Objective:To investigate the mutation of PIK3CA, AKT1 and PTEN genes in hormone receptor (HR)-positive and HER2-negative invasive breast cancer.Methods:A total of 44 formalin-fixed paraffin-embedded samples from HR-positive/HER2-negative female patients with breast cancer obtained between January 2020 and July 2024 in Peking Union Medical College Hospital were selected. The mutations of PIK3CA, AKT1 and PTEN genes were analyzed by next-generation sequencing (NGS), and the related clinicopathological characteristics were summarized.Results:In the cohort, 31 out of 44 cases (70.5%) exhibited alterations in the PIK3CA, AKT1 and PTEN genes. Of these, 83.9% (26/31) tumors harbored genetic abnormalities involving one gene, including 21 (47.7%, 21/44) PIK3CA, 2 (4.5%, 2/44) PTEN and 3 (6.8%, 3/44) AKT1 gene mutations. Mutations of both PIK3CA and PTEN genes were found in 16.1% (5/31) of specimens. Among the 26 cases with PIK3CA gene mutations, 13 variants were identified, including E542K, E545K, Q546K, H1047R, H1047L, G1049R, M1043I, C420R, P447_L455del, N345K, N345I, K711N and H1047L/V346G. In addition, 7 mutants of PTEN gene were determined (T319 *, T321Qfs *23, Q245 *, Q171H, L108P, Y68Ifs *6 and V343fs). For AKT1 gene mutation, only E17K was observed.Mutations of PIK3CA/AKT1/PTEN genes are more likely to occur over 40 year-old patients.In this cohort, the PIK3CA V346G mutation (co-existent PIK3CA H1047L) and the PTEN V343fs mutation were not found in previous publications. Conclusion:In addition to the predominance of common loci, PIK3CA and PTEN gene mutations also have rare loci mutations in the breast cancer, warranting further analysis with an expanded sample size.

Objective:To investigate the mutation of PIK3CA, AKT1 and PTEN genes in hormone receptor (HR)-positive and HER2-negative invasive breast cancer.Methods:A total of 44 formalin-fixed paraffin-embedded samples from HR-positive/HER2-negative female patients with breast cancer obtained between January 2020 and July 2024 in Peking Union Medical College Hospital were selected. The mutations of PIK3CA, AKT1 and PTEN genes were analyzed by next-generation sequencing (NGS), and the related clinicopathological characteristics were summarized.Results:In the cohort, 31 out of 44 cases (70.5%) exhibited alterations in the PIK3CA, AKT1 and PTEN genes. Of these, 83.9% (26/31) tumors harbored genetic abnormalities involving one gene, including 21 (47.7%, 21/44) PIK3CA, 2 (4.5%, 2/44) PTEN and 3 (6.8%, 3/44) AKT1 gene mutations. Mutations of both PIK3CA and PTEN genes were found in 16.1% (5/31) of specimens. Among the 26 cases with PIK3CA gene mutations, 13 variants were identified, including E542K, E545K, Q546K, H1047R, H1047L, G1049R, M1043I, C420R, P447_L455del, N345K, N345I, K711N and H1047L/V346G. In addition, 7 mutants of PTEN gene were determined (T319 *, T321Qfs *23, Q245 *, Q171H, L108P, Y68Ifs *6 and V343fs). For AKT1 gene mutation, only E17K was observed.Mutations of PIK3CA/AKT1/PTEN genes are more likely to occur over 40 year-old patients.In this cohort, the PIK3CA V346G mutation (co-existent PIK3CA H1047L) and the PTEN V343fs mutation were not found in previous publications. Conclusion:In addition to the predominance of common loci, PIK3CA and PTEN gene mutations also have rare loci mutations in the breast cancer, warranting further analysis with an expanded sample size.

The dynamic variation of folate content in the whole blood from ?-irra-diated rats have been observed. The level of folate, which did not alter significantly 24 hours after whole-body exposure of 800 rads, decreased dramatically to about 50 percent at the 5th day and to about 67 percent at the 10th day. After irradiation the haemoglobin concentration in rats also decreased, but there was no coincidence between the dynamic variation of folate level and haemoglobin concentration. It is probable that ionizing radiation induces the folic acid malnutrition of rats.