Association between p53 codon 72 polymorphism and sarcoma risk among Caucasians

p53 p.Pro72Arg (rs1042522) and Mouse Double Minute 2 (MDM2) Single-Nucleotide Polymorphism (SNP) 309 Variants and Their Interaction in Chronic Lymphocytic Leukemia(CLL): A Survey in CLL Patients from Western Iran

Background: Chronic lymphocytic leukemia (CLL) is the most common leukemia in adults. The MDM2 and p53 are interacting proteins that play crucial roles in cell biology. Genetic variations of p53 and MDM2 have been identified in many cancers including CLL; among which are SNP309 in the promoter of MDM2 and SNP codon72 in p53. Materials and Methods: In this study, we sought to find the impact of two SNPs of p53 and MDM2 in the pathogenesis of CLL. A total of 100 CLL patients and 102 healthy controls were recruited. Genomic DNA was extracted, and genotyping was performed using the PCR-RFLP method. The allele and genotype associations were analyzed using the χ2 test. The gene-gene interaction analysis was studied using GMDR v0.9. Results: Our study found the absence of a significant difference between CLL patients and controls related to the allelic frequencies or genotypic distributions for both MDM2 SNP309 and p53 codon72. A significantly higher frequency of p53 C allele was found in patients with disease duration of more than 36 compared to those less than 36 months. However, GMDR analysis suggests genetic interaction between the genes under study. Conclusion: Our findings indicated each polymorphism of p53 codon72 and MDM2 (SNP309) was not a risk factor for CLL but the p53 C allele could be associated with the disease duration. Besides, the interaction between p53/MDM2 genotypes may confer susceptibility to CLL. Our study could be useful in genetic association studies of CLL and the role of gene-gene interactions in the susceptibility to the disease.

No association of TP53 codon 72 and intron 3 16-bp duplication polymorphisms with breast cancer risk in Chinese Han women: new evidence from a population-based case-control investigation

Background

Many studies have demonstrated that the genetic variants of tumor suppressor gene TP53 contribute to the prediction of breast cancer risk. However, most of them focused on Europeans and Americans; the investigations about Asians, especially Chinese women, are scarce. Thus, the aim of this study was to explore the influence of TP53 codon 72 and intron 3 16-bp duplication polymorphisms on the breast cancer risk in Chinese women, especially those from eastern China.

Methods

Blood samples collected from 254 breast cancer patients and 252 healthy female individuals were investigated. Genotypes of the two polymorphisms were determined by direct sequencing and conventional PCR, respectively.

Results

Heterozygous Arg/Pro and homozygous Del/Del were the most frequent genotypes of the two polymorphisms, respectively. Heterozygous Arg/Pro had a higher prevalence in breast cancer cases (P_adj = 0.10; OR_adj = 1.43, 95% CI 0.93–2.18), and no homozygous 16-bp duplication (Ins/Ins) genotype was found in the whole 506 clinical samples. For the distributions of allele and haplotype frequencies, no statistically significant difference was observed between the two groups when multiple (additive, dominant and recessive) genetic models were utilized in the analysis (P_adj > 0.05).

Conclusion

The results suggested that the two TP53 polymorphisms did not affect breast cancer risk in Chinese Han women, but the heterozygous Arg/Pro may exist as the possible risk genotype of the codon 72 polymorphism in contrast to the homozygous Arg/Arg and Pro/Pro.

Electronic supplementary material

The online version of this article (10.1186/s40001-018-0345-6) contains supplementary material, which is available to authorized users.

Low Concentration of 5-Fluorouracil Increases the Effectiveness of Tumor RNA to Activate Murine Dendritic Cells

AIM

Considering the central role of dendritic cells (DCs) on the development of an antitumor immune response, in this study we used a murine model to evaluate how DC transfection with drug-treated tumor cell RNA changes their phenotype, and whether transfection enhances the in vivo effectiveness of a DC-based antitumor vaccine.

MATERIALS AND METHODS

MC-38 colorectal tumor cells were pretreated with the minimum effective concentration of 5-fluorouracil (5-FU), then their total RNA was extracted and transfected into DCs. These DCs were inoculated into C57Bl/6 mice bearing subcutaneous MC-38 tumor.

RESULTS

DC transfection with drug-treated tumor RNA increases the percentages of CD40⁺ (from 37.6% to 61.4%), CD86⁺ (from 39.8% to 53.4%), and major histocompatibility complex class II⁺ (from 51.2% to 75.3%) cells, whereas significantly increases the in vivo generation of interferon-γ producer lymphocytes.

CONCLUSION

These results reinforce our view that treatment of tumor cells with 5-FU induces transcriptional changes that can be transferred to DCs by RNA transfection, enhancing their ability to stimulate an antitumor response.

Association Between TP53 Gene Codon 72 Polymorphism and Acute Myeloid Leukemia Susceptibility: Evidence Based on a Meta-Analysis

Background

Many studies have reported that the p53 codon 72 polymorphism is associated with acute myeloid leukemia (AML) susceptibility; however, the conclusions are inconsistent. Therefore, we performed this meta-analysis to obtain a more precise result.

Material/Methods

We searched PubMed to identify relevant studies, and 6 published case-control studies were retrieved, including 924 AML patients and 3832 controls. Odds ratio (OR) with corresponding 95% confidence interval (95%CI) was applied to assess the association between p53 codon 72 polymorphism and AML susceptibility. The meta-analysis was performed with Comprehensive Meta-Analysis software, version 2.2.

Results

Overall, no significant association between p53 codon 72 polymorphism and AML susceptibility was found in this meta-analysis (Pro vs. Arg: OR=0.94, 95%CI=0.81–1.10; Pro/Pro vs. Arg/Arg: OR=0.93, 95%CI=0.71–1.22; Arg/Pro vs. Arg/Arg: OR=0.79, 95%CI=0.55–1.13; (Pro/Pro + Arg/Pro) vs. Arg/Arg: OR=0.84, 95%CI=0.62–1.13; Pro/Pro vs. (Arg/Arg + Arg/Pro): OR=1.06, 95%CI=0.83–1.35). Similar results were also found in stratified analysis according to ethnicity and source of controls.

Conclusions

Our meta-analysis demonstrates that p53 codon 72 polymorphism may not be a risk factor for AML, which should be verified in future studies.

Evaluation of the p53 Arg72Pro polymorphism and its association with cancer risk: a HuGE review and meta-analysis

Codon 72 is a hotspot of polymorphisms in the TP53 gene, which encodes a hub protein in the protein-protein interaction network of p53. It is thus a central player in the apoptotic pathway, preventing cancer. A large number of articles have been published exploring its association with an increased susceptibility to most common cancers. However, these studies have produced inconclusive results, which may be due to their small sample sizes or study designs. To comprehensively evaluate the potential correlation between the TP53 Pro72Arg polymorphism and cancer risk and to better characterize the Pro72Arg polymorphism, we performed a systematic HuGE review and meta-analysis of candidate studies through online resources, according to the proposal of MOOSE and the PRISMA statement. The identified articles were carefully examined according to the inclusion criteria. Pooled odds ratios were calculated on the basis of different genetic models, while heterogeneity was assessed through a chi-based Q-test and I2. After applying the inclusion filters, we obtained a pool of 54 eligible studies, representing 18 718 cases and 21 261 controls. Overall, non-significant cancer risk was observed in all the genetic models but their observed heterogeneity was extremely significant. In subgroup analysis, an increased susceptibility was observed in the case of colorectal cancer, while in cancers of the female reproductive system, significantly increased risk was detected in all the genetic models except the dominant model. In another subgroup analysis, significantly increased cancer risk was observed among Asians in homozygous and recessive models, while in Americans increased cancer risk was observed only in dominant and recessive models. No association was observed in the rest of the populations. In conclusion, pooled subgroup analysis on the basis of ethnicity proved that the TP53 Arg72Pro polymorphism is associated with an increased risk of cancer in Asians and Americans only and is not associated in other populations. It can therefore be concluded that this meta-analysis of available data suggests partial confirmation of the association between the TP53 Arg72Pro polymorphism and cancer risk susceptibility.