The Role And Mechanism Of DNAH10 Mutation In Primary Chemotherapy Resistance Of Small Cell Lung Cancer

Small cell lung cancer(SCLC)is an aggressive malignancy that accounts for 14%of all lung cancer diagnoses.Smoking is an important cause of DNA damage and is the leading cause of SCLC(>95%of patients).Previous studies have shown that the loss of biallelic function of RB1 and TP53 changes in almost all SCLC tumors,but the abundance and heterogeneity of mutations of unknown significance raises serious concerns for obtaining mechanistic studies on the pathophysiology of SCLC Challenge.Despite decades of active research,treatment options for SCLC remain limited.In the past few years,platinum-based chemotherapy has become the standard first-line treatment for patients with small cell lung cancer(SCLC).Most patients respond well to early chemotherapy,but are prone to drug resistance,and some patients develop chemotherapy resistance during the initial treatment stage.However,the mechanism of cisplatin resistance development in SCLC is not clear.Therefore,solving the chemotherapy resistance of small cell lung cancer has become a key issue to be addressed in the treatment of SCLC.In this study,the first part uses database information to analyze a full exon sequencing(WES)dataset from a cancer drug-sensitive genomics small cell lung cancer cell line(GDSC,N=55)and published studies of Cohort(N=101)WES data and overall survival(OS)to find cisplatin resistance target genes and genes associated with poor prognosis.The results showed that DNAH10 mutations in SCLC were significantly associated with primary cisplatin resistance(P=0.0350),poor OS(HR:3.445;P=0.00035),and poor progression-free survival(PFS)(P=0.0142).A single sample gene set enrichment analysis(ssGSEA)was then applied to explore the potential signaling pathway for cisplatin resistance.ssGSEA showed that DNAH10 mutation was negatively correlated with SPRY regulation of FGFR and FGF,positively correlated with non-classical WNT and AKT/IKK signaling pathways,and positively correlated with tumor mutation load(TMB).In the second part,three small cell lung cancer cell lines(DNAH10 mutant cells H2066 and wild-type cells H69 and H446)were selected.Through RT-PCR,Western blot,and CCK8 functional experiments,it was found that compared with DNAH10 wild-type cells,DANH10 mRNA levels and protein expression levels in DANH10 mutant cells were significantly increased.Further,through drug sensitivity experiments,IC50 values of mutant cells H2066 were significantly higher than those of other DANH10 wild-type cells(H69,H446).After knocking down the expression of DANH10 in H2066 cells,it was found that the IC50 value of H2066 knocking down DNAH10 was reduced.In the third part,the clinical tissue samples of 47 patients with small cell lung cancer were collected.DNAH10 protein was expressed in the cytoplasm of tumor cells by immunohistochemistry.Compared with patients without DNAH10 mutations,the expression was higher in the tumor tissues of patients with mutations;According to the clinical data of 47 patients,the survival of patients with mutations was lower than that of non-mutated patients,and the results were statistically significant.In summary,DNAH10 mutations may have potential value in predicting primary chemotherapy resistance and poor survival in small cell lung cancer.