Poor Prognosis In Colorectal Cancer Patients Research Articles

Tumor-intrinsic CD47 signal regulates glycolysis and promotes colorectal cancer cell growth and metastasis.

Rationale: CD47 plays a vital role in the immune escape of tumor cells, but its role in regulating immune-unrelated biological processes such as proliferation and metastasis remains unclear. We seek to explore the immune-independent functions of CD47 in colorectal cancer (CRC).Methods: The expression of CD47 in CRC was determined by immunohistochemistry. The biological effect of CD47 signaling on tumor cell proliferation and metastasis was evaluated in vitro and in vivo. RNA sequencing analysis was performed to identify pivotal signaling pathways modulated by CD47. The interaction between CD47 and ENO1 was verified by co-immunoprecipitation (co-IP). The effect of CD47 on glycolytic metabolites was analyzed by seahorse XF and targeted metabolomics.Results: The expression of CD47 was upregulated and correlated to poor prognosis in CRC patients. Functional assays revealed that CD47 promoted CRC cell growth and metastasis in vitro and in vivo. Our mechanistic investigations demonstrated that CD47 interacted with ENO1 and protected it from ubiquitin-mediated degradation, subsequently promoting glycolytic activity and phosphorylation of ERK in CRC cells. Inhibition of ENO1 diminished CD47-mediated cell growth and migration. Clinically, the combined expression of CD47 and ENO1 provided reliable predictive biomarkers for the prognosis of CRC patients.Conclusions: CD47 is overexpressed in CRC, and its expression is associated with poor prognosis. Through stabilizing ENO1, CD47 enhances the aerobic glycolysis and ERK activity in CRC cells, thereby promoting the progression of CRC. Our studies reveal an unconventional role of CD47, suggesting that targeting the CD47-ENO1 axis may provide a novel therapeutic avenue for CRC.

CSRP2 suppresses colorectal cancer progression via p130Cas/Rac1 axis-meditated ERK, PAK, and HIPPO signaling pathways.

Metastasis is a major cause of death in patients with colorectal cancer (CRC). Cysteine-rich protein 2 (CSRP2) has been recently implicated in the progression and metastasis of a variety of cancers. However, the biological functions and underlying mechanisms of CSRP2 in the regulation of CRC progression are largely unknown.Methods: Immunohistochemistry, quantitative real-time polymerase chain reaction (qPCR) and Western blotting (WB) were used to detect the expression of CSRP2 in CRC tissues and paracancerous tissues. CSRP2 function in CRC was determined by a series of functional tests in vivo and in vitro. WB and immunofluorescence were used to determine the relation between CSRP2 and epithelial-mesenchymal transition (EMT). Co-immunoprecipitation and scanning electron microscopy were used to study the molecular mechanism of CSRP2 in CRC.Results: The CSRP2 expression level in CRC tissues was lower than in adjacent normal tissues and indicated poor prognosis in CRC patients. Functionally, CSRP2 could suppress the proliferation, migration, and invasion of CRC cells in vitro and inhibit CRC tumorigenesis and metastasis in vivo. Mechanistic investigations revealed a physical interaction between CSRP2 and p130Cas. CSRP2 could inhibit the activation of Rac1 by preventing the phosphorylation of p130Cas, thus activating the Hippo signaling pathway, and simultaneously inhibiting the ERK and PAK/LIMK/cortactin signaling pathways, thereby inhibiting the EMT and metastasis of CRC. Rescue experiments showed that blocking the p130Cas and Rac1 activation could inhibit EMT induced by CSRP2 silencing.Conclusion: Our results suggest that the CSRP2/p130Cas/Rac1 axis can inhibit CRC aggressiveness and metastasis through the Hippo, ERK, and PAK signaling pathways. Therefore, CSRP2 may be a potential therapeutic target for CRC.

KRAS Mutation-Responsive miR-139-5p inhibits Colorectal Cancer Progression and is repressed by Wnt Signaling.

Introduction: Colorectal cancer (CRC) frequently harbors KRAS mutations that result in chemoresistance and metastasis. MicroRNAs (miRNAs) are usually dysregulated and play important regulatory roles in tumor progression. However, the KRAS mutation-responsive miRNA profile in CRC remains uninvestigated.Methods: miR-139-5p was identified and evaluated by small RNA sequencing, qRT-PCR and in situ hybridization. The roles of miR-139-5p in CRC cells with and without KRAS mutation were determined by Cell Counting Kit-8 (CCK-8), colony formation, flow cytometry and transwell assays in vitro and by tumorigenesis and metastasis assays in vivo. Microarrays followed by bioinformatic analyses, luciferase reporter assays and Western blotting were applied for mechanistic studies.Results: miR-139-5p was significantly downregulated in KRAS-mutated CRC cells and tissues compared with their wild-type counterparts. Low miR-139-5p expression was associated with aggressive phenotypes and poor prognosis in CRC patients. miR-139-5p overexpression inhibited CRC cell proliferation, migration and invasion in vitro, sensitized tumors to chemotherapy, and impaired tumor growth and metastasis in vivo. Transcriptomic profiling identified multiple modulators in the Ras (JUN and FOS) and Wnt (CTNNB1 and DVL1) signaling pathways and the epithelial-to-mesenchymal transition (EMT) process (ZEB1) as direct targets of miR-139-5p, and inverse correlations were confirmed in CRC clinical tissues. Aberrantly activated Wnt signaling in KRAS-mutant cells was demonstrated to transcriptionally repress miR-139-5p through TCF4, forming a miR-139-5p/Wnt signaling double-negative feedback loop.Conclusions: We identified miR-139-5p as a KRAS-responsive miRNA and demonstrated its involvement in CRC progression. KRAS mutation disrupted the miR-139-5p/Wnt signaling reciprocal negative feedback mechanism, which might cause miR-139-5p downregulation and derepression of oncogenic signaling pathways and EMT. These results reveal a transcriptional regulatory mode of KRAS-driven malignant transformation and highlight miR-139-5p as a novel regulator of crosstalk between the Ras and Wnt signaling pathways in CRC.

Downregulated SPINK4 is associated with poor survival in colorectal cancer

BackgroundSPINK4 is known as a gastrointestinal peptide in the gastrointestinal tract and is abundantly expressed in human goblet cells. The clinical significance of SPINK4 in colorectal cancer (CRC) is largely unknown.MethodsWe retrieved the expression data of 1168 CRC patients from 3 Gene Expression Omnibus (GEO) datasets (GSE24551, GSE39582, GSE32323) and The Cancer Genome Atlas (TCGA) to compare the expression level of SPINK4 between CRC tissues and normal colorectal tissues and to evaluate its value in predicting the survival of CRC patients. At the protein level, these results were further confirmed by data mining in the Human Protein Atlas and by immunohistochemical staining of samples from 81 CRC cases in our own center.ResultsSPINK4 expression was downregulated in CRC compared with that in normal tissues, and decreased SPINK4 expression at both the mRNA and protein levels was associated with poor prognosis in CRC patients from all 3 GEO datasets, the TCGA database and our cohort. Additionally, lower SPINK4 expression was significantly related to higher TNM stage. Moreover, in multivariate regression, SPINK4 was confirmed as an independent indicator of poor survival in CRC patients in all databases and in our own cohort.ConclusionsWe concluded that reduced expression of SPINK4 relates to poor survival in CRC, functioning as a novel indicator.

Girdin knockdown promotes apoptosis in colorectal cancer via miR-29c-3p/Girdin axis.

BackgroundIn recent years, the incidence and mortality of colorectal cancer (CRC) have increased year by year among young people. Increased levels of Girdin expression predict a poor prognosis of CRC, which presents a serious threat to human health globally. Herein, we investigated the role of Girdin in CRC and explored the underlying mechanisms in CRC.MethodsThe expression of Girdin was detected in human specimens. HCT116 cells with stably expressing or knock-out Girdin protein were successfully constructed to observe the biological function of gene. Protein expression was determined by immunohistochemistry, immunofluorescence and western blot.ResultsClinically, overexpression of Girdin was observed in the tumor tissue and poor prognosis of CRC patients. Gain-of-function and loss-of-function assays showed that Girdin promoted CRC cell proliferation in vitro. Mechanistically, Girdin knock-down significantly enhanced apoptosis, the mitochondrial membrane potential dropped, and the reactive oxygen species increased greatly. Last but not least, we analyzed the TargetScan dataset and found that Girdin was a regulated target of hsa-miR-29c-3p in CRC. Luciferase reporter assay was used to verify the interaction between hsa-miR-29c-3p and the 3’UTR of Girdin.ConclusionsOur findings suggest that Girdin has a crucial role in CRC progression via miR-29c-3p/Girdin axis, highlighting Girdin as a therapeutic target for CRC.

The impact of postoperative inflammation on recurrence in patients with colorectal cancer.

Systemic inflammatory response is strongly linked to among cancer development, progression and poor prognosis. The aim of this study was to clarify the impact of postoperative serum C-reactive protein (CRP) levels on the prognoses of patients with colorectal cancer (CRC). A total of 467 patients with stage I-III CRC who underwent curative surgery were retrospectively analyzed. To precisely evaluate the effect of postoperative inflammatory status on prognosis in CRC patients, we excluded patients with postoperative complication or elevated preoperative CRP level (CRP > 1.0mg/dL). Patients were divided into two groups based on their highest post-resection CRP levels (max CRP): the low CRP group (LCG; < 9.0mg/dL, n = 385) and high CRP group (HCG; ≥ 9.0mg/dL, n = 82). Furthermore, the effect of inflammation on malignant potential of CRC cells was evaluated using in vitro peritoneal dissemination model. HCG patients showed significantly worse recurrence-free survival (RFS) than LCG patients (p = 0.012). Multivariate analysis revealed that a higher max CRP was an independent prognostic factor for RFS (HR: 2.07, 95% CI 1.04-3.96, p = 0.038). Concerning the risk factors for high max CRP level, multivariate analysis revealed that older age (p < 0.001), male sex (p < 0.001), higher BMI (p = 0.005), right-sided colorectal cancer (p = 0.008), and longer operative time (p = 0.007) were independent risk factors. A higher max CRP was also significantly associated with peritoneal recurrence (p < 0.001). Additionally, recombinant cytokines enhanced the adhesive ability of CRC cells to mesothelial cell in vitro (p < 0.05). Postoperative inflammation may be a possible mechanism portending the poor prognosis of CRC patients.

H3K27 acetylation-induced lncRNA EIF3J-AS1 improved proliferation and impeded apoptosis of colorectal cancer through miR-3163/YAP1 axis.

Long noncoding RNAs (lncRNAs)are found to be aberrantly expressed and pose significant impacts in colorectal cancer (CRC), the most prevalent type malignancy in the gastrointestinal tract. This study aimed to find out the regulation of lncRNA EIF3J antisense RNA 1 (EIF3J-AS1) on CRC progression. Expressions of EIF3J-AS1, microRNA-3163 (miR-3163), and Yes-associated protein 1 (YAP1) in tissues and cells were evaluated by real-time quantitative polymerase chain reaction (RT-qPCR) and Western blot analysis. Association of EIF3J-AS1 with CRC prognosis was analyzed through the online bioinformatics tool GEPIA. The biological function of EIF3J-AS1 in CRC was investigated by Cell Counting Kit-8, colony formation, caspase-3 activity, and TUNEL staining. Competitive endogenous RNA (ceRNA) network of EIF3J-AS1/miR-3163/YAP1 was determined by luciferase reporter and RNA immunoprecipitation assays. Results showed that EIF3J-AS1 was upregulated in CRC tissues and cell lines, indicating poor prognosis of CRC patients. The silence of EIF3J-AS1 led to reduced proliferation and facilitated apoptosis of CRC cells. Mechanistcally, EIF3J-AS1 was upregulated by cAMP-response element-binding protein-binding protein-mediated histone H3 on lysine 27 acetylation (H3K27ac) at the promoter region, and EIF3J-AS1 upregulated YAP1 expression through sponging miR-3163 in CRC cells. In conclusion, we first found that H3K27 acetylation-induced lncRNA EIF3J-AS1 improved proliferation and impeded apoptosis of colorectal cancer through the miR-3163/YAP1 axis, which might potentially provide a novel molecular-targeted strategy for CRC treatment.

Karyopherin β1 deletion suppresses tumor growth and metastasis in colorectal cancer (CRC) by reducing MET expression

Colorectal cancer (CRC) has become the third most common type of cancer worldwide, and CRC liver metastasis (CRLM) is associated with poor survival rates. However, the molecular mechanisms driving this phenomenon remain unclear. Karyopherin β1 (KPNB1) is an adaptor protein that transports several proteins to the nuclear, and has been reported to play essential role in regulating many cancer-associated pathologies. Nevertheless, its role in CRC is unknown. The study was aimed to explore the role of KPNB1 as a pro-metastatic factor and to reveal the underlying mechanism. Here, the results indicated that KPNB1 expression was markedly increased in CRC samples. KPNB1 expression was gradually up-regulated with CRC development and was tightly correlated with poor prognosis in CRC patients. In vitro results demonstrated that KPNB1 decreasing markedly reduced CRC cell proliferation, migration and invasion, which was positively associated with the expression of MET proto-oncogene (MET). Further analysis revealed that KPNB1 decrease down-regulated the expression of epithelial-mesenchymal transition (EMT)-associated signals. In vivo experiments also demonstrated that KPNB1 knockdown evidently inhibited the tumor growth and metastasis in a CRC xenograft model. Importantly, we found that KPNB1 could interact with MET to modulate cell proliferation and metastasis in CRC. A subsequent mechanistic study illustrated that MET over-expression markedly eliminated KPNB1 silence-inhibited migration and invasion in CRC cells. In summary, KPNB1 deletion repressed the metastasis of CRC cells through interacting with MET, which could be served as a potential prognostic biomarker in CRC patients.

LNRRIL6, a novel long noncoding RNA, protects colorectal cancer cells by activating the IL-6-STAT3 pathway.

Long noncoding RNAs (lncRNAs) are emerging as critical regulators of cancer. There is a comparable number of lncRNAs to protein‐coding genes, but the expression patterns, functions, and molecular mechanisms of most lncRNAs in colorectal cancer (CRC) remain unclear. In this study, we report the identification of a novel lncRNA, named long noncoding RNA regulating IL‐6 transcription (LNRRIL6), which is upregulated in CRC tissues and cell lines. Increased LNRRIL6 expression is associated with aggressive clinicopathological characteristics and poor prognosis of CRC patients. Functional experiments showed that enhanced expression of LNRRIL6 promotes CRC cell proliferation and survival in vitro and CRC tumor growth in vivo. Conversely, depletion of LNRRIL6 inhibits CRC cell proliferation and survival in vitro and CRC tumor growth in vivo. Mechanistically, we revealed that LNRRIL6 physically binds to the IL‐6 promoter, thereby increasing IL‐6 transcription, inducing IL‐6 autocrine signaling, and activating the IL‐6/STAT3 pathway. The expression of IL‐6 is positively associated with that of LNRRIL6 in CRC tissues. Blocking the IL‐6/STAT3 pathway using the FDA‐approved IL‐6‐receptor antagonist antibody, tocilizumab, abolished the oncogenic role of LNRRIL6 in CRC. Taken together, these findings identify a novel lncRNA, LNRRIL6, that promotes CRC cell survival through activation of the IL‐6/STAT3 pathway and suggest that LNRRIL6 may be a potential prognostic biomarker and therapeutic target for CRC.

Impact of Fibroblast-Derived SPARC on Invasiveness of Colorectal Cancer Cells.

Secreted protein acidic and rich in cysteine (SPARC) is a matricellular protein modulating cell-matrix interactions and was found up-regulated in tumor stroma. To explore the effect of high stromal SPARC on colorectal cancer (CRC) cell behavior and clinical outcome, this study determined SPARC expression in patients suffering from stage II and III CRC using a publicly available mRNA data set and immunohistochemistry of tissue microarray sections. Moreover, in vitro co-culture models using CRC cell lines together with colon-associated fibroblasts were established to determine the effect of fibroblast-derived SPARC on cancer cells. In 466 patient samples, high SPARC mRNA was associated with a shorter disease-free survival. In 99 patients of the tissue microarray cohort, high stromal SPARC in the primary tumor was an independent predictor of shorter survival in patients with relapse (27 cases; HR = 4574, p = 0.004). In CRC cell lines, SPARC suppressed phosphorylation of focal adhesion kinase and stimulated cell migration. Colon-associated fibroblasts increased migration velocity by 30% and doubled track-length in SPARC-dependent manner. In a 3D co-culture system, fibroblast-derived SPARC enhanced tumor cell invasion. Taken together, stromal SPARC had a pro-metastatic impact in vitro and was a characteristic of aggressive tumors with poor prognosis in CRC patients.

KNK437 restricts the growth and metastasis of colorectal cancer via targeting DNAJA1/CDC45 axis.

As an inhibitor of heat shock proteins (HSPs), KNK437 has been reported to play an anti-tumor role in several cancers. But its therapeutic effect and mechanisms in colorectal cancer (CRC) remain unclear. Here, KNK437 sharply inhibited the level of DnaJ heat shock protein family (Hsp40) member A1 (DNAJA1), followed by DNAJB1, but had little effect on the levels of HSP27, HSP105, HSP90, and HSP70 in CRC cells. DNAJA1 promoted CRC cell proliferation in vitro and tumor growth and metastasis in vivo. Mechanistically, DNAJA1 was activated by E2F transcription factor 1 (E2F1) and then promoted cell cycle by stabilizing cell division cycle protein 45 (CDC45), which could be reversed by KNK437. DNAJA1 was significantly upregulated in CRC tissues and positively correlated with serosa invasion, lymph node metastasis. High level of DNAJA1 predicted poor prognosis for CRC patients. Its expression was highly linked with E2F1 and CDC45 in CRC tissues. More importantly, KNK437 significantly suppressed the growth of DNAJA1 expressing tumor in vivo. The combined treatment of KNK437 with 5-FU/L-OHP chemotherapy reduced liver metastasis of CRC. These data reveal a novel mechanism of KNK437 in anti-tumor therapy of CRC and provides a newly therapeutic strategy with potential translation to the CRC patients.

RBCK1 contributes to chemoresistance and stemness in colorectal cancer (CRC)

Chemotherapy is an essential treatment for colorectal cancer (CRC). However, colorectal cancer cells often develop resistance to chemotherapeutic drugs, resulting in relapse and poor patient prognosis. Growing studies indicate that tumor cells with stem cell-like features could promote resistance to chemotherapeutic agents. In this study, we demonstrated that RANBP2-type and C3HC4-type zinc finger-containing 1 (RBCK1) expression was markedly increased by cancer-associated fibroblasts (CAFs). First, we found that RBCK1 was over-expressed in chemoresistant CRC tumors and promoted chemoresistance in CRC cells. High RBCK1 expression was significantly correlated with poor prognosis in CRC patients. RBCK1 inhibition promoted sensitivity to chemotherapeutic drugs, and prevented migration and invasion in CRC cells. In addition, RBCK1 knockdown reduced cancer stemness by decreasing the expression of Nanog, Oct4, Sox2 and Klf4 in CRC cell lines. Furthermore, RBCK1 expression was significantly up-regulated in CRC cells cultured with conditioned medium (CM) derived from CAFs. Moreover, CAF-derived CM enhanced stemness and chemoresistance in CRC cells by over-expressing RBCK1. The in vivo experiments confirmed that RBCK1 knockdown promoted the chemotherapeutic drug sensitivity in a xenograft model. Taken together, these finding indicated that RBCK1 modulated chemosensitivity in CRC, and could be served as a promising therapeutic target for CRC prevention.

NAMPT and NAPRT, Key Enzymes in NAD Salvage Synthesis Pathway, Are of Negative Prognostic Value in Colorectal Cancer.

Nicotinamide adenine dinucleotide (NAD) is a profoundly important cofactor in redox reactions. Nicotinamide phosphoribosyltransferase (NAMPT) and nicotinate phosphoribosyltransferase (NAPRT) are key enzymes for NAD salvage biosynthesis pathway, which reciprocally synthesize NAD to supply the main source of NAD biosythesis. However, the prognostic value of NAMPT and NAPRT in colorectal cancer (CRC) remains largely unknown. Our present study detected NAMPT and NAPRT protein expression in cancer and adjacent tissues from 261 CRC using immunohistochemical staining. We found that high expression of NAMPT or NAPRT was associated with vascular invasion, invasion depth and advanced TNM stage in CRC. High expression of NAMPT or NAPRT predicts short overall survival and disease-free survival time in CRC patients, which were further confirmed by public datasets. Furthermore, positive correlation between expression of NAMPT and NAPRT was revealed in CRC tissues and cell lines. NAPRThigh/NAMPThigh patients tended to have the shortest survival time. Using the TCGA RNA-sequencing data, we showed that gene amplification, mutation, and methylation of NAPRT are more common than NAMPT. On the other hand, NAMPT gene might be targeted by more miRNAs. Finally, genes that are correlated with NAPRT or NAMPT are enriched in different pathways. In conclusion, we found that high expression of NAMPT or NAPRT predicts poor prognosis of CRC patients, but the regulatory mechanism might be distinct from each other.

Identification and Clinical Validation of a Novel 4 Gene-Signature with Prognostic Utility in Colorectal Cancer.

Colorectal cancer (CRC) is a high burden disease with several genes involved in tumor progression. The aim of the present study was to identify, generate and clinically validate a novel gene signature to improve prediction of overall survival (OS) to effectively manage colorectal cancer. We explored The Cancer Genome Atlas (TCGA), COAD and READ datasets (597 samples) from The Protein Atlas (TPA) database to extract a total of 595 candidate genes. In parallel, we identified 29 genes with perturbations in > 6 cancers which are also affected in CRC. These genes were entered in cBioportal to generate a 17 gene panel with highest perturbations. For clinical validation, this gene panel was tested on the FFPE tissues of colorectal cancer patients (88 patients) using Nanostring analysis. Using multivariate analysis, a high prognostic score (composite 4 gene signature—DPP7/2, YWHAB, MCM4 and FBXO46) was found to be a significant predictor of poor prognosis in CRC patients (HR: 3.42, 95% CI: 1.71–7.94, p < 0.001 *) along with stage (HR: 4.56, 95% CI: 1.35–19.15, p = 0.01 *). The Kaplan-Meier analysis also segregated patients on the basis of prognostic score (log-rank test, p = 0.001 *). The external validation using GEO dataset (GSE38832, 122 patients) corroborated the prognostic score (HR: 2.7, 95% CI: 1.99–3.73, p < 0.001 *). Additionally, higher score was able to differentiate stage II and III patients (130 patients) on the basis of OS (HR: 2.5, 95% CI: 1.78–3.63, p < 0.001 *). Overall, our results identify a novel 4 gene prognostic signature that has clinical utility in colorectal cancer.

Fusobacterium nucleatum tumor DNA levels are associated with survival in colorectal cancer patients

There is increasing evidence indicating a role for Fusobacterium nucleatum (F. nucleatum) in colorectal cancer (CRC) development and prognosis. This study evaluated F. nucleatum as a prognostic biomarker, by assessing its association with post-diagnosis survival from CRC. From September 2008 to April 2012 CRC patients (n = 190) were recruited from three hospitals within the Czech Republic. F. nucleatum DNA copies were measured in adjacent non-malignant and colorectal tumor tissues using quantitative real-time PCR. Cox Proportional Hazards (HR) models were applied to evaluate the association between F. nucleatum DNA and overall survival, adjusting for key confounders. Risk prediction modeling was conducted to evaluate the ability to predict survival based on F. nucleatum status. High, compared with low, levels of F. nucleatum in colorectal tumor tissues were associated with poorer overall survival (adjusted HR 1.68, 95% CI 1.02–2.77), which was slightly attenuated after additional adjustment for microsatellite instability status. However, inclusion of F. nucleatum in risk prediction models did not improve the ability to identify patients who died beyond known prognostic factors such as disease pathology staging. Although the increased presence of F. nucleatum was associated with poorer prognosis in CRC patients, this may have limited clinical relevance as a prognostic biomarker.

Long Non-Coding RNA LINC00525 Promotes the Stemness and Chemoresistance of Colorectal Cancer by Targeting miR-507/ELK3 Axis.

Background and ObjectivesThis study aims to explore the effects of a long non-coding RNA, LINC00525, on colorectal cancer (CRC) and its underlying molecular mechanisms.MethodsThe qPCR, MTT, colony formation, Western blotting, Luciferase reporter and biotin pull-down, shRNA knockdown and DNA fragmentation assays were performed in this study.ResultsHigh expressions of LINC00525 were associated with poor prognosis of CRC patients. LINC00525 knockdown decreased stemness properties and increased sensitivities to oxaliplatin. MiR-507 was a direct target of LINC00525 and overexpression of miR-507 significantly decreased abilities of tumorsphere formation and cell growth. Overexpression of miR-507 resulted in a decrease of expression of cancer stem cell markers and the increase of apoptosis rates. MiR-507 regulated the expression of ELK3. In addition, LINC00525 knockdown decreased the expression of ELK3. Restoration of ELK3 expression abrogated the effects of LINC00525 knockdown. LINC00525 could be served as prognostic marker of CRC.ConclusionsLINC00525 enhanced stemness properties and increased sensitivities of CRC cells to oxaliplatin by targeting miR-507/ELK3 axis.

Circ-0104631 promotes cell proliferation and invasion in colorectal cancer and predicts poor prognosis.

The aim of this study was to elucidate the effect of Circ-0104631 on the progression of colorectal cancer (CRC) and to demonstrate the underlying mechanism. Our research might provide new biological markers and molecular therapeutic targets for the diagnosis and therapy of CRC. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied to detect Circ-0104631 expression in human colorectal cancer tissues and normal control tissues. To further explore the effect of Circ-0104631 on CRC in vitro, we first knocked down Circ-0104631 in colorectal cancer cells (SW480 and LoVo) by shRNA transfection. Subsequently, we detected its effect on cell proliferation and invasion by cell counting kit-8 (CCK-8) assay, colony formation assay and cell invasion assay, respectively. The regulation of Circ-0104631 on the expressions of phosphate and tension homology deleted on chromosome ten (PTEN)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling pathway-related proteins was detected by Western blot. Besides, the regulatory mechanism of Circ-0104631 on the progression and metastasis of CRC was further verified by recovery experiments. QRT-PCR results showed that Circ-0104631 was highly expressed in tissues of patients with CRC when compared with that of normal control tissues. At the same time, we also found that the expression of Circ-010463 was significantly up-regulated in CRC tissues with high topography lymph node metastasis (TNM) stage and distant metastasis. Survival curve analysis indicated that high expression of Circ-010463 predicted poor prognosis of CRC patients. In vitro experiment demonstrated that inhibition of Circ-0104631 in SW480 and LoVo cells could markedly decrease cell growth and metastasis abilities. Meanwhile, Western blot results indicated that the protein expression of PTEN increased significantly, while p-Akt and p-mTOR decreased remarkably after knock-down of Circ-0104631 in CRC cells. Furthermore, recovery experiments illustrated that knockdown of PTEN in SW480 and LoVo cells partially attenuated the inhibitory effect of shRNA-Circ-0104631 on cell growth and metastasis. Circ-0104631 was highly expressed in CRC tissues. Furthermore, knockdown of Circ-0104631 could inhibit the growth and metastasis of CRC cells by regulating PTEN/Akt/mTOR signaling pathway.

Expression Profiling of Calcium Channels and Calcium-Activated Potassium Channels in Colorectal Cancer.

Background: Colorectal cancer (CRC) is a highly devastating cancer. Ca2+-dependent channels are now considered key regulators of tumor progression. In this study, we aimed to investigate the association of non-voltage gated Ca2+ channels and Ca2+-dependent potassium channels (KCa) with CRC using the transcriptional profile of their genes. Methods: We selected a total of 35 genes covering KCa channels KCNN1–4, KCNMA1 and their subunits KCNMB1–4, endoplasmic reticulum (ER) calcium sensors STIM1 and STIM2, Ca2+ channels ORAI1–3 and the family of cation channels TRP (TRPC1–7, TRPA1, TRPV1/2,4–6 and TRPM1–8). We analyzed their expression in two public CRC datasets from The Cancer Genome Atlas (TCGA) and GSE39582. Results: KCNN4 and TRPM2 were induced while KCNMA1 and TRPM6 were downregulated in tumor tissues comparing to normal tissues. In proximal tumors, STIM2 and KCNN2 were upregulated while ORAI2 and TRPM6 were downregulated. ORAI1 decreased in lymph node metastatic tumors. TRPC1 and ORAI3 predicted poor prognosis in CRC patients. Moreover, we found that ORAI3/ORAI1 ratio is increased in CRC progression and predicted poor prognosis. Conclusions: KCa and Ca2+ channels could be important contributors to CRC initiation and progression. Our results provide new insights on KCa and Ca2+ channels remodeling in CRC.

TIAM1 promotes chemoresistance and tumor invasiveness in colorectal cancer

Accumulating evidence suggests that cancer cells with stem cell-like features have higher resistance to chemotherapeutic agents. Herein, we identified T-lymphoma invasion and metastasis-inducing protein-1 (TIAM1) as one of the Wnt-signaling associated genes which drives self-renewal and its expression is upregulated by cancer associated fibroblasts (CAFs). TIAM1 expression was assessed in resected colorectal cancer (CRC) tissues from 300 patients who did or did not respond to chemotherapy. siRNA and CRISPR/Cas9 was used to examine whether the inhibition of TIAM1 affects chemosensitivity of CRC. We demonstrate that stemness through Wnt signaling regulates chemosensitivity and this phenomenon occurs exclusively in cancer stem cells. Subsequently, we established patient-derived CAFs and tested whether the drug sensitivity of CRC cell lines is altered with CAF-derived conditioned medium. High-TIAM1 expression correlated significantly with poor prognosis of CRC patients, and was overexpressed in patients who did not respond to chemotherapy. We demonstrated that the inhibition of TIAM1 enhanced sensitivity to chemotherapeutic drugs and reduced tumor invasiveness in a series of experiments in vitro. Moreover, CAF-derived conditioned media increased stemness and chemoresistance in CRC cell lines through TIAM1 overexpression. In addition, we validated TIAM1 associated drug sensitivity using a xenograft model. We have demonstrated that TIAM1 is overexpressed in CRC tumors from patients who did not respond to chemotherapeutic drugs and levels of TIAM1 expression served as an independent prognostic factor. Mechanistically, CAFs enhanced CRC chemoresistance through TIAM1 overexpression. Collectively, these results suggest that TIAM1 regulates chemosensitivity in tumors and stroma and thus may be an attractive therapeutic target.

SOX12 promotes colorectal cancer cell proliferation and metastasis by regulating asparagine synthesis

The sex-determining region Y (SRY)-box (SOX) family has a crucial role in carcinogenesis and cancer progression. However, the role of SOX12 and the mechanism by which it is dysregulated in colorectal cancer (CRC) remain unclear. Here we analyzed SOX12 expression patterns in two independent CRC cohorts (cohort I, n = 390; cohort II, n = 363) and found that SOX12 was significantly upregulated in CRC, indicating a poor prognosis in CRC patients. Overexpression of SOX12 promoted CRC cell proliferation and metastasis, whereas downregulation of SOX12 hampered CRC aggressiveness. Mechanistically, SOX12 facilitated asparagine synthesis by transactivating glutaminase (GLS), glutamic oxaloacetic transaminase 2 (GOT2), and asparagine synthetase (ASNS). Downregulation of GLS, GOT2, and ASNS blocked SOX12-mediated CRC cell proliferation and metastasis, whereas ectopic expression of GLS, GOT2, and ASNS attenuated the SOX12 knockdown-induced suppression of CRC progression. In addition, serial deletion, site-directed mutagenesis, luciferase reporter, and chromatin immunoprecipitation (ChIP) assays indicated that hypoxia-inducible factor 1α (HIF-1α) directly binds to the SOX12 promoter and induces SOX12 expression. Administration of l-asparaginase decreased SOX12-mediated tumor growth and metastasis. In human CRC samples, SOX12 expression positively correlated with GLS, GOT2, ASNS, and HIF-1α expression. Based on these results, SOX12 may serve as a prognostic biomarker and l-asparaginase represents a potential novel therapeutic agent for CRC.