Near-infrared fluorescent probe for fast track of cyclooxygenase-2 in Golgi apparatus in cancer cells

Cyclooxygenase-2(COX-2)has been used as an excellent traceable biomarker,and exists maximally in Golgi apparatus(Cancer cells).Celecoxib(CCB)is a selective inhibitor for COX-2,and has been used as one of non-steroidal anti-inflammatory drug.Herein we report the conjugation of nile blue(NB)with CCB via a six-carbon linkage to form a fluorescence probe NB-C6-CCB for the detection of COX-2.NB-C6-CCB displays strong fluorescence with the emission peak centered at near-infrared wavelength(700 nm)in tumor cells or tumor tissues with high expression of COX-2.Importantly,NB-C6-CCB can discriminate cancer cells(MCF-7)fluorescence intensity from normal ones(COS-7)in the co-culture medium under confocal microscope.Subcellular localization of the NBC6-CCB preferentially points to the Golgi apparatus and increases the fluorescent intensity.The competitive analysis(with CCB)and Native-PAGE analysis confirmed that NB-C6-CCB shows selective binding affinity towards COX-2 enzyme.Competitive analysis with CCB(flow cytometry assay)revealed the fluorescence intensity fluctuation due to pretreatment of CCB with different concentrations,indicating that the NB-C6-CCB is a precise or sensitive probe for the COX-2.Tumor tissue(depth:500μm),organs and mice imaging tests show excellent nearinfrared visualization,specific localization and identification of tumors.

Recent advances in fluorescence imaging of alkaline phosphatase

Phosphatase plays a vital important role in many biological functions due to the dephosphorylation serves varied roles in cellular regulation and signaling.Among the family of phosphatase,alkaline phosphatase(ALP)could act as crucial prognostic indicators for many diseases such as bone diseases and cancer.However,the detection of ALP is mainly limited to in vitro colorimetric method in clinic.Therefore,huge efforts have been paid on the fluorescence imaging that provides a reliable method to detect the real-time and in vivo changes of the level of ALP.In this review,we summarize recent advances in fluorescence imaging of phosphatase,mainly focused on ALP.The imaging probes of phosphatase are mainly classified according to their luminescence mechanisms.In the end,we assessed the challenges and future prospects of phosphatase probes.