NF1 gene silencing induces upregulation of vascular endothelial growth factor expression in both Schwann and non-Schwann cells.

Neurofibromatosis type I (NF1) is associated with typical hypervascular tumors, including neurofibroma, glioma, malignant peripheral nerve sheath tumors (MPNST) and glomus tumors. Previously, we and other groups reported that neurofibromas showed high-level expression of vascular endothelial growth factor (VEGF), a potent angiogenic factor involved in neovascularization. However, the molecular mechanism underlying the upregulation of VEGF in neurofibromas remains unclear. In this study, we examined the effects of Nf1 gene silencing on VEGF expression in Schwann cell and non-Schwann cell line and the upstream mTOR-HIF-1α - VEGF pathway in Schwann cell line. The results indicated that Nf1 gene silencing by lentiviral-mediated RNA interference resulted in elevated expression of VEGF, HIF-1α and phosphorylated mTOR at the protein level. The results obtained from Nf1 gene silencing in murine Schwann cell line analogously suggest that NF1 gene haploinsufficiency in human tumor Schwann cells may directly elicit upregulation of VEGF expression without the tumor microenvironment by activation of the mTOR-HIF-1α - VEGF pathway. We also showed that interleukin-6 is upregulated in Nf1 gene knock-down Schwann cells at the protein level.

Development of a highly efficient protein-secreting system in recombinant Lactobacillus casei.

The available techniques for heterologous protein secretion in Lactobacillus strains are limited. The aim of the present study was to develop an efficient protein-secretion system using recombinant lactobacilli for various applications such as live delivery of biotherapeutics. For the construction of expression vectors, the Lactobacillus brevis slpA promoter, Lactobacillus casei prtP signal sequence, and mouse IL-10 sequences were used as a model system. Interestingly, the slpA promoter exhibited strong activity in L. casei contrary to previous observations. In order to stabilize replication of the plasmid in E. coli, a removable terminator sequence was built into the promoter region. For the improvement of secretion efficiency, a DTNSD oligopeptide was added to the cleavage site of signal peptidase. The resulting plasmids provided remarkably efficient IL-10 secretion. Accumulation of the protein in the culture supernatant varied widely according to the pH conditions. By analysis of the secreted protein, formation of homodimers and biological activity, IL-10 was confirmed to be functional. The presently constructed plasmids could be useful tools for heterologous protein-secretion in L. casei.

Chemoradiation using low-dose cisplatin and 5-fluorouracil in locally advanced squamous cell carcinoma of the skin: a report of two cases.

Recently, low-dose 5-fluorouracil/cisplatin induction concurrent with radiation (chemoradiation) has been reported to be effective for locally advanced squamous cell carcinoma of the otorhinolaryngologic and gynecologic regions. However, to date, this therapeutic option has not been evaluated for squamous cell carcinoma of the skin. We evaluated chemoradiation therapy using cisplatin and 5-fluorouracil in two patients with locally advanced squamous cell carcinoma of the skin. Administration of cisplatin and 5-fluorouracil was conducted concurrently with conventionally fractionated radiation therapy. Cisplatin (patient 1: 4 mg/m(2)/d on days 1 to 5; patient 2: 15 mg/m(2)/d on days 1 to 5) and 5-fluorouracil (patient 1: 400 mg/m(2)/d for 7 days; patient 2: 850 mg/m(2)/d for 5 days) were administered intravenously for 1 hour and for 24 hours, respectively. Patient 1 underwent two courses of chemotherapy with a 3-week interval, and patient 2 underwent a single course of chemotherapy. The primary tumor of both patients showed complete regression, leaving ulceration. In patient 1, the ulceration completely resolved after 3 months. Patient 2 underwent surgical resection and full-thickness skin grafting. A histopathologic examination confirmed complete tumor regression. Neither patient suffered any serious side effects during this treatment. We conclude that chemoradiation using cisplatin and 5-fluorouracil was effective in these two patients with locally advanced squamous cell carcinoma of the skin. Several randomized studies have shown concurrent chemoradiation to be superior to radiation alone. This regimen is an option in managing patients who have unresectable primary tumors or who require preservation of local function.

[Two cases of Hansen's disease].

We report two cases of Hansen's disease. Case 1 was 71-year old Japanese man who developed left ulnar nerve palsy since 7 years ago, multiple erythema on his body since 2-3 years ago, and erythematous nodules on his face since 3 months ago. He had no history of living outside Ibaraki prefecture. The clinical feature, the skin biopsy, laboratory data showed that he had borderline lepromatous leprosy. He was treated with multi-drug therapy which was effective and was stopped 3 years after the bacterial index showed negative. Ten months later, erythema on his body and face appeared and the therapy was restarted. Case 2 was 68-year old Japanese man who developed 5 cm of nummular erythema with slight numbness on his right forearm since 3 months ago. He had lived in Brazil since he was 24 to 64 years old. The skin biopsy showed epithelioid cell granuloma in the dermis involving vessels and nerves. Polymerase chain reaction test showed the M.leprae DNA, and he was diagnosed as indeterminate leprosy. He was treated with dapson and rifampicin and 2 months later, erythema and numbness disappeared.

The POU domain transcription factors Oct-6 and Oct-11 negatively regulate loricrin gene expression in keratinocytes: association with AP-1 and Sp1/Sp3.

Loricrin is a major component of the epidermal cornified cell envelope, and is expressed only in terminally differentiated keratinocytes. This cell differentiation-specific expression pattern suggests specific regulatory mechanisms for activation and suppression of loricrin gene transcription in differentiated keratinocytes. Here, we identified a regulatory element in the proximal promoter region of the loricrin gene involved in suppression of its expression in keratinocytes. A database search indicated that this sequence contained a POU transcription factor binding motif. Electrophoretic mobility shift assay revealed that Oct-1, Oct-6, and Oct-11 actually bind to the motif. Constructs with point mutations in the POU-binding motif showed increased reporter activity, indicating that the POU factors negatively regulate loricrin gene transcription. Cotransfection experiments suggested that Oct-6 and Oct-11 suppress loricrin gene transcription in a cooperative manner with AP-1 and Sp1. Furthermore, in vitro experiments indicated that the Oct-6 and Oct-11 can physically associate with both AP-1 factors and Sp1/Sp3. These findings indicate that Oct-6 and Oct-11 contribute to the regulation of loricrin gene transcription via interaction with AP-1 factors and Sp1/Sp3.

Reversal of anticancer drug resistance by COTC based on intracellular glutathione and glyoxalase I.

Suppression of resistance to anticancer drugs by COTC of glyoxalase I (GloI) inhibitor targeting intracellular glutathione (GSH) and GloI was studied. Depletion of the cellular GSH content and inhibition of GloI by COTC increased chemotherapy-mediated apoptosis in apoptosis-resistant pancreatic adenocarcinoma AsPC-1 cells.

New entries in Lewis acid-Lewis base bifunctional asymmetric catalyst: catalytic enantioselective Reissert reaction of pyridine derivatives.

The first catalytic enantioselective Reissert reaction of pyridine derivatives that affords products with excellent regio- and enantioselectivity is described. The key for success is the development of new Lewis acid-Lewis base bifunctional asymmetric catalysts containing an aluminum as a Lewis acid and sulfoxides or phosphine sulfides as a Lewis base. These reactions are useful for the synthesis of a variety of chiral piperidine subunits, and catalytic enantioselective formal synthesis of CP-293,019, a selective D4 receptor antagonist, was achieved. Preliminary mechanistic studies indicated that both sulfoxides and phosphine sulfides can activate TMSCN as a Lewis base. In addition, the sulfoxides with appropriate stereochemistry might stabilize a highly enantioselective bimetallic complex (a presumed active catalyst) through internal coordination to aluminum.

Expression of angiogenic factors in neurofibromas.

We studied the expression of angiogenic factors (vascular endothelial growth factor, basic fibroblast growth factor, platelet-derived growth factor and hepatocyte growth factor) in cutaneous neurofibroma samples from patients with neurofibromatosis-1. Immunohistochemical staining and the reverse transcribed polymerase chain reaction (RT-PCR) method demonstrated that vascular endothelial and basic fibroblast growths factor are highly expressed in neurofibroma cells at both the protein and mRNA level. These data suggest that vascular endothelial and basic fibroblast growth factors may contribute to both the angiogenesis and hypervascularity of neurofibromas.