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.

Indisulam Reduces Viability and Regulates Apoptotic Gene Expression in Pediatric High-Grade Glioma Cells.

Pediatric high-grade glioma (pHGG) is one of the most aggressive brain tumors. Treatment includes surgery, radiotherapy, chemotherapy, or combination therapy in children older than 3−5 years of age. These devastating tumors are influenced by the hypoxic microenvironment that coordinatively increases the expression of carbonic anhydrases (CA9 and CA12) that are involved in pH regulation, metabolism, cell invasion, and resistance to therapy. The synthetic sulphonamide Indisulam is a potent inhibitor of CAs. The aim of this study was to evaluate the effects of Indisulam on CA9 and CA12 enzymes in pHGG cell lines. Our results indicated that, under hypoxia, the gene and protein expression of CA9 and CA12 are increased in pHGG cells. The functional effects of Indisulam on cell proliferation, clonogenic capacity, and apoptosis were measured in vitro. CA9 and CA12 gene and protein expression were analyzed by RT-PCR and western blot. The treatment with Indisulam significantly reduced cell proliferation (dose-time-dependent) and clonogenic capacity (p < 0.05) and potentiated the effect of apoptosis (p < 0.01). Indisulam promoted an imbalance in the anti-apoptotic BCL2 and pro-apoptotic BAX protein expression. Our results demonstrate that Indisulam contributes to apoptosis via imbalance of apoptotic proteins (BAX/BCL2) and suggests a potential to overcome chemotherapy resistance caused by the regulation these proteins.

MSI2 expression in adrenocortical carcinoma: Association with unfavorable prognosis and correlation with steroid and immune-related pathways.

Adrenocortical carcinoma (ACC) is a rare, but highly aggressive cancer of the adrenal cortex with a generally poor prognosis. Despite being rare, completely resected ACCs present a high risk of recurrence. Musashi-2 (MSI2) has recently been recognized as a potential prognostic biomarker and therapeutic target in many cancers. However, no studies have evaluated the clinical significance of MSI2 expression in ACC. Here, we addressed MSI2 expression and its association with ACC prognosis and clinicopathological parameters. MSI2 expression was analyzed in TCGA, GSE12368, GSE33371, and GSE49278 ACC datasets; and its correlation with other genes and immune cell infiltration were investigated by using the R2: Genomics Analysis and Visualization Platform and TIMER databases, respectively. Enrichment analysis was performed with the DAVID Functional Annotation Tool. Kaplan-Meier curves, log-rank tests, and Cox regression analyses were used to explore the prognostic role of MSI2 in ACC. Our findings demonstrated the potential value of MSI2 overexpression as an independent predictor of poor prognosis in patients with completely resected ACC (hazard ratio 6.715, 95% confidence interval 1.266 - 35.620, p =.025). In addition, MSI2 overexpression was associated with characteristics of unfavorable prognosis, such as cortisol excess (p = .002), recurrence (p =.003), and death (p =.015); positively correlated with genes related to steroid biosynthesis (p < .05); and negatively correlated with immune-related pathways (p < .05). Our findings demonstrate that MSI2 has value as a prognostic marker for completely resected ACC and reinforce the investigation of its role as a possible therapeutic target for patients with ACC.

The Carbonic Anhydrase Inhibitor E7070 Sensitizes Glioblastoma Cells to Radio- and Chemotherapy and Reduces Tumor Growth.

Glioblastomas (GBMs), the most common and lethal primary brain tumor, show inherent infiltrative nature and high molecular heterogeneity that make complete surgical resection unfeasible and unresponsive to conventional adjuvant therapy. Due to their fast growth rate even under hypoxic and acidic conditions, GBM cells can conserve the intracellular pH at physiological range by overexpressing membrane-bound carbonic anhydrases (CAs). The synthetic sulfonamide E7070 is a potent inhibitor of CAs that harbors putative anticancer properties; however, this drug has still not been tested in GBMs. The present study aimed to evaluate the effects of E7070 on CA9 and CA12 enzymes in GBM cells as well as in the tumor cell growth, migration, invasion, and resistance to radiotherapy and chemotherapy. We found that E7070 treatment significantly reduced tumor cell growth and increased radio- and chemotherapy efficacy against GBM cells under hypoxia. Our data suggests that E7070 has therapeutic potential as a radio-chemo-sensitizing in drug-resistant GBMs, representing an attractive strategy to improve the adjuvant therapy. We showed that CA9 and CA12 represent potentially valuable therapeutic targets that should be further investigated as useful diagnostic and prognostic biomarkers for GBM tailored therapy.

Antineoplastic Effects of NF-κB Inhibition by DHMEQ (Dehydroxymethylepoxyquinomicin) Alone and in Co-treatment with Radio-and Chemotherapy in Medulloblastoma Cell Lines.

BACKGROUND: NF-κB is a transcription factor involved in the transcriptional regulation of a large number of genes related to tumorigenesis in several cancer cell types, and its inhibition has been related to anticancer effect. DHMEQ (Dehydroxymethylepoxyquinomicin) is a compound that blocks the translocation of NF-κB from the cytoplasm to the nucleus, thus inhibiting its activity as a transcriptional activator. Several studies have shown the antineoplastic effects of DHMEQ in numerous tumor types, however, there are no surveys that tested their effects in MB. OBJECTIVES: The aim of the present study was to evaluate the effects of DHMEQ as NF-κB inhibitor in pediatric MB cell lines. METHOD: We used the UW402, UW473 and ONS-76 medulloblastoma (MB) cell lines to verify the effect of DHMEQ on proliferation, clonogenic capacity, apoptosis, cell invasion and migration, and evaluated the effect of the combination with other drugs and the potential as a radiosensitizator. RESULTS: A significant decrease in the cell growth, a strong inhibition of the clonogenic capacity, migration and cell invasion was observed after NF-κB inhibition in the three MB cell lines. Conversely, increased level of apoptosis rates were demonstrated. Additionally, treatments with DHMEQ combined with other chemotherapeutic agents were synergic in most points, and a strong radiosensitization by this compound was observed in the three MB cell lines. CONCLUSION: DHMEQ has potential antitumor effect on MB cells, and it may be considered a new therapeutic agent to improve treatment approaches in MB.

The aurora kinase inhibitor AMG 900 increases apoptosis and induces chemosensitivity to anticancer drugs in the NCI-H295 adrenocortical carcinoma cell line.

Adrenocortical tumor (ACT) is a malignancy with a low incidence rate and the current therapy for advanced disease has a limited impact on overall patient survival. A previous study from our group suggested that elevated expression of aurora-A and aurora-B is associated with poor outcome in childhood ACT. Similar results were also reported for adult ACTs. The present in-vitro study shows that AMG 900 inhibits aurora kinases in adrenocortical carcinoma cells. AMG 900 inhibited cell proliferation in NCI-H295 cells as well as in the ACT primary cultures and caused apoptosis in the cell line NCI-H295. Furthermore, it potentialized the mitotane, doxorubicin, and etoposide effects on apoptosis induction and acted synergistically with mitotane and doxorubicin in the inhibition of proliferation. In addition, we found that AMG 900 activated Notch signaling and rendered the cells sensitive to the combination of AMG 900 and Notch signaling inhibition. Altogether, these data show that aurora kinases inhibition using AMG 900 may be an adjuvant therapy to treat patients with invasive or recurrent adrenocortical carcinomas.

Shorter Maintenance Therapy in Childhood Acute Lymphoblastic Leukemia: The Experience of the Prospective, Randomized Brazilian GBTLI ALL-93 Protocol.

AIM: Maintenance therapy is an important phase of the childhood ALL treatment, requiring 2-year long therapy adherence of the patients and families. Weekly methotrexate with daily 6-mercaptopurine (6MP) constitutes the backbone of maintenance therapy. Reduction in the maintenance therapy could overweight problems related with poverty of children with ALL living in limited-income countries (LIC). OBJECTIVE: To compare, prospectively, the EFS rates of children with ALL treated according to two maintenance regimens: 18 vs. 24 months duration. MATERIALS AND METHODS: From October 1993 to September 1999, 867 consecutive untreated ALL patients <18 years of age were treated according to the Brazilian Cooperative Group for Childhood ALL Treatment (GBTLI) ALL-93 protocol. Risk classification was based exclusively on patient's age and leukocyte count (NCI risk group) and clinical extra medullary involvement of the disease. Data were analyzed by the intention-to-treat approach. RESULTS: Fourteen patients (1.6%) were excluded: wrong diagnosis (n = 7) and previous corticosteroid (n = 7). Of the 853 eligible patients, 421 were randomly allocated, at study enrollment, to receive 18-month (group 1) and 432 to receive 24-month (group 2) maintenance therapy. Complete remission rate was achieved in 96% of the patients (817/853). Twenty-eight patients (3.4%) died during the induction phase. Thirty-four patients (4.0%) were lost to follow-up. The overall EFS was 66.1 ± 1.7% at 15 years. No difference was seen according to maintenance: EFS15y was 65.8 ± 2.3% (group 1) and 66.3 ± 2.3% (group 2; p = 0.79). No difference between regimens was detected after stratifying the analyses according to factors associated with adverse prognosis in this study (age group <1 year or >10 years and high WBC at diagnosis). Overall death in remission rate was 6.85% (56 patients). Deaths during maintenance were 13 in group 1 and 12 in group 2, all due to infection. Over 15 years of follow-up, two patients both from group 2 presented a second malignancy (Hodgkin's disease and thyroid carcinoma) after 8.3 and 11 years off therapy, respectively. CONCLUSION: Six-month reduction of maintenance therapy in ALL children treated according to the GBTLI ALL-93 protocol provided the same overall outcome as 2-year duration regimen.

Unraveling the expression of the oncogene YAP1, a Wnt/beta-catenin target, in adrenocortical tumors and its association with poor outcome in pediatric patients.

BACKGROUND: Overexpression of the oncogene yes-associated-protein-1 (YAP1) is associated with increased cell proliferation in human cancers. YAP1 is a potential target of the Wnt/beta-catenin pathway, which plays an important role in adrenocortical tumors (ACT). The role of YAP1 in adrenocortical tumorigenesis has not been assessed. AIMS: To evaluate YAP1 expression in normal adrenals and pediatric ACT and its association with disease outcome. To investigate the interaction between YAP1 and the Wnt/beta-catenin pathway in adrenocortical cells. RESULTS: Strong YAP1 staining was present in fetal adrenals and pediatric ACT but weak in postnatal adrenals. In pediatric ACT, YAP1 mRNA overexpression was associated with death, recurrent/metastatic disease and lower overall survival. The inhibition of the Wnt/beta-catenin pathway increased YAP1 mRNA expression. siYAP1 increased CTNNB1/beta-catenin expression and nuclear staining regardless of DLV2, moreover, it decreased cell growth and impaired cell migration. MATERIALS AND METHODS: We assessed in 42 pediatric ACT samples the YAP1 protein expression by immunohistochemistry and mRNA expression by RT-qPCR and analyzed their association with outcome. As controls, we resort 32 fetal and postnatal normal adrenals for IHC and 10 normal adrenal cortices for RT-qPCR. The interaction between YAP1 and the Wnt/beta-catenin pathway was assessed in NCI-H295 adrenocortical cells by inhibiting the TCF/beta-catenin complex and by knocking down YAP1. CONCLUSION: YAP1 overexpression is a marker of poor prognosis for pediatric patients with ACT. In adrenocortical cells, there is a close crosstalk between YAP1 and Wnt/beta-catenin. These data open the possibility of future molecular therapies targeting Hippo/YAP1 signaling to treat advanced ACT.

The Antiproliferative and Pro-apoptotic Effects of Methoxyamine on Pediatric Medulloblastoma Cell Lines Exposed to Ionizing Radiation and Chemotherapy.

Medulloblastoma (MB) treatment is continuously evolving. Better treatment approaches, focused on particular molecular pathways involved in MB development and progression support new treatment strategies. This article explores the antiproliferative, proapoptotic and radiosensitizing effects of Methoxyamine (MX), a base excision repair (BER) inhibitor that has shown anticancer potential by sensitizing tumor cells to ionizing radiation and chemotherapy. The DAOY (a desmoplastic cerebellar-derived MB) and ONS-76 (classical MB) cell lines were treated with MX at different concentrations, either alone or combined with various chemotherapeutic compounds: cisplatin (CDDP), temozolomide (TMZ) and thiotepa (THIO). Additionally, cell lines were exposed to MX and treated at different ionizing radiation fractions. Measurement of cell growth by XTT assay, clonogenic assay and detection of apoptotic cell death through caspase activity was obtained. Exposure to MX significantly decreased cell proliferation (p<0.05) while increasing cell apoptosis (p<0.05). Growth reduction was concentration-dependent for both DAOY and ONS-76 cells lines. Conversely, MX failed to enhance the cytotoxicity of CDDP, TMZ, and THIO. Moreover, MX treatment radiosensitized both cell lines, with ONS-76 cells being more prone to radiation effects at higher doses of exposure. These data support the role of MX as a direct cytotoxic compound for pediatric MB cells by inhibiting the BER pathway. Nevertheless, an antagonism, rather than a synergic or additive effect of MX with different concentrations of CDDP, TMZ and THIO was observed. Likewise, the radiosensitizing effect on MB cell lines seems to depend on radiation doses and MB subtype. This information may be relevant for clinical study designs employing BER inhibitors for MB.

Low expression of HLA-DRA, HLA-DPA1, and HLA-DPB1 is associated with poor prognosis in pediatric adrenocortical tumors (ACT).

BACKGROUND: Low expression of HLA class II antigens has been associated with more aggressive disease in several human malignancies including adult adrenocortical tumors (ACT), but their clinical relevance in pediatric ACT needs to be investigated. PROCEDURE: This study analyzed the expression profile of three class II histocompatibility genes (HLA-DRA, HLA-DPA1, and HLA-DPB1) in 58 consecutive pediatric ACT (13 adenomas and 45 carcinomas) by quantitative real time PCR and their association with clinical and biological features. HLA-DPA1 protein level was determined by immunohistochemistry. RESULTS: A significant association (P < 0.01) was observed between lower expression levels of the three genes analyzed and poor prognostic factors such as age ≥ 4 years, tumor size ≥ 200 cm(3), tumor weight ≥ 100 g, and metastatic disease; the presence of an unfavorable event and death. Underexpression of the HLA-DRA, HLA-DPA1, and HLA-DPB1 genes were associated with lower 5-year event-free survival (EFS) (P = 0.017, P < 0.001, and P = 0.017, respectively). Cox multivariate analysis showed that HLA-DPA1 was an independent prognostic factor (P = 0.029) when analyzed in association with stage IV, age and tumor size. Significantly lower EFS was also observed in patients with negative/weak immunostaining for HLA-DPA1 (P = 0.002). Similar results were observed when only patients classified as having carcinomas were analyzed. CONCLUSION: 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.

Sonic hedgehog signaling is active in human adrenal cortex development and deregulated in adrenocortical tumors.

BACKGROUND: The sonic hedgehog (SHH) pathway plays a key role in rodent adrenal cortex development and is involved in tumorigenesis in several human tissues, but data in human adrenal glands are limited. OBJECTIVES: The objectives of the study were to analyze the involvement of the SHH pathway in human adrenal development and tumorigenesis and the effects of SHH inhibition on an adrenocortical tumor (ACT) cell line. PATIENTS AND METHODS: Expression of SHH pathway components was evaluated by immunohistochemistry in 51 normal adrenals (33 fetal) and 34 ACTs (23 pediatric) and by quantitative PCR in 81 ACTs (61 pediatric) and 19 controls (10 pediatric). The effects of SHH pathway inhibition on gene expression and cell viability in the NCI-H295A adrenocortical tumor cell line after cyclopamine treatment were analyzed. RESULTS: SHH pathway proteins were present in fetal and postnatal normal adrenals and showed distinct patterns of spatiotemporal expression throughout development. Adult adrenocortical carcinomas presented with higher expression of PTCH1, SMO, GLI3, and SUFU compared with normal adult adrenal cortices. Conversely, pediatric ACTs showed lower mRNA expression of SHH, PTCH1, SMO, GLI1, and GLI3 compared with normal pediatric adrenal cortices. In vitro treatment with cyclopamine resulted in decreased GLI3, SFRP1, and CTNNB1 mRNA expression and ß-catenin staining as well as decreased cell viability. CONCLUSIONS: The SHH pathway is active in human fetal and postnatal adrenals, up-regulated in adult adrenocortical carcinomas, and down-regulated in pediatric ACTs. SHH pathway antagonism impaired cell viability. The SHH pathway is deregulated in ACTs and might provide a new target therapy to be explored.

Altered expression of noncanonical Wnt pathway genes in paediatric and adult adrenocortical tumours.

CONTEXT: The role of planar cell polarity (Wnt/PCP) and calcium-dependent (Wnt/Ca) noncanonical Wnt pathways in adrenocortical tumours (ACTs) is unknown. OBJECTIVES: To investigate the gene expression of Wnt/PCP and Wnt/Ca pathways and its association with TP53 p.R337H and CTNNB1 mutations in paediatric and adult ACTs and to correlate these findings with clinical outcome. PATIENTS: Expression of noncanonical Wnt-related genes was evaluated in 91 ACTs (66 children and 25 adults) by qPCR and the expression of beta-catenin, P53 and protein effectors of Wnt/Ca (NFAT) and Wnt/PCP (JNK) by immunohistochemistry. TP53 and CTNNB1 genes were sequenced. RESULTS: TP53 p.R337H mutation frequency was higher in children (86% vs 28%), while CTNNB1 mutation was higher in adults (32% vs 6%). Mortality was higher in adults harbouring TP53 p.R337H and in children with CTNNB1 mutations. Overexpression of WNT5A, Wnt/Ca ligand, was observed in children and adults. Overexpression of MAPK8 and underexpression of PRICKLE, Wnt/PCP mediators, were observed in paediatric but not in adult cases. Cytoplasmic/nuclear beta-catenin and P53 accumulation was observed in the majority of paediatric and adult ACTs as well as NFAT and JNK. Overexpression of MAPK8 and underexpression of PRICKLE were associated with mortality in children, while overexpression of WNT5A and underexpression of PRICKLE were associated with mortality in adults. CONCLUSIONS: In our study, TP53 p.R337H and CTNNB1 mutations correlated with poor prognosis in adults and children, respectively. We demonstrate, for the first time, the activation of Wnt/PCP and Wnt/Ca noncanonical pathway genes, and their association with poor outcome in children and adults, suggesting their putative involvement in ACTs aggressiveness.

Zebularine induces chemosensitization to methotrexate and efficiently decreases AhR gene methylation in childhood acute lymphoblastic leukemia cells.

Acute lymphoblastic leukemia (ALL) is the most common hematologic malignancy in childhood. Despite the advances in treatment, about 20% of patients relapse and/or die, indicating the need for different therapies for this group. Zebularine (ZB) is a potent DNA methyltransferase (DNMT) inhibitor and has been associated with gene demethylation and enhancement of tumor chemosensitivity. This study aimed to evaluate the effects of ZB, alone or combined with chemotherapeutics (methotrexate and vincristine), on childhood ALL cell lines. Cell proliferation, apoptosis, and clonogenic capacity were studied in Jurkat and ReH cell lines. Bisulfite modification, followed by methylation-specific PCR was carried out to evaluate aryl hydrocarbon receptor (AhR) methylation status. Gene expression of DNMT1, DNMT3a, DNMT3b, and AhR was assessed using qRT-PCR. Both cell cultures were sensitive to ZB, showing a dose-dependent and time-dependent response (P<0.05). ZB induced apoptosis and decreased clonogenic capacity in both cell lines. Combination with methotrexate resulted in a strong synergistic effect, whereas combination with vincristine led to an antagonistic response in both cell lines. ZB treatment decreased gene expression of the three DNMTs and induced AhR gene promoter demethylation and its re-expression. These results indicate that ZB may be a promising drug for the adjuvant treatment of ALL, mainly when combined with methotrexate.

Antiproliferative in vitro effects of BI 2536-mediated PLK1 inhibition on cervical adenocarcinoma cells.

Cervical adenocarcinoma is one of the most common gynecological malignancies. Despite the improvements in multimodality treatment, advanced disease is still associated with a significantly poor prognosis making the search for more effective therapeutic agents imperative. BI 2536, an unambiguous inhibitor of Polo-like kinase 1 (PLK1), has shown anticancer activity in a variety of tumor cell types. Herein, we present more evidence of the antiproliferative effects of this drug on HeLa cells. Nanomolar concentrations (10-100 nmol/l) of the drug significantly decreased cell proliferation and clonogenic capacity. Our results also demonstrate that inhibition of PLK1 promoted G2/M arrest and resulted in a dramatic increase in the mitotic index after 24 h of treatment. Apoptosis onset was evinced by the accumulation of a sub-G1 population as well as by a significant increase in caspase-3 activity at longer periods of exposure. Taken together, our results reinforce the prospect of directing against PLK1 as a potential therapeutic target to be evaluated in different preclinical models for cervical carcinoma.

Cytostatic in vitro effects of DTCM-glutarimide on bladder carcinoma cells.

Bladder cancer is a common malignancy worldwide. Despite the increased use of cisplatin-based combination therapy, the outcomes for patients with advanced disease remain poor. Recently, altered activation of the PI3K/ Akt/mTOR pathway has been associated with reduced patient survival and advanced stage of bladder cancer, making its upstream or downstream components attractive targets for therapeutic intervention. In the present study, we showed that treatment with DTCM-glutaramide, a piperidine that targets PDK1, results in reduced proliferation, diminished cell migration and G1 arrest in 5637 and T24 bladder carcinoma cells. Conversely, no apoptosis, necrosis or autophagy were detected after treatment, suggesting that reduced cell numbers in vitro are a result of diminished proliferation rather than cell death. Furthermore previous exposure to 10 µg/ml DTCM- glutarimide sensitized both cell lines to ionizing radiation. Although more studies are needed to corroborate our findings, our results indicate that PDK1 may be useful as a therapeutic target to prevent progression and abnormal tissue dissemination of urothelial carcinomas.

Suppression of inflammatory cytokine secretion by an NF-ĸB inhibitor DHMEQ in nasal polyps fibroblasts.

BACKGROUND: NF-ĸB is an essential transcription factor strongly associated to inflammatory response in chronic rhinosinusitis with nasal polyps (CRSwNP). DHMEQ is a NF-ĸB inhibitor that has been previously described with a greatpotential indecreasing inflammation in diseases other than CRSwNP. The aim of study isto evaluate the ability of DHMEQ to reducethe inflammatory recruiters on CRSwNP and to compare its anti-inflammatory profile as a single-agent or in association with fluticasone propionate (FP). METHODS: nasal polyp fibroblasts were cultured in TNF-α enriched media. Cells were submitted to three different concentrations (1, 10 and 100nM) of either FP, DHMEQ or both. Inflammatory response was accessed by VCAM-1, ICAM-1 and RANTES expression (by RTQ-PCR) and protein levels by ELISA. Nuclear translocation of NF-ĸB was also evaluated. RESULTS: both FP and DHMEQ inhibited inflammatory recruiters' production and NF-ĸB nuclear translocation. Interestingly, the anti-inflammatory effect from the association steroids plus DHMEQ was more intense than of each drug in separate. CONCLUSION: DHMEQ seems efficient in modulating the inflammatory process in CRSwNP. The synergic anti-inflammatory effect of DHMEQ and steroids may be a promising strategy to be explored, particularly in the setting of steroid-resistant NP.

BI 2536-mediated PLK1 inhibition suppresses HOS and MG-63 osteosarcoma cell line growth and clonogenicity.

Osteosarcoma is the most common primary malignant tumor of bone, which frequently occurs in the second decade of life. Despite the improvements in neoadjuvant chemotherapy, the outcome of patients with chemoresistant or metastatic tumors is still poor. Therefore, there is a need for the development of more efficient therapeutic agents. BI 2536, an innovative selective inhibitor of Polo-like kinase 1, has shown anticancer potential promoting mitotic arrest and apoptosis in a variety of tumor cells, including osteosarcoma. Here, we present more evidence of the antiproliferative effects of BI 2536 on HOS and MG-63 osteosarcoma cell lines. Our results showed that nanomolar concentrations (10, 50, and 100 nmol/l) of the drug significantly decreased cell proliferation and clonogenic capacity, inducing mitotic arrest and aneuploidy. Interestingly, although BI 2536 mediated a moderate increase of apoptosis after 48 h in HOS cells, no increased caspase-3 activity was detected for MG-63 cells. In contrast to previous studies, we show that perturbation of normal mitotic progression by BI 2536 in these osteosarcoma cell lines results in caspase-independent mitotic catastrophe followed by necrosis. Our findings reinforce the likelihood of directing against Polo-like kinase 1 as a therapeutic option in the treatment of osteosarcoma.

Wnt/beta-catenin pathway deregulation in childhood adrenocortical tumors.

CONTEXT: CTNNB1/ß-catenin mutations and activation of Wnt/ß-catenin pathway are frequent in adult adrenocortical tumors (ACT), but data on childhood ACT are lacking. OBJECTIVE: The aim of the study was to investigate the presence of Wnt/ß-catenin pathway abnormalities in childhood ACT. PATIENTS AND METHODS: Clinicopathological findings and outcome of 62 childhood ACT patients were analyzed regarding CTNNB1 mutations and the expression of Wnt-related genes (CTNNB1; WNT4, a Wnt ligand; SFRP1, DKK3, and AXIN1, Wnt inhibitors; TCF7, a transcription factor; and MYC and WISP2, target genes) by quantitative PCR and immunohistochemistry. RESULTS: CTNNB1-activating mutations were found in only four of 62 ACT (6%), all of them harboring TP53 mutation. There was association between the presence of CTNNB1 mutations and death (P = 0.02). Diffuse ß-catenin accumulation was found in 71% of ACT, even in ACT without CTNNB1 mutations. Compared to normal adrenals, ACT presented increased expression of CTNNB1 (P = 0.008) and underexpression of Wnt inhibitor genes: DKK3 (P < 0.0001), SFRP1 (P = 0.05), and AXIN1 (P = 0.04). With regard to Wnt/ß-catenin target genes, ACT presented increased expression of WISP2 but lower expression of MYC. Higher overall survival was associated with underexpression of SFRP1 (P = 0.01), WNT4 (P = 0.004), and TCF7 (P < 0.01). CONCLUSIONS: CTNNB1 mutations are not common in childhood ACT but appear to associate with poor prognosis. Nevertheless, most ACT exhibit increased expression of ß-catenin and WISP2 and reduced expression of Wnt inhibitor genes (DKK3, SFRP1, and AXIN1). Thus, in addition to CTNNB1 mutations, other genetic events affecting the Wnt/ß-catenin pathway may be involved in childhood adrenocortical tumorigenesis.