Immune escape of multiple myeloma cells results from low miR29b and the ensuing epigenetic silencing of proteasome genes

BACKGROUND

Activation of CD28 on multiple myeloma (MM) plasma cells, by binding to CD80 and CD86 on dendritic cells, decreases proteasome subunit expression in the tumor cells and thereby helps them evade being killed by CD8+ T cells. Understanding how CD28 activation leads to proteasome subunit downregulation is needed to design new MM therapies.

METHODS

This study investigates the molecular pathway downstream of CD28 activation, using an in vitro model consisting of myeloma cell lines stimulated with anti-CD28-coated beads.

RESULTS

We show that CD28 engagement on U266 and RPMI 8226 cells activates the PI3K/AKT pathway, reduces miR29b expression, increases the expression of DNA methyltransferase 3B (DNMT3B, a target of miR29b), and decreases immunoproteasome subunit expression. In vitro transfection of U266 and RPMI 8226 cells with a miR29b mimic downregulates the PI3K/AKT pathway and DNMT3B expression, restores proteasome subunit levels, and promotes myeloma cell killing by bone marrow CD8+ T cells from MM patients. Freshly purified bone marrow plasma cells (CD138+) from MM patients have lower miR29b and higher DNMT3B (mRNA and protein) than do cells from patients with monoclonal gammopathy of undetermined significance. Finally, in MM patients, high DNMT3B levels associate with shorter overall survival.

CONCLUSIONS

Altogether, this study describes a novel molecular pathway in MM. This pathway starts from CD28 expressed on tumor plasma cells and, through the PI3K-miR29b-DNMT3B axis, leads to epigenetic silencing of immunoproteasome subunits, allowing MM plasma cells to elude immunosurveillance. This discovery has implications for the design of innovative miR29b-based therapies for MM.

Unraveling the Role of Peroxisome Proliferator-Activated Receptor β/Δ (PPAR β/Δ) in Angiogenesis Associated with Multiple Myeloma

Growing evidence suggests a role for peroxisome proliferator-activated receptor β/δ (PPAR β/δ) in the angiogenesis, growth, and metastasis of solid tumors, but little is known about its role in multiple myeloma (MM). Angiogenesis in the bone marrow (BM) is characteristic of disease transition from monoclonal gammopathy of undetermined significance (MGUS) to MM. We examined the expression and function of PPAR β/δ in endothelial cells (EC) from the BM of MGUS (MGEC) and MM (MMEC) patients and showed that PPAR β/δ was expressed at higher levels in MMEC than in MGEC and that the overexpression depended on myeloma plasma cells. The interaction between myeloma plasma cells and MMEC promoted the release of the PPAR β/δ ligand prostaglandin I2 (PGI2) by MMEC, leading to the activation of PPAR β/δ. We also demonstrated that PPAR β/δ was a strong stimulator of angiogenesis in vitro and that PPAR β/δ inhibition by a specific antagonist greatly impaired the angiogenic functions of MMEC. These findings define PGI2-PPAR β/δ signaling in EC as a potential target of anti-angiogenic therapy. They also sustain the use of PPAR β/δ inhibitors in association with conventional drugs as a new therapeutic approach in MM.

Asymptomatic bacteriuria in candidates for active treatment of renal stones: results from an international multicentric study on more than 2600 patients

The occurrence of asymptomatic bacteriuria concomitant to urolithiasis is an issue for patients undergoing renal stone treatment. Disposing of a preoperative urine culture is essential to reduce the risk of septic events. The endpoint of the study is to report which characteristics of candidates for renal stone treatment are frequently associated with positive urine culture. 2605 patients were retrospectively enrolled from 14 centers; inclusion criteria were age > 18 and presence of a single renal stone 1-2 cm in size. The variables collected included age, gender, previous renal surgery, comorbidities, skin-to-stone distance, stone size, location, density, presence of hydronephrosis. After a descriptive analysis, the association between continuous and categorical variables and the presence of positive urine culture was assessed using a logistic regression model. Overall, 240/2605 patients (9%) had preoperative bacteriuria. Positive urine culture was more frequent in females, patients with previous renal interventions, chronic kidney disease, congenital anomalies, larger stones, increased density. Multivariate analysis demonstrated that previous renal interventions (OR 2.6; 95% CI 1.9-3.4; p < 0.001), renal-related comorbidities (OR 1.31; 95% CI 1.19-1.4; p < 0.001), higher stone size (OR 1.06; 95% CI 1.02-1.1; p = 0.01) and density (OR 1.00; 95% CI 1.0-1.00; p = 0.02) were associated with bacteriuria; male gender and lower caliceal location were inversely related to it. Beyond expected risk factors, such as female gender, other parameters are seemingly favoring the presence of positive urine culture. The awareness of variables associated with bacteriuria allows to assess which individuals are at increased risk of presenting bacteriuria and reduce the rate of septic complications.

Halting the vicious cycle within the multiple myeloma ecosystem: blocking JAM-A on bone marrow endothelial cells restores angiogenic homeostasis and suppresses tumor progression

Interactions of malignant multiple myeloma (MM) plasma cells with the microenvironment control MM plasma-cell growth, survival, drug-resistance and dissemination. As microvascular density increases in the bone marrow in MM, we investigated whether bone marrow MM endothelial cells control disease progression via the junctional adhesion molecule-A (JAM-A). Membrane and cytoplasmic JAM-A levels were upregulated in MM endothelial cells in 111 patients with newly diagnosed MM and in 201 with relapsed/refractory MM compared to the levels in patients with monoclonal gammopathy of undetermined significance and healthy controls. Elevated membrane expression of JAM-A on MM endothelial cells predicted poor clinical outcome. Mechanistically, addition of recombinant JAM-A to MM endothelial cells increased angiogenesis, whereas inhibition of this adhesion molecule impaired angiogenesis and MM growth in two-dimensional and three-dimensional in vitro cell cultures and chorioallantoic membrane assays. To corroborate these findings, we treated MM-bearing mice with a JAM-A-blocking monoclonal antibody and demonstrated impaired MM progression, corresponding to decreased MM-related vascularity. These findings support the concept that JAM-A is an important mediator of MM progression through facilitating MM-associated angiogenesis. Elevated JAM-A expression on bone marrow endothelial cells is an independent prognostic factor for the survival of both patients with newly diagnosed MM and those with relapsed/refractory MM. Blocking JAM-A restricts angiogenesis in vitro, in utero and in vivo and represents a suitable druggable molecule to halt neo-angiogenesis and MM progression.

Bone marrow endothelial cells sustain a tumor-specific CD8+ T cell subset with suppressive function in myeloma patients

Endothelial cells (EC) line the bone marrow microvasculature and are in close contact with CD8⁺ T cells that come and go across the permeable capillaries. Because of these intimate interactions, we investigated the capacity of EC to act as antigen-presenting cells (APC) and modulate CD8⁺ T cell activation and proliferation in bone marrow of patients with multiple myeloma (MM) and monoclonal gammopathy of undetermined significance. We found that EC from MM patients show a phenotype of semi-professional APC given that they express low levels of the co-stimulatory molecules CD40, CD80 and CD86, and of the inducible co-stimulator ligand (ICOSL). In addition, they do not undergo the strong switch from immunoproteasome to standard proteasome subunit expression which is typical of mature professional APC such as dendritic cells. EC can trap and present antigen to CD8⁺ T cells, stimulating a central memory CD8⁺ T cell population that expresses Foxp3 and produces high amounts of IL-10 and TGF-β. Another CD8⁺ T cell population is stimulated by professional APC, produces IFN-γ, and exerts antitumor activity. Thus, two distinct CD8⁺ T cell populations coexist in the bone marrow of MM patients: the first population is sustained by EC, expresses Foxp3, produces IL-10 and TGF-β, and exerts pro-tumor activity by negatively regulating the second population. This study adds new insight into the role that EC play in MM biology and describes an additional immune regulatory mechanism that inhibits the development of antitumor immunity and may impair the success of cancer immunotherapy.

Adjuvant Hormone Therapy after Radical Prostatectomy: Indications and Results

Despite recent advances in staging modalities, nearly 30–40% of patients undergoing radical prostatectomy for clinically localized prostate cancer have residual disease. In these cases, one or more of the following conditions may be present: extracapsular disease, positive margins, invasion of the seminal vesicles, lymph node metastases or the postoperative persistence of PSA values above the biological threshold. The optimal management for residual prostate cancer remains controversial and in this setting adjuvant therapy could be appropriate. In the present review we examine the conditions in which hormonal adjuvant therapy can be indicated and the results available from retrospective or non-randomized studies. From the data in the literature and in the absence of randomized prospective studies, prudent conclusions could be drawn on the efficacy of adjuvant hormonal therapy. In cases of small volume, low grade (Gleason score «7) prostate cancer in stage C or D1, radical surgery coupled with adjuvant hormonal therapy leads to survival rates in stage C similar to those in the intraprostatic stage, and in stage D1 with minimal lymph involvement, seems to delay clinical development of metastases. Finally, the quality of life associated with adjuvant therapy and the drug regimens available for this therapy are reviewed.

Inhibition of mTOR complex 2 restrains tumor angiogenesis in multiple myeloma

The mammalian Target of Rapamycin (mTOR) is an intracellular serine/threonine kinase that mediates intracellular metabolism, cell survival and actin rearrangement. mTOR is made of two independent complexes, mTORC1 and mTORC2, activated by the scaffold proteins RAPTOR and RICTOR, respectively. The activation of mTORC1 triggers protein synthesis and autophagy inhibition, while mTORC2 activation promotes progression, survival, actin reorganization, and drug resistance through AKT hyper-phosphorylation on Ser473. Due to the mTOR pivotal role in the survival of tumor cells, we evaluated its activation in endothelial cells (ECs) from 20 patients with monoclonal gammopathy of undetermined significance (MGUS) and 47 patients with multiple myeloma (MM), and its involvement in angiogenesis. MM-ECs showed a significantly higher expression of mTOR and RICTOR than MGUS-ECs. These data were supported by the higher activation of mTORC2 downstream effectors, suggesting a major role of mTORC2 in the angiogenic switch to MM. Specific inhibition of mTOR activity through siRNA targeting RICTOR and dual mTOR inhibitor PP242 reduced the MM-ECs angiogenic functions, including cell migration, chemotaxis, adhesion, invasion, in vitro angiogenesis on Matrigel^®, and cytoskeleton reorganization. In addition, PP242 treatment showed anti-angiogenic effects in vivo in the Chick Chorioallantoic Membrane (CAM) and Matrigel^® plug assays. PP242 exhibited a synergistic effect with lenalidomide and bortezomib, suggesting that mTOR inhibition can enhance the anti-angiogenic effect of these drugs. Data to be shown indicate that mTORC2 is involved in MM angiogenesis, and suggest that the dual mTOR inhibitor PP242 may be useful for the anti-angiogenic management of MM patients.

Health-related quality of life and burden of fatigue in patients with primary immune thrombocytopenia by phase of disease

The main objective of this study was to compare health-related quality of life (HRQOL) of primary immune thrombocytopenia (pITP) patients with that of general population, overall, and by patient group (i.e., newly diagnosed, persistent, and chronic patients). Fatigue was also investigated as a secondary objective. Overall, 424 adult patients were enrolled in a multicenter observational study and the control group consisted of a representative sample from the general population. Propensity score matching plus further multivariate linear regression adjustment was used to compare HRQOL outcomes between pITP patients and general population. Mean age of patients was 54 years. Of those with HRQOL assessment, 99 patients (23.6%) were newly diagnosed, 53 (12.6%) were persistent, and 268 (63.8%) were chronic pITP patients. Comparison by patient group versus their respective peers in the general population revealed greater impairments in persistent pITP patients. Persistent pITP patients reported clinically meaningful impairments in physical functioning (-15; 95% CI -24.1 to -5.8; P = 0.002), social functioning (-15.3; 95% CI -25.5 to -5.1; P = 0.004), role physical (-28.4; 95% CI -43.1 to -13.7; P < 0.001), role emotional (-23.9; 95% CI -40.1 to -7.7; P = 0.004), and mental health scales (-11.3; 95% CI -21.2 to -1.4; P = 0.026) of the SF-36 questionnaire. Higher fatigue severity was associated with lower physical and mental HRQOL outcomes. Our findings suggest that the burden of the disease and treatment might depend on the disease phase and that persistent pITP patients are the most vulnerable subgroup. Am. J. Hematol. 91:995-1001, 2016. © 2016 Wiley Periodicals, Inc.

Complement Modulation of Anti-Aging Factor Klotho in Ischemia/Reperfusion Injury and Delayed Graft Function

Klotho is an anti-aging factor mainly produced by renal tubular epithelial cells (TEC) with pleiotropic functions. Klotho is down-regulated in acute kidney injury in native kidney; however, the modulation of Klotho in kidney transplantation has not been investigated. In a swine model of ischemia/reperfusion injury (IRI), we observed a remarkable reduction of renal Klotho by 24 h from IRI. Complement inhibition by C1-inhibitor preserved Klotho expression in vivo by abrogating nuclear factor kappa B (NF-kB) signaling. In accordance, complement anaphylotoxin C5a led to a significant down-regulation of Klotho in TEC in vitro that was NF-kB mediated. Analysis of Klotho in kidneys from cadaveric donors demonstrated a significant expression of Klotho in pre-implantation biopsies; however, patients affected by delayed graft function (DGF) showed a profound down-regulation of Klotho compared with patients with early graft function. Quantification of serum Klotho after 2 years from transplantation demonstrated significant lower levels in DGF patients. Our data demonstrated that complement might be pivotal in the down-regulation of Klotho in IRI leading to a permanent deficiency after years from transplantation. Considering the anti-senescence and anti-fibrotic effects of Klotho at renal levels, we hypothesize that this acquired deficiency of Klotho might contribute to DGF-associated chronic allograft dysfunction.

A HGF/cMET autocrine loop is operative in multiple myeloma bone marrow endothelial cells and may represent a novel therapeutic target

PURPOSE

The aim of this study was to investigate the angiogenic role of the hepatocyte growth factor (HGF)/cMET pathway and its inhibition in bone marrow endothelial cells (EC) from patients with multiple myeloma versus from patients with monoclonal gammopathy of undetermined significance (MGUS) or benign anemia (control group).

EXPERIMENTAL DESIGN

The HGF/cMET pathway was evaluated in ECs from patients with multiple myeloma (multiple myeloma ECs) at diagnosis, at relapse after bortezomib- or lenalidomide-based therapies, or on refractory phase to these drugs; in ECs from patients with MGUS (MGECs); and in those patients from the control group. The effects of a selective cMET tyrosine kinase inhibitor (SU11274) on multiple myeloma ECs' angiogenic activities were studied in vitro and in vivo.

RESULTS

Multiple myeloma ECs express more HGF, cMET, and activated cMET (phospho (p)-cMET) at both RNA and protein levels versus MGECs and control ECs. Multiple myeloma ECs are able to maintain the HGF/cMET pathway activation in absence of external stimulation, whereas treatment with anti-HGF and anti-cMET neutralizing antibodies (Ab) is able to inhibit cMET activation. The cMET pathway regulates several multiple myeloma EC activities, including chemotaxis, motility, adhesion, spreading, and whole angiogenesis. Its inhibition by SU11274 impairs these activities in a statistically significant fashion when combined with bortezomib or lenalidomide, both in vitro and in vivo.

CONCLUSIONS

An autocrine HGF/cMET loop sustains multiple myeloma angiogenesis and represents an appealing new target to potentiate the antiangiogenic management of patients with multiple myeloma.

Complement-dependent NADPH oxidase enzyme activation in renal ischemia/reperfusion injury

NADPH oxidase plays a central role in mediating oxidative stress during heart, liver, and lung ischemia/reperfusion injury, but limited information is available about NADPH oxidase in renal ischemia/reperfusion injury. Our aim was to investigate the activation of NADPH oxidase in a swine model of renal ischemia/reperfusion damage. We induced renal ischemia/reperfusion in 10 pigs, treating 5 of them with human recombinant C1 inhibitor, and we collected kidney biopsies before ischemia and 15, 30, and 60 min after reperfusion. Ischemia/reperfusion induced a significant increase in NADPH oxidase 4 (NOX-4) expression at the tubular level, an upregulation of NOX-2 expression in infiltrating monocytes and myeloid dendritic cells, and 8-oxo-7,8-dihydro-2'-deoxyguanosine synthesis along with a marked upregulation of NADPH-dependent superoxide generation. This burden of oxidative stress was associated with an increase in tubular and interstitial expression of the myofibroblast marker α-smooth muscle actin (α-SMA). Interestingly, NOX-4 and NOX-2 expression and the overall NADPH oxidase activity as well as α-SMA expression and 8-oxo-7,8-dihydro-2'-deoxyguanosine synthesis were strongly reduced in C1-inhibitor-treated animals. In vitro, when we incubated tubular cells with the anaphylotoxin C3a, we observed an enhanced NADPH oxidase activity and α-SMA protein expression, which were both abolished by NOX-4 silencing. In conclusion, our findings suggest that NADPH oxidase is activated during ischemia/reperfusion in a complement-dependent manner and may play a potential role in the pathogenesis of progressive renal damage in this setting.

Effects of ischemia-reperfusion injury in kidney transplantation: risk factors and early and long-term outcomes in a single center

INTRODUCTION

Ischemia-reperfusion injury (IRI) causes a high rate of delayed graft function (DGF), the most frequent complication in the immediate postoperative period after cadaveric donor kidney transplantation. Herein we evaluated the impact of donor and recipient characteristics on DGF development in terms of the incidence of acute rejection episodes, hospital stay, renal function, and long-term graft and patient survivals.

MATERIALS AND METHODS

Between February 1998 and July 2011, 761 patients underwent cadaveric donor kidney transplantations. DGF was defined as the need for dialysis in the first week. Patients were subdivided according to initial graft function as immediate graft function (IGF) or DGF.

RESULTS

DGF observed in 241 patients (31.6%) was associated independently with expanded criteria donors, extended cold ischemia time, Karpinsky histological score, and prior dialysis duration both univariate and multivariate analysis. The incidence of acute rejection episodes was 18.1% among the DGF group versus 1.3% in the IGF group (P < .01). DGF significantly reduced both graft and patient survivals at 6, 12, 36, and 60 months.

CONCLUSION

DGF was responsible for a longer hospital stay, worse early and long-term renal function, a higher incidence of acute rejection episodes as well as reduced graft and patient survivals.

Advanced age is not an exclusion criterion for kidney transplantation

INTRODUCTION

Renal transplantation in patients older than 60 years has long been regarded with skepticism owing to the increased risk of complications although, as compared with dialysis treatment, a graft seems to improve not only the quality of life but also long-term patient survival. This study sought to analyze the impact of recipient age older than 60 years on patient and graft outcomes.

MATERIALS AND METHODS

We retrospectively investigated the outcomes of 761 kidney transplant recipients from cadaveric donors performed between February 1998 and July 2011. While 69 subjects were at least 60 years of age (group A), 692 were younger than 60 years (group B) at the time of transplantation.

RESULT

Mean follow-up was 60.1 ± 38.5 months. Delayed graft function (DGF) requiring dialysis was observed in 36 group A (52.1%) and 205 group B (29.6%) subjects (P = .001). However, there were also significant differences between group A and group B in terms of mean donor age (60.3 vs 44.6 years; P < .001) and mean donor estimated creatinine clearance (57.8 vs 83.4 mL/min; P < .001). There were no significant differences in death-censored graft survival between the two groups, but elderly patients experienced worse survival (P = .0005). The most common causes of patient death were myocardial infarction, other cardiovascular complications, and tumors.

CONCLUSION

Kidney transplantation is a good option for elderly recipients with end-stage renal disease, providing long graft survival and a good quality of life, although these patients are more likely to develop cancer or cardiovascular disease. Our findings suggested that older patients should not be excluded a priori from transplantation, but meticulous screening for cancer and heart disease should be always be performed to improve outcomes.

HIF-1α of bone marrow endothelial cells implies relapse and drug resistance in patients with multiple myeloma and may act as a therapeutic target

PURPOSE

To investigate the role of hypoxia-inducible factor-1α (HIF-1α) in angiogenesis and drug resistance of bone marrow endothelial cells of patients with multiple myeloma.

EXPERIMENTAL DESIGN

HIF-1α mRNA and protein were evaluated in patients with multiple myeloma endothelial cells (MMEC) at diagnosis, at relapse after bortezomib- or lenalidomide-based therapies or on refractory phase to these drugs, at remission; in endothelial cells of patients with monoclonal gammapathies of undetermined significance (MGUS; MGECs), and of those with benign anemia (controls). The effects of HIF-1α inhibition by siRNA or panobinostat (an indirect HIF-1α inhibitor) on the expression of HIF-1α proangiogenic targets, on MMEC angiogenic activities in vitro and in vivo, and on overcoming MMEC resistance to bortezomib and lenalidomide were studied. The overall survival of the patients was also observed.

RESULTS

Compared with the other endothelial cell types, only MMECs from 45% of relapsed/refractory patients showed a normoxic HIF-1α protein stabilization and activation that were induced by reactive oxygen species (ROS). The HIF-1α protein correlated with the expression of its proangiogenic targets. The HIF-1α inhibition by either siRNA or panobinostat impaired the MMECs angiogenesis-related functions both in vitro and in vivo and restored MMEC sensitivity to bortezomib and lenalidomide. Patients with MMECs expressing the HIF-1α protein had shorter overall survival.

CONCLUSIONS

The HIF-1α protein in MMECs may induce angiogenesis and resistance to bortezomib and lenalidomide and may be a plausible target for the antiangiogenic management of patients with well-defined relapsed/refractory multiple myeloma. It may also have prognostic significance.

Middle and long-term outcomes of dual kidney transplant: a multicenter experience

INTRODUCTION

Dual kidney transplantation (DKTx) to reduce the disparity between demand and supply of organs was evaluated in two Italian centers (Bari and Novara).

MATERIALS AND METHODS

Between October 2000 and October 2011, we performed 97 DKT (26 ipsilateral/71 bilateral) following routine biopsy of all kidneys obtained from expanded criteria donors by Remuzzi-Karpinsky scores. The reference group was 379 single grafts from donors older than 60 years single kidney transplantation ([SKT] × > 60).

RESULTS

Good postoperative renal function was observed in 56 DKTx (57.7%); whereas acute tubular necrosis requiring dialysis was observed in 41 (42.3%) patients. After a mean follow-up of 60 months, DKTx graft survivals were 96%, 93%, and 90% and patient survivals, 96%, 91%, and 91% at 1, 3, and 5 years, respectively. Complications in expanded criteria donor kidney transplantations included a high rate of cytomegalovirus (CMV) disease especially dual kidney cases. DKTx represented the only independent risk factor for CMV disease upon multivariate analysis (odds ratio [OR] 2.33, 95% confidence interval [CI] 1.28-4.2; P = .006). We did not observe any significant difference in graft or patient survival between DKTx and SKTx > 60 years.

CONCLUSIONS

We observed good outcomes up to 5 years after transplantation in terms of graft and patient survival despite the use of inferior grafts. Comparing DKTx and SKT > 60, we noted that the mean Karpinski score for SKTx was significantly better than DKTx, although patient and graft survivals were similar. This trend confirms that the use of a biopsy to allocate expanded criteria donor kidneys may be too protective; therefore, the criteria to select DKTx require further refinement.

Allograft nephrectomy: what is the best surgical technique?

BACKGROUND

The objective of this study was to evaluate differences in outcomes of allograft nephrectomies performed by extracapsular versus intracapsular techniques.

METHODS

From 1993 to 2010, we performed 89 allograft nephrectomies, including 57 by extracapsular techniques and 32 by intracapsular, chosen according to feasibility at the beginning of the surgery. Fisher exact test and logistic regression were used for statistical analysis. Survival estimates after allograft nephrectomy were calculated according to the Kaplan-Meier method.

RESULTS

After a mean graft survival of 49.7 months, the indications for transplant nephrectomy were chronic rejection (39.3%), acute rejection (22.5%), infection/sepsis (19.1%), gross hematuria (6.7%), renal vein thrombosis (6.7%), renal artery thrombosis (3.4%), and graft rupture (2.3%). Mean operative time, blood loss, transfusions, and complications were similar between the extracapsular and intracapsular groups. The only difference in surgical aspects between the 2 groups was the mean hospital stay, which was longer for the extracapsular group (13.8 vs 7.6 days; P = .01), a result that was confirmed by multivariate analysis (odds ratio, 1.05; 95% confidence interval, 1.0-1.1; P = .03).

CONCLUSIONS

Our experience showed no significant advantages in favor of the intracapsular technique except for a shorter length of hospital stay than after the extracapsular procedure.

HER-2/neu in bladder carcinoma

A total of 66 bladder cancer patients were studied to verify possible relationships between HER-2/neu alterations and pathological characteristics, and to define a poor prognosis patient subgroup with respect to time to recurrence, time to progression and survival. Tumor and healthy tissue specimens were analyzed for HER-2/neu DNA amplification and protein overexpression by Southern and Western blot techniques and evaluated statistically. 13% of cases were amplified and 39% were overexpressed. HER-2/neu alterations were not significantly associated with pathological staging or tumor grading. Multifocal tumors had a higher percentage and overexpression with respect to monofocal tumors. Actuarial analyses did not show a significant statistical correlation between HER-2/neu amplification and overexpression and clinical outcome. Clinical evaluation of HER-2/neu status showed that this gene is not related to tumor relapse, progression or patient survival.

Pentraxin 3 (PTX3) inhibits plasma cell/stromal cell cross-talk in the bone marrow of multiple myeloma patients

Pentraxin 3 (PTX3) is a soluble pattern recognition receptor that binds with high affinity and selectivity to fibroblast growth factor-2 (FGF2), thus inhibiting its pro-angiogenic activity. Here we investigated the effects of PTX3 on monoclonal gammopathy of undetermined significance (MGUS) and multiple myeloma (MM) patient-derived bone marrow (BM) plasma cells (PCs), endothelial cells (ECs), and fibroblasts (FBs), and assessed whether PTX3 can modulate the cross-talk between PCs and those microenvironment cells. PTX3 and FGF2 expression was evaluated by ELISA. Functional studies, including cell viability, wound healing, chemotaxis, and Matrigel(®) assays, were performed on MGUS and MM ECs and FBs upon the PTX3 treatment. Through western blot PTX3-induced modulation in FGF2/FGF receptor signalling pathways was evaluated in MGUS and MM ECs and FBs through western blot. Co-cultures between MM ECs/FBs and human PC lines were used to evaluate possible PTX3 indirect effects on MM PCs. Adhesion molecules were studied by flow cytometry. PTX3 provides a direct time- and dose-dependent apoptotic effect on MM ECs and FBs, but not on either MM primary PCs or human PC lines. PTX3 inhibits migration of MM ECs and FBs in a dose-dependent manner, and impacts in vitro and in vivo FGF2-mediated MM angiogenesis. Co-cultures of PCs and ECs/FBs show that PTX3 treatment indirectly impairs PC viability and adhesion. We conclude that PTX3 is an anti-angiogenic factor in MM and behaves as a cytotoxic molecule on MM cells by inhibiting the cross-talk between PCs and ECs/FBs.

Four proteins governing overangiogenic endothelial cell phenotype in patients with multiple myeloma are plausible therapeutic targets

Bone marrow (BM) angiogenesis has an important role in the initiation and progression of multiple myeloma (MM). We looked at novel mechanisms of vessel formation in patients with MM through a comparative proteomic analysis between BM endothelial cells (ECs) of patients with active MM (MMECs) and ECs of patients with monoclonal gammopathy of undetermined significance (MGECs) and of subjects with benign anemia (normal ECs). Four proteins were found overexpressed in MMECs: filamin A, vimentin, α-crystallin B and 14-3-3ζ/δ protein, not yet linked to overangiogenic phenotype. These proteins gave a typical distribution in the BM of MM patients and in MMECs versus MGECs, plausibly according to a different functional state. Their expression was enhanced by vascular endothelial growth factor, fibroblast growth factor 2, hepatocyte growth factor and MM plasma cell conditioned medium in step with enhancement of MMEC angiogenesis. Their silencing RNA knockdown affected critical MMEC angiogenesis-related functions, such as spreading, migration and tubular morphogenesis. A gradual stabilization of 14-3-3ζ/δ protein was observed, with transition from normal ECs to MGECs and MMECs that may be a critical step for the angiogenic switch in MMECs and maintenance of the cell overangiogenic phenotype. These proteins were substantially impacted by anti-MM drugs, such as bortezomib, lenalidomide and panobinostat. Results suggest that these four proteins could be new targets for the antiangiogenic management of MM patients.

Rapamycin-induced hypophosphatemia and insulin resistance are associated with mTORC2 activation and Klotho expression

Rapamycin, an immunosuppressive drug used to prevent rejection after kidney transplantation, influences phosphate homeostasis, induces insulin resistance and has been shown to prolong lifespan in animal models. Because Klotho is an aging-suppressor gene controlling phosphate metabolism and insulin sensitivity, we investigated the influence of rapamycin on Klotho expression. A total of 100 kidney transplant recipients, 50 chronically treated with rapamycin and 50 with calcineurin inhibitors, were enrolled; 20 healthy subjects were employed as control. In the rapamycin group, serum phosphate was lower than in the CNI group with an increase in phosphate excretion and a reduction in its reabsorption. In addition, rapamycin increased insulin resistance as shown by HOMA index. Rapamycin treatment of an immortalized proximal tubular cell line induced the expression of Klotho, the phosphorylation of AKT in Ser473, downstream target of mTORC2 and the expression of RICTOR, mTORC2 main component. AKT inhibition reduced the rapamycin-induced expression of Klotho. In vivo rapamycin treatment induced higher degree of RICTOR and AKT Ser(473) expression directly correlating with long-term rapamycin exposure, FE(PO4) and HOMA index. In conclusion, our data would suggest that rapamycin may influence phosphate homeostasis and insulin resistance modulating Klotho expression through mTORC2 activation.

IL-17 expression by tubular epithelial cells in renal transplant recipients with acute antibody-mediated rejection

Acute rejection is still a common complication of kidney transplantation. IL-17 is known to be associated with allograft rejection but the cellular source and the role of this cytokine remains unclear. We investigated IL-17 graft expression in renal transplant recipients with acute antibody-mediated rejection (ABMR), acute T-cell-mediated rejection (TCMR), interstitial fibrosis and tubular atrophy (IFTA) and acute tubular damage due to calcineurin-inhibitor toxicity (CNI). In acute ABMR, tubular IL-17 protein expression was significantly increased compared to TCMR, where most of the IL-17⁺ cells were CD4⁺ graft infiltrating lymphocytes, IFTA and CNI control groups. The tubular expression of IL-17 in acute ABMR colocalized with JAK2 phosphorylation and peritubular capillaries C4d deposition. In addition, IL-17 tubular expression was directly and significantly correlated with the extension of C4d deposits. In cultured proximal tubular cells, C3a induced IL-17 gene and protein expression along with an increased in JAK2 phosphorylation. The inhibition of JAK2 abolished C3a-induced IL-17 expression. The use of steroids and monoclonal antibodies reduced IL-17 expression, JAK2 phosphorylation and C4d deposition in acute ABMR patients. Our data suggest that tubular cells represent a significant source of IL-17 in ABMR and this event might be mediated by the complement system activation featuring this condition.