Heart Failure Post-Myocardial Infarction Promotes Mammary Tumor Growth Through the NGF-TRKA Pathway

Background

Epidemiological investigations suggest that patients with heart failure have a higher incidence of cancer; however, the causal role of cardiac disease on cancer progression remains unclear.

Objectives

This study aimed to investigate the impact and underlying mechanisms of myocardial infarction (MI)-induced heart failure on tumor cell growth.

Methods

We generated a syngeneic mouse model by implanting mammary tumor-derived 4T1 cells into BALB/c mice with MI resulting from ligation of the left anterior descending artery.

Results

Mice with MI exhibited increased tumor volume, tumor weight, and Ki67-positive proliferative cells in the tumor tissue compared with the sham-operated mice. Furthermore, RNA sequencing analysis in the tumor tissue revealed significant enrichment of pathways related to tumor progression, particularly the PI3K-AKT pathway in the MI mice. Upregulation of tropomyosin receptor kinase A (TRKA) phosphorylation, an upstream regulator of PI3K-AKT signaling, was observed in the tumor tissue of the MI mice. We also observed elevated levels of circulating nerve growth factor (NGF), a ligand of TRKA, and increased NGF expressions in the myocardium after MI. In in vitro experiments, NGF stimulation led to increased cell proliferation, as well as phosphorylation of TRKA and AKT. Notably, inhibition of TRKA by small interfering RNA or the chemical inhibitor GW441756 effectively blocked these effects. Administration of GW441756 resulted in the suppression of tumor volume and cell proliferation in the MI mice.

Conclusions

Our study demonstrates that MI promotes mammary tumor growth through the NGF-TRKA pathway. Consequently, inhibiting TRKA could represent a therapeutic strategy for breast cancer patients concurrently experiencing heart failure after MI.

Regulating Tumorigenicity and Cancer Metastasis through TRKA Signaling

Tropomyosin receptor kinase (TRK) A, TRKA, is a specific binding receptor of nerve growth factor (NGF), which plays an essential role in the occurrence and progression of human cancers. TRKA overexpression has been proven to be a powerful carcinogenic driver and has been verified in many tumors. The TRKA receptor kinase domain is over-activated in an NGF-dependent manner, accompanied by activation of downstream signal pathways, such as RAS-MAPK, PI3K-AKT, JAK2-STAT3 pathway, PLC γ pathway, and Hippo pathway, which participate in tumor cell proliferation, invasion, epithelial-mesenchymal transition (EMT), perineural invasion (PNI), drug resistance, and cancer pain. In addition, chimeric oncogenes produced by the fusion of NTRK1 and other genes are also the direct cause of tumorigenesis and cancer development. The newly developed TRK inhibitors can improve symptoms and tumor regression in cancer patients with overexpression of TRKA or NTRK1 fusion gene. With the emergence of drug resistance, next generation of TRK inhibitors can still maintain strong clinical efficacy in the case of TRK kinase domain mutations, and these inhibitors are in clinical trials. This review summarizes the characteristics and research progress of TRKA, focusing on the regulatory role of the TRKA signal pathway in different tumors. In addition, we have summarized the clinical significance of TRKA and the TRK inhibitors. This review may provide a new reference for the study of the mechanism of TRKA in different tumors, and also provide a new perspective for the in-depth understanding of the role of TRKA as a biomarker and therapeutic target in human cancer.

NGF/TRKA Promotes ADAM17-Dependent Cleavage of P75 in Ovarian Cells: Elucidating a Pro-Tumoral Mechanism

Nerve growth factor (NGF) and its high-affinity receptor TRKA are overexpressed in epithelial ovarian cancer (EOC) displaying a crucial role in the disease progression. Otherwise, NGF interacts with its low-affinity receptor P75, activating pro-apoptotic pathways. In neurons, P75 could be cleaved by metalloproteinases (α and γ-secretases), leading to a decrease in P75 signaling. Therefore, this study aimed to evaluate whether the shedding of P75 occurs in EOC cells and whether NGF/TRKA could promote the cleavage of the P75 receptor. The immunodetection of the α-secretase, ADAM17, TRKA, P75, and P75 fragments was assessed by immunohisto/cytochemistry and Western blot in biopsies and ovarian cell lines. The TRKA and secretases' inhibition was performed using specific inhibitors. The results show that P75 immunodetection decreased during EOC progression and was negatively correlated with the presence of TRKA in EOC biopsies. NGF/TRKA increases ADAM17 levels and the fragments of P75 in ovarian cells. This effect is abolished when cells are previously treated with ADAM17, γ-secretase, and TRKA inhibitors. These results indicate that NGF/TRKA promotes the shedding of P75, involving the activation of secretases such as ADAM17. Since ADAM17 has been proposed as a screening marker for early detection of EOC, our results contribute to understanding better the role of ADAM17 and NGF/TRKA in EOC pathogenesis, which includes the NGF/TRKA-mediated cleavage of P75.

Prioritizing the Catalytic Gatekeepers through Pan- Inhibitory Mechanism of Entrectinib against ALK, ROS1 and TRKA Tyrosine Kinases

Despite the remarkable clinical activity of kinase inhibitors against anaplastic lymphoma kinase (ALK) and the closely related Ros1 and TRKA kinases, the emergence of resistance to these inhibitors often leads to relapse in most patients. Resistance is usually in the form of mutations and brain metastasis or inhibitors failing to penetrate the blood-brain barrier. The discovery of entrectinib has recently paved way for further exploration of kinase inhibitors that target ALK after it has reportedly demonstrated potency against ALK, Ros1, and TRKA kinases. However, the molecular mechanism surrounding its multi-targeting activity remains unresolved. As such, in this study, we investigate the pan-inhibitory mechanism of entrectinib towards ALK, Ros1, and TRKA, using in silico techniques. Findings show strong binding affinities of ALK = -40.92 kcal/mol, Ros1 = -36.60 kcal/mol, and TRKA = -45.99 kcal/mol for entrectinib towards ALK, Ros1, and TRKA, respectively. Pan-inhibitory binding of entrectinib is characterized by close interaction with peculiar gatekeeper residues on each tyrosine kinase. Entrectinib induced structural stability and rigidity in the backbone conformation of all three tyrosine kinases by showing a consistent pattern of structural alterations. These structural insights provided presents a baseline for the understanding of the pan-inhibitory activity of entrectinib. Establishing the cruciality of the interactions between the phenyl ring and gatekeeper residues could guide the structure-based design of novel tyrosine kinase inhibitors with improved therapeutic activities.

NGF/TRKA Decrease miR-145-5p Levels in Epithelial Ovarian Cancer Cells

Nerve Growth Factor (NGF) and its high-affinity receptor tropomyosin receptor kinase A (TRKA) increase their expression during the progression of epithelial ovarian cancer (EOC), promoting cell proliferation and angiogenesis through several oncogenic proteins, such as c-MYC and vascular endothelial growth factor (VEGF). The expression of these proteins is controlled by microRNAs (miRs), such as miR-145, whose dysregulation has been related to cancer. The aims of this work were to evaluate in EOC cells whether NGF/TRKA decreases miR-145 levels, and the effect of miR-145 upregulation. The levels of miR-145-5p were assessed by qPCR in ovarian biopsies and ovarian cell lines (human ovarian surface epithelial cells (HOSE), A2780 and SKOV3) stimulated with NGF. Overexpression of miR-145 in ovarian cells was used to evaluate cell proliferation, migration, invasion, c-MYC and VEGF protein levels, as well as tumor formation and metastasis in vivo. In EOC samples, miR-145-5p levels were lower than in epithelial ovarian tumors. Overexpression of miR-145 decreased cell proliferation, migration and invasion of EOC cells, changes that were concomitant with the decrease in c-MYC and VEGF protein levels. We observed decreased tumor formation and suppressed metastasis behavior in mice injected with EOC cells that overexpressed miR-145. As expected, ovarian cell lines stimulated with NGF diminished miR-145-5p transcription and abundance. These results suggest that the tumoral effects of NGF/TRKA depend on the regulation of miR-145-5p levels in EOC cells, and that its upregulation could be used as a possible therapeutic strategy for EOC.

Indole Compound NC009-1 Augments APOE and TRKA in Alzheimer's Disease Cell and Mouse Models for Neuroprotection and Cognitive Improvement

Alzheimer's disease (AD), associated with abnormal accumulation of amyloid-β (Aβ), is the most common cause of dementia among older people. A few studies have identified substantial AD biomarkers in blood but their results were inconsistent. Here we screened gene expression alterations on Aβ-GFP SH-SY5Y neuronal model for AD, and evaluated the findings on peripheral leukocytes from 78 patients with AD and 56 healthy controls. The therapeutic responses of identified biomarker candidates were further examined in Aβ-GFP SH-SY5Y neuronal and APP/PS1/Tau triple transgenic (3×Tg-AD) mouse models. Downregulation of apolipoprotein E (APOE) and tropomyosin receptor kinase A (TRKA) were detected in Aβ-GFP SH-SY5Y cells and validated by peripheral leukocytes from AD patients. Treatment with an in-house indole compound NC009-1 upregulated the expression of APOE and TRKA accompanied with improvement of neurite outgrowth in Aβ-GFP SH-SY5Y cells. NC009-1 further rescued the downregulated APOE and TRKA and reduced Aβ and tau levels in hippocampus and cortex, and ameliorated cognitive deficits in streptozocin-induced hyperglycemic 3×Tg-AD mice. These results suggest the role of APOE and TRKA as potential peripheral biomarkers in AD, and offer a new drug development target of AD treatment. Further studies of a large series of AD patients will be warranted to verify the findings and confirm the correlation between these markers and therapeutic efficacy.

Testing algorithm for identification of patients with TRK fusion cancer

The neurotrophic tyrosine receptor kinase (NTRK) gene family encodes three tropomyosin receptor kinases (TRKA, TRKB, TRKC) that contribute to central and peripheral nervous system development and function. NTRK gene fusions are oncogenic drivers of various adult and paediatric tumours. Several methods have been used to detect NTRK gene fusions including immunohistochemistry, fluorescence in situ hybridisation, reverse transcriptase polymerase chain reaction, and DNA- or RNA-based next-generation sequencing. For patients with TRK fusion cancer, TRK inhibition is an important therapeutic target. Following the FDA approval of the selective TRK inhibitor, larotrectinib, as well as the ongoing development of multi-kinase inhibitors with activity in TRK fusion cancer, testing for NTRK gene fusions should become part of the standard diagnostic process. In this review we discuss the biology of NTRK gene fusions, and we present a testing algorithm to aid detection of these gene fusions in clinical practice and guide treatment decisions.

Inhibiting TRK Proteins in Clinical Cancer Therapy

Gene rearrangements resulting in the aberrant activity of tyrosine kinases have been identified as drivers of oncogenesis in a variety of cancers. The tropomyosin receptor kinase (TRK) family of tyrosine receptor kinases is emerging as an important target for cancer therapeutics. The TRK family contains three members, TRKA, TRKB, and TRKC, and these proteins are encoded by the genes NTRK1, NTRK2, and NTRK3, respectively. To activate TRK receptors, neurotrophins bind to the extracellular region stimulating dimerization, phosphorylation, and activation of downstream signaling pathways. Major known downstream pathways include RAS/MAPK/ERK, PLCγ, and PI3K/Akt. While being rare in most cancers, TRK fusions with other proteins have been well-established as oncogenic events in specific malignancies, including glioblastoma, papillary thyroid carcinoma, and secretory breast carcinomas. TRK protein amplification as well as alternative splicing events have also been described as contributors to cancer pathogenesis. For patients harboring alterations in TRK expression or activity, TRK inhibition emerges as an important therapeutic target. To date, multiple trials testing TRK-inhibiting compounds in various cancers are underway. In this review, we will summarize the current therapeutic trials for neoplasms involving NTKR gene alterations, as well as the promises and setbacks that are associated with targeting gene fusions.

Novel NTRK1 mutations associated with congenital insensitivity to pain with anhidrosis verified by functional studies

Congenital insensitivity to pain with anhidrosis (CIPA), also known as hereditary sensory and autonomic neuropathy type IV, features loss of pain sensation, decreased or absent sweating (anhidrosis), recurrent episodes of unexplained fever, self-mutilating behavior, and variable mental retardation. Mutations in neurotrophic receptor tyrosine kinase 1 (NTRK1) have been reported to be associated with CIPA. We identified four novel NTRK1 mutations in six Korean patients from four unrelated families. Of the four mutations, we demonstrated using a splicing assay that IVS14+3A>T causes aberrant splicing of NTRK1 mRNA, leading to introduction of a premature termination codon. An NTRK1 autophosphorylation assay showed that c.1786G>A (p.Asp596Asn) abolished autophosphorylation of NTRK1. In addition, Western blotting showed that c.704C>G (p.Ser235*) and c.2350_2363del (p.Leu784Serfs*79) blunted NTRK1 expression to undetectable levels. The four novel NTRK1 mutations we report here will expand the repertoire of NTRK1 mutations in CIPA patients, and further our understanding of CIPA pathogenesis.

Neuroblast differentiation during development and in neuroblastoma requires KIF1Bβ-mediated transport of TRKA

Fell et al. deleted KIF1Bβ in the mouse sympathetic nervous system and observed impaired sympathetic nervous function and misexpression of genes required for sympathoadrenal lineage differentiation. They discovered that KIF1Bβ is required for NGF-dependent neuronal differentiation through anterograde transport of the NGF receptor TRKA.

We recently identified pathogenic KIF1Bβ mutations in sympathetic nervous system malignancies that are defective in developmental apoptosis. Here we deleted KIF1Bβ in the mouse sympathetic nervous system and observed impaired sympathetic nervous function and misexpression of genes required for sympathoadrenal lineage differentiation. We discovered that KIF1Bβ is required for nerve growth factor (NGF)-dependent neuronal differentiation through anterograde transport of the NGF receptor TRKA. Moreover, pathogenic KIF1Bβ mutations identified in neuroblastoma impair TRKA transport. Expression of neuronal differentiation markers is ablated in both KIF1Bβ-deficient mouse neuroblasts and human neuroblastomas that lack KIF1Bβ. Transcriptomic analyses show that unfavorable neuroblastomas resemble mouse sympathetic neuroblasts lacking KIF1Bβ independent of MYCN amplification and the loss of genes neighboring KIF1B on chromosome 1p36. Thus, defective precursor cell differentiation, a common trait of aggressive childhood malignancies, is a pathogenic effect of KIF1Bβ loss in neuroblastomas. Furthermore, neuropathy-associated KIF1Bβ mutations impede cargo transport, providing a direct link between neuroblastomas and neurodegeneration.

Fascaplysin Exerts Anti-Cancer Effects through the Downregulation of Survivin and HIF-1α and Inhibition of VEGFR2 and TRKA

Fascaplysin has been reported to exert anti-cancer effects by inhibiting cyclin-dependent kinase 4 (CDK4); however, the precise mode of action by which fascaplysin suppresses tumor growth is not clear. Here, we found that fascaplysin has stronger anti-cancer effects than other CDK4 inhibitors, including PD0332991 and LY2835219, on lung cancer cells that are wild-type or null for retinoblastoma (RB), indicating that unknown target molecules might be involved in the inhibition of tumor growth by fascaplysin. Fascaplysin treatment significantly decreased tumor angiogenesis and increased cleaved-caspase-3 in xenografted tumor tissues. In addition, survivin and HIF-1α were downregulated in vitro and in vivo by suppressing 4EBP1-p70S6K1 axis-mediated de novo protein synthesis. Kinase screening assays and drug-protein docking simulation studies demonstrated that fascaplysin strongly inhibited vascular endothelial growth factor receptor 2 (VEGFR2) and tropomyosin-related kinase A (TRKA) via DFG-out non-competitive inhibition. Overall, these results suggest that fascaplysin inhibits TRKA and VEGFR2 and downregulates survivin and HIF-1α, resulting in suppression of tumor growth. Fascaplysin, therefore, represents a potential therapeutic approach for the treatment of multiple types of solid cancer.

Identification and characterization of a novel SCYL3-NTRK1 rearrangement in a colorectal cancer patient

In colorectal cancer patients, chromosomal rearrangements involving NTRK1 gene (encoding the TRKA protein) are shown in a small subset of patients and are associated with the constitutive activation of the kinase domain of TRKA. In turn, activated TRKA-fusion proteins are associated with proliferation and survival in colorectal cancer tumors.

Here we report the identification and functional characterization of a new SCYL3-NTRK1 fusion gene in a 61-year-old colorectal cancer patient. To our knowledge, this fusion protein has never been previously documented in oncological patients. We show that this novel fusion is oncogenic and sensitive to TRKA inhibitors.

As suggested by other pieces of evidence, entrectinib - an orally available pan-TRK, ROS1 and ALK inhibitor - may have particular efficacy in patients with NTRK rearrangements. Therefore, screening for rearrangements involving NTRK genes may help identifying a subset of patients able to derive benefit from treatment with entrectinib or other targeted inhibitors.

A Comprehensive Functional Analysis of NTRK1 Missense Mutations Causing Hereditary Sensory and Autonomic Neuropathy Type IV (HSAN IV)

Hereditary sensory and autonomic neuropathy type IV (HSAN IV) is an autosomal recessive disorder characterized by a complete lack of pain perception and anhidrosis. Here, we studied a cohort of seven patients with HSAN IV and describe a comprehensive functional analysis of seven novel NTRK1 missense mutations, c.1550G >A, c.1565G >A, c.1970T >C, c.2096T >C, c.2254T >A, c.2288G >C, and c.2311C >T, corresponding to p.G517E, p.G522E, p.L657P, p.I699T, p.C752S, p.C763S, and p.R771C, all of which were predicted pathogenic by in silico analysis. The results allowed us to assess the pathogenicity of each mutation and to gain novel insights into tropomyosin receptor kinase A (TRKA) downstream signaling. Each mutation was systematically analyzed for TRKA glycosylation states, intracellular and cell membrane expression patterns, nerve growth factor stimulated TRKA autophosphorylation, TRKA-Y496 phosphorylation, PLCγ activity, and neurite outgrowth. We showed a diverse range of functional effects: one mutation appeared fully functional, another had partial activity in all assays, one mutation affected only the PLCγ pathway and four mutations were proved null in all assays. Thus, we conclude that complete abolition of TRKA kinase activity is not the only pathogenic mechanism underlying HSAN IV. By corollary, the assessment of the clinical pathogenicity of HSAN IV mutations is more complex than initially predicted and requires a multifaceted approach.

Chromosomal rearrangements involving the NTRK1 gene in colorectal carcinoma

Chromosomal rearrangements of the NTRK1 gene, which encodes the high affinity nerve growth factor receptor (tropomyosin related kinase, TRKA), have been observed in several epithelial cancers, such as colon cancer, papillary thyroid carcinoma or non small cell lung cancer. The various NTRK1 fusions described so far lead to constitutive activation of TRKA kinase activity and are oncogenic. We further investigated here the existence and the frequency of NTRK1 gene rearrangements in colorectal cancer. Using immunohistochemistry and quantitative reverse transcriptase PCR, we analyzed a series of human colorectal cancers. We identified two TRKA positive cases over 408, with NTRK1 chromosomal rearrangements. One of these rearrangements is a TPM3-NTRK1 fusion already observed in colon cancer, while the second one is a TPR-NTRK1 fusion never described in this type of cancer. These findings further confirm that translocations in the NTRK1 gene are recurring events in colorectal cancer, although occurring at a low frequency (around 0.5%).

The TPM3-NTRK1 rearrangement is a recurring event in colorectal carcinoma and is associated with tumor sensitivity to TRKA kinase inhibition

The NTRK1 gene encodes Tropomyosin-related kinase A (TRKA), the high-affinity Nerve Growth Factor Receptor. NTRK1 was originally isolated from a colorectal carcinoma (CRC) sample as component of a somatic rearrangement (TPM3-NTRK1) resulting in expression of the oncogenic chimeric protein TPM3-TRKA, but there has been no subsequent report regarding the relevance of this oncogene in CRC. The KM12 human CRC cell line expresses the chimeric TPM3-TRKA protein and is hypersensitive to TRKA kinase inhibition. We report the detailed characterization of the TPM3-NTRK1 genomic rearrangement in KM12 cells and through a cellular screening approach, the identification of NMS-P626, a novel highly potent and selective TRKA inhibitor. NMS-P626 suppressed TPM3-TRKA phosphorylation and downstream signaling in KM12 cells and showed remarkable antitumor activity in mice bearing KM12 tumors. Finally, using quantitative reverse transcriptase PCR and immunohistochemistry (IHC) we identified the TPM3-NTRK1 rearrangement in a CRC clinical sample, therefore suggesting that this chromosomal translocation is indeed a low frequency recurring event in CRC and that such patients might benefit from therapy with TRKA kinase inhibitors.

Twins with hereditary sensory and autonomic neuropathy type IV with preserved periodontal sensation

Turkish twin brothers affected with hereditary sensory and autonomic neuropathy type IV (HSAN IV) are reported. Their clinical findings were generally typical for HSAN IV. Interestingly they both had preserved periodontal sensation. Mutation analysis of the NTRK1 gene showed a homozygous c.2001C>T substitution in exon 15 in both twins. This base substitution is predicted to change a polar, positively charged amino acid arginine to the highly active amino acid cystein at position 654 (p.Arg654Cys). The parents were heterozygous for the mutation. This mutation has been reported previously in one Japanese and one Arab patients. The preserved periodontal sensation has not previously been reported in patients affected with HSAN IV. This preserved sensation in our patients might have been through Ruffini endings, the periodontal mechanoreceptors which have been reported to be present in TrkA knockout mice. Here we report the first twins affected with HSAN IV and the observation that periodontal sensation is not affected by mutation in NTRK1.