Potential Of Colorectal Cancer Cells Research Articles

Novel Amidine Derivative K1586 Sensitizes Colorectal Cancer Cells to Ionizing Radiation by Inducing Chk1 Instability.

Checkpoint kinase 1 (Chk1) is a key mediator of the DNA damage response that regulates cell cycle progression, DNA damage repair, and DNA replication. Small-molecule Chk1 inhibitors sensitize cancer cells to genotoxic agents and have shown preclinical activity as single agents in cancers characterized by high levels of replication stress. However, the underlying genetic determinants of Chk1-inhibitor sensitivity remain unclear. Although treatment options for advanced colorectal cancer are limited, radiotherapy is effective. Here, we report that exposure to a novel amidine derivative, K1586, leads to an initial reduction in the proliferative potential of colorectal cancer cells. Cell cycle analysis revealed that the length of the G2/M phase increased with K1586 exposure as a result of Chk1 instability. Exposure to K1586 enhanced the degradation of Chk1 in a time- and dose-dependent manner, increasing replication stress and sensitizing colorectal cancer cells to radiation. Taken together, the results suggest that a novel amidine derivative may have potential as a radiotherapy-sensitization agent that targets Chk1.

Cytoplasmic expression of UTP23 promotes colorectal cancer progression.

UTP23 (UTP23 small subunit processome component) plays a pivotal role in the intricate processing and maturation of the small subunit of ribosomes within the nucleolus. In cases of nucleolar stress, such as those observed in certain tumor cells, the aberrant nucleolar organization and structure can lead to the translocation of nucleolar proteins into the nucleus or cytoplasm, consequently impacting the physiological processes of the tumor cells through non-ribosome-related functions. Our investigation revealed altered localization of UTP23 protein in colorectal cancer clinical tissue samples. Upon analyzing UTP23 expression and its correlation with patient prognosis in a cohort of 143 colorectal cancer patients, the result suggested that high cytoplasmic expression pattern of UTP23 was occured in early-stage metastasis-free colorectal cancer and was significantly associated with poor prognosis. Furthermore, we demonstrated that cytoplasmic expression of UTP23 significantly promoted the metastatic and invasive capabilities of colorectal cancer cells, which was not showed in the nucleollcalised UTP23. Intriguingly, mass spectrometry result suggested that KRT5 bind to UTP23 and showed a regulatory influence on UTP23 metastatic potential in colorectal cancer cells. Conclusively, our study demonstrated that the localization of UTP23 play a key role in colorectal cancer metastatic progression, which may serve as a novel prognostic indicator.

FGF19-Induced Inflammatory CAF Promoted Neutrophil Extracellular Trap Formation in the Liver Metastasis of Colorectal Cancer.

Liver metastasis is the main cause of death in patients with colorectal cancer (CRC); thus, necessitating effective biomarkers and therapeutic targets for colorectal cancer liver metastasis (CRLM). Fibroblast growth factor 19 (FGF19) is a protumorigenic gene in numerous human malignancies. In this study, it is shown that FGF19 plays an indispensable role in CRLM. FGF19 expression and secretion aremarkedly correlated with liver metastasis and lower overall survival rates of patients with CRC. An in vivo metastasis model shows that FGF19 overexpression confers stronger liver-metastatic potential in CRC cells. Mechanistically, FGF19 exerts an immunomodulatory function that creates an environment conducive for metastasis in CRLM. FGF19 mediates the polarization of hepatic stellate cells to inflammatory cancer-associated fibroblasts (iCAFs) by activating the autocrine effect of IL-1α via the FGFR4-JAK2-STAT3 pathway. FGF19-induced iCAFs promote neutrophil infiltration and mediate neutrophil extracellular trap (NET) formation in liver metastatic niches via the production of complement C5a and IL-1β, which in turn accelerates the liver colonization of CRC cells. Importantly, targeting FGF19 signaling with fisogatinib efficiently suppresses FGF19-induced liver metastasis in a mouse model. In summary, thisstudy describes the mechanism by which FGF19 regulates CRLM, thereby providing a novel target for CRLM intervention.

KAT8 acetylation-controlled lipolysis affects the invasive and migratory potential of colorectal cancer cells

Epigenetic mechanisms involved in gene expression play an essential role in various cellular processes, including lipid metabolism. Lysine acetyltransferase 8 (KAT8), a histone acetyltransferase, has been reported to mediate de novo lipogenesis by acetylating fatty acid synthase. However, the effect of KAT8 on lipolysis is unclear. Here, we report a novel mechanism of KAT8 on lipolysis involving in its acetylation by general control non-repressed protein 5 (GCN5) and its deacetylation by Sirtuin 6 (SIRT6). KAT8 acetylation at K168/175 residues attenuates the binding activity of KAT8 and inhibits the recruitment of RNA pol II to the promoter region of the lipolysis-related genes adipose triglyceride lipase (ATGL) and hormone-sensitive lipase (HSL), subsequently down-regulating lipolysis to affect the invasive and migratory potential of colorectal cancer cells. Our findings uncover a novel mechanism that KAT8 acetylation-controlled lipolysis affects invasive and migratory potential in colorectal cancer cells.

Targeting Thymidylate Synthase and tRNA-Derived Non-Coding RNAs Improves Therapeutic Sensitivity in Colorectal Cancer.

Some colorectal cancer (CRC) patients are resistant to 5-fluorouracil (5-FU), and high expression levels of thymidylate synthase (TS) contribute to this resistance. This study investigated whether quercetin, a representative polyphenol compound, could enhance the effect of 5-FU in CRC cells. Quercetin suppressed TS levels that were increased by 5-FU in CRC cells and promoted the expression of p53. Quercetin also induced intracellular and mitochondrial reactive oxygen species (ROS) production and Ca2+ dysregulation in a 5-FU-independent pathway in CRC cells. Furthermore, quercetin decreased mitochondrial membrane potential in CRC cells and inhibited mitochondrial respiration. Moreover, quercetin regulated the expression of specific tiRNAs, including tiRNAHisGTG, and transfection of a tiRNAHisGTG mimic further enhanced the apoptotic effect of quercetin in CRC cells. An enhanced sensitivity to 5-FU was also confirmed in colitis-associated CRC mice treated with quercetin. The treatment of quercetin decreased survival rates of the CRC mouse model, with reductions in the number of tumors and in the disease activity index. Also, quercetin suppressed TS and PCNA protein expression in the distal colon tissue of CRC mice. These results suggest that quercetin has the potential to be used as an adjuvant with 5-FU for the treatment of CRC.

The cAMP/PKA/CREB and TGFβ/SMAD4 Pathways Regulate Stemness and Metastatic Potential in Colorectal Cancer Cells.

This study identifies signaling pathways essential for maintaining the stemness and metastatic potential of colorectal cancer cells and proposes CREB as a therapeutic target in metastatic colorectal cancer.

HER2 G776S mutation promotes oncogenic potential in colorectal cancer cells when accompanied by loss of APC function

Clinical cancer genome sequencing detects oncogenic variants that are potential targets for cancer treatment, but it also detects variants of unknown significance. These variants may interact with each other to influence tumor pathophysiology, however, such interactions have not been fully elucidated. Additionally, the effect of target therapy for those variants also unclarified. In this study, we investigated the biological functions of a HER2 mutation (G776S mutation) of unknown pathological significance, which was detected together with APC mutation by cancer genome sequencing of samples from a colorectal cancer (CRC) patient. Transfection of the HER2 G776S mutation alone slightly increased the kinase activity and phosphorylation of HER2 protein, but did not activate HER2 downstream signaling or alter the cell phenotype. On the other hand, the HER2 G776S mutation was shown to have strong oncogenic potential when loss of APC function was accompanied. We revealed that loss of APC function increased Wnt pathway activity but also increased RAS–GTP, which increased ERK phosphorylation triggered by HER2 G776S transfection. In addition, afatinib, a pan-HER tyrosine kinase inhibitor, suppressed tumor growth in xenografts derived from HER2 G776S-transfected CRC cells. These findings suggest that this HER2 mutation in CRC may be a potential therapeutic target.

Butyrate supplementation regulates expression of chromosome segregation 1‑like protein to reverse the genetic distortion caused by p53 mutations in colorectal cancer.

The chromosome segregation 1-like (CSE1L) protein, which regulates cellular mitosis and apoptosis, was previously found to be overexpressed in colorectal cancer (CRC) cells harboring mutations. Therefore, regulating CSE1L expression may confer chemotherapeutic effects against CRC. The gut microflora can regulate gene expression in colonic cells. In particular, metabolites produced by the gut microflora, including the short-chain fatty acid butyrate, have been shown to reduce CRC risk. Butyrates may exert antioncogenic potential in CRC cells by modulating p53 expression. The present study evaluated the association between CSE1L expression and butyrate treatment from two non-transformed colon cell lines (CCD-18Co and FHC) and six CRC cell lines (LS 174T, HCT116 p53+/+, HCT116 p53−/−, Caco-2, SW480 and SW620). Lentiviral knockdown of CSE1L and p53, reverse transcription-quantitative PCR (CSE1L, c-Myc and p53), western blotting [CSE1L, p53, cyclin (CCN) A2, CCNB2 and CCND1], wound healing assay (cell migration), flow cytometry (cell cycle analysis) and immunofluorescence staining (CSE1L and tubulin) were adopted to verify the effects of butyrate on CSE1L-expressing CRC cells. The butyrate-producing gut bacteria Butyricicoccus pullicaecorum was administered to mice with 1,2-dimethylhydrazine-induced colon tumors before the measurement of CSE1L expression. The effects of B. pullicaecorum on CSE1L expression were then assessed by immunohistochemical staining for CSE1L and p53 in tissues from CRC-bearing mice. Non-cancerous colon cells with the R273H p53 mutation or CRC cells haboring p53 mutations were found to exhibit significantly higher CSE1L expression levels. CSE1L knockdown in HCT116 p53−/− cells resulted in G1-and G2/M-phase cell cycle arrest. Furthermore, in HCT116 p53−/− cells, CSE1L expression was already high at interphase, increased at prophase, peaked during metaphase before declining at cytokinesis but remained relatively high compared with that in HCT116 expressing wild-type p53. Significantly decreased expression levels of CSE1L were also observed in HCT116 p53−/− cells that were treated with butyrate for 24 h. In addition, the migration of HCT116 p53−/− cells was significantly decreased after CSE1L knockdown or butyrate treatment. Tumors with more intense nuclear p53 staining and weaker CSE1L staining were found in mice bearing DMH/DSS-induced CRC that were administered with B. pullicaecorum. Taken together, the results indicated that butyrate can impair CSE1L-induced tumorigenic potential. In conclusion, butyrate-producing microbes, such as B. pullicaecorum, may reverse the genetic distortion caused by p53 mutations in CRC by regulating CSE1L expression levels.

Extracts from lichenLobaria retigeradecrease the stemness potential of colorectal cancer cells

Lichens are symbiotic organisms with the potential to be used in the pharmaceutical industry. To identify novel lichen extracts that inhibit the stemness potential of colorectal cancer cells, we tested acetone extracts ofLobaria retigeracollected in Vietnam. Crude acetone extracts ofL. retigeradecreased spheroid formation in CSC221, DLD1, and HT29 cells. In addition, mRNA levels of genes encoding cancer stem markers aldehyde dehydrogenase-1, CD44, CD133, Lgr5, and Musashi-1 were significantly downregulated in a dose-dependent manner after treatment withL. retigeraextract. Moreover,L. retigeraextract decreased the transcriptional activities of Gli and the Notch-relatedHes1promoter in reporter assays. Together, these results demonstrate thatL. retigeraextract is a potent inhibitor of colorectal cancer cell stemness.

The Role of Neuropilin-2 in the Epithelial to Mesenchymal Transition of Colorectal Cancer: A Systematic Review.

Neuropilin-2 (NRP-2) expression has been found in various investigations on the expression and function of NRP-2 in colorectal cancer. The link between NRP-2 and colorectal cancer, as well as the mechanism that regulates it, is still mostly unclear. This systematic review was carried out according to the Cochrane guidelines for systematic reviews. We searched PubMed, Embase®, MEDLINE, Allied & Complementary MedicineTM, Medical Toxicology & Environmental Health, DH-DATA: Health Administration for articles published before 1 October 2021. The following search terms were used: “neuropilin-2” “neuropilin 2”, “NRP2” and “NRP-2”, “colorectal cancer”, “colon cancer”. Ten articles researching either tumor tissue samples, cell lines, or mice models were included in this review. The majority of human primary and metastatic colon cancer cell lines expressed NRP-2 compared to the normal colonic mucosa. NRPs have been discovered in human cancers as well as neovasculature. The presence of NRP-2 appears to be connected to the epithelial–mesenchymal transition’s function in cancer dissemination and metastatic evolution. The studies were heterogeneous, but the data assessed indicates NRP-2 might have an impact on the metastatic potential of colorectal cancer cells. Nevertheless, further research is needed.

Interleukin-1 receptor antagonist inhibits metastatic potential by down-regulating CXCL12/CXCR4 signaling axis in colorectal cancer

BackgroundThe aim of this study was to investigate the co-operative role of CXCR4/CXCL12 axis and IL-1Ra in metastatic processes mechanism by interactions between colorectal cancer cells and stromal cells in their microenvironment.MethodsExpression of IL-1α, interleukin-1 receptor type I (IL-1 RI), CXCL12 and CXCR4 mRNA and proteins were determined by RT-PCR and Western blot. The effect of secreted level of CXCL12 by IL-1Ra on fibroblasts was measured by ELISA. CXCL12 regulate metastatic potential of colorectal cancer was evaluated by proliferation, invasion and angiogenesis assays, respectively, in which invasion and angiogenesis assays used an in vitro system consisting of co-cultured colorectal cells and stromal cells.ResultsIL-1α was expressed in high liver metastatic colorectal cancer cell lines (HT-29 and WiDr). The colorectal cancer cell-derived IL-1α and rIL-1α significantly promoted CXCL12 expression by fibroblasts, and this enhancing effect can be significantly inhibited by IL-1Ra (P < 0.01). CXCL12 not only enhanced the migration and proliferation of human umbilical vein endothelial cells, but also significantly enhanced angiogenesis (P < 0.01). Furthermore, the high liver-metastatic colorectal cancer cell line (HT-29), which secretes IL-1α, significantly enhanced angiogenesis compared to the low liver-metastatic cell line (CaCo-2), which does not produce IL-1α (P < 0.01). On the contrary, IL-1Ra can significantly inhibit migration, proliferation and angiogenesis (P < 0.01).ConclusionAutocrine IL-1α and paracrine CXCL12 co-enhances the metastatic potential of colorectal cancer cells; IL-1Ra can inhibit the metastatic potential of colorectal cancer cells via decrease IL-1α/CXCR4/CXCL12 signaling pathways.Graphical 7Qx8An2hePDujdT1wSZV-LVideo

MEX3A knockdown inhibits the tumorigenesis of colorectal cancer via modulating CDK2 expression.

Colorectal cancer (CRC) is a malignant tumor of the gastrointestinal tract and a leading cause of cancer-associated mortality worldwide. Mex-3 RNA binding family member A (MEX3A) promotes the progression of multiple types of cancer, including ovarian and cervical cancer. However, to the best of our knowledge, the role of MEX3A in CRC is not completely understood. Therefore, the present study aimed to investigate the function of MEX3A in CRC. The mRNA and protein expression levels of MEX3A in CRC cells were analyzed using reverse transcription-quantitative PCR and western blotting, respectively. Cell Counting Kit-8 assays were used to measure cell viability. Cell apoptosis and cell cycle distribution were detected via flow cytometry, and CRC cell invasion was analyzed by performing Transwell assays. Moreover, the mitochondrial membrane potential in CRC cells was measured via JC-1 staining. The results of the present study revealed that the expression levels of MEX3A were upregulated in CRC tissues compared with adjacent healthy tissues. MEX3A knockdown notably inhibited CRC cell viability, and induced apoptosis and mitochondrial injury. In addition, MEX3A knockdown markedly induced G1 phase cell cycle arrest in CRC cells via downregulating CDK2 expression. In conclusion, the findings of the present study suggested that MEX3A knockdown may inhibit the tumorigenesis of CRC cells by regulating CDK2 expression. Therefore, MEX3A may serve as a novel target for CRC treatment.

Adenine Inhibits the Invasive Potential of DLD-1 Human Colorectal Cancer Cell via the AMPK/FAK Axis.

Tumor metastasis is a major cause of death of patients with colorectal cancer (CRC). Our previous findings show that adenine has antiproliferation activity against tumor cells. However, whether adenine reduces the invasiveness of DLD-1 and SW480 CRC cells has not been thoroughly explored. In this study, we aimed to explore the effects of adenine on the invasion potential of DLD-1 cells. Our findings showed that adenine at concentrations of ≤200 μM did not influence the cell viability of DLD-1 and SW480 CRC cells. By contrast, adenine reduced the migratory potential of the CRC cells. Moreover, it decreased the invasion capacity of the CRC cells in a dose-dependent manner. We further observed that adenine downregulated the protein levels of tissue plasminogen activator, matrix metalloproteinase-9, Snail, TWIST, and vimentin, but upregulated the tissue inhibitor of metalloproteinase-1 expression in DLD-1 cells. Adenine decreased the integrin αV level and reduced the activation of integrin-associated signaling components, including focal adhesion kinase (FAK), paxillin, and Src in DLD-1 cells. Further observations showed that adenine induced AMP-activated protein kinase (AMPK) activation and inhibited mTOR phosphorylation in DLD-1 cells. The knockdown of AMPK restored the reduced integrin αV level and FAK/paxillin/Src signaling inhibited by adenine in DLD-1 cells. Collectively, these findings reveal that adenine reduces the invasion potential of DLD-1 cells through the AMPK/integrin/FAK axis, suggesting that adenine may have anti-metastatic potential in CRC cells.

LAD1 expression is associated with the metastatic potential of colorectal cancer cells

BackgroundAnchoring filament protein ladinin-1 (LAD1) was related to the aggressive progression of breast, lung, laryngeal and thyroid cancers. However, the association of LAD1 with colorectal cancer remained unknown. Here, to determine the relationship of LAD1 with colorectal cancer progression, we explored the effect of LAD1 loss on the malignant features of colorectal cancer cells.MethodsWe constructed LAD1-depleted cell lines and examined the effect of LAD1 deficiency on the phenotypic and molecular features of colorectal cancer cells in vitro. The function of LAD1 in metastasis in vivo was examined by establishing a spleen-to-liver metastasis mouse model. LAD1 protein expression in colorectal cancer patient specimens was assessed by immunohistochemistry of tumor microarrays.ResultsWe found that LAD1 was abundant in most colorectal cancer cells. In addition, high expression of LAD1 significantly correlated with poor patient outcome. LAD1 depletion inhibited the migration and invasion of two different colorectal cancer cell lines, SW620 and Caco-2, without affecting their proliferation. In addition, LAD1 loss led to defects in liver metastasis of SW620 cells in the mouse model. Immunohistochemistry of colorectal cancer tissues revealed LAD1 enrichment in metastatic tissues compared to that in primary tumor and normal tissues.ConclusionThese results suggest that LAD1 expression is associated with the metastatic progression of colorectal cancer by promoting the migration and invasion of cancer cells.

Impairment of Hypoxia-Induced CA IX by Beta-Blocker Propranolol-Impact on Progression and Metastatic Potential of Colorectal Cancer Cells.

The coexistence of cancer and other concomitant diseases is very frequent and has substantial implications for treatment decisions and outcomes. Beta-blockers, agents that block the beta-adrenergic receptors, have been related also to cancers. In the model of multicellular spheroids formed by colorectal cancer cells we described a crosstalk between beta-blockade by propranolol and tumour microenvironment. Non-selective beta-blocker propranolol decreased ability of tumour cells to adapt to hypoxia by reducing levels of HIF1α and carbonic anhydrase IX in 3D spheroids. We indicated a double action of propranolol in the tumour microenvironment by inhibiting the stability of HIF1α, thus mediating decrease of CA IX expression and, at the same time, by its possible effect on CA IX activity by decreasing the activity of protein kinase A (PKA). Moreover, the inhibition of β-adrenoreceptors by propranolol enhanced apoptosis, decreased number of mitochondria and lowered the amount of proteins involved in oxidative phosphorylation (V-ATP5A, IV-COX2, III-UQCRC2, II-SDHB, I-NDUFB8). Propranolol reduced metastatic potential, viability and proliferation of colorectal cancer cells cultivated in multicellular spheroids. To choose the right treatment strategy, it is extremely important to know how the treatment of concomitant diseases affects the superior microenvironment that is directly related to the efficiency of anti-cancer therapy

Differential regulation of mitochondrial complex I and oxidative stress based on metastatic potential of colorectal cancer cells.

Mitochondria serve a vital role in cellular homeostasis as they regulate cell proliferation and death pathways, which are attributed to mitochondrial bioenergetics, free radicals and metabolism. Alterations in mitochondrial functions have been reported in various diseases, including cancer. Colorectal cancer (CRC) is one of the most common metastatic cancer types with high mortality rates. Although mitochondrial oxidative stress has been associated with CRC, its specific mechanism and contribution to metastatic progression remain poorly understood. Therefore, the aims of the present study were to investigate the role of mitochondria in CRC cells with low and high metastatic potential and to evaluate the contribution of mitochondrial respiratory chain (RC) complexes in oncogenic signaling pathways. The present results demonstrated that cell lines with low metastatic potential were resistant to mitochondrial complex I (C-I)-mediated oxidative stress, and had C-I inhibition with impaired mitochondrial functions. These adaptations enabled cells to cope with higher oxidative stress. Conversely, cells with high metastatic potential demonstrated functional C-I with improved mitochondrial function due to coordinated upregulation of mitochondrial biogenesis and metabolic reprogramming. Pharmacological inhibition of C-I in high metastatic cells resulted in increased sensitivity to cell death and decreased metastatic signaling. The present findings identified the differential regulation of mitochondrial functions in CRC cells, based on CRC metastatic potential. Specifically, it was suggested that a functional C-I is required for high metastatic features of cancer cells, and the role of C-I could be further examined as a potential target in the development of novel therapies for diagnosing high metastatic cancer types.

A novel coordination complex of platinum (PT) induces cell death in colorectal cancer by altering redox balance and modulating MAPK pathway

BackgroundColorectal cancer (CRC) is a heterogeneous tumor having various genetic alterations. The current treatment options had limited impact on disease free survival due to therapeutic resistance. Novel anticancer agents are needed to treat CRC specifically metastatic colorectal cancer. A novel coordination complex of platinum, (salicylaldiminato)Pt(II) complex with dimethylpropylene linkage (PT) exhibited potential anti-cancer activity. In this study, we explored the molecular mechanism of PT-induced cell death in colorectal cancer.MethodsColony formation was evaluated using the clonogenic assay. Apoptosis, cell cycle analysis, reactive oxygen species, mitochondrial membrane potential and caspase-3/− 7 were assessed by flow cytometry. Glutathione level was detected by colorimetric assay. PT-induced alteration in pro-apoptotic/ anti-apoptotic proteins and other signaling pathways were investigated using western blotting. P38 downregulation was performed using siRNA.ResultsIn the present study, we explored the molecular mechanism of PT-mediated inhibition of cell proliferation in colorectal cancer cells. PT significantly inhibited the colony formation in human colorectal cancer cell lines (HT-29, SW480 and SW620) by inducing apoptosis and necrosis. This platinum complex was shown to significantly increase the reactive oxygen species (ROS) generation, depletion of glutathione and reduced mitochondrial membrane potential in colorectal cancer cells. Exposure to PT resulted in the downregulation of anti-apoptotic proteins (Bcl2, BclxL, XIAP) and alteration in Cyclins expression. Furthermore, PT increased cytochrome c release into cytosol and enhanced PARP cleavage leading to activation of intrinsic apoptotic pathway. Moreover, pre-treatment with ROS scavenger N-acetylcysteine (NAC) attenuated apoptosis suggesting that PT-induced apoptosis was driven by oxidative stress. Additionally, we show that PT-induced apoptosis was mediated by activating p38 MAPK and inhibiting AKT pathways. This was demonstrated by using chemical inhibitor and siRNA against p38 kinase which blocked the cytochrome c release and apoptosis in colorectal cancer cells.ConclusionCollectively, our data demonstrates that the platinum complex (PT) exerts its anti-proliferative effect on CRC by ROS-mediated apoptosis and activating p38 MAPK pathway. Thus, our findings reveal a novel mechanism of action for PT on colorectal cancer cells and may have therapeutic implication.

Placenta-specific protein 1 enhances liver metastatic potential and is associated with the PI3K/AKT/NF-κB signaling pathway in colorectal cancer.

To better explore the underlying mechanism of liver metastatic formation by placenta-specific protein 1 (PLAC1) in human colorectal cancer, we investigated the proliferation, invasion and angiogenic capabilities of human colorectal cancer cells with different liver metastatic potentials as well as the mechanism of action of PLAC1 in the metastatic process. The expression of PLAC1 was detected by reverse transcriptase PCR, western blot, and real-time PCR. The effect of PLAC1 on metastatic potential was determined by proliferation, invasion, and angiogenesis assays, including an in-vitro coculture system consisting of cancer cells and vascular endothelial cells that were used to detect the relationship between cancer cells and angiogenesis. In addition, we also determined PLAC1 downstream targets that preferentially contribute to the metastatic process. PLAC1 was expressed in HT-29, WiDr, and CaCo-2 colorectal cancer cells but not in Colo320 colorectal cancer cells. PLAC1 not only enhanced significantly the proliferation of CoLo320 and human umbilical vein endothelial cells (HUVECs) but also promoted the invasion of CoLo320 cells. The angiogenesis of HUVECs was enhanced by PLAC1 in a dose-dependent manner. In cocultured systems, angiogenesis was significantly increased by coculture with HT-29 cells. In addition, PLAC1 could promote angiogenesis in coculture with HT-29 cells. Furthermore, PLAC1-enhanced metastatic potential of colorectal cancer cells was dependent on the activation of the PI3K/Akt/NF-κB pathway. The activation of PI3K/Akt/NF-κB signaling by PLAC1 may be critical for metastasis of colorectal cancer cells. According to our results, we suggest that modification of PLAC1 function might be a promising new therapeutic approach to inhibit the aggressive spread of colorectal cancer.

Significance of G Protein-Coupled Estrogen Receptor in the Pathophysiology of Irritable Bowel Syndrome, Inflammatory Bowel Diseases and Colorectal Cancer.

The regulatory role of estrogens and nuclear estrogen receptors, i. e., estrogen receptor α and β has been reported in gastrointestinal diseases. However, the contribution of G protein-coupled estrogen receptor, the membrane-bound estrogen receptor, is still poorly understood. Unlike nuclear estrogen receptors, which are responsible for the genomic activity of estrogens, the G protein-coupled estrogen receptor affects the “rapid” non-genomic activity of estrogens, leading to modulation of many signaling pathways and ultimately changing gene expression. Recently, the crucial role of G protein-coupled estrogen receptor in intestinal pathogenesis has been documented. It has been shown that the G protein-coupled estrogen receptor can modulate the progression of irritable bowel syndrome, inflammatory bowel diseases such as Crohn's disease and ulcerative colitis as well as colorectal cancer. The G protein-coupled estrogen receptor appears to be a potent factor regulating abdominal sensitivity and pain, intestinal peristalsis, colitis development, proliferation and migration potential of colorectal cancer cells and seems to be a useful target in gastrointestinal diseases. In this review, we present the current state of knowledge about the contribution of the G protein-coupled estrogen receptor to irritable bowel syndrome, inflammatory bowel diseases and colorectal cancer.

Ceramide and palmitic acid inhibit macrophage-mediated epithelial\u2013mesenchymal transition in colorectal cancer

Accumulating evidence indicates that ceramide (Cer) and palmitic acid (PA) possess the ability to modulate switching of macrophage phenotypes and possess anti-tumorigenic effects; however, the underlying molecular mechanisms are largely unknown. The aim of the present study was to investigate whether Cer and PA could induce switching of macrophage polarization from the tumorigenic M2- towards the pro-inflammatory M1-phenotype, and whether this consequently altered the potential of colorectal cancer cells to undergo epithelial–mesenchymal transition (EMT), a hallmark of tumor progression. Our study showed that Cer- and PA-treated macrophages increased expression of the macrophage 1 (M1)-marker CD68 and secretion of IL-12 and attenuated expression of the macrophage 2 (M2)-marker CD163 and IL-10 secretion. Moreover, Cer and PA abolished M2 macrophage-induced EMT and migration of colorectal cancer cells. At the molecular level, this coincided with inhibition of SNAI1 and vimentin expression and upregulation of E-cadherin. Furthermore, Cer and PA attenuated expression levels of IL-10 in colorectal cancer cells co-cultured with M2 macrophages and downregulated STAT3 and NF-κB expression. For the first time, our findings suggest the presence of an IL-10-STAT3-NF-κB signaling axis in colorectal cancer cells co-cultured with M2 macrophages, mimicking the tumor microenvironment. Importantly, PA and Cer were powerful inhibitors of this signaling axis and, consequently, EMT of colorectal cancer cells. These results contribute to our understanding of the immunological mechanisms that underlie the anti-tumorigenic effects of lipids for future combination with drugs in the therapy of colorectal carcinoma.