The activity of class I, II, III and IV alcohol dehydrogenase isoenzymes and aldehyde dehydrogenase in cervical cancer

Activity of Total Alcohol Dehydrogenase, Alcohol Dehydrogenase Isoenzymes and Aldehyde Dehydrogenase in the Serum of Patients with Alcoholic Fatty Liver Disease

Background and objectives: The aim of the current study was to assess the use of determinations of total alcohol dehydrogenase and the activity of its isoenzymes as well as aldehyde dehydrogenase in the serum of patients with alcohol liver disease. Materials and Methods: The testing was performed on the serum of 38 patients with alcoholic fatty liver (26 males and 12 females aged 31–75). The total activity of ADH was determined by the colorimetric method. The activity of ADH I and ADH II, as well as ALDH, was determined by the spectrofluorometric method using fluorogenic specific substrates. The activity of isoenzymes of other classes was determined by spectrophotometric methods using substrates. Results: A statistically significantly higher ADH I activity was noted in the serum of patients with alcoholic fatty liver (4.45 mIU/L) compared to the control group (2.04 mIU/L). A statistically significant increase in the activity was also noted for the class II alcohol dehydrogenase isoenzyme (29.21 mIU/L, control group: 15.56 mIU/L) and the total ADH (1.41 IU/L, control group: 0.63 IU/L). Conclusions: The obtained results imply the diagnostic usefulness of the determination of AHD total, ADH I, and ADH II activity in the serum of patients with alcoholic fatty liver.

Critical review on the use and abuse of alcohol. When the dose makes the difference

Nowadays harmful alcohol consumption represents one of the most important risk factors for the development of several type of chronic and acute diseases in the western countries, contributing to a great number of deaths. Focusing the attention on cancer development and progression, the scientific community has a large consensus in declaring the existence of a harmful association between alcohol consumption and liver, breast, upper aerodigestive tract (mouth, oropharynx, hypopharynx, and esophagus), pancreas and colon cancer appearance. However the precise biological links by which the alcohol could be responsible for cancer initiation and progression are not fully understood yet, even if the International Agency for Research on Cancer (IARC) indicated both ethanol and acetaldehyde as carcinogen for humans. The possible explanation of the effect exerted by ethanol and acetaldehyde could be related to direct genotoxicity, hormonal disturbance, triggering of oxidative stress and inflammation. In this review, we examine the relationship between alcohol dosage and associated diseases, with focus on alcohol-related cancers. Furthermore, to understand the potential molecular mechanisms of these diseases, the results of in vivo experiments on animal models were discussed.

Prognostic value of alcohol dehydrogenase mRNA expression in gastric cancer

Previous studies have reported that alcohol dehydrogenase (ADH) isoenzymes possess diagnostic value in gastric cancer (GC). However, the prognostic value of ADH isoenzymes in GC remains unclear. The aim of the present study was to identify the prognostic value of ADH genes in patients with GC. The prognostic value of ADH genes was investigated in patients with GC using the Kaplan-Meier plotter tool. Kaplan-Meier plots were used to assess the difference between groups of patients with GC with different prognoses. Hazard ratios (HR) and 95% confidence intervals (CI) were used to assess the relative risk of GC survival. Overall, 593 patients with GC and 7 ADH genes were included in the survival analysis. High expression of ADH 1A (class 1), α polypeptide (ADH1A; log-rank P=0.043; HR=0.79; 95% CI: 0.64–0.99), ADH 1B (class 1), β polypeptide (ADH1B; log-rank P=1.9×10⁻⁰⁵; HR=0.65; 95% CI: 0.53–0.79) and ADH 5 (class III), χ polypeptide (ADH5; log-rank P=0.0011; HR=0.73; 95% CI: 0.6–0.88) resulted in a significantly decreased risk of mortality in all patients with GC compared with patients with low expression of those genes. Furthermore, protective effects may additionally be observed in patients with intestinal-type GC with high expression of ADH1B (log-rank P=0.031; HR=0.64; 95% CI: 0.43–0.96) and patients with diffuse-type GC with high expression of ADH1A (log-rank P=0.014; HR=0.51; 95% CI: 0.3–0.88), ADH1B (log-rank P=0.04; HR=0.53; 95% CI: 0.29–0.98), ADH 4 (class II), π polypeptide (log-rank P=0.033; HR=0.58; 95% CI: 0.35–0.96) and ADH 6 (class V) (log-rank P=0.037; HR=0.59; 95% CI: 0.35–0.97) resulting in a significantly decreased risk of mortality compared with patients with low expression of those genes. In contrast, patients with diffuse-type GC with high expression of ADH5 (log-rank P=0.044; HR=1.66; 95% CI: 1.01–2.74) were significantly correlated with a poor prognosis. The results of the present study suggest that ADH1A and ADH1B may be potential prognostic biomarkers of GC, whereas the prognostic value of other ADH genes requires further investigation.

Alcohol and Cancer: Mechanisms and Therapies

Several scientific and clinical studies have shown an association between chronic alcohol consumption and the occurrence of cancer in humans. The mechanism for alcohol-induced carcinogenesis has not been fully understood, although plausible events include genotoxic effects of acetaldehyde, cytochrome P450 2E1 (CYP2E1)-mediated generation of reactive oxygen species, aberrant metabolism of folate and retinoids, increased estrogen, and genetic polymorphisms. Here, we summarize the impact of alcohol drinking on the risk of cancer development and potential underlying molecular mechanisms. The interactions between alcohol abuse, anti-tumor immune response, tumor growth, and metastasis are complex. However, multiple studies have linked the immunosuppressive effects of alcohol with tumor progression and metastasis. The influence of alcohol on the host immune system and the development of possible effective immunotherapy for cancer in alcoholics are also discussed here. The conclusive biological effects of alcohol on tumor progression and malignancy have not been investigated extensively using an animal model that mimics the human disease. This review provides insights into cancer pathogenesis in alcoholics, alcohol and immune interactions in different cancers, and scope and future of targeted immunotherapeutic modalities in patients with alcohol abuse.

Distinct prognostic values of alcohol dehydrogenase mRNA expression in pancreatic adenocarcinoma

Background

Alcohol dehydrogenase (ADH) isoenzymes have been reported as a potential diagnostic marker for pancreatic cancer, but their prognostic value in pancreatic cancer remains unclear. The aim of this investigation was to identify the prognostic value of ADH genes in human patients with pancreatic adenocarcinoma (PAAD).

Materials and methods

An RNA sequencing dataset and corresponding survival profiles of PAAD were obtained from The Cancer Genome Atlas. Survival analysis and gene set enrichment analysis were used to investigate the prediction value and potential mechanism of ADH genes in PAAD prognosis.

Results

Survival analysis of ADH genes suggests that a high expression of ADH1A (adjusted P=0.037, adjusted hazard ratio [HR] =0.627, 95% CI =0.404–0.972) and ADH6 (adjusted P=0.018, adjusted HR =0.588, 95% CI =0.378–0.914) were associated with a significantly decreased risk of death, while a high expression of ADH5 was associated with a significantly increased risk of death (adjusted P=0.043, adjusted HR =1.564, 95% CI =1.013–2.414). Joint effects analysis of three ADH gene prognostic markers suggests that the prognosis difference for any marker combination was more significant than that for any individual marker. The potential mechanism of ADH1A and ADH6 in PAAD prognosis was that a high expression of ADH1A and ADH6 was involved in the P450 pathway and biological processes, while high ADH5 expression was involved in transforming growth factor β regulation-related pathways and biological processes, Wnt, the cell cycle, ErbB, and mitogen-activated protein kinase signaling pathways.

Conclusion

Our data suggest that ADH1A, ADH5, and ADH6 expression may be potential prognostic markers of PAAD and in combination have a strong interaction and better predictive value for PAAD prognosis.

Direct observation of redox reactions in Candida parapsilosis ATCC 7330 by Confocal microscopic studies

Confocal microscopic studies with the resting cells of yeast, Candida parapsilosis ATCC 7330, a reportedly versatile biocatalyst for redox enzyme mediated preparation of optically pure secondary alcohols in high optical purities [enantiomeric excess (ee) up to >99%] and yields, revealed that the yeast cells had large vacuoles under the experimental conditions studied where the redox reaction takes place. A novel fluorescence method was developed using 1-(6-methoxynaphthalen-2-yl)ethanol to track the site of biotransformation within the cells. This alcohol, itself non-fluorescent, gets oxidized to produce a fluorescent ketone, 1-(6-methoxynaphthalen-2-yl)ethanone. Kinetic studies showed that the reaction occurs spontaneously and the products get released out of the cells in less time [5 mins]. The biotransformation was validated using HPLC.

Alcohol dehydrogenase and aldehyde dehydrogenase in malignant neoplasms

According to International Agency for Research on Cancer, ethanol and acetaldehyde belong to group 1 of human carcinogens. The accurate mechanism by which alcohol consumption enhances carcinogenesis is still unexplained. Alcohol is oxidized primarily by alcohol dehydrogenase (ADH) to acetaldehyde, a substance capable of initiating carcinogenesis by forming adducts with proteins and DNA and causing mutations. Next, acetaldehyde is metabolized by aldehyde dehydrogenase (ALDH) to acetate. In tissues of many cancers, we can observe significantly higher activity of total alcohol dehydrogenase with any change in aldehyde dehydrogenase activity in comparison with healthy cells. Moreover, in malignant diseases of digestive system, significantly increased activity of ADH isoenzymes class I, III and IV was found. The gynecological, brain and renal cancers exhibit increased activity of class I ADH. ADH and ALDH can play also a crucial regulatory role in initiation and progression of malignant diseases by participation in retinoic acid synthesis and elimination of toxic acetaldehyde. Besides, changes of enzymes activities in tumor cells are reflected in serum of cancer patients, which create the possibilities of application ADH isoenzymes as cancer markers.

Role of Retinoic Acid-Metabolizing Cytochrome P450s, CYP26, in Inflammation and Cancer

Vitamin A (retinol) and its active metabolite, all-trans-retinoic acid (atRA), play critical roles in regulating the differentiation, growth, and migration of immune cells. Similarly, as critical signaling molecules in the regulation of the cell cycle, retinoids are important in cancers. Concentrations of atRA are tightly regulated in tissues, predominantly by the availability of retinol, synthesis of atRA by ALDH1A enzymes and metabolism and clearance of atRA by CYP26 enzymes. The ALDH1A and CYP26 enzymes are expressed in several cell types in the immune system and in cancer cells. In the immune system, the ALDH1A and CYP26 enzymes appear to modulate RA concentrations. Consequently, alterations in the activity of ALDH1A and CYP26 enzymes are expected to change disease outcomes in inflammation. There is increasing evidence from various disease models of intestinal and skin inflammation that treatment with atRA has a positive effect on disease markers. However, whether aberrant atRA concentrations or atRA synthesis and metabolism play a role in inflammatory disease development and progression is not well understood. In cancers, especially in acute promyelocytic leukemia and neuroblastoma, increasing intracellular concentrations of atRA appears to provide clinical benefit. Inhibition of the CYP26 enzymes to increase atRA concentrations and combat therapy resistance has been pursued as a drug target in these cancers. This chapter covers the current knowledge of how atRA and retinol regulate the immune system and inflammation, how retinol and atRA metabolism is altered in inflammation and cancer, and what roles atRA-metabolizing enzymes have in immune responses and cancers.

The activity of class I, II, III and IV alcohol dehydrogenase isoenzymes and aldehyde dehydrogenase in ovarian cancer and ovarian cysts

PURPOSE

The metabolism of cancerous cells is in many ways different than in healthy cells. In ovarian cancer, cells exhibit activity of alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH), which participate in metabolism of many biological substances. The aim of this study was to compare the metabolism of ovarian cancer cells, ovarian cysts and normal ovarian cells by measurement of ADH isoenzymes and ALDH activities.

MATERIAL AND METHODS

The study material consisted of 36 cancerous ovarian tissues. Class III, IV of ADH and total ADH activity was measured by the photometric method and class I, II ADH and ALDH activity by the fluorometric method with class-specific fluorogenic substrates.

RESULTS

The activity of the class I ADH isoenzyme and the total ADH was significantly higher in ovarian cancer as compared to ovarian cysts and healthy tissues but there are no significant differences between ovarian cysts and healthy cells. The other classes of ADH tested, did not show significant differences between activity of cancerous cells and healthy ovary.

CONCLUSION

The increased activity of total ADH in ovarian cancer, especially the class I isoenzyme and normal activity of ALDH, may be the factor for the disturbances in important biological substances metabolism and could increase the concentration of highly carcinogenic acetaldehyde.