Nerve growth factor-induced migration in oral and salivary gland tumour cells utilises the PI3K/Akt signalling pathway: Is there a link to perineural invasion?

Nerve-tumor crosstalk in tumor microenvironment: From tumor initiation and progression to clinical implications

The autonomic nerve system (ANS) innervates organs and tissues throughout the body and maintains functional balance among various systems. Further investigations have shown that excessive activation of ANS not only causes disruption of homeostasis, but also may promote tumor formation. In addition, the dynamic interaction between nerve and tumor cells in the tumor microenvironment also regulate tumor progression. On the one hand, nerves are passively invaded by tumor cells, that is, perineural invasion (PNI). On the other hand, compared with normal tissues, tumor tissues are subject to more abundant innervation, and nerves can influence tumor progression through regulating tumor proliferation, metastasis and drug resistance. A large number of studies have shown that nerve-tumor crosstalk, including PNI and innervation, is closely related to the prognosis of patients, and contributes to the formation of cancer pain, which significantly deteriorates the quality of life for patients. These findings suggest that nerve-tumor crosstalk represents a potential target for anti-tumor therapies and the management of cancer pain in the future. In this review, we systematically describe the mechanism by which nerve-tumor crosstalk regulates tumorigenesis and progression.

Nerve Growth Factor and the Role of Inflammation in Tumor Development

Nerve growth factor (NGF) plays a dual role both in inflammatory states and cancer, acting both as a pro-inflammatory and oncogenic factor and as an anti-inflammatory and pro-apoptotic mediator in a context-dependent way based on the signaling networks and its interaction with diverse cellular components within the microenvironment. This report aims to provide a summary and subsequent review of the literature on the role of NGF in regulating the inflammatory microenvironment and tumor cell growth, survival, and death. The role of NGF in inflammation and tumorigenesis as a component of the inflammatory system, its interaction with the various components of the respective microenvironments, its ability to cause epigenetic changes, and its role in the treatment of cancer have been highlighted in this paper.

Role of Akt/Protein Kinase B in Cancer Metastasis

Metastasis is a critical step in the process of carcinogenesis and a vast majority of cancer-related mortalities result from metastatic disease that is resistant to current therapies. Cell migration and invasion are the first steps of the metastasis process, which mainly occurs by two important biological mechanisms, i.e., cytoskeletal remodelling and epithelial to mesenchymal transition (EMT). Akt (also known as protein kinase B) is a central signalling molecule of the PI3K-Akt signalling pathway. Aberrant activation of this pathway has been identified in a wide range of cancers. Several studies have revealed that Akt actively engages with the migratory process in motile cells, including metastatic cancer cells. The downstream signalling mechanism of Akt in cell migration depends upon the tumour type, sites, and intracellular localisation of activated Akt. In this review, we focus on the role of Akt in the regulation of two events that control cell migration and invasion in various cancers including head and neck squamous cell carcinoma (HNSCC) and the status of PI3K-Akt pathway inhibitors in clinical trials in metastatic cancers.

Unraveling the Mysteries of Perineural Invasion in Benign and Malignant Conditions

Perineural invasion (PNI) is defined as the dissemination of neoplastic cells within the perineural space. PNI can be a strong indicator of malignancy and is linked to poor prognosis and adverse outcomes in various malignant neoplasms; nevertheless, it can also be seen in benign pathologic conditions. In this review article, we discuss various signaling pathways and neurotrophic factors implicated in the development and progression of PNI. We also describe the methodology, benefits, and limitations of different in vitro, ex vivo, and in vivo models of PNI. The spectrum of presentation for PNI can range from diffuse spread within large nerves ("named" nerves) all the way through localized spread into unnamed microscopic nerves. Therefore, the clinical significance of PNI is related to its extent rather than its mere presence or absence. In this article, we discuss the guidelines for the identification and quantification of PNI in different malignant neoplasms based on the College of American Pathologists (CAP) and World Health Organization (WHO) recommendations. We also describe benign pathologic conditions and neoplasms demonstrating PNI and potential mimics of PNI. Finally, we explore avenues for the future development of targeted therapy options via modulation of signaling pathways involved in PNI.

Perineural Invasion (PNI) Definition, Histopathological Parameters of PNI in Oral Squamous Cell Carcinoma With Molecular Insight and Prognostic Significance

Oral squamous cell carcinoma is associated with severe morbidity, recurrence of tumor, and reduced survival rate despite advances in treatment. Perineural invasion (PNI) is associated with neurotropic malignancy. PNI is due to the tropism of cancer cells toward nerve bundles in tissue. The aim of this literature review is to study the definition, patterns of PNI, Prognostic and therapeutic significance, and mechanism of PNI along with a molecular insight into oral cavity squamous cell carcinoma. Liebig type A pattern defines PNI as the presence of tumor cells within the peripheral nerve sheath & infiltration into the epineurium, perineurium, or endoneurium. Liebig type B pattern defines PNI as a tumor encircling at least 33% of a nerve. Few studies demonstrated an association between PNI and cervical metastasis which indicate poor prognosis. A higher level of expression of nerve growth factor and tyrosine kinase is associated with PNI in OSCC which can be considered as a biomarker of PNI. PNI needs to be studied in detail as it is associated with the aggressiveness of the tumor and decreased survival.

Perineural invasion-associated biomarkers for tumor development

Perineural invasion (PNI) is the process of neoplastic invasion of peripheral nerves and is considered to be the fifth mode of cancer metastasis. PNI has been detected in head and neck tumors and pancreatic, prostate, bile duct, gastric, and colorectal cancers. It leads to poor prognostic outcomes and high local recurrence rates. Despite the increasing number of studies on PNI, targeted therapeutic modalities have not been proposed. The identification of PNI-related biomarkers would facilitate the non-invasive and early diagnosis of cancers, the establishment of prognostic panels, and the development of targeted therapeutic approaches. In this review, we compile information on the molecular mediators involved in PNI-associated cancers. The expression and prognostic significance of molecular mediators and their receptors in PNI-associated cancers are analyzed, and the possible mechanisms of action of these mediators in PNI are explored, as well as the association of cells in the microenvironment where PNI occurs.

Neurotrophin Pathway Receptors NGFR and TrkA Control Perineural Invasion, Metastasis, and Pain in Oral Cancer

Oral squamous cell carcinoma (OSCC) patients suffer from poor survival due to metastasis or locoregional recurrence, processes that are both facilitated by perineural invasion (PNI). OSCC has higher rates of PNI than other cancer subtypes, with PNI present in 80% of tumors. Despite the impact of PNI on oral cancer prognosis and pain, little is known about the genes that drive PNI, which in turn drive pain, invasion, and metastasis. In this study, clinical data, preclinical, and in vitro models are leveraged to elucidate the role of neurotrophins in OSCC metastasis, PNI, and pain. The expression data in OSCC patients with metastasis, PNI, or pain demonstrate dysregulation of neurotrophin genes. TrkA and nerve growth factor receptor (NGFR) are focused, two receptors that are activated by NGF, a neurotrophin expressed at high levels in OSCC. It is demonstrated that targeted knockdown of these two receptors inhibits proliferation and invasion in an in vitro and preclinical model of OSCC, and metastasis, PNI, and pain. It is further determined that TrkA knockdown alone inhibits thermal hyperalgesia, whereas NGFR knockdown alone inhibits mechanical allodynia. Collectively the results highlight the ability of OSCC to co-opt different components of the neurotrophin pathway in metastasis, PNI, and pain.

Inflammatory bowel disease: an overview of Chinese herbal medicine formula-based treatment

Inflammatory bowel disease (IBD) is a chronic recurrent inflammatory disease of the intestine, including Crohn’s disease (CD) and ulcerative colitis (UC), whose etiology and pathogenesis have not been fully understood. Due to its prolonged course and chronic recurrence, IBD imposes a heavy economic burden and psychological stress on patients. Traditional Chinese Herbal Medicine has unique advantages in IBD treatment because of its symptomatic treatment. However, the advantages of the Chinese Herbal Medicine Formula (CHMF) have rarely been discussed. In recent years, many scholars have conducted fundamental studies on CHMF to delay IBD from different perspectives and found that CHMF may help maintain intestinal integrity, reduce inflammation, and decrease oxidative stress, thus playing a positive role in the treatment of IBD. Therefore, this review focuses on the mechanisms associated with CHMF in IBD treatment. CHMF has apparent advantages. In addition to the exact composition and controlled quality of modern drugs, it also has multi-component and multi-target synergistic effects. CHMF has good prospects in the treatment of IBD, but its multi-agent composition and wide range of targets exacerbate the difficulty of studying its treatment of IBD. Future research on CHMF-related mechanisms is needed to achieve better efficacy.

Receptor, Signal, Nucleus, Action: Signals That Pass through Akt on the Road to Head and Neck Cancer Cell Migration

Simple Summary

The ecosystem that surrounds a tumour, the microenvironment, has a huge impact on the spread of cancer, but its exact role in the molecular mechanism of spreading is still under scrutiny. This literature review aims to focus on the evidence published on the production of growth factors or proteins from the tumour microenvironment, which initiate signals in cancer cells. This review provides evidence that when Akt, a signalling protein, is activated by different growth factors such as epidermal growth factor, transforming growth factor α/β, vascular endothelial growth factor and nerve growth factor, head and neck cancer cell spreading is stimulated. In a nutshell, it demonstrates that the tumour microenvironment plays an important role in cancer spreading by synthesising and secreting growth factors and suggests that targeting growth-factor-activated Akt in combination therapy could be a valuable therapeutic approach in treating head and neck cancer patients.

Abstract

This review aims to provide evidence for the role of the tumour microenvironment in cancer progression, including invasion and metastasis. The tumour microenvironment is complex and consists of tumour cells and stromal-derived cells, in addition to a modified extracellular matrix. The cellular components synthesise growth factors such as EGF, TGFα and β, VEGF, and NGF, which have been shown to initiate paracrine signalling in head and neck cancer cells by binding to cell surface receptors. One example is the phosphorylation, and hence activation, of the signalling protein Akt, which can ultimately induce oral cancer cell migration in vitro. Blocking of Akt activation by an inhibitor, MK2206, leads to a significant decrease, in vitro, of cancer-derived cell migration, visualised in both wound healing and scatter assays. Signalling pathways have therefore been popular targets for the design of chemotherapeutic agents, but drug resistance has been observed and is related to direct tumour–tumour cell communication, the tumour–extracellular matrix interface, and tumour–stromal cell interactions. Translation of this knowledge to patient care is reliant upon a comprehensive understanding of the complex relationships present in the tumour microenvironment and could ultimately lead to the design of efficacious treatment regimens such as targeted therapy or novel therapeutic combinations.

Oxidative Stress and AKT-Associated Angiogenesis in a Zebrafish Model and Its Potential Application for Withanolides

Oxidative stress and the AKT serine/threonine kinase (AKT) signaling pathway are essential regulators in cellular migration, metastasis, and angiogenesis. More than 300 withanolides were discovered from the plant family Solanaceae, exhibiting diverse functions. Notably, the relationship between oxidative stress, AKT signaling, and angiogenesis in withanolide treatments lacks comprehensive understanding. Here, we summarize connecting evidence related to oxidative stress, AKT signaling, and angiogenesis in the zebrafish model. A convenient vertebrate model monitored the in vivo effects of developmental and tumor xenograft angiogenesis using zebrafish embryos. The oxidative stress and AKT-signaling-modulating abilities of withanolides were highlighted in cancer treatments, which indicated that further assessments of their angiogenesis-modulating potential are necessary in the future. Moreover, targeting AKT for inhibiting AKT and its AKT signaling shows the potential for anti-migration and anti-angiogenesis purposes for future application to withanolides. This particularly holds for investigating the anti-angiogenetic effects mediated by the oxidative stress and AKT signaling pathways in withanolide-based cancer therapy in the future.

Expression of cartilage oligomeric matrix protein (COMP) associates with capsular invasion in salivary gland pleomorphic adenoma

BACKGROUND

Accumulating evidence shows that pleomorphic adenoma (PA) exhibits a unique capsular invasion and with a crucial role in recurrence. This study was designed to explore RNA expression profiles in salivary gland PA in an attempt to further analyse genes associate with capsule invasion.

METHODS

We evaluated the expression profiles of 4 salivary gland PA patients by RNA-sequencing. The principal functions of the differentially expressed mRNAs (DEGs) were explored using GO and KEGG analysis. Then, RT-qPCR and correlation analyses were performed to verify the candidate DEGs in 59 PA patients, and immunohistochemical examinations were conducted to validate candidate DEGs. Finally, the COMP-related genes were screened using correlation and biological pathway enrichment analysis, and further validated by RT-qPCR.

RESULTS

A total of 974 DEGs were significantly upregulated and 1464 were downregulated (fold change ≥2.0; p < 0.05). Based on GO and KEGG analyses, extracellular matrix organization and the PI3K-Akt signaling pathway might play pivotal roles in the tumorigenesis of PA. 40 DEGs were screened and validated by RT-qPCR, 11 upregulated and 5 downregulated DEGs were consistent with the sequencing results. Cartilage oligomeric matrix protein (COMP) was identified to have a significant correlation with the capsular invasion of PA and expression of COMP in patients with invasive capsular PA was significantly stronger than PA. Finally, further results could reveal that 5 highest-scoring genes were screened as hub genes for COMP.

CONCLUSIONS

These findings suggested that COMP may be a prognostic target for PA and might contribute to its capsular invasion.

Molecular and Cellular Mechanisms of Perineural Invasion in Oral Squamous Cell Carcinoma: Potential Targets for Therapeutic Intervention

Simple Summary

Squamous cell carcinoma is the most common type of oral cavity cancer. It can spread along and invade nerves in a process called perineural invasion. Perineural invasion can increase the chances of tumor recurrence and reduce survival in patients with oral cancer. Understanding how oral cancer interacts with nerves to facilitate perineural invasion is an important area of research. Targeting key events that contribute to perineural invasion in oral cavity cancer may reduce tumor recurrence and improve survival. In this review, we describe the impact of perineural invasion in oral cancer and the mechanisms that contribute to perineural invasion. Highlighting the key events of perineural invasion is important for the identification and testing of novel therapies for oral cancer with perineural invasion.

Abstract

The most common oral cavity cancer is squamous cell carcinoma (SCC), of which perineural invasion (PNI) is a significant prognostic factor associated with decreased survival and an increased rate of locoregional recurrence. In the classical theory of PNI, cancer was believed to invade nerves directly through the path of least resistance in the perineural space; however, more recent evidence suggests that PNI requires reciprocal signaling interactions between tumor cells and nerve components, particularly Schwann cells. Specifically, head and neck SCC can express neurotrophins and neurotrophin receptors that may contribute to cancer migration towards nerves, PNI, and neuritogenesis towards cancer. Through reciprocal signaling, recent studies also suggest that Schwann cells may play an important role in promoting PNI by migrating toward cancer cells, intercalating, and dispersing cancer, and facilitating cancer migration toward nerves. The interactions of neurotrophins with their high affinity receptors is a new area of interest in the development of pharmaceutical therapies for many types of cancer. In this comprehensive review, we discuss diagnosis and treatment of oral cavity SCC, how PNI affects locoregional recurrence and survival, and the impact of adjuvant therapies on tumors with PNI. We also describe the molecular and cellular mechanisms associated with PNI, including the expression of neurotrophins and their receptors, and highlight potential targets for therapeutic intervention for PNI in oral SCC.

Polymorphous Adenocarcinoma, Low Grade Variant, Colliding with a Neurofibroma

Collision tumors, composed of two distinct benign or malignant neoplasms, are rarely reported in the oral cavity. We present a case of a 61-year-old female with an asymptomatic non-demarcated lump on the soft palate of unknown duration. An incisional biopsy revealed the presence of two neoplastic populations, a neurofibroma that was partially infiltrated by a polymorphous adenocarcinoma, low-grade variant. Total surgical excision was performed, with uneventful follow-up period. The development of collision tumors may be incidental, although molecular events may influence the pathogenetic mechanism of the phenomenon.

Effect of tyrosine kinase inhibitors on cell migration and epithelial-to-mesenchymal transition in Asian head and neck cancer cell lines

BACKGROUND

We investigated the role of epidermal growth factor (EGF) and transforming growth factor α (TGFα) on Asian head and neck cancer patient cell lines; in terms of epithelial-to-mesenchymal transition (EMT) and cell migration to determine whether these changes could be reversed using tyrosine kinase inhibitors (Gefitinib and Erlotinib).

METHODS

Cell migration, protrusion and EMT were assessed using both Scatter assay and Scratch assay. Protein expression and localisation were evaluated using immunofluorescence, SDS-PAGE and Western blotting techniques to identify the involvement of phosphorylated MAPK (Thr202/Tyr204), phosphorylated EGFR (Y1068) and phosphorylated AKT (Ser473) protein expression.

RESULTS

EGF and TGFα induced an EMT-like phenotypical change, cellular protrusion and cell migration while Gefitinib and Erlotinib blocked these morphological changes and cell migration. We also examined the effect of EGF/TGF α± tyrosine kinase inhibitors on phosphorylation sites Y1068 of epidermal growth factor receptor (EGFR). Y1068 was phosphorylated in all test conditions, and all tested concentrations of inhibitors did not inhibit Y1068 phosphorylation. EGF and TGFα increased phosphorylation of MAPK (Thr202/Tyr204) residues compared with serum-free control while a one-hour pre-treatment with tyrosine kinase inhibitor(s) before addition of growth factors completely blocked this phosphorylation. Phosphorylation of Akt Ser 473 was also induced by EGF and TGFα, and a one-hour pre-treatment with the tyrosine kinas inhibitor(s) reduced this phosphorylation.

CONCLUSION

These data suggest that Gefitinib and Erlotinib prevent activation of downstream signalling proteins MAPK (Thr202/Tyr204) and Akt (Ser473) thereby blocking phenotypic change and cell migration. This study supports the potential therapeutic value of Gefitinib and Erlotinib in targeting head and neck cancer.

Nerve growth factor orchestrates NGAL and matrix metalloproteinases activity to promote colorectal cancer metastasis

PURPOSE

Colorectal cancer (CRC) is one most cancer type of high incidence and high mortality rate. Metastasis play an important role in survival rate and life quality of colorectal cancer patients. Nerve growth factor (NGF) has been shown to be involved in the metastasis and deterioration in many cancers, but the detail mechanisms in promoting the metastasis of colorectal cancer remain unknown. In this study, we aimed to explore the mechanism of NGF promoting colorectal cancer metastasis to provide new insights for developing NGF anti-colorectal cancer drugs.

METHODS

We examined the expression of NGF in human colorectal cancer by immunohistochemical staining, and Western blot to evaluate the relationship between NGF and colorectal cancer metastasis. Using biochemical experiments including wound healing assay, transwell migration and invasion assay, RT-PCR, Western blot and ELISA to explore the relative mechanism of NGF promoting colorectal cancer cells metastasis in vivo.

RESULTS

Our results found that the high expression of NGF was related with high incidence of metastasis. The binding of NGF to TrkA phosphorylated TrkA, which activated MAPK/Erk signaling pathway increasing the expression NGAL to enhance the activity of MMP2 and MMP9, promoted colorectal cancer metastasis.

CONCLUSION

Our finding demonstrated that NGF increased NGAL expression to enhance MMPs activity to promoted colorectal cancer cell metastasis by TrkA-MAPK/Erk axis.

Costunolide Induces Apoptosis via the Reactive Oxygen Species and Protein Kinase B Pathway in Oral Cancer Cells

Oral cancer (OC) has been attracted research attention in recent years as result of its high morbidity and mortality. Costunolide (CTD) possesses potential anticancer and bioactive abilities that have been confirmed in several types of cancers. However, its effects on oral cancer remain unclear. This study investigated the potential anticancer ability and underlying mechanisms of CTD in OC in vivo and in vitro. Cell viability and anchorage-independent colony formation assays were performed to examine the antigrowth effects of CTD on OC cells; assessments for migration and invasion of OC cells were conducted by transwell; Cell cycle and apoptosis were investigated by flow cytometry and verified by immunoblotting. The results revealed that CTD suppressed the proliferation, migration and invasion of oral cancer cells effectively and induced cell cycle arrest and apoptosis; regarding the mechanism, CTD bound to AKT directly by binding assay and repressed AKT activities through kinase assay, which thereby downregulating the downstream of AKT. Furthermore, CTD remarkably promotes the generation of reactive oxygen species by flow cytometry assay, leading to cell apoptosis. Notably, CTD strongly suppresses cell-derived xenograft OC tumor growth in an in vivo mouse model. In conclusion, our results suggested that costunolide might prevent progression of OC and promise to be a novel AKT inhibitor.

The Migration and Invasion of Oral Squamous Carcinoma Cells: Matrix, Growth Factor and Signalling Involvement

The link between the migration of cancer cells and the spread of cancers has been established for many years [...].

Perineural Invasion in Adenoid Cystic Carcinoma of the Salivary Glands: Where We Are and Where We Need to Go

Adenoid cystic carcinoma of the salivary gland (SACC) is a rare malignant tumors of the head and neck region, but it is one of the most common malignant tumors that are prone to perineural invasion (PNI) of the head and neck. The prognosis of patients with SACC is strongly associated with the presence of perineural spread (PNS). Although many contributing factors have been reported, the mechanisms underlying the preferential destruction of the blood-nerve barrier (BNB) by tumors and the infiltration of the tumor microenvironment by nerve fibers in SACC, have received little research attention. This review summarizes the current knowledge concerning the characteristics of SACC in relation to the PNI, and then highlights the interplay between components of the tumor microenvironment and perineural niche, as well as their contributions to the PNI. Finally, we provide new insights into the possible mechanisms underlying the pathogenesis of PNI, with particular emphasis on the role of extracellular vesicles that may serve as an attractive entry point in future studies.

Cadherin-11 cooperates with inflammatory factors to promote the migration and invasion of fibroblast-like synoviocytes in pigmented villonodular synovitis

Rationale: Pigmented villonodular synovitis (PVNS) is a destructive benign tumor-like hyperplastic disease that occurs in synovial tissue. Fibroblast-like synoviocytes (FLS) are the predominant cell type comprising the structure of the PVNS synovial lining layer. Due to a high recurrence rate, high invasion, migration, and cartilage destruction ability, PVNS causes substantial damage to patients and the efficacy of surgical resection is not satisfactory. Therefore, exploring the pathogenesis and identifying novel therapeutic targets for PVNS are urgently required. Currently, the pathogenesis of PVNS remains unclear, and there is uncertainty and controversy regarding whether PVNS is an inflammatory or a neoplastic disease. Cadherin-11 is a classical molecule that mediates hemophilic cell-to-cell adhesion in FLS and plays an important role in the normal synovium lining layer formation. This study aimed to explore the role of inflammation and cadherin-11 in PVNS pathogenesis and determine the effects of cadherin-11 as a molecular target for PVNS treatment.

Methods: FLS were primarily cultured from PVNS patients during arthroscopic synovectomy. The level of cytokines in the PVNS synovial fluid was evaluated using a human antibody array. Cadherin-11 expression of PVNS FLS was detected by qPCR, Western blots, tissue immunohistochemistry, and cell immunofluorescence. Cadherin-11 was down-regulated by siRNA or up-regulated with a plasmid, with or without inflammatory factor stimulation, and PI3K/Akt was inhibited with LY294002. The capacity of migration and invasion of PVNS FLS was tested using Transwell and wound-healing assays. Activation of the nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) pathways was detected by Western blots. Chondrocyte damage by PVNS FLS was assessed with a co-culture assay.

Results: Inflammatory factors (IL-1β and TNF-α) in the synovial fluid of PVNS patients were significantly up-regulated. Cadherin-11 was highly expressed in the FLS of PVNS patients, and positively correlated with recurrence, extra-articular migration, and cartilage destruction of PVNS. Knocking down of cadherin-11 inhibited the migration and invasion of PVNS FLS. Moreover, inflammatory factors up-regulated the expression of cadherin-11, which activated the NF-κB and MAPK signaling pathways and led to cartilage destruction. Inhibition of cadherin-11 blocked IL-1β- and TNF-α-induced activation of the above pathways, migration and invasion of PVNS FLS, and damage of chondrocyte. In addition, the elevation of cadherin-11 expression, together with the migration and invasion, of PVNS FLS was down-regulated by the inhibition of the PI3K/Akt signaling pathway.

Conclusions: Cadherin-11 plays an important role in the pathogenesis of PVNS and forms a positive feedback loop with inflammatory factors, which further activates the NF-κB and MAPK pathways to trigger an inflammatory cascade. Cadherin-11-mediated inflammation results in PVNS with high recurrence, invasiveness, and strong cartilage destruction ability, and eventually promotes the transformation of PVNS from the initial inflammatory disease to neoplastic disease. Thus, inhibition of cadherin-11 together with its related inflammatory reaction, represents a new therapeutic strategy for PVNS.

Perineural invasion in oral squamous cell carcinoma: Incidence, prognostic impact and molecular insight

BACKGROUND

The objective of this study was to characterise the incidence and prognostic correlation of perineural invasion (PNI) in oral squamous cell carcinoma and determine whether nerve growth factor and its receptor tyrosine Kinase A expression could be used as biological markers for PNI.

METHODS

A retrospective review of pathology reports of 430 patients with oral squamous cell carcinoma who were treated from 1992 to 2014 in Tayside, Scotland, was carried out. The expression of nerve growth factor and tyrosine kinase A was assessed with immunohistochemistry in 132 tissue sections of oral squamous cell carcinoma.

RESULTS

Perineural invasion was identified in 17.4% of oral squamous cell carcinomas. High expression of nerve growth factor and tyrosine kinase A was seen in 84% and 92% of oral squamous cell carcinoma, respectively. Tumours with PNI expressed nerve growth factor and tyrosine kinase A with a greater frequency than tumours without PNI. PNI and high expression of nerve growth factor were significantly associated with pain. PNI was significantly associated with stage IV tumours and poor disease-specific survival.

CONCLUSIONS

A higher level of expression of nerve growth factor and tyrosine kinase A may predict PNI and therefore may be considered as biological markers for PNI in oral squamous cell carcinoma. PNI and nerve growth factor overexpression may contribute to the pain generation in oral cancer patients. PNI and nerve growth factor expression can predict the aggressiveness and prognosis of oral squamous cell carcinoma patients.