| Background:Pancreatic cancer is a malignant tumor of digestive tract with fatality rate.Due to its inconspicuous early symptoms and rapid onset,the 5-year survival rate of patients is less than 10%.At present,surgical resection,adjuvant chemotherapy and radiotherapy are mainly used in clinical treatment strategies,but the prognosis is not well.Therefore,it is an urgent need to deeply explore the molecular mechanisms of pancreatic cancer evolution in order to provide new strategies for the diagnosis and treatment of pancreatic cancer.A number of studies have confirmed that abnormal lipid metabolism is one of the top ten signs of malignant tumors.The lipid metabolism factor--hydroxysteroid dehydrogenase-like 2(HSDL2),a member of the steroid dehydrogenase family,can bind to reduced coenzyme II(NADPH)and participate in the synthesis of cholesterol.It has been reported that overexpression of HSDL2,it can promote intracellular cholesterol synthesis,resulting in a significant increase in total cholesterol content intracellular.Studies have also confirmed that HSDL2 plays a role in promoting cancer in the progression of papillary thyroid carcinoma,glioma,and ovarian cancer.However,the role of HSDL2 in pancreatic cancer is still unclear.Objective:To study the expression and clinicopathological significance of HSDL2 in pancreatic cancer.To explore the effect of HSDL2 on the biological function of pancreatic cancer cells,provide theoretical and experimental basis for HSLD2 as a new target for clinical treatment of pancreatic cancer.Materials and methods:1.Analysis of pancreatic cancer tissue samples:1)Immunohistochemical staining was used to detect the expression of HSDL2 in pancreatic cancer tissues and paracancerous tissues.2)The correlation between the expression of HSDL2 and clinicopathological parameters of patients was analyzed by chi-square test.3)Kaplan-Meier survival curve and Cox proportional hazards model were used to analyze the significance of HSDL2 expression in the clinical prognosis evaluation of pancreatic cancer patients.2.Experiments in vitro:1)HSDL2 silence cell lines were constructed using small interfering RNA(siRNA),and their silencing effects were verified by Western blot experiments.2)The effects of HSDL2 cell proliferation were detected by thiazolyl blue(MTT),plate cloning,and 5-ethynyl-2’-deoxyuridine(EdU)nuclide incorporation experiments.3)The biological functions that HSDL2 may be involved were analyzed by STRING database and GEPIA database searches.4)The effects of HSDL2 cell metabolism were detected by lipid relevant kits,BODIPYTM493/503 staining,and Western blot experiments.Results:1.HSDL2 was highly expressed in pancreatic cancer tissues:Immunohistochemical staining showed that HSDL2 was mainly expressed in the cytoplasm,its expression was positive or strongly positive in pancreatic cancer tissues,negative in paracancerous tissues.And the positive expression rate in pancreatic cancer tissues(76.2%)was significantly higher than that in paracancerous tissues(53.7%,P<0.05),the strong positive rate(53.0%)was also higher than in paracancerous tissues(16.7%,P<0.01).Forest map showed that the expression of HSDL2 was significantly correlated with histological grade(P=0.038)and tumor site(P=0.015).2.High expression of HSDL2 was correlated with poor prognosis of pancreatic cancer patients:The Human Protein Atlas(HPA)database analysis showed that the overall survival of pancreatic cancer patients with high expression of HSDL2 was shorter than that of patients with low expression of HSDL2(P<0.05).Univariate and multivariate Cox regression model analysis showed that HSDL2 expression level can be used as an independent risk indicator for evaluating the prognosis of overall survival in pancreatic cancer patients(P<0.05).3.HSDL2 promoted the proliferation of pancreatic cancer cells:MTT,cloning and EdU radionuclide incorporation assay results showed that the cell viability,colony formation ability and DNA replication ability of pancreatic cancer cells in the HSDL2 silencing group were significantly decreased compared with the control group(P<0.05).Western blot assay results showed that silencing HSDL2 could down-regulate the expression levels of cell cycle-related proteins,such as CDK1,cyclin B and cyclin D.4.HSDL2 promoted lipid metabolism of pancreatic cancer cells:The results of lipid metabolism kit showed that silencing HSDL2 could reduce the triglyceride,total cholesterol and phospholipid contents in pancreatic cancer cells.The results of BODIPYTM493/503 staining showed that silencing HSDL2 could reduce the lipid droplet production in pancreatic cancer cells,The results of further Western blot experiments showed that silencing HSDL2 could significantly down-regulate the expression of synthesis-related proteins,such as FASN,ACC1,SREBP1 and ACSL1.Conclusion:High HSLD2 expression predicts poor prognosis in patients with pancreatic cancer.Overexpression of HSDL2 promotes pancreatic cancer progression by regulating the proliferation and lipid metabolism of pancreatic cancer cells. |
PDF Full Text Request