Tricho-dento-osseous Syndrome Mutant Dlx3 Shows Lower Transactivation Potential but Has Longer Half-life than Wild-type Dlx3

Dlx3 is a homeodomain protein and is known to play a role in development and differentiation of many tissues. Deletion of four base pairs in DLX3 (NT3198) is causally related to tricho-dento-osseous (TDO) syndrome (OMIM #190320), a genetic disorder manifested by taurodontism, hair abnormalities, and increased bone density in the cranium. The molecular mechanisms that explain the phenotypic characteristics of TDO syndrome have not been clearly determined. In this study, we examined phenotypic characteristics of wild type DLX3 (wtDlx3) and 4-BP DEL DLX3 (TDO mtDlx3) in C2C12 cells. To investigate how wtDlx3 and TDO mtDlx3 differentially regulate osteoblastic differentiation, reporter assays were performed by using luciferase reporters containing the promoters of alkaline phosphatase, bone sialoprotein or osteocalcin. Both wtDlx3 and TDO mtDlx3 enhanced significantly all the reporter activities but the effect of mtDlx3 was much weaker than that of wtDlx3. In spite of these differences in reporter activity, electrophoretic mobility shift assay showed that both wtDlx3 and TDO mtDlx3 formed similar amounts of DNA binding complexes with Dlx3 binding consensus sequence or with ALP promoter oligonucleotide bearing the Dlx3 binding core sequence. TDO mtDlx3 exhibits a longer half-life than wtDlx3 and it corresponds to PESTfind analysis result showing that potential PEST sequence was missed in carboxy terminal of TDO mtDlx3. In addition, co-immunoprecipitation demonstrated that TDO mtDlx3 binds to Msx2 more strongly than wtDlx3. Taken together, though TDO mtDlx3 acted as a weaker transcriptional activator than wtDlx3 in osteoblastic cells, there is possibility that during in vivo osteoblast differentiation TDO mtDlx3 may antagonize transcriptional repressor activity of Msx2 more effectively and for longer period than wtDlx3, resulting in enhancement of osteoblast differentiation

Changes of Peripheral Blood Lymphocyte Subtypes in Patients with End Stage Cancer Administered Localized Radiotherapy and Bojungikki-Tang

Localized radiotherapy (RT) can cause immune dysfunction. Bojungikki-tang is known to restore immune function. We investigated the absolute counts and percentages of peripheral blood (PB) lymphocyte subtypes in end stage cancer patients before and after RT and after oral administration of Bojungikki-tang water extract (BJITE) and to evaluate the changes mediated by RT and BJITE. Absolute counts and percentages of lymphocyte and lymphocyte subsets were determined in whole blood using the TetraONE System (Beckman Coulter, USA). Flow cytometry results were compared before and after RT and after administration of BJITE. Absolute numbers of CD3+, CD4+, and CD8+ T cells and CD19+ B cells decreased significantly after RT (P<0.05). Absolute numbers of CD3-CD56+ cells did not change in both groups. No significant differences were observed in the absolute counts of lymphocyte subtypes before and after administration of BJITE or vitamin group. When BJITE group was compared with vitamin group, absolute numbers of CD19+ B cells increased. RT-induced decrease in T cells and B cells in PB suggests that immune deterioration occurs after RT. Administration of BJITE might be effective in the restoration of number of B cells

Primary Retroperitoneal Mucinous Cystadenocarcinoma: A Case Report and Review of the Literature

Primary retroperitoneal mucinous cystadenocarcinoma is a rare tumor. Only about 30 such cases have been reported in the worldwide literature, and a few Korean cases have been reported. The pathogenesis is not clear, and coelomic metaplasia of the retroperitoneal mesothelium has gained wide support. There is no consensus on the appropriate treatment, but surgical exploration is needed for the diagnosis and treatment, and adjuvant chemotherapy may be recommended following complete surgical excision. The long-term prognosis has not been established

Meningeal Relapse in a Patient with Acute Promyelocytic Leukemia: A Case Report and Review of the Literature

The involvement of central nervous system is rare in acute promyelocytic leukemia (APL). We report a APL patient of a 41 yr-old Korean male who presented with fever and petechia. Complete molecular remission was achieved with all-trans retinoic acid (ATRA), idarubicin, and cytarabine. Ten months later, he complained of a mild headache. The results of the physical examination and the complete blood counts were normal. The examination of cerebrospinal fluid showed the presence of promyelocyte. Bone marrow studies showed cytogenetic remission but with molecular relapse. He was treated with intrathecal and systemic chemotherapy

The Hematologic Response to Anti-apoptotic Cytokine Therapy: Results of Pentoxifylline, Ciprofloxacin, and Dexamethasone Treatment for Patients with Myelodysplastic Syndrome

TNF-α mediated apoptosis of the hematopoietic cells has been thought to contribute to the ineffective hematopoiesis observed in myelodysplastic syndrome (MDS). The combination of pentoxifylline (P) and ciprofloxacin (C) has been shown to reduce the serum levels of TNF-α, and an earlier trial of P and C with dexamethasone (D) provided good palliation for patients with MDS. The purpose of this study is to assess the hematologic response to PCD therapy for patients suffering with MDS. 21 of 25 patients who completed at least of 12 weeks of treatment were evaluable for the treatment efficacy. At baseline, the patient's median age was 60 yr (range: 18-75 yr). The diagnoses according to WHO classification included: RA (n=5), RCMD (n=10), RARS (n=1), RCMD/RS (n=1), RAEB (3), and CMML (n=1). 11 patients (52%) had at least single lineage response. 3 patients (11%) showed improvement of triple lineage cytopenia. There were no differences in the response rates between the FAB subtypes. The median time to response was 4 weeks (range: 2-12 weeks), and it is interesting that 9 of 11 patients who had a response remained without relapse for a median of 177 days (range: 78-634 days). These preliminary results indicate that anti-cytokine therapy with PCD is an effective and well tolerated palliative treatment for patients with MDS

Dlx3 Plays a Role as a Positive Regulator of Osteoclast Differentiation

Dlx3 is a homeodomain protein and is known to playa role in development and differentiation of many tissues. Deletion of four base pairs in DLX3 (NT3198) is causally related to tricho-dento-osseous (TDO) syndrome (OMIM # 190320), a genetic disorder manifested by taurodontism, hair abnormalities, and increased bone density in the cranium. Although the observed defects of TDO syndrome involves bone, little is known about the role of Dlx3 in bone remodeling process. In this study, we examined the effect of wild type DLX3 (wtDlx3) expression on osteoclast differentiation and compared it with that of 4-BP DEL DLX3 (TDO mtDlx3). To examine whether Dlx3 is expressed during RANKL-induced osteoclast differentiation, RAW264.7 cells were cultured in the presence of receptor activator of nuclear factor-B ligand (RANKL). Dlx3 protein level increased slightly after RANKL treatment for 1 day and peaked when the fusion of prefusion osteoclasts actively progressed. When wtDlx3 and TDO mtDlx3 were overexpressed in RAW264.7 cells, they enhanced RANKL-induced osteoclastogenesis and the expression of osteoclast differentiation marker genes such as calcitonin receptor, vitronectin receptor and cathepsin K. Since osteoclast differentiation is critically regulated by the balance between RANKL and osteoprotegerin (OPG), we examined the effect of Dlx3 overexpression on expression of RANKL and OPG in C2C12 cells in the presence of bone morphogenetic protein 2. Overexpression of wtDlx3 enhanced RANKL mRNA expression while slightly suppressed OPG expression. However, TDO mtDlx3 did not exert significant effects. This result suggests that inability of TDO mtDlx3 to regulate expression of RANKL and OPG may contribute to increased bone density in TDO syndrome patients. Taken together, it is suggested that Dlx3 playa role as a positive regulator of osteoclast differentiation via up-regulation of osteoclast differentiation-associated genes in osteoclasts, as well as via increasing the ratio of RANKL to OPG in osteoblastic cells.This study was supported by a grant from the Basic Research Program of the Korea Science & Engineering Foundation (R01-2005-000-106650) and by the Korea Science & Engineering Foundation(KOSEF) grant funded by the government(MOST)(No. M10646010002-06N4601-00210)