Showing papers in "Anticancer Research in 2006"

The association of solar ultraviolet B (UVB) with reducing risk of cancer: multifactorial ecologic analysis of geographic variation in age-adjusted cancer mortality rates.

Abstract: Background: Solar ultraviolet B (UVB) irradiance and vitamin D are associated with reduced cancer mortality rates. However, the previous ecologic study of UVB and cancer mortality rates in the U.S. (Grant, 2002) did not include other risk factors in the analysis. Materials and Methods: An ecologic study was performed using age-adjusted annual mortality rates for Caucasian Americans for 1950-69 and 1970-94, along with state-averaged values for selected years for alcohol consumption, Hispanic heritage, lung cancer (as a proxy for smoking), poverty, degree of urbanization and UVB in multiple regression analyses. Results: Models were developed that explained much of the variance in cancer mortality rates, with stronger correlations for the earlier period. Fifteen types of cancer were inversely-associated with UVB. In the earlier period, most of the associations of cancer death rates with alcohol consumption (nine), Hispanic heritage (six), the proxy for smoking (ten), urban residence (seven) and poverty (inverse for eight) agreed well with the literature. Conclusion: These results provide additional support for the hypothesis that solar UVB, through photosynthesis of vitamin D, is inversely- associated with cancer mortality rates, and that various other cancer risk-modifying factors do not detract from this link. It is thought that sun avoidance practices after 1980, along with improved cancer treatment, led to reduced associations in the latter period. The results regarding solar UVB should be studied further with additional observational and intervention studies of vitamin D indices and cancer incidence, mortality and survival rates. There is an increasing awareness that deficiency of vitamin D is associated with an increased risk of internal cancer. UVB and/or vitamin D have been identified as a risk

Anticancer potential of silymarin: from bench to bed side.

Abstract: Silymarin consists of a family of flavonoids (silybin, isosilybin, silychristin, silydianin and taxifoline) commonly found in the dried fruit of the milk thistle plant Silybum marianum. Although silymarin's role as an antioxidant and hepatoprotective agent is well known, its role as an anticancer agent has begun to emerge. Extensive research within the last decade has shown that silymarin can suppress the proliferation of a variety of tumor cells (e.g., prostate, breast, ovary, colon, lung, bladder); this is accomplished through cell cycle arrest at the G1/S-phase, induction of cyclin-dependent kinase inhibitors (such as p15, p21 and p27), down-regulation of anti-apoptotic gene products (e.g., Bcl-2 and Bcl-xL), inhibition of cell-survival kinases (AKT, PKC and MAPK) and inhibition of inflammatory transcription factors (e.g., NF-kappaB). Silymarin can also down-regulate gene products involved in the proliferation of tumor cells (cyclin D1, EGFR, COX-2, TGF-beta, IGF-IR), invasion (MMP-9), angiogenesis (VEGF) and metastasis (adhesion molecules). The antiinflammatory effects of silymarin are mediated through suppression of NF-kappaB-regulated gene products, including COX-2, LOX, inducible iNOS, TNF and IL-1. Numerous studies have indicated that silymarin is a chemopreventive agent in vivo against a variety of carcinogens/tumor promoters, including UV light, 7,12-dimethylbenz(a)anthracene (DMBA), phorbol 12-myristate 13-acetate (PMA) and others. Silymarin has also been shown to sensitize tumors to chemotherapeutic agents through down-regulation of the MDR protein and other mechanisms. It binds to both estrogen and androgen receptors, and down-regulates PSA. In addition to its chemopreventive effects, silymarin exhibits antitumor activity against human tumors (e.g., prostate and ovary) in rodents. Various clinical trials have indicated that silymarin is bioavailable and pharmacologically safe. Studies are now in progress to demonstrate the clinical efficacy of silymarin against various cancers.

Expressions of MMP-2, MMP-9 and VEGF are closely linked to growth, invasion, metastasis and angiogenesis of gastric carcinoma

Abstract: Background: Gastric carcinoma is still a major leading cause of cancer death in East Asia. Since angiogenesis is a necessary condition for invasion and metastasis, its regulation is of essential significance. Materials and Methods: Expressions of MMP-2, MMP-9 and VEGF were examined with microarray of gastric carcinoma tissue samples (n=249) by immunostaining. In addition, microvessel density (MVD) was assessed after labelling with the anti-CD34 antibody. Data were cross-compared with clinicopathological parameters of tumors, including PTEN expression. Results: Expressions of MMP-2, MMP-9 and VEGF were positively correlated with tumour size, depth of invasion, lymphatic and venous invasion, lymph node metastasis, UICC staging and MVD of gastric carcinomas (p<0.05). VEGF expression was positively linked with levels of MMP-2 and MMP-9 (p<0.05), but negatively with PTEN (p<0.05). The latter was also inversely associated with the MVD in gastric carcinomas (p<0.05). Conclusion: MMP-2, MMP-9 and VEGF largely contribute to the angiogenesis and progression of gastric carcinomas. PTEN might inhibit the processes by down- regulating VEGF expression. These parameters should be regarded as good markers to indicate pathobiological behaviours of gastric carcinomas. Like most solid tumors, gastric carcinomas require neovascularisation, if they are to grow beyond a few millimeters in diameter. The new vessels not only help to meet the growing metabolic demands of the tumor by supplying additional nutrients, but also provide potential routes for tumor dissemination and metastasis. As the gastric carcinoma continues to develop, so does angiogenesis, since tumor- stroma interaction enhances neovascluarisation through angiogenic factors, such as matrix metalloproteinases (MMPs) and vascular epithelial growth factor (VEGF). When chronic exposure to these angiogenic factors either supports proteolysis of the basement membrane or antagonizes endothelial-pericyte functions, the network of vessels will become highly permeable, facilitating extravasation and ultimately metastasis of the tumour cells (1, 2).

Curcumin-induced Apoptosis of Human Colon Cancer Colo 205 Cells through the Production of ROS, Ca2+ and the Activation of Caspase-3

Abstract: Curcumin (diferuloylmethane), the yellow pigment in turmeric (Curcuma longa), is known to inhibit proliferation of cancer cells by arresting them at various phases of the cell cycle and to induce apoptosis in tumor cells. Curcumin-induced apoptosis mainly involves the activation of caspase-3 and mitochondria-mediated pathway in various cancer cells of different tissue origin. In the present study, the induction of apoptosis and cytotoxicity by curcumin in colon cancer colo 205 cells was investigated by using flow cytometry. The results demonstrated that curcumin induced cytotoxicity and apoptosis dose- and time-depedently. Curcumin induced the production of reactive oxygen species (ROS) and Ca+2, decreased the levels of mitochondria membrane potential and induced caspase-3 activity. Curcumin also promoted the expression of Bax, cytochrome C, p53 and p21 but inhibited the expression of Bcl-2. These observations suggest that curcumin may have a possible therapeutic potential in colon cancer patients.

Antioxidant and apoptosis-inducing activities of ellagic acid.

Abstract: Background: Antioxidant, antiproliferative and apoptosis inducing activities of a natural polyphenolic compound, ellagic acid, were studied. Materials and Methods: DPPH radical scavenging and lipid peroxidation inhibitory activities were observed. Activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) were measured in ellagic acid-treated V79- 4 cells. For apoptotic inducing activity, human osteogenic sarcoma (HOS) cell proliferation, chromosomal DNA degradation and changes in apoptosis-related protein levels were measured. Results: Ellagic acid showed high DPPH radical scavenging and lipid peroxidation inhibition activities. SOD, CAT and GPX activities were significantly increased in ellagic acid-treated V79-4 cells. Ellagic acid significantly reduced HOS cell proliferation, and induced apoptosis evidenced by chromosomal DNA degradation and apoptotic body appearance. Bax expression was induced and caspase-3 was activated by ellagic acid treatment. Conclusion: Ellagic acid exhibited both antioxidant activity in V79-4 cells and apoptosis-inducing activity in HOS cells through the up- regulation of Bax and activation of caspase-3. Green tea has been the most highly consumed beverage, along with water, for many centuries in Asian countries. Since the beneficial effects of green tea are known, many studies have focused on the identification of the

Antitumor effect of cordycepin (3'-deoxyadenosine) on mouse melanoma and lung carcinoma cells involves adenosine A3 receptor stimulation.

Abstract: An attempt was made to elucidate the molecular targetfor the antitumor effects of cordycepin (3'-deoxyadenosine) using non-selective and selective adenosine A1, A2a, A2b and A3 receptor agonists and antagonists. Although adenosine and 2'-deoxyadenosine (up to 100 microM) had no effect, cordycepin showed remarkable inhibitory effects on the growth curves of B16-BL6 mouse melanoma (IC50= 39 microM) and mouse Lewis lung carcinoma (IC50 = 48 microM) cell lines in vitro. Among the adenosine receptor agonists and antagonists used (up to 100 microM), only 2-chloro-N6-(3-iodobenzyl)-adenosine-5'-N-methyluronamide (Cl-IB-MECA), a selective adenosine A3 receptor agonist, notably inhibited the growth of both mouse tumor cell lines (B16-BL6; IC50 = 5 microM, LLC; 14 microM). In addition, the tumor growth inhibitory effect of cordycepin was antagonized by 3-ethyl 5-benzyl 2-methyl-6-phenyl-4-phenylethynyl-1,4-(+/-)-dihydropyridine-3,5-dicarboxylate (MRS1191), a selective adenosine A3 receptor antagonist. These results suggest that cordycepin exerts inhibitory effects on the growth of mouse melanoma and lung carcinoma cells by stimulating adenosine A3 receptors on tumor cells.

Inhibition of pancreatic and lung adenocarcinoma cell survival by curcumin is associated with increased apoptosis, down-regulation of COX-2 and EGFR and inhibition of Erk1/2 activity.

Abstract: Background: Several studies suggested that curcumin inhibits growth of malignant cells via inhibition of cyclooxygenase-2 (COX-2) activity. Other studies indicated that epidermal growth factor receptor (EGFR) is also inhibited by curcumin in vitro and in vivo. Moreover, recent investigations revealed an intracellular cross-talk between EGFR signaling and the COX-2 pathway. Our aim was to evaluate whether the curcumin inhibitory effect on the survival of cancer cells is associated with simultaneous down-regulation of COX-2 and EGFR and inhibition of Erk1/2 (extra-cellular signal regulated kinase) signaling pathway. Materials and Methods: Lung and pancreas adenocarcinoma cell lines co-expressing COX-2 and EGFR (PC-14 and p34, respectively) and those expressing EGFR but deficient in COX-2 (H1299 and Panc-1, respectively) were exposed for 72 h to curcumin (0-50 IM). Cell viability was assessed by the XTT assay. Apoptosis was determined by FACS analysis. COX-2, EGFR, ErbB-2 and p-Erk1/2 expressions were measured by Western blot analysis. Results: Curcumin's inhibitory effect on survival and apoptosis of lung and pancreatic adenocarcinoma cell lines was significantly higher in the COX-2-expressing cells than in the COX-2-deficient cells. In the p34 and PC-14 cells, curcumin decreased COX-2, EGFR and p-Erk1/2 expressions in a dose- dependent manner. However, in the Panc-1 and H1299 cell lines, which did not express COX-2, curcumin did not affect EGFR levels. Conclusion: Curcumin co-inhibited COX-2 and EGFR expression and decreased Erk1/2 activity. This inhibition was associated with decreased survival and enhanced induction of apoptosis in lung and pancreatic adenocarcinoma cells. Cyclooxygenase-2 (COX-2) has been shown to be one of the key factors in carcinogenesis. COX-2 mRNA and protein levels are up-regulated in transformed cells (1, 2), as well as in both pre-malignant and malignant tissues, including

The antiproliferative effect of Quercetin in cancer cells is mediated via inhibition of the PI3K-Akt/PKB pathway.

Abstract: BACKGROUND The tumor suppressor gene PTEN, mutated in 40-50% of patients with brain tumors, especially those with glioblastomas, maps to chromosome 10q23.3 and encodes a dual-specificity phosphatase. PTEN exerts its effects partly via inhibition of protein tyrosine kinase B (Akt/Protein Kinase B), which is involved in the phosphatidylinositol (PtdIns) 3-kinase (PI3K)-mediated cell-survival pathway. The naturally occurring bioflavonoid Quercetin (Qu) shares structural homology with the commercially available selective PI3K inhibitor, LY 294002 (LY). Here, the effects of Qu on the Akt/PKB pathway were evaluated. MATERIALS AND METHODS The human breast carcinoma cell lines, HCC1937, with homozygous deletion of the PTEN gene, and T47D, with intact PTEN, were time-treated with Qu or LY and analyzed for activated levels of Akt by measuring phospho-Akt (p-Akt) levels using immunoblotting analysis. To detect p-Akt, the T47D cells were treated with EGF prior to treatment with or without Qu or LY Cell proliferation after 24-h treatment with Qu or LY was quantified by the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. RESULTS Treatment with Qu (25 microM) for 0.5, 1 and 3 h completely suppressed constitutively activated Akt/PKB phosphorylation at Ser-473 in HCC1937 cells. Pre-exposing T47D cells to Qu (25 microM) or LY (10 microM) abrogated EGF-induced Akt/PKB phosphorylation at Ser-473. Both Qu (100 microM) and LY (50 microM) treatments for 24 h significantly decreased cell proliferation, as shown by the MTT assay. CONCLUSION Pharmacologically safe doses of the naturally occurring bioflavonoid Qu inhibit the PI3K-Akt/PKB pathway, in a manner similar to that of the commercially available LY. Overall, our results indicated that Qu inhibited the constitutively activated-Akt/PKB pathway in PTEN-null cancer cells, and suggest that this compound may have therapeutic benefit against tumorigenesis and cancer progression.

Aberrant crypt foci.

Abstract: Colon cancer evolves through epithelial cell deregulation and inappropriate proliferation. These histopathological characteristics are exemplified in the biochemical, immunohistochemical, genetic and epigenetic elements detected within colonic mucosa. Early detection is paramount for the prevention of colon cancer deaths. Aberrant crypt foci (ACF) are thought to be the earliest identifiable neoplastic lesions in the colon carcinogenetic model. The progression of ACF to polyp and, subsequently, to cancer parallels the accumulation of several biochemical alterations and mutations whereby a small fraction of ACF evolve to colon cancer. Recent data indicate that, not uncommonly, some ACF bypass the polyp stage in their carcinogenesis thus reinforcing the importance of their early detection and our understanding of their pathogenesis. Since ACF were first detected in carcinogen-treated mice, research efforts have focused on these microscopically visible lesions both in animal and human models. ACF show variable histological features, characterized by Kudo (20) and, therefore, can be grouped into differing categories by in vivo examination with high-magnification-chromoscopic-colonoscopy (HMCC). As expected, ACF are more frequently detected in distal animal and human colons coinciding with the geographic distribution of colorectal cancer (CRC). Various proteomic (Prot) markers may be altered within ACF suggesting possible prospective pathological changes. These markers include Calreticulin, Transgelin, Serotransferrin, Triphosphate isomerase and Carbonic anhydrase II. Other markers of importance include carcinoembryonic antigen (CEA), B-catenin, placental cadherin (P-cadherin), epithelial cadherin (E-cadherin), inducible nitric oxide synthase (iNOS), cyclooxygenase (COX-2) and P16INK4a. Genetic mutations of K-ras, B-Raf APC and p53 have been demonstrated in ACF as well as the epigenetic alterations of CpG island methylation. Genomic instabilities (GI), illustrated by a higher GI Index (GII), microsatellite instability (MSI), loss of heterozygosity (LOH) and defects in mismatch repair (MMR) systems, are also expressed. These transformations may lead to the identification of the earliest pathological features initiating colon tumorigenesis. In this review, the advances in ACF research as precursors of CRCs are highlighted.

Effect of 2-Deoxy-D-glucose on Various Malignant Cell Lines In Vitro

Abstract: Background: 2-Deoxy-D-glucose (2-DG) is an analog of glucose that is preferentially captured by tumors and is accumulated in transformed cells, because the phosphorylated molecule (2-DG-6P) cannot be metabolized or diffused outside the cells. Targeted with a fluorine atom, 18F-DG is currently used to visualize malignant tumors (PET scan). Although cancer cells have been reported to be strongly dependent on glycolysis (Warburg effect), very few reports have studied the inhibitory effects of 2-DG on cancer. Materials and Methods: Our objective was to study, in a large panel of human malignant cells of various origins (ovarian, squamous, cerebral, hepatic, colonic and mesothelial), if the inhibitory activity of 2DG against tumor growth could be considered a general phenomenon and to determine its effect on the cell cycle. Results: Four types of response in the different cell lines were observed when cells were cultured in the presence of 2-DG (5 mM) continuous exposure: proliferation slow down; proliferation arrest without signs of apoptosis; strong cell cycle arrest accompanied by moderate apoptosis induction; massive apoptosis. Conclusion: 2-DG appears as an interesting new therapeutic agent against cancer in vitro, and should be tested in in vivo studies.

Treatment of Advanced Gastric Cancer by Chemotherapy Combined with Autologous Cytokine-induced Killer Cells

Abstract: The effects of autologous cytokine-induced killer (CIK) (CD3+CD56+) cells together with chemotherapy were investigated in patients who suffered from advanced gastric cancers (stage IV). Fifty-seven patients were divided into two groups: chemotherapy plus CIK biotherapy and chemotherapy alone. CIK cells were induced from autologous peripheral blood mononuclear cells in vitro and separated by flow cytometry and then transfused into the patients. The T-lymphocyte subgroups (CD3+, CD4+ or CD8+), CIK cells and NK cells (CD3-CD56+) were separated and determined by flow cytometry and the serum levels of MG7-Ag, CA72-4, CA19-9 and CEA were determined by ELISA or ECLIA. It was demonstrated that the cytotoxic activity of CIK cells reached a maximum between days 14 to 21 (68.7+/-10.9% and 65.3+/-10.4%, respectively). The amounts of CIK cells were gradually increased from day 0 to day 21 and slightly decreased in the further incubations. Thereafter, the CIK cells on days 14 to 21 (with the highest population of CIK cells) transfused back to the patients. The serum levels of the tumor markers were significantly decreased, the host immune function was increased and the short-term curative effect as well as the quality of life (QOL) were improved in the patients treated by chemotherapy plus CIK cells compared to the patients treated by chemotherapy alone. Moreover, the 2-year life-span was prolonged in the group treated by chemotherapy plus CIK cells compared to the group treated with chemotherapy alone. It is concluded that chemotherapy plus CIK cells has obvious benefits for patients who suffer from advanced gastric cancers.

Curcumin Inhibits Cell Migration of Human Colon Cancer Colo 205 Cells through the Inhibition of Nuclear Factor kappa B /p65 and Down-regulates Cyclooxygenase-2 and Matrix Metalloproteinase-2 Expressions

Abstract: Curcumin (diferuloylmethane) is a chemical derived from several Curcuma species (turmeric), possessing anti-inflammatory and antioxidant properties and which, thus, may be a potential anticancer drug. However, its mechanism of action is not fully understood. Our previous studies had shown that curcumin induced cytotoxicity, cell cycle arrest and apoptosis in human colon cancer colo 205 cells. In this study, curcumin affected the levels of NF-kappaB/ p65 in a time-dependent manner but did not affect NF-kappaB/ p50, based on Western blotting methods. In vitro experiments revealed that curcumin inhibited Cox-2 levels, but promoted those of Cox-1 in colo 205 cells. Curcumin also inhibited MMP-2 levels and promoted MMP-9 levels, but did not affect MMP-7 levels, based on Western blotting assays. These effects were also confirmed by cDNA microarray. Remarkably, curcumin not only exerted its effect on the protein levels of NF-kappaB, Cox-1 and -2, MMP-2 and -7, but also directly inhibited their mRNA levels. Curcumin was also found to significantly repress the in vitro invasion of colo 205 cells.

Trans-arterial chemoembolization (TACE) of liver metastases from colorectal cancer using irinotecan-eluting beads: preliminary results.

Abstract: Purpose: The purpose of the study was to evalutate the feasibility of irinotecan drug-eluting beads (DC Beadi) administered as trans-arterial chemoembolization (TACE) in patients with liver metastases from colorectal cancer (CRC). Patients and Methods: Ten patients with liver metastases from CRC were treated with TACE adopting irinotecan-eluting beads at a dose of 100 mg every 3 weeks. Computed Tomography (CT) was performed 24h before and after TACE. Results: TACE with irinotecan eluting beads was found to be feasible and well- tolerated. Right upper quadrant pain (RUQP) lasting 4 days (range 2-7) was reported by all the patients. After 30 days, a reduction >50% of CEA levels and of the lesional contrast enhancement was observed in all the patients. Conclusion: Irinotecan drug-eluting beads administered as TACE were shown to be active and safe in patients with liver metastases from CRC. Patients with liver metastases from CRC have a poor prognosis with 1- and 3-year survival rates of 31% and 2.6%, respectively (1-3). Surgery is feasible in only a minority of patients and most patients are treated with systemic chemotherapy. Irinotecan is an active drug in the first- and second-line treatment of advanced colorectal cancer (4). The advantage of delivering chemotherapy by hepatic arterial infusion is the administration of a high-dose of the drug in the target tissue (5-6). The intra- arterial infusion of irinotecan showed to be safe and feasible as reported in phase I and II studies (6-8). TACE is a combination of local drug infusion with selective embolization of the feeding arteries of the tumor. The use of irinotecan drug-eluting beads seems to optimize this method. The objectives of this study were to determine the safety, feasibility, tolerance of and response to TACE using irinotecan loaded DC Beadi (Biocompatibles UK Ltd) for the treatment of unresectable metastasis to the liver in patients with CRC. Patients and Methods Patients. All patients had histologically confirmed colorectal carcinoma with unresectable liver metastases comprising less than 70% of the liver parenchyma and with no evidence of extrahepatic disease. To be eligible, patients were required to have disease measurable by CT, normal metabolic and laboratory conditions, a Karnofsky performance status of 60% or greater and the absence of infection or ascites. Exclusion criteria included a history of inflammatory bowel disease or extensive intestinal resection, central nervous system involvement, uncontrolled infection, and a history of other cancer except adequately treated in situ carcinoma of the cervix or basal or squamous carcinoma of the skin. Prior treatment with systemic chemotherapy was required. All the patients submitted written informed consents. CT was used to determine the extent of liver involvement and to assess the responses.

Development of rational in vitro models for drug resistance in breast cancer and modulation of MDR by selected compounds.

Abstract: Backgroud: The effectiveness of chemotherapy is limited by the emergence of multidrug resistance (MDR). MDR is caused by the activity of various ATP binding cassette (ABC) transporters that pump anticancer drugs out of the cells in an ATP-dependent manner. Additionally some other cellular mechanisms of MDR have been reported. The purpose of this study was to investigate mechanisms of MDR in drug resistant MCF-7 cell lines and to modulate P-glycoprotein (P-gp) and MRP1-based MDR. Materials and Methods: Paclitaxel (MCF- 7/Pac), docetaxel (MCF-7/Doc), doxorubicin (MCF-7/Dox) and vincristine (MCF-7/Vinc) resistant sublines were developed from the parent MCF-7 cell line (MCF-7/S) by stepwise selection in dose increments over two years. Flow cytometry, MTT cytotoxicity assay, RT-PCR, caspase-3 activity assay and checkerboard combination assay were performed to investigate the degree of resistance developed in sublines and to reverse drug resistance phenotype. Results: The flow cytometry histograms of drug accumulation assays demonstrated that the drug-resistant cell lines are P-gp and MRP1 positive. RT-PCR results showed that the resistant sublines express both MDR1 and MRP1 genes. Resistance indices of each subline to each anticancer drug were determined using the MTT cytotoxicity assay and it was found that all the sublines were resistant to their respective agents. Caspase-3 activities of the cell lines were also determined. Caspase-3 activity is an important indicator of apoptosis in the cell. The reversal of MDR was attempted by two cinnamylidene ketone and two organosilicon compounds. The results indicated that these compounds modulated P-gp effectively, but they were not very effective at reversing MRP1 activity in the MCF-7 sublines. Four selective anticancer drugs (paclitaxel, docetaxel, doxorubicin and vincristine) and four

Augmented antitumor effects of radiation therapy by 4-1BB antibody (BMS-469492) treatment.

Abstract: Background: 4-1BB (CD137) is a member of the tumor necrosis factor receptor superfamily. It interacts with 4-1BB ligand (4-1BBL) and delivers a costimulatory signal for T cell activation. The immune response induced by 4-1BB monoclonal antibodies (mAbs) has been shown to have a marked augmentation of tumor-selective cytolytic T cell activity. Materials and Methods: The antitumor efficacy of agonistic 4-1BB mAbs (BMS-469492, Bristol-Meyer Squibb), used alone or in combination with radiation therapy, was evaluated in murine lung (M109) and breast (EMT6) carcinoma models. Results: Treatment with BMS-469492 led to only a modest growth retardation in M109 tumors (3 days, p>0.05), but a significant growth delay in EMT6 tumors (12.5 days, p<0.05). When BMS-469492 was administered in conjunction with single dose radiation therapy (5, 10 or 15 Gy), enhanced tumor responses were noted only at the highest evaluated radiation dose (15 Gy). In contrast, in the EMT6 model, BMS-469492 treatment resulted in enhanced antitumor effects at all radiation doses. In addition, the response of EMT6 tumors to fractionated radiotherapy also was significantly increased when BMS-469492 was included in the treatment protocol. Conclusion: These results suggest that monoclonal antibodies against 4-1BB may not only be

Curcumin-induced Cell Cycle Arrest and Apoptosis in Human Acute Promyelocytic Leukemia HL-60 Cells via MMP Changes and Caspase-3 Activation

Abstract: Curcumin (diferuloylmethane), is a natural product derived from the root of the plant Curcuma longa. For centuries, it has been used as a spice and as a herbal medicine in Chinese populations. Curcumin has been shown to inhibit cell proliferation, cell cycle arrest, cyclooxygenase (COX)-1 and -2 expression and apoptosis in several human cancer cell lines. The aim of this investigation was to clarify the mechanisms by which curcumin induced cytotoxicity and apoptosis in human leukemia HL-60 cells. The effects of curcumin on the levels of reactive oxygen species (ROS), Ca+2 production, cyclin E, cdc25c, wee1, Bcl-2, Bax, the changes of mitochondrial membrane potential (MMP), cytochrome c release and the activation of caspase-3 were also investigated in the HL-60 cells. Results of flow cytometry and DAPI staining assays indicated that curcumin induced cytotoxicity and apoptosis in the examined cells. The results from flow cytometry assay indicated that curcumin induced ROS and Ca+2 productions, decreased the levels of MMP and increased the activity of caspase-3, leading to cell apoptosis. Western blot assay also revealed that curcumin increased the levels of Bax and the release of cytochrome c, and decreased the levels of Bcl-2 in the examined cells. The inhibition of caspase-3 activation by z-VAD-fmk (broad-spectrum caspase inhibitor) completely blocked curcumin-induced apoptosis in HL-60 cells.

Targeted radionuclide therapy with 90Y-DOTATOC in patients with neuroendocrine tumors.

Abstract: Background: The aim of this study was to assess the efficacy and safety of targeted radionuclide therapy with ( 90 Y-DOTA 0 ,Tyr 3 )-octreotide ( 90 Y-DOTATOC) in patients with metastatic neuroendocrine tumors. Patients and Methods: One hundred and sixteen patients with metastatic neuroendocrine tumors were included. All patients were pre- therapeutically staged with morphological imaging procedures and with somatostatin receptor scintigraphy. The scintigraphy was positive in all cases. The patients were treated with 162- 200 mCi/m 2 body surface. In 57 patients, the quality of life was assessed with the National Cancer Institute grading criteria (NCI-CTC). Restaging was performed 8 - 12 weeks after the last treatment cycle. Blood samples were drawn every 2 weeks after the treatment to evaluate toxicity. Results: Complete remissions were found in 4%, partial remissions in 23%, stabilization in 62% and progressive disease in 11%. A significant reduction of symptoms was found in 83%. No serious adverse event occurred and the toxicity was acceptable. Conclusion: 90 Y-DOTATOC is a safe and effective treatment for patients with metastatic neuroendocrine tumors. Neuroendocrine tumors (NET) are a large, inhomogeneous group of malignancies considered to be derived from the diffuse neuroendocrine system (1). Most of these tumors

Apoptosis of human leukemia HL-60 cells and murine leukemia WEHI-3 cells induced by berberine through the activation of caspase-3.

Abstract: The aim of this study was to clarify the mechanisms of apoptosis, cytotoxicity, DNA damage and fragmentation, as well as the production of reactive oxygen species (ROS) and Ca+2, induced by berberine in human promyelocytic leukemia HL-60 and murine myelomonocytic leukemia WEHI-3 cells. The levels of Bcl-2 and Bax, the changes of mitochondria membrane potential (MMP), cytochrome c release and activation of caspase-3 were also investigated in both cell lines. The flow cytometry and DAPI staining assays indicated that berberine induced cytotoxicity in both cell lines examined. Flow cytometry assay also showed that berberine induced ROS and Ca+2 production, decreased the levels of MMP and increased the activity of caspase-3 in both cell lines examined. Berberine-induced apoptosis was accompanied by increased levels of Ca+2 and a decrease in the mitochondrial membrane potential, leading to the release of cytochrome c and the cleavage of pro-caspase-3. Western blotting also showed that berberine increased the levels of Bax and cytochrome c and decreased the levels of Bcl-2 in both cell lines. Inhibition of caspase-3 activation (z-VAD-fmk: cell-permeable broad-spectrum caspase inhibitor) completely blocked berberine-induced apoptosis in both HL-60 and WEHI-3 cells. Therefore, berberine induced apoptosis in both examined cell lines through the activation of caspase-3.

Down-regulation of cyclin B1 and up-regulation of Wee1 by berberine promotes entry of leukemia cells into the G2/M-phase of the cell cycle.

Abstract: Berberine has a wide range of biological actions that suggest it may be of use in cancer prevention. It was previously reported that berberine induced cell cycle arrest, not only at the G0/G1-phase, but also at the G2/M-phase in a dose-dependent manner. However, the mechanism of berberine-induced G2/M-phase arrest in leukemia cells is not fully understood. In the present study, the effects of the naturally occurring berberine (the major constituent of Coptis chinensis) on the cell cycle, as well as on CDK1, cyclin B1, 14-3-3sigma, Wee1 and Cdc25c expressions, were investigated in the human promyelocytic leukemia HL-60 cells and in the murine myelomonocytic leukemia WEHI-3 cells. The flow cytometry assays indicated that berberine induced G2/M-phase arrest in both examined cell lines. The berberine-induced G2/M-phase arrest in both examined cell lines was accompanied by increased levels of Wee1 and 14-3-3sigma, but decreased levels of Cdc25c, CDK1 and cyclin B1. However, CDK2 expression was not affected as revealed by Western blotting assay. Berberine induced G2/M arrest in both the examined cells via the inhibition of cyclin B1 and the promotion of Wee1.

Quality of life is improved in breast cancer patients by Standardised Mistletoe Extract PS76A2 during chemotherapy and follow-up: a randomised, placebo-controlled, double-blind, multicentre clinical trial.

Abstract: The objective of this randomised, multicentre, double-blind clinical trial was to investigate the impact of PS76A2, an aqueous mistletoe extract standardised to mistletoe lectins, on quality of life (QoL) in breast cancer patients. A total of 352 patients were randomly allocated to 2 groups receiving PS76A2 (15 ng mistletoe lectin/0.5 ml) or matching placebo twice weekly for 4 to 6 cycles of CMF (cyclophosphamide, methotrexate, fluorouracil) chemotherapy followed by 2 months follow-up. The primary efficacy end-point was the change from baseline of 3 FACT-G subscales (physical, emotional and functional well-being) during the fourth CMF cycle. Secondary measures included GLQ-8 (8 linear analogue self-assessment scales), Spitzer's uniscale and haematological variables. The main variables of safety analysis were adverse events, including injection site reactions and clinical laboratory tests. The results showed that physical, emotional and functional well-being improved upon PS76A2, but deteriorated following placebo. The treatment differences were statistically significant for the 3 subscales as well as for the summary score FACT-G, which was analysed as O'Brien's rank sum of its 3 subscales: The total score increased by 4.40 +/- 11.28, indicating a higher QoL after PS76A2, but decreased by 5.11 +/- 11.77 with placebo (p<0.0001). The GLQ-8 sum of 8 LASA scales was analysed as a summary score of GLQ-5 (sum of item nos. 1, 5, 6, 7, 8) and GLQ-3 (sum of item nos. 2, 3, 4). GLQ-5 characterises typical aspects of QoL, while GLQ-3 consists of 3 side-effects of CMF (feeling sick, numbness or pins and needles, loss of hair). GLQ-5 decreased by 42.9 +/- 125.0 upon PS76A2, indicating an improvement in QoL, but increased by 60.3 +/- 94.0 upon placebo (p<0.0001). GLQ-3 deteriorated in both groups (PS76A2: 13.9 +/- 52.4; placebo: 34.5 +/- 57.0), but the differences in favour of PS76A2 were, nevertheless, statistically significant (p=0.0007). The total score GLQ-8 improved by 28.9 +/- 154.6 after PS76A2 and deteriorated by 94.8 +/- 141.1 after placebo (p<0.0001). Spitzer's uniscale improved by 12.2 +/- 30.7 upon PS76A2 and deteriorated by 10.8 +/- 26.1 with placebo (p<0.0001). After follow-up without chemotherapy, a significant treatment difference in favour of PS76A2 was determined by means of FACT-G, GLQ-8 and Spitzer's uniscale. PS76A2 was well tolerated in this trial, with the exception of slight local reactions in 17.6% of the PS76A2 group. In conclusion, PS76A2 (15 ng mistletoe lectin/0.5 ml twice weekly) was shown to be safe and effective in improving QoL in breast cancer patients during chemotherapy and follow-up.

Vitamin D and cancer.

Abstract: The correlation between decreased morbidity and mortality of cancer and exposure to sunlight is known. The many biological functions of vitamin D that contribute to cancer prevention have only recently begun to be appreciated. Once activated 1,25-dihydroxyvitamin D [1,25(OH)2D3] functions as a potent inhibitor of normal and cancer cellular proliferation. Vitamin D deficiency in mice led to a 60% increase in colon tumor growth, compared to vitamin D-sufficient mice. The ligand binding domain of the Vitamin D receptor was shown to accommodate a class of 1,25(OH)2D3-analogs that possess an additional side-arm. These novel Gemini analogs were evaluated in vitro and in vivo. Select Gemini analogs were 100 times or more effective in inhibiting colon tumor growth in mice, compared to their parent compound. Correcting vitamin D deficiency may decrease the risk of developing colon cancer, while the novel Gemini 1,25(OH)2D3-analogs have the potential for therapeutic application in human colon cancer.

Matrix metalloproteinase (MMP) -1, -2, -3 and -9 promoter polymorphisms in colorectal cancer.

Abstract: Background: Matrix metalloproteinases (MMPs) are a group of matrix-degrading proteins implicated in several pathological processes, e.g., invasion and metastasis in malignant diseases such as colorectal cancer (CRC). Materials and Methods: One hundred and twenty-seven CRC patients and 208 controls were genotyped for MMP-1, -2, -3 and -9 promoter polymorphisms. The genotyping was performed with PCR/primer-extension/DHPLC or PCR/RFLP. Results: The MMP-1 2G allele was significantly associated with CRC (p=0.037). No significant association between CRC and MMP-2, -3 or -9 polymorphisms was evident. The analysis of polymorphisms in the clinicopathological subgroups displayed no significant associations. Conclusion: The MMP-1 promoter polymorphism seems to affect the susceptibility to CRC, while MMP-2, -3 and -9 polymorphisms appear less likely to have any impact on CRC.

Elevated levels of circulating cell-free DNA in the blood of patients with hepatitis C virus-associated hepatocellular carcinoma.

Abstract: Background: Circulating cell-free DNA is present in increased amounts in the blood of patients with one of several forms of cancer. Materials and Methods: A real-time PCR assay with glutathione S-transferase pi (GSTP1) gene was used to measure cell-free DNA levels in the sera of 52 patients with hepatocellular carcinoma (HCC) associated with hepatitis C virus (HCV), which included 30 HCV carriers without known HCC and 16 HCV-negative non-cancer patients (controls). Results: Cell-free DNA levels were significantly higher in the sera from HCC patients than in the sera from HCV carriers or the control subjects. Cell-free DNA levels were associated with the degree of tumor differentiation and size but not patient age, gender, TNM stage or levels of alpha-fetoprotein (AFP) or protein induced by vitamin K absence (PIVKA-II). The cell-free DNA assay had a sensitivity of 69.2% and a specificity of 93.3% in discriminating HCC and HCV carriers at the optimal cut-off value of 73.0 ng/ml, with an area of 0.90 (95% CI, 0.83- 0.96) under the receiver operating characteristic curve. The discriminative power of cell-free DNA was superior to that of AFP or PIVKA-II. Conclusion: Our results showed that levels of circulating cell-free DNA are significantly increased in sera of patients with HCV-associated HCC, suggesting that circulating cell-free DNA may be a good biomarker specific for HCV-associated HCC.

Molecular immunological approaches to biotherapy of human cancers--a review, hypothesis and implications

Abstract: The immune system of the human organism comprises the innate system cells and the adaptive immune cells. The former include the hematopoietic cells, mast cells, basophils, monocytes, dendritic cells (DCs) and macrophages, and the latter include CD4+ T cells, CD8+ T cells, T regulatory cells (Tr) and B cells. The innate system DCs are the major antigen-presenting cells to Th(o) CD4+ T cells in lymph nodes that polarize into T helper 1 (Th1) and T helper 2 (Th2) cells, which subsequently produce different cytokines. Polarized Th1 cells produce interleukin (IL)-2, IL-12 and interferon (IFN)-gamma, and polarized Th2 cells and the hematopoietic cells produce IL-4, IL-5, IL-6, IL-10 and IL-13. In healthy individuals there is a Th1/Th2 cytokine balance, but during microbial-induced inflammation the pathogens induce an overproduction of the Th2 cytokines that inhibit the adaptive immune response against the pathogen. A review of studies on the Th1/Th2 cytokine balance in humans harboring different tumor types revealed that tumor cells induce increased Th2 cytokine levels in patients' sera that can serve as indicators for the existence of tumors. In this review, studies which correlated the presence of increased Th2 cytokines with the presence of early tumors and tumor progression are discussed. It was suggested that early monitoring of human populations for elevated Th2 cytokines may be used to identify individuals at an early stage of tumor development. A hypothesis is presented which suggests that increased Th2 cytokine synthesis in cancer patients, with early and late tumors, may be treated with Th2 cytokine antagonists. This new approach to cancer treatment will be supplemented by co-treatment with CpG oligodeoxynucleotides(ODNs) which reactivate the adaptive antitumor immune response. Studies that provide information on the efficiency of CpG ODN treatment of tumors in mice revealed that tumor regression was achieved by inducing Toll-like receptor 9+ plasmacytoid dendritic cells (PDCs) to release large amounts of type I interferons (IFN alpha and beta), which inhibit Th2 cytokine synthesis by hematopoietic cells and CD4+ T cells and enhance Th1 cytokine synthesis and activation of the adaptive immunity. It is hypothesized that Th2 cytokine (IL-4 and IL-6) antagonists may be an effective treatment for cancer patients since cytokine antagonists inhibit the increased Th2 cytokines in patients. Such an approach may replace Th2 cytokine monoclonal antibodies, the current treatment for cancer patients. It is hypothesized that the effective treatment of cancer patients with Th2 cytokine antagonists, combined with CpG ODNs, will lead to the inhibition of Th2 cytokines and reacTivation of the Th1-induced antitumor adaptive immunity that will destroy tumor cells and cure cancer patients.

Paclitaxel toxicity in post-mitotic dorsal root ganglion (DRG) cells

Abstract: Paclitaxel is an antineoplastic drug which acts by enhancing tubulin polymerization. The induction of peripheral neuropathy is the main dose-limiting side-effect of paclitaxel treatment. In this study, the neurotoxic effect of this drug in dorsal root ganglion (DRG) explants was analyzed by measuring the neurite length of DRG explants exposed to nerve growth factor (NGF). The neurotoxic effect of paclitaxel is dose- and time-dependent. Moreover, in DRG dissociated post-mitotic neurons, the molecular and morphological features of paclitaxel-induced cellular death were studied and the DRG neurons were observed to die by necrosis. On the contrary, the proliferating human neuroblastoma SH-SY5Y cells exposed to paclitaxel die by apoptosis, as reported for cortical neurons. The different response to the same stimulus of different neuronal populations underlines the importance of the biochemical and molecular phenotype of the neuronal population in determining cellular behavior and vulnerability to the same noxious stimulus.

Radiofrequency ablation of colorectal liver metastases: mid-term results in 68 patients.

Abstract: The aim of this retrospective study was to evaluate the efficacy and medium-term survival, after percutaneous radiofrequency ablation (RFA), in patients suffering from hepatic metastases of colorectal cancer. Patients and Methods: Between 2000 and 2004, 68 patients (42 men, 26 women; mean age 63 years, range: 38-87 years), with non- resectable liver metastases from colorectal cancer, were treated by RFA subsequently or parallel to chemotherapy. The procedures were mainly performed under conscious sedation and local anesthesia using computed tomography fluoroscopy guidance. The number of lesions, the primary success rate, complications, follow-up time and disease-free survival, as well as the local recurrence rate, were evaluated. Results: One- hundred and eighty-three metastases with a mean diameter of 22.8 mm (5-50 mm) in 68 patients (2.7 +/- 1.1 lesions / patient) were successfully treated using RFA. No major complications and only 4 minor complications were noted. Over an average follow-up period of 21.4 +/- 10.6 months (range, 8 to 38 months), Kaplan-Meier analysis demonstrated a probability of 82% of remaining locally disease-free and a probability of 68% of surviving the first 38 months after treatment. Conclusion: For patients with non-resectable hepatic metastases of colorectal cancer, RFA is a safe option in a multimodal treatment concept and may lead to an improvement in survival.

Tumor-associated tissue eosinophilia in human esophageal squamous cell carcinoma.

Abstract: Background: Inflammatory cell infiltration around the sites of carcinoma invasion is believed to play important roles in carcinoma biological behavior. Materials and Methods: The status of inflammatory cell infiltration at the sites of frank invasion in 97 cases of esophageal squamous cell carcinoma (SCC) were examined, with special emphasis on the status of tumor-associated tissue eosinophilia (TATE). Infiltration of the CD4+T-cells, CD8+T-cells, CD68+macrophages, L26+B-cells, mast cells and eosinophils was quantitatively evaluated in histological tissue sections. The results were then statistically correlated with clinicopathological factors. Results: Among tumor- associated inflammatory cells, the number of tumor- associated eosinophils was significantly correlated with the presence or absence of vascular invasion, lymph node (LN) metastasis and recurrence. The cases were tentatively classified into 2 categories, small and large groups, according to the median and/or average number of tissue eosinophils. The survival curve of the patients was evaluated according to this classification. No statistically significant differences were detected between these 2 groups in the cases without LN metastasis. However, the large group was associated with a statistically significant better prognosis in cases associated with LN metastasis, especially in those with invasion to adventitia (T3) of the esophagus. Conclusion: The possible function of tumor-associated eosinophils has not yet been elucidated, but these findings indicate the importance of TATE in the biological behavior of SCC of the esophagus. Inflammatory cell infiltration around the tumor, especially

Improved survival after gross total resection of malignant gliomas in pediatric patients from the HIT-GBM studies.

Abstract: The present study was performed to investigate the prognostic impact of tumor resection on survival in children and adolescents with malignant gliomas. From the HIT-GBM data base of the Gesellschaft fur Paediatrische Onkologie und Haematologie (GPOH), 85 pediatric patients with malignant non-pontine gliomas were analyzed. Histological diagnosis and extent of tumor resection had been confirmed by central neuropathological review and post-surgical imaging. The extent of tumor resection represented the most prominent prognostic factor for overall (OS) and event-free survival (EFS) in univariate and Cox regression analyses. Four-year survival after gross total tumor resection was 48.0 +/- 12.0% (OS) and 14.1 +/- 8.9% (EFS), after non-total resection 13.2 +/- 6.1% and 2.9 +/- 2.8%, respectively. From several clinical parameters, only histological grading displayed a similar statistical significance in Cox regression analysis. In conclusion, gross total tumor resection improves survival in pediatric patients with malignant gliomas and should always be attempted when possible.

Thymidine kinase 1 in serum predicts increased risk of distant or loco-regional recurrence following surgery in patients with early breast cancer.

Abstract: Background The prognostic value of the concentration of serum thymidine kinase 1 (S-TK1) with regard to recurrence in low risk breast cancer patients, 3 months after surgery was evaluated. Patients and methods The concentration of S-TK1 in serum was determined in 120 breast cancer patients at the time of surgery and in 67 patients 3 months after surgery, by anti-TK1 chicken IgY antibody, using a dot-blot immuno-assay. The S-TK1 concentration was compared with the serological activity of thymidine kinase (STK) and of carbohydrate antigen (CA 15-3). Results A statistically significant trend (unadjusted) was found for recurrence (distant or loco-regional) in patients with a higher S-TK1 concentration, as compared with patients with a lower S-TK1 concentration. A multivariate analysis gave the same results. The hazard rate ratio for developing distant and/or loco-regional recurrence in patients with a higher S-TK1 concentration was about six to seven times higher than in patients with a lower S-TK1 concentration. Conclusion Our results indicate that the S-TK1 concentration is higher in patients developing distant and/or loco-regional recurrence 3 months post-surgery.

Prospect for anti-HER2 receptor therapy in breast cancer.

Abstract: The carcinogenesis process is characterized, in part, by the dysfunction of cellular communication pathways, such as the one involving HER2. HER2 is a member of the EGF receptor family, which participates in cell growth and proliferation. HER2 may be overexpressed in 15 to 30% of breast cancer cases and is associated with poor prognosis, shortened overall survival and shorter time to disease progression. Furthermore, an increasing number of studies have demonstrated the relevance of HER2 serum concentrations (sHER2, extracellular domain released into blood by proteolysis) as a predictive marker of resistance to chemotherapy in HER2-overexpressing metastatic breast cancer. The determination of HER2 overexpression/ amplification in the diagnosis of relapse of breast cancer is currently a routine procedure. Immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) techniques, which are used to detect HER2 expression in the tumor, are improving constantly, and other parallel techniques such as chromogenic in situ hybridization (CISH) are starting to emerge. sHER2 concentrations can be measured using ELISA techniques, which can be automated. All of these procedures still need to be standardized. The discovery of a monoclonal antibody (4D5) that can inhibit the growth and proliferation of cells overexpressing HER2 led to the development of trastuzumab. Like 4D5, trastuzumab recognizes an epitope on the extracellular domain of HER2. Moreover, trastuzumab is also able to stimulate antibody-dependent cellular toxicity (ADCC). It is administered alone or in combination (with navelbine, taxol, carboplatin...) in patients with metastatic breast cancer overexpressing HER2. Other active antibodies have since been discovered, as well as other specific molecules, such as tyrosine kinase inhibitors which will undoubtedly find a place in the therapeutic arsenal used in breast cancer, especially to avoid the emergence of resistance to treatment.