Impact of MDM2, TP53 and P14ARF Polymorphisms on Endometrial Cancer Risk and Onset

The Cdkn2a gene product p19 alternative reading frame (p19ARF) is a critical regulator of IFNβ-mediated Lyme arthritis

Type I interferon (IFN) has been identified in patients with Lyme disease, and its abundant expression in joint tissues of C3H mice precedes development of Lyme arthritis. Forward genetics using C3H mice with severe Lyme arthritis and C57BL/6 (B6) mice with mild Lyme arthritis identified the Borrelia burgdorferi arthritis-associated locus 1 (Bbaa1) on chromosome 4 (Chr4) as a regulator of B. burgdorferi-induced IFNβ expression and Lyme arthritis severity. B6 mice introgressed with the C3H allele for Bbaa1 (B6.C3-Bbaa1 mice) displayed increased severity of arthritis, which is initiated by myeloid lineage cells in joints. Using advanced congenic lines, the physical size of the Bbaa1 interval has been reduced to 2 Mbp, allowing for identification of potential genetic regulators. Small interfering RNA (siRNA)-mediated silencing identified Cdkn2a as the gene responsible for Bbaa1 allele-regulated induction of IFNβ and IFN-stimulated genes (ISGs) in bone marrow-derived macrophages (BMDMs). The Cdkn2a-encoded p19 alternative reading frame (p19ARF) protein regulates IFNβ induction in BMDMs as shown by siRNA silencing and overexpression of ARF. In vivo studies demonstrated that p19ARF contributes to joint-specific induction of IFNβ and arthritis severity in B. burgdorferi-infected mice. p19ARF regulates B. burgdorferi-induced IFNβ in BMDMs by stabilizing the tumor suppressor p53 and sequestering the transcriptional repressor BCL6. Our findings link p19ARF regulation of p53 and BCL6 to the severity of IFNβ-induced Lyme arthritis in vivo and indicate potential novel roles for p19ARF, p53, and BCL6 in Lyme disease and other IFN hyperproduction syndromes.

Lyme disease is caused by infection with the tick-transmitted bacterium Borrelia burgdorferi. Although different isolates of B. burgdorferi have distinct potential for dissemination and tissue invasion, factors intrinsic to the infected host also play an important role in directing the severity of Lyme disease. In the animal model, infected C3H mice develop severe Lyme arthritis following elevation of type I IFN in joint tissue, while in C57BL/6 (B6) mice arthritis is mild and not associated with type I IFN. We demonstrated that the Borrelia burgdorferi arthritis-associated locus 1 (Bbaa1) on chromosome 4 (Chr4) intrinsically controls the magnitude of IFNβ production and the severity of Lyme arthritis in C3H vs B6 mice. The Cdkn2a gene was positionally identified as the regulator of IFNβ within Bbaa1, and determined to function through its protein product p19 alternative reading frame (p19ARF). ARF regulates IFNβ expression and Lyme arthritis severity by modulating the activities of the tumor suppressor p53 and transcriptional repressor BCL6. Our study provides new insight and potential therapeutic targets for the investigation of type I IFN-dependent Lyme arthritis and other IFN-driven diseases.

Genetic polymorphisms and protein levels in vocal fold leukoplakia: a systematic review

Vocal fold leukoplakia (VFL) has a risk of malignant transformation. Therefore, patients can have symptoms such as dysphonia, vocal strain, difficulty breathing, and dysphagia. Additionally, there is a genetic predisposition that can be associated with genetic polymorphisms. We aimed to evaluate the influence of genetic polymorphisms and protein levels in the etiology of VFL. Our study followed the PRISMA checklist and was registered on PROSPERO database. The questions were: "Are genetic polymorphisms involved in the etiology of VFL? Are protein levels altered in patients with VFL?". Eligibility criteria were case control studies that compared the presence of polymorphisms or/and protein levels of subjects diagnosed with VFL and healthy controls. Of the 905 articles retrieved, five articles with a total of 1038 participants were included in this study. The C allele of the single nucleotide polymorphisms (SNP)-819 T/C IL-10, A allele of the SNP -592 A/C IL-10, CT genotype of the SNP rs11886868 C/T BCL11A, GG genotype of the SNP rs4671393 A/G BCL11A, LL genotype, and L allele of (GT)n repeat polymorphisms of the HO-1 were risk factors for VFL development. Nevertheless, there was a lack of association between VFL and the -1082 A/G IL-10, rs14024 CK-1, and -309 T/G Mdm2 SNPs. The concentrations of the MDM2, BCL11A, and HO-1 proteins were modified, while IL-10 levels were normally expressed in these subjects. In conclusion, most markers evaluated in this review could be potential indicators to develop effective therapies, avoiding a malignant transformation of the lesion.

Association of SNPs in CDKN2A (P14ARF) Tumour Suppressor Gene With Endometrial Cancer in Postmenopausal Women

BACKGROUND/AIM

This research was aimed to evaluate the association between three selected single nucleotide polymorphisms (SNPs) within the CDKN2A (P14ARF) tumour suppressor gene and the incidence of endometrial cancer (EC) in postmenopausal women.

PATIENTS AND METHODS

The study included 194 postmenopausal women; 144 with EC and 50 non-cancer controls. Genotypes in P14ARF rs3088440, rs3731217 and rs3731245 polymorphisms were assayed using PCR-RFLP and confirmed by sequencing.

RESULTS

Regarding the rs3088440 polymorphism, CT, and CT-TT genotypes, were more prevalent among EC patients than in controls (OR=5.55, p=0.023, OR=5.29, p=0.027; and OR=2.92, p=0.023, respectively). The T allele within rs3088440 was more prevalent in EC females than in controls (χ²=4.7, p=0.030). Considering rs3731217, TG and TG-GG genotypes were less prevalent among EC (OR=0.34, p=0.024 or p=0.023; and OR=0.38, p=0.035, respectively).

CONCLUSION

Polymorphisms in the CDKN2A gene are associated with EC in postmenopausal women.

Correlation between MDM2 T309G single nucleotide polymorphism and esophageal cancer susceptibility: An updated meta-analysis

Background

The aim of this study was to investigate the correlation between MDM2 T309G single nucleotide polymorphism (SNP) and esophageal cancer susceptibility through pooling the open published data.

Methods

By systematic searching the databases of Medline, EMBASE, CBM and CNKI, the case‐control or cohort studies related to MDM2 T309G single nucleotide polymorphism and esophageal cancer risk were screened. Genetic phenotype data of T309G single nucleotide was extracted from the original included studies. The correlation between MDM2 T309G single nucleotide polymorphism and esophageal cancer susceptibility was demonstrated by the odds ratio (OR) and its corresponding 95% confidence interval (95% CI). Publication bias was investigated by Egger's line regression test and begg's funnel plot.

Results

After systematic searching of the relevant database, nine publications were finally included in the present study. The combined data demonstrated that the subjects with the G genotype had an increased risk of developing esophageal cancer in dominant (OR = 1.13, 95% CI: 1.00–1.27, P = 0.043), recessive (OR = 1.27, 95% CI: 1.12–1.45, P = 0.000) and homozygous (OR = 1.34, 95% CI:1.04–1.74, P = 0.024) genetic model through random or fixed data pooling method. Both begg's and Egger's line regression test indicated no significant publication bias.

Conclusion

Based on the present data, there was a significant correlation between MDM2 T309G single nucleotide polymorphism and esophageal cancer susceptibility. Individuals with G genotype may have an increased risk of developing esophageal cancer.