PIPKIγ Regulates CCL2 Expression in Colorectal Cancer by Activating AKT-STAT3 Signaling

The role of innate immune cells in the colorectal cancer tumor microenvironment and advances in anti-tumor therapy research

Innate immune cells in the colorectal cancer microenvironment mainly include macrophages, neutrophils, natural killer cells, dendritic cells and bone marrow-derived suppressor cells. They play a pivotal role in tumor initiation and progression through the secretion of diverse cytokines, chemokines, and other factors that govern these processes. Colorectal cancer is a common malignancy of the gastrointestinal tract, and understanding the role of innate immune cells in the microenvironment of CRC may help to improve therapeutic approaches to CRC and increase the good prognosis. In this review, we comprehensively explore the pivotal role of innate immune cells in the initiation and progression of colorectal cancer (CRC), alongside an extensive evaluation of the current landscape of innate immune cell-based immunotherapies, thereby offering valuable insights for future research strategies and clinical trials.

Pip5k1γ promotes anabolism of nucleus pulposus cells and intervertebral disc homeostasis by activating CaMKII-Ampk pathway in aged mice

Degenerative disc disease (DDD) represents a significant global health challenge, yet its underlying molecular mechanisms remain elusive. This study aimed to investigate the role of type 1 phosphatidylinositol 4-phosphate 5-kinase (Pip5k1) in intervertebral disc (IVD) homeostasis and disease. All three Pip5k1 isoforms, namely Pip5k1α, Pip5k1β, and Pip5k1γ, were detectable in mouse and human IVD tissues, with Pip5k1γ displaying a highest expression in nucleus pulposus (NP) cells. The expression of Pip5k1γ was significantly down-regulated in the NP cells of aged mice and patients with severe DDD. To determine whether Pip5k1γ expression is required for disc homeostasis, we generated a Pip5k1γfl/fl; AggrecanCreERT2 mouse model for the conditional knockout of the Pip5k1γ gene in aggrecan-expressing IVD cells. Our findings revealed that the conditional deletion of Pip5k1γ did not affect the disc structure or cellular composition in 5-month-old adult mice. However, in aged (15-month-old) mice, this deletion led to several severe degenerative disc defects, including decreased NP cellularity, spontaneous fibrosis and cleft formation, and a loss of the boundary between NP and annulus fibrosus. At the molecular level, the absence of Pip5k1γ reduced the anabolism of NP cells without markedly affecting their catabolic or anti-catabolic activities. Moreover, the loss of Pip5k1γ significantly dampened the activation of the protective Ampk pathway in NP cells, thereby accelerating NP cell senescence. Notably, Pip5k1γ deficiency blunted the effectiveness of metformin, a potent Ampk activator, in activating the Ampk pathway and mitigating lumbar spine instability (LSI)-induced disc lesions in mice. Overall, our study unveils a novel role for Pip5k1γ in promoting anabolism and maintaining disc homeostasis, suggesting it as a potential therapeutic target for DDD.

ENO1 deletion potentiates ferroptosis and decreases glycolysis in colorectal cancer cells via AKT/STAT3 signaling

Colorectal cancer (CRC) is one of the most prevailing and lethal forms of cancer globally. α-enolase (ENO1) has been well documented to be involved in the progression and drug resistance of CRC. The present study was designed to specify the role of ENO1 in major events during the process of CRC and to introduce its latent functional mechanism. ENO1 expression was determined by western blot analysis. Extracellular acidification rates were assessed using an XF96 extracellular flux analyzer. Glucose uptake, lactic acid production, total iron levels and ferroptosis-related markers were examined with corresponding kits. A dichlorodihydrofluorescein diacetate probe measured intracellular reactive oxygen species content. Western blotting detected the expression of glycolysis- and ferroptosis-related proteins. CCK-8 and EdU staining assays assessed cell proliferation. In the current study, ENO1 was highly expressed in CRC cells. Knockdown of ENO1 markedly reduced the glycolysis and accelerated the ferroptosis in CRC cells. Moreover, the inhibitory effects of WZB117, a specific inhibitor of glycolysis-related glucose transporter type 1, on CRC cell proliferation were further enhanced by ENO1 interference. In addition, silencing of ENO1 inactivated the AKT/STAT3 signaling. The AKT activator SC79 partially reversed the effects of ENO1 deficiency on the AKT/STAT3 signaling, glycolysis, proliferation as well as ferroptosis in CRC cells. In summary, inactivation of AKT/STAT3 signaling mediated by ENO1 inhibition might boost the ferroptosis and suppress the glycolysis in CRC cells.

STAT3 as a newly emerging target in colorectal cancer therapy: Tumorigenesis, therapy response, and pharmacological/nanoplatform strategies

Colorectal cancer (CRC) ranks as the third most aggressive tumor globally, and it can be categorized into two forms: colitis-mediated CRC and sporadic CRC. The therapeutic approaches for CRC encompass surgical intervention, chemotherapy, and radiotherapy. However, even with the implementation of these techniques, the 5-year survival rate for metastatic CRC remains at a mere 12-14%. In the realm of CRC treatment, gene therapy has emerged as a novel therapeutic approach. Among the crucial molecular pathways that govern tumorigenesis, STAT3 plays a significant role. This pathway is subject to regulation by cytokines and growth factors. Once translocated into the nucleus, STAT3 influences the expression levels of factors associated with cell proliferation and metastasis. Literature suggests that the upregulation of STAT3 expression is observed as CRC cells progress towards metastatic stages. Consequently, elevated STAT3 levels serve as a significant determinant of poor prognosis and can be utilized as a diagnostic factor for cancer patients. The biological and malignant characteristics of CRC cells contribute to low survival rates in patients, as the upregulation of STAT3 prevents apoptosis and promotes pro-survival autophagy, thereby accelerating tumorigenesis. Furthermore, STAT3 plays a role in facilitating the proliferation of CRC cells through the stimulation of glycolysis and promoting metastasis via the induction of epithelial-mesenchymal transition (EMT). Notably, an intriguing observation is that the upregulation of STAT3 can mediate resistance to 5-fluorouracil, oxaliplatin, and other anti-cancer drugs. Moreover, the radio-sensitivity of CRC diminishes with increased STAT3 expression. Compounds such as curcumin, epigallocatechin gallate, and other anti-tumor agents exhibit the ability to suppress STAT3 and its associated pathways, thereby impeding tumorigenesis in CRC. Furthermore, it is worth noting that nanostructures have demonstrated anti-proliferative and anti-metastatic properties in CRC.

LncRNA LINC01094 Promotes Cells Proliferation and Metastasis through the PTEN/AKT Pathway by Targeting AZGP1 in Gastric Cancer

Long noncoding RNAs (lncRNAs) were recently reported to play an essential role in multiple cancer types. Herein, through next-generation sequencing, we screened metastasis-driving molecules by using tissues from early-stage gastric cancer (GC) patients with lymph node metastasis, and we identified a lncRNA LINC01094, which was associated with the metastasis of GC. According to the clinical data from the TCGA, GSE15459, and GSE62254 cohorts, the high expression of LINC01094 was associated with an unfavorable prognosis. Moreover, 106 clinical GC and paired normal samples were collected, and the qRT-PCR results showed that the high expression of LINC01094 was associated with high T and N stages and a poor prognosis. We found that LINC01094 promotes the proliferation and metastasis of GC in vitro and in vivo. AZGP1 was found as the protein-binding partner of LINC01094 by using RNA pulldown and RNA-binding protein immunoprecipitation (RIP) assays. LINC01094 antagonizes the function of AZGP1, downregulates the expression of PTEN, and further upregulates the AKT pathway. Collectively, our results suggested that LINC01094 might predict the prognosis of GC patients and become the therapy target for GC.

Advances in the role of STAT3 in macrophage polarization

The physiological processes of cell growth, proliferation, differentiation, and apoptosis are closely related to STAT3, and it has been demonstrated that aberrant STAT3 expression has an impact on the onset and progression of a number of inflammatory immunological disorders, fibrotic diseases, and malignancies. In order to produce the necessary biological effects, macrophages (M0) can be polarized into pro-inflammatory (M1) and anti-inflammatory (M2) types in response to various microenvironmental stimuli. STAT3 signaling is involved in macrophage polarization, and the research of the effect of STAT3 on macrophage polarization has gained attention in recent years. In order to provide references for the treatment and investigation of disorders related to macrophage polarization, this review compiles the pertinent signaling pathways associated with STAT3 and macrophage polarization from many fundamental studies.

Chromosome 12 Open Reading Frame 49 Promotes Tumor Growth and Predicts Poor Prognosis in Colorectal Cancer

BACKGROUND AND AIMS

Little is known about the role of chromosome 12 open reading frame 49 (C12ORF49)-induced metabolic signal transduction in tumor growth. We investigated the relationship between C12ORF49 expression and prognosis in colorectal cancer (CRC) patients.

METHODS

C12ORF49 protein expression was measured in CRC tissues by Western blot and immunohistochemistry staining. Knock out of C12ORF49 in CRC cells was then performed, and the role of C12ORF49 in CRC cell proliferation and growth was examined. The expression of C12ORF49 in CRC was analyzed in Gene Expression Profiling Interactive Analysis (GEPIA) databases. A prognosis model with 11 C12ORF49-associated genes (CAGs) was generated by TCGA databases.

RESULTS

C12ORF49 expression was significantly higher in CRC tumor tissue than in non-tumor tissue. Furthermore, in vitro and in vivo loss-of-function experiments, showed that C12ORF49 plays critical roles in promoting tumor cell growth. There was a significant correlation between C12ORF49 protein and the presence of tumor necrosis. C12ORF49 is critical for its interaction with SREBF1, TMEM41A, and S1PR3 in the poor prognosis of CRC.

CONCLUSIONS

Our results suggest that C12ORF49 plays a key role in CRC tumor growth.

Cardamonin suppresses pro-tumor function of macrophages by decreasing M2 polarization on ovarian cancer cells via mTOR inhibition

Ovarian cancer is the most fatal tumor characterized by an abundance of tumor-associated macrophage (TAM) infiltrations in women. Functional TAMs, which mainly present M2-like phenotypes and perform key functions on tumor progress, have been considered an attractive target for ovarian cancer therapy. Cardamonin showed an excellent antitumor activity in multiple tumor cells. This study aimed to investigate the role of cardamonin on TAMs. With the conditioned medium of ovarian cancer cells, macrophages were induced to TAMs and, accordingly, promoted the proliferation, migration, and invasion of ovarian cancer cells. Cardamonin suppressed alternatively activated (M2) polarization of TAMs and downregulated TAM-secreted tumorigenic factors, thereby hindering the pro-tumor function of TAMs on ovarian cancer cells. Moreover, cardamonin inhibited tumor growth in xenograft nude mice and lowered the expression of CD163 and CD206. Mechanistically, cardamonin inhibited the phosphorylation of mammalian target of rapamycin (mTOR) and signal transducer and activator of transcription 3 (STAT3), resulting in the suppression of M2 polarization. Furthermore, STAT3 is tightly related with mTOR activity. Altogether, these findings implied that cardamonin suppresses the pro-tumor function of TAMs by decreasing M2 polarization via mTOR inhibition, and cardamonin may be a potential therapeutic agent for ovarian cancer.

Chemokines in progression, chemoresistance, diagnosis, and prognosis of colorectal cancer

Plenty of factors affect the oncogenesis and progression of colorectal cancer in the tumor microenvironment, including various immune cells, stromal cells, cytokines, and other factors. Chemokine is a member of the cytokine superfamily. It is an indispensable component in the tumor microenvironment. Chemokines play an antitumor or pro-tumor role by recruitment or polarization of recruiting immune cells. Meanwhile, chemokines, as signal molecules, participate in the formation of a cross talk among signaling pathways and non-coding RNAs, which may be involved in promoting tumor progression. In addition, they also function in immune escape. Chemokines are related to drug resistance of tumor cells and may even provide reference for the diagnosis, therapy, and prognosis of patients with colorectal cancer.

Usefulness of serum CCL2 as prognostic biomarker in prostate cancer: a long-term follow-up study

OBJECTIVE

Prostate-specific antigen is considered the most useful biomarker for prostate cancer, but not in all cases. In a previous study, we have shown that a risk classification combining prostate-specific antigen ≥100 ng/mL and chemokine (CC motif) ligand 2 ≥ 320 pg/mL can predict survivals. We investigated the long-term usefulness of serum chemokine (CC motif) ligand 2 as a complementary biomarker to prostate-specific antigen and developed a novel risk classification system.

METHODS

Serum samples were collected from 379 patients who underwent prostate biopsy at Kanazawa University Hospital between 2007 and 2013, and 255 patients with histologically diagnosed prostate cancer were included in this study. We retrospectively examined the efficacy of serum chemokine (CC motif) ligand 2 as a prognostic biomarker.

RESULTS

Patients with chemokine (CC motif) ligand 2 ≥ 320 pg/mL exhibited a significantly shorter overall survival, prostate cancer-specific survival and castration-resistant prostate cancer-free survival than those with chemokine (CC motif) ligand 2 < 320 pg/mL. Multivariate analysis was performed to determine whether chemokine (CC motif) ligand 2 was a useful prognostic factor. Independent significant predictors of worse overall survival were prostate-specific antigen ≥ 100 ng/mL, Gleason score ≥ 8 and chemokine (CC motif) ligand 2 ≥ 320 pg/dL. Prognostic predictors of prostate cancer-specific survival or cancer-free survival in multivariate analysis were prostate-specific antigen ≥ 100 ng/mL and Gleason score ≥ 8. A novel risk classification system was created to predict overall survival in patients based on the number of risk factors present (chemokine (CC motif) ligand 2 ≥ 320 pg/mL, prostate-specific antigen ≥ 100 ng/mL, Gleason score ≥ 8). Scores 2 or 3, 1 and 0 indicated Poor, Intermediate and Good risk groups, respectively.

CONCLUSIONS

This study demonstrated the utility of serum chemokine (CC motif) ligand 2 level as a predictive biomarker of long-term overall survival in prostate cancer. A novel risk classification system that predicts long-term overall survival based on the combined indications of chemokine (CC motif) ligand 2 level, prostate-specific antigen level and Gleason score may be a useful prognostic tool for prostate cancer.

Modulation of Pulmonary Toxicity in Metabolic Syndrome Due to Variations in Iron Oxide Nanoparticle-Biocorona Composition

Nanoparticles (NPs) interact with biomolecules by forming a biocorona (BC) on their surface after introduction into the body and alter cell interactions and toxicity. Metabolic syndrome (MetS) is a prevalent condition and enhances susceptibility to inhaled exposures. We hypothesize that distinct NP-biomolecule interactions occur in the lungs due to MetS resulting in the formation of unique NP-BCs contributing to enhanced toxicity. Bronchoalveolar lavage fluid (BALF) was collected from healthy and MetS mouse models and used to evaluate variations in the BC formation on 20 nm iron oxide (Fe₃O₄) NPs. Fe₃O₄ NPs without or with BCs were characterized for hydrodynamic size and zeta potential. Unique and differentially associated proteins and lipids with the Fe₃O₄ NPs were identified through proteomic and lipidomic analyses to evaluate BC alterations based on disease state. A mouse macrophage cell line was utilized to examine alterations in cell interactions and toxicity due to BCs. Exposures to 6.25, 12.5, 25, and 50 μg/mL of Fe₃O₄ NPs with BCs for 1 h or 24 h did not demonstrate overt cytotoxicity. Macrophages increasingly associated Fe₃O₄ NPs following addition of the MetS BC compared to the healthy BC. Macrophages exposed to Fe₃O₄ NPs with a MetS-BC for 1 h or 24 h at a concentration of 25 μg/mL demonstrated enhanced gene expression of inflammatory markers: CCL2, IL-6, and TNF-α compared to Fe₃O₄ NPs with a healthy BC. Western blot analysis revealed activation of STAT3, NF-κB, and ERK pathways due to the MetS-BC. Specifically, the Jak/Stat pathway was the most upregulated inflammatory pathway following exposure to NPs with a MetS BC. Overall, our study suggests the formation of distinct BCs due to NP exposure in MetS, which may contribute to exacerbated inflammatory effects and susceptibility.

ELOVL5-mediated fatty acid elongation promotes cellular proliferation and invasion in renal cell carcinoma

Renal cell carcinoma (RCC) features altered lipid metabolism and accumulated polyunsaturated fatty acids (PUFAs). Elongation of very long–chain fatty acid (ELOVL) family enzymes catalyze fatty acid elongation, and ELOVL5 is indispensable for PUFAs elongation, but its role in RCC progression remains unclear. Here, we show that higher levels of ELOVL5 correlate with poor RCC clinical prognosis. Liquid chromatography/electrospray ionization‐tandem mass spectrometry analysis showed decreases in ELOVL5 end products (arachidonic acid and eicosapentaenoic acid) under CRISPR/Cas9‐mediated knockout of ELOVL5 while supplementation with these fatty acids partially reversed the cellular proliferation and invasion effects of ELOVL5 knockout. Regarding cellular proliferation and invasion, CRISPR/Cas9‐mediated knockout of ELOVL5 suppressed the formation of lipid droplets and induced apoptosis via endoplasmic reticulum stress while suppressing renal cancer cell proliferation and in vivo tumor growth. Furthermore, CRISPR/Cas9‐mediated knockout of ELOVL5 inhibited AKT Ser473 phosphorylation and suppressed renal cancer cell invasion through chemokine (C‐C motif) ligand‐2 downregulation by AKT‐mTOR‐STAT3 signaling. Collectively, these results suggest that ELOVL5‐mediated fatty acid elongation promotes not only cellular proliferation but also invasion in RCC.

Alpinetin inhibits macrophage infiltration and atherosclerosis by improving the thiol redox state: Requirement of GSk3β/Fyn-dependent Nrf2 activation

Alpinetin is a plant flavonoid isolated from Alpinia katsumadai Hayata with antioxidant and anti-inflammatory properties. Monocyte infiltration into the intima promotes atherosclerotic development and causes plaque instability at the later stage, which is profoundly influenced by various oxidants. In this study, we investigated whether alpinetin restores the redox state to inhibit monocyte infiltration and ameliorates atherosclerosis. ApoE-deficient (ApoE^-/- ) mice were fed a high-fat diet and treated with alpinetin. We found that alpinetin significantly attenuated atherosclerotic lesions and reduced necrotic core size associated with the reduction in infiltrated macrophages within the plaques. Alpinetin inhibited macrophage adhesion and migration, and the expression of chemokines and adhesion molecules, such as MCP-1, VCAM-1, and ICAM-1. Intraplaque MMP2 and MMP9 were reduced, while collagen contents were increased and elastin fiber was prevented from degradation in the alpinetin-treated mice. Data further showed that alpinetin reduced reactive oxygen species generation and promoted thiol-dependent glutathione and thioredoxin antioxidant systems in macrophages. Alpinetin activated Nfr2, an upstream activator of the thiol-dependent redox signaling by increasing the nuclear translocation. The nuclear accumulation of Nrf2 was enhanced by reducing nuclear export, which was achieved through the regulation of the GSk3β/Fyn pathway. Finally, inhibition of Nrf2 in HFD-apoE^-/- mice blockaded the effect of alpinetin, which increased aortic macrophage recruitment and aggravated atherosclerosis concurrently with elevating the expression of MCP-1, VCAM-1, and ICAM-1. Altogether, these findings indicated that alpinetin improved Nrf2-mediated redox homeostasis, which consequently inhibited macrophage infiltration and atherosclerosis, suggesting a useful compound for treating atherosclerosis.

Functional and Therapeutic Significance of Tumor-Associated Macrophages in Colorectal Cancer

The role of the tumor microenvironment (TME) in the progression of colorectal cancer (CRC) and its acquisition of resistance to treatment become the research hotspots. As an important component of TME, the tumor-associated macrophages (TAMs) regulate multiple critical oncogenic processes, namely, occurrence, proliferation, metastasis, and drug resistance in CRC. In this review, we have discussed the functional and therapeutic significance of TAMs in CRC. M1 macrophages act as the tumor suppressor while M2 macrophages promote CRC. The polarization of TAMs is mainly regulated by the pathways such as NFKB1 pathways, STAT3 pathways, WNT5A pathways, and PI3K pathways in CRC. Furthermore, the M2 polarization of TAMs is not only controllable but also reversible. Finally, we provide insights into the TAMs-targeted therapeutic strategies.

Pip5k1c Loss in Chondrocytes Causes Spontaneous Osteoarthritic Lesions in Aged Mice

Osteoarthritis (OA) is the most common degenerative joint disease affecting the older populations globally. Phosphatidylinositol-4-phosphate 5-kinase type-1 gamma (Pip5k1c), a lipid kinase catalyzing the synthesis of phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2), is involved in various cellular processes, such as focal adhesion (FA) formation, cell migration, and cellular signal transduction. However, whether Pip5k1c plays a role in the pathogenesis of OA remains unclear. Here we show that inducible deletion of Pip5k1c in aggrecan-expressing chondrocytes (cKO) causes multiple spontaneous OA-like lesions, including cartilage degradation, surface fissures, subchondral sclerosis, meniscus deformation, synovial hyperplasia, and osteophyte formation in aged (15-month-old) mice, but not in adult (7-month-old) mice. Pip5k1c loss promotes extracellular matrix (ECM) degradation, chondrocyte hypertrophy and apoptosis, and inhibits chondrocyte proliferation in the articular cartilage of aged mice. Pip5k1c loss dramatically downregulates the expressions of several key FA proteins, including activated integrin β1, talin, and vinculin, and thus impairs the chondrocyte adhesion and spreading on ECM. Collectively, these findings suggest that Pip5k1c expression in chondrocytes plays a critical role in maintaining articular cartilage homeostasis and protecting against age-related OA.

Impaired non-canonical transforming growth factor-β signalling prevents profibrotic phenotypes in cultured peptidylarginine deiminase 4-deficient murine cardiac fibroblasts

Transforming growth factor‐β (TGF‐β) becomes rapidly activated in the infarcted heart. Hence, TGF‐β‐mediated persistent activation of cardiac fibroblasts (CFs) and exaggerated fibrotic responses may result in adverse cardiac remodelling and heart failure. Additionally, peptidylarginine deiminase 4 (PAD4) was described to be implicated in organ fibrosis. Here, we investigated the impact of PAD4 on CF function and myofibroblast transdifferentiation in vitro. The expression of fibrosis‐related genes was largely similar in cultured WT and PAD4^‐/‐ CFs of passage 3, although collagen III was reduced in PAD4^‐/‐ CFs. Exposure to TGF‐β inhibited proliferation and increased contractile activity and migration of WT CFs, but not of PAD4^‐/‐ CFs. However, under baseline conditions, PAD4^−/− CFs showed comparable functional characteristics as TGF‐β‐stimulated WT CFs. Although the SMAD‐dependent TGF‐β pathway was not disturbed in PAD4^‐/‐ CFs, TGF‐β failed to activate protein kinase B (Akt) and signal transducer and activator of transcription 3 (STAT3) in these cells. Similar results were obtained in WT CFs treated with the PAD4 inhibitor Cl‐amidine. Abrogated Akt activation was associated with diminished levels of phosphorylated, inactive glycogen synthase kinase‐3β (GSK‐3β). Consequently, PAD4^‐/‐ CFs did not upregulate collagen I and α‐smooth muscle actin (α‐SMA) expression after TGF‐β treatment. Thus, PAD4 is substantially involved in the regulation of non‐canonical TGF‐β signalling and may represent a therapeutic target for the treatment of adverse cardiac remodelling.

Roles of CCL2-CCR2 Axis in the Tumor Microenvironment

Chemokines are a small family of cytokines that were first discovered as chemotactic factors in leukocytes during inflammation, and reports on the relationship between chemokines and cancer progression have recently been increasing. The CCL2-CCR2 axis is one of the major chemokine signaling pathways, and has various functions in tumor progression, such as increasing tumor cell proliferation and invasiveness, and creating a tumor microenvironment through increased angiogenesis and recruitment of immunosuppressive cells. This review discusses the roles of the CCL2-CCR2 axis and the tumor microenvironment in cancer progression and their future roles in cancer therapy.

Oral vitamin D supplementation induces transcriptomic changes in rectal mucosa that are linked to anti-tumour effects

BACKGROUND

The risk for several common cancers is influenced by the transcriptomic landscape of the respective tissue-of-origin. Vitamin D influences in vitro gene expression and cancer cell growth. We sought to determine whether oral vitamin D induces beneficial gene expression effects in human rectal epithelium and identify biomarkers of response.

METHODS

Blood and rectal mucosa was sampled from 191 human subjects and mucosa gene expression (HT12) correlated with plasma vitamin D (25-OHD) to identify differentially expressed genes. Fifty subjects were then administered 3200IU/day oral vitamin D3 and matched blood/mucosa resampled after 12 weeks. Transcriptomic changes (HT12/RNAseq) after supplementation were tested against the prioritised genes for gene-set and GO-process enrichment. To identify blood biomarkers of mucosal response, we derived receiver-operator curves and C-statistic (AUC) and tested biomarker reproducibility in an independent Supplementation Trial (BEST-D).

RESULTS

Six hundred twenty-nine genes were associated with 25-OHD level (P < 0.01), highlighting 453 GO-term processes (FDR<0.05). In the whole intervention cohort, vitamin D supplementation enriched the prioritised mucosal gene-set (upregulated gene-set P < 1.0E-07; downregulated gene-set P < 2.6E-05) and corresponding GO terms (P = 2.90E-02), highlighting gene expression patterns consistent with anti-tumour effects. However, only 9 individual participants (18%) showed a significant response (NM gene-set enrichment P < 0.001) to supplementation. Expression changes in HIPK2 and PPP1CC expression served as blood biomarkers of mucosal transcriptomic response (AUC=0.84 [95%CI 0.66-1.00]) and replicated in BEST-D trial subjects (HIPK2 AUC=0.83 [95%CI 0.77-0.89]; PPP1CC AUC=0.91 [95%CI 0.86-0.95]).

CONCLUSIONS

Higher plasma 25-OHD correlates with rectal mucosa gene expression patterns consistent with anti-tumour effects, and this beneficial signature is induced by short-term vitamin D supplementation. Heterogenous gene expression responses to vitamin D may limit the ability of randomised trials to identify beneficial effects of supplementation on CRC risk. However, in the current study blood expression changes in HIPK2 and PPP1CC identify those participants with significant anti-tumour transcriptomic responses to supplementation in the rectum. These data provide compelling rationale for a trial of vitamin D and CRC prevention using easily assayed blood gene expression signatures as intermediate biomarkers of response.

CCL2: An Important Mediator Between Tumor Cells and Host Cells in Tumor Microenvironment

Tumor microenvironment (TME) formation is a major cause of immunosuppression. The TME consists of a considerable number of macrophages and stromal cells that have been identified in multiple tumor types. CCL2 is the strongest chemoattractant involved in macrophage recruitment and a powerful initiator of inflammation. Evidence indicates that CCL2 can attract other host cells in the TME and direct their differentiation in cooperation with other cytokines. Overall, CCL2 has an unfavorable effect on prognosis in tumor patients because of the accumulation of immunosuppressive cell subtypes. However, there is also evidence demonstrating that CCL2 enhances the anti-tumor capability of specific cell types such as inflammatory monocytes and neutrophils. The inflammation state of the tumor seems to have a bi-lateral role in tumor progression. Here, we review works focusing on the interactions between cancer cells and host cells, and on the biological role of CCL2 in these processes.

Weighted Gene Co-expression Network Analysis Identifies CALD1 as a Biomarker Related to M2 Macrophages Infiltration in Stage III and IV Mismatch Repair-Proficient Colorectal Carcinoma

Immunotherapy has achieved efficacy for advanced colorectal cancer (CRC) patients with a mismatch-repair-deficient (dMMR) subtype. However, little immunotherapy efficacy was observed in patients with the mismatch repair-proficient (pMMR) subtype, and hence, identifying new immune therapeutic targets is imperative for those patients. In this study, transcriptome data of stage III/IV CRC patients were retrieved from the Gene Expression Omnibus database. The CIBERSORT algorithm was used to quantify immune cellular compositions, and the results revealed that M2 macrophage fractions were higher in pMMR patients as compared with those with the dMMR subtype; moreover, pMMR patients with higher M2 macrophage fractions experienced shorter overall survival (OS). Subsequently, weighted gene co-expression network analysis and protein–protein interaction network analysis identified six hub genes related to M2 macrophage infiltrations in pMMR CRC patients: CALD1, COL6A1, COL1A2, TIMP3, DCN, and SPARC. Univariate and multivariate Cox regression analyses then determined CALD1 as the independent prognostic biomarker for OS. CALD1 was upregulated specifically the in CMS4 CRC subtype, and single-sample Gene Set Enrichment Analysis (ssGSEA) revealed that CALD1 was significantly correlated with angiogenesis and TGF-β signaling gene sets enrichment scores in stage III/IV pMMR CRC samples. The Estimation of STromal and Immune cells in MAlignant Tumor tissues using Expression data (ESTIMATE) algorithm and correlation analysis revealed that CALD1 was significantly associated with multiple immune and stromal components in a tumor microenvironment. In addition, GSEA demonstrated that high expression of CALD1 was significantly correlated with antigen processing and presentation, chemokine signaling, leukocyte transendothelial migration, vascular smooth muscle contraction, cytokine–cytokine receptor interaction, cell adhesion molecules, focal adhesion, MAPK, and TGF-beta signaling pathways. Furthermore, the proliferation, invasion, and migration abilities of cancer cells were suppressed after reducing CALD1 expression in CRC cell lines. Taken together, multiple bioinformatics analyses and cell-level assays demonstrated that CALD1 could serve as a prognostic biomarker and a prospective therapeutic target for stage III/IV pMMR CRCs.

The Regulation of Intestinal Inflammation and Cancer Development by Type 2 Immune Responses

The gut is among the most complex organs of the human body. It has to exert several functions including food and water absorption while setting up an efficient barrier to the outside world. Dysfunction of the gut can be life-threatening. Diseases of the gastrointestinal tract such as inflammatory bowel disease, infections, or colorectal cancer, therefore, pose substantial challenges to clinical care. The intestinal epithelium plays an important role in intestinal disease development. It not only establishes an important barrier against the gut lumen but also constantly signals information about the gut lumen and its composition to immune cells in the bowel wall. Such signaling across the epithelial barrier also occurs in the other direction. Intestinal epithelial cells respond to cytokines and other mediators of immune cells in the lamina propria and shape the microbial community within the gut by producing various antimicrobial peptides. Thus, the epithelium can be considered as an interpreter between the microbiota and the mucosal immune system, safeguarding and moderating communication to the benefit of the host. Type 2 immune responses play important roles in immune-epithelial communication. They contribute to gut tissue homeostasis and protect the host against infections with helminths. However, they are also involved in pathogenic pathways in inflammatory bowel disease and colorectal cancer. The current review provides an overview of current concepts regarding type 2 immune responses in intestinal physiology and pathophysiology.

Is the C-C Motif Ligand 2-C-C Chemokine Receptor 2 Axis a Promising Target for Cancer Therapy and Diagnosis?

C-C motif ligand 2 (CCL2) was originally reported as a chemical mediator attracting mononuclear cells to inflammatory tissue. Many studies have reported that CCL2 can directly activate cancer cells through a variety of mechanisms. CCL2 can also promote cancer progression indirectly through increasing the recruitment of tumor-associated macrophages into the tumor microenvironment. The role of CCL2 in cancer progression has gradually been understood, and various preclinical cancer models elucidate that CCL2 and its receptor C-C chemokine receptor 2 (CCR2) are attractive targets for intervention in cancer development. However, clinically available drugs that regulate the CCL2-CCR2 axis as anticancer agents are not available at this time. The complete elucidation of not only the oncological but also the physiological functions of the CCL2-CCR2 axis is required for achieving a satisfactory effect of the CCL2-CCR2 axis-targeted therapy.

Targeting tumor cell-derived CCL2 as a strategy to overcome Bevacizumab resistance in ETV5+ colorectal cancer

In our previous study, ETV5 mediated-angiogenesis was demonstrated to be dependent upon the PDGF-BB/PDGFR-β/Src/STAT3/VEGFA pathway in colorectal cancer (CRC). However, the ability of ETV5 to affect the efficacy of anti-angiogenic therapy in CRC requires further investigation. Gene set enrichment analysis (GSEA) and a series of experiments were performed to identify the critical candidate gene involved in Bevacizumab resistance. Furthermore, the ability of treatment targeting the candidate gene to enhance Bevacizumab sensitivity in vitro and in vivo was investigated. Our results revealed that ETV5 directly bound to the VEGFA promoter to promote translation of VEGFA. However, according to in vitro and in vivo experiments, ETV5 unexpectedly accelerated antiVEGF therapy (Bevacizumab) resistance. GSEA and additional assays confirmed that ETV5 could promote angiogenesis by inducing the secretion of another tumor angiogenesis factor (CCL2) in CRC cells to facilitate Bevacizumab resistance. Mechanistically, ETV5 upregulated CCL2 by activating STAT3 to facilitate binding with the CCL2 promoter. ETV5 induced-VEGFA translation and CCL2 secretion were mutually independent mechanisms, that induced angiogenesis by activating the PI3K/AKT and p38/MAPK signaling pathways in human umbilical vein endothelial cells (HUVECs). In CRC tissues, ETV5 protein levels were positively associated with CD31, CCL2, and VEGFA protein expression. CRC patients possessing high expression of ETV5/VEGFA or ETV5/CCL2 exhibited a poorer prognosis compared to that of other patients. Combined antiCCL2 and antiVEGFA (Bevacizumab) treatment could inhibit tumor angiogenesis and growth more effectively than single treatments in CRCs with high expression of ETV5 (ETV5⁺ CRCs). In conclusion, our results not only revealed ETV5 as a novel biomarker for anti-angiogenic therapy, but also indicated a potential combined therapy strategy that involved in targeting of both CCL2 and VEGFA in ETV5⁺ CRC.

DICER1-AS1 Promotes the Malignant Behaviors of Colorectal Cancer Cells by Regulating miR-296-5p/STAT3 Axis

Background

Long non-coding RNA (lncRNA) exerts a regulatory role in the occurrence and progression of tumors. This study aimed at probing into the function and mechanism of lncRNA DICER1 antisense RNA 1 (DICER1-AS1) in colorectal cancer (CRC).

Methods

The expressions of DICER1-AS1, miR-296-5p and STAT3 mRNA were tested by quantitative real-time polymerase chain reaction (qRT-PCR). Cell counting kit-8 (CCK-8) assay was employed to detect cell proliferation, and Transwell was used to detect cell migration and invasion. In addition, the expressions of apoptosis-related proteins Bax and Bcl2 were detected by Western blot. Interactions between DICER1-AS1 and miR-296-5p, and miR-296-5p and STAT3 were predicted and determined by bioinformatics analysis, luciferase reporter assay and RNA binding protein immunoprecipitation (RIP) assay.

Results

The expressions of DICER1-AS1 and STAT3 mRNA were significantly up-regulated while miR-296-5p expression was remarkably down-regulated in CRC tissues and cell lines. Over-expression of DICER1-AS1 or transfection of miR-296-5p inhibitors could promote the proliferation, migration and invasion and inhibit apoptosis of CRC cells, whereas knockdown of DICER1-AS1 or transfection of miR-296-5p mimics had the opposite effects. Additionally, DICER1-AS1 could down-regulate miR-296-5p expression via sponging it. DICER1-AS1 also enhanced the expression of STAT3, which was identified as a target gene of miR-296-5p.

Conclusion

DICER1-AS1 acts as an oncogenic lncRNA in CRC via modulating miR-296-5p/STAT3 axis. Our results provide a new direction for the diagnosis and treatment of CRC.

Flurbiprofen suppresses the inflammation, proliferation, invasion and migration of colorectal cancer cells via COX2

Colorectal cancer is an aggressive disease with a poor prognosis and low survival rate at the advanced stage, therefore new innovative targets are urgently required. Flurbiprofen has been reported to exhibit therapeutic effects in other types of cancer, such as esophageal cancer, breast cancer and colorectal cancer. Therefore, the present study aimed to investigate the function of flurbiprofen in colorectal cancer. SW620 colorectal cancer cells were treated with different concentrations of flurbiprofen to determine the optimum concentration. Subsequently, COX2 expression affected by flurbiprofen was tested using western blotting, reverse transcription-quantitative PCR and immunofluorescence. Enzyme-linked immunosorbent assay was used to determine the levels of tumor necrosis factor-α, interleukin (IL)-6 and IL-1β. Cell Counting Kit-8, colony formation and flow cytometry assays were used to assess the proliferation and apoptosis of SW620 cells in various groups. Western blotting was performed to investigate the expression of proliferation-, apoptosis- and migration-related proteins after different treatments. Wound healing and Transwell assays were performed to measure the invasion and migration of colorectal cancer cells, respectively. The results demonstrated that flurbiprofen inhibited colorectal cancer cell proliferation. Furthermore, it was identified that flurbiprofen inhibited the expression of COX2. Notably, flurbiprofen suppressed the expression of inflammatory factors by inhibiting COX2. Moreover, flurbiprofen inhibited the proliferation, invasion and migration of colorectal cancer cells by inhibiting COX2. In conclusion, the present study revealed that flurbiprofen inhibited COX2 expression in colorectal cancer, and affected the proliferation, invasion, migration and apoptosis of colorectal cancer cells. These results expand the understanding of the function of COX2 in colorectal cancer and the effect of flurbiprofen on COX2 expression.