The monoterpene d limonene inhibit the plasma membrane associated P21 ras expression and the posttranslational isoprenylation of P21 ras , a mechanism that may contribute to its efficacy in the chemoprevent...The monoterpene d limonene inhibit the plasma membrane associated P21 ras expression and the posttranslational isoprenylation of P21 ras , a mechanism that may contribute to its efficacy in the chemoprevention and therapy of chemically induced rodent cancers and some human solid tumor cells. In the present study,the relative abilities of d limonene to inhibit membrane associated P21 ras expression in pancreas tumor cell(PaCa) was carried out with Western blotting, and the inhibition of farnesyl protein transferase (FTPase) activity during the Ras protein isoprenylation and cell proliferation were determined.Concomitantly,the effects of d limonene on P21 ras localization by immunohistochemistry and H ras oncogene expression in PaCa tumor cell line by Northern blotting were observed. The results showed that d limonene inhibited FPTase activity, thus to reduce P21H ras isoprenylation. d limonene could decrease P21 ras membrane association and increase cytosolic accumulation of P21 ras . This phenomenon was also noted when d limonene treated PaCa cells were stained immunohistochemically with anti P21 ras antibody. It is suggested that the inhibition of FPTase activity was closely related with the inhibiton of P21 ras membrane association and the alteration of P21 ras localization. Inhibition of farnesylation of P21 ras altered their intracellular localization and, hence, disrupted their biological activity,but no relationship with H ras oncogene expression was found.展开更多
Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups w...Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A （control group） cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 （NK1） antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance （ANOVA）. Results： The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small bluepurple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls. Conclusions： SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.展开更多
文摘The monoterpene d limonene inhibit the plasma membrane associated P21 ras expression and the posttranslational isoprenylation of P21 ras , a mechanism that may contribute to its efficacy in the chemoprevention and therapy of chemically induced rodent cancers and some human solid tumor cells. In the present study,the relative abilities of d limonene to inhibit membrane associated P21 ras expression in pancreas tumor cell(PaCa) was carried out with Western blotting, and the inhibition of farnesyl protein transferase (FTPase) activity during the Ras protein isoprenylation and cell proliferation were determined.Concomitantly,the effects of d limonene on P21 ras localization by immunohistochemistry and H ras oncogene expression in PaCa tumor cell line by Northern blotting were observed. The results showed that d limonene inhibited FPTase activity, thus to reduce P21H ras isoprenylation. d limonene could decrease P21 ras membrane association and increase cytosolic accumulation of P21 ras . This phenomenon was also noted when d limonene treated PaCa cells were stained immunohistochemically with anti P21 ras antibody. It is suggested that the inhibition of FPTase activity was closely related with the inhibiton of P21 ras membrane association and the alteration of P21 ras localization. Inhibition of farnesylation of P21 ras altered their intracellular localization and, hence, disrupted their biological activity,but no relationship with H ras oncogene expression was found.
文摘Objective： To investigate the molecular pathway of substance P （SP） to induce osteoblastic differentiation. Methods： Mesenchymal stem cells were isolated and cultured. The cultures were divided into four groups with Group A （control group） cultured without any factors, Group B cultured with SP, Group C cultured with SP and SP receptor neurokinin-1 （NK1） antagonist, and Group D cultured with SP NK1 antagonist respectively to induce osteoblastic cells differentiation. Osterix gene expression was detected by reverse transcription-polymerase chain reaction （RT-PCR） for three times after 1-2 weeks of cultivation and the results were analyzed by one-way analysis of variance （ANOVA）. Results： The log phase of bone marrow stromal cells appeared at 4-6 days. ALP staining revealed that the majority of cells, more than 95%, were positive and small bluepurple granules were found in the cytoplasm. And Group B, treated with SP, showed a higher level of ALP activity than the other three groups. Meanwhile, RT-PCR found that Osterix expression in Group B was obviously up-regulated, compared with other groups. But Osterix expression in Group D had no remarkable differences, compared with the controls. Conclusions： SP can up-regulate Osterix gene expression to stimulate differentiation of mesenchymal stem cells into osteoblastic cells at the final stage. The regulatory effect of SP on Osterix expression was dependant on SP NK1 receptors.
