KAI1(CD82) is a key molecule to control angiogenesis and switch angiogenic milieu to quiescent state.

BACKGROUND: Little is known about endogenous inhibitors of angiogenic growth factors. In this study, we identified a novel endogenous anti-angiogenic factor expressed in pericytes and clarified its underlying mechanism and clinical significance. METHODS: Herein, we found Kai1 knockout mice showed significantly enhanced angiogenesis. Then, we investigated the anti-angiogenic roll of Kai1 in vitro and in vivo. RESULTS: KAI1 was mainly expressed in pericytes rather than in endothelial cells. It localized at the membrane surface after palmitoylation by zDHHC4 enzyme and induced LIF through the Src/p53 pathway. LIF released from pericytes in turn suppressed angiogenic factors in endothelial cells as well as in pericytes themselves, leading to inhibition of angiogenesis. Interestingly, KAI1 had another mechanism to inhibit angiogenesis: It directly bound to VEGF and PDGF and inhibited activation of their receptors. In the two different in vivo cancer models, KAI1 supplementation significantly inhibited tumor angiogenesis and growth. A peptide derived from the large extracellular loop of KAI1 has been shown to have anti-angiogenic effects to block the progression of breast cancer and retinal neovascularization in vivo. CONCLUSIONS: KAI1 from PC is a novel molecular regulator that counterbalances the effect of angiogenic factors.

Neuropathic pain after sarcoma surgery: Prevalence and predisposing factors.

Surgery for sarcoma frequently causes nerve damage as the dissection often violates the internervous plane. Nerve damage may cause neuropathic pain (NP), which can result in persistent pain after surgery. This is the first study to investigate the prevalence and associated factors of postoperative NP in patients who underwent surgery for sarcoma of the extremities or pelvis.Patients (n = 144) who underwent curative surgery at least 6 months prior to the visit for histologically confirmed sarcoma were enrolled. The presence of NP was assessed by administering PainDetect, a widely used questionnaire for detecting NP. Patients with PainDetect scores ≥13 were considered to have NP. The possible factors that might be associated with the development of NP were investigated: patient characteristics, tumor characteristics, extent of surgery, and adjuvant therapy.Out of 144 patients, 36 patients (25%) had NP. Patients with NP had significantly worse visual analog scale score (P < .001), Toronto Extremity Salvage Score (P < .001), and Musculoskeletal Tumor Society Rating Scale score (P < .001) than patients without NP. Among the possible factors associated with NP, patients with NP were more likely to have undergone pelvic surgery (P = .002) and multiple surgeries (P = .014) than patients without NP. In logistic regression analysis, pelvic surgery (odds ratio = 5.05, P = .005) and multiple surgeries (odds ratio = 2.33, P = .038) were independent factors associated with NP after sarcoma surgery.This study suggests that the prevalence of NP after surgery for sarcoma is considerable. Surgery of the pelvis and multiple surgeries are predictive of postoperative persistent NP.

Factors associated with local recurrence after surgery for bone metastasis to the extremities.

BACKGROUND AND OBJECTIVES: With increasing life expectancy of patients with bone metastasis, durable surgical stabilization of bone metastasis is necessary. Local recurrence (LR) can compromise surgical stabilization and necessitate retreatment. We analyzed LR rate and factors associated with LR in patients undergoing surgery for bone metastasis. METHODS: Patients (n = 301) who underwent surgery for bone metastasis to the extremities were reviewed. Possible factors that might be associated with LR were investigated. RESULTS: LR rate was 16% (49/301). Surgical margin was associated with LR, as patients with en-bloc resection had significantly less LR than patients who underwent curettage (5/66 vs 44/235, P = 0.03). Prostate cancer had lowest rate (0%) of LR and colon cancer had highest rate (31%). Interval from surgery to LR differed among primary cancer types (4.5 ± 3.9 months [lung cancer], vs 12.3 ± 12.9 months [other cancers], P = 0.041). In multivariate analysis, en-bloc surgical margins (HR = 0.372, P = 0.036) and primary cancers of breast or prostate (HR = 0.391, P = 0.049) were independent factors associated with longer LR-free survival. CONCLUSIONS: LR after surgery for bone metastasis to extremities is affected by surgical margin and primary cancer type. These factors, along with expected patient survival, need to be considered when planning surgery for bone metastasis to extremities.

Preoperative Factors Associated with Infiltrative Histologic Growth Patterns in Extremity Soft Tissue Sarcoma.

Soft tissue sarcoma (STS) with an infiltrative histologic growth pattern, when compared to STS with an expansile pattern, may pose difficulties in local control. Preoperative assessment of the presence of infiltrative histologic growth pattern would be helpful in deciding treatment strategies. A review of 144 patients who underwent surgery for extremity STS was performed. Microscopically, the histologic growth pattern was defined as infiltrative if the penetration of the tumor cells into the surrounding tissue was observed. Possible clinicopathologic factors that might be associated with infiltrative histologic growth pattern were investigated with regard to patient demographics, tumor characteristics, and MRI findings. Of the 144 tumors, 71 (49%) showed infiltrative histologic growth pattern. On multivariate analysis, histological subtypes other than liposarcoma (OR = 4.57, p = 0.02) and infiltrative border on MRI (OR = 2.48, p = 0.01) were independent factors associated with infiltrative histologic growth pattern. Predictive index based on these two factors showed a significant improved accuracy (ROC-AUC = 0.647) for predicting infiltrative histologic growth pattern compared to either factor alone. Our data suggests that liposarcoma histology and tumor border on MRI can predict histologic growth pattern in extremity STS.

Surveillance for lung metastasis from giant cell tumor of bone.

BACKGROUND AND OBJECTIVES: Literature on surveillance for lung metastasis from giant cell tumor of bone (GCTB) is scarce. We aimed to develop one by determining: (1) the optimal surveillance schedule by analyzing time-to-event data, taking into account the predictive factors, and (2) the effective diagnostic modality. METHODS: A total of 333 patients who underwent surgery for GCTB were followed for at least 2 years. All had chest radiography, and 169 had additional CT for surveillance. Time to lung metastasis and cumulative incidence were calculated, and diagnostic performance between chest radiography and CT was compared. RESULTS: Twenty-five (7.5%) of 333 patients developed lung metastasis, and local recurrence (LR) was the only predictive factor (RR = 6.54). Median interval from LR to metastasis was 15 months, and 17 (85%) of the 20 metastases with LR occurred within 3 years of LR. Cumulative post-LR incidences at 1, 3, and 5 years were 15.4%, 21.5%, and 21.5%, respectively. CT was more sensitive (100% vs 32%), and had higher positive predictive value (81% vs 57%) and accuracy (96% vs 93%). CONCLUSIONS: Intensified lung surveillance is warranted for GCTB patients with LR, especially for 3 years from diagnosis of LR. CT is effective for detecting lung metastasis from GCTB.

CD82/KAI1 Maintains the Dormancy of Long-Term Hematopoietic Stem Cells through Interaction with DARC-Expressing Macrophages.

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we examine the role of CD82/KAI1 in niche-mediated LT-HSC maintenance. We found that CD82/KAI1 is expressed predominantly on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs). In Cd82(-/-) mice, LT-HSCs were selectively lost as they exited from quiescence and differentiated. Mechanistically, CD82-based TGF-ß1/Smad3 signaling leads to induction of CDK inhibitors and cell-cycle inhibition. The CD82 binding partner DARC/CD234 is expressed on macrophages and stabilizes CD82 on LT-HSCs, promoting their quiescence. When DARC(+) BM macrophages were ablated, the level of surface CD82 on LT-HSCs decreased, leading to cell-cycle entry, proliferation, and differentiation. A similar interaction appears to be relevant for human HSPCs. Thus, CD82 is a functional surface marker of LT-HSCs that maintains quiescence through interaction with DARC-expressing macrophages in the BM stem cell niche.

Long-term Outcome of Chondrosarcoma: A Single Institutional Experience.

PURPOSE: The prognostic factors of chondrosarcoma remain uncertain as only a few large studies with long-term follow-up have been reported. The aim of this study was to analyze oncological outcomes and prognostic factors. MATERIALS AND METHODS: A retrospective review of oncological outcomes and prognostic factors was performed on 125 consecutive chondrosarcoma patients who underwent surgery at our institution. RESULTS: Overall survival was 91.6%±2.5%, 84.1%±3.8%, and 84.1%±3.8% at 5, 10, and 15 years respectively. Among the histological types, dedifferentiated type showed the worst survival (p < 0.001). As for conventional type chondrosarcoma, histologic grade and anatomical location predicted outcome, with high-grade with axial location having the worst outcome (p < 0.001). In contrast, low-grade chondrosarcoma of appendicular skeleton could be treated safely by intralesional curettage. CONCLUSION: Histological type was significantly associated with the outcome of chondrosarcoma. For the conventional type, histologic grade and anatomical location predicted outcome, with high-grade with axial location having the worst outcome.

Erythropoietin priming improves the vasculogenic potential of G-CSF mobilized human peripheral blood mononuclear cells.

AIMS: From our previous clinical trials, intracoronary infusion of granulocyte-colony stimulating factor (G-CSF)-mobilized peripheral blood mononuclear cells ((mob)PBMCs) proved to be effective in improving myocardial contractility and reducing infarct volume in acute myocardial infarction. We tested the effect of priming (mob)PBMCs with erythropoietin (EPO) to augment its therapeutic efficacy. METHODS AND RESULTS: (mob)PBMCs were obtained from healthy volunteers after a 3-day subcutaneous injection of G-CSF (10 µg/kg). About 40% of (mob)PBMCs were EPO receptor (EPOR) (+) and responded to 6 h EPO-priming (10 IU/mL) by increasing the expression of vasculogenic factors (i.e. IL8, IL10, bFGF, PDGF, MMP9) and adhesion molecules (i.e. integrin αV, ß1, ß2, ß8) through the JAK2 and Akt pathway. These responses were also observed in PBMCs from elderly patients with coronary disease. The conditioned media from EPO-primed (mob)PBMCs contained various cytokines such as IL8, IL10, TNFα, and PDGF, which enhanced the migration and tube formation capability of endothelial cells. EPO-primed (mob)PBMCs also showed increased adhesion on endothelial cells or fibronectin. Augmented vasculogenic potential of EPO-primed (mob)PBMCs was confirmed in a Matrigel plug assay, ischaemic hindlimb, and myocardial infarction models of athymic nude mice. There were two action mechanisms: (i) cellular effects confirmed by direct incorporation of human (mob)PBSCs into mouse vasculature and (ii) indirect humoral effects confirmed by the therapeutic effect of the supernatant of EPO-primed (mob)PBMCs. CONCLUSION: Brief ex vivo EPO-priming is a novel method to augment the vasculogenic potential of human (mob)PBMCs, which would help to achieve better results after intracoronary infusion in myocardial infarction patients.

Activated platelet supernatant can augment the angiogenic potential of human peripheral blood stem cells mobilized from bone marrow by G-CSF.

Platelets not only play a role in hemostasis, but they also promote angiogenesis and tissue recovery by releasing various cytokines and making an angiogenic milieu. Here, we examined autologous 'activated platelet supernatant (APS)' as a priming agent for stem cells; thereby enhance their pro-angiogenic potential and efficacy of stem cell-based therapy for ischemic diseases. The mobilized peripheral blood stem cells ((mob)PBSCs) were isolated from healthy volunteers after subcutaneous injection of granulocyte-colony stimulating factor. APS was collected separately from the platelet rich plasma after activation by thrombin. (mob)PBSCs were primed for 6h before analysis. Compared to naive platelet supernatants, APS had a higher level of various cytokines, such as IL8, IL17, PDGF and VEGF. APS-priming for 6h induced (mob)PBSCs to express key angiogenic factors, surface markers (i.e. CD34, CD31, and CXCR4) and integrins (integrins α5, ß1 and ß2). Also (mob)PBSCs were polarized toward CD14(++)/CD16(+) pro-angiogenic monocytes. The priming effect was reproduced by an in vitro reconstruction of APS. Through this phenotype, APS-priming increased cell-cell adhesion and cell-extracellular matrix adhesion. The culture supernatant of APS-primed (mob)PBSCs contained high levels of IL8, IL10, IL17 and TNFα, and augmented proliferation and capillary network formation of human umbilical vein endothelial cells. In vivo transplantation of APS-primed (mob)PBSCs into athymic mice ischemic hindlimbs and Matrigel plugs elicited vessel differentiation and tissue repair. In safety analysis, platelet activity increased after mixing with (mob)PBSCs regardless of priming, which was normalized by aspirin treatment. Collectively, our data identify that APS-priming can enhance the angiogenic potential of (mob)PBSCs, which can be used as an adjunctive strategy to improve the efficacy of cell therapy for ischemic diseases.

Human podoplanin-positive monocytes and platelets enhance lymphangiogenesis through the activation of the podoplanin/CLEC-2 axis.

Emerging studies suggested that murine podoplanin-positive monocytes (PPMs) are involved in lymphangiogenesis. The goal of this study was to demonstrate the therapeutic lymphangiogenesis of human PPMs by the interaction with platelets. Aggregation culture of human peripheral blood mononuclear cells (PBMCs) resulted in cellular aggregates termed hematospheres. During 5-day culture, PPMs expanded exponentially and expressed several lymphatic endothelial cell-specific markers including vascular endothelial growth factor receptor (VEGFR)-3 and well-established lymphangiogenic transcription factors. Next, we investigated the potential interaction of PPMs with platelets that had C-type lectin-like receptor-2 (CLEC-2), a receptor of podoplanin. In vitro coculture of PPMs and platelets stimulated PPMs to strongly express lymphatic endothelial markers and upregulate lymphangiogenic cytokines. Recombinant human CLEC-2 also stimulated PPMs through Akt and Erk signaling. Likewise, platelets in coculture with PPMs augmented secretion of a lymphangiogenic cytokine, interleukin (IL)-1-ß, via podoplanin/CLEC-2 axis. The supernatant obtained from coculture was able to enhance the migration, viability, and proliferation of lymphatic endothelial cell. Local injection of hematospheres with platelets significantly increased lymphatic neovascularization and facilitated wound healing in the full-thickness skin wounds of nude mice. Cotreatment with PPMs and platelets augments lymphangiogenesis through podoplanin/CLEC-2 axis, which thus would be a promising novel strategy of cell therapy to treat human lymphatic vessel disease.

Highly angiogenic CXCR4(+)CD31(+) monocyte subset derived from 3D culture of human peripheral blood.

Ex vivo expansion of human circulating angiogenic cells is a major challenge in autologous cell therapy for ischemic diseases. Here, we demonstrate that hematosphere-derived CXCR4(+)CD31(+) myeloid cells using peripheral blood possess robust proangiogenic capacity such as formation of vessel-like structures and tip cell-like morphology in Matrigel. We also found that CD31 positive myeloid cells are principal cellular component of hematospheres by magnetic cell sorting. Flow cytometry analysis showed that fresh peripheral blood contained 40.3 ± 15.2% of CXCR4(+)CD31(+) myeloid cells, but at day 5 of hematosphere culture, most of myeloid cells were CXCR4(+)CD31(+) by 86.9 ± 5.4%. Hematosphere culture significantly increased the production of angiogenic niche-supporting cytokines. Moreover, CD31-homophilic interaction and VEGF-VEGF receptor loop signaling were essential for sphere formation and acquisition of angiogenic capacity in hematospheres. Matrigel plug and ischemic hindlimb model provide in vivo evidence that hematosphere-derived myeloid cells have highly vasculogenic capacities, participate in new and mature vessel formation, and exert therapeutic effects on ischemic hindlimb. In conclusion, our strategy for ex vivo expansion of human CXCR4(+)CD31(+) angiogenic cells using hematospheres provides an autologous therapeutic cell source for ischemic diseases and a new model for investigating the microenvironment of angiogenesis.

New method to differentiate human peripheral blood monocytes into insulin producing cells: Human hematosphere culture.

Strategy to differentiate stem cells into insulin producing cells (IPCs) in vitro has been a promising one to get cell source of ß-cell replacement therapy for diabetes. It has been suggested that islets and neurons share features and nestin-positive cells could differentiate into IPCs. We have recently developed a three-dimensional culture system using human peripheral blood cells named as blood-born hematosphere (BBHS). Here we showed that most of BBHS were composed of nestin-positive cells. Under the four-stage differentiation protocol for IPCs, we plated nestin-positive BBHS onto fibronectin-coated dish. These cells form islet-like clusters and most of them expressed insulin. Pancreatic specific genes were turned on, such as transcription factors (Pdx-1, Ngn3 and Nkx6.1), genes related to endocrine function (Glut-2 and PC2) or ß cell function (Kir6.2, SUR1). Furthermore islet differentiation was confirmed by dithizone (DTZ) staining to detect zinc ion which binds insulin protein within the cells. Finally, IPCs derived from BBHS showed capability to secrete insulin in response to glucose stimulation. Taken together, our novel protocol successfully induced islet-like human insulin producing cells out of BBHS. This strategy of ex vivo expansion of IPCs using BBHS provides an autologous therapeutic cell source for the treatment of diabetes.