Molecular Characterization of Microrna Interference and Aristolochic Acid Intoxication Found in Upper Tract Urothelial Carcinoma in Patients with Balkan Endemic Nephropathy: A Systematic Review of the Current Literature

The term “aristolochic acid nephropathy” (AAN) is used to include any form of toxic interstitial nephropathy that is caused either by ingestion of plants containing aristolochic acids (AA) or by the environmental contaminants in food such as in Balkan endemic nephropathy (BEN). Aristolochic acid (AA) intoxication is strongly associated with the development of upper tract urothelial carcinoma (UTUC); however, the underlying molecular mechanism remains to be defined. MicroRNAs (miRNA) regulate several biological processes, including cell proliferation, differentiation, and metabolism, acting as oncogenes or tumor suppressors. A unique miRNA expression profile suggested that miRNAs could function as regulators in UTUC developmental processes. This review aimed to summarize data available in the literature about underlying molecular mechanisms leading to the expression of miRNAs in AA-UTUC patients with BEN. Strong correlation in AA-UTUC has a distinctive gene alteration pattern, AL-DNA adducts, and a unique tumor protein (TP53) mutational spectrum AAG to TAG (A: T→T: A) transversion in codon 139 (Lys → Stop) of exon 5 activates the p53 tumor suppressor protein. Further, p53 protein is responsible not only for the expression of miRNAs but also acts as a target molecule for miRNAs and plays a crucial function in the AA-UTUC pathogenicity through activation of cyclin-dependent kinase (CyclinD1) and cyclin protein kinase 6(CDK6) to support cell cycle arrest. This study, proposed a molecular mechanism that represented a possible unique relationship between AA intoxication, miRNAs expression, and the progression of UTUC in patients with BEN.