scholarly journals Recurrent DMD Deletions Highlight Specific Role of Dp71 Isoform in Soft-Tissue Sarcomas

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 922 ◽  
Author(s):  
Olivier Mauduit ◽  
Vanessa Delcroix ◽  
Tom Lesluyes ◽  
Gaëlle Pérot ◽  
Pauline Lagarde ◽  
...  

Soft-tissue sarcomas (STS) are rare tumors whose oncogenesis remains unknown and for which no common therapeutic target has yet been identified. Analysis of 318 STS by CGH array evidenced a frequent deletion affecting the DMD gene (encoding dystrophin isoforms) in 16.5% of STS, including sarcomas with complex genomics, gastrointestinal tumors (GIST), and synovial sarcomas (SS). These deletions are significantly associated with metastatic progression, thus suggesting the role of DMD downregulation in the acquisition of aggressive phenotypes. We observed that targeted deletions of DMD were restricted to the 5’ region of the gene, which is responsible for the transcription of Dp427. Analysis of STS tumors and cell lines by RNA sequencing revealed that only the Dp71 isoform was widely expressed. Dp427 depletion had no effect on cell growth or migration. However, Dp71 inhibition by shRNA dramatically reduced the cell proliferation and clonogenicity of three STS cell lines, likely by altering the cell cycle progression through the G2/M-phase. Our work demonstrates that DMD deletions are not restricted to myogenic tumors and could be used as a biomarker for metastatic evolution in STS. Dp71 seems to play an essential role in tumor growth, thus providing a potential target for future STS treatments.

2021 ◽  
Vol 12 ◽  
Author(s):  
Matthieu Roulleaux Dugage ◽  
Elise F. Nassif ◽  
Antoine Italiano ◽  
Rastislav Bahleda

Anti-PD-(L)1 therapies yield a disappointing response rate of 15% across soft-tissue sarcomas, even if some subtypes benefit more than others. The proportions of TAMs and TILs in their tumor microenvironment are variable, and this heterogeneity correlates to histotype. Tumors with a richer CD8+ T cell, M1 macrophage, and CD20+ cells infiltrate have a better prognosis than those infiltrated by M0/M2 macrophages and a high immune checkpoint protein expression. PD-L1 and CD8+ infiltrate seem correlated to response to immune checkpoint inhibitors (ICI), but tertiary lymphoid structures have the best predictive value and have been validated prospectively. Trials for combination therapies are ongoing and focus on the association of ICI with chemotherapy, achieving encouraging results especially with pembrolizumab and doxorubicin at an early stage, or ICI with antiangiogenics. A synergy with oncolytic viruses is seen and intratumoral talimogene laherpavec yields an impressive 35% ORR when associated to pembrolizumab. Adoptive cellular therapies are also of great interest in tumors with a high expression of cancer-testis antigens (CTA), such as synovial sarcomas or myxoid round cell liposarcomas with an ORR ranging from 20 to 50%. It seems crucial to adapt the design of clinical trials to histology. Leiomyosarcomas are characterized by complex genomics but are poorly infiltrated by immune cells and do not benefit from ICI. They should be tested with PIK3CA/AKT inhibition, IDO blockade, or treatments aiming at increasing antigenicity (radiotherapy, PARP inhibitors). DDLPS are more infiltrated and have higher PD-L1 expression, but responses to ICI remain variable across clinical studies. Combinations with MDM2 antagonists or CDK4/6 inhibitors may improve responses for DDLPS. UPS harbor the highest copy number alterations (CNA) and mutation rates, with a rich immune infiltrate containing TLS. They have a promising 15-40% ORR to ICI. Trials for ICB should focus on immune-high UPS. Association of ICI with FGFR inhibitors warrants further exploration in the immune-low group of UPS. Finally translocation-related sarcomas are heterogeneous, and although synovial sarcomas a poorly infiltrated and have a poor response rate to ICI, ASPS largely benefit from ICB monotherapy or its association with antiangiogenics agents. Targeting specific neoantigens through vaccine or adoptive cellular therapies is probably the most promising approach in synovial sarcomas.


Cells ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 3327
Author(s):  
Zhixiang Wang

The cell cycle is the series of events that take place in a cell, which drives it to divide and produce two new daughter cells. The typical cell cycle in eukaryotes is composed of the following phases: G1, S, G2, and M phase. Cell cycle progression is mediated by cyclin-dependent kinases (Cdks) and their regulatory cyclin subunits. However, the driving force of cell cycle progression is growth factor-initiated signaling pathways that control the activity of various Cdk–cyclin complexes. While the mechanism underlying the role of growth factor signaling in G1 phase of cell cycle progression has been largely revealed due to early extensive research, little is known regarding the function and mechanism of growth factor signaling in regulating other phases of the cell cycle, including S, G2, and M phase. In this review, we briefly discuss the process of cell cycle progression through various phases, and we focus on the role of signaling pathways activated by growth factors and their receptor (mostly receptor tyrosine kinases) in regulating cell cycle progression through various phases.


1995 ◽  
Vol 311 (2) ◽  
pp. 549-554 ◽  
Author(s):  
M Wick ◽  
R Härönen ◽  
D Mumberg ◽  
C Bürger ◽  
B R Olsen ◽  
...  

The gene encoding tissue inhibitor of metalloproteinases-3 (TIMP-3) is regulated during development, mitogenic stimulation and normal cell cycle progression. The TIMP-3 gene is structurally altered or deregulated in certain diseases of the eye and in tumour cells. A detailed knowledge of the TIMP-3 gene and its regulatory elements is therefore of paramount importance to understand its role in development, cell cycle progression and disease. In this study, we present the complete structure of the human TIMP-3 gene. We show that TIMP-3 is a TATA-less gene, which initiates transcription at one major site, is composed of five exons and four introns spanning a region of approximately 30 kb, and gives rise to three distinct mRNAs, presumably due to the usage of alternative polyadenylation signals. Using somatic cell hybrids the TIMP-3 locus was mapped to chromosomal location 22q13.1 We also show that the TIMP-3 5′ flanking region is sufficient to confer both high basal level expression in growing cells and cell cycle regulation in serum-stimulated cells. While the first 112 bases of the promoter, which harbour multiple Sp1 sites, were found to suffice for high basal level activity, the adjacent region spanning positions -463 and -112 was found to be a major determinant of serum inducibility. These results provide an important basis for further investigations addressing the role of TIMP-3 in physiological processes and pathological conditions.


Metabolomics ◽  
2020 ◽  
Vol 16 (12) ◽  
Author(s):  
Irena Roci ◽  
Jeramie D. Watrous ◽  
Kim A. Lagerborg ◽  
Mohit Jain ◽  
Roland Nilsson

Abstract Introduction Choline is an essential human nutrient that is particular important for proliferating cells, and altered choline metabolism has been associated with cancer transformation. Yet, the various metabolic fates of choline in proliferating cells have not been investigated systematically. Objectives This study aims to map the metabolic products of choline in normal and cancerous proliferating cells. Methods We performed 13C-choline tracing followed by liquid chromatography-high resolution mass spectrometry (LC-HRMS) analysis of metabolic products in normal and in vitro-transformed (tumor-forming) epithelial cells, and also in tumor-derived cancer cell lines. Selected metabolites were quantified by internal standards. Results Untargeted analysis revealed 121 LCMS peaks that were 13C-labeled from choline, including various phospholipid species, but also previously unknown products such as monomethyl- and dimethyl-ethanolamines. Interestingly, we observed formation of betaine from choline specifically in tumor-derived cells. Expression of choline dehydrogenase (CHDH), which catalyzes the first step of betaine synthesis, correlated with betaine synthesis across the cell lines studied. RNAi silencing of CHDH did not affect cell proliferation, although we observed an increased fraction of G2M phase cells with some RNAi sequences, suggesting that CHDH and its product betaine may play a role in cell cycle progression. Betaine cell concentration was around 10 µM, arguing against an osmotic function, and was not used as a methyl donor. The function of betaine in these tumor-derived cells is presently unknown. Conclusion This study identifies novel metabolites of choline in cancer and normal cell lines, and reveals altered choline metabolism in cancer cells.


2005 ◽  
Vol 3 (2) ◽  
pp. 198-205
Author(s):  
Margaret von Mehren

Medical management of soft tissue sarcomas (STS) has been restricted by the limited availability of active drugs. A plethora of new oncologic agents are now available, many of which have specific therapeutic targets. Gemcitabine and docetaxel is a combination of drugs that have limited single-agent activity. Yondelis, a novel chemotherapeutic that binds DNA and functions partially by inhibiting transcription, is being tested alone and in combination with doxorubicin. Inhibitors of mTOR, a serine/threonine kinase that regulates cell cycle activation and cell growth, are also being tested. Growth factor receptor inhibitors are being evaluated in a variety of sarcomas that have been found to express the targets. In addition, a variety of agents are being assessed in gastrointestinal stromal tumors (GIST). Single agents and agents combined with imatinib are being tested in imatinib-refractory and in metastatic GIST. The increased use of targeted agents underscores the need for understanding sarcoma biology.


2009 ◽  
Vol 37 (1) ◽  
pp. 42-48 ◽  
Author(s):  
Merdan Fayda ◽  
Gorkem Aksu ◽  
Fulya Yaman Agaoglu ◽  
Ahmet Karadeniz ◽  
Emin Darendeliler ◽  
...  

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