72 Arg/Pro gene polymorphism with colorectal cancer risk in Asian population: a bioinformatics analysis and meta-analysis

TP53 mutation status and consensus molecular subtypes of colorectal cancer in patients from Rwanda

BACKGROUND

Mutations in the TP53 tumor suppressor gene are well-established drivers of colorectal cancer (CRC) development. However, data on the prevalence of TP53 variants and their association with consensus molecular subtype (CMS) classification in patients with CRC from Rwanda are currently lacking. This study addressed this knowledge gap by investigating TP53 mutation status concerning CMS classification in a CRC cohort from Rwanda.

METHODS

Formalin-fixed paraffin-embedded (FFPE) tissue blocks were obtained from 51 patients with CRC at the University Teaching Hospital of Kigali, Rwanda. Exons 4 to 11 and their flanking intron-exon boundaries in the TP53 gene were sequenced using Sanger sequencing to identify potential variants. The recently established immunohistochemistry-based classifier was employed to determine the CMS of each tumor.

RESULTS

Sequencing analysis of cancerous tissue DNA revealed TP53 pathogenic variants in 23 of 51 (45.1%) patients from Rwanda. These variants were predominantly missense types (18/23, 78.3%). The most frequent were c.455dup (p.P153Afs*28), c.524G > A (p.R175H), and c.733G > A (p.G245S), each identified in three tumors. Trinucleotide sequence context analysis of the 23 mutations (20 of which were single-base substitutions) revealed a predominance of the [C > N] pattern among single-base substitutions (SBSs) (18/20; 90.0%), with C[C > T]G being the most frequent mutation (5/18, 27.8%). Furthermore, pyrimidine bases (C and T) were preferentially found at the 5' flanking position of the mutated cytosine (13/18; 72.2%). Analysis of CMS subtypes revealed the following distribution: CMS1 (microsatellite instability-immune) (6/51, 11.8%), CMS2 (canonical) (28/51, 54.9%), CMS3 (metabolic) (9/51, 17.6%), and CMS4 (mesenchymal) (8/51, 15.7%). Interestingly, the majority of TP53 variants were in the CMS2 subgroup (14/23; 60.1%).

CONCLUSION

Our findings indicate a high frequency of TP53 variants in CRC patients from Rwanda. Importantly, these variants are enriched in the CMS2 subtype. This study, representing the second investigation into molecular alterations in patients with CRC from Rwanda and the first to explore TP53 mutations and CMS classification, provides valuable insights into the molecular landscape of CRC in this understudied population.

Prevalence of TP53 gene Pro72Arg (rs1042522) single nucleotide polymorphism among Egyptian breast cancer patients

Background

The P53 protein has an essential role in several cellular processes, including DNA repair, apoptosis, and cell cycle arrest. The pathophysiology of many cancer types has frequently been linked to polymorphisms in the TP53 locus. Over 200 single nucleotide polymorphisms (SNPs) have been identified in TP53. However, Pro72Arg (rs1042522) at codon 72, shows contradictory results in terms of cancer risk. In this study, we aimed to determine if the Pro72Arg (rs1042522) SNP in the TP53 gene would be linked to breast cancer (BC) risk among Egyptian patients.

Materials and Methods

Genomic DNA was extracted from blood samples of 100 healthy volunteers and 100 breast cancer patients (50 familial and 50 non-familial). TP53 Genotyping was performed using tetra-primer amplification refractory mutation (Tetra-ARMS) PCR. Data were analyzed using SNPstat software.

Results

The prevalence of TP53 (Pro72Arg) rs1042522 genotypes carrying the high-risk allele [Pro/Arg (CG) and Arg/Arg (GG)] were significantly higher in BC patients compared to healthy volunteers and were associated with BC susceptibility (OR 0.2; [95% CI 0.11–0.38]; P = 0.0001). However, there was no statistical significant difference in the prevalence of TP53 (Pro72Arg) rs1042522 genotypes carrying the high-risk allele between familial and non-familial BC patients. In addition, there was no association between the prevalence of TP53 (Pro72Arg) rs1042522 genotypes carrying the high-risk allele and BC patients’ clinical and pathological characteristics including tumor size, tumor grade, lymph node status, presence of lymphovascular invasion, expression of ER, PR and Her-2 in both of familial and non-familial BC patients.

Conclusions

TP53 (Pro72Arg) rs1042522 is more prevalent among BC patients but not associated with disease progression.

Association of β-Catenin, APC, SMAD3/4, Tp53, and Cyclin D1 Genes in Colorectal Cancer: A Systematic Review and Meta-Analysis

Objectives

Accumulating evidence indicates that the expression and/or variants of several genes play an essential role in the progress of colorectal cancer (CRC). The current study is a meta-analysis undertaken to estimate the prognosis and survival associated with CTNNB1/β-catenin, APC, Wnt, SMAD3/4, TP53, and Cyclin D1 genes among CRC patients.

Methods

The authors searched PubMed, EMBASE, and Science Direct for relevant reports published between 2000 and 2020 and analyzed them to determine any relationship between the (immunohistochemically/sequencing-detected) gene expression and variants of the selected genes and the survival of CRC patients.

Results

The analysis included 34,074 patients from 64 studies. To evaluate association, hazard ratios (HRs) were estimated for overall survival (OS) or disease-free survival (DFS), with a 95% confidence interval (CIs). Pooled results showed that β-catenin overexpression, APC mutation, SMAD-3 or 4 loss of expression, TP53 mutations, and Cyclin D1 expression were associated with shorter OS. β-Catenin overexpression (HR: 0.137 (95% CI: 0.131–0.406)), loss of expression of SMAD3 or 4 (HR: 0.449 (95% CI: 0.146–0.753)), the mutations of TP53 (HR: 0.179 (95% CI: 0.126–0.485)), and Cyclin D1 expression (HR: 0.485 (95% CI: 0.772–0.198)) also presented risk for shorter DFS.

Conclusions

The present meta-analysis indicates that overexpression or underexpression and variants of CTNNB1/β-catenin, APC, SMAD3/4, TP53, and Cyclin D1 genes potentially acted as unfavorable biomarkers for the prognosis of CRC. The Wnt gene was not associated with prognosis.

Genetic polymorphisms of TP53 (rs1042522) and MDM2 (rs2279744) and colorectal cancer risk: An updated meta-analysis based on 59 case-control studies

OBJECTIVE

Several earlier reports implicated TP53 (rs1042522) and MDM2 (rs2279744) variants in outcome of colorectal cancer (CRC), but with inconclusive findings. This current meta-analysis designed to uncover the role of these variants in CRC risk.

METHODOLOGY

Two independent investigators extracted 59 eligible case-control studies from different electronic databases involving Scopus, Web of Science and PubMed prior to June 2019. Pooled odds ratios (ORs) and "95% confidence intervals (CIs)" were computed for different hereditary models. Stratification and heterogeneity analyses, and "Begg's funnel plots" were conducted. In silico data analyses of the functional and structural properties of the study variants were applied.

RESULTS

In general, 47 and 16 case-control reports for TP53 (11,589 patients and 13,622 controls) and MDM2 (6841 CRC patients and 8792 healthy controls), respectively were enrolled in this meta-analysis. A significant association of TP53 (rs1042522) variant with increased CRC risk in overall pooled subjects under recessive model [(CC vs. GC + GG, OR = 1.134, 95% CI = 1.006-1.278, P = 0.039)] was observed. Moreover, an evidence of MDM2 (rs2279744) association with increased CRC risk in overall pooled subjects under dominant and heterozygote models [(TG + GG vs. TT, OR = 1.120, 95% CI = 1.003-1.250, P = 0.044) and (TG vs. TT, OR = 1.189, 95% CI = 1.076-1.313, P = 0.001), respectively] was reported. Additionally, TP53 (rs1042522) and MDM2 (rs2279744) showed an association with CRC risk among Asians and Africans under a recessive model, and among Asians under different genetic models, respectively, by stratification analysis.

CONCLUSION

TP53 (rs1042522) and MDM2 (rs2279744) variants might represent candidate risk factors for CRC susceptibility.

Integrated bioinformatics analysis revealing independent prognostic long non-coding RNAs DNAH17-AS1 and RP11-400N13.2 and their potential oncogenic roles in colorectal cancer

The aberrant expression of long non-coding RNAs (lncRNAs) has been associated with a variety of malignancies, including colorectal cancer (CRC); however, the key lncRNAs associated with patient prognosis and their biological roles in CRC are yet to be determined. The aim of the present study was to determine the key lncRNAs associated with patient prognosis as well as their biological roles in CRC. Therefore, a dataset from The Cancer Genome Atlas containing the lncRNA expression data of 521 CRC and normal colorectal mucosal tissues, as well as the corresponding clinical data, were screened. A total of 1,180 significantly differentially expressed lncRNAs were associated with CRC as determined by t-tests in edgeR. Kaplan-Meier analysis revealed that 56 of the 1,180 lncRNAs were associated with overall survival (OS); 7 of the 56 lncRNAs were identified as key lncRNAs associated with the Tumor-Node-Metastasis stage of CRC by Kruskal-Wallis test. Subsequent univariate and multivariate Cox regression analyses of the 7 lncRNAs revealed 2 lncRNAs, DNAH17-AS1 and RP11-400N13.2, as potential independent prognostic factors for the OS of patients with CRC. Furthermore, the expression levelsof these 2 lncRNAs were significantly upregulated in CRC compared with those in normal tissues, which suggested that they may serve an oncogenic role in CRC. In addition, networks comprising the 2 lncRNAs and their respective co-expressed protein-coding genes (PCGs) were constructed using cor.test in R. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses of these PCGs were conducted; DNAH17-AS1- and RP11-400N13.2-associated PCGs were reported to be involved in G-protein coupling-related functions. Thus, these independent prognostic lncRNAs and their associated functions identified in the present study may provide novel insight into potential prognostic biomarkers and therapeutic targets for the treatment of CRC.

Association of the TP53 rs1042522 C>G polymorphism and hepatoblastoma risk in Chinese children

The TP53 gene encodes an important class of cell cycle and tumor-suppressing factors that play critical roles in maintaining genomic stability. The TP53 Arg72Pro (rs1042522 C>G) polymorphism has been reported to be associated with the risk of several types of adult cancers; however, its risk for pediatric cancers remains unclear. Here, we analyzed the association of the TP53 gene rs1042522 C>G polymorphism with hepatoblastoma (HB) susceptibility in a hospital-based study among Chinese children. A total of 213 HB patients and 958 healthy controls were enrolled in the study. Genotypes were determined by a TaqMan assay, and the strength of the association was assessed by the odds ratios and 95% confidence intervals generated from logistic regression models, adjusted for age, gender, and clinical stage. No significant association between the TP53 rs1042522 C>G polymorphism and HB susceptibility was detected in the main analysis or in stratification analyses of age, gender, and clinical stages. Overall, the TP53 gene rs1042522 C>G polymorphism is not associated with HB susceptibility in the Chinese population, other polymorphisms alone or in combination should be investigated to further clarify HB susceptibility.