No significant association between p53 codon 72 Arg/Pro polymorphism and risk of oral cancer

The TP53 Codon 72 Arginine Polymorphism Is Found with Increased TP53 Somatic Mutations in HPV(-) and in an Increased Percentage among HPV(+) Norwegian HNSCC Patients

BACKGROUND

Somatic TP53 mutations are frequent in head and neck squamous cell carcinoma (HNSCC) and are important pathogenic factors.

OBJECTIVE

To study TP53 mutations relative to the presence of human papillomavirus (HPV) in tumors in HNSCC patients.

METHODS

Using a custom-made next-generation sequencing (NGS) panel on formalin-fixed, paraffin-embedded tumor tissue, we analyzed somatic TP53 mutations and the TP53 single-nucleotide polymorphism (SNP) codon 72 (P72R; rs1042522) (proline → arginine) from 104 patients with HNSCC.

RESULTS

Only 2 of 44 patients with HPV-positive (HPV(+)) HNSCC had a TP53 somatic mutation, as opposed to 42/60 HPV-negative (HPV(-)) HNSCC patients (p < 0.001). Forty-five different TP53 somatic mutations were detected. Furthermore, in HPV(-) patients, we determined an 80% prevalence of somatic TP53 mutations in the TP53 R72 polymorphism cohort versus 40% in the TP53 P72 cohort (p = 0.001). A higher percentage of patients with oral cavity SCC had TP53 mutations than HPV(-) oropharyngeal (OP) SCC patients (p = 0.012). Furthermore, 39/44 HPV(+) tumor patients harbored the TP53 R72 polymorphism in contrast to 42/60 patients in the HPV(-) group (p = 0.024).

CONCLUSIONS

Our observations show that TP53 R72 polymorphism is associated with a tumor being HPV(+). We also report a higher percentage of somatic TP53 mutations with R72 than P72 in HPV(-) HNSCC patients.

Hallmarks of Cancer Applied to Oral and Oropharyngeal Carcinogenesis: A Scoping Review of the Evidence Gaps Found in Published Systematic Reviews

Simple Summary

This scoping review of systematic reviews aims to accurately assess the degree of existing scientific evidence on the cancer hallmarks proposed in 2011 by Hanahan and Weinberg, in the form of systematic reviews and meta-analyses, applied to oral potentially malignant disorders, oral cavity and oropharyngeal squamous cell carcinomas, in order to point out gaps in evidence and lines of research that should be implemented in the future to improve the malignant transformation prediction, diagnosis and/or prognosis of these diseases.

Abstract

In 2000 and 2011, Hanahan and Weinberg published two papers in which they defined the characteristics that cells must fulfil in order to be considered neoplastic cells in all types of tumours that affect humans, which the authors called “hallmarks of cancer”. These papers have represented a milestone in our understanding of the biology of many types of cancers and have made it possible to reach high levels of scientific evidence in relation to the prognostic impact that these hallmarks have on different tumour types. However, to date, there is no study that globally analyses evidence-based knowledge on the importance of these hallmarks in oral and oropharyngeal squamous cell carcinomas. For this reason, we set out to conduct this scoping review of systematic reviews with the aim of detecting evidence gaps in relation to the relevance of the cancer hallmarks proposed by Hanahan and Weinberg in oral and oropharyngeal cancer, and oral potentially malignant disorders, and to point out future lines of research in this field.

Differential Transcriptional Regulation of Polymorphic p53 Codon 72 in Metabolic Pathways

p53 is a transcription factor that is activated under DNA damage stress and regulates the expression of proapoptotic genes including the expression of growth arrest genes to subsequently determine the fate of cells. To investigate the functional differences of polymorphic p53 codon 72, we constructed isogenic lines encoding each polymorphic p53 codon 72 based on induced pluripotent stem cells, which can endogenously express each polymorphic p53 protein only, encoding either the arginine 72 (R72) variant or proline 72 (P72) variant, respectively. We found that there was no significant functional difference between P72 and R72 cells in growth arrest or apoptosis as a representative function of p53. In the comprehensive analysis, the expression pattern of the common p53 target genes, including cell cycle arrest or apoptosis, was also increased regardless of the polymorphic p53 codon 72 status, whereas the expression pattern involved in metabolism was decreased and more significant in R72 than in P72 cells. This study noted that polymorphic p53 codon 72 differentially regulated the functional categories of metabolism and not the pathways that determine cell fate, such as growth arrest and apoptosis in cells exposed to genotoxic stress.

Polymorphisms in genes involved in breast cancer among Iranian patients

This review gives a summary of the important genetic polymorphisms in breast cancer with a focus on people in Iran. Several single nucleotide polymorphisms were considered as breast cancer susceptibility polymorphisms within genes (STK15, ERRs, ESR1, p53, SEP15, AURKA, SHBG, SRC, FAS, VEGF, XRCC1, GST, NFκB1, XPC, XRCC3, sirtuin-3, NKG2D). Cytosine-adenine repeat (IGF-I), rs3877899, G-2548A, GGC (eRF3a/GSPT1), IVS2nt-124A/G have shown an increased risk of breast cancers and a decreased risk has been observed in 4G/5G (PAI-1), rs6505162, tri-nucleotide (GCG TGFBR1). We observed that the signaling pathways and antioxidant related genes are the main molecular processes associated with breast cancer progression. Further studies on types of polymorphisms in breast cancer could validate the prognostic value of biomarkers.

Effect of TP53 rs1042522 on the susceptibility of patients to oral squamous cell carcinoma and oral leukoplakia: a meta-analysis

Background

There are different and inconsistent conclusions regarding the genetic relationship between the human tumor suppressor p53 (TP53) rs1042522 polymorphism and the risk of oral squamous cell carcinoma (OSCC) and oral leukoplakia (OL). Therefore, the aim of the study was to comprehensively reassess this association through the performance of an updated meta-analysis.

Methods

After searching the available databases, we systematically screened and included the eligible case-control studies, which contain the full genotype frequency data of the TP53 rs1042522 polymorphism for both OSCC/OL patients and the negative control groups. P_A (P-value of the association test) and ORs (odd ratios) with their corresponding 95% CIs (confidence intervals) were calculated to quantitatively evaluate the influence of TP53 rs1042522 on the susceptibility of patients to OSCC or OL.

Results

In total, twenty eligible case-control articles were finally enrolled. Compared with the controls, no increased or decreased risk of OSCC was observed in the cases for six genetic models including allele C vs. G (P_A = 0.741), carrier C vs. G (P_A = 0.853), homozygote CC vs. GG (P_A = 0.085), heterozygote GC vs. GG (P_A = 0.882), dominant GC + CC vs. GG (P_A = 0.969), and recessive CC vs. GG + GC (P_A = 0.980). Furthermore, no statistically significant difference between the cases and controls was detected in most subgroup meta-analyses (P_A > 0.05). For the risk of OL, we did not observe the difference between the cases and controls for most genetic models in the overall meta-analysis and subsequent subgroup analysis (P_A > 0.05). Begg’s test and Egger’s test excluded the large risk of publication bias within the included studies in the meta-analysis of OSCC. The sensitivity analysis indicated the above relatively stable results.

Conclusions

Our updated meta-analysis (based on the current evidence) shows that TP53 rs1042522 may not confer susceptibility to OSCC. In addition, for the first time, we provided evidence regarding the negative association between TP53 rs1042522 and OL risk.

Electronic supplementary material

The online version of this article (10.1186/s12903-018-0603-6) contains supplementary material, which is available to authorized users.

Association of p53 codon 72 Arg>Pro polymorphism and risk of cancer in Iranian population: A systematic review and meta-analysis

Background: Different studies have investigated the association between p53 codon 72 Arg>Pro polymorphism and cancer risk. Because of the lack of consensus of the results in individual studies, we conducted this meta-analysis by pooling all currently available case-control studies to estimate the effect of p53 codon 72 Arg/Pro polymorphism on cancer susceptibility in Iranian population. Methods: A comprehensive search was undertaken and primary data from all peer-reviewed journals indexed in PubMed, Google Scholar, Scopus, Magiran, Scientific Information Databank (SID), Iran Medex, and CAB abstract electronic were used to conduct this meta-analysis. We considered some exclusion and inclusion criteria to select the articles. Statistical heterogeneity was explored using the I-square. Publication bias was assessed graphically and statistically by Begg's funnel plot and Egger test. All statistical analyses were performed using StatsDirect software and a two- tailed test. P-value less than 0.05 was considered statistically significant for any test. Results: Our dataset, which included 35 case-control studies, consisted of 2426 cancer cases and 2928 controls. Pooled OR and 95%CI indicated that codon 72 Arg>Pro polymorphism was not associated with odds of developing cancer among Iranian population in the dominant model (Pro/Pro+Arg/Pro vs. Arg/Arg: OR= 0.96, 95%CI= 0.74 to 1.24 chi2= 0.06, p= 0.8). Moreover, no significant association was detected in variant allele (Pro vs Arg: OR= 1.075, 95%CI= 0.91 to 1.25), homozygous (Pro/Pro vs Arg/Arg: OR=0.911 95%CI= 0.66 to 1.25), and heterozygous (Arg/Pro vs Arg/Arg: OR= 0.84, 95%CI= 0.7 to 1). Conclusion: Our study revealed that p53 codon 72 Arg>Pro polymorphism was not associated with overall cancer odds in Iranian population.

Association between p53 Arg72Pro polymorphism and the risk of human papillomavirus-related head and neck squamous cell carcinoma: a meta-analysis

This study aimed to investigate the association between p53 Arg72Pro polymorphism and the risk of human papillomavirus (HPV)-related head and neck squamous cell carcinoma (HNSCC) by conducting meta-analysis. The PubMed database was searched for relevant studies until May 30, 2013. Relevant studies were selected and data were extracted by two independent authors. Overall, subgroup, and sensitivity analyses were then conducted using the Comprehensive Meta- Analysis v2.2 software. Wild-genotype ArgArg was considered as reference [odds ratio (OR) = 1.00]. Nine studies involving 1071 HNSCC cases were obtained. Meta-analysis results indicated no association between p53 Arg72Pro polymorphism and the risk of HPV-related HNSCC: for Pro/Pro vs. Arg/Arg, OR = 1.17, 95% confidence interval (CI) = 0.70-1.98; for Arg/Pro vs. Arg/ Arg, OR = 1.25, 95% CI = 0.97-1.72; and for (Pro/Pro + Arg/Pro) vs. Arg/Arg, OR = 1.28, 95% CI = 0.95-1.70. These meta-analysis results were supported by subgroup and sensitivity analysis results. In conclusions, p53 Arg72Pro polymorphism is a potential marker of HP infection-related HNSCC rather than a susceptibility gene polymorphism.

Association between the TP53 codon 72 polymorphism and risk of oral squamous cell carcinoma in Asians: a meta-analysis

Background

Several epidemiological studies have previously investigated the association between the TP53 codon 72 polymorphism and oral squamous cell carcinoma (OSCC) susceptibility; however, current results are inconsistent. We therefore performed this meta-analysis to thoroughly investigate any association among Asian patients.

Methods

A comprehensive search of PubMed and Embase databases was performed up to December 2013. We only considered studies consisting of patients diagnosed with OSCC by pathological methods. Statistical analyses were performed using Review Manager (RevMan) 5.2 software and odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association.

Results

A total of 11 case–control studies involving 2,298 OSCC patients and 2,111 controls were included. We found no association between the TP53 codon 72 polymorphism and OSCC susceptibility [(OR = 0.77, 95% CI = 0.48–1.22) for Arg vs. Pro; (OR = 0.67, 95% CI = 0.31–1.43) ArgArg vs. ProPro; (OR = 1.14, 95% CI = 0.97–1.35) ArgPro vs. ProPro; (OR = 0.85, 95% CI = 0.53–1.34) (ArgPro + ArgArg) vs. ProPro; or (OR = 0.34, 95% CI = 0.34–1.23) for ArgArg vs. (ProPro + ArgPro)]. However, subgroup analysis demonstrated an association between the TP53 codon 72 polymorphism and human papillomavirus (HPV)-related OSCC patients. Although statistical heterogeneity was detected, there was no evidence of publication bias.

Conclusions

Current results suggest that the TP53 codon 72 polymorphism is not associated with OSCC in Asians without the presence of HPV infection. Further research is necessary to determine if such a relationship exists in HPV-related OSCC patients.

TP53 single nucleotide polymorphism rs1042522 in salivary gland neoplasms

BACKGROUND

The TP53 single nucleotide polymorphism (SNP) rs1042522 encodes arginine (Arg) or proline (Pro). The Arg variant is more effective at inducing apoptosis than the Pro.

METHODS

We assessed this SNP through direct sequencing of benign and malignant salivary neoplasms of Brazilian patients and compared the results with healthy controls' data. BAX, BCL-2, and CASPASE-3 mRNA levels were assessed by quantitative polymerase chain reaction (qPCR) in a set of salivary tumors, and the results were correlated with the tumor genotype.

RESULTS

We found a higher frequency of the Arg/Arg genotype in the malignant group. However, the SNP did not influence the age of onset in either benign or malignant tumors. The SNP was not associated with the transcription levels of apoptotic/antiapoptotic genes.

CONCLUSION

Malignant salivary neoplasms showed a higher frequency of the allele encoding Arg and a higher frequency of the Arg/Arg genotype. However, the different genotypes did not impact the transcription of genes involved in apoptosis.

Glutathione S-transferase T1 null genotype is associated with oral cancer susceptibility in Asian populations

Though there are many studies assessing the association between glutathione S-transferase T1 (GSTT1) null genotype and oral cancer risk, the association between GSTT1 null genotype and oral cancer in Asian populations is still inconclusive. We performed a meta-analysis of 19 studies including 2,845 cases and 4,295 controls to derive a more precise estimation of the relationship. The pooled odds ratio (OR) with its corresponding 95 % confidence interval (95 % CI) was used to assess the relationship. Meta-analysis of those 19 studies suggested that there was an association between GSTT1 null genotype and elevated risk of oral cancer risk (OR = 1.25, 95 % CI = 1.00-1.56, P = 0.047). Sensitivity analysis by omitting one study at a time showed that the significance of the corresponding pooled ORs was materially altered frequently, indicating that the pooled ORs were not statistically stable. In addition, there was no obvious risk of publication bias in the meta-analysis. Therefore, the present meta-analysis suggests that the GSTT1 null genotype is a risk allele for oral cancer development in Asian populations, but more studies with large sample and well-matched controls are needed to further confirm the finding from the meta-analysis.