Phenethyl Isothiocyanate Inhibits Oxidative Phosphorylation to Trigger Reactive Oxygen Species-mediated Death of Human Prostate Cancer Cells

Phenethyl isothiocyanate (PEITC), a constituent of edible cruciferous vegetables such as watercress, not only affords significant protection against chemically induced cancer in experimental rodents but also inhibits growth of human cancer cells by causing apoptotic and autophagic cell death. However, the underlying mechanism of PEITC-induced cell death is not fully understood. Using LNCaP and PC-3 human prostate cancer cells as a model, we demonstrate that the PEITC-induced cell death is initiated by production of reactive oxygen species (ROS) resulting from inhibition of oxidative phosphorylation (OXPHOS). Exposure of LNCaP and PC-3 cells to pharmacologic concentrations of PEITC resulted in ROS production, which correlated with inhibition of complex III activity, suppression of OXPHOS, and ATP depletion. These effects were not observed in a representative normal human prostate epithelial cell line (PrEC). The ROS production by PEITC treatment was not influenced by cyclosporin A. The Rho-0 variants of LNCaP and PC-3 cells were more resistant to PEITC-mediated ROS generation, apoptotic DNA fragmentation, and collapse of mitochondrial membrane potential compared with respective wild-type cells. The PEITC treatment resulted in activation of Bax in wild-type LNCaP and PC-3 cells, but not in their respective Rho-0 variants. Furthermore, RNA interference of Bax and Bak conferred significant protection against PEITC-induced apoptosis. The Rho-0 variants of LNCaP and PC-3 cells also resisted PEITC-mediated autophagy. In conclusion, the present study provides novel insight into the molecular circuitry of PEITC-induced cell death involving ROS production due to inhibition of complex III and OXPHOS.     

Simultaneous flow cytometric detection of nuclear DNA and tumor-associated antigens in lung cancers

Flow cytometric (FCM) determinations of DNA index were found to be insufficient to distinguish the presence of tumor cells from normal ones in neoplastic tissues obtained from 29 patients with lung cancer. Therefore, the DNA and tumor-associated antigen (TAA) contents of cultured human lung cancer cells were simultaneously analyzed using FCM to assess whether this dual technique would help in distinguishing tumor cells from normal ones. For the study, cells from PC-10 (a squamous cell carcinoma line), PC-3 (an adenocarcinoma line) and PC-6 (a small cell carcinoma line) were mixed with normal peripheral lymphocytes. The TAAs studied were carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCCA) and neuron-specific enolase (NSE). The alcohol-fixed cells were treated with the respective primary TAA, followed by fluorescein-isothiocyanate-conjugated secondary antibody; the cellular DNA was then stained using propidium iodide. Red and green fluorescences were measured simultaneously by FCM. The results showed CEA mainly in PC-3 cells, SCC in PC-10 cells and NSE in PC-6 cells; thus, each cell type had a relatively specific TAA. DNA content and cell size analyses differentiated neoplastic cells from normal lymphocytes for PC-3 and PC-10 cells, but not for PC-6 cells. Simultaneous FCM analyses of DNA and the TAA specific for the individual cell type made it possible to distinguish all tumor cell types from normal lymphocytes.     

前列腺细胞REGⅣ基因功能的初步研究

目的:探讨人再生基因Ⅳ(REGIV)在前列腺细胞中的表达及意义.方法:构建REGIV基因的全序列过表达质粒.将全序列过表达质粒采用脂质体转染的方式转入前列腺细胞系PC-3中.应用Real-time-PCR方法检测REGIV基因mRNA表达,Westembloting检测REGIV基因蛋白质表达,MTT法分析细胞增殖活性.结果:通过荧光显微镜观察计数,细胞转染成功.REGIV基因的全序列过表达使REGIV基因mRNA的表达,蛋白表达提高,细胞增殖能力增强.结论:应用全序列过表达技术可以使前列腺癌REGIV表达水平特异性增高.前列腺癌增值能力的增强说明REGW可能与肿瘤快速增长有关.     

Tocotrienol-rich fraction of palm oil induces cell cycle arrest and apoptosis selectively in human prostate cancer cells

One of the requisite of cancer chemopreventive agent is elimination of damaged or malignant cells through cell cycle inhibition or induction of apoptosis without affecting normal cells. In this study, employing normal human prostate epithelial cells (PrEC), virally transformed normal human prostate epithelial cells (PZ-HPV-7), and human prostate cancer cells (LNCaP, DU145, and PC-3), we evaluated the growth-inhibitory and apoptotic effects of tocotrienol-rich fraction (TRF) extracted from palm oil. TRF treatment to PrEC and PZ-HPV-7 resulted in almost identical growth-inhibitory responses of low magnitude. In sharp contrast, TRF treatment resulted in significant decreases in cell viability and colony formation in all three prostate cancer cell lines. The IC(50) values after 24h TRF treatment in LNCaP, PC-3, and DU145 cells were in the order 16.5, 17.5, and 22.0 microg/ml. TRF treatment resulted in significant apoptosis in all the cell lines as evident from (i) DNA fragmentation, (ii) fluorescence microscopy, and (iii) cell death detection ELISA, whereas the PrEC and PZ-HPV-7 cells did not undergo apoptosis, but showed modestly decreased cell viability only at a high dose of 80 microg/ml. In cell cycle analysis, TRF (10-40 microg/ml) resulted in a dose-dependent G0/G1 phase arrest and sub G1 accumulation in all three cancer cell lines but not in PZ-HPV-7 cells. These results suggest that the palm oil derivative TRF is capable of selectively inhibiting cellular proliferation and accelerating apoptotic events in prostate cancer cells. TRF offers significant promise as a chemopreventive and/or therapeutic agent against prostate cancer.     

Theaflavins induce G2/M arrest by modulating expression of p21waf1/cip1, cdc25C and cyclin B in human prostate carcinoma PC-3 cells

Cancer of the prostate gland (PCA) is the most common invasive malignancy and is the second leading cause of cancer-related death in males. The polyphenolic constituents of black tea have gained considerable attention as chemopreventive agents. Many studies have shown that black tea reduces the risk of several cancer types. In the present study, we studied the effect of a black tea polyphenol, theaflavin (TF), on cellular proliferation and cell death in the human prostate cancer cell line, PC-3. We showed that TF inhibits cell proliferation in a dose- and time-dependent manner. Studies on cell cycle progression have shown that the anti-proliferative effect of TF is associated with an increase in the G2/M phase of PC-3 cells. Western blot results showed that TF-induced G2/M phase arrest was mediated through the inhibition of cyclin-regulated signaling pathways. TF induces cyclin kinase inhibitor p21(waf1/cip1) expression and inhibits cdc25C and cyclin B expression. Increased exposure time to TF caused apoptosis of PC-3 cells, which was associated with up-regulation of the pro-apoptotic proteins Bax, caspase-3 and caspase-9 and down-regulation of anti-apoptotic protein Bcl-2. The role of caspase-induced apoptosis was further confirmed by a reduction in mitochondria membrane potential and the appearance of a DNA laddering pattern. Thus, it can be concluded that TF acts as an effective anti-proliferative agent by modulating cell growth regulators in prostate cancer cells.     

Dental pulp stem cells (DPSCs) increase prostate cancer cell proliferation and migration under in vitro conditions

Cancer as a multistep and complicated disease is regulated by several molecular and cellular events. Cancer treatment could be managed at the early stages when the tumor is confined in the tissue. However, disseminated cancer cells metastasize to other body parts and generate new tumors resulting in mortality. Mesenchymal stem cells (MSCs) are found in different body parts and helps adult tissue regeneration. The role of MSCs in cancer progression has emerged as one of the important aspects in cancer biology and is the aim of interest in recent years. In the current study, effects of Dental Pulp Stem Cells (DPSCs) on PC-3 prostate cancer cell proliferation and migration were conducted by cell proliferation, apoptosis, gene expression and cell migration analysis in vitro. Condition medium (CM) obtained from DPSCs increased cell proliferation of PC-3 cells and decreased apoptosis. Either administration of CM or trans well co-culture of DPSCs increased cell migration in scratch assay, confirmed by gene expression analysis of migratory genes including fibronectin, laminin and collagen type I (Col I). Furthermore, DPSCs participated in a self-organized structure with PC-3 cells in co-culture conditions. Overall, results indicated that DPSCs could promote PC-3 cancer cell proliferation and metastasis in co-culture conditions in vitro.     

HoxA10 Induces Proliferation in Human Prostate Carcinoma PC-3 Cell Line

The objectives of this study were to examine the expression levels of Homeobox A10 (HoxA10) in prostate cancer cells and to study the molecular mechanism of HoxA10-mediated regulation of prostate cancer cell growth and development. We investigated the effect of HoxA10 on cell proliferation by stably overexpressing or silencing HoxA10 in prostate cancer PC-3 cell line using lentiviral vectors. Quantitative real-time PCR and western blotting analysis were used to compare the expressions of HoxA10 in prostate cancer cell lines and normal prostate epithelium. Cancer cell proliferation was examined by MTT assay and colony formation assay. The levels of HoxA10 expression were significantly increased in prostate cancer cell lines and tissues compared to those in normal prostate epithelium. Overexpression of HoxA10 in PC-3 cells induced significant cancer cell proliferation, whereas silencing of HoxA10 expression by RNAi resulted in decreased proliferation rates. HoxA10 was highly expressed in prostate cancer cells and tissues, suggesting its functional involvement in cancer cell proliferation. We successfully overexpressed or silenced HoxA10 in prostate cancer PC-3 cell line and discovered that the levels of HoxA10 directly correlate with cancer cell proliferation. These findings contribute to a better understanding of the regulatory mechanism of HoxA10 in prostate cancer.     

Characterization of an in vitro model to study the possible role of polyomavirus BK in prostate cancer

Prostate cancer (PCa) is the most common male neoplasms in the Western world. Various risk factors may lead to carcinogenesis, including infectious agents such as polyomavirus BK (BKPyV), which infects the human renourinary tract, establishes latency, and encodes oncoproteins. Previous studies suggested that BKPyV plays a role in PCa pathogenesis. However, the unspecific tropism of BKPyV and the lack of in vitro models of BKPyV-infected prostate cells cast doubt on this hypothesis. The aim of the present study was to determine whether BKPyV could (a) infect normal and/or tumoral epithelial prostate cells and (b) affect their phenotype. Normal epithelial prostate RWPE-1 cells and PCa PC-3 cells were infected with BKPyV for 21 days. Cell proliferation, cytokine production, adhesion, invasion ability, and epithelial-to-mesenchymal transition (EMT) markers were analyzed. Our results show that (a) RWPE-1 and PC-3 cells are both infectable with BKPyV, but the outcome of the infection varies, (b) cell proliferation and TNF-α production were increased in BKPyV-infected RWPE-1, but not in PC-3 cells, (c) adhesion to matrigel and invasion abilities were elevated in BKPyV-infected RWPE-1 cells, and (d) loss of E-cadherin and expression of vimentin occurred in both uninfected and infected RWPE-1 cells. In conclusion, BKPyV may change some features of the normal prostate cells but is not needed for maintaining the transformed phenotype in the PCa cells The fact that RWPE-1 cells exhibit some phenotype modifications related to EMT represents a limit of this in vitro model.     

Immunohistochemical characterisation of the monoclonal antibody BLCA-38 for the detection of prostate cancer

Background: Monoclonal antibodies (MAbs) can be used to detect, image and treat cancers. This study aimed to characterise the binding of BLCA-38 MAbs to human prostate cancer cell lines, human prostate cancer biopsy samples and normal tissues to enable future targeted studies. Methods: BLCA-38 antigen expression on cancer lines was determined by flow cytometry; that on patient specimens from normal tissues and cancers was tested by immunohistochemistry using fresh frozen tissues or paraffin-embedded tissues that had undergone antigen retrieval. Results: Cell surface BLCA-38 antigen expression was seen on DU-145, PC-3, PC-3 M and PC-3 M-MM2 prostate cancer lines, but LNCaP, MDA PCa 2a or MDA PCa 2b lines were negative. Other human lines, including 8/12 bladder cancer and A431 vulval epidermoid cells, but not breast cancer lines, expressed BLCA-38 antigen. Staining occurred in glandular epithelial cells in the majority of frozen, and paraffin-embedded prostate cancer tissues and was occasionally seen in prostatic intraepithelial neoplasia (PIN). No staining was observed in normal cadaver tissues or in benign areas from various other cancer tissues. Conclusions: The BLCA-38 antibody binds to the majority of human prostate cancers but not to normal cells, and has potential for targeting novel therapies in patients with this disease.     

Adrenomedullin prevents apoptosis in prostate cancer cells

The 52-aminoacid peptide adrenomedullin (AM) is expressed in the normal and malignant prostate. We have previously shown that prostate cancer cells produce and secrete AM, which acts as an autocrine growth inhibitory factor. We have evaluated in the present study the role of AM in prostate cancer cell apoptosis, induced either by serum deprivation or treatment with the chemotherapeutic agent etoposide (which acts as an inhibitor of topoisomerase II). For this purpose we over-expressed AM in PC-3, DU 145 and LNCaP cells, which were transfected with an expression vector carrying AM. We also treated the parental cell lines with synthetic AM in normal culture conditions and in conditions of induced-apoptosis. After serum removal, AM prevented apoptosis in DU 145 and PC-3 cells, but not in LNCaP cells. When treated with etoposide, AM prevented apoptosis in PC-3 and LNCaP cells, but not in DU 145 cells. Cell cycle analysis demonstrated a significant decrease in the percentage of AM-overexpressing PC-3 cells in the subG0/G1 phase after treatment with etoposide, as compared to the percentage of mock-transfected PC-3 treated cells. Western blot showed that protein levels of phosphorylated ERK1/2 increased in parental PC-3 cells after treatment with etoposide. In PC-3 cells overexpressing AM, phosphorylated ERK1/2 basal levels were lower than basal levels of parental PC-3 cells, and treatment with etoposide did not result in such an increase. Etoposide produced a significant increase in cleaved PARP in parental PC-3 cells. However, PC-3 clones overexpressing AM that were treated with etoposide only showed a mild increase in fragmented PARP. The ratio Bcl-2/Bax was reduced in parental or mock-transfected PC-3 cells after treatment with etoposide. On the contrary, this ratio was not reduced in PC-3 clones with AM overexpression that were treated with etoposide. All these data demonstrate that AM plays a protective role against induced apoptosis in prostate cancer cells. These results may have important implications in prostate cancer resistance to chemotherapeutic agents.     

miRNA-191对前列腺癌的增殖、迁移侵袭能力的影响及其机制*

目的:观察miRNA-191对前列腺癌的增殖、迁移和侵袭能力的影响,并探讨其机制。方法:分别检测4种人前列癌细胞系(PC-3、DU-145、LNCa P、22RU1)及人正常前列腺细胞RWPE-2中miRNA-191的表达水平,并选择前列腺癌细胞系PC-3作为实验对象。将PC-3细胞分为3组:空白对照组(不转染)、miRNA-191 NC组(Inhibitor NC转染PC-3细胞)、miRNA-191 Inhibitor组(miRNA-191 Inhibitor转染PC-3细胞),每组设置3个复孔。采用RT-qPCR法检测PC-3细胞miRNA-191和PLCD1的mRNA表达水平;采用CCK8法检测PC-3细胞增殖水平;采用划痕实验和侵袭实验分别检测PC-3细胞迁移能力和侵袭能力;通过Targetscan靶基因预测网站,筛选PLCD1作为miRNA-191的靶向蛋白,并用双荧光素酶靶标实验验证;采用Western blot法检测PC-3细胞PLCD1的蛋白表达。结果:与RWPE-2细胞相比,人前列癌细胞中miNRA-191的表达水平显著升高(P＜0.05),且miRNA-191的表达水平在PC-3中较其他3种细胞系显著上调(P＜0.05)。抑制miRNA-191的表达水平后,PLCD1表达水平显著升高,PC-3细胞增殖能力受到抑制,迁移和侵袭能力较空白对照组和miRNA-191 NC组显著降低(P＜0.05)。双荧光素酶报告基因实验结果显示,PLCD1基因是miRNA-191的靶基因。结论:miRNA-191通过靶向PLCD1促进前列腺癌PC-3细胞的增殖、迁移和侵袭能力。     

Role of Zn in epigallocatechin gallate affecting the growth of PC-3 cells

Green tea has chemo-preventive effects to human carcinoma including prostate cancer. Epigallocatechin gallate (EGCG) is the major active component in green tea. Zn(2+) is indispensable to our health, and plays an important role in the normal function and pathology of the prostate gland, and might be a good marker for diagnosing prostate cancer. Effects of Zn(2+), EGCG and their interactions on the growth of androgen-insensitive prostate cancer cell (PC-3) were investigated in the present paper. The results show that Zn(2+) and EGCG inhibited the growth of PC-3 cells in a time- and dose-dependent manner, but effects of interactions of EGCG with Zn(2+) were extremely dependent on their concentrations and added orders. Inhibitory effects of Zn(2+) were significantly decreased in the presence of EGCG on PC-3 cell growth. Therefore, we hypothesize that complexation of EGCG with Zn(2+) might be responsible for the observed decrease of the bioactivities of Zn(2+) against PC-3 cells.     

Isolation and characterization of the major form of human MUC18 cDNA gene and correlation of MUC18 over-expression in prostate cancer cell lines and tissues with malignant progression.

Ectopical expression of huMUC18, a cell adhesion molecule in the immunoglobulin gene superfamily, causes a non-metastatic human melanoma cell line to become metastatic in a nude mouse system. To determine if MUC18 expression correlates with the development and malignant progression of prostate cancer, we investigated differential expression of human MUC18 (huMUC18) in normal prostate epithelial cells, prostate cancer cell lines, and prostatic normal and cancer tissues. We cloned and characterized the human MUC18 (huMUC18) cDNA gene from three human prostate cancer cell lines and three human melanoma cell lines. The cDNA sequences from the six human cancer cell lines were identical except differences in one to five nucleotides. The deduced amino acid sequences of the longest ORF were 646 amino acids that were identical in these cDNAs except for one to three amino acid residues. The amino acid sequences of all our huMUC18 cDNA genes are similar to that cloned by other group (GenBank access #M28882) except differences in the same seven amino acids. We conclude that huMUC18 cDNA gene reported here represents the gene product from a major allele. The MUC18 mRNA and protein was expressed in three metastatic prostate cancer cell lines (TSU-PR1, DU145, and PC-3), but not in one non-metastatic prostate cancer cell line (LNCaP.FGC). The expression of huMUC18 in these four cell lines is positively related to their extent of in vitro motility and invasiveness and in vivo metastasis in nude mice. HuMUC18 protein was also expressed at high levels in extracts prepared from tissue sample sections containing high grade prostatic intraepithelial neoplasia (PIN), but weakly expressed in extracts prepared from cultured primary normal prostatic epithelial cells and the normal prostate gland. Immunohistochemical analysis showed that huMUC18 was expressed at higher levels in the epithelial cells of high-grade PIN and prostatic carcinomas, and in cells of a perineural invasion, a lymph node, and a lung metastases compared to that in normal or benign hyperplastic epithelium (BPH). We therefore conclude that MUC18 expression is increased during prostate cancer initiation (high grade PIN) and progression to carcinoma, and in metastatic cell lines and metastatic carcinoma. Increased expression of MUC18 is implicated to play an important role in developing and malignant progression of human prostate cancer. Furthermore, the lacking of predominant cytoplasmic membrane expression of MUC18 appeared to correlate with malignant progression of prostate cancer.     

Parathyroid hormone-related protein enhances PC-3 prostate cancer cell growth via both autocrine/paracrine and intracrine pathways

Parathyroid hormone-related protein (PTHrP) is expressed by human prostatic tissue and prostate cancer cell lines, and positively influences primary prostate tumor growth in vivo. The human prostate cancer cell line PC-3, which expresses functional PTH/PTHrP receptors, was used as a model to study the effects of PTHrP on prostate cancer cell growth. Addition of PTHrP (1-34), (1-86), and (1-139) increased cell number and [3H]thymidine incorporation; these effects were reversed by anti-PTHrP antiserum. This antiserum also decreased endogenous PC-3 cell growth. Clonal PTHrP-overexpressing PC-3 cell lines also showed enhanced cell growth and [3H]thymidine incorporation and were enriched in the G2+M phase of the cell cycle, suggesting an effect of PTHrP on mitosis. Overexpression of PTHrP with the nuclear localization sequence (NLS) deletion partially reversed the growth-stimulatory effects. The growth rate of these cells was midway between that of wild-type PTHrP-overexpressing and control cells, presumably because NLS-mutated PTHrP is still secreted and acts through the cell surface PTH/PTHrP receptor. In contrast to NLS-mutated PTHrP, wild-type protein showed preferential nuclear localization. These results suggest that the proliferative effects of PTHrP in PC-3 cells are mediated via both autocrine/paracrine and intracrine pathways, and that controlling PTHrP production in prostate cancer may be therapeutically beneficial.     

Inflammatory Cytokines and Survival Factors from Serum Modulate Tweak-Induced Apoptosis in PC-3 Prostate Cancer Cells

Tumor necrosis factor-like weak inducer of apoptosis (TWEAK, TNFSF12) is a member of the tumor necrosis factor superfamily. TWEAK activates the Fn14 receptor, and may regulate cell death, survival and proliferation in tumor cells. However, there is little information on the function and regulation of this system in prostate cancer. Fn14 expression and TWEAK actions were studied in two human prostate cancer cell lines, the androgen-independent PC-3 cell line and androgen-sensitive LNCaP cells. Additionally, the expression of Fn14 was analyzed in human biopsies of prostate cancer. Fn14 expression is increased in histological sections of human prostate adenocarcinoma. Both prostate cancer cell lines express constitutively Fn14, but, the androgen-independent cell line PC-3 showed higher levels of Fn14 that the LNCaP cells. Fn14 expression was up-regulated in PC-3 human prostate cancer cells in presence of inflammatory cytokines (TNFα/IFNγ) as well as in presence of bovine fetal serum. TWEAK induced apoptotic cell death in PC-3 cells, but not in LNCaP cells. Moreover, in PC-3 cells, co-stimulation with TNFα/IFNγ/TWEAK induced a higher rate of apoptosis. However, TWEAK or TWEAK/TNFα/IFNγ did not induce apoptosis in presence of bovine fetal serum. TWEAK induced cell death through activation of the Fn14 receptor. Apoptosis was associated with activation of caspase-3, release of mitochondrial cytochrome C and an increased Bax/BclxL ratio. TWEAK/Fn14 pathway activation promotes apoptosis in androgen-independent PC-3 cells under certain culture conditions. Further characterization of the therapeutic target potential of TWEAK/Fn14 for human prostate cancer is warranted.     

Flavonoid ampelopsin inhibits the growth and metastasis of prostate cancer in vitro and in mice

The objective of this study was to evaluate the chemopreventive effect of a novel flavonoid, ampelopsin (AMP) on the growth and metastasis of prostate cancer cells. AMP showed the more potent activity in inhibiting the proliferation of androgen-sensitive LNCaP and, to less extent, androgen-independent PC-3 human prostate cancer cell lines in vitro, primarily by induction of apoptosis associated with down-regulation of bcl-2. On the other hand, AMP showed much less activity in inhibiting the proliferation of normal prostate epithelial cells than that of prostate cancer cell lines. AMP also inhibited the migration and invasion of PC-3 cells in vitro associated with down-regulation of CXCR4 expression. In the animal study using an orthotopic prostate tumor model, AMP (150 and 300 mg/kg body weight) inhibited the growth of PC-3 tumors and lymph node and lung metastases in a dose-dependent manner. Compared to the control mice, mice treated with AMP at 300 mg/kg BW had reduced final tumor weight by 49.2% (P<0.05), lymph node metastases by 54.5% (P?=?0.3) and lung metastases by 93% (P<0.05), but had no apparent alteration on food intake or body weight. The in vivo anti-growth and anti-metastasis activities of AMP were associated with induction of apoptosis and inhibition of proliferation of prostate cancer cells, reduction of prostate tumor angiogenesis, and reduction of CXCR4 expression. Our results provide supporting evidence to warrant further investigation to develop AMP as a novel efficacious and safe candidate agent against progression and metastasis of prostate cancer.     

无花果果浆对肿瘤细胞增殖抑制和诱导凋亡作用

为了探讨无花果果浆(Fig fruit latex,FFL)对人肿瘤细胞的生长抑制作用及其机制,用无花果果浆处理体外培养的人肿瘤细胞,细胞增殖试验(MTT法)、克隆形成试验研究FFL对人肿瘤细胞的增殖抑制作用,Brdu掺人试验、吖啶橙/溴乙啶(AO/EB)染色、流式细胞术检测FFL对肿瘤细胞DNA合成、凋亡和细胞周期的影响.结果,用FFL处理后,肿瘤细胞增殖活性降低(P＜0.05),克隆形成下降(P＜0.05),Brdu标记指数降低(P＜0.05),吖啶橙染色凋亡细胞增多(P＜0.05);细胞周期分布改变,凋亡指数升高(P＜0.01),G0/G1期细胞数增加(P＜0.01),S期细胞数减少(P＜0.01),在一定剂量内对正常细胞无明显影响.试验结果提示,FFL对所试肿瘤细胞的增殖有显著地抑制作用,其作用机理可能与抑制肿瘤细胞DNA合成,诱导肿瘤细胞凋亡及细胞周期阻滞有关.