Study On The Role And Mechanism Of LCK As A Biomarker In Melanoma

Objective: The tumor microenvironment refers to the environment in which tumor cells live,including tumor cells,immune cells and other components and structures.Tumor microenvironment is complex and constantly evolving.This research aims to study the mechanism of immunotherapy in melanoma about LCK(Lymphocyte specific protein tyrosine kinase)within the tumor microenvironment.To explore whether LCK has antitumor effect in melanoma,whether LCK can specificly regulate immune infiltration,and whether LCK can be used as a prognostic biomarker for remodeling tumor microenvironment by using bioinformatics analysis and laboratory techniques in order to provide a theoretical basis for whether LCK is a therapeutic target for melanoma.Methods: In this study,melanoma single-cell and transcriptomic sequencing data sets were integrated and a series of correlation analyses were performed using bioinformatics techniques in conjunction with molecular experiments to better validate the specific mechanism of action of LCK as a biomarker in melanoma.First,genes related to immune escape were screened,then prognostic factors were analyzed by prognostic analysis,and a risk prognostic model was constructed to verify whether LCK was a favorable factor.We evaluated the relationship between LCK and tumor immune microenvironment by EPIC,TIMER,quan Tiseq,MCPcounter and other algorithms.We used single-cell sequencing,protein interaction analysis,and Estimate algorithms to investigate the association between LCK and immune infiltration.We used single-cell sequencing and Cell Chat analysis to reveal the mechanism of LCK involving in immune regulation of melanoma.Finally,we preliminatively verified the expression of LCK in melanoma by RT-q PCR.Results:(1)LCK may be a key independent prognostic factor for melanoma and a favorable prognostic factor.(2)LCK may prolong the overall survival of melanoma patients.We found that the higher the risk factor,the higher the mortality rate.In the survival curve of the constructed risk-prognosis model,lowrisk scores suggest that high survival has a longer overall survival.(3)LCK can affect the remodeling of tumor microenvironment.The heat map suggested that LCK had a higher level of immune infiltration.Analysis of the relationship between LCK expression level and clinical parameters suggested that LCK expression level was significantly down-regulated with the clinical progress of melanoma.Meanwhile,RT-q PCR results suggested that LCK expression was significantly increased in melanoma cell lines(A2058,SKMEL28)compared with human normal skin cells(PIG1 cell line).(4)In melanoma,LCK is significantly correlated with immune infiltration and predicts immunotherapy response.The correlation analysis between LCK expression level and immune checkpoint showed that LCK expression level was significantly positively correlated with immunity.(5)LCK promotes anti-tumor immune response by binding to CD8 receptors and is associated with lower Ic50 of anti-tumor drugs.Conclusion:(1)LCK can be used as a favorable prognostic factor to prolong overall survival.(2)LCK can affect the remodeling of tumor microenvironment.(3)LCK is a potential biomarker for melanoma and may contribute to its immunotherapy.