Fes tyrosine kinase expression in the tumor niche correlates with enhanced tumor growth, angiogenesis, circulating tumor cells, metastasis, and infiltrating macrophages

Non-Receptor Tyrosine Kinases: Their Structure and Mechanistic Role in Tumor Progression and Resistance

Protein tyrosine kinases (PTKs) function as key molecules in the signaling pathways in addition to their impact as a therapeutic target for the treatment of many human diseases, including cancer. PTKs are characterized by their ability to phosphorylate serine, threonine, or tyrosine residues and can thereby rapidly and reversibly alter the function of their protein substrates in the form of significant changes in protein confirmation and affinity for their interaction with protein partners to drive cellular functions under normal and pathological conditions. PTKs are classified into two groups: one of which represents tyrosine kinases, while the other one includes the members of the serine/threonine kinases. The group of tyrosine kinases is subdivided into subgroups: one of them includes the member of receptor tyrosine kinases (RTKs), while the other subgroup includes the member of non-receptor tyrosine kinases (NRTKs). Both these kinase groups function as an "on" or "off" switch in many cellular functions. NRTKs are enzymes which are overexpressed and activated in many cancer types and regulate variable cellular functions in response to extracellular signaling-dependent mechanisms. NRTK-mediated different cellular functions are regulated by kinase-dependent and kinase-independent mechanisms either in the cytoplasm or in the nucleus. Thus, targeting NRTKs is of great interest to improve the treatment strategy of different tumor types. This review deals with the structure and mechanistic role of NRTKs in tumor progression and resistance and their importance as therapeutic targets in tumor therapy.

Multi-omics analysis of overexpressed tumor-associated proteins: gene expression, immunopeptide presentation, and antibody response in oropharyngeal squamous cell carcinoma, with a focus on cancer-testis antigens

Introduction

The human leukocyte antigen complex (HLA) is essential for inducing specific immune responses to cancer by presenting tumor-associated peptides (TAP) to T cells. Overexpressed tumor associated antigens, mainly cancer-testis antigens (CTA), are outlined as essential targets for immunotherapy in oropharyngeal squamous cell carcinoma (OPSCC). This study assessed the degree to which presentation, gene expression, and antibody response (AR) of TAP, mainly CTA, are correlated in OPSCC patients to evaluate their potential as immunotherapy targets.

Materials and methods

Snap-frozen tumor (NLigand/RNA=40), healthy mucosa (NRNA=6), and healthy tonsils (NLigand=5) samples were obtained. RNA-Seq was performed using Illumina HiSeq 2500/NovaSeq 6000 and whole exome sequencing (WES) utilizing NextSeq500. HLA ligands were isolated from tumor tissue using immunoaffinity purification, UHPLC, and analyzed by tandem MS. Antibodies were measured in serum (NAb=27) utilizing the KREX™ CT262 protein array. Data analysis focused on 312 proteins (KREX™ CT262 panel + overexpressed self-proteins).

Results

183 and 94 of HLA class I and II TAP were identified by comparative profiling with healthy tonsils. Genes from 26 TAP were overexpressed in tumors compared to healthy mucosa (LFC>1; FDR<0.05). Low concordance (r=0.25; p<0.0001) was found between upregulated mRNA and class I TAP. The specific mode of correlation of TAP was found to be dependent on clinical parameters. A lack of correlation was observed both between mRNA and class II TAP, as well as between class II tumor-unique TAP (TAP-U) presentation and antibody response (AR) levels.

Discussion

This study demonstrates that focusing exclusively on gene transcript levels fails to capture the full extent of TAP presentation in OPSCC. Furthermore, our findings reveal that although CTA are presented at relatively low levels, a few CTA TAP-U show potential as targets for immunotherapy.

Stromal Co-Cultivation for Modeling Breast Cancer Dormancy in the Bone Marrow

Cancers metastasize to the bone marrow before primary tumors can be detected. Bone marrow micrometastases are resistant to therapy, and while they are able to remain dormant for decades, they recur steadily and result in incurable metastatic disease. The bone marrow microenvironment maintains the dormancy and chemoresistance of micrometastases through interactions with multiple cell types and through structural and soluble factors. Modeling dormancy in vitro can identify the mechanisms of these interactions. Modeling also identifies mechanisms able to disrupt these interactions or define novel interactions that promote the reawakening of dormant cells. The in vitro modeling of the interactions of cancer cells with various bone marrow elements can generate hypotheses on the mechanisms that control dormancy, treatment resistance and reawakening in vivo. These hypotheses can guide in vivo murine experiments that have high probabilities of succeeding in order to verify in vitro findings while minimizing the use of animals in experiments. This review outlines the existing data on predominant stromal cell types and their use in 2D co-cultures with cancer cells.

Integrative multi-omic analysis identifies genetically influenced DNA methylation biomarkers for breast and prostate cancers

Aberrant DNA methylation has emerged as a hallmark in several cancers and contributes to risk, oncogenesis, progression, and prognosis. In this study, we performed imputation-based and conventional methylome-wide association analyses for breast cancer (BrCa) and prostate cancer (PrCa). The imputation-based approach identified DNA methylation at cytosine-phosphate-guanine sites (CpGs) associated with BrCa and PrCa risk utilising genome-wide association summary statistics (N_BrCa = 228,951, N_PrCa = 140,254) and prebuilt methylation prediction models, while the conventional approach identified CpG associations utilising TCGA and GEO experimental methylation data (N_BrCa = 621, N_PrCa = 241). Enrichment analysis of the association results implicated 77 and 81 genetically influenced CpGs for BrCa and PrCa, respectively. Furthermore, analysis of differential gene expression around these CpGs suggests a genome-epigenome-transcriptome mechanistic relationship. Conditional analyses identified multiple independent secondary SNP associations (P_cond < 0.05) around 28 BrCa and 22 PrCa CpGs. Cross-cancer analysis identified eight common CpGs, including a strong therapeutic target in SREBF1 (17p11.2)—a key player in lipid metabolism. These findings highlight the utility of integrative analysis of multi-omic cancer data to identify robust biomarkers and understand their regulatory effects on cancer risk.

Methylome-wide association studies identify genetically-influenced CpGs associated with breast and prostate cancer risk and (epi)genome-transcriptome mechanistic relationships, with lipid metabolism genes implicated as potential therapeutic targets.

Immunophenotype-associated gene signature in ductal breast tumors varies by receptor subtype, but the expression of individual signature genes remains consistent

BACKGROUND

In silico deconvolution of invasive immune cell infiltration in bulk breast tumors helps characterize immunophenotype, expands treatment options, and influences survival endpoints. In this study, we identify the differential expression (DE) of the LM22 signature to classify immune-rich and -poor breast tumors and evaluate immune infiltration by receptor subtype and lymph node metastasis.

METHODS

Using publicly available data, we applied the CIBERSORT algorithm to estimate immune cells infiltrating the tumor into immune-rich and immune-poor groups. We then tested the association of receptor subtype and nodal status with immune-rich/poor phenotype. We used DE to test individual signature genes and over-representation analysis for related pathways.

RESULTS

CCL19 and CXCL9 expression differed between rich/poor signature groups regardless of subtype. Overexpression of CHI3L2 and FES was observed in triple negative breast cancers (TNBCs) relative to other subtypes in immune-rich tumors. Non-signature genes, LYZ, C1QB, CORO1A, EVI2B, GBP1, PSMB9, and CD52 were consistently overexpressed in immune-rich tumors, and SCUBE2 and GRIA2 were associated with immune-poor tumors. Immune-rich tumors had significant upregulation of genes/pathways while none were identified in immune-poor tumors.

CONCLUSIONS

Overall, the proportion of immune-rich/poor tumors differed by subtype; however, a subset of 10 LM22 genes that marked immune-rich status remained the same across subtype. Non-LM22 genes differentially expressed between the phenotypes suggest that the biologic processes responsible for immune-poor phenotype are not yet well characterized.

Targeting BRD9 for Cancer Treatment: A New Strategy

Bromodomain-containing protein 9 (BRD9) is a newly identified subunit of the non-canonical barrier-to-autointegration factor (ncBAF) complex and a member of the bromodomain family IV. Studies have confirmed that BRD9 plays an oncogenic role in multiple cancer types, by regulating tumor cell growth. The tumor biological functions of BRD9 are mainly due to epigenetic modification mediated by its bromodomain. The bromodomain recruits the ncBAF complex to the promoter to regulate gene transcription. This review summarizes the potential mechanisms of action of BRD9 in carcinogenesis and the emerging strategies for targeting BRD9 for cancer therapeutics. Although the therapeutic potential of BRD9 has been exploited to some extent, research on the detailed biological mechanisms of BRD9 is still in its infancy. Therefore, targeting BRD9 to study its biological roles will be an attractive tool for cancer diagnosis and treatment, but it remains a great challenge.

Epigenomic profiling of DNA methylation for hepatocellular carcinoma diagnosis and prognosis prediction

BACKGROUND AND AIM

DNA hypermethylation has emerged as a novel molecular biomarker for the diagnosis and prognosis prediction of many cancers. We aimed to identify clinically useful biomarkers regulated by DNA methylation in hepatocellular carcinoma (HCC).

METHODS

Genome-wide methylation analysis in HCCs and paired noncancerous tissues was performed using an Illumina Infinium HumanMethylation 450K BeadChip array. Methylation-specific polymerase chain reaction and pyrosequencing were used to validate the methylation status of selected genes in 100 paired HCCs and noncancerous samples.

RESULTS

A total of 97 027 (20.0%) out of 485 577 CpG sites significantly were differed between HCC and noncancerous tissues. Among all the significant CpG sites, 48.8% are hypermethylated and 51.2% are hypomethylated in HCCs. Multiple signaling pathways (AMP-activated protein kinase, estrogen, and adipocytokine) involved in gene methylation were identified in HCC. FES was selected for further analysis based on its high level of methylation confirmed by polymerase chain reaction and pyrosequencing. The result showed that FES hypermethylation was correlated with tumor size (0.001), serum alpha fetoprotein (0.023), and tumor differentiation (0.006). FES protein was significantly downregulated in 51/100 (51%) HCCs, and 94.12% (48/51) of them were due to promoter hypermethylation. Both FES hypermethylation and protein downregulation were associated with the progression-free survival and overall survival of HCC patients. Overexpressed and knockdown of FES confirmed its inhibitory effect on the proliferation and migration of HCC cells.

CONCLUSIONS

We identified many new differentially methylated CpGs in HCCs and demonstrate that FES functions as a tumor suppressor gene in HCC and its methylation status could be used as an indicator for prognosis of HCC.

Identification of FES as a Novel Radiosensitizing Target in Human Cancers

PURPOSE

The identification of novel targets for developing synergistic drug-radiation combinations would pave the way to overcome tumor radioresistance. We conducted cell-based screening of a human kinome siRNA library to identify a radiation-specific kinase that has a synergistic toxic effect with radiation upon inhibition and is not essential for cell survival in the absence of radiation.

EXPERIMENTAL DESIGN

Unbiased RNAi screening was performed by transfecting A549 cells with a human kinome siRNA library followed by irradiation. Radiosensitizing effects of a target gene and involved mechanisms were examined.

RESULTS

We identified the nonreceptor protein tyrosine kinase FES (FEline Sarcoma oncogene) as a radiosensitizing target. The expression of FES was increased in response to irradiation. Cell viability and clonogenic survival after irradiation were significantly decreased by FES knockdown in lung and pancreatic cancer cell lines. In contrast, FES depletion alone did not significantly affect cell proliferation without irradiation. An inducible RNAi mouse xenograft model verified in vivo radiosensitizing effects. FES-depleted cells showed increased apoptosis, DNA damage, G₂-M phase arrest, and mitotic catastrophe after irradiation. FES depletion promoted radiation-induced reactive oxygen species formation, which resulted in phosphorylation of S6K and MDM2. The radiosensitizing effect of FES knockdown was partially reversed by inhibition of S6K activity. Consistent with the increase in phosphorylated MDM2, an increase in nuclear p53 levels was observed, which appears to contribute increased radiosensitivity of FES-depleted cells.

CONCLUSIONS

We uncovered that inhibition of FES could be a potential strategy for inducing radiosensitization in cancer. Our results provide the basis for developing novel radiosensitizers.

Synthesis and Evaluation of the Anticancer and Trypanocidal Activities of Boronic Tyrphostins

Molecules containing an (cyanovinyl)arene moiety are known as tyrphostins because of their ability to inhibit proteins from the tyrosine kinase family, an interesting target for the development of anticancer and trypanocidal drugs. In the present work, (E)-(cyanovinyl)benzeneboronic acids were synthesized by Knoevenagel condensations without the use of any catalysts in water through a simple protocol that completely avoided the use of organic solvents in the synthesis and workup process. The in vitro anticancer and trypanocidal activities of the synthesized boronic acids were also evaluated, and it was discovered that the introduction of the boronic acid functionality improved the activity of the boronic tyrphostins. In silico target fishing with the use of a chemogenomic approach suggested that tyrosine-phosphorylation-regulated kinase 1a (DYRK1A) was a potential target for some of the designed compounds.

Pathological significance and prognostic significance of FES expression in bladder cancer vary according to tumor grade

Purpose

The feline sarcoma oncogene protein (FES) is a non-receptor tyrosine kinase implicated in both oncogenesis and tumor suppression. Here, cancer cell lines and human tissues were employed to clarify the pathological and prognostic significance of FES in bladder cancer.

Methods

The relationship between FES expression and cancer aggressiveness was investigated using 3 cell lines (T24: corresponding to grade 3, 5637: corresponding to grade 2, and RT4: corresponding to grade 1) and 203 tissues derived from human bladder malignancies. Proliferation, invasion, and migration of cancer cells were assessed following the knockdown (KD) of FES expression by the siRNA method. Relationships between FES expression and pathological features, aggressiveness, and outcome were investigated.

Results

FES-KD inhibited the proliferation, migration, and invasion of T24 cells but not of RT4 cells and 5637 cells. Considering all patients, FES expression demonstrated a negative relationship with grade but no association with muscle invasion or cancer cell proliferation. However, it was positively correlated with pT stage and cell proliferation in high-grade tumors (p = 0.002); no such association was found for low-grade tumors. In addition, elevated FES expression was a negative prognostic indicator of metastasis after radical surgery for patients with high-grade tumors (p = 0.021) but not for those with low-grade malignancies.

Conclusions

FES appeared to act as a suppressor of carcinogenesis, being associated with low tumor grade in the overall patient group. However, its expression correlated with cancer aggressiveness and poor outcome in high-grade bladder cancer. FES, therefore, represents a potential therapeutic target and useful prognostic factor for such patients.

Interleukin-4 Expressed By Neoplastic Cells Provokes an Anti-Metastatic Myeloid Immune Response

OBJECTIVE

Interleukin-4 (IL-4) can induce macrophages to undergo alternative activation and polarize toward an M2-like or wound healing phenotype. Tumor associated macrophages (TAMs) are thought to assume M2-like properties, and it has been suggested they promote tumor growth and metastasis through effects on the tumor stroma, including extracelluar matrix remodeling and angiogenesis. IL-4 also promotes macrophage survival and formation of multinucleated giant cells, which have enhanced phagocytic behavior. This study was designed to explore the effect of cancer cell derived IL-4 on the tumor immune stroma and metastasis.

METHODS

The metastatic mouse mammary carcinoma cell line AC2M2 was transduced with control or IL-4 encoding retroviruses and employed in orthotopic engraftment models. Tumor growth and metastasis were assessed. The cellular composition and biomarker expression of tumors were examined by immunohistochemical staining and flow cytometry; the transcriptome of the immune stroma was analyzed by nanoString based transcript quantitation; and in vivo and in vitro interactions between cancer cells and macrophages were assessed by flow cytometry and co-culture with video-time lapse microscopy, respectively.

RESULTS

Unexpectedly, tumors from IL-4 expressing AC2M2 engrafted cells grew at reduced rates, and most surprising, they lost all metastatic potential relative to tumors from control AC2M2 cells. Myeloid cell numbers were not increased in IL-4 expressing tumors, but their expression of the M2 marker arginase I was elevated. Transcriptome analysis revealed an immune signature consistent with IL-4 induced M2 polarization of the tumor microenvironment and a generalized increase in myeloid involvement in the tumor stroma. Flow cytometry analysis indicated enhanced cancer cell phagocytosis by TAMs from IL-4 expressing tumors, and co-culture studies showed that IL-4 expressing cancer cells supported the survival and promoted the in vitro phagocytic behavior of macrophages.

CONCLUSIONS

Although M2-like TAMs have been linked to enhanced tumorigenesis, this study shows that IL-4 production by cancer cells is associated with suppressed tumor growth and loss of metastatic potential as well as enhanced phagocytic behavior of TAMs.

Discovery of I-BRD9, a Selective Cell Active Chemical Probe for Bromodomain Containing Protein 9 Inhibition

Acetylation of histone lysine residues is one of the most well-studied post-translational modifications of chromatin, selectively recognized by bromodomain "reader" modules. Inhibitors of the bromodomain and extra terminal domain (BET) family of bromodomains have shown profound anticancer and anti-inflammatory properties, generating much interest in targeting other bromodomain-containing proteins for disease treatment. Herein, we report the discovery of I-BRD9, the first selective cellular chemical probe for bromodomain-containing protein 9 (BRD9). I-BRD9 was identified through structure-based design, leading to greater than 700-fold selectivity over the BET family and 200-fold over the highly homologous bromodomain-containing protein 7 (BRD7). I-BRD9 was used to identify genes regulated by BRD9 in Kasumi-1 cells involved in oncology and immune response pathways and to the best of our knowledge, represents the first selective tool compound available to elucidate the cellular phenotype of BRD9 bromodomain inhibition.

Pharmacological profiling of kinase dependency in cell lines across triple-negative breast cancer subtypes

Triple-negative breast cancers (TNBC), negative for estrogen receptor, progesterone receptor, and ERBB2 amplification, are resistant to standard targeted therapies and exhibit a poor prognosis. Furthermore, they are highly heterogeneous with respect to genomic alterations, and common therapeutic targets are lacking though substantial evidence implicates dysregulated kinase signaling. Recently, six subtypes of TNBC were identified based on gene expression and were proposed to predict sensitivity to a variety of therapeutic agents including kinase inhibitors. To test this hypothesis, we screened a large collection of well-characterized, small molecule kinase inhibitors for growth inhibition in a panel of TNBC cell lines representing all six subtypes. Sensitivity to kinase inhibition correlated poorly with TNBC subtype. Instead, unsupervised clustering segregated TNBC cell lines according to clinically relevant features including dependence on epidermal growth factor signaling and mutation of the PTEN tumor suppressor. We further report the discovery of kinase inhibitors with selective toxicity to these groups. Overall, however, TNBC cell lines exhibited diverse sensitivity to kinase inhibition consistent with the lack of common driver mutations in this disease. Although our findings support specific kinase dependencies in subsets of TNBC, they are not associated with gene expression-based subtypes. Instead, we find that mutation status can be an effective predictor of sensitivity to inhibition of particular kinase pathways for subsets of TNBC.

SPE-8, a protein-tyrosine kinase, localizes to the spermatid cell membrane through interaction with other members of the SPE-8 group spermatid activation signaling pathway in C. elegans

Background

The SPE-8 group gene products transduce the signal for spermatid activation initiated by extracellular zinc in C. elegans. Mutations in the spe-8 group genes result in hermaphrodite-derived spermatids that cannot activate to crawling spermatozoa, although spermatids from mutant males activate through a pathway induced by extracellular TRY-5 protease present in male seminal fluid.

Results

Here, we identify SPE-8 as a member of a large family of sperm-expressed non-receptor-like protein-tyrosine kinases. A rescuing SPE-8::GFP translational fusion reporter localizes to the plasma membrane in all spermatogenic cells from the primary spermatocyte stage through spermatids. Once spermatids become activated to spermatozoa, the reporter moves from the plasma membrane to the cytoplasm. Mutations in the spe-8 group genes spe-12, spe-19, and spe-27 disrupt localization of the reporter to the plasma membrane, while localization appears near normal in a spe-29 mutant background.

Conclusions

These results suggest that the SPE-8 group proteins form a functional complex localized at the plasma membrane, and that SPE-8 is correctly positioned only when all members of the SPE-8 group are present, with the possible exception of SPE-29. Further, SPE-8 is released from the membrane when the activation signal is transduced into the spermatid.

Comprehensive analysis of the genome transcriptome and proteome landscapes of three tumor cell lines

We here present a comparative genome, transcriptome and functional network analysis of three human cancer cell lines (A431, U251MG and U2OS), and investigate their relation to protein expression. Gene copy numbers significantly influenced corresponding transcript levels; their effect on protein levels was less pronounced. We focused on genes with altered mRNA and/or protein levels to identify those active in tumor maintenance. We provide comprehensive information for the three genomes and demonstrate the advantage of integrative analysis for identifying tumor-related genes amidst numerous background mutations by relating genomic variation to expression/protein abundance data and use gene networks to reveal implicated pathways.

The BAR Domain Superfamily Proteins from Subcellular Structures to Human Diseases

Eukaryotic cells have complicated membrane systems. The outermost plasma membrane contains various substructures, such as invaginations and protrusions, which are involved in endocytosis and cell migration. Moreover, the intracellular membrane compartments, such as autophagosomes and endosomes, are essential for cellular viability. The Bin-Amphiphysin-Rvs167 (BAR) domain superfamily proteins are important players in membrane remodeling through their structurally determined membrane binding surfaces. A variety of BAR domain superfamily proteins exist, and each family member appears to be involved in the formation of certain subcellular structures or intracellular membrane compartments. Most of the BAR domain superfamily proteins contain SH3 domains, which bind to the membrane scission molecule, dynamin, as well as the actin regulatory WASP/WAVE proteins and several signal transduction molecules, providing possible links between the membrane and the cytoskeleton or other machineries. In this review, we summarize the current information about each BAR superfamily protein with an SH3 domain(s). The involvement of BAR domain superfamily proteins in various diseases is also discussed.

Targeting the tumor microenvironment: focus on angiogenesis

Tumorigenesis is a complex multistep process involving not only genetic and epigenetic changes in the tumor cell but also selective supportive conditions of the deregulated tumor microenvironment. One key compartment of the microenvironment is the vascular niche. The role of angiogenesis in solid tumors but also in hematologic malignancies is now well established. Research on angiogenesis in general, and vascular endothelial growth factor in particular, is a major focus in biomedicine and has led to the clinical approval of several antiangiogenic agents including thalidomide, bevacizumab, sorafenib, sunitinib, pazopanib, temesirolimus, and everolimus. Indeed, antiangiogenic agents have significantly changed treatment strategies in solid tumors (colorectal cancer, renal cell carcinoma, and breast cancer) and multiple myeloma. Here we illustrate important aspects in the interrelationship between tumor cells and the microenvironment leading to tumor progression, with focus on angiogenesis, and summarize derived targeted therapies.