Photoinduced Charge-Transfer State of 4-Carbazolyl-3-(trifluoromethyl)benzoic Acid: Photophysical Property and Application to Reduction of Carbon-Halogen Bonds as a Sensitizer.

The photoinduced persistent intramolecular charge-transfer state of 4-carbazolyl-3-(trifluoromethyl)benzoic acid was confirmed. It showed a higher catalytic activity in terms of yield and selectivity in the photochemical reduction of alkyl halides compared to the parent carbazole. Even unactivated primary alkyl bromides could be reduced by this photocatalyst. The high catalytic activity is rationalized by considering the slower backward single-electron transfer owing to the spatial separation of the donor and acceptor subunits.

Retrospective analysis of risk factors for central nervous system metastases in operable breast cancer: effects of biologic subtype and Ki67 overexpression on survival.

OBJECTIVE: Identifying factors that predispose patients to central nervous system (CNS) metastases may hasten disease detection and improve treatment outcomes. METHODS: We reviewed the records of patients who were diagnosed with clinical stage I-III primary breast cancer at the National Cancer Center Hospital East from 2003 to 2005. Cox proportional hazard models were fitted to reveal risk factors for CNS metastases. RESULTS: The median follow-up period after the operation was 53.5 months. Among the 591 identified patients with breast cancer, 76 experienced a relapse. Seventeen patients developed CNS metastases. Multivariate analysis indicated that the triple negative (TN) subtype (hazard ratio = 5.5) and a high Ki67 labeling index (LI; hazard ratio = 3.9) were associated with a higher risk for CNS metastases. At 4 years, the TN subtype was associated with significantly worse overall and disease-free survival rates and a higher cumulative incidence of CNS metastases compared with hormone receptor-positive/ human epidermal growth factor receptor-2-negative tumors. Breast cancers with a Ki67 LI ≥30% were also associated with lower overall and disease-free survival rates and a higher cumulative incidence of CNS metastases compared with cancers with a Ki67 LI <30%. CONCLUSION: TN or Ki67-overexpressing breast cancer produced earlier CNS metastases and lower disease-free and overall survival rates.

Homeobox B9 induces epithelial-to-mesenchymal transition-associated radioresistance by accelerating DNA damage responses.

Homeobox 9 (HOXB9), a nontransforming transcription factor overexpressed in breast cancer, alters tumor cell fate and promotes tumor progression and metastasis. Here we show that HOXB9 confers resistance to ionizing radiation by promoting DNA damage response. In nonirradiated cells, HOXB9 induces spontaneous DNA damage, phosphorylated histone 2AX and p53 binding protein 1 foci, and increases baseline ataxia telangiectasia mutated (ATM) phosphorylation. Upon ionizing radiation, ATM is hyperactivated in HOXB9-expressing cells during the early stages of the double-stranded DNA break (DSB) response, accelerating accumulation of phosphorylated histone 2AX, mediator of DNA-damage checkpoint 1, and p53 binding protein 1, at DSBs and enhances DSB repair. The effect of HOXB9 on the response to ionizing radiation requires the baseline ATM activity before irradiation and epithelial-to-mesenchymal transition induced by TGF-ß, a HOXB9 transcriptional target. Our results reveal the impact of a HOXB9-TGF-ß-ATM axis on checkpoint activation and DNA repair, suggesting that TGF-ß may be a key factor that links tumor microenvironment, tumor cell fate, DNA damage response, and radioresistance in a subset of HOXB9-overexpressing breast tumors.

Development of targeted therapy with paclitaxel incorporated into EGF-conjugated nanoparticles.

BACKGROUND: 2-Methacryloyloxyethyl phosphorylcholine (MPC) polymer is a suitable vehicle for paclitaxel (PTX) delivery. A new targeted therapy has been developed by conjugating epidermal growth factor (EGF) to MPC polymer and its growth inhibitory and antitumor effects on cancer cells overexpressing EGF receptors (EGFR) has been investigated. MATERIALS AND METHODS: EGF was conjugated to poly [MPC-co-n-butyl methacrylate-co-p-nitrophenyloxycarbonyl poly (ethylene glycol) methacrylate] (PMBN) and mixed with PTX. The cytotoxicity of the resulting PTX incorporated into EGF-conjugated PMBN (EGF-PMBN-PTX) on EGFR-overexpressing and EGFR-deficient cell lines was compared with PTX incorporated into PMBN alone (PMBN-PTX) and PTX alone. Suspensions of the cells were injected into nude mice subcutaneously. EGF-PMBN-PTX, PMBN-PTX, PTX or NaCl solution was injected intraperitoneally. RESULTS: The cytotoxicity and antitumor effect of EGF-PMBN-PTX were significantly greater than those of PMBN-PTX for EGFR-overexpressing cells but not for an EGFR-deficient line. CONCLUSION: These results suggest that EGF-PMBN-PTX may represent a more potent targeted therapy for tumors overexpressing EGFR.

Predictors to assess non-sentinel lymph node status in breast cancer patients with sentinel lymph node metastasis.

The next step of sentinel lymph node biopsy (SLNB) in breast cancer is to determine which patients need axillary lymph node dissection (ALND) following a positive SLNB. A prospective database of 239 patients who underwent SLNB followed by complete ALND at Keio University Hospital from January 2001 to June 2005 was reviewed. A total of 131 patients with one or more positive sentinel lymph nodes (SLNs) were further analyzed. A univariate analysis showed a significant correlation between non-SLN involvement and lymphatic invasion, vascular invasion, number of tumor-involved SLNs, radioactivity of SLNs, and size of SLN metastasis (p = 0.0002, p = 0.004, p = 0.006, p = 0.04, p = 0.03, respectively). By multivariate analysis, lymphatic invasion and the number of tumor-involved SLNs remained significant predictors of non-SLN involvement. In breast cancer patients with a positive SLN, lymphatic invasion and the number of tumor-involved SLNs were both independent predictors of non-SLN involvement.

Development of gene vectors for pinpoint targeting to human hepatocytes by cationically modified polymer complexes.

We developed a vector that might enable gene therapy of metabolic liver disease or hepatoma. Here we demonstrate the use of cationically modified biocompatible phospholipid polymer conjugated with hepatitis B surface (HBs) antigen for the specific transfer of genes into human hepatocytes. Poly(2-methacryloyloxyethyl phosphorylcholine (MPC)- co-N,N-dimethylaminoethyl methacrylate (DMAEMA)-co- p-nitrophenylcarbonyloxyethyl methacrylate(NPMA))(polyMDN) was prepared as a frame of vector. The specific expression of sFlt-1 or GFP by polyMDN conjugated with HBs containing plasmid (plasmid/polyMDN-HBs), polyMDN containing plasmid (plasmid/polyMDN), plasmid only and PBS were assessed in tumor cells (HepG2 or WiDr) in vitro and in vivo. The histological findings, organ weight changes, and degree of liver dysfunction were examined in the mice administered by several reagents. The sFlt-1 and GFP expression was observed only in the HepG2 cells transfected with sFlt-1 or GFP/polyMDN-HBs. None of the side effects mentioned above was observed. In conclusion, these results suggest that polyMDN-HBs is a human hepatocyte-specific gene delivery vector that might not have serious side effects.