Expression analysis of SPARC/osteonectin in oral squamous cell carcinoma patients: from saliva to surgical specimen

Epithelial and fibroblast SPARC expression patterns in oral leukoplakia and oral squamous cell carcinoma

OBJECTIVE

This study evaluated and compared the expression of secreted protein acidic and rich in cysteine (SPARC) in epithelial cells and fibroblasts of oral leukoplakia (OL) and oral squamous cell carcinoma (OSCC) using normal oral mucosa as a control.

STUDY DESIGN

The expression of SPARC was determined in samples of normal oral mucosa (n = 12), OL without dysplasia (n = 31), OL with dysplasia (n = 54), and OSCC (n = 69) using immunohistochemistry. The percentage of positive cells in epithelial cells and fibroblasts was independently evaluated.

RESULTS

Epithelial SPARC was found in 33.3%, 35.5%, 25.9%, and 66.7% of normal oral mucosa, OL without dysplasia, OL with dysplasia, and OSCC, respectively. Fibroblast SPARC was found in 50.0%, 29.0%, 46.3%, and 84.1% of normal oral mucosa, OL without dysplasia, OL with dysplasia, and OSCC, respectively. OSCC had higher epithelial and fibroblast SPARC expression than normal oral mucosa, OL without dysplasia, and OL with dysplasia (P < .05). No significant differences were observed in epithelial and fibroblast SPARC among normal oral mucosa or OL with and without dysplasia.

CONCLUSION

Overexpression of epithelial and fibroblast SPARC was observed in OSCC but not in OL, suggesting that SPARC is involved in the late stage of oral carcinogenesis.

Boron Neutron Capture Therapy (BNCT) Mediated by Maleimide-Functionalized Closo-Dodecaborate Albumin Conjugates (MID:BSA) for Oral Cancer: Biodistribution Studies and In Vivo BNCT in the Hamster Cheek Pouch Oral Cancer Model

Background: BNCT (Boron Neutron Capture Therapy) is a tumor-selective particle radiotherapy that combines preferential boron accumulation in tumors and neutron irradiation. Although p-boronophenylalanine (BPA) has been clinically used, new boron compounds are needed for the advancement of BNCT. Based on previous studies in colon tumor-bearing mice, in this study, we evaluated MID:BSA (maleimide-functionalized closo-dodecaborate conjugated to bovine serum albumin) biodistribution and MID:BSA/BNCT therapeutic effect on tumors and associated radiotoxicity in the hamster cheek pouch oral cancer model. Methods: Biodistribution studies were performed at 30 mg B/kg and 15 mg B/kg (12 h and 19 h post-administration). MID:BSA/BNCT (15 mg B/kg, 19 h) was performed at three different absorbed doses to precancerous tissue. Results: MID:BSA 30 mg B/kg protocol induced high BSA toxicity. MID:BSA 15 mg B/kg injected at a slow rate was well-tolerated and reached therapeutically useful boron concentration values in the tumor and tumor/normal tissue ratios. The 19 h protocol exhibited significantly lower boron concentration values in blood. MID:BSA/BNCT exhibited a significant tumor response vs. the control group with no significant radiotoxicity. Conclusions: MID:BSA/BNCT would be therapeutically useful to treat oral cancer. BSA toxicity is a consideration when injecting a compound conjugated to BSA and depends on the animal model studied.

Osteonectin/SPARC Expression in Head and Neck Squamous Cell Carcinoma: A Tissue Microarray Study

BACKGROUND

Some studies have correlated secreted protein acidic and rich in cysteine (SPARC) expression with more aggressive behavior in head and neck squamous cell carcinoma (SCC). We investigated the impact of SPARC expression on patient outcomes in a large cohort of SCCs.

MATERIALS AND METHODS

Patients with SCC were identified by searching institutional databases. A tissue microarray of paraffin-embedded tumor specimens was constructed, and SPARC immunohistochemistry was performed. Cellular and stromal SPARC expression were quantitated and correlated with clinicopathologic features.

RESULTS

Of 191 cases, 171 were adequate for SPARC evaluation. A total of 112 (65%) cases showed SPARC tumor cell staining, and 167 (98%) cases showed stromal staining. Increased SPARC stromal expression was correlated with poorer overall survival (OS) [mean (SD) survival, 64.3 (3.25) vs. 42.8 (3.25) mo; P=0.0015] and poorer disease-specific survival (DSS) [mean (SD) survival, 51.1 (1.58) vs. 38.3 (1.832) mo; P=0.0381]. Human papillomavirus-positive status correlated with both stromal and tumor SPARC expression (P=0.0047 and 0.0408, respectively). SPARC staining did not correlate with OS or DSS in multivariate analyses. Among nonchemotherapy patients, SPARC stromal expression was associated with poorer OS and DSS (P=0.0074 and 0.033, respectively). In multivariate analyses, increased stromal SPARC expression was associated with a longer disease-free interval [P=0.0170 (hazard ratio, 1.384)].

CONCLUSIONS

SPARC expression is frequently present in tumoral stroma of head and neck SCCs. In contravention to prior studies, we found that SPARC expression did not correlate with survival overall. This suggests that previously reported associations may not, in fact, exist highlighting the need to meticulously adjust for confounding variables in novel biomarker studies. However, subgroup analysis showed that stromal SPARC expression is associated with better disease-free survival among patients who are not treated with chemotherapy.

Functions of Matricellular Proteins in Dental Tissues and Their Emerging Roles in Orofacial Tissue Development, Maintenance, and Disease

Matricellular proteins (MCPs) are defined as extracellular matrix (ECM) associated proteins that are important regulators and integrators of microenvironmental signals, contributing to the dynamic nature of ECM signalling. There is a growing understanding of the role of matricellular proteins in cellular processes governing tissue development as well as in disease pathogenesis. In this review, the expression and functions of different MP family members (periostin, CCNs, TSPs, SIBLINGs and others) are presented, specifically in relation to craniofacial development and the maintenance of orofacial tissues, including bone, gingiva, oral mucosa, palate and the dental pulp. As will be discussed, each MP family member has been shown to have non-redundant roles in development, tissue homeostasis, wound healing, pathology and tumorigenesis of orofacial and dental tissues.

SPARC promotes the proliferation and metastasis of oral squamous cell carcinoma by PI3K/AKT/PDGFB/PDGFRβ axis

Oral squamous cell carcinoma (OSCC) is a highly lethal cancer in the world, and the prognosis of OSCC is poor with a 60% 5-year survival rate in recent decades. Here, we introduced a novel secretory and acid glycoprotein with cysteine rich (secreted protein acidic and rich in cysteine, SPARC), which is correlated with the worst pattern of invasion (WPOI) and prognosis of OSCC. SPARC expression levels were measured in OSCC tissues and normal tissues using quantitative polymerase chain reaction and immunohistochemistry. The influence of SPARC on cell proliferation was examined by cell counting kit-8, colony formation, and Edu tests. Then, the effect of SPARC on the metastasis of OSCC cells was detected by wound healing and transwell migration assays. Next, the biologic characteristics of SPARC shared by STRING were analyzed. Furthermore, the underlying mechanisms were confirmed by western blot analysis. SPARC revealed higher expression in OSCC tissues than nontumor tissues. Higher SPARC expression was correlated with poorer tumor differentiation, poorer WPOI pattern, and significantly and shorter overall survival. Knockdown SPARC significantly restrained OSCC cell growth, migration, and invasion. In addition, bioinformatics analysis found SPARC had a coexpression network with the platelet-derived growth factor-B (PDGFB) and PI3K/AKT signaling pathways with minimal false discovery rate. Furthermore, SPARC promotes OSCC cells metastasis by regulating the expressions of PDGFB, PDGFRβ, p-PDGFRβ , and the PI3K/AKT pathway. Higher SPARC expression was positively correlated with poor WPOI and differentiation in OSCC. SPARC activates the PI3K/AKT/PDGFB/PDGFRβ axis to promote proliferation and metastasis by OSCC cell lines. Therefore, SPARC may be a potential therapeutic target for patients with OSCC.

Screening and identification of potential target genes in head and neck cancer using bioinformatics analysis

Head and neck cancer (HNC) is the sixth most common cancer worldwide. Recent studies on the pathogenesis of HNC have identified some biochemical associations of this disease, but the molecular mechanisms are not clear. To explore the genetic alterations in head and neck tumors, to identify new high-specificity and high-sensitivity tumor markers, and to investigate potentially effective therapeutic targets, in silico methods were used to study HNC. The GSE58911 microarray dataset was downloaded from the Gene Expression Omnibus online database to identify potential target genes in the carcinogenesis and progression of HNC. Differentially expressed genes (DEGs) were identified and functional enrichment analysis was performed. In addition, a protein-protein interaction network was also constructed, and gene analysis was undertaken using Search Tool for the Retrieval of Interacting Genes and Cytoscape. A total of 648 differentially expressed genes were identified. Kyoto Encyclopedia of Genes and Genomes pathway and Gene Ontology functional enrichment analysis of DEGs included muscle system process, extracellular matrix organization, actin binding, structural molecule activity, structural constituent of muscle, extracellular region part, ECM-receptor interaction, amoebiasis, focal adhesion, drug metabolism-cytochrome P450, and chemical carcinogenesis. There were 26 hub genes identified and biological process analysis revealed that these genes were mainly enriched in extracellular matrix organization, serine-type endopeptidase activity, extracellular matrix, and complement and coagulation cascades. Survival analysis revealed that interleukin (IL)-8 (C-X-C motif chemokine ligand 8), IL1B, and serpin family A member 1 may be involved in the carcinogenesis of HNC. In summary, the DEGs and hub genes identified in the present study may increase understanding of the molecular mechanisms of development of HNC and provide potential target genes for clinical diagnosis and targeted therapy.

Apoptotic signaling in salivary mucoepidermoid carcinoma

BACKGROUND

Mucoepidermoid carcinoma is the most common malignant tumor of salivary glands. Apoptosis plays an important role in organogenesis of glandular structures, and aberrations of apoptotic mechanisms is associated with a wide array of pathologic conditions.

METHODS

The immunoexpression of proteins associated with apoptosis and proliferation was evaluated in 40 mucoepidermoid carcinoma cases.

RESULTS

Par-4, Survivin, MUC1, PHLDA1, Fas, and Ki-67 were predominantly expressed in mucoepidermoid carcinoma. FasL was rarely expressed, and Caspase-3 expression was observed in almost 50% of the cases. SPARC expression was associated with low-grade tumors, and Ki-67 expression was associated with lymph node metastasis. Expression of Fas and decreased expression of Ki-67 and Caspase-3 were associated with better overall cancer-specific survival rates.

CONCLUSIONS

The association of SPARC and Ki-67 expression with pathological features and the association of Fas, Caspase-3, and Ki-67 with survival probabilities suggest that these proteins may be useful prognostic markers for mucoepidermoid carcinoma.

Testican 1 (SPOCK1) and protein tyrosine phosphatase, receptor type S (PTPRS) show significant increase in saliva of tobacco users with oral cancer

Objectives:

To identify potential candidate proteins which are secretory in nature and present at a higher abundance in oral cancer patients with tobacco habits.

Methods:

Conditioned media of tobacco-treated and -untreated non-neoplastic oral keratinocytes were analyzed using iTRAQ-based mass spectrometry. Hypersecreted proteins; SPARC (osteonectin), cwcv and kazal like domains proteoglycan 1 (SPOCK1); prosaposin (PSAP); and protein tyrosine phosphatase, receptor type S (PTPRS) were validated by enzyme-linked immunosorbent assay (ELISA) using saliva samples from oral cancer patients who are tobacco users.

Results:

Proteomic analysis of tobacco-treated and -untreated cells led to the identification of 2873 proteins. Among these, 378 proteins showed high abundance and 253 proteins showed low abundance (2-fold cutoff) in conditioned-media of tobacco-treated cells. ELISA-based validation showed significantly higher levels of SPOCK1, PSAP, and PTPRS in oral cancer patients with tobacco chewing habits compared to healthy controls. However, PSAP showed low specificity compared to SPOCK1 and PTPRS.

Conclusions:

This study indicates significantly increased levels of SPOCK1, PSAP, and PTPRS in saliva of oral cancer patients with tobacco habits. These protein biomarkers might be useful to identify tobacco users with high risk of developing oral cancers.

Insight into the preformed albumin corona on in vitro and in vivo performances of albumin-selective nanoparticles

Preformed albumin corona of albumin-nonselective nanoparticles (NPs) is widely exploited to inhibit the unavoidable protein adsorption upon intravenous administration. However, very few studies have concerned the preformed albumin corona of albumin-selective NPs. Herein, we report a novel type of albumin-selective NPs by decorating 6-maleimidocaproyl polyethylene glycol stearate (SA) onto PLGA NPs (SP NPs) surface, taking albumin-nonselective PLGA NPs as control. PLGA NPs and SP NPs were prepared by emulsion-solvent evaporation method and the resultant NPs were in spherical shape with an average diameter around 180 nm. The corresponding albumin-coating PLGA NPs (PLGA@BSA NPs) and albumin-coating SP NPs (SP@BSA NPs) were formulated by incubating SP NPs or PLGA NPs with bovine serum albumin solution, respectively. The impact of albumin corona on particle characteristics, stability, photothermal effect, cytotoxicity, cell uptake, spheroid penetration and pharmacokinetics was investigated. In line with previous findings of preformed albumin coating, PLGA@BSA NPs exhibited higher stability, cytotoxicity, cell internalization and spheroid penetration performances in vitro, and longer blood circulation time in vivo than those of albumin-nonselective PLGA NPs, but albumin-selective SP NPs is capable of achieving a comparable in vitro and in vivo performances with both SP@BSA NPs and PLGA@BSA NPs. Our results demonstrate that SA decorated albumin-selective NPs pave a versatile avenue for optimizing nanoparticulate delivery without preformed albumin corona.

In situlow-immunogenic albumin-conjugating-corona guiding nanoparticles for tumor-targeting chemotherapy

Thein siturecruited albumin corona enables NPs' tumor-targeting and enhanced antitumor activityin vivo.

Secreted Protein Acidic and Rich in Cysteine (SPARC) Enhances Cell Proliferation, Migration, and Epithelial Mesenchymal Transition, and SPARC Expression is Associated with Tumor Grade in Head and Neck Cancer

Secreted protein acidic and rich in cysteine (SPARC) is a secreted protein which is involved in various biological processes. SPARC expression is associated with tumor metastasis and poor prognosis in several types of cancer. However, the SPARC-induced signaling pathway was not fully understood in head and neck cancer. In this study, our results showed that SPARC treatment promoted cell proliferation and migration in head and neck cancer cell lines FaDu and Detroit 562. In addition, SPARC induced expression of epithelial mesenchymal transition (EMT) regulators, including Slug, Snail, and Twist in Detroit 562. The results of phospho-kinase array analysis showed that SPARC treatment increased phosphorylation of some molecules including protein kinase B (PKB/AKT), ribosomal S6 kinase (RSK), and extracellular signal–regulated kinases (ERK). The expression of SPARC-induced EMT regulator Slug was suppressed by AKT inhibitor, but not ERK and RSK inhibitors. The SPARC expression in grade IV tumor samples is higher when compared to that in grade I–III tumor samples. Our results suggest that SPARC treatment enhances the EMT signaling pathway via activation of AKT, and exogenous SPARC and tumor expressing SPARC might be associated with tumor progression in head and neck cancers.

The quality of health services provided to remote dwelling aboriginal infants in the top end of northern Australia following health system changes: a qualitative analysis

Background

In Australia the health outcomes of remote dwelling Aboriginal infants are comparable to infants in developing countries. This research investigates service quality, from the clinicians’ perspective and as observed and recorded by the researcher, in two large Aboriginal communities in the Top End of northern Australia following health system changes.

Methods

Data were collected from semi-structured interviews with 25 clinicians providing or managing child health services in the two study sites. Thirty hours of participant observation was undertaken in the ‘baby-rooms’ at the two remote health centres between June and December 2012. The interview and observational data, as well as field notes were integrated and analysed thematically to explore clinicians’ perspectives of service delivery to infants in the remote health centres.

Results

A range of factors affecting the quality of care, mostly identified before health system changes were instigated, persisted. These factors included ineffective service delivery, inadequate staffing and culturally unsafe practices. The six themes identified in the data: ‘very adhoc’, ‘swallowed by acute’, ‘going under’, ‘a flux’, ‘a huge barrier’ and ‘them and us’ illustrate how these factors continue, and when combined portray a ‘very chaotic system’.

Conclusion

Service providers perceived service provision and quality to be inadequate, despite health system changes. Further work is urgently needed to improve the quality, cultural responsiveness and effectiveness of services to this population.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0849-1) contains supplementary material, which is available to authorized users.

PDGFRβ Is a Novel Marker of Stromal Activation in Oral Squamous Cell Carcinomas

Carcinoma associated fibroblasts (CAFs) form the main constituents of tumor stroma and play an important role in tumor growth and invasion. The presence of CAFs is a strong predictor of poor prognosis of head and neck squamous cell carcinoma. Despite significant progress in determining the role of CAFs in tumor progression, the mechanisms contributing to their activation remain poorly characterized, in part due to fibroblast heterogeneity and the scarcity of reliable fibroblast surface markers. To search for such markers in oral squamous cell carcinoma (OSCC), we applied a novel approach that uses RNA-sequencing data derived from the cancer genome atlas (TCGA). Specifically, our strategy allowed for an unbiased identification of genes whose expression was closely associated with a set of bona fide stroma-specific transcripts, namely the interstitial collagens COL1A1, COL1A2, and COL3A1. Among the top hits were genes involved in cellular matrix remodeling and tumor invasion and migration, including platelet-derived growth factor receptor beta (PDGFRβ), which was found to be the highest-ranking receptor protein genome-wide. Similar analyses performed on ten additional TCGA cancer datasets revealed that other tumor types shared CAF markers with OSCC, including PDGFRβ, which was found to significantly correlate with the reference collagen expression in ten of the 11 cancer types tested. Subsequent immunostaining of OSCC specimens demonstrated that PDGFRβ was abundantly expressed in stromal fibroblasts of all tested cases (12/12), while it was absent in tumor cells, with greater specificity than other known markers such as alpha smooth muscle actin or podoplanin (3/11). Overall, this study identified PDGFRβ as a novel marker of stromal activation in OSCC, and further characterized a list of promising candidate CAF markers that may be relevant to other carcinomas. Our novel approach provides for a fast and accurate method to identify CAF markers without the need for large-scale immunostaining experiments.

Novel technologies for oral squamous carcinoma biomarkers in diagnostics and prognostics

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a highly prevalent malignant pathology of the oral cavity. Despite the significant progress accomplished in the field of OSCC, the diagnosis is performed mostly in advanced stages; thus, novel biomarkers need to be developed for the diagnostic and prognostic of this malignancy. Many new technologies are used to provide indispensable information related to the pathogenesis of OSCC. The molecular profiling studies that incorporate genetic and epigenetic alterations need to be integrated in clinical practice as routine approaches to facilitate a better diagnostic and prognostic.

REVIEW

In this review, the authors present a summary of these novel technologies in the field of genomics, transcriptomics or proteomics, capable of generating data related to personalized diagnostic and treatment.

Knock-down of ABCE1 gene induces G1/S arrest in human oral cancer cells

PURPOSE

This study aims to explore the clinical characteristics of ATP binding cassette E1 (ABCE1) in oral squamous cell carcinomas (OSCC) and its roles in the proliferation, invasiveness, migration and apoptosis of the human oral squamous cell carcinoma cells CAL-27.

METHODS

The expression of ABCE1 and its target protein-RNase L, were first studied in tumor tissues of OSCC and adjacent non-tumor tissues. Moreover, CAL-27cells were transfected by ABCE1-specific shRNA, then MTT assay, the transwell and scratch assay were used to study cell proliferation and migration activity; the apoptosis rate and cell cycle distribution were tested by flow cytometry. Western blot and RT-PCR assay were adopted to measure their silencing efficacy.

RESULTS

ABCE1 expression is low in the adjacent non-tumor tissues while the expression is high in the oral cancer; the expression is reversely proportional to the differentiation degrees. The expression of RNaseL was in contrary to ABCE1. After transfected with ABCE1-siRNA, the proliferation, invasiveness and migration capabilities of cells decreased significantly whilst the apoptosis rate enhanced greatly (P < 0.01). Meanwhile, the expression of ABCE1 in CAL-27 cells was blocked (P < 0.01) while the expression of RNase L increased significantly (P < 0.01).

CONCLUSION

ABCE1 is closely connected with the pathogenesis and development of oral cancer, which acts through the cellular pathways of 2-5A/RNase L.