A Novel Preclinical In Vitro 3D Model of Oral Carcinogenesis for Biomarker Discovery and Drug Testing.

This study aimed to develop an in vitro three-dimensional (3D) cell culture model of oral carcinogenesis for the rapid, scalable testing of chemotherapeutic agents. Spheroids of normal (HOK) and dysplastic (DOK) human oral keratinocytes were cultured and treated with 4-nitroquinoline-1-oxide (4NQO). A 3D invasion assay using Matrigel was performed to validate the model.

Transcriptomic Biomarker Signatures for Discrimination of Oral Cancer Surgical Margins.

Relapse after surgery for oral squamous cell carcinoma (OSCC) contributes significantly to morbidity, mortality and poor outcomes. The current histopathological diagnostic techniques are insufficiently sensitive for the detection of oral cancer and minimal residual disease in surgical margins. We used whole-transcriptome gene expression and small noncoding RNA profiles from tumour, close margin and distant margin biopsies from 18 patients undergoing surgical resection for OSCC.

Exome sequencing of oral leukoplakia and oral squamous cell carcinoma implicates DNA damage repair gene defects in malignant transformation.

Objectives: To map the genomic pathways of patients with oral leukoplakia (OLK) which transformed to cancer (progressive) and those which did not (non-progressive), and to compare their exomic profiles.

Materials And Methods: Whole exome sequencing was performed on 42 sequential samples from five progressive and eight non-progressive patients. Association of genomic variant frequencies with progression or lesion severity were analysed by non-parametric tests (Kruskal-Wallis and Mann-Whitney-Wilcoxon) and multivariate sparse partial least squares discriminant analysis (sPLS-DA).

Dysplastic oral leukoplakia is molecularly distinct from leukoplakia without dysplasia.

Objective: The molecular mechanisms underlying the development of dysplasia in leukoplakia are unknown. We used RNA sequencing to examine the molecular and biological pathway differences in oral leukoplakia with and without oral epithelial dysplasia.

Materials And Methods: Excisional biopsy specimens (25) were taken from 24 patients with oral leukoplakia diagnosed histopathologically as either oral epithelial dysplasia (13) or epithelial hyperplasia and keratosis without dysplasia (12).

Transcriptome changes induced in vitro by alcohol-containing mouthwashes in normal and dysplastic oral keratinocytes.

Background: The role of alcohol-containing mouthwash as a risk factor for the development of oral cancer is a subject of conflicting epidemiological evidence in the literature despite alcohol being a recognised carcinogen. The aim of this study was to use in vitro models to investigate mechanistic and global gene expression effects of exposure to alcohol-containing mouthwash.

Methods: Two brands of alcohol-containing mouthwash and their alcohol-free counterparts were used to treat two oral cell lines derived from normal (OKF6-TERT) and dysplastic (DOK) tissues.

Integrated miRNA-mRNA spatial signature for oral squamous cell carcinoma: a prospective profiling study of Narrow Band Imaging guided resection.

Oral squamous cell carcinoma (OSCC) is a common malignancy for which there is poor prognosis and limited therapeutic options. The objective was to identify mRNA targets of dysregulated miRNAs in OSCC using integrated analysis and understand molecular abnormality in surgical margins. We used biopsies along the spatial axis from normal tissue defined by narrow band imaging (NBI) through conventional white light (WL) margins to tumour from 18 patients undergoing surgical resection for OSCC.

The Wnt regulator SFRP4 inhibits mesothelioma cell proliferation, migration, and antagonizes Wnt3a via its netrin-like domain.

Secreted frizzled related proteins (SFRPs) are a family of Wnt regulators which are frequently downregulated in cancers. In malignant mesothelioma (MM), downregulation of SFRP4 has been reported as a mechanism which contributes to aberrant activation of oncogenic Wnt signaling. Here we investigated the biological consequences of SFRP4 in two mesothelioma cell models where this protein is downregulated.

Number and brightness analysis of sFRP4 domains in live cells demonstrates vesicle association signal of the NLD domain and dynamic intracellular responses to Wnt3a.

The Wnts are secreted, lipidated glycoproteins that play a role in cellular processes of differentiation, proliferation, migration, survival, polarity and stem cell self-renewal. The majority of Wnts biological effects are through binding to specific frizzled (Fzd) receptor complexes leading to activation of downstream pathways. Secreted frizzled-related proteins (sFRPs) were first identified as antagonists of Wnt signalling by binding directly to Wnts.

Secreted frizzled related proteins: Implications in cancers.

The Wnt (wingless-type) signaling pathway plays an important role in embryonic development, tissue homeostasis, and tumor progression becaluse of its effect on cell proliferation, migration, and differentiation. Secreted frizzled-related proteins (SFRPs) are extracellular inhibitors of Wnt signaling that act by binding directly to Wnt ligands or to Frizzled receptors. In recent years, aberrant expression of SFRPs has been reported to be associated with numerous cancers.

Expression profile and function of Wnt signaling mechanisms in malignant mesothelioma cells.

Malignant mesothelioma (MM) is an uncommon and particularly aggressive cancer associated with asbestos exposure, which currently presents an intractable clinical challenge. Wnt signaling has been reported to play a role in the neoplastic properties of mesothelioma cells but has not been investigated in detail in this cancer. We surveyed expression of Wnts, their receptors, and other key molecules in this pathway in well established in vitro mesothelioma models in comparison with primary mesothelial cultures.

Mechanisms of cisplatin-induced cell death in malignant mesothelioma cells: role of inhibitor of apoptosis proteins (IAPs) and caspases.

Malignant mesothelioma (MM) is an aggressive and highly chemoresistant tumour. Although cisplatin is used in frontline therapy of this disease treatment remains palliative at best. The biochemical pathways activated by cisplatin and the mechanisms of resistance in mesothelioma cells are poorly understood.

Regulated chemokine gene expression in mouse mesothelioma and mesothelial cells: TNF-α upregulates both CC and CXC chemokine genes.

Many cancers express an array of chemokines which have the capacity to modulate the nature and function of intratumoural leukocyte infiltrates. In malignant mesothelioma (MM) neither the chemokine signalling networks nor their regulation have been investigated despite the prominence of leucocytic infiltrates in both clinical and experimental tumours. In this study, we examined constitutive and cytokine-regulated expression of CC and CXC chemokine genes in mesothelioma and mesothelial cell cultures derived from two different mouse strains (BALB/C and CBA/CaH).

Synthesis and antimalarial evaluation of novel isocryptolepine derivatives.

A series of mono- and di-substituted analogues of isocryptolepine have been synthesized and evaluated for in vitro antimalarial activity against chloroquine sensitive (3D7) and resistant (W2mef) Plasmodium falciparum and for cytotoxicity (3T3 cells). Di-halogenated compounds were the most potent derivatives and 8-bromo-2-chloroisocryptolepine displayed the highest selectivity index (106; the ratio of cytotoxicity (IC(50)=9005 nM) to antimalarial activity (IC(50)=85 nM)). Our evaluation of novel isocryptolepine compounds has demonstrated that di-halogenated derivatives are promising antimalarial lead compounds.

Cisplatin and TNF-alpha downregulate transcription of Bcl-xL in murine malignant mesothelioma cells.

Malignant mesothelioma (MM) is an aggressive and highly chemo-resistant tumour. In this study, we examined cisplatin-induced apoptosis in mouse models of this disease and investigated the role of constitutive and inducible expression of apoptosis related genes in this process. All of the four mouse MM cell lines examined expressed Bax, Bcl-xL, c-Myc, and caspase-3 but not Bcl-2.

Identification of differentially expressed genes in murine mesothelioma cell lines of differing tumorigenicity using suppression subtractive hybridization.

We have previously prepared two B7-1 transfectant clones (AC29 B7-6 and AC29 B7-7) from the AC29 murine mesothelioma (MM) cell line which displayed markedly different in vivo growth rates and susceptibility to cytotoxic T cell killing. Using suppression subtractive hybridisation (SSH), we searched for factors which may determine the biological distinction seen in these clones. We isolated 19 cDNA clones from two SSH generated libraries by screening using subtracted cDNA probes and characterised them using Northern hybridisation, sequencing, RT-PCR and real-time RT-PCR.