Novel Molecular Events in Oral Carcinogenesis via Integrative Approaches

Oral epithelial dysplasia with lichenoid features shares proteomic overlap with oral epithelial dysplasia without lymphocytic immune response

OBJECTIVE

This study investigates the proteomic profiles of oral epithelial dysplasia with lichenoid features (OEDwithLF) and evaluates its relevance as a histopathological feature for lichenoid mucositis (LM) through differential proteomic characterization.

STUDY DESIGN

SWATH-MS proteomic profiling was conducted on FFPE samples from 6 OEDwithLF, 5 OED cases without associated lymphocytic infiltration, and 5 LM cases. Protein expression levels were quantified and compared. In silico analysis examined the biological and molecular functions of dysregulated proteins.

RESULTS

A total of 460 proteins were identified. Unsupervised clustering revealed significant differences between LM and OEDwithLF, with fewer differences observed between OEDwithLF and OED. Bioinformatic analysis indicated dysregulated proteins are involved in nucleic acid binding, ribosome function, and developmental biology. Key potential biomarkers include KRT17, LYSC, CAL5, and CRNN.

CONCLUSIONS

The proteomic profile of OEDwithLF is similar to OED without associated lymphocytic infiltration, but significantly different from LM. OED is relevant in lichenoid tissues, and its proteomic changes can be detected. Although OED may coexist with interface mucositis, it is not a defining feature of LM. This challenges the exclusion of epithelial dysplasia from lichenoid diagnoses. Based on this hypothesis-generating study, further investigation is warranted.

Therapeutic application of nicotinamide: As a potential target for inhibiting fibrotic scar formation following spinal cord injury

AIM

We aimed to confirm the inhibitory effect of nicotinamide on fibrotic scar formation following spinal cord injury in mice using functional metabolomics.

METHODS

We proposed a novel functional metabolomics strategy to establish correlations between gene expression changes and metabolic phenotypes using integrated multi-omics analysis. Through the integration of quantitative metabolites analysis and assessments of differential gene expression, we identified nicotinamide as a functional metabolite capable of inhibiting fibrotic scar formation and confirmed the effect in vivo using a mouse model of spinal cord injury. Furthermore, to mimic fibrosis models in vitro, primary mouse embryonic fibroblasts and spinal cord fibroblasts were stimulated by TGFβ, and the influence of nicotinamide on TGFβ-induced fibrosis-associated genes and its underlying mechanism were examined.

RESULTS

Administration of nicotinamide led to a reduction in fibrotic lesion area and promoted functional rehabilitation following spinal cord injury. Nicotinamide effectively downregulated the expression of fibrosis genes, including Col1α1, Vimentin, Col4α1, Col1α2, Fn1, and Acta2, by repressing the TGFβ/SMADs pathway.

CONCLUSION

Our functional metabolomics strategy identified nicotinamide as a metabolite with the potential to inhibit fibrotic scar formation following SCI by suppressing the TGFβ/SMADs signaling. This finding provides new therapeutic strategies and new ideas for clinical treatment.

Modular microfluidics for life sciences

The advancement of microfluidics has enabled numerous discoveries and technologies in life sciences. However, due to the lack of industry standards and configurability, the design and fabrication of microfluidic devices require highly skilled technicians. The diversity of microfluidic devices discourages biologists and chemists from applying this technique in their laboratories. Modular microfluidics, which integrates the standardized microfluidic modules into a whole, complex platform, brings the capability of configurability to conventional microfluidics. The exciting features, including portability, on-site deployability, and high customization motivate us to review the state-of-the-art modular microfluidics and discuss future perspectives. In this review, we first introduce the working mechanisms of the basic microfluidic modules and evaluate their feasibility as modular microfluidic components. Next, we explain the connection approaches among these microfluidic modules, and summarize the advantages of modular microfluidics over integrated microfluidics in biological applications. Finally, we discuss the challenge and future perspectives of modular microfluidics.

Anti-cancer and analgesic effects of resolvin D2 in oral squamous cell carcinoma

Oral cancer is often painful and lethal. Oral cancer progression and pain may result from shared pathways that involve unresolved inflammation and elevated levels of pro-inflammatory cytokines. Resolvin D-series (RvDs) are endogenous lipid mediators derived from omega-3 fatty acids that exhibit pro-resolution and anti-inflammatory actions. These mediators have recently emerged as a novel class of therapeutics for diseases that involve inflammation; the specific roles of RvDs in oral cancer and associated pain are not defined. The present study investigated the potential of RvDs (RvD1 and RvD2) to treat oral cancer and alleviate oral cancer pain. We found down-regulated mRNA levels of GPR18 and GPR32 (which code for receptors RvD1 and RvD2) in oral cancer cells. Both RvD1 and RvD2 inhibited oral cancer proliferation in vitro. Using two validated mouse oral squamous cell carcinoma xenograft models, we found that RvD2, the more potent anti-inflammatory lipid mediator, significantly reduced tumor size. The mechanism of this action might involve suppression of IL-6, C-X-C motif chemokine 10 (CXCL10), and reduction of tumor necrosis. RvD2 generated short-lasting analgesia in xenograft cancer models, which coincided with decreased neutrophil infiltration and myeloperoxidase activity. Using a cancer supernatant model, we demonstrated that RvD2 reduced cancer-derived cytokines/chemokines (TNF-α, IL-6, CXCL10, and MCP-1), cancer mediator-induced CD11b⁺Ly6G^- myeloid cells, and nociception. We infer from our results that manipulation of the endogenous pro-resolution pathway might provide a novel approach to improve oral cancer and cancer pain treatment.

Clinicopathological and prognostic significance of preoperative serum epidermal growth factor levels in patients with oral squamous cell carcinoma

Epidermal growth factor (EGF) promotes tumourigenesis and tissue repair of epithelial and mesenchymal cells and has a role in chemotaxis, mitogenesis, cell motility, and cytoprotection. It also enhances the growth of cancers. EGF may therefore have a role in the initiation or promotion of oral carcinogenesis. The cases of 152 patients with oral squamous cell carcinoma whose preoperative serum EGF level was determined by enzyme-linked immunosorbent assay were analyzed retrospectively, along with those of 40 age- and sex-matched controls. Patients with higher levels of EGF were more likely to have neck lymph node metastasis (P=0.026), advanced stage cancer (P=0.04), and a worse survival status (P=0.0019). Multivariate analysis using the Cox proportional hazards model indicated that the EGF level was an independent predictor of poor survival (hazard ratio 1.99, P=0.018). Patients with higher preoperative serum EGF levels had significantly poorer cancer-specific survival by Kaplan-Meier analysis (P=0.032). This study indicates that a higher preoperative serum EGF level is associated with neck lymph node metastasis, more advanced stage, and poor survival. EGF should be considered as a potential prognostic biomarker and a therapeutic target for patients with oral cancer.

Cell proliferation is associated with intensity of tumor budding in oral squamous cell carcinoma

BACKGROUND

Tumor budding is a morphological marker of cancer invasion, defined as the presence of isolated or small clusters of neoplastic cells at the tumor invasive front. This study aimed to evaluate the association between intensity of tumor budding and cell proliferation in oral squamous cell carcinoma (OSCC).

METHODS

Immunohistochemistry was employed in 163 OSCC samples to detect the cell proliferation marker Ki-67 and multicytokeratin (to identify OSCC cells in tumor budding evaluation). The Mann-Whitney test was used to evaluate differences in the cell proliferation index between samples with high-intensity tumor budding and samples with low-intensity or no tumor budding. In samples with high-intensity tumor budding, the Wilcoxon test was used to evaluate differences in the cell proliferation index between the budding area and the area outside the budding. The chi-square test assessed the association between cell proliferation index and intensity of tumor budding.

RESULTS

The cell proliferation index was higher in samples with high-intensity tumor budding than in samples with low-intensity or no tumor budding (P < .05). Tumors with high-intensity tumor budding showed a higher cell proliferation index in the budding area than in the area outside the budding (P < .05). Finally, samples showing high-intensity tumor budding were associated with high cell proliferation index (P < .05).

CONCLUSION

Cell proliferation is positively associated with intensity of tumor budding in OSCC. Moreover, in tumors showing high-intensity tumor budding, the budding area is the location of higher cell proliferation. These findings reinforce the hypothesis that tumor budding is associated with the biological behavior of OSCC.

High level of calpain1 promotes cancer cell invasion and migration in oral squamous cell carcinoma

Calpain1, termed conventional calpain and a member of the Ca²⁺-dependent neutral cysteine proteases, is considered to be involved in cancer formation and development. However, the effect of calpain1 on oral squamous cell carcinoma (OSCC) remains poorly understood. The aim of the present study was to evaluate the possibility of calpain1 as a potential molecular target for OSCC diagnosis and therapy. The present study demonstrates that calpain1 was overexpressed in OSCC cell lines and 4/7 of the tumor tissues in paired samples of tumor and noncancerous matched tissues (NCMT). In a cohort of 125 patients with primary OSCC, the high expression of calpain1 was an independent predictor for overall survival in a multivariate analysis (P=0.022). Furthermore, RNA interference-mediated suppression of calpain1 expression reduced the proliferation, migration and invasion potential of the HSC3 and CAL27 OSCC cell lines, but did not increase their apoptosis. These findings indicate that calpain1 may be a useful biomarker for novel prognostic and therapeutic strategies in oral squamous cell carcinoma.

Biomarkers in saliva for the detection of oral squamous cell carcinoma and their potential use for early diagnosis: a systematic review

Objective To determine the capacity of salivary biomarkers in the early diagnosis of oral squamous cell carcinoma. Study design A systematic review of the literature was performed based on the English titles listed in the PubMed, EBSCO, Cochrane, Science Direct, ISI web Science and SciELO databases using the following search descriptors: Oral cancer, diagnosis, biomarkers, saliva and oral squamous cell carcinoma. Abstracts and full-text articles were assessed independently by two reviewers. International checklists for assessment of methodological quality were used. Levels of evidence and grades of recommendation through the Scottish Intercollegiate Guidelines Network (SIGN) template were recognized. The units of analysis were identified through a reference matrix. Results Through the research strategy and after application of different filters and considering choosing criteria, six studies were obtained for analysis. Salivary biomarkers for oral cancer most frequently found were mRNA and proteins for IL-8, CD44, MMP-1 and MMP-3. New peptide-biomarkers such as Cyfra 21-1 and ZNF510 were found. ZNF 510 was the only biomarker which increased in the population with tumour stage T1 + T2 and T3 + T4. Only one study showed a sensitivity and specificity of 96% when the biomarker ZNF 510 is employed to discriminate early and late tumour stages. Conclusions There is no sufficient scientific evidence to support the capacity of the identified salivary biomarkers for the early diagnosis of oral cancer (sub-clinical stages of the pathogenic period before cancer phenotypes are manifested). Salivary biomarkers, however, may be employed to discriminate between healthy and cancer patients.

Elevated Matrix Metalloproteinase-9 Expression Correlates With Advanced Stages of Oral Cancer and Is Linked to Poor Clinical Outcomes

PURPOSE

Using a meta-analytic approach, the relation between increased matrix metalloproteinase-9 (MMP-9) expression, tumor stage, and clinical outcomes in oral cancers was investigated.

MATERIALS AND METHODS

Multiple English- and Chinese-language electronic databases were searched to identify high-quality case-and-control studies relevant to this meta-analysis. Methodologic quality of the included trials was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology statement to ensure consistency in reviewing and reporting the results. Statistical analyses were carried out with STATA 12.0 statistical software.

RESULTS

Nine case-and-control studies containing a combined total of 419 patients with oral cancer were included in the present meta-analysis. Results showed that patients who were positive for MMP-9 expression had a significantly poorer overall survival compared with those negative for MMP-9 (effect size = 2.10; 95% confidence interval, 0.98 to 3.22; P < .001). MMP-9 expression also positively correlated with lymph node metastasis and advanced T-stage groups (P < .05 for all comparisons). Further, high MMP-9 expression level correlated with increased oral cancer risk in Asians (P < .05 for all comparisons) as shown by method-stratified subgroup analysis.

CONCLUSION

The present results strongly suggest that MMP-9 expression level influences tumor invasion and metastasis in oral cancers. Based on these results, MMP-9 can be an excellent therapeutic target in patients with oral cancer.

Distinct pattern of chromosomal alterations and pathways in tongue and cheek squamous cell carcinoma

BACKGROUND

The purpose of this study was to investigate the cause of behavioral difference between tongue and cheek squamous cell carcinomas (SCCs) by verifying the copy number alterations (CNAs).

METHODS

Array comparative genomic hybridization (aCGH) was used to profile unique deletions and amplifications that are involved with tongue and cheek SCC, respectively. This was followed by pathway analysis relating to CNA genes from both sites.

RESULTS

The most frequently amplified regions in tongue SCC were 4p16.3, 11q13.4, and 13q34; whereas the most frequently deleted region was 19p12. For cheek SCC, the most frequently amplified region was identified on chromosome 9p24.1-9p23; whereas the most common deleted region was located on chromosome 8p23.1. Further analysis revealed that the most significant unique pathway related to tongue and cheek SCCs was the cytoskeleton remodeling and immune response effect on the macrophage differentiation pathway.

CONCLUSION

This study has showed the different genetic profiles and biological pathways between tongue and cheek SCCs. © 2013 Wiley Periodicals, Inc. Head Neck 36: 1268-1278, 2014.

The mucosal immune system in the oral cavity-an orchestra of T cell diversity

The mucosal immune system defends against a vast array of pathogens, yet it exhibits limited responses to commensal microorganisms under healthy conditions. The oral-pharyngeal cavity, the gateway for both the gastrointestinal and respiratory tracts, is composed of complex anatomical structures and is constantly challenged by antigens from air and food. The mucosal immune system of the oral-pharyngeal cavity must prevent pathogen entry while maintaining immune homeostasis, which is achieved via a range of mechanisms that are similar or different to those utilized by the gastrointestinal immune system. In this review, we summarize the features of the mucosal immune system, focusing on T cell subsets and their functions. We also discuss our current understanding of the oral-pharyngeal mucosal immune system.

Beclin1 inhibits proliferation, migration and invasion in tongue squamous cell carcinoma cell lines

OBJECTIVES

The role of autophagy is still a controversy in cancer development. In our previous study, we confirmed that decrease of autophagy activity promotes malignant progression of tongue squamous cell carcinoma (TSCC). However, the role of autophagy-related protein, Beclin1, has not well been documented in TSCC. In this study, we aim to elucidate the role of beclin1 in TSCC progression and investigate its potential mechanisms.

MATERIALS AND METHODS

TSCC cell lines, SCC9 and SCC15 were used to generate the stable cells with transfection lentivirus BECN1 and sh-BECN1. Then, Beclin1 expression was detected with qPCR and western blot. Moreover, the expressions of autophagy-related proteins and tumor metastasis associated proteins were examined by western blot and ELISA. For functional analysis, MTT assay were performed to evaluate the proliferation activity and transwell assay was used to assess the migration and invasion ability. Finally, TSCC xenograft models were established to confirm the effect of Beclin1 on TSCC in vivo.

RESULTS

The results showed that BECN1 and sh-BECN1 virus transfection significantly increased or decreased the mRNA and protein expression of Beclin1 in the transfected TSCC cells. Meanwhile, we also observed that Beclin1 could enhance the expression levels of LC3-II, ATG4 and ATG5. Then, we revealed that overexpression of Beclin1 inhibited proliferation, migration and invasion while knockdown of Beclin1 promoted proliferation, migration and invasion in TSCC cells. Furthermore, we demonstrated that vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 and -9 were involved in Beclin1-mediated inhibition of migration and invasion. More importantly, our data also confirmed that Beclin1 inhibited TSCC xenograft growth in vivo.

CONCLUSION

Taken together, the results indicate that autophagy regulating gene, Beclin1, may contribute to the malignant phenotypes of TSCC cells and can be a potential target for oral cancer gene therapy.

Promoter hypermethylation of the gene encoding heat shock protein B1 in oral squamous carcinoma cells

OBJECTIVE

The mechanism responsible for the regulation of HSPB1 expression in oral squamous cell carcinoma was explored in this study.

STUDY DESIGN

The expression and the methylation status of HSPB1 in oral squamous carcinoma cells were examined using real-time reverse transcription-PCR, methylation-specific PCR and pyrosequencing.

RESULTS

HSPB1 expression was weakly expressed in oral squamous carcinoma cell lines (N = 4) as compared to that of normal human oral keratinocytes. The lower expressed HSPB1 was associated with promoter hypermethylation of the HSPB1 gene, and the expression of HSPB1 could be induced by treating the cells with a DNA methyltransferase inhibitor, RG108. Promoter hypermethylation of the HSPB1 gene was also noted in primary oral squamous carcinomas, concomitant with reduced levels of HSPB1 gene expression, as compared to those of the paired neighboring normal tissues.

CONCLUSION

Aberrant promoter hypermethylation of the HSPB1 gene may explain the reduced expression of HSPB1 noted in oral cancer cells.

Skin melanoma: from systematic biology to the personalized therapy

Systematic biology is a new field of biomedicine based on the integrative approach to molecular mechanisms of the operation of living systems including in case of the development of pathological processes. In this connection, up-to-date therapeutic approaches to skin melanoma treatment can be considered on the basis of key changes in intermolecular interactions taking place during tumor development.

Calreticulin, an endoplasmic reticulum-resident protein, is highly expressed and essential for cell proliferation and migration in oral squamous cell carcinoma

OBJECTIVES

Oral squamous cell carcinoma (OSCC) has emerged as one of the major malignant tumors of the head and neck cancers. However, the molecular mechanism behind tumorigenesis of OSCC is not fully understood. The aim of this study was to investigate the role of calreticulin (CRT), an endoplasmic reticulum-resident protein, in OSCC cells.

MATERIALS AND METHODS

Sixteen paired samples of tumor and non-cancerous matched tissue (NCMT), six OSCC cell lines and normal human oral keratinocytes (NHOKs), and oral tissue microarray were used to reveal the expression of CRT by Western blotting and immunohistochemistry. Later, shRNA-mediated stable knockdown of CRT in OSCC cells was generated. The knockdown cell line was used to analyze cell proliferation, colony formation, anchorage-independent growth and cell migration in vitro.

RESULTS

CRT was differentially expressed in fresh tumor samples and six OSCC cell lines but not adjacent NCMTs and NHOKs. In oral tissue microarray, we showed that there was positive CRT staining in the vast majority of tumor cases (99/103), in sharp contrast to that in NCMT cases (29/92) (p<0.001). Stable knockdown of CRT in oral cancer cells resulted in significantly reduced growth rate, colony-forming capacity and anchorage-independent growth. This may be attributed to the induction of G0/G1 cell cycle arrest when CRT was depleted in the cells. Both horizontal and vertical movements of the CRT-knockdown stable line were markedly impaired. The phosphorylation levels of focal adhesion kinase (FAK), paxillin and ERK1/2 and the activity of matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9) were decreased in the CRT-knockdown cells. These results suggest that CRT can regulate oral cancer cell migration through activation of the FAK signaling pathway accompanied with proteolytic degradation of the extracellular matrix (ECM) by MMP-2 and MMP-9.

CONCLUSION

Together, this study has defined a novel biological role for CRT in oral cancer. CRT is a potential biomarker and may contribute to the malignant phenotypes of OSCC cells.