Editorial on role of p53 in esophageal cancer from a meta-analysis of 16 studies by Fisher et al

Gene polymorphisms of cyclin-dependent kinase inhibitor and matrix metalloproteinase-9 in Sudanese patients with esophageal squamous cell carcinoma

BACKGROUND

The polymorphisms of the cyclin-dependent kinase inhibitor (CDKN1A) gene and matrix metalloproteinase-9 (MMP9) gene may increase one's susceptibility to malignancies. In this study, the association of the single nucleotide polymorphisms (SNPs) CDKN1A rs1059234 c.70C>T at the 3' untranslated region and MMP9 rs17576 (c.836A>G, p.Gln279Arg) with esophageal squamous cell carcinoma (ESCC) in Sudanese individuals were investigated.

MATERIALS AND METHODS

A case-control study involving age- and gender-matched groups were conducted in a cancer center in eastern Sudan (Gadarif) between April and October 2020. The case group consisted of ESCC patients, whereas the control group comprised healthy subjects. Polymerase chain reaction-restriction fragment length polymorphism was performed for the genotyping of the CDKN1A rs1059234 and MMP9 rs17576 SNPs. The genotyping results were confirmed by Sanger sequencing.

RESULTS

The genotype distributions for CDKN1A rs1059234 and MMP9 rs17576 were in agreement with the Hardy-Weinberg equilibrium. The variant allele T in CDKN1 rs1059234 c.70C>T was significantly more prevalent in the ESCC patients than in the healthy controls [51.3% vs. 19.2%; OR = 4.4; 95% CI (2.6-7.4); p < 0.001]. Moreover, in CDKN1A rs1059234, the genotype TC + TT [76.9% vs. 38.4%; OR = 5.3; 95% CI (2.6-10.7); p < 0.001] was more frequent in the cases than in the controls, and it was significantly associated with ESCC risk. In MMP9 rs17576, the variant allele G was also significantly prevalent in the cases relative to the controls, and it was significantly associated with increased ESCC risk in the cases compared with the controls [27.5% vs. 1.9%; OR = 19.4; 95%CI (5.8-64.1); p < 0.001]. Both genotypes containing the allele G (AG + GG) were the most common genotypes in the cases [48.7% vs. 3.8%; OR = 23.7; 95%CI (6.8-81.7); p < 0.001], and they significantly increased the risk of ESCC.

CONCLUSION

A significant increase in ESCC risk is associated with the SNPs CDKN1A rs1059234 and MMP9 rs17576.

Chaperones and Ubiquitin Ligases Balance Mutant p53 Protein Stability in Esophageal and Other Digestive Cancers

The incidence of esophageal adenocarcinoma (EAC) and other gastrointestinal (GI) cancers have risen dramatically, thus defining the oncogenic drivers to develop effective therapies are necessary. Patients with Barrett's Esophagus (BE), have an elevated risk of developing EAC. Around 70%-80% of BE cases that progress to dysplasia and cancer have detectable TP53 mutations. Similarly, in other GI cancers higher rates of TP53 mutation are reported, which provide a significant survival advantage to dysplastic/cancer cells. Targeting molecular chaperones that mediate mutant p53 stability may effectively induce mutant p53 degradation and improve cancer outcomes. Statins can achieve this via disrupting the interaction between mutant p53 and the chaperone DNAJA1, promoting CHIP-mediated degradation of mutant p53, and statins are reported to significantly reduce the risk of BE progression to EAC. However, statins demonstrated sub-optimal efficacy depending on cancer types and TP53 mutation specificity. Besides the well-established role of MDM2 in p53 stability, we reported that individual isoforms of the E3 ubiquitin ligase GRAIL (RNF128) are critical, tissue-specific regulators of mutant p53 stability in BE progression to EAC, and targeting the interaction of mutant p53 with these isoforms may help mitigate EAC development. In this review, we discuss the critical ubiquitin-proteasome and chaperone regulation of mutant p53 stability in EAC and other GI cancers with future insights as to how to affect mutant p53 stability, further noting how the precise p53 mutation may influence the efficacy of treatment strategies and identifying necessary directions for further research in this field.

Meta-Analysis Results on the Association Between TP53 Codon 72 Polymorphism With the Susceptibility to Oral Cancer

Objectives: TP53 is an important tumor suppressor gene to maintain genomic integrity, and its mutations increase the susceptibility to oral carcinoma. Previous published studies have reported the relation of TP53 codon 72 polymorphism with the risk of oral carcinoma, but the results remain controversial and inconclusive.

Methods: We therefore utilized meta-analysis based on a comprehensive search in PubMed, EMBASE, and Google of Scholar databases up to August 19, 2017.

Results: Total 3,525 cases and 3,712 controls from 21 case-control studies were selected. We found no significant association between TP53 codon 72 polymorphism and oral carcinoma susceptibility in all genetic contrast models, including subgroup analysis based on control source and ethnicity. Furthermore, TP53 codon 72 polymorphism was not significant associated with oral carcinoma susceptibility in tobacco or alcohol use, and HPV infection status. Our results were confirmed by sensitivity analysis and no publication bias was found.

Conclusions: Taken together, our data indicate that TP53 codon 72 polymorphism is not associated with the susceptibility to oral carcinoma.