The landscape of genetic aberrations in myxofibrosarcoma.

Myxofibrosarcoma (MFS) is a rare subtype of sarcoma, whose genetic basis is poorly understood. We analyzed 69 MFS cases using whole-genome (WGS), whole-exome (WES) and/or targeted-sequencing (TS). Newly sequenced genomic data were combined with additional deposited 116 MFS samples. WGS identified a high number of structural variations (SVs) per tumor most frequently affecting the TP53 and RB1 loci, 40% of tumors showed a BRCAness-associated mutation signature, and evidence of chromothripsis was found in all cases. Most frequently mutated/copy number altered genes affected known disease drivers such as TP53 (56.2%), CDKN2A/B (29.7%), RB1 (27.0%), ATRX (19.5%) and HDLBP (18.9%). Several previously unappreciated genetic aberrations including MUC17, FLG and ZNF780A were identified in more than 20% of patients. Longitudinal analysis of paired diagnosis and relapse time points revealed a 1.2-fold mutation number increase accompanied with substantial changes in clonal composition over time. Our study highlights the genetic complexity underlying sarcomagenesis of MFS.

Quality of life of GIST patients with and without current tyrosine kinase inhibitor treatment: Cross-sectional results of a German multicentre observational study (PROSa).

OBJECTIVE: We investigated the health-related quality of life (HRQoL) of patients with gastrointestinal stromal tumours (GIST). METHODS: In the multicentre PROSa study, the HRQoL of adult GIST patients was assessed between 2017 and 2019 using the European Organisation for Research and Treatment of Cancer HRQoL questionnaire (EORTC QLQ-C30). We performed group comparisons and multivariate linear regressions. RESULTS: Among 130 patients from 13 centres, the mean global HRQoL was 63.3 out of 100 points. Higher sores indicate better HRQoL. The highest restrictions were in emotional, social, role functioning, insomnia, fatigue, and pain. In multivariate linear regression, we found no significant differences between patients receiving tyrosine kinase inhibitor (TKI) treatment and those without TKI treatment as well as between patients treated with curative or with palliative intent. Patients who received multiple lines of TKI treatment had the most restrictions, notably in physical (unstandardized regression coefficient [B] = -15.7), role (B = -25.7), social (B = -18.4), and cognitive functioning (B = -19.7); fatigue (B = 15.93); general health (B = -14.23); and EORTC-sum score (B = -13.82) compared to all other patients. CONCLUSION: The highest HRQoL restrictions were in GIST patients receiving multiple lines of TKI therapy. Underlying causes need further investigation.

PARP-1 expression as a prognostic factor in Desmoid-type fibromatosis.

Desmoid-type fibromatoses (or desmoid tumors) are entities of intermediate biological potential and are locally invasive. Radical surgery, as state of the art therapy, is frequently limited by incomplete resections. Hormone modifying therapies are promising but further research is required. Poly Adenosine Diphosphate Ribose Polymerase-1 (PARP-1), a DNA repairing enzyme, might be a pathogenetic factor and could become a potential target for therapy as shown by the successful treatment of selected carcinomas and sarcomas by PARP-inhibition. In this study, we investigated the expression of estrogen receptors (ER) α (1) and ß (2), progesterone receptor (PR), androgen receptor (AR), as well as PARP-1 via immunohistochemistry and quantitative RT-PCR in 69 tissue samples of desmoid tumors. Immunohistochemistry was quantified using the Immunoreactivity Score (IRS). Overall expression patterns were correlated with clinical-pathologic parameters to determine their value as a prognostic factor. Among the investigated hormone receptors only ERß showed partial cytoplasmic reactivity. PARP-1 revealed variable nuclear positivity with IRS ranging from 0 to 6. Univariate survival analysis showed that higher expression of estrogen receptor 1 was associated with shorter disease-free survival (p = 0.005). Uni- (p = 0.03) and multivariate (p = 0.003) analyses of mRNA data revealed that higher PARP-1 expression correlated with earlier recurrence. According to this study PARP-1 expression is associated with poorer prognosis, that is faster recurrence, highlighting the possibility of PARP-1-targeting agents as a therapeutic option. Hormone receptors were of minor prognostic relevance in this study.

Neoadjuvant chemotherapy plus radiation versus chemotherapy plus regional hyperthermia in high-grade soft tissue sarcomas: a retrospective comparison.

PURPOSE: Localized adult high-grade soft tissue sarcomas (STS) usually require multimodality treatment including surgery, radiotherapy, chemotherapy and hyperthermia. If maximal preoperative tumor-shrinkage is envisaged, neoadjuvant chemotherapy + radiation (CRT) is often applied, however at the expense of relatively high toxicities and increased postoperative complication rates. This study aims to compare preoperative CRT with neoadjuvant chemotherapy + regional hyperthermia (HCT) regarding histopathological response, toxicity and outcome. METHODS: In this retrospective analysis, 61 consecutive high-grade STS patients treated between 2009 and 2016 were included. All patients were treated within a prospective treatment protocol. 28 patients received neoadjuvant CRT 33 patients HCT. CRT consisted of four cycles doxorubicin/ifosfamide and two cycles ifosfamide concomitant to 50.4 Gray external beam radiotherapy. HCT consisted of 4-6 cycles doxorubicin/ifosfamide with deep regional hyperthermia administered bi-weekly during each cycle. Association of treatment modality with overall survival (OS), local control (LC) and freedom from distant metastases (FFDM) was evaluated by Kaplan-Meier and log-rank analyses. RESULTS: The overall patient characteristics were well balanced. Histopathological tumor response did not differ significantly between both groups (p = .67), neither did higher-grade toxicities during neoadjuvant treatment. Wound dehiscence (p = .018) and surgical hospital re-admissions (p < .001) were both significantly more frequent in the CRT group. Two-year OS, LC and FFDM rates of all patients were 93, 85 and 71% with no significant differences between CRT and HCT. CONCLUSION: Compared to CRT, HCT seems equally efficient and appears to bear less surgical complications. Interpretation should be cautious due to the low number of patients and the retrospective nature of this study.

Multiple myeloma cells modify VEGF/IL-6 levels and osteogenic potential of bone marrow stromal cells via Notch/miR-223.

Bone marrow mesenchymal stromal cells (BMMSCs) represent a crucial component of multiple myeloma (MM) microenvironment supporting its progression and proliferation. Recently, microRNAs have become an important point of interest for research on micro-environmental interactions in MM with some evidence of tumor supportive roles in MM. In this study, we examined the role of miR-223 for MM support in BMMSCs of 56 patients with MM (MM-BMMSCs). miR-223 expression in MM-BMMSCs was reduced by the presence of MM cells in vitro in a cell-contact dependent manner compared to mono-cultured MM-BMMSCs. Co-cultivation of MM cells and MM-BMMSCs induced activation of notch amongst others via jagged-2/notch-2 leading to increased expression of Hes1, Hey2, or Hes5 in both cell types. Cultivation of MM-BMMSCs with increasing levels of recombinant jagged-2 reduced miR-223 and increased Hes1 levels in a concentration-dependent manner. Transient reduction of miR-223 levels increased VEGF and IL-6 expression and secretion by MM-BMMSCs. In addition, reduction of miR-223 degraded the osteogenic differentiation potential of MM-BMMSCs. Inhibition of notch signaling induced apoptosis in both MM cells and MM-BMMSCs. Furthermore, it increased miR-223 levels and reduced expression of VEGF and IL-6 by both cell types. These data provide first evidence that miR-223 participates in different MM supporting pathways in MM-BMMSCs inlcuding regulation of cytokine secretion and expression as well as osteogenic differentiation of MM-BMMSCs. More insights on the role of miR-223 in MM-BMMSCs and in cellular interactions between MM cells and MM-BMMSCs could provide starting points for a more efficient anti-myeloma treatment by targeting of notch signaling. © 2015 Wiley Periodicals, Inc.

Multiple myeloma cells alter the senescence phenotype of bone marrow mesenchymal stromal cells under participation of the DLK1-DIO3 genomic region.

BACKGROUND: Alterations and senescence in bone marrow mesenchymal stromal cells of multiple myeloma patients (MM-BMMSCs) have become an important research focus. However the role of senescence in the pathophysiology of MM is not clear. METHODS: Correlation between senescence, cell cycle and microRNA expression of MM-BMMSCs (n = 89) was analyzed. Gene expression analysis, copy number analysis and methylation specific PCR were performed by Real-Time PCR. Furthermore, cyclin E1, cyclin D1, p16 and p21 genes were analyzed at the protein level using ELISA. Cell cycle and senescence were analyzed by FACS. MiRNA transfection was performed with miR-485-5p inhibitor and mimic followed by downstream analysis of senescence and cell cycle characteristics of MM-BMMSCs. Results were analyzed by Mann-Whitney U test, Wilcoxon signed-rank test and paired t-test depending on the experimental set up. RESULTS: MM-BMMSCs displayed increased senescence associated ß-galactosidase activity (SA-ßGalA), cell cycle arrest in S phase and overexpression of microRNAs. The overexpressed microRNAs miR-485-5p and miR-519d are located on DLK1-DIO3 and C19MC, respectively. Analyses revealed copy number accumulation and hypomethylation of both clusters. KMS12-PE myeloma cells decreased SA-ßGalA and influenced cell cycle characteristics of MM-BMMSCs. MiR-485-5p was significantly decreased in co-cultured MM-BMMSCs in connection with an increased methylation of DLK1-DIO3. Modification of miR-485-5p levels using microRNA mimic or inhibitor altered senescence and cell cycle characteristics of MM-BMMSCs. CONCLUSIONS: Here, we show for the first time that MM-BMMSCs have aberrant methylation and copy number of the DLK1-DIO3 and C19MC genomic region. Furthermore, this is the first study pointing that multiple myeloma cells in vitro reduce both the senescence phenotype of MM-BMMSCs and the expression of miR-223 and miR-485-5p. Thus, it is questionable whether senescence of MM-BMMSCs plays a pathological role in active multiple myeloma or is more important when cell interaction with myeloma cells is inhibited. Furthermore, we found that MiR-485-5p, which is located on the DLK1-DIO3 cluster, seems to participate in the regulation of senescence status and cell cycle characteristics of MM-BMMSCs. Thus, further exploration of the microRNAs of DLK1-DIO3 could provide further insights into the origin of the senescence state and its reversal in MM-BMMSCs.

Geriatric Assessment of Older Patients Receiving Trabectedin in First-Line Treatment for Advanced Soft Tissue Sarcomas: The E-TRAB Study from The German Interdisciplinary Sarcoma Group (GISG-13).

E-TRAB was a non-interventional, prospective trial investigating the feasibility and predictive value of geriatric assessments (GA) in older STS patients treated with trabectedin as first-line therapy. Primary endpoints were overall survival (OS), quality of life and individual clinical benefit assessed by the patient-reported outcome measures QLQ-C30 and PRO-CTCAE. Further, several GA tools were applied and correlated with clinical outcomes and treatment-related toxicities. The final analyses included 69 patients from 12 German-speaking sites. The median age of patients was 78 years (range: 55 to 88). Baseline data on PROs and GA identified a diverse population of older patients with respect to their global health status, although a large proportion of them suffered from limitations, required geriatric help and had a high risk of morbidity. The Cancer and Age Research Group (CARG) score classified 38%, 29% and 23% of the patients with low, intermediate and high risks for therapy-related side effects, respectively. Median OS was 11.2 months [95%CI: 5.6; 19.4]. The study confirmed that trabectedin as first-line treatment in older patients with STS has an acceptable and manageable safety profile. Potential prognostic factors for clinical outcome and therapy-related toxicity were identified among the GA tools. Long Timed Up and Go (TUG) showed a significant correlation to OS and early death, whereas a high CARG score (>9) was associated with an increase in unplanned hospitalizations and the incidence of toxicities grade ≥ 3.

A post hoc analysis of the EPAZ trial: The role of geriatric variables in elderly soft tissue sarcoma patients on toxicity and outcome.

OBJECTIVE: The EPAZ study (NCT01861951) showed recently that pazopanib was non-inferior to doxorubicin in patients ≥60 years treated in first line for advanced soft tissue sarcoma . The current post-hoc analysis aimed to assess the prognostic impact of frailty. METHODS: Geriatric assessments were evaluated at baseline. Age >75 years, liposarcoma, ECOG = 2, G8 ≤14, instrumental activities of daily living (IADL) ≥1 and Charlson Comorbidity Index ≥2 were tested for their impact on progression-free survival (PFS), overall survival (OS), CTCAE grade 3/4 adverse events (AEs) or serious AEs (SAEs), using univariate and multivariate analysis models. RESULTS: univariate analysis showed an increased risk of grade 3/4 AEs and SAEs for ECOG = 2, G8 score ≤14 or IADL ≥1, independent of treatment. The multivariate analysis exhibited for pazopanib a significantly reduced risk for grade 3/4 AEs (HR 0.53; p = 0.033), and in patients with G8 ≤14 an increased risk for SAEs (HR 2.67; p = 0.011). In the multivariate analysis, G8 ≤14 was a negative prognostic factor for PFS (HR 1.82; p = 0.009) and IADL ≥1 for OS (HR 2.02; p = 0.007). ECOG = 2 was the strongest negative predictor for PFS (HR 4.39; p = 0.001) and OS (HR 3.74; p = 0.004). Neither age nor Charlson Comorbidity Index showed any impact on PFS, OS, incidence of grade 3/4 AEs or SAEs. CONCLUSIONS: This post hoc analysis demonstrated that age is not a denominator for outcome or toxicity in elderly patients with soft tissue sarcoma . Instead, geriatric and functional assessments should be used to counsel patients and tailor therapy to individual needs. Moreover, pazopanib has a reduced risk for grade 3/4 AEs compared to doxorubicin.

Efficacy of Pazopanib With or Without Gemcitabine in Patients With Anthracycline- and/or Ifosfamide-Refractory Soft Tissue Sarcoma: Final Results of the PAPAGEMO Phase 2 Randomized Clinical Trial.

IMPORTANCE: Pazopanib and gemcitabine have shown good tolerability, albeit modest single-agent activity in pretreated soft tissue sarcoma. A combined regimen to improve outcomes is required. OBJECTIVE: To determine the efficacy of gemcitabine and pazopanib compared with pazopanib alone. DESIGN, SETTING, AND PARTICIPANTS: This multicenter, randomized phase 2 clinical trial was conducted in Germany from September 2011 to July 2014 and included patients with an Eastern Cooperative Oncology Group performance status score of 0 to 2, adequate organ function, measurable lesion, and progression after at least 1 prior treatment with anthracyclines and/or ifosfamide. Data analysis was performed during 2019 and 2020. INTERVENTIONS: Patients were randomized to pazopanib with gemcitabine (A) or without gemcitabine (B). MAIN OUTCOMES AND MEASURES: The primary end point was progression-free survival rate (PFSR) at 12 weeks; secondary end points included toxicity, quality of life, overall survival, and response rates. RESULTS: A total of 90 patients were randomized, and 86 eligible patients (43 women [50%]) were evaluable, with a median age of 57 (range, 22-84) years and Eastern Cooperative Oncology Group performance status score of 0/1 in 77 participants (90%). The predominant histological subtypes were leiomyosarcoma (22 [26%]) and liposarcoma (16 [19%]). After a median follow-up of 12.4 (range, 1-48) months, the primary end point was met, with a PFSR at 12 weeks of 74% (A) vs 47% (B) (hazard ratio [HR], 1.60; 90% CI, 1.15-2.23; P = .01). In the combination arm, PFSR was significantly longer, with a median of 5.6 vs 2.0 months (HR, 0.58; 95% CI, 0.36-0.92; P = .02) compared with single-agent pazopanib, whereas overall survival was similar, with 13.1 vs 11.2 months (HR, 0.98; 95% CI, 0.60-1.58; P = .83). The objective response rate was overall low, with 11% (A) vs 5% (B) (P = .10). The toxicity of the combination of pazopanib and gemcitabine was increased, but it was manageable and mainly hematological. CONCLUSIONS AND RELEVANCE: This phase 2 randomized clinical trial of patients with soft tissue sarcoma found that the addition of gemcitabine to pazopanib was tolerable, and PFSR at 12 weeks was significantly higher compared with pazopanib alone. These results suggest clinical activity of the combination, but they should be confirmed in a phase 3 trial in a more homogeneous population (eg, leiomyosarcoma). TRIAL REGISTRATION: German Clinical Trials Identifier: DRKS00003139.

Large paraganglioma of the abdominal cavity: a case report and review of the literature.

BACKGROUND: Paragangliomas are rare tumors that derive from cells of the autonomic nervous system. They are usually located in the neck, i.e. arising from the glomus caroticum or glomus jugulare, but may also be located in the mediastinum and abdominal cavity arising from other ganglia. Paraganglioma located in the adrenal gland are called pheochromocytoma. CASE REPORT: We report a case of an oligosymptomatic 50-year-old man presenting with a large intraabdominal tumor mass measuring 24 x 22 x 12 cm. Core needle biopsy revealed a tumor of mesenchymal origin with no clear-line differentiation, so the highly vascularized tumor was resected after embolization of the tumor vessels. Histology revealed epithelioid cells with expression of CD68 and CD10 but no expression of Pan-CK, CD30, or CD45. Ki67 staining was 20%. Lymphangiosis and angioinvasion were demonstrated. Differential diagnosis included histiocytic sarcoma and c-kit-negative gastrointestinal stromal tumor; the final diagnosis was paraganglioma. The 6-month follow-up showed no evidence of recurrence. CONCLUSIONS: Paraganglioma is a rare disease and should be considered in the differential diagnosis of abdominal masses. To our knowledge, this report is of the largest paraganglioma that has been described in the literature so far. Nomenclature, pathogenesis, and treatment options are discussed.

Randomised phase II trial of trofosfamide vs. doxorubicin in elderly patients with untreated metastatic soft-tissue sarcoma.

Doxorubicin represents the standard first-line treatment for metastatic soft-tissue sarcoma. We assessed the efficacy and safety of trofosfamide in elderly patients. In this controlled phase II trial, we randomly (1:2) assigned 120 previously untreated patients with soft-tissue sarcoma, older than 60 years, with an Eastern Cooperative Oncology Group score of 0-2, to receive either doxorubicin for 6 cycles (arm A) or oral trofosfamide (arm B). The primary end-point was a 6-month progression-free rate (PFR) in the experimental arm (clinical trial information: NCT00204568). Between August 2004 and October 2012, forty and 80 patients were randomly assigned to arm A and arm B, respectively, in 16 centres. The median age was 70 years (range, 60-89). The primary study end-point (6-month PFR) was exceeded, with 27.6% in arm B (95% confidence interval [CI], 18.0-39.1) and 35.9% in arm A: (95% CI, 21.2-52.8). Survival data in terms of progression-free survival were 4.3 months (95% CI, 2.2-6.3) and 2.8 months (95% CI, 1.7-3.6) and in terms of overall survival were 9.8 months (95% CI, 6.7-11.6) and 12.3 months (95% CI, 9.6-16.2), respectively. The number of serious adverse event (SAE) was 59% in arm A and 30.3% in arm B (p = 0.005). Trofosfamide caused more often dyspnoea and low-grade fatigue, whereas with doxorubicin, more often leukocytopenia, neutropenia and mucositis were seen. Discontinuation rates for reasons other than disease progression were 15.4% (arm A) vs. 7.9% (arm B). In an elderly population of patients, oral trofosfamide achieved the estimated primary end-point 6-month PFR and was associated with a favourable toxicity profile compared with doxorubicin.

Randomized Comparison of Pazopanib and Doxorubicin as First-Line Treatment in Patients With Metastatic Soft Tissue Sarcoma Age 60 Years or Older: Results of a German Intergroup Study.

PURPOSE: Doxorubicin is a standard of care in patients with advanced, inoperable soft tissue sarcoma (STS). We tested whether pazopanib has efficacy comparable to that of doxorubicin in elderly patients with STS and offers superior tolerability for hematologic toxicity. PATIENTS AND METHODS: Patients age 60 years or older without previous systemic treatment for progressive advanced or metastatic STS who had Eastern Cooperative Oncology Group performance status of 0 to 2 and adequate organ function were included. Treatment consisted of pazopanib 800 mg once per day or doxorubicin 75 mg/m2 once every 3 weeks (≤ 6 cycles) after being randomly assigned in a 2:1 ratio. Noninferiority was assumed for progression-free survival (PFS), if the upper limit of the 95% CI for the hazard ratio (HR) was less than 1.8. Neutropenia and febrile neutropenia were key secondary end points. The European Organisation for Research and Treatment of Cancer (30-item) Quality of Life Questionnaire and geriatric assessment were used to measure patient-reported outcomes. Cox regression analysis and Kaplan-Meier curves were used for analysis. RESULTS: Pazopanib and doxorubicin were given to 81 and 39 patients, respectively. The median age was 71 years (range, 60-88 years). PFS was noninferior (HR, 1.00; 95% CI, 0.65 to 1.53) and the incidence of grade 4 neutropenia and febrile neutropenia favored pazopanib. Objective response rates for pazopanib and doxorubicin were 12.3% and 15.4%, respectively. Overall survival did not differ significantly between arms (HR, 1.08; 95% CI, 0.68 to 1.72; P = .735). Geriatric assessment revealed 2 or more comorbidities in 15.8% of the patients and impairment of activities of daily living in 28.3% of patients. CONCLUSION: Pazopanib was noninferior to doxorubicin, rendering pazopanib a putative therapeutic option in the first-line treatment of STS in patients age 60 years or older. The distinct adverse event profile may be used to counsel patients and tailor therapy to individual needs.

Quality of life and added value of a tailored palliative care intervention in patients with soft tissue sarcoma undergoing treatment with trabectedin: a multicentre, cluster-randomised trial within the German Interdisciplinary Sarcoma Group (GISG).

OBJECTIVES: The choice of drug treatment in advanced soft tissue sarcoma (STS) continues to be a challenge regarding efficacy, quality of life (QoL) and toxicity. Unlike other cancer types, where integrating patient-reported outcomes (PRO) has proven to be beneficial for QoL, there is no such evidence in patients with STS as of now. The YonLife trial aimed to explore the effect of a tailored multistep intervention on QoL, symptoms and survival in patients with advanced STS undergoing treatment with trabectedin as well as identifying predictors of QoL. DESIGN: YonLife is a cluster-randomised, open-label, proof-of-concept study. The intervention incorporates electronic PRO assessment, a case vignette and expert-consented treatment recommendations. PARTICIPANTS: Six hospitals were randomised to the control arm (CA) or interventional arm (IA). Seventy-nine patients were included of whom 40 were analysed as per-protocol analysis set. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary end point was the change of Functional Assessment for Cancer Therapy (FACT-G) total score after 9 weeks. Secondary outcomes included QoL (FACT-G subscales), anorexia and cachexia (Functional Assessment of Anorexia/Cachexia Therapy (FAACT)), symptoms (MD Anderson Symptom Inventory (MDASI)), anxiety and depression (HADS), pain intensity and interference (Brief Pain Inventory (BPI)) and survival assessment. RESULTS: After 9 weeks of treatment, QoL declined less in the IA (ΔFACT-G total score: -2.4, 95% CI: -9.2 to 4.5) as compared with CA (ΔFACT-G total score: -3.9; 95% CI:-11.3 to 3.5; p=0.765). In almost all FACT-G subscales, average declines were lower in IA, but without reaching statistical significance. Smaller adverse trends between arms were observed for MDASI, FAACT, HADS and BPI scales. These trends failed to reach statistical significance. Overall mean survival was longer in IA (648 days) than in CA (389 days, p=0.110). QoL was predicted by symptom severity, symptom interference, depression and anxiety. CONCLUSION: Our data suggest a potentially favourable effect of an electronic patient-reported outcomes based intervention on QoL that needs to be reappraised in confirmatory studies. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier (NCT02204111).

Hematopoietic lineage distribution and evolutionary dynamics of clonal hematopoiesis.

Clonal hematopoiesis of indeterminate potential (CHIP) occurs in an age-related manner and associates with an increased risk of hematologic cancer, atherosclerotic disease, and shorter overall survival. Little is known about the cell of origin, repartition patterns of clonal mutations within the hematopoietic differentiation tree, and its dynamics under evolutionary pressure. Using targeted sequencing, CHIP was identified in 121 out of 437 elderly individuals (27.7%). Variant allele frequencies (VAFs) of 91 mutations were studied in six peripheral blood cell fractions. VAFs were significantly higher in monocytes, granulocytes, and NK-cells compared to B- or T cells. In all cases with available bone marrow material, mutations could be identified in Lin-CD34+CD38- HSCs with subsequent expansion to myeloid primed progenitors. In 22 patients with solid cancer receiving (radio-)chemotherapy, longitudinal study of 32 mutations at 121 time points identified relative VAF changes of at least 50% in 13/32 mutations. VAFs of DNMT3A, were stable in 12/13 cases (P < .001). Cancer patients with a clonal mutation other than DNMT3A required more often red blood cell transfusions and dose reductions. Our results provide novel insights into cellular distribution of clonal mutations, their dynamics under chemotherapy, and advocate for systematic analyses for CHIP in cancer patients.

DNA hypermethylation and aberrant expression of the EMP3 gene at 19q13.3 in Human Gliomas.

Allelic losses on 19q are found in the majority of oligodendroglial tumors and approximately one-third of diffuse astrocytomas. However, the tumor suppressor genes (TSG) on 19q are still elusive. Using cDNA microarray expression profiling, EMP3 at 19q13.3 was among those genes showing the most pronounced expression differences. In line with this, other authors reported EMP3 as being epigenetically silenced in neuroblastomas and astrocytomas. To further investigate EMP3 as a TSG candidate on 19q13.3, we performed molecular analysis of this gene in 162 human gliomas. Mutation analysis did not reveal EMP3 alteration in 132 gliomas. In oligodendroglial tumors, we found that aberrant methylation in the 5'-region of EMP3 was significantly associated with reduced mRNA expression and LOH 19q. In astrocytomas, EMP3 hypermethylation was also paralleled by reduced expression but was independent of the 19q status. EMP3 hypermethylation was detected in more than 80% of diffuse, anaplastic astrocytomas and secondary glioblastomas. Primary glioblastomas, however, mostly lacked EMP3 hypermethylation and frequently overexpressed EMP3. Our data corroborate that oligodendroglial and astrocytic gliomas often show EMP3 hypermethylation and aberrant expression. Furthermore, our findings suggest that primary and secondary glioblastomas are not only characterized by distinct genetic profiles but also differ in their epigenetic aberrations.

Identification of novel oligodendroglioma-associated candidate tumor suppressor genes in 1p36 and 19q13 using microarray-based expression profiling.

Loss of heterozygosity (LOH) on chromosomal arms 1p and 19q is the most common genetic alteration in oligodendroglial tumors and associated with response to radio- and chemotherapy as well as favorable prognosis. Using microsatellite analysis, we previously identified the chromosomal regions 1p36.22-p36.31 and 19q13.3, as candidate tumor suppressor gene regions being commonly deleted in these tumors. To identify genes within these regions that are downregulated in oligodendroglial tumors with LOH 1p/19q, we performed cDNA microarray-based RNA expression profiling of 35 gliomas with known allelic status on 1p and 19q, including 7 oligodendrogliomas and 8 diffuse astrocytomas of World Health Organization (WHO) grade II, as well as 14 anaplastic oligodendrogliomas and 6 anaplastic oligoastrocytomas of WHO grade III. The microarrays used for expression profiling carried approximately 7,000 gene-specific cDNAs, with complete coverage of the genes located in 1p36.13-p36.31 and 19q13.2-q13.33. Microarray analysis identified 8 genes from these regions (MGC4399, SRM, ICMT, RPL18, FTL, ZIN, FLJ10781 and DBP), which all showed significantly lower expression in 1p/19q-deleted gliomas when compared to gliomas without 1p/19q losses. Quantitative real-time reverse transcription-PCR analyses were performed for the MGC4399, ICMT and RPL18 genes and confirmed the microarray findings. In addition, we found that the cytosolic phospholipase A2 (PLA2G4C) gene at 19q13.3 demonstrated significantly lower expression in anaplastic oligodendrogliomas (WHO grade III) when compared to well-differentiated oligodendrogliomas (WHO grade II). Taken together, our study provides a set of interesting novel candidate genes that may play important roles in the pathogenesis of oligodendroglial tumors.