Application Of Upconversion Optogenetics In The Integration Of Tumor Diagnosis And Treatment

Optogenetics combines optical technology with genetic engineering technology to achieve precise regulation of the physiological functions of cells,tissues and organs by expressing photosensitive proteins in specific cells or tissues and activating them with corresponding wavelengths of light.Optogenetics has shown superior potential for precise regulation in areas such as neuroscience,gene therapy and cancer treatment,but the excitation wavelengths of most photosensitive proteins are located in the UV-visible region,which makes optogenetics have some limitations:(i)irradiation with high-energy UV-visible light may lead to DNA damage and cell death;(ii)biological tissues such as fur,skin,tissues and food of study subjects have significant autofluorescence resulting in low signal-to-noise ratio;(iii)the penetration depth of UV-visible light in biological tissues is low.The lanthanide-doped upconversion nanoprobes as an emerging class of luminescent bioprobes can convert near-infrared light to UV-visible light by successive absorption of multiple photons or energy transfer,and this special upconversion luminescence makes upconversion nanoprobes have some unique optical properties,such as long luminescence lifetime,narrow emission band,low cytotoxicity,high tissue penetration,and large anti-Stokes shift.This paper focuses on research related to the integration of tumor diagnosis and treatment using upconversion nanoprobes and optogenetic technologies,as follows.The specific research work is as follows:1.Construct si RNA-encapsulated upconversion nanoprobes based on optogenetics to achieve photodynamic therapy and cascade gene therapy for tumors.Combining two or more cancer treatment modalities together to form a multifunctional tumor treatment integrated system is gaining attention.Based on this,this paper constructs a tumor treatment system of near-infrared light-controlled photodynamic therapy and cascade reactive oxygen response gene therapy.We constructed plasmids capable of specifically expressing biophotosensitizers,while small interfering RNA(si RNA)was modified onto the surface of upconversion nanoprobes through reactive oxygen-sensitive bonds.Under nearinfrared light,upconversion nanoprobes convert near-infrared light to ultraviolet-visible light to activate biophotosensitizers,and the reactive oxygen species generated further stimulates reactive oxygen-sensitive bonds to release si RNA for cascade gene therapy,and photodynamic therapy and cascade gene therapy act synergistically to promote apoptosis of cancer cells.2.Construction of ubiquitin-mediated photocontrolled protein degradation system based on optogenetics.Protein degradation techniques,as one of the most direct and effective methods to interfere with protein function,can effectively affect molecular processes and cellular activity.However,the activity of the commonly used small molecule degraders is difficult to control with high spatial and temporal accuracy,resulting in the protein degradation process cannot be precisely regulated.Therefore,we constructed a ubiquitin-mediated precision protein degradation system based on optogenetics,using the photoinduced dimer CRY2-CIB1 protein as the lightcontrolled switch of the protein degradation system.Under the stimulation of blue light,the CRY2 protein undergoes structural heterogeneity and rapidly binds to the CIB1 protein,which becomes an intermediate linking ubiquitin and target protein,ubiquitinating the target protein and then using the intracellular ubiquitin-proteasome system to degrade the target protein precisely and effectively.