ABSTRACT
There is an explosive interest in the immediate and cost-effective analysis of field-collected biological samples, as many advanced biodetection tools are highly sensitive, yet immobile. On-site biosensors are portable and convenient sensors that provide detection results at the point of care. They are designed to secure precision in highly ionic and heterogeneous solutions with minimal hardware. Among various methods that are capable of such analysis, field-effect biosensors are promising candidates due to their unique sensitivity, manufacturing scalability, and integrability with computational circuitry. Recent developments in nanotechnological surface modification show promising results in sensing from blood, serum, and urine. This report gives a particular emphasis on the on-site efficacy of recently published field-effect biosensors, specifically, detection limits in physiological solutions, response times, and scalability. The survey of the properties and existing detection methods of four promising biotargets, exosomes, bacteria, viruses, and metabolites, aims at providing a roadmap for future field-effect and other on-site biosensors.
Subject(s)
Biosensing Techniques/methods , Bacteria/isolation & purification , Biomarkers/blood , Biomarkers/urine , Biosensing Techniques/instrumentation , Graphite/chemistry , Humans , Microfluidics/methods , Nanostructures/chemistry , Nanotubes, Carbon/chemistry , Point-of-Care Systems , Transistors, Electronic , Viruses/isolation & purificationABSTRACT
We found that non-small-cell lung cancer (NSCLC) cells express high levels of multiple aldehyde dehydrogenase (ALDH) isoforms via an informatics analysis of metabolic enzymes in NSCLC and immunohistochemical staining of NSCLC clinical tumor samples. Using a multiple reaction-monitoring mass spectrometry analysis, we found that multiple ALDH isozymes were generally abundant in NSCLC cells compared with their levels in normal IMR-90 human lung cells. As a result of the catalytic reaction mediated by ALDH, NADH is produced as a by-product from the conversion of aldehyde to carboxylic acid. We hypothesized that the NADH produced by ALDH may be a reliable energy source for ATP production in NSCLC. This study revealed that NADH production by ALDH contributes significantly to ATP production in NSCLC. Furthermore, gossypol, a pan-ALDH inhibitor, markedly reduced the level of ATP. Gossypol combined with phenformin synergistically reduced the ATP levels, which efficiently induced cell death following cell cycle arrest.
Subject(s)
Aldehyde Dehydrogenase/metabolism , Carcinoma, Non-Small-Cell Lung/metabolism , Energy Metabolism , Lung Neoplasms/metabolism , Adenosine Triphosphate/metabolism , Aldehyde Dehydrogenase/analysis , Aldehyde Dehydrogenase/genetics , Carcinoma, Non-Small-Cell Lung/genetics , Carcinoma, Non-Small-Cell Lung/pathology , Cell Line , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Humans , Lung/metabolism , Lung/pathology , Lung Neoplasms/genetics , Lung Neoplasms/pathology , NAD/metabolism , Protein Isoforms/analysis , Protein Isoforms/genetics , Protein Isoforms/metabolismABSTRACT
Among ALDH isoforms, ALDH1L1 in the folate pathway showed highly increased expression in non-small-cell lung cancer cells (NSCLC). Based on the basic mechanism of ALDH converting aldehyde to carboxylic acid with by-product NADH, we suggested that ALDH1L1 may contribute to ATP production using NADH through oxidative phosphorylation. ALDH1L1 knockdown reduced ATP production by up to 60% concomitantly with decrease of NADH in NSCLC. ALDH inhibitor, gossypol, also reduced ATP production in a dose dependent manner together with decrease of NADH level in NSCLC. A combination treatment of gossypol with phenformin, mitochondrial complex I inhibitor, synergized ATP depletion, which efficiently induced cell death. Pre-clinical xenograft model using human NSCLC demonstrated a remarkable therapeutic response to the combined treatment of gossypol and phenformin.