ALBERT

Description: Angiogenesis has a critical role in the pathophysiology of multiple myeloma (MM); however, the molecular mechanisms underlying this process are not completely elucidated. The new tumor-suppressor gene inhibitor of growth family member 4 (ING4) has been recently implicated in solid tumors as a repressor of angiogenesis. In this study, we found that ING4 expression in MM cells was correlated with the expression of the proangiogenic molecules interleukin-8 (IL-8) and osteopontin (OPN). Moreover, we demonstrate that ING4 suppression in MM cells up-regulated IL-8 and OPN, increasing the hypoxia inducible factor-1α (HIF-1α) activity and its target gene NIP-3 expression in hypoxic condition. In turn, we show that the inhibition of HIF-1α by siRNA suppressed IL-8 and OPN production by MM cells under hypoxia. A direct interaction between ING4 and the HIF prolyl hydroxylase 2 (HPH-2) was also demonstrated. Finally, we show that ING4 suppression in MM cells significantly increased vessel formation in vitro, blunted by blocking IL-8 or OPN. These in vitro observations were confirmed in vivo by finding that MM patients with high IL-8 production and microvascular density (MVD) have significantly lower ING4 levels compared with those with low IL-8 and MVD. Our data indicate that ING4 exerts an inhibitory effect on the production of proangiogenic molecules and consequently on MM-induced angiogenesis.

Description: It is well established that osteoblast formation and function are profoundly impaired in multiple myeloma (MM) patients. Osteoblastic cells also regulate myeloma cell growth and increasing bone formation result in a reduction of tumoral burden in mice. Recent data suggest that ubiquitin-proteasome pathway, the major cellular degradative system and therapeutic target in myeloma cells, also regulates osteoblast differentiation. Further it has been demonstrated that different proteasome inhibitors may stimulate bone formation in mice. Finally, preliminary observations obtained in MM patients treated with the proteasome inhibitor Bortezomib show an increase of bone specific alkaline phosphatase in responder patients as compared to non-responder ones. Currently it is not know whether the proteasome inhibitor Bortezomib may have a direct effect on osteoblast and bone formation in vitro human cultures and in vivo in MM patients. To clarify this issue first we checked the effect of Bortezomib either on osteoblast differentiation and formation or on osteoblast proliferation, survival and function. In long-term human BM cultures we found that Bortezomib did not reduce the number of both early bone marrow (BM) osteoblast progenitors Colony Forming Unit-Fibroblast (CFU-F) and late ones Colony Forming Bone nodules (CFU-OB). On the other hand we found that Bortezomib (2–3 nM) significantly induced osteoblast phenotype in human mesenchymal cells incubated in presence of osteogenic factors. A stimulatory effect on osteoblast markers was observed after 24 hours of Bortezomib treatment. Consistently we found that Bortezomib significantly increased the activity of the transcription factor Runx2/Cbfa1 in human osteoblast progenitors without affecting the canonical WNT signaling pathway checked by the evaluation of nuclear and cytoplasmatic active beta-catenin levels. Using the human osteoblast like cells MG-63 and immortalized normal osteoblasts (HOBIT) we found that Bortezomib at concentration ranging between 2nM and 5nM did not inhibit osteoblast proliferation or induce osteoblast apoptosis. Similarly, Bortezomib did not affect the expression of osteoblast markers, Runx2/Cbfa1 activity and WNT signaling in both MG-63 and HOBIT cells. To extent our in vitro observation we have evaluated the potential effect of Bortezomib in vivo in MM patients. Bone histomorphometry as well as immunostainig for Runx2/Cbfa1 and beta-catenin was performed on BM biopsies obtained from 15 MM patients before and after 6–8 cycles of Bortezomib administrated in mono-therapy. A significant increase in the number of osteoblastic cells X mm2 of bone tissue and in the number of Runx2/Cbfa1 positive osteoblastic cells was observed only in responder patients showing an early increase of the serum alkaline phosphatase. In conclusion our data indicate that Bortezomib may increase osteoblast differentiation in human mesenchymal cells without affecting the proliferation, survival and function of mature osteoblasts. In vivo and in vitro observations support the hypothesis that both direct and indirect effects on bone formation process could occur during Bortezomib treatment.

Description: Recently, it has been demonstrated that Wnt inhibitors, as DKK-1 and sFRP-3 are produced by MM cells. High DKK-1 levels in MM cells have been shown to correlate with the presence of focal bone lesions in MM patients. However no data are available concerning the potential relationship between sFRP-3 and DKK-1 expression by MM cells, their BM levels and the presence of bone disease. In this study we have investigated DKK-1 and sFRP-3 mRNA expression by RT-PCR in fresh purified CD138+ MM cells (purity〉95%) obtained from 50 newly diagnosed MM patients and 16 MGUS. The expression of both molecules was also evaluated by microarray analysis (Affimetrix U133A chips) in an independent larger database of 102 newly diagnosed MM patients. DKK-1 and sFRP-3 protein expression in MM cell lysates was detected by western blot analysis. In addition DKK-1 and sFRP-3 levels were detected by ELISA into the bone marrow (BM) plasma. Bone status in all MM patients tested was evaluated by total X-rays scan. By RT-PCR we found that 74% of MM patients were positive for DKK-1 mRNA at the diagnosis whereas 60% expressed sFRP-3 mRNA. DKK-1 and sFRP-3 expression was further analyzed in relationship with the bone status of MM patients. Although DKK1 and sFRP-3 were found positive in 81% and 73% of osteolytic patients, and 50% and 37% of non-osteolytic ones respectively, these values do not reach a statistical significance (Chi Square 2-tailed p=0.2) and 36% sFRP-3 (p=0.069). On the other hand, comparing MM patients positive for DKK-1 and sFRP-3 with those negative for both molecules we found a significant statistical correlation with the presence of bone lesions (p=0.03). In agreement with RT-PCR analysis, supervised gene expression profiling of 102 MM patients failed to find a significant correlation between the level of DKK-1 and sFRP-3 mRNA expression and the presence of bone lesions in MM patients. When we analyzed DKK-1 and sFRP-3 protein expression in malignant purified plasma cells we found that a lower number of MM patients expressed Wnt inhibitors as compared to mRNA. On the other hand, DKK-1 and sFRP-3 were was detectable in bone marrow (BM) plasma of 90% and 76% of of MM patients, respectively. Significant higher DKK-1 and sFRP-3 levels were detected in MM patients (median DKK-1 levels: 2.84 ng/mL, range:0,55–91,55 ng/mL; sFRP-3: 1,53 ng/mL, range: 0–27 ng/mL) as compared to MGUS subjects (DKK-1: 1,5 ng/ml, range: 0–4,12 ng/mL; sFRP-3: 0,55 ng/mL, range: 0–6,82 ng/mL) (Nonparametric 2-tailed test. p=0.005 and p=0.003, respectively). Considering the bone status of MM patients we found that osteolytic patients showed significant higher BM DKK-1 levels as compared to non-osteolytic ones (median: 6,85 vs 1,19 ng/m; p= 0.05) whereas BM sFRP-3 ones did not reach a statistical significance (3,3 vs. 1,12 ng/mL p=0.3). In conclusion, our results support the hypothesis that Wnt inhibitors DKK1 and s-FRP-3 may have a role in bone disease in MM indicating that DKK-1 and sFRP-3 double positive MM patients may have higher incidence of bone lesions. Finally, our study indicate that BM levels DKK-1 rather than the level of mRNA expression by MM cells better correlated with the presence of bone lesions in MM patients suggesting the involvement of the BM microevironment as source of DKK-1.

Description: Studies of gene expression performed on multiple myeloma (MM) cells have leaded to identify molecules able to inhibit osteoblast differentiation. Whereas potential alterations occurring in the bone microevironment cells in MM patients are not completely elucidated. To clarify this issue we have developed a method to direct isolate mesenchymal cells (MSC) and osteoblastic cells (OB) without in vitro differentiation from trabecular bone biopsies obtained by iliac crest of MM patients (n°=24) with or without osteolytic bone lesions. Bone status was evaluated in all MM patients by total X rays scan and NMR for the spine. MSC and OB isolated from trabecular bone of healthy donors underwent to orthopedics surgery was used as controls. Cell proliferation in relationship with growth substrate (bone and glass) was evaluated in isolated MSC (osteolytic n°=9, non-osteolityc n° 15) and OB cells (osteolytic n°=9, non-osteolityc n°=11) as well as immunophenotype by FACS analysis, protein pattern by immunohistochemical staining and ELISA assay and finally gene expression profiling by microarray (Affimetrix). First the presence of potential contaminating cells was excluded by FACS analysis in all the samples tested being both MCS and OB obtained negative for CD3, CD14, CD20 and CD138 antigens. We found that cell proliferation was significantly higher in MSC as compared to OB in MM patients and that both MSC and OB cells have higher cell doubling rate as compared to controls. Immunophenotype reveals a different pattern of expression of the chemokine receptors CXCR4, CXCR5, CCR6 in MSC and OB in the different group of patients. Higher alkaline phosphatase (AP) expression was observed in OB versus MSC in non-osteolitic patients but not in osteolityc ones. In line with these observations we found that the expression of the osteoblast transcrition factor Runx2/CBFA1 was higher in MSC obtained from non-osteolytic patients as compared with osteolytic ones. Hierarchical clustering by unsupervised analysis of gene expression profiles (Affymetrix U133A chips) identified two major cluster branches containing respectively MSC and OB cells, with subgroups correlated with the bone status. Following supervised analysis, a total of 121 probe-set were found differentially expressed in MSCs from patients with/without osteolytic lesions (57 up-regulated and 64 down-regulated) Distinct patterns of gene expression profiling were observed in MSCs versus Obs when osteolityc or non-osteolytic patients were compared. Interestingly, markers and transcription factors known to be specific for osteoblast cells were up-regulated in OB versus MSC in non-osteolytic patients but not in osteolytic ones. Notably, a significant downregulation of Runx2 and AP-1 related pathways was observed in OB of osteolytic MM patients as compared to non-osteolytic ones. In conclusion in this study for the first time we have identified a different pattern of growth, phenotype and gene expression in isolated MSC and OB cells in relationship with the bone status of MM patients highlighting the critical role of the block of osteoblast differentiation and the involvement of the related signature pathways.

Description: Osteoblast impairment occurs within myeloma (MM) cell infiltration into the bone marrow (BM). Wnt signaling is involved in the regulation of osteoblast formation. Canonical Wnt signaling pathway is activated by Wnt 1/3a that induce the activation of GSK3/Axin complex leading to the stabilization and nuclear translocation of beta-catenin that in turn activates the transcription system Lef1/TCF. Recently it has been reported that MM cells produce the Wnt inhibitors DKK-1 demonstrating a correlation between its expression and the presence of bone lesions in MM patients. However the effect of MM cells on Wnt signaling cascade in osteoblasts and osteoblast progenitors has not been investigated. To clarify this issue, first we checked DKK-1 production by human myeloma cell lines (HMCLs), purified CD138+ MM cells and BM plasma of MM patients by PCR and ELISA. Following we performed a co-culture system with HMCLs or CD138+ MM cells and either human osteoblast line (HOBIT) and with BM osteoprogenitor cells (PreOB) obtained after differentiation from mesenchymal cells or murine osteoprogenitor cell lines C2C12 and MC3T3. Both DKK-1 positive HMCLs (XG-1 and JJN3) and negative ones (RPMI-8226, OPM-2) have been used in co-culture as well as DKK-1 positive and negative purified CD138+ MM cells. Similarly we tested the effect of BM plasma of MM patients positive and negative for DKK-1 production on both human and murine cells. Wnt signaling in osteoblasts and osteoblast progenitors was evaluated either at mRNA level by specific human and murine Wnt Array kits and by quantitative PCR or at protein one by Western blot analysis for GSK3b/Axin and LEF-1/TCF expression. We evaluated active de-phosphorylated beta-catenin and inactive phosphorilated one by westernblot and by ELISA in cytosolic and nuclear extracts. DKK-1 median levels detected in the conditioned media of XG-1 and JJN3, MM cells and in BM plasma of DKK-1 positve MM patients were 0.60 ng/mL and 0.38 and 8.84 (range: 1.55–91) ng/mL respectively. Any significant inhibitory effect on WNT signaling and active beta-catenin expression and levels was not observed in HOBIT and human PreOB after co-culture with both HMCLs and MM cells or BM plasma independently to DKK-1 expression. On the contrary DKK-1 positive MM cells or BM plasma suppressed active beta-catenin expression in murine osteoprogenitor cell lines in presence of BMP-2. Consistently Wnt3a stimulation as well as anti-DKK-1 abs. did not restore the inhibitory effects on osteoblast formation and differentiation induced by MM cells in human PreOB. Consistently any significant difference was not detected on beta-catenin expression by stromal/osteoblastic cells on bone biopsies by immunohistochemistry between osteolytic (n°=10) and non-osteolytic (N°=10) MM patients. The different behavior between human and murine osteoblastic cells was further investigated. We found that both cells expressed significant levels of active beta-catenin however DKK-1 suppressed active nuclear and cytosol beta-catenin at concentration of 20–30 ng/mL in C2C12 and MC3T3 whereas only DKK-1 concentrations higher to 500 ng/mL are able to inhibited beta-catenin in HOBIT and human PreOB as well as osteoblast formation and differentiation in human BM cultures. In conclusion our data indicate that MM cells block canonical Wnt signaling in murine osteoblastic cells but not in human osteoblasts and osteoblast progenitors. Beta-catenin independent mechanisms could be involved in DKK-1 mediated bone destruction in MM patients.

Description: The proteasome inhibitor bortezomib may increase osteoblast-related markers in multiple myeloma (MM) patients; however, its potential osteoblastic stimulatory effect is not known. In this study, we show that bortezomib significantly induced a stimulatory effect on osteoblast markers in human mesenchymal cells without affecting the number of osteoblast progenitors in bone marrow cultures or the viability of mature osteoblasts. Consistently we found that bortezomib significantly increased the transcription factor Runx2/Cbfa1 activity in human osteoblast progenitors and osteoblasts without affecting nuclear and cytoplasmatic active β-catenin levels. Consequently a stimulatory effect of bortezomib on bone nodule formation was also demonstrated in osteoblast progenitors. These in vitro observations were confirmed in vivo by the finding of a significant increase in the number of osteoblastic cells × mm2 of bone tissue and in the number of Runx2/Cbfa1-positive osteoblastic cells that was observed in MM patients who responded to bortezomib. Our in vitro and in vivo observations support the hypothesis that a direct stimulatory effect on bone formation process could occur during bortezomib treatment.

Description: The presentation of common acute diseases in older age is often referred to as “atypical”. Frequently, the symptoms are neither single nor tissue related. In most cases, the onset of symptoms and diseases is the expression of a diminished reserve with a failure of the body system and imbalance of brain function. Delirium is one of the main devastating and prevalent atypical symptoms and could be considered as a geriatric syndrome. It encompasses an array of neuropsychiatric symptoms and represents a disarrangement of the cerebral function in response to one or more stressors. The most recent definition, reported in the DSM-V, depicts delirium as a clear disturbance in attention and awareness. The deficit is to be developed in a relatively short time period (usually hours or days). The attention disorder must be associated with another cognitive impairment in memory, orientation, language, visual-spatial or perception abilities. For the treatment, it is imperative to remove the potential causes of delirium before prescribing drugs. Even a non-pharmacological approach to reducing the precipitating causes should be identified and planned. When we are forced to approach the pharmacological treatment of hyperactive delirium in older persons, we should select highly cost-effective drugs. High attention should be devoted to the correct balance between improvement of psychiatric symptoms and occurrence of side effects. Clinicians should be guided in the correct choice of drugs following cluster symptoms presentation, excluding drugs that could potentially produce complications rather than advantages. In this brief point-of-view, we propose a novel pharmacological flow-chart of treatment in relation to the basic clusters of diseases of an older patient acutely admitted to the hospital and, in particular, we emphasize “What We Should Not Do!”, with the intention of avoiding possible side effects of drugs used.

Description: Gene expression alterations occurring in the bone microenvironment cells and their potential relationships with the occurrence of bone lesions in multiple myeloma (MM) patients have never been investigated. In this study, we have isolated both mesenchymal (MSC) and osteoblastic (OB) cells, without in vitro differentiation, from bone biopsies obtained by iliac crest of 24 MM patients, 7 MGUS subjects and 8 healthy donors (N) who underwent orthopedics surgery. Bone status was evaluated in all MM patients by total X rays scan and MRI for the spine. Firstly, we evaluated cell proliferation in relationship with growth substrate (bone and glass) and cell phenotype by flow cytometry and immunohistochemistry. We found that both MSC and OB cells have higher cell doubling rate in MM patients as compared to N. Higher expression of alkaline phosphatase and Runx2 was observed in OB as compared to MSC cells in both N and MM patients without osteolytic lesions, but not in osteolytic ones. We performed a gene expression profiling analysis of isolated MSC and OB cells using GeneChip® Affymetrix HG-U133A oligonucleotide arrays. An unsupervised analysis of the most variable genes across the dataset generated a hierarchical clustering with the two major branches containing respectively MSC and OB samples. A multiclass analysis of N, MGUS and MM patients identified 33 differentially expressed probe-set (specific for 27 genes) in MSC cells, and 19 differentially expressed probe-set (13 genes) in OB, and the identified transcripts mainly characterized N versus MM and MGUS samples. A supervised analysis between N and MM samples identified 65 probes (56 genes: 17 up-regulated and 39 down-regulated) differentially expressed in MSC and 35 probes (29 genes, 12 up-regulated and 17 down-regulated) in OB. Notably, genes encoding the Homeobox class proteins, such as HOXB2-6-7, were up-regulated in both MSC and OB of MM patients as compared to N. As regards the bone status, a total of 60 probe-sets (3 up-regulated and 57 down-regulated genes) were found differentially expressed in MSC from osteolytic vs. non-osteolytic MM patients, whereas MGUS-MSC exhibited an intermediate transcriptional profile between osteolytic and non-osteolytic MM patients. A distinct pattern of gene expression profiling was also observed in MSC versus OB when osteolytic and non-osteolytic MM patients were compared (26 vs. 94 differentially expressed probe-sets, respectively), including transcription factors related to MSC osteogenic differentiation belonging to Runx2 pathway (HEY1) or Wnt and BMP signaling On the other hand, few genes were found differentially expressed in OB cells in relationship with the presence of bone lesions. In conclusion, we identified a distinctive transcriptional fingerprint in isolated MSC and OB cells of MM patients as compared to N subjects, which mainly correlated with cell proliferation. Moreover, a different gene expression profile was observed in MSC cells of MM patients according to the presence/absence of bone lesions, highlighting the critical role of the block of the osteogenic differentiation.

Description: Osteoclast (OC) activation in multiple myeloma (MM) is primarily due to the imbalance of the critical osteoclastogenic system RANKL/OPG in the bone microenvironment. Recent evidences indicate that chemokines, small chemoattractant proteins involved in cancer cell homing, may contribute to osteoclast formation and activation. However, whereas the role of the chemokine macrophage inflammatory protein (MIP)-1α in MM-induced OC activation is well established, the involvement of other chemokines is not known. In this study, we evaluated the potential role of MIP-3α/CCL20 and its receptor CCR6 in the pathophysiology of OC formation and osteolytic lesions in MM. First the effect of MIP-3α/CCL20 on in vitro osteoclast formation by peripheral monocytes was evaluated. (MIP)-3α/CCL20 significantly increased both the number of multinucleated TRAP+ OCs and RANK+ OC progenitor cells in presence of RANKL. In addition we found that (MIP)-3α/CCL20 increases RANKL mRNA levels in both human osteoblastic (OB) and bone marrow (BM) osteoprogenitor cells (preOB). Following, the potential production of (MIP)-3α/CCL20 by human MM cell lines (HMCLs) and fresh purified CD138+ MM cells was also checked. Significant levels of (MIP)-3α/CCL20 were detected in one out of nine HMCLs tested and in about 10% of purified MM cells by ELISA and immunohystochemistry. On the other hand we found that MM cells up-regulated (MIP)-3α/CCL20 secretion, in OB/PreOB cells and in OCs as well as its receptor CCR6 in OCs in co-culture systems in presence of a transwell insert. Among potential soluble factors involved in the up-regulation of MIP-3α/CCL20 by MM cells we found that IL-1β and TNFα together stimulate MIP-3α/CCL20 production in both OB and PreOB. The role of MIP-3α/CCL20 in OC activation by MM cells was finally demonstrated by finding that both blocking anti-(MIP)-3α/CCL20 and anti-CCR6 Abs. but not anti-IgG control significantly decreased OC formation induced by the conditioned medium of MM cells co-cultured with OB and OC, respectively. This chemokine system was further studied in vivo in MM patients. MIP-3α/CCL20 levels were detected in the BM plasma of MGUS subjects (n°=16) and in MM (n°=52) patients at the diagnosis in relationship with the presence of bone lesions (osteolytic n°= 32; non-osteolytic: n°=20). Significant higher MIP-3α/CCL20 levels were detected in MM patients vs. MGUS (mean ± SD: 51.9±2 vs. 21±3 pg/mL; p=0.01) and in MM osteolytic patients vs. non-osteolytic ones (mean ± SD: 70.8±5.9 vs. 13.8±1.1 pg/mL; p=0.001). Interestingly, no significant differences were observed between MGUS and non-osteolytic MM patients. By immunohystochemistry performed on BM biopsies, we consistently found that MIP-3α/CCL20 was over-expressed in OBs in osteolytic MM patients as compared to non-osteolytic ones. In addition we found that OCs showed a strong CCR6 staining in the areas with an increased number of OCs. In conclusion our data indicate that (MIP)-3α/CCL20 its receptor CCR6 are up-regulated in bone microenvironment by MM cells and involved in osteoclast formation and bone lesions in MM patients.

Description: Multiple myeloma (MM) cells produce several angiogenic molecules as VEGF, Angiopoietin-1 (Ang-1), interleukin-8 (IL-8) and osteopontin (OPN), however the molecular mechanisms underlying the angiogenic switch are not completely elucidated. The candidate tumor suppressor gene inhibitor of growth family member 4 (p29ING4) has been recently implicated in solid tumors as a repressor of angiogenesis and tumor growth through the suppression of angiogenic related molecules including interleukin-8 (IL-8) and the hypoxia inducible factor (HIF)-1 alpha. In this study we investigate the potential involvement of p29ING4 in the angiogenic switch in MM. First using quantitative real time PCR we compared p29ING4 with VEGF, Ang-1, IL-8 and OPN mRNA levels in eight human myeloma cell lines (HMCLs). A significantly negative correlation was observed between ING4 and IL-8 and a trend of correlation with OPN. Following we transfected HMCLs JJN3, OPM-2 and RPMI-8226 with specific siRNA to completely block the expression of p29ING4 checking the effect on the expression and production of the myeloma-related angiogenic molecules VEGF, Ang-1, IL-8 and OPN by quantitative real time PCR and ELISA assay. p29ING4 suppression in HMCLs did not affect VEGF and Ang-1 production but induced a strong up-regulation of IL-8 mRNA and IL-8 protein secretion. Similarly an induction of OPN mRNA expression as well as OPN secretion was induced by siRNA anti-p29ING4. Moreover conditioned media of HMCLs transfected with siRNA anti p29ING4 significantly increased vessel formation in an experimental in vitro model of angiogenesis (ANGIO kit) as compared to controls. Further we investigate the role of p29ING4 in the production of angiogenic molecule by MM cells in hypoxic condition compared to normoxic one as well as its potential relationship with HIF-1alpha system. Hypoxia induced HIF-1alpha expression at nuclear level and its activity in HMCLs and p29ING4 suppression by siRNA further induced HIF-1alpha transcriptional activity with an increase of its target gene Nip-3 in HMCLs. In turn the block of HIF1-alpha by specific siRNA up-regulated p29ING4 and suppressed IL-8 and OPN mRNA expression by HMCLs suggesting a relationship between p29ING4 and HIF-1alpha activity. These in vitro observations have been extended in vivo by the finding of a significant correlation between bone marrow (BM) plasma IL-8 levels and p29ING4 mRNA expression in purified MM cells obtained from 40 newly diagnosed MM patients (R=−0.58 Spearman’s 2-tailed test: p=0.04), consistently MM patients with higher BM IL-8 levels have a significantly lower p29ING4 mRNA levels. Similarly MM patients positive for OPN expression with high OPN BM levels had a significant lower p29ING4 levels (p=0.02). Finally we found that MM patients with high microvalscular density (MVD〉30) have significant lower p29ING4 levels as compared to those with low MVD (