Clinical Applications of Adipose-Derived Stem Cell (ADSC) Exosomes in Tissue Regeneration.

Adipose-derived stem cells (ADSCs) are mesenchymal stem cells with a great potential for self-renewal and differentiation. Exosomes derived from ADSCs (ADSC-exos) can imitate their functions, carrying cargoes of bioactive molecules that may affect specific cellular targets and signaling processes. Recent evidence has shown that ADSC-exos can mediate tissue regeneration through the regulation of the inflammatory response, enhancement of cell proliferation, and induction of angiogenesis. At the same time, they may promote wound healing as well as the remodeling of the extracellular matrix. In combination with scaffolds, they present the future of cell-free therapies and promising adjuncts to reconstructive surgery with diverse tissue-specific functions and minimal adverse effects. In this review, we address the main characteristics and functional properties of ADSC-exos in tissue regeneration and explore their most recent clinical application in wound healing, musculoskeletal regeneration, dermatology, and plastic surgery as well as in tissue engineering.

Helicobacter pylori Eradication Reverses DNA Damage Response Pathway but Not Senescence in Human Gastric Epithelium.

Helicobacter pylori (H. pylori) infection induces DNA Double-Strand Breaks (DSBs) and consequently activates the DNA Damage Response pathway (DDR) and senescence in gastric epithelium. We studied DDR activation and senescence before and after the eradication of the pathogen. Gastric antral and corpus biopsies of 61 patients with H. pylori infection, prior to and after eradication treatment, were analyzed by means of immunohistochemistry/immunofluorescence for DDR marker (γH2AΧ, phosporylated ataxia telangiectasia-mutated (pATM), p53-binding protein (53BP1) and p53) expression. Samples were also evaluated for Ki67 (proliferation index), cleaved caspase-3 (apoptotic index) and GL13 staining (cellular senescence). Ten H. pylori (-) dyspeptic patients served as controls. All patients were re-endoscoped in 72-1361 days (mean value 434 days), and tissue samples were processed in the same manner. The eradication of the microorganism, in human gastric mucosa, downregulates γH2AΧ expression in both the antrum and corpus (p = 0.00019 and p = 0.00081 respectively). The expression of pATM, p53 and 53BP1 is also reduced after eradication. Proliferation and apoptotic indices were reduced, albeit not significantly, after pathogen clearance. Moreover, cellular senescence is increased in H. pylori-infected mucosa and remains unaffected after eradication. Interestingly, senescence was statistically increased in areas of intestinal metaplasia (IM) compared with adjacent non-metaplastic mucosa (p < 0.001). In conclusion, H. pylori infection triggers DSBs, DDR and senescence in the gastric epithelium. Pathogen eradication reverses the DDR activation but not senescence. Increased senescent cells may favor IM persistence, thus potentially contributing to gastric carcinogenesis.

The Role of mTOR in B Cell Lymphoid Malignancies: Biologic and Therapeutic Aspects.

Non-Hodgkin lymphoma's (NHL) incidence is rising over time, and B cell lymphomas comprise the majority of lymphomas. The phosphoinositide 3-kinase (PI3K)/v-akt murine thymoma viral oncogene homologue 1 (Akt)/mammalian target of the rapamycin (mTOR) signaling pathway plays a critical role in a variety of cellular processes, such as cell proliferation and survival. Its role in lymphomagenesis is confirmed in many different types of B cell lymphomas. This review is mainly focused on the PI3K/v-akt/mTOR pathway-related oncogenic mechanisms in B cell NHLs with an emphasis on common B cell lymphoma types [diffuse large B cell lymphoma (DLBCL) and mantle cell lymphoma (MCL)]. Furthermore, it summarizes the literature regarding the clinical applications of the mTOR inhibitors temsirolimus and everolimus in B cell NHLs, which have been tested in a range of clinical trials enrolling patients with B cell malignancies, either as monotherapy or in combination with other agents or regimens.

Polycystin-1 regulates cell proliferation and migration through AKT/mTORC2 pathway in a human craniosynostosis cell model.

Craniosynostosis is the premature fusion of skull sutures and has a severe pathological impact on childrens' life. Mechanical forces are capable of triggering biological responses in bone cells and regulate osteoblastogenesis in cranial sutures, leading to premature closure. The mechanosensitive proteins polycystin-1 (PC1) and polycystin-2 (PC2) have been documented to play an important role in craniofacial proliferation and development. Herein, we investigated the contribution of PC1 to the pathogenesis of non-syndromic craniosynostosis and the associated molecular mechanisms. Protein expression of PC1 and PC2 was detected in bone fragments derived from craniosynostosis patients via immunohistochemistry. To explore the modulatory role of PC1 in primary cranial suture cells, we further abrogated the function of PC1 extracellular mechanosensing domain using a specific anti-PC1 IgPKD1 antibody. Effect of IgPKD1 treatment was evaluated with cell proliferation and migration assays. Activation of PI3K/AKT/mTOR pathway components was further detected via Western blot in primary cranial suture cells following IgPKD1 treatment. PC1 and PC2 are expressed in human tissues of craniosynostosis. PC1 functional inhibition resulted in elevated proliferation and migration of primary cranial suture cells. PC1 inhibition also induced activation of AKT, exhibiting elevated phospho (p)-AKT (Ser473) levels, but not 4EBP1 or p70S6K activation. Our findings indicate that PC1 may act as a mechanosensing molecule in cranial sutures by modulating osteoblastic cell proliferation and migration through the PC1/AKT/mTORC2 cascade with a potential impact on the development of non-syndromic craniosynostosis.

Molecular analysis of NUT-positive poromas and porocarcinomas identifies novel break points of YAP1::NUTM1 fusions.

BACKGROUND: Poromas, and their malignant counterparts, porocarcinomas, harbor recurrent translocations involving YAP1-MAML2, YAP1-NUTM1, and infrequently WWTR1-NUTM1; YAP1-NUTM1 being the most common in porocarcinomas. NUT immunohistochemistry (IHC) can be used to identify NUTM1-translocated tumors. This study sought to investigate potential novel NUTM1-fusion partners among NUT IHC-positive poromas and porocarcinomas. METHODS: Thirteen NUT IHC-positive poroid tumors (four poromas and nine porocarcinomas) were identified within a multi-institutional international cohort. Next-generation sequencing (NGS) assessed for NUTM1 fusion partners. RESULTS: NGS detected a NUTM1 fusion in 12 of 13 cases: YAP1-NUTM1 (11/12 cases) and WWTR1-NUTM1 (1/12 cases). Two of the cases (2/12) with NUTM1 fusion were not called by the NGS algorithm but had at least one read-spanning YAP1-NUTM1 break point upon manual review. A NUTM1 fusion was not identified in one case; however, the sample had low RNA quality. The following fusion events were identified: YAP1 exon 4::NUTM1 exon 3 in six cases, YAP1 exon 6::NUTM1 exon 2 in one case, YAP1 exon 3::NUTM1 exon 3 in three cases, WWTR1 exon 3::NUTM1 exon 3 in one case, and YAP1 exon 8::NUTM1 exon 3 fusion in one case. CONCLUSION: While no novel NUTM1 fusion partners were identified within our cohort, 12 of 13 cases had discoverable NUTM1 fusions; YAP1-NUTM1 fusion was detected in 11 cases (92%) and WWTR1-NUTM1 in 1 case (8%). These data corroborate findings from other recent investigations and further substantiate the utility of NUT IHC in diagnosing a subset of poroid neoplasms. In addition, two of our cases harbored fusions of YAP1 exon 6 to NUTM1 exon 3 and YAP1 exon 8 to NUTM1 exon 2, which have not been reported before in poroid neoplasms and indicate novel break points of YAP1.

Unraveling the Role of Histone Variant CENP-A and Chaperone HJURP Expression in Thymic Epithelial Neoplasms.

Background: Recent advances demonstrate the role of chromatin regulators, including histone variants and histone chaperones, in cancer initiation and progression. Methods: Histone H3K4me3, histone variant centromere protein (CENP-A) and histone chaperones Holliday junction recognition protein (HJURP) as well as DAXX expression were examined immunohistochemically in 95 thymic epithelial tumor (TET) specimens. Our results were compared with the expression profile of DAXX, HJURP and CENP-A in gene expression profiling interactive analysis (GEPIA2). Results: The lymphocyte-poor B3- and C-type TETs were more frequently DAXX negative (p = 0.043). B3 and C-Type TETs showed higher cytoplasmic and nuclear CENP-A (p = 0.007 and p = 0.002) and higher cytoplasmic HJURP H-score (p < 0.001). Higher nuclear CENP-A and cytoplasmic HJURP expression was associated with advanced Masaoka−Koga stage (p = 0.048 and p < 0.001). A positive correlation between HJURP and CENP-A was also observed. The presence of cytoplasmic CENP-A expression was correlated with a favorable overall survival (p = 0.03). CENP-A overexpression in survival analysis of TCGA TETs showed similar results. H3K4me3 expression was not associated with any clinicopathological parameters. Conclusions: Our results suggest a significant interaction between CENP-A and HJURP in TETs. Moreover, we confirmed the presence of a cytoplasmic CENP-A immunolocalization, suggesting also a possible favorable prognostic value of this specific immunostaining pattern.

Novel CTNND2-TERT fusion in a spindle cell liposarcoma.

Soft tissue tumors can be categorized molecularly into two categories: tumors which are known to have recurrent molecular alterations and tumors which do not have consistent recurrent molecular alterations or translocations. These "nontranslocation" associated sarcomas are clinically more aggressive than their more stable counterparts. However, recent advances in RNA sequencing have discovered recurrent novel fusions within the latter group, namely TERT-TRIO fusions. Furthermore, a recent report discovered this fusion in a spindle cell liposarcoma. Our case describes a novel fusion of CTNND2, a neighbor gene of TRIO, and TERT in a spindle cell liposarcoma, and provides further evidence that spindle cell liposarcoma should be a distinct entity from dedifferentiated liposarcoma.

A concise review of angiofibroma of soft tissue: A rare newly described entity that can be encountered by dermatopathologists.

Angiofibroma of soft tissue (AFST) is a newly described, rare mesenchymal neoplasm with fibroblastic and vascular components; it can be seen in both sexes and in a broad age range. It presents as a slowly enlarging mass, most often in the deep tissues of the upper and lower extremities, but occasionally in a superficial location where it may be encountered by dermatopathologists. It has a benign clinical course with a very low probability of recurrence after complete excision. This lesion has a prominent vasculature and may have an infiltrative growth pattern. These features could lead to a misdiagnosis, such as malignant vascular tumor, by an unwary dermatopathologist. The diagnosis of AFST initially relied solely on morphology and immunohistochemistry but, more recently, molecular studies have begun to play a role. Because of the potential for misdiagnosis, we present this review to raise awareness.

Diagnosis and treatment complications of primary cardiac lymphoma in an immunocompetent 28-year old man: a case report.

BACKGROUND: Primary cardiac lymphomas (PCL) represent extremely rare cardiac tumors which are accompanied by poor prognosis, unless they are timely diagnosed and treated. CASE PRESENTATION: Herein we present a 28-year-old, immunocompetent man who presented to our hospital due to progressively worsening symptoms and signs of superior vena cava syndrome. Multi-modality imaging demonstrated a large intracardiac tumor, which was proven, by biopsy, to be a PCL. The patient received targeted chemotherapy which led to total remission of his disease, with no relapse over a 15-month follow-up period. CONCLUSIONS: Although PCLs are rare, they should always be kept in mind in the differential diagnosis of cardiac tumors. Timely diagnosis of PCLs and appropriate chemotherapy, alone or in combination with radiotherapy, seems to provide the best results.

A Unique Case of Primary Extranodal Marginal Zone Lymphoma of the Anal Canal.

Marginal zone lymphomas represent approximately 10-12% of all B-cell lymphomas. Extranodal marginal zone lymphomas (EMZL) or mucosa-associated lymphoid tissue (MALT) lymphomas are the most common subtype. Almost half of all MALT lymphomas arise in the gastrointestinal (GI) tract and, while the stomach is the most common site of GI involvement, the small and large intestines can also be involved. Rare cases of MALT lymphoma involving the rectum have been reported; however, to our knowledge, involvement of the anal canal has never been reported in the literature. Here, we describe a unique case of MALT lymphoma of the anal canal. Infectious agents have been implicated in the pathogenesis of MALT lymphomas, possibly through persistent antigenic stimulation of the area; however, in our case no such infection was documented.

A novel MAP3K7CL-ERG fusion in a molecularly confirmed case of dermatofibrosarcoma protuberans with fibrosarcomatous transformation.

Dermatofibrosarcoma protuberans (DFSP) is a translocation-associated, low-grade sarcoma with fibroblastic differentiation. It is the most common superficial sarcoma, almost exclusively arising within the dermis. In a minority of cases, there is a transition from the conventional morphology to a fibrosarcomatous pattern, known as a fibrosarcomatous DFSP (FS-DFSP). Although a number of different molecular alterations have been described to account for this transformation, it remains poorly understood. Herein we report the first case of a FS-DFSP with a fusion between ERG, an ETS family transcription factor, and MAP3K7CL, a kinase gene rarely observed in fusion gene events.

Numerous Ontogenetic Roads to Mantle Cell Lymphoma: Immunogenetic and Immunohistochemical Evidence.

To obtain insight into the ontogeny of mantle cell lymphoma (MCL), we assessed 206 patients from a morphological, immunohistochemical, and immunogenetic perspective. Our series included nodal (n = 151), extranodal (n = 28), and primary splenic (n = 27) MCL cases. Skewing of the immunoglobulin heavy variable (IGHV) gene repertoire was noted, with only four IGHV genes accounting for 46% of cases and approximately 70% of cases (107/154) bearing an imprint of somatic hypermutation (SHM) ranging from minimal to pronounced. Interestingly, a distinctive immunophenotypic and immunogenetic profile was identified for primary splenic MCL, which was enriched for DBA.44-positive cases (P < 0.001) and used the IGHV1-8 gene more frequently (P = 0.02) compared to nodal or extranodal cases, alluding to distinct immunopathogenetic and antigen selection processes. Expression of CD27 (considered a marker of activated B cells) was generally dissociated from SHM and was more prevalent in cases with no or minimal/borderline SHM. These findings support the idea that antigen drive is relevant for most MCL cases, although the specific antigens and the precise location of affinity maturation remain to be elucidated. Moreover, they raise the intriguing hypothesis of multiple cellular origins for MCL.

Frequent NFKBIE deletions are associated with poor outcome in primary mediastinal B-cell lymphoma.

We recently reported a truncating deletion in the NFKBIE gene, which encodes IκBε, a negative feedback regulator of NF-κB, in clinically aggressive chronic lymphocytic leukemia (CLL). Because preliminary data indicate enrichment of NFKBIE aberrations in other lymphoid malignancies, we screened a large patient cohort (n = 1460) diagnosed with different lymphoid neoplasms. While NFKBIE deletions were infrequent in follicular lymphoma, splenic marginal zone lymphoma, and T-cell acute lymphoblastic leukemia (<2%), slightly higher frequencies were seen in diffuse large B-cell lymphoma, mantle cell lymphoma, and primary central nervous system lymphoma (3% to 4%). In contrast, a remarkably high frequency of NFKBIE aberrations (46/203 cases [22.7%]) was observed in primary mediastinal B-cell lymphoma (PMBL) and Hodgkin lymphoma (3/11 cases [27.3%]). NFKBIE-deleted PMBL patients were more often therapy refractory (P = .022) and displayed inferior outcome compared with wild-type patients (5-year survival, 59% vs 78%; P = .034); however, they appeared to benefit from radiotherapy (P =022) and rituximab-containing regimens (P = .074). NFKBIE aberrations remained an independent factor in multivariate analysis (P = .003) and when restricting the analysis to immunochemotherapy-treated patients (P = .008). Whole-exome sequencing and gene expression profiling verified the importance of NF-κB deregulation in PMBL. In summary, we identify NFKBIE aberrations as a common genetic event across B-cell malignancies and highlight NFKBIE deletions as a novel poor-prognostic marker in PMBL.

A driver role for GABA metabolism in controlling stem and proliferative cell state through GHB production in glioma.

Cell populations with differing proliferative, stem-like and tumorigenic states co-exist in most tumors and especially malignant gliomas. Whether metabolic variations can drive this heterogeneity by controlling dynamic changes in cell states is unknown. Metabolite profiling of human adult glioblastoma stem-like cells upon loss of their tumorigenicity revealed a switch in the catabolism of the GABA neurotransmitter toward enhanced production and secretion of its by-product GHB (4-hydroxybutyrate). This switch was driven by succinic semialdehyde dehydrogenase (SSADH) downregulation. Enhancing GHB levels via SSADH downregulation or GHB supplementation triggered cell conversion into a less aggressive phenotypic state. GHB affected adult glioblastoma cells with varying molecular profiles, along with cells from pediatric pontine gliomas. In all cell types, GHB acted by inhibiting α-ketoglutarate-dependent Ten-eleven Translocations (TET) activity, resulting in decreased levels of the 5-hydroxymethylcytosine epigenetic mark. In patients, low SSADH expression was correlated with high GHB/α-ketoglutarate ratios, and distinguished weakly proliferative/differentiated glioblastoma territories from proliferative/non-differentiated territories. Our findings support an active participation of metabolic variations in the genesis of tumor heterogeneity.

Detection of L265P MYD-88 mutation in a series of clonal B-cell lymphocytosis of marginal zone origin (CBL-MZ).

Clonal B-cell lymphocytosis of marginal zone origin (CBL-MZ) is a recently described entity characterized by the presence of clonal B cells in the blood and/or bone marrow (BM) with morphologic and immunophenotypic features consistent with marginal zone derivation in otherwise healthy individuals. CBL-MZ is commonly associated with paraproteinemia, usually immunoglobulin M (IgM), raising diagnostic difficulties from Waldenstrom macroglobulinemia (WM). The aim of the present study was to determine the presence of MYD-88 L265P mutation in a well-characterized series of CBL-MZ to identify cases that may in fact represent WM. Fifty-three CBL-MZ cases were retrospectively evaluated. MYD-88 L265P mutation was determined by allele-specific polymerase chain reaction in blood and/or BM mononuclear cells. Almost half of the CBL-MZ cases (49%) were associated with paraproteinemia mainly of the IgM type (65%). MYD-88 L265P mutation was identified in 10 cases (19%). These cases may truly represent WM, whereas 43 cases (81%) are still classified as CBL-MZ. Mutated cases were all associated with paraproteinemia compared with 37% of the nonmutated ones (P < .0001). In addition, mutated cases displayed more frequently CD38 and CD25 positivity (P = .002 and P = .005, respectively). Moreover, cases without paraproteinemia presented more frequently with lymphocytosis, irrespective of the presence of the MYD-88 mutation (P = .02). The present study demonstrates that MYD-88 L265P mutation may represent the only sensitive marker for the differentiation of CBL-MZ from probable WM. However, further studies are warranted to better define the biological significance of MYD-88 L265P mutation and to clarify whether the presence of the mutation establishes WM diagnosis or that it can also be present in borderline cases associated with paraproteinemia.

Expression and prognostic significance of VEGF and mTOR pathway proteins in metastatic renal cell carcinoma patients: a prognostic immunohistochemical profile for kidney cancer patients.

PURPOSE: To identify prognostic molecular profiles in patients with mRCC treated with sunitinib, we performed immunohistochemical analysis for VEGF and PI3K/Akt/mTOR pathway components. METHODS: The immunohistochemical expression of VEGF, p85α, p110γ, PTEN, p-Akt, p-mTOR, p-4E-BP1 and p-p70S6K was studied in 79 patients with mRCC who received first-line treatment with sunitinib. Expression was correlated with clinicopathological features and survival. RESULTS: VEGF was highly expressed (median H-Score 150), while positivity for the markers of the PI3K/Akt/mTOR pathway was: p85α 43/66 (65 %), p110γ41/60 (68 %), PTEN 32/64 (50 %), p-Akt57/63 (90 %), p-mTOR48/64 (75 %), p-4E-BP1 58/64 (90 %) and p-p70S6K 60/65 (92 %). No single immunohistochemical marker was found to have prognostic significance. Instead, the combination of increased p-mTOR and low VEGF expression was adversely correlated with overall survival (OS) (3.2 vs. 16.9 months, P = 0.001). CONCLUSION: Immunohistochemistry for VEGF and p-mTOR proteins may discriminate patients refractory to first-line sunitinib with poor prognosis. Prospective validation of our findings is needed.

Advanced glycation end products upregulate lysyl oxidase and endothelin-1 in human aortic endothelial cells via parallel activation of ERK1/2-NF-κB and JNK-AP-1 signaling pathways.

Endothelial dysfunction involves deregulation of the key extracellular matrix (ECM) enzyme lysyl oxidase (LOX) and the vasoconstrictor protein, endothelin-1 (ET-1), whose gene expression can be modulated by the transcriptional activators nuclear factor kappa B (NF-κB) and activator protein-1 (AP-1). Advanced glycation end products (AGEs) present an aggravating factor of endothelial dysfunction which upon engagement to their receptor RAGE induce upregulation of mitogen-activated protein kinases (MAPKs), leading to NF-κB and AP-1 potentiation. We hypothesized that AGEs could induce NF-κΒ- and AP-1-dependent regulation of LOX and ET-1 expression via the AGE/RAGE/MAPK signaling axis. Western blot, real-time qRT-PCR, FACS analysis and electrophoretic mobility-shift assays were employed in human aortic endothelial cells (HAECs) following treatment with AGE-bovine serum albumin (AGE-BSA) to investigate the signaling pathway towards this hypothesis. Furthermore, immunohistochemical analysis of AGEs, RAGE, LOX and ET-1 expression was conducted in aortic endothelium of a rat experimental model exposed to high- or low-AGE content diet. HAECs exposed to AGE-BSA for various time points exhibited upregulation of LOX and ET-1 mRNA levels in a dose- and time-dependent manner. Exposure of HAECs to AGE-BSA also showed specific elevation of phospho(p)-ERK1/2 and p-JNK levels in a dose- and time-dependent fashion. AGE administration significantly increased NF-κΒ- and AP-1-binding activity to both LOX and ET-1 cognate promoter regions. Moreover, LOX and ET-1 overexpression in rat aortic endothelium upon high-AGE content diet confirmed the functional interrelation of these molecules. Our findings demonstrate that AGEs trigger NF-κΒ- and AP-1-mediated upregulation of LOX and ET-1 via the AGE/RAGE/MAPK signaling cascade in human endothelial cells, thus contributing to distorted endothelial homeostasis by impairing endothelial barrier function, altering ECM biomechanical properties and cell proliferation.

Castleman's disease of the spleen.

INTRODUCTION: Castleman's disease (CD), also known as giant or angiofolicular lymphoid hyperplasia or lymphoid hamartoma, is a group of atypical lymphoproliferative disorders that share common lymph node histological features and may be localized either to a single lymph node (unicentric) or occur systemically (multicentric). PATIENT AND METHOD: Herein, we present a rare case of a of 75-year-old female patient who was referred to our department and after a thorough work-up, underwent splenectomy with synchronous resection of an accessory spleen, splenic artery lymph nodes, and splenic hilar lymph nodes due to splenic involvement in a multicentric CD. RESULTS: The pathology of the specimens led to the conclusion that it was a case of polycentric HHV-8-positive CD, affecting the spleen, the accessory spleen, and the lymph nodes. CONCLUSIONS: Incidence of this rare condition is believed to be approximately 0.001-0.05%. CD has been linked to the human immunodeficiency virus (HIV), human herpes virus 8 (HHV-8), and is associated with malignancies. The pathogenesis mechanism is considered to be a dysregulation and hypersecretion of cytokines, either idiopathic or secondary to a viral infection, with the latter considered the most frequent. Solid organ involvement is very rare as is splenic involvement.