Study On The Mechanical Properties Of Prostate Cancer And Its Molecular Mechanism By Atomic Force Microscopy

Prostate carcinoma(PCa)is a common malignant tumor in men,and has become the second most common cancer threatening men’s physical and psychological health,with its incidence rate second only to lung cancer.Due to the aging population,PCa affects the quality of life and life expectancy of men over 50 years of age in China,seriously threatening the physical and mental health of the male population in China,and has become an important public health issue in China.Research studies have shown that if prostate tumors are located in the prostate gland at the time of diagnosis and there are no distant metastases,90% of patients have a survival rate of more than 10 years.However,most high-risk PCa patients have poor prognosis or even clinical treatment failure due to the occurrence of distant metastases.On the other hand,prostate-specific antigen screening is not able to directly differentiate between limited and metastatic PCa.the current situation exacerbates the urgent need for accurate screening indicators for PCa in China,therefore,there is an urgent need to find molecular markers specific for PCa in order to provide new quantitative reference indicators for clinical diagnosis.Atomic force microscopy(AFM)is an advanced medical optical imaging technology that can identify and analyze the intrinsic biochemical components of biological samples at the level of cells and tissues.Because of its high spatial resolution and force-sensing sensitivity,it has been rapidly developed in the field of life sciences and has become one of the frontier topics in biomedical research at home and abroad.At present,although there are many studies based on cellular AFM imaging,there is no systematic study on the changes of nanomechanical characteristics involved in the whole process of prostate tumor occurrence and development,and there is no study on the application of these mechanical characteristics changes for PCa prognosis and histological grading prediction,therefore,we propose "Atomic Force Microscopy Based Imaging Technology for Prostate Cancer Therefore,we propose "Study on the mechanical properties of prostate cancer and its molecular mechanism by atomic force microscopy",which has a certain research foundation,but also has a deeper and more innovative basis,and has important clinical application value.Nanomechanical characterization of prostate tumor malignancy and metastatic ability was achieved using AFM.We first optimized the mechanical properties of the prostate cells,including the print pressure and scan rate,in order to obtain stable and valid experimental results.Based on these parameters,a series of mechanical characterization studies on the malignancy and metastatic ability of prostate tumors were conducted.The results showed that the cell elasticity and viscosity tended to decrease as PCa cancer progressed,i.e.,the more metastatic the cells were,the less stiff they were and the more mobile the cytoplasm was.In addition,the adhesion between cells and substrate and the work done by adhesion also decreased with the progression of PCa carcinoma,indicating that cells with stronger metastatic ability were more likely to break free from the extracellular substrate and metastasize to other places.Further,studying the changes in mechanical properties of prostate tumor tissues with different malignant progression and analyzing them with Gaussian mixture modeling algorithm,we found that the cell elasticity and viscosity also tended to decrease with the progression of prostate tumor malignancy,and the stiffness of the Extracellular Matrix(ECM)decreased,the results affirmed that prostate tumor malignancy at the tissue level The results confirm that the higher the malignancy of prostate tumors,the greater the risk of invasion and metastasis,i.e.,the cells are less flexible,more mobile,and the reduced ECM deposition is more convenient for cancer metastasis.The results of the study provide a more convenient and objective method to assist in the early clinical diagnosis and tumor grading of prostate tumors.The regulatory process of cellular basal stiffness on the migration of prostate tumor cells was quantitatively analyzed.We used transcriptome sequencing to screen the differentially expressed genes associated with PCa malignant progression,and enrichment analysis to obtain the ECM,a key influencing factor in the process of PCa progression from medium to high risk.The effect of substrate hardness on PCa migration was investigated by combining AFM technique and confocal microscopic imaging to quantify the relationship between substrate hardness and PCa cell migration.The results showed that PC-3 cells on hard substrates enhanced their migration ability by protruding filamentous pseudopods,aggregating actin into bundles and reducing viscosity values.Moreover,the results of Blebbistatin action further suggested that the response of PCa cells to different extracellular environments might be caused by the difference of F-actin cytoskeleton to change the mechanical properties of the cells themselves.This study provides a new perspective on the migration mechanism of PCa cells,and provides an important reference to further unravel the molecular mechanism of the peripheral environment of tumor cells on tumorigenesis and development,and the F-actin cytoskeleton-mediated migration of PCa cells also helps in the screening and development of cancer therapeutic drugs.For the first time,C11orf52 was proposed to play a role as a potential tumor suppressor in regulating PCa survival progression.Differentially expressed genes between intermediate and high-risk PCa tissues were first targeted to assess their relationship with survival prognosis,and the C11orf52 gene was screened as a positive prognostic factor for PCa survival by combining information from clinical samples of PCa patients in the TCGA database.Then,the low expression of C11orf52 was jointly revealed from tissue level and cellular level to be involved in the malignant progression of PCa tumors.The plasmid transfection method was successfully constructed to construct a stable PCa cell line with C11orf52 overexpression,and the specific effect of C11orf52 on PCa malignant progression was explored on this basis.The results revealed that it prevented cancer cell proliferation by suppressing cells in mitotic active phase,and inhibited PCa cell migration and invasion by altering epithelial mesenchymal transition.Further,AFM mechanics measurements revealed that C11orf52 significantly reduced the deformability(elasticity enhancement)of the cells,enhanced the roughness of the plasma membrane surface of PCa cells and the adhesion between the cells and the extracellular substrate,thereby reducing the metastatic ability by anchoring them more firmly in their initial position.The results provide the first explanation of the changes in cellular physical properties and the changes in plasma membrane surface microstructure of C11orf52 inhibition of PCa metastasis from a cellular mechanics perspective,and provide biophysical indicators of C11orf52 inhibition of cell metastasis.These results may stimulate a deeper understanding of PCa metastasis and provide a powerful strategy for improving the clinical treatment of prostate tumors.