The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme—GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.

Objectives Propolis is a honeybee product used extensively in traditional medicine for its antioxidant, anti-inflammatory, immunomodulatory and anticancer effects. Propolis exhibits a broad spectrum of biological activities because it is a complex mixture of natural substances. In this review, the antitumour effects of propolis extracts and its constituents (e.g. flavonoids, terpenes and caffeic acid phenethyl ester) are discussed. Key findings The effect of propolis on experimental carcinogenesis is discussed, as well as its possible mechanisms of action against tumours, involving apoptosis, cell cycle arrest and interference on metabolic pathways. Propolis seems to be efficient against different tumour cells both in vitro and in vivo, which suggests its potential in the development of new anticancer drugs. Summary Propolis extracts may be important economically and would allow a relatively inexpensive cancer treatment. Preclinical investigations are needed to further elucidate the benefits of propolis and its antitumour properties.

It is well known that the etiology of human breast cancer is significantly affected by environmental factors. Virus-associated cancer refers to a cancer where viral infection results in the malignant transformation of the host's infected cells. Human papillomaviruses (HPV), mouse mammary tumor virus (MMTV) and Epstein-Barr (EBV) virus are prime candidate viruses as agents of human breast cancer. The precise role that viruses play in tumorigenesis is not clear, but it seems that they are responsible for causing only one in a series of steps required for cancer development. The idea that a virus could cause breast cancer has been investigated for quite some time, even though breast cancer could be a hereditary disease; however, hereditary breast cancer is estimated to account for a small percentage of all breast cancer cases. Based on current research, this review present at moment, substantial, but not conclusive, evidence that HPV, EBV and MMTV may be involved in breast cancer.

Current understanding of the role of several cancer risk factors is more comprehensive, as reported for a number of sites, including the brain, colon, breasts, and ovaries. Despite such advances, the incidence of breast cancer continues to increase worldwide. Signals from the microenviroment have a profound influence on the maintenance or progression cancers. Although T cells present the most important immunological response in tumor growth in the early stages of cancer, they become suppressive CD4(+) and CD8(+) regulatory T cells (Tregs) after chronic stimulation and interactions with tumor cells, thus promoting rather than inhibiting cancer development and progression. Tregs have an important marker protein which is FoxP3, though it does not necessarily confer a Treg phenotype when expressed in CD4(+) T lymphocytes. High Treg levels have been reported in peripheral blood, lymph nodes, and tumor specimens from patients with different types of cancer. The precise mechanisms by which Tregs suppress immune cell functions remain unclear, and there are reports of both direct inhibition through cell-cell contact and indirect inhibition through the secretion of anti-inflammatory mediators such as interleukin. In this review, we present the molecular and immunological aspects of Treg cells in the metastasis of breast cancer.

The FOXP3 gene encodes a transcription factor thought to be important for the development and function of regulatory T cells (Treg cells). These cells are involved in the regulation of T cell activation and therefore are essential for normal immune homeostasis. Signals from microenvironment have a profound influence on the maintenance or progression of diseases. Thus, Tregs have an important marker protein, FOXP3, though it does not necessarily confer a Treg phenotype when expressed. FOXP3 polymorphisms that occur with high frequency in the general populations have been studied in common multifactorial human diseases. Dysfunction of FOXP3 gene product could result in lack of Treg cells and subsequently chronically activated CD4+ T cells which express increased levels of several activation markers and cytokines, resulting in some autoimmune diseases. In contrast, high Treg levels have been reported in peripheral blood, lymph nodes, and tumour specimens from patients with different types of cancer. The present study discusses the polymorphisms located in intron, exon and promoter regions of FOXP3 which have already been investigated by many researchers. FOXP3 has received considerable attention in attempts to understand the molecular aspect of Treg cells. Therefore, in the present study, the relationship between genetic polymorphism of FOXP3 in Treg-cell role and in disease development are reviewed considering the interactive effect of genetic factors.

Breast cancer is one of the most common cancers with greater than 1,300,000 cases and 450,000 deaths each year worldwide. The development of breast cancer involves a progression through intermediate stages until the invasive carcinoma and finally into metastatic disease. Given the variability in clinical progression, the identification of markers that could predict the tumor behavior is particularly important in breast cancer. The determination of tumor markers is a useful tool for clinical management in cancer patients, assisting in diagnostic, staging, evaluation of therapeutic response, detection of recurrence and metastasis, and development of new treatment modalities. In this context, this review aims to discuss the main tumor markers in breast carcinogenesis. The most well-established breast molecular markers with prognostic and/or therapeutic value like hormone receptors, HER-2 oncogene, Ki-67, and p53 proteins, and the genes for hereditary breast cancer will be presented. Furthermore, this review shows the new molecular targets in breast cancer: CXCR4, caveolin, miRNA, and FOXP3, as promising candidates for future development of effective and targeted therapies, also with lower toxicity.

The natural history and pathogenic processes of infection by the human immunodeficiency virus type 1 (HIV-1) are complex, variable, and dependent upon a multitude of viral and host factors and their interactions. The CCR5-Delta32 allele remains the most important genetic factor known to be associated with host resistance to the HIV-1 infection. However, other mutations in the CCR5, CCR2, CX(3)CR1, CXCL12 (SDF1), and CCL5 (RANTES) genes have been identified and associated with host resistance and/or susceptibility to HIV-1 infection and disease progression. Some studies have also suggested that chemokine receptor gene polymorphisms may affect response to potent antiretroviral therapy. This article reviews the polymorphisms already described in the mutant chemokine receptors or ligands and their impact on the host susceptibility to HIV-1 infection and on the clinical course of the disease, as well as the development of new anti-HIV therapies that takes into account these potential targets in the host. These genetic polymorphisms could be used as genetic markers to detect individuals at higher risk of developing either a faster disease progression or therapeutic failure. Once these individuals are identified, therapeutic strategies based on either different, more aggressive drugs or combinations of drugs can be used, either alone or in combination with shorter intervals for therapeutic monitoring. Pharmacogenetics is very likely to underlie future therapies for HIV-1 infection, and current patients with multi-resistance to the existing antiretroviral agents could also benefit from this approach. These developments also underscore the importance of continuing the investigation of new therapies targeted to the host in order to inhibit the HIV-1 entry into the host cells.

Solid tumors are embedded in a stromal microenvironment consisting of immune cells, such as macrophages and lymphocytes, as well as nonimmune cells, such as endothelial cells and fibroblasts. Chemokines are a type of small secreted chemotactic cytokine and together with their receptors play key roles in the immune defense. Critically, they regulate cancer cellular migration and also contribute to their proliferation and survival. The CCR5 chemokine receptor is involved in leucocytes chemotaxis to sites of inflammation and plays an important role in the macrophages, T cells, and monocytes recruitment. Additionally, CCR5 may have an indirect effect on cancer progression by controlling the antitumor immune response, since it has been demonstrated that its expression could promote tumor growth and contribute to tumor metastasis, in different types of malignant tumors. Furthermore, it was demonstrated that a CCR5 antagonist may inhibit tumor growth, consisting of a possible therapeutic target. In this context, the present review focuses on the establishment of CCR5 within the interface of host immunity, tumor microenvironment, and its potential as a targeting to immunotherapy.