7 research outputs found
Caffeic Acid Phenethyl Ester Causes p21Cip1 Induction, Akt Signaling Reduction, and Growth Inhibition in PC-3 Human Prostate Cancer Cells
Caffeic acid phenethyl ester (CAPE) treatment suppressed proliferation, colony formation, and cell cycle progression in PC-3 human prostate cancer cells. CAPE decreased protein expression of cyclin D1, cyclin E, SKP2, c-Myc, Akt1, Akt2, Akt3, total Akt, mTOR, Bcl-2, Rb, as well as phosphorylation of Rb, ERK1/2, Akt, mTOR, GSK3α, GSK3β, PDK1; but increased protein expression of KLF6 and p21Cip1. Microarray analysis indicated that pathways involved in cellular movement, cell death, proliferation, and cell cycle were affected by CAPE. Co-treatment of CAPE with chemotherapeutic drugs vinblastine, paclitaxol, and estramustine indicated synergistic suppression effect. CAPE administration may serve as a potential adjuvant therapy for prostate cancer
Risk factors of new Aujeszky's disease virus infection in swine herds in Brittany (France)
Brittany is the main pig production area in France. About 14 million fatteners are
produced every year in this province. There are about 9 300 farms holding 690 000 sows. Vaccination
against Aujeszky's disease is compulsory, and all vaccines which are used are marker vaccines. Since 1994,
a yearly general serological screening has been performed. All herds are bled at least once a year.
Fifteen sows are bled in each breeding stocks and 15 fatteners in each fattening stock. All serological
analyses are GE ELISA. The seroprevalence of herds has been decreased dramatically during this period.
Twenty four percent of the herds had at least one positive serum in 1995 whereas only 4.5% were positive
in 1998. Nevertheless, some new infections still occur. A case control study was carried out in 80
commercial herds to identify and to rank the risk factors which are associated with new infections.
Different possible risk factors were assumed and classified regarding into 3 categories according to
consecutive steps of contamination of a herd. These 3 categories were:
Cases and control herds were chosen
out of the population of all herds with at least one serological control per year for 3 consecutive years.
These 3 years were from the first of July 1994 to the 30th of June 1997. Both cases and controls were
seronegative during the first 2 years. Control herds remained free of infection on the third year. On the
contrary, newly infected cases were defined as those herds which became seropositive on the third year.
In
order to eliminate potential false positives, herds with less than 3 positive sows or 2
positive fatteners
were excluded from the analysis. Forty four case herds met these criterion. Forty of them were studied.
Seventy percent of the cases were Farrow-to-Finish herds (FAFI), 28% were Feeder-to-Finish herds (FEFI)
and the last farm was a Farrow-to-Feeder (FAFE). Controls were individually matched to cases
considering their herd type (FAFE, FAFI, FEFI), size (the difference in herd size had to be lower than
30%), location (the control had to be located within 25 kilometres from the case) and producer
organisation (in order to facilitate data collection). Variables describing the possible risk
factors were
obtained (1) with a questionnaire describing the herd and herd management (a single investigator
performed the survey in all herds) and (2) by using the regional database which describes the
location and
the serological status of all herds in Brittany, in order to assess the risk of being contaminated
by the neighbourhood. The herd questionnaire contained 95 variables which described the purchase of pigs
(9 variables), passive vectors (21), quarantine (8), bio-security (16), herd structure (8) and
vaccination scheme (33). Seven variables were calculated to describe the risk associated to neighbourhood.
These variables described pig density and the number of infected herds within 1, 3 and
6 kilometre radiuses. The statistical analysis was performed with 2 different stages:
Bio-security is an example of a summary variable defined after the first
step of analysis. 9 variables are summarised in it. Although the real world is not black and
white, large differences between the groups of herds with good or bad bio-securities were observed.
Seventy-eight percent of the farms with a good bio-security had a locker and clothes for
visitors whereas 79% of the bad group had none. In the same way the good bio-security group was better
for locking the door (78% did whereas 90% of the bad group did not), more of them avoided
the entry of slaughterhouse lorry drivers within the premises (88% did whereas 62% of the
bad group did
not). Considering the logistic regression, three risk factors were associated with the new
infections: (1) the presence of at least one herd within 1 kilometre from the case
(, );
(2) a high number of infected herds between 1 and 6 kilometres (,
).
A "high number" was more than 3 infected herds between 1 and 3 kilometres and more than 11
infected herds
between 3 and 6 kilometres; (3) the frequency of piglet deliveries (,
).
No relation was shown between new infection by Aujeszky's disease virus and other variables including,
quarantine, herd-structure, vaccination and bio-security. The results suggest that the two
main risk factors for new infection by Aujeszky's disease virus are airborne transmission
and purchase of
infected piglets. The fact that the other potential risk factors, in particular the quality
of vaccination, were not found to be associated with risks of new infection, has to be further
discussed.
A good vaccination does not prevent herds from being infected by Aujeszky's disease virus.
Nevertheless, vaccination remains necessary in high density areas to prevent neighbouring herds
from being
contaminated by infected herds and to achieve eradication of Aujeszky's disease
Molecular Mode of Action and Role of TP53 in the Sensitivity to the Novel Epothilone Sagopilone (ZK-EPO) in A549 Non-Small Cell Lung Cancer Cells
Sagopilone, an optimized fully synthetic epothilone, is a microtubule-stabilizing compound that has shown high in vitro and in vivo activity against a broad range of human tumor models. We analyzed the differential mechanism of action of sagopilone in non-small cell lung cancer cell lines in vitro. Sagopilone inhibited proliferation of non-small cell lung cancer cell lines at lower nanomolar concentration. The treatment with sagopilone caused strong disturbances of cellular cytoskeletal organization. Two concentration-dependent phenotypes were observed. At 2.5 nM sagopilone or 4 nM paclitaxel an aneuploid phenotype occur whereas a mitotic arrest phenotype was induced by 40 nM sagopilone or paclitaxel. Interestingly, treatment with 2.5 nM of sagopilone effectively inhibited cell proliferation, but - compared to high concentrations (40 nM) - only marginally induced apoptosis. Treatment with a high versus a low concentration of sagopilone or paclitaxel regulates a non-overlapping set of genes, indicating that both phenotypes substantially differ from each other. Genes involved in G2/M phase transition and the spindle assembly checkpoint, like Cyclin B1 and BUBR1 were upregulated by treatment with 40 nM sagopilone. Unexpectedly, also genes involved in DNA damage response were upregulated under that treatment. In contrast, treatment of A549 cells with a low concentration of sagopilone revealed an upregulation of direct transcriptional target genes of TP53, like CDKN1A, MDM2, GADD45A, FAS. Knockdown of TP53, which inhibited the transcriptional induction of TP53 target genes, led to a significant increase in apoptosis induction in A549 cells when treated with a low concentration of sagopilone. The results indicate that activation of TP53 and its downstream effectors like CDKN1A by low concentrations of sagopilone is responsible for the relative apoptosis resistance of A549 cells and might represent a mechanism of resistance to sagopilone
p21 (WAF1)-mediated transcriptional targeting of inducible nitric oxide synthase gene therapy sensitizes tumours to fractionated radiotherapy
Cancer gene therapy that utilizes toxic transgene products requires strict transcriptional targeting to prevent adverse normal tissue effects. We report on the use of a promoter derived from the cyclin dependent kinase inhibitor, p21((WAF1)), to control transgene expression. We demonstrate that this promoter is relatively silent in normal cells (L132, FSK, HMEC-1) compared to the almost constitutive expression obtained in tumour cells (DU145, LNCaP, HT29 and MCF-7) of varying p53 status, a characteristic that will be important in gene therapy protocols. In addition, we found that the p21(WAF1) promoter could be further induced by both external beam radiation (up to eight-fold in DU145 cells), intracellular-concentrated radionuclides ([At-211] MABG) (up to 3.5-fold in SK-N-BE(2c) cells) and hypoxia (up to four-fold in DU145 cells). We have previously achieved significant radiosensitization of tumour cells both in vitro and in vivo by using inducible nitric oxide synthase (iNOS) gene therapy to generate the potent radiosensitizer, nitric oxide (NO center dot). Here, we report that a clinically relevant schedule of p21((WAF1))-driven iNOS gene therapy significantly sensitized both p53 wild-type RIF-1 tumours and p53 mutant HT29 tumours to fractionated radiotherapy. Our data highlight the utility of this p21((WAF1))/iNOS-targeted approach