Pediatric adrenocortical tumors (ACT) are rare aggressive neoplasms with heterogeneous prognosis. Despite extensive efforts, identifying reliable prognostic factors for pediatric patients with ACT ...remains a challenge. MicroRNA (miRNA) signatures have been associated with cancer diagnosis, treatment response, and prognosis of several types of cancer. However, the role of miRNAs has been poorly explored in pediatric ACT. In this study, we performed miRNA microarray profiling on a cohort of 37 pediatric ACT and nine nonneoplastic adrenal (NNA) samples and evaluated the prognostic significance of abnormally expressed miRNAs using Kaplan–Meier plots, log‐rank test, and Cox regression analysis. We identified a total of 98 abnormally expressed miRNAs; their expression profile discriminated ACT from NNAs. Among the 98 deregulated miRNAs, 17 presented significant associations with patients’ survival. In addition, higher expression levels of hsa‐miR‐630, ‐139‐3p, ‐125a‐3p, ‐574‐5p, ‐596, ‐564, ‐1321, and ‐423‐5p and lower expression levels of hsa‐miR‐377‐3p, ‐126‐3p, ‐410, ‐136‐3p, ‐29b‐3p, ‐29a‐3p, ‐337‐5p, ‐143‐3p, and 140‐5p were significantly associated with poor prognosis, tumor relapse, and/or death. Importantly, the expression profile of these 17 miRNAs stratified patients into two groups of ACTs with different clinical outcomes. Although some individual miRNAs exhibit potential prognostic values in ACTs, only the 17 miRNA‐based expression clustering was considered an independent prognostic factor for 5‐year event‐free survival (EFS) compared to other clinicopathological features. In conclusion, our study reports for the first time associations between miRNA profiles and childhood ACT prognosis, providing evidence that miRNAs could be useful biomarkers to discriminate patients with favorable and unfavorable clinical outcomes.
Purposes
Pilocytic astrocytoma (PA) is a low-grade neoplasm frequently found in childhood. PA is characterized by slow growth and a relatively good prognosis. Genetic mechanisms such as activation of ...MAPK, BRAF gene deregulation and neurofibromatosis type 1 (NF1) syndrome have been associated with PA development. Epigenetic signature and miRNA expression profile are providing new insights about different types of tumor, including PAs.
Methods
In the present study we evaluated global miRNA expression in 16 microdissected pediatric PA specimens, three NF1-associated PAs and 11 cerebral white matter (WM) samples by the microarray method. An additional cohort of 20 PAs was used to validate by qRT-PCR the expression of six miRNAs differentially expressed in the microarray data.
Results
Unsupervised hierarchical clustering analysis distinguished one cluster with nine PAs, including all NF1 cases and a second group consisting of the WM samples and seven PAs. Among 88 differentially expressed miRNAs between PAs and WM samples, the most underexpressed ones regulate classical pathways of tumorigenesis, while the most overexpressed miRNAs are related to pathways such as focal adhesion, P53 signaling pathway and gliomagenesis. The PAs/NF1 presented a subset of underexpressed miRNAs, which was also associated with known deregulated pathways in cancer such as cell cycle and hippo pathway.
Conclusions
In summary, our data demonstrate that PA harbors at least two distinct miRNA signatures, including a subgroup of patients with NF1/PA lesions.
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 24h, 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 (>1μM) showed limited reduction of cell viability, suggesting that OSI-906 alone could not be a suitable therapy to abolish carcinoma cell growth.
Introduction
Glioblastoma (GBM) is the most common malignant primary brain tumor affecting adults. In pediatric patients, GBM exhibits genetic variations distinct from those identified in the adult ...GBM phenotype. This tumor exhibits complex genetic changes leading to malignant progression and resistance to standard therapies including radiotherapy and temozolomide treatment. The
GDF15
gene codes for a growth factor whose expression is altered in the presence of inflammations and malignancies.
GDF15
is associated with a poor prognosis and with radio- and chemoresistance in a variety of tumors. The aim of this study was to compare the response to
GDF15
knockdown in adult (U343) and pediatric (KNS42) GBM cell line models.
Methods
The expression of the
GDF15
gene was investigated by qRT-PCR and overexpression was identified in both GBM cell lines. The KNS42 and U343 cell lines were submitted to lentiviral transduction with shRNA of GDF15 and validated at the protein level. To understand the difference between cell lines, RNAseq was performed after
GDF15
knockdown.
Results
The data obtained demonstrated that the pathways were differentially expressed in adult GBM and pediatric GBM cell lines. This was confirmed by functional assays perfomed after independent treatments (radiotherapy and TMZ).
Conclusion
These results demonstrated that GBM cell lines had distinct responses to
GDF15
knockdown, a fact that can be explained by the different molecular profile of pediatric and adult GBM.
Glioblastoma (GBM) is the most common primary malignant neoplasm of the central nervous system and, despite the standard therapy; the patients’ prognoses remain dismal. The miRNA expression profiles ...have been associated with patient prognosis, suggesting that they may be helpful for tumor diagnosis and classification as well as predictive of tumor response to treatment. We described the microRNA expression profile of 29 primary GBM samples (9 pediatric GBMs) and 11 non-neoplastic white matter samples as controls (WM) by microarray analysis and we performed functional in vitro assays on these 2 most differentially expressed miRNAs. Hierarchical clustering analysis showed 3 distinct miRNA profiles, two of them in the GBM samples and a group consisting only of cerebral white matter. When adult and pediatric GBMs were compared to WM, 37 human miRNAs were found to be differentially expressed, with miR-10b-5p being the most overexpressed and miR-630 the most underexpressed. The overexpression of miR-630 was associated with reduced cell proliferation and invasion in the U87 GBM cell line, whereas the inhibition of miR-10b-5p reduced cell proliferation and colony formation in the U251 GBM cell line, suggesting that these miRNAs may act as tumor-suppressive and oncogenic miRNAs, respectively. The present study highlights the distinct epigenetic profiling of adult and pediatric GBMs and underscores the biological importance of mir-10b-5p and miR-630 for the pathobiology of these lethal tumors.
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 ( and ) 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.
Summary
CD4+ Foxp3+ regulatory T cells inhibit the production of interferon‐γ, which is 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. We observed that after homologous immunization with the 65 000 molecular weight heat‐shock protein (hsp 65) DNA vaccine, there was a significantly higher number of spleen CD4+ Foxp3+ cells compared with non‐immunized mice. Heterologous immunization using bacillus Calmette–Guérin (BCG) to prime and DNA‐hsp 65 to boost (BCG/DNA‐hsp 65) or BCG to prime and culture filtrate proteins (CFP)‐CpG to boost (BCG/CFP‐CpG) induced a significantly higher ratio of spleen CD4+/CD4+ Foxp3+ cells compared with non‐immunized mice. In addition, the protection conferred by either the BCG/DNA‐hsp 65 or the BCG/CFP‐CpG vaccines was significant compared with the DNA‐hsp 65 vaccine. Despite the higher ratio of spleen CD4+/CD4+ Foxp3+ 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 DNA‐hsp 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.
Using two mouse strains with different abilities to generate interferon (IFN)‐γ production after Mycobacterium 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‐γ 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‐γ 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.
Summary
CD
4
+
F
oxp3
+
regulatory
T
cells inhibit the production of interferon‐γ, which is the major mediator of protection against
M
ycobacterium 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. We observed that after homologous immunization with the 65 000 molecular weight heat‐shock protein (hsp 65)
DNA
vaccine, there was a significantly higher number of spleen
CD
4
+
F
oxp3
+
cells compared with non‐immunized mice. Heterologous immunization using bacillus Calmette–Guérin (
BCG
) to prime and
DNA
‐
hsp
65 to boost (
BCG
/
DNA
‐
hsp
65) or
BCG
to prime and culture filtrate proteins (
CFP
)‐
C
p
G
to boost (
BCG
/
CFP
‐
C
p
G
) induced a significantly higher ratio of spleen
CD
4
+
/
CD
4
+
F
oxp3
+
cells compared with non‐immunized mice. In addition, the protection conferred by either the
BCG
/
DNA
‐
hsp
65 or the
BCG
/
CFP
‐
C
p
G
vaccines was significant compared with the
DNA
‐
hsp
65 vaccine. Despite the higher ratio of spleen
CD
4
+
/
CD
4
+
F
oxp3
+
cells found in
BCG
/
DNA
‐
hsp
65‐immunized or
BCG
/
CFP
‐
C
p
G
‐immunized mice, the lungs of both groups of mice were better preserved than those of
DNA
‐
hsp
65‐immunized mice. These results confirm the protective efficacy of
BCG
/
DNA
‐
hsp
65 and
BCG
/
CFP
‐
C
p
G
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
CD
4
+
and regulatory (
CD
4
+
F
oxp3
+
) 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.
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