Fig. 1: B lymphoid cells express β-catenin mRNA but lack β-catenin protein expression.
a, Representative immunohistochemical staining for β-catenin (brown) on tissue microarrays from lung cancer (n = 15 tumors, biological replicates), colon cancer (n = 25 tumors, biological replicates) and malignant melanoma (n = 5 tumors, biological replicates) in comparison to MCL (n = 26 tumors, biological replicates), follicular lymphoma (n = 38 tumors, biological replicates), DLBCL (n = 35 tumors, biological replicates) and HD (n = 44 tumors, biological replicates). b, Western blot analysis for β-catenin, β-tubulin and TBP on nuclear fractions of lung cancer (n = 7 cell lines, biological replicates), colon cancer (n = 6 cell lines, biological replicates), malignant melanoma (n = 3 cell lines, biological replicates), B-ALL (n = 7 cell lines, biological replicates), DLBCL (n = 5 cell lines, biological replicates), MCL (n = 3 cell lines, biological replicates), Burkitt’s lymphoma (n = 3 cell lines, biological replicates), HD (n = 2 cell lines, biological replicates) and multiple myeloma (MM; n = 2 cell lines, biological replicates). c, Top, transcriptional analysis of 779 cancer cell lines by RNA-seq (PRJNA523380) for the expression of CTNNB1 in 692 solid tumor cell lines (biological replicates) compared to 87 B cell leukemia and lymphoma cell lines (biological replicates). Bottom, protein levels of β-catenin were measured by RPPA (CCLE2019) in B cell leukemia and lymphoma cell lines (n = 86 cell lines, biological replicates), as well as solid tumor cell lines (n = 646 cell lines, biological replicates). TPM, transcripts per million. d,e, Fluorescent protein stability assay to compare rate of β-catenin degradation in epithelial cell lines, including colon (SW480) and lung (H82) cancer cell lines and cells derived from normal epithelial tissues including human embryonic kidney (HEK) and normal breast epithelial cells (MCF10) and in B lymphoid cells including B-ALL (KOPN8 and TOM1), MCL (JEKO) and DLBCL (TMD8). GFP-tagged WT β-catenin (protein) or GFP tag was expressed along with mScarlet (mRNA) reporter and stability of β-catenin was assessed by flow cytometric measurement of GFP and mScarlet signal. d, Representative FACS plots are shown for cells expressing β-catenin–GFP fusion protein along with mScarlet mRNA reporter. e, Frequencies of cells expressing β-catenin–GFP fusion protein within mScarlet+ cells are shown and an unpaired two-tailed t-test was performed to compare β-catenin protein and mRNA expression in all B lymphoid cells (B-ALL and B-NHL; n = 10 cell lines, biological replicates) versus all epithelial cells (normal epithelial, colon cancer and lung cancer; n = 9 cell lines, biological replicates) (P = 2.23 × 10−8). f, Representative immunohistochemical staining for β-catenin (brown; top) and β-catenin phosphorylated by GSK3β (S37, brown; bottom) on tissue microarrays from lung cancer (n = 41 tumors, biological replicates), colon cancer (n = 13 tumors, biological replicates), breast cancer (n = 58 tumors, biological replicates), ovarian cancer (n = 9 tumors, biological replicates), malignant melanoma (n = 13 tumors, biological replicates), MCL (n = 21 tumors, biological replicates), follicular lymphoma (n = 54 tumors, biological replicates), DLBCL (n = 47 tumors, biological replicates) and HD (n = 20 tumors, biological replicates) using hematoxylin (blue) as the counterstain. g, Western blot analysis for total β-catenin, N-terminal phosphorylated β-catenin by GSK3β (S33, S37 and T41) and nonphosphorylated (active) β-catenin in a panel of lung (n = 2 cell lines, biological replicates) and colon (n = 4 cell lines, biological replicates) cancer cell lines in comparison to human B-ALL (n = 3 cell lines, biological replicates), MCL (n = 2 cell lines, biological replicates) and postgerminal center lymphoma (n = 2 cell lines, biological replicates) (three technical repeats). The exposure time for total and nonphosphorylated β-catenin was 185 s; the exposure time for N-terminal phosphorylated β-catenin (S33, S37 and T41) was 1,199 s.
