AIB1 predicts bladder cancer outcome and promotes bladder cancer cell proliferation through AKT and E2F1

Abstract

Background:We previously demonstrated that AIB1 overexpression is an independent molecular marker for shortened survival of bladder cancer (BC) patients. In this study, we characterised the role and molecular mechanisms of AIB1 in BC tumorigenicity.Methods:AIB1 expression was measured by immunohistochemistry in non-muscle-invasive BC tissue and adjacent normal bladder tissue. In addition, the tumorigenicity of AIB1 was assessed with in vitro and in vivo functional assays.Results:Overexpression of AIB1 was observed in tissues from 46 out of 146 patients with non-muscle-invasive BC and was an independent predictor for poor progression-free survival. Lentivirus-mediated AIB1 knockdown inhibited cell proliferation both in vitro and in vivo, whereas AIB1 overexpression promoted cell proliferation in vitro. The growth-inhibitory effect induced by AIB1 knockdown was mediated by G1 arrest, which was caused by reduced expression of key cell-cycle regulatory proteins through the AKT pathway and E2F1.Conclusion:Our results suggest that AIB1 promotes BC cell proliferation through the AKT pathway and E2F1. Furthermore, AIB1 overexpression predicts tumour progression in patients with non-muscle-invasive BC.

Steroid Receptor Coactivator-3 Regulates Glucose Metabolism in Bladder Cancer Cells through Coactivation of Hypoxia Inducible Factor 1α

“…Multiple lines of evidence from recent reports indicate that SRC-3 may also activate transcription factors such as AP-1 and PEA3 (25,(32)(33)(34)(35). Very recently, SRC-3 was reported to coactivate the E2F1 transcriptional factor and drive cell cycle proteins in bladder cancer cells (36). Consistent with these findings, we demonstrated that SRC-3 could also coactivate the HIF1␣ transcription factor and up-regulate genes in the glycolytic pathway.…”

Identification and validation of AIB1 and EIF5A2 for noninvasive detection of bladder cancer in urine samples

“…Previously, we demonstrated that AIB1 overexpression is correlated with cancer progression after transurethral resection of bladder tumor (TUR-Bt) for BCa [20, 21], and Zhang et al confirmed that AIB1 was significantly upregulated in BCa tissues [28]. Our further studies demonstrated that AIB1 knockdown mediated by ACC/CaIP6/siRNA complex transfection resulted in inhibited BCa cell proliferation in vitro and in vivo [22].…”

Overexpression of HMGB3 protein promotes cell proliferation, migration and is associated with poor prognosis in urinary bladder cancer patients

“…As summarized in Table 1, HMGB3 expression was significantly correlated with tumor size (P = 0.019), tumor grade (P = 0.031), pN (P = 0.017), and pT (P=0.028) status. Furthermore, overall survival (OS) of UBC patients was evaluated by Kaplan-Meier survival analysis as performed in previous reports [17,18]. Logrank test showed that high HMGB3 groups had significantly lower OS than the low HMGB3 group (P=0.0079; Fig.…”