Cytokines-activated nuclear IKKα-FAT10 pathway induces breast cancer tamoxifen-resistance.

Endocrine therapy that blocks estrogen signaling is the most effective treatment for patients with estrogen receptor positive (ER+) breast cancer. However, the efficacy of agents such as tamoxifen (Tam) is often compromised by the development of resistance. Here we report that cytokines-activated nuclear IKKα confers Tam resistance to ER+ breast cancer by inducing the expression of FAT10, and that the expression of FAT10 and nuclear IKKα in primary ER+ human breast cancer was correlated with lymphotoxin ß (LTB) expression and significantly associated with relapse and metastasis in patients treated with adjuvant mono-Tam. IKKα activation or enforced FAT10 expression promotes Tam-resistance while loss of IKKα or FAT10 augments Tam sensitivity. The induction of FAT10 by IKKα is mediated by the transcription factor Pax5, and coordinated via an IKKα-p53-miR-23a circuit in which activation of IKKα attenuates p53-directed repression of FAT10. Thus, our findings establish IKKα-to-FAT10 pathway as a new therapeutic target for the treatment of Tam-resistant ER+ breast cancer.

Triple-Negative Breast Cancer Intrinsic FTSJ1 Favors Tumor Progression and Attenuates CD8+ T Cell Infiltration.

FtsJ RNA 2'-O-methyltransferase 1 (FTSJ1) is a member of the methyltransferase superfamily and is involved in the processing and modification of ribosomal RNA. We herein demonstrate that FTSJ1 favors TNBC progression. The knockdown of FTSJ1 inhibits TNBC cell proliferation and development, induces apoptosis of cancer cells, and increases the sensitivity of TNBC cells to T-cell-mediated cytotoxicity. Furthermore, the high expression of FTSJ1 in TNBC attenuates CD8+T cell infiltration in the tumor microenvironment (TME) correlated with poorer prognosis for clinical TNBC patients. In this study, we establish that FTSJ1 acts as a tumor promotor, is involved in cancer immune evasion, and may serve as a potential immunotherapy target in TNBC.

DDX5 Functions as a Tumor Suppressor in Tongue Cancer.

DEAD-box polypeptide 5 (DDX5), a DEAD-box RNA helicase, is a multifunctional protein that plays important roles in many physiological and pathological processes. Contrary to its documented oncogenic role in a wide array of cancers, we herein demonstrate that DDX5 serves as a tumor suppressor in tongue cancer. The high expression of DDX5 is correlated with better prognosis for clinical tongue cancer patients. DDX5 downregulates the genes associated with tongue cancer progression. The knockdown of DDX5 promotes, while the overexpression of DDX5 inhibits, tongue cancer proliferation, development, and cisplatin resistance. Furthermore, the expression of DDX5 in tongue cancer is associated with immune cell infiltration in the tumor microenvironment. Specifically, the expression of DDX5 is associated with the reduced infiltration of M2 macrophages and increased infiltration of T cell clusters, which may contribute to anticancer effects in the tumor microenvironment. In this study, we establish DDX5 as a valuable prognostic biomarker and an important tumor suppressor in tongue cancer.

The Human Respiratory Microbiome: Current Understandings and Future Directions.

Microorganisms colonize the human body. The lungs and respiratory tract, previously believed to be sterile, harbor diverse microbial communities and the genomes of bacteria (bacteriome), viruses (virome), and fungi (mycobiome). Recent advances in amplicon and shotgun metagenomic sequencing technologies and data-analyzing methods have greatly aided the identification and characterization of microbial populations from airways. The respiratory microbiome has been shown to play roles in human health and disease and is an area of rapidly emerging interest in pulmonary medicine. In this review, we provide updated information in the field by focusing on four lung conditions, including asthma, chronic obstructive pulmonary disease, cystic fibrosis, and idiopathic pulmonary fibrosis. We evaluate gut, oral, and upper airway microbiomes and how they contribute to lower airway flora. The discussion is followed by a systematic review of the lower airway microbiome in health and disease. We conclude with promising research avenues and implications for evolving therapeutics.

Tumor-derived OBP2A promotes prostate cancer castration resistance.

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa); although most patients initially respond to ADT, almost all cancers eventually develop castration-resistant PCa (CRPC). Currently, most research focuses on castration-resistant tumors, and the role of tumors in remission is almost completely ignored. Here, we report that odorant-binding protein (OBP2A) released from tumors in remission during ADT catches survival factors, such as CXCL15/IL8, to promote PCa cell androgen-independent growth and enhance the infiltration of myeloid-derived suppressor cells (MDSCs) into tumor microenvironment, leading to the emergence of castration resistance. OBP2A knockdown significantly inhibits CRPC and metastatic CRPC development and improves therapeutic efficacy of CTLA-4/PD-1 antibodies. Treatment with OBP2A-binding ligand α-pinene interrupts the function of OBP2A and suppresses CRPC development. Furthermore, α-pinene-conjugated doxorubicin/docetaxel can be specifically delivered to tumors, resulting in improved anticancer efficacy. Thus, our studies establish a novel concept for the emergence of PCa castration resistance and provide new therapeutic strategies for advanced PCa.

Exploring the patient-microbiome interaction patterns for pan-cancer.

Microbes play important roles in human health and disease. Immunocompromised cancer patients are more vulnerable to getting microbial infections. Regions of hypoxia and acidic tumor microenvironment shape the microbial community diversity and abundance. Each cancer has its own microbiome, making cancer-specific sets of microbiomes. High-throughput profiling technologies provide a culture-free approach for microbial profiling in tumor samples. Microbial compositional data was extracted and examined from the TCGA unmapped transcriptome data. Biclustering, correlation, and statistical analyses were performed to determine the seven patient-microbe interaction patterns. These two-dimensional patterns consist of a group of microbial species that show significant over-representation over the 7 pan-cancer subtypes (S1-S7), respectively. Approximately 60% of the untreated cancer patients have experienced tissue microbial composition and functional changes between subtypes and normal controls. Among these changes, subtype S5 had loss of microbial diversity as well as impaired immune functions. S1, S2, and S3 had been enriched with microbial signatures derived from the Gammaproteobacteria, Actinobacteria and Betaproteobacteria, respectively. Colorectal cancer (CRC) was largely composed of two subtypes, namely S4 and S6, driven by different microbial profiles. S4 patients had increased microbial load, and were enriched with CRC-related oncogenic pathways. S6 CRC together with other cancer patients, making up almost 40% of all cases were classified into the S6 subtype, which not only resembled the normal control's microbiota but also retained their original "normal-like" functions. Lastly, the S7 was a rare and understudied subtype. Our study investigated the pan-cancer heterogeneity at the microbial level. The identified seven pan-cancer subtypes with 424 subtype-specific microbial signatures will help us find new therapeutic targets and better treatment strategies for cancer patients.

Choosing Kinase Inhibitors for Androgen Deprivation Therapy-Resistant Prostate Cancer.

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa). Although most patients initially respond to ADT, almost all cancers eventually develop castration resistance. Castration-resistant PCa (CRPC) is associated with a very poor prognosis, and the treatment of which is a serious clinical challenge. Accumulating evidence suggests that abnormal expression and activation of various kinases are associated with the emergence and maintenance of CRPC. Many efforts have been made to develop small molecule inhibitors to target the key kinases in CRPC. These inhibitors are designed to suppress the kinase activity or interrupt kinase-mediated signal pathways that are associated with PCa androgen-independent (AI) growth and CRPC development. In this review, we briefly summarize the roles of the kinases that are abnormally expressed and/or activated in CRPC and the recent advances in the development of small molecule inhibitors that target kinases for the treatment of CRPC.

Targeting Inflammatory Signaling in Prostate Cancer Castration Resistance.

Although castration-resistant prostate cancer (CRPC) as a whole, by its name, refers to the tumors that relapse and/or regrow independently of androgen after androgen deprivation therapy (ADT), untreated tumor, even in early-stage primary prostate cancer (PCa), contains androgen-independent (AI) PCa cells. The transformation of androgen-dependent (AD) PCa to AI PCa under ADT is a forced evolutionary process, in which the small group of AI PCa cells that exist in primary tumors has the unique opportunity to proliferate and expand selectively and dominantly, while some AD PCa cells that have escaped from ADT-induced death acquire the capability to survive in an androgen-depleted environment. The adaptation and reprogramming of both PCa cells and the tumor microenvironment (TME) under ADT make PCa much stronger than primary tumors so that, currently, there are no effective therapeutic methods available for the treatment of CRPC. Many mechanisms have been found to be related to the emergence and maintenance of PCa castration resistance; in this review, we focus on the role of inflammatory signaling in both PCa cells and the TME for the emergence and maintenance of CRPC and summarize the recent advances of therapeutic strategies that target inflammatory signaling for the treatment of CRPC.

Targeting INMT and interrupting its methylation pathway for the treatment of castration resistant prostate cancer.

BACKGROUND: Castration-resistant prostate cancer (CRPC) is associated with a very poor prognosis, and the treatment of which remains a serious clinical challenge. METHODS: RNA-seq, qPCR, western blot and immunohistochemistry were employed to identify and confirm the high expression of indolethylamine N-methyltransferase (INMT) in CRPC and the clinical relevance. Chip assay was used to identify Histone-Lysine N-Methyltransferase (SMYD3) as a major epigenetic regulator of INMT. LC-MS/MS were used to identify new substrates of INMT methylation in CRPC tissues. Gene knockdown/overexpression, MTT and mouse cancer models were used to examine the role of INMT as well as the anticancer efficacy of INMT inhibitor N,N-dimethyltryptamine (DMT), the SMYD3 inhibitor BCl-12, the selenium compounds methaneseleninic acid (MSA) and Se-(Methyl)selenocysteine hydrochloride (MSC), and the newly identified endogenous INMT substrate Bis(7)-tacrine. RESULTS: We found that the expression of INMT was highly increased in CRPC and was correlated with poor prognosis of clinical prostate cancer (PCa). INMT promoted PCa castration resistance via detoxification of anticancer metabolites. Knockdown of INMT or treatment with INMT inhibitor N,N-dimethyltryptamine (DMT) significantly suppressed CRPC development. Histone-Lysine N-Methyltransferase SMYD3 was a major epigenetic regulator of INMT expression, treatment with SMYD3 inhibitor BCl-121 suppressed INMT expression and inhibits CRPC development. Importantly, INMT knockdown significantly increased the anticancer effect of the exogenous selenium compounds methaneseleninic acid (MSA) and Se-(Methyl)selenocysteine hydrochloride (MSC) as well as the endogenous metabolite Bis(7)-tacrine. CONCLUSIONS: Our study suggests that INMT drives PCa castration resistance through detoxification of anticancer metabolites, targeting INMT or its regulator SMYD3 or/and its methylation metabolites represents an effective therapeutic avenue for CRPC treatment.

A Simple and Efficient System for Producing Recombinant Human CXCL8 in Escherichia coli.

Multifunctional pro-inflammatory cytokine CXCL8 is a small peptide of 8-10 kDa in size and it functions as a monomer or dimer. CXCL8 harbors 2 disulfide bonds for its stability. Although production of the CXCL8 protein in a large quantity in both mammalian and bacterial systems has been reported, the processes are complicated and lengthy. Here, we develop a new bacterial expression system for recombinant CXCL8 and simplify the purification system to yield a high amount of protein quickly. The purified CXCL8 protein from our new system develops a crystal structure that is identical to that produced through the mammalian expression system. Thus, we have established a simple and efficient recombinant CXCL8-producing system, which can be easily operated and is suitable to those requiring a large quantity of CXCL8.

Targeting Tumor Microenvironment by Small-Molecule Inhibitors.

The tumor microenvironment (TME) is a hypoxic, acidic, and immune/inflammatory cell-enriched milieu that plays crucial roles in tumor development, growth, progression, and therapy resistance. Targeting TME is an attractive strategy for the treatment of solid tumors. Conventional cancer chemotherapies are mostly designed to directly kill cancer cells, and the effectiveness is always compromised by their penetration and accessibility to cancer cells. Small-molecule inhibitors, which exhibit good penetration and accessibility, are widely studied, and many of them have been successfully applied in clinics for cancer treatment. As TME is more penetrable and accessible than tumor cells, a lot of efforts have recently been made to generate small-molecule inhibitors that specifically target TME or the components of TME or develop special drug-delivery systems that release the cytotoxic drugs specifically in TME. In this review, we briefly summarize the recent advances of small-molecule inhibitors that target TME for the tumor treatment.

A Constitutive Intrinsic Inflammatory Signaling Circuit Composed of miR-196b, Meis2, PPP3CC, and p65 Drives Prostate Cancer Castration Resistance.

Androgen deprivation therapy is the most effective treatment for advanced prostate cancer, but almost all cancer eventually becomes castration resistant, and the underlying mechanisms are largely unknown. Here, we show that an intrinsic constitutively activated feedforward signaling circuit composed of IκBα/NF-κB(p65), miR-196b-3p, Meis2, and PPP3CC is formed during the emergence of castration-resistant prostate cancer (CRPC). This circuit controls the expression of stem cell transcription factors that drives the high tumorigenicity of CRPC cells. Interrupting the circuit by targeting its individual components significantly impairs the tumorigenicity and CRPC development. Notably, constitutive activation of IκBα/NF-κB(p65) in this circuit is not dependent on the activation of traditional IKKß/NF-κB pathways that are important in normal immune responses. Therefore, our studies present deep insight into the bona fide mechanisms underlying castration resistance and provide the foundation for the development of CRPC therapeutic strategies that would be highly efficient while avoiding indiscriminate IKK/NF-κB inhibition in normal cells.

Bis-aryl urea derivatives as potent and selective LIM kinase (Limk) inhibitors.

The discovery/optimization of bis-aryl ureas as Limk inhibitors to obtain high potency and selectivity and appropriate pharmacokinetic properties through systematic SAR studies is reported. Docking studies supported the observed SAR. Optimized Limk inhibitors had high biochemical potency (IC50 < 25 nM), excellent selectivity against ROCK and JNK kinases (>400-fold), potent inhibition of cofilin phosphorylation in A7r5, PC-3, and CEM-SS T cells (IC50 < 1 µM), and good in vitro and in vivo pharmacokinetic properties. In the profiling against a panel of 61 kinases, compound 18b at 1 µM inhibited only Limk1 and STK16 with ≥80% inhibition. Compounds 18b and 18f were highly efficient in inhibiting cell-invasion/migration in PC-3 cells. In addition, compound 18w was demonstrated to be effective on reducing intraocular pressure (IOP) on rat eyes. Taken together, these data demonstrated that we had developed a novel class of bis-aryl urea derived potent and selective Limk inhibitors.

Selective TBK1/IKKi dual inhibitors with anticancer potency.

Increasing evidence suggests that the noncanonical IKKs play critical roles in tumor genesis and development, leading to the notion that noncanonical IKKs may be good targets for cancer therapy. Here, we demonstrate that although TBK1 is not overexpressed or constitutively activated in some tumor cells, targeting IKKi induces the activation of TBK1. Therefore, simultaneously targeting both kinases is necessary to efficiently suppress tumor cell proliferation. We show that three TBK1/IKKi dual inhibitors, which are based on a structurally rigid 2-amino-4-(3'-cyano-4'-pyrrolidine)phenyl-pyrimidine scaffold, potently inhibit cell viability in human breast, prostate and oral cancer cell lines. Treatment with these TBK1/IKKi dual inhibitors significantly impairs tumor development in xenograft and allograft mouse models. The anticancer function of these inhibitors may be partially due to their suppression of TBK1/IKKi-mediated AKT phosphorylation and VEGF expression. Most importantly, these TBK1/IKKi dual inhibitors have drug-like properties including low molecular weight, low cytochrome P450 inhibition and high metabolic stability. Therefore, our studies provide proof of concept for further drug discovery efforts that may lead to novel strategies and new therapeutics for the treatment of human cancer.

IL6-mediated suppression of miR-200c directs constitutive activation of inflammatory signaling circuit driving transformation and tumorigenesis.

Abnormal inflammatory signaling activation occurs commonly in cancer cells. However, how it is initiated and maintained and its roles in early stages of tumorigensis are largely unknown. Here, we report that the monocyte-derived MCP-1-induced transformation of immortal breast epithelial cells is triggered by transient activation of MEK/ERK and IKK/NF-κB pathways and maintained by constitutive activation of a feed-forward inflammatory signaling circuit composed of miR-200c, p65, JNK2, HSF1, and IL6. Suppression of miR-200c by IL6 constitutively activates p65/RelA and JNK2, and the latter phosphorylates and activates HSF1. In turn, HSF1 triggers demethylation of the IL6 promoter that facilitates the binding of p65 and c-Jun, which together drive constitutive IL6 transcription. Importantly, this signaling circuit is manifest in human cancer cells and in a mouse model of ErbB2-driven breast cancer, where IL6 loss significantly impairs tumorigenesis. Therefore, targeting this signaling circuit represents an effective therapeutic avenue for breast cancer prevention and treatment.

Nonoverlapping functions for Notch1 and Notch3 during murine steady-state thymic lymphopoiesis.

Notch1 signaling is absolutely essential for steady-state thymic lymphopoiesis, but the role of other Notch receptors, and their potential overlap with the function of Notch1, remains unclear. Here we show that like Notch1, Notch3 is differentially expressed by progenitor thymocytes, peaking at the DN3 progenitor stage. Using mice carrying a gene-trapped allele, we show that thymic cellularity is slightly reduced in the absence of Notch3, although progression through the defined sequence of TCR-αß development is normal, as are NKT and TCRγδ cell production. The absence of a profound effect from Notch3 deletion is not explained by residual function of the gene-trapped allele because insertion mapping suggests that the targeted allele would not encode functional signaling domains. We also show that although Notch1 and Notch3 are coexpressed on some early intrathymic progenitors, the relatively mild phenotype seen after Notch3 deletion does not result from the compensatory function of Notch1, nor does Notch3 function explain the likewise mild phenotype seen after conditional (intrathymic) deletion of Notch1. Our studies indicate that Notch1 and Notch3 carry out nonoverlapping functions during thymocyte differentiation, and that while Notch1 is absolutely required early in the lymphopoietic process, neither receptor is essential at later stages.

B-cell-derived lymphotoxin promotes castration-resistant prostate cancer.

Prostate cancer (CaP) progresses from prostatic intraepithelial neoplasia through locally invasive adenocarcinoma to castration-resistant metastatic carcinoma. Although radical prostatectomy, radiation and androgen ablation are effective therapies for androgen-dependent CaP, metastatic castration-resistant CaP is a major complication with high mortality. Androgens stimulate growth and survival of prostate epithelium and early CaP. Although most patients initially respond to androgen ablation, many develop castration-resistant CaP within 12-18 months. Despite extensive studies, the mechanisms underlying the emergence of castration-resistant CaP remain poorly understood and their elucidation is critical for developing improved therapies. Curiously, castration-resistant CaP remains androgen-receptor dependent, and potent androgen-receptor antagonists induce tumour regression in castrated mice. The role of inflammation in castration-resistant CaP has not been addressed, although it was reported that intrinsic NF-kappaB activation supports its growth. Inflammation is a localized protective reaction to injury or infection, but it also has a pathogenic role in many diseases, including cancer. Whereas acute inflammation is critical for host defence, chronic inflammation contributes to tumorigenesis and metastatic progression. The inflammation-responsive IkappaB kinase (IKK)-beta and its target NF-kappaB have important tumour-promoting functions within malignant cells and inflammatory cells. The latter, including macrophages and lymphocytes, are important elements of the tumour microenvironment, but the mechanisms underlying their recruitment remain obscure, although they are thought to depend on chemokine and cytokine production. We found that CaP progression is associated with inflammatory infiltration and activation of IKK-alpha, which stimulates metastasis by an NF-kappaB-independent, cell autonomous mechanism. Here we show that androgen ablation causes infiltration of regressing androgen-dependent tumours with leukocytes, including B cells, in which IKK-beta activation results in production of cytokines that activate IKK-alpha and STAT3 in CaP cells to enhance hormone-free survival.

Haematopoietic malignancies caused by dysregulation of a chromatin-binding PHD finger.

Histone H3 lysine 4 methylation (H3K4me) has been proposed as a critical component in regulating gene expression, epigenetic states, and cellular identities1. The biological meaning of H3K4me is interpreted by conserved modules including plant homeodomain (PHD) fingers that recognize varied H3K4me states. The dysregulation of PHD fingers has been implicated in several human diseases, including cancers and immune or neurological disorders. Here we report that fusing an H3K4-trimethylation (H3K4me3)-binding PHD finger, such as the carboxy-terminal PHD finger of PHF23 or JARID1A (also known as KDM5A or RBBP2), to a common fusion partner nucleoporin-98 (NUP98) as identified in human leukaemias, generated potent oncoproteins that arrested haematopoietic differentiation and induced acute myeloid leukaemia in murine models. In these processes, a PHD finger that specifically recognizes H3K4me3/2 marks was essential for leukaemogenesis. Mutations in PHD fingers that abrogated H3K4me3 binding also abolished leukaemic transformation. NUP98-PHD fusion prevented the differentiation-associated removal of H3K4me3 at many loci encoding lineage-specific transcription factors (Hox(s), Gata3, Meis1, Eya1 and Pbx1), and enforced their active gene transcription in murine haematopoietic stem/progenitor cells. Mechanistically, NUP98-PHD fusions act as 'chromatin boundary factors', dominating over polycomb-mediated gene silencing to 'lock' developmentally critical loci into an active chromatin state (H3K4me3 with induced histone acetylation), a state that defined leukaemia stem cells. Collectively, our studies represent, to our knowledge, the first report that deregulation of the PHD finger, an 'effector' of specific histone modification, perturbs the epigenetic dynamics on developmentally critical loci, catastrophizes cellular fate decision-making, and even causes oncogenesis during mammalian development.