Teachers are highly reliant on textbooks for teaching. In the Republic of Korea, science textbooks help students to understand scientific terms through inquiry activities. However, there is a lack of analysis on whether the inquiry activities suggested in these textbooks appropriately cover the terms included in the main text. Therefore, this study assesses the life science units included in widely used lower secondary school science textbooks in the Republic of Korea by analysing the connection between the terms presented in the inquiry activities and the main text using the NetMiner 4.0 programme. The results reveal that the life science units included in the lower secondary school science textbooks are well structured for learning life science terms through the inquiry activities, as the terms presented in the inquiry activities and the main text are well connected. However, the number of terms included in each unit greatly differs and needs to be supplemented with the optimization of the number of terms per unit. The results provide basic data for the future development of lower secondary school science textbooks. Future research should analyse how the terms used in inquiry activities and the main text are connected in real science classes. Keywords: biological terms, connection network, terms connection, inquiry activity, main text

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer; however, pathogenesis of TNBC has not yet been fully understood. Here, we identified dysregulated microRNAs (miRNAs) by analyzing miRNA microarray of TNBC patients. MiR-371b-5p expression was reduced, and ectopic expression of miR-371b-5p significantly inhibited TNBC progression in vitro and in vivo. In addition, we found that expression of cold shock domain-containing protein E1 (CSDE1), a direct target gene of miR-371b-5p, was upregulated in TNBC cells, and inhibition of CSDE1 alleviated TNBC cell growth by decreasing RAC1 known as pro-metastatic gene. Mechanistically, CSDE1, phosphorylated C-terminal domain (p-CTD) of RNA polymerase II (RNAPII), and CDK7 form a complex, and downregulation of CSDE1 results in weak interaction between RNAPII p-CTD and CDK7, which leads to a decrease in RNAPII p-CTD expression to reduce RAC1 transcript levels in CSDE1-deficient TNBC cells. Our data revealed the oncogenic function of miR-371b/CSDE1 involved in Rac1 transcription regulation, thus providing a basis for the pathological mechanism of TNBC along with potential biomarkers for TNBC. Citation Format: Yesol Kim, Je Yeong Ko, Soo-Been Lee, Jaehee Jun, Yejin Ahn, Jinui Min, Chaewon Oh, Jong Hoon Park. Dysregulated miR-371b-5p/CSDE1/RAC1 axis is involved in pathogenesis of triple-negative breast cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4738.