Traf2- And Nck-interacting Kinase Research Articles

Inhibiting renal Traf2 and NCK interacting kinase (TNIK) decreases NKKC2 phosphorylation and blunts salt-sensitive hypertension

The Na/K/2Cl cotransporter NKCC2 mediates the NaCl reabsorption in the thick ascending limb (TAL). Phosphorylation at Thr-96,101 and traffcking to the surface are increased in the Dahl salt-sensitive (DSS) rat together with SPAK phosphorylation, an upstream kinase for Thr-96,101 in NKCC2. We previously found that deletion of SPAK in the DSS, lowers NKCC2 phosphorylation and blunts salt-sensitive hypertension, but doesn’t completely abolish NKCC2 phosphorylation. Therefore, other kinases may be involved in NKCC2 phosphorylation. We recently found the Traf2 and NCK interacting kinase (TNIK) phosphorylates NKCC2 and is overexpressed in the TALs of DSS rats. We hypothesized that TNIK contributes to salt-sensitive hypertension by increasing NKCC2 hyperphosphorylation in DSS rats. We approached TNIK inhibition in two ways, using a pharmacological inhibitor and its genomic deletion with CRISPR/Cas9. First, we studied the small molecule TNIK inhibitor NCB-0846, and whether it could decrease baseline NKCC2 phosphorylation in TALs from DSS rats. Treating TALs from DSS with NCB-0846 (0.1 μM) for 25 min decreased NKCC2 Thr-96,101 phosphorylation by 21 ± 2% compared to the vehicle group (p<0.001, n=3). To study in vivo effcacy of NCB-0846, we directly infused NCB (or vehicle) into the left kidney via implanted renal medullary catheters connected to minipumps in DSS rats fed 4% NaCl diet. We found that NCB-0846 decreased SBP by 30 mmHg within four days compared to the vehicle-infused group, and BP remained lower for 7 days (n=5, p<0.03 vs control). To decrease TNIK gene expression we used Cas9 mediated gene editing. For this, we designed gRNA sequences targeting TNIK and tested their effcacy in C6 cells. One of the gRNAs designed decreased TNIK expression by 48 ± 22% compared to control (p=0.101, n=3). To decrease TNIK in TALs in vivo, we injected the renal medulla of the left kidney with AAV-gRNA-TNIK together with AAV-NKCC2 promoter-Cas9. After 2 weeks, we isolated medullary TALs and measured TNIK expression and NKCC2 phosphorylation. TNIK expression was decreased by 50 ± 5.5% (n=4, p<0.0001), and pThr-96,101-NKCC2 was decreased by 38.1 ± 10.6% in transduced TALs compared to kidneys transduced with AV-control (n=4, p<0.05). The expression of related kinases SPAK and OSR1 was not modified (SPAK 79.2 ± 18.3%, OSR1 81.3 ± 13.3%, n=4, ns). We conclude that NKCC2 phosphorylation in the DSS rat is in part caused by TNIK and that this new kinase could be a target for salt sensitive hypertension. Future experiments will test the effect of gene editing TNIK in salt sensitive hypertension. 23POST1019882 AHA15GRNT25710369. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 1125: TNIK induced chemoradiation resistance in small cell lung cancer

Abstract Chemoradiation (CRT) is the standard first-line therapy for limited stage small cell lung cancer (LS-SCLC), which is characterized by early metastasis, intrinsic-acquired CRT resistance and tumor recurrence. CRT confers a 20-25% 5-year overall survival in patients with LS-SCLC. In this study, we utilized patient-derived xenograft (PDX) models to demonstrate CRT resistance of SCLC and identified CRT resistance candidate genes from various SCLC PDX that represent the majority of molecular subtypes (n=4 that include SCLC-A and SCLC-N subtypes). RNA-seq data identified TNIK (Traf2- and Nck-interacting kinase) as one such gene that is consistently upregulated in SCLC PDXs exposed to CRT compared to single modality treatments. Copy number gains of TNIK were also present in human SCLC samples. Overcoming this CRT resistance is crucial in improving treatment outcomes and patient survival. Genetic depletion or pharmacological inhibition of TNIK reduced the in vitro clonogenic survival of TNIKhigh SCLC cells, NCI-H446 and makes them increasingly sensitive to CRT. In vivo, pharmacological inhibition of TNIK with the inhibitor NCB-0846, enhances the CRT sensitivity of NCI-H446 cell line-derived xenografts (CDX) in NOD SCID immunodeficient mice. Furthermore, pharmacological inhibition of TNIK in vivo demonstrated sensitivity to CRT in LX33 PDX. In conclusion, our results indicate that TNIK plays a role in conferring resistance to CRT in vitro in SCLC cell lines and in vivo in SCLC CDX and PDX models and therefore, can be a potential therapeutic target in limited stage SCLC. Citation Format: Dipanwita Dutta Chowdhury, Eddie Imada, Nick Connis, Triet Nguyen, Jinhee Chang, Danielle Council, Audrey Lafargue, Mohammad Rezaee, Phuoc T. Tran, Luigi Marchionni, Christine L. Hann. TNIK induced chemoradiation resistance in small cell lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1125.

Abstract 603: BB5523, a multiple kinase inhibitor with HPK1, VEGFR2 and TNIK inhibition, enhanced antitumor immunity in tumor models

Abstract Introduction: Immuno-suppressive micro-environment and abnormal signaling pathways are crucial for the proliferation of tumor cells. Hematopoietic progenitor kinase 1 (HPK1) inhibitor plays important roles in activation of exhausted T cells and enhancement of anti-tumor immune responses. VEGF/VEGFR2 pathway is the central therapeutic target in anti-angiogenic treatment in multiple cancers. Traf2- and Nck-interacting kinase (TNIK) is a member of the germinal center kinase family, and is reported to be essential for Wnt signaling and colorectal cancer (CRC) proliferation and progression. Blockade of critical kinases in multiple signaling pathways inhibits the proliferation, invasion and metastasis of cancer cells. Therefore, intergradation of these functions in a small molecule serves as the next generation of immune-oncology small molecules for cancer therapy. Methods: BB5523 was developed through structure-based drug design, and optimized by SAR analysis and medicinal chemistry iteration. Biochemical assays and cell-base functional assays were applied in compound evaluation. Pharmacokinetic (PK) and preliminary toxicity studies were performed with mice. CDX and syngeneic tumor models in mice were conducted to evaluate the in vivo efficacy of BB5523 as a single agent. Results: BB5523 shows high inhibition potency on HPK1 with good selectivity against other TCR signaling-related kinases, such as FYN and ZAP70. Inhibition of HPK1 kinase activity (IC50 = 3.3 nM) by BB5523 strongly suppresses the phosphorylation of the downstream biomarker protein SLP-76 (IC50 = 30 nM); and boosts the IL-2 secretion in purified human T cells and human peripheral blood mononuclear cells. BB5523 also shows good activities on VEGFR2 (IC50 = 1.6 nM) and TNIK (IC50 = 0.7 nM) which are crucial for the proliferation of cancer cells. In in vitro experiments, BB5523 significantly inhibits the proliferation of various tumor cell lines at sub-micromolar concentrations. PK profile of BB5523 shows good oral bioavailability (F > 80%). In preliminary safety evaluation, no abnormal symptoms were observed in mice dosed up to 100 mpk for 14 days. BB5523 showed significant tumor-growth inhibition efficacy in TE-8, JIMT-1, B16-F10 and MC38 tumor models. Conclusion: As a potent and oral available small molecule kinase inhibitor, BB5523 boosts anti-tumor immunity through HPK1 inhibition, while also blocking crucial signaling pathways in tumor micro-environment. BB5523 shows promising in vitro and in vivo efficacy with a well-tolerated safety profile. The preclinical study of BB5523 is in progress. Citation Format: Gongping Duan, Min Li, Puyong Zhang, Wei Hua, Enlun Hao, Shipeng Wang, Xiaoyi Ma, Junheng Wang, Lijie Wei, Xingmin Zhang. BB5523, a multiple kinase inhibitor with HPK1, VEGFR2 and TNIK inhibition, enhanced antitumor immunity in tumor models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 603.

A Compact Reprogrammed Genetic Code for De Novo Discovery of Proteolytically Stable Thiopeptides.

Thiopeptides make up a group of structurally complex peptidic natural products holding promise in bioengineering applications. The previously established thiopeptide/mRNA display platform enables de novo discovery of natural product-like thiopeptides with designed bioactivities. However, in contrast to natural thiopeptides, the discovered structures are composed predominantly of proteinogenic amino acids, which results in low metabolic stability in many cases. Here, we redevelop the platform and demonstrate that the utilization of compact reprogrammed genetic codes in mRNA display libraries can lead to the discovery of thiopeptides predominantly composed of nonproteinogenic structural elements. We demonstrate the feasibility of our designs by conducting affinity selections against Traf2- and NCK-interacting kinase (TNIK). The experiment identified a series of thiopeptides with high affinity to the target protein (the best KD = 2.1 nM) and kinase inhibitory activity (the best IC50 = 0.15 μM). The discovered compounds, which bore as many as 15 nonproteinogenic amino acids in an 18-residue macrocycle, demonstrated high metabolic stability in human serum with a half-life of up to 99 h. An X-ray cocrystal structure of TNIK in complex with a discovered thiopeptide revealed how nonproteinogenic building blocks facilitate the target engagement and orchestrate the folding of the thiopeptide into a noncanonical conformation. Altogether, the established platform takes a step toward the discovery of thiopeptides with high metabolic stability for early drug discovery applications.

A small-molecule TNIK inhibitor targets fibrosis in preclinical and clinical models.

Idiopathic pulmonary fibrosis (IPF) is an aggressive interstitial lung disease with a high mortality rate. Putative drug targets in IPF have failed to translate into effective therapies at the clinical level. We identify TRAF2- and NCK-interacting kinase (TNIK) as an anti-fibrotic target using a predictive artificial intelligence (AI) approach. Using AI-driven methodology, we generated INS018_055, a small-molecule TNIK inhibitor, which exhibits desirable drug-like properties and anti-fibrotic activity across different organs in vivo through oral, inhaled or topical administration. INS018_055 possesses anti-inflammatory effects in addition to its anti-fibrotic profile, validated in multiple in vivo studies. Its safety and tolerability as well as pharmacokinetics were validated in a randomized, double-blinded, placebo-controlled phase I clinical trial (NCT05154240) involving 78 healthy participants. A separate phase I trial in China, CTR20221542, also demonstrated comparable safety and pharmacokinetic profiles. This work was completed in roughly 18 months from target discovery to preclinical candidate nomination and demonstrates the capabilities of our generative AI-driven drug-discovery pipeline.

Fragment growth-based discovery of novel TNIK inhibitors for the treatment of colorectal cancer

Traf2-and Nck-interacting protein kinase (TNIK) plays an important role in regulating signal transduction of the Wnt/β-catenin pathway and is considered an important target for the treatment of colorectal cancer. Inhibiting TNIK has potential to block abnormal Wnt/β-catenin signal transduction caused by colorectal cancer mutations. We discovered a series of 6-(1-methyl-1H-imidazole-5-yl) quinoline derivatives as TNIK inhibitors through Deep Fragment Growth and virtual screening. Among them, 35b exhibited excellent TNIK kinase and HCT116 cell inhibitory activity with IC50 values of 6 nM and 2.11 μM, respectively. 35b also shown excellent kinase selectivity, PK profiles, and oral bioavailability (84.64%). At a p. o. dosage of 50 mg/kg twice daily 35b suppressed tumor growth on the HCT116 xenograft model. Taken together, 35b is a promising lead compound of TNIK inhibitors, which merits further investigation.

TNIK regulation of interferon signaling and endothelial cell response to virus infection.

Traf2 and Nck-interacting kinase (TNIK) is known for its regulatory role in various processes within cancer cells. However, its role within endothelial cells (ECs) has remained relatively unexplored. Leveraging RNA-seq data and Ingenuity Pathway Analysis (IPA), we probed the potential impact of TNIK depletion on ECs. Examination of RNA-seq data uncovered more than 450 Differentially Expressed Genes (DEGs) in TNIK-depleted ECs, displaying a fold change exceeding 2 with a false discovery rate (FDR) below 0.05. IPA analysis unveiled that TNIK depletion leads to the inhibition of the interferon (IFN) pathway [-log (p-value) >11], downregulation of IFN-related genes, and inhibition of Hypercytokinemia/Hyperchemokinemia [-log (p-value) >8]. The validation process encompassed qRT-PCR to evaluate mRNA expression of crucial IFN-related genes, immunoblotting to gauge STAT1 and STAT2 protein levels, and ELISA for the quantification of IFN and cytokine secretion in siTNIK-depleted ECs. These assessments consistently revealed substantial reductions upon TNIK depletion. When transducing HUVECs with replication incompetent E1-E4 deleted adenovirus expressing green fluorescent protein (Ad-GFP), it was demonstrated that TNIK depletion did not affect the uptake of Ad-GFP. Nonetheless, TNIK depletion induced cytopathic effects (CPE) in ECs transduced with wild-type human adenovirus serotype 5 (Ad-WT). Our findings suggest that TNIK plays a crucial role in regulating the EC response to virus infections through modulation of the IFN pathway.

TNIK drives castration-resistant prostate cancer via phosphorylating EGFR

The development of castration-resistant prostate cancer (CRPC) is driven by intricate genetic and epigenetic mechanisms. Traf2- and Nck-interacting kinase (TNIK) has been reported as a serine/threonine kinase associated with tumor cell proliferation or unfavorable cancer behavior. The microarray approach revealed a substantial upregulation of TNIK expression levels, enabling us to investigate the functional behaviors of the TNIK gene in CRPC. Specifically, we discovered that AR suppresses TNIK gene transcription in LNCaP and C4-2 cells by forming a complex with H3K27me3. Following the reduction of AR levels induced by androgen deprivation therapy (ADT), TNIK is recruited to activate EGFR signaling through phosphorylation in C4-2 cells, thereby promoting CRPC progression. Our findings unveil a regulatory role of AR as a repressor for TNIK while also highlighting how TNIK activates the EGFR pathway via phosphorylation to drive CRPC progression. Consequently, targeting TNIK may represent an appealing therapeutic strategy for CRPC.

The Traf2 and NcK interacting kinase inhibitor NCB-0846 suppresses seizure activity involving the decrease of GRIA1

Epilepsy, one of the most common neurological disorders, is characterized by spontaneous recurrent seizures. Temporal lobe epilepsy (TLE) is one of the most common medically intractable seizure disorders. Traf2-and NcK-interacting kinase (TNIK) has recently attracted attention as a critical modulation target of many neurological and psychiatric disorders, but its role in epilepsy remains unclear. In this study, we hypothesized the involvement of TNIK in epilepsy and investigated TNIK expression in patients with intractable TLE and in a pilocarpine-induced rat model of epilepsy by western blotting, immunofluorescence, and immunohistochemistry. A pentylenetetrazole (PTZ)-induced epilepsy rat model was used to determine the effect of the TNIK inhibitor NCB-0846 on behavioral manifestations of epilepsy. Coimmunoprecipitation (Co-IP)/mass spectrometry (MS) was used to identify the potential mechanism. Through Co-IP, we detected and confirmed the main potential TNIK interactors. Subcellular fractionation was used to establish the effect of NCB-0846 on the expression of the main interactors in postsynaptic density (PSD) fractions. We found that TNIK was primarily located in neurons and decreased significantly in epilepsy model rats and TLE patients compared with controls. NCB-0846 delayed kindling progression and decreased seizure severity. Co-IP/MS identified 63 candidate TNIK interactors in rat hippocampi, notably CaMKII. Co-IP showed that TNIK might correlate with endogenous GRIA1, SYN2, PSD-95, CaMKIV, GABRG1, and GABRG2. In addition, the significant decrease in GRIA1 in hippocampal total lysate and PSDs after NCB-0846 treatment might help modify the progression of PTZ kindling. Our results suggest that TNIK contributes to epileptic pathology and is a potential antiepileptic drug target.

Molecular Docking and Pharmacoinformatics Studies Reveal Potential Phytochemicals against Target TNIK Receptors in Colorectal Cancer

AbstractColorectal cancer (CRC) is the third most common cancer worldwide and can occur due to multiple reasons, one being induced by constitutive activation of the Wnt pathway. Traf2‐ and Nck‐interacting kinase (TNIK), the regulatory component of the Wnt pathway is responsible for the increase in the infiltrative capability of cancerous cells in CRC. The purpose of this study was to identify a phytochemical that could act as a drug to combat CRC by targeting TNIK. The TNIK model was docked against a dataset of 5000 phytochemicals using Molecular Operating Environment software which revealed seven‐candidate phytochemicals namely Berbamine, Epigallocatechin Gallate, Nimbothalin, Blepharocalyxin E, Rutin, BYCHRKNAQYPJPR‐DAZOONRXSA‐N and Blepharocalyxin B as potential inhibitor of TNIK. The Berbamine, Nimbothalin, and Epigallocatechin Gallate were selected for MD simulation study ascribed to sound pharmacokinetic features and propitious ADMET properties. Further studies are required to scrutinize these phytochemicals as a mainstream drug for TNIK in colorectal cancer.

Deficiency of germinal center kinase TRAF2 and NCK-interacting kinase (TNIK) in B cells does not affect atherosclerosis.

Atherosclerosis is the underlying cause of many cardiovascular diseases, such as myocardial infarction or stroke. B cells, and their production of pro- and anti-atherogenic antibodies, play an important role in atherosclerosis. In B cells, TRAF2 and NCK-interacting Kinase (TNIK), a germinal center kinase, was shown to bind to TNF-receptor associated factor 6 (TRAF6), and to be involved in JNK and NF-κB signaling in human B cells, a pathway associated with antibody production. We here investigate the role of TNIK-deficient B cells in atherosclerosis. ApoE-/-TNIKfl/fl (TNIKBWT) and ApoE-/-TNIKfl/flCD19-cre (TNIKBKO) mice received a high cholesterol diet for 10 weeks. Atherosclerotic plaque area did not differ between TNIKBKO and TNIKBWT mice, nor was there any difference in plaque necrotic core, macrophage, T cell, α-SMA and collagen content. B1 and B2 cell numbers did not change in TNIKBKO mice, and marginal zone, follicular or germinal center B cells were unaffected. Total IgM and IgG levels, as well as oxidation specific epitope (OSE) IgM and IgG levels, did not change in absence of B cell TNIK. In contrast, plasma IgA levels were decreased in TNIKBKO mice, whereas the number of IgA+ B cells in intestinal Peyer's patches increased. No effects could be detected on T cell or myeloid cell numbers or subsets. We here conclude that in hyperlipidemic ApoE-/- mice, B cell specific TNIK deficiency does not affect atherosclerosis.

CAMP stimulated NKCC2 phosphorylation at Thr-96,101 is in part independent from SPAK: a Role for TNIK

Abnormally enhanced NaCl reabsorption by the thick ascending limb of the loop of Henle (TAL) contributes to the development of salt-sensitivity. NaCl reabsorption by the TAL is mediated by the apical Na/K/2Cl cotransporter NKCC2. NKCC2 activity can be stimulated by phosphorylation at Thr 96,101 by upstream kinases SPAK or OSR1. We found that Thr 96,101 phosphorylation is enhanced in TALs of Dahl Salt Sensitive rats (Dahl SS) on normal or high salt diet. Genetic deletion of SPAK in Dahl SS lowers NKCC2 phosphorylation by 40% and blunts salt-sensitive hypertension but does not completely restore these to baseline. Other kinases may be involved in NKCC2 phosphorylation. Using a targeted proteomics approach, we identified TNIK (Traf2 and NCK interacting kinase) as a kinase that binds and phosphorylates Thr 96,101 in NKCC2 in rats and mice (manuscript under revision). In addition, we and others found that cAMP is a potent stimulus for NKCC2 Thr-96,101 phosphorylation. We hypothesize that TNIK is in part responsible for cAMP-stimulated NKCC2 phosphorylation at Thr-96,101. First, we tested the ability of a novel TNIK inhibitor (NCB-0846) to decrease baseline NKCC2 phosphorylation in Dahl SS rats. Treating TALs from Dahl SS with NCB-0846 (0.1 μM) for 25 min decreased NKCC2 Thr 96,101 phosphorylation by 21 ± 2% compared to the vehicle group (p<0.0001, n=3). Next, we measured NKCC2 phosphorylation in rats with genetic deletion of SPAK in a Dahl SS background. In SPAK KO rats, the cAMP analogue db-cAMP (500 μM) increased NKCC2 phosphorylation at Thr 96,101 by 626 ± 46% (p<0.0001, n=3) and the TNIK inhibitor NCB-0846, blunted cAMP-stimulated NKCC2 phosphorylation by 56 ± 4.3% (p=0.0013, n=3). There was no significant decrease in phosphorylation at phospho-Ser 126 NKCC2 (cAMP=46 ± 7-fold vs cAMP+NCB= 31±5-fold, n.s). These data indicate that in the absence of SPAK, TNIK mediates cAMP-stimulated NKCC2 phosphorylation at Thr-96,101. To further support this, we studied TALs from whole animal TNIK knock-out mice (TNIK KO). db-cAMP (500 μM) increased NKCC2 phosphorylation by 1330 ± 268% in wild-type mice (p<0.01) whereas cAMP-stimulated NKCC2 phosphorylation was blunted by 49 ± 15% in TNIK KO TALs (p<0.05, n=3). No significant difference was found in cAMP-stimulated NKCC2-Ser 126 phosphorylation in TNIK KO (WT=23 ± 12-fold vs TNIK KO=15 ± 4-fold, n=3). We conclude that enhanced NKCC2 phosphorylation at baseline in Dahl SS TALs is in part caused by TNIK and that cAMP-stimulated NKCC2 Thr-96,101 phosphorylation in TALs is in part independent from SPAK and involves TNIK. Our data point to potential role for TNIK in renal ion transport, blood pressure regulation and urine concentration. AHA15GRNT25710369 This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Abstract 1679: Unraveling the function of TRAF2 and NCK interacting kinase (TNIK) in high-grade serous ovarian cancer

Abstract The large majority of high grade serous ovarian cancer (HGSOC) patients will eventually become resistant to platinum-based chemotherapy, highlighting the urgent need to develop novel therapeutics targeting recurrent, platinum-resistant disease. To study this, our lab generated two patient derived platinum-resistant tumor spheres from platinum-sensitive primary patient cells to better understand the biology behind recurrent disease and identify novel therapeutic targets. Utilizing an artificial intelligence (AI) powered model, we screened a library that consisted of compounds predicted to target known or postulated resistance mechanisms and involved a novel therapeutic target. From this screen, we identified a TNIK kinase inhibitor as the only compound to effectively kill HGSOC spheres while sparing non-malignant fallopian tube cells. TNIK plays a key role in Wnt pathway activation, which our lab has previously shown to be critical in driving cancer stemness and epithelial ovarian cancer platinum resistance. Additionally, patient data shows that TNIK is amplified in ovarian cancer more than any other cancer type and is highly activated in ovarian cancer patients. We found that this compound was able to decrease overall Wnt activity in our platinum-resistant cells and could resensitize our platinum-resistant cells to cisplatin. This work demonstrates the abilities of using AI to expedite the drug discovery process as well as uncover novel therapeutic targets which may lead to future therapeutic strategies for HGSOC patients who no longer respond to standard of care platinum chemotherapy. Citation Format: Noah Puleo, Michele Cusato, Dylan Carvette, Chantelle Husdon, Analisa DiFeo. Unraveling the function of TRAF2 and NCK interacting kinase (TNIK) in high-grade serous ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1679.

Structural Insight into TNIK Inhibition.

TRAF2- and NCK-interacting kinase (TNIK) has emerged as a promising therapeutic target for colorectal cancer because of its essential role in regulating the Wnt/β-catenin signaling pathway. Colorectal cancers contain many mutations in the Wnt/β-catenin signaling pathway genes upstream of TNIK, such as the adenomatous polyposis coli (APC) tumor suppressor gene. TNIK is a regulatory component of the transcriptional complex composed of β-catenin and T-cell factor 4 (TCF4). Inhibition of TNIK is expected to block the aberrant Wnt/β-catenin signaling caused by colorectal cancer mutations. Here we present structural insights into TNIK inhibitors targeting the ATP-binding site. We will discuss the effects of the binding of different chemical scaffolds of nanomolar inhibitors on the structure and function of TNIK.

Inhibition of Wnt Signaling in Colon Cancer Cells via an Oral Drug that Facilitates TNIK Degradation.

We have synthesized an oxetane derivative of the benzimidazole compound mebendazole (OBD9) with enhanced solubility and strong anticancer activity in multiple types of cancer cells, especially colorectal cancer. In this report, we provide evidence that OBD9 suppresses colorectal cancer growth by interfering with the Wnt signaling pathway, a main driver of cell growth in colorectal cancer. Specifically, we find that OBD9 induces autophagic degradation of TNIK (traf2 and Nck-interacting kinase), which promotes T-cell factor-4 (TCF4)/beta-catenin-mediated gene expression. Thus, OBD9 as a TNIK inhibitor blocks Wnt/beta-catenin signaling at the final step of transcriptional activation. We suggest that OBD9 provides a potential novel autophagy-mediated, Wnt-damping therapeutic strategy for the treatment of colorectal cancer.

Computational study on new natural compound inhibitors of Traf2 and Nck-interacting kinase (TNIK).

Traf2 and Nck-interacting kinase (TNIK) is the downstream molecule of Wnt/β-catenin signal pathway. As the activation kinase of β-catenin/T-cell factor 4 transcription complex, it can fully activate Wnt signalling and promote the growth and invasion of tumor cells. We conducted computer-assisted virtual screening and a series of analyses to find potential inhibitors of TNIK. First, LibDock was used for molecular docking of natural small molecules. Then, ADME (Adsorption, Distribution, Metabolism and Excretion) analysis and toxicity prediction were performed on the top 80 small molecules which have higher scores. Additionally, in order to further determine the affinity and binding mechanism of TNIK-ligands, we analyzed the pharmacophores and used CDOCKER for more accurate molecular docking. Last but not least, molecular, dynamics simulation was used to evaluate the stability of receptor-ligand complexes in natural environment. The results showed that natural small molecules (ZINC000040976869 and ZINC000008214460) had high affinity and low interaction energy with TNIK. They were predicted to have excellent pharmacological properties, such as high plasma protein binding capacity and water solubility, no hepatotoxicity, no blood-brain barrier permeability and tolerant with cytochrome P450 2D6 (CYP2D6). In addition, they have less rodent carcinogenicity, AMES mutagenicity, and developmental toxicity potential. Molecular dynamics simulations showed that the two compounds could achieve the stability of potential energy and Root-Mean-Square Deviation (RMSD) at different time nodes. This study proves that ZINC000040976869 and ZINC000008214460 are ideal lead compounds with inhibition targeting to TNIK. These compounds provide valuable ideas and information for the development of new colorectal cancer targeting drugs.

De Novo Discovery of Thiopeptide Pseudo-natural Products Acting as Potent and Selective TNIK Kinase Inhibitors.

Bioengineering of ribosomally synthesized and post-translationally modified peptides (RiPPs) is an emerging approach to explore the diversity of pseudo-natural product structures for drug discovery purposes. However, despite the initial advances in this area, bioactivity reprogramming of multienzyme RiPP biosynthetic pathways remains a major challenge. Here, we report a platform for de novo discovery of functional thiopeptides based on reengineered biosynthesis of lactazole A, a RiPP natural product assembled by five biosynthetic enzymes. The platform combines in vitro biosynthesis of lactazole-like thiopeptides and mRNA display to prepare and screen large (≥1012) combinatorial libraries of pseudo-natural products. We demonstrate the utility of the developed protocols in an affinity selection against Traf2- and NCK-interacting kinase (TNIK), a protein involved in several cancers, which yielded a plethora of candidate thiopeptides. Of the 11 synthesized compounds, 9 had high affinities for the target kinase (best KD = 1.2 nM) and 10 inhibited its enzymatic activity (best Ki = 3 nM). X-ray structural analysis of the TNIK/thiopeptide interaction revealed the unique mode of substrate-competitive inhibition exhibited by two of the discovered compounds. The thiopeptides internalized to the cytosol of HEK293H cells as efficiently as the known cell-penetrating peptide Tat (4-6 μM). Accordingly, the most potent compound, TP15, inhibited TNIK in HCT116 cells. Altogether, our platform enables the exploration of pseudo-natural thiopeptides with favorable pharmacological properties in drug discovery applications.

SPAK‐Independent NKCC2 Phosphorylation in Dahl SS Rats: A Role for TNIK in NKCC2 Hyperphosphorylation

Increased NaCl reabsorption in the Thick Ascending Limb (TAL) is implicated in salt sensitive hypertension. NaCl reabsorption by the TAL is mediated by the apical Na/K/2Cl cotransporter NKCC2. We reported that NKCC2 phosphorylation at Tre 96,101 and surface expression are enhanced in Dahl Salt sensitive rats (Dahl SS) on normal or high salt diets. The phosphorylation of SPS1‐related proline/alanine‐rich kinase (SPAK), an upstream kinase for Thre 96,101 in NKCC2, was found to be higher in Dahl SS TALs. Deletion of SPAK in Dahl SS, lowers NKCC2 phosphorylation and expression and blunts salt‐sensitive hypertension, but does not completely prevent this. Other kinases may be involved in NKCC2 phosphorylation. Using a targeted proteomics approach, we identified TNIK (Traf2 and NCK interacting kinase) as a kinase that binds and phosphorylates Thre 96,101 in NKCC2. We hypothesize that TNIK is in part responsible for enhanced NKCC2 phosphorylation in Dahl SS rats. We first measured total expression of SPAK, OSR1 and TNIK by Western blot in TALs isolated form Dahl SS and control rats. SPAK and OSR1 expression (normalized to GAPDH) was similar between strains whereas TNIK expression was 3‐fold higher in Dahl SS TALs (control: 100, Dahl SS: 396±80%, n =5, p<.025). We then tested whether a novel TNIK inhibitor (KY‐05009) decreased NKCC2 phosphorylation in Dahl SS rats. Treating TALs from Dahl SS with KY‐05009 (1 µM) for 25 min decreased NKCC2 Thre 96,101 phosphorylation by 40±4% (p<0.05, n=5). To study whether NKCC2 phosphorylation can be stimulated in the absence of SPAK, we used SPAK knockout Dahl SS rats. Baseline NKCC2 expression and phosphorylation in TALs was 50% lower in Dahl SS‐SPAK KO TALs, however, stimulation of Beta‐adrenergic receptors with Isoproterenol increased NKCC2 phosphorylation by 192±49% (p<0.01, n =4) in SPAK‐KO. Similarly, the cAMP analogue db‐cAMP (500 µM) increased NKCC2 phosphorylation by 939±183% in SPAK KO (p<0.01 n=4) and by 497±105% (p<0.01 n=4) in control rat TALs, indicating that a kinase other than SPAK is essential for baseline and cAMP‐stimulated NKCC2 phosphorylation in Dahl SS rats. We conclude that enhanced NKCC2 phosphorylation at baseline in Dahl SS TALs is in part caused by TNIK, which show 3‐fold higher expression in this strain. SPAK also contributes to higher baseline NKCC2 phosphorylation, whereas a kinase other than SPAK (either TNIK or OSR1) is involved in cAMP‐stimulated NKCC2 Thre 96,101 phosphorylation in Dahl SS TALs.

Discovery of benzo[d]oxazol-2(3H)-one derivatives as a new class of TNIK inhibitors for the treatment of colorectal cancer

Colorectal cancer (CRC) is one of the most commonly diagnosed cancer types and Traf2- and Nck-interacting kinase (TNIK) has been thought as a potential target for CRC treatment. Herein we report the discovery and structure–activity relationship (SAR) of benzo[d]oxazol-2(3H)-one derivatives as a new class of TNIK inhibitors. The most potent compound 8g showed an IC50 value of 0.050 μM against TNIK. It effectively suppressed proliferation and migration of colorectal cancer cells. Western blot analysis indicated that 8g could inhibit aberrant transcription activation of Wnt signaling. Collectively, this study provides a potential lead compound for subsequent drug discovery targeting TNIK.

The Traf2 and Nck-Interacting Kinase Is a Conserved Regulator of Self-Renewal in Hematopoietic and Leukemia Stem Cells

The Traf2 and Nck-interacting kinase (TNIK) is a member of the germinal center kinase (GCK) family. We have recently found that signaling through the tumor necrosis factor superfamily receptor CD27 activates Wnt target genes through Traf2-TNIK-β-catenin signaling, promoting leukemia development and progression in acute and chronic myeloid leukemia (AML and CML).To explore how TNIK signaling regulates hematopoietic and leukemia stem cells (HSCs and LSCs), we generated a constitutive TNIK-/- knockout mouse.Under steady-state conditions, total bone marrow (BM) cellularity of naïve TNIK-/- mice was slightly reduced (mean BM count (x108): TNIK-/- = 1.42; TNIKwt/wt = 2.15, p < 0.0132). In contrast, no differences in absolute number of lineage negative (Lin-) cells, as well as the more primitive subset Lin-; Sca1+; c-kit+ (LSK) cells could be observed. Similarly, proportions of long-term HSCs (LT-HSCs), short-term HSCs (ST-HSCs) and multipotent progenitors (MPPs) did not differ between TNIK-/- and TNIKwt/wt mice. Functionally, naïve TNIK-/- and TNIKwt/wt HSCs displayed in vitro a comparable serial colony formation capacity in methylcellulose. Altogether these data suggest that TNIK does not affect the maintenance and self-renewal of HSCs under steady-state conditions.Next the impact of TNIK on hematopoietic recovery after genotoxic stress was analyzed in vivo. TNIK-/- and TNIKwt/wt mice were injected i.p. with 5-Fluorouracil (5-FU) (150mg/g bodyweight) and BM cellularity as well as HSC phenotype and function were assessed 9 days post injection. The total BM cellularity was significantly higher in TNIK-/- mice compared to controls (mean BM count (x106/ml): TNIK-/- =10.25; TNIKwt/wt =4.55, p< 0.0382). Furthermore, LSKs were significantly reduced in frequency in TNIK-/- mice (% LSK of whole BM: TNIK-/- = 2.93; TNIKwt/wt = 7.073, p < 0.0009) but not in absolute numbers. Interestingly, however, the total number LT-HSCs was significantly reduced in the BM of TNIK-/- mice (mean LT-HSC count (x103): TNIK-/- = 5.628; TNIKwt/wt = 16.725, p < 0.0101). These results were functionally confirmed in vivo by competitive BM transplantation (BMTx) of whole BM from 5-FU treated mice into lethally irradiated secondary recipients. Mice receiving BM from 5-FU-treated TNIK-/- mice showed a significantly reduced peripheral engraftment capacity 6 weeks post BMTx compared to controls (mean peripheral blood chimerism: TNIK-/- = 64.6%; TNIKwt/wt = 35.4%, p < 0.0001), suggesting that TNIK signaling mediates HSC maintenance during genotoxic stress conditions in vivo.In parallel the role of TNIK signaling was analyzed in myeloid LSCs. CML-like disease was induced in mice by transplanting pMSCV-BCR-ABL1-IRES-GFP transduced TNIK-/- or TNIKwt/wt LSKs into BL/6 mice. Even though CML developed similarly as indicated by measuring BCR-ABL1-GFP+ granulocytes in the peripheral blood, primary TNIK-/- CML mice survived significantly longer compared to TNIKwt/wt CML mice (Median survival (days): TNIK-/- = 33, TNIKwt/wt = 23.5, p < 0.0216) with 2 out of 7 mice surviving long-term. Next, we determined the effect of TNIK signaling on the functionality of FACS sorted Lin-; GFP+; Sca1+; c-kit+ LSC in vitro in serial colony forming assays and in vivo in secondary transplantations. Serial colony formation capacity of TNIK-/- CML LSCs was significantly reduced after re-plating in vitro (CFUs fold change (TNIK-/- vs TNIKwt/wt): 1st Plating = 0.89, P<0.5149, 2nd Plating = 0.42, 9 < 0.0002). In line with these findings, only 1 out of 9 mice secondarily transplanted with LSCs from primary TNIK-/- CML mice developed CML within 90 days, while all 9 recipients receiving TNIKwt/wt LSCs succumbed to the disease within 23 days after transplantation (p < 0.0001). These results suggest that TNIK signaling also promotes self-renewal of CML LSCs.To summarize, we have described for the first time TNIK signaling as a commonly conserved regulator in stress-induced hematopoiesis and CML, which promotes stem cell self-renewal and maintenance. As TNIK inhibitors are currently developed for the treatment of different kinds of solid tumors, TNIK may be an attractive therapeutic target for LSCs in myeloid leukemia. DisclosuresNo relevant conflicts of interest to declare.