Malignant transformation of mature cystic teratoma to squamous cell carcinoma involves altered expression of p53- and p16/Rb-dependent cell cycle regulator proteins.

Ovarian mature cystic teratomas (MCT) uncommonly undergo malignant transformation to squamous cell carcinoma (SCC). While alterations in the p53 tumor suppressor gene and protein have been shown, few studies have analyzed other molecular changes leading to this malignant conversion. The purpose of the present study was to investigate 21 samples of SCC arising in MCT for altered expression in known p53- and p16/Rb-dependent cell cycle regulatory proteins, and the association between their expression and cellular proliferation and histological features. Overexpression of the p53 protein was observed in 14 SCC (67%), while four (19%) had point mutations in the p53 gene. Reduced expression of the p16 protein was observed in 18 SCC (86%), while p16 gene alterations (hypermethylation (29%) and point mutation (33%)) were found in 11 (52%). Furthermore, a statistically significant correlation was observed between p53 and Rb overexpression (P=0.0010), and the overexpression of both p53 and Rb was respectively significantly correlated with increased cellular proliferation. The results indicate that alterations in both the p53 and p16-Rb pathways are associated with SCC arising in MCT.

Ovarian undifferentiated carcinoma resembling giant cell carcinoma of the lung.

Giant cell carcinoma (GCC) is a highly aggressive variant of sarcomatoid carcinoma of the lung. To date, however, there have been no reported cases of ovarian carcinoma mainly composed of GCC. Herein is reported the case of a 54-year-old Japanese woman with an undifferentiated ovarian carcinoma producing granulocyte colony-stimulating factor (G-CSF) and an inflammatory cytokine. Histologically, the tumor was composed of cohesive nests or discohesive pleomorphic mononucleated or multinucleated tumor giant cells, accompanied by inflammatory cell infiltration and emperipolesis. Immunohistochemically, the tumor cells were focally positive for epithelial membrane antigen and cytokeratin 7. Clinically, after the initial surgery, the tumor had rapid regrowth along with the production of G-CSF and an inflammatory cytokine. Adjuvant chemotherapy was administered but induced severe heart failure and severe neutropenia, probably due to the presence of hypercytokinemia and excess G-CSF. Upon the appearance of these fatal side-effects the chemotherapy was immediately discontinued and replaced with radiotherapy. The recognition of this type of ovarian tumor is important for clinical management, because adjuvant chemotherapy is the standard treatment for clinical management of epithelial ovarian cancer.

Reduction of in vivo tumor growth by MMI-166, a selective matrix metalloproteinase inhibitor, through inhibition of tumor angiogenesis in squamous cell carcinoma cell lines of head and neck.

Matrix metalloproteinases (MMPs) have been implicated in tumor invasion, metastasis, and angiogenesis. We have recently shown that MMI-166, a new orally active MMP inhibitor specific for MMP-2 and -9, suppressed experimental metastasis of Lewis lung cancer, C-H1 human colon cancer, and pancreatic cancer without affecting tumor growth in vitro. In the present study, we determined whether oral administration of MMI-166 reduces tumor growth not only in such tumors but also in squamous cell carcinoma of head and neck (SCCHN). MMI-166 inhibited both activity of MMP-2 and -9 without affecting steady state levels of their mRNAs in SCCHN. Interestingly, protein levels of MMP-2 and -9 from the cultures were drastically diminished by culturing with MMI-166. This was also observed in xenografts of MMI-166-administered mice. In addition, daily oral administration of MMI-166 (100mg/kg) inhibited local tumor growth accompanied by the reduction of blood vessel density and Ki-67-positivity and increase in terminal deoxynucleotidyl transferase-mediated cUDP nick-end labeling (TUNEL)-positivity. These results suggested that orally administered MMI-166 reduced in vivo tumor growth of SCCHN through inhibition of angiogenesis and induction of apoptosis accompanied by the reduction of MMP productions and activities. Therefore, MMI-166 seems to be useful for tumor dormancy therapy of SCCHN.

Anti-tumor effect of vitamin A and D on head and neck squamous cell carcinoma.

OBJECTIVES: Vitamin A and D(3) have a very strong differentiation induction effect. STUDY DESIGN: We examined the anti tumor effect on head and neck squamous cell carcinoma (HNSCC) by treatment with several vitamins having strong differentiation induction effects in vitro. METHODS: We used KB cell that an oral floor squamous cell carcinoma, vitamins as all-trans retinoic acid (ATRA), 4-[3,5-bis (trimethylsilyl) benzamido] benzoic acid (TAC-101), 1alpha,25(OH)(2)D(3) (calcitriol) and 22-oxa-1,25-(OH)(2)D(3) (OCT). We determined receptors of vitamin A and D(3) using RT-PCR. Furthermore, we investigated the proliferation of tumor cells in concentration dependency using [3H]TdR uptake method, apoptosis and apoptosis related factors using TUNEL method and real-time PCR, cell cycle changes using flow cytometry, changing of the sensitivity of using MTT method, cytokine production and the angiogenesis factor using ELISA, by treatment with these vitamins. RESULTS: The deficit of RAR-beta was found in the KB cell. Each vitamin suppressed the cell proliferation, induced apoptosis, and cell cycle arrest, upregulated sensitivity of the chemotherapeutics drugs and downregulated several angiogenesis factors and an apoptotic factor; survivin. CONCLUSIONS: These results support the idea that vitamin A, D(3) and their derivatives are useful for preventing and/or treating patients with HNSCC.