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The contributions of the three winners (L Hartwell, RT Hunt and PM Nurse) of the 2001 Nobel Prize for physiology or medicine revealed the mystical veil of cell cycle control. It was of far-reaching significance for exploring new method for cancer treatment. It will also give a good deal of enlightenment to the basic research of traditional Chinese medicine. Their understanding about the cause and development of cancers changed from the static view to dynamic dialectical analysis, from simplex study to comprehensive analysis; they stressed regulation, instead of killing in the treatment of cancer; and they thought that the numerous factors driving the normal process of the cell cycle could be summarized as positive and negative factors. These opinions were similar to some theories of traditional Chinese medicine, such as treatment based on syndrome differentiation, integrative treatment, and keeping the balance between yin and yang, and established a connection between traditional Chinese medicine and the western medicine, which would further widen the research on compound prescriptions of Chinese herbs.
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Objective To investigate the in vitro effects of compound Chinese herbal medicine Zilongjin on prostate cancer cell lines. Methods MTT assay,flow cytometry, colony on soft agar,and fluorescence microscopy were used to observe the effects of Zilongjin on anti proliferation,inhibition of clonal growth,cell cycle arrest and apoptosis induction.RT PCR method was used to study the regulative effect of Zilongjin on prostate marker genes PSA,AR,apoptosis related genes Bcl 2,Bax and tumor suppressing gene p16. Results Zilongjin caused notable anti proliferative effect,and induced G 0/G 1 phase arrest dose dependently on LNCaP,DU 145 and PC 3 cell lines.Inhibition of cell growth by 50% (IC 50 ) was observed with Zilongjin at concentrations of 0.79,0.42 and 0.52 mg/ml,respectively.Apoptosis induction was seen in LNCaP and DU 145 cell lines.Zilongjin also caused inhibition of clonal growth of DU 145 cell line.In addition,Zilongjin down regulated the expression of PSA,AR and Bcl 2 genes in LNCaP cell line;and down regulated Bcl 2,up regulated Bax and p16 genes expression in DU 145 cell line. Conclusions It is demonstrated that Zilongjin has antitumor action through anti proliferation,inhibition of clonal growth,G 0/G 1 phase arrest,apoptosis induction and regulating the expression of PSA,AR,Bcl 2,Bax and p16 genes.
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AIM To study the features of cell death induced by the anticancer antibiotic lidamycin (LDM) in human hepatoma BEL-7402 cells. METHODS Chromatin condensation was observed by co-staining with fluorescent dyes, hoechst 33342 and propidium iodide. “G1 sub-peak” was detected by flow cytometry and DNA ladder was observed using agarose gel electrophoresis. The caspase-3, 6 activities were measured with kits specific for them. RESULTS Typical apoptotic chromatin condensations appeared when the BEL-7402 cells were treated with the conventional antitumor agent mitomycin C 30 μmol.L-1 for 12 h. However, an abnormal type of chromatin condensation occurred when the cells were treated with LDM 1 μmol.L-1 for 6 h, which was characterized with keeping the completeness of nuclear membrane and not forming apoptotic bodies. The DNA ladder patterns were observed using agarose gel electrophoresis. The “G1 sub-peak” occurred only in the cells treated with LDM for 24 h, though chromatin condensation was earlier detected in treatment with LDM for 6 h. The caspase-3, 6 activities were increased about 5 and 4 folds, after the cells were treated with LDM 1 μmol.L-1 for 6 h, as did mitomycin C. The time of initiating chromatin condensation was earlier than that of the high peak activities of caspase-6. CONCLUSION The characterization of cell death induced by lidamycin in the human hepatoma BEL-7402 cells differs from typical apoptosis. The results make it helpful to explain the molecular mechanism of the highly potent cytotoxicities of lidamycin toward tumor cells.
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The distribution of receptor sites for concanavalin A (Con A) on the cellsurface of human gastric cancer cell line (MGC 80-3) and fibroblast cell cultures wasstudied with electron and light microscope after application of Con A-peroxidasemethod.The cytochemical reaction of the majority of non-prefixed MGC 80-3 cellsshows a striking tendency to be more uneven distribution than on fibroblasts.Clustering,patching and capping of Con A binding sites on the cancer cells anduniform distribution on the fibroblasts were observed.The effects of incubationtemperature,prefix treatment,different phase of cell cycles and cell growth condi-tions on the distribution of Con A receptor complexes were observed.The possiblereasons for the more irregular distribution of the cytochemical reaction product onthe MGC 80-3 cells than the fibroblasts are discussed.
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A rat monoclonal antibody of the IgG1 class, McAb B5A8, specific for the cAMP-dependent protein kinase(PKA) was produced. Western blot analysis revealed specific binding of the antibody to protein of 52-56 kd.The affinity-purified McAb BSA8 was labeled with FITC. Immunofluorescent localization of PKA was examined in human fibroblasts, gastric cancer cell line (MGc 80-3)and EAC cells. The distribution of PKA on the cytoplasmic microtubule network, Golgi region and nucleoli were observed. PKA was localized in the nuclear region in G2 phase of synchronized MGc 80-3 cells, and it was only found around the nuclei of MGc 80-3 cells which were incubated with DBcAMP. The changes in the distribution of PKA in cells are discussed.
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This experiment was carried out in young adult albino mice,which were injectedwith Ehrlich ascites tumor cells intraperitoneally to produce Ehrlich ascites tumor.The animals were divided into 2 groups.The first group received cAMP plusaminophylline for 5 to 13 days after inoculation.The second group received saline ascontrol.We found that in the administration of cAMP together with aminophylline,thegrowth of Ehrlich ascites tumor cells was inhibited to the extent of 53% at the 9thdays after inoculation.Early or later than the 9th day,the inhibitory rates were marklylower.By using cAMP immunocytochemical method,it was found that on the9th day of inoculation,there was an increase of the intensity of intracellualr cAMPspecific fluorescence in tumor cells of the cAMP treated mice in comparison withthose of the control.It also inhibited the 3',5'-cAMP-PDE activity on the 5th to 7thday after inoculation.Under the dark field microscope on the surface of the Ehrlich tumor cells therewere numerous“brush-like”microvilli,but they were not visible on the surfaceafter treated with cAMP together with aminophylline.The agglutination by theCon.A,was decreased markly on the 7th to 9th day after the inoculation.The possible relationship between the level of intracellular cAMP and of the3',5'-cAMP-PDE,and especially the inhibition of the formation of microvilli onthe treated tumor cell surface is discussed in this paper.
ABSTRACT
Synchronous cells in different phase (G_1, S, G_2, M) of cell cycle were obtained from human gastric low-differentiated mucous adenocarcinoma cells (MGC 80-3), which werec ultured with nitrous oxide under high pressure and blocked with overdosage of TdR. Dynamic changes of the mitochondria stained with Rhodamine-123 and succinate dehydrogenase demonstrated by cytochemical method were observed in various phase of the cells at 0, 24, 36, 60 hours after treatment with HPD plus red light. The results showed that mitochonodria of all four phases are of impairment immediately after photoradiation, SDH reactivity is decreased slightly at 24 hours, the activities of SDH is the weakest. As time goes on, we observed that mitochondria gradually recovered to its original structure and then SDH returned to its normal level. The recovery rate of mitochondria and SDH was in the following order, i. e. S, G_1, G_2, andM. The relationship between these changes and cell killing is briefly discussed.