Search

Simple Summary: Thymomas are rare malignant epithelial tumors of the thymus. They show a spectrum of microscopic appearances (histotypes) that correlate with the risk of killing patients. The various high- and low-risk thymoma histotypes must be distinguished from each other (i.e., classified) to make correct treatment decisions. However, classification is often difficult, even for expert pathologists, since unequivocal microscopic and genetic features may not be present in each thymoma. Therefore, the current study had the aim to improve the classification of thymomas through the application of a novel method—artificial intelligence-assisted methylation profiling—that measures and compares the absence or presence of methyl groups (a chemical modification of the genetic material, i.e., DNA) across cohorts of tumors. The analysis of 113 thymomas revealed that most cases of each microscopically defined thymoma histotype shared a distinct methylation profile. However, tumor cases with overlapping profiles ('borderliners') and cases with quite different profiles ('outliers') were also detected. In conclusion, this type of methylation profiling is a valuable new tool to improve therapeutic decision-making through the refined classification of thymomas. It holds promise for identifying new thymoma variants and opening novel, personalized therapeutic perspectives. Background: Thymomas are malignant thymic epithelial tumors that are difficult to diagnose due to their rarity and complex diagnostic criteria. They represent a morphologically heterogeneous class of tumors mainly defined by "organo-typical" architectural features and cellular composition. The diagnosis of thymoma is burdened with a high level of inter-observer variability and the problem that some type-specific morphological alterations are more on the continuum than clear-cut. Methylation pattern-based classification may help to increase diagnostic precision, particularly in borderline cases. Methods and Results: We applied array-based DNA methylation analysis to a set of 113 thymomas with stringent histological annotation. Unsupervised clustering and t-SNE analysis of DNA methylation data clearly segregated thymoma samples mainly according to the current WHO classification into A, AB, B1, B2, B2/B3, B3, and micronodular thymoma with lymphoid stroma. However, methylation analyses separated the histological subgroups AB and B2 into two methylation classes: mono-/bi-phasic AB-thymomas and conventional/"B1-like" B2-thymomas. Copy number variation analysis demonstrated methylation class-specific patterns of chromosomal alterations. Interpretation: Our study demonstrates that the current WHO classification is generally well reflected at the methylation level but suggests that B2- and AB-thymomas are (epi)genetically heterogeneous. Methylation-based classifications could help to refine diagnostic criteria for thymoma classification, improve reproducibility, and may affect treatment decisions. [ABSTRACT FROM AUTHOR]

This study aimed to compare post-operative morbidity, mortality, and completeness of resection following endoscopic vs. radical surgical resection for ampullary lesions. A retrospective analysis of the prospectively collected data from a surgical database for patients with ampullary lesions at our institution was performed. All consecutive patients undergoing endoscopic papillectomy (EP) or pancreaticoduodenectomy (PD) for ampullary lesions between 2007 and 2021 were eligible for this analysis. A total of 85 patients were included of whom 42 underwent EP whereas 43 received a PD. The resected lesion was a tubulovillous adenoma in 26 patients (61.9%) in the EP cohort, and 37 patients (86.0%) in the PD cohort had adenocarcinomas. The completeness of resection was equal in both cohorts. Significantly more patients of the PD cohort had to undergo reinterventions. After a mean follow up of 36 months (EP) vs. 16 months (PD), the rate of tumor recurrence did not differ between both groups. Equivalently high completeness of resection rates and correspondingly low recurrence rates can be achieved after EP and PD. Our results regarding residual tumor and recurrence rates show that even large tumors can be resected endoscopically with high primary success and completeness of resection rates. [ABSTRACT FROM AUTHOR]

Nasal septum defects can currently only be reconstructed using autologous cartilage grafts. In this study, we examine the reconstruction of septal cartilage defects in a rabbit model using porcine decellularized nasal septal cartilage (DNSC) functionalized with recombinant platelet-derived growth factor-BB (PDFG-BB). The supportive function of the transplanted DNSC was estimated by the degree of septum deviation and shrinkage using magnetic resonance imaging (MRI). The biocompatibility of the transplanted scaffolds was evaluated by histology according to international standards. A study group with an autologous septal transplant was used as a reference. In situ regeneration of cartilage defects was assessed by histological evaluation 4 and 16 weeks following DNSC transplantation. A study group with non-functionalized DNSC was introduced for estimation of the effects of PDFG-BB functionalization. DNSC scaffolds provided sufficient structural support to the nasal septum, with no significant shrinkage or septal deviations as evaluated by the MRI. Biocompatibility analysis after 4 weeks revealed an increased inflammatory reaction of the surrounding tissue in response to DNSC as compared to the autologous transplants. The inflammatory reaction was, however, significantly attenuated after 16 weeks in the PDGF-BB group whereas only a slight improvement of the biocompatibility score was observed in the untreated group. In situ regeneration of septal cartilage, as evidenced by the degradation of the DNSC matrix and production of neocartilage, was observed in both experimental groups after 16 weeks but was more pronounced in the PDFG-BB group. Overall, DNSC provided structural support to the nasal septum and stimulated in situ regeneration of the cartilage tissue. Furthermore, PDFG-BB augmented the regenerative potential of DNSC and enhanced the healing process, as demonstrated by reduced inflammation after 16 weeks. [ABSTRACT FROM AUTHOR]

TREAT‐ME‐1, a Phase 1/2 open‐label multicenter, first‐in‐human, first‐in‐class trial, evaluated the safety, tolerability and efficacy of treatment with genetically modified autologous mesenchymal stromal cells (MSC), MSC_ apceth_101, in combination with ganciclovir in patients with advanced gastrointestinal adenocarcinoma. Immunological and inflammatory markers were also assessed. All patients (3 in Phase 1; 7 in Phase 2) received three treatment cycles of MSC_apceth_101 at one dose level on Day 0, 7, and 14 followed by ganciclovir administration according to the manufacturer's instructions for 48─72 h after MSC_apceth_101 injection. Ten patients were treated with a total dose of 3.0 x 106 cells/kg MSC_apceth_101. 36 adverse events and six serious adverse events were reported. Five patients achieved stable disease (change in target lesions of −2 to +28%). For all patients, the median time to progression was 1.8 months (95% CI: 0.5, 3.9 months). Median overall survival could not be estimated as 8/10 patients were still alive at the end of the study (1 year) and therefore censored. Post‐study observation of patients showed a median overall survival of 15.6 months (ranging from 2.2─27.0 months). Treatment with MSC_apceth_101 and ganciclovir did not induce a consistent increase or decrease in levels of any of the tumor markers analyzed. No clear trends in the immunological markers assessed were observed. MSC_apceth_101 in combination with ganciclovir was safe and tolerable in patients with advanced gastrointestinal adenocarcinoma, with preliminary signs of efficacy in terms of clinical stabilization of disease. What's new? The first clinical trial of human autologous genetically engineered mesenchymal stem cells (MSCs) for solid tumor treatment appears successful. MSCs have been an attractive vehicle for delivering tumor‐killing factors because many cancers recruit them to the tumor site for a growth boost. Here, the authors tested cells called MSC_apceth_101, which are engineered to selectively express herpes simplex virus tyrosine kinase (HSV‐TK) when they reach the tumor site. HSV‐TK phosphorylates ganciclovir, generating a toxic metabolite. In this phase I/II clinical trial, the authors showed that MSC_apceth_101 cells combined with ganciclovir was safe and tolerated by patients with advanced gastrointestinal adenocarcinoma. [ABSTRACT FROM AUTHOR]

Colorectal adenomas are common precancerous lesions with the potential for malignant transformation to colorectal adenocarcinoma. Endoscopic polypectomy provides an opportunity for cancer prevention; however, recurrence rates are high. We collected formalin‐fixed paraffin‐embedded tissue of 15 primary adenomas with recurrence, 15 adenomas without recurrence, and 14 matched pair samples (primary adenoma and the corresponding recurrent adenoma). The samples were analysed by array‐comparative genomic hybridisation (aCGH) and single‐cell multiplex interphase fluorescence in situ hybridisation (miFISH) to understand clonal evolution, to examine the dynamics of copy number alterations (CNAs) and to identify molecular markers for recurrence prediction. The miFISH probe panel consisted of 14 colorectal carcinogenesis‐relevant genes (COX2, PIK3CA, APC, CLIC1, EGFR, MYC, CCND1, CDX2, CDH1, TP53, HER2, SMAD7, SMAD4 and ZNF217), and a centromere probe (CEP10). The aCGH analysis confirmed the genetic landscape typical for colorectal tumorigenesis, that is, CNAs of chromosomes 7, 13q, 18 and 20q. Focal aberrations (≤10 Mbp) were mapped to chromosome bands 6p22.1‐p21.33 (33.3%), 7q22.1 (31.4%) and 16q21 (29.4%). MiFISH detected gains of EGFR (23.6%), CDX2 (21.8%) and ZNF217 (18.2%). Most adenomas exhibited a major clone population which was accompanied by multiple smaller clone populations. Gains of CDX2 were exclusively seen in primary adenomas with recurrence (25%) compared to primary adenomas without recurrence (0%). Generation of phylogenetic trees for matched pair samples revealed four distinct patterns of clonal dynamics. In conclusion, adenoma development and recurrence are complex genetic processes driven by multiple CNAs whose evaluations by miFISH, with emphasis on CDX2, might serve as a predictor of recurrence. What's new? Colonoscopy screening helps detecting and removing adenomas before progression to cancer but predicting recurrence remains challenging. Here the authors performed single‐cell multiplex interphase fluorescence in situ hybridisation to detect copy number changes of 14 genes implicated in colon carcinogenesis in primary and recurrent colorectal adenomas. Intestine‐specific transcription factor CDX2 was identified as a potential marker of recurrence as it was exclusively upregulated in adenomas with recurrence. [ABSTRACT FROM AUTHOR]

Background: The clinicopathological significance of the mucinous subtype of colorectal cancer (CRC) remains controversial. As of today, none of the current guidelines differentiate treatment with respect to mucinous or nonmucinous cancer. Due to the lack of substantiated data, best treatment remains unclear and the mucinous subtype of CRC is usually treated along the lines of recommendations for adenocarcinoma of the colon. Methods: We investigated an East-Bavarian cohort of 8,758 patients with CRC. These included 613 (7.0%) patients with a mucinous subtype, who were analyzed for assessing their characteristics in clinical course and for evaluating the efficacy of common chemotherapy protocols. Results and Conclusion: Mucinous CRC was predominantly located in the right hemicolon; it was diagnosed at more advanced stages and occurred with preponderance in women. A higher rate of G3/4 grading was observed at diagnosis (all p < 0.001). An association of mucinous CRC with younger age at initial diagnosis, previously reported by other groups, could not be confirmed. Patients with mucinous stage IV colon cancer demonstrated poorer survival (p = 0.006). In contrast, no differences in survival were observed for specific stages I–III colon cancer. Stage-dependent analysis of rectal cancer stages I–IV also showed no differences in survival. However, univariable overall analysis resulted in significant poorer survival of mucinous compared to nonmucinous rectal cancer (p = 0.029). Also, combined analysis of all patients with mucinous CRC revealed poorer overall survival (OS) of these patients compared to nonmucinous CRC patients (median 48.4 vs. 60.2 months, p = 0.049) but not in multivariable analysis (p = 0.089). Chemotherapeutic treatment showed comparable efficacy regarding OS for mucinous and nonmucinous cancers in both an adjuvant and palliative setting for colon cancer patients (p values comparing mucinous and nonmucinous cancers < 0.001–0.005). [ABSTRACT FROM AUTHOR]

A cation exchange matrix with zwitterionic and multimodal properties was synthesized by a simple reaction sequence coupling sulfanilic acid to a chitosan based support. The novel chromatographic matrix was physico‐chemically characterized by ss‐NMR and ζ potential, and its chromatographic performance was evaluated for lysozyme purification from diluted egg white. The maximum adsorption capacity, calculated according to Langmuir adsorption isotherm, was 50.07 ± 1.47 mg g−1 while the dissociation constant was 0.074 ± 0.012 mg mL−1. The process for lysozyme purification from egg white was optimized, with 81.9% yield and a purity degree of 86.5%, according to RP‐HPLC analysis. This work shows novel possible applications of chitosan based materials. The simple synthesis reactions combined with the simple mode of use of the chitosan matrix represents a novel method to purify proteins from raw starting materials. © 2017 American Institute of Chemical Engineers Biotechnol. Prog., 34:387–396, 2018 [ABSTRACT FROM AUTHOR]

Genetic changes during tumorigenesis are usually acquired sequentially. However, a recent study showed that in 2% to 3% of all cancers a single catastrophic event, termed chromothripsis, can lead to massive genomic rearrangements confined to one or a few chromosomes. To explore whether the degree of genomic instability and chromothripsis influences prognosis in cancer, we retrospectively applied array-comparative genomic hybrid- ization (aCGH) to 20 malignant melanomas that showed, despite comparable conventional clinical and pathologic parameters, a profoundly different clinical course. We compared 10 patients who died of malignant melanoma 3.7 years (median, range 0.9-7.6 years) after diagnosis with 10 patients who survived malignant melanoma and had amedian disease-free survival of 14.8 years (range 12.5-16.7 years; P=0.00001). We observed a striking association between the degree of chromosomal instability, both numerical and structural, and outcome. Malignant melanomas associated with good prognosis showed only few chromosomal imbalances (mean 1.6 alterations per case), predominantly whole chromosome or chromosome arm gains and losses, whereas malignant melanomas with poor prognosis harbored significantly more chromosomal aberrations (13.9 per case; P = 0.008). Array-based CGH showed that these aberrations were mostly focal events, culminating in two cases in a pattern consistent with the phenomenon of chromothripsis, which was confirmed by paired-end sequencing. This is the first description of chromothripsis in primarymalignantmelanomas. Our study therefore links focal copy number alterations and chromothripsis with poor outcome in patients with malignant melanomas (P = 0.0002) and provides a genetic approach to predict outcome in malignant melanomas. [ABSTRACT FROM AUTHOR]

Flavan-3-ols are potent antioxidants in vitro, but convincing evidence for antioxidant action in vivo is lacking. We examined whether an oxidative stress-mediated increase in plasma F2-isoprostanes is counteracted by a flavanol-rich cocoa beverage. Twenty volunteers were examined in a comparative randomized double-blind crossover design with respect to ingestion of high-flavanol cocoa drink (HFCD; 187 mg flavan-3-ols/100 ml) vs. low-flavanol cocoa drink (LFCD; 14 mg/100 ml). With 10 individuals, the treatment was combined with strenuous physical exercise. Total (esterified plus nonesterified) F2-isoprostanes were analyzed by GC/MS. LFCD caused a slight increase in the mean (± SEM) plasma concentrations of F2-isoprostanes 2 and 4 h after intake (2.16 ± 0.19 nM at 4 h vs. 1.76 ± 0.11 nM at 0 h, n = 10), which may be attributable to postprandial oxidative stress. This increase did not occur with HFCD (1.57 ± 0.06 nM at 4 h vs. 1.65 ± 0.10 nM at 0 h, n = 10). The difference in F2-isoprostanes 2 and 4 h after intake of HFCD vs. LFCD became statistically significant when the intake was combined with physical exercise (P < 0.01, ANOVA). We conclude that dietary flavanols, using cocoa drink as example, can lower the plasma level of F2-isoprostanes, indicators of in vivo lipid peroxidation. [Copyright &y& Elsevier]

We have introduced two specific techniques for the quantitative measurement of monohydroxyeicosatetraenoic acids (HETEs) and F 2 -isoprostanes by gas chromatography-mass spectrometry/negative ion chemical ionization (GC-MS/NICI) to study lipid peroxidation in isolated rat brain mitochondria by iron/ascorbate. The analysis of HETEs involved hydrogenation, solid phase extraction on a C 18 -cartridge, formation of pentafluorobenzyl bromide and trimethylsilyl ether derivatives. In the case of F 2 -isoprostanes, the analytical procedure was similar to that of HETEs except that the hydrogenation step was omitted. We found that HETE content (sum of 5-, 8-12-, and 15-isomers) in freshly prepared rat brain mitochondria was 220±40 pmol/mg protein. The corresponding content for the F 2 -isoprostane, 8-iso-PGF 2α , was 0.21±0.10 pmol/mg protein. HETEs and 8-iso-PGF 2α were predominantly present in the esterified form. The content of both HETEs and 8-iso-PGF 2α were increased in presence of iron/ascorbate as oxidation system. After 30 min incubation with Fe 2+ + ascorbate, the content of HETE isomers was increased about 6-fold compared with base-line levels whereas that for 8-iso-PGF 2α was elevated 100-fold. Formation of HETEs and F 2 -isoprostanes corresponded to the consumption of arachidonic acid (AA) and α-tocopherol, respectively. There were almost no changes in the content of free (non-esterified) HETEs and 8-iso-PGF 2α during the course of iron/ascorbate induced oxidation of the brain mitochondria. Our data provide the first direct evidence for the presence of HETEs and F 2 -isoprostanes in freshly isolated rat brain mitochondria and that esterified HETEs and 8-iso-PGF 2α are predominantly generated during iron/ascorbate induced lipid peroxidation. Sensitive quantification of these products of non-enzymatic lipid peroxidation as indicators of oxidant injury opens new areas of investigation regarding the role of free radicals in the pathogenesis of human diseases. In addition, HETEs and F 2 -isoprostanes may be important mediators for mitochondrial functions. [ABSTRACT FROM AUTHOR]

Simple Summary: The majority (69.7%) of women diagnosed with breast cancer are above the age of 55. The population of older breast cancer patients is growing. Nevertheless, older patients are underrepresented in cancer research. Therefore, our study set the focus on breast cancer patients aged 50 years and older with a median age of 67 years aiming to understand the influence of aneuploidy, genomic instability and inter- and intratumor heterogeneity on disease outcome, being a major obstacle for precise prognostication and successful treatment. We analyzed chromosomal copy number changes, ploidy and specific gene mutations and found an enormous degree of genomic instability and intratumor heterogeneity in our cohort. However, neither the ploidy, the degree of intratumor heterogeneity nor the presence of specific gene mutations was correlated with prognosis. Our findings provide a precise description of the degree of intratumor heterogeneity, genomic instability, and gene mutations in breast cancer patients aged 50 years and older, revealing significant differences between diploid and aneuploid tumors regarding copy number alterations and the extent of genomic instability. Purpose: Older breast cancer patients are underrepresented in cancer research even though the majority (81.4%) of women dying of breast cancer are 55 years and older. Here we study a common phenomenon observed in breast cancer which is a large inter- and intratumor heterogeneity; this poses a tremendous clinical challenge, for example with respect to treatment stratification. To further elucidate genomic instability and tumor heterogeneity in older patients, we analyzed the genetic aberration profiles of 39 breast cancer patients aged 50 years and older (median 67 years) with either short (median 2.4 years) or long survival (median 19 years). The analysis was based on copy number enumeration of eight breast cancer-associated genes using multiplex interphase fluorescence in situ hybridization (miFISH) of single cells, and by targeted next-generation sequencing of 563 cancer-related genes. Results: We detected enormous inter- and intratumor heterogeneity, yet maintenance of common cancer gene mutations and breast cancer specific chromosomal gains and losses. The gain of COX2 was most common (72%), followed by MYC (69%); losses were most prevalent for CDH1 (74%) and TP53 (69%). The degree of intratumor heterogeneity did not correlate with disease outcome. Comparing the miFISH results of diploid with aneuploid tumor samples significant differences were found: aneuploid tumors showed significantly higher average signal numbers, copy number alterations (CNAs) and instability indices. Mutations in PIKC3A were mostly restricted to luminal A tumors. Furthermore, a significant co-occurrence of CNAs of DBC2/MYC, HER2/DBC2 and HER2/TP53 and mutual exclusivity of CNAs of HER2 and PIK3CA mutations and CNAs of CCND1 and PIK3CA mutations were revealed. Conclusion: Our results provide a comprehensive picture of genome instability profiles with a large variety of inter- and intratumor heterogeneity in breast cancer patients aged 50 years and older. In most cases, the distribution of chromosomal aneuploidies was consistent with previous results; however, striking exceptions, such as tumors driven by exclusive loss of chromosomes, were identified. [ABSTRACT FROM AUTHOR]

Simple Summary: Patients with malignant soft tissue tumors, called soft tissue sarcoma (STS), show alterations in their deoxyribonucleic acid (DNA). Pathologists use these alterations for classification of STS and as drug-related biomarkers. Some drugs show better effectiveness in association with certain genetic alterations. In this study, we examined STS tumor tissue from a specific sarcoma study (GISG-04/NOPASS) with massively parallel DNA sequencing in order to find genetic biomarkers for pazopanib, a multi-target tyrosine kinase inhibitor approved for the treatment of advanced STS. While we could not clearly identify a specific genetic target, we were able to improve diagnostic accuracy and could detect mutations that are potentially useful for individualized therapy. In the framework of the German Interdisciplinary Sarcoma Group GISG-04/NOPASS trial, we evaluated soft tissue sarcoma samples taken before and after neoadjuvant pazopanib therapy using histopathology and next generation sequencing (NGS) to find potential predictive biomarkers. We also aimed to improve the genetically based sarcoma classification and to elucidate additional potentially druggable mutations. In total, 30 tumor samples from 18 patients consisting of 12 pre-therapeutic biopsies and 18 resection specimens following neoadjuvant pazopanib therapy were available for analyses. NGS was performed with the Oncomine Focus Assay (Ion Torrent) covering 0.03 Mb of DNA and enabled the detection of genetic variants in 52 cancer-relevant genes. Pathological analysis showed significant regression (≥50%) after pazopanib treatment in only one undifferentiated (pleomorphic) sarcoma. NGS analyses revealed a very high frequency of CDK4 amplification (88%; 7/8) in the group of dedifferentiated liposarcoma. In addition, two potentially druggable mutations, a MAP2K1 missense mutation (E203K) and a BRAF missense mutation (V600E), were traceable in two undifferentiated (pleomorphic) sarcoma patients (11%; 2/18). Our findings demonstrate that NGS testing is a powerful technology helping to improve diagnostic accuracy and offering some patients the chance for personalized medicine even in a "mutation unlikely" cohort like STS. [ABSTRACT FROM AUTHOR]

Tetraploidy, or whole-genome duplication, is a common phenomenon in cancer and preludes chromosome instability, which strongly correlates with disease progression, metastasis, and treatment failure. Therefore, it is reasonable to hypothesize that tetraploidization confers multidrug resistance. Nevertheless, the contribution of whole-genome duplication to chemo-radiotherapy resistance remains unclear. Here, using isogenic diploid and near-tetraploid clones from three colorectal cancer cell lines and one non-transformed human epithelial cell line, we show a consistent growth impairment but a divergent tumorigenic potential of near-tetraploid cells. Next, we assessed the effects of first-line chemotherapeutic drugs, other commonly used agents and ionizing radiation, and found that whole-genome duplication promoted increased chemotherapy resistance and also conferred protection against irradiation. When testing the activation of apoptosis, we observed that tetraploid cells were less prone to caspase 3 activation after treatment with first-line chemotherapeutic agents. Furthermore, we found that pre-treatment with ataxia telangiectasia and Rad3 related (ATR) inhibitors, which targets response to replication stress, significantly enhanced the sensitivity of tetraploid cells to first-line chemotherapeutic agents as well as to ionizing radiation. Our findings provide further insight into how tetraploidy results in greater levels of tolerance to chemo-radiotherapeutic agents and, moreover, we show that ATR inhibitors can sensitize near-tetraploid cells to commonly used chemo-radiotherapy regimens. [ABSTRACT FROM AUTHOR]