Non-coding RNAs in Wilms' tumor: biological function, mechanism, and clinical implications.

Non-coding RNAs are involved with maintenance and regulation of physiological mechanisms and are involved in pathological processes, such as cancer. Among the small ncRNAs, miRNAs are the most explored in tumorigenesis, metastasis development, and resistance to chemotherapy. These small molecules of ~ 22 nucleotides are modulated during early renal development, involved in the regulation of gene expression and Wilms' tumor progression. Wilms' tumors are embryonic tumors with few mutations and complex epigenetic dysregulation. In recent years, the small ncRNAs have been explored as potentially related both in physiological development and in the tumorigenesis of several types of cancer. Besides, genes regulated by miRNAs are related to biological pathways as PI3K, Wnt, TGF-ß, and Hippo signaling pathways, among others, which may be involved with the underlying mechanisms of resistance to chemotherapy, and in this way, it has emerged as potential targets for cancer therapies, including for Wilms' tumors.

Challenges on participation in a cooperative group of childhood renal tumors in Brasil.

OBJECTIVE: Children with renal tumors included in clinical trials have significantly better outcomes. In Brasil, the enrollment of patients in clinical trials remains challenging. Here we aimed to describe participation accrual in the Brazilian Wilms Tumor Study Group (BWTSG) and to identify barriers to trial registration of children with renal tumors. METHODS: We determined the numbers of renal tumor diagnoses in 105 hospital-based cancer registries from 2001-2009. We then compared these totals with the numbers of renal tumor cases registered in the BWTSG from the same hospitals during the same time period. We also invited members of the Brazilian Pediatric Oncology Society to complete a 5-point Likert-type scale questionnaire regarding their opinions of the importance of participation in cooperative group trials. RESULTS: The accrual rate of patient participation per hospital varied from 25% to 76%, and was highest in the South region. The accrual rate of hospital participation also varied according to the region (20-31%) and was highest in the Southeast region. For the questionnaire regarding the importance of participation in cooperative groups, the responses showed an agreement of >75% on 10 of the 13 statements. CONCLUSION: Our results demonstrated low accrual of participation in a cooperative group trial in Brasil. We identified variations in registration rates according to geographic region and hospital, which may help targeted efforts to increase registration rates. The survey responses demonstrated that colleagues understand the importance of trial participation.

Challenges on participation in a cooperative group of childhood renal tumors in Brasil

SUMMARY OBJECTIVE Children with renal tumors included in clinical trials have significantly better outcomes. In Brasil, the enrollment of patients in clinical trials remains challenging. Here we aimed to describe participation accrual in the Brazilian Wilms Tumor Study Group (BWTSG) and to identify barriers to trial registration of children with renal tumors. METHODS We determined the numbers of renal tumor diagnoses in 105 hospital-based cancer registries from 2001-2009. We then compared these totals with the numbers of renal tumor cases registered in the BWTSG from the same hospitals during the same time period. We also invited members of the Brazilian Pediatric Oncology Society to complete a 5-point Likert-type scale questionnaire regarding their opinions of the importance of participation in cooperative group trials. RESULTS The accrual rate of patient participation per hospital varied from 25% to 76%, and was highest in the South region. The accrual rate of hospital participation also varied according to the region (20-31%) and was highest in the Southeast region. For the questionnaire regarding the importance of participation in cooperative groups, the responses showed an agreement of >75% on 10 of the 13 statements. CONCLUSION Our results demonstrated low accrual of participation in a cooperative group trial in Brasil. We identified variations in registration rates according to geographic region and hospital, which may help targeted efforts to increase registration rates. The survey responses demonstrated that colleagues understand the importance of trial participation.

RESUMO OBJETIVO Crianças com tumores renais incluídas em ensaios clínicos apresentam melhora significativa na sobrevida. No entanto, o envolvimento desses pacientes em ensaios clínicos continua sendo um desafio no Brasil. Nosso objetivo neste estudo é descrever a taxa de aderência e adesão no Grupo Cooperativo Brasileiro para tratamento de Tumor de Wilms (GCBTTW) e identificar barreiras na participação ao protocolo. MÉTODOS Identificamos o número de casos de tumores renais diagnosticados em 105 registros hospitalares de câncer no período de 2001 a 2009. O número total desses casos foi então comparado ao número de casos de tumores renais registrados no GCBTTW provenientes das mesmas unidades hospitalares e durante o mesmo período. Os membros da Sociedade Brasileira de Oncologia Pediátrica foram convidados para completar um questionário com escala do tipo likert com o objetivo de conhecer suas opiniões sobre a importância e as dificuldades na participação em ensaios clínicos de grupos cooperativos. RESULTADOS A aderência de pacientes por hospital variou de 25% a 76% e foi maior na região Sul. A adesão da participação do hospital também variou de acordo com a região (20-31%) e foi maior na região Sudeste. Com relação ao questionário referente à importância da participação em grupos cooperativos, as respostas mostraram concordância de mais de 75% em 10 das 13 afirmações. CONCLUSÃO Nossos resultados demonstraram uma baixa participação em grupos cooperativos no Brasil. Houve variações nas taxas de adesão e aderência de acordo com a região geográfica e unidade hospitalar, o que pode auxiliar em futuros esforços para a melhora dessas taxas. As respostas ao questionário demonstraram que os profissionais entendem a importância da participação em grupos cooperativos.

Intra-tumor genetic heterogeneity in Wilms tumor samples

SUMMARY Childhood renal tumors account for ~7% of all childhood cancers, and most cases are embryonic Wilms' tumors (WT). Children with WT are usually treated by either COG or SIOP. The later treats the children using preoperative chemotherapy, but both have around 90% of overall survival in five years. WT is a genetically heterogeneous group with a low prevalence of known somatic alterations. Only around 30% of the cases present mutation in known genes, and there is a relatively high degree of intra-tumor genetic heterogeneity (ITGH). Besides potentially having an impact on the clinical outcome of patients, ITGH may interfere with the search for molecular markers that are prospectively being tested by COG and SIOP. In this review, we present the proposal of the current UMBRELLA SIOP Study 2017/Brazilian Renal Tumor Group that requires the multi-sampling collection of each tumor to better evaluate possible molecular markers, as well as to understand WT biology

RESUMO Os tumores renais pediátricos correspondem a aproximadamente 7% de todos os tumores infantis, sendo o mais frequente o tumor de Wilms (TW). Crianças com TW são geralmente tratadas seguindo dois distintos protocolos terapêuticos (COG ou SIOP), sendo que no último, os pacientes recebem tratamento quimioterápico pré-operatório. Ambos apresentam sobrevida global em cinco anos em torno de 90%. TW é geneticamente heterogêneo, apresentando baixa prevalência de alterações somáticas conhecidas, com cerca de 30% dos casos apresentando mutações em genes conhecidos e um alto grau de heterogeneidade genética intratumoral (HGIT). Além de potencialmente ter um impacto sobre o desfecho clínico dos pacientes, a HGIT pode interferir na busca de marcadores moleculares que estão sendo testados prospectivamente pelos grupos COG e Siop. Nesta revisão, apresentamos a proposta do atual estudo Umbrella Siop 2017/Grupo de Tumores Renais Brasileiros (GTRB), que orienta a coleta de três diferentes regiões do tumor para melhor avaliar possíveis marcadores moleculares, bem como para compreender a biologia do TW.

Intra-tumor genetic heterogeneity in Wilms tumor samples.

Childhood renal tumors account for ~7% of all childhood cancers, and most cases are embryonic Wilms' tumors (WT). Children with WT are usually treated by either COG or SIOP. The later treats the children using preoperative chemotherapy, but both have around 90% of overall survival in five years. WT is a genetically heterogeneous group with a low prevalence of known somatic alterations. Only around 30% of the cases present mutation in known genes, and there is a relatively high degree of intra-tumor genetic heterogeneity (ITGH). Besides potentially having an impact on the clinical outcome of patients, ITGH may interfere with the search for molecular markers that are prospectively being tested by COG and SIOP. In this review, we present the proposal of the current UMBRELLA SIOP Study 2017/Brazilian Renal Tumor Group that requires the multi-sampling collection of each tumor to better evaluate possible molecular markers, as well as to understand WT biology.

TP53 germline and somatic mutations in a patient with fibrolamellar hepatocellular carcinoma.

Li-Fraumeni syndrome is a rare hereditary cancer predisposition syndrome associated with germline pathogenic variants in TP53 gene. The phenotype may vary from classical to variant forms, known as Li-Fraumeni-like phenotypes. We searched for pathogenic variants in TP53 in a 14 year-old female diagnosed with fibrolamellar hepatocellular carcinoma, a rare subtype of hepatocellular carcinoma. The proband is a heterozygote carrier of the TP53 c.467G>A (p.Arg156His) in exon 5, and her mother is an asymptomatic carrier. Analysis of tumor DNA disclosed an additional somatic mutation in TP53, c.461G>A; p.Gly154Asp. The TP53 germline and somatic pathogenic variants may have acted as possible driver mutations, resulting in genomic instability and tumor development. The fibrolamellar subtype of hepatocellular carcinoma may be part of the broad spectrum of tumors associated with Li-Fraumeni phenotype.

Evaluation of Bcl-2, Bcl-x and cleaved caspase-3 in malignant peripheral nerve sheath tumors and neurofibromas.

AIMS: To study the expression of Bcl-2, Bcl-x, as well the presence of cleaved caspase-3 in neurofibromas and malignant peripheral nerve sheath tumors. The expression of Bcl-2 and Bcl-x and the presence of cleaved caspase 3 were compared to clinicopathological features of malignant peripheral nerve sheath tumors and their impact on survival rates were also investigated. MATERIALS AND METHODS: The evaluation of Bcl-2, Bcl-x and cleaved caspase-3 was performed by immunohistochemistry using tissue microarrays in 28 malignant peripheral nerve sheath tumors and 38 neurofibromas. Immunoquantification was performed by computerized digital image analysis. CONCLUSIONS: Apoptosis is altered in neurofibromas and mainly in malignant peripheral nerve sheath tumors. High levels of cleaved caspase-3 are more common in tumors with more aggressive histological features and it is associated with lower disease free survival of patients with malignant peripheral nerve sheath tumors.

Both osteopontin-c and osteopontin-b splicing isoforms exert pro-tumorigenic roles in prostate cancer cells.

BACKGROUND: Alternative splicing of the osteopontin (opn, spp1) gene generates three protein splicing isoforms (OPN-SI), designated as OPNa, OPNb, and OPNc, which have demonstrated specific roles in different tumor models. This work aims to investigate the roles of each OPN-SI in prostate cancer (PCa) progression by using in vivo and in vitro functional assays. METHODS: The expression levels of OPN-SI in prostate cell lines were analyzed by qRT-PCR. PC-3 was stably transfected with expression vectors containing OPNa, OPNb, and OPNc, as well as empty vector controls. PC-3 cells overexpressing each construct were analyzed for in vivo tumor growth and in relation to different aspects mimicking tumor progression, such as cell proliferation, migration, invasion, and soft agar colony formation. RESULTS: OPN-SI are overexpressed in PCa as compared to non-tumoral prostate cell lines. OPNc and OPNb overexpressing cells significantly activated enhanced xenograft tumor growth and PC-3 proliferation, migration, invasion, and soft agar colony formation, as well as the expression of MMP-2, MMP-9, and VEGF. These isoforms also support sustained proliferative survival. We found that both OPNc and OPNb pro-tumorigenic roles are mainly mediated through PI3K signaling. Inhibition of this pathway by using LY294002 specifically inhibited tumor progression features evoked by OPNc and OPNb overexpression. CONCLUSIONS: Our data provide evidence that both OPNc and OPNb splicing isoforms promote distinct aspects of PCa progression by inducing PI3K signaling. These data give support to strategies aiming to downregulate OPNc and OPNb expression as an approach to inhibit PCa progression.

Amyloid-like fibrils are not detected in non-small cell lung cancer tissue samples.

Some proteins, canonically not associated with amyloid diseases, can aggregate into amyloid-like fibrils under special conditions. Our group hypothesized that stressful cancer microenvironment might induce the formation of insoluble deposits of p53 mutant protein. A cohort of 28 non-small cell lung cancer (NSCLC) patients was used to test the aforementioned hypothesis. Tumor specimens were assessed for TP53 mutations using DNA sequencing and for amyloid formation by Congo red staining. TP53 mutations were present in 57% of patients, whereas no amyloid deposits were detected in tissue sections under polarized light microscopy. Mutant p53 proteins are not associated with the appearance of amyloid-like fibrils in NSCLC samples, and DNA sequencing remains the standard method to detect such abnormality.

Quantitative evaluation of SPRR3 expression in esophageal squamous cell carcinoma by qPCR and its potential use as a biomarker.

Esophageal squamous cell carcinoma (ESCC) is highly fatal due to late diagnosis and inefficient treatment. Early disease detection could improve diagnosis and patient survival. Esophageal squamous epithelial cells express SPRR3, a member of the small proline-rich protein family, which is downregulated in ESCC. Therefore, SPRR3 expression may be used as a biomarker to follow the transition from healthy mucosa to ESCC. Both SPRR3 mRNA splice variants, v1 and v2, were evaluated by real time PCR in tumor and histologically normal adjacent tissue biopsies from 84 ESCC patients and 18 healthy controls. SPRR3-v1 was most highly expressed in the esophageal mucosa of healthy subjects, with an increasingly lower expression in the adjacent mucosa of ESCC patients and in tumors, respectively. SPRR3-v2 expression was low in normal mucosa and in tumors but it was higher in the adjacent mucosa of ESCC patients. In addition, we found a significant correlation between a lower SPRR3-v1 and SPRR3-v2 expression and age and alcohol consumption, respectively. SPRR3 protein expression presented a good correlation with SPRR3 mRNA expression. Cut-off points to discriminate between healthy mucosa, tumor and adjacent mucosa were determined with receiver operating characteristic (ROC) curves. This analysis showed that SPRR3-v1 expression discriminates the esophageal mucosa of healthy subjects from the adjacent mucosa and the tumor of ESCC patients with high sensitivity and specificity. Our data shows that the quantitative analysis of SPRR3 mRNA is a robust and reliable method to monitor the malignant transformation of the healthy esophageal mucosa into ESCC.

Interferon-inducible guanylate binding protein (GBP)-2: a novel p53-regulated tumor marker in esophageal squamous cell carcinomas.

TP53 mutations are common in esophageal squamous cell carcinomas (SCC). To identify biological markers of possible relevance in esophageal SCC, we (i) searched for genes expressed in a p53-dependent manner in TE-1, an esophageal SCC cell line expressing the temperature-sensitive TP53 mutant V272M, and (ii) investigated the expression of one of those genes, the interferon-inducible Guanylate Binding Protein 2 (GBP-2), in esophageal SCC tissues. Clontech Human Cancer 1.2 arrays containing 1,176 human cancer gene-related sequences were used to identify differentially expressed genes in TE-1 cells at permissive (32 degrees C) and nonpermissive (37 degrees C) temperatures. The expression of GBP-2 and IRF-1, its main transcriptional regulator, was analyzed by immunohistochemistry in a retrospective series of 41 esophageal SCC cases with a clear transition zone from noncancer, apparently normal epithelium to invasive cancer. The expression of the GBP-2 gene is consistently increased in TE-1 at 32 degrees C in a p53-dependent manner, as confirmed by inhibition of p53 expression by RNA interference. Increase in GBP-2 is accompanied by an increase in protein levels of IRF-1, the main transcriptional regulator of GBP-2, and in the formation of complexes between p53 and IRF-1. GBP-2 expression is significantly higher in esophageal SCC than in adjacent normal epithelium (p<0.01), in which GBP-2 staining is limited to the basal layer. Our results suggest that p53 up-regulates GBP-2 by cooperating with IRF-1. The association of GBP-2 expression with proliferative squamous cells suggests that GBP-2 may represent a marker of interest in esophageal SCC.