Advanced urothelial bladder cancer (UBC) patients are tagged by a dismal prognosis and high mortality rates, mostly due to their poor response to standard-of-care platinum-based therapy. Mediators of ...chemoresistance are not fully elucidated. This work aimed to study the metabolic profile of advanced UBC, in the context of cisplatin resistance. Three isogenic pairs of parental cell lines (T24, HT1376 and KU1919) and the matching cisplatin-resistant (R) sublines were used. A set of functional assays was used to perform a metabolic screening on the cells. In comparison to the parental sublines, a tendency was observed towards an exacerbated glycolytic metabolism in the cisplatin-resistant T24 and HT1376 cells; this glycolytic phenotype was particularly evident for the HT1376/HT1376R pair, for which the cisplatin resistance ratio was higher. HT1376R cells showed decreased basal respiration and oxygen consumption associated with ATP production; in accordance, the extracellular acidification rate was also higher in the resistant subline. Glycolytic rate assay confirmed that these cells presented higher basal glycolysis, with an increase in proton efflux. While the results of real-time metabolomics seem to substantiate the manifestation of the Warburg phenotype in HT1376R cells, a shift towards distinct metabolic pathways involving lactate uptake, lipid biosynthesis and glutamate metabolism occurred with time. On the other hand, KU1919R cells seem to engage in a metabolic rewiring, recovering their preference for oxidative phosphorylation. In conclusion, cisplatin-resistant UBC cells seem to display deep metabolic alterations surpassing the Warburg effect, which likely depend on the molecular signature of each cell line.
Timely diagnosis is crucial to improve the long-term survival of bladder cancer (BC) patients. The discovery of new BC biomarkers based in urine analysis is very attractive because this biofluid is ...in direct contact with the inner bladder layer, in which most of the neoplasms develop, and is non-invasively collected. Hence, this work aimed to unveil alterations in the urinary volatile profile of patients diagnosed with BC compared with cancer-free individuals, as well as differences among patients diagnosed at different tumor stages, to identify candidate biomarkers for non-invasive BC diagnosis and staging. Urine analysis was performed by headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry (HS-SPME-GC-MS). The results unveiled that BC patients have a distinct urinary volatile profile characterized by higher levels of several alkanes and aromatic compounds, and lower levels of aldehydes, ketones and monoterpenes. Seventeen significantly altered volatiles were used to evaluate the performance for overall BC detection, disclosing 70% sensitivity, 89% specificity and 80% accuracy. Moreover, distinct urinary volatile profiles were found among patients diagnosed at different tumor stages (Ta/Tis, T1 and ≥T2). This work identified distinct urinary volatile signatures of BC patients with potential for non-invasive detection and staging of bladder cancer.
Bladder cancer (BC) represents a significant global health concern, for which early detection is essential to improve patient outcomes. This review evaluates the potential of the urinary volatile ...organic compounds (VOCs) as biomarkers for detecting and staging BC. The methods used include gas chromatography-mass spectrometry (GC-MS)-based metabolomics and electronic-nose (e-nose) sensors. The GC-MS studies that have been published reveal diverse results in terms of diagnostic performance. The sensitivities range from 27 % to an impressive 97 %, while specificities vary between 43 % and 94 %. Furthermore, the accuracies reported in these studies range from 80 to 89 %. In the urine of BC patients, a total of 80 VOCs were discovered to be significantly altered when compared to controls. These VOCs encompassed a variety of chemical classes such as alcohols, aldehydes, alkanes, aromatic compounds, fatty acids, ketones, and terpenoids, among others. Conversely, e-nose-based studies displayed sensitivities from 60 to 100 %, specificities from 53 to 96 %, and accuracies from 65 to 97 %. Interestingly, conductive polymer-based sensors performed better, followed by metal oxide semiconductor and optical sensors. GC-MS studies have shown improved performance in detecting early stages and low-grade tumors, providing valuable insights into staging. Based on these findings, VOC-based diagnostic tools hold great promise for early BC detection and staging. Further studies are needed to validate biomarkers and their classification performance. In the future, advancements in VOC profiling technologies may significantly contribute to improving the overall survival and quality of life for BC patients.
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•Early detection of bladder cancer is essential to improve patient outcomes.•Urinary volatile metabolites show promise for bladder cancer detection and staging.•Gas chromatography‒mass spectrometry (GC-MS) and electronic nose approaches have been used for volatile fingerprinting.•GC-MS provide high accuracy for detecting early stages and low-grade tumors.•Electronic nose sensors offer fast, low-cost and accurate detection of bladder cancer.
Introduction: Cancer represents one of the biggest causes of death worldwide, being bladder cancer (BCa) the 10thmost common cancer worldwide, with higher incidence and mortality rates specially in ...men. While many diagnostic tests are available and currently practiced today, such as urine cytology, cystoscopy, and imaging tests, some of those methods are invasive, expensive and present low sensitivity to detect cancer in its early stages. Considering these struggles, metabolomic analysis based on the detection of volatile organic compounds (VOCs) has been presented as an important approach in many investigation studies of new diagnostic methods about cancer in the last years.Aim:The aims of this work were to investigate the potential of VOCs, in general, and volatile carbonyl compounds (VCCs) for BCa detection in urine by headspace solid-phase microextraction/gas chromatography-mass spectrometry (HS-SPME/GC-MS).Methods:A total of 120 patients were included in this study, 60 BCa patients, being 17 women and 43 men; and 60 cancer-free individuals (controls). The extraction of VOCs and VCCs from urine samples of BCa and cancer-free individuals was performed by HSSPME. Statistical analysis included both multivariate, like principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA) and univariate tests. Area under the curve (AUC), sensitivity, specificity and accuracy were calculated through receiver operating characteristics (ROC).Results:The volatile profile of urine (VOCs and VCCs) was able to discriminate BCa patients from controls. Statistically significant alterations were observed in the levels of 30 metabolites, demonstrating an AUC of 0.924, 85% sensitivity, 82% specificity and 83% accuracy for BCa detection. The main classes of the discriminant compounds were aldehydes, alkanes, ketones and aromatic hydrocarbons. Considering the discrimination of different BCa stages, namely stages II, III and IV compared with stage 0a, statistically significant alterations were also identified, demonstrating an AUC of 0.830, 50% sensitivity, 82% specificity and 80% accuracy.Discussion/Conclusions:This work was able to demonstrate the important role of metabolomic analysis for the detection of BCa in urine samples. Some of the identified compounds were also found on previous works presented on the literature which proves that a panel of biomarkers for BCa detection can be established in the future as a diagnostic tool. Several challenges still exist regarding the clarification of metabolic pathways associated with the release of volatile compounds in cancer patients and controls. More studies using urine samples of BCa and controls are necessary to elucidate VOCs metabolism as well as its potential applicability in portable medical devices. In that way, it will be possible to ensure an earlier diagnosis, with a more adapted treatment and less costs.
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