journal contribution posted on 2023-04-03, 15:08 authored by Khoa Nguyen, Yuanqing Yan, Bin Yuan, Abhishek Dasgupta, Jeffrey Sun, Hong Mu, Kim-Anh Do, Naoto T. Ueno, Michael Andreeff, V. Lokesh Battula
Supplementary Table 1. Signaling pathways downregulated in ST8SIA1-knockout cells. GSEA analysis was performed using genes that were differentially expressed in Cas9-Control and ST8SIA1-KO cells (Fig 4A). Supplementary Table 2. Proteomic analysis of GD2+ and GD2- SUM159 cells. GD2+ and GD2-SUM159 cells FACS-sorted as shown in Fig 5A, protein expression and phosphorylation was examined by Kinexus antibody array. Supplementary Table 3. Antibodies used in the western blot analysis. Supplementary Figure 1. ST8SIA1 mRNA expression in breast cancer cell lines. Supplementary Figure 2. Correlation of gene expression with ST8SIA1 expression in primary breast tumors. Supplementary Figure 3. DNA sequencing to determine the genomic alteration made by CRISPR-Cas9 in the ST8SIA1 gene. Supplementary Figure 4. Characterization of ST8SIA1-KO TNBC cells. Supplementary Figure 5. Knockout of ST8SIA1 inhibits BCSC function in vitro.
Breast Cancer Research Foundation (BCRF)
MD Anderson Cancer Center
Paul and Mary Haas Chair in Genetics
Bone Disease Program of Texas
ARTICLE ABSTRACTBreast cancer stem-like cells (BCSC) are implicated in cancer recurrence and metastasis of triple-negative breast cancer (TNBC). We have recently discovered that ganglioside GD2 expression defines BCSCs and that ST8SIA1 regulates GD2 expression and BCSC function. In this report, we show that ST8SIA1 is highly expressed in primary TNBC; its expression is positively correlated with the expression of several BCSC-associated genes such as BCL11A, FOXC1, CXCR4, PDGFRβ, SOX2, and mutations in p53. CRISPR knockout of ST8SIA1 completely inhibited BCSC functions, including in vitro tumorigenesis and mammosphere formation. Mechanistic studies discovered activation of the FAK–AKT–mTOR signaling pathway in GD2+ BCSCs, and its tight regulation by ST8SIA1. Finally, knockout of ST8SIA1 completely blocked in vivo tumor growth and metastasis by TNBC cells. In summary, these data demonstrate the mechanism by which ST8SIA1 regulates tumor growth and metastasis in TNBC and identifies it as a novel therapeutic target.