Chemotherapy is one of the most established and effective treatments for almost all types of cancer. However, the elevated toxicity due to the non-tumor-associated effects, development of secondary ...malignancies, infertility, radiation-induced fibrosis and resistance to treatment limit the effectiveness and safety of treatment. In addition, these multiple factors significantly impact quality of life. Over the last decades, our increased understanding of cancer epigenetics has led to new therapeutic approaches and the promise of improved patient outcomes. Epigenetic alterations are commonly found in cancer, especially the increased expression and activity of histone deacetylases (HDACs). Dysregulation of HDACs are critical to the development and progression of the majority of tumors. Hence, HDACs inhibitors (HDACis) were developed and now represent a very promising treatment strategy. The use of HDACis as monotherapy has shown very positive pre-clinical results, but clinical trials have had only limited success. However, combinatorial regimens with other cancer drugs have shown synergistic effects both in pre-clinical and clinical studies. At the same time, these combinations have enhanced the efficacy, reduced the toxicity and tumor resistance to therapy. In this review, we will examine examples of HDACis used in combination with other cancer drugs and highlight the synergistic effects observed in recent preclinical and clinical studies.
Ewing sarcoma is the second most frequent bone tumour of childhood and adolescence that can also arise in soft tissue. Ewing sarcoma is a highly aggressive cancer, with a survival of 70-80% for ...patients with standard-risk and localized disease and ~30% for those with metastatic disease. Treatment comprises local surgery, radiotherapy and polychemotherapy, which are associated with acute and chronic adverse effects that may compromise quality of life in survivors. Histologically, Ewing sarcomas are composed of small round cells expressing high levels of CD99. Genetically, they are characterized by balanced chromosomal translocations in which a member of the FET gene family is fused with an ETS transcription factor, with the most common fusion being EWSR1-FLI1 (85% of cases). Ewing sarcoma breakpoint region 1 protein (EWSR1)-Friend leukaemia integration 1 transcription factor (FLI1) is a tumour-specific chimeric transcription factor (EWSR1-FLI1) with neomorphic effects that massively rewires the transcriptome. Additionally, EWSR1-FLI1 reprogrammes the epigenome by inducing de novo enhancers at GGAA microsatellites and by altering the state of gene regulatory elements, creating a unique epigenetic signature. Additional mutations at diagnosis are rare and mainly involve STAG2, TP53 and CDKN2A deletions. Emerging studies on the molecular mechanisms of Ewing sarcoma hold promise for improvements in early detection, disease monitoring, lower treatment-related toxicity, overall survival and quality of life.
Endoglin in the Spotlight to Treat Cancer González Muñoz, Teresa; Amaral, Ana Teresa; Puerto-Camacho, Pilar ...
International journal of molecular sciences,
03/2021, Volume:
22, Issue:
6
Journal Article
Peer reviewed
Open access
A spotlight has been shone on endoglin in recent years due to that fact of its potential to serve as both a reliable disease biomarker and a therapeutic target. Indeed, endoglin has now been assigned ...many roles in both physiological and pathological processes. From a molecular point of view, endoglin mainly acts as a co-receptor in the canonical TGFβ pathway, but also it may be shed and released from the membrane, giving rise to the soluble form, which also plays important roles in cell signaling. In cancer, in particular, endoglin may contribute to either an oncogenic or a non-oncogenic phenotype depending on the cell context. The fact that endoglin is expressed by neoplastic and non-neoplastic cells within the tumor microenvironment suggests new possibilities for targeted therapies. Here, we aimed to review and discuss the many roles played by endoglin in different tumor types, as well as the strong evidence provided by pre-clinical and clinical studies that supports the therapeutic targeting of endoglin as a novel clinical strategy.
Ewing's sarcoma family tumors (EFT) are characterized by specific chromosomal translocations, which lead to EWS/ETS transcription factors. Elucidation of EWS/ETS target gene networks within the ...context of other signaling pathways, together with the identification of the initiating cell, and the development of genetically engineered mice will hopefully lead to biology-based therapeutic strategies for these tumors.
Ewing sarcoma (EWS) is an aggressive bone and soft tissue tumor with high susceptibility to metastasize. The underlying molecular mechanisms leading to EWS metastases remain poorly understood. ...Epigenetic changes have been implicated in EWS tumor growth and progression. Linking epigenetics and metastases may provide insight into novel molecular targets in EWS and improve its treatment. Here, we evaluated the effects of a selective G9a histone methyltransferase inhibitor (BIX01294) on EWS metastatic process. Our results showed that overexpression of G9a in tumors from EWS patients correlates with poor prognosis. Moreover, we observe a significantly higher expression of G9a in metastatic EWS tumor as compared to either primary or recurrent tumor. Using functional assays, we demonstrate that pharmacological G9a inhibition using BIX01294 disrupts several metastatic steps in vitro, such as migration, invasion, adhesion, colony formation and vasculogenic mimicry. Moreover, BIX01294 reduces tumor growth and metastases in two spontaneous metastases mouse models. We further identified the sialidase NEU1 as a direct target and effector of G9a in the metastatic process in EWS. NEU1 overexpression impairs migration, invasion and clonogenic capacity of EWS cell lines. Overall, G9a inhibition impairs metastases in vitro and in vivo through the overexpression of NEU1. G9a has strong potential as a prognostic marker and may be a promising therapeutic target for EWS patients.
Detection of epidermal growth factor receptor (EGFR) mutations in exons 18-21 is recommended in all patients with advanced Non-small-cell lung carcinoma due to the demonstrated efficiency of the ...standard therapy with tyrosine kinase inhibitors in EGFR-mutated patients. Therefore, choosing a suitable technique to test EGFR mutational status is crucial to warrant a valid result in a short turnaround time using the lowest possible amount of tissue material. The Idylla™ EGFR Mutation Test is a simple, fast and reliable method designed for the detection of EGFR mutations from formalin-fixed paraffin-embedded samples. The aim of this study was the Clinical Performace Evaluation of the Idylla™ EGFR Mutation Test on the Idylla™ System.
EGFR mutational status was determined on 132 archived formalin-fixed paraffin-embedded tissue sections with Idylla™ technology. Results were compared with the results previously obtained by routine method in the reference lab (Therascreen® EGFR RGQ PCR v2, Qiagen in Molecular Pathology lab, Hospital Universitario Virgen del Rocío de Sevilla).
The overall agreement between results obtained with the Idylla™ EGFR Mutation Test and the Comparator test method was 95.38% (with 1-sided 95% lower limit of 91.7%) showing Positive Diagnostic Agreement of 93.22% and Negative Diagnostic Agreement of 97.18%, with a Limit Of Detection ≤5%.
The Idylla™ EGFR Mutation Test passed its clinical validity performance characteristics for accuracy.
The effectiveness of targeted therapies with tyrosine kinase inhibitors in non-small-cell lung cancer (NSCLC) depends on the accurate determination of the genomic status of the tumour. For this ...reason, molecular analyses to detect genetic rearrangements in some genes (ie,
,
,
) have become standard in patients with advanced disease. Since immunohistochemistry is easier to implement and interpret, it is normally used as the screening procedure, while fluorescence in situ hybridisation (FISH) is used to confirm the rearrangement and decide on ambiguous immunostainings. Although FISH is considered the most sensitive method for the detection of
and
rearrangements, the interpretation of results requires detailed guidelines. In this review, we discuss the various technologies available to evaluate
and
genomic rearrangements using these techniques. Other techniques such as real-time PCR and next-generation sequencing have been developed recently to evaluate
and
gene rearrangements, but some limitations prevent their full implementation in the clinical setting. Similarly, liquid biopsies have the potential to change the treatment of patients with advanced lung cancer, but further research is required before this technology can be applied in routine clinical practice. We discuss the technical requirements of laboratories in the light of quality assurance programmes. Finally, we review the recent updates made to the guidelines for the determination of molecular biomarkers in patients with NSCLC.
Recurrent gene fusions (GFs) in translocated sarcomas are recognized as major oncogenic drivers of the disease, as well as diagnostic markers whose identification is necessary for differential ...diagnosis.
is a 'promiscuous' gene that can fuse with many different partner genes, defining different entities among a broad range of mesenchymal neoplasms. Molecular testing of
translocation traditionally relies on FISH assays with break-apart probes, which are unable to identify the fusion partner. Therefore, other ancillary molecular diagnostic modalities are being increasingly adopted for accurate classification of these neoplasms. Herein, we report three cases with rare GFs involving
in undifferentiated mesenchymal neoplasms with uncertain differential diagnoses, using targeted RNA-seq and confirming with RT-PCR and Sanger sequencing. Two GFs involved hormone nuclear receptors as 3' partners,
and
, which have not been previously reported.
may functionally replace
, the usual 3' partner in extraskeletal myxoid chondrosarcoma. The third GF,
, has previously been reported in a subtype of astroblastoma and other rare entities, including a single case of a soft-tissue tumor that we discuss in this work. In conclusion, our findings indicate that the catalogue of mesenchymal neoplasm-bearing
fusions continues to grow, underscoring the value of using molecular ancillary techniques with higher diagnostic abilities in the routine clinical setting.
KIT/PDGFRA oncogenic tyrosine kinase signaling is the central oncogenic event in most gastrointestinal stromal tumors (GIST), which are human malignant mesenchymal neoplasms that often feature ...myogenic differentiation. Although targeted inhibition of KIT/PDGFRA provides substantial clinical benefit, GIST cells adapt to KIT/PDGFRA driver suppression and eventually develop resistance. The specific molecular events leading to adaptive resistance in GIST remain unclear. By using clinically representative in vitro and in vivo GIST models and GIST patients' samples, we found that the E3 ubiquitin ligase Atrogin-1 (FBXO32)-the main effector of muscular atrophy in cachexia-resulted in the most critical gene derepressed in response to KIT inhibition, regardless the type of KIT primary or secondary mutation. Atrogin-1 in GISTs is transcriptionally controlled by the KIT-FOXO3a axis, thus indicating overlap with Atrogin-1 regulation mechanisms in nonneoplastic muscle cells. Further, Atrogin-1 overexpression was a GIST-cell-specific pro-survival mechanism that enabled the adaptation to KIT-targeted inhibition by apoptosis evasion through cell quiescence. Buttressed on these findings, we established in vitro and in vivo the preclinical proof-of-concept for co-targeting KIT and the ubiquitin pathway to maximize the therapeutic response to first-line imatinib treatment.
Ewing sarcoma (EWS) is an aggressive bone and soft tissue tumor of children and young adults in which the principal driver is a fusion gene, EWSR1-FLI1. Although the essential role of EWSR1-FLI1 ...protein in the regulation of oncogenesis, survival, and tumor progression processes has been described in-depth, little is known about the regulation of chimeric fusion-gene expression. Here, we demonstrate that the active nuclear HDAC6 in EWS modulates the acetylation status of specificity protein 1 (SP1), consequently regulating the SP1/P300 activator complex binding to EWSR1 and EWSR1-FLI1 promoters. Selective inhibition of HDAC6 impairs binding of the activator complex SP1/P300, thereby inducing EWSR1-FLI1 downregulation and significantly reducing its oncogenic functions. In addition, sensitivity of EWS cell lines to HDAC6 inhibition is higher than other tumor or non-tumor cell lines. High expression of HDAC6 in primary EWS tumor samples from patients correlates with a poor prognosis in two independent series accounting 279 patients. Notably, a combination treatment of a selective HDAC6 and doxorubicin (a DNA damage agent used as a standard therapy of EWS patients) dramatically inhibits tumor growth in two EWS murine xenograft models. These results could lead to suitable and promising therapeutic alternatives for patients with EWS.
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