Identification of distinct genomic features reveals frequent somatic AHNAK and PTEN mutations predominantly in primary malignant melanoma presenting in the ureter

Abstract

Background Primary malignant melanoma of the ureter is extremely rare. Genetic variants to the increased risk of developing the disease have not yet been investigated. Methods Tumour mutation profiling for primary malignant melanoma of the ureter was performed by whole-exome sequencing. Immunohistochemistry was performed to verify histopathological features and the variants of predisposing genes and driver mutation genes. Furthermore, we conducted a literature review and Surveillance, Epidemiology and End Result-based study by searching public databases. Results We identified 38 somatic single nucleotide variants and 9 somatic insertions and deletions (INDELs) in tumour specimens. After filtering with the Cancer Gene Census database, seven predisposing genes and two driver mutation genes were identified. Moreover, the immunohistochemical profile showed that tumour cells were positive for Melan-A, melanoma gp100 human melanoma black 45 (HMB45), S100 beta and P53. The expression levels of two driver mutation genes (phosphatase and tensin homolog (PTEN) and desmoyokin (AHNAK) and five predisposing genes (AT-rich interaction domain 1B (ARID1B), catalase, eukaryotic translation initiation factor 4 gamma 3 (EIF4G3), ANK3 and collagen type I) were significantly downregulated in tumour tissues compared to paracancerous tissues. In the literature review and Surveillance, Epidemiology and End Results-based study, patients with primary malignant melanoma of the urinary tract had worse clinical outcomes than patients with primary urothelial carcinoma after 1:2 propensity score matching (P = 0.010). Additionally, Cox multivariate analysis for patients with primary malignant melanoma of the urinary tract indicated that distant metastasis (hazard ratio = 1.185; P = 0.044) was an independent predictor for overall survival, and tumour focality (hazard ratio = 0.602; P = 0.017) and non-surgery (hazard ratio = 0.434; P = 0.003) were independent factors for tumour progression. Conclusions Our study is the first to provide evidence that the distinct phenotypes of primary malignant melanoma of the ureter may be due to different genetic variations. The prognosis of primary malignant melanoma of the urinary tract was poorer than that of primary urothelial carcinoma of the urinary tract.

A comprehensive analysis of the prognostic and immunological role of ANK3 in pan-cancer

“…The overall mutation rate was 7%, and the mutation types were deep deletions and diploidy. According to the literature, alterations in ANK3 and type I collagen may increase the risk of developing ureteral primary malignant melanoma ( 25 ). The ectopic expression of ANK3 significantly increased E-calcineurin expression and restricted the progression of papillary thyroid carcinoma (PTC), which suggests that ANK3 has an anti-cancer action in PTC development, and serves as the inert maintainer of PTC ( 26 ).…”

AHNAKs roles in physiology and malignant tumors

“…Huang et al. reported that AHNAK expression was downregulated in primary malignant melanoma PMM in ureteral tissue compared to paracancerous ureteral tissue ( 59 ). Another study noted that AHNAK expression was significantly downregulated in melanoma and correlated with poor prognosis, and that knockdown of AHNAK in primary melanocytes resulted in reduced expression of E-calcineurin ( 60 ).…”

Intra-Abdominal Malignant Melanoma: Challenging Aspects of Epidemiology, Clinical and Paraclinical Diagnosis and Optimal Treatment—A Literature Review

“…Ureter-originating malignant melanoma is considered to be extremely uncommon [ 77 ]. Genetic variants associated with the increased disease risk have not yet been investigated.…”