Zebrafish embryo extracts enhance 5-FU anti-cancer effects upon breast cancer cells.

OBJECTIVE: The inhibition of the metastatic capability of cancer cells is a pivotal aim of current anticancer strategies. We investigated herein the anti-migrating and anti-invasive properties of Zebrafish embryo extracts (SL) - an integrative formula comprising morphogenetic factors extracted from zebrafish embryos - alone or in association with 5-Fluoro-Uracil (5-FU), when added to metastatic breast cancer cells (MDA-MB-231) and in normal epithelial breast cells (MCF10A) committed toward an inflammatory phenotype upon TGF-ß1 stimulation. MATERIALS AND METHODS: Invasiveness, migrating capability, cytoskeleton architecture and related molecular factors involved in the epithelial-mesenchymal transition were studied after treatment with 5-FU, with and without SL. RESULTS: Remarkably, in both circumstances, embryo extracts amplify the migratory inhibition triggered by the anticancer drug 5-Fu. The fact that such an effect is noticed in normal as well as in cancerous cells suggests that the critical target of embryo extracts is specifically represented by the migrating/invasive phenotype. However, while 5-FU was unable in antagonizing the invasiveness of cancerous cells, the association with SL can significantly impair the invasive capability of tumor cells. These findings are noticeably associated with the reversion of the EMT phenotype in SL-treated cells, as documented by the contemporary downregulation of TCTP and some EMT-related molecular effectors, like α-SMA and Vimentin. CONCLUSIONS: Embryo fish extracts significantly counteract the migrating and invasive phenotype of cancerous and inflammatory breast cells treated with the chemotherapeutic drug 5-FU. The availability of a compound able to amplify 5-Fu activity while significantly hampering the invasive phenotype of breast cancer should provide invaluable benefits, namely if we consider that this compound is substantially deprived of side-effects.

Natural products - alpha-lipoic acid and acetyl-L-carnitine - in the treatment of chemotherapy-induced peripheral neuropathy.

OBJECTIVE: Cancer patients frequently experience Chemotherapy-Induced Peripheral Neuropathy (CIPN), as a typical side effect related to time of administration and dose of anticancer agents. Yet, CIPN pathophysiology is poorly understood, and there is a lack of well-tolerated pharmacological remedies helpful to prevent or treat it. Therefore, new safe and effective compounds are highly warranted, namely if based on an adequate understanding of the pathogenic mechanisms. MATERIAL AND METHODS: Herein we reviewed and discussed scientific data related to the beneficial role of some non-conventional treatments able to counteract CIPN, focusing our attention on alpha-lipoic acid (ALA) and L-acetyl-carnitine (LAC), two natural products that have been demonstrated to be promising preventive drugs. RESULTS: Although a growing body of in vitro and in vivo studies support ALA as a molecule able to counteract CIPN symptoms, mostly due to its antioxidant and anti-inflammatory properties, only two randomized clinical trials evaluated ALA usefulness in preventing chemotherapy-related neuropathy. Unfortunately, these studies were inconclusive and clinical outcomes showed to be highly dependent on the route of administration (oral versus or intravenous injection). LAC has demonstrated beneficial effects on both in vitro and in animal studies. Yet, some controversies aroused from randomized clinical trials. Indeed, while CIPN-patients treated with Taxane showed no benefit from LAC treatment, CIPN-patients treated with platinum compounds exhibit significant improvement of CIPN-related symptoms. Therefore, LAC treatment should be used, and thoroughly investigated only in patients treated with chemotherapy protocols Taxanes-free. CONCLUSIONS: Mechanisms of toxicity triggered by each single drug need to be deeply explored to better identify effective compounds to prevent or treat them. Moreover, additional experiments are mandatory to establish effective doses and length of treatment for each clinical situation in order to perform large and long-term randomized studies.

Inositol hexaphosphate (InsP6) as an effective topical treatment for patients receiving adjuvant chemotherapy after breast surgery.

OBJECTIVE: Oral treatment with inositol hexaphosphate (InsP6) has shown to be efficient in decreasing adverse effects in patients with breast cancer under chemotherapy. This study was aimed at evaluating and comparing the efficacy of topical InsP6 in improving quality of life in women treated with anticancer drugs. PATIENTS AND METHODS: The study was a double-blind, randomized controlled trial (RCT) with allocation concealment of 20 patients in two groups, one (experimental) applied 4% topical formulation of InsP6 once a day, whereas the second one (control) a gel containing hyaluronic acid. InsP6 therapy started 6 weeks after lumpectomy. Blood tests were monitored in both groups and quality of life was assessed using standardized QLQ-C30 and QLQ-BR23. RESULTS: Patients who applied InsP6 on the breast significantly improved their quality of life and functional status reducing side effects compared to control group; moreover, after treatment, a significant difference between the two groups was observed in the white blood cells and platelets count values. CONCLUSIONS: Topical InsP6 treatment has demonstrated to be effective and safe in preventing and/or mitigating chemotherapy-induced side effects as well as the preserving quality of life in women with ductal breast cancer.

A randomized trial of Boswellia in association with betaine and myo-inositol in the management of breast fibroadenomas.

OBJECTIVE: Breast fibroadenoma is a common finding in young women and actually accounts for the majority of benign breast lumps. Fibroadenoma does not require any treatment unless clinical symptoms (mostly mastalgia) or histological markers of cancer risk (atypia) impose specific medical or surgical intervention. In symptomatic fibroadenoma, anti-estrogenic treatments provided evidence of success. Yet, these therapies are often associated with relevant side effects that lead to drug treatment discontinuation. Additionally, in such cases, relapse is a frequent issue. Therefore, an optimal strategy is still warranted. Boswellia, betaine and myo-inositol have already been proved to modulate different pathways - inflammatory, metabolic, oxidative and endocrine processes - in a wide array of human tissues. Based on that background, we hypothesized that these substances can effectively synergize in inducing the regression of fibroadenoma. PATIENTS AND METHODS: We included 64 patients ≤ 30 years of age with fibroadenoma. The patients were randomized into two groups. The experimental group was treated with an association of Boswellia, betaine, myo-inositol, B-group vitamins and N-acetylcysteine for 6 months; otherwise, the placebo group was treated only with B-group vitamins and N-acetylcysteine. Patients were monitored at the enrollment and the end of the study for evaluating the clinical response. RESULTS: A significant clinical improvement was observed in the experimental arm. Fibroadenoma median volume reduction averaged 17.86% in the experimental group and 5.96% in the placebo group. Moreover, 14 out of 36 (38.88%) patients showed a reduction of fibroadenoma volume compared to 5/28 (17.85%) observed in the placebo group (p = 0.005). CONCLUSIONS: A supplementation with Boswellia, betaine and myo-inositol reduces fibroadenoma dimension in young women. No relevant side effects have been recorded.

An association of boswellia, betaine and myo-inositol (Eumastós) in the treatment of mammographic breast density: a randomized, double-blind study.

OBJECTIVE: Mammographic breast density is a recognized risk factor for breast cancer. The causes that lead to the proliferation of the glandular breast tissue and, therefore, to an increase of breast density are still unclear. However, a treatment strategy to reduce the mammary density may bring about very relevant clinical outcomes in breast cancer prevention. Myo-inositol is a six-fold alcohol of cyclohexane, has already been proved to modulate different pathways: inflammatory, metabolic, oxidative and endocrine processes, in a wide array of human diseases, including cancer and the genesis of mammary gland and breast diseases, like fibrosis, as well as metabolic and endocrine cues. Similarly, boswellic acid and betaine (three-methyl glycine) both inhibit inflammation and exert protective effects on breast physiology. Based on this scientific background, we hypothesized that a combination including, boswellic acid, betaine and myo-inositol would be able to reduce breast density working on different pathways. PATIENTS AND METHODS: In this study, seventy-six premenopausal women were randomly assigned to the placebo and the experimental drug arms (Eumastós) for six months. RESULTS: After 6 months of treatment, statistically significant difference between the two groups was recorded on the breast density reduction (60% vs. 9%), using mammographic as well as ultrasound examination. CONCLUSIONS: Preliminary data collected here with support the starting assumptions, that the association comprising boswellic acid, betaine and myo-inositol significantly reduces mammary density, providing the first evidence for a new and safe approach for the management of mammographic density treatment.

Physical forces and non linear dynamics mould fractal cell shape: quantitative morphological parameters and cell phenotype.

Cell shape is mainly determined by biophysical constraints, interacting according to non-linear dynamics upon the basic units provided by the genome. In turn, the specific configuration a cell acquires plays a fundamental, permissive role in modulating gene expression and many other complex biological functions. Cell shape is tightly connected to cell activity and can be considered the most critical determinant of cell function. As a consequence, measurable parameters describing shape could be considered as 'omics' descriptors of the specific level of observation represented by the cell-stroma system. Such an approach promises to formalize some of the underlying basic mechanisms and, ultimately, provide a holistic understanding of the biological processes.

Quantitative shape analysis of chemoresistant colon cancer cells: correlation between morphotype and phenotype.

Morphological, qualitative observations allow pathologists to correlate the shape the cells acquire with the progressive, underlying neoplastic transformation they are experienced. Cell morphology, indeed, roughly scales with malignancy. A quantitative parameter for characterizing complex irregular structures is the Normalized Bending Energy (NBE). NBE provides a global feature for shape characterization correspondent to the amount of energy needed to transform the specific shape under analysis into its lowest energy state. We hypothesized that a chemotherapy resistant cancer cell line would experience a significant change in its shape, and that such a modification might be quantified by means of NBE parameterization. We checked out the usefulness of a mathematical algorithm to distinguish wild and 5-fluorouracil (5-FU)-resistant colon cancer HCT-8 cells (HCT-8FUres). NBE values, as well as cellular and molecular parameters, were recorded in both cell populations. Results demonstrated that acquisition of drug resistance is accompanied by statistically significant morphological changes in cell membrane, as well as in biological parameters. Namely, NBE increased progressively meanwhile cells become more resistant to increasing 5-FU concentrations. These data indicate how tight the relationships between morphology and phenotype is, and they support the idea to follow a cell transition toward a drug-resistant phenotype by means of morphological monitoring.

Fractal analysis in a systems biology approach to cancer.

Cancer is a highly complex disease due to the disruption of tissue architecture. Thus, tissues, and not individual cells, are the proper level of observation for the study of carcinogenesis. This paradigm shift from a reductionist approach to a systems biology approach is long overdue. Indeed, cell phenotypes are emergent modes arising through collective non-linear interactions among different cellular and microenvironmental components, generally described by "phase space diagrams", where stable states (attractors) are embedded into a landscape model. Within this framework, cell states and cell transitions are generally conceived as mainly specified by gene-regulatory networks. However, the system's dynamics is not reducible to the integrated functioning of the genome-proteome network alone; the epithelia-stroma interacting system must be taken into consideration in order to give a more comprehensive picture. Given that cell shape represents the spatial geometric configuration acquired as a result of the integrated set of cellular and environmental cues, we posit that fractal-shape parameters represent "omics" descriptors of the epithelium-stroma system. Within this framework, function appears to follow form, and not the other way around.

Zebrafish stem cell differentiation stage factors suppress Bcl-xL release and enhance 5-Fu-mediated apoptosis in colon cancer cells.

Stem cell differentiation stage factors (SCDSF), taken from Zebrafish embryos during the stage in which totipotent stem cells are differentiating into pluripotent stem cells, have been shown to inhibit proliferation and induce apoptosis in colon tumors. In order to ascertain if these embryonic factors could synergistically/additively interact with 5-Fluorouracil (5-Fu), whole cell-count, flow-cytometry analysis and apoptotic parameters were recorded in human colon cancer cells (Caco2) treated with Zebrafish stem cell differentiation stage factors (SCDSF 3 µg/ml) in association or not with 5-Fu in the sub-pharmacological therapeutic range (0.01 mg/ml). Cell proliferation was significantly reduced by SCDSF, meanwhile SCDSF+5-Fu leads to an almost complete growth-inhibition. SCDSF produces a significant apoptotic effect, meanwhile the association with 5-FU leads to an enhanced additive apoptotic rate at both 24 and 72 hrs. SCDSF alone and in association with 5-Fu trigger both the extrinsic and the intrinsic apoptotic pathways, activating caspase-8, -3 and -7. SCDSF and 5-Fu alone exerted opposite effects on Bax and Bcl-xL proteins, meanwhile SCDSF+5-Fu induced an almost complete suppression of Bcl-xL release and a dramatic increase in the Bax/Bcl-xL ratio. These data suggest that zebrafish embryo factors could improve chemotherapy efficacy by reducing anti-apoptotic proteins involved in drug-resistance processes.

Embryonic morphogenetic field induces phenotypic reversion in cancer cells. Review article.

Cancer cells introduced into developing embryos can be committed to a complete reversion of their malignant phenotype. It is unlikely that such effects could be ascribed to only few molecular components interacting according to a simple linear-dynamics model, and they claim against the somatic mutation theory of cancer. Some 50 years ago, Needham and Waddington speculated that cancer represents an escape from morphogenetic field like those which guide embryonic development. Indeed, disruption of the morphogenetic field of a tissue can promote the onset as well as the progression of cancer. On the other hand, placing tumor cells into a "normal" morphogenetic field - like that of an embryonic tissue - one can reverse malignant phenotype, "reprogramming" tumor into normal cells. According to the theoretical framework provided by the thermodynamics of dissipative systems, morphogenetic fields could be considered as distinct attractors, to which cell behaviors are converging. Cancer-attractors are likely positioned somewhat close to embryonic-attractors. Indeed, tumors share several morphological and ultra-structural features with embryonic cells. The recovering of an "embryonic-like" cell shape might enable the gene regulatory network to reactivate embryonic programs, and consequently to express antigenic and biochemical embryonic characters. This condition confers to cancer an unusual sensitivity to embryonic regulatory cues. Thus, it is not surprising that cancer cells exposed to specific embryonic morphogenetic fields undergoes significant modifications, eventually leading to a complete phenotypic reversion.

Multiwalled carbon nanotube buckypaper: toxicology and biological effects in vitro and in vivo.

AIM: We evaluated the effect of buckypaper (BP) on cancer and primary cell lines in vitro and in vivo in laboratory rats. BP is an innovative material with interesting physical/chemical properties that has possible pharmacological and prosthetic employment. Given that precautions need to be taken where carbon nanotubes are injected into human body for drug delivery, as contrast agent-carrying entities for MRI or as the material of a new prosthesis generation, we assessed the toxicity of BP carbon nanotubes. BP has structural resemblance to asbestos, whose toxicity has been linked to cancer. RESULTS: BP decreased proliferation of human colorectal, breast and leukemic cancer cell lines in vitro. However, BP had no effect on the proliferation and viability of normal human arterial smooth muscle cells and human dermal fibroblasts in vitro. in vivo, BP induced a moderate inflammatory reaction but had no mutagenic effects. After BP implantation the animals showed an inflammatory reaction followed 2 weeks later by a cicatrization reaction with the organization and fibrosis of the scar. CONCLUSION: These results show a low toxicity of BP both in vitro and in vivo.

Beyond the oncogene paradigm: understanding complexity in cancerogenesis.

In the past decades, an enormous amount of precious information has been collected about molecular and genetic characteristics of cancer. This knowledge is mainly based on a reductionistic approach, meanwhile cancer is widely recognized to be a 'system biology disease'. The behavior of complex physiological processes cannot be understood simply by knowing how the parts work in isolation. There is not solely a matter how to integrate all available knowledge in such a way that we can still deal with complexity, but we must be aware that a deeply transformation of the currently accepted oncologic paradigm is urgently needed. We have to think in terms of biological networks: understanding of complex functions may in fact be impossible without taking into consideration influences (rules and constraints) outside of the genome. Systems Biology involves connecting experimental unsupervised multivariate data to mathematical and computational approach than can simulate biologic systems for hypothesis testing or that can account for what it is not known from high-throughput data sets. Metabolomics could establish the requested link between genotype and phenotype, providing informations that ensure an integrated understanding of pathogenic mechanisms and metabolic phenotypes and provide a screening tool for new targeted drug.

Locoregional IL-2 therapy in the treatment of colon cancer. Cell-induced lesions of a murine model.

BACKGROUND: Local therapy with IL-2 may be very effective in the treatment of different forms of cancer. The aim of this study was to determine the effectiveness of IL-2 locoregional application in the treatment of colon cancer. MATERIALS AND METHODS: Twenty eight syngenic BDIX rats were utilized in this study. The rats were divided into two groups of fourteen animals: group T (treatment) and group C (control). All rats of both groups were injected, under the splenic capsule, with T 10(7) DHD/K2/ TRb neoplastic cells. Then, within and around the site of the previous inoculation, the T group was injected with 1 ml of glucosate solutions + 0.1% albumin (BSA) containing 2.5 x 10(6) IU of IL-2 ( Proleukin-Chiron), whereas the C group was injected with 1 ml of BSA alone. After three weeks, rats were sacrificed and the liver and spleen were removed. The following parameters were considered: volume and weight, neoplastic-non neoplastic tissue index of the spleen, mitotic index and vascular density of splenic and hepatic lesions. RESULTS: All the studied parameters showed statistically significant differences in treated and untreated animals. CONCLUSION: This study of a murine model demonstrated that IL-2 locoregional therapy may be effective in the treatment of colon cancer.

Dual role of VEGF in pretreated experimental ePTFE arterial grafts.

BACKGROUND: Lack of endothelialization and abnormal smooth muscle cell (SMC) growth adversely affect the outcome of vascular synthetic grafts. The aims of our study were to investigate how a coating of extracellular matrix (ECM) and vascular endothelial growth factor (VEGF) might affect the endothelialization rate, smooth muscle cells (SMC) proliferation, and myointimal hyperplasia in experimental arterial ePTFE grafts. METHODS: In each of 30 male Lewis rats, a 1-cm-long ePTFE graft was inserted at the level of the abdominal aorta. Animals were randomized in five groups (six animals each): groups A and A1 received ePTFE grafts coated with a synthetic extracellular matrix (growth factor-reduced matrigel) containing VEGF; groups B and B1 received ePTFE grafts coated with synthetic ECM; and group C received ePTFE grafts alone. The grafts were explanted at 30 days from surgery for immunohistochemical analysis. RESULTS: Both endothelialization rate and myointimal hyperplasia were augmented in group A versus groups B and C, and these findings were statistically significant. SMC density resulted significantly higher in group A versus groups B and C, and this was associated with an altered expression of bFGF and TGFbeta. CONCLUSIONS: Pretreating ePTFE grafts with synthetic ECM and VEGF results in better endothelialization, but also in undesired higher SMC density and myointimal hyperplasia.

Nicotine reorganizes cytoskeleton of vascular endothelial cell through platelet-derived growth factor BB.

BACKGROUND: Cigarette smoking has been directly linked to atherosclerosis formation and vascular graft failures but the role of nicotine in these processes is not yet completely understood. We investigated the release of platelet-derived growth factor BB (PDGF BB) by the bovine aortic endothelial cell (EC) after nicotine administration at concentrations similar to those found in plasma of active and passive smokers and the role of PDGF BB, autocrinally released, in EC cytoskeletal modification. METHODS: EC were stimulated in a serum-free medium for 72 h with (-)-nicotine (from 6 x 10(-4) to 6 x 10(-8) M). The release of PDGF BB was assessed by inhibition antibody-binding assay and confirmed by Western blotting. Mitogenic activity of nicotine on EC was also determined. The EC cytoskeleton was studied with specific antibodies anti-alpha-actin fibers and anti-vimentin and the modification induced by PDGF BB was assessed by blocking PDGF BB activity with specific antibodies. RESULTS: The greatest PDGF BB release was noted at a (-)-nicotine concentration of 6 x 10(-6) M (P < 0.001). The addition of antibody anti-PDGF BB to EC exposed to (-)-nicotine decreased tritiated thymidine uptake by 20% (P < 0.001). EC exposed to (-)-nicotine concentrations of 6 x 10(-6) and 6 x 10(-8) M had a significant alteration in the expression of alpha-actin fibers and vimentin as compared with control. Administration of the antibody anti-PDGF BB in the culture medium reversed cytoskeletal alteration. CONCLUSIONS: Nicotine enhanced the release of PDGF BB by EC which in turn caused an alteration in cytoskeletal organization.

In vitro proliferation and in vivo malignancy of cell lines simultaneously derived from a chemically-induced heterogeneous rat mammary tumor.

Identification of clones in primary tumors responsible for proliferation, invasion, and metastasis was carried out. Four different aneuploid established cell lines derived from a ductal infiltrating mammary rat tumor induced by 7,12-dimethylbenz[a]anthracene were studied for proliferative and growth features in vitro and for tumorigenic and metastatic potential in vivo in nude mice. Clones, named RM1, RM2, RM3, and RM4, were characterized by different proliferative activity. Clone RM1 showed the highest proliferative activity by both tritiated thymidine incorporation and S-phase flow cytometry, followed by clone RM4. Conversely, clones RM2 and RM3 showed a lower proliferation rate. Growth-promoting activity, tested on 3T3 Swiss cells, was high in all clones, although RM1 showed significantly lower growth factors-releasing activity. Nude mice tumorigenesis demonstrated a strong tumor induction of line RM1 (100% of the mice after 47 +/- 7 d) and a slightly lower tumor induction of line RM4 (70% of the mice after 69 +/- 9 d). Line RM3 showed tumor induction in 40% of the mice after 186 +/- 16 d. Lines RM2 showed no tumor induction. Metastasis occurred in mice treated with line RM1 only. Therefore, tumorigenesis and metastasis correlate with proliferation but not with the release of growth factors. In conclusion, flow cytometry monitoring of clones from heterogeneous primary tumors proved to be a suitable model for the study of in vivo malignancy and in vitro proliferation.

Nicotine-induced smooth muscle cell proliferation is mediated through bFGF and TGF-beta 1.

BACKGROUND: Cigarette smoking influences and enhances the development of atherosclerosis. We investigated if nicotine, an important constituent of cigarette smoking, has a stimulatory effect on bovine smooth muscle cell proliferation in vitro through the mediation of bFGF and TGF-beta 1. METHODS: Bovine aortic smooth muscle cells (SMC) were stimulated with (-)-nicotine at various concentrations ranging from 6 x 10(-4) mol/L to 6 x 10(-8) mol/L. SMC viability and count were assessed. The presence of bFGF and TGF-beta 1 in serum-free conditioned media was determined by the inhibition antibody-binding assay, and the mitogenic activity of (-)-nicotine on SMC was analyzed by the 3H-thymidine uptake. Polymerase chain reaction was used to study the expression of bFGF and TGF-beta 1. RESULTS: The bFGF release after (-)-nicotine stimulation was greater than in the controls, whereas TGF-beta 1 release was lower. The greatest mitogenic activity was found at a (-)-nicotine concentration of 6 x 10(-6) mol/L. The addition of monoclonal antibody anti-bFGF decreased the 3H-thymidine uptake of SMC exposed to (-)-nicotine, whereas the addition of monoclonal antibody anti-TGF-beta 1 increased the 3H-thymidine uptake of stimulated SMC. bFGF mRNA expression was significantly higher in SMC exposed to (-)-nicotine than in the controls, but TGF-beta 1 mRNA expression was significantly lower in SMC exposed to 6 x 10(-6) mol/L (-)-nicotine than in SMC treated with the other concentrations of (-)-nicotine and in controls. CONCLUSIONS: Nicotine is a potent regulator of bFGF and TGF-beta 1 production and release by aortic SMC, and it seems to play an important role in the development and progression of atherosclerosis and neointimal fibrous hyperplasia.

Nicotine induces platelet-derived growth factor release and cytoskeletal alteration in aortic smooth muscle cells.

BACKGROUND: Cigarette smoking is implicated in atherosclerotic plaque formation, but the role of nicotine in this process is not completely understood. The release of platelet-derived growth factor (PDGF) by the bovine aortic smooth muscle cell (SMC) after nicotine administration at a concentration similar to that ingested by active and passive smokers and the role of PDGF in SMC cytoskeletal modification were studied. METHODS: SMC, harvested with enzymatic digestion from calf aorta, were stimulated in a serum-free medium for 72 hours with (-)-nicotine (from 6 x 10(-4) mol/L to 6 x 10(-8) mol/L). The release of PDGF was assessed by inhibition antibody-binding assay and confirmed by Western blotting. Mitogenic activity of nicotine on SMCs was also determined. The SMC cytoskeleton was studied with specific antibodies anti-alpha-actin fibers, anti-vimentin, and anti-beta-tubulin, and the modification induced by PDGF was assessed by blocking PDGF activity with specific antibodies. RESULTS: The greatest PDGF release (1.24 +/- 0.14 ng/10(4) cells vs control 0.43 +/- 0.07 ng/10(4) cells) was noted at a (-)-nicotine concentration of 6 x 10(-7) mol/L (P < .001). The addition of monoclonal antibody anti-PDGF decreased the tritiated thymidine uptake of SMCs exposed to (-)-nicotine compared with the control (29% vs 5%-P < .001). SMCs exposed to (-)-nicotine concentration of 6 x 10(-7) mol/L and 6 x 10(-8) mol/L had a significant alteration in the expression of alpha-actin fibers, vimentin, and beta-tubulin compared with control. The administration of antibody anti-PDGF in the culture medium reversed cytoskeletal alteration. CONCLUSIONS: Nicotine enhanced the release of platelet-derived growth, which in turn caused an alteration in cytoskeletal organization.

Basic fibroblast growth factor and myointimal hyperplasia after experimental polytetrafluoroethylene arterial grafting.

OBJECTIVE: To assess the role of polyclonal antibodies to basic fibroblast growth factor (bFGF) in inhibiting myointimal hyperplasia after insertion of polytetrafluoroethylene (PTFE) grafts in rats. DESIGN: Experimental study. SETTING: University laboratory, Italy. ANIMALS: 24 inbred Lewis rats. INTERVENTIONS: A segment of PTFE I cm long was interposed in the abdominal aorta. The animals were randomised in two groups, n = 12 in each. The first were given polyclonal antibodies to bFGF at the time of operation, and for the first two postoperative days; and the second were given non-specific IgG at the same time periods. MAIN OUTCOME AND MEASURES: Two animals died during the immediate postoperative period of anaesthetic complications. 12 animals (6 in each group) were killed 7 days postoperatively (24 hours after injection of 5-bromo-deoxyuridine BrdU) to assess smooth muscle cell proliferation. The remaining 10 animals (5 in each group) were killed after 1 month to assess the degree of anastomotic myointimal hyperplasia. RESULTS: Antibodies to bFGF resulted in less smooth muscle cell proliferation at the anastomoses as well as anastomotic myointimal hyperplasia. Smooth muscle cell proliferation was reduced to about half in animals treated with anti-bFGF antibodies. Neointimal thickness was reduced in treated animals. CONCLUSIONS: We conclude that after PTFE arterial grafting there is increased production of bFGF at the anastomotic regions that leads to smooth muscle cell proliferation and formation of myointimal hyperplasia. Agents that reduce the production of bFGF may also reduce the development of myointimal hyperplasia after PTFE arterial grafting.

Increased production of cytokines and growth factors by aortic allografts: A possible explanation for myointimal hyperplasia formation.

Accelerated myointimal hyperplasia is a major complication of arterial allografts. The aim of our study was to analyze the role of growth factors in the genesis of myointimal hyperplasia in arterial allografts. Two groups of experiments were performed: Isografts and Allografts. The Isograft group consisted of 18 inbred Lewis rats in which a 1-cm long segment of aorta was inserted as abdominal aortic interposition graft. The aortic segments were obtained from syngeneic Lewis rats. The Allograft group consisted of 18 inbred Lewis rats, in which a 1-cm long segment of aorta was interposed at the level of the abdominal aorta. The aortic segments were obtained from allogeneic Brown-Norway rats. No immunosuppression was used. The animals were sacrificed 4 weeks after surgery and the aortic grafts were analyzed by light, electron microscopy (n = 3 for each group) and immunohistochemistry (n = 3 for each group). In addition, aortic segments (n = 12 for each group) were put in an organ culture to assess production of growth factors. All allografts showed evidence of severe myointimal hyperplasia, which was minimal in isografts. PDGF, bFGF and TGF-beta(1) production, generally considered to be the cause of myointimal hyperplasia, was not increased in allografts, whereas IL-1, TNF-alpha and GM-CSF production was increased in allografts and probably lymphocytes were the source of these cytokines (p < 0.001). We conclude that myointimal hyperplasia in aortic allografts is associated with an increase of IL-1, TNF-alpha and GM-CSF produced by lymphocytes.