Targeting B cell receptor signalling in cancer: preclinical and clinical advances

B cell receptor signaling drives APOBEC3 expression via direct enhancer regulation in chronic lymphocytic leukemia B cells

Constitutively activated B cell receptor (BCR) signaling is a primary biological feature of chronic lymphocytic leukemia (CLL). The biological events controlled by BCR signaling in CLL are not fully understood and need investigation. Here, by analysis of the chromatin states and gene expression profiles of CLL B cells from patients before and after Bruton's tyrosine kinase inhibitor (BTKi) ibrutinib treatment, we show that BTKi treatment leads to a decreased expression of APOBEC3 family genes by regulating the activity of their enhancers. BTKi treatment reduces enrichment of enhancer marks (H3K4me1 and H3K27ac) and chromatin accessibility at putative APOBEC3 enhancers. CRISPR-Cas9 directed deletion or inhibition of the putative APOBEC3 enhancers leads to reduced APOBEC3 expression. We further find that transcription factor NFATc1 couples BCR signaling with the APOBEC3 enhancer activity to control APOBEC3 expression. We also find that enhancer-regulated APOBEC3 expression contributes to replication stress in malignant B cells. In total we demonstrate a novel mechanism for BTKi suppression of APOBEC3 expression via direct enhancer regulation in an NFATc1-dependent manner, implicating BCR signaling as a potential regulator of leukemic genomic instability.

A Novel Triple-Action Inhibitor Targeting B-Cell Receptor Signaling and BRD4 Demonstrates Preclinical Activity in Chronic Lymphocytic Leukemia

B-cell chronic lymphocytic leukemia (CLL) results from intrinsic genetic defects and complex microenvironment stimuli that fuel CLL cell growth through an array of survival signaling pathways. Novel small-molecule agents targeting the B-cell receptor pathway and anti-apoptotic proteins alone or in combination have revolutionized the management of CLL, yet combination therapy carries significant toxicity and CLL remains incurable due to residual disease and relapse. Single-molecule inhibitors that can target multiple disease-driving factors are thus an attractive approach to combat both drug resistance and combination-therapy-related toxicities. We demonstrate that SRX3305, a novel small-molecule BTK/PI3K/BRD4 inhibitor that targets three distinctive facets of CLL biology, attenuates CLL cell proliferation and promotes apoptosis in a dose-dependent fashion. SRX3305 also inhibits the activation-induced proliferation of primary CLL cells in vitro and effectively blocks microenvironment-mediated survival signals, including stromal cell contact. Furthermore, SRX3305 blocks CLL cell migration toward CXCL-12 and CXCL-13, which are major chemokines involved in CLL cell homing and retention in microenvironment niches. Importantly, SRX3305 maintains its anti-tumor effects in ibrutinib-resistant CLL cells. Collectively, this study establishes the preclinical efficacy of SRX3305 in CLL, providing significant rationale for its development as a therapeutic agent for CLL and related disorders.

Kinase-deficient BTK mutants confer ibrutinib resistance through activation of the kinase HCK

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib irreversibly binds BTK at Cys⁴⁸¹, inhibiting its kinase activity and thus blocking transduction of B cell receptor (BCR) signaling. Although ibrutinib is durably effective in patients with B cell malignancies, many patients still develop ibrutinib-resistant disease. Resistance can arise because of mutations at the ibrutinib-binding site in BTK. Here, we characterized the mechanism by which two BTK mutations, C481F and C481Y, may lead to ibrutinib resistance. Both mutants lacked detectable kinase activity in in vitro kinase assays. Structural modeling suggested that bulky Phe and Tyr side chains at position 481 sterically hinder access to the ATP-binding pocket in BTK, contributing to loss of kinase activity. Nonetheless, BCR signaling still propagated through BTK C481F and C481Y mutants to downstream effectors, the phospholipase PLCγ2 and the transcription factor NF-κB. This maintenance of BCR signaling was partially achieved through the physical recruitment and kinase-independent activation of hematopoietic cell kinase (HCK). Upon BCR activation, BTK C481F or C481Y was phosphorylated by Src family kinases at Tyr⁵⁵¹, which then bound to the SH2 domain of HCK. Modeling suggested that this binding disrupted an intramolecular autoinhibitory interaction in HCK. Activated HCK subsequently phosphorylated PLCγ2, which propagated BCR signaling and promoted clonogenic cell proliferation. This kinase-independent mechanism could inform therapeutic approaches to CLL bearing either the C481F or C481Y BTK mutants.

Trial Watch: combination of tyrosine kinase inhibitors (TKIs) and immunotherapy

The past decades witnessed the clinical employment of targeted therapies including but not limited to tyrosine kinase inhibitors (TKIs) that restrain a broad variety of pro-tumorigenic signals. TKIs can be categorized into (i) agents that directly target cancer cells, (ii) normalize angiogenesis or (iii) affect cells of the hematologic lineage. However, a clear distinction of TKIs based on this definition is limited by the fact that many TKIs designed to inhibit cancer cells have also effects on immune cells that are being discovered. Additionally, TKIs originally designed to target hematological cancers exhibit bioactivities on healthy cells of the same hematological lineage. TKIs have been described to improve immune recognition and cancer immunosurveillance, providing the scientific basis to combine TKIs with immunotherapy. Indeed, combination of TKIs with immunotherapy showed synergistic effects in preclinical models and clinical trials and some combinations of TKIs normalizing angiogenesis with immune checkpoint blocking antibodies have already been approved by the FDA for cancer therapy. However, the identification of appropriate drug combinations as well as optimal dosing and scheduling needs to be improved in order to obtain tangible progress in cancer care. This Trial Watch summarizes active clinical trials combining TKIs with various immunotherapeutic strategies to treat cancer patients.

Tumor Infiltration with CD20+CD73+ B Cells Correlates with Better Outcome in Colorectal Cancer

Immunotherapy has become increasingly important in the treatment of colorectal cancer (CRC). Currently, CD73, also known as ecto-5′-nucleotidase (NT5E), has gained considerable interest as a potential therapeutic target. CD73 is one of the key enzymes catalyzing the conversion of extracellular ATP into adenosine, which in turn exerts potent immune suppressive effects. However, the role of CD73 expression on various cell types within the CRC tumor microenvironment remains unresolved. The expression of CD73 on various cell types has been described recently, but the role of CD73 on B-cells in CRC remains unclear. Therefore, we analyzed CD73 on B-cells, especially on tumor-infiltrating B-cells, in paired tumor and adjacent normal tissue samples from 62 eligible CRC patients. The highest expression of CD73 on tumor-infiltrating B-cells was identified on class-switched memory B-cells, followed by naive B-cells, whereas no CD73 expression was observed on plasmablasts. Clinicopathological correlation analysis revealed that higher CD73⁺ B-cells infiltration in the CRC tumors was associated with better overall survival. Moreover, metastasized patients showed a significantly decreased number of tumor-infiltrating CD73⁺ B-cells. Finally, neoadjuvant therapy correlated with reduced CD73⁺ B-cell numbers and CD73 expression on B-cells in the CRC tumors. As promising new immune therapies are being developed, the role of CD73⁺ B-cells and their subsets in the development of colorectal cancer should be further explored to find new therapeutic options.

Activation and expansion of T-follicular helper cells in chronic lymphocytic leukemia nurselike cell co-cultures

Interactions between chronic lymphocytic leukemia (CLL) cells and T-cell subsets in the lymph node microenvironment are thought to play a central role in disease biology. To study these interactions in a model of the CLL lymph node microenvironment, we characterized T-cell subsets in CLL nurselike cell (NLC) co-cultures. We focused on T-follicular helper (Tfh) cells, which are characterized by CXCR5 expression and localization to B-cell follicles. In co-cultures from 28 different CLL patients, we detected an expansion of Tfh cells based on PD-1, BCL6, and ICOS expression, with increased IL-21 and downmodulated CD40L surface expression. Regulatory T cells (Treg), which promote immune tolerance, also expanded in NLC co-cultures. T-cell receptor (TR) gene repertoire analyses confirmed the clonal expansion of CD4+ T cells, with an enrichment of TR clonotypes commonly expanded also in primary CLL samples. Multicolor confocal microscopy revealed that Tfh, but not Treg co-localize with proliferating CLL cells in CLL lymph node sections. Collectively, these data provide new insight into the cellular and molecular cross-talk between CLL and T-cell subsets, resulting in clonal expansion of T-helper cells and interaction of Tfh cells with proliferating CLL cells which may open new avenues for therapeutic targeting.

A loss-of-adhesion CRISPR-Cas9 screening platform to identify cell adhesion-regulatory proteins and signaling pathways

The clinical introduction of the Bruton’s tyrosine kinase (BTK) inhibitor ibrutinib, which targets B-cell antigen-receptor (BCR)-controlled integrin-mediated retention of malignant B cells in their growth-supportive lymphoid organ microenvironment, provided a major breakthrough in lymphoma and leukemia treatment. Unfortunately, a significant subset of patients is intrinsically resistant or acquires resistance against ibrutinib. Here, to discover novel therapeutic targets, we present an unbiased loss-of-adhesion CRISPR-Cas9 knockout screening method to identify proteins involved in BCR-controlled integrin-mediated adhesion. Illustrating the validity of our approach, several kinases with an established role in BCR-controlled adhesion, including BTK and PI3K, both targets for clinically applied inhibitors, are among the top hits of our screen. We anticipate that pharmacological inhibitors of the identified targets, e.g. PAK2 and PTK2B/PYK2, may have great clinical potential as therapy for lymphoma and leukemia patients. Furthermore, this screening platform is highly flexible and can be easily adapted to identify cell adhesion-regulatory proteins and signaling pathways for other stimuli, adhesion molecules, and cell types.

Targeting integrin-mediated retention of malignant B cells in their protective microenvironment is an efficacious treatment for lymphoma and leukemia. Here, the authors present an unbiased loss-of-adhesion CRISPR screening method, identifying therapeutic targets for these B-cell malignancies.

Overarching roles of diacylglycerol signaling in cancer development and antitumor immunity

Diacylglycerol (DAG) is a lipid second messenger that is generated in response to extracellular stimuli and channels intracellular signals that affect mammalian cell proliferation, survival, and motility. DAG exerts a myriad of biological functions through protein kinase C (PKC) and other effectors, such as protein kinase D (PKD) isozymes and small GTPase-regulating proteins (such as RasGRPs). Imbalances in the fine-tuned homeostasis between DAG generation by phospholipase C (PLC) enzymes and termination by DAG kinases (DGKs), as well as dysregulation in the activity or abundance of DAG effectors, have been widely associated with tumor initiation, progression, and metastasis. DAG is also a key orchestrator of T cell function and thus plays a major role in tumor immunosurveillance. In addition, DAG pathways shape the tumor ecosystem by arbitrating the complex, dynamic interaction between cancer cells and the immune landscape, hence representing powerful modifiers of immune checkpoint and adoptive T cell-directed immunotherapy. Exploiting the wide spectrum of DAG signals from an integrated perspective could underscore meaningful advances in targeted cancer therapy.

Proteolysis-targeting chimeras (PROTACs) in cancer therapy

Proteolysis-targeting chimeras (PROTACs) are engineered techniques for targeted protein degradation. A bifunctional PROTAC molecule with two covalently-linked ligands recruits target protein and E3 ubiquitin ligase together to trigger proteasomal degradation of target protein by the ubiquitin-proteasome system. PROTAC has emerged as a promising approach for targeted therapy in various diseases, particularly in cancers. In this review, we introduce the principle and development of PROTAC technology, as well as the advantages of PROTACs over traditional anti-cancer therapies. Moreover, we summarize the application of PROTACs in targeting critical oncoproteins, provide the guidelines for the molecular design of PROTACs and discuss the challenges in the targeted degradation by PROTACs.

Depleting Tumor Infiltrating B Cells to Boost Antitumor Immunity with Tumor Immune-Microenvironment Reshaped Hybrid Nanocage

Tumor infiltrating B cells (TIBs)-dependent immunotherapy has emerged as a promising method for tumor treatment. Depleting TIBs to boost antitumor immunity is a highly desirable yet challenging approach to TIBs-dependent immunotherapy. Herein, a tumor immune-microenvironment reshaped hybrid nanocage CPN-NLI/MLD coloaded with the Bruton's tyrosine kinase inhibitor ibrutinib, and cytotoxic drug docetaxel was developed for stepwise targeting TIBs and tumor cells, respectively. The tumor microenvironment responsive CPN-NLI/MLD promoted charge reversal and size reduction under acidic conditions (pH < 6.5). The accumulation of CPN-NLI/MLD in tumor tissues was achieved through CD13 targeting, and cellular uptake was increased due to the differ-targeting delivery. Targeting of docetaxel to tumor cells was achieved by the interaction of α-MSH modified on inner docetaxel-particle MLD and melanocortin-1 receptor on the surface of tumor cells. Targeting of ibrutinib to TIBs was achieved by the interaction of Neu5Ac modified on inner ibrutinib-particle NLI and CD22 on the surface of TIBs. The boosted antitumor immunity was achieved mainly by the inhibition of Bruton's tyrosine kinase activation mediated by ibrutinib, which reduced the proportion of TIBs, enhanced infiltration of CD8⁺ and CD4⁺ T cells, increased the secretion of immunogenic cytokines including IL-2 and IFN-γ, and inhibited the proliferation of regulatory T cells and secretion of immunosuppressive cytokines including IL-10, IL-4, and TGF-β. Furthermore, CPN-NLI/MLD improved the antitumor efficiency of chemoimmunotherapy by reshaping tumor immune-microenvironment by TIBs depletion. Taken together, CPN-NLI/MLD represents a promising method for effective tumor treatment and combination therapy by TIBs-dependent immunotherapy.

Rintatolimod (Ampligen®) Enhances Numbers of Peripheral B Cells and Is Associated with Longer Survival in Patients with Locally Advanced and Metastasized Pancreatic Cancer Pre-Treated with FOLFIRINOX: A Single-Center Named Patient Program

Background: Treatment with the TLR-3 agonist rintatolimod may improve pancreatic cancer patients’ survival via immunomodulation, but the effect is unproven. Methods: In this single-center named patient program, patients with locally advanced pancreatic cancer (LAPC) or metastatic disease were treated with rintatolimod (six weeks total, twice per week, with a maximum of 400 mg per infusion). The primary endpoints were the systemic immune-inflammation index (SIII), the neutrophil to lymphocyte ratio (NLR), and the absolute counts of 18 different populations of circulating immune cells as measured by flow cytometry. Secondary endpoints were progression-free survival (PFS) and overall survival (OS). Subgroup analyses were performed in long-term survivors (>1-year overall survival after starting rintatolimod) and compared to short-term survivors (≤1 year). Results: Between January 2017 and February 2019, twenty-seven patients with stable LAPC or metastatic disease were pre-treated with FOLFIRINOX and treated with rintatolimod. Rintatolimod treatment was well-tolerated. The SIII and NLR values were significantly lower in the 11 long-term survivors, versus 16 short-term survivors. The numbers of B-cells were significantly increased in long-term survivors. Numbers of T cells and myeloid cells were not significantly increased after treatment with rintatolimod. Median PFS was 13 months with rintatolimod, versus 8.6 months in a subset of matched controls (n = 27, hazard ratio = 0.52, 95% CI = 0.28−0.90, p = 0.007). The median OS was 19 months with rintatolimod, versus 12.5 months in the matched control (hazard ratio = 0.51, 95% CI = 0.28−0.90, p = 0.016). Conclusions: Treatment with rintatolimod showed a favorable effect on the numbers of peripheral B cells in patients with pancreatic cancer and improved survival in pancreatic cancer, but additional evidence is required.

One shoot, three birds: Targeting NEK2 orchestrates chemoradiotherapy, targeted therapy, and immunotherapy in cancer treatment

Combinational therapy has improved the cancer therapeutic landscape but is associated with a concomitant increase in adverse side reactions. Emerging evidence proposes that targeting one core target with multiple critical roles in tumors can achieve combined anti-tumor effects. This review focuses on NEK2, a member of serine/threonine kinases, with broad sequence identity to the mitotic regulator NIMA of the filamentous fungus Aspergillus nidulans. Elevated expression of NEK2 was initially found to promote tumorigeneses through abnormal regulation of the cell cycle. Subsequent studies report that NEK2 is overexpressed in a broad spectrum of tumor types and is associated with tumor progression and therapeutic resistance. Intriguingly, NEK2 has recently been revealed to mediate tumor immune escape by stabilizing the expression of PD-L1. Targeting NEK2 is thus becoming a promising approach for cancer treatment by orchestrating chemoradiotherapy, targeted therapy, and immunotherapy. It represents a novel strategy for inducing combined anti-cancer effects using a mono-agent.

Targeted Agents in the Treatment of Indolent B-Cell Non-Hodgkin Lymphomas

Targeted therapies continue to change the landscape of lymphoma treatment, resulting in improved therapy options and patient outcomes. Numerous agents are now approved for use in the indolent lymphomas and many others under development demonstrate significant promise. In this article, we review the landscape of targeted agents that apply to the indolent lymphomas, predominantly follicular lymphoma, lymphoplasmacytic lymphoma/Waldenstrom macroglobulinaemia and marginal zone lymphoma. The review covers small molecule inhibitors, immunomodulators and targeted immunotherapies, as well as presenting emerging and promising combination therapies.

Recent development of BTK-based dual inhibitors in the treatment of cancers

Bruton's tyrosine kinase (BTK) is a promising target in the treatment of various cancers. Despite the early success of BTK inhibitors in the clinic, these single-target drug therapies have limitations in their clinical applications, such as drug resistance. Several alternative strategies have been developed, including the use of dual inhibitors, to maximize the therapeutic potential of anticancer drugs. In this review, we highlight the scientific background and theoretical basis for developing BTK-based dual inhibitors, as well as the status of these agents in preclinical and clinical studies, and discuss further options in this field. We posit that these advances in BTK-based dual inhibitors confirm their feasibility for the treatment of refractory tumors, including those with drug resistance, and provide a framework for future drug design in this field. Accordingly, we anticipate increasingly rapid progress in the development of novel potent dual inhibitors and advanced clinical research on BTK-based dual inhibitors.

Enhancement of Gene Knockdown on CD22-Expressing Cells by Chemically Modified Glycan Ligand-siRNA Conjugates

Extrahepatic targeted delivery of oligonucleotides, such as small interfering RNA (siRNA) and antisense oligonucleotides (ASOs), is an attractive technology for the development of nucleic acid-based medicines. To target CD22-expressing B cells, several drug platforms have shown promise, including antibodies, antibody-drug conjugates, and nanoparticles, but to date CD22-targeted delivery of oligonucleotide therapeutics has not been reported. Here we report the uptake and enhancement of siRNA gene expression knockdown in CD22-expressing B cells using a chemically stabilized and modified CD22 glycan ligand-conjugated siRNA. This finding has the potential to broaden the use of siRNA technology, opening up novel therapeutic opportunities, and presents an innovative approach for targeted delivery of siRNAs to B cell lymphomas.

Regulation of B-Cell Receptor Signaling and Its Therapeutic Relevance in Aggressive B-Cell Lymphomas

The proliferation and survival signals emanating from the B-cell receptor (BCR) constitute a crucial aspect of mature lymphocyte's life. Dysregulated BCR signaling is considered a potent contributor to tumor survival in different subtypes of B-cell non-Hodgkin lymphomas (B-NHLs). In the last decade, the emergence of BCR-associated kinases as rational therapeutic targets has led to the development and approval of several small molecule inhibitors targeting either Bruton's tyrosine kinase (BTK), spleen tyrosine kinase (SYK), or phosphatidylinositol 3 kinase (PI3K), offering alternative treatment options to standard chemoimmunotherapy, and making some of these drugs valuable assets in the anti-lymphoma armamentarium. Despite their initial effectiveness, these precision medicine strategies are limited by primary resistance in aggressive B-cell lymphoma such as diffuse large B-cell lymphoma (DLBCL) and mantle cell lymphoma (MCL), especially in the case of first generation BTK inhibitors. In these patients, BCR-targeting drugs often fail to produce durable responses, and nearly all cases eventually progress with a dismal outcome, due to secondary resistance. This review will discuss our current understanding of the role of antigen-dependent and antigen-independent BCR signaling in DLBCL and MCL and will cover both approved inhibitors and investigational molecules being evaluated in early preclinical studies. We will discuss how the mechanisms of action of these molecules, and their off/on-target effects can influence their effectiveness and lead to toxicity, and how our actual knowledge supports the development of more specific inhibitors and new, rationally based, combination therapies, for the management of MCL and DLBCL patients.

An Asian-specific variant in human IgG1 represses colorectal tumorigenesis by shaping the tumor microenvironment

Emerging studies have focused on ways to treat cancers by modulating T cell activation. However, whether B cell receptor signaling in the tumor microenvironment (TME) can be harnessed for immunotherapy is unclear. Here, we report that an Asia-specific variant of human IgG1 containing a Gly396 to Arg396 substitution (hIgG1-G396R) conferred improved survival of patients with colorectal cancer (CRC). Mice with knockin of the murine functional homolog mIgG2c-G400R recapitulated the alleviated tumorigenesis and progression in murine colon carcinoma models. Immune profiling of the TME revealed broad mobilizations of IgG1⁺ plasma cells, CD8⁺ T cells, CD103⁺ DCs, and active tertiary lymphoid structure formation, suggesting an effective antitumor microenvironment in hIgG1-G396R CRC patients. Mechanistically, this variant potentiated tumor-associated antigen–specific (TAA-specific) plasma cell differentiation and thus antibody production. These elevated TAA-specific IgG2c antibodies in turn efficiently boosted the antibody-dependent tumor cell phagocytosis and TAA presentation to effector CD8⁺ T cells. Notably, adoptive transfer of TAA-specific class-switched memory B cells harboring this variant exhibited therapeutic efficacy in murine tumor models, indicating their clinical potential. All these results prompted a prospective investigation of hIgG1-G396R in patients with CRC as a biomarker for clinical prognosis and demonstrated that manipulating the functionality of IgG1⁺ memory B cells in tumors could improve immunotherapy outcomes.

The spliceosome component Usp39 controls B cell development by regulating immunoglobulin gene rearrangement

The spliceosome is a large ribonucleoprotein complex responsible for pre-mRNA splicing and genome stability maintenance. Disruption of the spliceosome activity may lead to developmental disorders and tumorigenesis. However, the physiological role that the spliceosome plays in B cell development and function is still poorly defined. Here, we demonstrate that ubiquitin-specific peptidase 39 (Usp39), a spliceosome component of the U4/U6.U5 tri-snRNP complex, is essential for B cell development. Ablation of Usp39 in B cell lineage blocks pre-pro-B to pro-B cell transition in the bone marrow, leading to a profound reduction of mature B cells in the periphery. We show that Usp39 specifically regulates immunoglobulin gene rearrangement in a spliceosome-dependent manner, which involves modulating chromatin interactions at the Igh locus. Moreover, our results indicate that Usp39 deletion reduces the pre-malignant B cells in Eμ-Myc transgenic mice and significantly improves their survival.

Engineering DNA Nanostructures to Manipulate Immune Receptor Signaling and Immune Cell Fates

Immune cells sense, communicate, and logically integrate a multitude of environmental signals to make important cell-fate decisions and fulfill their effector functions. These processes are initiated and regulated by a diverse array of immune receptors and via their dynamic spatiotemporal organization upon ligand binding. Given the widespread relevance of the immune system to health and disease, there have been significant efforts toward understanding the biophysical principles governing immune receptor signaling and activation, as well as the development of biomaterials which exploit these principles for therapeutic immune engineering. Here, how advances in the field of DNA nanotechnology constitute a growing toolbox for further pursuit of these endeavors is discussed. Key cellular players involved in the induction of immunity against pathogens or diseased cells are first summarized. How the ability to design DNA nanostructures with custom shapes, dynamics, and with site-specific incorporation of diverse guests can be leveraged to manipulate the signaling pathways that regulate these processes is then presented. It is followed by highlighting emerging applications of DNA nanotechnology at the crossroads of immune engineering, such as in vitro reconstitution platforms, vaccines, and adjuvant delivery systems. Finally, outstanding questions that remain for further advancing immune-modulatory DNA nanodevices are outlined.

The evolving role of immune cells in prostate cancer

Prostate cancer is the most commonly diagnosed cancer and the second leading cause of cancer-related death among men in western countries. Androgen deprivation therapy (ADT) is considered the standard therapy for recurrent prostate cancer; however, this therapy may lead to ADT resistance and tumor progression, which seems to be regulated by epithelial-mesenchymal transition (EMT) and/or neuroendocrine differentiation (NED). In addition, recent data suggested the involvement of either adaptive or innate infiltrated immune cells in the initiation, progression, metastasis, and treatment of prostate cancer. In this review, we outlined the characteristics and roles of these immune cells in the initiation, progression, metastasis, and treatments of prostate cancer. We also summarized the current therapeutic strategies in targeting immune cells of the prostate tumor microenvironment.

Comprehensive lncRNA and mRNA profiles in peripheral blood mononuclear cells derived from ankylosing spondylitis patients by RNA-sequencing analysis

The present study aimed to investigate the comprehensive expression profiles of long non-coding RNA (lncRNA) in ankylosing spondylitis (AS).The peripheral blood samples were collected from 6 AS patients and 6 age- and gender-matched healthy controls (HCs), and separated for peripheral blood mononuclear cells, followed by RNA-sequencing. Further bioinformatics analyses were performed to explore the significantly enriched biological processes, signaling pathways of differentially expressed lncRNAs (DElncRNAs) (based on cis-target and trans-target genes) and differentially expressed mRNAs (DEmRNAs).Principal component analysis plots indicated that both lncRNA and mRNA expression profiles could distinguish AS patients from HCs; heatmap diagram exhibited a relatively good consistency and tendency of lncRNA and mRNA expression profiles in AS patients and HCs, respectively; volcano plots exhibited 114 upregulated and 45 downregulated DElncRNAs, 284 upregulated and 435 downregulated DEmRNAs in AS patients compared with HCs; Gene ontology enrichment analyses indicated that DElncRNAs (based on cis-target and trans-target genes) and DEmRNAs were enriched in molecular functions (including DNA binding, protein binding, etc) and biological process (including immune response, inflammatory response, etc); Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed that these DElncRNAs (based on cis-target and trans-target genes) and DEmRNAs were enriched in immune and inflammation-related signaling, such as B cell receptor signaling pathway, TNF signaling pathway, NF-kappa B signaling pathway, etc.Our study displays the comprehensive expression profiles and functions of lncRNAs involved in AS, which provides reference for further researches discovering candidate lncRNAs with value in assisting early AS diagnosis.

Streamlined single-cell proteomics by an integrated microfluidic chip and data-independent acquisition mass spectrometry

Single-cell proteomics can reveal cellular phenotypic heterogeneity and cell-specific functional networks underlying biological processes. Here, we present a streamlined workflow combining microfluidic chips for all-in-one proteomic sample preparation and data-independent acquisition (DIA) mass spectrometry (MS) for proteomic analysis down to the single-cell level. The proteomics chips enable multiplexed and automated cell isolation/counting/imaging and sample processing in a single device. Combining chip-based sample handling with DIA-MS using project-specific mass spectral libraries, we profile on average ~1,500 protein groups across 20 single mammalian cells. Applying the chip-DIA workflow to profile the proteomes of adherent and non-adherent malignant cells, we cover a dynamic range of 5 orders of magnitude with good reproducibility and <16% missing values between runs. Taken together, the chip-DIA workflow offers all-in-one cell characterization, analytical sensitivity and robustness, and the option to add additional functionalities in the future, thus providing a basis for advanced single-cell proteomics applications.

Genetic polymorphisms of FCGR2A, ORAI1 and CD40 are associated with risk of lung cancer

FCGR2A, ORAI1 and CD40 are all involved in the immune and inflammatory responses in the human body, whereas its association with lung cancer is still unclear. This study aimed to investigate the effects of polymorphisms in these genes on the susceptibility to lung cancer. Six candidate single nucleotide polymorphisms (SNPs) were genotyped using a MassARRAY platform in a discovery cohort, including 400 lung cancer patients and 400 healthy controls, and validated in a replication cohort, including 529 lung cancer cases and 532 controls. Comparing the allele frequency distributions, we found that the rs1801274-G, rs511278-T and rs1883832-T were risk alleles for lung cancer (P < 0.05), whereas the minor allele of rs12320939-T was a protective allele for the disease (P = 0.037). Comparing the genotype frequency distributions, we found that rs1801274-GG, rs511278-CT and of rs1883832-TT were risk genotype for lung cancer (P < 0.05). Genetic model analysis showed that the rs1801274 A>G was correlated with an elevated risk of lung cancer in recessive and log-additive models (P < 0.05); rs511278 C>T exhibited an increased risk of disease in dominant and log-additive models (P < 0.05); rs1883832 C>T had a strong relationship with risk of disease in all three models (P < 0.001), whereas rs12320939 G>T was correlated to a reduced risk of disease in recessive and log-additive models (P < 0.05). Finally, the association between the above SNPs and lung cancer risk was validated in a replication cohort (P < 0.05). These results shed new light on the association between immune-related genes and risk of lung cancer, and might be useful for the identification of high-risk individuals.

Nanomedicines in B cell-targeting therapies

B cells play multiple roles in immune responses related to autoimmune diseases as well as different types of cancers. As such, strategies focused on B cell targeting attracted wide interest and developed intensively. There are several common mechanisms various B cell targeting therapies have relied on, including direct B cell depletion, modulation of B cell antigen receptor (BCR) signaling, targeting B cell survival factors, targeting the B cell and T cell costimulation, and immune checkpoint blockade. Nanocarriers, used as drug delivery vehicles, possess numerous advantages to low molecular weight drugs, reducing drug toxicity, enhancing blood circulation time, as well as augmenting targeting efficacy and improving therapeutic effect. Herein, we review the commonly used targets involved in B cell targeting approaches and the utilization of various nanocarriers as B cell-targeted delivery vehicles. STATEMENT OF SIGNIFICANCE: As B cells are engaged significantly in the development of many kinds of diseases, utilization of nanomedicines in B cell depletion therapies have been rapidly developed. Although numerous studies focused on B cell targeting have already been done, there are still various potential receptors awaiting further investigation. This review summarizes the most relevant studies that utilized nanotechnologies associated with different B cell depletion approaches, providing a useful tool for selection of receptors, agents and/or nanocarriers matching specific diseases. Along with uncovering new targets in the function map of B cells, there will be a growing number of candidates that can benefit from nanoscale drug delivery.

PI3K Targeting in Non-solid Cancer

Despite the therapeutic progress, relapse remains a major problem in the treatment of acute lymphoblastic leukemia (ALL). Most leukemia cells that survive chemotherapy are found in the bone marrow (BM), thus resistance to chemotherapy and other treatments may be partially attributed to pro-survival signaling to leukemic cells mediated by leukemia cell-microenvironment interactions. Adhesion of leukemia cells to BM stromal cells may lead to cell adhesion-mediated drug resistance (CAM-DR) mediating intracellular signaling changes that support survival of leukemia cells. In ALL and chronic lymphocytic leukemia (CLL), adhesion-mediated activation of the PI3K/AKT signaling pathway has been shown to be critical in CAM-DR. PI3K targeting inhibitors have been approved for CLL and have been evaluated preclinically in ALL. However, PI3K inhibition has yet to be approved for clinical use in ALL. Here, we review the role of PI3K signaling for normal hematopoietic and leukemia cells and summarize preclinical inhibitors of PI3K in ALL.

Inhibition of TRIM32 by ibr-7 treatment sensitizes pancreatic cancer cells to gemcitabine via mTOR/p70S6K pathway

Pancreatic cancer is one of the most notorious diseases for being asymptomatic at early stage and high mortality rate thereafter. However, either chemotherapy or targeted therapy has rarely achieved success in recent clinical trials for pancreatic cancer. Novel therapeutic regimens or agents are urgently in need. Ibr‐7 is a novel derivative of ibrutinib, displaying superior antitumour activity in pancreatic cancer cells than ibrutinib. In vitro studies showed that ibr‐7 greatly inhibited the proliferation of BxPC‐3, SW1990, CFPAC‐1 and AsPC‐1 cells via the induction of mitochondrial‐mediated apoptosis and substantial suppression of mTOR/p70S6K pathway. Moreover, ibr‐7 was able to sensitize pancreatic cancer cells to gemcitabine through the efficient repression of TRIM32, which was positively correlated with the proliferation and invasiveness of pancreatic cancer cells. Additionally, knockdown of TRIM32 diminished mTOR/p70S6K activity in pancreatic cancer cells, indicating a positive feedback loop between TRIM32 and mTOR/p70S6K pathway. To conclude, this work preliminarily explored the role of TRIM32 in the malignant properties of pancreatic cancer cells and evaluated the possibility of targeting TRIM32 to enhance effectiveness of gemcitabine, thereby providing a novel therapeutic target for pancreatic cancer.

REC8 enhances stemness and promotes metastasis of colorectal cancer through BTK/Akt/β-catenin signaling pathway

Cancer/testis antigens (CTAs) are often aberrantly expressed in cancer stem cells (CSCs) which are responsible for tumor metastasis. Rec8 meiotic recombination protein (REC8), a member of CTAs, shares distinct roles in various cancers, while its contribution to CSCs and colorectal cancer (CRC) remains unclear. We found that overexpression of REC8 facilitated the migration and invasion of CRC cells (DLD-1 and SW480 cells) in vitro and promoted the liver metastasis of CRC in vivo. Moreover, REC8 is highly expressed in CRC stem-like cells and is required for the maintenance of CSC stemness. Mechanistic studies suggested that REC8 mediated through the activation of Bruton tyrosine kinase (BTK). Inhibition of BTK by ibrutinib not only suppressed the migration and invasion-promoting ability, but also declined the increased expression of p-BTK, p-Akt, β-catenin, and CSC markers upon REC8 overexpression. Importantly, high expression of REC8 in cancerous tissues was related to advanced clinical stage and lymph node metastasis of 62 CRC patients, and REC8 was enriched in the cancerous cells positive for CSC markers. Collectively, our results indicate that REC8 promotes CRC metastasis by increasing cell stemness through BTK/Akt/β-catenin pathway.

The role of Bruton's tyrosine kinase in the immune system and disease

Bruton's tyrosine kinase (BTK) is a TEC kinase with a multifaceted role in B-cell biology and function, highlighted by its position as a critical component of the B-cell receptor signalling pathway. Due to its role as a therapeutic target in several haematological malignancies including chronic lymphocytic leukaemia, BTK has been gaining tremendous momentum in recent years. Within the immune system, BTK plays a part in numerous pathways and cells beyond B cells (i.e. T cells, macrophages). Not surprisingly, BTK has been elucidated to be a driving factor not only in lymphoproliferative disorders but also in autoimmune diseases and response to infection. To extort this role, BTK inhibitors such as ibrutinib have been developed to target BTK in other diseases. However, due to rising levels of resistance, the urgency to develop new inhibitors with alternative modes of targeting BTK is high. To meet this demand, an expanding list of BTK inhibitors is currently being trialled. In this review, we synopsize recent discoveries regarding BTK and its role within different immune cells and pathways. Additionally, we discuss the broad significance and relevance of BTK for various diseases ranging from haematology and rheumatology to the COVID-19 pandemic. Overall, BTK signalling and its targetable nature have emerged as immensely important for a wide range of clinical applications. The development of novel, more specific and less toxic BTK inhibitors could be revolutionary for a significant number of diseases with yet unmet treatment needs.

Neurologic Complications of Cancer Therapies

PURPOSE OF REVIEW

To review the neurologic complications of systemic anti-cancer therapies and radiation therapy.

RECENT FINDINGS

Although many of the newer systemic therapies have more favorable side effect profiles than traditional cytotoxic chemotherapy, neurotoxicity has been seen with some of newer targeted therapies, immunotherapy, and T cell engaging therapies, including CAR-T therapy. The most recent advances in radiation-induced neurotoxicity have focused on the prevention and the management of cognitive dysfunction, a known long-term complication of brain irradiation. Cancer therapies can damage both the central and the peripheral nervous systems, and the damage may not always be reversible. Neurologists and oncologists must be aware of the neurotoxicities associated with newer treatments, particularly CAR-T therapy and immunotherapy. Early recognition and appropriate management can help minimize neurologic injury.

Nucleolar and spindle associated protein 1 enhances chemoresistance through DNA damage repair pathway in chronic lymphocytic leukemia by binding with RAD51

Nucleolar and spindle-associated protein 1 (NUSAP1) is an essential regulator of mitotic progression, spindle assembly, and chromosome attachment. Although NUSAP1 acts as an oncogene involved in the progression of several cancers, the exact role of chronic lymphocytic leukemia (CLL) remains elusive. Herein, we first discovered obvious overexpression of NUSAP1 in CLL associated with poor prognosis. Next, the NUSAP1 level was modulated by transfecting CLL cells with lentivirus. Silencing NUSAP1 inhibited the cell proliferation, promoted cell apoptosis and G0/G1 phase arrest. Mechanistically, high expression of NUSAP1 strengthened DNA damage repairing with RAD51 engagement. Our results also indicated that NUSAP1 knockdown suppressed the growth CLL cells in vivo. We further confirmed that NUSAP1 reduction enhanced the sensitivity of CLL cells to fludarabine or ibrutinib. Overall, our research investigates the mechanism by which NUSAP1 enhances chemoresistance via DNA damage repair (DDR) signaling by stabilizing RAD51 in CLL cells. Hence, NUSAP1 may be expected to be a perspective target for the treatment of CLL with chemotherapy resistance.

BTK inhibitors, irrespective of ITK inhibition, increase efficacy of a CD19/CD3-bispecific antibody in CLL

Bruton tyrosine kinase inhibitors (BTKis) are a preferred treatment of patients with chronic lymphocytic leukemia (CLL). Indefinite therapy with BTKis, although effective, presents clinical challenges. Combination therapy can deepen responses, shorten treatment duration, and possibly prevent or overcome drug resistance. We previously reported on a CD19/CD3-bispecific antibody (bsAb) that recruits autologous T-cell cytotoxicity against CLL cells in vitro. Compared with observations with samples from treatment-naïve patients, T cells from patients being treated with ibrutinib expanded more rapidly and exerted superior cytotoxic activity in response to the bsAb. In addition to BTK, ibrutinib also inhibits interleukin-2 inducible T-cell kinase (ITK). In contrast, acalabrutinib, does not inhibit ITK. Whether ITK inhibition contributes to the observed immune effects is unknown. To better understand how BTKis modulate T-cell function and cytotoxic activity, we cultured peripheral blood mononuclear cells (PBMCs) from BTKi-naive and ibrutinib- or acalabrutinib-treated CLL patients with CD19/CD3 bsAb in vitro. T-cell expansion, activation, differentiation, and cytotoxicity were increased in PBMCs from patients on treatment with either BTKi compared with that observed for BKTi-naïve patients. BTKi therapy transcriptionally downregulated immunosuppressive effectors expressed by CLL cells, including cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and CD200. CTLA-4 blockade with ipilimumab in vitro increased the cytotoxic activity of the bsAb in BTKi-naïve but not BTKi-treated PBMCS. Taken together, BTKis enhance bsAb-induced cytotoxicity by relieving T cells of immunosuppressive restraints imposed by CLL cells. The benefit of combining bsAb immunotherapy with BTKis needs to be confirmed in clinical trials.

Discovery of 1-Amino-1H-imidazole-5-carboxamide Derivatives as Highly Selective, Covalent Bruton's Tyrosine Kinase (BTK) Inhibitors

Bruton's tyrosine kinase (BTK) inhibitors suppressing the aberrant activation of BTK have led to a paradigm shift in the therapy of B-cell malignancies. However, there is an urgent need to discover more selective covalent BTK inhibitors owing to the off-target adverse effects of the approved inhibitor, ibrutinib. Herein, we disclose the discovery and preliminary activity studies of novel BTK inhibitors carrying 1-amino-1H-imidazole-5-carboxamide as a hinge binder. The most potent BTK inhibitor 26 demonstrates impressive selectivity, favorable pharmacokinetic properties, and robust antitumor efficacy in vivo, which indicates its potential as a novel therapeutic option for B-cell lymphomas. Importantly, to the best of our knowledge, this is the first example of a 1-amino-1H-imidazole-5-carboxamide scaffold used as the hinge binder of kinase inhibitors, which will largely expand the chemical diversity of kinase inhibitors.

Targeted Anti-Tumor Immunotherapy Using Tumor Infiltrating Cells

In the tumor microenvironment, T cells, B cells, and many other cells play important and distinct roles in anti-tumor immunotherapy. Although the immune checkpoint blockade and adoptive cell transfer can elicit durable clinical responses, only a few patients benefit from these therapies. Increased understanding of tumor-infiltrating immune cells can provide novel therapies and drugs that induce a highly specific anti-tumor immune response to certain groups of patients. Herein, the recent research progress on tumor-infiltrating B cells and T cells, including CD8+ T cells, CD4+ T cells, and exhausted T cells and their role in anti-tumor immunity, is summarized. Moreover, several anti-tumor therapy approaches are discussed based on different immune cells and their prospects for future applications in cancer treatment.

Comprehensive Analysis of the Prognostic Value and Immune Infiltrates of the Three-m5C Signature in Colon Carcinoma

Background

The 5-methylcytosine (m5C) is one of the important forms of RNA post modification, and its regulatory mechanism in tumors has received increasing attention. However, its potential role in colorectal cancer remains unclear.

Materials and Methods

Here, we systematically investigated the genetic variation and prognostic value of the 14 m5c RNA methylation regulators in colon cancer. The prognostic risk score was constructed using three m5C regulators, which was verified in the GSE17536 (N=177), GSE41258 (N=248) and GSE38832 (N=122) datasets.

Results

The risk score developed from the three-m5C signature represents an independent prognostic factor, which can accurately predict the prognosis of patients with colon cancer in multiple datasets. The cytokine–cytokine receptor interaction and chemokine signaling pathway were significantly enriched in the low-risk score group. Further analysis showed that the three-m5C signature was related to tumor immune microenvironment (TIME), affecting the abundance of tumor-infiltrating immune cells. Especially, patients with low risk score had higher immune score than those with high risk score. In addition, gene set enrichment analysis (GSEA) confirmed that all three regulatory factors are associated with the MAPK/p38 signaling pathway.

Conclusion

In conclusion, our study illustrates that the three-m5C signature may be involved in the regulation of colon cancer immune microenvironment in synergy with the MAPK signaling pathway. Therefore, further studying the three-m5C signature regulatory mechanisms might provide promising targets for improving the responsiveness of colon cancer to immunotherapy.

Development and Verification of the Hypoxia- and Immune-Associated Prognostic Signature for Pancreatic Ductal Adenocarcinoma

We aim to construct a hypoxia- and immune-associated risk score model to predict the prognosis of patients with pancreatic ductal adenocarcinoma (PDAC). By unsupervised consensus clustering algorithms, we generate two different hypoxia clusters. Then, we screened out 682 hypoxia-associated and 528 immune-associated PDAC differentially expressed genes (DEGs) of PDAC using Pearson correlation analysis based on the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression project (GTEx) dataset. Seven hypoxia and immune-associated signature genes (S100A16, PPP3CA, SEMA3C, PLAU, IL18, GDF11, and NR0B1) were identified to construct a risk score model using the Univariate Cox regression and the Least Absolute Shrinkage and Selection Operator (LASSO) Cox regression, which stratified patients into high- and low-risk groups and were further validated in the GEO and ICGC cohort. Patients in the low-risk group showed superior overall survival (OS) to their high-risk counterparts (p < 0.05). Moreover, it was suggested by multivariate Cox regression that our constructed hypoxia-associated and immune-associated prognosis signature might be used as the independent factor for prognosis prediction (p < 0.001). By CIBERSORT and ESTIMATE algorithms, we discovered that patients in high-risk groups had lower immune score, stromal score, and immune checkpoint expression such as PD-L1, and different immunocyte infiltration states compared with those low-risk patients. The mutation spectrum also differs between high- and low-risk groups. To sum up, our hypoxia- and immune-associated prognostic signature can be used as an approach to stratify the risk of PDAC.

Kinobead Profiling Reveals Reprogramming of BCR Signaling in Response to Therapy within Primary CLL Cells

PURPOSE

B-cell receptor (BCR) signaling is critical for the pathogenesis of chronic lymphocytic leukemia (CLL), promoting both malignant cell survival and disease progression. Although vital, understanding of the wider signaling network associated with malignant BCR stimulation is poor. This is relevant with respect to potential changes in response to therapy, particularly involving kinase inhibitors. In the current study, we describe a novel high-resolution approach to investigate BCR signaling in primary CLL cells and track the influence of therapy on signaling response.

EXPERIMENTAL DESIGN

A kinobead/mass spectrometry-based protocol was used to study BCR signaling in primary CLL cells. Longitudinal analysis of samples donated by clinical trial patients was used to investigate the impact of chemoimmunotherapy and ibrutinib on signaling following surface IgM engagement. Complementary Nanostring and immunoblotting analysis was used to verify our findings.

RESULTS

Our protocol isolated a unique, patient-specific signature of over 30 kinases from BCR-stimulated CLL cells. This signature was associated with 13 distinct Kyoto Encyclopedia of Genes and Genomes pathways and showed significant change in cells from treatment-naïve patients compared with those from patients who had previously undergone therapy. This change was validated by longitudinal analysis of clinical trials samples where BCR-induced kinome responses in CLL cells altered between baseline and disease progression in patients failing chemoimmunotherapy and between baseline and treatment in patients taking ibrutinib.

CONCLUSIONS

These data comprise the first comprehensive proteomic investigation of the BCR signaling response within CLL cells and reveal unique evidence that these cells undergo adaptive reprogramming of this signaling in response to therapy.

Progress in the development of small molecular inhibitors of the Bruton's tyrosine kinase (BTK) as a promising cancer therapy

Bruton tyrosine kinase (BTK) is a key kinase in the B cell antigen receptor signal transduction pathway, which is involved in the regulation of the proliferation, differentiation and apoptosis of B cells. BTK has become a significant target for the treatment of hematological malignancies and autoimmune diseases. Ibrutinib, the first-generation BTK inhibitor, has made a great contribution to the treatment of B cell malignant tumors, but there are still some problems such as resistance or miss target of site mutation. Therefore, there is an imperative need to develop novel BTK inhibitors to overcome these problems. Besides, proteolysis targeting chimera (PROTAC) technology has been successfully applied to the development of BTK degradation agents, which has opened a fresh way for the BTK targeted treatment. This paper reviews the biological function of BTK, the discovery and development of BTK targeted drugs as a promising cancer therapy. It mainly reviews the binding sites and structural characteristics of BTK, structure-activity relationships, activity and drug resistance of BTK inhibitors, as well as potential treatment strategies to overcome the resistance of BTK, which provides a reference for the rational design and development of new powerful BTK inhibitors.

PI3K inhibitors are finally coming of age

Overactive phosphoinositide 3-kinase (PI3K) in cancer and immune dysregulation has spurred extensive efforts to develop therapeutic PI3K inhibitors. Although progress has been hampered by issues such as poor drug tolerance and drug resistance, several PI3K inhibitors have now received regulatory approval - the PI3Kα isoform-selective inhibitor alpelisib for the treatment of breast cancer and inhibitors mainly aimed at the leukocyte-enriched PI3Kδ in B cell malignancies. In addition to targeting cancer cell-intrinsic PI3K activity, emerging evidence highlights the potential of PI3K inhibitors in cancer immunotherapy. This Review summarizes key discoveries that aid the clinical translation of PI3Kα and PI3Kδ inhibitors, highlighting lessons learnt and future opportunities.

Glycan-Lectin Interactions in Cancer and Viral Infections and How to Disrupt Them

Glycan-lectin interactions play an essential role in different cellular processes. One of their main functions is involvement in the immune response to pathogens or inflammation. However, cancer cells and viruses have adapted to avail themselves of these interactions. By displaying specific glycosylation structures, they are able to bind to lectins, thus promoting pathogenesis. While glycan-lectin interactions promote tumor progression, metastasis, and/or chemoresistance in cancer, in viral infections they are important for viral entry, release, and/or immune escape. For several years now, a growing number of investigations have been devoted to clarifying the role of glycan-lectin interactions in cancer and viral infections. Various overviews have already summarized and highlighted their findings. In this review, we consider the interactions of the lectins MGL, DC-SIGN, selectins, and galectins in both cancer and viral infections together. A possible transfer of ways to target and disrupt them might lead to new therapeutic approaches in different pathological backgrounds.

Network Pharmacology-Based Study to Uncover Potential Pharmacological Mechanisms of Korean Thistle (Cirsium japonicum var. maackii (Maxim.) Matsum.) Flower against Cancer

Cirsium japonicum var. maackii (Maxim.) Matsum. or Korean thistle flower is a herbal plant used to treat tumors in Korean folk remedies, but its essential bioactives and pharmacological mechanisms against cancer have remained unexplored. This study identified the main compounds(s) and mechanism(s) of the C. maackii flower against cancer via network pharmacology. The bioactives from the C. maackii flower were revealed by gas chromatography-mass spectrum (GC-MS), and SwissADME evaluated their physicochemical properties. Next, target(s) associated with the obtained bioactives or cancer-related targets were retrieved by public databases, and the Venn diagram selected the overlapping targets. The networks between overlapping targets and bioactives were visualized, constructed, and analyzed by RPackage. Finally, we implemented a molecular docking test (MDT) to explore key target(s) and compound(s) on AutoDockVina and LigPlot+. GC-MS detected a total of 34 bioactives and all were accepted by Lipinski's rules and therefore classified as drug-like compounds (DLCs). A total of 597 bioactive-related targets and 4245 cancer-related targets were identified from public databases. The final 51 overlapping targets were selected between the bioactive targets network and cancer-related targets. With Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment, a total of 20 signaling pathways were manifested, and a hub signaling pathway (PI3K-Akt signaling pathway), a key target (Akt1), and a key compound (Urs-12-en-24-oic acid, 3-oxo, methyl ester) were selected among the 20 signaling pathways via MDT. Overall, Urs-12-en-24-oic acid, 3-oxo, methyl ester from the C. maackii flower has potent anti-cancer efficacy by inactivating Akt1 on the PI3K-Akt signaling pathway.

Cerebral aspergillosis and facial acneiform lesions following initiation of ibrutinib in a patient with chronic lymphocytic leukemia

A case of a 67-year-old male with CLL, presented with prolonged pancytopenia after his first cycle of fludarabine, cyclophosphamide, and rituximab (FCR) chemotherapy. He was then treated with ibrutinib oral monotherapy. Shortly after ibrutinib treatment initiation, he developed a brain abscess and pulmonary disease as a part of an invasive aspergillosis. The patient improved after brain abscess drainage and the anti-fungal therapy voriconazole. Upon resuming ibrutinib four months after his hospitalization, he developed extensive acneiform facial lesions. This case is the first to report on the development of two separate complications in one patient related to ibrutinib, namely, Aspergillus infection, and severe acneiform skin lesions.

Targeting the tumor microenvironment in chronic lymphocytic leukemia

The tumor microenvironment (TME) plays an essential role in the development, growth, and survival of the malignant B-cell clone in chronic lymphocytic leukemia (CLL). Within the proliferation niches of lymph nodes, bone marrow, and secondary lymphoid organs, a variety of phenotypically and functionally altered cell types, including T cells, natural killer cells, monocytes/macrophages, endothelial and mesenchymal stroma cells, provide crucial survival signals, along with CLL-cellinduced suppression of antitumor immune responses. The B-cell receptor pathway plays a pivotal role in mediating the interaction between CLL cells and the TME. However, an increasing number of additional components of the multifactorial TME are being discovered. Although the majority of therapeutic strategies employed in CLL hitherto have focused on targeting the leukemic cells, emerging evidence implies that modulation of microenvironmental cells and CLL-TME interactions by novel therapeutic agents significantly affect their clinical efficacy. Thus, improving our understanding of CLL-TME interactions and how they are affected by current therapeutic agents may improve and guide treatment strategies. Identification of novel TME interactions may also pave the road for the development of novel therapeutic strategies targeting the TME. In this review, we summarize current evidence on the effects of therapeutic agents on cells and interactions within the TME. With a growing demand for improved and personalized treatment options in CLL, this review aims at inspiring future exploration of smart drug combination strategies, translational studies, and novel therapeutic targets in clinical trials.

Genetics of Chronic Lymphocytic Leukemia

ABSTRACT

During the past 10 years, relevant advances have been made in the understanding of the pathogenesis of chronic lymphocytic leukemia via the integrated analysis of its genome and related epigenome, and transcriptome. These analyses also had an impact on our understanding of the initiation, as well as of the evolution of chronic lymphocytic leukemia, including resistance to chemotherapy and sensitivity and resistance to novel targeted therapies. This chapter will review the current state of the art in this field, with emphasis on the genetic heterogeneity of the disease and the biological pathways that are altered by the genetic lesions.

Comprehensive analysis of ubiquitin-proteasome system genes related to prognosis and immunosuppression in head and neck squamous cell carcinoma

The ubiquitin-proteasome system (UPS) with a capacity of degrading multiple intracellular proteins is an essential regulator in tumor immunosurveillance. Tumor cells that escape from recognition and destruction of immune system have been consistently characterized an important hallmark in the setting of tumor progression. Little know about the exact functions of UPS-related genes (UPSGs) and their relationships with antitumor immunity in head and neck squamous cell carcinoma (HNSCC) patients. In this study, for the first time, we comprehensively identified 114 differentially expressed UPSGs (DEUPSGs) and constructed a prognostic risk model based on the eight DEUPSGs (BRCA1, OSTM1, PCGF2, PSMD2, SOCS1, UCHL1, UHRF1, and USP54) in the TCGA-HNSCC database. This risk model was validated using multiple data sets (all P < 0.05). The high-risk score was found to be an independently prognostic factor in HNSCC patients and was significantly correlated with T cells suppression. Accordingly, our risk model can act as a prognostic signature and provide a novel concept for improving the precise immunotherapy for patients with HNSCC.

Recent Advances in BTK Inhibitors for the Treatment of Inflammatory and Autoimmune Diseases

Bruton’s tyrosine kinase (BTK) plays a crucial role in B-cell receptor and Fc receptor signaling pathways. BTK is also involved in the regulation of Toll-like receptors and chemokine receptors. Given the central role of BTK in immunity, BTK inhibition represents a promising therapeutic approach for the treatment of inflammatory and autoimmune diseases. Great efforts have been made in developing BTK inhibitors for potential clinical applications in inflammatory and autoimmune diseases. This review covers the recent development of BTK inhibitors at preclinical and clinical stages in treating these diseases. Individual examples of three types of inhibitors, namely covalent irreversible inhibitors, covalent reversible inhibitors, and non-covalent reversible inhibitors, are discussed with a focus on their structure, bioactivity and selectivity. Contrary to expectations, reversible BTK inhibitors have not yielded a significant breakthrough so far. The development of covalent, irreversible BTK inhibitors has progressed more rapidly. Many candidates entered different stages of clinical trials; tolebrutinib and evobrutinib are undergoing phase 3 clinical evaluation. Rilzabrutinib, a covalent reversible BTK inhibitor, is now in phase 3 clinical trials and also offers a promising future. An analysis of the protein–inhibitor interactions based on published co-crystal structures provides useful clues for the rational design of safe and effective small-molecule BTK inhibitors.

Non-Covalent BTK Inhibitors-The New BTKids on the Block for B-Cell Malignancies

The B-cell receptor signalling pathway plays a critical role in development of B-cell malignancies, and the central role of Bruton’s tyrosine kinase (BTK) activation in this pathway provides compelling rationale for BTK inhibition as a therapeutic strategy for these conditions. Covalent BTK inhibitors (BTKi) have transformed the treatment landscape of B-cell malignancies, but adverse events and treatment resistance have emerged as therapeutic challenges, with the majority of patients eventually discontinuing treatment due to toxicity or disease progression. Non-covalent BTKi have alternative mechanisms of binding to BTK than covalent BTKi, and therefore offer a therapeutic alternative for patients with B-cell malignancies, including those who have been intolerant to, or experienced disease progression during treatment with a covalent BTKi. Here, we summarise the clinical data, adverse events and mechanisms of resistance observed with covalent BTKi and describe the emerging data for non-covalent BTKi as a novel treatment for B-cell malignancies.