Upregulation of tropomyosin alpha-4 chain in patients' saliva with oral squamous cell carcinoma as demonstrated by Phage display.

Patients with oral squamous cell carcinoma (OSCC) present significant alterations in their saliva proteome. We have used the shotgun Phage Display (PD) technology to identify candidate proteins that were upregulated in saliva of OSCC by selecting ligands to salivary proteins from a single-chain variable fragment (scFv) PD combinatorial library. After two selection cycles, the highly reactive clone scFv-D09 was able to distinguish saliva of OSCC patients from healthy subjects by enzyme-linked immunosorbent assay (ELISA) with sensitivity and specificity of 96.67%. Additionally, the scFv-D09 clone presented a positive immunostaining for invasive malignant epithelial cells in the connective tissue, keratin pearls in the OSCC, and ducts of salivary glands. We have further identified the target protein as the tropomyosin alpha-4 chain (TPM4) by two-dimensional polyacrylamide gel electrophoresis and mass spectrometry, and its binding to the scFV-D09 was demonstrated by bioinformatics. Briefly, we have identified TPM4 as upregulated salivary protein in patients with OSCC, which plays a central role in stabilizing cytoskeleton actin filaments, probably linked with tumor tissue remodeling. Long-term longitudinal studies are needed to validate TPM4 as a potential marker of a malignant process.

Pathologic significance of AKT, mTOR, and GSK3ß proteins in oral squamous cell carcinoma-affected patients.

Phosphatidylinositol-3-kinases are kinases that lead to AKT phosphorylation and thus mTOR and GSK3ß activation. These proteins are linked to tumorigenesis, but their roles in driving cervical lymph node (CLN) metastasis of oral squamous cell carcinoma (OSCC) cells are unknown. This study aimed to investigate the role of AKT, mTOR, and GSK3ß proteins in the occurrence of CLN metastasis in OSCC patients. Ninety and 18 paraffin-embedded OSCC and oral mucosa samples were included, respectively. We divided our OSCC patients into non-metastasizing (PNM) and metastasizing (PM) groups, and the expression of total AKT, pAKT1Thr308, pAKTSer473, GSK3ß, pGSK3ßSer9, and pmTORSer2448 was analyzed by immunohistochemistry. The mean expression of GSK3ß, pGSK3ßSer9, total AKT, and pmTOR2448 was always higher in the OSCC tissues than that in the controls. A positive correlation was also found among these proteins. Total AKT, pmTORSer2448, and pGSK3ßSer9 expression was significantly higher in the PNM and PM groups than that in the control group. However, only GSK3ß expression was significantly higher in the PM group compared with the PNM group. High expression levels of GSK3ß and pGSK3ßSer9 were significantly associated with CLN metastasis, but only GSK3ß remained an independent predictor of CLN metastasis. pGSK3ßSer9 and CLN metastasis were associated with a poor prognosis, but only the latter remained an independent prognostic parameter. Kaplan-Meier survival curves showed that pGSK3ßSer9 and CLN metastasis were significantly related to reduced survival rates. These results suggest that AKT and mTOR proteins are involved in OSCC biology and that GSK3ß itself may drive CLN metastatic spread of OSCC cells.

Myoepithelial carcinoma of the submandibular gland: report of a case with multiple cutaneous metastases.

Myoepithelial carcinoma is a rare and aggressive neoplasm of the salivary glands. One-third of the patients may develop regional distant metastases, and lungs and kidneys have been regarded as the most usual sites for implantation. There is, however, little information on the metastatic behavior of this malignancy. We report the first case of patient with multiple cutaneous metastases from a myoepithelial carcinoma of the submandibular gland, which depicted a very aggressive clinical course.