Differentially expressed proteins of MCF-7 human breast cancer cells affected by Zilongjin, a complementary Chinese herbal medicine.

PURPOSE: Zilongjin, a complementary Chinese herbal medicine, has been used to alleviate the adverse effects of chemotherapeutic drugs in cancer therapy. However, the mechanisms of anti-cancer activity of Zilongjin are still largely unkonwn. EXPERIMENTAL DESIGN: First, the proteomic approach of combined 2-DE and ESI-MS/MS was used to investigate the effect of Zilongjin on the protein expression in MCF-7 cells. Then, the differential expression of some proteins was confirmed by Western blot, cytoimmunofluoresecnce, and quantitative real-time RT-PCR analysis. RESULTS: The identified proteins with differential expression, involved in such events as protein translation, cellular signal transduction, cytoskeleton formation and transportation, include seven downregulating proteins, such as Eukaryotic translation initiation factor 3 subunit I, Eukaryotic translation initiation factor 1A Y-chromosomal, Ran-specific GTPase-activating protein, Ubiquitin-conjugating enzyme E2 N, Tropomodulin-3, Macrophage-capping protein, and Tumor protein D52, as well as two upregulating proteins, HSP ß-1 and keratin18. Moreover, the differential expression of three proteins was confirmed. CONCLUSIONS AND CLINICAL RELEVANCE: (i) These results provide a new insight into the molecular mechanisms of Zilongjin on therapy for breast cancer. (ii) The application of the proteomic approaches will result in the more extended appreciation of Chinese medicine than those known at present.

[Differential transcription of Bcl-2 and Bax through the cell cycle in prostate cancer cell line].

OBJECTIVE: To investigate the differential expression of apoptosis associated gene Bcl-2 and Bax through cell cycle and its possible clinical meaning. METHODS: The prostate cancer cell line PC-3 was synchronized in M, G1, S and G2 phase using modified thymine deoxyriboside blockage and high pressure N2O technique. The efficiency of synchronization was detected by flow-cytometry. RT-PCR and Western blot methods were used to examine the expression of Bcl-2 and Bax in mRNA and protein level. RESULTS: The synchronized rate of M, G1, S and G2 phase were 92.1%, 87.0%, 80.2% and 75.9% respectively. Bcl-2 was constitutively expressed through the cell cycle, but both the mRNA and protein expression level of Bcl-2 were very high in the G1 phase, dramatically decreased in M, S and G2 phase. The expression level of Bax had no change through the cell cycle. CONCLUSIONS: Cell cycle could influence the expression level of Bcl-2 significantly but not Bax, these might have some clinical relevance.

[Inspiration to basic researches of traditional Chinese medicine from the 2001 Nobel Prize].

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.

[In vitro effect of zilongjin on prostate cancer cell line LNCaP].

OBJECTIVE: To investigate the effect of Zilongjin (ZLJ) on human androgen-dependent type of prostate cancer cell line LNCaP. METHODS: MTT assay, flow cytometry and fluorescence microscopy were used to observe the effect of ZLJ in anti-proliferation, cell cycle arresting and apoptosis induction. RT-PCR was used to examine the effect of ZLJ on expressions of prostate marker gene (PSA), androgen receptor (AR), apoptosis related genes (bcl-2 and bax), and Western blot assay was used to detect the effect on protein expression of bcl-2 and bax. RESULTS: ZLJ could cause apparent inhibition on proliferation, induce G0/G1 phase arresting and apoptosis in time- and dose-dependent manner on LNCaP cells. The concentration for inhibiting cell growth by 50% (IC50) in 72 hrs was 0.79 mg/ml. ZLJ could down-regulate the expression of PSA, AR, bcl-2 genes and lower bcl-2 protein expression, but showed ineffective on bax protein expression. CONCLUSION: ZLJ displays its anti-tumor effects by way of inhibiting the cell proliferation, arresting the G0/G1 phase, inducing apoptosis, down-regulating PSA, AR, bcl-2 gene expression and lowering bcl-2 protein expressions.

Activation of astrocytes by advanced glycation end products: cytokines induction and nitric oxide release.

AIM: To investigate whether two kinds of in vitro prepared advanced glycation end products (AGE), Glu-BSA and Gal-BSA, could induce proinflammatory mediators IL-1beta and TNF-alpha, as well as oxidative stress and nitric oxide (NO), in astrocytes, thus contributing to brain injury. METHODS: Radioimmunoassay and RT-PCR technique were used to detect two cytokines' level and existence of receptor for AGE (RAGE). DTNB reaction was used to measure reduced glutathione (GSH) level. NO content was assayed using Griess reagent provided by Promega. RESULTS: Enhanced protein levels of both cytokines in supernatants and cell lysates of astroglia cultures were detected after treated with AGE-BSA 1 g/L, especially Gal-BSA, for 72 h. The increases were also in a concentration-dependent manner. Changes in protein levels might be attributed to changes in transcriptional levels documented by semi-quantitative RT-PCR. Both AGE-BSA could also reduce astrocytic GSH and induce NO release. RAGE was detected in astrocytes. CONCLUSION: Enhanced levels of astrocytic proinflammatory mediators IL-1beta and TNF-alpha, and oxidative stress caused by AGE might contribute to, at least partially, the detrimental effects of AGE in neuronal disorders and aging brain.

Characteristics of mitotic cell death induced by enediyne antibiotic lidamycin in human epithelial tumor cells.

Mitotic cell death, a different cell death mode from apoptosis, has been focused on in tumor therapy. It may involve the mechanism of highly potent cytotoxicities of enediyne antibiotics toward tumor cells. We describe the characteristics of mitotic cell death induced by enediyne antibiotic lidamycin at low concentrations (0.01-1 nM), in the human hepatoma BEL-7402 cells and human breast carcinoma MCF-7 cells. The cells exerting mitotic cell death showed retardation at G2+M phase, enlargement of cell volume and multinucleation, some of which were positive in senescence-associate beta-galactosidase staining. The multinucleated living cells did not show apoptotic features by co-staining with mitochondria-specific dye Mitosensor and DNA-specific dye Hoechst 33342. The DNA polyploidy rather than increased with incubation time for the lidamycin-treated BEL-7402 cells. The proliferation status of BEL-7402 cells was shown by flow cytometry after the cells were labeled with PKH-67, a fluorescent dye for labeling living cells, but the fluorescent intensity of the lidamycin-treated cells was little changed. The smear DNA pattern was detected in the multinucleated cells by agarose gel electrophoresis. The results provide the first evidence for elucidating the potent cytotoxicities of lidamycin toward tumor cells and further describing characteristics of mitotic cell death.