Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.3.13 (lysyl oxidase)
 1,248 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Promoter hypermethylation is one of the common mechanisms leading to gene silencing in various human cancers. Using a combination of pharmacologic unmasking and microarray techniques, we identified 59 candidate hypermethylated genes, including LOXL1, a lysyl oxidase-like gene, in human bladder cancer cells. We further showed that LOXL1 and LOXL4 are commonly silenced genes in human bladder cancer cells, and this silence is predominantly related to promoter methylation. We also found LOXL1 and LOXL4 gene methylation and loss of expression in primary bladder tumors. In addition, somatic mutations were identified in LOXL4, but not in LOXL1 in bladder cancer. Moreover, reintroduction of LOXL1 and LOXL4 genes into human bladder cancer cells leads to a decrease of colony formation ability. Further studies indicated that the overexpression of LOXL1 and LOXL4 could antagonize Ras in activating the extracellular signal-regulated kinase (ERK) signaling pathway. Thus, our current study suggests for the first time that lysyl oxidase-like genes can act as tumor suppressor genes and exert their functions through the inhibition of the Ras/ERK signaling pathway in human bladder cancer.
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PMID:LOXL1 and LOXL4 are epigenetically silenced and can inhibit ras/extracellular signal-regulated kinase signaling pathway in human bladder cancer. 1745 85

While the pro-tumorigenic function of heparanase is well taken, the role of its close homolog, heparanase 2 (Hpa2) in cancer is by far less investigated. Utilizing immunohistochemical analysis we found that Hpa2 is expressed by normal bladder transitional epithelium and its levels are decreased substantially in bladder cancer. Notably, tumors that retain high levels of Hpa2 were diagnosed as low grade (p=0.001) and low stage (p=0.002), suggesting that Hpa2 is required to preserve cell differentiation and halt cell motility. Indeed, migration of 5637 bladder carcinoma cells was attenuated significantly by exogenous addition of purified Hpa2, and over expression of Hpa2 in 5637 cells resulted in smaller tumors that were diagnosed as low grade. We also noted that tumors produced by Hpa2 over expressing cells are abundantly decorated with stromal cells and collagen deposition evident by Masson's/Trichrome staining, correlating with a marked increase in lysyl oxidase (LOX) staining. The association between Hpa2 and LOX was further confirmed clinically, because of the 16 cases that exhibited strong staining of Hpa2, 14 (87.5%) were also stained strongly for LOX (p=0.05). Collectively, our results suggest that Hpa2 functions as a tumor suppressor in bladder cancer, maintaining cellular differentiation and decreasing cell motility in a manner that appears to be independent of regulating heparanase activity.
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PMID:Heparanase 2 expression inversely correlates with bladder carcinoma grade and stage. 2696 15