Loss of heterozygosity impacts MHC expression on the immune microenvironment in CDK12-mutated prostate cancer

BACKGROUND

In prostate cancer (PCa), well-established biomarkers such as MSI status, TMB high, and PDL1 expression serve as reliable indicators for favorable responses to immunotherapy. Recent studies have suggested a potential association between CDK12 mutations and immunotherapy response; however, the precise mechanisms through which CDK12 mutation may influence immune response remain unclear. A plausible explanation for immune evasion in this subset of CDK12-mutated PCa may be reduced MHC expression.

RESULTS

Using genomic data of CDK12-mutated PCa from 48 primary and 10 metastatic public domain samples and a retrospective cohort of 53 low-intermediate risk primary PCa, we investigated how variation in the expression of the MHC genes affected associated downstream pathways. We classified the patients based on gene expression quartiles of MHC-related genes and categorized the tumors into "High" and "Low" expression levels. CDK12-mutated tumors with higher MHC-expressed pathways were associated with the immune system and elevated PD-L1, IDO1, and TIM3 expression. Consistent with an inflamed tumor microenvironment (TME) phenotype, digital cytometric analyses identified increased CD8 + T cells, B cells, γδ T cells, and M1 Macrophages in this group. In contrast, CDK12-mutated tumors with lower MHC expression exhibited features consistent with an immune cold TME phenotype and immunoediting. Significantly, low MHC expression was also associated with chromosome 6 loss of heterozygosity (LOH) affecting the entire HLA gene cluster. These LOH events were observed in both major clonal and minor subclonal populations of tumor cells. In our retrospective study of 53 primary PCa cases from this Institute, we found a 4% (2/53) prevalence of CDK12 mutations, with the confirmation of this defect in one tumor through Sanger sequencing. In keeping with our analysis of public domain data this tumor exhibited low MHC expression at the RNA level. More extensive studies will be required to determine whether reduced HLA expression is generally associated with primary tumors or is a specific feature of CDK12 mutated PCa.

CONCLUSIONS

These data show that analysis of CDK12 alteration, in the context of MHC expression levels, and LOH status may offer improved predictive value for outcomes in this potentially actionable genomic subgroup of PCa. In addition, these findings highlight the need to explore novel therapeutic strategies to enhance MHC expression in CDK12-defective PCa to improve immunotherapy responses.

Identification of tumor-agnostic biomarkers for predicting prostate cancer progression and biochemical recurrence

The diverse clinical outcomes of prostate cancer have led to the development of gene signature assays predicting disease progression. Improved prostate cancer progression biomarkers are needed as current RNA biomarker tests have varying success for intermediate prostate cancer. Interest grows in universal gene signatures for invasive carcinoma progression. Early breast and prostate cancers share characteristics, including hormone dependence and BRCA1/2 mutations. Given the similarities in the pathobiology of breast and prostate cancer, we utilized the NanoString BC360 panel, comprising the validated PAM50 classifier and pathway-specific signatures associated with general tumor progression as well as breast cancer-specific classifiers. This retrospective cohort of primary prostate cancers (n=53) was stratified according to biochemical recurrence (BCR) status and the CAPRA-S to identify genes related to high-risk disease. Two public cohort (TCGA-PRAD and GSE54460) were used to validate the results. Expression profiling of our cohort uncovered associations between PIP and INHBA with BCR and high CAPRA-S score, as well as associations between VCAN, SFRP2, and THBS4 and BCR. Despite low levels of the ESR1 gene compared to AR, we found strong expression of the ER signaling signature, suggesting that BCR may be driven by ER-mediated pathways. Kaplan-Meier and univariate Cox proportional hazards regression analysis indicated the expression of ESR1, PGR, VCAN, and SFRP2 could predict the occurrence of relapse events. This is in keeping with the pathways represented by these genes which contribute to angiogenesis and the epithelial-mesenchymal transition. It is likely that VCAN works by activating the stroma and remodeling the tumor microenvironment. Additionally, SFRP2 overexpression has been associated with increased tumor size and reduced survival rates in breast cancer and among prostate cancer patients who experienced BCR. ESR1 influences disease progression by activating stroma, stimulating stem/progenitor prostate cancer, and inducing TGF-β. Estrogen signaling may therefore serve as a surrogate to AR signaling during progression and in hormone-refractory disease, particularly in prostate cancer patients with stromal-rich tumors. Collectively, the use of agnostic biomarkers developed for breast cancer stratification has facilitated a precise clinical classification of patients undergoing radical prostatectomy and highlighted the therapeutic potential of targeting estrogen signaling in prostate cancer.

Identification of HDAC4 as a potential therapeutic target and prognostic biomarker for ZFTA-fused ependymomas

Members of the HDAC family are predictive biomarkers and regulate the tumorigenesis in several cancers. However, the role of these genes in the biology of intracranial ependymomas (EPNs) remains unexplored. Here, an analysis of eighteen HDACs genes in an EPN transcriptomic dataset, revealed significantly higher levels of HDAC4 in supratentorial ZFTA fusion (ST-ZFTA) compared with ST-YAP1 fusion and posterior fossa EPNs, while HDAC7 and SIRT2 were downregulated in ST-ZFTA. HDAC4 was also overexpressed in ST-ZFTA as measured by single-cell RNA-Seq, quantitative real time-polymerase chain reaction, and immunohistochemistry. Survival analyses showed a significantly worse outcome for EPNs with higher HDAC4 and SIRT1 mRNA levels. Ontology enrichment analysis showed an HDAC4-high signature consistent with viral processes while collagen-containing extracellular matrix and cell-cell junction were enriched in those with an HDAC4-low signature. Immune gene analysis demonstrated a correlation between HDAC4 expression and low levels of NK resting cells. Several small molecules compounds targeting HDAC4 and ABCG2, were predicted by in silico analysis to be effective against HDAC4-high ZFTA. Our results provide novel insights into the biology of the HDAC family in intracranial ependymomas and reveal HDAC4 as a prognostic marker and potential therapeutic target in ST-ZFTA.

Abstract 1818: ZEB1 expression is associated with the PTEN loss and TMPRSS2 ERG fusion immune evasion phenotype in prostate cancer

Prostate cancer (PCa) is considered immunologically cold with a tumor microenvironment (TME) that evades effective immune responses. PTEN loss and TMPRSS2-ERG fusion are common somatic mutations in PCa and both alterations have recently been suggested to impact TME immune infiltration. Interestingly, both mutations are considered to play a role in epithelial to mesenchymal transition (EMT). ZEB1, a stemness and EMT driver has also been associated with immune evasion in different types of tumors. In this study, we investigated the role of ZEB1 in the immune TME of prostate cancer and the putative cooperation between ZEB1 expression, PTEN loss and TMPRSS2-ERG fusion. Immunohistochemistry for PTEN, ERG and ZEB1 were analyzed in 43 PCa cases collected after radical prostatectomy, correlation analysis of expression and immune cell abundance prediction were accessed using PCa expression data from TCGA (n=494). Correlation analysis between ZEB1 expression and 395 genes involved in immune response showed a positive correlation with ERG (r=0.1941, P<0.0001), PTEN (r=0.3514, P<0.0001), STAT3 (r=0.3129, P<0.0001), BRCA2 (r=0.2381, P<0.0001), CSF1R (r=0.6041, P<0.0001), PDCD1 (r=0.2536, P<0.0001), CD274 (r=0.4044, P<0.0001), IL10 (r=0.3655, P<0.0001), IL2 (r=0.1973, P<0.0001), CCR7 (r=0.3325, P<0.0001) and CXCL8 (r=0.424, P<0.0001). When the cohort was dichotomized to compare fusion-positive to fusion-negative samples, ZEB1 correlation with ERG remained positive in fusion-negative samples (r=0.6422, P<0.0001) but was negative (r=-0.2147, P=0.0022) in fusion-positive samples. Immune cell abundance prediction showed a positive correlation between ZEB1 and Tregs (r=0.35, P<0.0001), monocytes (r=0.3874, P<0.0001), dendritic cells (r=0.3934, P<0.0001) and macrophages M1 (r=0.2176, P<0.0001) and a negative correlation with plasma cells (r=-0.2003, P<0.0001), CD8+ naïve T cells (r=-0.3565, P<0.0001), th1 cells (r=-0.4562, P<0.0001) and pro B-cells (r=-0.3539, P<0.0001). Immunohistochemistry analysis showed a high expression of ZEB1 in non-neoplastic basal epithelium plus variable intensitiy of expression in adenocarcinomas and corroborated the correlation between ZEB1, PTEN and ERG expression levels. ZEB1 correlation with immunosuppressive cytokines and receptors such as CCR7, IL2, IL10, IL8 and PD-L1 provides evidence that ZEB1 and EMT may play an immune evasive role in PCa. The positive correlation with Tregs also supports this putative role. ZEB1 expression may indicate that stemness is associated with activation of downstream pathways modulated by PTEN and ERG. The correlation with BRCA2 may indicate an increased stemness-related role for this DNA damage response pathway. These observations, and our IHC findings, are in agreement with recently published data showing that ZEB1 is critical to a subset of basal stem cells in murine prostate samples.

Citation Format: Luiz P. Chaves, Andre L. Caliari, Camila M. Melo, Fabiano P. Saggioro, Jeremy A. Squire. ZEB1 expression is associated with the PTEN loss and TMPRSS2 ERG fusion immune evasion phenotype in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1818.

Phosphorylation of S6 Protein as a Potential Biomarker in Surgically Treated Refractory Epilepsy

The tuberous sclerosis complex (TSC), focal cortical dysplasia IIB (FCD IIB), and hemimegalencephaly (HME) exhibit similar molecular features that are dependent on the hyperactivation of the mTOR pathway. They are all associated with refractory epilepsy and the need for surgical resection with varying outcomes. The phosphorylated protein S6 (pS6) is a downstream target of mTOR, whose increased expression might indicate mTOR hyperactivation, but which is also present when there is no alteration in the pathway (such as in FCD type I). We have performed immunohistochemical marking and quantification of pS6 in resected brain specimens of 26 patients clinically and histologically diagnosed with TSC, FCD IIB, or HME and compared this data to a control group of 25 patients, to measure the extent of pS6 positivity and its correlation with clinical aspects. Our results suggest that pS6 may serve as a reliable biomarker in epilepsy and that a greater percentage of pS6 marking can relate to more severe forms of mTOR-dependent brain anomalies.

mTOR pathway somatic variants and the molecular pathogenesis of hemimegalencephaly

Objectives

Recently, defects in the protein kinase mTOR (mammalian target of rapamycin) and its associated pathway have been correlated with hemimegalencephaly (HME). mTOR acts as a central regulator of important physiological cellular functions such as growth and proliferation, metabolism, autophagy, death, and survival. This study was aimed at identifying specific variants in mTOR signaling pathway genes in patients diagnosed with HME.

Methods

Using amplicon and whole exome sequencing (WES) of resected brain and paired blood samples from five HME patients, we were able to identify pathogenic mosaic variants in the mTOR pathway genes MTOR, PIK3CA, and DEPDC5.

Results

These results strengthen the hypothesis that somatic variants in PI3K-Akt-mTOR pathway genes contribute to HME. We also describe one patient presenting with a pathogenic variant on DEPDC5 gene, which reinforces the role of DEPDC5 on cortical structural changes due to mTORC1 hyperactivation. These findings also provide insights into when in brain development these variants occurred. An early developmental variant is expected to affect a larger number of cells and to result in a larger malformation, whereas the same variant occurring later in development would cause a minor malformation.

Significance

In the future, numerous somatic variants in known or new genes will undoubtedly be revealed in resected brain samples, making it possible to draw correlations between genotypes and phenotypes and allow for a genetic clinical diagnosis that may help to predict a given patient's outcome.

PTEN-deficient prostate cancer is associated with an immunosuppressive tumor microenvironment mediated by increased expression of IDO1 and infiltrating FoxP3+ T regulatory cells

BACKGROUND

Accumulating evidence shows that tumor cell-specific genomic changes can influence the cross talk between cancer cells and the surrounding tumor microenvironment (TME). Loss of the PTEN tumor suppressor gene is observed in 20% to 30% of prostate cancers (PCa) when first detected and the rate increases with PCa progression and advanced disease. Recent findings implicate a role for PTEN in cellular type I interferon response and immunosuppression in PCa. However, the way that PTEN inactivation alters antitumor immune response in PCa is poorly understood.

MATERIALS AND METHODS

To investigate the changes associated with PTEN loss and an immunosuppressive TME in PCa, we used CIBERSORT to estimate the relative abundance of 22 immune-cell types from 741 primary and 96 metastatic tumors. Our in silico findings were then validated by immunohistochemical analysis of immune cells and IDO1 and PDL1 checkpoint proteins in a cohort of 94 radical prostatectomy specimens.

RESULTS

FoxP3+ T regulatory cells (Tregs) were significantly increased in PTEN-deficient PCa in all three public domain cohorts. Loss of PTEN in bone metastases was associated with lower CD8+ T-cell abundance, but in liver metastasis, FoxP3+ Tregs were present at higher levels. PTEN-deficient lymph node metastasis had a distinct profile, with high levels of CD8+ T cells. Moreover, we found that metastatic PCa presents higher abundance of FoxP3+ Treg when compared to primary lesions. Since PTEN-deficient tumors are likely to be immunosuppressed as a consequence of increased FoxP3+ Tregs, we then evaluated the localization and expression of IDO1, PDL1 immune checkpoints, and the corresponding density of FoxP3+ Treg and CD8+ T cells using our validation cohort (n = 94). We found that IDO1 protein expression and FoxP3+ Treg density were higher in neoplastic glands compared with benign adjacent tissue. Moreover, higher densities of FoxP3+ Treg cells in both stromal (P = 0.04) and tumor (P = 0.006) compartments were observed in PTEN-deficient tumors compared to tumors that retained PTEN activity. Similarly, IDO1 protein expression was significantly increased in the tumor glands of PTEN-deficient PCa (P < 0.0001). Spearman correlation analysis showed that IDO1 expression was significantly associated with FoxP3+ Treg and CD8+ T-cell density (P < 0.01).

CONCLUSIONS

Our findings imply that PTEN deficiency is linked to an immunosuppressive state in PCa with distinct changes in the frequency of immune cell types in tumors from different metastatic sites. Our data suggest that determining PTEN status may also help guide the selection of patients for future immunotherapy trials in localized and metastatic PCa.

Skin cancer treatment effectiveness is improved by iontophoresis of EGFR-targeted liposomes containing 5-FU compared with subcutaneous injection

Squamous cell carcinoma (SCC) is a malignant tumor in which epidermal growth factor receptor (EGFR) overexpression is associated with poor prognosis and malignancy. For SCC treatment, cetuximab, an anti-EGFR antibody, is administered in combination with a chemotherapeutic drug for improved efficacy. In this work, an EGFR-targeted immunoliposome loaded with 5-fluorouracil (5- FU) was developed to allow co-administration of the antibody and the chemotherapeutic agent and selective delivery to SCC cells. Topically applied iontophoresis and subcutaneous injections of the 5-FU-loaded immunoliposomes were employed in an SCC xenograft animal model to evaluate the influence of the administration route on therapeutic efficacy. In vitro, cellular uptake of cetuximab-immunoliposomes by EGFR-positive SCC cells was 3.5-fold greater than the uptake of control liposomes. Skin penetration studies showed that iontophoresis of immunoliposomes doubled the 5-FU penetration into the viable epidermis compared with the same treatment with control liposomes. In vivo, subcutaneous injection of immunoliposomes reduced tumor volume by >60% compared with the negative control and approximately 50% compared with the 5-FU solution and control liposome treatments. Interestingly, topical administration via iontophoresis improved tumor reduction by almost 2-fold compared with subcutaneous administration of 5-FU solution and control liposomes but was equally effective for the immunoliposome treatment. However, histological analysis showed that iontophoresis of immunoliposomes was more effective than subcutaneous injection in reducing cell proliferation, resulting in cells with less aggressive characteristics. In conclusion, topical administration of immunoliposomes containing 5-FU using iontophoresis is a promising strategy for SCC treatment.

P27/CDKN1B Translational Regulators in Pituitary Tumorigenesis

In pituitary tumors, P27(CDKN1B) is underexpressed. We aimed to clarify whether translational regulation underlies this phenomenon. This study evaluated the expression of P27/CDKN1B, its targets (CCNE1, CDK2) and translational regulators (DKC1, RPS13, miR221, miR222) and screened for DKC1 variants in sporadic pituitary adenomas. Samples were obtained during transsphenoidal surgery from 48 patients with pituitary adenomas: 10 ACTH-, 17 GH-secreting, and 21 nonfunctioning (NFPA). The control group comprised 7 normal pituitaries (NP) obtained during autopsies. Gene expression was assessed by RT-PCR and protein expression by immunohistochemistry. The 15 exons of DKC1 were sequenced. P27 protein underexpression was observed in all adenomas subtypes (p=0.001). CCNE1 mRNA (p=0.01) overexpression, but not protein, was observed in NFPA. No differential gene expression among groups was observed in CDKN1B regulators RPS13 (p=0.23) and DKC1 (p=0.34). The expression of miR221 and miR222 was similar among tumors and NP. Frequent DKC1 variants (SNPs) were found in exon 14 and in the 3'-UTR in similar frequency to NCBI-dsSNP databases. We also observed rare DKC1 variants in 11% of the studied tumor samples, indicating a high prevalence in pituitary adenomas, however, in silico studies failed to indicate deleterious effects. The high frequency of DKC1 variants may influence, in some extent, pituitary tumors development, without clear role in its tumorigenesis. Our data reinforce the P27 underexpression in pituitary adenomas and provide further evidence of the post-translational machinery involvement, although this phenomenon cannot be explained either by mis-expression of P27 translational regulators - DKC1, RPS13, miR221, miR222 - or directly by DKC1 mutations.

Lymph node or perineural invasion is associated with low miR-15a, miR-34c and miR-199b levels in head and neck squamous cell carcinoma

Background

MicroRNAs (miRNAs or miRs) are post-transcriptional regulators of eukaryotic cells and knowledge of differences in miR levels may provide new approaches to diagnosis and therapy.

Methods

The present study measured the levels of nine miRs in head and neck squamous cell carcinomas (HNSCC) and determined whether clinical pathological features are associated with differences in miR levels. SET (I2PP2A) and PTEN protein levels were also measured, since their levels can be regulated by miR-199b and miR-21, respectively. Nine miRs (miR-15a, miR-21, miR-29b, miR-34c, miR-100, miR-125b, miR-137, miR-133b and miR-199b) were measured by real time qRT-PCR in HNSCC samples from 32 patients and eight resection margins. SET (I2PP2A) and PTEN protein levels were estimated by immunohistochemistry in paired HNSCC tissues and their matched resection margins.

Results

In HNSCC, the presence of lymph node invasion was associated with low miR-15a, miR-34c and miR-199b levels, whereas the presence of perineural invasion was associated with low miR-199b levels. In addition, miR-21 levels were high whereas miR-100 and miR-125b levels were low in HNSCC compared to the resection margins. When HNSCC line HN12, with or without knockdown of SET, were transfected with miR-34c inhibitor or miR-34c mimic, the miR-34c inhibitor increased cell invasion capacity while miR-34c mimic decreased the cell invasion.

Conclusions

We showed that the levels of specific miRs in tumor tissue can provide insight into the maintenance and progression of HNSCC.

General significance

MiRNAs are up- or down-regulated during cancer development and progression; they can be prognosis markers and therapeutic targets in HNSCC.

•

Association between miR-15a, miR-34c and miR-199b levels and lymph node metastasis in HNSCC.

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miR-199b is reduced while SET protein is accumulated in HNSCC.

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Levels of miR-34c control invasion in HNSCC.

Abstract 716: STAT1 expression in the tumor-stroma microenvironment is influenced by loss of PTEN in prostate cancer

The prostate cancer (PCa) microenvironment is an admixture of stromal cells, such as lymphocytes, fibroblasts, myofibroblasts and blood vessel endothelium. The reactive stromal microenvironment of PCa facilitates tumor growth through cytokine and chemokine-mediated cell signaling. STAT1, a transcription factor, induces cell cycle arrest, apoptosis and modulates immune and inflammatory response through IFN-á/ã cytokine activation. IFN-á/ã may be secreted in response to PI3K/AKT activation, since this pathway is associated with JAK/STAT signaling. In addition, the PI3K/AKT pathway can become activated when the PTEN prognostic biomarker is deleted in PCa. The rationale for this project is that the immediate stromal microenvironment of PCa may become pro-tumorigenic as a result of induction of inflammatory cytokines caused by PTEN deletions and activation of PI3K/AKT. We performed FISH analysis of the PTEN gene on 172 cores on a PCa tissue microarray (TMA) derived from 43 patients with intermediate risk disease. Analysis of cytoplasmic and nuclear STAT1 in both the tumor and stromal compartments was performed on each TMA core using immunohistochemistry (IHC) to determine whether the tumor PTEN deletion status was associated with STAT1 expression. In each core, tumor and stromal cell histologies were evaluated independently to estimate the percentage area that was stained positive by IHC. The staining was graded as percentage of positive cells with 0 (negative), 1 (less than 10%), 2 (11% to 50%), and 3 (more than 51%). We found that STAT1 expression in stroma was increased when the PTEN gene in the adjacent tumor was homozygously deleted (p = 0,04). We also showed that mean STAT1 expression in benign tissue cores was reduced when compared to the average score from tumor tissue with one (p = 0.01) or two copies (p = 0.03) of the PTEN gene. STAT1 expression and PTEN gene copy numberPTEN copy numberMean STAT1 in StromaMean STAT1 in Tumor&gt;2 copies0.410.822 copies0.510.651 copy0.600.700 copies0.850.85

These results suggest that the STAT1 pathway may be influenced by PTEN loss in this tumor, suggesting that the JAK/STAT inflammatory pathway may have future clinical applications in PCa.

Citation Format: Thiago Vidotto, Clarissa G. Picanço-Albuquerque, Fabiano P. Saggioro, Rodolfo Borges dos Reis, David Robert Siemens, Madhuri Koti, Jeremy A. Squire. STAT1 expression in the tumor-stroma microenvironment is influenced by loss of PTEN in prostate cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 716.

Sarcoma Radioinduzido Pós-Tratamento de Glioblastoma: Relato de Caso

Introdução: O glioblastoma multiforme é a neoplasia de sistema nervoso central mais letal, com sobrevida media em torno de 13 meses e a de pior prognostico dentre todos os gliomas. A abordagem terapêutica do glioblastoma consiste em neurocirurgia com ressecção máxima possivel do volume tumoral, seguida de radioterapia e quimioterapia. A radioterapia reduz o risco de recidiva tumoral por meio de lesao direta e indireta ao acido desoxirribonucleico tumoral. Os efeitos em longo prazo da radioterapia incluem necrose tecidual, vasculopatia e neoplasia induzida pela radiação. Os tumores malignos intracranianos secundários mais reportados incluem meningiomas, gliomas e sarcomas. O período de latência entre a radioterapia de cranio e o surgimento de lesões radioinduzida varia na literatura entre seis meses a 47 anos, com media de 18,7 anos. Relato de caso: O presente relato descreve o surgimento de sarcoma fusocelular de alto grau radioinduzido apos dez meses em paciente que recebeu tratamento de glioblastoma no Hospital das Clinicas de Ribeirao Preto da Universidade de São Paulo. Conclusão: A raridade dessa associacao se deve provavelmente a baixa sobrevida dos pacientes com glioblastoma, limitando assim o tempo para desenvolvimento de neoplasias secundarias.

Telomere length and telomerase expression in pituitary tumors

PURPOSE

Telomere dysfunction and telomerase activation underlie cancer transformation. This study aims to investigate the contribution of telomere biology to pituitary tumor behavior.

SUBJECTS AND METHODS

Samples from 50 patients with pituitary tumors (11 ACTH-secreting, 18 GH-secreting, and 21 non-secreting tumors) and 7 subjects without pituitary lesions were collected. The expressions of telomerase essential components TERT and TERC and tumor telomere content were measured by quantitative PCR techniques.

RESULTS

Telomerase (TERT) expression was detected in 36% of tumors. No correlation was observed between TERT and TERC expression level and tumor size in any tumor type. There was no association between gene expression and clinical findings. Telomere content (T/S ratio) was similar between pituitary adenomas (0.39 ± 0.16) and normal pituitaries (0.47 ± 0.12; p = 0.24) and also was between the different adenoma types: ACTH-secreting (0.43 ± 0.08), GH-secreting (0.31 ± 0.12), and non-secreting (0.42 ± 0.20; p = 0.10) tumors.

CONCLUSIONS

The telomere content and expression of telomerase components are comparable between normal pituitary glands and tumor tissues, suggesting that telomere biology does not play an important role in pituitary tumor development.

Halofuginone inhibits phosphorylation of SMAD-2 reducing angiogenesis and leukemia burden in an acute promyelocytic leukemia mouse model

Background

Halofuginone (HF) is a low-molecular-weight alkaloid that has been demonstrated to interfere with Metalloproteinase-2 (MMP-2) and Tumor Growth Factor-β (TGF-β) function and, to present antiangiogenic, antiproliferative and proapoptotic properties in several solid tumor models. Based on the fact that high levels of Vascular Endothelial Growth Factor (VEGF) and increased angiogenesis have been described in acute myeloid leukemia and associated with disease progression, we studied the in vivo effects of HF using an Acute Promyelocytic Leukemia (APL) mouse model.

Methods

NOD/SCID mice were transplanted with leukemic cells from hCG-PML/RARA transgenic mice (TM) and treated with HF 150 μg/kg/day for 21 days. The leukemic infiltration and the percentage of VEGF+ cells were evaluated by morphology and flow cytometry. The effect of HF on the gene expression of several pro- and antiangiogenic factors, phosphorylation of SMAD2 and VEGF secretion was assessed in vitro using NB4 and HUVEC cells.

Results

HF treatment resulted in hematological remission with decreased accumulation of immature cell and lower amounts of VEGF in BM of leukemic mice. In vitro, HF modulated gene expression of several pro- and antiangiogenic factors, reduced VEGF secretion and phosphorylation of SMAD2, blocking TGF-β-signaling.

Conclusion

Taken together, our results demonstrate that HF inhibits SMAD2 signaling and reduces leukemia growth and angiogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-015-0181-2) contains supplementary material, which is available to authorized users.

SAGE analysis highlights the putative role of underexpression of ribosomal proteins in GH-secreting pituitary adenomas

BACKGROUND

Although the molecular pathogenesis of pituitary adenomas has been assessed by several different techniques, it still remains partially unclear. Ribosomal proteins (RPs) have been recently related to human tumorigenesis, but they have not yet been evaluated in pituitary tumorigenesis.

OBJECTIVE

The aim of this study was to introduce serial analysis of gene expression (SAGE), a high-throughput method, in pituitary research in order to compare differential gene expression.

METHODS

Two SAGE cDNA libraries were constructed, one using a pool of mRNA obtained from five GH-secreting pituitary tumors and another from three normal pituitaries. Genes differentially expressed between the libraries were further validated by real-time PCR in 22 GH-secreting pituitary tumors and in 15 normal pituitaries.

RESULTS

Computer-generated genomic analysis tools identified 13,722 and 14,993 exclusive genes in normal and adenoma libraries respectively. Both shared 6497 genes, 2188 were underexpressed and 4309 overexpressed in tumoral library. In adenoma library, 33 genes encoding RPs were underexpressed. Among these, RPSA, RPS3, RPS14, and RPS29 were validated by real-time PCR.

CONCLUSION

We report the first SAGE library from normal pituitary tissue and GH-secreting pituitary tumor, which provide quantitative assessment of cellular transcriptome. We also validated some downregulated genes encoding RPs. Altogether, the present data suggest that the underexpression of the studied RP genes possibly collaborates directly or indirectly with other genes to modify cell cycle arrest, DNA repair, and apoptosis, leading to an environment that might have a putative role in the tumorigenesis, introducing new perspectives for further studies on molecular genesis of somatotrophinomas.

An experimental model of meningoencephalomyelitis by Rocio flavivirus in BALB/c mice: inflammatory response, cytokine production, and histopathology

Rocio virus (ROCV) is a flavivirus, probably transmitted by Culex mosquitoes and maintained in nature as a zoonosis of wild birds. Rocio virus caused a human epidemic of severe encephalitis that lasted from 1973 to 1980 in the Ribeira valley, in the southeastern coast of Brazil. After this outbreak, serologic evidence of ROCV circulation has been reported and public health authorities are concerned about a return of ROCV outbreaks in Brazil. We show here a study on the pathogenesis and the physiopathology of ROCV disease in the central nervous system of a Balb/C young adult mice experimental model. The animals were intraperitoneally infected by ROCV and followed from 0 to 9 days after infection, when all of them died. Nervous tissue samples were collected from infected animals for immunohistochemistry and molecular biology analysis. We observed the virus in the central nervous system, the inflammatory changes induced by Th1 and Th2 cytokines, and the final irreversible damage of nervous tissues by neuronal degeneration and apoptosis. These findings can help to better understand the pathogenesis and physiopathology of the human meningoencephalomyelitis by ROCV and other flaviviruses.

High expression of cancer testis antigens MAGE-A, MAGE-C1/CT7, MAGE-C2/CT10, NY-ESO-1, and gage in advanced squamous cell carcinoma of the larynx

BACKGROUND

Despite diagnostic and therapeutic advances in head and neck cancer, the 5-year survival of patients with laryngeal cancer has not improved in the last 30 years. Several recent studies indicate that specific targets for immunotherapeutic approaches can be useful in the control of cancer. There is considerable interest in the expression of cancer testis antigens in human cancers since they may serve as the basis for an immunologic approach to therapy.

METHODS

We evaluated by immunohistochemical analysis the expression of cancer testis antigens MAGE-A4 (57B), MAGE-C1 (CT7-33), MAGE-A1 (MA454), MAGE-A3 (M3H67), MAGE-C2 (CT10.5), NY-ESO-1 (E978), and GAGE (GAGE) in squamous cell carcinoma (SCC) of the larynx.

RESULTS

A total of 63 cases (57 men and 6 women) of laryngeal SCC were available for this study. The findings were correlated with the clinical course and laboratory data. Expression of at least 1 cancer testis antigen was detected in 42 of 63 of the laryngeal SCCs (67%). In 34 of 42 of the positive cases (81%) there was simultaneous expression of ≥2 cancer testis antigens. There was significant correlation between antigen expression and advanced tumor stage (stage III/IV) in cases with reactivity to only 1 antibody (p = .01) as well as in the cases with reactivity to ≥2 primary antibodies (≥2 mAbs, p = .04). There was no association between survival and expression of any of the analyzed antigens.

CONCLUSIONS

We find a high incidence of cancer testis antigen expression in SCCs of the larynx, which was correlated with advanced clinical stage. Our data indicate that cancer testis antigens could be valuable vaccine targets in laryngeal tumors, especially in those with a worse prognosis.

Sudan Black B treatment reduces autofluorescence and improves resolution of in situ hybridization specific fluorescent signals of brain sections

Interference by autofluorescence is one of the major concerns of immunofluorescence analysis of in situ hybridization-based diagnostic assays. We present a useful technique that reduces autofluorescent background without affecting the tissue integrity or direct immunofluorescence signals in brain sections. Using six different protocols, such as ammonia/ethanol, Sudan Black B (SBB) in 70% ethanol, photobleaching with UV light and different combinations of them in both formalin-fixed paraffin-embedded and frozen human brain tissue sections, we have found that tissue treatment of SBB in a concentration of 0.1% in 70% ethanol is the best approach to reduce/eliminate tissue autofluorescence and background, while preserving the specific fluorescence hybridization signals. This strategy is a feasible, non-time consuming method that provides a reasonable compromise between total reduction of the tissue autofluorescence and maintenance of specific fluorescent labels.

Central mucoepidermoid carcinoma: Report of 2 cases

Central mucoepidermoid carcinoma is a rare mandibular neoplasm. The objective of this paper was to report two cases.

Flow cytometry characterization of leukemic phase of nasal NK/T-cell lymphoma in tumor biopsies and peripheral blood

We report the findings of the immunophenotypic profile of three cases of nasal T/NK cell lymphoma in leukemic phase. Flow cytometry analysis was carried out using cell suspensions of tumor nasal biopsies and peripheral blood. Tumor samples were composed by a mixture of a predominant subset of medium-size true NK cytCD3epsilon-, sCD3epsilon-, CD56+ cells mixed with a minor subset of medium-size T/NK sCD3epsilon+, CD56+ cells. Both subsets were also detected in peripheral blood. In addition, an infiltration of small-size sCD3epsilon+, CD56- normal T lymphocytes was also present.

Six cases of leprosy associated with allogeneic hematopoietic SCT

We report here the first six cases of leprosy associated with HLA-identical allogeneic SCT in different phases and with different findings and outcomes. Skin and peripheral nerves may be sites of leprosy associated with SCT, stressing the importance of differential diagnosis between leprosy and GVHD or drug reactions. Clinical manifestations of leprosy before or after transplantation did not influence the outcome of SCT in our cases.

Hantavirus infection induces a typical myocarditis that may be responsible for myocardial depression and shock in hantavirus pulmonary syndrome

Despite clinical evidence of myocardial dysfunction, there is no pathological evidence of myocardial injury in hantavirus pulmonary syndrome (HPS). The dominant opinion is that the primary cardiac lesion is functional rather than structural. The present study describes hantaviral antigen and particles in the cardiac endothelium and interstitial macrophages in association with a typical myocarditis in HPS. Human hearts from 14 individuals who died of HPS were compared with hearts from 14 individuals who died of acute necrotizing pancreatitis associated with acute lung injury and 4 individuals who died accidental deaths without thoracic injury (as controls); all cases were selected from autopsies. Transmural blocks of myocardial tissue were excised from the middle portion of the left-ventricular free wall and fixed in formalin. Small samples of myocardial tissue from 4 HPS cases and 4 non-HPS controls were fixed in glutaraldehyde for electron microscopic study. Histomorphometric, immunohistochemical, and ultrastructural methods were employed to detect the presence of hantavirus in the myocardium and to evaluate interstitial edema and the minor diameter of myocytes, to characterize the immunophenotype, and to estimate the number of inflammatory cells and in situ cytokine-producing cells and the T helper cell subset 1 and 2 immune responses (tumor necrosis factor [TNF]-alpha, interferon-gamma, interleukin [IL]-10, and IL-4). Cardiac remodeling; hantaviral antigen and particles in the endothelium and macrophages; scattered foci of myofiber necrosis; greater interstitial cellular infiltration, mainly composed of macrophages and memory T lymphocytes and a significant number of T helper and B lymphocytes; and TNF-alpha protein expression in macrophage-type cells and cardiomyocytes were observed to a greater extent in HPS myocardium than in normal and acute pancreatitis control myocardium. These findings give support to the opinion that structural changes could be responsible for myocardial depression and shock in HPS, and it should be properly named as "hantavirus cardiopulmonary syndrome" (HCPS).

MYOCARDIAL STRUCTURAL CHANGES IN LONG-TERM HUMAN SEVERE SEPSIS/SEPTIC SHOCK MAY BE RESPONSIBLE FOR CARDIAC DYSFUNCTION

The present investigation sought to determine the cellular mechanisms directly dependent on long-term severe sepsis/septic shock that could lead to myocardial structural changes in humans. Human hearts from eight cases of long-term severe sepsis/septic shock arising from infection, as defined by the ACCP/SCCM Consensus Conference; eight cases of acute necrotizing pancreatitis and acute lung injury, a noninfectious pathologic cause of systemic inflammatory response; and three cases of accidental death without thoracic injury selected from autopsies were studied. Transmural blocks of myocardial tissue were excised from the middle portion of the left ventricular free wall and were fixed in formalin or were frozen. Histochemical and immunohistochemical methods were used to evaluate the cross-striations of the myocardial cells, the number and size of interstitial macrophages, the intracardiomyocyte accumulation of lipid, the actin/myosin contractile apparatus, and the expression of iNOS, nitrotyrosine, and TNF-alpha in the myocardia of septic and control hearts. Greater interstitial cellular infiltration composed of larger and elongated macrophages and TNF-alpha protein expression in myofibers, interstitial macrophage cell types, and smooth muscle cells and endothelial cell in the vessels; intracardiomyocyte lipid accumulation; scattered foci of actin/myosin contractile apparatus disruption; and increased expression for iNOS and nitrotyrosine in myocytes and interstitial macrophage cell types could be observed in long-term human septic myocardium as compared with normal and acute pancreatitis control myocardia. These findings give support to an opinion that structural changes could be responsible for long-term sepsis-induced myocardial dysfunction. The higher number of macrophages, most of them with morphological features of "activation," and TNF-alpha protein expression could favor the reduction of cardiac function in septic hearts. The intramyocyte lipid accumulation in these hearts very likely reflects myocardium ventricular contractile dysfunction. In addition, the increased expression of iNOS and the evidence for the significant presence of peroxynitrite in cardiomyocytes and interstitial macrophage cell types suggest that oxidative damage may play a role in actin/myosin disruption in the hearts of septic patients.

Hantavirus cardiopulmonary syndrome: immune response and pathogenesis

Hantaviruses are emerging viruses in the Americas that cause cardiopulmonary syndrome with high lethality. The intense cellular immune response to hantavirus alters normal endothelial cell barrier functions and seems to be harmful to the host. On the other hand, the humoral immune response seems to be essential for recovery from infection.

Pseudoangiomatous hyperplasia of mammary stroma associated with gynaecomastia

AIMS

To evaluate the prevalence of pseudoangiomatous hyperplasia of mammary stroma in gynaecomastia and its immunohistochemical profile in this setting.

METHODS

Eighty eight cases of gynaecomastia recovered from the files of the department of pathology, Botucatu School of Medicine from 1976 to 1996 were studied. In the cases associated with pseudoangiomatous hyperplasia of mammary stroma, immunoreactivity for cytokeratins (CAM 5.2), vimentin, CD34, factor VIII related antigen, and the oestrogen and progesterone receptors were studied.

RESULTS

Pseudoangiomatous hyperplasia of mammary stroma was found in 21 of 88 cases of gynaecomastia (23.8%). In all cases, the cells lining the spaces were positive for vimentin, whereas CAM 5.2 and factor VIII related antigen were consistently negative. Nineteen of the 21 cases showed immunoreactivity for CD34. Ductal epithelial cells were positive for both the oestrogen receptor and the progesterone receptor, whereas stromal cells were negative.

CONCLUSIONS

Pseudoangiomatous hyperplasia of mammary stroma was present in approximately one quarter of the cases of gynaecomastia. This immunohistochemical study confirms the mesenchymal origin of the stromal cells that line the pseudovascular spaces, as has been found in female cases of pseudoangiomatous hyperplasia of mammary stroma.