Effect of Extracellular Signal-Regulated Protein Kinase 5 Inhibition in Clear Cell Renal Cell Carcinoma

(1) Background: Extracellular signal-regulating kinase 5 (ERK5) has been implicated in many cellular functions, including survival, proliferation, and vascularization. Our objectives were to examine the expression and effect of ERK5 in clear cell renal cell carcinoma (ccRCC). (2) Methods: The expressions of ERK5 and its regulating micro-RNA miR-143 were investigated using immunohistochemistry and quantitative reverse transcriptase PCR in surgical specimens of ccRCC patients. With invitro and in vivo studies, we used pharmacologic ERK5 inhibitor XMD8-92, RNA interference, pre-miR-143 transduction, Western blotting, MTS assay, apoptosis assay, and subcutaneous xenograft model. (3) Results: A strong ERK5 expression in surgical specimen was associated with high-grade (p = 0.01), high-recurrence free rate (p = 0.02), and high cancer-specific survival (p = 0.03). Expression levels of ERK5 and miR-143 expression level were correlated (p = 0.049). Pre-miR-143 transduction into ccRCC cell A498 suppressed ERK5 expression. ERK5 inhibition enhanced cyclin-dependent kinase inhibitor p21 expression and decreased anti-apoptotic molecules BCL2, resulting in decreased cell proliferation and survival both in ccRCC and endothelial cells. In the xenograft model, ERK5 inhibitor XMD8-92 suppressed tumor growth. (4) Conclusions: ERK5 is regulated by miR-143, and ERK5 inhibition is a promising target for ccRCC treatment

Additional file 3: of A GRIA2 and PAX8-positive renal solitary fibrous tumor with NAB2-STAT6 gene fusion

Results of reverse transcription-polymerase chain reaction (RT-PCR). Fusion of the NAB2-STAT6 gene was detected by RT-PCR with several sets of specifically designed forward and reverse PCR primers. Sequences of the PCR primers are given in Additional file 2. SFT, solitary fibrous tumor. (PNG 73 kb

Additional file 2: Figure S2. of GSK-3 directly regulates phospho-4EBP1 in renal cell carcinoma cell-line: an intrinsic subcellular mechanism for resistance to mTORC1 inhibition

Different effects of GSK-3 inhibition on Akt and 4EBP1 phosphorylation. (A) ACHN cells were treated with AR-A014418 (25 μM) or rapamycin (100 nM) for the indicated times. Cells were lysed and analyzed for pAkt by immunoblotting. (B) Caki1 and A498 cells were treated with AR-A014418 at 25 μM or 50 μM for 24 h or 48 h, respectively. Immunoblotting was performed after cell lysis. In (A) and (B), Data are representative of at least three separate immunoblot analyses. (PPTX 107 kb

Additional file 1: Figure S1. of GSK-3 directly regulates phospho-4EBP1 in renal cell carcinoma cell-line: an intrinsic subcellular mechanism for resistance to mTORC1 inhibition

Differences in suppressive effects of mTORC1 and GSK-3 inhibitors on cell proliferation. Relative cell viability was measured by an MTS assay in ACHN, Caki1 and A498 cells treated with rapamycin (A), and AR-A014418 (B) at the indicated concentrations at 72 h. A498 cells, highly insensitive to rapamycin, did not reach maximal inhibitory effect even at 10 μM rapamycin, with IC50 not assessable (NA). Data are the mean ± SE from six replicates of each cell line. In (A) and (B), significant interaction between cell lines and drug concentrations was statistically detected with two-way ANOVA (p < 0.05). As for the simple main effect, the difference in cell lines (ACHN, Caki1 or A498) was statistically significant for rapamycin (one-way ANOVA; p < 0.05, Bonferroni test; p < 0.05 for ACHN vs. Caki1 and A498) and not significant for AR-A014418 (one-way ANOVA; p = 0.47). (PPTX 60 kb