Active Targeting Molecular Probe Based On LyP-1 Used For The Diagnosis And Treatment Of Triple Negative Breast Cancer

It remains a great challenge to effectively diagnose and treat triple negative breast cancer clinically.Active targeting system based on tumor homing peptide is an effective method to deliver payloads such as imaging agents or drugs into specific diseased tissue and avoid accumulation in non-specific healthy tissue.Therefore,active targeting molecular probe is expected to be an effective diagnostic tool and treatment method for triple negative breast cancer.Due to the fact that p32,the receptor of LyP-1,can be both overexpressed and aberrantly presented at the cell membrane of triple negative breast cancer cell line,LyP-1 can be used as a targeting peptide in this molecular probe and shows the properties of specific targeting,internalization,pro-apoptosis and hypoxia recognition.The construction of active targeting molecular probe can be prepared by directly labeling imaging agents or drug on targeting molecular,or it can be based on nanomedicine.For the latter,as it can delivery targeting molecular,imaging agent and drug,dendrimer has been widely used as a nanocarrier in the establishment of active targeting molecular probe.In addition,study has shown that the dendrimers modified by multi-targeting molecules have stronger binding ability to their receptors than single target molecules.In this study,two kinds of active targeting molecular probes were prepared.One was to directly label ^99mTc on LyP-1 to prepare diagnostic active targeting molecular probe.The other is to use the fifth generation dendrimers as nanocarriers,modified with LyP-1 and labeled with ¹³¹I)to prepare the multi-functional nano system for diagnosis and treatment.The details are as follows:(1)We selected LyP-1 as a targeting peptide and labeled them it with a radionuclide of ^99mTc.For ^99mTc labeling,the N-termini of LyP-1 was modified with a hexahistidine tag and radiolabeled with a[^99mTc(OH₂)₃(CO)₃]+complex to prepare ^99mTc-LyP-1.The yield obtained by this method was high,no additional purification was needed and the stability of the products was satisfactory.In 4T1 tumor bearing mice,^99mTc-LyP-1 exhibited satisfactory SPECT imaging effect.(2)The fifth generation dendrimers were used as nanocarriers,modified with LyP-1 and labeled with ¹³¹I by ch-T method,and obtained the final product of ¹³¹I/LyP-1-dendrimer NPs.The results showed that each dendrimer was labeled with 33.1 LyP-1,The radiochemical purity of ¹³¹I labeled product purified by PD-10 column was more than 99%,and it was stable in vitro.In the in vitro and tumor bearing mice experiment,SPECT imaging showed that ¹³¹I/LyP-1-dendrimer NPs had good imaging effect in4T1 cells and in tumors.(3)We evaluated the anti-tumor and anti-metastasis ability of ¹³¹I/LyP-1-dendrimer NPs in the experiments of in vitro and tumor bearing mice based on 4T1 cell.The results showed that LyP-1 modified on dendrimer could significantly inhibit the growth of 4T1 cells and tumor,and significantly reduce the metastatic ability of 4T1 cell and tumor.In tumor microenvironment,¹³¹I/LyP-1-dendrimer NPs can reduce the expression level of biomarkers associated with proliferation and metastasis,increase the apoptosis,decrease angiogenesis and improve the hypoxia situation.In summary,active targeting molecular probe based on LyP-1 in our study can be used for SPECT imaging,antitumor and antimetastasis therapy.