Influence of norcantharidin on proliferation, proliferation-related gene proteins proliferating cell nuclear antigen and Ki-67 of human gallbladder carcinoma GBC-SD cells

BACKGROUND

Gallbladder carcinoma is a highly lethal and aggressive disease with early metastasis, strong invasion and poor prognosis. Most patients with this disease are at the advanced and un-resectable stage and should be considered for palliative treatment such as chemotherapy and radiotherapy. Unfortunately, reports of chemotherapy and radiotherapy for gallbladder carcinoma are disappointing. We investigated the influence of norcantharidin (NCTD) on proliferation, proliferation-related gene proteins PCNA and Ki-67 of human gallbladder carcinoma GBC-SD cells in vitro.

METHODS

GBC-SD cell lines of human gallbladder carcinoma were cultured by the cell culture technique. The experiment was divided into NCTD group and control group. The tetrazolium-based colorimetric assay was used to evaluate cell growth. The streptavidin-biotin complex method was used to determine the expressions of proliferation-related gene proteins PCNA and Ki-67 of human gallbladder carcinoma GBC-SD cells.

RESULTS

NCTD inhibited the growth and proliferation of GBC-SD cells from 10 mg/L or after 6 hours in a dose-and time-dependent manner, with the IC50 value of 56.18 microg/ml at 48 hours. After treatment with NCTD, the expression of PCNA (0.932+/-0.031 vs. 0.318+/-0.023, P<0.001) and Ki-67 (0.964+/-0.092 vs. 0.297+/-0.018, P<0.001) proteins were decreased significantly.

CONCLUSION

NCTD inhibits the proliferation of human gallbladder carcinoma GBC-SD cells in vitro and the expression of their proliferation-related gene proteins PCNA and Ki-67.

Adventitious root growth and ginsenoside accumulation in Panax ginseng cultures as affected by methyl jasmonate

Adventitious roots of ginseng were treated with methyl jasmonate (MJ) up to 150 microM and cultured for 40 days. Up to 100 microM MJ inhibited the root growth but increase ginsenoside accumulation. In a two-stage bioreactor culture, total ginsenosides, after elicitation with 100 microM MJ peaked after 10 days at 48 mg g(-1) dry wt and then dropped sharply. Of the two groups of ginsenosides (Rb and Rg), higher amounts of Rb accumulated in the adventitious roots.

Preferential target is mitochondria in α-mangostin-induced apoptosis in human leukemia HL60 cells

Our previous study has shown that alpha-mangostin, a xanthone from the pericarps of mangosteen, induces caspase-3-dependent apoptosis in HL60 cells. In the current study, we investigated the mechanism of apoptosis induced by alpha-mangostin in HL60 cells. Alpha-mangostin-treated HL60 cells demonstrated caspase-9 and -3 activation but not -8, which leads us to assume that alpha-mangostin may mediate the mitochondrial pathway in the apoptosis. Parameters of mitochondrial dysfunction including swelling, loss of membrane potential (deltapsim), decrease in intracellular ATP, ROS accumulation, and cytochrome c/AIF release, were observed within 1 or 2 h after the treatment. On the other hand, alpha-mangostin-treatment did not affect expression of bcl-2 family proteins and activation of MAP kinases. These findings indicate that alpha-mangostin preferentially targets mitochondria in the early phase, resulting in indication of apoptosis in HL60 cells. Furthermore, we examined the structure-activity relationship between xanthone derivatives including alpha-mangostin and the potency of deltapsim-loss in HL60 cells. Interestingly, replacement of hydroxyl group by methoxy group remarkably decreased its potency. It was also shown that the cytotoxicity substantially correlated with deltapsim decrease. These results indicate that alpha-mangostin and its analogs would be candidates for preventive and therapeutic application for cancer treatment.

The inhibitory effect of a herbal formula comprising ginseng and carthamus tinctorius on breast cancer

A compound (Zhu-xiang) from herbal extracts containing ginseng and carthamus tinctorius was used to treat the MDA-MB-231 breast cancer cell and normal human mammary gland cell lines. The inhibition of cell proliferation by Zhu-xiang, epirubicin, 5-fluorouracil and cyclophosphamide was determined by WST-1 assays. The apoptotic effect was studied by flow cytometry analysis of DNA strand breaks and ApopTag Peroxidase In Situ Apoptosis kit by the TUNEL assay. The proliferation index as well as cell cycle progression were also evaluated by flow cytometry using Ki-67 and propidium iodide respectively as markers. The Zhu-xiang showed significantly inhibition in cell proliferation and the inhibition was dose dependent. The inhibitory effect of Zhu-xiang was significantly greater than commonly used cytotoxic drugs. The inhibitory effect is a result of the induction of apoptosis, which is concentration- and time-dependent. DNA histograms indicate that the compound causes accumulation of cells mainly in the S phase. The viability of cells in breast solid tumours was measured by ATP bioluminescence assay to determine the drug-induced cytotoxicity of Zhu-xiang. The three different concentrations of Zhu-xiang all exhibited the ability to inhibit proliferation in solid tumour. Zhu-xiang could be a useful anti-cancer compound against breast cancer.

l-Arginine modulates CD3ζ expression and T cell function in activated human T lymphocytes

Engagement of the T cell receptor (TCR) by antigen or anti-CD3 antibody results in a cycle of internalization and re-expression of the CD3zeta. Following internalization, CD3zeta is degraded and replaced by newly synthesized CD3zeta on the cell surface. Here, we provide evidence that availability of the amino acid L-arginine modulates the cycle of internalization and re-expression of CD3zeta and cause T cell dysfunction. T cells stimulated and cultured in presence of L-arginine, undergo the normal cycle of internalization and re-expression of CD3zeta. In contrast, T cells stimulated and cultured in absence of L-arginine, present a sustained down-regulation of CD3zeta preventing the normal expression of the TCR, exhibit a decreased proliferation, and a significantly diminished production of IFNgamma, IL5, and IL10, but not IL2. The replenishment of L-arginine recovers the expression of CD3zeta. The decreased expression of CD3zeta is not caused by a decreased CD3zeta mRNA, an increased CD3zeta degradation or T cell apoptosis.

Enhanced lymphocyte proliferation responses in pediatric patients early after myelosuppressive chemotherapy

BACKGROUND

It has long been known that patients both after myelosuppressive chemotherapy (ChTh) and after myeloablative bone marrow transplantation (BMT) show a long lasting impairment of cellular immune functions. However, recent reports have revealed that early after BMT a passing state of augmented immune responsiveness exists. Adoptive T cell therapy in this period of lymphopenia-induced (homeostatic) proliferation has shown better results than in steady state in murine studies.

PROCEDURE

To determine whether also early after myelosuppressive ChTh enhanced immune responses can be found, we have determined proliferation of peripheral blood lymphocytes and calcium influx and performed immunophenotyping in pediatric patients recovering from myelosuppressive ChTh in comparison to immunoreconstituted patients late after BMT.

RESULTS

The lymphocytes of the ChTh patients were found to proliferate vigorously in response to stimulation with a variety of antibodies and mitogens, while in the BMT patients any stimulation was severely reduced. The increase of intracellular calcium after stimulation was similar in both patient groups. ChTh patients showed an expansion of an activated "naive" phenotype (CD45RO- HLA-DR+) in both the CD4 and CD8 subsets. In contrast, BMT patients showed a prominent expansion of "memory type" T lymphocytes (CD45RO+ HLA-DR+).

CONCLUSIONS

Early after ChTh, a period of immunoaugmentation seems to exist. Whether this observation can be used clinically to increase cure rates remains to be elucidated.

[Heparin inhibits metastatization of experimental melanoma]

Heparin treatment, at human equivalent doses, modulates coagulation parameters in mice similarly to the human situation. Heparins were tested in various melanoma metastasis models for their antimetastatic activity. Heparins were active against melanoma metastasis without influencing the primary tumor. Tumor cell-induced platelet aggregation was not the primary target of heparins, since melanoma cells were not active in this respect. Our results support the notion that heparins have antimetastatic activity.

Peptide YY inhibits the growth of Barrett's esophageal adenocarcinoma in vitro

BACKGROUND

Peptide YY (PYY) is an endogenous gut hormone that inhibits the growth of certain cancers. Adenocarcinoma of the esophagus usually arises from Barrett's esophagus. We hypothesized that treatment of Barrett's adenocarcinoma with PYY would result in decreased proliferation.

METHODS

Barrett's cancer cell lines (BIC and SEG-1) were treated with PYY (3-36) at 500 pmol/mL. Viability was measured by MTT at 24 and 72 hours. Apoptosis and necrosis was evaluated by flow cytometry.

RESULTS

PYY reduced proliferation in SEG-1 cells at 24 hours (21.2% +/- 3.4%, P <0.001) and 72 hours (14.2% +/- 6.2%, P <0.001). In the BIC cells, growth was inhibited by 7.9% +/- 7.0%, P = 0.021 after 72 hours. PYY increased late apoptotic activity in SEG-1 cells by 31%, P = 0.014.

CONCLUSIONS

This is the first report of antiproliferative effects of PYY against Barrett's carcinoma in vitro. Reductions in cell growth appear to be mediated by proapoptotic mechanisms. Further investigation of PYY in the treatment of Barrett's adenocarcinoma is warranted.

In vitro effects of pentosan polysulfate against malignant breast cells

BACKGROUND

Pentosan polysulfate (Elmiron); (Alza Pharmaceuticals, Mountain View, CA) is the only Food and Drug Administration-approved oral therapy for interstitial cystitis (IC). Women with IC and breast cancer are often in the same age range; therefore, we hypothesize that pentosan polysulfate may also have a therapeutic effect on breast cancer cells in vitro.

METHODS

Breast cancer lines MCF-7, ZR75-1, and HTB26 were treated with pentosan polysulfate at various concentrations. Cell viability was measured at 24 hours by MTT. Annexin V assay was used to determine the effect of pentosan polysulfate on apoptotic and necrotic activity.

RESULTS

Pentosan polysulfate significantly inhibited the growth of the ZR75-1 cells; however, significant cellular proliferation was observed in the MCF-7 cells. A significant change in late apoptotic activity was observed with pentosan polysulfate treatment in vitro.

CONCLUSIONS

Caution should be used in prescribing pentosan polysulfate for the treatment of IC in patients who are both in high-risk groups for breast cancer and premenopausal females.

Combination with water-soluble antioxidants increases the anticancer activity of quercetin in human leukemia cells

While accumulation of reactive oxygen species (ROS) is believed to be harmful to organisms, recent studies show that quercetin (QU), a promising antioxidant and anticancer drug, exerts its anticancer role through either diminishing or promoting ROS generation under different conditions. In the present study, it was investigated whether the water-soluble antioxidants ascorbic acid (ASA), N-acetyl-cysteine (NAC) and reduced glutathione (GSH) can enhance both the antioxidant and anticancer activity of quercetin in human myeloid leukemia cells (HL-60 cells). Proliferation, viability and ROS accumulation (indicated by the level of malondialdehyde, MDA) was significantly decreased by QU in HL-60 cells. 50 microM H2O2 markedly attenuated the antioxidant and anticancer activity of QU, proving that diminution of ROS accumulation considerably contributes to the QU-induced decrease of HL-60 cells proliferation and viability. When the effects of water-soluble antioxidants were tested, ASA at 1 mM, NAC at 500 microM, or GSH at 250 microM significantly enhanced QU-mediated proliferation arrest, cell death and ROS diminution. These results indicate that certain amounts of ROS are critical for the proliferation and viability of HL-60 cells, while water-soluble antioxidants enhance the anticancer activity of QU through scavenging ROS. Combing QU with water-soluble antioxidants could be a useful strategy to improve the anticancer activity of QU by increasing its antioxidant activity.

A napin-like polypeptide with translation-inhibitory, trypsin-inhibitory, antiproliferative and antibacterial activities from kale seeds

A heterodimeric napin-like polypeptide with translation-inhibiting and antibacterial activities has been isolated from kale seeds. The purification procedure entailed ion-exchange chromatography on dielthylaminoethyl (DEAE)-cellulose, affinity chromatography on Affi-gel blue gel, ion-exchange chromatography by fast protein liquid chromatography (FPLC) on Mono S, and gel filtration by FPLC on Superdex 75. The napin-like polypeptide was unadsorbed on DEAE-cellulose but adsorbed on Affi-gel blue gel and Mono S. Its 7-kDa large subunit differs in N-terminal amino acid sequence from the 4-kDa small subunit. The polypeptide inhibited translation in the rabbit reticulocyte lysate system with an IC50 of 37.5 nM. This activity was preserved between pH 5 and pH 11, and between 10 and 40 degrees C. It fell to a low level at pH 3 and pH 13 and at 70 degrees C. Antibacterial activity against Bacillus, Megabacterium, and Pseudomonas species and antiproliferative activity against leukemia L1210 cells were observed. However, the polypeptide did not exert antifungal, ribonuclease, or protease activity.

Simvastatin induces proliferation inhibition and apoptosis in C6 glioma cells via c-jun N-terminal kinase

The lipid-lowering drugs, statins, induce apoptosis in a variety of tumor cells. Here we investigated the apoptotic effect of the lipophilic statin, simvastatin, in C6 glioma cells and the underlying effects on intracellular signal transduction. Simvastatin inhibited cell proliferation totally after 20h of treatment as shown by the decrease in proliferating cell nuclear antigen expression in the nucleus. Subsequently, simvastatin caused apoptotic cell death by shrinkage of cytoplasm and condensation of chromatin, and DNA fragmentation. The features of apoptosis were visible only after 48 h of treatment, possibly reflecting a requirement for cell commitment to growth arrest. In immunocytochemical and immunoblotting experiments we have shown that simvastatin markedly increased the phosphorylation of ATF-2 and c-jun in the nucleus of the C6 glioma cells at early time points which was preserved even 24 h after treatment. In contrast, activities of protein kinases Erk1/2 and AKT in the cell survival pathway remained unchanged throughout the treatment. Selective inhibitor of JNK, but not p38 kinase, reduced simvastatin-induced cell death and ATF-2 and c-jun phosphorylation suggesting that JNK-dependent activation of ATF-2 and c-jun may play an important role in simvastatin-induced proliferation inhibition and apoptosis in C6 glioma cells. These observations suggest that statins may have clinical significance in the prevention of glial tumors beyond their cholesterol-lowering effect and JNK may be a rational target for sensitizing glioma cells to chemotherapeutic agents.

[Biological effects of soluble CD40 ligand on lung cancer cell line A549 and its mechanism]

BACKGROUND & OBJECTIVE

Although the roles of CD40 in B cells have been intensively studied, little is known on the function of CD40 in lung cancer cell lines. This study was to investigate biological effects of soluble CD40 ligand (sCD44L) on lung cancer cell line A549 (CD40 positive), and its possible mechanism.

METHODS

A549 cells were co-incubated with sCD40L, cell proliferation was detected by MTT assay and 3H-TdR incorporation method. Immunofluorescence technique and flow cytometry (FCM) were used to evaluate changes in cell phenotypes and cell cycle. Cell apoptosis, and expression changes of Bcl-2 and Bax were observed by FCM, reverse transcriptase-polymerase chain reaction (RT-PCR), and Western blot.

RESULTS

Compared with control cells, proliferation of A549 cells co-incubated with sCD40L was inhibited (P< 0.05). Positive rates of cell surface molecules, CD49e, CD54, TNFRI, and CD95L, in A549 cells co-incubated with sCD40L for 72 h were (61.2+/-4.8)%, (31.2+/-6.1)%,(42.7+/-5.9)%, and (38.2+/-3.4)%, respectively, while those in control cells were (34.7+/-2.1)%, (7.1+/-1.6)%, (15.2+/-4.1)%, and (10.1+/-2.3)%, respectively (P< 0.05). However, positive rate of TNFRII in A549 cells co-incubated with sCD40L[(8.7+/-0.8)%] was lower than that in control cells [(58.1+/-3.6)%] (P< 0.05). G1 phase of A549 cells treated with sCD40L for 72 h was (76.0+/-9.1)%, more than that of control cells [(56.7+/-6.9)%], while S phase of sCD40L-treated A549 cells [(10.3+/-5.7)%] was less than that of control cells [(32.7+/-5.5)%]. No significant apoptosis of A549 cells was observed after co-incubated with sCD40L for 72 h, but Bax expression was up-regulated.

CONCLUSION

sCD40L may inhibit cell proliferation, cause changes in phenotype and cell cycle of A549 cells, and alter expression of apoptosis-associated gene, such as Bax.

[Inhibitory effect of viral macrophage inflammatory protein-II on metastasis of breast cancer cell line MCF-7 through antagonising CXCR4]

BACKGROUND & OBJECTIVE

CXCR4-stromal cell-derived factor-1 (CXCR4-SDF-1alpha) system has been proved to be involved in targeting metastasis of breast cancer. Some antagonists of CXCR4 have inhibitory effects on metastasis of breast cancer. This study was to investigate effect of viral macrophage inflammatory protein-II (vMIP-II), an antagonist of CXCR4, on metastasis of breast cancer cell line MCF-7.

METHODS

Proliferation of MCF-7 cells stimulated by vMIP-II of different concentrations (10, 50, 100, 500, and 1 000 ng /ml) was detected by MTT assay, clone formation rate was assessed by agar clone assay. Adhesion and chemotaxis assays were also used to evaluate the effect of vMIP-II on MCF-7 cells in different steps of metastasis.

RESULTS

MCF-7 cells treated with vMIP-II of a series of concentrations for 72 h showed no proliferation change (P >0.05). vMIP-II (50-1 000 ng /ml) suppressed colony formation of MCF-7 cells in a concentration-dependent manner. After MCF-7 cells treated with 300 ng/ml of vMIP-II for different time (0, 0.5, 2, and 6 h), inhibition peak of cell adherence to fibronectin (FN) and Matrigel was observed. The number of migration was low in MCF-7 cells in the presence of vMIP-II of 500 ng/ml (24+/-10) was lower than that of control MCF-7 cells (60+/-9) (P< 0.05).

CONCLUSIONS

The clone formation rate of MCF-7 cells may negatively correlates with the concentration of vMIP-II. vMIP-II may inhibit MCF-7 cells adhesion to FN and Matrigel, and suppress chemotactic activity of MCF-7 cells toward extracts of human lung protein.

Inhibitory effects of glycoprotein-120 (G-120) from Ulmus davidiana Nakai on cell growth and activation of matrix metalloproteinases

Excessive breakdown of extracellular matrix by metalloproteinases (MMPs) occurs in many pathological conditions. Consequently, methods for inhibiting MMP activity have therapeutic potential. In this study, we investigated the effect of G-120, a 120 kDa glycoprotein purified from the Oriental herbal plant, Ulmus davidiana Nakai (UDN), on the activity and production of several MMPs by evaluating its growth inhibitory effect on NIH 3T3 cells. Tritium uptake assays showed that proliferation of NIH 3T3 cells was strongly suppressed, and G-120-mediated inhibition of DNA synthesis proved to involve a cytostatic, rather than a cytotoxic, effect, as shown by cytotoxicity and apoptosis assays. More importantly, G-120 strongly reduced the gelatinolytic and collagenase activities of MMP proteins, as well as expression of MMP-2 and MMP-9. Electrophoretic mobility shift assays revealed that it suppressed the DNA binding activity of NF-kappaB. Collectively, our observations show that G-120 strongly inhibits the activation of MMPs and NF-kappaB.

High-resolution magnetic resonance imaging of iron-labeled myoblasts using a standard 1.5-T clinical scanner

Myoblast transplantation is a promising means of restoring cardiac function in infarcted areas. For optimization of transplant protocols, tracking the location and fate of the injected cells is necessary. An attractive imaging modality for this is magnetic resonance imaging (MRI) as it is noninvasive and as iron-labeled myoblasts provide a signal attenuation in T2*-weighted protocols. The aim of this study was to develop an efficient iron-labeling protocol for myoblasts and to visualize single-labeled cells using a clinical 1.5-T scanner. Pig myoblasts were labeled with a superparamagnetic iron oxide (SPIO) agent using a liposome transfection agent. Labeling efficiency, toxicity, cell viability, and proliferative capacity were measured for 10 days. Magnetic resonance (MR) of myoblast cultures used a T2*-weighted three-dimensional protocol with a maximum in-plane resolution of 19.5 x 26.0 microm2 and 50 microm slices. Use of liposomes improved SPIO labeling efficiency. Labeling did not induce toxicity or affect cell viability or proliferation. The cell distribution as observed with light and fluorescence microscopy matched the signal voids observed in the MRI datasets. Liposomes promote fast, nontoxic and efficient SPIO labeling of myoblasts that can be tracked by MRI microscopy in clinical scanners using susceptibility-weighted protocols.

Measurement of daughter cell accumulation during lymphocyte proliferation in vivo

We describe a method to characterize the effects that immunological adjuvants have on in vivo lymphocyte proliferation at the level of daughter cell accumulation. We used standard 5,6-carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeling techniques to follow T cells through multiple rounds of division in experimentally treated mice and measured both the fold-increase in cell number and average number of divisions undergone by each cell. These data were then incorporated into a calculation to determine the average number of daughter cells that accumulated from each round of mitosis, termed the daughter cell accumulation index. In vivo proliferation of T cells that had been stimulated by antigen in the absence of adjuvant was associated with an index value of 1.2, far below the theoretical maximum of 2.0. Low index values indicate poor daughter cell accumulation during proliferation, either because the newly produced cells died or persisted without dividing again. Inclusion of the natural adjuvant lipopolysaccharide (LPS) led to average accumulation of 1.75 daughter cells per cell cycle and an exponential increase in peak clonal expansion. Adjuvant-induced increases in average daughter cell accumulation appeared to account for more of the enhancement in clonal expansion than did adjuvant-induced increases in the number of cell divisions undergone by each cell. Therefore measurement of changes in daughter cell accumulation can be important to understanding how adjuvants influence the yield of proliferating lymphocytes. Measurement of average daughter cell accumulation is likely to be helpful in any cellular context in which it is useful to characterize strictly mitogenic versus accumulative effects.

Synthetic Biocompatible Cyclodextrin-Based Constructs for Local Gene Delivery to Improve Cutaneous Wound Healing

The localized, sustained delivery of growth factors for wound healing therapy is actively being explored by gene transfer to the wound site. Biocompatible matrices such as bovine collagen have demonstrated usefulness in sustaining gene therapy vectors that express growth factors in local sites for tissue repair. Here, new synthetic biocompatible materials are prepared and shown to deliver a protein to cultured cells via the use of an adenoviral delivery vector. The synthetic construct consists of a linear, beta-cyclodextrin-containing polymer and an adamantane-based cross-linking polymer. When the two polymers are combined, they create an extended network by the formation of inclusion complexes between the cyclodextrins and adamantanes. The properties of the network are altered by controlling the polymer molecular weights and the number of adamantanes on the cross-linking polymer, and these modifications and others such as replacement of the beta-cyclodextrin (host) and adamantane (guest) with other cyclodextrins (hosts such as alpha, gamma, and substituted members) and inclusion complex forming molecules (guests) provide the ability to rationally design network characteristics. Fibroblasts exposed to these synthetic constructs show proliferation rates and migration patterns similar to those obtained with collagen. Gene delivery (green fluorescent protein) to fibroblasts via the inclusion of adenoviral vectors in the synthetic construct is equivalent to levels observed with collagen. These in vitro results suggest that the synthetic constructs are suitable for in vivo tissue repair applications.

Selective cytotoxicity and telomere damage in leukemia cells using the telomerase inhibitor BIBR1532

Telomerase represents an attractive target for a mechanism-based therapeutic approach because its activation has been associated with unlimited proliferation in most cancer cells. Recently, a nonnucleosidic small molecule inhibitor, BIBR1532 (2-[(E)-3-naphtalen-2-yl-but-2-enoylamino]-benzoic acid), has been identified that is highly selective for inhibition of telomerase, resulting in delayed growth arrest of tumor cells. Here we examined the effects of BIBR1532 in different leukemia cell lines as well as in primary cells from patients with acute myeloid leukemia (AML) and chronic lymphocytic leukemia (CLL) in short-term culture assays. We observed a dose-dependent direct cytotoxicity in concentrations ranging from 30 to 80 microM. Interestingly, cell death was not dependent on the catalytic activity of telomerase but was delayed in cells with very long telomeres. We observed time-dependent individual telomere erosion, which was associated with loss of telomeric repeat binding factor 2 (TRF2) and increased phosphorylation of p53. Importantly, the proliferative capacity of normal CD34(+) cells from cord blood and leukapheresis samples was not affected by treatment with BIBR1532. We conclude that using this class of telomerase inhibitor at higher concentrations exerts a direct cytotoxic effect on malignant cells of the hematopoietic system, which appears to derive from direct damage of the structure of individual telomeres and must be dissected from telomerase-suppressed overall telomere shortening.

Sole BCR-ABL inhibition is insufficient to eliminate all myeloproliferative disorder cell populations

Protein kinase inhibitors can be effective in treating selected cancers, but most suppress several kinases. Imatinib mesylate has been useful in the treatment of Philadelphia chromosome-positive chronic myelogenous leukemia and B cell acute lymphoblastic leukemia through the inhibition of BCR-ABL tyrosine kinase activity. Imatinib mesylate has also been shown to inhibit KIT, ARG, and platelet-derived growth factor receptors alpha and beta, and potentially other tyrosine kinases. We have produced a mutant allele of BCR-ABL (T315A) that is uniquely inhibitable by the small molecule 4-amino-1-tert-butyl-3-(1-naphthyl)pyrazolo[3,4-d]pyrimidine and used it to demonstrate that sole suppression of BCR-ABL activity was insufficient to eliminate BCR-ABL(+) KIT(+)-expressing immature murine myeloid leukemic cells. In contrast, imatinib mesylate effectively eliminated BCR-ABL(+) KIT(+)-expressing leukemic cells. In the cellular context of mature myeloid cells and Pro/Pre B cells that do not express KIT, monospecific BCR-ABL inhibition was quantitatively as effective as imatinib mesylate in suppressing cell growth and inducing apoptosis. These results suggest that the therapeutic effectiveness of small molecule drugs such as imatinib mesylate could be due to the inhibitor's ability to suppress protein kinases in addition to the dominant target.

beta1-Integrins mediate enhancement of airway smooth muscle proliferation by collagen and fibronectin

Airway smooth muscle (ASM) accumulation and enrichment of the extracellular matrix (ECM) with type I collagen and fibronectin are major pathologic features of airway remodeling in asthma. These ECM components confer enhanced ASM proliferation in vitro, but a requirement for specific integrin ECM receptors has not been examined. Here, we examined the mitogen platelet-derived growth factor (PDGF)-BB on beta1-integrin expression on human ASM cells cultured on these ECM substrates and defined the involvement of specific integrins in cell attachment and proliferation using integrin-neutralizing antibodies. PDGF-BB-dependent proliferation was enhanced two- to threefold by monomeric type I collagen or fibronectin and to a lesser extent by vitronectin; other interstitial ECM components (fibrillar type I and III collagen and tenascin-C) had no effect. Except for increased alpha3 expression induced by PDGF-BB and monomeric type I collagen or fibronectin, alpha1, alpha2, alpha4, alpha5, alphav, and alphavbeta3 integrins were unchanged compared with unstimulated cells on plastic. Blocking antibodies revealed alpha2beta1- and alphavbeta3-mediated attachment to monomeric type I collagen, whereas attachment to fibronectin required alpha5beta1. In contrast, enhancement of PDGF-BB-dependent proliferation by either monomeric type I collagen or fibronectin required alpha2beta1, alpha4beta1, and alpha5beta1 integrins. These data suggest multiple beta1-integrins regulate enhanced ASM proliferative responses.

Suicide gene therapy: conversion of ethanol to acetaldehyde mediated by human beta 2 alcohol dehydrogenase

Acetaldehyde (AcH) produced in the physiological metabolism of ethanol can be potentially toxic and immunomodulating. The antitumour activity of a suicide gene system using adenovirus delivered alcohol dehydrogenase (ADH) to convert ethanol to acetaldehyde inside cancer cells has been investigated in vitro and in vivo. In vitro experiments confirmed the toxicity of acetaldehyde to a number of tumour cell lines. Daudi lymphoma cells grown in normal media increased by Day 4 to 650% of their starting number, while those exposed to 250 microM, 500 microM and 1 mM acetaldehyde reached 138, 30 and 5% respectively. Adenocarcinoma cells appeared to be less sensitive with CMT-64 cells and HeLa cells numbering 105 and 53% of their starting number by Day 4 with 1 mM acetaldehyde. After transduction with an adenovirus containing the human ADH beta 2 cDNA, CMT-64 cells exposed to 20 mM ethanol had a reduction in number to 74% by Day 2 and to 36% by Day 4. In a preclinical model with Ad-ADH CMT-64 cells, mice exposed to daily pulses of ethanol for 5 days formed tumours only 30% on Day 6 and 42% on Day 13 of the volume of those in mice exposed to water. The ability of this easily administered suicide gene system to produce significant effects on cell proliferation in vivo suggests that further optimized development is warranted.

Undersulfated, low-molecular-weight glycol-split heparin as an antiangiogenic VEGF antagonist

Vascular endothelial growth factor (VEGF) represents a target for antiangiogenic therapies in a wide spectrum of diseases, including cancer. As a novel strategy to generate nonanticoagulant antiangiogenic substances exploiting binding to VEGF while preventing receptor engagement, we assessed the VEGF-antagonist activity of a low-molecular-weight (LMW) compound (ST2184, Mw = 5800) generated by depolymerization of an undersulfated glycol-split heparin derivative. The parental compound was obtained by introducing regular sulfation gaps along the prevalently N-sulfated heparin regions, followed by glycol-splitting of all nonsulfated uronic acid residues (approximately 50% of total uronic acid residues). ST2184 was endowed with a negligible anticoagulant activity after S.C. injection in mice. ST2184 binds VEGF165 as evaluated by its capacity to retard 125I-VEGF165 electrophoretic migration in a gel mobility shift assay and to prevent VEGF165 interaction with heparin immobilized onto a BIAcore sensor chip. Unlike heparin, ST2184 was unable to present 125I-VEGF165 to its high-affinity receptors in endothelial cells and inhibited VEGF165-induced neovascularization in the chick embryo chorioallantoic membrane. Undersulfated, LMW glycol-split heparins may therefore provide the basis for the design of novel nonanticoagulant angiostatic compounds.

Empirical models of the proliferative response of cytokine-dependent hematopoietic cell lines

There is an expanding need for predictive mathematical models to accelerate the optimization of cell therapy culture processes. Here we demonstrate the ability of simple mathematical models to describe quantitatively the cytokine growth-rate dependence of two human hematopoietic cell lines, TF-1 and MO7e. These cells are immortal but depend on either interleukin-3 (IL-3) or granulocyte-macrophage colony stimulating factor (GM-CSF) for their continued survival and maximal proliferation. They are also responsive to interleukin-6 (IL-6) and exhibit saturation kinetics when these cytokines are limiting. A Monod-type relationship consistently failed to fit measured cytokine dose-proliferation response curves while a Hill-type relationship showed a good fit. Cytokine interactions were first modeled by modifying the Hill-function to include an interaction parameter, gamma. This model did not indicate either synergistic or even additive effects between IL-3 and GM-CSF. Based on the reported competition between IL-3 and GM-CSF for their common receptor (beta(c)) subunit, a competitive model was also developed. This model had no new parameters beyond those obtained from single cytokine cultures and provided improved prediction of the growth rates for both cell lines exposed to combinations of IL-3 and GM-CSF over a wide range of concentrations. As expected, the competitive model failed to fit the data for IL-6 in combination with either IL-3 or GM-CSF, since IL-6 signaling does not involve the beta(c) chain of the IL-3/GM-CSF receptors. Interestingly, the cell-specific rates of GM-CSF uptake and cell proliferation were found to be uncoupled processes. Taken together, these results illustrate the utility of appropriately designed empirical models to describe the proliferative responses of hematopoietic cells to cytokine stimulation.

Selective activation of vitamin D receptor by lithocholic acid acetate, a bile acid derivative

The vitamin D receptor (VDR), a member of the nuclear receptor superfamily, mediates the biological actions of the active form of vitamin D, 1alpha,25-dihydroxyvitamin D(3). It regulates calcium homeostasis, immunity, cellular differentiation, and other physiological processes. Recently, VDR was found to respond to bile acids as well as other nuclear receptors, farnesoid X receptor (FXR) and pregnane X receptor (PXR). The toxic bile acid lithocholic acid (LCA) induces its metabolism through VDR interaction. To elucidate the structure-function relationship between VDR and bile acids, we examined the effect of several LCA derivatives on VDR activation and identified compounds with more potent activity than LCA. LCA acetate is the most potent of these VDR agonists. It binds directly to VDR and activates the receptor with 30 times the potency of LCA and has no or minimal activity on FXR and PXR. LCA acetate effectively induced the expression of VDR target genes in intestinal cells. Unlike LCA, LCA acetate inhibited the proliferation of human monoblastic leukemia cells and induced their monocytic differentiation. We propose a docking model for LCA acetate binding to VDR. The development of VDR agonists derived from bile acids should be useful to elucidate ligand-selective VDR functions.

Chronic olanzapine or fluoxetine administration increases cell proliferation in hippocampus and prefrontal cortex of adult rat

BACKGROUND

There has been increasing evidence that atypical antipsychotics are effective in the treatment of mood disorders or for augmenting 5-hydroxytryptamine selective reuptake inhibitors for treatment-resistant depression.

METHODS

Upregulation of neurogenesis in the adult hippocampus is a marker of antidepressant activity, and the present study investigated the influence of the atypical antipsychotic drug olanzapine on cell proliferation in the hippocampus of adult rat. The regulation of cell proliferation in the prelimbic cortex of adult rat was also examined.

RESULTS

Chronic (21 days) olanzapine administration increased the number of newborn cells in the dentate gyrus of the hippocampus to the same extent as fluoxetine. Olanzapine or fluoxetine treatment also increased the number of proliferating cells in the prelimbic cortex. In contrast, there was no effect of either drug in the subventricular zone or primary motor cortex, and there was a trend for an increase in the striatum. Subchronic (7 days) administration of olanzapine had no effect on cell proliferation in hippocampus or prelimbic cortex, consistent with the time course for the effect of fluoxetine and the therapeutic actions of antidepressant treatment. The combination of olanzapine plus fluoxetine did not result in a greater induction of cell proliferation in either brain region. Analysis of the cell phenotype demonstrated that approximately 20% of the newborn cells in the prelimbic cortex differentiated into endothelial cells but not neurons, in contrast to the dentate gyrus, where most newborn cells differentiated into neurons.

CONCLUSIONS

The results demonstrate that antidepressant or atypical antipsychotic medications can increase the proliferation of glia in limbic brain structures, an effect that could reverse the loss of glia that has been observed in depressed patients.

Targeting cyclooxygenase-2 with sodium butyrate and NSAIDs on colorectal adenoma/carcinoma cells

AIM: The protective effects of sodium butyrate and NSAIDs (especially the highly selective COX-2 inhibitors) have attracted considerable interest recently. In this study, primary adenoma cells and HT-29 were used to investigate whether the above drugs would be effective for reducing proliferation and inducing apoptosis. Additionally, it was investigated whether NSAIDs would strengthen the effects of sodium butyrate and its possible mechanisms.

METHODS: In vitro primary cell culture of colorectal adenomas and HT-29 were used for this investigation. PGE₂ isolated from HT-29 cell culture supernatants was investigated by ELISA. MTT was employed to detect the anti-proliferative effects on both adenoma and HT-29 culture cells. FCM was used for apoptosis rate and cell cycle analysis. The morphology of apoptotic cells was investigated by means of electromicroscopy.

RESULTS: Sodium butyrate could stimulate the secretion of PGE₂, while NSAIDs inhibited it to below 30 pg/10⁶ cells. Both butyrate and NSAIDs could inhibit cell proliferation and induce apoptosis. The effects were time- and dose-dependent (P < 0.05). Aspirin and NS-398 could enhance the effects of sodium butyrate. The effects were stronger while sodium butyrate was used in combination with NS-398 than it was used in combination with Aspirin.

CONCLUSION: Butyrate and NSAIDs could inhibit cell proliferation and induce apoptosis respectively. NSAIDs could enhance the effects of sodium butyrate by down-regulating COX-2 expression. Selective COX-2 inhibitor is better than traditional NSAIDs.

Down-modulation of heat shock protein 70 and up-modulation of Caspase-3 during schisandrin B-induced apoptosis in human hepatoma SMMC-7721 cells

AIM: To investigate the effect of schisandrin B (Sch B) on proliferation and apoptosis of human hepatoma SMMC-7721 cells in vitro and regulation of Hsp70 and Caspases-3, 7, 9 expression by Sch B.

METHODS: Human hepatoma cell line SMMC-7721 was cultured and treated with Sch B at various concentrations. Growth suppression was detected with MTT colorimetric assay. Cell apoptosis was confirmed by DNA ladder detection and flow cytometric analysis. The expression of Hsp70, Caspases-3, 7, 9 were analyzed by Western blot analysis.

RESULTS: Sch B inhibited the growth of hepatoma SMMC-7721 cells in a dose-dependent manner, leading to a 50% decrease in cell number (LC50) value of 23.50 mg/L. Treatment with Sch B resulted in degradation of chromosomal DNA into small internucleosomal fragments, evidenced by the formation of a 180-200 bp DNA ladder on agarose gels. FCM analysis showed the peak areas of subdiploid at the increased concentration of Sch B. The results of Western bolt analysis showed that Hsp70 was down-regulated and Caspase-3 was up-regulated, while the activity of Caspases-7, -9 had no significant change.

CONCLUSION: Sch B is able to inhibit the proliferation of human hepatoma SMMC-7721 cells and induce apoptosis, which goes through Caspase-3-dependent and Caspase-9-independent pathway accompanied with the down-regulation of Hsp70 protein expression at an early event.

Apoptotic effect of PP2 a Src tyrosine kinase inhibitor, in murine B cell leukemia

Src is a non-receptor protein tyrosine kinase that transduces signals regulating cell growth and differentiation. We report here that activation of signaling pathway after blockade of tyrosine phosphorylation by PP2 (4-amino-5-(4-chloro-phenyl)-7-(t-butyl)pyrazolo[3,4-d]pyrimidine), a potent and selective inhibitor of the Src-family tyrosine kinase, can lead to cell death in murine B cell leukemia, 70Z/3. Death from PP2 occurred by apoptosis as indicated by the induction of caspase activation and annexin V/propidium iodide staining. Interestingly, PP2 was found to be able to enhance the DNA binding activity of nuclear factor kappaB (NF-kappaB) before induction of apoptosis without accompanying by increased phosphorylation of inhibitor of NF-kappaB-alpha (IkappaB-alpha). Additionally, immunoblotting analysis with PP2-treated cell extract demonstrated that, compared to other protein kinase C (PKC) isotypes, the translocation of novel PKC isotypes from the cytosol to membrane fraction was sustained for a longer time. These data suggest that the inhibition of Src-mediated tyrosine phosphorylation by PP2 may tilt the balance between each PKC isotypes, which in turn, activate NF-kappaB transcription factor, leading to apoptosis.

Role of allopregnanolone on cerebellar granule cells neurogenesis

The role of allopregnanolone on immature cerebellar granule cells (CGC) proliferation was studied. Allopregnanolone (0.1-1 microM) increased [(3)H]thymidine incorporation and cell number determined by neuronal counting and by an MTT colorimetric assay. The effect of the neurosteroid was completely prevented by preincubation with 10 mM MgCl(2), 10 microM nifedipine, 10 microM picrotoxin or by 50 microM bicuculine. We conclude that ALLO affects cerebellar neurogenesis by increasing calcium influx through voltage-gated calcium channels and GABA(A) receptors activation.

Aryl hydrocarbon receptor-activating polychlorinated biphenyls and their hydroxylated metabolites induce cell proliferation in contact-inhibited rat liver epithelial cells

Polychlorinated biphenyls (PCBs) exhibit tumor-promoting effects in experimental animals. We investigated effects of six model PCB congeners and hydroxylated PCB metabolites on proliferation of contact-inhibited rat liver epithelial WB-F344 cells. The 'dioxin-like' PCB congeners, PCB 126, PCB 105, and 4'-OH-PCB 79, a metabolite of the planar PCB 77 congener, induced cell proliferation in a concentration-dependent manner. In contrast, the 'non-dioxin-like' compounds that are not aryl hydrocarbon receptor (AhR) agonists, PCB 47, PCB 153, and 4-OH-PCB 187, an abundant noncoplanar PCB metabolite, had no effect on cell proliferation at concentrations up to 10 muM. The concentrations of dioxin-like PCBs leading to cell proliferation corresponded with the levels inducing the expression of cytochrome P450 1A1 mRNA, suggesting that the release from contact inhibition was associated with AhR activation. The effects of PCB 126 and PCB 153 on expression of proteins controlling G0/G1-S-phase transition and S-phase progression were compared. Only PCB 126 was found to upregulate cyclin A and D2 protein levels, and to increase both total cyclin-dependent kinase 2 (cdk2) and cyclin A/cdk2 complex activities. Despite the observed upregulation of cyclin D2, no increase in cdk4 activity was observed. The expression of cdk inhibitor p27Kip1 was not affected by either PCB 126 or PCB 153. These results suggest that dioxin-like PCBs can induce cell proliferation of contact-inhibited rat liver epithelial cells by increasing cyclin A protein levels, a process that then leads to upregulation of cyclin A/cdk2 activity and initiation of DNA replication. This mechanism could be involved in tumor-promoting effects of dioxin-like PCBs.

Characterization of the N-methoxyindole-3-carbinol (NI3C)--induced cell cycle arrest in human colon cancer cell lines

Recent results have shown that indole-3-carbinol (I3C) inhibits the cellular growth of human cancer cell lines. In some cruciferous vegetables, another indole, N-methoxyindole-3-carbinol (NI3C), is found beside I3C. Knowledge about the biological effects of NI3C is limited. The aim of the present study was to show the effect of NI3C on cell growth of two human colon cancer cell lines, DLD-1 and HCT-116. For the first time it is shown that NI3C inhibits cellular growth of DLD-1 and HCT-116 and that NI3C is a more potent inhibitor of cell proliferation than I3C. In addition to the inhibition of cellular proliferation, NI3C caused an accumulation of HCT-116 cells in the G2/M phase, in contrast to I3C, which led to an accumulation of the colon cells in G0/G1 phase. Furthermore, NI3C delays the G1-S phase transition of synchronized HCT-116 cells. The indole-mediated cell-cycle arrest may be related to the increased levels of the CDK-inhibitors p21 and p27 (only induced by NI3C). Only an initial increase of cdc2 protein was observed, whereas prolonged treatment with NI3C or I3C downregulates the mRNA and proteins of cyclin-dependent kinases and cyclins. These results indicate that both NI3C and I3C inhibit the proliferation of human colon cells but via different mechanisms.

Mitogen-activated protein kinase signalling pathways in IL-1 beta-dependent rat airway smooth muscle proliferation

Asthma is associated with abnormal airway smooth muscle (ASM) growth that may contribute to airway narrowing and hyperresponsiveness. We investigated the role of mitogen-activated protein kinase (MAPK) pathway in IL-1beta induced ASM proliferation in the rat. Rat tracheal ASM cells were dissociated and maintained in culture. We examined the effect of selective MAPK inhibitors, SB239063 (a p38 MAPK inhibitor), U0126 (a mitogen-activated and extracellular regulated kinase kinase, MEK-1, inhibitor which inhibits downstream extracellular regulated kinase, ERK, activity), and SP600125 (a c-jun N-terminal kinase, JNK, inhibitor) on IL-1beta-induced proliferation. Proliferation of ASM cells was significantly increased following exposure to IL-1beta in a dose-dependent manner. p38, JNK and ERK MAPKs were activated by IL-1beta in a time-dependent manner, with peak activation time at 30, 60 min and at 6 h, respectively. This activation was inhibited by their respective inhibitors. SP600125 (20 microM) had no effect on IL-1beta-induced ERK and p38 phosphorylation. SB239063, U0126 and SP600125 dose-dependently inhibited IL-1beta-dependent proliferation at doses that inhibit the activities of p38, ERK and JNK MAPKs, respectively. No additive or synergistic effects were observed on proliferative responses with any combination of these compounds. In conclusion, the three major MAPK pathways, ERK as well as the p38 MAPK and JNK pathways, are independent regulators of IL-1beta-dependent proliferation of rat ASM.

Implication of peroxisome proliferator-activated receptor gamma and proinflammatory cytokines in gastric carcinogenesis: link to Helicobacter pylori-infection

Peroxisome proliferator-activated receptor gamma (PPARgamma) is a ligand-dependent transcription factor involved in various processes including the inflammation and carcinogenesis. The aim of the present study was 1) to examine the mRNA and protein expression of PPARgamma in gastric cancer (GC); 2) to evaluate the effect of PPARgamma ligand (ciglitazone) on the proliferation and apoptosis of GC cell line; and 3) to assess the levels of gastric tissue proinflammatory cytokines, IL-1beta and IL-8, and plasma gastrin in GC patients before and after Helicobacter pylori (H. pylori) eradication. The trial material included 30 H. pylori-negative controls and 30 sex- and age-matched GC patients without or with H. pylori before and after its eradication. Expression of tissue PPARgamma, tissue levels of IL-1beta and IL-8, and plasma concentration of gastrin were significantly higher in H. pylori-positive GC compared to controls, but H. pylori eradication significantly reduced these parameters. Kato III cells incubated with alive H. pylori upregulated PPARgamma expression and ciglitazone inhibited cell proliferation and induced apoptosis. PPARgamma, proinflammatory cytokines and plasma gastrin appear to be implicated in H. pylori-related gastric carcinogenesis and PPARgamma agonists may have potential in cancer therapy.

CD74 Is Expressed by Multiple Myeloma and Is a Promising Target for Therapy

PURPOSE

CD74 (HLA-DR-associated invariant chain) plays a role in antigen presentation. In addition to its expression on antigen-presenting cells, it is expressed by carcinomas of renal, lung, gastric, and thymic origin and by certain sarcomas. The restricted expression of CD74 by normal tissues and its very rapid internalization make CD74 an attractive therapeutic target for both cancer and immunologic diseases. Preclinical efficacy of anti-CD74 monoclonal antibody (mAb) therapy has been demonstrated in B-lymphoma models. Because there are few validated antigenic targets in multiple myeloma, CD74 expression was examined.

EXPERIMENTAL DESIGN

CD74 expression was assessed by immunohistochemistry in bone marrow biopsies of known multiple myeloma cases. Its expression was measured by flow cytometry in multiple myeloma lines, and CD74 mRNA expression was determined by reverse transcription-PCR. In addition, the in vitro antiproliferative effect of LL1 mAb was evaluated on a CD74+ multiple myeloma cell line using a [3H]thymidine incorporation assay.

RESULTS

CD74 expression was observed in 19 of 22 cases of multiple myeloma, with most expressing moderate to high levels in the majority of malignant plasma cells. CD74 was expressed by most multiple myeloma cell lines, as was CD74 mRNA, at levels mirroring CD74 protein. Also, unlabeled LL1 mAb mediated in vitro growth inhibition of a CD74+ multiple myeloma cell line.

CONCLUSIONS

CD74 expression is frequent in multiple myeloma, with predominant expression by the malignant plasma cells. Because anti-CD74 mAbs internalize very rapidly and LL1 mAb has shown efficacy in B-lymphoma models, CD74 represents a novel and promising target for treatment of multiple myeloma. Therefore, LL1 mAb is well suited as a carrier of radionuclides, drugs, or toxins, and also has activity as an unlabeled mAb, thereby supporting its development for this unmet need in cancer therapy.

Characterization of the Hollow Fiber Assay for the Determination of Microtubule Disruption In vivo

PURPOSE

The hollow fiber assay is used successfully as a routine in vivo screening model to quantitatively define anticancer activity by the National Cancer Institute. This study investigates whether the hollow fiber assay can be used as a short-term in vivo model to demonstrate specific pharmacodynamic end points, namely microtubule and cell cycle disruption.

EXPERIMENTAL DESIGN

The growth of A549 cells was characterized within hollow fibers over 5 days in vivo at both subcutaneous (s.c.) and intraperitoneal (i.p.) sites. Drugs were administered on day 4 (i.p.).

RESULTS

At 24 hours, cells were retrieved from fibers at both i.p. and s.c. sites of paclitaxel-treated (20 mg/kg) and combretastatin A1 phosphate-treated (150 mg/kg) mice. Cell cycle analysis after paclitaxel treatment revealed a mean G(2)-M phase population of 48.04% (i.p.) and 25.76% (s.c.) compared with vehicle group mice (6.78 and 5.56%, respectively; P = <0.001 and 0.005, respectively). Tumor cells retrieved from combretastatin A1 phosphate-treated mice had a mean G2-M phase population of 36.3% (i.p.) and 29.36% (s.c.) compared with cells retrieved from vehicle group mice (5.58 and 5.49%, respectively; P = <0.001). Using fluorescence and laser-confocal microscopy, paclitaxel was revealed to induce the formation of spindle asters and tubulin polymerization. Combretastatin A1 phosphate was shown to hold cells in mitosis. Changes in nuclear morphology were also observed.

CONCLUSION

These data demonstrate that the hollow fiber assay can be used as a short-term in vivo model for studying the pharmacodynamic effects of both standard and novel compounds on microtubules. Evidence has also been provided to support the routine use of the in vivo hollow fiber assay for demonstrating the mechanism of action of a drug.

A Selective c-Met Inhibitor Blocks an Autocrine Hepatocyte Growth Factor Growth Loop in ANBL-6 Cells and Prevents Migration and Adhesion of Myeloma Cells

PURPOSE

We wanted to examine the role of the hepatocyte growth factor (HGF) receptor c-Met in multiple myeloma by applying a novel selective small molecule tyrosine kinase inhibitor, PHA-665752, directed against the receptor.

EXPERIMENTAL DESIGN

Four biological sequels of HGF related to multiple myeloma were studied: (1) proliferation of myeloma cells, (2) secretion of interleukin-11 from osteogenic cells, (3) migration of myeloma cells, and (4) adhesion of myeloma cells to fibronectin. We also examined effects of the c-Met inhibitor on intracellular signaling pathways in myeloma cells.

RESULTS

PHA-665752 effectively blocked the biological responses to HGF in all assays, with 50% inhibition at 5 to 15 nmol/L concentration and complete inhibition at around 100 nmol/L. PHA-665752 inhibited phosphorylation of several tyrosine residues in c-Met (Tyr(1003), Tyr(1230/1234/1235), and Tyr(1349)), blocked HGF-mediated activation of Akt and p44/42 mitogen-activated protein kinase, and prevented the adaptor molecule Gab1 from complexing with c-Met. In the HGF-producing myeloma cell line ANBL-6, PHA-665752 revealed an autocrine HGF-c-Met-mediated growth loop. The inhibitor also blocked proliferation of purified primary myeloma cells, suggesting that autocrine HGF-c-Met-driven growth loops are important for progression of multiple myeloma.

CONCLUSIONS

Collectively, these findings support the role of c-Met and HGF in the proliferation, migration, and adhesion of myeloma cells and identify c-Met kinase as a therapeutic target for treatment of patients with multiple myeloma.

High dose of glucose promotes chondrogenesis via PKC? and MAPK signaling pathways in chick mesenchymal cells

We investigated the molecular mechanism of the glucose effect on the regulation of chondrogenesis. Exposure of chick wing bud mesenchymal cells to high concentrations of glucose stimulated chondrogenesis 2-fold to 2.5-fold without affecting cell proliferation. Glucose increased protein levels and the membrane translocation of protein kinase C alpha (PKCalpha), leading to a reduction of extracellular signal-regulated kinase (ERK) phosphorylation. Phosphorylation of p38 was also increased in a PKC-independent manner by glucose treatment. Glucose also increased cell adhesion molecules such as fibronectin, integrin beta1, and N-cadherin at early stages and then decreased these adhesion molecules at later stages of chondrogenesis. These alterations in protein level of adhesion molecules and in the phosphorylation of mitogen-activated protein kinases by glucose were blocked by inhibition of PKC or p38 but were synergistically increased by the inhibition of ERK. Therefore, high doses of glucose induce the down-regulation of ERK activity via PKCalpha and the up-regulation of p38 and result in the stimulation of chondrogenesis of chick mesenchymal cells through modulating the expression of adhesion molecules.

Dexamethasone delays ulcer healing by inhibition of angiogenesis in rat stomachs

Using the non-ulcerogenic doses of dexamethasone, we explored the action of glucocorticoids on ulcer healing and its relationship with angiogenic factors in the gastric mucosa. We applied dexamethasone (0.1 or 0.2 mg/kg/day) intragastrically in rats with acetic acid-induced gastric ulcer. The mucosal prostaglandin E(2) level and protein expressions of basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) at the ulcer margin were determined. Ulcer induction significantly increased protein expressions of bFGF, VEGF, and prostaglandin E(2) level at the ulcer margin together with angiogenesis at the ulcer margin and base. The non-ulcerogenic doses of dexamethasone inhibited angiogenesis at the ulcer margin and ulcer base and delayed ulcer healing. These were associated with a significant decrease of prostaglandin E(2) level and VEGF expression, but not the bFGF expression. Supplementation with prostaglandin E(2) attenuated the inhibitory action of dexamethasone on VEGF expression and reversed the adverse effects of dexamethasone on angiogenesis and ulcer healing, without influencing bFGF expression. We concluded that dexamethasone given at non-ulcerogenic doses could decrease angiogenesis and delay acetic acid-induced ulcer healing; these actions were at least, in part, due to depletion of prostaglandin E(2) level followed by down-regulation of VEGF at the ulcer margin of the stomach.

Sequence of IGF-I, IGF-II, and HGF expression in regenerating skeletal muscle

Various cytokines are thought to play a role in muscle regeneration, however, the interaction and mechanisms of action of these cytokines remains largely unknown. In this study, we investigated the role of HGF, IGF-I, and IGF-II during myogenesis using the regeneration model of skeletal muscle as well as myoblast culture. RT-PCR analysis revealed that HGF and IGF-I expressions were markedly upregulated, in regenerating muscle. In contrast, there was no significant difference in IGF-II expression between normal and regenerating muscle. Immunohistochemical analysis demonstrated that HGF was expressed mostly by myocytes during the early stages of muscle regeneration. Additionally, HGF inhibited the formation of myotubes by myoblasts, but promoted cellular proliferation. Otherwise, IGF-I and IGF-II were expressed by myocytes through the early to middle stages of muscle regeneration. The addition of HGF to myoblast growing in vitro significantly increased the number of cells. These findings indicate that these three cytokines have pleiotropic effects in regenerating skeletal muscle.

TGF-beta1 treated murine dendritic cells are maturation resistant and down-regulate Toll-like receptor 4 expression

OBJECTIVE

To explore the effects of transforming growth factor beta1 (TGF-beta1) on dendritic cells (DC).

METHODS

Murine bone marrow cells were cultured with GM-CSF and TGF-beta1 to develop TGF-beta1-treated DC (TGFbeta-DC). Then they were stimulated by lipopolysaccharide (LPS). Their phenotypes were assessed by flow cytometry (FCM). The allogeneic stimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using BrdU ELISA method and IL-12p70 protein was detected by ELISA. The expression of Toll-like receptor 4 (TLR4) was analyzed by semi quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and FCM.

RESULTS

Compared to immature DC (imDC) cultured by GM-CSF alone, the TGFbeta-DC express lower CD80, CD86, I-Ab and CD40. The TGFbeta-DC were resistant to maturation with LPS. Maturation resistance was evident from a failure to up-regulate co-stimulatory molecules (CMs), to stimulate larger T cells proliferation and to enhance secretion of IL-12p70. We also found that TGF-beta1 could down-regulate TLR4 expression on TGFbeta-DC.

CONCLUSION

TGFbeta-DC are resistant to maturation stimulus (LPS) and might have some correlation with the down-modulation of TLR4 expression.

Inferring ethanol tolerance of Saccharomyces and non-Saccharomyces yeasts by progressive inactivation

The kinetics of cell inactivation in the presence of ethanol at 20, 22.5% and 25% (v/v), was measured by progressive sampling and viable counting, and used as an inference of the ethanol resistance status of five non-Saccharomyces strains and one strain of Saccharomyces cerevisiae. The capacity of standard inocula of the same strains to establish growth at increasing initial ethanol concentrations was employed as a comparison. The effect of various different pre-culture conditions on the ethanol resistance of the 6 strains was analysed by the cell inactivation method and by the cell growth method. Exposing cells to 25% (v/v) ethanol for 4 min enabled the differentiation of the yeasts in terms of their resistance to ethanol. The results suggest that the two methods are generally concordant and that the cell inactivation method can, thus, be used to infer ethanol resistance of yeast strains.

In vitro effects on proliferation, telomerase activity and apoptosis of an eremophilanoid sesquiterpene from Senecio oldhamianus maxim in cultured human tumor cell lines

8,11-Dioxol-6-en-9alpha, 10alpha-epoxy-8beta-hydroxyeremophilane (HEM), a new eremophilanoid sesquiterpene, was isolated from Senecio oldhamianus Maxim. Its effects of cytotoxicity, telomerase activity, apoptosis and related genes expression in two human tumor cell lines, human hepatoma cells SMMC-7721 and human oophoroma cells HO-8910, were studied. Hydroxycamptothecine (HCPT) was used as a positive control. The IC50 of cytotoxicity by HEM were 24.9 +/- 2.1 and 19.4 1.6 microM in SMMC-7721 and HO-8910 cells respectively, and 0.35 +/- 0.10 and 0.27 +/- 0.08 microM for HCPT. HEM inhibited telomerase activity with the IC50 35.9 +/- 3.2 microM in SMMC-7721 and 25.6 +/- 2.6 microM in HO-8910 cells, while HCPT had no effect on telomerase activity in both tumor cell lines. HEM 20-30 microM induced apoptosis in SMMC-7721 cells from 5.7% to 18.4% and in HO-8910 cells from 7.6% to 67.1%. While HCPT 0.1-0.5 microM induced apoptosis in SMMC-7721 cells from 6.5% to 13.3% and in HO-8910 cells from 9.9% to 30.9%. HEM 30 microM significantly decreased Bcl-2 protein expression to 58.7% in SMMC-7721 and to 57.6% in HO-8910 cells. While HCPT 0.5 microM significantly decreased Bcl-2 protein expression to 64.3% in SMMC-7721 and to 70.0% in HO-8910 cells. HEM 25 microM and 30 microM significantly increased P53 protein expression 2.3-3.6-fold in SMMC-7721 and 3.0-5.7- fold in HO-8910 cells. While HCPT 0.5 microM significantly increased P53 protein expression 3.3-fold in SMMC-7721 and 2.7-fold in HO-8910 cells. Overall, HCPT exhibited a more potent effect on cytotoxicity and apoptosis in the two tumor cell lines than HEM did. However HEM can inhibit telomerase activity in the two tumor cell lines but HCPT cannot.

The expression of core fucosylated E-cadherin in cancer cells and lung cancer patients: prognostic implications

It is well documented that the glycosylation of E-cadherin is correlated with cancer metastasis, but whether E-cadherin could be core fucosylated remains largely unknown. We found that E-cadherin was core fucosylated in highly metastatic lung cancer cells while absent in lowly metastatic lung cancer cells. Since alpha-1,6 Fucosyltransferase (alpha-1,6 FucT) is known to catalyze the reaction of core fucosylation, we investigated the biological function of core fucosylation on E-cadherin by alpha-1,6 FucT targeted RNAi and transfecting alpha-1,6 FucT expression vector. As a result, calcium dependent cell-cell adhesion mediated by E-cadherin was strengthened with the reduction of core fucosylation on E-cadherin after RNAi and was weakened with the elevated core fucosylation on E-cadherin after alpha-1,6 FucT over expression. Our data indicated that alpha-1,6 FucT could regulate E-cadherin mediated cell adhesion and thus play an important role in cancer development and progression. Computer modeling showed that core fucosylation on E-cadherin could significantly impair three-dimensional conformation of N-glycan on E-cadherin and produce conformational asymmetry so as to suppress the function of E-cadherin. Furthermore, the relationship between the expression of core fucosylated E-cadherin and clinicopathological background of lung cancer patients was explored in lung cancer tissue of patients. It turns out to demonstrate that core fucosylated E-cadherin could serve as a promising prognostic indicator for lung cancer patients.

[The respective roles of gonadotrophins on follicular growth and oocyte maturation]

Around 400 follicles sequentially mature and ovulate during an average woman's reproductive lifetime. Follicular growth to the stage of antrum formation is independent of gonadotrophic stimulation and might be dependent of androgen exposure. During the follicular phase, effects of LH must be considered according to the stages of follicular development: in the early follicular phase, LH acts through specific receptors, constitutively present on thecal cells, for stimulating androgen production. Androgens seem to be positively involved in the folliculogenesis in primates. Indeed, a positive correlation has been recently established between androgen receptor expression and follicular cell proliferation. Nevertheless, LH, beyond a certain ceiling level, suppresses granulosa proliferation, and initiates atresia or premature luteinisation. The development-related response to LH shown by the pre-ovulatory follicle raises the possibility that exogenous LH might be used as an adjunct to therapy with exogenous FSH in clinical ovulation induction regimens where the aim is to induce monovulation. Rec LH will allow the opportunity to provide LH support in a flexible and responsive way, with the possibility of fine tuning FSH action on follicular development. Availability of pure, standalone LH will allow a re-evaluation of follicular stimulation based on physiological principles, leading to new treatment protocols.

Cytotoxic saponins from Schefflera rotundifolia

Eight new oleanane and lupane saponins (1-8) as well as two new benzyl glycosides (9 and 10) were isolated from the aerial parts of Schefflera rotundifolia (Ten) Frodin (Araliaceae) together with two known benzyl glycosides. Their structures were established using 1D- and 2D-NMR spectroscopy and mass spectrometry. The antiproliferative activity of all compounds was evaluated using three continuous murine and human culture cell lines J774.A1, HEK-293, and WEHI-164. Compounds 7 and 8, having betulinic acid as aglycone, were the most active constituents.

[Establishment of K562 cell lines resistant to STI571 and a preliminary biological study]

To produce leukemic STI571-resistant cell lines and to explore the molecular mechanism of STI571-resistance, cell lines K562-n and K562-n/VCR were induced by exposing cells to gradually increasing STI571 concentration of culture medium to have STI571-resistance and major biological characteristics between these subclones and the parent cells were compared. The results showed that a STI571-resistant cell line based on multidrug-resistance was established, which exhibited 23.41-fold resistance to STI571, 662.26-fold resistance to VCR and cross-resistance to HHT. K562-n/STI was generated from K562-n and had some characteristics of MDR. The intracellular accumulation of DNR in K562-n/STI and K562-n/VCR/STI were 33.24 and 18.76 respectively. Transcription of mdr-1 gene in both K562-n/STI and K562-n/VCR/STI was positive. Cell doubling time of K562-n/STI and K562-n/VCR/STI was significantly longer than that in their parent cells (P <0.05). And proliferation index was also higher than that in parent cells (P <0.05). It is conclusion that the tolerance of K562-n cells to STI571 can be augmented by adding low-dose of STI571 into the culture medium repeatedly. K562-n/STIs expressed MDR at some extent, and transcription of mdr-1 gene in K562-n/STIs was positive. As K562-n is a cell line used to develop human leukemia in nude mice, K562-n/STI and K562-n/VCR/STI 571 will contribute to the study of mechanism of STI571-resistance as in vitro and in vivo experimental models.

[Effect of sodium butyrate in combination with ATRA on the proliferation/differentiation of MDS cell line SKM-1]

The study was purposed to explore the molecular mechanisms of sodium butyrate (NaB) action on SKM-1 cell proliferation/differentiation and to study its synergistic effect with all-trans retinoic acid (ATRA). SKM-1 cells were grown in the absence or presence of NaB and/or ATRA; the percentage of viable cells was determined by trypan blue exclusion; differentiation was investigated by nitro-blue tetrazolium (NBT) reduction; adhesion molecules of cell surface were analysed by FACS; cell cycle distribution was studied after DNA staining by propidium iodide; D-type cyclins, CDK and P21 mRNA were detected by reverse transcription-polymerase chain reaction (RT-PCR). The results showed that NaB and/or ATRA blocked cells mainly in the G0/G1 phase of the cell cycle; ATRA inhibited the mRNA expression of CDK6, CDK4, cyclin D3 and cyclin D1; NaB inhibited the mRNA expression of CDK2, cyclin D2 and cyclin D1; ATRA and NaB inhibited the mRNA expression of CDK6, CDK4, CDK2, cyclin D1, cyclin D2 and cyclin D3; ATRA and/or NaB both stimulated p21 expression at the mRNA levels. It is concluded that the NaB effect on cell proliferation/differentiation may be linked to its ability to induce expression of p21 mRNA and inhibit the cyclin D-CDK complexes. These observations support the claim that NaB has the synergistic effect with ATRA.

Ectopic expression of clusterin/apolipoprotein J or Bcl-2 decreases the sensitivity of HaCaT cells to toxic effects of ropivacaine

Local anesthetics inhibit cell proliferation and induce apoptosis in various cell types. Ropivacaine, a unique, novel tertiary amine-type anesthetic, was shown to inhibit the proliferation of several cell types including keratinocytes. We found that Ropivacaine could inhibit the proliferation and induce apoptosis in an immortalized human keratinocyte line, HaCaT, in a dose- and time-dependent manner and with the deprivation of serum. The dose-dependent induction of apoptosis by ropivacaine was demonstrated by DNA fragmentation analysis and the proteolytic cleavage of a caspase-3 substrate-poly (ADP-ribose) polymerase (PARP). In addition, ropivacaine downregulated the expression of clusterin/ apoliporotein J, a protein with anti-apoptotic properties, in a dose-dependent manner, which well correlated with the induction of apoptosis of HaCaT cells. To investigate the role of clusterin/apoliporotein J in ropivacaine-induced apoptosis, HaCaT cells overexpressing clusterin/apoliporotein J were generated and compared to cells expressing the well established anti-apoptotic Bcl-2 protein. Ectopic overexpression of the secreted form of clusterin/apoliporotein J or Bcl-2 decreased the sensitivity of HaCaT cells to toxic effects of ropivacaine as demonstrated by DNA fragmentation, the proteolytic cleavage of PARP and by a reduction in procaspase-3 expression. Furthermore, the downregulation of endogenous clusterin/apolipoprotein J levels by ropivacaine suggested that this might be one mechanism by which ropivacaine induced cell death in HaCaT cells. In conclusion, the ability of ropivacaine to induce antiproliferative responses and to suppress the expression of the anti-apoptotic protein clusterin/apolipoprotein J, combined with previously reported anti-inflammatory activity and analgesic property of the drug, suggests that ropivacaine may have potential utility in the local treatment of tumors.

Biological in vitro effects of fibrin glue: fibroblast proliferation, expression and binding of growth factors

BACKGROUND

Fibrin glue is used in the endoscopic therapy of bleeding ulcerations. Accelerated closure of ulcers has been documented for this treatment in comparison with other injection techniques; the biological reason, however, remains unclear.

METHODS

In an in vitro model the effects of fibrin glue on the expression and secretion of growth factors by gastric epithelial (AGS, KATO III) and mesenchymal cells (fibroblasts) as well as their proliferative response and their interaction were compared with those of other matrices.

RESULTS

Native fibrin glue does not release vascular endothelial growth factor (VEGF) but is able to bind this growth factor in biologically relevant concentrations of 152.6 pg/mL. The addition of fibrin glue to a collagen type I matrix led to an increased proliferation rate of gastric wall fibroblasts. The transcription of VEGF and platelet-derived growth factor (PDGF) mRNA was significantly increased in epithelial cells. Co-culture of fibroblasts grown on fibrin glue containing matrix and epithelial cells resulted in an increased secretion of VEGF by both cell lines.

CONCLUSIONS

Fibrin glue leads to increased proliferation of fibroblasts and local accumulation of VEGF. These findings might at least partly explain the accelerated closure of bleeding ulcers treated by fibrin glue injection.