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.

[Effects of zilongjin on proliferation and apoptosis of human breast cancer cell line MCF-7].

OBJECTIVE: To study the effect of Zilongjin (ZLJ, a composite Chinese drug) on proliferation and apoptosis of human breast carcinoma cell line MCF-7. METHODS: MCF-7 cells were randomly divided into four groups depending on the culture solution used, the control group, cultured with 1640 medium not contained ZLJ; and the three ZJL groups cultured with medium contained low (1.5 mg/mL), moderate (3 mg/mL) and high (6 mg/mL) dosage of ZLJ crude drug respectively. The changes of cell proliferation were assessed by cell growth curve assay and methyl thiazolyl tetrazolium (MTT) assay. And the cell apoptosis was analyzed by flow cytometry, Hoechst 33342 staining and DNA ladder assay. RESULTS: Compared with that in the normal control, the counts of cells in the three ZLJ groups were decreased significantly (P<0.05) at such time point as 24, 48, 72, 96, 120, and 144 h. Furthermore, apart from the comparison of the growth inhibition rate between the low and moderate dosage group at 24 and 72 h which were found to be no significant difference (P>0.05), the comparison f that among the three ZLJ groups appeared to be significant difference (P<0.05). The inhibitory effect of ZLJ on cell proliferation of MCF-7 was time- and dose-dependent; it could retard cells in G0/G1 cell phase; apoptosis of MCF-7 cell was induced by moderate and high dosage of ZLJ with revealing of apoptotic body and DNA ladder formation. CONCLUSION: ZLJ shows cell proliferation inhibitory and apoptosis inducing effects on human breast cancer cell line MCF-7, and thus to realize its anti-tumor action.

[Experimental study on suppressive effect of zilongjin on growth of human breast cancer cell line MCF-7 in vitro and in vivo].

OBJECTIVE: To investigate the suppressive effect and mechanism of action of Zilongjin (ZLJ, a composite Chinese drug) on the growth of human breast carcinoma cell line MCF-7 in vivo and in vivo. METHODS: The cell survival rate and clone forming efficiency were observed by direct cell counting with trypan blue staining and double layers soft agar test; the p-ERK 1/2 expression was analyzed using Western blotting; 17-beta-estrogen pellet embedding was adopted to make the subcutaneous transplanted tumor MCF-7 cell in BALB/c nude mice for detecting the tumor growth suppressive effect of ZLJ (20 g crude drug/kg). RESULTS: The survival rate of MCF-7 cell was obviously decreased by ZLJ in a time and dose-dependent manner; only few and small clones on soft agar could be found after treated with ZLJ, the inhibition rates of clone formation(%) for 0.75, 1.5, 3, 6 mg/mL of ZLJ were 12.66 +/- 1.54, 88.83 +/- 2.13, 100 and 100, respectively, as compared with that of non-treated. The expression of p-ERK 1/2 was suppressed and the ability of the tumorigenicity in nude mice was reduced effectively by ZLJ. The mean volumes and weights of tumor in the test group and the control group were (0.73 +/- 0.58) cm3 vs (1.36 +/- 0.64) cm3 and (1.02 +/- 0.25) g vs (1.66 +/- 0.09) g respectively, showing significant difference (P<0.05), and the tumor inhibition rate of ZLJ was 38.55%. CONCLUSION: ZLJ shows obviously suppressive actions on malignant proliferation, transformation and tumorigenicity of human breast carcinoma cell line MCF-7; the down-regulation of p-ERK 1/2 protein may involve in these effects.

[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.