ABSTRACT
Objective To propose a method for determing cell Poisson’s ratio based on micropipette aspiration technique. Methods Based on the assumption of deformation symmetry, the analytical expression between Poisson’s ratio and the amount of deformation was derived by extracting the extrusion deformation characteristics of the cells under micropipette aspiration according to the generalized Hooke’s law. The accurate determination of Poisson’s ratio of cells was realized according to position changes of markers on the surface of cell membrane. ResultsThe Poisson’s ratio of LNCaP cells in prostate cancer cells was measured. The result showed that the Poisson’s ratio of LNCaP cells was between 0.44 and 0.46, with an average value of 0.45. The influence of the location of the same cell feature points on calculation results of Poisson’s ratio was within the error range of 1.6%. Conclusions This method is simple and feasible, can improve the measurement accuracy of Poisson’s ratio of cells, and is helpful for cell detection and screening by using cell mechanical properties in clinic.
ABSTRACT
Objective: To investigate the relationship between genetic factor and prostate cancer (Pca) risk and the possible cause in it. Methods: The polymorphisms of cytochrome P450 family 17 (CYPl7) rs743572, p27 V109G and androgen receptor (AR) gene CAG repeat length in peripheral blood from 70 cases and 70 controls were detected through the polymerase chain reaction-restriction fragment length polymorphism technique or short tandem repeat-polymerase chain reaction technique. Then, according to the results of case-control study, the recombinant plasmids containing the wild/mutant p27 gene were constructed and transfected Pca LNcap cells. After 24 and 72 h of transfection, the cell proliferative activity was determined by MTT method, cell cycle distribution and apoptosis was detected by flow cytometry, and the expression level of bcl-2, caspase-3 and p27 protein was determined by Western-blot. Results: In three target polymorphisms, only p27 V109G polymorphism was related to Pca risk (P = 0.030, OR = 0.202, 95% CI = 0.042-0.973). Pca risk of p27-109G allele was lower than -109V allele (P = 0.006, OR = 0.285, 95% CI = 0.110-0.737). Cells transfected with wild/mutant p27 gene both showed the higher cells apoptosis rate and the lower cell proliferative activity than mock cells (P < 0.05 or 0.01), the regulatory effect of mutant p27 on cell proliferation and apoptosis was stronger than the wild p27 (P < 0.05). Conclusions: p27-109G allele that could cause higher p27 protein expression than -109V allele in LNcap cells, maybe is the protective factor of Pca.
ABSTRACT
OBJECTIVE@#To investigate the relationship between genetic factor and prostate cancer (Pca) risk and the possible cause in it.@*METHODS@#The polymorphisms of cytochrome P450 family 17 (CYPl7) rs743572, p27 V109G and androgen receptor (AR) gene CAG repeat length in peripheral blood from 70 cases and 70 controls were detected through the polymerase chain reaction-restriction fragment length polymorphism technique or short tandem repeat-polymerase chain reaction technique. Then, according to the results of case-control study, the recombinant plasmids containing the wild/mutant p27 gene were constructed and transfected Pca LNcap cells. After 24 and 72 h of transfection, the cell proliferative activity was determined by MTT method, cell cycle distribution and apoptosis was detected by flow cytometry, and the expression level of bcl-2, caspase-3 and p27 protein was determined by Western-blot.@*RESULTS@#In three target polymorphisms, only p27 V109G polymorphism was related to Pca risk (P = 0.030, OR = 0.202, 95% CI = 0.042-0.973). Pca risk of p27-109G allele was lower than -109V allele (P = 0.006, OR = 0.285, 95% CI = 0.110-0.737). Cells transfected with wild/mutant p27 gene both showed the higher cells apoptosis rate and the lower cell proliferative activity than mock cells (P < 0.05 or 0.01), the regulatory effect of mutant p27 on cell proliferation and apoptosis was stronger than the wild p27 (P < 0.05).@*CONCLUSIONS@#p27-109G allele that could cause higher p27 protein expression than -109V allele in LNcap cells, maybe is the protective factor of Pca.
ABSTRACT
Objective To compare profiles of microRNA between the LNCaP and LNCaP-AI cell lines, so as to futher elucidate the post-transcritional mechanism regulating the progression to androgen-independence. Methods The microRNA profiles of LNCaP and LNCaP-AI cell lines were examined by Agilent's microassay. The expression of six microRNAs was verified by RT-PCR. The functions of differentially expressed microRNAs were eludicated by a search with miRBase software (http://www.mirbase.org/). Results The Aglint's microRNA microassay showed that 11 microRNAs were up-regulated and 27 were down-regulated during the LNCaP progression to androgen-independence. RT-PCR results were consistent with those of the Agilent's microassay chips. By searching the targets of microRNAs in the miRBase software, we found that the differentically expressed microRNAs were mainly involved in regulation of matrix metalloproteinase 9 (MMP-9), Bcl-2, and epithelial growth factor receptor (EGFR) and genes mediating androgen metabolism. Conclusion There is alteration of microRNA during the progression of LNCaP to androgen-independence, which may involve androgen receptor related pathway, metalloenzyme, anti-apoptotic gene and genes related to androgen metabolism.
ABSTRACT
In this study, we examined whether melatonin promotes apoptotic cell death via p53 in prostate LNCaP cells. Melatonin treatment significantly curtailed the growth of LNCaP cells in a dose- and time-dependent manner. Melatonin treatment (0 to 3 mM) induced the fragmentation of poly(ADP-ribose) polymerase (PARP) and activation of caspase-3, caspase-8, and caspase-9. Moreover, melatonin markedly activated Bax expression and decreased Bcl-2 expression in dose increments. To investigate p53 and p21 expression, LNCaP cells were treated with 0 to 3 mM melatonin. Melatonin increased the expressions of p53, p21, and p27. Treatment with mitogen-activated protein kinase (MAPK) inhibitors, PD98059 (ERK inhibitor), SP600125 (JNK inhibitor) and SB202190 (p38 inhibitor), confirmed that the melatonin-induced apoptosis was p21-dependent, but ERK-independent. With the co-treatment of PD98059 and melatonin, the expression of p-p53, p21, and MDM2 did not decrease. These effects were opposite to the expression of p-p53, p21, and MDM2 observed with SP600125 and SB202190 treatments. Together, these results suggest that p53-dependent induction of JNK/p38 MAPK directly participates in apoptosis induced by melatonin.
Subject(s)
Anthracenes , Apoptosis , Caspase 3 , Caspase 8 , Caspase 9 , Cell Death , Flavonoids , Imidazoles , Melatonin , Poly(ADP-ribose) Polymerases , Prostate , Protein Kinases , PyridinesABSTRACT
In order to investigate the inhibitory effect of matrine on the expression of prostate specific antigen (PSA) and. Androgen receptor (AR) in prostate cancer cell line LNCaP in vitro, LNCaP cells were treated with matrine at different concentrations (0.5, 1.0, 1.5, 2.0 g/L) for 12-36 h. The growth activities of cancer cells were determined by MTI" colorimetric assay, The AR level was measured by Western blotting. The expression of PSA was detected by using AXSYM system-chemical luciferase methods. The results showed that matrine could effectively inhibit the growth of androgen-dependent prostate cancer cell line LNCaP in vitro in a time- and dose-dependent manner (P<0.05). It could obviously decrease the level of AR (P<0.01) and inhibit the expression of PSA in a dose-dependent manner (P<0.05) in LNCaP cells. It was concluded that matrine could significantly suppress the growth of LNCaP cells and inhibit the expression of PSA and AR of prostate cancer cells.
ABSTRACT
AIM: To observe the effect of exogenous androgen responsive element decoy on the promoter of prostate specific antigen (PSA) and the growth of LNCaP cells for searching the possibility of gene therapy for prostate cancer. METHODS: Firstly, pGL3 - PSA luciferase expression vector containing 640bp - promoter fragment of PSA gene was constructed. Then, a 23 -mer phosphorothioated ARE decoy based on the deduced ARE sequence at the promoter region of PSA gene was synthesized. pGL3 - PSA and ARE decoy DNA were cotransfected into PC3 - M cell by lipofectamineTM 2000. Through detecting the activity of luciferase, the effect of ARE decoy on the promoter of PSA was studied. Then the ARE decoy DNA was transfected into LNCaP cells. The effect of decoy DNA on the proliferation of LNCaP cells was examined by using MTT assay. The effects of apoptosis were detected by phase contrast microscopy, DNA agrose gel electrophoresis and flow cytometry. Meanwhile, the nuclear extract was prepared from LNCaP cells and DNA - protein interactions were examined by electrophoretic mobility shift assay (EMSA). RESULTS: The reporter assay showed that the aetivity of luciferase was significantly reduced in the ARE decoy - transfected cells, bnt not in the cells transfected with the control decoy. EMSA demonstrated specific binding of the ARE decoy to androgen receptor. The growth of LNCaP was remarkably inhibited and apoptotic morphological changes as well as DNA fragmentation were observed in the ARE decoy- transfected cells. The rate of apoptosis was 22.4% detected by FCM. CONCLUSION: The ARE decoy is capable of inhibiting the promoter of PSA gene and inducing the apoptosis in prostate cancer cells. It may become a potential therapeutic tool for prostate cancers.