Fig 2: Characterization of MYBBP1A expression and MYBBP1A binding to c-MYB in renal carcinoma cell lines. (A) Measurement of MYBBP1A, c-MYB, p53 and pVHL levels in renal carcinoma cell lines A498, 786-O, ACHN and CaKi-1 by western blot. Cells were cultured in 4500 mg/L glucose media. (B) Measurement of MYBBP1A, c-MYB, p53, acetyl-p53 and pVHL levels in A498, 786-O, ACHN and CaKi-1 by western blot. Cells were cultured in 1000 mg/L or 100 mg/L glucose media. (C) MYBBP1A and c-MYB co-localize in the nucleolus of renal carcinoma cell lines. Cells were stained using DAPI (nuclear control), MYBBP1A and c-MYB antibodies. Scale Bar: 8 µM. (D) Co-immunoprecipitation of c-MYB and MYBBP1A in renal carcinoma cells. Protein extracts from 786-O and A498 were subject to immunoprecipitation with c-MYB or normal IgG antibodies. The resultant immunoprecipitates were then analyzed by WB with c-MYB and MYBBP1A antibodies.

Fig 3: Immunolocalization of cMyb and SRY in human bone tissue.a–c Bone tissue of a male patient with osteoporotic fracture. a cMyb staining is observed in the nuclei of lining cells, individual bone marrow cells, and osteocytes. b In inactive bone, SRY staining is observed in various cells of the bone marrow (blue arrow) and in the lining cells (black arrows), while osteocytes are negative for SRY (red arrow), similar to what was observed with cMyb. c In bone with active processes of bone remodeling, in addition to the cells in bone marrow, SRY was observed in active osteoblasts (closed arrows) and osteocytes (open arrows) just beneath the trabecular bone surface, which suggests its role in bone remodeling via RANKL. d No positive SRY staining was observed in female patients with osteoporotic fracture. e, f Bone tissue of a male patient with osteoporotic fractures showing costaining of cMyb and SRY in osteoblast-like cells (arrows) on the surface of trabecular bone (e); single-positive SRY or cMyb cells (arrowheads, e, f) are present in bone marrow (BM); and cMyb single-positive cells are also present on the surface of trabecular bone (TB) (e, f). g, h Costaining for SRY and cMyb in bone tissue of a male patient with osteoarthritis (g) and in a male donor with no musculoskeletal disease (h) show similar patterns of localization; i.e., SRY single-positive cells (arrowheads) and SRY and cMyb double-positive cells (arrows) in bone marrow (BM). Immunohistochemistry (a–d) and double immunofluorescence (e–h) of human bone tissue. N = 3 donors per group (fracture, osteoarthritis and control group). Scale bars: 50 µm

Fig 4: The positive expression rate of c-Myb and COX-2 in CRC. A) IHC detection of c-Myb in 202 paired of CRC and noncancerous tissues (paired Student's t test; ***, p < 0.001); B) IHC detection of COX-2 in 202 paired of CRC and noncancerous tissues (paired Student's t test; ***, p < 0.001). C) Correlation of c-Myb expression with COX-2 expression (linear regression; r = 0.391, p < 0.001). D) Western blot analysis of the protein expression of c-Myb and COX-2 in the CRC tissues, as compared with noncancerous tissues.

Fig 5: MYBBP1A knock down increases c-MYB activity. (A) MYBBP1A knock down by the expression of a specific shRNA. Cell lines were transfected with MYBBP1A shRNA (sh) or a scramble vector (V). After selection, cells were grown to 80% confluence, and proteins were extracted. The figure shows the western blot results of MYBBP1A expression in all cell lines. Scale Bar: 8 µM. (B) Quantification of MYBBP1A expression in cells expressing MYBBP1A shRNA (sh) related to the scramble vector (V). (C) MYBBP1A knock down increases the expression of c-MYB target genes. mRNA levels of genes directly transcribed by c-MYB were measured by Q-RT-PCR. Graphs represent mRNA levels of cells expressing MYBBP1A shRNA normalized to mRNA levels of control cells. (D) Percentage of CD34+ cells measured by flow cytometry. (E) Percentage of CXCR4+ cells measured by flow cytometry. (B–D) Graphs show the mean ± SD of three independent experiments performed in triplicate. * p < 0.05; ** p < 0.01.