adrenomedullin and Urinary-Bladder-Neoplasms

Our study aimed to explore long non-coding RNAs (lncRNAs) contributing to the development of bladder cancer, as well as to identify more critical DEGs and lncRNAs that would characterize low- and high-grade bladder cancer. The microarray data of GSE55433 was downloaded from Gene Expression Omnibus database, including 57 urothelial cancer samples (23 low-grade NMI, 14 high-grade NMI and 20 invasive tumors) and 26 normal controls. The differentially expressed genes (DEGs) and differentially expressed lncRNAs were identified in 3 groups (low-grade NMI vs. normal, high-grade NMI vs. normal and invasive UC vs. normal). Functional enrichment analysis was performed upon the DEGs in different groups. Besides, protein-protein interaction (PPI) network was constructed based on common DEGs and remaining DEGs in each group. Co-expression analysis was performed to identify the co-expressed DEG-lncRNAs pairs. Different number of DEGs and differentially expressed lncRNAs were respectively identified from those 3 groups. NONHSAG013805 (down-regulated) and NONHSAG009271 (down-regulated) were common lncRNAs. NONHSAG013805 was connected with the down-regulated gene EIF3E and NONHSAG009271 was linked to MYL12A (down-regulated). Moreover, NONHSAG034203 (up-regulated) was co-expressed with ADM5 (up-regulated) in low-grade NMI cancer, while the down-regulated NONHSAG045391 was connected with the down-regulated DEGs DAD1 and STUB1 in high-grade NMI cancer and invasive bladder cancer. Our study indicates that NONHSAG013805 and NONHSAG009271 may play key roles in bladder cancer via co-expressing with EIF3E and MYL12A, respectively. Moreover, NONHSAG034203 may be involved in low-grade NMI bladder cancer via targeting ADM5, while NONHSAG045391 may contribute to high-grade NMI and invasive bladder cancer via targeting DAD1 and STUB1.

Topics: Adrenomedullin; Carcinoma; Case-Control Studies; Eukaryotic Initiation Factor-3; Gene Expression Regulation, Neoplastic; Gene Regulatory Networks; Humans; Myosin Light Chains; RNA, Long Noncoding; Ubiquitin-Protein Ligases; Urinary Bladder Neoplasms

Adrenomedullin (ADM) is a potent, long-lasting angiogenic peptide that was originally isolated from human pheochromocytoma. ADM signaling is of particular significance in endothelial cell biology because the peptide protects cells from apoptosis, and ADM has been shown to be pro-tumorigenic in that it stimulates tumor cell growth and angiogenesis. ADM may be involved in micro-vessel proliferation and partially in the release of hypoxia in solid tumors, contributing to the proliferation of tumor cells as well as local tumor invasion and metastasis. However, the effect of hypoxia-induced ADM expression in bladder cancer remains unclear. Here, we found that the levels of ADM protein in tumor tissue from patients with bladder urothelial cell carcinoma were significantly increased compared to the adjacent non-tumor bladder tissues (p < 0.01). Under hypoxic conditions, the expression of ADM was significantly elevated in a time-dependent manner in human bladder cancer cell lines. Furthermore, the knockdown of ADM by shRNA in T24 cells showed obvious apoptosis compared to untransfected controls (p < 0.0001). In addition, the combination of cisplatin and ADM-shRNA significantly reduces the tumor growth in vivo compared to treatment with cisplatin (p = 0.0046) or ADM-shRNA alone (p < 0.0001). These data suggest that ADM plays an important role in promoting bladder cancer cell growth under hypoxia and that the inhibition of ADM may provide a target for bladder cancer therapy.

Topics: Adrenomedullin; Adult; Aged; Animals; Apoptosis; Carcinoma; Cell Line, Tumor; Cell Proliferation; Cisplatin; Female; Humans; Hypoxia-Inducible Factor 1, alpha Subunit; Male; Mice; Mice, Inbred BALB C; Middle Aged; RNA Interference; RNA, Messenger; Urinary Bladder; Urinary Bladder Neoplasms; Urothelium; Vascular Endothelial Growth Factor A