Karen Brajão de Oliveira

CXCL12 rs1801157 Polymorphism in Patients with Breast Cancer, Hodgkin's Lymphoma, and Non-Hodgkin's Lymphoma

Chemokines and their receptors regulate the trafficking of immune cells during their development, inflammation, and tissue repair. The single‐nucleotide polymorphism (SNP) rs1801157 (previously known as CXCL12‐A/ stromal cell‐derived factor‐1 (SDF1)‐3′A) in CXCL12/SDF1 gene was assessed in breast cancer, Hodgkins lymphoma (HL), and non‐Hodgkins lymphoma (NHL), since the chemokine CXCL12, previously known as SDF1, and its receptor CXCR4 regulate leukocyte trafficking and many essential biological processes, including tumor growth, angiogenesis, and metastasis of different types of tumors. Genotyping was performed by PCR‐RFLP (polymerase chain reaction followed by restriction fragment length polymorphism) using a restriction enzyme HpaII cleavage. No significant difference was observed in genotype distribution between breast cancer patients (GG: 57.3%; GA: 39.8%; AA: 2.9%) and healthy female controls (GG: 62.9%; GA: 33%; AA: 4.1%) nor between HL patients (GG: 61.1%; GA:27.8%; AA: 11.1%) and healthy controls (GG: 65.6%; GA: 28.9%; AA: 5.5%), whereas a significant difference was observed in genotype distribution between NHL patients (GG: 51.4%; GA: 47.1%; AA: 1.5%) and healthy controls (GG: 65.6%; GA: 28.9%; AA: 5.5%). Further studies will be necessary to elucidate the cancer chemokine network. However, this study suggests that CXCL12 rs1801157 polymorphism may have important implications in the pathogenesis of NHL. J. Clin. Lab. Anal. 23:387–393, 2009.

CC Chemokine Receptor 5: The Interface of Host Immunity and Cancer

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.

Analysis of the CC chemokine receptor 5 delta32 polymorphism in a Brazilian population with cutaneous leishmaniasis.

Abstract:  Patients with mucocutaneous leishmaniasis (MCL) show a vigorous T‐cell immune response against Leishmania braziliensis. Because the Th response is associated with inflammation, the non‐functional CC chemokine receptor 5 (CCR5) may rely in a less severe inflammatory state. The aim of this study was to investigate the CCR5 gene in a Brazilian population with leishmaniasis compared with healthy control subjects and to determine the progression from cutaneous to MCL in the Δ32 allele carriers. Among 100 patients with Montenegro skin test and indirect immunofluorescence assay (IIF) values positive for leishmaniasis, there were 32% women and 68% men. The patients were 89% CCR5/CCR5, 10% CCR5/Δ32, and 1% Δ32/Δ32, while healthy subjects showed a 91% incidence of CCR5/CCR5, 8% of CCR5/Δ32, and 1% of Δ32/Δ32. The CCR5/CCR5 patients (89%) showed a large spectrum of clinical manifestations, where 22.47% had active mucous lesions and 77.53% had cutaneous lesions. In this work, the Δ32 allele carriers (10%) showed only cutaneous manifestations when compared with wild‐type individuals. Finally, with regard to the Δ32 allele carriers, a less severe spectrum of clinical manifestations was observed in comparison with wild‐type individuals. Although a lack of mucocutaneous lesions was evident among Δ32 allele carriers, the number of individuals studied was small. Therefore, further investigations are needed to elucidate the role of CCR5 in the clinical aspects of leishmaniasis.

Immunohistochemical expression of CXCR4 on breast cancer and its clinical significance.

Many tumor cells express chemokines and chemokine receptors, and, for this reason, these molecules can affect the tumor progression. It is known that breast cancer is a complex and heterogeneous neoplasia comprising distinct diseases, histological characteristics, and clinical outcomes. The most studied role for CXCL12 chemokine and its receptor CXCR4 in breast cancer pathogenesis is the metastasis event, although several reports have demonstrated its involvement in other processes, such as angiogenesis and tumor growth. It has been found that CXCR4 is required for breast cancer cell migration to other sites such as lung, bone, and lymph nodes, which express high levels of CXCL12 chemokine. Therefore, CXCR4 is being considered a prognostic marker in breast cancer. Within this context, this review summarizes established studies involving expression of CXCR4 on breast cancer, focusing on its clinical significance.

TGF-β1 functional polymorphisms: a review

Transforming Growth Factor β (TGF-β) is a multifunctional cytokine that plays a role in several biological processes. TGF-β1 is the most abundantly expressed isoform, associated with susceptibility to various diseases, and several polymorphisms have been described in the TGF-β1 gene structure, and some of them have been associated with functional implications. To date, eight single-nucleotide polymorphisms (SNPs) and one deletion/insertion polymorphism have been shown to affect TGF-β1 expression (rs2317130, rs11466313, rs1800468, rs1800469, rs11466314, rs1800471, rs1800470, and rs11466316); some of these interfere with transcriptional regulation by affecting the binding of transcription factors binding, while others interfere with protein production. These polymorphisms have been associated with different types of diseases (i.e., cancers, cardiac diseases, inflammatory diseases, and others) and could therefore be used as susceptibility biomarkers. Since polymorphism clusters are likely to be more reliable than single polymorphisms in this respect, it is hoped that haplotype analysis of TGF-β1 may reveal the genetic basis of disease susceptibility associated with the TGF-β1 gene.Transforming Growth Factor β (TGF-β) is a multifunctional cytokine that plays a role in several biological processes. TGF-β1 is the most abundantly expressed isoform, associated with susceptibility to various diseases, and several polymorphisms have been described in the TGF-β1 gene structure, and some of them have been associated with functional implications. To date, eight single-nucleotide polymorphisms (SNPs) and one deletion/insertion polymorphism have been shown to affect TGF-β1 expression (rs2317130, rs11466313, rs1800468, rs1800469, rs11466314, rs1800471, rs1800470, and rs11466316); some of these interfere with transcriptional regulation by affecting the binding of transcription factors binding, while others interfere with protein production. These polymorphisms have been associated with different types of diseases (i.e., cancers, cardiac diseases, inflammatory diseases, and others) and could therefore be used as susceptibility biomarkers. Since polymorphism clusters are likely to be more reliable than single polymorphisms in this respect, it is hoped that haplotype analysis of TGF-β1 may reveal the genetic basis of disease susceptibility associated with the TGF-β1 gene.

FOXP3 transcription factor: a candidate marker for susceptibility and prognosis in triple negative breast cancer.

Triple negative breast cancer (TNBC) is a relevant subgroup of neoplasia which presents negative phenotype of estrogen and progesterone receptors and has no overexpression of the human epidermal growth factor 2 (HER2). FOXP3 (forkhead transcription factor 3) is a marker of regulatory T cells (Tregs), whose expression may be increased in tumor cells. This study aimed to investigate a polymorphism (rs3761548) and the protein expression of FOXP3 for a possible involvement in TNBC susceptibility and prognosis. Genetic polymorphism was evaluated in 50 patients and in 115 controls by allele-specific PCR (polymerase chain reaction). Protein expression was evaluated in 38 patients by immunohistochemistry. It was observed a positive association for homozygous AA (OR = 3.78; 95% CI = 1.02–14.06) in relation to TNBC susceptibility. Most of the patients (83%) showed a strong staining for FOXP3 protein in the tumor cells. In relation to FOXP3-positive infiltrate, 47% and 58% of patients had a moderate or intense intratumoral and peritumoral mononuclear infiltrate cells, respectively. Tumor size was positively correlated to intratumoral FOXP3-positive infiltrate (P = 0.026). In conclusion, since FOXP3 was positively associated with TNBC susceptibility and prognosis, it seems to be a promising candidate for further investigation in larger TNBC samples.

Genetic Polymorphism and Expression of CXCR4 in Breast Cancer.

CXCR4 genetic polymorphisms, as well as their expression level, have been associated with cancer development and prognosis. The present study aimed to investigate the influence of CXCR4 rs2228014 polymorphism on its mRNA and protein expression in breast cancer samples. It was observed that patients presented higher CXCR4 mRNA relative expression (5.7-fold) than normal mammary gland, but this expression was not correlated with patients clinicopathological features (nuclear grade, nodal status, ER status, PR status, p53 staining, Ki67 index, and HER-2 status). Moreover, CXCR4 mRNA relative expression also did not differ regarding the presence or absence of T allele (p = 0.301). In the immunohistochemical assay, no difference was observed for CXCR4 cytoplasmic protein staining in relation to different genotypes (p = 0.757); however, high cytoplasmic CXCR4 staining was verified in invasive breast carcinoma (p < 0.01). All in all, the results from present study indicated that rs2228014 genetic variant does not alter CXCR4 mRNA or protein expression. However, this receptor was more expressed in tumor compared to normal tissue, in both RNA and protein levels, suggesting its promising applicability in the general context of mammary carcinogenesis.

Detection of TT virus in HIV-1 exposed but uninfected individuals and in HIV-1 infected patients and its influence on CD4+ lymphocytes and viral load.

The TT virus (TTV) was detected for the first time in the serum of a patient with post-transfusion hepatitis of unknown origin. TTV was subsequently, also found in the serum of blood donors with no history of blood transfusion. In the present study, the percentage of TTV carriers among HIV-infected and noninfected patients was determined. The study was conducted to evaluate CD4 count and HIV viral load in 100 asymptomatic patients infected with HIV-1, 100 symptomatic patients with AIDS, 100 HIV-1 exposed but uninfected individuals and 100 normal healthy blood donors. In this work, the presence of TTV was investigated by nested-PCR. TTV was detected in 6% of normal donors, 12.5% of HIV-infected individuals and 21% of exposed individuals. The presence of TTV was statistically significant in the HIV-exposed individuals (21/100) compared with blood donors (6/100). Odds ratio=4.16 (95%CI 1.60-10.83). No inter-group relations were found for CD4 and CD8 counts or HIV viral load. In the symptomatic group, patients with TTV presented minor viral load. This work demonstrated that TTV was detected in HIV-exposed individuals and no relation was verified for CD4, CD8 and viral load in the asymptomatic and symptomatic HIV patients.

The role of interleukin 10 in human papilloma virus infection and progression to cervical carcinoma

Although Human Papillomavirus (HPV) exerts a vital influence on cervical carcinogenesis, other factors influence the development of a squamous intraepithelial lesion (SIL) that may or not progress to cervical cancer. Among several cytokines, Interleukin 10 (IL-10) stands out as an important anti-inflammatory factor, leading to immune system evasion through an immunosuppressive state. In the cervical microenvironment, during different stages of HPV infection, IL-10 production can be induced and maintained by different cell sources, including infected keratinocytes, some subsets of dendritic cells (DC), tumor associated macrophages (TAM), T regulatory cells (Treg) and tumor cells. Further, a wide range of effects can be exerted by IL-10 on different cell populations, such as inhibiting proinflammatory cytokine production, DCs differentiation, antigen presenting function and T-helper 1 (Th1) polarization. IL-10 is one of several cytokines involved in cancer development and sustenance, although its role in cancer is still controversial and poorly understood. However, cervical IL-10 levels tend to increase in parallel to SIL development and are even higher within cervical tumors. Accumulating data have shown that after HPV infection, IL-10 levels are enhanced as a result of HPV E2, E6 and E7 proteins action over IL-10 gene transcription, while IL-10 stimulates HPV E6 and E7 expression. Therefore, this interplay between HPV and IL-10 creates a vicious cycle that could favor an immunosuppressive microenvironment in the cervix, facilitating the progression of a simple HPV infection to SIL or cervical cancer.

Torque teno virus: a ubiquitous vírus

caid et al. showed that the TTV encodes a miRNA in vivo that orque teno virus (TTV) is a non-enveloped human DNA virus solated by Nishizawa et al. in 1997.1 TTV, recently classified s the Alphatorquevirus genus within the Anelloviridae family by he International Committee on Taxonomy of Viruses (ICTV), as the first human virus with a single-stranded circular DNA enome to be identified.2 Thus far, five main genetic groups Groups 1–5) involving at least 39 genotypes have been identied based on phylogenetic analysis.3 The TTV genome can be divided into an untranslated egion (UTR) of 1.2 kb and a potential coding region of 2.6 kb. he UTR is relatively conserved, suggesting that it plays n important regulatory role in viral replication. The codng region contains two large open reading frames: ORF1 and RF2. Several other open reading frames have been described, nd the peptides that they encode differ in length for different solates.4 This virus is characterized by an extremely high prevaence, with relatively uniform distribution worldwide and a igh level of genomic heterogeneity.4 Although this virus as a very high prevalence in the general population across he globe, neither its interaction with its hosts nor its direct nvolvement in the etiology of specific diseases is fully undertood. After the discovery of TTV, its detection has been by olymerase chain reaction (PCR) with primers targeting the RF1 (N22 region, the first described sequence), nevertheless rimers derived from the N22 region can detect only a portion f TTV variants mainly representing genetic group 1 TTV 5,6 Genotypes 1–6). As the UTRs of the viral genome are more onserved when compared to the ORF regions, UTR-targeting rimers (used later for the detection of TTV DNA) can detect