Validation of gene expression profiles of candidate genes using low density array in peripheral blood of tobacco consuming head and neck cancer patients and auto/taxi drivers with preneoplastic lesions

Cancer-associated fibroblast-like fibroblasts in vocal fold leukoplakia suppress CD8+T cell functions by inducing IL-6 autocrine loop and interacting with Th17 cells

The characteristics of fibroblast cells in head and neck precancerous lesion and its ability to secrete inflammatory cytokines and affect CD8⁺T cell functions remain unclear. Herein, we reported the existence of fibroblasts in human-derived vocal fold leukoplakia (VFL) with positive staining of fibroblast activation protein (FAP) and α-smooth muscle actin (α-SMA). The fibroblasts from VFL and cancer-associated fibroblasts (CAFs) from head and neck squamous cell carcinoma (HNSCC) displayed similar cellular functions and robust inflammatory cytokine secretions. The effects of fibroblasts from VFL in inducing the apoptosis, depletion of CD8⁺ T cells and recruitment of regulatory T cells (Treg cells) were observed. We further assessed the autocrine loop within VFL fibroblasts to self-stimulate by secreting IL-6, TGF-β through the IL-6/JAK2/STAT3 pathway. The synergistic stimulation of IL-6 and TGF-β promoted Th17 cell differentiation and IL-17A secretion, which could result in fibroblast activation in another positive loop. Tocilizumab (TOC), a monoclonal antibody targeting IL-6R, managed to suppress the overexpression of both IL-6 and TGF-β in VFL fibroblasts, and thus blocking IL-6 autocrine loop and CAF-Th17 loop in vitro. In a murine model of oral leukoplakia (OL), local injection of TOC inhibited the outgrowth of lesions and showed notable effect in control of OL progression in vivo. Our findings establish a novel rationale for blocking the IL-6/JAK2/STAT3 pathway to inhibit vocal fold (oral) leukoplakia progression and postpone HNSCC tumorigenesis.

Polymorphism in cytochrome P4502A6 reduces the risk to head and neck cancer and modifies the treatment outcome

The present case-control study consisting of 1300 cases of head and neck squamous cell carcinoma (HNSCC) and the equal number of controls aimed to investigate the association of functionally important polymorphisms in cytochrome P4502A6 (CYP2A6*1B, CYP2A6*4C, CYP2A6*9-rs28399433) with HNSCC and the treatment response in cases receiving a combination of chemotherapy/radiotherapy (CT/RT). A significant decrease in risk to HNSCC was observed in the cases with deletion (CYP2A6*4B and CYP2A6*4C) or reduced activity genotypes (CYP2A6*9) of CYP2A6. This risk to HNSCC was further reduced significantly in tobacco users among the cases when compared to nontobacco users among the cases. The risk was also reduced to a slightly greater extent in alcohol users among the cases when compared to nonalcohol users among the cases. In contrast with decreased risk to HNSCC, almost half of the cases with variant genotypes of CYP2A6 (CYP2A6*1A/*4C+*1B/*4C+*4C/*4C and *9/*9) did not respond to the treatment. Likewise, the survival rate in cases receiving the treatment, after 55 months of follow-up was significantly lower in cases with deletion (6.3%) or reduced activity (11.9%) allele than in the cases with common alleles (41%). The present study has shown that CYP2A6 polymorphism significantly reduces the risk to HNSCC. Our data further suggested that CYP2A6 polymorphism may worsen the treatment outcome in the cases receiving CT/RT.

Cancer chemoprevention through Frizzled receptors and EMT

Frizzled (FZD) transmembrane receptors are well known for their role in β-catenin signaling and development and now understanding of their role in the context of cancer is growing. FZDs are often associated with the process of epithelial to mesenchymal transition (EMT) through β-catenin, but some also influence EMT through non-canonical pathways. With ten different FZDs, there is a wide range of activity from oncogenic to tumor suppressive depending on the tissue context. Alterations in FZD signaling can occur during development of premalignant lesions, supporting their potential as targets of chemoprevention agents. Agonizing or antagonizing FZD activity may affect EMT, which is a key process in lesion progression often targeted by chemoprevention agents. Recent studies identified a specific FZD as important for activity of an EMT inhibiting chemopreventive agent and other studies have highlighted the previously unrecognized potential for targeting small molecules to FZD receptors. This work demonstrates the value of investigating FZDs in chemoprevention and here we provide a review of FZDs in cancer EMT and their potential as chemoprevention targets.

Identification of cytokeratin24 as a tumor suppressor for the management of head and neck cancer

To improve management of head and neck squamous cell carcinoma patients, we need to increase our understanding of carcinogenesis, to identify biomarkers, and drug targets. This study aimed to identify novel biomarkers by providing transcriptomics profiles of matched primary tumors, lymph node metastasis, and non-malignant tissue of 20 HNSCC patients as well as by bioinformatic analyses of a TCGA HNSCC cohort, comprising 554 patients. We provide cancer cell signaling networks differentially expressed in tumors versus metastases, such as mesenchymal-epithelial transition, and structural integrity networks. As a proof of principle study, we exploited the data sets and performed functional analyses of a novel cytokeratin, cytokeratin24 (cKRT24), which had not been described as biomarker for tumors before. Survival analysis revealed that low cKRT24 expression correlated with poor overall survival in HNSCC. Experimentally, downregulation of cKRT24 in primary tumors, metastases, and HNSCC cell lines was verified on mRNA and protein level. Cloning and ectopic overexpression of cKRT24 not only affected viability and growth of HNSSC cell lines, but also inhibited tumor growth in murine xenograft studies. We conclude that cKRT24 functions as a tumor suppressor in HNSCC, and may serve as an additional prognostic biomarker and novel target to support current HNSCC treatments.

The Relationship between the Expression of Fatty Acyl Desaturase 2 (fads2) Gene in Peripheral Blood Cells (PBCs) and Liver in Gilthead Seabream, Sparus aurata Broodstock Fed a Low n-3 LC-PUFA Diet

The principle aim of this study is to elucidate the relationship between the fatty acid desaturase 2 gene (fads2) expression pattern in peripheral blood cells (PBCs) and liver of gilthead seabream (GSB), Sparus aurata broodstock in order to determine the possible use of fads2 expression as a potential biomarker for the selection of broodstock. This selection could be utilized for breeding programs aiming to improve reproduction, health, and nutritional status. Passive Integrated Transponder (PIT)-tagged GSB broodstock (Male-1.22 ± 0.20 kg; 44.8 ± 2 cm and female-2.36 ± 0.64 kg; 55.1 cm) were fed a diet containing low levels of fish meal and fish oil (EPA 2.5; DHA 1.7 and n-3 LC-PUFA 4.6% TFA) for one month. After the feeding period, fads2 expression in PBCs and liver of both male and female broodstock were highly significantly correlated (r = 0.89; p < 0.001). Additionally, in male broodstock, liver fads2 expression was significantly correlated (p < 0.05) to liver contents in 16:0 (r = 0.95; p = 0.04) and total saturates (r = 0.97; p = 0.03) as well as to 20:3n–6/20:2n–6 (r = 0.98; p = 0.02) a Fads2 product/precursor ratio. Overall, we found a positive and significant correlation between fads2 expression levels in the PBCs and liver of GSB broodstock. PBCs fads2 expression levels indicate a strong potential for utilization as a non-invasive method to select animals having increased fatty acid bioconversion capability, better able to deal with diets free of fish meal and fish oil.