1.Correlation between ARID5B Gene SNP and MTX Resistance in Children with ALL.
Li-Fen ZHANG ; Yu MA ; Lian LI ; Wen-E LIU ; Xiao-Chun ZHANG
Journal of Experimental Hematology 2023;31(2):333-337
		                        		
		                        			OBJECTIVE:
		                        			To investigate the correlation between single-nucleotide polymorphism (SNP) of ARID5B gene and resistance to methotrexate (MTX) in children with acute lymphoblastic leukemia (ALL).
		                        		
		                        			METHODS:
		                        			A total of 144 children with ALL who were treated in General Hospital of Ningxia Medical University from January 2015 to November 2021 were enrolled and divided into MTX resistant group and non-MTX resistant group, with 72 cases in each group. Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) technology was used to measure the SNP of ARID5B gene in all children and analyze its correlation with MTX resistant.
		                        		
		                        			RESULTS:
		                        			There were no significant differences in the genotype and gene frequency of rs7923074, rs10821936, rs6479778, and rs2893881 between MTX resistant group and non-MTX resistant group (P>0.05). The frequency of C/C genotype in the MTX resistant group was significantly higher than that in the non-MTX resistant group, while the frequency of T/T genotype was opposite (P<0.05). The frequency of C allele in the MTX resistant group was significantly higher than that in the non-MTX resistant group, while the frequency of T allele was opposite (P<0.05). Multivariate logistic regression analysis showed that ARID5B gene rs4948488 TT genotype and T allele frequency were risk factors for MTX resistant in ALL children (P<0.05).
		                        		
		                        			CONCLUSION
		                        			The SNP of ARID5B gene is associated with MTX resistant in ALL children.
		                        		
		                        		
		                        		
		                        			Child
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			DNA-Binding Proteins/genetics*
		                        			;
		                        		
		                        			Gene Frequency
		                        			;
		                        		
		                        			Genotype
		                        			;
		                        		
		                        			Methotrexate
		                        			;
		                        		
		                        			Polymorphism, Single Nucleotide
		                        			;
		                        		
		                        			Precursor Cell Lymphoblastic Leukemia-Lymphoma/genetics*
		                        			;
		                        		
		                        			Transcription Factors/genetics*
		                        			;
		                        		
		                        			Drug Resistance, Neoplasm
		                        			
		                        		
		                        	
2.Research Advance of BCR-ABL Mutation and the Efficacy of Second and Third Generation TKI in Chronic Myeloid Leukemia--Review.
Journal of Experimental Hematology 2023;31(2):585-588
		                        		
		                        			
		                        			The treatment of chronic myeloid leukemia (CML) was revolutionized with the advent of the first-generation tyrosine kinase inhibitors (TKIs), but drug resistance developed during treatment, leading to the development of the second-generation (dasatinib, nilotinib, and bosutinib) and third-generation (ponatinib) TKI. Compared with previous treatment regimens, specific TKI can significantly improve the response rate, overall survival rate and prognosis of CML. Only a few patients with BCR-ABL mutation are insensitive to the second-generation TKIs, so it is suggested to select the second-generation TKIs for patients with specific mutations. For patients with other mutations and without mutations, the second-generation TKI should be selected according to the patient's medical history, while the third-generation TKIs should be selected for mutations that are insensitive to the second-generation TKIs, such as T315I mutation that is sensitive to ponatinib. Due to different BCR-ABL mutations in patients with different sensitivity to the second and third-generation TKIs, this paper will review the latest research progress of the efficacy of the second and third-generation TKIs in CML patients with BCR-ABL mutations.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Antineoplastic Agents/pharmacology*
		                        			;
		                        		
		                        			Dasatinib/pharmacology*
		                        			;
		                        		
		                        			Drug Resistance, Neoplasm/genetics*
		                        			;
		                        		
		                        			Fusion Proteins, bcr-abl/genetics*
		                        			;
		                        		
		                        			Leukemia, Myelogenous, Chronic, BCR-ABL Positive/drug therapy*
		                        			;
		                        		
		                        			Mutation
		                        			;
		                        		
		                        			Protein Kinase Inhibitors/therapeutic use*
		                        			
		                        		
		                        	
3.Progress and challenges in RET-targeted cancer therapy.
Xueqing HU ; Ujjwol KHATRI ; Tao SHEN ; Jie WU
Frontiers of Medicine 2023;17(2):207-219
		                        		
		                        			
		                        			The rearranged during transfection (RET) is a receptor protein tyrosine kinase. Oncogenic RET fusions or mutations are found most often in non-small cell lung cancer (NSCLC) and in thyroid cancer, but also increasingly in various types of cancers at low rates. In the last few years, two potent and selective RET protein tyrosine kinase inhibitors (TKIs), pralsetinib (BLU-667) and selpercatinib (LOXO-292, LY3527723) were developed and received regulatory approval. Although pralsetinib and selpercatinib gave high overall response rates (ORRs), < 10% of patients achieved a complete response (CR). The RET TKI-tolerated residual tumors inevitably develop resistance by secondary target mutations, acquired alternative oncogenes, or MET amplification. RET G810 mutations located at the kinase solvent front site were identified as the major on-target mechanism of acquired resistance to both selpercatinib and pralsetinib. Several next-generation of RET TKIs capable of inhibiting the selpercatinib/pralsetinib-resistant RET mutants have progressed to clinical trials. However, it is likely that new TKI-adapted RET mutations will emerge to cause resistance to these next-generation of RET TKIs. Solving the problem requires a better understanding of the multiple mechanisms that support the RET TKI-tolerated persisters to identify a converging point of vulnerability to devise an effective co-treatment to eliminate the residual tumors.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Carcinoma, Non-Small-Cell Lung/genetics*
		                        			;
		                        		
		                        			Neoplasm, Residual
		                        			;
		                        		
		                        			Lung Neoplasms/genetics*
		                        			;
		                        		
		                        			Mutation
		                        			;
		                        		
		                        			Protein Kinase Inhibitors/therapeutic use*
		                        			;
		                        		
		                        			Proto-Oncogene Proteins c-ret/genetics*
		                        			
		                        		
		                        	
4.Thoracic SMARCA4-deficient undifferentiated tumor-pathological diagnosis and combined immune checkpoint inhibitor treatment.
Yan XIONG ; Bo ZHANG ; Li Gong NIE ; Shi Kai WU ; Hu ZHAO ; Dong LI ; Ji Ting DI
Journal of Peking University(Health Sciences) 2023;55(2):351-356
		                        		
		                        			
		                        			We explored clinicopathological features and treatment strategies for thoracic SMARCA4-deficient undifferentiated tumor (SMARCA4-UT). Thoracic SMARCA4-UT is a new entity recently acknowledged in the 2021 edition of World Health Organization Classification of Thoracic Tumors, and doctors are relatively unfamiliar with its diagnosis, treatment, and prognosis. Taking a case of SMARCA4-UT treated in Peking University First Hospital as an example, this multi-disciplinary discussion covered several hot issues on diagnosing and treating thoracic SMARCA4-UT, including histological features, immu- nohistochemical and molecular phenotype, immune checkpoint inhibitor (ICI) therapy, and pathological assessment of neoadjuvant therapy response. The patient was an older man with a long history of smoking and was admitted due to a rapidly progressing solid tumor in the lower lobe of the right lung. Histologically, tumor cells were epithelioid, undifferentiated, diffusely positive for CD34, and partially positive for SALL4.The expression of BRG1 protein encoded by SMARCA4 gene was lost in all of tumor cells, and next-generation sequencing(NGS)confirmed SMARCA4 gene mutation (c.2196T>G, p.Y732Ter). The pathological diagnosis reached as thoracic SMARCA4-UT, and the preoperative TNM stage was T1N2M0 (ⅢA). Tumor proportion score (TPS) detected by immunohistochemistry of programmed cell death 1-ligand 1 (PD-L1, clone SP263) was 2%. Tumor mutation burden (TMB) detected by NGS of 1 021 genes was 16. 3/Mb. Microsatellite detection showed the tumor was microsatellite stable (MSS). Neo-adjuvant therapy was implemented with the combined regimen of chemotherapy and ICI. Right lower lobectomy was performed through thoracoscopy after the two weeks' neoadjuvant. The pathologic assessment of lung tumor specimens after neoadjuvant therapy revealed a complete pathological response (CPR). The post-neoadjuvant tumor TNM stage was ypT0N0M0. Then, five cycles of adjuvant therapy were completed. Until October 2022, neither tumor recurrence nor metastasis was detected, and minimal residual disease (MRD) detection was negative. At present, it is believed that if BRG1 immunohistochemical staining is negative, regardless of whether SMARCA4 gene mutation is detected, it should be classified as SMARCA4-deficient tumors. SMARCA4-deficient tumors include a variety of carcinomas and sarcomas. The essential criteria for diagnosing SMARCA4-UT includes loss of BRG1 expression, speci-fic histological morphology, and exclude other common thoracic malignant tumors with SMARCA4-deficiency, such as squamous cell carcinoma, adenocarcinoma and large cell carcinoma. SMARCA4-UT is a very aggressive malignant tumor with a poor prognosis. It has almost no targeted therapy mutations, and little response to chemotherapy, but ICI is currently the only effective drug. The successful diagnosis and treatment for this case of SMARCA4-UT should enlighten significance for various kinds of SMARCA4-deficient tumors.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Immune Checkpoint Inhibitors
		                        			;
		                        		
		                        			Neoplasm Recurrence, Local
		                        			;
		                        		
		                        			Lung Neoplasms/genetics*
		                        			;
		                        		
		                        			Thoracic Neoplasms/pathology*
		                        			;
		                        		
		                        			Adenocarcinoma
		                        			;
		                        		
		                        			DNA Helicases
		                        			;
		                        		
		                        			Nuclear Proteins
		                        			;
		                        		
		                        			Transcription Factors
		                        			
		                        		
		                        	
5.Application of the WHO Classification of Thoracic Tumors (2021) grading system in invasive pulmonary adenocarcinoma and its correlation with the targeted genes' variations.
Li Kun HOU ; Li Ping ZHANG ; Yan HUANG ; Zheng Wei DONG ; Hui Kang XIE ; Wei ZHANG ; Wei WU ; Chun Yan WU
Chinese Journal of Pathology 2023;52(2):129-135
		                        		
		                        			
		                        			Objective: To investigate the applicability of the 2021 WHO classification of thoracic tumors' new grading system for invasive pulmonary adenocarcinoma (IPA) with different clinical stages and its correlation with the characteristics of targeted genes' variation. Methods: A total of 2 467 patients with surgically resected primary IPA in Shanghai Pulmonary Hospital, Shanghai, China from September to December 2020 were retrospectively analyzed. Eligible cases were graded using the new grading system of IPA of the 2021 WHO classification of thoracic tumors. The clinicopathological data and targeted-gene abnormality were collected. The utility of new grading system of IPA in different clinical stages was investigated. The correlation of clinicopathological features and targeted-gene abnormality in different grades of IPA were compared. Results: All 2 311 cases of IPA were included. There were 2 046 cases of stage Ⅰ IPA (88.5%), 169 cases of stage Ⅱ (7.3%), and 96 cases of stage Ⅲ (4.2%). According to the new classification system of IPA, 186 cases (9.1%), 1 413 cases (69.1%) and 447 cases (21.8%) of stage-Ⅰ adenocarcinoma were classified as Grade 1, Grade 2 and Grade 3, respectively. However, there were no Grade 1 adenocarcinomas in stages Ⅱ and Ⅲ cases. Among stage-Ⅱ and Ⅲ IPA cases, there were 38 Grade 2 cases (22.5%) and 131 Grade 3 cases (77.5%), and 3 Grade 2 cases (3.1%) and 93 Grade 3 cases (96.9%), respectively. In stage-Ⅰ cases, no tumor cells spreading through airspace (STAS), vascular invasion or pleural invasion was found in Grade 1 of IPA, while the positive rates of STAS in Grade 2 and 3 IPA cases were 11.3% (159/1 413) and 73.2% (327/447), respectively. There was a significant difference among the three grades (P<0.01). Similarly, the rates of vascular and pleural invasion in Grade 3 IPA cases were 21.3% (95/447) and 75.8% (339/447), respectively, which were significantly higher than those of 1.3% (19/1 413) and 3.0% (42/1 413) in Grade 2 (P<0.01). EGFR mutational rates in Grades 1, 2 and 3 IPA were 65.7% (94/143), 76.4% (984/1 288) and 51.3% (216/421), respectively. The differences among the three grades were statistically significant (P<0.01). No fusion genes were detected in Grade 1 IPA, while the positive rates of ROS1 and ALK fusion genes in Grade 3 were 2.4% (10/421) and 8.3% (35/421), respectively, which were significantly higher than that of 0.5% (7/1 288) and 1.6% (20/1 288) in Grade 2 (P<0.01). In stage-Ⅱ cases, only EGFR mutation rate in Grade 2 adenocarcinoma (31/37, 83.8%) was higher than that in Grade 3 adenocarcinoma (71/123, 57.7%; P<0.01). However, the correlation between the new grade system of IPA and the distribution characteristics of targeted-gene variation cannot be evaluated in stage Ⅲ cases. Conclusions: The new grading system for IPA is mainly applicable to clinical stage-Ⅰ patients. Tumor grades of IPA are strongly correlated with the high-risk factors of prognosis and the distribution features of therapeutic targets. It is of great significance and clinical value to manage postoperative patients with early-stage IPA.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Lung Neoplasms/pathology*
		                        			;
		                        		
		                        			Protein-Tyrosine Kinases/genetics*
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Proto-Oncogene Proteins/genetics*
		                        			;
		                        		
		                        			China
		                        			;
		                        		
		                        			Adenocarcinoma of Lung/pathology*
		                        			;
		                        		
		                        			Adenocarcinoma/pathology*
		                        			;
		                        		
		                        			Prognosis
		                        			;
		                        		
		                        			ErbB Receptors/genetics*
		                        			;
		                        		
		                        			World Health Organization
		                        			;
		                        		
		                        			Neoplasm Staging
		                        			
		                        		
		                        	
6.Liver transplantation for the treatment of acute liver failure in 3 cases with NBAS gene deficiency and literature review.
Zhong Die LI ; Yu Chuan LI ; Cong Huan SHEN ; Jian She WANG ; Xin Bao XIE
Chinese Journal of Pediatrics 2023;61(1):66-69
		                        		
		                        			
		                        			Objective: To investigate the clinical efficacy of liver transplantation in the treatment of acute liver in children with NBAS gene deficiency disease and their outcome. Methods: This retrospective study enrolled children with NBAS gene deficiency who were admitted to the Children's Hospital of Fudan University for liver transplantation from January 2013 to June 2022. The clinical data were collected and analyzed. Medical literature published before June 2022 was searched with the keywords of "NBAS" "neuroblastoma amplified sequence recurrent" "acute liver failure" "SOPH syndrome" "short stature with optic nerve atrophy" "Pelger-Huët anomaly" in PubMed, China National Knowledge Infrastructure and Wanfang database. Results: Liver transplantation was performed in 3 patients (2 males and 1 female) with NBAS deficiency. All patients presented with fever-triggered recurrent acute liver failure. The genetic detection found compound heterozygous NBAS gene pathogenic variants in them. The total episodes of acute liver failure before liver transplantation were 11, 2, and 4 respectively, and the age at liver transplantation was 3.5, 2.3, and 2.0 years respectively. During liver transplantation, patient 1 was in the convalescent phase of acute liver failure, patient 2 was in the acute phase, presenting with hepatic encephalopathy (grade V) and respiratory failure, and patient 3 was considered to be in the acute phase. After liver transplantation, patient 1 recovered normal liver function within 1 month and had no liver transplantation-related complications. Patient 2 had secondary epilepsy, intellectual disability, movement disorder, and transiently elevated transaminases. Patient 3 died of severe infection within 1 month. There was no literature in Chinese, 6 in English, 8 NBAS-deficient patients who were treated with liver transplantation. Total 11 patients presented with fever-triggered recurrent acute liver failure. Their age at liver transplantation ranged from 0.9 to 5.0 years. Postoperative complications occurred in 3 patients. Until the last visit, they were followed up for 0.7 to 14.0 years. Total 2 patients died and the 9 surviving patients did not develop acute liver failure. Conclusions: Liver transplantation is effective for the treatment of acute liver failure associated with NBAS gene disease. However, postoperative complications of liver transplantation may occur. The timing of liver transplantation still needs further research.
		                        		
		                        		
		                        		
		                        			Child
		                        			;
		                        		
		                        			Male
		                        			;
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Female
		                        			;
		                        		
		                        			Infant
		                        			;
		                        		
		                        			Child, Preschool
		                        			;
		                        		
		                        			Retrospective Studies
		                        			;
		                        		
		                        			Neoplasm Proteins/genetics*
		                        			;
		                        		
		                        			Optic Atrophy/genetics*
		                        			;
		                        		
		                        			Pelger-Huet Anomaly/genetics*
		                        			;
		                        		
		                        			Liver Failure, Acute/complications*
		                        			
		                        		
		                        	
7.Correlation between the mRNA levels of BCRP and LUNX genes and pathological types and stages of patients with non-small cell lung cancer.
Dong CHEN ; Wenjie HAN ; Pei WANG ; Hongbin MA
Chinese Journal of Medical Genetics 2023;40(2):202-207
		                        		
		                        			OBJECTIVE:
		                        			To analyze the correlation between the mRNA levels of breast cancer resistance protein (BCRP) and lung-specific X protein (LUNX) genes with pathological types and stages of patients with non-small cell lung cancer (NSCLC) and their significance for prognosis.
		                        		
		                        			METHODS:
		                        			Eighty nine patients with NSCLC admitted to Huaihe Hospital of Henan University between June 2015 and June 2018 were recruited, with 55 patients with benign lung lesions admitted during the same period of time selected as the control group. The mRNA levels of BCRP and LUNX genes were detected in the peripheral blood samples from the two groups, and their correlation with the clinicopathological characteristics and prognosis of the patients was analyzed.
		                        		
		                        			RESULTS:
		                        			The expression rates of BCRP and LUNX mRNA in the NSCLC group were significantly higher compared with the control group (P < 0.05). The level of BCRP mRNA of the NSCLC patients has correlated with the degree of differentiation and TNM staging (P < 0.05), but not with gender, age, smoking, pathological types and lymph node metastasis (P > 0.05). The level of LUNX mRNA of them has correlated with the degree of differentiation, TNM staging and lymph node metastasis (P < 0.05), but not with gender, age, smoking, and pathological types (P > 0.05). Compared with those with no expression, the overall survival rate of patients with BCRP and LUNX expression was significantly lower (P < 0.05). The degree of differentiation, TNM staging, lymph node metastasis, and expression of the BCRP and LUNX mRNA may all affect the prognosis of the patients.
		                        		
		                        			CONCLUSION
		                        			The levels of BCRP and LUNX mRNA in the peripheral blood of patients with NSCLC are significantly increased. The expression of BCRP mRNA is correlated with the degree of differentiation and TNM staging, whilst the expression of LUNX mRNA is correlated with the differentiation degree, TNM staging and lymph node metastasis. Both may be used as independent predictors for the prognosis of patients with NSCLC.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			ATP Binding Cassette Transporter, Subfamily G, Member 2/genetics*
		                        			;
		                        		
		                        			Biomarkers, Tumor/genetics*
		                        			;
		                        		
		                        			Carcinoma, Non-Small-Cell Lung/pathology*
		                        			;
		                        		
		                        			Glycoproteins/genetics*
		                        			;
		                        		
		                        			Lung Neoplasms/pathology*
		                        			;
		                        		
		                        			Lymphatic Metastasis
		                        			;
		                        		
		                        			Neoplasm Proteins/genetics*
		                        			;
		                        		
		                        			Phosphoproteins/genetics*
		                        			;
		                        		
		                        			Prognosis
		                        			;
		                        		
		                        			RNA, Messenger/genetics*
		                        			
		                        		
		                        	
8.Effect of Inhibiting SIX1 Expression on Drug-resistance of Acute Myeloid Leukemia Cell Line HL-60/ADR Cells.
Li-Yuan LI ; Zi-Yuan NIE ; Xiao-Yan ZHANG ; Jian-Min LUO ; Lin YANG ; Qian WANG
Journal of Experimental Hematology 2023;31(4):1038-1043
		                        		
		                        			OBJECTIVE:
		                        			To establish HL-60 cells and adriamycin resistant HL-60 cells (H-60/ADR) in which the expression of homologous box gene 1 (SIX1) was inhibited, and investigate the effect of inhibiting the expression of SIX1 on the drug resistance.
		                        		
		                        			METHODS:
		                        			Lentivirus was used to transfect HL-60 and HL-60/ADR cells, and the cell lines stably inhibiting the expression of SIX1 were screened by puromycin. CCK-8 assay was used to detect the proliferation ability of cells in each group, apoptosis kit was used to detect the cell apoptosis, and real-time quantitative PCR was used to detect the expression level of drug-resistant related genes.
		                        		
		                        			RESULTS:
		                        			HL-60 and HL-60/ADR stably transfected cell lines with down-regulation of SIX1 expression were successfully constructed. Compared with control group, the inhibition of SIX1 expression significantly inhibited the proliferation of HL-60 and HL-60/ADR cells (P <0.05), increased the apoptosis rate (P <0.05), and the sensitivity of cells to adriamycin increased after inhibition of SIX1 expression.
		                        		
		                        			CONCLUSION
		                        			Inhibition of SIX1 expression can improve cell sensitivity to adriamycin, and its role in reversing drug resistance may be related to the promotion of apoptosis gene expression.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			HL-60 Cells
		                        			;
		                        		
		                        			Drug Resistance, Neoplasm/genetics*
		                        			;
		                        		
		                        			Leukemia, Myeloid, Acute
		                        			;
		                        		
		                        			Doxorubicin/pharmacology*
		                        			;
		                        		
		                        			Apoptosis
		                        			;
		                        		
		                        			Cell Proliferation
		                        			;
		                        		
		                        			Homeodomain Proteins/genetics*
		                        			
		                        		
		                        	
9.Recent Advance of Newly Therapy for Chronic Myeloid Leukemia with BCR-ABLT315I Mutation--Review.
Hu-Rong LAI ; Qian-Miao WU ; Ya-Zhi YANG ; Jian LI
Journal of Experimental Hematology 2023;31(5):1579-1583
		                        		
		                        			
		                        			BCR-ABLT315I mutation is the main mechanism of resistance to the first and second generation tyrosine kinase inhibitor (TKI) for patients with chronic myeloid leukemia (CML). Ponatinib as the third generation TKI has been found that can significantly improve the prognosis of CML patients with T315I mutation. However, the latest report has discovered that the T315I compound mutant is even resistant to ponatinib, which aroused the enthusiasm of research on the mechanism of CML resistance and targeted therapy once again. Previous studies have shown that TKI combined with other targeted drugs is effective to CML patients with drug resistance or relapse due to T315I mutation. The latest research has found that the allosteric inhibitor asciminib combined with TKI therapy is equally effective to CML patients with T315I compound mutant, but the specific mechanism is not yet clarified. This review will focus on the latest research progress of therapy for CML with BCR-ABLT315I mutation, hoping to provide reference for researching new drugs and improve therapy for treating CML with T315I mutation.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Drug Resistance, Neoplasm/genetics*
		                        			;
		                        		
		                        			Leukemia, Myelogenous, Chronic, BCR-ABL Positive/genetics*
		                        			;
		                        		
		                        			Fusion Proteins, bcr-abl/genetics*
		                        			;
		                        		
		                        			Protein Kinase Inhibitors/therapeutic use*
		                        			;
		                        		
		                        			Mutation
		                        			;
		                        		
		                        			Antineoplastic Agents/pharmacology*
		                        			
		                        		
		                        	
10.Tyro3 and CDK9 as biomarkers for drug resistance to breast cancer anti-PD-1 therapies.
Chinese Journal of Oncology 2023;45(8):651-656
		                        		
		                        			
		                        			Objective: PD-1/PD-L1 immune checkpoint treatment is effective for some triple-negative breast cancer populations with PD-L1 expression, but the response rate is still not satisfactory. This study aims to explore the mechanism of drug resistance to breast cancer anti-PD-1 therapies and the strategies for overcoming the resistance to PD-1therapies. Methods: By constructing a human triple-negative breast cancer drug-resistant cell line called BT-549R5 and a mouse breast cancer drug-resistant cell line called 4T1R3, and applying the whole-gene shRNA library screening, candidate drug resistance-associated molecules were obtained and verified by cytological experiments. The expression of Tyro3, Axl and MerTK of the TAM family in the 4T1R3 group was tested using the Western blot method. The down-regulation of CDK9 on the effect of T cells killing the BT-549R5 cells was observed through T cell killing tests, while the down-regulation of Tyro3 and CDK9 on the effect of anti-PD-1 therapies for transplanted breast tumors was observed in mouse tumor formation experiments. Results: The cell lines and animal models of breast cancer resistant to PD-1 treatment were successfully constructed. Tyro3, Axl and MerTK were highly expressed in 4T1R3 cells. Whole genome sequencing showed that Tyro3 and CDK9 were highly expressed in BT-549R5 cells. T cell killing experiment showed that the survival rate of BT-549R5 cells in the CDK9 down-regulated group and the control group decreased gradually with the increase of T cells, but the survival rate of BT-549R5 cells in the CDK9 down-regulated group decreased rapidly. Tumor formation experiment in mice showed that under anti-PD-1 treatment, the transplanted tumor in the 4T1R3 cell group grew rapidly compared with the 4T1 cell group (P<0.05), and the tumor volume of the 4T1R3 group was larger than that of the 4T1 group on Day 20. Nevertheless, the tumor growth rates in the CDK9-knockdown 4T1R3 cell group and the Tyro3-knockdown 4T1R3 cell group were similar to that of the 4T1 cell group, and the tumor volumes at day 20 were signiference lower than that of 4T1R3 cell group(P<0.05). Conclusions: Tyro3 and CDK9 are associated with the drug resistance to anti-PD-1 therapies for breast cancer. Inhibiting the expression of Tyro3 and CDK9 can reverse the drug resistance to breast cancer treatment.
		                        		
		                        		
		                        		
		                        			Humans
		                        			;
		                        		
		                        			Animals
		                        			;
		                        		
		                        			Mice
		                        			;
		                        		
		                        			c-Mer Tyrosine Kinase/metabolism*
		                        			;
		                        		
		                        			Receptor Protein-Tyrosine Kinases/genetics*
		                        			;
		                        		
		                        			Axl Receptor Tyrosine Kinase
		                        			;
		                        		
		                        			Proto-Oncogene Proteins/metabolism*
		                        			;
		                        		
		                        			B7-H1 Antigen/genetics*
		                        			;
		                        		
		                        			Triple Negative Breast Neoplasms/genetics*
		                        			;
		                        		
		                        			Drug Resistance, Neoplasm
		                        			;
		                        		
		                        			Biomarkers
		                        			;
		                        		
		                        			Cell Line, Tumor
		                        			;
		                        		
		                        			Cyclin-Dependent Kinase 9
		                        			
		                        		
		                        	
            
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