Osteolytic Lesions In Multiple Myeloma Research Articles

P-066 BCMA-CAR-T cells with synthetic circuits of CST6 lyse tumor cells and suppress osteolytic lesions in multiple myeloma

P-066 BCMA-CAR-T cells with synthetic circuits of CST6 lyse tumor cells and suppress osteolytic lesions in multiple myeloma

CST6 suppresses osteolytic bone disease in multiple myeloma by blocking osteoclast differentiation.

Osteolytic bone disease is a hallmark of multiple myeloma (MM). A significant fraction (~20%) of MM patients do not develop osteolytic lesions (OLs). The molecular basis for the absence of bone disease in MM is not understood. We combined PET-CT and gene expression profiling (GEP) of purified BM CD138+ MM cells from 512 newly diagnosed MM patients to reveal that elevated expression of cystatin M/E (CST6) was significantly associated with the absence of OL in MM. An enzyme-linked immunosorbent assay revealed a strong correlation between CST6 levels in BM serum/plasma and CST6 mRNA expression. Both recombinant CST6 protein and BM serum from patients with high CST6 significantly inhibited the activity of the osteoclast-specific protease cathepsin K and blocked osteoclast differentiation and function. Recombinant CST6 inhibited bone destruction in ex vivo and in vivo myeloma models. Single-cell RNA-Seq showed that CST6 attenuates polarization of monocytes to osteoclast precursors. Furthermore, CST6 protein blocks osteoclast differentiation by suppressing cathepsin-mediated cleavage of NF-κB/p100 and TRAF3 following RANKL stimulation. Secretion by MM cells of CST6, an inhibitor of osteoclast differentiation and function, suppresses osteolytic bone disease in MM and probably other diseases associated with osteoclast-mediated bone loss.

A prospective study of Skeletal survey versus Low-dose whole-body CT for Osteolytic lesions in Multiple Myeloma.

To compare WBLDCT to CSS for identifying progressive bone disease in MM in a prospective setting. Ninety-six patients with MM at Odense University Hospital and Stavanger Hospital were followed for up to four years. Patients were scanned with WBLDCT and CSS every year for the first two years and every six months thereafter or at suspicion of progression. Nineteen cases of progressive bone disease were found using WBLDCT vs eight cases using CSS (p<0.001). All cases of progressive bone disease using CSS were also identified by WBLDCT. Progression not found by CSS was primarily in the spine, sternum, and pelvis. Of the 19 cases, five patients had progressive bone disease only without other criteria for clinical progression. WBLDCT consistently identified more bone lesions per patient, 8.2 CI(6.8;9.6) vs CSS, 3.6 CI(2.7;4.5). WBLDCT outperformed CSS for finding progressive bone disease and osteolytic lesions. More new lesions were found during follow-up by WBLDCT than CSS. Using CSS for lytic lesions will underestimate progression rates. Our data offer prospective evidence for the current recommendation using WBLDCT for skeletal evaluations in patients with multiple myeloma.

Prediction of Malignant Cell Infiltration Patterns with Texture Features of Biopsy-Correlated Positron Emission Tomography of Osteolytic Lesions in Multiple Myeloma

Prediction of Malignant Cell Infiltration Patterns with Texture Features of Biopsy-Correlated Positron Emission Tomography of Osteolytic Lesions in Multiple Myeloma

P-146: A prospective study of conventional skeletal survey versus Whole-body CT for osteolytic lesions in Multiple Myeloma

Background Multiple Myeloma (MM) is a bone marrow cancer with high prevalence of osteolytic disease. Evaluating bone involvement is essential as it is an important criterion for starting treatment. For many years conventional skeletal survey (CSS) has been used but based on retrospective data. The International Myeloma Working Group now recommends using Whole Body CT (WBCT). This study compares CSS to WBCT at baseline and prospectively for up to 4 years for finding progression of bone involvement. Methods 96 MM patients from the cooperating hospitals were followed for up to 4 years. Patients were scanned every year for the first 2 years and every 6 months thereafter or if suspicion of bone disease was raised. Progressive bone disease was defined as new lesions of at least 5 mm or growth of lesions by at least 5 mm. For evaluation paired t-test for numeric analysis of lesions and McNemars exact test for comparison of proportions of paired observations were used. Results 534 investigations (267 pairs) were evaluated. WBCT consistently found more bone lesions per patient 8.2 (CI 6.8;9.6) vs CSS 3.6 (CI 2.7;4.5). The additional lesions found by WBCT were primarily in the axial skeleton while there was no difference in the skull. In the extremities a few more lesions were found on CSS 0.40 (CI 0.2-0.5) vs WBCT 1.80 (CI 1.1;2.4). In total 23.6% (CI 20.6;26.6) of patients had a negative CSS and a positive WBCT (P<0.0001). Over the period a total of 19 cases of progressive bone disease (PBD) was found with 20 new lesions and 3 growing lesions found on WBCT vs 8 cases with 8 new lesions on CSS (P<0.001). The cases not found on CSS were primarily in the spine, sternum, and pelvic region. There were no cases of PBD on CSS not found on WBCT. Of the 19 cases of progressive bone disease, 5 cases were “bone only” progressors with no biochemical signs of progression. Conclusions WBCT consistently outperformed CSS for finding osteolytic lesions. This supports the current recommendation for using WBCT for skeletal evaluations. Significantly more new lesions were found during follow-up by WBCT compared to CSS suggesting that using only CSS is likely to underestimate progression rates. Multiple Myeloma (MM) is a bone marrow cancer with high prevalence of osteolytic disease. Evaluating bone involvement is essential as it is an important criterion for starting treatment. For many years conventional skeletal survey (CSS) has been used but based on retrospective data. The International Myeloma Working Group now recommends using Whole Body CT (WBCT). This study compares CSS to WBCT at baseline and prospectively for up to 4 years for finding progression of bone involvement. 96 MM patients from the cooperating hospitals were followed for up to 4 years. Patients were scanned every year for the first 2 years and every 6 months thereafter or if suspicion of bone disease was raised. Progressive bone disease was defined as new lesions of at least 5 mm or growth of lesions by at least 5 mm. For evaluation paired t-test for numeric analysis of lesions and McNemars exact test for comparison of proportions of paired observations were used. 534 investigations (267 pairs) were evaluated. WBCT consistently found more bone lesions per patient 8.2 (CI 6.8;9.6) vs CSS 3.6 (CI 2.7;4.5). The additional lesions found by WBCT were primarily in the axial skeleton while there was no difference in the skull. In the extremities a few more lesions were found on CSS 0.40 (CI 0.2-0.5) vs WBCT 1.80 (CI 1.1;2.4). In total 23.6% (CI 20.6;26.6) of patients had a negative CSS and a positive WBCT (P<0.0001). Over the period a total of 19 cases of progressive bone disease (PBD) was found with 20 new lesions and 3 growing lesions found on WBCT vs 8 cases with 8 new lesions on CSS (P<0.001). The cases not found on CSS were primarily in the spine, sternum, and pelvic region. There were no cases of PBD on CSS not found on WBCT. Of the 19 cases of progressive bone disease, 5 cases were “bone only” progressors with no biochemical signs of progression. WBCT consistently outperformed CSS for finding osteolytic lesions. This supports the current recommendation for using WBCT for skeletal evaluations. Significantly more new lesions were found during follow-up by WBCT compared to CSS suggesting that using only CSS is likely to underestimate progression rates.

Diffuse Medullary Hyperdensities of the Femora and Humeri on Whole-Body Low-Dose Computed Tomography Identify Diffuse MRI Pattern of Involvement and Correlate with Advanced Disease Stage in Patients with Multiple Myeloma

Whole-Body Low-Dose Computed Tomography (WBLDCT) is considered one of the most accurate methods for the detection of osteolytic lesions in multiple myeloma (MM). On WBLDCT, hyperdense tumor deposits in the medullary cavities of the femora and humeri are often observed; these may represent the only evidence of myeloma in patients without osteolyses. These abnormal hyperdensities may be nodular or diffuse and their density is quantitated by Hounsfield Units (HU). The importance of these deposits has not been fully evaluated in MM. Furthermore, there are anecdotal observations that hyperdense myeloma deposits are more common in patients with a diffuse MRI pattern. The aim of this study was to evaluate the incidence and type of hyperdensities in newly-diagnosed MM (NDMM) patients with a diffuse MRI pattern who also underwent a WBLDCT at the time of diagnosis, compare the results with NDMM patients who had a normal or focal MRI pattern and correlate them with disease characteristics.Seventy-four newly-diagnosed MM patients were evaluated. WBLDCT and MRI of the spine and pelvis were performed at diagnosis, before the administration of any kind of therapy. The median age of patients was 70.5 years; per ISS, 37% had ISS-1 disease, 35% ISS-2 and 28% ISS-3; per R-ISS, 23% had stage 1 disease, 62% stage 2 and 15% stage 3; per MRI, 29 patients had a diffuse pattern, 15 patients a focal and 30 patients a normal pattern. Patients with a diffuse MRI pattern had more often ISS-3 (n=16, 55%) and R-ISS-3 (n=10, 34%) disease. All MRIs and WBLDCTs were evaluated in consensus by two experienced radiologists (VK and LAM) who were blinded to the clinical data.Five types of hyperdensities were identified: 1) Fatty (F) - only negative HUs were recorded throughout the medullary cavity, consistent with the presence of normal fatty (yellow) marrow, 2) Fatty marrow intermingled with indistinct hyperdensities (FIH) - a pattern more commonly seen in patients with a normal MRI pattern, consistent with the presence of various amounts of hematopoietic (red) and fatty marrow, 3) Nodular hyperdensities (N) - one or more circumscribed hyperdense nodules presumably representing tumor deposits. A variant of this pattern consisted of the presence of multiple confluent nodules, 4) Diffuse hyperdensities (D) - characterized by the presence of a very dense, homogeneous appearance of part or the whole of the medullary cavity, presumably representing diffuse tumoral involvement.Out of the 29 patients with a diffuse MRI pattern 11 (38%) had no osteolyses on WBLDCT. 28/29 patients (97%) had medullary hyperdensities in the femora and/or humeri: 22 patients (76%) had diffuse hyperdensities (D) in at least one of the four bones (average density 68.7 HU) and 6 patients (21%) had only nodular hyperdensities (average density 76.5 HU). Interestingly, all patients with ISS-3 or R-ISS-3 and a diffuse MRI pattern had diffuse hyperdensities (D) on WBLDCT. Out of the 15 patients with a focal MRI pattern, only one patient (6.7%) displayed a diffuse hyperdensity (D) in at least one long bone; 7/15 patients (46.7%) had nodular hyperdensity lesions (N) in at least one long bone. Finally, out of the 30 patients with normal MRI pattern, there was only one patient (3.3%) with diffuse hyperdensities (D). In most of these patients either a fatty (F) or a mixed fatty with indistinct hyperdensities (FIH) pattern was identified on WBLDCT.The presence of diffuse hyperdensities (D) in the medullary cavity of at least one bone had 96.5% sensitivity and 95.5% specificity for the diagnosis of a diffuse MRI pattern. In 10/29 patients (34.4%) medullary hyperdensities were the only sign of bone involvement, since no osteolyses were detected (1/29 patient had neither osteolyses nor hyperdensities).In conclusion, in about one third of patients with multiple myeloma and a diffuse MRI pattern of involvement, the presence of hyperdensities in the medullary cavities of the femora and humeri may be the only abnormality detected on WBLDCT. Diffuse hyperdensities are the most commonly encountered type in this subset of patients and they seem to be associated with advanced myeloma at initial diagnosis (ISS-3 or R-ISS-3). Studies with larger number of patients and long follow-up will reveal if the type and extent of hyperdensities, as well as the levels of HU, can also provide prognostic information in myeloma patients. DisclosuresTerpos:Abbvie: Honoraria; Takeda: Honoraria, Other: SC member; Janssen: Honoraria, Research Funding; Amgen: Honoraria, Other: SC member, Research Funding; GSK: Honoraria; BMS: Honoraria; Genesis/Celgene: Honoraria, Other: DMC member, Research Funding. Kastritis:Amgen: Honoraria, Research Funding; Takeda: Honoraria; Genesis pharma: Honoraria; Janssen: Honoraria; Prothena: Honoraria. Dimopoulos:Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Onyx Pharmaceuticals, an Amgen subsidiary, Takeda Oncology: Consultancy, Honoraria, Other: Advisory Committee: Amgen Inc, Celgene Corporation, Janssen Biotech Inc, Onyx Pharmaceuticals, an Amgen subsidiary, Takeda Oncology; Genesis Pharma: Research Funding; Novartis: Consultancy, Honoraria.

Osteolytic lesions in Multiple Myeloma

Osteolytic lesions in Multiple Myeloma

Dickkopf-related protein 1 expression in bone marrow of multiple myeloma patients: correlation with bone disease and plasma cell malignancy type.

Previous studies have pointed out the role of dickkopf-related protein 1 (DKK1)- Wnt inhibitor, which is essential for osteoblast functioning, in the development of osteolytic lesions in multiple myeloma (MM). To assess the DKK1expression displayed by myeloma cells in bone marrow trephine biopsies of patients with and without osteolytic lesions, and in different malignancy grades of the disease. The expression level of DKK1was assessed immunohistochemically in bone marrow of 49MM patients presented with and without osteolytic lesions (the 1st and the 2nd group, respectively). Levels of weak, moderate, and strong DKK1expression were distributed- as 43.33, 27.78and 25.56%, and 63.91, 18.80, and 1.50%, respectively when evaluating the samples obtained from the 1st and the 2nd group. Statistically significant differences were found when the levels of DKK1expression in the 1st and the 2nd group were compared (χ2= 51; df= 3; p< 0.001). DKK1contributes to the development of osteolytic lesions in MM. The present study provides morphological evidence that inhibition in Wnt signaling may lead to bone damage observed in the advanced stage of the disease.

Myeloma Cells Deplete Bone Marrow Glutamine and Inhibit Osteoblast Differentiation Limiting Asparagine Availability.

Simple SummaryOsteolytic bone lesions represent an important clinical feature of multiple myeloma (MM). MM cells metabolize very high amounts of glutamine (Gln) and significantly lower Gln in the bone marrow. In this contribution we demonstrate that MM-dependent Gln depletion impairs the differentiation of bone marrow mesenchymal stromal cells into osteoblasts, the cells that form new bone tissue. We also found that osteoblast differentiation is associated with increased expression of glutaminase, the main enzyme that metabolizes Gln, SNAT2, a transporter able to accumulate Gln into the cells, and asparagine synthetase, the enzyme that uses Gln to obtain asparagine (Asn). Asn rescued osteoblast differentiation of Gln-starved mesenchymal stromal cells. These results demonstrate that MM cells impair osteoblast differentiation, hindering mesenchymal Asn synthesis through Gln depletion. Besides providing a metabolic mechanism underlying osteolytic lesions in MM, these results suggest that Asn supplementation may prevent bone disease in MM patients.Multiple myeloma (MM) cells consume huge amounts of glutamine and, as a consequence, the amino acid concentration is lower-than-normal in the bone marrow (BM) of MM patients. Here we show that MM-dependent glutamine depletion induces glutamine synthetase in stromal cells, as demonstrated in BM biopsies of MM patients, and reproduced in vitro by co-culturing human mesenchymal stromal cells (MSCs) with MM cells. Moreover, glutamine depletion hinders osteoblast differentiation of MSCs, which is also severely blunted by the spent, low-glutamine medium of MM cells, and rescued by glutamine restitution. Glutaminase and the concentrative glutamine transporter SNAT2 are induced during osteoblastogenesis in vivo and in vitro, and both needed for MSCs differentiation, pointing to enhanced the requirement for the amino acid. Osteoblastogenesis also triggers the induction of glutamine-dependent asparagine synthetase (ASNS), and, among non-essential amino acids, asparagine rescues differentiation of glutamine-starved MSCs, by restoring the transcriptional profiles of differentiating MSCs altered by glutamine starvation. Thus, reduced asparagine availability provides a mechanistic link between MM-dependent Gln depletion in BM and impairment of osteoblast differentiation. Inhibition of Gln metabolism in MM cells and supplementation of asparagine to stromal cells may, therefore, constitute novel approaches to prevent osteolytic lesions in MM.

Mechanical suppression of osteolytic bone metastases in advanced breast cancer patients: a randomised controlled study protocol evaluating safety, feasibility and preliminary efficacy of exercise as a targeted medicine

BackgroundSkeletal metastases present a major challenge for clinicians, representing an advanced and typically incurable stage of cancer. Bone is also the most common location for metastatic breast carcinoma, with skeletal lesions identified in over 80% of patients with advanced breast cancer. Preclinical models have demonstrated the ability of mechanical stimulation to suppress tumour formation and promote skeletal preservation at bone sites with osteolytic lesions, generating modulatory interference of tumour-driven bone remodelling. Preclinical studies have also demonstrated anti-cancer effects through exercise by minimising tumour hypoxia, normalising tumour vasculature and increasing tumoural blood perfusion. This study proposes to explore the promising role of targeted exercise to suppress tumour growth while concomitantly delivering broader health benefits in patients with advanced breast cancer with osteolytic bone metastases.MethodsThis single-blinded, two-armed, randomised and controlled pilot study aims to establish the safety, feasibility and efficacy of an individually tailored, modular multi-modal exercise programme incorporating spinal isometric training (targeted muscle contraction) in 40 women with advanced breast cancer and stable osteolytic spinal metastases. Participants will be randomly assigned to exercise or usual medical care. The intervention arm will receive a 3-month clinically supervised exercise programme, which if proven to be safe and efficacious will be offered to the control-arm patients following study completion. Primary endpoints (programme feasibility, safety, tolerance and adherence) and secondary endpoints (tumour morphology, serum tumour biomarkers, bone metabolism, inflammation, anthropometry, body composition, bone pain, physical function and patient-reported outcomes) will be measured at baseline and following the intervention.DiscussionExercise medicine may positively alter tumour biology through numerous mechanical and non-mechanical mechanisms. This randomised controlled pilot trial will explore the preliminary effects of targeted exercise on tumour morphology and circulating metastatic tumour biomarkers using an osteolytic skeletal metastases model in patients with breast cancer. The study is principally aimed at establishing feasibility and safety. If proven to be safe and feasible, results from this study could have important implications for the delivery of this exercise programme to patients with advanced cancer and sclerotic skeletal metastases or with skeletal lesions present in haematological cancers (such as osteolytic lesions in multiple myeloma), for which future research is recommended.Trial registrationanzctr.org.au, ACTRN-12616001368426. Registered on 4 October 2016.

Meta-Analysis Illustrates Role of Interferon-γ Signaling in Multiple Myeloma Pathogenesis

Background: Multiple myeloma (MM) is a clonal B cell neoplasia that comes from growth of malignant B cells in the bone marrow. Stromal cells, including inflammatory cells, in the bone marrow enable MM persistence and growth. MM is characterized by an uncoordinated cytokine system with an increase in proinflammatory cytokines. While proinflammatory cytokines are essential in mounting an anti-tumor response, they can also drive cancer progression. Ultimately, it is the effects of the cytokine milieu in the immune microenvironment that help determine MM development. While the role of IFNγ in MM remains mixed and unclear, our analysis suggests IFNγ plays an oncogenic role in MM and offers other insights to MM pathology.Methods: The National Center for Biotechnology Information (NCBI) GEO is an open database of more than 2 million samples of functional genomics experiments. The Search Tag Analyze Resource for GEO (STARGEO) platform allows for meta-analysis of genomic signatures of disease and tissue. We employed the STARGEO platform to search the Gene Expression Omnibus and performed meta-analysis on 517 peripheral blood samples from multiple myeloma patients using 97 healthy peripheral blood samples as a control. We then analyzed the signature in Ingenuity Pathway Analysis (IPA) to help define the genomic signature of MM and identify disease pathways. We analyzed genes that showed statistical significance disease and control samples (p<0.05) and an absolute experimental log ratio of at least 0.1.Results: We identified IFNγ signaling, primary immunodeficiency signaling, B cell development, and antigen presentation as the top canonical pathways. Top regulators included IFNγ, TNF, the oncogenic transcription regulator SMARC4, and CNOT7 (with predicted inhibition). We found inhibition of Wnt-signaling through stark upregulation of DKK1 (correlated with osteolytic lesions in MM) and the Wnt-binding protein antagonist FRZB. We also noted increased B cell survival through upregulation of the ADP-ribonyltransferase and B cell survival regulator PAPR14 and CPEB4, a gene required for cell cycle progression. Additionally, apoptotic signaling was diminished through downregulation of CNOT7 (limits B cell proliferation), genes involved in lysosomal disruption during apoptosis such as cathepsin H and lysozymes, the apoptotic Bcl-2 family protein BNIP3, and the pattern recognition receptor NOD2 (involved in autophagy). B cell development was impaired through downregulation of essential genes such as BLNK, a linker protein involved in B cell receptor signaling. Epigenetic changes were reflected by upregulation of the histone genes such as histone 1 genes HIST1H1C/1H2BD. Among histone 1's related pathways are E2F-mediated DNA replication and hypoxia-independent gene expression. Additionally, we found upregulation of tumorigenic genes such as neuron derived neurotrophic factor, NDNF, and hepatocyte growth factor, HGF, which has yet to be described in MM. Interestingly, pathway analysis demonstrated that this diverse set of disease processes are downstream of IFNγ signaling (see figure 1).Conclusion: MM pathogenesis reflects several disease processes that remain largely obscure. Our analysis clarifies the role of several mechanisms in MM such as inhibition of Wnt-signaling, defective B cell apoptosis, increased proliferation, loss of epigenetic integrity, and impaired B cell development. Activation of the antigen presentation pathway in our analysis may seem paradoxical to MM progression but recent evidence illustrates increased antigen presentation to T-regulatory cells, leading to immune tolerance. Most importantly, we are beginning to clarify the multifactorial, oncogenic qualities of IFNγ signaling in MM and are working to validate these results with analysis of our patient samples. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Whole-body computed tomography versus conventional skeletal survey in patients with multiple myeloma: a study of the International Myeloma Working Group

For decades, conventional skeletal survey (CSS) has been the standard imaging technique for multiple myeloma (MM). However, recently whole-body computed tomography (WBCT) has been implemented into the diagnostic criteria of MM. This analysis compares sensitivity and prognostic significance of WBCT and CSS in patients with smoldering MM (SMM) and MM. Fifty-four of 212 patients (25.5%) had a negative CSS and a positive WBCT for osteolytic lesions (P<0.0001). Of 66 patients with SMM based on CSS, 12 (22.2%) had osteolytic lesions on WBCT. In comparison, WBCT failed to detect some bone destructions in the appendicular skeleton possibly due to limitations of the field of view. Presence of lytic bone lesions in WBCT was of borderline prognostic significance (P=0.051) for SMM patients, with a median time to progression of 38 versus 82 months for those without bone destructions. In conclusion, WBCT identifies significantly more sites of bone destruction than CSS. More than 20% of patients with SMM according to CSS have in fact active MM detectable with WBCT. On the basis of this and other studies, WBCT (either computed tomography (CT) alone or as part of a positron emission tomography-CT protocol) should be considered the current standard for the detection of osteolytic lesions in MM.

Multiple myeloma-derived MMP-13 mediates osteoclast fusogenesis and osteolytic disease.

Multiple myeloma (MM) cells secrete osteoclastogenic factors that promote osteolytic lesions; however, the identity of these factors is largely unknown. Here, we performed a screen of human myeloma cells to identify pro-osteoclastogenic agents that could potentially serve as therapeutic targets for ameliorating MM-associated bone disease. We found that myeloma cells express high levels of the matrix metalloproteinase MMP-13 and determined that MMP-13 directly enhances osteoclast multinucleation and bone-resorptive activity by triggering upregulation of the cell fusogen DC-STAMP. Moreover, this effect was independent of the proteolytic activity of the enzyme. Further, in mouse xenograft models, silencing MMP-13 expression in myeloma cells inhibited the development of osteolytic lesions. In patient cohorts, MMP-13 expression was localized to BM-associated myeloma cells, while elevated MMP-13 serum levels were able to correctly predict the presence of active bone disease. Together, these data demonstrate that MMP-13 is critical for the development of osteolytic lesions in MM and that targeting the MMP-13 protein - rather than its catalytic activity - constitutes a potential approach to mitigating bone disease in affected patients.

“Bisphosphonates: Possible Modes of Action and Implications for Dental Implant Treatment. A Review of the Literature”

Bisphosphonates (BP) have been commonly used over the past 40 years to treat osteoporosis, Pagets’ disease, hypercalcemia of malignancy, osteolytic lesions of multiple myeloma and bone metastases associated with breast, prostate, lung and other soft tissue tumours. The main aims of this review are to: 1. Highlight the fundamental pharmacophysiological modes of action of both nitrogen and non-nitrogen bisphosphonates on bone 2. Explore their potential effects on oral hard and soft tissues 3. Discuss the implications of bisphosphonate therapy on dental implants, in particular their contribution to implant failure 4. Discuss the current recommendations and guidelines for dental implant therapy in patients receiving bisphosphonate therapy based on the available evidence. Two distinct types of bisphosphonates have been classified and differentiated according to their mode of action, chemical structure, potency, delivery, bioavailability, dosage and half-life. Bisphosphonates are classified as: 1) Nonnitrogen containing bisphosphonates (BP) and 2) Nitrogen containing bisphosphonates (N-BP). 27 studies met the study inclusion and exclusion criteria, with 8 retrospective studies and 2 case series studies evaluating the success rate of dental implants in patients with a history of bisphosphonate use, while the remaining 17 articles consisted of case series and case reports. While there are shortcomings associated with many of the reported studies, there does appear to be a certain risk associated with the both implant placement and the maintanence of osseointegrated implants in patients receiving oral bisphosphonates. A Southern Austrailian study estimated the risk of implant failure in patients receiving oral bisphosphonates to be 0.88%. Late implant failures appear to occur in patients treated with oral bisphosphonate exposure for a period >3 years especially in patients who have existing integrated implants,while early failures appear to occur in patients treated with bisphosphonates before or at the time of implant placement. Although the results from these retrospective studies and case series are conflicting to some extent, they have heightened awareness of the possible complication of BRONJ and bisphosphonate related implant failure from long term bisphosphonate use, be it oral or iv-bisphosphonates.

Involvement of T-Cells in the Bone Pathology of Multiple Myeloma

Introduction: Multiple myeloma (MM) is a plasma cell dyscrasia that is heavily dependent on a permissive BM micro-environment. Components of the WNT pathway have been implicated in this process and specifically, WNT-inhibitors such as Dkk1, have been blamed for the osteolytic lesions of MM. WNT signaling is required for proper osteoblast development while the pathway is also involved in enhancing the self renewal potential of various stem cells. A source of WNT ligands in the BM are the T-cells; when stimulated by parathormone, T-cells secrete wnt10b that affects hematopoietic stem cell numbers. In the present study, we evaluated WNT signaling in the T-cells of patients with MM in order to test whether these bystander T-cells have an altered phenotype that could influence disease pathology.Methods: A total of 18 MM patients was analyzed after informed consent was obtained; the patients underwent BM biopsy for diagnostic and staging purposes. T-cells were isolated from BM mononuclear cells using magnetic beads with a purity of around 90%. Normal controls were T-cells isolated from healthy subjects. RNA was isolated and analyzed by RT-PCR for expression of PTH receptor (PTH1R), wnt10b and the canonical WNT signal transducer, b-catenin (bCAT).Results and discussion: BM concentration of T-cells was 15%, close to the normal values, indicating no major deviation from normal conditions. Activity of the WNT pathway was estimated by bCAT mRNA levels; relative to the control, bCAT levels in MM T-cells were uniformily suppressed. In a total of 8 evaluable samples, there was a 3x decrease in bCAT levels. Although WNT activity could be influenced by different factors, there is a possibility that it may be related to PTH activity and PTH receptor expression on patient T-cells. In all our cases, calcium was recorded within normal range and PTH values were also normal. However, PTH1R mRNA levels in MM T-cells were 14.2x lower compared to normal T-cells, a value that argues for a biological role in disease pathogenesis. A direct consequence of low PTH1R mRNA levels, according to our hypothesis, would lead to a decrease in WNT10b. Indeed, WNT10b levels were on average 90% of the normal with relative wide variation; in 3 samples, there was an average 3.2x increase while in 8, the levels were on average 21% of normal. On the clinical level, lower wnt10b activity, was more often associated with bone pathology while higher wnt10b activity was more often associated with extramedullary plasmacytomas. Our data show that T-cells may not be bystanders in the MM disease progression and certain manifestations sush as bone disease, could be associated with, aberrant T cell function. Ongoing studies are under way to link clinical and laboratory data. DisclosuresNo relevant conflicts of interest to declare.

The Composition and Clinical Impact of Focal Lesions and Their Impact on the Microenvironment in Myeloma

Introduction: Focal lesions (FL) are detected by magnetic resonance imaging (MRI) and positron emission tomography (PET) and precede the development of osteolytic lesions in multiple myeloma (MM). FLs are absent in most patients with benign disease and their detection is associated with earlier disease progression suggesting that a distinct MM cell niche in the FLs is associated with conditions that promote the transition to MM. Studying the nature of this niche can significantly enhance our understanding of the biology and progression of MM.Methods: Random BM aspiration samples were taken from the posterior superior iliac crest whereas FL samples were sampled under CT guidance from newly diagnosed MM patients. Gene expression profiling (GEP) was performed on CD138-enriched plasma cells (PC, n=170) and non-enriched BM trephine biopsies (n=49) from paired RBM and FL samples from the same patients and from unrelated RBM cases with no detectable FL (n=79). 8-multicolor flow cytometry (MFC) analysis was performed on 25 paired PC samples and selected genes were validated using immunohistochemistry (IHC).Results: AComparison of GEP from paired RBM-PC and FL-PC showed discrepancies in GEP-based risk score and molecular subgroups and lower Polyclonal-PC score (reflecting the proportion of normal PC infiltration) in FL-PC samples (p=0.0001). There is 89% concordance for the GEP70 risk signature with 10 patients having low-risk PCs in RBM but high-risk PCs in the paired FL, and 8 patients showing high-risk PCs in RBM but low-risk PCs in the paired FL samples. In this setting progression-free and overall survival are mediated by the presence of a high-risk score in either sample. When molecular subgroups were identified there were more high risk-associated PR cases in FL samples (n=28) compared to only 16 PR cases in respective paired RBM-PC samples (p=0.005).Flow cytometry data from 25 paired MM cell samples showed consistently lower surface expression of CD138 in FL (p=0.0001). Cases with detectable CD81 had lower CD81 expression on FL-PC (p=0.03). Discrepancies were also observed in cell surface expression of CD38 and CD45.Pathway's analysis was based on of 523 differentially expressed genes between paired FL and RBM-PC samples (n=170; FDR<0.001) after adjusting for the level of normal PC infiltration. The top KEGG-based pathways enrichment analysis were associated with energy and drug metabolism, survival, cell-cell contact interaction and factors involved in activity of dexamethasone (e.g. NR3C1) and IMiDs (e.g. IZKF1), Figure 1A. Differential expression of ABCA1, the most upregulated gene in FL, was validated by IHC in biopsies. To test whether PCs from patients with FL have specific characteristics irrespective of their location, we compared RBM-PC GEP with RBM-PC GEP of unrelated patients with no detectable FLs. We detected increased expression of cell cycle genes in PC from patients with detectable FL.Reduced osteogenesis and interaction with mesenchymal and vascular lineages have been linked with MM cell phenotypes and dissemination in BM. Microenvironmental reactive stroma (e.g. POSTN, collagen genes) and angiogenic (e.g. EDNRA) gene signatures were significantly upregulated in non-enriched FL biopsies albeit expected high proportion of PC in this site, whereas osteoblastic markers such as BGLAP and IBSP were underexpressed in these samples in comparison to paired non-enriched RBM trephine biopsies, Figure 1B.Conclusions: PC in FL and RBM sites of the same patient are heterogeneous in their phenotype, molecular classification based on risk-score and subgroups, and pathways. GEP signatures of MM cells and the stroma in this niches stressing the biological and clinical relevance of FL as a hallmark in MM. [Display omitted] DisclosuresYaccoby:University of Arkansas for Medical Sciences: Employment. Epstein:University of Arkansas for Medical Sciences: Employment. Johnson:University of Arkansas for Medical Sciences: Employment. Qu:Cancer Research and Biostatistics: Employment. van Rhee:University of Arkansa for Medical Sciences: Employment. Jethava:University of Arkansas for Medical Sciences: Employment. Stein:University of Arkansas for Medical Sciences: Employment. Mitchell:Cancer Research and Biostatistics: Employment. Heuck:Millenium: Other: Advisory Board; University of Arkansas for Medical Sciences: Employment; Celgene: Consultancy; Janssen: Other: Advisory Board; Foundation Medicine: Honoraria. Davies:Millenium: Consultancy; Janssen: Consultancy; Celgene: Consultancy; University of Arkansas for Medical Sciences: Employment; Onyx: Consultancy. Crowley:Cancer Research and Biostatistics: Employment. Weinhold:Janssen Cilag: Other: Advisory Board; University of Arkansas for Medical Sciences: Employment. Barlogie:University of Arkansas for Medical Sciences: Employment. Morgan:Takeda: Honoraria, Membership on an entity's Board of Directors or advisory committees; Bristol Myers Squibb: Honoraria, Membership on an entity's Board of Directors or advisory committees; CancerNet: Honoraria; Weismann Institute: Honoraria; MMRF: Honoraria; University of Arkansas for Medical Sciences: Employment; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Sotatercept in patients with osteolytic lesions of multiple myeloma

This phase IIa study evaluated the safety and tolerability of sotatercept, and its effects on bone metabolism and haematopoiesis in newly diagnosed and relapsed multiple myeloma (MM) patients. Patients were randomized (4:1) to receive four 28-d cycles of sotatercept (0·1, 0·3, or 0·5 mg/kg) or placebo. Patients also received six cycles of combination oral melphalan, prednisolone, and thalidomide (MPT). Thirty patients were enrolled; six received placebo and 24 received sotatercept. Overall, 25% of patients received all four sotatercept doses; 71% of sotatercept-treated patients had ≥1 dose interruption mainly due to increases in haemoglobin levels. Grade ≥3 adverse events (AEs) were reported in 17% of patients receiving placebo and 58% receiving sotatercept. Grade 4 AEs in sotatercept-treated patients were neutropenia, granulocytopenia, and atrial fibrillation (one patient each). In patients without bisphosphonate use, anabolic improvements in bone mineral density and in bone formation relative to placebo occurred, whereas bone resorption was minimally affected. Increases in haemoglobin levels, versus baseline, and the duration of the increases, were higher in the sotatercept-treated patients, with a trend suggesting a dose-related effect. Multiple doses of sotatercept plus MPT appear to be safe and generally well-tolerated in MM patients.

Challenge test to bisphosphonates in patients with hypersensitivity reactions to drugs

BackgroundBisphosphonates are a commonly used class of drugs with known efficacy in the prevention and treatment of postmenopausal and steroid-induced osteoporosis, Paget's disease of bone, hypercaelcemia of malignancy, osteolytic lesions of multiple myeloma, and bone metastases. Nitrogen-containing bisphosphonates have a favourable tolerability and safety profile, cutaneous reactions have been reported. MethodsThis is a retrospective case series study, based on the analysis of data from 1429 patients admitted to the Allergy and Clinical Immunology Division of the University of Messina between January 2011 and December 2012. Most patients had previous adverse drug reactions (ADRs) and referred to us for a challenge test with an alternative drug. ResultsWe observed six patients with a past history of adverse drug reaction who needed to be tested for bisphosphonates: three patients for risedronate, two for clodronate and one for alendronate. In two years only two patients were referred to us for an adverse reaction to bisphosphonates: one to alendronate and one to risedronate. Another patient presented a previous reaction to strontium ranelate. The other three patients reported previous hypersensitivity reactions to at least two different classes of drugs. All the patients experienced no reaction using the tested drugs. ConclusionsIn our experience drug challenge tests for bisphosphonates are safe and reliable.

THU0009 Differential expression of DKK1 in synovial fibroblasts from resolving and early rheumatoid arthritis

BackgroundMechanisms preventing the resolution of inflammation and promoting joint damage underlie the persistence of RA and the development of damage early in disease. Dickkopf related protein 1 (DKK1) is an...

Targeting Notch and Hedgehog Embryonic Signaling Pathways Has Potent Anti-Tumor Activity in Myeloma and Is Effective in Myeloma Bone Disease.

AbstractAbstract 2938Notch and Hedgehog are embryonic signaling pathways which regulate normal stem cells and cancer stem cells in a variety of solid and hematopoietic malignancies. It has been demonstrated that Hedgehog signaling maintains a tumor stem cell compartment in multiple myeloma (MM). We previously demonstrated that aberrant activity of Notch is a hallmark of MM cells and is indispensable for their survival. MM cells interact with their microenvironment and activate osteoclasts via Notch in vitro, possibly contributing to characteristic osteolytic lesions in MM. Hence, we speculated that Notch pathway inhibition has anti-tumor activity and controls bone disease in a murine MM model. Recently, we used the gamma-secretase inhibitor (GSI) XII, which blocks ligand-induced cleavage of Notch receptors and hinders release of the activated intracellular part of Notch and transcriptional Notch target gene activation. In this study, we treated the newly established BALB/c-derived plasmacytoma cell line MOPC315.BM.Luc with GSI XII in vitro and assessed its anti-tumor activity. In vivo-selected MOPC315.BM.Luc cells have a tropism for bone marrow and cause neoplastic lesions which closely resemble human disease with particular respect to (1) secretion of high monoclonal dinitrophenyl(DNP)-specific immunoglobulin (Ig)A serum levels and (2) bone lesions. DNP-IgA levels correlate with tumor burden in this MM model. MOPC315.BM.Luc cells show activated Notch signaling, as evidenced by high nuclear levels of intracellular Notch1. GSI XII treatment of MOPC315.BM.Luc cells resulted in decreased Notch activity and subsequently induced apoptosis in vitro. For in vivo experiments, MOPC315.BM.Luc cells were injected into tail veins of recipient BALB/c mice. Bone lesions were detected and quantified employing micro-CT analysis. High-resolution CT scans allowed for quantitative assessment of bone density of cortical and trabecular bone, trabecular numbers and bone mineral content. Large lesions appeared as punctured bone in CT images or even as macroscopically visible holes in bone cortex. 10 mg/kg GSI XII was administered intraperitoneally for two weeks as soon as DNP-specific IgA levels reached 20 μg/ml. As a result GSI XII-treated mice exhibited significantly slower increases of DNP-IgA levels as compared to vehicle treated controls. In addition, in a small number of mice micro-CT scans of tibiae and femora revealed higher relative bone volume and bone mineral content in GSI XII treated versus control animals. Therefore, our data indicated anti-tumor activity of GSI XII treatment in the murine MOPC315.BM.Luc MM model. We further studied simultaneous targeting of Notch and the aberrantly activated embryonic signaling pathway Hedgehog in MM. It has been shown that cross-talk interaction between Notch and Hedgehog regulates self-renewal of cancer cell lines. Hedgehog inhibition through the Smoothened antagonists cyclopamine and GDC-0449 drastically sensitized MOPC315.BM.Luc cells to GSI XII treatment in vitro. Further in vivo studies with Hedgehog inhibitors and analysis of the molecular basis for potential cross-talk of both pathways in MM are under current investigation. Disclosures:No relevant conflicts of interest to declare.