Possible direct influence of complement 3 in decreasing insulin sensitvity in a cohort of overweight and obese subjects

A group of 608 apparently healthy patients, 136 men and 472 women, either overweight or obese, aged 18-69 years, were examined. BMI, waist circumference, fasting blood glucose (FBG), insulin, and complement 3 (C3) serum levels were measured; the homeostasis model assessment (HOMAIR) was used to evaluate insulin resistance; and physical activity was quantified by a questionnaire.

RESULTS

HOMAIR showed a positive correlation with BMI (r: 0.478, p < 0.001), waist circumference (r: 0.487, p < 0.001), and C3 (r: 0.445, p < 0.001). Moreover, it was significantly associated with gender (F Fisher = 22.12, p < 0.001), and the mean HOMAIR levels were significantly different among the three groups of physical activity, with the lowest level of insulin resistance at the highest level of physical activity (F=7,31, p < 0.001). A multiple regression analysis was carried out with HOMAIR as the dependent variable and gender, age, BMI, waist circumference, C3 and the level of physical activity as independent variables (fitted model: F = 41.24, P<0.001, R2 = 0.328). HOMAIR maintained an independent association with C3 (β = 0.678, P<0.001), sex (β = 0.189, P<0.001), BMI (β = 0.637, P<0.01), and age (β = -0.004, P<0.05).

CONCLUSIONS

This study of a cohort of overweight and obese subjects has shown that insulin resistance (dependent variable) is positively associated with C3 serum levels, independently of age, gender, anthropometric parameters and physical activity, suggesting that higher C3 serum levels may directly increase insulin resistance in obesity.

Obesity and heart failure

Epidemiological studies have recently shown that obesity, and abdominal obesity in particular, is an independent risk factor for the development of heart failure (HF). Higher cardiac oxidative stress is the early stage of heart dysfunction due to obesity, and it is the result of insulin resistance, altered fatty acid and glucose metabolism, and impaired mitochondrial biogenesis. Extense myocyte hypertrophy and myocardial fibrosis are early microscopic changes in patients with HF, whereas circumferential strain during the left ventricular (LV) systole, LV increase in both chamber size and wall thickness (LV hypertrophy), and LV dilatation are the early macroscopic and functional alterations in obese developing heart failure. LV hypertrophy leads to diastolic dysfunction and subendocardial ischemia in obesity, and pericardial fat has been shown to be significantly associated with LV diastolic dysfunction. Evolving abnormalities of diastolic dysfunction may include progressive hypertrophy and systolic dysfunction, and various degrees of eccentric and/or concentric LV hypertrophy may be present with time. Once HF is established, overweight and obese have a better prognosis than do their lean counterparts with the same level of cardiovascular disease, and this phenomenon is called "obesity paradox". It is mainly due to lower muscle protein degradation, brain natriuretic peptide circulating levels and cardio-respiratory fitness than normal weight patients with HF.

Targeting bone metastatic cancer: Role of the mTOR pathway

One of the great challenges of cancer medicine is to develop effective treatments for bone metastatic cancer. Most patients with advanced solid tumors will develop bone metastasis and will suffer from skeletal related events associated with this disease. Although some therapies are available to manage symptoms derived from bone metastases, an effective treatment has not been developed yet. The mammalian target of rapamycin (mTOR) pathway regulates cell growth and survival. Alterations in mTOR signaling have been associated with pathological malignancies, including bone metastatic cancer. Inhibition of mTOR signaling might therefore be a promising alternative for bone metastatic cancer management. This review summarizes the current knowledge on mTOR pathway signaling in bone tissue and provides an overview on the known effects of mTOR inhibition in bone cancer, both in in vitro and in vivo models.

New insights into the molecular pathogenesis of langerhans cell histiocytosis

Langerhans cell histiocytosis (LCH) is a rare proliferative disorder characterized by an accumulation of cells sharing the major phenotypic features of cutaneous Langerhans cells. Given its variable clinical evolution, ranging from self-limiting lesions to multisystemic forms with a poor prognosis, in the last decades it has been debated whether LCH might not have a neoplastic rather than an inflammatory nature. However, although the fundamental events underlying the pathogenesis of LCH are still elusive, recent advances have strikingly improved our understanding of the disease. In particular, the identification of multiple interplays between LCH cells and their tumor microenvironment, along with the recognition of the lesional cytokine storm as a key determinant of LCH progression, has substantiated new opportunities for devising targeted therapeutic approaches. Strikingly, the detection of the rapidly accelerated fibrosarcoma isoform B(V600E) gain-of-function mutation as a genetic alteration recurring in more than 50% of patients has fueled the paradoxical picture of LCH as a tumor of the antigen-presenting cells that can evade rejection by the immune system. Thus, new evidence regarding the ontogeny of LCH cells, as well as a better understanding of the putative immune system frustrating strategy in LCH, may help to define the precise pathogenesis.

Molecular target therapy for bone metastasis: starting a new era with denosumab, a RANKL inhibitor

INTRODUCTION

The skeleton is generally the primary, and sometimes the only, site of metastasis in patients with advanced solid tumors. Bone metastases are the most frequent cause of cancer-related pain and the origin of severe morbidity in patients. Among the treatment options available for the prevention of skeletal-related events (SREs) associated with bone metastasis, zoledronic acid, an antiresorptive treatment from the group of bisphosphonates, is currently the standard of care in this setting.

AREAS COVERED

Zoledronic acid, together with denosumab (a monoclonal antibody against the receptor activator of nuclear factor kappa B ligand), is the most frequent approach for the prevention of cancer-related events in skeleton. This paper reviews several trials evaluating the efficacy of denosumab in comparison with zoledronic acid in patients with solid osteotropic tumors. In this setting of skeleton-invading cancers, denosumab was demonstrated to be superior to zoledronic acid in preventing or delaying SREs. In comparison with zoledronic acid, denosumab significantly delayed the time to first SRE by 17%.

EXPERT OPINION

Current research on denosumab is addressed to prove the immunomodulator effect of this agent in humans. Other avenue of research is focused on its antitumor activity observed in some Phase III trials.

Cell fusion in myeloma marrow microenvironment: role in tumor progression

Multiple myeloma (MM) is a B cell malignancy characterized by uncontrolled expansion of malignant plasma cells within the bone marrow that contribute to formation of multiple osteolytic bone disease and severe skeletal devastation. Recently, direct and indirect observations suggest that fusion events between cells housed within the MM marrow microenvironment often occur and may play a role in tumor progression, including myeloma bone disease (MBD). A number of cells resident in the marrow, such as myeloid progenitors and dendritic cells, have inherited fusogenicity and osteoclastogenic potential due to the expression of a number of fusogenic proteins as well as a high sensitivity to fusogenic factors produced within the MM marrow milieu. Similarly, osteoclasts (OC), as bone-resorbing multinucleated cells resulting from the fusion of marrow monocyte/ macrophages, have been reported to improperly fuse with malignant plasma cells and drive transition of these cells into OC-like cells exerting bone-resorbing capacity. Further, based on indirect cytogenetic and molecular evidence, it has been proposed that MM cells may generate a hybrid progeny with high metastatic potential and drug resistance, ultimately pointing to uncontrolled homotypic fusions that accelerate MBD progression.

Bendamustine overcomes resistance to melphalan in myeloma cell lines by inducing cell death through mitotic catastrophe

Melphalan has been a mainstay of multiple myeloma (MM) therapy for many years. However, following treatment with this alkylator, malignant plasma cells usually escape both apoptosis and cell cycle control, and acquire drug-resistance resulting in tumor progression. Bendamustine is being used in MM patients refractory to conventional DNA-damaging agents, although the mechanisms driving this lack of cross-resistance are still undefined. Here, we investigated the molecular pathway of bendamustine-induced cell death in melphalan-sensitive and melphalan-resistant MM cell lines. Bendamustine affected cell survival resulting in secondary necrosis, and prompted cell death primarily through caspase-2 activation. Also, bendamustine blocked the cell cycle in the G2/M phase and induced micronucleation, erratic chromosome spreading and mitotic spindle perturbations in melphalan-resistant MM cells. In these cells, both Aurora kinase A (AURKA) and Polo-like kinase-1 (PLK-1), key components of the spindle-assembly checkpoint, were down-regulated following incubation with bendamustine, whereas levels of Cyclin B1 increased as a consequence of the prolonged mitotic arrest induced by the drug. These findings indicate that, at least in vitro, bendamustine drives cell death by promoting mitotic catastrophe in melphalan-resistant MM cells. Hence, activation of this alternative pathway of cell death may be a novel approach to the treatment of apoptosis-resistant myelomas.

Immature dendritic cells in multiple myeloma are prone to osteoclast-like differentiation through interleukin-17A stimulation

Interleukin 17A (IL17A), a cytokine involved in allergy, inflammation and osteoclastogenesis, was investigated in multiple myeloma (MM) to assess its role in the osteoclast (OC)-like activity of marrow immature dendritic cells (iDCs). Comparing nine MM patients with control subjects affected by monoclonal gammopathy of undetermined significance, we found high IL17A expression in the marrow plasma of MM patients in parallel with its deposits within the stromal matrix. Increased expression of the IL17A receptor (IL17RA) was also found in primary myeloma iDCs, which underwent OC-like transdifferentiation after IL17A stimulation. To assess the role of IL17A, we measured the activity of the IL17/IL17RA pathway in IL17A-transdifferentiated iDCs and the expression of functional OC genes by Western blotting and real-time polymerase chain reaction. These cells showed increased RNA transcription of genes enrolled in the maturation of OCs, while NFATC1 and FOS were induced by IL17A, independently of NFKB1 phosphorylation. Moreover, the concurrent phosphorylation of the Lip isoform of CEBPB and the down-regulation of MAFB supported the activation of IL17RA pathway in OC-like transdifferentiated iDCs that was apparently unrelated to TNFRSF11A signalling. These data emphasize the involvement of iDCs in MM hyperactive osteoclastogenesis and suggest that their bone resorption activity is also regulated, at least in vitro, by IL17RA.

Obesity as a major risk factor for cancer

The number of cancer cases caused by being obese is estimated to be 20% with the increased risk of malignancies being influenced by diet, weight change, and body fat distribution together with physical activity. Reports from the International Agency for Research into Cancer and the World Cancer Research Fund (WCRF) have shown that the strongest evidence exists for an association of obesity with the following cancer types: endometrial, esophageal adenocarcinoma, colorectal, postmenopausal breast, prostate, and renal, whereas the less common malignancies are leukemia, non-Hodgkin's lymphoma, multiple myeloma, malignant melanoma, and thyroid tumours. To be able to develop novel methods in prevention and treatment, we first must understand the underlying processes which link cancer to obesity. Four main systems have been identified as potential producers of cancer in obesity: insulin, insulin-like growth factor-I, sex steroids, and adipokines. Various novel candidate mechanisms have been proposed: chronic inflammation, oxidative stress, crosstalk between tumour cells and surrounding adipocytes, migrating adipose stromal cells, obesity-induced hypoxia, shared genetic susceptibility, and the functional defeat of immune function. Herein, we review the major pathogenic links between obesity and susceptibility to cancer.

[Bone health in the oncologic patient]

Progressive bone loss, resulting in both osteoporosis and osteomalacia, is a frequent long-term complication in cancer patients undergoing common anti-tumor treatment programs. Monitoring of bone health by both imaging techniques and biochemical markers measurement, is useful in preventing the severe skeleton default.

Pharmacogenetics and pharmacogenomics: role of mutational analysis in anti-cancer targeted therapy

The goal of cancer pharmacogenomics is to obtain benefit from personalized approaches of cancer treatment and prevention. Recent advances in genomic research have shed light on the crucial role of genetic variants, mainly involving genes encoding drug-metabolizing enzymes, drug transporters and targets, in driving different treatment responses among individuals, in terms of therapeutic efficacy and safety. Although a considerable amount of new targeted agents have been designed based on a finely understanding of molecular alterations in cancer, a wide gap between pharmacogenomic knowledge and clinical application still persists. This review focuses on the relevance of mutational analyses in predicting individual response to antitumor therapy, in order to improve the translational impact of genetic information on clinical practice.

Therapeutic approaches to myeloma bone disease: an evolving story

Bone disease is a major morbidity factor in patients with multiple myeloma and significantly affects their overall survival. A complex interplay between malignant plasma cells and other marrow cells results in the generation of a microenvironment capable of enhancing both tumor growth and bone destruction. Bisphosphonates have consistently reduced the incidence of skeletal-related events in patients with multiple myeloma and other osteotropic tumors as well. However, their use is burdened with side-effects, including the risks of osteonecrosis of the jaw and kidney failure, suggesting that they should be discontinued after prolonged administration. New molecular targets of cell cross-talk in myeloma bone marrow are therefore under intensive investigation and new drugs are being explored in preclinical and clinical studies of myeloma bone disease. Compounds targeting osteoclast activation pathways, such as receptor activator of nuclear factor-κB/receptor activator of nuclear factor-κB ligand/osteoprotegerin, B-cell activating factor, mitogen-activated protein kinase and macrophage inflammatory protein-1α/chemokine receptor for macrophage inflammatory protein-1α axes, or soluble agents that improve osteoblast differentiation by modulating specific inhibitors such as Dickkopf-1 and transforming growth factor-β, as well as novel approaches of cytotherapy represent a new generation of promising drugs for the treatment of myeloma bone disease.

[Cell-based strategies: novel perspectives for cancer therapy]

Cellular therapies represent an emerging field in oncology. Several studies support the efficacy of cell-based immunotherapies for different solid tumors. Recent approaches, however, have been optimized in using adult stem cells, genetically modified to produce cytotoxic molecules for fighting cancer. In this review, we focused major preclinical and clinical results in this fascinating field of cell-based strategies against cancer.

Abdominal obesity is characterized by higher pulse pressure: possible role of free triiodothyronine

Objective. This study examined whether obesity is characterized by higher 24 h mean pulse pressure (24 h mean SBP-24 h mean DBP) and whether free thyroid hormones (FT(3) and FT(4)) have a relationship with 24 h mean pulse pressure. Methods. A total of 231 euthyroid overweight and obese patients, 103 women and 128 men, aged 18-68 yrs, normotensive (n = 69) or with recently developed hypertension (n = 162), never treated with antihypertensive drugs, were investigated. Fasting insulin, TSH, FT(3), FT(4), glucose, and lipid serum concentrations were measured. Waist circumference was measured as an indirect parameter of central fat accumulation. Ambulatory blood pressure monitoring (ABPM) was performed. Results. 24 h mean pulse pressure (PP) showed a significant positive correlation with BMI (P < 0.001), waist circumference (P < 0.001), and FT(3) (P < 0.001) and insulin serum levels (P < 0.05). When a multivariate analysis was performed, and 24 h PP was considered as the dependent variable, and waist circumference, FT(3), insulin, male sex, and age as independent parameters, 24 h mean PP maintained a significant association only with waist circumference (P < 0.001) and FT(3) levels (P < 0.05). Conclusion. Our results suggest that FT(3) per se may contribute to higher pulse pressure in obese subjects.

Urokinase receptor (uPAR) ligand based recombinant toxins for human cancer therapy

The urokinase receptor (uPAR) exerts essential functions in the pathophysiology of cancers and therefore constitutes an important drug target. In order to generate efficient drugs against uPAR, a new approach includes chimeric proteins associating one molecular address to specifically target uPAR and one bacterial or plant toxin that will eventually kill the tumoural cell. Using this frame, several recombinant toxins have been designed namely DTAT, DTAT13, EGFATFKDEL 7 mut, and ATF-SAP. As molecular address, all of these fusion proteins use the amino-terminal fragment of urokinase that binds with high affinity to uPAR through its growth factor domain (GFD). The various toxin moieties were derived from either diphtheria toxin, Pseudomonas exotoxin A (PE38), or saporin. In this review, we describe the rational, design, production and therapeutic anti-cancer potential of these chimeric toxins.

Effect of low-level laser irradiation on osteoblast proliferation and bone formation

Applications of laser therapy in biostimulation and healing injured tissues are widely described in medical literature. The present study focuses on the effects of laser irradiation on the growth rate and differentiation of human osteoblast-like cells seeded on titanium or zirconia surfaces. Cells were laser irradiated with low therapeutical doses at different intervals and the effects of irradiation were evaluated at each time-point. After 3 hours lasered cells showed an enhanced mitogen activity compared to non-lasered control cells and a higher alkaline phosphatase activity, marker of bone formation. At the same time, the mRNA of RUNX2 and OSTERIX, two genes involved in osteoblast differentiation, showed a clear decrease in lasered cells. This reached the lowest value 6 to 12 hours after irradiation, after which the transcripts started to increase, indicating that the laser treatment did promote the osteogenic potential of growth-induced cells. These results indicate that Low Level Laser Treatment (LLLT) stimulates osteogenic cell proliferation.