The purpose of this systematic review was to map out and summarize scientific evidence on dysregulated microRNAs (miRNAs) that can be possible biomarkers or therapeutic targets for cisplatin nephrotoxicity and have already been tested in humans, animals, or cells. In addition, an in silico analysis of the two miRNAs found to be dysregulated in the majority of studies was performed. A literature search was performed using eight databases for studies published up to 4 July 2021. Two independent reviewers selected the studies and extracted the data; disagreements were resolved by a third and fourth reviewers. A total of 1002 records were identified, of which 30 met the eligibility criteria. All studies were published in English and reported between 2010 and 2021. The main findings were as follows: (a) miR-34a and miR-21 were the main miRNAs identified by the studies as possible biomarkers and therapeutic targets of cisplatin nephrotoxicity; (b) the in silico analysis revealed 124 and 131 different strongly validated targets for miR-34a and miR-21, respectively; and (c) studies in humans remain scarce.

Cisplatin is associated with dose-limiting nephrotoxicity, and the timely detection of acute kidney injury (AKI) can affect morbimortality. Therefore, this study aimed to investigate the tools for monitoring renal function in AKI. This was a retrospective, cohort study. Cisplatin-treated patients with head and neck cancer were included. Nephrotoxicity was assessed using serum creatinine, estimated creatinine clearance, serum electrolytic alterations, and plasma kidney injury molecule-1 (KIM-1). The toxicity severity was classified according to Common Terminology Criteria for Adverse Events (CTCAE), and AKI was classified by Risk, Injury, Failure, Loss, and End-stage kidney disease (RIFLE) and Acute Kidney Injury Network (AKIN). A total of 81 participants were included, of whom only 32 did not have AKI. Almost 90% of participants had a decreased estimated glomerular filtration rate five (D5) days after chemotherapy. The AKI estimate differs between AKIN and RIFLE; more participants were diagnosed by the RIFLE at D5, 19.5% versus 2.4% by AKIN, and fifteen had a discordance between these classifications. All laboratory markers showed significant changes on D5. KIM-1 appeared a possible biomarker when considering CTCAE or AKIN classifications (p < 0.05 on D5), but not when RIFLE classification was used (p = 0.0780). Further studies may seek to understand the profiles of different biomarkers together.

The microRNA (miRNA) expression profile by qRT-PCR depends directly on the most appropriate normalization strategy adopted; however, currently there is no universally adequate reference gene. Therefore, this study aimed to determine, considering RNA-Seq results, the most adequate endogenous normalizer for use in the relative quantification of urine miRNAs from head and neck cancer patients, treated with cisplatin chemoradiotherapy. The massive sequencing was performed to identify the miRNAs differentially expressed between the group with cisplatin nephrotoxicity (n = 6) and the one without (n = 6). The candidate endogen normalizer was chosen according to four criteria: (1) the miRNA must be expressed in most samples; (2) the miRNA must have a fold change value between 0.99 and 1.01; (3) the miRNA must have a p-value ≥ 0.98; and (4) the miRNA must not be commented on by the final GeneGlobe (Qiagen, Hilden, Germany) analysis. Four miRNAs met all the criteria (hsa-miR-363-5p, hsa-miR-875-5p, hsa-miR-4302, and hsa-miR-6749-5p) and were selected for validation by qRT-PCR in a cohort of 49 patients (including the 12 sequencing participants). Only hsa-miR-875-5p was shown to be an adequate normalizer for the experimental condition under investigation, as it exhibited invariant expression between the two groups.

Background: Recent studies have associated the presence of the CYP2C:TG haplotype with increased metabolism of CYP2C19 substrates such as escitalopram and sertraline, suggesting a potential regulatory interaction between CYP2C18 and CYP2C19. However, this association has not been demonstrated for other CYP2C19 substrates. Objective: This study aims to elucidate the role of the CYP2C:TG haplotype in modulating CYP2C19 activity using the omeprazole metabolic ratio (MR) within a cocktail drug approach, to characterize its distribution and prevalence among Native Mexican populations, and to evaluate its potential impact on CYP2C19 metabolic phenotypes. Materials and Methods: A total of 256 volunteers from various ethnic native groups from Mexico were genotyped for CYP2C19 (*2, *3, *4, *5, *17) and the CYP2C haplotype (rs2860840 and rs11188059). The MR of omeprazole to 5-hydroxyomeprazole was analyzed to determine individual CYP2C19 metabolic phenotypes and assess metabolic capacity. Results: The CYP2C:TG haplotype was the most prevalent (42.77%), followed by CYP2C:CG (35.74%) and CYP2C:TA (21.48%). The CYP2C:TG haplotype was consistently associated with the CYP2C19*1 allele. Significant differences in logMR values were observed between individuals with and without the TG haplotype (p = 0.02). A trend toward increased metabolic activity associated with CYP2C:TG was observed across most CYP2C19 metabolizer groups, except for rapid metabolizers. No significant association was found between molecular ancestry and the presence or functionality of the haplotype. Conclusions: The CYP2C:TG haplotype appears to be associated with increased CYP2C19 activity, warranting further functional validation before clinical implementation.