Potential role of hematopoietic pre-B-cell leukemia transcription factor-interacting protein in oral carcinogenesis.

BACKGROUND: Hematopoietic pre-B-cell leukemia transcription factor-interacting protein (HPIP) is a corepressor of pre-B-cell leukemia homeobox (PBX) 1 and is known to play a role in hematopoiesis. Recently, HPIP was demonstrated to promote breast cancer cell proliferation and hepatocellular carcinoma growth. Moreover, it has been revealed that homeobox and PBX proteins, the expression of which is regulated by HPIP, play key roles in cancer of various organs, including oral squamous cell carcinoma (OSCC). Nevertheless, there has not been any study regarding the role of HPIP in OSCC. This study investigated the expression of HPIP in normal oral mucosa, epithelial precursor lesion (OEPL), and OSCC, and the functional roles of HPIP in OSCC cells and normal keratinocytes. MATERIALS AND METHODS: Immunohistochemical analysis of HPIP, Ki-67, and involucrin was performed in OSCC specimens, and the change in involucrin expression following RNA interference treatment against HPIP was examined by quantitative RT-PCR and Western blot analysis in SCC9 and NHEK cells undergoing extracellular calcium-induced differentiation. Matrigel transwell and cell proliferation assays for both cell lines transfected with HPIP siRNA were also conducted. RESULTS: HPIP expression increased in OEPL and OSCC specimens. In vitro analysis revealed that HPIP suppressed differentiation and proliferation of SCC9 cells and transwell migration of NHEK cells, while HPIP promoted invasion of SCC9 and proliferation of NHEK cells. However, HPIP has no significant effect on NHEK cell differentiation. CONCLUSION: HPIP may play a critical role in oral carcinogenesis and is thus a potential target for anticancer therapy, with particular emphasis on its involvement in differentiation and migration/metastasis.

ANGPTL4 regulates the metastatic potential of oral squamous cell carcinoma.

Lymph node metastasis is a major factor for poor prognosis in oral squamous cell carcinoma (OSCC). However, the molecular mechanisms of lymph node metastasis are unclear. We determined that angiopoietin-like protein 4 (ANGPTL4) mRNA and protein expression were increased in OSCC cells established from the primary site in metastatic cases. In addition, ANGPTL4 expression in biopsy specimens was correlated with the presence of lymph node metastasis. Therefore, our initial findings suggest that OSCC cells expressing ANGPTL4 may possess metastatic ability. Furthermore, cell culture supernatants from OSCC cells that metastasized to the lymph node contain ANGPTL4 and promote invasive ability. These findings suggest that secreted ANGPTL4 may affect the invasive ability of OSCC. Moreover, the rates of positive ANGPTL4 expression at the primary site were significantly higher in the lymph node metastasis group. These results demonstrate that ANGPTL4 contributes to OSCC metastasis by stimulating cell invasion. Therefore, ANGPTL4 is a potential therapeutic target for preventing cancer metastasis.

Sclerosing odontogenic carcinoma with benign fibro-osseous lesion of the mandible: an extremely rare case report.

A case of sclerosing odontogenic carcinoma (SOC) admixed with a benign fibro-osseous lesion (BFOL) is reported herein. A 67-year-old male had paresthesia in the mental region. Computed tomography detected an intragnathic mass that was focally expansile with disappearance of cortical bone, and contained admixed radiolucency and radio-opacity. Under the pathological diagnosis as benign fibro-osseous lesion, it was surgically removed by curettage. Microscopic analysis showed that a few parts of the resected materials contained dispersed thin cords and small nests of epithelial cells accompanied by fibrous stroma. Cellular atypia and mitotic figures were not evident. The diagnosis of BFOL with hyperplastic and metaplastic odontogenic epithelia was ultimately made. Eight months after the operation, the lesion recurred and segmental mandibulectomy was carried out. Histologically, the lesion was predominantly occupied by the fibro-osseous component with irregular-shaped foci of epithelial component. The epithelial component exhibited mostly thin cord or small nest patterns and showed definite perineural infiltration. Immunohistochemically, the epithelial cells were positive for p63, cytokeratin (CK) 6 and CK19, and focally positive for CK7 but negative for vimentin. MIB-1 positive nuclei were inconspicuous. To the best of our knowledge, this report is the first case of SOC with BFOL.