Engineered interleukin-6-derived cytokines recruit artificial receptor complexes and disclose CNTF signaling via the OSMR.

Ciliary neurotrophic factor (CNTF) activates cells via the non-signaling α-receptor CNTF receptor (CNTFR) and the two signaling ß-receptors glycoprotein 130 (gp130) and leukemia inhibitory factor receptor (LIFR). The CNTF derivate, Axokine, was protective against obesity and insulin resistance, but clinical development was halted by the emergence of CNTF antibodies. The chimeric cytokine IC7 used the framework of interleukin (IL-)6 with the LIFR-binding site from CNTF to activate cells via IL-6R:gp130:LIFR complexes. Similar to CNTF/Axokine, IC7 protected mice from obesity and insulin resistance. Here, we developed CNTF-independent chimeras that specifically target the IL-6R:gp130:LIFR complex. In GIL-6 and GIO-6, we transferred the LIFR binding site from LIF or OSM to IL-6, respectively. While GIO-6 signals via gp130:IL-6R:LIFR and gp130:IL-6R:OSMR complexes, GIL-6 selectively activates the IL-6R:gp130:LIFR receptor complex. By re-evaluation of IC7 and CNTF, we discovered the Oncostatin M receptor (OSMR) as an alternative non-canonical high-affinity receptor leading to IL-6R:OSMR:gp130 and CNTFR:OSMR:gp130 receptor complexes, respectively. The discovery of OSMR as an alternative high-affinity receptor for IC7 and CNTF designates GIL-6 as the first truly selective IL-6R:gp130:LIFR cytokine, whereas GIO-6 is a CNTF-free alternative for IC7.

Immunosuppressive role of BDNF in therapy-induced neuroendocrine prostate cancer.

Prostate stromal cells play a crucial role in the promotion of tumor growth and immune evasion in the tumor microenvironment (TME) through intricate molecular alterations in their interaction with prostate cancer (PCa) cells. While the impact of these cells on establishing an immunosuppressive response and influencing PCa aggressiveness remains incompletely understood. Our study shows that the activation of the leukemia inhibitory factor (LIF)/LIF receptor (LIFR) pathway in both prostate tumor and stromal cells, following androgen deprivation therapy (ADT), leads to the development of an immunosuppressive TME. Activation of LIF/LIFR signaling in PCa cells induces neuroendocrine differentiation (NED) and upregulates immune checkpoint expression. Inhibition of LIF/LIFR attenuates these effects, underscoring the crucial role of LIF/LIFR in linking NED to immunosuppression. Prostate stromal cells expressing LIFR contribute to NED and immunosuppressive marker abundance in PCa cells, while LIFR knockdown in prostate stromal cells reverses these effects. ADT-driven LIF/LIFR signaling induces brain-derived neurotrophic factor (BDNF) expression, which, in turn, promotes NED, aggressiveness, and immune evasion in PCa cells. Clinical analyses demonstrate elevated BDNF levels in metastatic castration-resistant PCa (CRPC) and a positive correlation with programmed death-ligand 1 (PDL1) and immunosuppressive signatures. This study shows that the crosstalk between PCa cells and prostate stromal cells enhances LIF/LIFR signaling, contributing to an immunosuppressive TME and NED in PCa cells through the upregulation of BDNF.

The LIFR Inhibitor EC359 Effectively Targets Type II Endometrial Cancer by Blocking LIF/LIFR Oncogenic Signaling.

Endometrial cancer (ECa) is the most common female gynecologic cancer. When comparing the two histological subtypes of endometrial cancer, Type II tumors are biologically more aggressive and have a worse prognosis than Type I tumors. Current treatments for Type II tumors are ineffective, and new targeted therapies are urgently needed. LIFR and its ligand, LIF, have been shown to play a critical role in the progression of multiple solid cancers and therapy resistance. The role of LIF/LIFR in the progression of Type II ECa, on the other hand, is unknown. We investigated the role of LIF/LIFR signaling in Type II ECa and tested the efficacy of EC359, a novel small-molecule LIFR inhibitor, against Type II ECa. The analysis of tumor databases has uncovered a correlation between diminished survival rates and increased expression of leukemia inhibitory factor (LIF), suggesting a potential connection between altered LIF expression and unfavorable overall survival in Type II ECa. The results obtained from cell viability and colony formation assays demonstrated a significant decrease in the growth of Type II ECa LIFR knockdown cells in comparison to vector control cells. Furthermore, in both primary and established Type II ECa cells, pharmacological inhibition of the LIF/LIFR axis with EC359 markedly decreased cell viability, long-term cell survival, and invasion, and promoted apoptosis. Additionally, EC359 treatment reduced the activation of pathways driven by LIF/LIFR, such as AKT, mTOR, and STAT3. Tumor progression was markedly inhibited by EC359 treatment in two different patient-derived xenograft models in vivo and patient-derived organoids ex vivo. Collectively, these results suggest LIFR inhibitor EC359 as a possible new small-molecule therapeutics for the management of Type II ECa.

PCBP1 regulates LIFR through FAM3C to maintain breast cancer stem cell self-renewal and invasiveness.

The poly(rC) binding protein 1 gene (PCBP1) encodes the heterogeneous nuclear ribonucleoprotein E1 (hnRNPE1), a nucleic acid-binding protein that plays a tumor-suppressive role in the mammary epithelium by regulating phenotypic plasticity and cell fate. Following the loss of PCBP1 function, the FAM3C gene (encoding the Interleukin-like EMT inducer, or "ILEI" protein) and the leukemia inhibitory factor receptor (LIFR) gene are upregulated. Interaction between FAM3C and LIFR in the extracellular space induces phosphorylation of signal transducer and activator of transcription 3 (pSTAT3). Overexpression and/or hyperactivity of STAT3 has been detected in 40% of breast cancer cases and is associated with a poor prognosis. Herein, we characterize feed-forward regulation of LIFR expression in response to FAM3C/LIFR/STAT3 signaling in mammary epithelial cells. We show that PCBP1 upregulates LIFR transcription through activity at the LIFR promoter, and that FAM3C participates in transcriptional regulation of LIFR. Additionally, our bioinformatic analysis reveals a signature of transcriptional regulation associated with FAM3C/LIFR interaction and identifies the TWIST1 transcription factor as a downstream effector that participates in the maintenance of LIFR expression. Finally, we characterize the effect of LIFR expression in cell-based experiments that demonstrate the promotion of invasion, migration, and self-renewal of breast cancer stem cells (BCSCs), consistent with previous studies linking LIFR expression to tumor initiation and metastasis in mammary epithelial cells.

Structural insights into the assembly of gp130 family cytokine signaling complexes.

The interleukin-6 (IL-6) family cytokines signal through gp130 receptor homodimerization or heterodimerization with a second signaling receptor and play crucial roles in various cellular processes. We determined cryo-electron microscopy structures of five signaling complexes of this family, containing full receptor ectodomains bound to their respective ligands ciliary neurotrophic factor, cardiotrophin-like cytokine factor 1 (CLCF1), leukemia inhibitory factor, IL-27, and IL-6. Our structures collectively reveal similarities and differences in the assembly of these complexes. The acute bends at both signaling receptors in all complexes bring the membrane-proximal domains to a ~30 angstrom range but with distinct distances and orientations. We also reveal how CLCF1 engages its secretion chaperone cytokine receptor-like factor 1. Our data provide valuable insights for therapeutically targeting gp130-mediated signaling.

Genome-wide screening for differentially methylated long noncoding RNAs identifies LIFR-AS1 as an epigenetically regulated lncRNA that inhibits the progression of colorectal cancer.

BACKGROUND: Aberrant DNA methylation is an epigenetic marker that has been linked to the pathogenesis of colorectal cancer (CRC). Long noncoding RNAs (lncRNAs) have been increasingly identified to be associated with tumorigenic processes of CRC. Identifying epigenetically dysregulated lncRNAs and characterizing their effects during carcinogenesis are focuses of cancer research. METHODS: Differentially methylated loci and expressed lncRNAs were identified by integrating DNA methylome and transcriptome analyses using The Cancer Genome Atlas database. Bisulfite sequencing PCR (BSP) was performed to analyze LIFR-AS1 promoter methylation status. The functional roles of LIFR-AS1 in CRC were determined by in vitro and in vivo experiments. RESULTS: We identified a novel hypermethylated lncRNA, LIFR-AS1, that was downregulated and associated with tumorigenesis, metastasis, and poor prognosis in CRC. High methylation burden of LIFR-AS1 indicated a poor survival of CRC patients. Promoter hypermethylation of LIFR-AS1 in tumor tissues was confirmed by BSP. Functional assays revealed that LIFR-AS1 could competitively bind to hsa-miR-29b-3p, and repressed colon cancer cell proliferation, colony formation and invasion. LIFR-AS1 also inhibited tumor growth in a mouse xenograft model of CRC. CONCLUSIONS: Our results showed that the identified DNA methylation-dysregulated lncRNAs may be potential biomarkers and highlighted a role for LIFR-AS1 as a tumor suppressor in CRC.

Long Noncoding RNA LIFR-AS1: A New Player in Human Cancers.

Emerging evidence has indicated that aberrantly expressed long noncoding RNAs (lncRNAs) play a vital role in various biological processes associated with tumorigenesis. Leukemia inhibitory factor receptor antisense RNA1 (LIFR-AS1) is a recently identified lncRNA transcribed in an antisense manner from the LIFR gene located on human chromosome 5p13.1. LIFR-AS1 regulates tumor proliferation, migration, invasion, apoptosis, and drug resistance through different mechanisms. Its expression level is related to the clinicopathological characteristics of tumors and plays a key role in tumor occurrence and development. In this review, we summarize the role of LIFR-AS1 in the development and progression of different cancers and highlight the potential for LIFR-AS1 to serve as a biomarker and therapeutic target for a variety of human cancers.

The ILEI/LIFR complex induces EMT via the Akt and ERK pathways in renal interstitial fibrosis.

BACKGROUND: Chronic kidney disease (CKD) is characterized by high morbidity and mortality and is difficult to cure. Renal interstitial fibrosis (RIF) is a major determinant of, and commonly occurs within, CKD progression. Epithelial mesenchymal transition (EMT) has been identified as a crucial process in triggering renal interstitial fibrosis (RIF). Interleukin-like EMT inducer (ILEI) is an important promotor of EMT; this study aims to elucidate the mechanisms involved. METHODS: Male C57BL6/J mouse were randomly divided into 6 groups: sham (n = 10), sham with negative control (NC) shRNA (sham + NC, n = 10), sham with ILEI shRNA (sham + shILEI, n = 10), unilateral ureteral obstruction (UUO, n = 10), UUO with NC (UUO + NC, n = 10) and UUO with ILEI shRNA (UUO + shILEI, n = 10). Hematoxylin and eosin (H&E), Masson, and immunohistochemical (IHC) staining and western blotting (WB) were performed on murine kidney tissue to identify the function and mechanism of ILEI in RIF. In vitro, ILEI was overexpressed to induce EMT in HK2 cells and analyzed via transwell, WB, real-time PCR, and co-immunoprecipitation. Finally, tissue from 12 pediatric CKD patients (seven with RIF and five without RIF) were studied with H&E, Masson, and IHC staining. RESULTS: Our in vitro model revealed that ILEI facilitates RIF in the UUO model via the Akt and ERK pathways. Further experiments in vivo and in vitro revealed that ILEI promotes renal tubular EMT by binding and activating leukemia inhibitory factor receptor (LIFR), in which phosphorylation of Akt and ERK is involved. We further find markedly increased expression levels of ILEI and LIFR in kidneys from pediatric CKD patients with RIF. CONCLUSION: Our results indicate that ILEI may be a useful biomarker for renal fibrosis and a potential therapeutic target for modulating RIF.

Lidocaine Suppresses Gastric Cancer Development Through Circ_ANO5/miR-21-5p/LIFR Axis.

BACKGROUND: Lidocaine has been manifested to exert anti-tumor role in gastric cancer (GC) progression. However, the action mechanism by which Lidocaine functions in GC has not been fully elucidated. AIM: The study aimed to reveal the molecular mechanism of Lidocaine in GC progression. METHODS: Cell clonogenicity and viability were assessed by colony formation and methyl thiazolyl tetrazolium assays, respectively. Transwell assay was employed to detect cell migration and invasion. Flow cytometry was implemented to monitor cell apoptosis. Relative expression of circular RNA ANO5 (circ_ANO5), microRNA (miR)-21-5p and Leukemia inhibitory factor receptor (LIFR) was examined by quantitative reverse transcription-polymerase chain reaction. Western blot assay was performed to analyze the levels of LIFR and cell metastasis-related proteins. The target relationship between miR-21-5p and circ_ANO5 or LIFR was confirmed by dual-luciferase reporter assay. In addition, xenograft model was established to explore the role of Lidocaine in vivo. RESULTS: Lidocaine inhibited cell proliferation, migration and invasion, while promoted apoptosis of GC cells. Lidocaine upregulated circ_ANO5 and LIFR expression, but downregulated miR-21-5p expression in GC cells. Additionally, expression of circ_ANO5 and LIFR was decreased, while miR-21-5p expression was increased in GC cells. Circ_ANO5 depletion or miR-21-5p overexpression attenuated Lidocaine-induced anti-proliferative and anti-metastatic effects on GC cells. Circ_ANO5 could sponge miR-21-5p, and miR-21-5p targeted LIFR. Moreover, Lidocaine suppressed the tumor growth in vivo. CONCLUSION: Lidocaine might GC cell malignancy by modulating circ_ANO5/miR-21-5p/LIFR axis, highlighting a novel insight for GC treatment.

A targetable LIFR-NF-κB-LCN2 axis controls liver tumorigenesis and vulnerability to ferroptosis.

The growing knowledge of ferroptosis has suggested the role and therapeutic potential of ferroptosis in cancer, but has not been translated into effective therapy. Liver cancer, primarily hepatocellular carcinoma (HCC), is highly lethal with limited treatment options. LIFR is frequently downregulated in HCC. Here, by studying hepatocyte-specific and inducible Lifr-knockout mice, we show that loss of Lifr promotes liver tumorigenesis and confers resistance to drug-induced ferroptosis. Mechanistically, loss of LIFR activates NF-κB signaling through SHP1, leading to upregulation of the iron-sequestering cytokine LCN2, which depletes iron and renders insensitivity to ferroptosis inducers. Notably, an LCN2-neutralizing antibody enhances the ferroptosis-inducing and anticancer effects of sorafenib on HCC patient-derived xenograft tumors with low LIFR expression and high LCN2 expression. Thus, anti-LCN2 therapy is a promising way to improve liver cancer treatment by targeting ferroptosis.

Long non-coding RNA LIFR-AS1 suppressed the proliferation, angiogenesis, migration and invasion of papillary thyroid cancer cells via the miR-31-5p/SIDT2 axis.

Long non-coding RNA LIFR-AS1 is low-expressed in many cancers, but its functions in papillary thyroid carcinoma (PTC) were not defined and require further study. The relationship between LIFR-AS1 expression and clinicopathological characteristics of patients with PTC was statistically analyzed. The downregulation of LIFR-AS1 in PTC tissues and cell lines was predicted by bioinformatics analysis and verified by qRT-PCR. After overexpressing or silencing LIFR-AS1, the regulatory role of LIFR-AS1 in PTC was examined by performing MTT, colony formation, wound healing, Transwell, ELISA, tube formation and xenograft tumor experiment. MiR-31-5p and SID1 transmembrane family member 2 (SIDT2) expressions in PTC tissues or cell lines were detected by qRT-PCR, Western blot, or in situ hybridization. The relationship between miR-31-5p and LIFR-AS1/SIDT2 was predicted by LncBase, TargetScan or Pearson correlation test and then verified by Dual-Luciferase Reporter assay, RNA pull-down assay and qRT-PCR. The regulatory effect of LIFR-AS1/miR-31-5p/SIDT2 axis on the biological behaviors of PTC cells was confirmed by functional experiments and rescue experiments mentioned above. The tumor size and lymphatic metastasis were correlated with LIFR-AS1 overexpression. Overexpressed LIFR-AS1 suppressed tumorigenesis in vivo. LIFR-AS1 and SIDT2 expressions were suppressed in PTC tissues, while that of miR-31-5p was elevated in PTC tissues. LIFR-AS1 was negatively correlated with miR-31-5p. LIFR-AS1 sponged miR-31-5p to upregulate SIDT2, thereby inhibiting the viability, proliferation, migration, invasion, and the secretion of vascular endothelial growth factor (VEGF) of PTC cells and angiogenesis of human umbilical vein endothelial cells (HUVECs). This paper demonstrates that LIFR-AS1/miR-31-5p/SIDT2 axis modulated the development of PTC.

M6A-mediated up-regulation of LncRNA LIFR-AS1 enhances the progression of pancreatic cancer via miRNA-150-5p/ VEGFA/Akt signaling.

N6-methyladenosine (m6A) modification, the most abundant internal methylation of eukaryotic RNA transcripts, is critically implicated in RNA processing. There is extensive evidence indicating that long non-coding RNAs (lncRNAs) serve as key regulators of oncogenesis and tumor progression in humans. Through prior study has assessed that LIFR-AS1 plays a key role in various kinds of malignant tumors. However, the exact role of m6A induced LIFR-AS1 in pancreatic cancer (PC) and its potential molecular mechanisms remain largely unknown. In this study, we determined that PC cell lines and tumors exhibit increased LIFR-AS1 expression that correlates with larger tumor size, lymph node metastasis, and more advanced TNM stage. Functionally, loss-of-function studies indicated that LIFR-AS1 knockdown decreased the proliferation, migration, and invasion of PC cells in vitro. Mechanistically, we found that METTL3 induced m6A hyper-methylation on the 3' UTR of LIFR-AS1 to enhance its mRNA stability and LIFR-AS1 could directly interact with miR-150-5p, thereby indirectly up-regulating VEGFA expressions within cells. Through rescue experiments, we were able to confirm that the unfavorable impact of LIFR-AS1 knockdown on VEGFA /PI3K/Akt Signaling could be reversed via the inhibition of miR-150-5p expression. Together, these findings indicate that a noval m6A-LIFR-AS1 axis promotes PC progression at least in part via regulation of the miR-150-5p/VEGFA axis, indicating that this regulatory axis may be a viable clinical target for the treatment of PC.

Interactions between cancer cells and immune cells drive transitions to mesenchymal-like states in glioblastoma.

The mesenchymal subtype of glioblastoma is thought to be determined by both cancer cell-intrinsic alterations and extrinsic cellular interactions, but remains poorly understood. Here, we dissect glioblastoma-to-microenvironment interactions by single-cell RNA sequencing analysis of human tumors and model systems, combined with functional experiments. We demonstrate that macrophages induce a transition of glioblastoma cells into mesenchymal-like (MES-like) states. This effect is mediated, both in vitro and in vivo, by macrophage-derived oncostatin M (OSM) that interacts with its receptors (OSMR or LIFR) in complex with GP130 on glioblastoma cells and activates STAT3. We show that MES-like glioblastoma states are also associated with increased expression of a mesenchymal program in macrophages and with increased cytotoxicity of T cells, highlighting extensive alterations of the immune microenvironment with potential therapeutic implications.

An engineered ligand trap inhibits leukemia inhibitory factor as pancreatic cancer treatment strategy.

Leukemia inhibitory factor (LIF), a cytokine secreted by stromal myofibroblasts and tumor cells, has recently been highlighted to promote tumor progression in pancreatic and other cancers through KRAS-driven cell signaling. We engineered a high affinity soluble human LIF receptor (LIFR) decoy that sequesters human LIF and inhibits its signaling as a therapeutic strategy. This engineered 'ligand trap', fused to an antibody Fc-domain, has ~50-fold increased affinity (~20 pM) and improved LIF inhibition compared to wild-type LIFR-Fc, potently blocks LIF-mediated effects in pancreatic cancer cells, and slows the growth of pancreatic cancer xenograft tumors. These results, and the lack of apparent toxicity observed in animal models, further highlights ligand traps as a promising therapeutic strategy for cancer treatment.

Cross-reactivity of two human IL-6 family cytokines OSM and LIF explored by protein-protein docking and molecular dynamics simulation.

BACKGROUND: Oncostatin M (OSM) and leukemia inhibitory factor (LIF) are two important pro-inflammatory cytokines of the interleukin-6 (IL-6) family. The two cytokines mediated signaling was recently found to be closely associated with cancer and chronic inflammation, which represent promising therapeutic targets for the treatment of many solid tumors and inflammatory disease. As the most closely related members, cross-reactivity of them may result in undesired activation of off-target cells, leading to toxicity or lack of efficacy of the therapeutic effects. However, the mechanism of the cross-reactivity of OSM and LIF is not well understood. METHODS: In this work, protein-protein docking, molecular dynamics (MD) simulations with explicit solvent and post endpoints binding free energy (BFE) analysis were carried out to further understand the structural and energetic principles of interactions between the two cytokines and the shared receptor LIFR. RESULTS: For the first time, the simulation given a computational model of OSM-LIFR interaction, and provided significant insights into the mechanism of OSM and LIF cross-react with LIFR. The identified common features shared by OSM and LIF bind to LIFR involving 10 "conserved" residues (90% similarity) distributed at the binding site III comprised of AB loop, BC loop and D helix. In addition, 11 shared residues were identified in LIFR contribute 77.85% and 84.63% energies for OSM and LIF binding, which play a critical role in the formation of the two cytokine-receptor complexes. Moreover, the "nonconserved" residues at the same position of cytokines such as Asp41 in OSM and Pro51 in LIF as well as the three residues (Glu338, Asn201 and Glu260) in LIFR were also discovered. CONCLUSIONS: These important information may facilitate the rational design of novel chemical or biological agents with less toxicity and improved efficacy.

Long noncoding RNA LIFR-AS1 suppresses proliferation, migration and invasion and promotes apoptosis through modulating miR-4262/NF-κB pathway in glioma.

AIM: This study aimed to explore the role of lncRNA leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1) on glioma and its underlying molecular mechanism. METHODS: The expression of LIFR-AS1 and miR-4262 was detected by quantitative real-time polymerase chain reaction (qRT-RCR) in both glioma tissues and cell lines. Colony formation assay, 5-ethynyl-20-deoxyuridine (EdU) assay, flow cytometry and transwell assay were respectively conducted to detect cell clones, proliferation, apoptosis, migration and invasion. The effect of LIFR-AS1 on the chemoresistance to temozolomide (TMZ) of glioma cells was also analyzed. In addition, dual-luciferase reporter gene assay was performed to evaluate the luciferase activity. The expressions of nuclear factor-κB (NF-κB) p65, p-NF-κB p65 and inhibitor of κBα (IκBα) in glioma cells were measured by western blot. RESULTS: LIFR-AS1 was lowly expressed and miR-4262 was highly expressed in glioma tissues and cell lines. LIFR-AS1 overexpression inhibited the proliferation, migration and invasion and promoted apoptosis of glioma cells. LIFR-AS1 overexpression also reduced the chemoresistance to TMZ of glioma cells. Moreover, LIFR-AS1 overexpression suppressed the activation of NF-κB signaling pathway in glioma cells. miR-4262 was the target gene of LIFR-AS1. We also found that miR-4262 abrogated the functions of LIFR-AS1 on cell proliferation, apoptosis, migration and invasion of glioma cells in the NF-κB pathway. CONCLUSION: LIFR-AS1 could suppress the proliferation, migration and invasion and promote the apoptosis through modulating miR-4262/NF-κB pathway in glioma.

EGFR-upregulated LIFR promotes SUCLG2-dependent castration resistance and neuroendocrine differentiation of prostate cancer.

Neuroendocrine (NE) differentiation is a well-recognized phenotypic change of prostate cancer after androgen deprivation therapy (ADT), and it ultimately develops into an aggressive subset of this disease. However, the contribution of signaling pathways that lead to metabolic disorders and NE differentiation of prostate cancer remains unclear. In this study, we identified that ADT induced upregulation of the succinate-CoA ligase GDP-forming beta subunit (SUCLG2), which regulates succinate metabolism and NE differentiation of prostate cancer. We demonstrated a connection that upregulation of epidermal growth factor receptor (EGFR)-leukemia inhibitory factor receptor (LIFR) signaling induced SUCLG2 expression in prostate cancer cells. The LIFR is upregulated by nuclear EGFR, which acts as a transcriptional regulator, directly binds to the LIFR promoter, and drives NE differentiation and glycolysis of prostate cancer. LIFR upregulation is associated with SUCLG2, which increased succinate synthesis and enzymatic activities of mitochondrial nucleoside diphosphate kinase (NDPK) in prostate cancer cells. Knockdown of SUCLG2 suppressed NE differentiation in cultured cells and reduced prostate tumor growth in a xenograft model. Analysis of prostate tissue samples showed increased intensity of nuclear EGFR associated with the LIFR and SUCLG2 in castration-resistant prostate cancer tumors. Our study provides a mechanism whereby ADT upregulates EGFR-LIFR signaling that activates SUCLG2, which subsequently stimulates the metabolic changes associated with NE differentiation and aggressive prostate cancer phenotype.

Engineering a potent receptor superagonist or antagonist from a novel IL-6 family cytokine ligand.

Interleukin-6 (IL-6) family cytokines signal through multimeric receptor complexes, providing unique opportunities to create novel ligand-based therapeutics. The cardiotrophin-like cytokine factor 1 (CLCF1) ligand has been shown to play a role in cancer, osteoporosis, and atherosclerosis. Once bound to ciliary neurotrophic factor receptor (CNTFR), CLCF1 mediates interactions to coreceptors glycoprotein 130 (gp130) and leukemia inhibitory factor receptor (LIFR). By increasing CNTFR-mediated binding to these coreceptors we generated a receptor superagonist which surpassed the potency of natural CNTFR ligands in neuronal signaling. Through additional mutations, we generated a receptor antagonist with increased binding to CNTFR but lack of binding to the coreceptors that inhibited tumor progression in murine xenograft models of nonsmall cell lung cancer. These studies further validate the CLCF1-CNTFR signaling axis as a therapeutic target and highlight an approach of engineering cytokine activity through a small number of mutations.

Novel Long Non-coding RNA lncAMPC Promotes Metastasis and Immunosuppression in Prostate Cancer by Stimulating LIF/LIFR Expression.

Long non-coding RNAs (lncRNAs) participate in the development and progression of prostate cancer (PCa). We aimd to identify a novel lncRNA, named lncRNA activated in metastatic PCa (lncAMPC), and investigate its mechanisms and clinical significance in PCa. First, the biological capacity of lncAMPC in PCa was demonstrated both in vitro and in vivo. The lncAMPC was overexpressed in tumor tissue and urine of metastatic PCa patients and promoted PCa tumorigenesis and metastasis. Then, a mechanism study was conducted to determine how the lncAMPC-activated pathway contributed to PCa metastasis and immunosuppression. In the cytoplasm, lncAMPC upregulated LIF expression by sponging miR-637 and inhibiting its activity. In the nucleus, lncAMPC enhanced LIFR transcription by decoying histone H1.2 away from the upstream sequence of the LIFR gene. The lncAMPC-activated LIF/LIFR expressions stimulated the Jak1-STAT3 pathway to simultaneously maintain programmed death-ligand 1 (PD-L1) protein stability and promote metastasis-associated gene expression. Finally, the prognostic value of the expression of lncAMPC and its downstream genes in PCa patients was evaluated. High LIF/LIFR levels indicated shorter biochemical recurrence-free survival among patients who underwent radical prostatectomy. Therefore, the lncAMPC/LIF/LIFR axis plays a critical role in PCa metastasis and immunosuppression and may serve as a prognostic biomarker and potential therapeutic target.

Knockdown of Musashi RNA Binding Proteins Decreases Radioresistance but Enhances Cell Motility and Invasion in Triple-Negative Breast Cancer.

The therapeutic potential of Musashi (MSI) RNA-binding proteins, important stemness-associated gene expression regulators, remains insufficiently understood in breast cancer. This study identifies the interplay between MSI protein expression, stem cell characteristics, radioresistance, cell invasiveness and migration. MSI-1, MSI-2 and Notch pathway elements were investigated via quantitative polymerase chain reaction (qPCR) in 19 triple-negative breast cancer samples. Measurements were repeated in MDA-MB-231 cells after MSI-1 and -2 siRNA-mediated double knockdown, with further experiments performed after MSI silencing. Flow cytometry helped quantify expression of CD44 and leukemia inhibitory factor receptor (LIFR), changes in apoptosis and cell cycle progression. Proliferation and irradiation-induced effects were assessed using colony formation assays. Radiation-related proteins were investigated via Western blots. Finally, cell invasion assays and digital holographic microscopy for cell migration were performed. MSI proteins showed strong correlations with Notch pathway elements. MSI knockdown resulted in reduction of stem cell marker expression, cell cycle progression and proliferation, while increasing apoptosis. Cells were radiosensitized as radioresistance-conferring proteins were downregulated. However, MSI-silencing-mediated LIFR downregulation resulted in enhanced cell invasion and migration. We conclude that, while MSI knockdown results in several therapeutically desirable consequences, enhanced invasion and migration need to be counteracted before knockdown advantages can be fully exploited.