85 Regulation of mammalian target of rapamycin signaling post-fertilisation is essential for efficient development of bovine pre-implantation embryos

The phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) signaling pathway is considered a key regulator of various cellular responses related to growth, proliferation, survival, apoptosis, and autophagy. The expression of mTOR in cumulus cells and all oocyte stages highlights a role in embryonic development, but its function in the context of embryo development is not completely clarified. In the current study, we investigated the effect of mTOR activation on the total cleavage and blastocyst development rates in bovine. Oocytes collected from bovine ovaries were invitro matured (around 50 oocytes per group) and fertilised before incubation with the mTOR activator MHY1485 (1 µM) for 72h at 38.5°C and 5% CO2. The total cleavage rate at Day 4 post-fertilisation and the blastocyst development rate at Day 8 post-fertilisation were recorded. The expression levels of the mTOR and PI3K in Day 8 blastocysts were investigated using immunofluorescence and imaged using confocal laser-scanning microscope, whereas the fluorescence intensity was analysed using ImageJ software. The difference between groups was analysed using Student's t-test (GraphPad Prism). Results of microscopic investigations showed higher rates of Day 4 cleavage (83.7±1.3 vs. 72±0.8% for control) and Day 8 blastocyst development (40.4±1.7 vs. 33±1.8% for control) upon addition of MHY1485 (P<0.05). The immunofluorescence showed higher mTOR and PI3K expression levels in MHY1485-treated group than the untreated control (P<0.05). The total number of cells per blastocyst, using 4′,6-diamidino-2-phenylindole (DAPI) staining of the nuclei, was higher in the mTOR-activated group (194.9±4.8 vs. 171.3±3.5 for control). In conclusion, our data reflect the essential role of the mTOR signaling for bovine pre-implantation embryonic development.

A role for surgery in the treatment of relapsed Hodgkin lymphoma

Treatment of Hodgkin lymphoma (HL) has advanced over time, rendering a fatal disease now largely curable. Multiagent chemotherapy regimens, hematopoietic stem cell transplantation, and radiotherapy are the mainstays of care. Surgical intervention is rarely indicated other than for biopsy at diagnosis. However, for patients with recurrent relapsed HL isolated to one anatomical location, refractory to all other therapy, there may be a beneficial role for surgical excision. Herein, we report the surgical management of three relapsed patients with stage IVB HL who were refractory to multiple other therapeutic approaches, who all achieved good event-free survival after operative management.

Age at diagnosis predicts local recurrence in women treated with breast-conserving surgery and postoperative radiation therapy for ductal carcinoma in situ: a population-based outcomes analysis

PURPOSE

The main goal of treating ductal carcinoma in situ (dcis) is to prevent the development of invasive breast cancer. Most women are treated with breast-conserving surgery (bcs) and radiotherapy. Age at diagnosis may be a risk factor for recurrence, leading to concerns that additional treatment may be necessary for younger women. We report a population-based study of women with dcis treated with bcs and radiotherapy and an evaluation of the effect of age on local recurrence (lr).

METHODS

All women diagnosed with dcis in Ontario from 1994 to 2003 were identified. Treatments and outcomes were collected through administrative databases and validated by chart review. Women treated with bcs and radiotherapy were included. Survival analyses were performed to evaluate the effect of age on outcomes.

RESULTS

We identified 5752 cases of dcis; 1607 women received bcs and radiotherapy. The median follow-up was 10.0 years. The 10-year cumulative lr rate was 27% for women younger than 45 years, 14% for women 45-50 years, and 11% for women more than 50 years of age (p < 0.0001). The 10-year cumulative invasive lr rate was 22% for women younger than 45 years, 10% for women 45-50 years, and 7% for women more than 50 years of age (p < 0.0001). On multivariate analyses, young age (<45 years) was significantly associated with lr and invasive lr [hazard ratio (hr) for lr: 2.6; 95% confidence interval (ci): 1.9 to 3.7; p < 0.0001; hr for invasive lr: 3.0; 95% ci: 2.0 to 4.4; p < 0.0001]. An age of 45-50 years was also significantly associated with invasive lr (hr: 1.6; 95% ci: 1.0 to 2.4; p = 0.04).

CONCLUSIONS

Age at diagnosis is a strong predictor of lr in women with dcis after treatment with bcs and radiotherapy.

30 A TRANSCRIPTION ACTIVATOR-LIKE EFFECTOR NUCLEASE (TALEN)-MEDIATED UNIVERSAL GENE KNOCK-IN STRATEGY FOR MAMMARY GLANDS-SPECIFIC EXPRESSION OF RECOMBINANT PROTEINS IN DAIRY CATTLE

To harness the great capability of producing biologically active recombinant proteins with animal mammary glands, active research has been carried out in the past several decades to develop transgenic animals as bioreactors. However, when a transgene is introduced in the animal genome by random integration, the transgene tends to be subjected to epigenetic silencing, due to the so-called position effect from the chromatin environments surrounding the transgene integration sites, thereby resulting in low-level expression or total suppression. We report a universal transgenic strategy to knock in (KI) transgenes into the bovine β-casein gene locus allowing the expression of a transgene to be totally under the control of the endogenous regulatory sequences of the bovine β-casein gene. This universal KI strategy comprises two key components: one is the design of transcription activator-like effector nuclease (TALEN) constructs targeting the start codon region of bovine β-casein gene, and the other is the design of KI vectors in which a transgene of choice is flanked with homologous arms isolated from the ~500-bp bovine genomic DNAs immediately 5′ and 3′, respectively, of the translation start codon of the bovine β-casein gene. By using the human erythropoietin (hEPO) as the model transgene, we demonstrated that a transgene can be highly efficiently integrated immediately after the translation start codon of the bovine β-casein gene. In brief, the TALEN constructs were assembled by using the Golden Gate protocol. To KI the hEPO transgene, early passage (<5) of fibroblasts established from Holstein dairy cattle were cultured into full confluence in Dulbecco's modified Eagle medium (DMEM) supplemented with 10% fetal bovine serum (FBS), harvested with 0.25% trypsin-EDTA, and co-transfected with KI vector and the TALEN constructs by the Amaxa Nucleofector system. For each experiment, 106 cells were transfected with 5 μg of KI vector and 5 μg of TALEN constructs. After 72 h post-transfection, cells were harvested and subjected to limiting dilution to obtain single-cell derived colonies. To screen for single-cell derived colonies carrying the correctly KI of hEPO in the β-casein locus, we performed genomic PCR amplifying the genomic junctions created by the KI of hEPO gene into the bovine genome. We identified and established 2 hEPO transgenic bovine fibroblast cell lines after screening 10 single-cell derived colonies from the transfected cells (20%). The genotype of these 2 colonies was also confirmed by sequencing the PCR products. We have initiated the effort to produce hEPO transgenic cattle by somatic cell nuclear transfer (SCNT), and the animal cloning results will be reported at the conference.

Sequence analysis of a beta-agarase gene (pjaA) from Pseudomonas sp. isolated from marine environment

The pjaA gene of Pseudomonas sp. W7 consists of an open reading frame of 1926 bp encoding beta-agarase, a protein of 642 amino acids and a molecular weight of 69,540 Da. The expressed protein of plasmid pEAG3-3, in which 259 amino acid residues from C-terminus of the overexpression plasmid (pEAG3) were eliminated, led to the complete loss of agarolytic activity.

The contribution of genetically determined oxidation status to inter-individual variation in phenacetin disposition

The oxidative O-de-ethylation and aromatic 2-hydroxylation of phenacetin have been investigated in panels of extensive (EM, n = 13) and poor (PM, n = 10) metabolizers of debrisoquine. The EM group excreted in the urine significantly more paracetamol (EM: 40.8 +/- 14.9% dose/0-8 h; PM: 29.2 +/- 8.7% dose/0-8 h, 2P less than 0.05) and significantly less 2-hydroxylated metabolites (EM: 4.7 +/- 2.3% dose/0-8 h; PM: 9.7 +/- 3.5% dose/0-8 h, 2P less than 0.005) than the PM group. Apparent first-order rate constants, calculated from pooled phenotype data, for overall elimination of phenacetin (k) and formation of paracetamol (kml) were higher in the EM group (EM: k = 0.191 +/- 0.151 h-1; kml = 0.091 +/- 0.025 h-1; PM: k = 0.098 +/- 0.035 h-1, 2P less than 0.05, kml = 0.052 +/- 0.019 h-1, 2P less than 0.05) than the PM group. The apparent first-order rate constant for 2-hydroxylation displayed no significant inter-phenotype differences. Correlation analysis demonstrated that genetically determined oxidation status accounted for approximately 50% of the inter-individual variability in phenacetin disposition encountered in this study.