Altered Expression of Sphingosine-1-Phosphate Metabolizing Enzymes in Oral Cancer Correlate With Clinicopathological Attributes.

We have determined the gene expression of sphingosine-1-phosphate (S1P) metabolizing enzymes (SphK1, SphK2, SGPL1, SGPP1, SGPP2, PPAP2A, PPAP2B, and PPAP2C) by quantitative real-time polymerase chain reaction in tumor tissues and adjacent normal tissues of 50 oral squamous cell carcinoma (OSCC) patients. Expression of SphK1 and SGPP1 genes was up-regulated significantly in 70% and 75% OSCC tumors respectively. Importantly, expression of SphK2 and PPAP2B was down-regulated in the tumor tissues of 70% OSCC patients. Expression of SphK2 and PPAP2B negatively correlated with tumor-node-metastasis (TNM) staging and tumor volume respectively. Furthermore, LPP1 is an independent predictor of TNM staging and lymph node ratio.

Multifunctional Ultrasmall Theranostic Nanohybrids Developed by Ultrasonic Atomizer for Drug Delivery and Magnetic Resonance Imaging.

Theranostic nanoparticulate systems (TNPs) have shown potential in addressing problems related to spatial localization and temporally controlled release of drugs with the capabilities of real-time imaging to evaluate the progress of therapy. The current study reports the ultrasonic atomization-led synthesis of in vitro and in vivo evaluations of ultrasmall chitosan-based theranostic nanohybrid formulations with encapsulated doxorubicin (DOX) and iron-oxide magnetic nanoparticles. The nanohybrid particles are characterized using transmission electron microscopy, powder X-ray diffraction, FTIR, DOX encapsulation efficiency, in vitro release, cellular uptake, and toxicity. These formulations were also tested for the capability of invivo tumor reduction and simultaneous magnetic resonance imaging using Swiss albino mice. Ultrasonic atomizer-led synthesis resulted in chitosan-magnetic nanohybrids (CMNPs) having sizes of 15 ± 3 nm which comprise MNP of 10 ± 3 nm. The encapsulation of DOX in CMNP was around 25%, resulting in an 80% sustained release over 10 days at pH 5 and 7. CMNP was also found to be an efficient DOX delivery vehicle tested on cancer cells (HeLa). The CMNPs were able to reduce the tumor volume by 60% in 15 days. The inherent magnetic property and nanoscale size of CMNPs also provided for enhanced contrast efficiency in magnetic resonance imaging of tumors. Thus, such multifunctional theranostic nanoparticles can be an efficient tool for targeted diagnostic and therapeutic success.

Association of single nucleotide polymorphism miRNA-146a (rs2910164) with increased predisposition to oral squamous cell carcinoma in central India population.

BACKGROUND: miRNAs play a crucial role in the genesis of cancer, either as tumor suppressor genes or as oncogenes. Single Nucleotide Polymorphisms (SNPs) in the seed region of microRNAs (miRNAs) can dysregulate their levels in the tissues and thereby affect carcinogenesis. The association of SNP in miR-146a (rs2910164) with the risk of oral squamous cell carcinoma (OSCC) has not been understood. OBJECTIVE: In the present study, we have determined the association and functional significance of miR-146a (rs2910164) SNP with susceptibility to OSCC predisposition. METHODS: In the present case-control study, we enrolled 430 subjects from central India (215 OSCC cases and 215 healthy controls). We performed genotyping by Kompetitive Allele Specific PCR (KASP), and their correlation with OSCC susceptibility was analyzed. miRNA expression profiling in tumor tissues and adjacent normal tissues from six OSCC patients was done by a NanoString n-Counter-based assay. Subsequently, gene ontology and pathway analysis were performed with FunRich version 3.13. RESULTS: The CC genotype of rs2910164 miR-146a was significantly associated with the increased risk for OSCC (CC vs GC, OR = 2.62; 95% CI: 1.48-4.66; p value = 0.001). However, the GC genotype was protective with GC vs CC (OR = 0.38, 95%CI =0.21-0.67, p-value = 0.001), and GC vs GG (OR = 0.58, 95%CI = 0.37-0.89, p-value = 0.01). CONCLUSION: Our finding suggests that SNP rs2910164 of miR-146a may be a genetic risk factor for OSCC susceptibility in the Central India population. However, more extensive multicenter studies are required to validate these findings.

Single Nucleotide Polymorphisms in Cytokine Genes are Associated with the Susceptibility to Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is the most common type of cancer among men in the Indian subcontinent. Cytokines regulate inflammation and angiogenesis in a variety of cancers. Genetic variability in the cytokine genes can potentially influence the predisposition to oral carcinogenesis. The aim of the current study was to investigate the associations of SNPs in cytokine genes with the susceptibility of oral squamous cell carcinoma. In the present study, we have analyzed the allelic frequency of 32 single nucleotide polymorphisms (SNPs) using MassArray-based iPLEX assay in 16 cytokine genes in 166 OSCC patients and 151 healthy subjects from central India. Out of 32 SNPs analyzed, five SNPs were significantly associated with the risk of OSCC. AA and GG genotypes of IL-1ß +3953 were associated with an increased and decreased risk of OSCC, respectively. In several genetic models, GG genotype and G allele in IL-12A 3'UTR G>A were found to be associated with an increased risk of OSCC. Similarly, the GG genotype of IL-12B +1188 T>G was associated with increased susceptibility to OSCC. We conclude that SNPs in the genes coding for IL-1ß, IL-12A and IL-12B are associated with increased genetic susceptibility to OSCC in the central Indian population.

Regulation of Tumor Immune Microenvironment by Sphingolipids and Lysophosphatidic Acid.

The tumor microenvironment (TME) consists of cancer cells that interact with stromal components such as the extracellular matrix, blood, and lymphatic networks, fibroblasts, adipocytes, and the cells of the immune system. Further, the tumor immune microenvironment, majorly represented by the tumor-infiltrating immune cells (TIIC), plays an important role in cancer therapeutics and patient prognosis. In fact, a high density of TIICs within the tumor microenvironment is known to be associated with better outcomes in several types of cancers. Towards this, two bioactive lipid molecules, lysophosphatidic acid (LPA) and sphingosine-1-phosphate (S1P), regulate the homing of immune cells to the TME. In the present review, we will uncover the role of LPA and S1P signaling in the tumor immune environment, highlighting the latest progress in this field.

Downregulation of Lipid Phosphate Phosphatase 3 Correlates With Tumor-Infiltrating Immune Cells in Oral Cancer.

Background Sphingosine-1-phosphate (S1P) is a potent oncogenic lipid. Intracellular levels of S1P are tightly regulated by eight S1P-metabolizing enzymes. S1P synthesis is catalyzed by two sphingosine kinases, i.e., sphingosine kinase 1 (SphK1) and sphingosine kinase 2 (SphK2). Five lipid phosphatases (two S1P phosphatases and lipid phosphate phosphatases (LPPs) 1, 2, and 3) reversibly convert S1P back to sphingosine. Previously, we have determined the mRNA expression profile of eight S1P-metabolizing enzymes in tumor tissues and adjacent normal tissues from oral squamous cell carcinoma (OSCC) patients. Except for SphK1, the role of S1P-metabolizing enzymes in OSCC has been poorly studied. Methods We have determined the protein expression of four S1P-metabolizing enzymes (SphK1, SphK2, sphingosine-1-phosphate phosphatase 1 (SGPP1), and lipid phosphate phosphatase 3 (LPP3)) by immunohistochemistry (IHC) in tumor tissues of 46 OSCC patients. Six subjects with non-dysplastic oral mucosa were also included in the study. The immunoreactivity score (IRS) was calculated for each protein in every subject. Further, we determined the associations of expression of S1P-metabolizing enzymes with clinicopathological features of OSCC patients. Results We demonstrate the low IRS for SphK2 and LPP3 in OSCC tumors. Importantly, expression of SphK2 and LPP3 was downregulated in malignant epithelial cells compared to non-malignant mucosa. Further, LPP3 expression negatively correlated with tumor­node­metastasis (TNM) staging of patients (r = -0.307, p = 0.043). Importantly, expression of LPP3 in tumors was found to be an independent predictor of perinodal extension (b = -0.440, p = 0.009), lymphovascular invasion (b = -0.614, p < 0.001), lymph node ratio (b = 0.336, p = 0.039), and TNM staging (b = -0.364, p = 0.030). Conclusion Taken together, our data show that expression of SphK2 and LPP3 is decreased compared to normal mucosa. Thus, the S1P signaling pathway could represent a potential therapeutic target.

Do patients with oral squamous cell carcinoma express receptor tyrosine kinase-like orphan receptor 1? Results of an observational study.

CONTEXT: The receptor tyrosine kinase-like orphan receptor 1 (ROR1) is a transmembrane protein of the receptor tyrosine kinase family. The expression of ROR1 has been linked to cancers. AIMS: This study aimed to investigate the expression of ROR1 in oral squamous cell carcinoma (OSCC). SETTINGS AND DESIGN: This prospective observational study was conducted at a tertiary referral center for treatment of oral carcinoma from November 2013 to December 2016. SUBJECTS AND METHODS: One-step quantitative reverse transcription-polymerase chain reaction (30 oral cancer tissues and ten normal oral tissue samples) was performed to characterize the expression of the ROR1 gene in oral cancer. STATISTICAL ANALYSIS USED: Analyses of all tumor samples were carried out at least twice, and the mean value was calculated. The differences in ROR1 messenger RNA (mRNA) expression between OSCC tissue and nontumorous gingival tissue was statistically analyzed using Mann-Whitney U-test. The correlations between the clinicopathological parameters and ROR1 mRNA expression were analyzed using Kruskal-Wallis test χ2 value. RESULTS: There were 17, 5, 3 and 1 cases of OSCC of buccal mucosa, tongue and lower alveolus lip, respectively. Nearly 88.5% of cases had a history of tobacco consumption. The most common OSCC type was T2N1M0. There was no difference in ROR1 fold change between controls and cases (P = 0.06), but there was a trend for downregulation of ROR1 expression from controls to cases. Subgroup analysis revealed the downregulation of ROR1 expression in controls versus Grade II that was significant (P = 0.04). CONCLUSIONS: There was no change in the expression of ROR1 between cases and controls. A study involving a larger sample size needs to be formulated and conducted for investigating the relation between expression and regulation of ROR1 in OSCC.

Expression of H19 long non-coding RNA is down-regulated in oral squamous cell carcinoma.

Long non-coding RNAs (lncRNAs) are a group of non-protein-coding RNAs which are longer than 200 nucleotides. LncRNAs play important roles in epigenetic modification, transcription and post-transcriptional regulation, maintenance of normal tissue development and differentiation. LncRNA could serve as a biomarker for diagnosis and prognosis as well as a molecular target for therapy in oral squamous cell carcinoma (OSCC). Therefore, we have determined the expression profile of 5-lncRNAs namely UCA1, TUG1, HOTAIR, MALAT1, and H19 by quantitative real-time PCR in tumor tissues and adjacent normal tissue of 32 OSCC patients. To determine the expression, methylation status and genomic alterations in lncRNAs across pancancer, TCGA datasets were analyzed by UALCAN, MEXPRESS and cBioPortal database. Then, we determined the association between lncRNA expression and clinicopathological attributes of patients by Spearman's rank test. Expression of UCA1 and TUG1 genes was up-regulated in 54.83 % and 53.12 % OSCC tumors, respectively. Importantly, expression of MALAT1 and H19 was down-regulated in tumor tissues of 62.5 % and 81.25 % respectively of OSCC patients. Except for MALAT1, our experimental data showed concordance with the TCGA analysis. Expression of HOTAIR in OSCC tumors was positively correlated with tumor volume, whereas MALAT1 and H19 negatively correlated with the smoking status of patients.

Emerging role of sphingosine-1-phosphate signaling in head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is the sixth most frequent cancer type, with an annual incidence of approximately half a million people worldwide. It has a high recurrence rate and an extremely low survival rate. This is due to limited availability of effective therapies to reduce the rate of recurrence, resulting in high morbidity and mortality of patients with advanced stages of the disease. HNSCC often develops resistance to chemotherapy and targeted drug therapy. Thus, to overcome the problem of drug resistance, there is a need to explore novel drug targets. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid involved in inflammation, tumor progression, and angiogenesis. S1P is synthesized intracellularly by two sphingosine kinases (SphKs). It can be exported to the extracellular space, where it can activate a family of G-protein-coupled receptors. Alternatively, S1P can act as an intracellular second messenger. SphK1 regulates tumor progression, invasion, metastasis, and chemoresistance in HNSCC. SphK1 expression is highly elevated in advanced stage HNSCC tumors and correlates with poor survival. In this article, we review current knowledge regarding the role of S1P receptors and enzymes of S1P metabolism in HNSCC carcinogenesis. Furthermore, we summarize the current perspectives on therapeutic approaches for targeting S1P pathway for treating HNSCC.