Structural variations in (CuL)2Ln complexes of a series of lanthanide ions with a salen-type unsymmetrical Schiff base(H2L): Dy and Tb derivatives as potential single-molecule magnets.

A new series of heterometallic trinuclear Cu2Ln complexes [lanthanide ions Ln = Gd (1), Tb (2), Dy (3), Ho (4) and Er (5)] has been synthesized using a Cu(ii)-metalloligand derived from a N2O2 donor unsymmetrical Schiff base, H2L (where H2L = N-α-methylsalicylidene-N'-salicylidene-1,3-propanediamine), and structurally characterized. Among these complexes, [(CuL)2Gd(NO3)3(CH3CN)2] (1), [(CuL)2Tb(NO3)3(CH3CN)2] (2) and [(CuL)2Dy(NO3)3(CH3CN)2] (3) are isomorphic and isostructural. In these complexes two metalloligands coordinate to the central Ln(iii) (Ln = Gd, Tb and Dy respectively) ion in a transoid fashion viaµ2-phenoxido oxygen atoms. The Ln(iii) ions are deca-coordinated with a distorted tetradecahedron geometry. The two terminal Cu(ii) ions of the complexes possess a hexa-coordinated distorted octahedral geometry. In contrast, in complexes [(CuL)2Ho(NO3)3(CH3CN)], (4) and [(CuL)2Er(NO3)3(CH3CN)]·0.5(CH3CN) (5), the two metalloligands coordinated to the Ln(iii) ions in a cisoid fashion. The Ho(iii) ion in 4 is nona-coordinated with a distorted tricapped trigonal prismatic geometry and the Er(iii) ion in 5 is octa-coordinated with a distorted square antiprismatic geometry. The two terminal Cu(ii) ions in complexes 4 and 5 are penta-coordinated with a distorted square-pyramidal geometry. The dc magnetic susceptibilities and field dependent magnetization measurement of complex 1 reveal the occurrence of ferromagnetic interactions between Cu(ii) and Gd(iii) ions as well as intermolecular antiferromagnetic interactions. Both complexes 2 and 3 show ferromagnetic interactions between Cu(ii) and Ln(iii) ions. The ac magnetic susceptibilities of all the complexes were also recorded and it was found that only complexes 2 and 3 exhibit slow relaxation of magnetization reorientation below 10 K at 2000 Oe applied dc field, this being characteristic of single molecule magnets.

[A case of sarcomatoid malignant peritoneal mesothelioma responding to combination chemotherapy of cyclophosphamide, vincristine, adriamycin and dacarbazine(CYVADIC)].

A 66-year-old woman was seen at our hospital because of abdominal fullness. A computed tomography(CT)revealed massive tumors in abdominal cavity. The patient underwent surgery consisting of tumorectomy, segmental gastrectomy, partial resection of small intestin, transverse colectomy, left oophorectomy and gastrostomy. By using immunohistochemical staining, the patient was diagnosed as sarcomatoid malignant peritoneal mesothelioma. Rapidly abdominal fullness occurred as of 22 days after the operation, and an abdominal CT revealed the massive recurrent tumors. We started a combination chemotherapy of cyclophosphamide, vincristine, adriamycin and dacarbazine (CYVADIC). The recurrent tumors showed remarkable reduction after the two courses of CYVADIC chemotherapy. Although we next started carboplatin and paclitaxel combination chemotherapy, she died due to rapidly progression of the disease with disseminated intravascular coagulation after 132 days of the operation. Malignant mesothelioma, especially sarcomatoid mesothelioma, is known to have a poor prognosis. However, our case suggests that we could improve the prognosis of sarcomatoid malignant mesothelioma by aggressive chemotherapy.

High volume hydrodynamic injection of plasmid DNA via the hepatic artery results in a high level of gene expression in rat hepatocellular carcinoma induced by diethylnitrosamine.

BACKGROUND: Hydrodynamic injection of naked plasmid DNA (pDNA) via the tail vein is a safe and effective method of gene transfer to the liver. However, successful gene transfer has yet to be shown for hepatocellular carcinoma (HCC); therefore, we investigated the feasibility and efficacy of hydrodynamic injection via the tail vein and hepatic artery in a diethylnitrosamine (DEN)-induced HCC model in rats. METHODS: HCC was induced in Sprague-Dawley rats by 100 ppm DEN in drinking water. pCMV-SPORT-beta-galactosidase (beta-gal, 400 microg) was injected (i) via the tail vein in a volume of 0.1 ml/g in 30 s or (ii) via the hepatic artery in a volume of 5 or 10 ml at 1 ml/s, either with or without temporary occlusion of the inferior vena cava (IVC) and portal vein (PV). The liver was harvested 24 h after administration, and beta-gal expression was evaluated with X-gal staining and measurement of enzymatic activity in tissue homogenates. RESULTS: Hydrodynamic injection via the tail vein achieved transgene expression only in non-cancerous tissue (tumor: 0.16 +/- 0.04%, non-tumor: 5.07 +/- 1.66%). Hydrodynamic injection via the hepatic artery was tolerated, but failed to produce efficient transgene expression in tumor and non-tumor cells. On the other hand, concomitant use of temporary IVC/PV occlusion with hydrodynamic injection via the hepatic artery dramatically increased transgene expression in cancer cells, but tumor-selective gene transfer was not achieved with this procedure (tumor: 7.38 +/- 3.66%, non-tumor: 7.77 +/- 1.06%). CONCLUSIONS: High-volume hydrodynamic injection of a pDNA solution via the hepatic artery with IVC/PV occlusion achieved a high level of gene expression in a HCC rat model. This gene transfer technique may have potential in clinical gene therapy for HCC.

Blocking of PI3K/Akt pathway enhances apoptosis induced by SN-38, an active form of CPT-11, in human hepatoma cells.

Hepatocellular carcinoma (HCC) is a common malignancy and often resistant to chemotherapy. Many chemotherapy regimens have been tried to control advanced HCC, but have produced a low response rate and no clear impact. CPT-11, a derivative of camptothecin, works as type-I DNA topoisomerase inhibitor and showed a major objective response rate in patients with metastatic colorectal cancer. In this study, the mechanism underlying chemo-resistance to SN-38, an active form of CPT-11, in HCC was investigated in relation to anti-apoptotic pathways NF-kappaB and PI3K/Akt. Hep3B was the most resistant to SN-38 among three hepatoma cell lines. NF-kappaB was constitutively activated in Hep3B, and SN-38 further enhanced the nuclear translocation of NF-kappaB. However, inactivation of NF-kappaB by adenovirus expressing IkappaB super-repressor or MG-132, proteasome inhibitor, did not sensitize Hep3B to SN-38-induced apoptosis. On the other hand, SN-38 phosphorylated Akt and pretreatment with PI3K inhibitors increased SN-38-induced apoptosis, indicating that resistance to SN-38 in Hep3B occurs partly through the PI3K/Akt not the NF-kappaB pathway. Blocking of PI3K/Akt may thus be helpful for overcoming chemo-resistance of HCC.

Akt activation protects rat liver from ischemia/reperfusion injury.

BACKGROUND: Apoptosis as well as necrosis may play an important role in hepatic ischemia/reperfusion (I/R) injury. Akt, a serine-threonine protein kinase, is known to promote cell survival. We investigated whether gene transfer of constitutively active or dominant negative Akt could affect hepatic I/R injury. MATERIALS AND METHODS: Hepatic I/R injury was induced in rats by Pringle's maneuver for 20 min followed by reperfusion. Adenoviruses encoding a constitutively active form of Akt (myrAkt), a dominant negative form of Akt (dnAkt), or beta-galactosidase (LacZ) were injected through the tail vein 72 h before hepatic I/R. RESULTS: Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick-end labeling (TUNEL) staining demonstrated a significant increase in the positive cells 240 min after reperfusion. Immunoblotting with phospho-Akt antibody showed phosphorylation of Akt from 90 to 180 min after reperfusion. The expression of myrAkt reduced the number of TUNEL-positive cells and hepatic necrosis around the central veins in the liver after reperfusion. This expression also significantly inhibited the increase in serum alanine aminotransferase (297 +/- 131 IU/L, P < 0.05) 120 min after I/R, compared with increases in uninfected (1761 +/- 671 IU/L), LacZ adenovirus (1528 +/- 671 IU/L)-, and dnAkt adenovirus (1342 +/- 485 IU/L)-infected rats. MyrAkt expression phosphorylated Bad and inhibited the release of cytochrome-c after reperfusion. No difference in nuclear translocation of nuclear factor (NF)-kappaB, p65 was seen among the three groups of rats, however. CONCLUSION: Adenoviral gene transfer of myrAkt could inhibit apoptotic cell death and subsequent hepatic I/R injury in the rat, through Bad, not NF-kappaB.