Urothelial carcinoma of the graft kidney with molecular analyses: a rare case report

Background

Malignancy after transplantation is a leading cause of death among kidney transplant recipients. However, donor-derived malignancies are rare. We report a case of a high grade papillary urothelial carcinoma arising in a transplanted kidney.

Case presentation

A 62-year-old female who received a kidney transplantation more than 30 years ago presented with urinary tract infection, acute renal failure, and hydronephrosis of the transplant kidney. Anterograde nephrostogram showed a large filling defect in the lower pole of the transplant kidney and in the proximal 3–4 cm of the ureter. A biopsy from the renal pelvic mass showed a high grade urothelial carcinoma. She underwent an anterior exenteration, resection of both transplant and native kidneys and bilateral pelvic lymph node dissection. Pathologic examination showed a high grade papillary urothelial carcinoma which appeared to arise in the pelvis of the graft kidney, involve the graft ureter and native urinary bladder. The tumor had metastasized to one left obturator lymph node but spared the two native kidneys and ureters. Short tandem repeat (STR) analysis confirmed the tumor to be of donor origin. Next-generation sequencing identified amplification of TERT and loss of CDKN2A/CDKN2B in the primary tumor.

Conclusion

While it is known that transplant recipients have an increased risk of urothelial carcinoma compared to the general population, the lack of the well-documented risk factors, such as older age at transplantation, BK polyomavirus infection, and prolonged post-transplantation history and dissemination of the tumor in this case shed light on the de novo tumorigenesis of the graft kidney within the host microenvironment. Amplification of Telomerase reverse transcriptase (TERT) and loss of cyclin dependent kinase inhibitor 2A/2B (CDKN2A/CDKN2B) detected in the tumor by next gene sequencing suggests that they may play an important role in this case.

Association of CDKN2A/CDKN2B with inflammatory bowel disease in Koreans

BACKGROUND AND AIM

CDKN2A/CDKN2B locus on 9p21 is reported to be associated with various diseases, including cancer and cardiovascular and inflammatory diseases. Significant downregulation of CDKN2B-AS1 in inflamed colon tissue of inflammatory bowel disease (IBD) cases was reported in Europeans. This study aimed to confirm the suggestive association of CDKN2A/CDKN2B with IBD identified in our recent genome-wide association study (GWAS).

METHODS

We examined the association of CDKN2A/CDKN2B locus with IBD in an additional sample of 574 IBD cases and 542 controls, totaling 4068 cases and 8074 controls. In silico study was performed at various levels for functional annotation of the causal variant. Co-localization of the GWAS association signals and the corresponding expression quantitative trait loci in IBD-related tissues was evaluated using eCAVIAR.

RESULTS

An expanded GWAS showed genome-wide significant association of rs3731257 at 9p21 with IBD (odds ratio = 1.17, 95% confidence interval = 1.12-1.22, P_combined  = 5.68 × 10^-9 ) and Crohn's disease (odds ratio = 1.22, 95% confidence interval = 1.15-1.28, P_combined  = 8.85 × 10^-9 ) in the Korean population. Co-localization study suggested that both CDKN2B-AS1 and CDKN2A might be functionally associated with the locus in the small intestine.

CONCLUSIONS

rs3731257 in CDKN2A/CDKN2B is an IBD-susceptible locus in Koreans, with a suggestive role for small intestine-specific gene regulation. Our findings suggested that alterations of the CDKN2A/CDKN2B locus could affect the pathophysiology of IBD.

APOL1, CDKN2A/CDKN2B, and HDAC9 polymorphisms and small vessel ischemic stroke

OBJECTIVE

Worldwide, the highest frequencies of APOL1-associated kidney variants are found in indigenous West Africans among whom small vessel disease (SVD) ischemic stroke is the most common stroke phenotype. The objective of this study was to investigate the association and effect sizes of 23 selected SNPs in 14 genes of relevance, including the APOL1 G1 variants, with the occurrence of SVD ischemic stroke among indigenous West African participants in the Stroke Investigative Research and Education Network (SIREN) Study.

MATERIALS AND METHODS

Cases were consecutively recruited consenting adults (aged 18 years or older) with neuroimaging-confirmed first clinical stroke. Stroke-free controls were ascertained using a locally validated version of the Questionnaire for Verifying Stroke-Free Status (QVSFS). Logistic regression models adjusting for known vascular risk factors were fitted to assess the associations of the 23 SNPs in rigorously phenotyped cases (N = 154) of SVD ischemic stroke and stroke-free (N = 483) controls.

RESULTS

Apolipoprotein L1 (APOL1) rs73885319 (OR = 1.52; CI: 1.09-2.13, P-value = .013), rs2383207 in CDKN2A/CDKN2B (OR = 3.08; CI: 1.15-8.26, P -value = .026) and rs2107595 (OR = 1.70; CI: 1.12-2.60, P-value = .014) and rs28688791 (OR = 1.52; CI: 1.03-2.26, P-value = .036) in HDAC9 gene were associated with SVD stroke at 0.05 significance level. Polymorphisms in other genes did not show significant associations.

CONCLUSION

This is the first report of a specific association of APOL1 with a stroke subtype. Further research is needed to confirm these initial findings and deepen understanding of the genetics of stroke in people of African ancestry with possible implications for other ancestries as all humans originated from Africa.

Effect of CDKN2A/B rs4977756 polymorphism on glioma risk: a meta-analysis of 16 studies including 24077 participants

So far, epidemiological studies have been performed to investigate the association of CDKN2A/B rs4977756 polymorphism and glioma risk. However, the results from different studies remain inconsistent. To clarify these conflicts and to quantitatively evaluate the effect of rs4977756 polymorphism on glioma risk, a meta-analysis was conducted using relevant published clinical studies about rs4977756 polymorphisms and glioma risk. Relevant studies concerning the association between rs4977756 polymorphism and risk of glioma were included in this meta-analysis. Odds ratio (OR) and 95 % confidence interval (CI) were calculated under fixed or random effects models when appropriate. Subgroup analyses were performed by race. This meta-analysis included 13 studies with a total of 8129 cases and 15,858 controls. The pooled results showed that there was an obvious association of CDKN2A/B rs4977756 polymorphism with risk of glioma in all four comparison models (dominant model/AG + GG vs. AA: OR = 1.36, 95 %CI = 1.20-1.54, p < 0.01; heterozygote comparison/AG vs. AA: OR = 1.31, 95 %CI = 1.12-1.53, p < 0.01; homozygote comparison/GG versus AA: OR = 1.49, 95 %CI = 1.36-1.64, p < 0.01; additive model/G vs. A: OR = 1.23, 95 %CI = 1.18-1.28, p < 0.01, respectively). For the subgroup analyses of ethnicities, similar results were observed in Caucasians. However, the association was not found between rs4977756 polymorphism and the risk of glioma in all models for the Asian studies. The CDKN2A/B rs4977756 polymorphism is obvious increase the risk of glioma in Caucasians. Future studies are needed to confirm the results in other ethnic populations.