Sdhd and Sdhd/H19 Knockout Mice Do Not Develop Paraganglioma or Pheochromocytoma

BACKGROUND: Mitochondrial succinate dehydrogenase (SDH) is a component of both the tricarboxylic acid cycle and the electron transport chain. Mutations of SDHD, the first protein of intermediary metabolism shown to be involved in tumorigenesis, lead to the human tumors paraganglioma (PGL) and pheochromocytoma (PC). SDHD is remarkable in showing an 'imprinted' tumor suppressor phenotype. Mutations of SDHD show a very high penetrance in man and we postulated that knockout of Sdhd would lead to the development of PGL/PC, probably in aged mice. METHODOLOGY/PRINCIPAL FINDINGS: We generated a conventional knockout of Sdhd in the mouse, removing the entire third exon. We also crossed this mouse with a knockout of H19, a postulated imprinted modifier gene of Sdhd tumorigenesis, to evaluate if loss of these genes together would lead to the initiation or enhancement of tumor development. Homozygous knockout of Sdhd results in embryonic lethality. No paraganglioma or other tumor development was seen in Sdhd KO mice followed for their entire lifespan, in sharp contrast to the highly penetrant phenotype in humans. Heterozygous Sdhd KO mice did not show hyperplasia of paraganglioma-related tissues such as the carotid body or of the adrenal medulla, or any genotype-related pathology, with similar body and organ weights to wildtype mice. A cohort of Sdhd/H19 KO mice developed several cases of profound cardiac hypertrophy, but showed no evidence of PGL/PC. CONCLUSIONS: Knockout of Sdhd in the mouse does not result in a disease phenotype. H19 may not be an initiator of PGL/PC tumorigenesis

ECCO Essential Requirements for Quality Cancer Care : Soft Tissue Sarcoma in Adults and Bone Sarcoma. A critical review

Background: ECCO essential requirements for quality cancer care (ERQCC) are checklists and explanations of organisation and actions that are necessary to give high-quality care to patients who have a specific tumour type. They are written by European experts representing all disciplines involved in cancer care. ERQCC papers give oncology teams, patients, policymakers and managers an overview of the elements needed in any healthcare system to provide high quality of care throughout the patient journey. References are made to clinical guidelines and other resources where appropriate, and the focus is on care in Europe. Sarcoma: essential requirements for quality care Sarcomas - which can be classified into soft tissue and bone sarcomas - are rare, but all rare cancers make up more than 20% of cancers in Europe, and there are substantial inequalities in access to high-quality care. Sarcomas, of which there are many subtypes, comprise a particularly complex and demanding challenge for healthcare systems and providers. This paper presents essential requirements for quality cancer care of soft tissue sarcomas in adults and bone sarcomas. High-quality care must only be carried out in specialised sarcoma centres (including paediatric cancer centres) which have both a core multidisciplinary team and an extended team of allied professionals, and which are subject to quality and audit procedures. Access to such units is far from universal in all European countries. It is essential that, to meet European aspirations for high-quality comprehensive cancer control, healthcare organisations implement the requirements in this paper, paying particular attention to multidisciplinarity and patient-centred pathways from diagnosis and follow-up, to treatment, to improve survival and quality of life for patients. Conclusion: Taken together, the information presented in this paper provides a comprehensive description of the essential requirements for establishing a high-quality service for soft tissue sarcomas in adults and bone sarcomas. The ECCO expert group is aware that it is not possible to propose a 'one size fits all' system for all countries, but urges that access to multidisciplinary teams is guaranteed to all patients with sarcoma. (C) 2016 The Authors. Published by Elsevier Ireland Ltd.Peer reviewe

Outcomes from a mechanistic biomarker multi-arm and randomised study of liposomal MTP-PE (Mifamurtide) in metastatic and/or recurrent osteosarcoma (EuroSarc-Memos trial)

The phase III clinical study of adjuvant liposomal muramyl tripeptide (MTP-PE) in resected high-grade osteosarcoma (OS) documented positive results that have been translated into regulatory approval, supporting initial promise for innate immune therapies in OS. There remains, however, no new approved treatment such as MTP-PE for either metastatic or recurrent OS. Whilst the addition of different agents, including liposomal MTP-PE, to surgery for metastatic or recurrent high-grade osteosarcoma has tried to improve response rates, a mechanistic hiatus exists in terms of a detailed understanding the therapeutic strategies required in advanced disease. Here we report a Bayesian designed multi-arm, multi-centre, open-label phase II study with randomisation in patients with metastatic and/or recurrent OS, designed to investigate how patients with OS might respond to liposomal MTP-PE, either given alone or in combination with ifosfamide. Despite the trial closing because of poor recruitment within the allocated funding period, with no objective responses in eight patients, we report the design and feasibility outcomes for patients registered into the trial. We demonstrate the feasibility of the Bayesian design, European collaboration, tissue collection with genomic analysis and serum cytokine characterisation. Further mechanistic investigation of liposomal MTP-PE alone and in combination with other agents remains warranted in metastatic OS. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12885-022-09697-9

Similar gene expression profiles of sporadic, PGL2-, and SDHD-linked paragangliomas suggest a common pathway to tumorigenesis

Contains fulltext : 81540.pdf (publisher's version ) (Open Access)BACKGROUND: Paragangliomas of the head and neck are highly vascular and usually clinically benign tumors arising in the paraganglia of the autonomic nervous system. A significant number of cases (10-50%) are proven to be familial. Multiple genes encoding subunits of the mitochondrial succinate-dehydrogenase (SDH) complex are associated with hereditary paraganglioma: SDHB, SDHC and SDHD. Furthermore, a hereditary paraganglioma family has been identified with linkage to the PGL2 locus on 11q13. No SDH genes are known to be located in the 11q13 region, and the exact gene defect has not yet been identified in this family. METHODS: We have performed a RNA expression microarray study in sporadic, SDHD- and PGL2-linked head and neck paragangliomas in order to identify potential differences in gene expression leading to tumorigenesis in these genetically defined paraganglioma subgroups. We have focused our analysis on pathways and functional gene-groups that are known to be associated with SDH function and paraganglioma tumorigenesis, i.e. metabolism, hypoxia, and angiogenesis related pathways. We also evaluated gene clusters of interest on chromosome 11 (i.e. the PGL2 locus on 11q13 and the imprinted region 11p15). RESULTS: We found remarkable similarity in overall gene expression profiles of SDHD -linked, PGL2-linked and sporadic paraganglioma. The supervised analysis on pathways implicated in PGL tumor formation also did not reveal significant differences in gene expression between these paraganglioma subgroups. Moreover, we were not able to detect differences in gene-expression of chromosome 11 regions of interest (i.e. 11q23, 11q13, 11p15). CONCLUSION: The similarity in gene-expression profiles suggests that PGL2, like SDHD, is involved in the functionality of the SDH complex, and that tumor formation in these subgroups involves the same pathways as in SDH linked paragangliomas. We were not able to clarify the exact identity of PGL2 on 11q13. The lack of differential gene-expression of chromosome 11 genes might indicate that chromosome 11 loss, as demonstrated in SDHD-linked paragangliomas, is an important feature in the formation of paragangliomas regardless of their genetic background.1 p

Amplification of 17p11.2 approximately p12, including PMP22, TOP3A, and MAPK7, in high-grade osteosarcoma

Amplification of region 17p11.2 approximately p12 has been found in 13%-29% of high-grade osteosarcomas, suggesting the presence of an oncogene or oncogenes that may contribute to their development. To determine the location of these putative oncogenes, we established 17p11.2 approximately p12 amplification profiles by semiquantitative PCR, using 15 microsatellite markers and seven candidate genes in 19 high-grade osteosarcomas. Most of the tumors displayed complex amplification profiles, with frequent involvement of marker D17S2041 in 17p12 and TOP3A in 17p11.2 and, in some cases, very high-level amplification of PMP22 and MAPK7 in 17p11.2. Our findings suggest that multiple amplification targets, including PMP22, TOP3A, and MAPK7 or genes close to these candidate oncogenes, may be present in 17p11.2 approximately p12 and thus contribute to osteosarcoma tumorigenesi

Coactivated platelet-derived growth factor receptor {alpha} and epidermal growth factor receptor are potential therapeutic targets in intimal sarcoma.

Intimal sarcoma (IS) is a rare, malignant, and aggressive tumor that shows a relentless course with a concomitant low survival rate and for which no effective treatment is available. In this study, 21 cases of large arterial blood vessel IS were analyzed by immunohistochemistry and fluorescence in situ hybridization and selectively by karyotyping, array comparative genomic hybridization, sequencing, phospho-kinase antibody arrays, and Western immunoblotting in search for novel diagnostic markers and potential molecular therapeutic targets. Ex vivo immunoassays were applied to test the sensitivity of IS primary tumor cells to the receptor tyrosine kinase (RTK) inhibitors imatinib and dasatinib. We showed that amplification of platelet-derived growth factor receptor α (PDGFRA) is a common finding in IS, which should be considered as a molecular hallmark of this entity. This amplification is consistently associated with PDGFRA activation. Furthermore, the tumors reveal persistent activation of the epidermal growth factor receptor (EGFR), concurrent to PDGFRA activation. Activated PDGFRA and EGFR frequently coexist with amplification and overexpression of the MDM2 oncogene. Ex vivo immunoassays on primary IS cells from one case showed the potency of dasatinib to inhibit PDGFRA and downstream signaling pathways. Our findings provide a rationale for investigating therapies that target PDGFRA, EGFR, or MDM2 in IS. Given the clonal heterogeneity of this tumor type and the potential cross-talk between the PDGFRA and EGFR signaling pathways, targeting multiple RTKs and aberrant downstream effectors might be required to improve the therapeutic outcome for patients with this disease

Sex and genotype ratios of <i>Sdhd</i> KO mice.

*<p>not all mice could not genotyped.</p><p>Sex and genotype ratios of the offspring of +/− mice backcrossed with wildtype mice of the 129P2/Ola and C57BL/6J genetic backgrounds are normal. Absence of live homozygous offspring from the crossing of heterozygous mice (129P2/Ola +/−<b>×</b>+/−) indicates that homozygous loss of <i>Sdhd</i> is not compatible with life.</p

Tyrosine hydroxylase immunohistochemistry of the carotid body.

<p>Pictures are representative for completely serially sectioned carotid bodies from <i>Sdhd</i>+/+ and <i>Sdhd</i>+/− mice (n = 6 carotid bodies for <i>Sdhd</i>+/+ and 8 for <i>Sdhd</i>+/−). The ratio of <i>Sdhd</i>+/+ vs. <i>Sdhd</i>+/− TH staining is 1.0∶1.12 (P = 0.45).</p

Generation and analysis of <i>Sdhd</i>-deficient mice.

<p><b>A.</b> Schematic diagram of the strategy used to target the mouse <i>Sdhd</i> locus. The structure of the endogenous murine <i>Sdhd</i> gene (wildtype allele -wt) is shown in the middle with the targeting vector above and the disrupted allele below. Genomic DNA is represented by narrow horizontal lines with exons (shaded boxes), orientation of transcription (arrows), translation initiation and stop codons indicated; Genomic sequences flanking the betaGeo selection-reporter cassette (open box) in the targeting vector are represented by broad lines. Primers for genotyping (small arrows) and RT-PCR (arrowheads) are indicated below and above their target sequences, respectively. The dumbbells indicate the location of Southern blot probes used. <b>B.</b> Long-range PCR analysis of <i>Sdhd</i> gene targeting. The 7.1 kb normal allele amplified by primers LR-F and LR-R1 is present in the wildtype (lane 1) and heterozygous <i>Sdhd</i> knockout mouse (lane 3), whereas the 8.1 kb betaGeo targeted <i>Sdhd</i> allele amplified by primers LR-F and LR-R2 is present in the heterozygous <i>Sdhd</i> knockout mouse (lane 4) and not in the wildtype (lane 2) M = 10kb ladder marker. <b>C.</b> RT-PCR analysis of targeted gene expression. The C57BL/6J wt <i>Sdhd</i> allele is represented by 603bp and 391bp bands, and a 129P2/Ola wt allele, the 994bp band. Lanes 1 & 2; F1 pups from a C57BL/6J wt×129P2/Ola <i>Sdhd</i>+/− cross show only a single C57BL/6J wildtype <i>Sdhd</i> allele. Lanes 3, 4 & 5 = controls. Lane 3: C57BL/6J wt mouse. Lane 4: 129P2/Ola wt mouse. Lane 5: 129P2/Ola wt×C57BL/6J wt F1 mouse. The absence of a 129P2/Ola wildtype allele in the F1 offspring of the 129P2/Ola <i>Sdhd</i>+/−×C57BL/6Jwt cross demonstrates that they carry the <i>Sdhd</i>/betaGeo targeted allele, indicating correct targeting of the 129P2/Ola <i>Sdhd</i> locus. M = 100bp marker. <b>D.</b> Routine <i>Sdhd</i> genotyping of pups. M = marker, lanes 1 & 3; wt mice, primers WT-F & WT-R. Lanes 2 & 4; heterozygote mice, primers WT-F & bG-R.</p