Low Molecular Mass Polypeptides Research Articles

Candida parapsilosis: Heterogeneous and strain-specific expression of secreted aspartic proteases (Sapp1 and Sapp2).

The increasing prevalence of Candida parapsilosis as a causative agent of fungal infections underscores the need to comprehensively understand its virulence factors. Secreted aspartic proteases (Saps) play a significant role in adhesion events, promoting biofilm formation, causing tissue damage and evading the host's immune response. In C. parapsilosis, three Saps have been identified: Sapp1, Sapp2 and Sapp3. The present study investigates the production dynamics of Sapp1 and Sapp2 across 10 clinical isolates of C. parapsilosis using various approaches. Each fungal isolate demonstrated the capability to utilize bovine serum albumin (BSA) as the sole nitrogen source, as evidenced by its degradation in a cell-free culture medium, forming low molecular mass polypeptides. Interestingly, the degradation of different proteinaceous substrates, such as BSA, human serum albumin (HSA), gelatin and hemoglobin, was typically isolate-dependent. Notably, higher proteolysis of HSA compared to BSA, gelatin and hemoglobin was observed. A quantitative assay revealed that the cleavage of a peptide fluorogenic substrate (cathepsin D) was isolate-specific, ranging from 44.15 to 270.61 fluorescence arbitrary units (FAU), with a mean proteolysis of 150.7 FAU. The presence of both Sapp1 and Sapp2 antigens on the cell surface of these fungal isolates was confirmed through immunological detection employing specific anti-Sapp1 and anti-Sapp2 antibodies. The surface levels of Sapp1 were consistently higher, up to fourfold, compared to Sapp2. Similarly, higher levels of Sapp1 than Sapp2 were detected in fungal secretions. This study provides insights into the dynamic expression and regulation of Sapps in C. parapsilosis, highlighting a known virulence factor that is considered a potential target for drug development against this increasingly prominent pathogen.

LMP2 and TAP2 impair tumor growth and metastasis by inhibiting Wnt/β-catenin signaling pathway and EMT in cervical cancer

BackgroundThe roles of low molecular mass polypeptide 2 (LMP2) and transporter-associated with antigen processing (TAP2) in tumorigenesis are controversial. Here we aimed to explore the effect of LMP2 and TAP2 on the oncogenesis and metastasis of cervical cancer cells.MethodsThe expressions of LMP2 and TAP2 in cervical cancer and normal tissues were determined by qPCR. Plate colony formation, cell counting kit-8 analysis and in vivo tumor xenograft assays were used to detect the tumor growth. Wound healing and transwell assays were used to detect the metastasis of cervical cancer. Gelatin zymography and western blotting assays were used to detect the effect of LMP2 and TAP2 on the EMT and Wnt/β-catenin pathway in cervical cancer cells.ResultsIn the present study, we reported that LMP2 and TAP2 levels were overexpressed in cervical cancer. Overexpression of LMP2 and TAP2 impaired the proliferation of Hela cells. In vivo studies substantiated that LMP2 and TAP2 antagonized tumor growth. Likewise, LMP2 and TAP2 overexpression decreased the migration and invasion ability of Hela cells by regulating the process of epithelial-mesenchymal transition (EMT). Mechanically, LMP2 and TAP2 subverted the protein abundance of Wnt1 and β-catenin, thereby downregulating their downstream targets Cyclin D1 and c-Myc. In addition, Wnt1 overexpression partially rescued the observed consequences of ectopic expression of LMP2 and TAP2 in cervical cancer cells. Taken together, our study revealed that LMP2 and TAP2 suppress the oncogenesis and metastasis of cervical cancer cells by Wnt/β-catenin pathway and altering EMT.ConclusionLMP2 and TAP2 may inhibit the oncogenesis and metastasis of cervical cancer cells by inhibiting the process of EMT and the Wnt/β-catenin signaling pathway, which may provide important insight into prospective targets for the treatment of cervical cancer.

Emulsifying Capacity of Cowpea Protein Isolates. Effect of Thermal and Hydrolytic Treatment.

In this work, modifications due to the effect of thermal treatments (TT 70 and 90°C) and partial hydrolysis by digestion with alcalase (LH) on the emulsifying properties of cowpea protein isolates (CPIs) extracted at pH 8 and 10 were analyzed. In addition, the influence of protein concentration [0.1 and 1% (w/v)] was evaluated. Emulsions (O:W) were prepared and particle size, stability, interfacial composition, and microstructure were studied. Fresh emulsions formulated with TT CPIs presented lower values of volume-weighted mean droplet size (D4.3), with the increase in temperature and treatment time, compared to the untreated CPIs. After seven days of storage, D4.3 and the indexes of flocculation (FI) and coalescence (CI) increased, mainly at 90°C. On the other hand, the emulsions with LH CPIs presented lower D4.3 values compared to all the conditions tested, remaining unchanged during the storage time. The destabilization process in the TT CPIs emulsions revealed coalescence at 0.1% (w/v) and cremated-flocculation at 1% (w/v). The presence of polypeptides of low molecular mass (MM) at the interface would be responsible for the better stability found in emulsions with LH CPIs, compared to those formulated with untreated and TT CPIs. Increasing the protein concentration resulted in a significant improvement of all emulsifying properties.

Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography

Leptospirosis is an emerging zoonosis that affects humans and animals. Immunochromatography rapid test is widely used for early diagnosis of leptospirosis, but with low sensitivity and specificity.To evaluate Leptospira interrogans insoluble fraction as a potential antigen source for lateral flow immunochromatography.Insoluble fraction derived from the crude bacterial extract was obtained by serial centrifugation. The polypeptide profile was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Immune reactivity of this fraction was assessed by Western Blotting and lateral flow immunochromatography (LFI). It was tested 160 microagglutination test (MAT)-positive sera from patients in the acute phase, 100 MAT-negative sera from patients with acute febrile illness, and 45 patients with other infectious diseases.There was a predominance of low molecular mass-polypeptide bands, ranging from 2 to 37 kDa. The antibody reactivity of theses polypeptides was found to range from 13-50%, especially between 10 and 38 kDa. Among MAT-positive sera of patients with leptospirosis in the acute phase, 97% were also positive in LFI, indicating high sensitivity. Among MAT-negative sera, all were negative in LFI, indicating high specificity. Only 2% of cross-reactivity was detected.The insoluble fraction can be a valuable antigen source for development of point-of-care diagnosis test for leptospirosis.

PR-957 Suppresses Th1 and Th17 Cell Differentiation via Inactivating PI3K/AKT Pathway in Alzheimer’s Disease

PR-957 [low molecular mass polypeptide (LMP)-7 selective inhibitor] regulates T helper (Th) cell differentiation and inflammatory response in multiple neurological diseases. Hence, this study aimed to explore the effect of PR-957 on Th1/Th2/Th17 cell differentiation, therapeutic efficacy and its potential mechanisms in Alzheimer’s disease (AD). The LMP7 expressions in peripheral blood mononuclear cells from 30 AD patients and 30 healthy controls (HC) were detected. PR-957 was added for the incubation of naive cluster of differentiation (CD)4+ T cells from AD patients, then SC79 [phosphorylated protein kinase B (pAKT) agonist] was added. LMP7, Th1 cells, and Th17 cells were upregulated, while Th2 cells were downregulated in AD patients compared to HC. Also, LMP7 was positively related to Th1 cells and Th17 cells, but it did not correlate with Th2 cells in AD patients. PR-957 treatment downregulated Th1 cells, Th17 cells, and their secreted cytokines as well as phosphorylated phosphoinositide 3-kinase (pPI3K)/PI3K and pAKT/AKT expressions in AD CD4+ T cells. SC79 addition upregulated pAKT/AKT expression, Th1 cells, and Th17 cells, while downregulated Th2 cells; also SC79 could alleviate the effect of PR-957 on regulating PI3K/AKT pathway and Th1, Th2, and Th17 cell differentiation in AD CD4+ T cells. Furthermore, PR-957 attenuated cognitive impairment and neurofibrillary tangle; also it inhibited Th17 cell differentiation and PI3K/AKT pathway in the brain and spleen of AD mice. In conclusion, PR-957 suppresses Th1 and Th17 cell differentiation, attenuates neural injury and improves cognitive function via inactivating PI3K/AKT pathway in AD.

Inhibition of immunoproteasome subunit low molecular mass polypeptide 7 with ONX-0914 improves hypoxic-ischemic brain damage via PI3K/Akt signaling.

The immunoproteasome subunit low molecular mass polypeptide 7 (LMP7) leads to brain injuries, such as autoimmune neuritis and ischemic stroke, by activating inflammation. However, the roles and mechanisms of LMP7 in hypoxic-ischemic brain damage (HIBD) remain unclear. This study explored these issues in a rat model of HIBD. Pathology was evaluated using hematoxylin-eosin staining. LMP7 expression was detected using western blot analysis, reverse transcription-quantitative PCR (RT-qPCR), and immunohistochemical staining. The presence of proinflammatory cytokines, including tumor necrosis factor-a, interleukin-6, and interleukin-1β, was tested using ELISA and RT-qPCR. Behavioral performance was evaluated using a short-term neurological function score and the Morris water maze test. Compared to those in the Sham group, the HIBD group exhibited obvious upregulated LMP7 and pro-inflammatory cytokine levels. HIBD rats exhibited severe pathological and behavioral damage. LMP7 inhibition with ONX-0914 reduced proinflammatory cytokine expression, attenuated pathological damage, and enhanced behavioral performance of rats with HIBD. Inhibition of phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signaling with LY29400 increased LMP7 expression and abolished the protective effects of ONX-0914 in HIBD rats. Our findings indicate that LMP7 aggravates brain injury by triggering inflammatory responses in HIBD rats. LMP7 inhibition with ONX-0914 exerts protective effects on HIBD rats, possibly via PI3K/Akt signaling.

HDAC6-Selective Inhibitor Overcomes Bortezomib Resistance in Multiple Myeloma.

Although multiple myeloma (MM) patients benefit from standard bortezomib (BTZ) chemotherapy, they develop drug resistance, resulting in relapse. We investigated whether histone deacetylase 6 (HDAC6) inhibitor A452 overcomes bortezomib resistance in MM. We show that HDAC6-selective inhibitor A452 significantly decreases the activation of BTZ-resistant markers, such as extracellular signal-regulated kinases (ERK) and nuclear factor kappa B (NF-κB), in acquired BTZ-resistant MM cells. Combination treatment of A452 and BTZ or carfilzomib (CFZ) synergistically reduces BTZ-resistant markers. Additionally, A452 synergizes with BTZ or CFZ to inhibit the activation of NF-κB and signal transducer and activator of transcription 3 (STAT3), resulting in decreased expressions of low-molecular-mass polypeptide 2 (LMP2) and LMP7. Furthermore, combining A452 with BTZ or CFZ leads to synergistic cancer cell growth inhibition, viability decreases, and apoptosis induction in the BTZ-resistant MM cells. Overall, the synergistic effect of A452 with CFZ is more potent than that of A452 with BTZ in BTZ-resistant U266 cells. Thus, our findings reveal the HDAC6-selective inhibitor as a promising therapy for BTZ-chemoresistant MM.

LMP7 inhibits the activation of NLRP3 inflammasome through interaction with NLRP3

The innate immune system recognizes pathogen-associated molecular patterns (PAMPs) and damage-associated molecular patterns (DAMPs) by coding pattern recognition receptors (PRRs). As a well-known inflammasome, NLRP3 plays an essential role in helping the host immune response and driving antiviral processes. Low molecular mass polypeptide (LMP7) is a critical component of the immunoproteasome that participates in host antiviral activity, as well as T cell function and development. This is the first study to report the direct interaction between LMP7 and NLRP3. Also, LMP7 was found to inhibit the activation of the NLRP3 inflammasome, which is of great significance in exploring the role of the immune proteasome in regulating the activation of NLRP3.

LMP2 Inhibitors as a Potential Treatment for Alzheimer's Disease.

The immunoproteasome (iP), an inducible proteasome variant harboring three immunosubunits, low molecular mass polypeptide-2 (LMP2), multicatalytic endopeptidase complex subunit-1, and low molecular mass polypeptide-7 (LMP7), is involved in multiple facets of inflammatory responses. We recently reported that YU102, a dual inhibitor of the iP subunit LMP2 and the constitutive proteasome catalytic subunit β1, ameliorates cognitive impairments in mouse models of Alzheimer's disease (AD) independently of amyloid deposits. To investigate whether inhibition of LMP2 is sufficient to improve the cognitive functions of AD mice, here we prepared 37 YU102 analogues and identified a potent LMP2 inhibitor DB-310 (28) (IC50: 80.6 nM) with improved selectivity and permeability in cells overexpressing ABCB1 transporters. We show that DB-310 induces suppression of IL-1α production in microglia cells and improves cognitive functions in the Tg2576 transgenic mouse model of AD. This study supports that inhibition of LMP2 is a promising therapeutic strategy for treatment of AD.

Characteristics of Leiomyosarcoma: Induction of Hematogenous Metastasis by Isolated Uterine Mesenchymal Tumor Stem-like Cells.

Uterine leiomyosarcoma (Ut-LMS) is a refractory tumor that repeatedly recurs with hematogenous metastasis, which may be due to the presence of drug-resistant tumor stem cells. Its treatment is limited to surgical procedures. We previously reported that Ut-LMS spontaneously developed in mice deficient in the proteasome component low-molecular mass polypeptide 2 (LMP2). We showed that LMP2 expression was significantly attenuated specifically in human Ut-LMS. The aim of this study was to investigate the role of LMP2 in hematogenous metastasis using xenograft models with tumor stem-like cells. We isolated tumor stem-like cells from LMP2-negative primary human Ut-LMS cells established from a human Ut-LMS tissue using the side population (SP) procedure. These cells were used to develop xenograft models with tumor stem-like cells. Human Ut-LMS stem-like cells showed stronger hematogenous metastatic potential than normal Ut-LMS cells. Tumor stem-like cells also had the potential to differentiate into vascular endothelial cells through VEGF-A signaling. These results reflect frequent hematogenous metastasis by human Ut-LMS in clinical settings, and may lead to the development of treatments that inhibit hematogenous metastasis in Ut-LMS.

Required Immunoproteasome Subunit Inhibition Profile for Anti-Inflammatory Efficacy and Clinical Candidate KZR-616 ((2 S,3 R)- N-(( S)-3-(Cyclopent-1-en-1-yl)-1-(( R)-2-methyloxiran-2-yl)-1-oxopropan-2-yl)-3-hydroxy-3-(4-methoxyphenyl)-2-(( S)-2-(2-morpholinoacetamido)propanamido)propenamide).

Selective immunoproteasome inhibition is a promising approach for treating autoimmune disorders, but optimal proteolytic active site subunit inhibition profiles remain unknown. We reveal here our design of peptide epoxyketone-based selective low molecular mass polypeptide-7 (LMP7) and multicatalytic endopeptidase complex subunit-1 (MECL-1) subunit inhibitors. Utilizing these and our previously disclosed low molecular mass polypeptide-2 (LMP2) inhibitor, we demonstrate a requirement of dual LMP7/LMP2 or LMP7/MECL-1 subunit inhibition profiles for potent cytokine expression inhibition and in vivo efficacy in an inflammatory disease model. These and additional findings toward optimized solubility led the design and selection of KZR-616 disclosed here and presently in clinical trials for treatment of rheumatic disease.

Do the two transcription factors form a positive feedback amplifier circuit in their common fight against pathogens?

Do the two transcription factors form a positive feedback amplifier circuit in their common fight against pathogens?

Amelioration of autoimmunity with an inhibitor selectively targeting all active centres of the immunoproteasome.

Multicatalytic endopeptidase complex-like-1 (β2i), low molecular mass polypeptide (LMP) 2 (β1i) and LMP7 (β5i) are the proteolytically active subunits of the immunoproteasome, a special type of proteasome mainly expressed in haematopoietic cells. Targeting LMP7 has been shown to be therapeutically effective in preclinical models of autoimmune diseases. In this study, we investigated the selectivity and biological activity of LU-005i, a recently described inhibitor of the immunoproteasome. The specificity of LU-005i and other immunoproteasome-selective inhibitors was characterized using fluorogenic peptide substrates. The effect of proteasome inhibition on cytokine release was investigated in endotoxin-stimulated mouse splenocytes or human peripheral blood mononuclear cells (PBMCs). The effect of proteasome inhibition on inflammatory bowel disease in the dextran sulfate sodium (DSS)-induced colitis model was assessed by measuring weight loss and colon length. LU-005i is the first human and mouse immunoproteasome-selective inhibitor that targets all three proteolytically active immunoproteasome subunits. LU-005i inhibited cytokine secretion from endotoxin-stimulated mouse splenocytes or human PBMCs. Furthermore, differentiation of naïve T helper cells to T helper 17 cells was impaired in the presence of LU-005i. Additionally, LU-005i ameliorated DSS-induced colitis. This study with a novel pan-immunoproteasome inhibitor substantiates that the immunoproteasome is a promising drug target for the treatment of inflammatory diseases and that exclusive inhibition of LMP7 is not necessary for therapeutic effectiveness. Our results will promote the design of new generations of immunoproteasome inhibitors with optimal therapeutic efficacy for clinical use in the treatment of autoimmunity and cancer.

Trichosporon asahii secretes a 30-kDa aspartic peptidase

Trichosporon asahii is a fungal opportunistic pathogen that causes superficial and deep-seated infections presenting high mortality. Very little is known about the virulence attributes produced by this fungus. Herein, aspartic peptidase production was identified in Brazilian clinical isolates of T. asahii by different methodologies. Initially, T. asahii strain 250 (from skin lesion) was inoculated in both liquid and solid culture media containing bovine serum albumin (BSA) as the sole nitrogenous source. A translucent halo around the fungal colony was observed from the 5th day of culture. The cell-free culture supernatant revealed that soluble BSA was hydrolyzed along the growth, generating low molecular mass polypeptides as observed by electrophoresis. Subsequently, the secretions from four clinical strains of T. asahii were analyzed by BSA-SDS-PAGE and a single proteolytic band of 30-kDa was detected under acidic pH at 37°C. The secreted aspartic peptidase of T. asahii efficiently cleaved the cathepsin D peptide substrate, but not the substrates with specificity to HIV-1 peptidase and rennin. The capability to cleave either cathepsin D substrate in a fluorogenic assay or BSA immobilized within a gel matrix varied according to the T. asahii isolate. T. asahii extracellular peptidase activity was strongly inhibited by pepstatin A and HIV peptidase inhibitors, classifying it as an aspartic-type peptidase. Human serum albumin, mucin, non-immune immunoglobulin G and gelatin induced, in different levels, the secretion of this aspartic peptidase. With these results, T. asahii must be included in the list of many human fungal opportunistic pathogens able to secrete an aspartic-type peptidase.

Discovery of Highly Selective Inhibitors of the Immunoproteasome Low Molecular Mass Polypeptide 2 (LMP2) Subunit.

Building upon the success of bortezomib (VELCADE) and carfilzomib (KYPROLIS), the design of a next generation of inhibitors targeting specific subunits within the immunoproteasome is of interest for the treatment of autoimmune disease. There are three catalytic subunits within the immunoproteasome (low molecular mass polypeptide-7, -2, and multicatalytic endopeptidase complex subunit-1; LMP7, LMP2, and MECL-1), and a campaign was undertaken to design a potent and selective LMP2 inhibitor with sufficient properties to allow for sustained inhibition in vivo. Screening a focused library of epoxyketones revealed a series of potent dipeptides that were optimized to provide the highly selective inhibitor KZR-504 (12).

Immunoproteasome subunit deficiency has no influence on the canonical pathway of NF-κB activation.

Activation of the pro-inflammatory transcription factor NF-κB requires signal-induced proteasomal degradation of the inhibitor of NF-κB (IκB) in order to allow nuclear translocation. Most cell types are capable of expressing two types of 20S proteasome core particles, the constitutive proteasome and immunoproteasome. Inducible under inflammatory conditions, the immunoproteasome is mainly characterized through an altered cleavage specificity compared to the constitutive proteasome. However, the question whether immunoproteasome subunits affect NF-κB signal transduction differently from constitutive subunits is still up for debate. To study the effect of immunoproteasomes on LPS- or TNF-α-induced NF-κB activation, we used IFN-γ stimulated peritoneal macrophages and mouse embryonic fibroblasts derived from mice deficient for the immunoproteasome subunits low molecular mass polypeptide (LMP) 2, or LMP7 and multicatalytic endopeptidase complex-like 1 (MECL-1). Along the canonical signaling pathway of NF-κB activation no differences in the extent and kinetic of IκB degradation were observed. Neither the nuclear translocation and DNA binding of NF-κB nor the production of the NF-κB dependent cytokines TNF-α, IL-6, and IL-10 differed between immunoproteasome deficient and proficient cells. Hence, we conclude that immunoproteasome subunits have no specialized function for canonical NF-κB activation.

Three Gene Signature for Predicting the Development of Hepatocellular Carcinoma in Chronically Infected Hepatitis C Virus Patients.

Hepatitis C virus (HCV) is the leading cause of liver fibrosis and hepatocellular carcinoma (HCC). At present, there is no predictive biomarker for the patients at high risk of developing HCC. In this study, we examined the association between single-nucleotide polymorphisms (SNPs) in 3 innate immunity genes [2'-5'oligoadenylate synthetase 1 (OAS1) rs10774671, interleukin 28B (IL28B) rs12979860, and low molecular mass polypeptide 7 (LMP-7) at codon 49] besides cytomegalovirus (CMV) coinfection and susceptibility to HCC in genotype 4 (GT4) chronically infected Egyptian patients. SNPs were determined using restriction fragment length polymorphism analysis in DNA from HCC patients (n = 34) and compared with either controls (n = 70) or patients with early grades of liver fibrosis (n = 49). Our results demonstrated that patients bearing the genetic combination consisting of LMP-7 CA/AA [OR 4.75, 95% confidence interval (CI) 1.443-15.631, P = 0.007] and IL28B rs12979860 CT/TT (OR 6.00, 95% CI 1.603-22.455, P = 0.004) and positive for CMV viremia (OR 3.11, 95% CI 1.151-8.412, P = 0.02) were more likely to have HCC. However, OAS1 rs10774671 does not seem to contribute to the development of HCC. Binary regression analysis indicated that HCC risk significantly increases with the presence of each unfavorable genotype (LMP-7 CA/AA, IL28B rs12979860 CT/TT), when accompanied by the existence of CMV coinfection (probability of HCC risk is 0.8 for combined factors versus 0.14, 0.07, and 0.07 for individual factor IL28B, LMP-7, and CMV; respectively). These data suggest that the 2 SNPs and the coinfection in concert have potential in predicting the risk of HCC development in patients infected with HCV GT4.

Drought-induced changes in photosynthetic apparatus and antioxidant components of wheat (Triticum durum Desf.) varieties

Water deficit is a key factor influencing the yield and quality of crops. In the present study, the photosynthetic responses by means of chlorophyll fluorescence of chloroplasts, thylakoid membrane proteins, and antioxidant components were analyzed in wheat (Triticum durum Desf.) plants differing in their tolerance to drought. Two durum winter wheat varieties, Barakatli 95 (drought tolerant) and Garagylchyg 2 (drought sensitive) were grown under field well-watered and drought conditions. It was found that contents of the PS I core (CPI) with Mr of 123 kD and apoprotein P700 with Mr of 63 kD were relatively higher in Barakatli 95 variety under drought stress compared with the control plants. Synthesis of α- and β-subunits of CF1 ATP-synthase complex with Mr of 55 and 53.5 kD also slightly increased in the tolerant Barakatli 95 and decreased in the drought sensitive variety Garagylchyg 2. A decrease in the intensity of 30 kD band and a significant increase were found in the content of the 25-16 kD region in Garagylchyg 2 variety. The synthesis of 60 kD and content of low molecular mass polypeptides (21.5 and 12 kD) were increased in the tolerant genotype Barakatli 95. The intensity of peaks at 687, 695, and 742nm considerably increases in the fluorescence spectra (77K) of chloroplasts isolated from the sensitive variety Garagylchyg 2, and there is a stimulation of the ratio of fluorescence band intensity F687/F740. At the same time, higher level of glycine betaine was found in the drought tolerant variety compared with the control one throughout the different periods of growth.

Low Molecular Mass Polypeptide 7 Single Nucleotide Polymorphism is Associated with the Progression of Liver Fibrosis in Patients Infected with Hepatitis C Virus Genotype 4.

The hepatitis C virus (HCV) is a leading cause of liver disease and the consequent complications of cirrhosis. However, there is no precise biomarker to predict the patients at high risk of developing progressive disease. We showed previously the implication of low molecular mass polypeptide-7 (LMP-7) single nucleotide varia- tions in the response to combined pegylated IFN and ribavirin therapy in patients infected with HCV genotype 4. In this study, we examined the possible relationship between LMP-7 genotypes and both the degree of liver fibrosis and the transition from end stage of fibrosis to hepatocellular carcinoma (HCC). LMP-7 single nucleotide variation at codon 49 (substitution from A to C) was determined using restriction fragment length polymorphism analysis in leucocyte DNA from healthy subjects (n = 36) and HCV-chronically infected patients of genotype 4 either with different grades of liver fibrosis (n = 77) or with hepatocellular carci- noma (n = 25). Chronic HCV-infected patients having liver fibrosis were categorized into two groups based on the degree of fibrosis, early fibrosis (F0-F2, n = 37) and late fibrosis (F3-F4, n = 40). Our results demonstrated that patients with the LMP-7 CA/AA genotypes were more likely to have advanced fibrosis scores than those bearing the CC genotype, although LMP-7 polymorphism does not seem to contribute to the progression from the late stage of fibrosis to hepatocellular carcinoma. These results suggest that LMP-7 polymorphism is a candidate prognostic marker in mathematical models designed for predicting the progression of HCV-related liver disease. Nevertheless, the mechanism whereby LMP-7 leads to the progression of liver fibrosis remains to be determined.

Weekly Carfilzomib with Dexamethasone for Patients with Relapsed or Refractory Multiple Myeloma: Updated Results from the Phase 1/2 Study Champion-1 (NCT01677858)

Introduction: Carfilzomib is an irreversible proteasome inhibitor that is approved as a single agent in the United States and other countries for the treatment of relapsed and refractory multiple myeloma (MM); carfilzomib in combination with lenalidomide (LEN) and dexamethasone is also approved in the United States for the treatment of relapsed MM. The approved dose and schedule of carfilzomib is a twice-weekly, 10-min intravenous (IV) infusion on days 1, 2, 8, 9, 15, and 16 of 28-day cycles (starting dose: 20 mg/m2 [days 1 and 2 of cycle 1]; escalated to a target dose of 27 mg/m2 thereafter). Here we present updated results from the multicenter, phase 1/2 study CHAMPION-1 (NCT01677858), which evaluated the safety and efficacy of once-weekly carfilzomib with dexamethasone (Kd) in patients with relapsed or refractory MM.Methods: Patients with relapsed or refractory MM (1-3 prior lines of therapy) were eligible. Patients received carfilzomib as a 30-min IV infusion on days 1, 8, and 15 of 28-day cycles. The phase 1 portion of the study utilized a standard 3+3 dose-escalation scheme. All patients received carfilzomib at 20 mg/m2 on day 1 of cycle 1; patients received 45, 56, 70, or 88 mg/m2 beginning on day 8 of cycle 1 in successive dose-level cohorts until the maximum tolerated dose (MTD) was reached. All patients received dexamethasone 40 mg (IV or oral administration) on days 1, 8, 15, and 22 of cycles 1-8; dexamethasone was omitted on day 22 in cycles ≥ 9. In the phase 2 portion, patients received carfilzomib at the MTD (carfilzomib dose of 20 mg/m2 on cycle 1, day 1; escalating to the MTD for subsequent doses) and dexamethasone at the same dose and schedule. Kd was administered until unacceptable toxicity or disease progression. The primary objective of the phase 1 portion was to determine the MTD of carfilzomib in the Kd regimen; the primary objective of the phase 2 portion was to determine the overall response rate (ORR [≥partial response]). Blood samples were collected for pharmacokinetic and pharmacodynamic analyses.Results: A total of 27 patients were enrolled in phase 1; the MTD of carfilzomib was determined to be 70 mg/m2. Results are presented for all patients treated with Kd at the carfilzomib MTD in both the phase 1b (n=15) and phase 2 (n=89) portions of the study. Among these 104 patients, median patient age was 68.5 years (range, 41-88). Patients received a median of 1 prior line of therapy (range, 1-3); 83% of patients had received prior bortezomib (BTZ), 49% of patients were BTZ-refractory, 27% were LEN-refractory, and 16% were refractory to both BTZ and LEN. Median carfilzomib treatment duration was 7.7 months (range, 0.03-24.2). The ORR was 77% (95% confidence interval [CI]: 68%-85%); the clinical benefit rate (≥minimal response) was 84% (95% CI: 75%-90%). Kaplan-Meier median progression-free survival was 12.6 months (95% CI: 9.0-not estimable). Twelve patients (12%) discontinued treatment due to an adverse event. The most common adverse events of any grade and of grade ≥3 are shown in the Table. Five patients died on study: 1 patient each had cause of death reported as disease progression, acute respiratory distress syndrome, acute respiratory failure, acute kidney injury, and cardiopulmonary arrest. The mean area under the curve and maximum concentration following a 70-mg/m2 carfilzomib dose was 1050 ng×h/mL and 2510 ng/mL, respectively. At 1 hour post dosing of carfilzomib 70 mg/m2, the activity of the predominant chymotrypsin-like proteasome catalytic subunit in peripheral blood mononuclear cells (ie, low molecular mass polypeptide 7) was strongly inhibited (97% inhibition as determined by an enzyme-linked immunosorbent assay [ProCISE]; 93% inhibition as determined by a fluorogenic substrate assay).Conclusions: CHAMPION-1 is the first clinical study to evaluate carfilzomib on a weekly dosing schedule. Once-weekly carfilzomib (70 mg/m2) with dexamethasone demonstrated acceptable safety and tolerability with promising efficacy for patients with relapsed or refractory MM. The dose and schedule of carfilzomib used in the CHAMPION-1 study (20/70 mg/m2) is currently being compared with the regulatory-approved carfilzomib dose and schedule (20/27 mg/m2 administered twice-weekly) in the ongoing, phase 3, superiority study ARROW (NCT02412878). [Display omitted] DisclosuresLyons:Amgen: Consultancy, Honoraria; Insyte: Consultancy, Honoraria; BMS: Consultancy, Honoraria; Novartis: Consultancy, Honoraria. Harb:Onyx Pharmaceuticals: Consultancy. Boccia:Incyte Corporation: Honoraria. Moss:Onyx: Honoraria, Research Funding. Rifkin:Onyx Pharmaceuticals: Consultancy, Membership on an entity's Board of Directors or advisory committees; Millennium Pharmaceuticals, Inc., Cambridge, MA, USA, a wholly owned subsidiary of Takeda Pharmaceutical Company Limited: Consultancy, Membership on an entity's Board of Directors or advisory committees; Celgene: Consultancy, Membership on an entity's Board of Directors or advisory committees. Schupp:Amgen: Employment, Equity Ownership. Dixon:Onyx/Amgen: Employment, Equity Ownership. Ou:Onyx/Amgen: Employment, Equity Ownership. Anderl:Onyx/Amgen: Employment, Equity Ownership. Berdeja:Abbvie: Research Funding; BMS: Research Funding; Acetylon: Research Funding; Celgene: Research Funding; Takeda: Research Funding; Onyx: Research Funding; Janssen: Research Funding; Novartis: Research Funding; MEI: Research Funding; Array: Research Funding; Curis: Research Funding.