A novel tetrapeptide fluorescence sensor for early diagnosis of prostate cancer based on imaging Zn2+ in healthy versus cancerous cells

Zinc as a biomarker can be used to diagnose the early stage prostate cancer, while ZIP1 protein, a zinc transporter is significantly down-regulated in prostate cancer cells. This behavior leads to the apparent alteration of the enrichment ability for zinc between early prostate cancer tissues and healthy tissues. This difference inspires us to develop a novel Zn2+ sensor that applies to the clinic diagnosis of early prostate cancer. We designed a tetrapeptide sensor H2L (Dansyl-Gly-Pro-Trp-Gly-NH2) according to the photo-induced electron transfer principle (PET), and it performed adequately in Zn2+ imaging of prostate cell lines. Based on the assessment of Zn2+ enrichment ability, there was distinctly lower Zn2+ concentrate in prostate cancer cell lines than healthy prostate epithelial cells. Furthermore, H2L displayed high sensitivity with a detection limit as low as 49.5 nM, and high specificity for Zn2+ detection. Also the low toxicity and the superior cell permeability of H2L made the imaging of Zn2+ ions detection safe and rapid. We expect that H2L to be a powerful tool for early diagnosis of prostate cancer and a good indicator for the precise resection of cancer tissue during surgery.