Quantitative Loop-Mediated Isothermal Amplification (qLAMP) for the Rapid Discrimination of Normal and Cancerous Tissue Models: An Arduino-Based Portable Cancer Detection System Assisted by a pH Microelectrode

Cancer, the second leading cause of death worldwide, is a significant global challenge, and widespread, accessible, and early diagnostics are recognized as the most cost-effective strategies for reducing cancer burdens. Point-of-care (POC) systems offer an attractive alternative by enabling rapid and cost-effective diagnoses. We introduce a novel POC strategy for cancer biomarker identification based on monitoring the isothermal amplification of relevant cancer markers using a portable Arduino-based loop-mediated isothermal amplification (LAMP) system. The trajectory of the LAMP reaction during the first 3 min of the reaction is used as an indicator of the rate of amplification (defined as the mP3 value). We obtained sets of mP3 values that showed statistically significant differences in the genetic expression of four genes (ESR 1, PGR, Her2, and Ki67) within and between tissue spheroids derived from the MCF7, MDA-MB-231, Du145, and BJ fibroblast cell lines. We then used principal component analysis and clustering techniques to demonstrate that the mP3 value sets derived from the expression of the four selected genes are sufficient to distinguish tissue spheroids derived from four different commercial cell lines. Further qPCR and immunostaining assays confirmed the quantitative LAMP (qLAMP) experimental trends. The immunostaining results were consistent with previous literature reports and with our qLAMP and qPCR results. We present a proof-of-concept demonstration of the use of a LAMP-based POC platform for the identification or discrimination of cancer tissues. Our strategy can be extended to other diseases associated with altered gene expression in body tissues or fluids.