Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare mesenchymal tumor of intermediate malignancy. PHAT, and the related hemosiderotic fibrolipomatous tumor, show a recurrent t(1;10)(p22;q24). Fluorescence in situ hybridization (FISH) and BAC (bacterial artificial chromosome) clones have previously identified TGFBR3 and MGEA5 as fusion partners. However, targeted RNA-sequencing allowed for the correct identification of FBXW4 and not MGEA5 as the fusion partner of TGFBR3 in a subcutaneous PHAT, a finding further confirmed by RT-PCR. FBXW4 and MGEA5 share a common cytogenetic location at 10q24.32, thereby suggesting that the use of less precise technology may have led to inaccurate gene identification. The study of additional cases is however required.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a low grade soft tissue sarcoma with a predilection for acral sites, being associated with a high rate of local recurrence but very infrequent distant metastases. Although a t(1;10) translocation resulting in TGFBR3-MGEA5 fusion has been reported as a recurrent genetic event in MIFS, this abnormality is seen only in a subset of cases. As no studies to date have investigated the spectrum of alternative genetic alterations in TGFBR3-MGEA5 fusion negative MIFS, we undertook a genetic analysis of this particular cohort for further molecular classification. Triggered by an index case occurring in the finger of a 37-year-old female and harboring a novel TOM1L2-BRAF fusion by targeted RNA sequencing we investigated potential recurrent BRAF abnormalities by screening a large group of 19 TGFBR3-MGEA5 fusion negative MIFS by fluorescence in situ hybridization. There were 6 (32%) additional MIFS with BRAF genetic abnormalities, including 5 gene rearrangements and one showing BRAF amplification. Interestingly, VGLL3 amplification, a recurrent genetic abnormality coexisting with t(1;10) in some MIFS, was also detected by fluorescence in situ hybridization in 4/6 (67%) BRAF-rearranged MIFS, but not in the BRAF-amplified case. Up-regulated VGLL3 mRNA expression was also demonstrated in the index case by RNA sequencing. The 7 BRAF-rearranged/amplified MIFS arose in the fingers (n=3), and 1 each in wrist, forearm, foot, and knee, of adult patients (36 to 74 y; M:F=4:3). The histologic spectrum ranged from predominantly solid growth of plump histiocytoid to epithelioid tumor cells with focal myxoid change to a predominantly myxoid background with scattered tumor cells. Varying degree of inflammatory infiltrates and large tumor cells with virocyte-like macronucleoli were observed in most cases. Immunohistochemical stains of phosphorylated ERK, a downstream effector of BRAF activation, were positive in all 4 cases tested (2 diffuse strong, 2 focal strong). Unlike t(1;10), BRAF rearrangements were only found in MIFS but not in 6 hemosiderotic fibrolipomatous tumor (HFLT) lacking TGFBR3-MGEA5 fusions (including 2 pure HFLT, 2 hybrid HFLT-MIFS, and 2 associated with pleomorphic hyalinizing angiectatic tumors).

Myxoinflammatory fibroblastic sarcoma (MIFS) is a rare low-grade sarcoma that most often involves the distal extremities of adults. Some MIFSs have been reported to show TGFBR3 and MGEA5 rearrangements. TGFBR3 and MGEA5 rearrangements have also been reported in hemosiderotic fibrolipomatous tumor (HFLT), in pleomorphic hyalinizing angiectatic tumor (PHAT), and in rare tumors allegedly showing features of both HFLT and MIFS (hybrid HFLT-MIFS). These findings have led to speculation that HFLT, MIFS, PHAT, and hybrid HFLT-MIFS are closely related; however, areas resembling HFLTs are only very rarely encountered in previous series of MIFSs. We studied classic examples of these tumors with the goal of clarifying the relationship between MIFS and HFLT-MIFS. Cases of MIFS (n=31), hybrid HFLT-MIFS (n=8), PHAT (n=2), HFLT (n=1), and undifferentiated pleomorphic sarcoma (n=4) were retrieved from our archives, and the diagnoses were verified by 5 soft tissue pathologists. Using previously validated break-apart fluorescence in situ hybridization probes, we analyzed for TGFBR3 and MGEA5 rearrangements. Only 2 of 31 MIFSs harbored MGEA5 rearrangements; all lacked TGFBR3 rearrangements. Six of 8 hybrid HFLT-MIFSs harbored rearrangements of TGFBR3 and/or MGEA5. Both PHATs were positive for rearrangements of TGFBR3 and/or MGEA5. The HFLT was positive for rearrangements of both TGFBR3 and MGEA5. All undifferentiated pleomorphic sarcomas with focal myxoid change were negative. We conclude that (1) TGFBR3 and/or MGEA5 rearrangements are much more common in hybrid HFLT-MIFSs than in classic MIFSs, (2) HFLTs and MIFSs may be unrelated lesions, and (3) hybrid HFLT-MIFSs most likely represent HFLTs with sarcomatous progression, rather than tumors strictly related to classic MIFSs.

BACKGROUND: Pleomorphic hyalinizing angiectatic tumor (PHAT) and hemosiderotic fibrolipomatous tumor (HFLT) are low-grade neoplasms that share clinicopathologic features and recurring translocation t(1;10)(p22;q24) involving the TGFBR3 and MGEA5 genes. Coexistence of these tumors with a high-grade sarcoma is exceedingly rare and the cytologic features have not been widely described in the literature.
CASE: A 55-year-old female presented with a soft tissue tumor on the dorsum of the foot. Cytologic smears and corresponding core biopsies were composed of a population of markedly pleomorphic spindle cells seen singly and in loose clusters within a myxofibrous matrix and infiltrating fat, with coarse chromatin, prominent nucleoli, irregular nuclear contours and delicate to vacuolated cytoplasm. Intracytoplasmic hemosiderin granules and rare intranuclear cytoplasmic pseudoinclusions were identified. The histologic features of the excisional biopsy mirrored those of the cytologic preparations, but also demonstrated cellular foci of higher-grade sarcoma composed of markedly pleomorphic tumor cells with large vesicular nuclei and prominent nucleoli, exhibiting a mitotic index of 12 mitotic figures per 10 high-powered fields.
CONCLUSION: While HFLT/PHAT generally can be managed by wide local excision, it is important to be aware of their capacity to harbor higher-grade lesions with metastatic potential which may require more radical surgical excision.

We describe 9 cases of pleomorphic hyalinizing angiectatic tumor (PHAT). Recently described TGFBR3 and MGEA5 gene rearrangements in these tumors have confirmed the long-hypothesized link between PHAT and another soft tissue entity, the myxoinflammatory fibroblastic sarcoma (MIFS). Myxoinflammatory fibroblastic sarcoma and PHAT share the same translocation and in addition have a very similar clinical presentation. However, to our best knowledge, no study has ever addressed the striking morphologic similarities between MIFS and PHAT. Our findings based on histological criteria suggest that most, if not all, tumors diagnosed as PHAT might, in fact, represent examples of MIFS that, in addition to a conventional MIFS morphology, manifest aberrant angiectatic hyalinized vessels.

Aberrant protein O-GlcNAcylation may contribute to the development and malignant behavior of many cancers. This modification is controlled by O-linked β-N-acetylglucosamine transferase (OGT) and O-GlcNAcase (OGA). The aim of this study was to determine the expression of O-GlcNAc cycling enzymes mRNA/protein and to investigate their relationship with clinicopathological parameters in laryngeal cancer. The mRNA levels of OGT and MGEA5 genes were determined in 106 squamous cell laryngeal cancer (SCLC) cases and 73 non-cancerous adjacent laryngeal mucosa (NCLM) controls using quantitative real-time PCR. The level of OGT and OGA proteins was analyzed by Western blot. A positive expression of OGT and MGEA5 transcripts and OGT and OGA proteins was confirmed in 75.5 and 68.9 % and in 43.7 and 59.4 % samples of SCLC, respectively. Higher levels of mRNA/protein for both OGT and OGA as well as significant increases of 60 % in total protein O-GlcNAcylation levels were noted in SCLC compared with NCLM (p < 0.05). As a result, an increased level of OGT and MGEA5 mRNA was related to larger tumor size, nodal metastases, higher grade and tumor behavior according to TFG scale, as well as incidence of disease recurrence (p < 0.05). An inverse association between OGT and MGEA5 transcripts was determined with regard to prognosis (p < 0.05). In addition, the highest OGT and OGA protein levels were observed in poorly differentiated tumors (p < 0.05). No correlations with other parameters were noted, but the results showed a trend of more advanced tumors to be more frequently OGT and OGA positive. The results suggest that increased O-GlcNAcylation may have an effect on tumor aggressiveness and prognosis in laryngeal cancer.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a malignant mesenchymal neoplasm most frequently arising in the distal extremities of adults, which usually behaves in a low-grade manner but is capable of metastasizing to local and distant sites, rarely leading to death. It is a rare tumor whose unusual morphology can lead to erroneous histologic diagnosis, either as a nonneoplastic (infectious or inflammatory) process or as a variety of neoplastic diseases. While its exact origin is uncertain, ultrastructural studies have shown at least some of the constituent cells to be modified fibroblasts. Distinct and reproducible genetic abnormalities identified in MIFS are translocation t(1;10)(p22:q24), with rearrangements of the TGFBR3 and MGEA5 genes associated with increased levels of FGF8, and formation of marker/ring chromosome 3, with amplification of the VGLL3 locus. Because these genetic abnormalities are shared by both MIFS and hemosiderotic fibrohistiocytic lipomatous tumor, it is thought that these 2 morphologically distinct neoplasms may comprise a spectrum of disease defined by these genetics. We review the literature on MIFS and discuss morphology (including that of MIFS/hemosiderotic fibrohistiocytic lipomatous tumor hybrid lesions), immunohistochemistry, the differential diagnosis, and recent molecular genetic developments.

Pleomorphic hyalinizing angiectatic tumor (PHAT) is a rare, locally aggressive tumor of the distal extremities with a proclivity for local recurrence. PHATs contain characteristic ectatic, thin-walled vessels, lined by fibrin, and are surrounded by groups of variably pleomorphic spindled to epithelioid neoplastic cells. The putative precursor lesion of PHAT, originally termed "early PHAT" shares many clinicopathologic features with hemosiderotic fibrolipomatous tumor (HFLT). HFLT, myxoinflammatory fibroblastic sarcoma (MIFS), and tumors showing hybrid features of HFLT and MIFS often show TGFBR3 and MGEA5 gene rearrangements. To date, only a small number of PHATs has been tested for either rearrangement; all have been negative. We hypothesized that PHATs contain TGFBR3 and/or MGEA5 rearrangements. Cases of PHAT (all containing areas of HFLT) (N=10), HFLT (N=7), MIFS (N=6), hybrid HFLT/MIFS (N=3), and PHAT-like undifferentiated pleomorphic sarcomas (N=7) were retrieved from our institutional and consultation archives and analyzed for TGFBR3 and MGEA5 rearrangements using a break-apart probe strategy for FISH. Six of 10 PHATs harbored TGFBR3 and/or MGEA5 gene rearrangements: 4 cases had both TGFBR3 and MGEA5 rearrangements, and 2 cases contained MGEA5 rearrangements. Two of 7 HFLTs were positive: 1 case had a TGFBR3 rearrangement, and 1 case had an MGEA5 rearrangement. One of 6 MIFSs had an MGEA5 rearrangement. All 3 hybrid HFLT/MIFS cases were positive: 2 cases had both TGFBR3 and MGEA5 rearrangements, and 1 case had a TGFBR3 rearrangement. All PHAT-like undifferentiated pleomorphic sarcomas were negative. We report, for the first time, the presence of TGFBR3 and/or MGEA5 rearrangements in tumors showing mixed features of HFLT and PHAT. The presence of such rearrangements strongly suggests that HFLT is related to both PHAT and MIFS and that the latter 2 tumors may represent morphologic variants of a single, genetically defined entity in which only MIFS has acquired the capacity to metastasize.

BACKGROUND: The mRNA expression of genes coding enzymes involved in O-GlcNAcylation were analyzed in urine obtained from 176 bladder cancer (BC) patients and 143 healthy persons.
METHODS: MGEA5 and OGT expression was measured by a real-time PCR assay.
RESULTS: OGT expression was not detected in urine of healthy persons but it was found in 51.7% of BC samples. Positive expression of MGEA5 was found in urine of both healthy persons (47.1%) and BC patients (52.3%). Poorly differentiated BC (grade III) showed significantly lower MGEA5 expression than grade I tumors. Contrary, OGT transcript level was significantly higher in grade II and III in comparison to grade I BC. Moreover, there was significant difference in OGT expression between early bladder cancers and invasive or advanced bladder cancers.
CONCLUSIONS: These results suggest that analysis of urinary content of MGEA5 and OGT may be useful for bladder cancer diagnostics.

OBJECTIVES: O-GlcNAcylation is an abundant modification of cellular proteins which consist of single N-acetylglucosamine residues attached by O-linkage to serine or threonine residues. Abnormal O-GlcNAcylation seems to be a feature of malignant cancer cells. The aim of the present study was to determine the relationship between the expression of genes encoding O-GlcNAc cycling enzymes (OGT and MGEAS) and clinicopathological parameters of endometrial carcinomas.
MATERIALS AND METHODS: The mRNA expression levels of O-GlcNAc cycling enzymes in series of 76 samples of endometrial carcinoma were studied by real time RT-PCR method.
RESULTS: The OGT and MGEA5 mRNA expression was significantly higher in tumors of higher histological grade than in well-differentiated tumors. Statistically significant association was found between OGT and MGEA5 mRNA expression and depth of myometrial invasion. Both OGT and MGEA5 expression profiles showed no significant association with the clinical stage of endometrial cancer.
CONCLUSION: O-GlcNAcylation may be an important regulatory modification involved in endometrial cancer pathogenesis but the actual significance of this modification for endometrial cancer progression needs to be investigated further.

Despite their shared predilection for superficial soft tissue of distal extremities and frequent local recurrences, myxoinflammatory fibroblastic sarcoma (MIFS) and hemosiderotic fibrolipomatous tumor (HFLT) have distinct morphologic appearances. Recent studies have identified an identical t(1;10)(p22;q24) in five cases of MIFS and two of HFLT, as well as common amplifications on 3p11-12. To investigate further their potential relationship and to determine the incidence of t(1;10) in a larger cohort, we subjected seven MIFS, 14 HFLT, and three cases with mixed morphology, to molecular and cytogenetic analysis. Fluorescence in situ hybridization (FISH) analysis for rearrangements of TGFBR3 on 1p22 and of MGEA5 on 10q24 was performed in all cases, whereas the status of VGLL3 gene amplification on 3p12.1 was investigated in 12 cases. Conventional karyotyping was performed in one HFLT and two cases with mixed MIFS/HFLT histology. Overall 83% of cases showed rearrangements in both TGFBR3 and MGEA5. All three cases with mixed features of MIFS and HFLT were positive. Cytogenetic analysis performed in three cases confirmed an unbalanced der(10)t(1;10)(p22;q24). VGLL3 gene amplification was noted in 10/12 cases of both histologies. The high incidence of t(1;10) in MIFS and HFLT reinforces a shared pathogenetic relationship. Furthermore, the co-existence of both components either synchronously or metachronously in a primary or subsequent recurrence, suggest either different morphologic variants or different levels of tumor progression of a single biologic entity. FISH analysis for TGFBR3 and MGEA5 rearrangements can be applied as a reliable diagnostic molecular test when confronted with limited material or a challenging diagnosis.

O-GlcNAcylation is an abundant, dynamic, and inducible posttranslational modification in which single β-N-acetylglucosamine residues are attached by O-glycosidic linkage to serine or treonine residues. It is suggested that abnormally regulated O-GlcNAcylation may contribute to the pathology of cancer. Cycling of O-GlcNAc residues on intracellular proteins is controlled by two enzymes, O-GlcNAc transferease (OGT), which catalyses the addition of O-GlcNAc residues and nucleocytoplasmic β-N-acetylglucosaminidase (O-GlcNAcase; encoded by MGEA5 gene), an enzyme involved in the removal of O-GlcNAc. In this study, relationship between the mRNA expressions of genes coding O-GlcNAc cycling enzymes in breast ductal carcinomas and clinicopathological parameters were analyzed. The results showed that poorly differentiated tumors (grade II and III) had significantly higher OGT expression than grade I tumors. Contrary, MGEA5 transcript levels were significantly lower in grade II and III in comparison with grade I tumors. The Spearman rank correlation showed the expressions of OGT and MGEA5 in breast cancer was negatively correlated (r = -0.430, P = 0.0002). Lymph node metastasis status was significantly associated with decreased MGEA5 mRNA expression. This result suggests that elevation in O-GlcNAc modification of proteins may be implicated in breast tumor progression and metastasis.

Myxoinflammatory fibroblastic sarcoma (MIFS) is a low-grade malignant neoplasm for which limited genetic information, including a t(1;10)(p22;q24) and amplification of chromosome 3 material, is available. To further characterize these aberrations, we have investigated eight soft tissue sarcomas diagnosed as MIFS, haemosiderotic fibrolipomatous tumour (HFT), myxoid spindle cell/pleomorphic sarcoma with MIFS features, and inflammatory malignant fibrous histiocytoma/undifferentiated pleomorphic sarcoma with prominent inflammation (IMFH) harbouring a t(1;10) or variants thereof and/or ring chromosomes with possible involvement of chromosome 3. Using chromosome banding, fluorescence in situ hybridization, array-based comparative genomic hybridization, global gene expression, and real-time quantitative PCR analyses, we identified the breakpoint regions on chromosomes 1 and 10, demonstrated and delineated the commonly amplified region on chromosome 3, and assessed the consequences of these alterations for gene expression. The breakpoints in the t(1;10) mapped to TGFBR3 in 1p22 and in or near MGEA5 in 10q24, resulting in transcriptional up-regulation of NPM3 and particularly FGF8, two consecutive genes located close to MGEA5. The ring chromosomes contained a commonly amplified 1.44 Mb region in 3p11-12, which was associated with increased expression of VGLL3 and CHMP2B. The identified genetic aberrations were not confined to MIFS; an identical t(1;10) was also found in a case of HFT and the amplicon in 3p was seen in an IMFH.

OBJECTIVE: The interactions of CD44 with hyaluronan are thought to be crucial for tumor cell attachment to the extracellular matrix, migration, and invasion. For migration to occur, however, the interactions between hyaluronan and cell surface receptors need to be transient. Hyaluronidases may facilitate the degradation of hyaluronan bound to the cell surface and thus reduce the interactions of the cells with the matrix, whereas the overproduction of hyaluronan in the absence of hyaluronidase activity may prevent cells from proliferating or invading normal surrounding tissue.
METHODS: We analyzed the effects in vitro and in vivo of hyaluronan synthase-2 (HAS2) overexpression on a murine glioma cell line that is deficient in hyaluronidase activity. In addition, we evaluated the expression levels of HAS and hyaluronidase genes in human glioma cell lines and in glioma specimens.
RESULTS: Increased hyaluronan synthesis had no effect on the in vitro proliferation of the cells but diminished their in vivo growth rate. Several human glioma cell lines were found to overexpress hyaluronan synthases, but they did so in conjunction with hyaluronidase Hyal2 and MGEA5 expression. Similarly, all glioblastomas multiforme expressed hyaluronidases MGEA5 and Hyal2.
CONCLUSION: The data suggest that an increased synthesis of hyaluronan by astrocytoma cells is only promoting tumor cell growth in vivo if the cells express hyaluronidases as well.

By screening a meningioma expression library with autologous serum we identified four cDNA clones representing a novel gene with striking homology to Caenorhabditis elegans hyaluronidase as indicated by BLASTP analysis. In humans hyaluronidase has been implicated in cancer development and three human genes are known to encode proteins with hyaluronidase activity. None of the human genes, however, showed any homology at the nucleotide or amino acid sequence level to the newly isolated antigen we termed meningioma expressed antigen 5 (MGEA5). Somatic cell hybrid mapping and fluorescence in situ hybridization mapped the gene for MGEA5 to chromosomal band 10q24.1-q24.3. Reverse transcription (RT)-PCR and northern blot hybridization revealed expression of the gene encoding MGEA5 in several meningioma and additional human tissues. Expression analysis also indicated an alternative splicing event giving rise to a shorter and altered transcript termed MGEA5s. The expression of MGEA5 and MGEA5s as fusion proteins revealed an approximate molecular weight of 92 and 54 kDa, respectively. Using heterologous sera we found antibodies against MGEA5s in five out of 23 meningioma patients, whereas no immune reaction was detected in 12 control sera from healthy individuals. Confirmation of hyaluronidase activity was independently achieved by turbidometric analysis and a gel matrix assay. A model for involvement of the novel hyaluronidase gene in meningioma development is proposed.