Qualitative expression of hypoxia-inducible factor-1α in malignant transformation of oral submucous fibrosis: An immunohistochemical study

Computational analysis of phytocompounds in Centella asiatica for its antifibrotic and drug-likeness properties - Herb to drug study

Oral submucous fibrosis (OSMF) is a potentially malignant disorder with no permanent cure that affects the quality of life due to trismus. Computational pharmacology has accelerated the discovery of drug candidates for the treatment of incurable diseases. The present study aimed to screen the compounds of the miracle herb Centella asiatica with drug-likeness properties based on the absorption, distribution, metabolism, and excretion (ADME) properties. The pharmacological actions of these screened compounds against OSMF were identified by network pharmacology, gene ontology, pathway enrichment analysis, molecular docking, and simulation. Fifteen drug-like ligands were identified after virtual screening viz; asiatic acid, kaempferol, quercetin, luteolin, apigenin, bayogenin, gallic acid, isothankunic acid, madecassic acid, madasiatic acid, arjunolic acid, terminolic acid, catechin, epicatechin, and nobiletin. 850 potential targets were predicted for the ligands, which were analyzed against 354 proteins associated with OSMF. Compound pathway analysis and disease pathway analysis identified 53 common proteins. The GO enrichment analysis identified 472 biological process terms, 76 molecular function terms, and 44 cellular component terms. Pathway enrichment analysis predicted 142 KEGG pathways, 35 Biocarta pathways, and 236 Reactome pathways for the target proteins. The analysis revealed that the herb targets crucial events of fibrosis such as inflammation, oxidative stress, apoptosis, collagen deposition, and epithelial-mesenchymal transition. The common 53 proteins were used for protein-protein interaction (PPI) network analysis, which revealed 4 key proteins interacting with the phytocompounds viz; transforming growth factor-β1 (TGF-β1), mothers against decapentaplegic-3 (SMAD-3), mitogen-activated protein kinase-1 (MAPK-1) and proto-oncogene tyrosine-protein kinase (SRC). Molecular docking revealed that all ligands had a good binding affinity to the target proteins. Bayogenin had the highest binding affinity towards MAPK-1 (-9.7 kcal/mol), followed by isothankunic acid towards SRC protein (-9.3 kcal/mol). Madasiatic acid had the highest binding affinity to SMAD-3 (-7.6 kcal/mol) and TGF-β1 (-7.1 kcal/mol). Molecular dynamics simulation demonstrated stable ligand protein interactions of bayogenin and MAPK complex, isothankunic acid and SRC complex. This in silico study is the first to identify potential phytochemicals present in Centella asiatica and their target molecules, which might be responsible for reversing OSMF.

An enigmatic pathogenetic mechanism of hypoxia inducible factor - 1/2 alpha in the progression of fibrosis of oral submucous fibrosis and its malignant transformation: A systematic review and meta-analysis

OBJECTIVE

Oral submucous fibrosis is a frequently reported potentially malignant disorder characterized by fibrosis and a malignant transformation rate of 7-30%. The role of hypoxia-inducible factor-1/2α in malignant transformation mechanisms of oral submucous fibrosis remains uncharted territory owing to a scarcity of studies. Thus the present systematic review and meta-analysis aimed to determine the role of hypoxia-inducible factor-1/2α in the progression of fibrosis of oral submucous fibrosis and its malignant transformation.

MATERIAL AND METHODS

Using PubMed, Google Scholar, and Cochrane Library databases, full-text articles that investigated hypoxia-inducible factor-1/2α in oral submucous fibrosis were entailed for review. A modified Newcastle-Ottawa scale was employed to evaluate risk of bias in all articles and Review Manager was utilized for meta-analysis.

RESULTS

Eighteen and eight qualified articles respectively were included for qualitative and quantitative data synthesis. Progressive upregulation of hypoxia-inducible factor-1/2α in oral submucous fibrosis is associated with fibrosis-induced carcinogenesis. A Random-effects model uncloaked that oral submucous fibrosis cases with significantly increased expression of hypoxia-inducible factor-1α had an increased associated risk of malignant transformation compared with controls (combined odds ratio 523.83, 95% confidence interval 125.74- 2182.28, p < 0.00001).

CONCLUSION

The existing evidence substantiates the notion that hypoxia-inducible factor-1/2α, a fundamental pathogenetic mechanism of progression and malignant transformation of oral submucous fibrosis in the background of fibrosis.

The Study of Expression of Hypoxia-Inducible Factor-1 Alpha (HIF-1 Alpha) and Hypoxia-Inducible Factor-2 Alpha (HIF-2 Alpha) in Oral Squamous Cell Carcinoma: An Immunohistochemical Study

CONTEXT

Oral cancer is the major cause of mortality and morbidity worldwide. There are many factors that influence the tumor microenvironment that promotes tumorigenesis. Hypoxia is one of the factors that affects the process of angiogenesis by inducing proangiogenic factors to maintain the blood supply which in turn enhances the aggressiveness of the tumor and prognosis of solid tumors such as oral squamous cell carcinoma.

AIM AND OBJECTIVE

The aim of the study was to compare the expression of hypoxia-inducible factor 1α (HIF-1α) and hypoxia-inducible factor 2α (HIF-2α) in various histological grades of oral squamous cell carcinoma immunohistochemically.

METHODOLOGY

Immunohistochemical evaluation of HIF-1α and HIF-2α was done in 90 samples of oral squamous cell carcinoma which were graded histologically into 30 samples each of well, moderately and poorly differentiated squamous cell carcinoma. Statistical evaluation: Statistical analysis was done to study the prognostic significance of the biomarkers.

RESULTS

All the cases showed positivity for expression of HIF-1α and HIF-2α. The number of positive staining in both markers reduced as the tumor severity increased from well to poorly differentiated. The expression of MIL of HIF-2α was higher than HIF 1α and HIF 2α expression was mostly seen in cytoplasmic in well-differentiated and nuclear in both moderately and poorly differentiated OSCC suggestive that HIF-2α is a more specific marker to hypoxia.

CONCLUSION

Hypoxia is an essential factor that triggers other angiogenic switch and inflammatory factors which facilitates the process of tumorigenesis. This is also important for predicting the treatment outcome and prognosis of the patients. HIF-2α is a more sensitive marker that appears to be correlated and could perhaps serve as a good surrogate marker of hypoxia.

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.