Oral cancer, one of the six most common human cancers with an overall 5-year survival rate of <50%, is often not diagnosed until it has reached an advanced stage. The aim of the current study is to explore salivary metabolomics as a disease diagnostic and stratification tool for oral cancer and leukoplakia and evaluate the potential of salivary metabolome for detection of oral squamous cell carcinoma (OSCC). Saliva metabolite profiling for a group of 37 OSCC patients, 32 oral leukoplakia (OLK) patients and 34 healthy subjects was performed using ultraperformance liquid chromatography coupled with quadrupole/time-of-flight mass spectrometry in conjunction with multivariate statistical analysis. The OSCC, OLK and healthy control groups demonstrate characteristic salivary metabolic signatures. A panel of five salivary metabolites including c-aminobutyric acid, phenylalanine, valine, n-eicosanoic acid and lactic acid were selected using OPLS-DA model with S-plot. The predictive power of each of the five salivary metabolites was evaluated by receiver operating characteristic curves for OSCC. Valine, lactic acid and phenylalanine in combination yielded satisfactory accuracy (0.89, 0.97), sensitivity (86.5% and 94.6%), specificity (82.4% and 84.4%) and positive predictive value (81.6% and 87.5%) in distinguishing OSCC from the controls or OLK, respectively. The utility of salivary metabolome diagnostics for oral cancer is successfully demonstrated in this study and these results suggest that metabolomics approach complements the clinical detection of OSCC and stratifies the two types of lesions, leading to an improved disease diagnosis and prognosis. About 1.5 million new cancer cases are expected to be diagnosed in 2009 in the United States and >0.5 million Americans are expected to die of cancer this year, averaging about 1,500 deaths per day.1 These numbers have been steadily increasing over the past 15 years, despite significant progress in cancer treatment. Oral cancer represents one of the six most common human cancers with a high morbidity rate and an overall 5-year survival rate of <50%.2,3 Reports indicate an increasing worldwide incidence of oral cancer at an earlier age.4-6 Over 90% of oral cancer is oral squamous cell carcinoma (OSCC) which arises from the oral mucosal lining.7 A critical factor in the lack of prognostic improvement is the fact that a significant proportion of cancers initially are asymptomatic lesions and are not diagnosed or treated until Key words: metabolomics, saliva, oral squamous cell carcinoma, ultraperformance liquid chromatography quadrupole-time of flight mass spectrometry, multivariate statistical analysis, receiver operating characteristics Abbreviations:: OSCC: oral squamous cell carcinoma; OLK: oral leukoplakia; UPLC-QTOFMS: ultraperformance liquid chromatographyquadrupole/time-of-flight mass spectrometry; PCA: principal component analysis; OPLS-DA: orthogonal partial least squares-discriminant analysis; ROC: receiver operating characteristic; LR: logistic regression; VIP: va...

Deregulation of the b-catenin signaling has long been associated with cancer. Intracellular components of this pathway, including axin, APC, and b-catenin, are frequently mutated in a range of human tumors, but the contribution of specific extracellular ligands that promote cancer development through this signaling axis remains unclear. We conducted a reporter-based screen in a panel of human tumors to identify secreted factors that stimulate b-catenin signaling. Through this screen and further molecular characterization, we found that R-spondin (RSPO) proteins collaborate with Wnt proteins to activate b-catenin. RSPO family members were expressed in several human tumors representing multiple malignancies, including ovarian, pancreatic, colon, breast, and lung cancer. We generated specific monoclonal antibody antagonists of RSPO family members and found that anti-RSPO treatment markedly inhibited tumor growth in human patient-derived tumor xenograft models, either as single agents or in combination with chemotherapy. Furthermore, blocking RSPO signaling reduced the tumorigenicity of cancer cells based on serial transplantation studies. Moreover, geneexpression analyses revealed that anti-RSPO treatment in responsive tumors strongly inhibited b-catenin target genes known to be associated with cancer and normal stem cells. Collectively, our results suggest that the RSPO family is an important stimulator of b-catenin activity in many human tumors and highlight a new effective approach for therapeutically modulating this fundamental signaling axis. Cancer Res; 76(3); 713-23. Ó2015 AACR.

Our previous study demonstrated a progressive glycolytic perturbation during the course of DMBA-induced hamster oral carcinogenesis, which was attenuated by salvianolic acid B (Sal-B) treatment along with decreased incidences of oral squamous cell carcinoma (OSCC) formation. It was proposed that metabolic modulation should be an additional mode of action attributable to Sal-B’s anti-carcinogenic activity. However, the molecular mechanisms underlying Sal-B-induced metabolic modulation function remained elusive. In the present study, we performed next-generation sequencing (NGS) profiling in the same animal model and found Sal-B treatment evoked a general downregulation of the phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) and hypoxia inducible factor 1α subunit (HIF-1α) signaling pathways, which might contribute to Sal-B’s metabolic modulation activity. The inhibitory effects of Sal-B on aerobic glycolysis, as well as PI3K/AKT and HIF-1α signaling pathways, were validated in two well-characterized OSCC cell lines (Cal27 and HN4), and premalignant oral Leuk1 cells and Sal-B treatment led to elevation of the loss of mitochondrial membrane potential (MMP), increased cell apoptosis, and reduced abilities of colony formation. Rescue assays suggested that compared with Sal-B treatment group, Akt or hif-1a overexpression attenuated the inhibitory effect of Sal-B on glucose uptake and intracellular lactate level. Taken together, our results suggested that Sal-B modulated aberrant glucose metabolism via the PI3K/AKT/HIF-1α signaling pathways, which might contribute to the anti-carcinogenic activity of Sal-B.