Dvl2 facilitates the coordination of NF‐κB and Wnt signaling to promote colitis‐associated colorectal progression

Colitis‐associated colorectal cancer (CAC) arises due to prolonged inflammation and has distinct molecular events compared with sporadic colorectal cancer (CRC). Although inflammatory NF‐κB signaling was activated by pro‐inflammatory cytokines (such as TNFα) in early stages of CAC, Wnt/β‐catenin signaling later appears to function as a key regulator of CAC progression. However, the exact mechanism responsible for the cross‐regulation between these 2 pathways remains unclear. Here, we found reciprocal inhibition between NF‐κB and Wnt/β‐catenin signaling in CAC samples, and the Dvl2, an adaptor protein of Wnt/β‐catenin signaling, is responsible for NF‐κB inhibition. Mechanistically, Dvl2 interacts with the C‐terminus of tumor necrosis factor receptor 1 (TNFRI) and mediates TNFRI endocytosis, leading to NF‐κB signal inhibition. In addition, increased infiltration of the pro‐inflammatory cytokine interleukin‐13 (IL‐13) is responsible for upregulating Dvl2 expression through STAT6. Targeting STAT6 effectively decreases Dvl2 levels and restrains colony formation of cancer cells. These findings demonstrate a unique role for Dvl2 in TNFRI endocytosis, which facilitates the coordination of NF‐κB and Wnt to promote CAC progression.     

Long noncoding RNA LINC01578 drives colon cancer metastasis through a positive feedback loop with the NF‐κB/YY1 axis

Metastasis accounts for poor prognosis of cancers and related deaths. Accumulating evidence has shown that long noncoding RNAs (lncRNAs) play critical roles in several types of cancer. However, which lncRNAs contribute to metastasis of colon cancer is still largely unknown. In this study, we found that lncRNA LINC01578 was correlated with metastasis and poor prognosis of colon cancer. LINC01578 was upregulated in colon cancer, associated with metastasis, advanced clinical stages, poor overall survival, disease‐specific survival, and disease‐free survival. Gain‐of‐function and loss‐of‐function assays revealed that LINC01578 enhanced colon cancer cell viability and mobility in vitro and colon cancer liver metastasis in vivo. Mechanistically, nuclear factor kappa B (NF‐κB) and Yin Yang 1 (YY1) directly bound to the LINC01578 promoter, enhanced its activity, and activated LINC01578 expression. LINC01578 was shown to be a chromatin‐bound lncRNA, which directly bound NFKBIB promoter. Furthermore, LINC01578 interacted with and recruited EZH2 to NFKBIB promoter and further repressed NFKBIB expression, thereby activating NF‐κB signaling. Through activation of NF‐κB, LINC01578 further upregulated YY1 expression. Through activation of the NF‐κB/YY1 axis, LINC01578 in turn enhanced its own promoter activity, suggesting that LINC01578 and NF‐κB/YY1 formed a positive feedback loop. Blocking NF‐κB signaling abolished the oncogenic roles of LINC01578 in colon cancer. Furthermore, the expression levels of LINC01578, NFKBIB, and YY1 were correlated in clinical tissues. Collectively, this study demonstrated that LINC01578 promoted colon cancer metastasis via forming a positive feedback loop with NF‐κB/YY1 and suggested that LINC01578 represents a potential prognostic biomarker and therapeutic target for colon cancer metastasis.

Abbreviations

ChIP

chromatin immunoprecipitation

ChIRP

chromatin isolation by RNA purification

COAD

colon adenocarcinoma

CPAT

Coding‐Potential Assessment Tool

CPC

coding potential calculator

DFS

disease‐free survival

DSS

disease‐specific survival

EdU

5‐ethynyl‐2''‐deoxyuridine

H&E

hematoxylin and eosin

HR

hazard ratio

IHC

immunohistochemistry

IKK

IκB kinase

IκB

inhibitory κB

lncRNAs

long noncoding RNAs

NC

negative control

NCBI

National Center for Biotechnology Information

NF‐κB

nuclear factor kappa B

qRT‐PCR

quantitative real‐time polymerase chain reaction

RIP

RNA immunoprecipitation

RPISeq

RNA‐Protein Interaction Prediction

TCGA

The Cancer Genome Atlas

TNF

tumor necrosis factor

TUNEL

TdT‐mediated dUTP Nick‐End Labeling

YY1

Yin Yang 1

     

Adoptive transfer of immature myeloid cells lacking NF‐κB p50 (p50‐IMC) impedes the growth of MHC‐matched high‐risk neuroblastoma

High‐risk neuroblastomas harbor abundant myeloid cells that suppress antitumor immunity and support tumor growth. Macrophages lacking the inhibitory NF‐κB p50 subunit adopt a pro‐inflammatory phenotype. We now report that murine 9464D neuroblastoma cells, which express high levels of exogenous MYCN, grow slower in syngeneic p50(f/f);Lys‐Cre mice that lack p50 in macrophages and neutrophils, compared with p50(f/f) littermates. Tumors in p50(f/f);Lys‐Cre mice possess increased numbers of total and activated CD4⁺ and CD8⁺ T cells, and depletion of both of these T‐cell populations accelerates tumor growth. Anti‐PD‐1 T‐cell checkpoint blockade, or DNA methyltransferase and histone deacetylase inhibition, further slows tumor growth. In addition, adoptive transfer of immature myeloid cells lacking NF‐κB p50 (p50‐IMC), generated either from the bone marrow of p50^−/− mice or via nucleofection of a p50 sgRNA:Cas9 complex into wild‐type hematopoietic progenitors, also slowed growth of MHC‐matched 9464D tumors but not of MHC‐mismatched Neuro2A tumors. These findings further validate the utility of targeting myeloid NF‐κB p50 as a strategy for cancer therapy and demonstrate activity of p50‐IMC generated by gene editing of syngeneic marrow cells, a cell product relevant to clinical translation.     

α1,4‐Linked N‐acetylglucosamine suppresses gastric cancer development by inhibiting Mucin‐1‐mediated signaling

Gastric cancer is the second leading cause of cancer deaths worldwide, and more understanding of its molecular basis is urgently needed. Gastric gland mucin secreted from pyloric gland cells, mucous neck cells, and cardiac gland cells of the gastric mucosa harbors unique O‐glycans carrying terminal α1,4‐linked N‐acetylglucosamine (αGlcNAc) residues. We previously reported that αGlcNAc loss correlated positively with poor outcomes for patients with differentiated‐type gastric cancer. However, the molecular mechanisms underlying these outcomes remained poorly understood. Here, we examined the effects of upregulated αGlcNAc expression on malignant phenotypes of the differentiated‐type gastric cancer cell lines, AGS and MKN7. Upregulation of αGlcNAc following ectopic expression of its biosynthetic enzyme attenuated cell proliferation, motility, and invasiveness of AGS and MKN7 cells in vitro. Moreover, AGS cell tumorigenicity was significantly suppressed by αGlcNAc overexpression in a xenograft model. To define the molecular mechanisms underlying these phenotypes, we investigated αGlcNAc binding proteins in AGS cells and identified Mucin‐1 (MUC1) and podocalyxin. Both proteins were colocalized with αGlcNAc on human gastric cancer cells. We also found that αGlcNAc was bound to MUC1 in murine normal gastric mucosa. When we assessed the effects of αGlcNAc binding to MUC1, we found that αGlcNAc blocked galectin‐3 binding to MUC1, phosphorylation of the MUC1 C‐terminus, and recruitment of Src and β‐catenin to that C‐terminus. These results suggest that αGlcNAc regulates cancer cell phenotypes by dampening MUC1 signal transduction.     

LAMC1 upregulation via TGFβ induces inflammatory cancer‐associated fibroblasts in esophageal squamous cell carcinoma via NF‐κB–CXCL1–STAT3

Cancer‐associated fibroblasts (CAF) are a heterogeneous cell population within the tumor microenvironment,and play an important role in tumor development. By regulating the heterogeneity of CAF, transforming growth factor β (TGFβ) influences tumor development. Here, we explored oncogenes regulated by TGFβ1 that are also involved in signaling pathways and interactions within the tumor microenvironment. We analyzed sequencing data of The Cancer Genome Atlas (TCGA) and our own previously established RNA microarray data ({"type":"entrez-geo","attrs":{"text":"GSE53625","term_id":"53625"}}GSE53625), as well as esophageal squamous cell carcinoma (ESCC) cell lines with or without TGFβ1 stimulation. We then focused on laminin subunit gamma 1 (LAMC1), which was overexpressed in ESCC cells, affecting patient prognosis, which could be upregulated by TGFβ1 through the synergistic activation of SMAD family member 4 (SMAD4) and SP1. LAMC1 directly promoted the proliferation and migration of tumor cells, mainly via Akt–NFκB–MMP9/14 signaling. Additionally, LAMC1 promoted CXCL1 secretion, which stimulated the formation of inflammatory CAF (iCAF) through CXCR2–pSTAT3. Inflammatory CAF promoted tumor progression. In summary, we identified the dual mechanism by which the upregulation of LAMC1 by TGFβ in tumor cells not only promotes ESCC proliferation and migration, but also indirectly induces carcinogenesis by stimulating CXCL1 secretion to promote the formation of iCAF. This finding suggests that LAMC1 could be a potential therapeutic target and prognostic marker for ESCC.     

Tumor‐associated macrophage‐derived transforming growth factor‐β promotes colorectal cancer progression through HIF1‐TRIB3 signaling

Tumor‐associated macrophages (TAMs), one of the most common cell components in the tumor microenvironment, have been reported as key contributors to cancer‐related inflammation and enhanced metastatic progression of tumors. To explore the underlying mechanism of TAM‐induced tumor progression, TAMs were isolated from colorectal cancer patients, and the functional interaction with colorectal cancer cells was analyzed. Our study found that coculture of TAMs contributed to a glycolytic state in colorectal cancer, which promoted the stem‐like phenotypes and invasion of tumor cells. TAMs produced the cytokine transforming growth factor‐β to support hypoxia‐inducible factor 1α (HIF1α) expression, thereby upregulating Tribbles pseudokinase 3 (TRIB3) in tumor cells. Elevated expression of TRIB3 resulted in activation of the β‐catenin/Wnt signaling pathway, which eventually enhanced the stem‐like phenotypes and cell invasion in colorectal cancer. Our findings provided evidence that TAMs promoted colorectal cancer progression in a HIF1α/TRIB3‐dependent manner, and blockade of HIF1α signals efficiently improved the outcome of chemotherapy, describing an innovative approach for colorectal cancer treatment.     

Metformin inhibits the proliferation and invasion of ovarian cancer cells by suppressing tripartite motif‐containing 37‐induced tumor necrosis factor receptor‐associated factor 2 ubiquitination

Ovarian cancer is the leading cause of death in gynecological malignancies worldwide. Our previous studies have proved that metformin inhibited the proliferation and invasion of ovarian cancer in vitro and in vivo. However, the underlying mechanisms have not been fully elucidated. Immunohistochemistry was carried out to detect the expression of tripartite motif‐containing 37 (TRIM37), Ki‐67, and MMP‐9 in ovarian cancer and normal tissues. The influence of TRIM37 on the proliferation and invasion of ovarian cancer cells was verified by the real‐time cellular analysis proliferation test, colony formation test, and Transwell assay. Western blot analysis and immunoprecipitation were used to detect the expression of the nuclear factor‐κB (NF‐κB) pathway and the interaction between TRIM37 and tumor necrosis factor receptor‐associated factor 2 (TRAF2). Ubiquitination detection was carried out to detect the ubiquitination level of TRAF2. The present study revealed that TRIM37 expression was significantly increased in ovarian cancer tissues compared with normal control tissues, and its overexpression was closely associated with proliferation and metastasis. Metformin inhibited the NF‐κB signaling pathway by downregulating TRIM37. Metformin also inhibited the ubiquitination of TRAF2 induced by TRIM37 overexpression. Metformin inhibits the proliferation and invasion of ovarian cancer cells by suppressing TRIM37‐induced TRAF2 ubiquitination.     

ICAM1 promotes bone metastasis via integrin‐mediated TGF‐β/EMT signaling in triple‐negative breast cancer

Bone‐related events caused by breast cancer bone metastasis substantially compromise the survival and quality of life of patients. Because triple‐negative breast cancer (TNBC) lacks hormone receptors and Her2‐targeted therapeutic options, progress in the treatment of TNBC bone metastasis has been very slow. Intercellular adhesion molecule 1 (ICAM1) is highly expressed in various cancers and plays an important role in tumorigenesis and metastasis. However, the effect and mechanism of ICAM1 in TNBC bone metastasis are still unknown. We found that ICAM1 was highly expressed in TNBC and correlated with prognosis in TNBC patients. Cell lines with high expression of ICAM1 exhibited enhanced bone metastasis in tumor‐bearing mice, and silencing ICAM1 expression significantly inhibited bone metastasis in mice. ICAM1 interacted with integrins to activate the epithelial‐to‐mesenchymal transition program through TGF‐β/SMAD signaling, ultimately enhancing cell invasiveness. Therefore, the findings of the present study provide a strong rationale for the application of ICAM1‐targeted therapy in TNBC patients with bone metastasis.     

CPI‐203 improves the efficacy of anti‐PD‐1 therapy by inhibiting the induced PD‐L1 overexpression in liver cancer

Hepatocellular carcinoma (HCC) is one of the commonest lethal malignancies worldwide, and often diagnosed at an advanced stage, without any curative therapy. Immune checkpoint blockers targeting the programmed death receptor 1 (PD‐1) have shown impressive antitumor activity in patients with advanced‐stage HCC, while the response rate is only 30%. Inducible PD‐L1 overexpression may result in a lack of response to cancer immunotherapy, which is attributed to a mechanism of adaptive immune resistance. Our study investigated that the overexpression of PD‐L1 promoted the invasion and migration of liver cancer cells in vitro, and the induced overexpression of PD‐L1 in the tumor microenvironment could weaken the effects of anti‐PD‐1 immunotherapy in a BALB/c mouse model of liver cancer. CPI‐203, a small‐molecule bromodomain‐containing protein 4 (BRD4) inhibitor, which can potently inhibit PD‐L1 expression in vitro and in vivo, combined with PD‐1 antibody improved the response to immunotherapy in a liver cancer model. Cell transfection and chromatin immunoprecipitation assay manifested that BRD4 plays a key role in PD‐L1 expression; CPI‐203 can inhibit PD‐L1 expression by inhibiting the BRD4 occupation of the PD‐L1 promoter region. This study indicates a potential clinical immunotherapy method to reduce the incidence of clinical resistance to immunotherapy in patients with HCC.     

Far‐infrared radiation alleviates cisplatin‐induced vascular damage and impaired circulation via activation of HIF‐1α

Severe vascular damage and complications are often observed in cancer patients during treatment with chemotherapeutic drugs such as cisplatin. Thus, development of potential options to ameliorate the vascular side effects is urgently needed. In this study, the effects and the underlying mechanisms of far‐infrared radiation (FIR) on cisplatin‐induced vascular injury and endothelial cytotoxicity/dysfunction in mice and human umbilical vein endothelial cells (HUVECs) were investigated. An important finding is that the severe vascular stenosis and poor blood flow seen in cisplatin‐treated mice were greatly mitigated by FIR irradiation (30 minutes/day) for 1‐3 days. Moreover, FIR markedly increased the levels of phosphorylation of PI3K and Akt, and VEGF secretion, as well as the expression and the activity of hypoxia‐inducible factor 1α (HIF‐1α) in cisplatin‐treated HUVECs in a promyelocytic leukemia zinc finger protein (PLZF)‐dependent manner. However, FIR‐stimulated endothelial angiogenesis and VEGF release were significantly diminished by transfection with HIF‐1α siRNA. We also confirmed that HIF‐1α, PI3K, and PLZF contribute to the inhibitory effect of FIR on cisplatin‐induced apoptosis in HUVECs. Notably, FIR did not affect the anticancer activity and the HIF‐1α/VEGF cascade in cisplatin‐treated cancer cells under normoxic or hypoxic condition, indicating that the actions of FIR may specifically target endothelial cells. It is the first study to demonstrate that FIR effectively attenuates cisplatin‐induced vascular damage and impaired angiogenesis through activation of HIF‐1α–dependent processes via regulation of PLZF and PI3K/Akt. Taken together, cotreatment with the noninvasive and easily performed FIR has a therapeutic potential to prevent the pathogenesis of vascular complications in cancer patients during cisplatin treatment.     

Dual inhibition of TGF‐β and PD‐L1: a novel approach to cancer treatment

Transforming growth factor‐β (TGF‐β) and programmed death ligand 1 (PD‐L1) initiate signaling pathways with complementary, nonredundant immunosuppressive functions in the tumor microenvironment (TME). In the TME, dysregulated TGF‐β signaling suppresses antitumor immunity and promotes cancer fibrosis, epithelial‐to‐mesenchymal transition, and angiogenesis. Meanwhile, PD‐L1 expression inactivates cytotoxic T cells and restricts immunosurveillance in the TME. Anti‐PD‐L1 therapies have been approved for the treatment of various cancers, but TGF‐β signaling in the TME is associated with resistance to these therapies. In this review, we discuss the importance of the TGF‐β and PD‐L1 pathways in cancer, as well as clinical strategies using combination therapies that block these pathways separately or approaches with dual‐targeting agents (bispecific and bifunctional immunotherapies) that may block them simultaneously. Currently, the furthest developed dual‐targeting agent is bintrafusp alfa. This drug is a first‐in‐class bifunctional fusion protein that consists of the extracellular domain of the TGF‐βRII receptor (a TGF‐β ‘trap’) fused to a human immunoglobulin G1 (IgG1) monoclonal antibody blocking PD‐L1. Given the immunosuppressive effects of the TGF‐β and PD‐L1 pathways within the TME, colocalized and simultaneous inhibition of these pathways may potentially improve clinical activity and reduce toxicity.