Using two mouse strains with different abilities to generate interferon (IFN)-c production afterMycobacterium tuberculosis infection, we tested the hypothesis that the frequency and activity of regulatory T (Treg) cells are influenced by genetic background. Our results demonstrated that the suppressive activity of spleen Treg cells from infected or uninfected BALB/c mice was enhanced, inhibiting IFN-c and interleukin (IL)-2 production. Infected C57BL/6 mice exhibited a decrease in the frequency of lung Treg cells and an increased ratio CD4 + :CD4 + Foxp3 + cells compared with infected BALB/c mice and uninfected C57BL/6 mice. Moreover, infected C57BL/6 mice also had a decrease in the immunosuppressive capacity of spleen Treg cells, higher lung IFN-c and IL-17 production, and restricted the infection better than BALB/c mice. Adoptive transfer of BALB/c Treg cells into BALB/c mice induced an increase in bacterial colony-forming unit (CFU) counts. Furthermore, BALB/c mice treated with anti-CD25 antibody exhibited lung CFU counts significantly lower than mice treated with irrelevant antibody. Our results show that in BALB/c mice, the Treg cells have a stronger influence than that in C57BL/6 mice. These data suggest that BALB/c and C57BL/6 mice may use some different mechanisms to control M. tuberculosis infection. Therefore, the role of Treg cells should be explored during the development of immune modulators, both from the perspective of the pathogen and the host.

Our results suggest that lower expression of HLA-DRA, HLA-DPA1, and HLA-DPB1 genes may contribute to more aggressive disease in pediatric ACT. HLA-DPA1 immunostaining may represent potential aggressiveness marker in this tumor.

Summary CD4+ Foxp3 + regulatory T cells inhibit the production of interferon-c, whichis the major mediator of protection against Mycobacterium tuberculosis infection. In this study, we evaluated whether the protection conferred by three different vaccines against tuberculosis was associated with the number of spleen and lung regulatory T cells. found in BCG/DNA-hsp 65-immunized or BCG/CFP-CpG-immunized mice, the lungs of both groups of mice were better preserved than those of DNAhsp 65-immunized mice. These results confirm the protective efficacy of BCG/DNA-hsp 65 and BCG/CFP-CpG heterologous prime-boost vaccines and the DNA-hsp 65 homologous vaccine. Additionally, the prime-boost regimens assayed here represent a promising strategy for the development of new vaccines to protect against tuberculosis because they probably induce a proper ratio of CD4 + and regulatory (CD4 + Foxp3 + ) cells during the immunization regimen. In this study, this ratio was associated with a reduced number of regulatory cells and no injury to the lungs.

Deregulation of the IGF system observed in human tumors indicates a role in malignant cell transformation and in tumor cell proliferation. Although overexpression of the IGF2 and IGF1R genes was described in adrenocortical tumors (ACTs), few studies reported their profiles in pediatric ACTs. In this study, the IGF2 and IGF1R expression was evaluated by RT-qPCR according to the patient's clinical/pathological features in 60 pediatric ACT samples, and IGF1R protein was investigated in 45 samples by immunohistochemistry (IHC). Whole transcriptome and functional assays were conducted after IGF1R inhibition with OSI-906 in NCI-H295A cell line. Significant IGF2 overexpression was found in tumor samples when compared with non-neoplastic samples (P < 0.001), significantly higher levels of IGF1R in patients with relapse/metastasis (P = 0.031) and moderate/strong IGF1R immunostaining in 62.2% of ACTs, but no other relationship with patient survival and clinical/pathological features was observed. OSI-906 treatment downregulated genes associated with MAPK activity, induced limited reduction of cell viability and increased the apoptosis rate. After 24 h, the treatment also decreased the expression of genes related to the steroid biosynthetic process, the protein levels of the steroidogenic acute regulatory protein (STAR), and androgen secretion in cell medium, supporting the role of IGF1R in steroidogenesis of adrenocortical carcinoma cells. Our data showed that the IGF1R overexpression could be indicative of aggressive ACTs in children. However, in vitro treatments with high concentrations of OSI-906 (>1 μM) showed limited reduction of cell viability, suggesting that OSI-906 alone could not be a suitable therapy to abolish carcinoma cell growth. 23:6Research R C P Lira et al.IGF1R in pediatric adrenocortical tumor IGF2 and IGF1R in pediatric adrenocortical tumors: roles in metastasis and steroidogenesis

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miRNAs have been identified as key regulators of almost all cellular processes, therefore, their dysregulation is involved with several diseases, including cancer. miRNAs specifically related to the metastastic cascade are called metastamiRs and can be involved with different steps of this process, including loss of adhesion. Osteosarcoma (OS) is the most common primary malignant pediatric bone tumor that often presents metastatic disease at diagnosis; therefore, a deeper study of adhesion-associated miRNAs could shed light on its pathophysiology. Online databases were used to select four miRNAs (miR-139; miR-181b; miR-584; miR-708) predicted or validated to target proteins related to adherent junctions and focal adhesion pathways, and their expression levels and possible associations with clinical features evaluated in primary OS samples. Our results showed downregulation of miR-139-5p and miR-708-5p in OS samples compared to non-neoplastic controls. Moreover, lower expression of miR-708-5p was associated with poor overall survival and higher expression of miR-181b-5p related to worst chemotherapy response (low HUVOS level). Based on these results, we selected miR-139-5p and miR-708-5p for further functional testing. Inducing the expression of miR-139-5p diminished the clonogenic capacity of the HOS cell line, while upregulation of miR-708-5p was related to a lower cellular adhesion. In summary, this work identified new signatures of microRNA dysregulation that may serve as useful prognostic markers in this aggressive pediatric bone tumor.

Chromosomal heterogeneity is a hallmark of most tumors and it can drive critical events as growth advantages, survival advantages, progression and karyotypic evolution. Medulloblastoma (MB) is the most common malignant central nervous system tumor in children. This work attempted to investigate chromosomal heterogeneity and instability profiles of two MB pediatric cell lines and their relationship with cell phenotype. We performed GTG-banding and cytokinesis-block micronucleus cytome assays, as well as morphological characterization, cell population doubling time, colony-forming efficiency, and chemo-sensitivity assays in two pediatric MB cell lines (UW402 and UW473). Both MB cells showed a high chromosomal heterogeneity. UW473 cells showed *2 fold higher both clonal-and non-clonal chromosomal alterations than UW402 cells. Besides, UW473 showed two clonal-groups well-differentiated by ploidy level (\2n[and\4n[) and also presented a significantly higher number of chromosomal instability biomarkers. These results were associated with high morphological heterogeneity and survival advantages for UW473 and proliferation advantages for UW402 cells. Moreover, UW473 was significantly more sensitive to methotrexate, temozolomide and cisplatin while UW402 cells were more sensitive to doxorubicin. These data suggest that distinct different degrees of karyotypic heterogeneity and instability may affect neoplasic phenotype of MB cells. These findings bring new insights into cell and tumor biology.

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