Proliferative Disorders Research Articles

Enhanced anti-psoriatic efficacy and regulation of oxidative stress of a novel topical babchi oil (Psoralea corylifolia) cyclodextrin-based nanogel in a mouse tail model

Psoriasis is a proliferative inflammatory skin disorder with relapsing episodes. Herein, the efficacy of babchi oil (BO) loaded nanostructure gel was evaluated for antipsoriatic activity and oxidative stress biomarkers assessment using mouse tail model. BO was entrapped into cyclodextrin-based nanocarriers (360.9 ± 19.55 nm), followed by incorporation into Carbopol gel and characterised for viscosity, spreadability, and texture analysis. The gels were topically applied on mouse-tails once daily for fourteen days. Evaluation of antipsoriatic activity as determined by histopathological observations of orthokeratotic epidermis revealed two times higher efficacy of BO nanogel in comparison to the native BO gel. Further, significantly enhanced superoxide dismutase (SOD) and reduced glutathione (GSH) levels, and diminished malondialdehyde (MDA) and nitrite (NO) levels revealed that prepared nanogels played a major role in the management of reactive oxygen species (ROS) associated in psoriasis pathogenesis. Hence, this study provides strong evidence for use of cyclodextrin-based nanogels as a safe and better delivery carrier of BO for management of psoriasis.

Cutaneous Rasai-Dorfman disease

Rosai-Dorfman disease (RDD) is a rare histiocytic proliferative disorder. The etiology and pathogenesis of RDD are still unclear, and may be associated with the activation of signal transduction pathways and inflammatory reactions induced by infection and immune dysfunction. CRDD is defined as the RDD involving only the skin. Histopathological examination of CRDD lesions shows that a large amount of histiocytes, lymphocytes and plasma cells infiltrate the dermis, and intact endocytosed lymphocytes can be observed in the cytoplasm of histiocytes, which is called emperipolesis. Immunohistochemical study shows that histiocytes are stained positive for S-100 and CD68, but negative for CD1a. The treatment of CRDD includes surgical excision, local therapy and systemic therapy. Lesions can subside spontaneously in some patients, and it usually has a favorable prognosis. Key words: Histiocytosis, sinus; Cutaneous Rosai-Dorfman disease

Tumor⁻Microenvironment Interaction: Analysis of Mast Cell Populations in Normal Tissue and Proliferative Disorders of the Canine Prostate.

Mast cells (MCs) are involved in angiogenesis, tissue remodeling and immunomodulation in several human and animal tumors, although their exact role is still controversial. Since no information is available in canine prostate carcinoma (PC) and normal prostate tissues, the aims of this study were to evaluate the possible correlations between MC distribution, molecular expression and microvessel density (MVD) in normal prostatic tissue and proliferative disorders of the canine prostate. All samples (6 normal, 15 benign prostate hyperplasia-BPH, 8 PC) were stained with Toluidine Blue and immunohistochemically evaluated for tryptase, c-Kit (CD117) and CD31. Mast cell density (MCD) and MVD were quantified by the hot-spot method. MCD was significantly increased in periglandular/peritumoral areas, when compared with intraglandular/intratumoral areas, in all groups (p = 0.03). C-Kit expression was strongly associated with PC (ρ = 0.75 p = 0.03), whereas positive correlation between tryptase and c-Kit expression (ρ = 0.64 p = 0.01) was observed in periglandular areas of BPH. MVD showed a correlation with MCD in BPH (ρ = 0.54 p = 0.04). Our data support the importance of c-Kit in regulating MC proliferation. The predominant location of MCs in peritumoral areas of canine PC was similar to the human counterpart, in which PC cells are supposed to produce substances attracting MCs to the tumor microenvironment.

Targeting mTORC1/2 with OSI-027 inhibits proliferation and migration of keloid keratinocytes.

Keloid is a dermal proliferative disorder characterized by the excessive proliferation and migration of keratinocytes and fibroblasts. Over-activation of the serine/threonine protein kinase, mammalian target of rapamycin (mTOR), plays a pivotal role in the process. Here, we show that both mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) were hyper-activated in keloid-derived primary keratinocytes. Further, OSI-027, an mTOR kinase inhibitor, potently inhibited proliferation and migration of keloid keratinocytes. At the molecular level, OSI-027 disrupted the assembly of mTORC1 (mTOR-Raptor) and mTORC2 (mTOR-Rictor-mLST8). Further, OSI-027 almost completely blocked the phosphorylation of the mTORC1 substrates, S6K1, S6 and 4EBP1, and the mTORC2 substrate, AKT, at Ser-473. The OSI-027 treatment of keloid keratinocytes showed more effectively inhibited cell proliferation and migration compared to the mTORC1 inhibitor, rapamycin. Moreover, restoring mTORC1 activation by the introduction of the constitutively active S6K1 only partly alleviated OSI-027-induced inhibition of keloid keratinocytes. Notably, mTOR2 inhibition by Rictor siRNAs also inhibited keloid keratinocyte proliferation and migration, but less efficiently than OSI-027. Together, our results imply that concurrent targeting of mTORC1/2 by OSI-027 potently inhibits the proliferation and the migration of keloid keratinocytes. Thus, OSI-027 may have translational value for the treatment of keloid.

Comparison of two serum free light chain assays for the diagnosis of primary plasma cell malignant proliferative disease.

Background and aimsThe serum free light chain assay (sFLC) is well established for aiding in the diagnosis, prognosis, and monitoring of plasma cell proliferative disorders. There are currently two commercially available sFLC immunoassays, Freelite, based on polyclonal antibody technology, and N Latex FLC, based on monoclonal antibodies. This study aimed to compare the analytical and clinical performance of these two assays in a Chinese population.MethodsThis study included 74 consecutive patients who were newly diagnosed with monoclonal gammopathies (MGs) including multiple myeloma (MM), AL amyloidosis, and light chain deposition disease (LCDD) between January 2014 and May 2015 at the First Affiliated Hospital of Zhejiang University. Alongside serum and urine electrophoresis analysis, the serum samples were retrospectively tested with both sFLC assays according to the manufacturers' instructions.ResultsThe two sFLC assays showed a moderate correlation for κFLC (Passing‐Bablok slope = 0.645, coefficient of determination (R 2) = 0.83, and Spearman coefficient = 0.904). However, for λFLC, a poor correlation was found (Passing‐Bablok slope = 0.690, R 2 = 0.39, and Spearman coefficient = 0.852). The concordance rate of κFLC, λFLC, and κ/λ FLC ratio were 83.78%, 75.68%, and 86.49%, respectively. The clinical sensitivity of the κ/λ ratios were 83.8% for the Freelite assay and 75.7% for the N Latex FLC assay.ConclusionAlthough the concordance and the clinical sensitivity of the two assays appeared comparable, a number of discrepancies were observed. There is a low correlation between the two assays in clinical practice, suggesting that the assays are not equivalent and, thus, current IMWG guidelines, based on Freelite, cannot be cross‐applied to N Latex FLC.

The T197A Knock-in Model of Cdkn1b Gene to Study the Effects of p27 Restoration In Vivo.

The CDK inhibitor, p27kip1, encoded by the Cdkn1b gene can negatively modulate cell proliferation. The control of p27 activity during the cell cycle is regulated at multiple levels, including transcription, translation, and protein stability. The last residue of p27 (threonine 198 in human, threonine 197 in mouse) is involved in the control of protein stability. We have generated a murine knock-in model (Cdkn1b T197A) in which threonine 197 is replaced by alanine, which renders p27 protein highly unstable due to a high rate of proteasomal degradation. Expectedly, Cdkn1b T197A/T197A mice present with increased body size and weight, organomegaly, and multiple organ hyperplasia, similar to what is observed in Cdkn1b KO/KO mice. We investigated the effects exerted by the restoration of normal levels of p27 protein in the tissue of Cdkn1b T197A/T197A mice. We found that proteasome inhibition with bortezomib rescues the hyperplasia induced by the lack of p27 expression in Cdkn1b T197A/T197A but not in Cdkn1b KO/KO mice. However, BAY 11-7082, a proteasome inhibitor that stabilizes IκB but not p27, fails to rescue hyperplasia in Cdkn1b T197A/T197A mice. Bortezomib increases p27 half-life and reduces the proliferation in MEFs derived from Cdkn1b T197A/T197A but not from Cdkn1b WT/WT mice, whereas BAY 11-7082 had no effect on the protein levels of p27 and on the proliferation rate of Cdkn1b T197A/T197A MEFs.The results presented here demonstrate that Cdkn1b T197A/T197A mice represent an attractive in vivo model to investigate whether the targeting of p27 degradation machinery might prove beneficial in the treatment of a variety of human proliferative disorders caused by increased turnover of p27 protein.

Evaluation of Serum Adenosine Deaminase and Inflammatory Markers in Psoriatic Patients.

Background:Adenosine deaminase (ADA) is an enzyme involved in purine metabolism and it is a marker of nonspecific T-cell activation. Few studies have shown high levels of ADA in the epidermis and sera of psoriatic patients. Other inflammatory markers such as high-sensitive C-reactive protein (hsCRP), erythrocyte sedimentation rate (ESR), and serum uric acid (SUA) have shown correlations with psoriasis area severity index (PASI) score. The correlation between ADA and PASI score is still a matter of debate.Aims:The aim of this study was to evaluate serum ADA, hsCRP, SUA, and ESR in psoriatic patients and their correlation with PASI score.Patients and Methods:This study included 60 psoriatic patients divided according to PASI score into three groups (mild, moderate, and severe) each containing 20 patients. PASI score <10 was defined as mild, (10–20) moderate, and >20 severe. Twenty healthy subjects of matched age and sex were included as control. Serum ADA, hsCRP, SUA, and ESR were evaluated for patients and controls. Correlations of ADA, hsCRP, SUA, and ESR with PASI scores were done.Results:While ADA, hsCRP, SUA, and ESR showed a significant increase in psoriatic patients compared with that of the controls (P<001), they showed no significant difference between different psoriatic groups (P>0.05) and no correlations with PASI score (P>0.05). The frequency of joint affection increased with increasing severity of psoriasis (5%, 10%, and 25% in mild, moderate, and severe psoriasis, respectively).Conclusion:Serum ADA, hsCRP, SUA, and ESR showed higher levels among psoriatic patients than in controls. The increased ADA in psoriatic patients supports the role of T-cell activation and proliferative disorder in the pathogenesis of psoriasis. No significant correlations were found between these biomarkers and PASI score. Further studies are needed to validate these biomarkers as diagnostic and prognostic factors in psoriasis.

Cerebral amyloid angiopathy-related inflammation (CAARI): case report

Cerebral amyloid angiopathy-related inflammation is a new disease entity whose proper diagnosis may be difficult due to the fact that the early phase and radiological image resemble other conditions such as intracerebral haemorrhage or proliferative disorder. Also, the brain biopsy, which is an important part of the evaluation to confirm the diagnosis and rule out mimics, cannot be performed in each patient. In this paper we present the case of a 58yearold man who was correctly diagnosed with cerebral amyloid angiopathy-related inflammation (CAARI) based on the results of the histopathological examination of the brain tissue, which was possible mainly owing to the inclusion of the expansive process as the underlying cause in the initial differentiation. Further progression of the disease, despite applying treatment of increasing intensity in response to progressive deterioration of the patient's condition, revealed the multiplicity of clinical courses that a new and not easily pinpointed entity can take.

Isolated Extranodal Rosai-Dorfman Disease on 18F-FDG PET-CT Scan.

Rosai–Dorfman disease (RDD) is an uncommon proliferative histiocytic disorder. Patients usually present with painless massive cervical lymphadenopathy with fever and leukocytosis. Isolated extranodal disease is rare and more severe fibrosis, fewer histiocytosis in lesions make diagnosis more difficult as compared to nodal disease. Here, we report a case of isolated extranodal RDD on fluorodeoxyglucose (FDG) positron emission tomography-computed tomography (PET-CT) scan. FDG-avidity of RDD lesions is attributable to the intense glucose dependence of the proliferating histiocytes. PET-CT scan not only demonstrates the complete staging of the disease but also provide functional information about the disease activity to guide biopsy.

Isolated Intramedullary Spinal Rosai–Dorfman Disease in a Child: A Case Report

Rosai–Dorfman disease (RDD) is an uncommon benign histiocytic proliferative disorder commonly involving the cervical lymph nodes and, less frequently, extranodal sites. The histological hallmark of RDD is emperipolesis displayed by lesional histiocytes. Central nervous system involvement is rare and usually intracranial; intramedullary spinal involvement is even less common and, to our knowledge, rarely reported in children. Herein, we report a case of RDD with isolated intramedullary spinal involvement in a child, which, to our knowledge, is the first case reported in an infant.

Identification of a rhodanine derivative BML-260 as a potent stimulator of UCP1 expression.

Identification of proper agents to increase or activate UCP1+ cells in adipose tissues remains a potent therapeutic strategy to combat obesity. Screening systems for UCP1 activators have been previously established and allow for unbiased discovery of effective compound(s).Methods: A previously established Ucp1-2A-GFP reporter system was applied to a chemical library containing 33 phosphatase inhibitors. Compounds that can significantly activate UCP1 expression were further tested in vivo in mouse adipose tissues. Possible underlying mechanism was explored via RNA profiling, CMAP analysis, CRISPR targeting as well as inhibitor treatments.Results: We identified BML-260, a known potent inhibitor of the dual-specific phosphatase JSP-1, that significantly increased UCP1 expression in both brown and white adipocytes. BML-260 treatment also activated oxidative phosphorylation genes, increased mitochondrial activity as well as heat generation in vitro and in vivo. Mechanistic studies revealed that effect of BML-260 on adipocytes was partly through activated CREB, STAT3 and PPAR signaling pathways, and was unexpectedly JSP-1 independent.Conclusion: The rhodanine derivate BML-260 was previously identified to be a JSP-1 inhibitor, and thus was proposed to treat inflammatory and proliferative disorders associated with dysfunctional JNK signaling. This work provides evidences that BML-260 can also exert a JSP-1-independent effect in activating UCP1 and thermogenesis in adipocytes, and be potentially applied to treat obesity.

Retromastoid Approach for Posterior Fossa Skull Base Rosai-Dorfman Disease-A Rare Pathology: 3-Dimensional Operative Video.

Rosai-Dorfman disease, originally described by Juan Rosai and Ronald F. Dorfman, is a rare benign histiocytic proliferative disorder, classically presenting with massive lymphadenopathy and a self-limiting clinical course.1 Isolated intracranial skull base involvement is extremely rare and often resembles meningiomas, schwannomas, or other benign skull base lesions.2 The disease is difficult to diagnose radiographically, and tissue diagnosis with open skull base approaches has significant perioperative risks.2,3 We present the case of a 48-yr-old Caucasian male presenting with progressively worsening headaches, giddiness, hearing difficulty, and diplopia. Magnetic resonance imaging of the brain revealed T1-weighted isointense, T2-weighted hypointense, and contrast-enhancing dural-based lesion in the left cerebellopontine angle. The patient underwent maximally safe resection of the lesion through the retromastoid approach with careful preservation of the lower cranial nerve complex. The intraoperative findings of a variegated and lobulated mass adherent to the skull base, the surgical strategy of safe resection, and eventual good outcome in this patient are depicted in this 3-dimensional video presentation. The majority of patients with skull base Rosai-Dorfman disease reported in literature have had stable or regression of disease (78%) after initial conservative surgical treatment and hence aggressive surgical resection is of unproven efficacy.3 The patient has consented to depiction of his surgical video and intraoperative images in this video manuscript.

Role of ultrasound in the diagnosis and management of gestational trophoblastic disease in Rwanda Rural health facilities- A case report

Introduction Gestational trophoblastic disease (GTD) is a rare kind of proliferative disorder of trophoblastic cells which develops from the placenta in early pregnancy and the complete hydatidiform mole (CHM) sub-type which limited to endometrium is most common. It has excellent prognosis if early appropriate diagnosis and management are done. A well performed ultrasound(US) play a primordial role in the diagnosis of maternal health disorders during routine prenatal care. This helps in avoiding complications and consequently aids in achieving the objectives of the Millennium Development Goals (MDGs) in Rwanda. Aim To understand the definition of Gestational trophoblastic disease(GTD); To recognize key diagnostic findings of complete molar pregnancy on ultrasound and appropriate management in maternal follow up and To review the differential diagnosis for ultrasound findings seen with GTD. Methods The case has been referred in ultrasound unit for scan from outpatient department and follow up US was ordered and done during management period while the patient lies on a bed while operator moves the 3,5 MHz lubricated transducer of frequency with gel on the abdomino- pelvic region with full urinary bladder and Mindray ultrasound Machine has been used. Results There was a large moderately hyperechogenic mass completely filling the endometrial cavity with numerous small cystic spaces of different size. Post 5 days under treatment, anechoic area within endometrial cavity and myometrium well outlined was discharged and in 3rd medical visit after 2 weeks, US were normal. Conclusion Ultrasound is the first modality to be used in all rural health facilities for diagnosis of suspected Gestational trophoblastic disease (GTD) for better results. It is available and free of radiation. Recommendation -The US is the baseline modalities to be used in 1st trimester in pregnancy women with GTD suspicion bleeding. -All rural health facilities should have empowered and capable trained Medical imaging practitioners for appropriate carrying out the ultrasonographic investigation for better care service delivery on GTD(Medical imaging practitioners Role extension project after formal training by Prof. Kawooya).

Cytological and histopathological diagnosis of a multifocal Rosai dorfman disease with involvement of Pinna– A rare case report

Rosai-Dorfman disease (RDD) is a rare lymph proliferative disorder with nodal and extranodal involvements. We are presenting this case of Rosai dorfman disease with presentation in pinna of ear and with previous history of Rosai dorfman disease at multiple sites including lymph node. Cytological and histological examination of the submandibular lymph nodes and skin biopsy demonstrated evidences of RDD.

(-)-Epigallocatechin-3-gallate, reduces corneal damage secondary from experimental grade II alkali burns in mice

BackgroundSince recent reports have shown that (-)-Epigallocatechin-3-gallate (EGCG) could be used for treating proliferative and inflammatory disorders, we explored its use for the management of corneal chemical burns. Materials and methodsInitially, EGCG was assayed on the rabbit corneal epithelial cell line RCE1(5T5) to establish the best testing conditions, and to avoid unwanted outcomes in the experimental animals. Then, we studied its effects on cell proliferation, cell cycle progression and cell differentiation. Afterwards, we instilled EGCG in experimental grade II corneal alkali burns in mice, three times a day up to 21days, and evaluated by slit lamp examination and histological sections of corneal epithelial, corneal endothelial and stromal edema, as well as the presence of inflammatory cells and neovascularization. ResultsEGCG reduced cell growth and led to a decline in the proportion of proliferative cells in a concentration dependent manner. At 10μM, EGCG promoted cell differentiation, an effect not related with apoptosis or cytotoxicity. When 10μM EGCG was instilled in corneal alkali burns in mice three times a day up to 21days, EGCG significantly reduced corneal opacity and neovascularization. The improved clinical appearance of the cornea was associated to a controlled epithelial growth; epithelial morphology was similar to that observed in normal epithelium and contrasted with the hyperproliferative, desquamating epithelium observed in control burn wounds. EGCG reduced corneal, stromal and endothelial edema, and wound inflammation. ConclusionThis work constitutes the first evidence for the use of EGCG in the acute phase of a corneal alkali burn, representing a possible novel alternative to improve patient outcomes as an add-on therapy.

Diagnosis and clinical criteria for chronic endometritis

Currently, the urgency of the problem of chronic endometritis is of medical and social importance, since it leads to impaired reproductive function. Among the risk factors there is a predominance of intrauterine devices and inflammatory complications after childbirth and abortion. Prolonged persistence of infectious agents in the endometrium in chronic endometritis leads to marked changes in the structure and function of the tissue, causes proliferative disorders, as well as disorders in cyclic transformation. Morphofunctional damage to the endometrium is not only the cause of infertility, unsuccessful attempts of in vitro fertilization (IVF) and embryo transfer (PE), miscarriage, and a decrease in the quality of life of women due to chronic pain, dyspareunia, uterine bleeding and discharge from the genital tract. Timely and accurate diagnosis is key to the success of the restoration of reproductive function. Treatment of chronic endometritis is a complex, phased process. One of the new methods is photodynamic therapy, which leads to the development of a photochemical reaction that destroys bacterial and tumor cells, and also has an antiviral effect.

Design and Evaluation of Heterobivalent PAR1-PAR2 Ligands as Antagonists of Calcium Mobilization.

A novel class of bivalent ligands targeting putative protease-activated receptor (PAR) heteromers has been prepared based upon reported antagonists for the subtypes PAR1 and PAR2. Modified versions of the PAR1 antagonist RWJ-58259 containing alkyne adapters were connected via cycloaddition reactions to azide-capped polyethylene glycol (PEG) spacers attached to imidazopyridazine-based PAR2 antagonists. Initial studies of the PAR1-PAR2 antagonists indicated that they inhibited G alpha q-mediated calcium mobilization in endothelial and cancer cells driven by both PAR1 and PAR2 agonists. Compounds of this novel class hold promise for the prevention of restenosis, cancer cell metastasis, and other proliferative disorders.

The Critical Role of HDAC1-IRF4-Pim-2 Axis in Myeloma Cell Growth and Survival: Therapeutic Impacts of Targeting the HDAC1-IRF4-Pim-2 Axis

Multiple myeloma (MM) is a heterogeneous clonal plasma cell proliferative disorder with CRAB features. Although survival of MM patients has been greatly prolonged by recent implementation of various combinatory treatments with novel anti-MM agents, MM still remains incurable. MM cells preferentially grow and expand in the bone marrow to elicit the alteration of gene expression and thereby drug resistance. To improve the therapeutic efficacy, we urgently need to develop novel treatment strategies targeting the BM microenvironment-mediated drug resistance. The serine/threonine kinase Pim-2 is constitutively over-expressed and acts as a pro-survival mediator in MM cells. We have reported that cocultures with bone marrow stromal cells (BMSCs) or osteoclasts (OCs) further up-regulate Pim-2 expression in MM cells to confer drug resistance (Leukemia 2011, 2015). Therefore, Pim-2 appears to be an important therapeutic target to impair the BM microenvironment-mediated drug resistance in MM.Histone deacetylases (HDACs) are generally accepted to be therapeutic targets for MM treatment. However, clinical application of currently available pan-HDAC inhibitors is limited with their adverse effects induced by a non-selective HDAC inhibition. To develop safe and effective HDAC inhibitor-based treatment, the therapeutic roles of HDAC isoform-specific inhibition should be elucidated. In this regard, we have recently reported therapeutic impacts on MM cells of inhibition of class-I HDACs, especially HDAC1 and HDAC3. HDAC3-selective inhibitor BG45 induces anti-MM activity in combination with DNA methyltransferase (DNMT) inhibitor azacytidine (Leukemia 2017). In the present study, we aimed to clarify the underlying mechanisms for impairment of MM cell growth and survival by HDAC1 inhibition.We first referenced the expression of class-I HDACs using a publicly available GSE6691 data set. Among class-I HDACs, HDAC1 and HDAC3 were highly expressed in MM cells. We then knockdowned HDAC1 gene using lentiviral shRNA system in MM cell lines. The HDAC1 gene silencing induced MM cell death with caspase-3 activation, indicating the critical role of HDAC1 in MM cell growth and survival. To determine target molecules of HDAC1, we carried out RNA-sequencing with and without the HDAC1 gene silencing in RPMI 8226 cells. Among genes whose expression significantly changed by the HDAC1 knockdown (adjusted P values < 0.05, log fold change > 0.5), we focused on IRF4 together with PIM2, because MM cell has been demonstrated to addict to aberrant IRF4-c-Myc regulatory network (Nature 2008). Downregulation of IRF4 and Pim-2 by the HDAC1 knockdown was further confirmed by quantitative PCR (Q-PCR) and immunoblotting in RPMI 8226 and MM.1S cells. Treatment with the class I HDAC-selective inhibitor MS-275 (entinostat) also induced MM cell death along with reduction of IRF4 and Pim-2 expression.Since previous study has shown that IRF4 binds to PIM2 promoter in MM cells (Nature 2008), we examined whether IRF4 regulates PIM2 expression. We found that IRF4 binds to the PIM2 promoter region by analyzing ChIP-Seq data in KMS-12 cells (GSE22901). We further confirmed the binding of IRF4 on PIM2 promoter by ChIP-Q-PCR. Indeed, the IRF4 knockdown downregulated Pim-2 expression in RPMI 8226 cells. These results suggest that HDAC1 inhibition downregulates IRF4 expression, thereby transcriptionally reducing PIM2 expression in MM cells.Pim-2 expression can also be augmented by multiple signaling pathways, including HIF-1a, JAK-STAT and NF-kB-mediated ones in MM cells through the interaction with BM microenvironment. Interestingly, the Pim inhibitor SMI-16a and MS-275 cooperatively induced apoptotic cell death in MM cell lines and CD138-positive primary MM cells even in the presence of BMSCs.Taken together, our results demonstrate the critical role of the HDAC1-IRF4-Pim-2 axis in MM cell growth and survival, and provoke the novel treatment strategy targeting the HDAC1-IRF4-Pim-2 axis in MM cells. DisclosuresAnderson:Takeda Millennium: Consultancy; Gilead: Membership on an entity's Board of Directors or advisory committees; Oncopep: Equity Ownership; C4 Therapeutics: Equity Ownership; Celgene: Consultancy; Bristol Myers Squibb: Consultancy.

Durable Responses with Ipilimumab Plus Lenalidomide after Allogeneic and Autologous Stem Cell Transplantation for Patients with Lymphoid Malignancies

Background: Prevention or treatment of relapsed lymphoid malignancies after SCT requires novel strategies. We previously reported on safety and early responses of ipilimumab combined with lenalidomide in 16 treated patients (pts.) (Khouri et al. Clin Cancer Res, 2018). Here, we update the published data on a larger cohort of pts. with a longer follow-up. In addition, we define immune phenotpyes that correlated with response. Patients andMethods: Pts. with lymphoma or CLL who relapsed after alloSCT, with no active GVHD were eligible. Pts. with autologous SCT were included within 6 mos post-SCT if they were still in CR, but had high risk features for relapse. Treatment consisted of 4 total cycles of lenalidomide 10 mg PO daily for 21 days (cycles 1 and 3) alternating with ipilimumab 3 mg/kg IV on day 1 (Cycles 2 and 4). Considering the favorable safety profile in the initial patients treated, number of cycles was amended to 8 cycles in 6/2017. PBMC's from 20 pts (12 responders and 8 non-responders) were analyzed by flow cytometry. Results: Twenty-two pts. were enrolled. Autologous group (n=11): Median age was 57 yrs (range, 33-68). Histologies included diffuse-large-B-cell lymphoma (DLBCL) [n=6; including 3 with double-hit lymphoma (DHL)], mantle cell lymphoma (MCL) (n=2; one with CNS involvement), Hodgkin's disease (n=2; with persistent PET+ post-SCT), and follicular lymphoma (n=1, PIF with response to 4th line of therapy). Median time to enrollment after SCT was 3.8 months (range, 1.4-5.5). With a median follow-up duration of 23.4 months (range, 10.1- 48), median OS was not reached. Three pts. relapsed at a median of 6.7 months; 1 pt. died after developing T-cell lymph proliferative disorder 2 years after finishing treatment and ten pts. remain alive. The most common other AEs were 19 events of neutropenia (n=5, gr 4; n=2 gr 3, n=12 gr 2), two patients had thrombocytopenia gr 2, and one developed pulmonary embolism. All AEs resolved. An immune-related AE occurred in one patient (dermatitis, gr 3) after the second ipilimumab dose and resolved with steroids. AEs were similar in pts. who received 4 or 8 cycles (n=5). Allogeneic group (n=11): Median age was 55 yrs (range, 44- 66). Histologies included [Follicular (n=2), CLL (n=3), MCL (n=2), DLBCL (n=3; 2 of whom were DHL), and T-cell anaplastic lymphoma (n=1)]. Median number of therapies excluding the alloSCT was 3 (range 2-7). Two failed a prior autoSCT, one had 2 prior alloSCT, and three failed prior donor lymphocyte infusions, and one CLL pt. failed prior FCR, lenalidomide/ofatumumab, ibrutinib, idelalisib, CAR-T cell and venetoclax. Two pts. relapsed within 3 mos of their alloSCT prior to enrollment on study. One pt. was taken off study after cycle 1 of lenalidomide due to flare of previously diagnosed liver and skin GVHD, which responded to steroids. Another pt. developed chronic GVHD after cycle 4 which precluded treatment with the pre-planned 8 cycles. No other cases of GVHD were noted. ORR rate was 73%. Five (45%) pts. had CRs (four of which were durable at 14+, 32+, 33+ and 34+ months; including the CLL pt. who failed small molecule inhibitors and CAR-T), and 3 (27%) had PR. With a median follow-up time of 30.8 mos (range, 3-45.1), 9 (82%) pts. remain alive. One PR pt. died secondary to cardiac complications after a hip replacement; and 1 died of progression. AEs included eight episodes of neutropenia (n=2, gr 4; n=2, gr 3; n =4, gr 2), anemia gr 2 (n=1), thrombocytopenia gr 2 (n=1), diarrhea (gr 2; n=1), nausea (gr 2, n=1), headache (gr 2; n=1), hypertension (gr 2; n=1), hypoalbuminemia (gr 2; n=1). All AEs resolved. Immune monitoring of 20 transplant pts showed a Th1 type anti-tumor immune response in responding pts. In the responders, there was a higher frequency of CD4+ICOS+PD-1+ and CD8+PD+1 T effector cells at baseline when compared to non-responding pts. In contrast, the non-responders had a Th2 type response with a higher frequency of CD4+GATA3+ T effector memory cells at baseline when compared to responders (Figure). Conclusions: Follow-up results demonstrate better than expected response rates that are durable in pts. with lymphoid malignancies who relapsed after alloSCT. Continuous remission duration was also observed after autologous SCT. Immune monitoring analysis suggests that CD4+GATA3+ T cells could be a potentially valuable biomarker for stratification of pts. for lenalodimide+ipilimumab combination therapy. DisclosuresJabbour:novartis: Research Funding.

Exosomes Play a Key Role in Multiple Myeloma Bone Disease and Tumor Development

Multiple Myeloma (MM) is an often incurable plasma cell proliferative disorder, representing about 10% of all hematologic malignancies. Osteolysis is one of the hallmarks of this malignancy, meaning that almost every patient will manifest with an osteolytic lesion during their disease course, resulting in increased morbidity and pain with ultimately a severe impact on the quality of life.The development and progression of MM is largely dependent on the bone marrow (BM) microenvironment wherein communication through different factors including extracellular vesicles (EVs) takes place. This crosstalk not only leads to drug resistance but also to the development of osteolysis. Targeting vesicle secretion could therefore simultaneously ameliorate drug response and bone disease.Here we examined the effects of MM exosomes on different aspects of osteolysis using the 5TGM1 murine model. This syngeneic murine model highly mimics human MM disease and presents with typical MM characteristics such as osteolysis, angiogenesis and a serum M-spike.We first investigated the effects of 5TGM1 small EVs or exosomes, sized 50-120nm in diameter, on osteoclasts and osteoblasts in vitro. 5TGM1 exosomes were able to enhance the resorptive active of osteoclasts. In contrast, these exosomes induced apoptosis in pre-osteoblasts while also blocking their differentiation to mature osteoblasts. RT-PCR showed a downregulation of Runx2, Osterix and Collagen 1A1 expression, while DKK-1 expression was upregulated. Mechanistically, we confirmed the presence of DKK-1 on the 5TGM1 exosomes, which led to a downregulation of the Wnt pathway in osteoblasts.In vivo, we uncovered that 5TGM1 exosomes could induce osteolysis in a similar pattern as the MM cells themselves. We injected C57BL/KalwRij intravenously during three weeks with 5TGM1 exosomes, and analyzed the femurs by micro-computed tomography. These mice had a significantly lower trabecular bone volume, as the result of a lower trabecular number combined with a higher trabecular separation.Next, we inhibited exosome secretion in 5TGM1-inoculated mice to prevent bone loss and increase sensitivity to bortezomib. For blocking exosome secretion we used the neutral sphingomyelinase inhibitor GW4869. This increased cortical bone volume and decreased bone resorption markers (C-terminal telopeptide of collagen type I) without significantly affecting tumor load. This indicates that inhibiting exosome secretion in the MM microenvironment has a protective effect on myeloma bone disease, not associated with effects on tumor load. Furthermore, blocking exosome secretion by GW4869 also sensitized the myeloma cells to bortezomib, leading to a strong anti-tumor response in vivo when GW4869 and bortezomib were combined.Altogether, our results indicate a key role for exosomes in the myeloma BM microenvironment and suggest a novel therapeutic target for anti-myeloma therapy. DisclosuresNo relevant conflicts of interest to declare.