SOX11 augments BCR signaling to drive MCL-like tumor development.

Mantle cell lymphoma (MCL) is characterized by increased B-cell receptor (BCR) signaling, and BTK inhibition is an effective therapeutic intervention in MCL patients. The mechanisms leading to increased BCR signaling in MCL are poorly understood, as mutations in upstream regulators of BCR signaling such as CD79A, commonly observed in other lymphomas, are rare in MCL. The transcription factor SOX11 is overexpressed in the majority (78% to 93%) of MCL patients and is considered an MCL-specific oncogene. So far, attempts to understand SOX11 function in vivo have been hampered by the lack of appropriate animal models, because germline deletion of SOX11 is embryonically lethal. We have developed a transgenic mouse model (Eµ-SOX11-EGFP) in the C57BL/6 background expressing murine SOX11 and EGFP under the control of a B-cell-specific IgH-Eµ enhancer. The overexpression of SOX11 exclusively in B cells exhibits oligoclonal B-cell hyperplasia in the spleen, bone marrow, and peripheral blood, with an immunophenotype (CD5+CD19+CD23-) identical to human MCL. Furthermore, phosphocytometric time-of-flight analysis of the splenocytes from these mice shows hyperactivation of pBTK and other molecules in the BCR signaling pathway, and serial bone marrow transplant from transgenic donors produces lethality with decreasing latency. We report here that overexpression of SOX11 in B cells promotes BCR signaling and a disease phenotype that mimics human MCL.

Nanocellulose composites with enhanced interfacial compatibility and mechanical properties using a hybrid-toughened epoxy matrix.

Although there is a growing interest in utilizing nanocellulose fibres (NCFs) based composites for achieving a higher sustainability, mechanical performance of these composites is limited due to the poor compatibility between fibre reinforcement and polymer matrices. Here we developed a bio-nanocomposite with an enhanced fibre/resin interface using a hybrid-toughened epoxy. A strong reinforcing effect of NCFs was achieved, demonstrating an increase up to 88% in tensile strength and 298% in tensile modulus as compared to neat petro-based P-epoxy. The toughness of neat P-epoxy was improved by 84% with the addition of 10wt% bio-based E-epoxy monomers, which also mitigated the amount of usage of bisphenol A (BPA). The morphological analyses showed that the hybrid epoxy improved the resin penetration and fibre distribution significantly in the resulting composites. Thus, our findings demonstrated the promise of developing sustainable and high performance epoxy composites combing NCFs with a hybrid petro-based and bio-based epoxy resin system.

From Structure to Properties of Composite Films Derived from Cellulose Nanocrystals.

Many natural materials exhibit a multilayer structure in which adjacent layers rotate in a helicoidal manner. The remarkable optical and mechanical properties of these materials have motivated research and development of man-made materials with similar morphology. Among them, composite materials by cellulose nanocrystals (CNCs) and polymers have attracted great interest; however, the relationship between the cholesteric structure and the material properties is not well understood. We used the composite CNC-polymer latex films with random, stratified, and cholesteric morphologies, all with the same compositions, to explore the effect of structure on the optical and mechanical properties of the composite films. Films with a cholesteric structure exhibited strong extinction, circular dichroism, and high stiffness; however, they had lower toughness than the films with the cholesteric stratified morphology. Films with disordered morphologies exhibited the highest toughness and the lowest stiffness. These trends were attributed to the confinement effects and the difference in polymer distribution in the films. These results provide guidance for the preparation of biomimetic cholesteric films with targeted optical and mechanical properties.

Dual Targeting of CDK4 and ARK5 Using a Novel Kinase Inhibitor ON123300 Exerts Potent Anticancer Activity against Multiple Myeloma.

Multiple myeloma is a fatal plasma cell neoplasm accounting for over 10,000 deaths in the United States each year. Despite new therapies, multiple myeloma remains incurable, and patients ultimately develop drug resistance and succumb to the disease. The response to selective CDK4/6 inhibitors has been modest in multiple myeloma, potentially because of incomplete targeting of other critical myeloma oncogenic kinases. As a substantial number of multiple myeloma cell lines and primary samples were found to express AMPK-related protein kinase 5(ARK5), a member of the AMPK family associated with tumor growth and invasion, we examined whether dual inhibition of CDK4 and ARK5 kinases using ON123300 results in a better therapeutic outcome. Treatment of multiple myeloma cell lines and primary samples with ON123300 in vitro resulted in rapid induction of cell-cycle arrest followed by apoptosis. ON123300-mediated ARK5 inhibition or ARK5-specific siRNAs resulted in the inhibition of the mTOR/S6K pathway and upregulation of the AMPK kinase cascade. AMPK upregulation resulted in increased SIRT1 levels and destabilization of steady-state MYC protein. Furthermore, ON123300 was very effective in inhibiting tumor growth in mouse xenograft assays. In addition, multiple myeloma cells sensitive to ON123300 were found to have a unique genomic signature that can guide the clinical development of ON123300. Our study provides preclinical evidence that ON123300 is unique in simultaneously inhibiting key oncogenic pathways in multiple myeloma and supports further development of ARK5 inhibition as a therapeutic approach in multiple myeloma.

Harnessing Noxa demethylation to overcome Bortezomib resistance in mantle cell lymphoma.

Bortezomib (BZM) is the first proteasome inhibitor approved for relapsed Mantle Cell Lymphoma (MCL) with durable responses seen in 30%-50% of patients. Given that a large proportion of patients will not respond, BZM resistance is a significant barrier to use this agent in MCL. We hypothesized that a subset of aberrantly methylated genes may be modulating BZM response in MCL patients. Genome-wide DNA methylation analysis using a NimbleGen array platform revealed a striking promoter hypomethylation in MCL patient samples following BZM treatment. Pathway analysis of differentially methylated genes identified molecular mechanisms of cancer as a top canonical pathway enriched among hypomethylated genes in BZM treated samples. Noxa, a pro-apoptotic Bcl-2 family member essential for the cytotoxicity of BZM, was significantly hypomethylated and induced following BZM treatment. Therapeutically, we could demethylate Noxa and induce anti-lymphoma activity using BZM and the DNA methytransferase inhibitor Decitabine (DAC) and their combination in vitro and in vivo in BZM resistant MCL cells. These findings suggest a role for dynamic Noxa methylation for the therapeutic benefit of BZM. Potent and synergistic cytotoxicity between BZM and DAC in vitro and in vivo supports a strategy for using epigenetic priming to overcome BZM resistance in relapsed MCL patients.

Integrative genomic analysis of temozolomide resistance in diffuse large B-cell lymphoma.

PURPOSE: Despite advances, there is an urgent need for effective therapeutics for relapsed diffuse large B-cell lymphoma, particularly in elderly patients and primary central nervous system (CNS) lymphoma. Temozolomide (TMZ), an oral DNA-alkylating agent routinely used in the therapy of glioblastoma multiforme, is active in patients with primary CNS lymphoma but the response rates are low. The mechanisms contributing to TMZ resistance are unknown. EXPERIMENTAL DESIGN: We undertook an unbiased and genome-wide approach to understand the genomic methylation and gene expression profiling differences associated with TMZ resistance in diffuse large B-cell lymphoma cell lines and identify mechanisms to overcome TMZ resistance. RESULTS: TMZ was cytotoxic in a subset of diffuse large B-cell lymphoma cell lines, independent of MGMT promoter methylation or protein expression. Using Connectivity Map (CMAP), we identified several compounds capable of reversing the gene expression signature associated with TMZ resistance. The demethylating agent decitabine (DAC) is identified by CMAP as capable of reprogramming gene expression to overcome TMZ resistance. Treatment with DAC led to increased expression of SMAD1, a transcription factor involved in TGF-ß/bone morphogenetic protein (BMP) signaling, previously shown to be epigenetically silenced in resistant diffuse large B-cell lymphoma. In vitro and in vivo treatment with a combination of DAC and TMZ had greater antilymphoma activity than either drug alone, with complete responses in TMZ-resistant diffuse large B-cell lymphoma murine xenograft models. CONCLUSIONS: Integrative genome-wide methylation and gene expression analysis identified novel genes associated with TMZ resistance and demonstrate potent synergy between DAC and TMZ. The evidence from cell line and murine experiments supports prospective investigation of TMZ in combination with demethylating agents in diffuse large B-cell lymphoma.

Akt inhibitors MK-2206 and nelfinavir overcome mTOR inhibitor resistance in diffuse large B-cell lymphoma.

PURPOSE: The mTOR pathway is constitutively activated in diffuse large B-cell lymphoma (DLBCL). mTOR inhibitors have activity in DLBCL, although response rates remain low. We evaluated DLBCL cell lines with differential resistance to the mTOR inhibitor rapamycin: (i) to identify gene expression profile(s) (GEP) associated with resistance to rapamycin, (ii) to understand mechanisms of rapamycin resistance, and (iii) to identify compounds likely to synergize with mTOR inhibitor. EXPERIMENTAL DESIGN: We sought to identify a GEP of mTOR inhibitor resistance by stratification of eight DLBCL cell lines with respect to response to rapamycin. Then, using pathway analysis and connectivity mapping, we sought targets likely accounting for this resistance and compounds likely to overcome it. We then evaluated two compounds thus identified for their potential to synergize with rapamycin in DLBCL and confirmed mechanisms of activity with standard immunoassays. RESULTS: We identified a GEP capable of reliably distinguishing rapamycin-resistant from rapamycin-sensitive DLBCL cell lines. Pathway analysis identified Akt as central to the differentially expressed gene network. Connectivity mapping identified compounds targeting Akt as having a high likelihood of reversing the GEP associated with mTOR inhibitor resistance. Nelfinavir and MK-2206, chosen for their Akt-inhibitory properties, yielded synergistic inhibition of cell viability in combination with rapamycin in DLBCL cell lines, and potently inhibited phosphorylation of Akt and downstream targets of activated mTOR. CONCLUSIONS: GEP identifies DLBCL subsets resistant to mTOR inhibitor therapy. Combined targeting of mTOR and Akt suppresses activation of key components of the Akt/mTOR pathway and results in synergistic cytotoxicity. These findings are readily adaptable to clinical trials.

Genomewide DNA methylation analysis reveals novel targets for drug development in mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a mostly incurable malignancy arising from naive B cells (NBCs) in the mantle zone of lymph nodes. We analyzed genomewide methylation in MCL patients with the HELP (HpaII tiny fragment Enrichment by Ligation-mediated PCR) assay and found significant aberrancy in promoter methylation patterns compared with normal NBCs. Using biologic and statistical criteria, we further identified 4 hypermethylated genes CDKN2B, MLF-1, PCDH8, and HOXD8 and 4 hypomethylated genes CD37, HDAC1, NOTCH1, and CDK5 when aberrant methylation was associated with inverse changes in mRNA levels. Immunohistochemical analysis of an independent cohort of MCL patient samples confirmed CD37 surface expression in 93% of patients, validating its selection as a target for MCL therapy. Treatment of MCL cell lines with a small modular immunopharmaceutical (CD37-SMIP) resulted in significant loss of viability in cell lines with intense surface CD37 expression. Treatment of MCL cell lines with the DNA methyltransferase inhibitor decitabine resulted in reversal of aberrant hypermethylation and synergized with the histone deacetylase inhibitor suberoylanilide hydroxamic acid in induction of the hypermethylated genes and anti-MCL cytotoxicity. Our data show prominent and aberrant promoter methylation in MCL and suggest that differentially methylated genes can be targeted for therapeutic benefit in MCL.

Dual fluorescent photochromic colorants bearing pyrano[3,2-c]chromen-5-one moiety.

In this study, the photochromic processes of 8-N,N-dimethylamino-2,2-dimethyl-2H-pyrano[3,2-c]chromen-5-one (1) and its derivatives (2, 3) are investigated with steady-state, temperature-dependent and time-resolved absorption and emission spectroscopy. The differences among compounds 1-3 lie in their various substituents anchored at the pyran moiety that is subject to the photoinduced ring-opening reaction. Compounds 1 and 2 exhibit salient photochromism with a very unique phenomenon, in which fluorescence is observed in 1 for both the ring-closed form (1-CF, lambda(max) approximately 445 nm) and the ring-open form (1-OF, lambda(max) approximately 650 nm in CH2Cl2). The yields of forward and reverse photochromism processes were determined to be 0.40 and 1.0% for 1. Along with fluorescence quantum yields of 9.5 x 10(-2) and 5.8 x 10(-3) for 1-CF and 1-OF, respectively, 1 enables fluorescence detection while it exhibits photochromism in both directions, that is, a photoinduced on/off fluorescence switch. An increase in on/off ratiometric fluorescence between 1-OF and 1-CF can reach a factor of 4.0 upon excitation at the absorption isosbestic point. The activation energies for the ground-state OFtrans --> CF thermal bleaching processes were determined to be 58.2 and 54.8 kJ/mol, with frequency factors of 1.7 x 10(5) and 3.6 x 10(5) s(-1) for 1 and 2, respectively. Conversely, bromo-substituted 3 did not undergo photochromic reaction, as evidenced by the lack of changes in the absorption spectrum after a prolonged (2 h) 354 nm (0.2 W/cm2) photolysis, manifesting the fact that other relaxation processes, such as enhanced intersystem crossing, may govern the deactivation of 3 (3-CF) upon excitation.

Reactions of 3-benzoyl-7-dimethylamino-4-hydroxycoumarin and their potential applications in solution- and solid-phase synthesis.

3-Benzoyl-7-dimethylamino-4-hydroxycoumarin was synthesized and its UV-vis spectra in various mixtures of MeOH and CH(2)Cl(2) were measured. The diketone lactone exists mainly in the exocyclic-enol form in protic solvents and the endocyclic-enol form in nonpolar solvents. Acetylation, amination and methylation products of the diketone lactone were characterized by X-ray crystallography. The results indicated that acetylation of coumarin-based diketone lactones occurs exclusively at the 4-hydroxy group, but that amination takes place specifically at the C-3 carbonyl group. Among the prepared compounds, amination products were found to exhibit photochromic property and colorimetric ion-sensing ability, and methylation product has the potential to function as a primary amine protection group.

Synthesis and characterization of coumarin-based spiropyran photochromic colorants.

Two coumarin-based spiropyran derivatives were synthesized and characterized in two steps to explore their photochromic properties. Both prepared compounds are sensitive to UV light and change colors upon irradiation. The resulting photogenerated zwitterions revert to the original compounds while being heated. A new family of organic photochromic colorants is introduced.

Design of a coumarin-based triketone as a fluorescent protecting group for primary amines.

A series of 3-acetyl-4-hydroxycoumarin and its derivatives were prepared and evaluated for their potential to function as a fluorescent primary amine protection group. When primary amines or amino acids react with the protecting group 3-acetyl-4-methoxy-7- N, N-dimethylaminocoumarin, the resulting compounds emit blue fluorescence with a quantum yield of 0.25-0.50 in methylene chloride. These protected compounds display satisfactory acid/base stability, and the protecting group can be removed with 5% hydrazine hydrate in DMF within 5 min at ambient temperature.

Novel oxazabicycles as a new class of photochromic colorants.

A new photochromic colorant with an oxazabicyclic moiety has been synthesized by an efficient method. It turns pale red upon UV irradiation and undergoes reverse reaction while being heated. This work may open an exciting new avenue for future development of the photochromic dyes with novel molecular structures.

Design and synthesis of a coumarin-based acidichromic colorant.

This paper describes the fine-tuning of the acidichromic properties of a coumarin-containing colorant 1 by incorporation of electron-donating and electron-withdrawing substituents on the coumarin moiety. Colorant 1 can undergo two distinct and reversible color changes under both strongly acidic and basic conditions, but not in the presence of gaseous ammonia. The results indicated that the bromo-substituted compound 5b changes from red to yellow when exposed to gaseous ammonia, both in solution and on polycarbonate film, suggesting that an electron-withdrawing group at the 7-position of the coumarin moiety made the enolic hydrogen on 5b more susceptible to deprotonation by a base than in the unsubstituted compound 1.

Enzyme inhibition potency enhancement by active site metal chelating and hydrogen bonding induced conformation-restricted cyclopropanecarbonyl derivatives.

Two cyclopropanecarbonyl derivatives were independently found to be 15 and 14 times more potent than the corresponding isopropylcarbonyl analogues as inhibitors of 4-hydroxyphenylpyruvate dioxygenase and dihydroorotate dehydrogenase, respectively. A thorough examination of the co-crystal structures of available enzyme inhibitor complexes and the conformation of X-ray crystal structures of several synthesized cyclopropanecarbonyl derivatives revealed that this enhancement by one order of magnitude of inhibition potency exhibited by cyclopropanecarbonyl derivatives in both enzymes is probably caused by respective metal chelating and hydrogen bonding interactions at the ligand-receptor binding site. These specific interactions subsequently cause the cyclopropyl group of the molecules to adopt a fixed bisected conformation, which is unavailable for isopropylcarbonyl derivatives.

Design and synthesis of novel diphenacoum-derived, conformation-restricted vitamin K 2,3-epoxide reductase inhibitors.

Two novel diphenacoum-derived analogues 5 and 6 are designed, synthesized and tested as potential vitamin K 2,3-epoxide reductase (VKOR) inhibitors. The inhibition studies indicated that 5 is a potent VKOR inhibitor, which confirmed that the replacement of the tetrahydronaphthalene on diphenacoum to a chroman functionality does not have a major impact on inhibition potency. The conformation-restricted compound 6 is a moderate inhibitor which may serve as a lead compound for further study of the mode of action of coumarin-type anticoagulants at the molecular level.