Activity of potassium channel-blockers in breast cancer

BACKGROUND: Potassium ion (K+) channels are known to play a key role in breast cancer proliferation. MATERIALS AND METHODS: We investigated the expression of Kv1.3 voltage-gated K+ channels in 60 human breast cancer specimens by immunohistochemistry. The effects of K+ channel-blockers on cellular proliferation were examined in vitro. RESULTS: No immunostaining was observed in 4 normal human breast specimens. Eighteen (30%) breast cancer specimens showed high, 35 (58%) moderate and 7 (12%) low Kv1.3 staining in the epithelial compartment. Minoxidil (K+ channel-opener) stimulated growth of MCF-7 human breast cancer cells (maximal approximately 60% at 10 micrograms/mL). K+ channel-blockers, dequalinium and amiodarone, had marked inhibitory effects on MCF-7 proliferation (> 90% inhibition at 1.5 micrograms/mL). Importantly, amiodarone and dequalinium potentiated the growth-inhibitory effects of tamoxifen on human breast (MCF-7, MDA-MB-231) as well as prostate (PC3, MDA-PCA-2B) and colon (Colo320DM, SW1116) cancer cell lines. CONCLUSION: Investigation of combination therapy with tamoxifen and K+ channel-blockers is warranted.     

Expression and activity of potassium ion channels in human prostate cancer

Four normal and 79 human prostate cancer (Pca) specimens were examined, by immunohistochemistry, for expression of voltage-gated potassium ion channels. Strong immunostaining (for Kv1.3) was observed in the normal and 47% (37/79) of Pca specimens. Twenty-nine percent (23/79) Pca specimens showed moderate and 24% (19/79) displayed low staining. Three potassium channel-openers at a concentration of 10 microg/mL, minoxidil (47.8 microM), 1-Ethyl-2-benzimidazolinone (EBIO) (61.7 microM) and diazoxide (43.3 microM), increased growth of PC3 cells by 30-50%. Potassium channel-blockers, dequalinium, amiodarone and glibenclamide, caused a dose-dependent, growth inhibition of four human Pca cell lines. Apoptosis occurred within 4h of treatment of PC3 cells with dequalinium (0.5 microg/mL, 0.9 microM), amiodarone (5 microg/mL, 7.3 microM) or glibenclamide (50 microg/mL, 0.1mM).     

Willow bark extract (BNO1455) and its fractions suppress growth and induce apoptosis in human colon and lung cancer cells

BACKGROUND: Recently, there have been extensive efforts to evaluate the chemopreventive role of substances present in natural products. The aim of this study was to examine the effects of the main groups of compounds (salicylalcohol derivates, flavonoids, proanthocyanidins), and salicin isolated from willow bark extract BNO 1455 on proliferation and apoptosis in human colon and cancer cells. METHODS: We used human colon cyclooxygenase-2 (COX-2)-positive HT 29 and (COX-2)-negative HCT 116 or lung COX-2 proficient A 549 and low COX-2 expressing SW2 cells. After treatment for 72 h with various concentrations of single substances and acetylsalicylic acid (ASA) as control, inhibition of cell growth and cytotoxicity were measured by colorimetric WST-1 assay and propidium iodide uptake by flow cytometry, respectively. Apoptotic cells were identified by annexin V adhesion using flow cytometry. RESULTS: Studies on dose-dependent effects of BNO 1455 and its fractions showed anti-proliferative activity of all compounds with 50% maximal growth inhibitory concentrations (GI(50)) between 33.3 and 103.3 microg/ml for flavonoids and proanthocyanidins fractions and 50.0-243.0 microg/ml for salicylalcohol derivates and extract. Apoptosis induction was confirmed by annexin V adherence and analysis of cell morphology based on light scattering characteristics using flow cytometry in all cell lines at GI(50). CONCLUSIONS: We showed that willow bark extract BNO 1455 an its fractions inhibit the cell growth and promote apoptosis in human colon and lung cancer cell lines irrespective of their COX-selectivity.     

Expression of delayed rectifier potassium channels and their possible roles in proliferation of human gastric cancer cells

Voltage-gated potassium (Kv) channels have been reported to be involved in the proliferation of many types of cells, including tumor cells. The overexpression of the Kv channels and related channel activity are involved in the neoplastic process. Our previous study has shown the existence of delayed rectifier potassium (I(K)) current in gastric cancer cells SGC7901. However, the expression and function of most delayed rectifier potassium (K(D)) channel subunits in gastric cancer cells are not completely resolved. Here we examine expression of K(D) channel subunits in Kv1-Kv3 families in immortalized gastric epithelial cells GES and various gastric cancer cells (including AGS, KATOIII, MKN28, MKN45, MGC803, SGC7901, SGC7901/ADR and SGC7901/VCR), and their roles in cell proliferation. RT-PCR analysis reveals that all cell lines examined express Kv1.3, Kv1.5, Kv1.6, Kv2.1 and Kv2.2. However, Kv1.2 and Kv3.2 genes are barely detectable in any given cancer cell lines. Kv1.5 protein, high mRNA levels in all cell lines examined, is also expressed in some cancer cells lines and more frequently detected in gastric cancer tissues. Downregulation of the expression of Kv1.5 in SGC7901 with RNA interference significantly inhibited the proliferation and tumorigenicity of SGC7901 cells. Moreover, in Ca(2+)-containing rather than Ca(2+)-free medium, KCl (50mM) stimulated a rapid increase in the concentration of cytosolic calcium in empty vector transfected cells that was blocked by verapamil. Likewise, decrease the expression of Kv1.5 with short interfering RNA also blocked the depolarization-induced influx of Ca(2+). This finding suggests that more than one kind of K(D) channel subunits are expressed in various gastric cancer cell lines. Kv1.5 may be involved in tumor cells proliferation by controlling Ca(2+) entry, and the interference of K(D) channels expression and/or activity could provide a novel strategy to reverse the malignant phenotype of gastric cancer cells.     

Pre-clinical evaluation of the activity of gemcitabine as a basis for regional chemotherapy of pancreatic and colorectal cancer.

AIMS: To estimate the potential activity of gemcitabine for hepatic arterial infusion (HAI) chemotherapy in pancreatic and colorectal cancer. METHODS: The anti-proliferative effects of gemcitabine were determined in MIA PaCa-2 and PMH2/89 pancreatic and HT29 and NMG64/84 colon cancer cell lines and in fresh tumours from patients with liver metastases of colon, rectal and pancreatic cancer in vitro using the human tumour colony forming assay. RESULTS: Gemcitabine showed concentration and time-dependent cytotoxic effects in all tested cell lines. The IC(50)of gemcitabine in MIA PaCa-2, PMH2/89, HT29 and NMG64/84 cells at 2 h exposure time were >100, 18, 100 and 2.5 microg/ml, respectively, at 4 h 15, 1.2, 45 and 0.5 microg/ml, respectively, and at 24 h 0.2, 0.1, 1.8 and 0.1 microg/ml, respectively. All tumours displayed concentration dependent inhibition of colony formation after exposure to gemcitabine for 2 h. The IC(50)values of gemcitabine in six of the 10 metastases were 相似文献   

Voltage-gated sodium ion channels in prostate cancer: expression and activity

BACKGROUND: High levels of voltage-gated sodium channels (VGSCs) have been previously associated with the invasiveness of rat and human prostate cancer (Pca) cell lines. MATERIALS AND METHODS: 4 normal prostate and 80 clinical Pca specimens on a tissue microarray slide were examined by immunohistochemistry using anti-sodium channel (III-IV linker region) antibody. The effects of a VGSC-opener and VGSC-blockers on the in vitro proliferation of 4 human Pca cell lines was examined. RESULTS: Fifty-five% (44 out of 80) Pca specimens showed higher VGSC levels compared to normal, with 14 (of 44) showing increased focal staining. VGSC-opener veratrine (1-50 microg/mL), increased growth of PC3, DU145, LNCaP and MDA-PCA-2B Pca cells. VGSC-blockers, flunarizine (IC50=2 microg/mL) and riluzole (IC50=10-30 microg/mL) caused dose-dependent growth-inhibition of all four cell lines. Western analysis of cell extracts showed VGSC-immunoreactivity in the 4 Pca cell lines. CONCLUSION: Our results indicate increased expression of VGSCs in Pca and VGSC involvement in Pca growth.     

Contribution of angiogenesis to the progression of colon cancer: possible inhibitory effect of angiogenesis inhibitor TNP-470 on tumor growth and hepatic metastasis

The contribution of angiogenesis to tumor growth and hepatic metastasis of colorectal cancer was investigated by means of immunohistochemical study and in vitro and in vivo experiments. Colorectal cancer specimens from 30 patients with hepatic metastasis and 39 patients without hepatic metastasis were studied by staining with antibodies against factor VIII-related antigen. Microvessel count in patients with liver metastasis was significantly higher than in those without liver metastasis (p<0.005). The effect of TNP-470 was evaluated with in vitro and in vivo experiments using human colon cancer cell line, LM and the highly hepatic metastasis cell line, LM-H5. The effect of TNP-470 on the proliferation of the cancer cells and human umbilical vein endothelial cells (HUVECs) was examined. TNP-470 inhibited more sensitively the proliferation of HUVECs than cancer cells in vitro. IC50 was approximately 3 pg/ml in HUVECs and approximately 2 microg/ml in cancer cells. The effect of TNP-470 on the growth of xenografts and liver metastases by LM-H5 in nude mice was examined. TNP-470 (30 mg/kg) was administered by subcutaneous injection every third day for 4 weeks. TNP-470 inhibited both the growth of xenograft and the hepatic metastasis. The number of metastatic foci in the liver was 78.2+/-30.1 in the control group and 20.6+/-16.5 in the treated group. These results suggest that TNP-470 is a potent agent to inhibit tumor growth and hepatic metastasis of colon cancer.     

Potentiation of the antiproliferative activity of MKT-077 by loperamide, diltiazem and tamoxifen

MKT-077, a delocalized lipophilic cation, selectively targets cancer cells. MKT-077 has been reported to inhibit the growth of several tumor types and has undergone phase I clinical testing. We have examined the effect of MKT-077, alone and in combination with the antidiarrheal drug loperamide. Ten human cancer cell lines, four prostate (PC3, DU145, LNCaP, MDA-PCA-2B), two breast (MCF-7 and MDA-MB-231) and four colon (LoVo, Colo320DM, SW1116 and LS174t) were tested in vitro. Cells were grown to confluency prior to treatment. Loperamide potentiated the antiproliferative effect of MKT-077 in all ten cell lines, in a dose-dependent manner. The sensitivity of MDA-PCA-2B cells, the two breast and four colon cancer cell lines to MKT-077 was relatively low (>2.5 microg/ml MKT-077 required to inhibit growth by 95%). In these cell lines, 0.5-5 microg/ml (1-10 microM) loperamide caused a marked increase in the response to MKT-077. Loperamide is known to activate micro-opioid receptors at nanomolar concentrations and block voltage-gated calcium channels at micromolar doses. We found that calcium channel-blockers diltiazem and nifedipine (10-20 microg/ml), as well as tamoxifen (1.5-2.5 microg/ml) can also potentiate the growth-inhibitory effects of MKT-077. These synergistic interactions could be exploited for therapeutic benefit.     

Growth-inhibitory activity of interferon-beta against human colorectal carcinoma cell lines

Recombinant human interferon beta (rIFN-beta) inhibited in a time- and dose-dependent manner the proliferation of 18/18 human colon carcinoma cell lines in monolayer culture and 8/9 lines in a soft agar assay but had no effect on 4 human fibroblast cell lines. Maximal inhibition of cell proliferation by rIFN-beta required repetitive treatment (every 2 days) with lymphokine (50 units/ml). Furthermore, the inhibitory activity of rIFN-beta was neutralized by polyclonal antibodies against natural IFN-beta. In contrast to rIFN-beta, rIFN-alpha was inactive against all colon cell lines tested, and rIFN-gamma, with the exception of HT-29 cells, was similarly ineffective. These data demonstrate that rIFN-beta is a potent growth inhibitor of colon carcinoma cells in vitro, and suggest that studies on its mechanism of action may lead to a better understanding of the regulation of colon tumor cell proliferation.     

Effect of recombinant monokines, lymphokines, and other agents on clonal proliferation of human lung cancer cell lines

The modulation of clonal growth of cells of 15 human lung cancer lines was examined by coculture with different recombinant lymphokines, monokines, and several agents which induce differentiation in other malignant cell systems. Recombinant human tumor necrosis factor alpha (TNF) was inhibitory to all non-small cell lung cancer cell lines with a 50% effective dose of clonal inhibition (ED50) in the range of 30-2000 units/ml. Two representative squamous lines (SK-MES and P3) had 150 to 250 high affinity (Kd approximately equal to pM) cell surface TNF receptors. In contrast, clonal growth of small cell lung cancer lines was not inhibited by TNF, and two representative lines (H69c and R592) expressed negligible cell surface TNF receptors. Recombinant alpha, beta, and gamma interferons (4000 units/ml) each inhibited greater than or equal to 30% clonal growth of more than 50% of the non-small cell lung cancer lines. TNF (100-1000 units/ml) in combination with gamma-interferon was synergistic in the inhibition of clonal growth of these cells. Further studies showed that synergism of clonal inhibition occurred even when the cells were initially exposed to gamma-interferon, washed, and plated in soft agar with TNF. All-trans-retinoic acid (ED50, 5 X 10(-7)-10(-6) M), dimethyl sulfoxide (ED50, 1.2-1.6%), and 12-O-tetradecanoylphorbol-13-acetate (ED50, 5 X 10(-8)-10(-10) M) inhibited clonal proliferation of 7 of 9, 7 of 9, and 8 of 9 non-small cell lung cancer lines, respectively. In contrast, clonal proliferation of cells of small cell lung cancer lines was decreased only slightly at almost all concentrations of each of the agents. Interleukin-1 and -2 and granulocyte-monocyte colony-stimulating factor had no effect on the clonal growth of any of the lung cancer lines. Our results suggest that TNF in combination with gamma-interferon may be therapeutically active for some patients with non-small cell lung cancer, but small cell lung cancer probably will be unresponsive to all the agents that we examined.     

瘦素和瘦素受体在结肠癌组织中的表达及瘦素对结肠癌细胞株HT-29增殖及凋亡的影响

探讨瘦素和瘦素受体在结肠癌组织中的表达及其与结肠癌临床病理特征的关系,及外源性瘦素对结肠癌细胞株HT-29细胞增殖、凋亡的影响。方法 采用流式细胞分析仪检测瘦素和瘦素受体在结肠癌组织中的表达情况;MTT法和流式细胞分析仪检测外源性瘦素对结肠癌细胞株HT-29细胞生长、凋亡及细胞周期的影响。结果 瘦素在结肠癌及正常肠黏膜组织中的阳性表达率分别为（80.30±1.83）%和（59.83±1.12）%,差异具有统计学意义（P<0.01）;瘦素受体在结肠癌及正常肠黏膜组织中的阳性表达率分别为（82.14±1.63）%和（65.21±1.45）%,差异具有统计学意义（P<0.05）。结肠癌组织中瘦素和瘦素受体的表达与结肠癌患者的性别、年龄、肿瘤分化程度、淋巴结、远处转移及临床分期无相关性（P＞0.05）。浓度为50、100和200 ng/ml的外源性瘦素可明显促进结肠癌细胞株HT-29细胞的增殖（P<0.05）,细胞在S期累积明显（P<0.05）,但对HT-29细胞的凋亡无明显影响（P＞0.05）。结论 瘦素和瘦素受体可能通过促进细胞增殖的方式在结肠癌发生过程中发挥重要作用。     

Non-invasive fluorescence imaging of cell death in fresh human colon epithelia treated with 5-Fluorouracil, CPT-11 and/or TRAIL

Apoptosis is instrumental in several physiological/pathophysiological processes and is a frequently used end-point in the development of anti-neoplastic compounds. Despite ample data on several colon cancer cell lines, little is known about the susceptibility of human colon to apoptosis following treatment with established chemotherapeutics. By treating fresh human colonic explants with 5-Fluorouracil (200 microg/ml), CPT-11 (100 microg/ml) and/or TRAIL (100 ng/ml) we readily detected a signal in situ using FITC-VAD-FMK at different time points, whereas labeling of colonic explants with EGFP-conjugated Annexin V proved less specific. Although TRAIL treatment alone appeared to cause little apoptosis in human colonic epithelia versus the control, we observed a greater number of cells undergoing apoptosis when a combination of CPT-11 and TRAIL was used as compared to either agent alone. This is the initial demonstration of TRAIL-induced apoptosis with or without a chemotherapeutic agent in fresh primary human colon epithelia explants. Thus, human colonic explants may provide a valuable reference point when candidate therapeutic compounds triggering apoptosis in colon cancer cell lines, xenografts or mouse models are developed. The results support the feasibility of developing non-invasive optical imaging strategies to detect apoptosis through direct visualization of injury to human colonic epithelia in vivo.     

Ganoderma lucidum causes apoptosis in leukemia, lymphoma and multiple myeloma cells

Over many centuries, herbal remedies have treated a variety of ailments. This empiric observational approach has produced a number of leads for formulated medicines. Ganoderma lucidum extract was screened for its anti-proliferative activity using a panel of 26 human cancer cell lines. The six most sensitive hematologic cell lines were: HL-60 (ED50 26 microg/ml), U937 (63 microg/ml), K562 (50 microg/ml), Blin-1 (38 microg/ml), Nalm-6 (30 microg/ml) and RPMI8226 (40 microg/ml). Cell cycle analyses revealed a G2/M arrest, most prominently in HL-60 cells. Four hematopoietic cell lines (HL-60, Blin-1, U937, RPMI8226) were examined for apoptosis, which ranged between 21 and 92%. After exposure to G. lucidum extract, HL-60 cells became multinucleated with an increased DNA content. These results indicate that G. lucidum extract has a profound activity against leukemia, lymphoma and multiple myeloma cells and may be a novel adjunctive therapy for the treatment of hematologic malignancies.     

Antitumor effect of nutrient synergy on human osteosarcoma cells U-2OS, MNNG-HOS and Ewing's sarcoma SK-ES.1

Current treatment of osteosarcoma is associated with poor prognosis, especially due to the increased risk of developing other cancers with chemotherapy. Therefore, new, safe and effective treatment strategies are needed. We investigated the effect of a unique mixture of nutrients containing lysine, proline, arginine, ascorbic acid, and epigallocatechin gallate (EGCG) on human osteosarcoma cell lines U-2OS, MNNG-HOS, and Ewing's sarcoma SK-ES-1 by measuring: cell proliferation, expression of matrix metalloproteinase-2 (MMP-2), MMP-9, and invasive and angiogenesis potential. Cell proliferation was evaluated by MTT assay, matrix metalloproteinases (MMP) expression by gelatinase zymography, VEGF expression by ELISA, and invasion through Matrigel. Cells were also treated with phorbol 12-myristate 13-acetate (PMA) to study enhanced MMP and VEGF expression. The invasion of osteosarcoma U-2OS and MNNG-HOS cells through Matrigel was significantly reduced in a dose-dependent fashion, with 100% inhibition of invasion of U-2OS cells at 100 microg/ml, and MNNG cells at 50 microg/ml concentration of the synergistically acting nutrient mixture. Ewing's sarcoma SK-ES-1 cells were not invasive. Nutrient synergy (NS) exhibited a dose response antiproliferative effect on osteosarcoma U-2OS cells, reaching 67% at 1000 microg/ml of NS; no significant suppression of cell proliferation was seen with MNNG or Ewing's sarcoma cells. Zymography showed dose-dependent inhibition of MMP secretion by all three cell lines in the presence of NS. VEGF secretion by U-2OS cells was completely blocked at 500 microg/ml of NS. Our results suggest NS is an excellent candidate for therapeutic use in the treatment of osteosarcoma, by inhibiting cancer cell invasion, and secretion of MMPs and VEGF, all critical parameters for cancer control and prevention.     

Anticancer effects of amooranin in human colon carcinoma cell line in vitro and in nude mice xenografts

Amooranin (AMR), a natural triterpenoid drug isolated and characterized from Amoora rohituka stem bark, is cytotoxic to SW620 human colon carcinoma cell line with an IC(50) value of 2.9 microg/ml. This novel compound caused depolarization of mitochondrial membrane and decrease of membrane potential, indicating initial signal of apoptosis induction. The percentage of cells with decreased mitochondrial potential ranged from 7.4% at 1 microg/ml to 60.5% at 100 microg/ml AMR. Flow cytometric analysis of apoptosis using Annexin-V-FITC staining showed that the percentage of apoptotic cells ranged from 7.5% at 1 microg/ml to 59.2% at 100 microg/ml AMR. AMR-induced apoptosis was accompanied by redistribution of cytochrome c from mitochondria to cytosol as well as down regulation of Bcl-2 and Bcl-X(L) proteins in a dose-dependent manner. SW620 human colon carcinoma xenograft mice treated with AMR showed significant reduction in tumor growth rates compared to saline- and doxorubicin-treated groups. The reduction in tumor growth rate was better in xenografts treated with 2 mg/kg AMR than 5 and 10 mg/kg treated mice. The analysis of global gene expression changes induced by AMR in xenograft tumors by microarray hybridization revealed that several genes involved in energy pathways, transport, apoptosis, immune response, nucleic acid metabolism, protein metabolism, cell growth and/or maintenance, signal transduction and cell communication, were affected by this natural cancer drug. These results suggest that the anticancer properties of AMR in SW620 human colon carcinoma cell line are mediated through its effects on functional genomics, targeting the apoptotic process.     

Human colon cancer cells surviving high doses of cisplatin or oxaliplatin in vitro are not defective in DNA mismatch repair proteins

PURPOSE: Alterations in the DNA mismatch repair (MMR) proteins have been associated with an increased resistance of many cancer cell lines to cisplatin. The aim of this work was to investigate whether defects in DNA MMR proteins are involved in the survival of human colorectal cancer cells in the presence of high concentrations of cisplatin and oxaliplatin, a diaminocyclohexane (DACH) platinum compound whose adducts are not recognized by the MMR system. METHODS: Six unselected human colon cancer cell lines (HT29, HCT15, HCT116, Caco2, SW480 and SW620) were treated with a single 3-h exposure to cisplatin or oxaliplatin at suprapharmacological concentrations, ranging from 50 to 200 microg/ml. The microsatellite stability and the expression of MMR proteins in the parental cell lines and in the drug-selected subpopulations were studied. RESULTS: Most cells underwent apoptosis in the days following the cisplatin or oxaliplatin treatment, but some colonies expanded 3 to 4 weeks after, suggesting the presence of innately resistant cells in the six parental cell lines. Microsatellite instability (MIN), which reflects genetic defects in the DNA MMR system, was detected only in the HCT116 parental cell line and its drug-selected counterparts, due to a known mutation in the hMLH1 gene. No acquired MIN was observed in the other cisplatin-selected sublines derived from the HT29, HCT15, Caco2, SW480 or SW620 parental cells. In the same way, Western blot analysis showed that expression of the DNA MMR proteins hMLH1, hPMS1, hPMS2, hMSH2 and hMSH6 did not differ between the parental and the drug-surviving cells. CONCLUSIONS: These results indicate that high-level resistance of human colon cancer cells to high doses of cisplatin and oxaliplatin does not seem to be related to acquired defects in the DNA MMR proteins.     

PC-SPES inhibits colon cancer growth in vitro and in vivo

PC-SPES is a mixture of eight herbs with antiproliferative activity in prostate cancer cell lines and antitumor effects in animal models of prostate cancer. In addition, evidence of clinical efficacy in advanced prostate cancer has been reported. PC-SPES has also been shown to have antitumor activity against several other cancer cell lines including breast and neuroepithelial cancer, melanoma, and leukemia cell lines. Because of these findings, we investigated the effects of PC-SPES in vitro in colon cancer cell lines SW480, SW620, and DLD-1 and in vivo in the Apc(min) mouse, a murine model for intestinal carcinogenesis. For the in vitro studies, colon cancer cell lines were exposed to an ethanolic extract of PC-SPES compared with a diluent control [ethanol < or = 0.3% (v/v)]. PC-SPES resulted in a marked suppression of cell proliferation in all colon cancer cells studied. PC-SPES (3 micro l/ml) caused a 95% inhibition of cell proliferation of the DLD-1 colon cancer cell line, and similar results were observed in the SW480 and SW620 colon cancer cell lines. Cell cycle analysis demonstrated a drastic (> or =60%) accumulation of cells in the G(2)-M phase with a concomitant decrease of cells in the G(0)-G(1) phase in all colon cancer cell lines studied after treatment with PC-SPES (1.5 micro l/ml for 48 h). Western blot analysis demonstrated a decrease in protein levels of beta-tubulin in the SW620 cell line exposed to PC-SPES. Terminal deoxynucleotidyl transferase-mediated nick end labeling analysis revealed an increase in apoptotic colon cancer cells incubated with PC-SPES. For the in vivo studies, female 4-5-week-old Apc(min) mice were randomized to two groups: a PC-SPES-treated group (n = 11) received 250 mg/kg/day (0.2 ml) PC-SPES via gastrointestinal gavage; and a control group (n = 10) received 0.2 ml of the vehicle solution (1.5% carboxymethylcellulose with 0.2% Tween 20) via gastrointestinal gavage. Both groups were treated five times a week for 10 weeks. After treatment, the gastrointestinal tract was dissected for polyp scoring by two observers blinded to treatment. The Apc(min) mice given PC-SPES had a 58% reduction in tumor number and a 56% decrease in tumor load. No effect on either food intake or body weight was observed in the treated versus sham groups. The present study is the first to report the potent activity of PC-SPES against colon cancer. Both cell cycle arrest and apoptosis occurred after treatment with PC-SPES. This suggests that the components of this herbal mixture, either independently or in combination, acted in colon cancer, resulting in a drastic effect on tumor initiation and tumor progression.     

Antiproliferative effect of polyphenols and sterols of virgin argan oil on human prostate cancer cell lines

BACKGROUND: The aim of our study has to evaluate the antiproliferative effect of polyphenols and sterols extracted from the virgin argan oil on three human prostatic cell lines (DU145, LNCaP, and PC3). METHODS: Cytotoxicity, anti-proliferative effects and nuclear morphological changes of cells were analyzed after treatment with sterols and polyphenols. The results were compared to 2-methoxyestradiol (2ME(2)) as positive control. RESULTS: Polyphenols and sterols of virgin argan oil and 2ME(2) exhibited a dose-response cytotoxic effect and antiproliferative action on the three tested cell lines. The antiproliferative effect of polyphenols was similar for the DU145 and LNCaP cell lines; the GI(50) (defined as the concentration inhibiting growth by 50% in comparison with the control) was respectively 73 and 70microg/ml. The antiproliferative effect of sterols was 46 and 60microg/ml as GI(50) for the DU145 and LNCaP cell lines. For the PC3 cell line, the best antiproliferative effect was obtained by argan sterols with GI(50)=43microg/ml. On the other hand, the nuclear morphology analyses have shown an increased proportion of pro-apoptotic of nuclei in LNCaP cell treated with IC(50) of polyphenols or sterols compared to control cells. Our results show for the first time the antiproliferative and pro-apoptotic effects of polyphenols and sterols extracted from virgin argan oil and confirm the antiproliferative and pro-apoptotic effects of 2ME(2) on prostate cancer cell lines. CONCLUSION: These data suggest that argan oil may be interesting in the development of new strategies for prostate cancer prevention.     

Anticancer and antiinflammatory activities of cucurbitacins from Cucurbita andreana

Bioassay-guided purification of an extract of Cucurbita andreana fruits yielded cucurbitacins B (1), D (2), E (3), and I (4). These cucurbitacins were evaluated for their inhibitory effects on the growth of human colon (HCT-116), breast (MCF-7), lung (NCI-H460), and central nervous system (CNS) (SF-268) cancer cell lines, cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) enzymes and on lipid peroxidation. Inhibitory activities of cucurbitacins B (1), D (2), E (3) and I (4), respectively, were for colon 81.5, 80.4, 77, and 65% at 0.4 microM, breast 87, 78, 66.5, and 12% at 0.4 microM, lung 96, 43, 37 and 2% at 0.1 microM and CNS 92, 25, 24 and 4% at 0.05 microM. Adriamycin (doxorubicin) was used as a positive control, which showed 64, 47, 45 and 71% inhibition of HCT-116 (colon), MCF-7 (breast), NCI-H460 (lung) and SF-268 (CNS) cell lines, respectively, at 0.3 x 10(-5) M. Compounds 1, 2, 3, and 4 inhibited the COX-2 enzyme by 32, 29, 35, and 27%, respectively, at 100 microg/ml. However these compounds did not inhibit the COX-1 enzyme at this concentration. Ibuprofen, naproxen and vioxx, commercial antiinflammatory drugs, were tested as controls for the inhibition of COX-1 and COX-2 enzymes at concentrations of 2.1, 2.5 and 1.67 microg/ml, respectively. Ibuprofen and naproxen exhibited 59 and 95% COX-1, and 53 and 79% COX-2 inhibitory activities, respectively. Vioxx showed specific COX-2 inhibition by 71%. Also, cucurbitacins 1 and 4 inhibited lipid peroxidation by 59 and 23%, respectively, at 100 microg/ml.