Caspase-3 expression in normal oral epithelium, oral submucous fibrosis and oral squamous cell carcinoma

Mechanisms and markers of malignant transformation of oral submucous fibrosis

Oral submucous fibrosis (OSF) is a chronic premalignant disease associated with betel quid chewing. Epidemiological studies indicate that there are approximately 5 million individuals suffering from OSF worldwide, with a concerning malignancy transformation rate of up to 4.2 %. When OSF progresses to oral squamous cell carcinoma (OSCC), the 5-year survival rate for OSCC drops to below 60 %. Therefore, early screening and diagnosis are essential for both preventing and effectively treating OSF and its potential malignant transformation. Numerous studies have shown that the malignant transformation of OSF is associated with various factors, including epigenetic reprogramming, epithelial-mesenchymal transition, hypoxia, cell cycle changes, immune regulation disturbances, and oxidative damage. This review article focuses on the unraveling the potential mechanisms underlying the malignant transformation of OSF, as well as the abnormal expression of biomarkers throughout this transformative process, with the aim of aiding early screening for carcinogenic changes in OSF. Furthermore, we discuss the significance of utilizing blood and saliva components from patients with OSF, along with optical diagnostic techniques, in the early screening of OSF malignant transformation.

Comparison of Immunohistochemical Markers in Oral Submucous Fibrosis and Oral Submucous Fibrosis Transformed to Oral Squamous Cell Carcinoma-A Systematic Review and Meta-Analysis

The objective of the study was to compare the expression of immunohistochemical (IHC) markers of oral submucous fibrosis (OSMF) (non-transformed group) to those of oral squamous cell carcinoma (OSCC) transformed from OSMF (transformed group). The search for comparative cross-sectional studies was carried out in PubMed and Scopus abiding to the PICO criteria, where expression of IHC markers in OSMF were compared with that of OSCC transformed from OSMF. The cellular distribution, number of positive cases, staining intensity, and mean immunoreactive score (IRS) of each IHC marker were evaluated in both groups. A total of 14 studies were included in the systematic review, in which immunoexpression of 15 epithelial and 4 connective tissue biomarkers were evaluated. Expression of β1-integrin, OCT-3, CD1a, CD207, survivin, Dickkopf-1, COX-2, hTERT, CTGF, MDM2, Ki-67, and α-SMA were increased during transformation of OSMF to OSCC. Conversely, expression of PTEN and lysyl oxidase decreased during transformation of OSMF to OSCC. Expression of a group of epithelial markers, such as COX2, hTERT, CTGF, survivin, MDM2, and p53, was 38 times lower in the non-transformed group cases compared to transformed group cases (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Meta-analysis of all markers involved in cell metabolism/apoptosis, which included β1-integrin along with the above markers also suggested 42 times lower expression in the non-transformed group as compared to the transformed group (95% CI: 58% to 10%; p = 0.01; and I² = 90%). Sub-group analyses on cytoplasmic and nuclear epithelial markers were inconclusive. Meta-analysis of connective tissue markers was also inconclusive. No publication bias was found. Instead of delving into numerous markers without a strong basis for their use, it is advisable to further study the markers identified in this study to explore their clinical utility.

Molecular pathways of oral submucous fibrosis and its progression to malignancy

OBJECTIVE

The review aims to comprehend various factors engaged in the alteration of molecular events resulting in Oral submucous fibrosis (OSMF) and its malignant transformation.

DESIGN

Literature pertinent to pathways involved in OSMF were explored in databases such as PubMed, Scopus and Google Scholar. The relevant literature was reviewed and critically appraised in this narrative review.

RESULTS

Areca nut components influence myriad of cellular molecules such as cytokines, growth factors, myofibroblasts, non-coding RNAs and alter their expression. These aberrantly expressed molecules drive the progression of OSMF from localized inflammation to fibrosis of buccal mucosa. The oral tissue suffers from oxidative stress, hypoxia, autophagy, aberration of cell cycle and DNA damage. Apoptosis of epithelial layer results in its atrophy facilitating deeper penetration of areca nut elements. With the advance of disease, epithelial-mesenchymal transition eventuates and promotes dysplasia. The jeopardized expression of various cellular molecules, suppressed apoptosis, along with increased genetic alterations and neovascularization favors the malignant transformation.

CONCLUSION

OSMF is a progressive disorder with complex mechanism of pathogenesis initiated by inflammation of oral mucosa. Continuous habit of areca nut chewing and the resulting insult to the tissues prevents healing process and is destined to debilitating disease which affects the quality of life with a higher probability of progression to malignancy.

Evaluation of Caspase-3 and Ki-67 expression in squamous cell hyperplasia of the stomach induced by Platycodi radix water extract in Sprague–Dawley rats

Platycodi radix is widely used in traditional herbal medicine for the treatment of bronchitis, asthma, pulmonary tuberculosis, hypertension, hyperlipidemia, and diabetes. This study aimed to investigate cell proliferation (Ki-67) and apoptosis (Caspase-3) potential in squamous cell hyperplasia of the stomach induced by a Platycodi radix water extract in a subchronic toxicity study. One hundred formalin-fixed, paraffin-embedded stomach tissues of rats treated with Platycodi radix at doses of 0, 500, 1,000, and 3,000 mg/kg body weight/day were used for the analysis. They were conventionally stained using hematoxylin and eosin (H&E) and immunohistochemically (IHC) stained using caspase-3 and Ki-67 antibodies. The incidence of squamous cell hyperplasia was significantly increased in the 3,000 mg/kg b.w./day treatment group in both sexes (p<0.01). However, the hyperplastic change was completely repaired after 4 weeks of recovery period. Ki-67 expression was similar in all groups, with no statistically significant differences among the groups. Caspase-3 expression was significantly increased in both sexes in the 3,000 mg/kg b.w./day treatment group (p<0.01), compared with the vehicle control groups, and then reduced to normal levels in the recovery groups in both sexes. In conclusion, this study showed that squamous cell hyperplasia induced by the Platycodi radix water extract in the limiting ridge of the stomach is not considered to be abnormal proliferative change; as a result, squamous cell hyperplasia is considered to be a non-adverse effect when induced by the oral administration of the Platycodi radix water extract once daily for 13 weeks in rats.

Effects of dose-dependent response to gamma radiation on circumvallate papilla by expression of caspase-3 in vivo

BACKGROUND

Radiotherapy is one of the most significant treatment modality of head and neck cancers. However, it has various hazards on the normal tissues in the radiation field. One of these affected tissues is the lingual mucosa with their papillae such as circumvallate papilla. The effects of radiation on the lingual specialized mucosa may be represented by radiation-induced mucositis and taste alteration including partial or complete loss of taste.

OBJECTIVES

The aim of the study was to evaluate the dose-dependent response of circumvallate papillae to gamma radiation by immunohistochemical expression of caspase-3.

MATERIAL AND METHODS

Twenty-four adult male albino rats were divided into 3 equal groups irradiated at 2.0, 4.0 and 6.0 Gy whole-body gamma radiation doses. Six non-irradiated rats were used as the control group. The radiation effects on circumvallate papillae were evaluated three days after irradiation via histomorphometric investigation of the papillary size and taste buds' distortion in addition to an immunohistochemical assessment of the apoptotic activity using Caspase-3 marker.

RESULTS

Dose-related changes were observed in the circumvallate papillae size and morphology and taste buds affection. The changes were obviously detected in rats irradiated at 4 Gy and 6 Gy doses. The detection of caspase-3 marker was evident in a dose-dependent manner in all the irradiated groups, more noticeably in the taste bud cells.

CONCLUSIONS

It could be concluded that circumvallate papillae are adversely affected in a dose-dependent manner by gamma radiation particularly in 4 Gy and 6 Gy doses.

Clinicopathological Correlation of Cyclooxygenase 2 Expression in Oral Submucous Fibrosis: An Immunohistochemical Study

Background:

Oral submucous fibrosis (OSMF) has a high prevalence in Southeast Asia with increased malignant transformation rates. Numerous biomarkers are currently being investigated to predict the disease prognosis and for early detection of malignant changes.

Materials and Methods:

A prospective study was conducted comprising 40 subjects with clinically and biopsy-proven OSMF being included in the study as experimental group (n = 28) and patients with no tobacco/betel nut habit, who underwent surgical removal of third molar, being included as control group (n = 12). About 5-μm sections from formalin-fixed paraffin-embedded tissue blocks were obtained for immunohistochemical (IHC) study. The expression of cyclooxygenase 2 (COX 2) was evaluated in the experimental group and compared in morphologically normal oral epithelium. The intensity of stain was assessed at different levels of epithelium (basal, stratum spinosum, superficial level) and connective tissue.

Results:

Based on IHC expression of COX 2, all the patients of the control group were negative for COX 2, and among the OSMF group, 19 patients (67.9%) were positive and 9 patients (32.1%) were found to be negative for COX 2. The association of COX2 expression on comparison of controls with OSMF was found to be statistically significant (χ² =21.955; P = 0.000). On comparison of immune expression of COX 2 in different clinical stages based on functional staging, we found significant association of COX 2 expression with the stage of OSMF (χ² = 7.368; P = 0.025).

Conclusion:

The significant expression of COX 2 in different clinical stages of OSMF when compared with normal shows the role of COX 2 in the pathogenesis of OSMF and could serve as a potent biomarker for assessing the disease progression.

Stress hormones promote DNA damage in human oral keratinocytes

Chronic stress increases the systemic levels of stress hormones norepinephrine and cortisol. As well as tobacco-specific carcinogen NNK (4-(methylnitrosamine)-1-(3-pyridyl)-1-butanone), they can induce expressive DNA damage contributing to the cancer development. However, it is unknown whether stress hormones have genotoxic effects in oral keratinocytes. This study investigated the effects of stress hormones on DNA damage in a human oral keratinocyte cell line (NOK-SI). NOK-SI cells stimulated with norepinephrine or cortisol showed higher DNA damage compared to untreated cells. Norepinephrine-induced DNA damage was reversed by pre-treatment with beta-adrenergic blocker propranolol. Cells treated with NNK combined to norepinephrine displayed reduced levels of caspases 3 and 7. Cortisol also reduced the activity of pro-apoptotic enzymes. NNK or norepinephrine promoted single-strand breaks and alkali-label side breaks in the DNA of NOK-SI cells. Pre-treatment of cells with propranolol abolished these effects. Carcinogen NNK in the presence or absence of cortisol also induced DNA damage of these cells. The genotoxic effects of cortisol alone and hormone combined with NNK were blocked partially and totally, respectively, by the glucocorticoid receptor antagonist RU486. DNA damage promoted by NNK or cortisol and carcinogen combined to the hormone led to intracellular γH2AX accumulation. The effects caused by NNK and cortisol were reversed by propranolol and glucocorticoid receptor antagonist RU486, respectively. Propranolol inhibited the oxidation of basis induced by NNK in the presence of DNA-formamidopyrimidine glycosylase. DNA breaks induced by norepinephrine in the presence or absence of NNK resulted in higher 8OHdG cellular levels. This effect was also induced through beta-adrenergic receptors. Together, these findings indicate that stress hormones induce DNA damage of oral keratinocytes and could contribute to oral carcinogenesis.

A systematic review on the mechanisms of malignant transformation of oral submucous fibrosis

Oral submucous fibrosis (OSMF), the most commonly encountered potentially premalignant oral epithelial lesion, is a chronic disorder associated with areca nut chewing. It has a relatively high potential for malignant transformation resulting into oral squamous cell carcinoma (OSCC), the most common oral malignancy with high mortality rate. Paymaster first described the malignant potential of OSMF in 1956, the rate of which had been estimated to be 7-13%. The pathogenesis of OSMF in itself is quite varied, and hence, its transformation to malignancy is also open to many varied mechanisms. The early diagnosis and sequentially, early treatment of OSMF is desirable so that the progression towards malignancy can be controlled. There are various theories that have been put forward explaining the probable pathway of malignant transformation of OSMF such as hypoxia, areca nut as a carcinogen or epithelial-mesenchymal transitions. Many recent molecular advances have also highlighted few biomarkers and genes that play a pivotal role in transformation of OSMF to OSCC. The purpose of this systematic review is to discuss all the possible mechanisms of malignant transformation of OSMF. Further research is still needed to establish the exact mechanism responsible for transformation of OSMF to OSCC and to reduce the mortality by newer interventions.

Loss of oral mucosal stem cell markers in oral submucous fibrosis and their reactivation in malignant transformation

The integrity of the basal stem cell layer is critical for epithelial homoeostasis. In this paper, we review the expression of oral mucosal stem cell markers (OM-SCMs) in oral submucous fibrosis (OSF), oral potentially malignant disorders (OPMDs) and oral squamous cell carcinoma (OSCC) to understand the role of basal cells in potentiating cancer stem cell behaviour in OSF. While the loss of basal cell clonogenicity triggers epithelial atrophy in OSF, the transition of the epithelium from atrophic to hyperplastic and eventually neoplastic involves the reactivation of basal stemness. The vacillating expression patterns of OM-SCMs confirm the role of keratins 5, 14, 19, CD44, β1-integrin, p63, sex-determining region Y box (SOX2), octamer-binding transcription factor 4 (Oct-4), c-MYC, B-cell-specific Moloney murine leukaemia virus integration site 1 (Bmi-1) and aldehyde dehydrogenase 1 (ALDH1) in OSF, OPMDs and OSCC. The downregulation of OM-SCMs in the atrophic epithelium of OSF and their upregulation during malignant transformation are illustrated with relevant literature in this review.

Significant elevation of serum caspase-3 levels in patients with intracerebral hemorrhage

BACKGROUND

Caspase-3 is a potential marker of apoptosis. We investigated whether serum caspase-3 concentrations were increased and its association with severity and prognosis after intracerebral hemorrhage (ICH).

METHODS

This prospective clinical study recruited 112 ICH patients and 112 healthy individuals. Serum was assayed for caspase-3 using enzyme-linked immunosorbent assay. Stroke severity was quantified by National Institute of Health Stroke Scale (NIHSS) and hematoma volume. Six-month outcome was measured by modified Rankin Scale. Analyses were performed using univariate and multivariate analyses.

RESULTS

Patients had significantly higher serum caspase-3 concentrations than controls. Capase-3 concentrations correlated with NIHSS score and hematoma volume. Serum caspase-3 emerged as an independent predictor for 6-month mortality and bad prognosis (modified Rankin scale score>2). Based on receiver operating characteristic curve, caspase-3 concentrations showed similar prognostic value when compared with NIHSS score and hematoma volume.

CONCLUSION

Serum caspase-3 concentrations are increased in ICH patients as well as correlate with clinical severity and prognosis.