DNA barcode is known to be successfully applied in identification on the members of Insecta. In recent studies, however, it was known that the DNA approach may fail in several taxa with following cases: (1) very recent speciation and hybridization, (2) recent diverged groups with complex gene histories, (3) the spread of maternally transmitted bacteria, (4) adding more than one geographical race and at least one congener, (5) different levels of dispersal. In this study, we taxonomically review on the Korean Hatchiana using the morphological data and DNA barcodes. In morphology, they are distinct from each other by the characteristics of body coloration, eye, pronotum, scutellum, and aedeagus. In molecular data, however, the interspecific sequence distance ranged from 0.0-3.4%. This result is caused by H. glochidiatus, of which the sequence divergence is 0.2-2.8% in H. rosinae, 0.8-2.6% in H. baekripoensis, and 0.0-3.3% in H. jirisanensis. Also, H. glochidiatus produces mixed-clusters with H. rosinae and H. jirisanensis in NJ phenogram. Through this presentation, therefore, we discuss on why the four Korean Hatchiana species distinct by morphological characters produce mixed-clusters in DNA barcoding.

Mutations in DLX3 are associated with both autosomal dominant hypoplastic hypomaturation amelogenesis imperfecta (ADHHAI) and tricho-dento-osseous (TDO) syndrome. ADHHAI is caused by a c.561_562delCT (2bp-del DLX3) mutation whereas TDO syndrome is associated with a c.571_574delGGGG (4bp-del DLX3) mutation. However, although the causal relationships between DLX3 and an enamel phenotype have been established, the pathophysiological role of DLX3 mutations in enamel development has not yet been clarified. In our current study, we prepared expression vectors for wild type and deletion mutant DLX3 products (4bp-del DLX3, 2bp-del DLX3) and examined the effects of their overexpression on the expression of the enamel matrix proteins and proteases. Wild type DLX3 enhanced the expression of matrix metalloprotease 20 (MMP20) mRNA and protein in murine ameloblast-like cells. However, neither a 4bp-del nor 2bp-del DLX3 increased MMP20 expression. Wild type DLX3, but not the above DLX3 mutants, also increased the activity of reporters containing 1.5 kb or 0.5 kb of the MMP20 promoter. An examination of protein stability showed that the half-life of wild type DLX3 protein was less than 12 h whilst that of both deletion mutants was longer than 24 h. Endogenous Dlx3 was also found to be continuously expressed during ameloblast differentiation. Since inactivating mutations in the gene encoding MMP20 are associated with amelogenesis imperfecta, the inability of 4bp-del or 2bp-del DLX3 to induce MMP20 expression suggests a possible involvement of such mutations in the enamel phenotype associated with TDO syndrome or ADHHAI.

Cell behavior of the transformed cells is known to affect by interaction with extracellular matrix (ECM) proteins and integrin. To investigate the alterations of both integrin expression and cell-matrix interaction during neoplastic conversion of human oral kerationcytes, we studied expression levels of integrin subunits by flow cytometry and cellular responses to the ECM proteins in normal human oral keratinocytes (NHOKs), HPV-immortalized HOK-16B line, and three oral cancer cell lines established from HOK-16B line, CTHOK-16B-BaP, CTHOK-16B-DMBA, and CTHOK-16B-Dexa lines. The expression levels of α and β integrin subunits were shown decreased tendency in human oral keratinocytes undergoing immortalization and tumorigenic transformation except CTHOK-16B-DMBA line tested. Although αuβ6 integrin is known to be highly expressed in squamous cell carcinomas, and the altered integrin expression is suspected to be associated with cellular carcinogenesis, αu integrin subunit and αuβ6 egrin did not express in oral cancer cell lines tested. Cell behavior to the ECM proteins in HOK-16B line was generally similar to that of exponentially proliferating NHOKs. The adhesion activity profiles of type I collagen were very similar to that of its laminin counterparts, but fibronectin showed minimal adhesion activity under our conditions compared to the BSA control. The ability of the CTHOK-16B-BaP line to spread upon type I collagen and laminin markedly decreased, but migration was notably increased on type I collagen. In contrast, CTHOK-16B-DMBA and CTHOK-16B-Dexa lines spread less but migrated more upon type I collagen than immortalized HOK-16B line. These data indicate that downregulation of integrin subunits causes the changes of cellular responses to the ECM proteins during neoplastic conversion of human oral keratinocytes, and that cellular responses to the ECM proteins in oral cancer cell lines established by exposing different carcinogens are variable according to chemical carcinogens treatment.

Chromosomal abnormality s uch as aneuploidy is one of the main factors to cause cancers This abnormality is caused by defects in centrosomal duplication‘ and most cancer cells have extra copies of centrosomes, r esulting in t he formation of multipolar spindles. Several kinases playing in mitotic phase have been implicated in regulating the centrosomal cycle‘ spindle checkpoint‘ and chromosome co ndensation and segregation. They also have Lhe ability to act as oncogenes. FOl studying the relationship between rnitotic kinase and oral cancers, the kinase activity of polo-like kinase-1, which is one of mitosis-specific kinases, is analyzed in oral carcinoma cells originated differently. Kinase activity was increased in these cancer cells compared to normal human gingival fibroblast primary cultured cells Moreover. the mitotic cell populations were a lso increased in these cell lines. Whereas the inhibition of Polo-like kinase-1 by C-terrninal domain in human gingival fibroblast cells induced multiploidy‘ the apoptotic cell population was increased in oral cancer cells overexpressed C-terminal domain 0 1' Polo- Ii ke kinase-1. These data suggested that polo-like kinase-1 might be involved in the on cogenic effect in oral cancer like other solid human carcinomas, and be target molecules for anti-cancer drug.

Osteoclasts are multinucleated cells with bone resorbing activity and differentiated from hematopoietic cell lineages of monocyte/macrophages in the presence of receptor activator of NF-xB ligand (RANKL) and M-CSF. However, the exact molecular mechanisms through which RANKL stimulates osteoclastogenesis remain to be elucidated. Here we report that activation of cAMP-response elementbinding protein (CREB) is not involved in osteoclastogenesis from osteoclast precursors in response to RANKL. RANKL induced CREB activation in osteoclast precursors. Using pharmacological inhibitors, we found that RANKL-induced CREB activation is dependent on p38 MAPK pathways. We also found that ectopic expressions of wild type and dominant negative forms of CREB in osteoclast precursors did not affect RANKL-induced osteoclast formation and bone resorbing activity. Furthermore, dominant negative forms of CREB did not alter the expression levels of osteoclast-specific marker genes. Taken together, these data suggest that CREB is dispensable for differentiation and resorbing activity of osteoclasts.