Cytochrome P450 isoforms 1A1, 1B1 AND 2W1 as targets for therapeutic intervention in head and neck cancer.

Epidemiological studies have shown that head and neck cancer (HNC) is a complex multistage process that in part involves exposure to a combination of carcinogens and the capacity of certain drug-metabolising enzymes including cytochrome P450 (CYP) to detoxify or activate such carcinogens. In this study, CYP1A1, CYP1B1 and CYP2W1 expression in HNC was correlated with potential as target for duocarmycin prodrug activation and selective therapy. In the HNC cell lines, elevated expression was shown at the gene level for CYP1A1 and CYP1B1 whereas CYP2W1 was hardly detected. However, CYP2W1 was expressed in FaDu and Detroit-562 xenografts and in a cohort of human HNC samples. Functional activity was measured in Fadu and Detroit-562 cells using P450-Glo™ assay. Antiproliferative results of duocarmycin prodrugs ICT2700 and ICT2706 revealed FaDu and Detroit-562 as the most sensitive HNC cell lines. Administration of ICT2700 in vivo using a single dose of ICT2700 (150 mg/kg) showed preferential inhibition of small tumour growth (mean size of 60 mm3) in mice bearing FaDu xenografts. Significantly, our findings suggest a potential targeted therapeutic approach to manage HNCs by exploiting intratumoural CYP expression for metabolic activation of duocarmycin-based prodrugs such as ICT2700.

Artificial Intelligence-based methods in head and neck cancer diagnosis: an overview.

BACKGROUND: This paper reviews recent literature employing Artificial Intelligence/Machine Learning (AI/ML) methods for diagnostic evaluation of head and neck cancers (HNC) using automated image analysis. METHODS: Electronic database searches using MEDLINE via OVID, EMBASE and Google Scholar were conducted to retrieve articles using AI/ML for diagnostic evaluation of HNC (2009-2020). No restrictions were placed on the AI/ML method or imaging modality used. RESULTS: In total, 32 articles were identified. HNC sites included oral cavity (n = 16), nasopharynx (n = 3), oropharynx (n = 3), larynx (n = 2), salivary glands (n = 2), sinonasal (n = 1) and in five studies multiple sites were studied. Imaging modalities included histological (n = 9), radiological (n = 8), hyperspectral (n = 6), endoscopic/clinical (n = 5), infrared thermal (n = 1) and optical (n = 1). Clinicopathologic/genomic data were used in two studies. Traditional ML methods were employed in 22 studies (69%), deep learning (DL) in eight studies (25%) and a combination of these methods in two studies (6%). CONCLUSIONS: There is an increasing volume of studies exploring the role of AI/ML to aid HNC detection using a range of imaging modalities. These methods can achieve high degrees of accuracy that can exceed the abilities of human judgement in making data predictions. Large-scale multi-centric prospective studies are required to aid deployment into clinical practice.

Beauty is only mucosa deep: a retrospective analysis of oral lumps and bumps caused by cosmetic fillers.

Introduction The injection of dermal fillers into orofacial tissues is becoming increasingly popular for cosmetic purposes, in particular for lip augmentation. Both natural and synthetic filler materials are available, producing a spectrum of clinical and histological appearances.Aims The aim of this study was to review the clinicopathological characteristics of dermal filler cases from 2006 to 2016, reported at a specialist oral pathology unit.Methods An archival search of the pathology database was performed to retrieve cases reported as being consistent with cosmetic fillers.Results Ten cases of orofacial cosmetic fillers were retrieved. Of these cases, 100% were from female patients and the mean age of presentation was 47.6 years (range 24-68 years). The lips were the most frequently involved site (80%, n = 8). The majority of provisional diagnoses were related to salivary gland disease, including neoplasms (30%, n = 3), cysts (20%, n = 2) or inflammatory disease (10%, n = 1). Only two cases (20%) were clinically thought to be related to previous cosmetic injections. A variety of filler materials were seen, including collagen, hydroxyapatite and silicone. However, hyaluronic acid-based materials were the most common (50%, n = 5).Conclusions Complications of cosmetic dermal fillers are becoming more common and should be considered within a differential diagnosis for unusual orofacial swellings.

Extranodal extension in oral cancer: A role for the nodal microenvironment?

Oral squamous cell carcinoma (OSCC) is a significant cause of morbidity and mortality worldwide and accounts for the majority of head and neck cancers. Metastasis of primary tumours, primarily to cervical lymph nodes in the neck, is associated with worsening prognosis. Furthermore, the prognosis of patients with extranodal extension of metastatic tumour from the lymph nodes into the neck tissues is particularly poor. The factors affecting this process are poorly understood, and detection is difficult pre-surgery. Mounting evidence shows that components of the tumour microenvironment including cancer-associated fibroblasts, vascular and lymphatic endothelial cells, the extracellular matrix and inflammatory immune cells, are important modulators of tumour behaviour in primary OSCC and other cancers. However, little is known about the lymph node microenvironment, its response to tumour presence and role in extranodal extension. In addition, there are many lymph node-specific cell types and structures, such as fibroblast reticular cells and high endothelial venules, making the lymph node microenvironment distinct from that found at primary tumour sites, and which contribute to the nodal response to tumour presence. This review details the current knowledge regarding the lymph node tumour microenvironment in OSCC and its role in lymph node metastasis and extranodal extension and relates this to features of the primary tumour. Understanding the role that the lymph node microenvironment plays in promoting tumour development and extranodal extension may aid the identification of novel biomarkers and alternative treatment strategies to improve the prognosis of patients with advanced OSCC.

Characterisation of DOG-1 Expression in Salivary Gland Tumours and Comparison with Myoepithelial Markers.

DOG1 is an established diagnostic marker for gastrointestinal stromal tumours (GIST), but has been reported in salivary gland tumours (SGT) as an acinar and intercalated duct marker. However, its specificity and distribution is not well established. The aim of this study was to evaluate the diagnostic utility of DOG-1 expression in SGT in addition to comparing it with myoepithelial markers. Normal salivary tissue and SGT (n = 184) were examined for expression of DOG1 and a range of myoepithelial markers. SGT included: acinic cell carcinoma (ACC, n = 15), secretory carcinoma (SC, n = 9), pleomorphic adenoma (PA, n = 49), carcinoma ex-PA (Ca ex-PA, n = 11), adenoid cystic carcinoma (AdCC, n = 20), polymorphous adenocarcinoma (PAC, n = 6), myoepithelioma (n = 6), myoepithelial carcinoma (MC, n = 2), basal cell adenoma (BCA, n = 14), canalicular adenoma (CA, n = 19), mucoepidermoid carcinoma (MEC, n = 11), oncocytoma (n = 2), adenocarcinoma NOS (AdNOS, n = 4), basal cell adenocarcinoma (BCAC, n = 2), salivary duct carcinoma (SDC, n = 3) and papillary cystadenocarcinoma (PCAC, n = 1). Normal acini and ACC (14/15) showed strong luminal DOG1 staining; SC were largely negative with only focal expression in 3/9 cases. Luminal staining was seen in PA (14/49), PAC (4/6), Ca ex-PA (4/11) and AdCC (6/20). 8/11 MEC showed luminal and/or mucous cell staining. No staining was seen in myoepithelioma, MC, CA, adNOS and BCAC. BCA showed strong staining of myoepithelial cells in some cases (5/14). Variable myoepithelial DOG1 staining was seen in PA, Ca ex PA, BCA, SDC and PCAC which was not as consistent as myoepithelial markers such as calponin, p63 and αSMA. Absence of DOG1 can differentiate ACC from SC, but staining is variable in PA, PLGA and Ca ex-PA. Myoepithelial staining in some tumours but not in normal gland suggests a wider distribution in SGT than originally envisaged.

Epigenetic changes in histone acetylation underpin resistance to the topoisomerase I inhibitor irinotecan.

The topoisomerase I (TOP1) inhibitor irinotecan triggers cell death by trapping TOP1 on DNA, generating cytotoxic protein-linked DNA breaks (PDBs). Despite its wide application in a variety of solid tumors, the mechanisms of cancer cell resistance to irinotecan remains poorly understood. Here, we generated colorectal cancer (CRC) cell models for irinotecan resistance and report that resistance is neither due to downregulation of the main cellular target of irinotecan TOP1 nor upregulation of the key TOP1 PDB repair factor TDP1. Instead, the faster repair of PDBs underlies resistance, which is associated with perturbed histone H4K16 acetylation. Subsequent treatment of irinotecan-resistant, but not parental, CRC cells with histone deacetylase (HDAC) inhibitors can effectively overcome resistance. Immunohistochemical analyses of CRC tissues further corroborate the importance of histone H4K16 acetylation in CRC. Finally, the resistant clones exhibit cross-resistance with oxaliplatin but not with ionising radiation or 5-fluoruracil, suggesting that the latter two could be employed following loss of irinotecan response. These findings identify perturbed chromatin acetylation in irinotecan resistance and establish HDAC inhibitors as potential therapeutic means to overcome resistance.

Accuracy of staging of oral squamous cell carcinoma of the tongue: should incisional biopsy be done before or after magnetic resonance imaging?

Accurate staging of oral squamous cell carcinoma (oral SCC) is essential. Some clinicians delay diagnostic biopsy until after magnetic resonance imaging (MRI). We retrospectively studied the clinical records and histopathological databases of 58 patients with SCC of the tongue; 39 had biopsy before MRI and 19 afterwards. In the group who had the biopsy first, eight were up-staged, nine were down-staged, and in 22 the T stage was accurate. In those who had MRI first, the corresponding figures were two, six, and 11, respectively. The time between initial biopsy and excision was significantly longer in the MRI group (43 days), than in the biopsy group (16 days) (p<0.001). Differences in staging between the two groups were not significant. Whether the biopsy was taken before or after MRI does not seem to affect the accuracy of clinical staging, and to delay biopsy until after staging may be unnecessary.

Cytogenetic and immunohistochemical characterization of mammary analogue secretory carcinoma of salivary glands.

OBJECTIVES: Mammary analogue secretory carcinoma (MASC), initially considered a subset of acinic cell carcinoma (ACC), harbors an ETV6 translocation [t(12:15)(p13:25 q)] and is now regarded as a distinct entity. Several putative markers to differentiate MASC from ACC have been reported; however, the immunohistochemical profile is still being explored and updated. The purpose of this study was to further explore the cytogenetic and immunohistochemical profile of MASC. STUDY DESIGN: Cases were analyzed for ETV6 translocation using fluorescent in situ hybridization and stained for CK8, amylase, mammaglobin, GCDFP-15, MUC1, MUC4, STAT5a, Ki-67 (n = 37), CK7, Cam5.2, CK14, SMA, p63, S100, vimentin and DOG1 (n = 42). Histochemical stains for mucins were also performed and data collected for age, sex, and site. RESULTS: Fluorescent in situ hybridization showed 9 cases with ETV6 rearrangement and 2 with increased ETV6 copies. These 11 cases showed an absence of PAS-D-resistant granules, with 10 of 11 showing strong S100, mammaglobin, and STAT5a staining. All ACCs showed diffuse DOG1 staining, whereas 8/11 MASCs were negative and 3 showed only focal DOG1 staining. CONCLUSION: DOG1 can be used in conjunction with PAS-D, S100, and mammaglobin to identify MASCs. Cases with increased ETV6 copies are a novel finding with a similar immunostaining profile and should be considered as MASCs.

High-grade urothelial carcinoma with squamous differentiation metastasizing to the tongue.

Tumors metastasizing to the head and neck region are uncommon. Metastasis of urothelial carcinoma to the maxillofacial region is exceedingly rare and mostly involves the jaw. We present a case of urothelial carcinoma metastasizing to the tongue. Immunohistochemistry in conjunction with fluorescent in situ hybridization was used to confirm the relation between the primary and metastatic lesions, making it the first such reported case employing the UroVysion (Catalogue number 02 J27-025, Abbott Molecular Inc., Des Plaines, IL, USA) fluorescent in situ hybridization probe in a metastatic lesion in the head and neck region.

The chemokine receptors CXCR1 and CXCR2 regulate oral cancer cell behaviour.

BACKGROUND: Chemokines regulate physiological and pathological leucocyte trafficking, and chemokine receptors play a role in tumorigenesis. Expression of interleukin-8 (IL-8) receptors CXCR1 and CXCR2 has been shown in oral squamous cell carcinoma (OSCC) but remains poorly characterised. This aim of this study was to investigate CXCR1 and CXCR2 expression on normal oral keratinocytes (NOKs) and oral cancer cell lines (OCCL) and their relative response when exposed to IL-8 and growth-related oncogene-α (which selectively binds CXCR2). METHODS: mRNA and protein expression was studied using RT-PCR, immunocytochemistry and flow cytometry. ELISAs were used to investigate ERK1/2 phosphorylation and MMP production, whereas a MTS-based assay was employed to study proliferation. Migration assays were carried out using modified Boyden chambers with a matrigel coating used for invasion assays. RESULTS: mRNA expression of CXCR1 and CXCR2 was seen in both NOKs and OCCL with significantly higher protein expression in OCCL. Exposure to IL-8 and GROα increased intracellular ERK phosphorylation, proliferation, migration and invasion with OCCL showing a greater response than NOKs. These effects were mediated through CXCR1 and CXCR2 (for IL-8) and CXCR2 (for GROα) as receptor-blocking antibodies significantly inhibited the responses. IL-8 and GROα also increased MMP-9 release from NOKs and OCCL with significantly higher amounts released by OCCL. However, an increase in MMP-7 production was only seen in OCCL. CONCLUSIONS: Functional CXCR1 and CXCR2 exist on normal and cancerous oral epithelial cells, and our data suggests a role for these receptors in oral cancer biology.

Plate-guided distraction osteogenesis to recreate two-thirds of the mandible including symphysis.

We report a case of plate-guided distraction osteogenesis to reconstruct a large mandibular defect caused by recurrence of an ameloblastoma in a 17-year-old male patient who had previously had reconstruction using a fibula bone graft.

Functional expression of the chemokine receptor XCR1 on oral epithelial cells.

Chemokines are chemoattractant cytokines which act on specific receptors and play an important role in leukocyte migration as well as physiological and pathological processes. We investigated the role of the chemokine receptor XCR1 and its ligand lymphotactin (Lptn/XCL1) in the regulation of oral epithelial cell behaviour. In vitro XCR1 mRNA and cell surface protein expression was detected in normal oral keratinocytes and oral squamous cell carcinoma cell lines. Lymphotactin mediated intracellular activation of the ERK1/2 signalling pathway and stimulated migration, invasion, and proliferation of all cells through XCR1. Oral cancer cells showed a greater response to lymphotactin than normal keratinocytes and a direct relationship between receptor expression and migration, invasion, and proliferation was observed. Exposure of normal keratinocytes to lymphotactin resulted in increased adhesion to fibronectin but not collagen and stimulated MMP-2 and MMP-9 but not MMP-7 release, whereas exposure of cancer cells resulted in increased adhesion to both collagen and fibronectin and stimulated production of MMP-2, MMP-9, and MMP-7. We observed XCR1 but not lymphotactin to be expressed by epithelial cells in normal oral mucosa in vivo, whilst both were expressed and up-regulated in inflammatory oral disease and oral cancer including primary and metastatic disease. Lymphotactin mRNA and constitutive intracellular protein were detected in normal keratinocytes and oral cancer cell lines in vitro. These findings show that XCR1 and its ligand, lymphotactin, are expressed by oral epithelial cells and suggest that they play a role in regulating the behaviour of these cells.