Comprehending the crosstalk between Notch, Wnt and Hedgehog signaling pathways in oral squamous cell carcinoma - clinical implications.

BACKGROUND: Oral squamous cell carcinoma (OSCC) is a malignant oral cavity neoplasm that affects many people, especially in developing countries. Despite several advances that have been made in diagnosis and treatment, the morbidity and mortality rates due to OSCC remain high. Accumulating evidence indicates that aberrant activation of cellular signaling pathways, such as the Notch, Wnt and Hedgehog pathways, occurs during the development and metastasis of OSCC. In this review, we have articulated the roles of the Notch, Wnt and Hedgehog signaling pathways in OSCC and their crosstalk during tumor development and progression. We have also examined possible interactions and associations between these pathways and treatment regimens that could be employed to effectively tackle OSCC and/or prevent its recurrence. CONCLUSIONS: Activation of the Notch signaling pathway upregulates the expression of several genes, including c-Myc, ß-catenin, NF-κB and Shh. Associations between the Notch signaling pathway and other pathways have been shown to enhance OSCC tumor aggressiveness. Crosstalk between these pathways supports the maintenance of cancer stem cells (CSCs) and regulates OSCC cell motility. Thus, application of compounds that block these pathways may be a valid strategy to treat OSCC. Such compounds have already been employed in other types of cancer and could be repurposed for OSCC.

Downregulation of Notch4 - a prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma / Regulação descendente de Notch4 - um marcador prognóstico na distinção entre carcinoma verrucoso oral e carcinoma de células escamosas oral

Abstract Introduction: Oral verrucous carcinoma is a special form of well-differentiated squamous cell carcinoma which possesses specific clinical, morphologic and cytokinetic features that differ from other types of oral cancers and hence diagnosis requires immense experience in histopathology. Hence it is certainly important to distinguish such a lesion from other oral tumors as treatment strategies vary widely between them. Objective: In search of a critical diagnostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma, Notch4 receptor, one of the key regulatory molecules of the Notch signaling family has been aberrantly activated in the progression of several types of tumors. However its function in oral verrucous carcinoma remains unexplored. Thus the present study aims in determining the differential expression pattern of Notch4 in oral verrucous carcinoma and oral squamous cell carcinoma. Methods: Ten patients reported positive for oral cancer (5 patients with oral verrucous carcinoma and 5 patients with oral squamous cell carcinoma). Five normal tissue samples were also obtained and evaluated for clinicopathological parameters and immunohistochemistry, western blotting and real time polymerase chain reaction for Notch4 expression. Results: Our results reveal that the expression of Notch4 was considerably high in oral squamous cell carcinoma lesions compared to normal tissue, whereas in oral verrucous carcinoma, irrespective of the clinicopathological features, complete regulação descendente of Notch4 was observed. Conclusions: These preliminary findings strongly support the fact that Notch4 is downregulated in oral verrucous carcinoma and could be considered as a suitable prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma. This distinguishing marker can help in improving therapeutic options in patients diagnosed with oral verrucous carcinoma.

Resumo Introdução: O carcinoma verrucoso de cavidade oral é uma forma especial de carcinoma de células escamosas bem diferenciada que tem características clínicas, morfológicas e citocinéticas específicas que diferem de outros tipos de cânceres orais. Por essa razão, o diagnóstico requer grande experiência em histopatologia. Portanto, é certamente importante distingui-lo de outros tumores orais, pois as respectivas estratégias de tratamento variam muito. Objetivo: Em busca de um marcador de diagnóstico crítico na distinção entre o carcinoma verrucoso e o carcinoma de células escamosas de cavidade oral, o receptor Notch4, uma das principais moléculas reguladoras da família de sinalizadores Notch, foi ativado de maneira anormal na progressão de vários tipos de tumores. No entanto, sua função no carcinoma verrucoso permanece inexplorada. Assim, o presente estudo tem como objetivo determinar o padrão de expressão diferencial de Notch4 no carcinoma verrucoso e de células escamosas de cavidade oral. Método: Dez pacientes tiveram resultado positivo para câncer oral (cinco pacientes com carcinoma verrucoso e cinco pacientes com carcinoma de células escamosas) e cinco amostras normais foram também obtidas. Além da avaliação dos parâmetros clínico-patológicos, foram feitos análise imuno-histoquímica, Western Blot e reação de polimerase em cadeia em tempo real para a expressão de Notch4. Resultados: Nossos resultados revelam que a expressão de Notch4 foi consideravelmente alta em carcinomas de células escamosas em comparação com os tecidos normais, enquanto que no carcinoma verrucoso, independentemente das características clínico-patológicas, observou-se regulação descendente completa de Notch4. Conclusão: Esses achados preliminares apoiam fortemente o fato de que Notch4 estava regulado para baixo no carcinoma verrucoso oral e poderia ser considerado um marcador prognóstico adequado para distinguir entre carcinoma verrucoso e carcinoma de células escamosas de cavidade oral. Esse marcador distintivo pode ajudar a melhorar as opções terapêuticas em pacientes com diagnóstico de carcinoma verrucoso oral.

Downregulation of Notch4 - a prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma.

INTRODUCTION: Oral verrucous carcinoma is a special form of well-differentiated squamous cell carcinoma which possesses specific clinical, morphologic and cytokinetic features that differ from other types of oral cancers and hence diagnosis requires immense experience in histopathology. Hence it is certainly important to distinguish such a lesion from other oral tumors as treatment strategies vary widely between them. OBJECTIVE: In search of a critical diagnostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma, Notch4 receptor, one of the key regulatory molecules of the Notch signaling family has been aberrantly activated in the progression of several types of tumors. However its function in oral verrucous carcinoma remains unexplored. Thus the present study aims in determining the differential expression pattern of Notch4 in oral verrucous carcinoma and oral squamous cell carcinoma. METHODS: Ten patients reported positive for oral cancer (5 patients with oral verrucous carcinoma and 5 patients with oral squamous cell carcinoma). Five normal tissue samples were also obtained and evaluated for clinicopathological parameters and immunohistochemistry, western blotting and real time polymerase chain reaction for Notch4 expression. RESULTS: Our results reveal that the expression of Notch4 was considerably high in oral squamous cell carcinoma lesions compared to normal tissue, whereas in oral verrucous carcinoma, irrespective of the clinicopathological features, complete regulação descendente of Notch4 was observed. CONCLUSIONS: These preliminary findings strongly support the fact that Notch4 is downregulated in oral verrucous carcinoma and could be considered as a suitable prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma. This distinguishing marker can help in improving therapeutic options in patients diagnosed with oral verrucous carcinoma.

Hypoxia induced EMT: A review on the mechanism of tumor progression and metastasis in OSCC.

Hypoxia, a condition of low oxygen tension in tissues, has emerged as a crucial factor in tumor pathophysiology. Hypoxic microenvironment gives rise to altered cellular metabolism and triggers varied molecular responses. These responses promote tumor progression and confer radiation resistance and chemo resistance to tumors. The predominant molecules that are associated with hypoxia research are the hypoxia inducible factors (HIFs). HIFs are known to regulate a large group of genes that are involved in cell survival, proliferation, motility, metabolism, pH regulation, extracellular matrix function, inflammatory cell recruitment and angiogenesis by inducing the expression of their downstream target genes. The process of epithelial to mesenchymal transition (EMT) has been associated with metastasis in cancer. Reports also suggest that hypoxia triggers EMT in several types of cancer including breast cancer, prostate cancer and oral cancer. Oral cancer is a predominant cancer in Central and South East Asia. However, in the recent times, the incidence rates of oral cancer have been increasing in Northern and Eastern Europe as well. This review articulates the role of hypoxia and the associated factors like HIFs in inducing EMT in oral cancer (OSCC).

Clinical Applications of Induced Pluripotent Stem Cells - Stato Attuale.

In an adult human body, somatic stem cells are present in small amounts in almost all organs with the function of general maintenance and prevention of premature aging. But, these stem cells are not pluripotent and are unable to regenerate large cellular loss caused by infarctions or fractures especially in cells with limited replicative ability such as neurons and cardiomyocytes. These limitations gave rise to the idea of inducing pluripotency to adult somatic cells and thereby restoring their regeneration, replication and plasticity. Though many trials and research were focused on inducing pluripotency, a solid breakthrough was achieved by Yamanaka in 2006. Yamanaka's research identified 4 genes (OCT-4, SOX-2, KLF-4 and c-MYC) as the key requisite for inducing pluripotency in any somatic cells (iPSCs). Our study, reviews the major methods used for inducing pluripotency, differentiation into specific cell types and their application in both cell regeneration and disease modelling. We have also highlighted the current status of iPSCs in clinical applications by analysing the registered clinical trials. We believe that this review will assist the researchers to decide the parameters such as induction method and focus their efforts towards clinical application of iPSCs.

Genotoxicity evaluation of metformin and glimepiride by micronucleus assay in exfoliated urothelial cells of type 2 diabetes mellitus patients.

Micronucleus (MN) assay was performed on the exfoliated urothelial cells to detect the genotoxic effects of the anti-hyperglycemic drugs, metformin and glimepiride in T2DM patients and to use it as a biomarker for DNA damage by assessing the frequency of micronuclei in the exfoliated urothelial cells. A total of 201 subjects (147 T2DM patients & 54 Normal cases) were selected from diverse age groups (25-75 years) and the mean MN frequency was examined per 1000 cells in all the subjects. Relative to the control group (5.02 ± 1.01), an increased MN frequency was observed in females (26.15 ± 2.15) when compared to males (23.08 ± 2.09) in T2DM patients. Further analysis showed that there was a profound increase in the number of MN in the patients using metformin alone (23.02 ± 4.44), or combination of metformin & glimepiride (24.98 ± 2.87) than to the subjects using glimepiride alone (17.52 ± 3.28). It has been proven by this simple, reliable and non-invasive method that metformin has a potential role in causing genotoxicity and that the MN observed in exfoliated urothelial cells could be used as a reliable biomarker in monitoring the genotoxic risk of the anti-hyperglycemic drugs.

Efficiency of the intestinal bacteria in the degradation of the toxic pesticide, chlorpyrifos.

Chlorpyrifos (CP) is the most commonly used pesticide throughout the world. Its widespread use in agriculture and its potential toxicity to humans from ingestion of CP contaminated food have raised concerns about its risk to health. Human intestinal microflora has the ability to degrade pesticides, but the exact mechanisms involved and the metabolite end-products formed are not well understood. The primary objective of this work was to analyse the in vitro degradation of CP by five model intestinal bacteria namely Lactobacillus lactis, L. fermentum, L. plantarum, Escherichia coli and Enterococcus faecalis. Plate assay results revealed that L. lactis, E. coli and L. fermentum could grow with high concentrations of CP (>1,400 µg/mL), whereas E. faecalis and L. plantarum could grow with concentrations as low as 400 and 100 µg/mL, respectively. The best three CP degraders were therefore used in further experiments. The degradation of CP-induced organophosphorous phosphatase (OPP) production and that OPP concentration were higher in the supernatant (extracellular) rather than inside the cells by factor of up to 28. L. fermentum degraded 70 % CP with 3,5,6-trichloro-2-pyridinol (TCP) detected as the end product. L.lactis degraded up to 61 % CP with chlorpyrifos oxon detected as the end product, whereas E.coli degraded a lesser concentration (16 %) to chlorpyrifos-oxon and diethylphosphate.