Phosphaturic mesenchymal tumours (PMTs) are uncommon soft tissue and bone tumours that typically cause hypophosphataemia and tumour-induced osteomalacia (TIO) through secretion of phosphatonins including fibroblast growth factor 23 (FGF23). PMT has recently been accepted by the World Health Organization as a formal tumour entity. The genetic basis and oncogenic pathways underlying its tumourigenesis remain obscure. In this study, we identified a novel FN1-FGFR1 fusion gene in three out of four PMTs by next-generation RNA sequencing. The fusion transcripts and proteins were subsequently confirmed with RT-PCR and western blotting. Fluorescence in situ hybridization analysis showed six cases with FN1-FGFR1 fusion out of an additional 11 PMTs. Overall, nine out of 15 PMTs (60%) harboured this fusion. The FN1 gene possibly provides its constitutively active promoter and the encoded protein's oligomerization domains to overexpress and facilitate the activation of the FGFR1 kinase domain. Interestingly, unlike the prototypical leukaemia-inducing FGFR1 fusion genes, which are ligand-independent, the FN1-FGFR1 chimeric protein was predicted to preserve its ligand-binding domains, suggesting an advantage of the presence of its ligands (such as FGF23 secreted at high levels by the tumour) in the activation of the chimeric receptor tyrosine kinase, thus effecting an autocrine or a paracrine mechanism of tumourigenesis.

Uterine mesenchymal tumors are genetically heterogenous; those with uniform cytomorphology, best exemplified by endometrial stromal tumors, often contain various fusion genes. Novel fusions involving ESR1 and GREB1, key factors in sex hormone pathways, have been implicated in rare uterine mesenchymal tumors. Particularly, the fusions between 5′-ESR1/GREB1 and 3′-NCOA2/NCOA3 were recently identified in 4 uterine tumors resembling ovarian sex-cord tumor (UTROSCT). By RNA sequencing, pathology review, and FISH screening, we identified 4 uterine sarcomas harboring rearranged GREB1, including GREB1-NCOA2 and the novel GREB1-NR4A3, GREB1-SS18, and GREB1-NCOA1, validated by RT-PCR and/or FISH. They occurred in the myometrium of postmenopausal women and were pathologically similar despite minor differences. Tumor cells were generally uniform and epithelioid, with vesicular nuclei and distinct to prominent nucleoli. Growth patterns included solid sheets, trabeculae/cords, nests, and fascicles. Only 1 tumor showed small foci of definitive sex-cord components featuring well-formed tubules, retiform structures, Leydig-like cells, and lipid-laden cells and exhibiting convincing immunoreactivity to sex-cord markers (calretinin, α-inhibin, and Melan-A). In contrast, all the 4 classic UTROSCT we collected occurred in premenopausal patients, consisted predominantly of unequivocal sex-cord elements, prominently expressed multiple sex-cord markers, and harbored ESR1-NCOA3 fusion. Combined with previously reported cases, GREB1-rearranged tumors involved significantly older women (P=0.001), tended to be larger and more mitotically active, showed more variable and often inconspicuous sex-cord differentiation, and appeared to behave more aggressively than ESR1-rearranged UTROSCT. Therefore, these 2 groups of tumors might deserve separate consideration, despite some overlapping features and the possibility of belonging to the same disease spectrum.

The classification of atypical adipocytic neoplasms with spindle cell features remains challenging. To better define this category of low-grade lipomatous neoplasms, we present herein the clinical, histologic, and immunohistochemical characteristics of a large series of 232 atypical spindle cell lipomatous tumors. The lesions affected 140 males and 92 females, at an average age of 54 years (range, 6 to 87 y), clinically presenting as a persistent or enlarging mass with a median size of 5 cm. The anatomic distribution of the tumors was wide, predominating in the limbs and limb girdles (147 cases, 63%), mainly in the hands and feet (17% and 11%, respectively), with equal distribution between subcutaneous and deeper locations. Microscopic examination revealed a spectrum of histologic appearances. All cases consisted of a poorly marginated proliferation of mildly atypical spindle cells set in a fibrous or myxoid stroma, with a variably prominent admixed adipocytic component showing variation in adipocyte size and scattered nuclear atypia, frequently with univacuolated or multivacuolated lipoblasts. Tumor cellularity and the relative proportion of the different components were very variable. Tumor margins were often ill defined with invasion into surrounding tissues. Two tumors showed morphologic features reminiscent of dedifferentiation. By immunohistochemistry, the neoplastic spindle cells expressed CD34 (64%), S100 protein (40%) and, less frequently, desmin (23%). Expression of Rb was lost in 57% of cases examined. MDM2 and CDK4 were never coexpressed and FISH for MDM2 amplification was consistently negative, highlighting critical biological differences from atypical lipomatous tumor/dedifferentiated liposarcoma. The morphologic differential diagnosis of atypical spindle cell lipomatous tumor is broad, and includes spindle cell lipoma, diffuse neurofibroma, mammary-type myofibroblastoma, dermatofibrosarcoma protuberans, fat-forming solitary fibrous tumor, and morphologically low-grade malignant peripheral nerve sheath tumor. Most patients underwent surgical excision of the primary mass. With a median follow-up of 4 years (range, 1 mo to 20 y), 87% of patients (63/72) were alive with no evidence of recurrence or metastatic disease. Local recurrence of the tumor was observed in 12% of patients (9 out of 72, multiple in 3 of them) at intervals between 6 months and 17 years after resection of the primary tumor. None of the patients developed tumor metastasis or died of disease. Identification of the neoplastic adipocytic component admixed with spindle cells, and recognition of the range of histologic appearances are key for the diagnosis of atypical spindle cell lipomatous tumor. Whereas the risk of metastatic dissemination is minimal, there is a non-negligible risk for local recurrence (13%) which warrants surgical resection with clear margins whenever feasible.

Curcumin, a constituent of the turmeric plant, has antitumor, anti-inflammatory, and antioxidative effects, but its effects on wound healing are unclear. We created back wounds in 72 mice and treated them with or without topical curcumin (0.2 mg/mL) in Pluronic F127 gel (20%) daily for 3, 5, 7, 9, and 12 days. Healing in wounds was evaluated from gross appearance, microscopically by haematoxylin and eosin staining, by immunohistochemistry for tumour necrosis factor alpha and alpha smooth muscle actin, and by polymerase chain reaction amplification of mRNA expression levels. Treatment caused fast wound closure with well-formed granulation tissue dominated by collagen deposition and regenerating epithelium. Curcumin increased the levels of tumour necrosis factor alpha mRNA and protein in the early phase of healing, which then decreased significantly. However, these levels remained high in controls. Levels of collagen were significantly higher in curcumin-treated wounds. Immunohistochemical staining for alpha smooth muscle actin was increased in curcumin-treated mice on days 7 and 12. Curcumin treatment significantly suppressed matrix metallopeptidase-9 and stimulated alpha smooth muscle levels in tumour necrosis factor alpha-treated fibroblasts via nuclear factor kappa B signalling. Thus, topical curcumin accelerated wound healing in mice by regulating the levels of various cytokines.

DOG1 (discovered on GIST 1), known also as TMEM16A and ANO1, has emerged in recent years as a promising biomarker for gastrointestinal stromal tumors (GIST). It was originally discovered through microarray expression profiling analysis as gene that is highly expressed in GIST, and subsequent immunohistochemical studies have shown its use in its diagnosis. The results from several series have shown a high overall sensitivity and specificity for DOG1 in the detection of GISTs and about 6% of GISTs overall exhibiting a DOG1+/KIT-immunoprofile. DOG1 antibodies are more sensitive than KIT antibodies in detecting tumors of gastric origin, tumors with epithelioid morphology, and tumors harboring PDGFRA mutation. Furthermore, DOG1 immunoreactivity is rarely observed in other mesenchymal and nonmesenchymal tumor types. These results support the use of DOG1 as a diagnostic biomarker for GIST. When used in combination with KIT, this panel of diagnostic biomarkers can help pathologists and clinicians to identify more patients who may benefit from targeted therapies.

Sorafenib has substantial clinical activity as third- or fourth-line treatment of imatinib- and sunitinib-resistant gastrointestinal stromal tumors (GIST). Because sorafenib targets both angiogenesis-related kinases (VEGFR) and the pathogenetic kinases found in GIST (KIT or PDGFRA), the molecular basis for sorafenib efficacy in this setting remains unknown. We sought to determine the spectrum of activity of sorafenib against different mutant kinases associated with drug-sensitive and drug-resistant GIST. We compared the activity of imatinib and sorafenib against transiently expressed mutant forms of KIT and PDGFRA, including various secondary mutations that have been identified in imatinib-resistant or sunitinib-resistant GISTs. We also examined these drugs against four GIST cell lines, three of which are imatinib resistant. In our in vitro studies, we determined that sorafenib inhibited imatinib-resistant mutations in exons encoding the ATP/drug-binding pocket and in exons encoding the activation loop, with the exception of substitutions at KIT codon D816 and PDGFRA codon 842. Notably our data indicate that sorafenib is more effective than imatinib or sunitinib for inhibiting the kinase activity of drug-resistant KIT mutants (as assessed by biochemical IC50). We hypothesize that a major determinant of the efficacy of sorafenib for treatment of advanced GIST is the activity of this agent against KIT or PDGFRA-mutant kinases. These results have implications for the further development of treatments for drug-resistant GIST.

Resveratrol, an edible polyphenolic phytoalexin, improves endothelial dysfunction and attenuates inflammation. However, the mechanisms have not been thoroughly elucidated. Therefore, we investigated the molecular basis of the effects of resveratrol on TNF-α-induced ICAM-1 expression in HUVECs. The resveratrol treatment significantly attenuated the TNF-α-induced ICAM-1 expression. The inhibition of p38 phosphorylation mediated the reduction in ICAM-1 expression caused by resveratrol. Resveratrol also decreased TNF-α-induced IκB phosphorylation and the phosphorylation, acetylation, and translocation of NF-κB p65. Moreover, resveratrol induced the AMPK phosphorylation and the SIRT1 expression in TNF-α-treated HUVECs. Furthermore, TNF-α significantly suppressed miR-221/-222 expression, which was reversed by resveratrol. miR-221/-222 overexpression decreased p38/NF-κB and ICAM-1 expression, which resulted in reduced monocyte adhesion to TNF-α-treated ECs. In a mouse model of acute TNF-α-induced inflammation, resveratrol effectively attenuated ICAM-1 expression in the aortic ECs of TNF-α-treated wild-type mice. These beneficial effects of resveratrol were lost in miR-221/222 knockout mice. Our data showed that resveratrol counteracted the TNF-α-mediated reduction in miR-221/222 expression and decreased the TNF-α-induced activation of p38 MAPK and NF-κB, thereby suppressing ICAM-1 expression and monocyte adhesion. Collectively, our results show that resveratrol attenuates endothelial inflammation by reducing ICAM-1 expression and that the protective effect was mediated partly through the miR-221/222/AMPK/p38/NF-κB pathway.

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