Tumor sections were stained with hematoxylin–eosin (HE) and immunohistochemically examined for CHI3L1 and CST3 using a Nichirei Histofine system (Nichirei Biosciences Inc.). Tissue sections were incubated with primary anti-CHI3L1 antibody (Cell Signaling, #47,066) and anti-CST3 antibody (Abcam, ab109508) at a 1:800 and 1:4000 dilution, respectively, and detected with HRP-labeled polymer-conjugated secondary antibody (Histofine Simple Stain MAX PO, multi, Nichirei). Color development was achieved with 3,3′-diaminobenzidine tetrahydrochloride. Organoids were fixed and paraffin-embedded using Epredia HistoGel Specimen Processing Gel (Thermo Scientific) and Tissue-Tec VIP (SAKURA, Japan). Immunohistochemical staining on the organoid sections was performed by incubating with anti-CHI3L1 antibody (Cell Signaling, #47,066) and anti-CST3 antibody (Abcam, ab109508) at a 1:400 and 1:500 dilution, respectively. Signals were detected using Dako EnVision + Dual Link System-HRP (Agilent).
Saeki S., Kumegawa K., Takahashi Y., Yang L., Osako T., Yasen M., Otsuji K., Miyata K., Yamakawa K., Suzuka J., Sakimoto Y., Ozaki Y., Takano T., Sano T., Noda T., Ohno S., Yao R., Ueno T, & Maruyama R. (2023). Transcriptomic intratumor heterogeneity of breast cancer patient-derived organoids may reflect the unique biological features of the tumor of origin. Breast Cancer Research : BCR, 25, 21.
+ Open protocol