Desmoid-type fibromatosis (DTF, aggressive fibromatosis) is a non-metastasizing mesenchymal neoplasm of deep soft tissue with a tendency towards local recurrence. Genetic alterations affecting canonical Wnt/β-catenin signaling are reported in the majority of DTF. While most sporadic DTF harbor somatic mutations in CTNNB1, germline mutations in adenomatous polyposis coli (APC) are known to occur in hereditary DTF types (FAP, Gardner-Syndrome). Additional single nucleotide variants (SNVs) in AKT1 (E17K) and BRAF (V600E) were reported in pediatric DTF with potential clinical implications. We performed targeted next-generation sequencing (NGS) in a large cohort of 204 formalin-fixed DTF samples, comprising 22 pediatric cases (patients age ≤18 years). The mutational status was correlated with clinicopathological characteristics. Overall, deleterious CTNNB1 mutations were detected in 89% of DTF, most frequently affecting the serine/threonine phosphorylation sites T41 and S45 of β-catenin. While the T41A CTNNB1 mutation was significantly more often identified in the mesenterial localization, DTF originating from extra-intestinal sites more frequently harbored the S45P CTNNB1 alteration. Beyond common mutations in CTNNB1, additional SNVs were demonstrated in 7% of the DTF cohort and in 18% of the pediatric DTF subgroup. The mutational spectrum included deleterious mutations in AKT1 (G311S/D and T312I), ALK (R806H and G924S), AR (A159T), EGFR (P848L), ERBB2 (H174Y), IDH2 (H354Y), KIT (V559D), RET (T1038A), SDHA (R325M), and SDHD (R115W), as characterized by in silico prediction tools. In conclusion, our study indicates that DTF may harbor a broader mutational spectrum beyond CTNNB1 mutations, comprising targetable alterations including the herewith first reported imatinib-sensitive KIT V559D mutation in DTF. Desmoid-type fibromatosis (aggressive fibromatosis, desmoid tumor, DTF) is an infiltrating, locally aggressive myofibroblastic neoplasm of intermediate malignant potential highly prone to local recurrence without the potential for metastatic spread. The tumors typically arise in deep soft tissue compartments of intra-and extra-abdominal localization. Pediatric forms usually affect the extremities, while in adults also the mesenterium and the abdominal wall are commonly involved sites; the latter predominantly affected in women 1. The majority of DTF harbor mutations affecting the canonical Wnt/β-catenin signaling pathway 2. While in patients with familial adenomatous polyposis (FAP) β-catenin is not degraded through inactivating mutations in APC, most sporadic DTF harbor alterations in CTNNB1; both leading to a nuclear accumulation of β-catenin and an oncogenic activation of the Wnt/β-catenin signal transduction pathway 3-6. In the sporadic subtype, alterations in CTNNB1 seem to be focused on the serine/threonine phosphorylation sites T41 and S45 7,8 with a higher risk of local recurrence reported in association with the S45F CTNNB1 mutation 8,9. Currently, no evidence-based approach for the treatment of DTF is establ...

Iron oxide nanoparticles (ION) are highly sensitive probes for magnetic resonance imaging (MRI) that have previously been used for in vivo cell tracking and have enabled implementation of several diagnostic tools to detect and monitor disease. However, the in vivo MRI signal of ION can overlap with the signal from endogenous iron, resulting in a lack of detection specificity. Therefore, the long-term fate of administered ION remains largely unknown, and possible tissue deposition of iron cannot be assessed with established methods. Herein, we combine nonradioactive 57Fe-ION MRI with ex vivo laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) imaging, enabling unambiguous differentiation between endogenous iron (56Fe) and iron originating from applied ION in mice. We establish 57Fe-ION as an in vivo MRI sensor for cell tracking in a mouse model of subcutaneous inflammation and for assessing the long-term fate of 57Fe-ION. Our approach resolves the lack of detection specificity in ION imaging by unambiguously recording a 57Fe signature.

Background: T cell infiltration in non-small cell lung cancer (NSCLC) is essential for the immunological response to malignant tissue, especially in the era of immune-checkpoint inhibition. To investigate the prognostic impact of CD4 + T helper cells (T h ), CD8 + cytotoxic (T c ) and FOXP3 + regulatory T (T reg ) cells in NSCLC, we performed this analysis.Methods: By counterstaining of CD4, CD8 and FOXP3 we used immunohistochemistry on tissue microarrays (TMA) to evaluate peritumoral T h cells, T reg cells and T c cells in n=294 NSCLC patients with pTNM stage I-III disease.Results: Strong CD4 + infiltration was associated with higher tumor stages and lymphonodal spread.However, strong CD4 + infiltration yielded improved overall survival (OS) (P=0.014) in adenocarcinoma (ADC) and large cell carcinoma (LCC) but not in squamous cell carcinoma (SCC). A CD4/CD8 ratio <1 was associated with high grade NSCLC tumors (P=0.020). High CD8 + T cell infiltration was an independent prognostic factor for OS (P=0.040) and progression-free survival (PFS) (P=0.012) in the entire study collective. The OS benefit of high CD8 + infiltration was especially prominent in PD-L1 negative NSCLC (P=0.001) but not in PD-L1 positive tissue (P=0.335). Moreover, positive FOXP3 + expression in tumor infiltrating lymphocytes was associated with increased OS (P=0.007) and PFS (P=0.014) in SCC but not in ADC and LCC (all P>0.05). Here, prognostic effects were prominent in PD-L1 positive SCC (P=0.023) but not in PD-L1 negative SCC (P=0.236).Conclusions: High proportion of CD8 + T c cells correlated with improved prognostic outcome in stage I-III NSCLC. T h cells and T reg cells have implications on outcome with respect to tumor histology and biology.

BackgroundEpithelial‐to‐mesenchymal transition (EMT) is a crucial step in lung cancer pathogenesis. Among others, cancer‐associated fibroblasts (CAFs) are reported to regulate this process.ObjectivesTo investigate the prognostic and clinical impact, we analyzed CD34+ and SMA+ CAFs in non‐small cell lung cancer (NSCLC).MethodsRetrospectively, immunohistochemistry was performed to study stromal protein expression of both CD34 and SMA in 304 NSCLC patients with pTNM stage I‐III disease. All tissue samples were embedded on tissue microarrays (TMAs).ResultsOur analysis revealed an association for CD34+ CAFs with G1/2 tumors and adenocarcinoma histology. Moreover CD34+ CAFs were identified as an independent prognostic factor (both for progression free survival [PFS] and overall survival [OS] in stage I‐III NSCLC). Besides, SMA+ expression correlated with higher pTNM‐tumor stages and lymphatic spread (pN stage). In turn, SMA‐negativity was associated with improved PFS, but no prognostic impact was found on OS. Of interest, neither CD34+ CAFs nor SMA+ CAFs were associated with the primary tumor size, localization and depth of infiltration (pT stage).ConclusionsCD34 was identified as an independent prognostic marker in pTNM stage I‐III NSCLC. Moreover, loss of CD34+ CAFs might influence the dedifferentiation of the NSCLC tumor from its cell origin. Finally, SMA+ CAFs are more prevalent in NSCLC tumors of higher stages and lymphonodal positive NSCLC.Key points Expression of CD34 on cancer associated fibroblasts (CAFs) is an independent prognostic factor in stage I‐III NSCLC.SMA+ cancer associated fibroblasts are associated with higher tumor stages in NSCLC and might contribute to tumor progression in NSCLC.

Background The nucleation-promoting factor cortactin is expressed and promotes tumor progression and metastasis in various cancers. However, little is known about the biological role of cortactin in the progression of pancreatic ductal adenocarcinoma (PDAC). Methods Cortactin and phosphorylated cortactin (Y421) were investigated immunohistochemically in 66 PDAC tumor specimens. To examine the functional role of cortactin in PDAC, we modulated cortactin expression by establishing two cortactin knockout cell lines (Panc-1 and BxPC-3) with CRISPR/Cas9 technique. Cortactin knockout was verified by immunoblotting and immunofluorescence microscopy and functional effects were determined by cell migration and invasion assays. A proteomic screening approach was performed to elucidate potential binding partners of cortactin. Results Immunohistochemically, we observed higher cortactin expression and Tyr421-phosphorylation in PDAC metastases compared to primary tumor tissues. In PDAC cell lines Panc-1 and BxPC-3, knockdown of cortactin impaired migration and invasion, while cell proliferation was not affected. Three-dimensional spheroid culturing as a model for collective cell migration enhanced cortactin expression and Tyr421-phosphorylation. The activation of cortactin as well as the migratory capacity of PDAC cells could significantly be reduced by dasatinib, a Src family kinase inhibitor. Finally, we identified gelsolin as a novel protein interaction partner of cortactin in PDAC. Conclusion Our data provides evidence that cohesive cell migration induces cortactin expression and phosphorylation as a prerequisite for the gain of an invasive, pro-migratory phenotype in PDAC that can effectively be targeted with dasatinib. Electronic supplementary material The online version of this article (10.1186/s12935-019-0798-x) contains supplementary material, which is available to authorized users.