The Construction And Application Of TEM1-Specific Fluorescence Probe And MRI Probe For Ovarian Cancer Diagnosis

ObjectiveOvarian cancer is one of the most mortality female reproductive system cancers,with less clinical symptoms and low diagnosis method.TEM is the new tumor tissue marker found recently.Tumor endothelial marker 1(TEM1)has been demonstrated as a novel marker that is highly expressed on vasculature and stromal cells in many kinds of solid tumors while it is absent or expressed at very low levels in normal tissues.Antibody-target diagnosis or therapy method seems become much more important today.The construction of the TEM1-target diagnosis probe will bring a new method for the ovarian caner diagnosis and therapy.MethodsAnti-TEM1 scFv,screened by the yeast-display method,show high affinity and specifity.Using PCR,a cys was added to the end of the scFv chain.The a linker with two different domain was used for the conjugation of the scFv and fluorescence or magnetic nanoparticles,based on the specific reaction between NHS and amine or MAL and cysteine.The affinity,specifity or internalization ability was measured by cell elisa,FACS or confocal microscopy.At last,the animal tumor model was used to evaluated the specificity of TEM1-targeted ICG probe or MRI probe in vivo.Results1.According to the result,after adding one cysteine at the end of the scFv chain,the affinity for the modified scFv is not been decreased,while is still showing the high affinity,which is almost 3.941 nM.This high affinity is the foundation for the next diagnosis part.2.TEM1-targeted MRI diagnosis probe was established successfully.And the specificity of this probe was also been evaluated by the animal tumor model in vivo.3.TEM1-target ICG fluorescent probe was constructed successfully.The affinity of this probe is 8.901 nM,using cell elisa method.And the specificity and internalization ability of scFv was not changed after adding the fluorescent dye.At last,the affinity and specificity of this fluorescent probe in vivo was measured by the animal testing.ConclusionsAfter modification of the scFv,the specific probe,both fluorescence and MRI probe,were established successfully.And all the results show the high affinity;high specificity and internalization ability of scFv are still been remained even after the antibody was modified by a larger domain,fluorescence dye or magnetic nanoparticle The animal results show the high specificity of these two probes in vivo.These results are the foundations for the clinical application of these probes.