Subcellular differential expression of Ep-ICD in oral dysplasia and cancer is associated with disease progression and prognosis.

BACKGROUND: Identification of patients with oral dysplasia at high risk of cancer development and oral squamous cell carcinoma (OSCC) at increased risk of disease recurrence will enable rigorous personalized treatment. Regulated intramembranous proteolysis of Epithelial cell adhesion molecule (EpCAM) resulting in release of its intracellular domain Ep-ICD into cytoplasm and nucleus triggers oncogenic signaling. We analyzed the expression of Ep-ICD in oral dysplasia and cancer and determined its clinical significance in disease progression and prognosis. METHODS: In a retrospective study, immunohistochemical analysis of nuclear and cytoplasmic Ep-ICD and EpEx (extracellular domain of EpCAM), was carried out in 115 OSCC, 97 oral dysplasia and 105 normal oral tissues, correlated with clinicopathological parameters and disease outcome over 60 months for oral dysplasia and OSCC patients. Disease-free survival (DFS) was determined by Kaplan-Meier method and multivariate Cox regression analysis. RESULTS: In comparison with normal oral tissues, significant increase in nuclear Ep-ICD and membrane EpEx was observed in dysplasia, and OSCC (p = 0.013 and < 0.001 respectively). Oral dysplasia patients with increased overall Ep-ICD developed cancer in short time period (mean = 47 months; p = 0.044). OSCC patients with increased nuclear Ep-ICD and membrane EpEx had significantly reduced mean DFS of 33.7 months (p = 0.018). CONCLUSIONS: Our study provided clinical evidence for Ep-ICD as a predictor of cancer development in patients with oral dysplasia and recurrence in OSCC patients, suggesting its potential utility in enhanced management of those patients detected to have increased risk of progression to cancer and recurrence in OSCC patients.

ER maleate is a novel anticancer agent in oral cancer: implications for cancer therapy.

ER maleate [10-(3-Aminopropyl)-3, 4-dimethyl-9(10H)-acridinone maleate] identified in a kinome screen was investigated as a novel anticancer agent for oral squamous cell carcinoma (OSCC). Our aim was to demonstrate its anticancer effects, identify putative molecular targets and determine their clinical relevance and investigate its chemosensitization potential for platinum drugs to aid in OSCC management. Biologic effects of ER maleate were determined using oral cancer cell lines in vitro and oral tumor xenografts in vivo. mRNA profiling, real time PCR and western blot revealed ER maleate modulated the expression of polo-like kinase 1 (PLK1) and spleen tyrosine kinase (Syk). Their clinical significance was determined in oral SCC patients by immunohistochemistry and correlated with prognosis by Kaplan-Meier survival and multivariate Cox regression analyses. ER maleate induced cell apoptosis, inhibited proliferation, colony formation, migration and invasion in oral cancer cells. Imagestream analysis revealed cell cycle arrest in G2/M phase and increased polyploidy, unravelling deregulation of cell division and cell death. Mechanistically, ER maleate decreased expression of PLK1 and Syk, induced cleavage of PARP, caspase9 and caspase3, and increased chemosensitivity to carboplatin; significantly suppressed tumor growth and increased antitumor activity of carboplatin in tumor xenografts. ER maleate treated tumor xenografts showed reduced PLK1 and Syk expression. Clinical investigations revealed overexpression of PLK1 and Syk in oral SCC patients that correlated with disease prognosis. Our in vitro and in vivo findings provide a strong rationale for pre-clinical efficacy of ER maleate as a novel anticancer agent and chemosensitizer of platinum drugs for OSCC.

Anticancer Activity of Apaziquone in Oral Cancer Cells and Xenograft Model: Implications for Oral Cancer Therapy.

Oral squamous cell carcinoma (OSCC) patients diagnosed in late stages have limited chemotherapeutic options underscoring the great need for development of new anticancer agents for more effective disease management. We aimed to investigate the anticancer potential of Apaziquone, [EOquin, USAN, E09, 3-hydroxy-5- aziridinyl-1-methyl-2(1H-indole-4,7-dione)-prop-ß-en-α-ol], a pro-drug belonging to a class of anti-cancer agents called bioreductive alkylating agents, for OSCC. Apaziquone treatment inhibited cell proliferation and induced apoptosis in OSCC cells in vitro. Apaziquone treated OSCC cells showed increased activation of Caspase 9 and Caspase 3, and Poly (ADP ribose) polymerase (PARP) cleavage suggesting induction of apoptosis by apaziquone in oral cancer cells. Importantly, apaziquone treatment significantly reduced oral tumor xenograft volume in immunocompromised NOD/SCID/Crl mice without causing apparent toxicity to normal tissues. In conclusion, our in vitro and in vivo studies identified and demonstrated the pre-clinical efficacy of Apaziquone, as a potential novel anti-cancer therapeutic candidate for oral cancer management.

Immunohistochemical Subcellular Localization of Protein Biomarkers Distinguishes Benign from Malignant Thyroid Nodules: Potential for Fine-Needle Aspiration Biopsy Clinical Application.

BACKGROUND: It is of critical clinical importance to select accurately for surgery thyroid nodules at risk for malignancy and avoid surgery on those that are benign. Using alterations in subcellular localization for seven putative biomarker proteins (identified by proteomics), this study aimed to define a specific combination of proteins in surgical tissues that could distinguish benign from malignant nodules to assist in future surgical selection by fine-needle aspiration biopsy (FNAB). METHODS: Immunohistochemical subcellular localization (IHC) analyses of seven proteins were retrospectively performed on surgical tissues (115 benign nodules and 114 papillary-based thyroid carcinomas [TC]), and a risk model biomarker panel was developed and validated. The biomarker panel efficacy was verified in 50 FNAB formalin-fixed and paraffin-embedded cell blocks, and 26 cytosmears were prepared from fresh surgically resected thyroid nodules. RESULTS: Selection modeling using these proteins resulted in nuclear phosphoglycerate kinase 1 (PGK1) loss and nuclear Galectin-3 overexpression as the best combination for distinguishing TC from benign nodules (area under the curve [AUC] 0.96 and 0.95 in test and validation sets, respectively). A computed malignancy score also accurately identified TC in benign and indeterminate nodules (test and validation sets: AUC 0.94, 0.90; specificity 98%, 99%). Its efficacy was confirmed in surgical FNAB cell blocks and cytosmears. CONCLUSION: Using surgical tissues, it was observed that a combination of PGK1 and Galectin-3 had high efficiency for distinguishing benign from malignant thyroid nodules and could improve surgical selection for TC among indeterminate nodules. Further validation in prospective preoperative FNAB will be required to confirm such a clinical application.

Anticancer activity of pyrithione zinc in oral cancer cells identified in small molecule screens and xenograft model: Implications for oral cancer therapy.

Oral squamous cell carcinoma (OSCC) patients diagnosed in late stages have limited chemotherapeutic options, underscoring the great need for development of new anticancer agents for more effective disease management. We aimed to identify novel anticancer agents for OSCC using quantitative high throughput assays for screening six chemical libraries consisting of 5170 small molecule inhibitors. In depth characterization resulted in identification of pyrithione zinc (PYZ) as the most effective cytotoxic agent inhibiting cell proliferation and inducing apoptosis in OSCC cells in vitro. Further, treatment with PYZ reduced colony forming, migration and invasion potential of oral cancer cells in a dose-dependent manner. PYZ treatment also led to altered expression of several key components of the major signaling pathways including PI3K/AKT/mTOR and WNT/ß-catenin in OSCC cells. In addition, treatment with PYZ also reduced expression of 14-3-3ζ, 14-3-3σ, cyclin D1, c-Myc and pyruvate kinase M2 (PKM2), proteins identified in our earlier studies to be involved in development and progression of OSCCs. Importantly, PYZ treatment significantly reduced tumor xenograft volume in immunocompromised NOD/SCID/Crl mice without causing apparent toxicity to normal tissues. Taken together, we demonstrate in vitro and in vivo efficacy of PYZ in OSCC. In conclusion, we identified PYZ in HTS assays and demonstrated in vitro and in vivo pre-clinical efficacy of PYZ as a novel anticancer therapeutic candidate in OSCC.