Angelica decursiva has been used in Korean traditional medicine as an antitussive, an analgesic, an antipyretic and a cough remedy. However, the anti-cancer properties of Angelica decursiva have not yet been well defined. In our current study the cytotoxic activity of ethanol extracts of Angelica decursiva root (EEAD) and the mechanism of cell death exhibited by EEAD were examined in FaDu human head and neck squamous cell carcinoma cells. The cytotoxic effects of EEAD upon the growth of FaDu cells were examined with an MTT assay. In addition, the mechanism of cell death induced by EEAD was evaluated by DNA fragmentation analysis, immunoblotting and caspase activation measurements. EEAD induced apoptotic cell death in FaDu cells in a concentration- and time-dependent manner, as determined by MTT assay and DNA fragmentation analysis. Furthermore, the proteolytic processing of caspase-3, -7 and -9 was increased by EEAD treatment of FaDu cells. In addition, the activation of caspase-3 and -7 was detected in living FaDu cells by fluorescence microscopy. These results suggest that EEAD can induce apoptosis and suppress cell growth in cancer cells and may have utility as a future anticancer therapy.

The tumor suppressor gene, phosphate and tensin homologue(PTEN) has been shown to dephosphorylate the phosphatidylinositol 3-kinase(PI 3-K)-generated phosphatidylinositol(3-5)-triphosphate in vivo, thus interfering with the potentially oncogenic signals emanating from PI 3-K. Promoter hypermethylation of CpG islands has recently been shown to be an epigenetic change resulting in loss of function in some genes involved in cell cycle regulation and DNA repair. Immunohistochemal staining for monoclonal antibody 6H2.1 was performed from paraffin embedded blocks of 20 benign epithelial lesions and 40 head and neck squamous cell carcinomas(HNSCCs). Immunoreactivity was graded semiquantitatively by considering the percentage and intensity of the staining of the tumor cells. Also, this study tried to identify PTEN methylation in benign epithelial lesions(24 cases) and HNSCCs(44 cases of paraffin embedded blocks, 4 cases of frozen tissues) using methylation-specific PCR(MSP). In HNSCCs, immunoreactive scores of stage 1 and 2(12 cases, average score 85.2) were higher than those of stage 3 and 4(15 cases, 41.9) and statistically significant(P=0.017). Immunoreactive scores of moderate and poorly differentiated carcinomas(22 cases, 61.6) are more or less lower than those of well differentiated carcinoma(15 cases, 87.0) but not significant(P=0.361). Among 24 cases of benign epithelial lesions, 12 cases showed unmethylated PTEN but none methylated. In HNSCCs, 22 of 44 paraffin embedded blocks showed unmethylated PTEN but none methylated, and all 4 frozen tissue revealed unmethylated PTEN, one of which(25%) methylated. We consider that the loss of PTEN protein expression may be associated with the progression of HNSCCs and the other alteration rather than methylation may be important in the inactivation of PTEN in HNSCCs.

Genomic imprinting is defined as parent-of-origin expression of specific genes and may play an important role in embryonal development of mammals. Loss of imprinting(LOI), biallelic expression of the imprinted genes, have been observed in a variety of human tumors and syndromes. H19, a paternally imprinted gene, is transcribed as an untranslated RNA that serves as a riboregulator. LOI of H19 is observed in a variety of human malignancies. In this study, LOI of H19 was examined in head and neck squamous cell carcinomas(HNSCCs). Four(28.6%) of the 14 HNSCCs and 8(28.6%) of the 28 inflammatory oral lesions were informative for imprinting analysis of H19. H19 was imprinted in all inflammatory oral lesions, however, 2(50%) of the 4 informative HNSCCs manifested LOI. These data suggest that LOI of the H19 may play a role in the oncogenesis of HNSCC.