Integrative Multi-Omics Analysis for the Determination of Non-Muscle Invasive vs. Muscle Invasive Bladder Cancer: A Pilot Study

Abstract

Objectives: The molecular landscape of non-muscle-invasive (NMIBC) and muscle-invasive (MIBC) bladder cancer based on molecular characteristics is essential but poorly understood. In this pilot study we aimed to identify a multi-omics signature that can distinguish MIBC from NMIBC. Such a signature can assist in finding potential mechanistic biomarkers and druggable targets. Methods: Patients diagnosed with NMIBC (n = 15) and MIBC (n = 11) were recruited at a tertiary-care hospital in Nanjing from 1 April 2021, and 31 July 2021. Blood, urine and stool samples per participant were collected, in which the serum metabolome, urine metabolome, gut microbiome, and serum extracellular vesicles (EV) proteome were quantified. The differences of the global profiles and individual omics measure between NMIBC vs. MIBC were assessed by permutational multivariate analysis and the Mann–Whitney test, respectively. Logistic regression analysis was used to assess the association of each identified analyte with NMIBC vs. MIBC, and the Spearman correlation was used to investigate the correlations between identified analytes, where both were adjusted for age, sex and smoking status. Results: Among 3168 multi-omics measures that passed the quality control, 159 were identified to be differentiated in NMIBC vs. MIBC. Of these, 46 analytes were associated with bladder cancer progression. In addition, the global profiles showed significantly different urine metabolome (p = 0.029), gut microbiome (p = 0.036), and serum EV (extracellular vesicles) proteome (p = 0.039) but not serum metabolome (p = 0.059). We also observed 17 (35%) analytes that had been developed as drug targets. Multiple interactions were obtained between the identified analytes, whereas for the majority (61%), the number of interactions was at 11–20. Moreover, unconjugated bilirubin (p = 0.009) and white blood cell count (p = 0.006) were also shown to be different in NMIBC and MIBC, and associated with 11 identified omics analytes. Conclusions: The pilot study has shown promising to monitor the progression of bladder cancer by integrating multi-omics data and deserves further investigations.

Unmasking the Metabolite Signature of Bladder Cancer: A Systematic Review

“…However, only one of the metabolites found, pelargonic acid, was present in serum and urine samples, suggesting that these human fluids may contain different molecular information on BCa progression and should be analyzed separately. More importantly, this study again found that of the metabolome profiles found, only the overall urine metabolome profile was significantly different in NMIBC and MIBC, suggesting that urine metabolomics may be a preferred approach for the discovery of potential biomarkers for the study of BCa progression [ 22 ].…”

“…The majority of experimental studies that performed an LC-MS-based analysis included the use of cold organic solvents, such as acetonitrile [ 18 , 22 , 30 , 31 ] or methanol [ 17 , 20 , 23 , 32 ], for deproteinization prior to separation by centrifugation. In addition, metabolite extraction may also include the use of a mixture of solvents, such as acetone and methanol or acetonitrile and methanol [ 22 , 33 , 34 ]. Meanwhile, two studies that performed a GC-MS-based analysis used polydimethylsiloxane/divinylbenzene for the solid-phase microextraction of metabolites [ 35 , 36 ].…”

“…As a result, they found 13 serum and 13 urine metabolites that were significantly different in NMIBC compared to MIBC samples. In addition, the mechanistic mapping performed by this research group revealed that the discovered metabolomic signature is related to immune, metabolic and inflammatory responses [ 22 ]. However, only one of the metabolites found, pelargonic acid, was present in serum and urine samples, suggesting that these human fluids may contain different molecular information on BCa progression and should be analyzed separately.…”

“…Moreover, metabolomic profiling has allowed the identification of potential biomarkers, not only for a better molecular classification but also to improve the understanding of the alterations underlying BCa development [ 17 , 18 , 19 ]. In the pursuit of promising strategies, metabolomic-based approaches applied to the analysis of non-invasively, or minimally invasively, collected body fluids have been demonstrated to be specific and cost-effective tools for the discovery of novel and specific biomarkers for early detection and diagnosis of BCa and high-risk patients, along with improved survival and interpretation of the disease status [ 20 , 21 , 22 , 23 ]. Moreover, efforts have been made to integrate data from metabolomics studies to propose biomarkers for BCa management [ 24 , 25 , 26 , 27 , 28 ].…”

Applications of Exosomes in Diagnosing Muscle Invasive Bladder Cancer

“…Exosomes support metastasis by carrying, transferring oncogenic cargoes, and hindering tumor suppressor exosomes [ 75 ]. Examples of such activity are evident in bladder cancer exosomes activating the ERK1/2 MAP kinase signaling pathway to promote malignancy of low tumor grade bladder cancer cells [ 79 ]. As bladder cancer metastasis continues, the tumor has a higher chance of developing into MIBC.…”