A non-invasive genomic diagnostic method for bladder cancer using size-based filtration and microchip electrophoresis.

Bladder cancer (BC) cells spontaneously exfoliated in the urine of patients with BC. Detection of exfoliated tumor cells has clinical significance in cancer therapy because it would enable earlier non-invasive screening, diagnosis, or prognosis of BC. In this research, a method for analyzing genetic abnormalities of BC cells collected from urine samples was developed. Target BC cells were isolated by filtration. To find conditions that achieve high cell recovery, we investigated the effects of filter type, concentration of fixative, and flow rate. Cells captured on the filter membrane were completely retrieved within 15s. Selected genes for genomic analysis, mutated genes (FGFR3, TERT and HRAS) and methylated genes (ALX4, RALL3, MT1A, and RUNX3) were amplified by polymerase chain reaction (PCR), and subsequently, were identified by microchip electrophoresis (MCE). Analysis by MCE reduces the risk of contamination, sample consumption, and analysis time. Our developed approach is economical, effectively isolates cancer cells, and permits flexible molecular characterization, all of which make this approach a promising method for non-invasive BC detection.