1.Detection of multi-pathway genes and analysis of gene mutations in breast cancer
Pengfei LIU ; Zhongling ZHUO ; Chang LIU ; Yanli CHEN ; Ziyao YANG ; Xiaotao ZHAO
Chinese Journal of Laboratory Medicine 2021;44(5):394-401
Objective:To investigate the germline mutation status in multi-pathway in Chinese female breast cancer patients and explore their correlation with clinicopathological characteristics. Aim to enrich the database of breast cancer germline gene mutations in Chinese population and provide laboratory evidence for the application of breast cancer targeted drugs.Methods:From January 2017 to July 2019, whole blood samples were collected from 148 women (age of onset concentrated in the 24~80 years old) diagnosed pathologically with breast cancer in the Department of breast surgery, Peking University People′s Hospital. Germline mutations in HR, MMR, BER, and KDR pathway related genes were detected by next-generation sequencing. The pathogenicity interpretation was performed, and pathogenic, likely pathogenic, and mutations of uncertain significance were screened. The clinicopathological characteristics including age at the onset, luminal typing, tumor size, metastasis, and family history were analyzed, and the correlation between mutations in different pathway genes and clinicopathological characteristics was analyzed by the Chi-squared test and Fisher′s exact probability test.Results:Among the 148 patients, there were 69 cases of HR mutations (including three types of mutations, including pathogenic, likely pathogenic and uncertain significance), 16 cases of MMR mutations, 6 cases of BER mutations and 8 cases of KDR mutation. ATM mutations in the HR pathway were associated with luminal typing ( P=0.054), and patients with HER2+breast cancer were more likely to carry ATM mutations. PMS2 mutations in the MMR pathway were correlated with tumor size ( P=0.060), and patients with tumor size>50 mm were more likely to carry PMS2 mutations. KDR mutations was significantly correlated with luminal typing and family history. ( P=0.021, P=0.024). Conclusion:The mutation frequency in BER, KDR, MMR and HR pathways in Chinese breast cancer patients increased successively. Germline mutations in ATM, PMS2 and KDR genes may be involved in the development of breast cancer in the Chinese population. Multi-pathway gene detection of breast cancer can provide laboratory evidence for the use of PARP inhibitors, trastuzumab and other targeted drugs.
2.Application of next-generation sequencing in detection of breast cancer susceptibility genes BRCA1/2,TP53 and PTEN germline mutation
Chang LIU ; Yinting MA ; Zhongling ZHUO ; Fei XIE ; Yuanyuan SUN ; Yan LONG ; Hui WANG ; Xiaotao ZHAO
Chinese Journal of Laboratory Medicine 2019;42(2):98-103
Objective To investigate germline mutation of breast cancer susceptibility genes BRCA1/2,TP53 and PTEN in Chinese breast cancer patients. Methods All of128 female breast cancer patients in Peking University People′s Hospital from January 2016 to August 2018 were selected as objects. Among them,44 cases were sporadic breast cancer and 84 werebreast cancer patients with genetic high risks. Germline mutations of BRCA1,BRCA2,TP53 and PTENwere detected by NGS.χ2 test was used to analyze the difference of pathogenic mutation rates between sporadic breast cancer group and breast cancer with high genetic risks.Groups were divided according to the clinical features of the patients(family history, triple-negative breast cancer,age and bilateral breast cancer).Among them,there were 42 cases with family history of breast cancer,34 cases of triple-negative breast cancer,33 cases of early-onset breast cancer and 7 cases of bilateral breast cancer. Fisher′s exact probability test compared the relationship between pathogenic mutations of BRCA1/2 gene and clinical characteristics of breast cancer patients with hereditary risk factors. Results In 128 cases of breast cancer,30 germline mutations of BRCA1/2 were detected, including 13 pathogenic mutations and 3 newly discovered mutations(BRCA1:c. 4760C>G,BRCA2:c. 44134414del and BRCA2:c. 64826485del). The new mutations may be unique mutations of Chinese population. There were 3 cases of TP53 mutations,including 1 pathogenic mutation. All of the 3 mutations were found in early-onset breast cancer. Germline mutation of T53 has important detection significance for early-onset hereditary breast cancer. There were 5 cases of PTEN mutations,including 3 pathogenic mutations. Among 84 breast cancer patients with genetic high risks,the carry mutation rate was 40.5%(34/84)and the pathogenic mutation rate was 15.4(13/84). Among 44 sporadic cases,the carry mutation rate was 9%(4/44). The pathogenic mutation rate was 6.8%(3/44). Breast cancer susceptibility genes were carried at a higher rate in breast cancer patients with genetic high risks(P<0.001). BRCA1/2 mutations did not show statistical differences among groups of breast cancer patients with hereditary high risk factors . Conclusion Germline mutation detection of breast cancer susceptibility genes by next-generation sequencing is of great significance in breast cancer risk prediction and prognosis evaluation.
3. Effects of CYP2C9 and VKORC1 genetic polymorphisms in Chinese Han population on maintenance dosage of warfarin
Pengfei LIU ; Zhongling ZHUO ; Ming SU ; Yan LONG ; Chang LIU ; Xiaotao ZHAO
Chinese Journal of Laboratory Medicine 2020;43(1):71-77
Objective:
To analyze CYP2C9 and VKORC1 gene polymorphisms in Chinese Han population and their correlation with the maintenance dosage of warfarin.
Methods:
From October 2017 to April 2018, 458 Chinese Han patients (213 males and 245 females, aged from 26 to 94 years old) who underwent coagulation analysis in Peking University People′s Hospital were included in this retrospective study. PCR-Fluorescent probe method was applied to detect CYP2C9*3 and VKORC1-1639A>G gene polymorphisms in 458 patients, and among them, 130 patients who took warfarin for anticoagulant therapy and reached the international standard ratio of prothrombin time (INR) within the range of 2.0-3.0 were recorded. The basic information, dosage of warfarin and INR were also recorded. The statistical analysis data were compared with the reference table of recommended dosage of warfarin for different genotypes of patients recommended by FDA and the formula of predicted dosage of warfarin was simply verified by SPSS.
Results:
Among the 458 patients who took anticoagulant therapy, the genotype frequencies of CYP2C9*1/*1(AA), CYP2C9*1/*3(AC) and CYP2C9*3/*3(CC) were 90.8%, 8.5%, and 0.7%; the genotype frequencies of VKORC1-1639GG and VKORC1-1639AG were 0.9% and 14.2%; the genotype frequencies of VKORC1-1639AA was 84.9%. After INR was reached, the results showed that the variant CYP2C9*1/*3 and CYP2C9*3/*3 required lower daily maintain dosage [(2.92±1.29) mg] than wild-type CYP2C9*1/*1 patients did [(3.91±1.63) mg], with statistically significant difference (