Mechanical Biomarkers and LHRH/EphA2-Molecular Biomarkers: A Theragnostic Approach for Triple Negative Breast Cancer Diagnosis/Treatment

Abstract

The adhesive interactions between molecular recognition units (such as specific peptides and antibodies) and antigens or other receptors on the surfaces of tumours are of great value in the design of targeted nanoparticles and drugs for the detection and treatment of specific cancers. In addition, the heterogeneous nature of cancer and difficult challenges in early detection has activated a high interest in the development of mechanical biomarkers for cancer diagnosis. This current study presented Luteinizing Hormone Releasing Hormone (LHRH) and Epherin type A2 (EphA2) as a promising biomarker to design a targeted therapy for diagnosis and treatment. Furthermore, the work provides insights through atomic force microscope (AFM) and Nanoindentation (NI) on the application of adhesion forces, adhesion energy, viscosity and statistical deconvolution as diagnostic tools to detect TNBC as well as to characterize it into different histological grades. To appraise these discoveries, TNBC tissue samples of different histological grades were selected (non-neoplastic or Grade 0) and (neoplastic of Grade I to Grade III). To evaluate the receptor overexpression, and their distributions on the human breast tissue extracts, using Immunohistochemistry (IHC) technique, as well as the actin cytoskeletal structures of non tumorigenic and tumorigenic breast tissues (grade I to grade III), a combination of immunofluorescence and confocal microscopy, and atomic force microscopy was used. The adhesion forces between LHRH or EphA2 and human TNBC breast tissues are measured using force microscopy techniques that account for the potential effects of capillary forces due to the presence of water vapor. A combination of nanoindentation and statistical techniques is then used to measure the deformations/viscoelastic properties of non-tumorigenic and human TNBC of different histological grades. The investigation of the underlying magnitude of antigen – antibody interactions corresponding to adhesion energy are also determined using adhesion contact theories/models. A Standard Fluid Model/Anti-Zener Model II is also used to characterize the viscoelastic properties of the non-tumorigenic and tumorigenic TNBC tissues of different grades. The results show that the pull off forces and adhesion energies associated with higher grades of TNBC are shown to be greater than those associated with normal/non-tumorigenic human breast tissues, which were studied as controls. The observed increase in adhesion forces and adhesion energies are also correlated with the increasing incidence of LHRH/EphA2 receptors at higher grades of TNBC. Moreover, the decrease in the viscoelastic properties as well as the actin cytoskeletal structural density observed to be connected to the TNBC tissue histological higher grade are lower than those of non-neoplastic breast tissues. The implications of the results are discussed for the development of targeted nanostructures for the detection and treatment of TNBC, also the potential application of nanoindentation and statistical deconvolution techniques to the development of mechanical biomarkers for TNBC detection /cancer diagnosis.