4-hydroxy-2-nonenal and Carcinoma--Squamous-Cell

Tumor growth is associated with oxidative stress, which causes lipid peroxidation. The most intensively studied product of lipid peroxidation is 4-hydroxy-2-nonenal (HNE), which is considered as a "second messenger of free radicals" that binds to proteins and acts as a growth-regulating signaling factor. The incidence of squamous cell carcinoma of the oropharynx is associated with smoking, alcohol and infection of human papilloma virus (HPV), with increasing incidence world-wide. The aim of this retrospective study involving 102 patients was to determine the immunohistochemical appearance of HNE-protein adducts as a potential biomarker of lipid peroxidation in squamous cell carcinoma of the oropharynx. The HNE-protein adducts were detected in almost all tumor samples and in the surrounding non-tumorous tissue, while we found that HNE is differentially distributed in squamous cell carcinomas in dependence of clinical stage and histological grading of these tumors. Namely, the level of HNE-immunopositivity was increased in comparison to the normal oropharyngeal epithelium in well- and in moderately-differentiated squamous cell carcinoma, while it was decreasing in poorly differentiated carcinomas and in advanced stages of cancer. However, more malignant and advanced cancer was associated with the increase of HNE in surrounding, normal tissue. This study confirmed the onset of lipid peroxidation, generating HNE-protein adducts that can be used as a valuable bioactive marker of carcinogenesis in squamous cell carcinoma of the oropharynx, as well as indicating involvement of HNE in pathophysiological changes of the non-malignant tissue in the vicinity of cancer.

Topics: Adult; Aged; Aged, 80 and over; Aldehydes; Biomarkers, Tumor; Carcinoma, Squamous Cell; Female; Humans; Immunohistochemistry; Lipid Peroxidation; Male; Middle Aged; Neoplasm Grading; Neoplasm Staging; Oropharyngeal Neoplasms; Oropharynx; Retrospective Studies; Tumor Microenvironment

Oxidative stress might participate in the carcinogenesis of human esophageal squamous cell carcinomas (hESCC). 4-Hydroxynonenal (HNE) is a major product of membrane lipid peroxidation with short life. It might act as an important mediator through the generation of adducts and activate epidermal growth factor receptor (EGFR) signaling. It is mainly trapped with glutathione (GSH) and catalyzed by glutathione S-transferases (GSTs). This study aimed to elucidate the possible participation of HNE, GSH/GST system, and EGFR signaling in hESCC development. Immunohistochemistry of HNE adducts, EGFR, and phosphorylated EGFR (pEGFR) was performed with hESCC specimens. The effect of HNE on the phosphorylation of EGFR and its downstream PhospholipaseCγ1 (PLCγ1) was investigated with KYSE30 cell-line. Pretreatment with GSH inducer N-acetylcysteine (NAC) or GSH inhibitor Buthionine sulfoximine (BSO) and mandatory transfection of hGSTA4 gene in KYSE30 were conducted to investigate the relationship between HNE and GSH/GST system. Immunoreactants of HNE adducts, EGFR, and pEGFR were increased in hESCC compared to non-cancerous epithelium with positive correlations. The treatment of HNE ligand-independently induced the phosphorylation of EGFR and PLCγ1 accompanying the diminishment of intracellular GSH level. NAC increased GSH contents but BSO decreased in dose-dependent manners. Reflecting changes in GSH, HNE-induced EGFR phosphorylation was suppressed by NAC, whereas it was promoted by BSO. Mandatory expression of hGSTA4 suppressed HNE-induced events. We first demonstrated that the ligand-independent activation of EGFR by the balance between the stimulation of HNE and the prevention of intrinsic GSH/GST system might participate in the development of hESCC.

Topics: Acetylcysteine; Aged; Aldehydes; Antimetabolites; Blotting, Western; Buthionine Sulfoximine; Carcinoma, Squamous Cell; Cell Line, Tumor; ErbB Receptors; Esophageal Neoplasms; Female; Gene Expression Regulation, Neoplastic; Glutathione; Glutathione Transferase; Humans; Immunohistochemistry; Male; Phosphorylation; Quinazolines; Reverse Transcriptase Polymerase Chain Reaction; Transfection; Tyrphostins

Excessive alcohol consumption is a common cause for upper gastrointestinal tract cancers. However, the primary mechanisms of alcohol-induced carcinogenesis have remained poorly defined.. We examined the generation and subcellular distribution of protein adducts with acetaldehyde (AA), the first metabolite of ethanol, and end products of lipid peroxidation, malondialdehyde (MDA) and 4-hydroxynonenal (HNE), from oral biopsy specimens obtained from 36 subjects (11 British, 25 Japanese) reporting alcohol misuse. All patients had been diagnosed with oral pre-cancer (leukoplakia, n = 7) or squamous cell carcinoma (SCC; n = 29). Automated immunostaining for AA, MDA and HNE adducts was performed using monospecific antibodies.. Positive staining for AA, MDA and HNE adducts was observed in the dysplastic or malignant epithelial cells, HNE being relatively the most abundant adduct species. The subgroup of Japanese patients had higher levels of AA and MDA, although not HNE, than the British sample. When the material was divided to those with SCC or leukoplakia, MDA adducts but not the other antigens were more prominent in the former group. Significant correlations were found between the different adducts (AA vs. MDA, r = 0.68, P < 0.001; AA vs. HNE, r = 0.47, P < 0.01 and MDA vs. HNE, r = 0.59, P < 0.001). In addition, cytochrome P450 2E1 staining was found in these samples, correlating with both AA and MDA adducts.. The data indicates that AA- and lipid peroxidation-derived adducts are formed in oral tissues of alcohol misusers with oral leukoplakia and cancer. The findings also support a pathogenic role of AA and excessive oxidative stress in carcinogenesis.

Topics: Acetaldehyde; Alcoholism; Aldehydes; Carcinoma, Squamous Cell; Cytochrome P-450 CYP2E1; Ethanol; Female; Humans; Immunohistochemistry; Japan; Leukoplakia, Oral; Lipid Peroxidation; Male; Malondialdehyde; Middle Aged; Mouth Neoplasms; Oxidative Stress; Protein Binding; United Kingdom