ABSTRACT
Objective To determine the expression of Caspase 8 and phospho-Akt(p-Akt)in condyloma acuminatum(CA)lesions, and to evaluate their significance. Methods Skin lesion samples were collected from 30 patients with CA, cancer tissue samples from 20 with cervical cancer, and normal skin samples from 20 healthy controls. All the samples were subjected to paraffin embedding. An immunohistochemical study was conducted to determine the expression and distribution of Caspase 8 and p-Akt in the above samples. Results The expression rate of Caspase 8 was significantly lower in CA lesions (23.33%)than in normal skin samples(90%, P < 0.01)and cervical cancer lesions(80%, P < 0.001). Moreover, the expression rate of p-Akt in CA lesions(93.33%)was significantly higher than that in the normal skin samples(90%, P<0.001), but lower than that in the cervical cancer lesions(95%, P<0.001). No significant correlations were observed between the expression of Caspase 8 and p-Akt in either CA lesions or normal skin samples. However, the expression of Caspase 8 was positively correlated with the expression of p-Akt in cervical cancer lesions(r=0.369, P<0.05). Conclusion Both suppressed apoptosis initiation of Caspase 8 and anti-apoptotic effect of p-Akt may be involved in the occurrence and development of CA.
ABSTRACT
Objective To investigate the regulatory effects of miR-145 on the proliferation,cell cycle and apoptosis of a human keratinocyte cell line HaCaT.Methods miR-145 mimics and negative control (NC) mimics were chemically synthesized and then transiently transfected into HaCaT cells respectively.After additional culture for different durations,real-time PCR was performed to determine the expression level of miR-145,MTS assay to estimate cell proliferation,and flow cytometry to detect cell apoptosis and cycle.Luciferase assay,real-time PCR and Western blot were conducted to determine whether NRAS was the target gene of miR-145.Results The miR-145 expression level in miR-145 mimic-transfected cells increased by 85.00 ± 1.21 folds compared with NC mimic-transfected cells (t =115.90,P ＜ 0.0001).The transfection with miR-145 mimics significantly inhibited the proliferation of HaCaT cells (F =8.76,P =0.008),and the inhibitory effect significantly varied with the duration (24-96 hours) of culture after transfection,with no interaction effect between the transfection with miR-145 mimics and culture duation (F =1.21,P =0.18).Compared with NC mimic-transfected cells,those transfected with miR-145 mimics showed a significant increase in the proportion of early apoptotic cells (18.9％ ± 4.1％ vs.4.3％ ± 1.2％,t =7.126,P ＜ 0.01),late apoptotic cells (9.3％ ± 2.3％ vs.3.6％ ± 1.6％,t =12.38,P ＜ 0.01),G1-phase cells (85.83％ ± 5.2％ vs.62.08％ ± 6.23％,t =11.78,P =0.007),but a significant decrease in the percentage of G2-phase cells (6.26％ ± 1.2％ vs.19.36％ ± 3.45％,t =7.610,P =0.017) and S-phase cells (7.91％ ± 1.3％ vs.18.56％ ± 5.23％,t =7.230,P=0.019).As luciferase assay showed,luciferase activity was significantly lower in HaCaT cells cotransfected with miR-145 mimics and a recombinant luciferase reporter vector psi-CHECK2-NRAS-wild carrying the wild-type 3'UTR of NRAS than in those cotransfected with NC mimics and the vector psi-CHECK2-NRAS-wild (t =11.09,P =0.008),but similar between cells cotransfected with miR-145 mimics and a recombinant luciferase reporter vector psi-CHECK2-NRAS-mut carrying the mutant-type 3'UTR of NRAS and those cotransfected with NC mimics and the vector psi-CHECK2-NRAS-mut (P ＞ 0.05).Real-time PCR and Western blot revealed that the overexpression of miR-145 mimics had no significant effect on NRAS mRNA expression (P ＞ 0.05),but significantly inhibited NRAS protein expression (1.52 ± 0.07 vs.0.20 ± 0.02,t =28.43,P＜ 0.01).Conclusion miR-145 might inhibit proliferation and promote apoptosis of HaCaT cells by influencing cell cycle via NRAS.