Lactate dehydrogenase isoenzymes in squamous cell carcinomas of the oral cavity

Evaluation of Serum and Salivary Lactate Dehydrogenase Levels in Patients with Oral Potentially Malignant Conditions/Lesions: A Clinical and Biochemical Study

Background

Oral cancer encompasses all malignancies that originate in the oral tissues and remains a major public health problem throughout the world as an important case of poor health and illness. Head and neck cancer accounts for 9.8% of the estimated 6,44,600 incidental cancer cases in India. Oral Squamous Cell Carcinoma (SCC) is a serious and developing concern globally, accounting for more than 90% of malignant cancers of the oral cavity. Salivary diagnostics have been demonstrated to have potential in the detection and screening of oral pre-cancer and cancer in a variety of research settings. The continual and close contact between saliva and the mucosa, where cancer develops, is the foundation of this diagnostic capability.

Materials and Methods

This research utilized spectrophotometry to quantify Lactate Dehydrogenase levels in serum and saliva of 30 healthy people which consisted the control group and 31 Oral Potentially Malignant people which constituted the study group.

Results

On estimation and comparison, the mean Lactate Dehydrogenase levels in serum (397.4968+71.6392 IU/L) and saliva (675.4935+139.3352 IU/L) among patients with Oral Potentially malignant lesions/conditions were higher than the mean Lactate Dehydrogenase levels in serum (390.8667+71.0953 IU/L) and saliva (201.3700+89.1439 IU/L) among controls.

Conclusion

Higher serum and salivary LDH levels in Oral Potentially malignant lesions/conditions than in control groups signifies the importance of assessing salivary LDH levels, in the prognosis of the same. Further prospective longitudinal studies are required to assess the salivary LDH levels among the patients with malignant transformation of Oral Potentially malignant lesions/conditions to oral cancers.

Serum and salivary levels of lactate dehydrogenase in oral squamous cell carcinoma, oral lichen planus and oral lichenoid reaction

BACKGROUND

Increased levels of lactate dehydrogenase (LDH) as a tumor marker have been reported in malignant and some premalignant oral lesions such as oral lichen planus (OLP) and oral lichenoid reactions (OLRs). This study aimed to assess the level of total LDH in the saliva and serum of patients with oral squamous cell carcinoma (OSCC), OLP and OLRs.

METHODS

In this case-control study, the participants were divided into four groups (n = 25) of healthy controls, OLP, OLRs, and OSCC. The serum and stimulated/unstimulated salivary levels of LDH were spectrophotometrically measured using standard LDH kits (Pars Azmoun). One-way ANOVA, Chi-square test, Pearson's correlation test, and receiver operating characteristic (ROC) analysis were applied to analyze the data.

RESULTS

The serum and salivary levels of LDH in OSCC patients were significantly higher than that the corresponding values in other groups (P = 0.0001). The serum level of LDH in OLR group was significantly higher than that in the control and OLP groups (P = 0.0001), but the difference in salivary level of LDH was not significant. The ROC analysis showed that both the serum and salivary levels of LDH had significant diagnostic ability for detection of OSCC and OLRs. Significant associations were noted between the serum and salivary levels of LDH.

CONCLUSIONS

Patients with OSCC and OLRs had higher serum levels of LDH than OLP and control groups. Further prospective longitudinal studies are required to assess the tissue level of LDH and monitor the transformation of OLRs because they have low rate of malignant transformation compared with other oral premalignant lesions.

Evaluation of lactate dehydrogenase enzyme activity in saliva and serum of oral submucous fibrosis patients

BACKGROUND

Of all oral precancerous conditions, Oral Submucous Fibrosis is of greater concern because of its disabling nature and relative greater chances of malignant transformation. This malignant transformation involves glycolytic pathways that can alter lactate dehydrogenase levels. Therefore the aim of this study was to estimate the LDH levels in saliva and serum of subjects with OSMF and to compare them with healthy controls and to correlate the relationship between pathogenesis of OSMF and the LDH enzyme.

METHODS

Sixty Subjects were recruited for this study and divided into two groups, 30 subjects with OSMF (Group A) and 30 healthy controls (Group B). Venous blood and unstimulated whole saliva measuring 1 ml was collected from each of these evaluated for LDH levels using the standard kit method. The data obtained were subjected to statistical analysis using the SPSS software version 17.

RESULTS

The average salivary LDH value for Group A was 606.83 ± 60.09 U/l and for Group B was 80.73 ± 20.06 U/l. salivary LDH was greater in group A than Group B and this was statistically significant. On comparing the serum and salivary LDH in Group A with the clinical staging of OSMF, the results were not statistically significant. Similarly no statistically significant relationship was found on comparing the serum and salivary LDH in Group A (OSMF subjects) with duration of habit.

CONCLUSION

This study provides additional rationale for the role of salivary LDH in the early diagnosis and prognosis of oral submucous fibrosis.

LDH enzyme activity in human saliva: the effect of exposure to cigarette smoke and its different components

OBJECTIVE

Aldehydes and reactive nitrogen species (RNS) are important chemically active agents in cigarette smoke (CS). Salivary lactate dehydrogenase (LDH) originates predominantly from oral epithelium and was identified as an oral state marker. Its activity in saliva decreases after CS exposure. The aims of the current study were to identify the specific damaging agents in CS responsible for this activity reduction and to understand the mechanisms participating in CS oxidative damage to the salivary enzymes.

METHODS

Purified and salivary LDH samples were exposed to different levels of CS, pure acrolein, acetaldehyde, peroxynitrite and RNS donors. Each response of the isolated agent to the exposure was examined by a spectrophotometric enzyme activity assay and a Western blot.

RESULTS

CS exposure caused a 34% reduction in LDH activity. Isolated treatment with unsaturated-aldehydes (acrolein, 10μmol) caused a 61% reduction, while saturated-aldehydes (acetaldehyde, 200μmol), peroxynitrite (200μM) and RNS donor (SIN-1, 2mM) caused no substantial effect. All five LDH isoenzymes reacted similarly. The carbonyl immunoblotting assay revealed a fourfold increase in carbonyl content when treated with CS and a sevenfold increase when treated with acrolein.

CONCLUSION

α,β-Unsaturated-aldehydes were identified as the main CS ingredient responsible for salivary LDH activity diminution. The effect of saturated-aldehydes and RNS donors was negligible. Unsaturated-aldehydes are capable of introducing carbonyl group into proteins, causing their dysfunction. This provides a molecular explanation for a decrease in LDH enzymatic activity in saliva.

Tissue markers of potentially malignant human oral epithelial lesions

Tissue markers of potential malignancy have been sought for many years. Cell surface markers, particularly blood group and histocompatibility antigens, have shown great promise and several squamous carcinoma antigens have been identified--but not fully studied in potentially malignant lesions. Growth factors and receptors also need further study. Cytoplasmic markers of potential malignancy have been examined and, of these, keratins, filaggrin, and some carcinoma antigens show most promise. Nuclear analyses have promise but are time-consuming and expensive. Image cytometric analyses appear to be sensitive and predictive: oncogene and tumour suppressor analyses remain to be fully evaluated. New investigative techniques at the cellular and molecular level show increasing promise at defining potentially malignant oral epithelial lesions but more prospective studies are required.