Reinforcing apoptosis-resistance of COS and myeloma cells by transfecting with bcl-2 gene

COS, myeloma and HeLa cells, which are commonly used for protein production by cell culture, were transfected with human bcl-2 gene encoded on the shuttle vector BCMGS. Expression of human bcl-2 improved survival of cells remarkably, mildly, or negligibly for COS, myeloma, and HeLa, respectively. Four clones were obtained from the human bcl-2 expressing cell population of COS cells. They expressed human bcl-2 almost at the same level. The viable cell numbers were 6, 2.5, 2.5, and 0.8 times as many for the clones #8, #5, #6, and #7, respectively, as for the control COS cells, when they were cultured at low (0.2%) serum concentration for 9 days. The bcl-2 overexpressing COS cells showed morphology different from that of the control COS cells in serum limited condition. When transfected with mouse lambda protein gene carried by an SV40-derived vector, clone #8 of the bcl-2 transfected COS cells continued the transient expression of lambda protein longer than the control COS cells.

Co-expression of bcl-2 and bag-1, apoptosis suppressing genes, prolonged viable culture period of hybridoma and enhanced antibody production

Human bcl-2 and bag-1 DNA were introduced into mouse hybridoma 2E3- O cells and expressed. The expression of bcl-2 in BCMGneo-bcl2 transfectants was confirmed by ELISA and that of bag-1 in pZeo-bag1 was confirmed by western blotting. In batch cultures, the over-expression of bcl-2 prolonged the culture period by 2 days and co-expression of bcl-2 and bag-1 prolonged the culture period by 3 days. The delayed increase in the dead cell number in culture of the bcl-2 and bag-1 cotransfectant indicated the additional antiapoptosis effect of bcl-2 and bag-1 cotransfection in comparison with the bcl-2 only transfection. The bcl-2 transfectants (2E3O-Bcl2) produced antibody twofold per batch culture in comparison with 2E3-O cells transfected with BCMGSneo (2E3O-Mock). Enhancement of this MoAb production was due to the improved survival of the cells and was not due to stimulation of antibody production rate per cell by Bcl-2 expression. And the bcl-2 and bag-1 co-transfectant (2E3O-Bcl2-BAG1) produced antibody approximately fourfold of 2E3O-Mock per batch culture. Enhancement of this MoAb production was due to the improved survival of the cells and was partly due to stimulation of MoAb production rate per cell in the non-growing phase by the cotransfection. The method to engineer hybridoma cells genetically with bcl-2 and bag-1 for increasing viability and productivity would be widely applied for improving antibody productivity of hybridoma cultures.

Overexpression of bcl-2, apoptosis suppressing gene: Prolonged viable culture period of hybridoma and enhanced antibody production

Human bcl-2 DNA was introduced into mouse hybridoma 2E3 cells and expressed at a high level by using BCMGSneo vector, which reportedly amplifies as multiple copies in the cells independently of their chromosomes. The high expression of bcl-2 in BCMGSneo-bcl-2 transfectants was confirmed by western blotting. In batch cultures, the overexpression of bcl-2 raised the maximum viable cell density by 45%, delayed the initiation of apoptosis by 2 days, and prolonged the viable culture period by 4 days. The delayed initiation of apoptosis was detected by emergence of the ladder pattern on DNA electrophoresis and increase of the dead cell number. The bcl-2 transfectants produced lgG(1) fourfold per batch culture in comparison with 2E3 cells transfected with BCMGSneo but not with bcl-2: a little less than twofold due to the improved survival of the cells and more than twofold due to the enhanced lgG(1) production rate per cell of the bcl-2 transfectants. The method to engineer hybridoma cells genetically with bcl-2 using BCMGSneo vector for increasing viability and productivity would be widely applied for improving antibody productivity of hybridoma cultures. (c) 1995 John Wiley & Sons, Inc.

Characterization and fed-batch culture of hybridoma overexpressing apoptosis suppressing gene bcl-2

Mouse hybridoma 2E3 transfected with human bcl-2 gene survived longer with increasing expression level of bcl-2 when cultured in DME medium supplemented with 9% serum. One of the transfectants, 2E3BCMGbcl-2, overexpressed bcl-2 and could maintain viable cell density higher than the initial density for more than four days at a low 0.5% serum concentration. In comparison a mock transfectant 2E3BCMG remained viable for only one day. However, both hybridomas died out within a day in serum-free medium. These results suggested that bcl-2 needed a small amount of some serum components to suppress apoptosis of the hybridoma. Overexpression of bcl-2 also suppressed apoptosis of the hybridoma induced by glutamine deprivation. When hybridoma 2E3BCMGbcl-2 was inoculated in DME medium supplemented with 9% serum and cultured for 10 d with additional 2% serum feed at day 4 of the culture, viable cell density increased 2-fold and antibody produced 3-fold, in comparison with mock transfected 2E3 cultured in the same manner. The mock transfectant with additional feed of serum at day 4 of the culture showed no difference in viable cell density and antibody production. These results suggested that the mock transfectant committed to apoptosis before day 4 of the culture and the additional serum at day 4 could not reverse the commitment.

Enhancement of radiosensitivity by a unique novel NF-κB inhibitor, DHMEQ, in prostate cancer

Background:

Inducible activation of nuclear factor (NF)-κB is one of the principal mechanisms through which resistant prostate cancer cells are protected from radiotherapy. We hypothesised that inactivation of inducible NF-κB with a novel NF-κB inhibitor, DHMEQ, would increase the therapeutic effects of radiotherapy.

Methods:

PC-3 and LNCaP cells were exposed to irradiation and/or DHMEQ. Cell viability, cell cycle analysis, western blotting assay, and NF-κB activity were measured. The antitumour effect of irradiation combined with DHMEQ in vivo was also assessed.

Results:

The combination of DHMEQ with irradiation resulted in cell growth inhibition and G2/M arrest relative to treatment with irradiation alone. Inducible NF-κB activity by irradiation was inhibited by DHMEQ treatment. The expression of p53 and p21 in LNCaP, and of 14-3-3σ in PC-3 cells, was increased in the combination treatment. In the in vivo study, 64 days after the start of treatment, tumour size was 85.1%, 77.1%, and 64.7% smaller in the combination treatment group than that of the untreated control, DHMEQ-treated alone, and irradiation alone groups, respectively.

Conclusion:

Blockade of NF-κB activity induced by radiation with DHMEQ could overcome radio-resistant responses and may become a new therapeutic modality for treating prostate cancer.

Transcriptional up-regulation of Sox9 by NF-κB in endometrial carcinoma cells, modulating cell proliferation through alteration in the p14(ARF)/p53/p21(WAF1) pathway

The Sox factors are a large family of transcription factors that play important roles in tumor development and progression in a variety of human malignancies and diverse developmental processes, but little is known about their roles in endometrial tumorigenesis. Herein, we focus on the functions of Sox9 in endometrial carcinomas. Cells stably overexpressing Sox9 showed a low proliferation rate, particularity in the exponential growth phase, along with increased amounts of p21(WAF1). Transient transfection of Sox9 caused transactivation of p21(WAF1) and p14(ARF) promoters, in cooperation with p53, resulting in activation of the p14(ARF)/p53/p21(WAF1) pathway. Overexpression of p65, and the constitutively active form myristylated Akt, led to an increase in Sox9 expression through transcriptional and posttranslational mechanisms. In normal endometrium, biphasic up-regulation of Sox9 expression was observed during the menstrual cycle, labeling indices being significantly higher in the proliferative stage than in the secretory stage. Moreover, expression also showed a significant stepwise increase from normal through grade 1 to grade 2/3 tumors, being correlated positively with labeling indices of p53, p21(WAF1), pp65, and Ki-67, probably due to a feedback system regarding cell proliferation through NF-κB and Akt signaling. These data, therefore, suggest that associations between Sox9 and NF-κB signaling, as well as Akt status, may participate in modulation of the cell kinetics of endometrial carcinomas cells through alteration in the p14(ARF)/p53/p21(WAF1) pathway.

YAP modifies cancer cell sensitivity to EGFR and survivin inhibitors and is negatively regulated by the non-receptor type protein tyrosine phosphatase 14

The Yes-associated protein (YAP) is a transcriptional factor involved in tissue development and tumorigenesis. Although YAP has been recognized as a key element of the Hippo signaling pathway, the mechanisms that regulate YAP activities remain to be fully characterized. In this study, we demonstrate that the non-receptor type protein tyrosine phosphatase 14 (PTPN14) functions as a negative regulator of YAP. We show that YAP forms a protein complex with PTPN14 through the WW domains of YAP and the PPXY motifs of PTPN14. In addition, PTPN14 inhibits YAP-mediated transcriptional activities. Knockdown of YAP sensitizes cancer cells to various anti-cancer agents, such as cisplatin, the EGFR tyrosine kinase inhibitor erlotinib, and the small-molecule antagonist of survivin, S12. YAP-targeted modalities may be used in combination with other cancer drugs to achieve maximal therapeutic effects.

A genome-wide scan for quantitative trait loci affecting respiratory disease and immune capacity in Landrace pigs

Respiratory disease is the most important health concern for the swine industry. Genetic improvement for disease resistance is challenging because of the difficulty in obtaining good phenotypes related with disease resistance; however, identification of genes or markers associated with disease resistance can help in the genetic improvement of pig health. The purpose of our study was to investigate whether quantitative trait loci (QTL) associated with disease resistance were segregated in a purebred population of Landrace pigs that had been selected for meat production traits and mycoplasmal pneumonia of swine (MPS) scores over five generations. We analysed 1395 pigs from the base to the fifth generation of this population. Two respiratory disease traits [MPS scores and atrophic rhinitis (AR) scores] and 11 immune-capacity traits were measured in 630-1332 animals at 7 weeks of age and when the animal's body weight reached 105 kg. Each of the pigs, except sires in the base population, was genotyped using 109 microsatellite markers, and then, QTL analysis of the full-sib family population with a multi-generational pedigree structure was performed. Variance component analysis was used to detect QTL associated with MPS or AR scores, and the logarithm of odds (LOD) score and genotypic heritability of the QTL were estimated. Five significant (LOD > 2.51) and 18 suggestive (LOD > 1.35) QTL for respiratory disease traits and immune-capacity traits were detected. The significant QTL for Log-MPS score, located on S. scrofa chromosome 2, could explain 87% of the genetic variance of this score in this analysis. This is the first report of QTL associated with respiratory disease lesions.

The function of platelet-derived growth factor in the differentiation of mouse tongue striated muscle

OBJECTIVE

To determine the function of platelet-derived growth factor (PDGF) in the final differentiation phase of tongue striated muscle cells.

MATERIALS AND METHODS

We analyzed the expressions of PDGF-A, -B, platelet-derived growth factor receptor (PDGFR)-α, and PDGFR-β in mouse tongues between embryonic days (E) 11 and 15. Furthermore, we examined the effects of human recombinant PDGF-AB and the peptide antagonist for PDGFRs using an organ culture system of mouse embryonic tongue. Mouse tongues at E12 were cultured in BGJb medium containing human recombinant PDGF-AB for 4 days or the peptide antagonist for PDGF receptors for 8 days.

RESULTS

PDGF-A, -B, PDGFR-α, and -β were expressed in the differentiating muscle cells between E11 and 15. The human recombinant PDGF-AB induced increases in the mRNA expressions of myogenin and muscle creatine kinase (MCK) and the number of fast myosin heavy chain (fMHC)-positive cells, markers for the differentiation of muscle cells. On the other hand, the peptide antagonist for PDGFRs induced suppressions in the mRNA expressions of myogenin and MCK, and the number of fMHC-positive cells. Both the PDGF-AB and the antagonist failed to affect the expressions of cell proliferation markers.

CONCLUSION

These results suggest that PDGF functions as a positive regulator in the final differentiation phase of tongue muscle cells in mouse embryos.

Establishment of an apoptosis-suppressible,cell-cycle arrestable cell line and its applicationfor enhancing protein production of serum-free or-supplemented culture

Expression of c-jun gene induces apoptosis ofcells cultured in serum-free medium. It also promotescell-cycling in serum-containing medium, leading cellsto die by overgrowth. Previously, we established anapoptosis-suppressible, cell-cycle arrestable cellline, c-jun AS, by transfecting Friend murineerythroleukemia (F-MEL) cells with adexamethasone-inducible antisense c-jun gene.Induction of the antisense c-jun transcriptionwith dexamethasone suppressed c-jun expression.As a result, c-jun AS cells survived inserum-free medium containing dexamethasone for a longtime, while F-MEL cells died quickly in the presenceor absence of dexamethasone. In serum-containingmedium, the growth of c-jun AS cells was viablyblocked by inducing antisense c-juntranscription, and the cells survived at thenon-growth state avoiding overgrowth. In the presentstudy, protein productivity of c-jun AS cellswas examined in comparison with that of wild typeF-MEL cells. C-jun AS and F-MEL cells werefurther transfected with a vector for expressingalkaline phosphatase as a protein to be produced, andnamed c-jun AS-SEAP and F-MEL-SEAP cells,respectively. In the serum-free medium withdexamethasone, c-jun AS-SEAP cells produced theprotein for up to 6 days, while F-MEL-SEAP cellsstopped production on day 3 due to cell death causedby serum deprivation. In the serum-containing mediumwith dexamethasone, c-jun AS-SEAP cells wereviably arrested in the cell cycle, and cell death dueto overgrowth was avoided. As the result, they couldproduce the protein for up to 18 days, whileF-MEL-SEAP cells stopped production within 7 days dueto cell death caused by overgrowth.

Effect of immunoglobulin G (IgG) interchain disulfide bond cleavage on efficacy of intravenous immunoglobulin for immune thrombocytopenic purpura (ITP)

Intravenous immunoglobulin (IVIG) has been used widely to treat immune thrombocytopenic purpura (ITP), but the mechanisms of its action remain unclear. We investigated the affinity for Fcγ receptors (FcγRs) and the thrombocytopenia-ameliorating effect of S-sulfonated gammaglobulin (SGG) and S-alkylated gammaglobulin (AGG), in comparison with unmodified gammaglobulin (GG), in a mouse ITP model. Cleavage of immunoglobulin (Ig)G interchain disulfide bonds by either S-sulfonation or S-alkylation did not decrease the affinity for FcγRIIA (CD32A) and FcγRIIB (CD32B), but did decrease the affinity for FcγRIA (CD64A) and FcγRIIIA (CD16A), presumably because of changes in H-chain configuration. The interchain disulfide bond cleavage decreased the affinity much more for mouse FcγRIV than for mouse FcγRIIB. The ability of AGG to ameliorate ITP was greatly diminished, while SGG, whose disulfide bonds are reconstituted in vivo, was as effective as GG. These results suggest that the interchain disulfide bonds are important for therapeutic effect. It is also suggested that the interaction of IVIG with the inhibitory receptor FcγRIIB is insufficient for effective amelioration of ITP and that, at least in this model, direct binding of IVIG to FcγRIIIA is also required.

Mean power frequency during speech in myalgia patients

The purpose of this study was to clarify a difference of mean power frequency (MPF) during speech between control and myalgia patients groups. The control group consisted of 20 asymptomatic volunteers and the myalgia patients group consisted of 19 patients. A bilateral electromyogram (EMG) of masseter muscles during speech movement was recorded using surface electrodes, and the EMG data were stored and analysed with a computer-based EMG analyzer. The MPF during the entire duration of EMG burst during speech was compared between the control and myalgia group. The average (SD) MPFs during speech in the myalgia and control groups were 214.06 (17.23) and 183.39 (22.35) Hz, respectively, significantly higher in the former (P < 0.001). In myalgia patients, firing rates or recruitment of motor units innervated by high threshold motoneurons might decrease and lead to a higher MPF. The result suggests the possibility that muscle pain, that is a subjective experience, could be evaluated by objective data that is calculated from electromyographic activities which is recorded during speech.

[Surgical treatment for Pancoast tumors--significance of surgical approach and induction chemoradiotherapy]

We analyzed 46 patients with Pancoast tumor who underwent surgical resection. Anterior approach was employed for 16 patients and hook approach for 30 patients. Twenty-one patients received preoperative treatment; chemotherapy for 1 patient, radiotherapy for 11 patients, and chemoradiotherapy for 9 patients. Complete resection was achieved in 59% (27/46) of patients. The overall 5-year survival rate was 10.9%. Five-year survival was significantly higher in the patients received complete resection than the patients received incomplete resection (18.5 vs 0%, p=0.0016). The complete resection rate has improved in recent cases, and one of the reasons seems to be the adoption of preoperative chemoradiotherapy. But postoperative complications occurred more frequently in patients who received induction therapy than the others. Optimal selection of surgical approach and induction chemoradiotherapy for Pancoast tumors appear to provide improved complete resection rate and long term survival.

A prostacyclin agonist with thromboxane inhibitory activity for airway allergic inflammation in mice

BACKGROUND

ONO-1301 is a novel drug that acts as a prostacyclin agonist with thromboxane A(2) (TxA(2)) synthase inhibitory activity. We investigated the effect of ONO-1301 on development of airway allergic inflammation.

METHODS

Mice sensitized and challenged to ovalbumin (OVA) received ONO-1301, OKY-046 (TxA(2) synthase inhibitor), beraprost, a prostacyclin receptor (IP) agonist, ONO-1301 plus CAY10449 (selective IP antagonist) or vehicle during the challenge period. Twenty-four hours after the OVA challenge, airway hyperresponsiveness (AHR) to methacholine was assessed and bronchoalveolar lavage was performed. Lung specimens were excised for goblet cell staining and analysis of lung dendritic cells (DCs). Bone marrow-derived dendritic cells (BMDCs) were generated, in the presence or absence of drugs, for analysis of DC function.

RESULTS

Mice that received ONO-1301 showed significantly lower AHR, airway eosinophilia, T-helper type 2 cytokine levels, mucus production and lung DCs numbers than vehicle-treated mice. These effects of ONO-1301 were mostly reversed by CAY10449. BMDCs treated with ONO-1301 alone showed lower DC functions, such as expression of costimulatory factors or stimulation to spleen T cells.

CONCLUSIONS

These data suggest that ONO-1301 may suppress AHR and airway allergic inflammation through modulation of DCs, mainly mediated through the IP receptor. This agent may be effective as an anti-inflammatory drug in the treatment of asthma.