CircCTNNA1 acts as a ceRNA for miR-363-3p to facilitate the progression of colorectal cancer by promoting CXCL5 expression

Hsa_circ_0001480 affects osteosarcoma progression by regulating the miR-363-3p/IBSP pathway

Osteosarcoma (OS) is a malignant bone tumor that commonly affects young individuals. Circular RNAs (circRNAs) are associated with OS progression. In this study, we aimed to determine the role of hsa_circ_0001480 (circ_0001480) in OS development. OS cell invasion, viability, and colony numbers were assessed via transwell, cell counting kit-8, and colony formation assays, respectively. Tumor growth in vivo was also assessed using an OS mouse model. Additionally, targeted associations among the integrin-binding sialoprotein (IBSP), microRNA (miR)-363-3p, and circ_0001480 were evaluated via RNA immunoprecipitation and dual luciferase reporter assays, whereas their expression levels in OS cells and tissues were determined via quantitative reverse transcription-polymerase chain reaction and western blotting. Loss of circ_0001480 or IBSP significantly inhibited the proliferation and invasion of OS cells, but this effect was reversed by miR-363-3p downregulation. Moreover, circ_0001480 knockdown inhibited neoplasm growth in vivo. circ_0001480 directly bound to miR-363-3p, which further modulated IBSP. Both circ_0001480 and IBSP levels were high, whereas miR-363-3p levels were low in OS cells. Furthermore, low miR-363-3p levels attenuated the suppressive effects of circ_0001480 silencing on the proliferation and invasion of OS cells; however, loss of IBSP partially reversed these effects. Overall, our findings revealed circ_0001480 an oncogenic circRNA stimulating OS progression by modulating the miR-363-3p/IBSP pathway, suggesting its potential for OS treatment.

Role of microRNA-363 during tumor progression and invasion

Recent progresses in diagnostic and therapeutic methods have significantly improved prognosis in cancer patients. However, cancer is still considered as one of the main causes of human deaths in the world. Late diagnosis in advanced tumor stages can reduce the effectiveness of treatment methods and increase mortality rate of cancer patients. Therefore, investigating the molecular mechanisms of tumor progression can help to introduce the early diagnostic markers in these patients. MicroRNA (miRNAs) has an important role in regulation of pathophysiological cellular processes. Due to their high stability in body fluids, they are always used as the non-invasive markers in cancer patients. Since, miR-363 deregulation has been reported in a wide range of cancers, we discussed the role of miR-363 during tumor progression and metastasis. It has been reported that miR-363 has mainly a tumor suppressor function through the regulation of transcription factors, apoptosis, cell cycle, and structural proteins. MiR-363 also affected the tumor progression via regulation of various signaling pathways such as WNT, MAPK, TGF-β, NOTCH, and PI3K/AKT. Therefore, miR-363 can be introduced as a probable therapeutic target as well as a non-invasive diagnostic marker in cancer patients.

CXCL1 promotes immune escape in colorectal cancer by autophagy-mediated MHC-I degradation

BACKGROUND

Immunotherapy is now seen as a potential remedy for colorectal cancer (CRC). Chemokines play a crucial role in tumors, including CRC, which contains CXCL1. We attempted to study how CXCL1 impacts immune escape in CRC.

METHODS

Bioinformatics analysis was used to examine CXCL1 level in CRC. qRT-PCR was used to assess CXCL1 and MHC-I (HLA-A, B, C) levels. Cell Counting Kit-8 (CCK-8) was used to measure cell viability. Cytotoxicity assay kit was utilized to assay CD8+ T cell cytotoxicity against CRC. Flow cytometry tested proliferation and apoptosis of CD8+ T cells. Chemotaxis assay evaluated chemotaxis of CD8+ T cells towards CRC. Immunofluorescence examined expression of autophagy marker LC3 and localization of NBR1/MHC-I. Western blot analysis measured protein levels of chemokines CXCL9 and CXCL10, autophagy-related proteins LC3-I and LC3-II, and MHC-I (HLA-A, B, C).

RESULTS

Bioinformatics analysis and qRT-PCR presented that CXCL1 was upregulated in CRC. Cell experiments demonstrated that CXCL1 overexpression promoted immune escape in CRC. Rescue experiments revealed that the autophagy inducer Rapa could attenuate the inhibitory effect of CXCL1 low expression on immune escape in CRC. Further studies showed that CXCL1 promoted immune escape in CRC by autophagy-mediated MHC-I degradation.

CONCLUSION

CXCL1 promoted immune escape in CRC by autophagy-mediated MHC-I degradation, suggesting that CXCL1 may be a possible immunotherapeutic target for CRC.

CXCL5 and CXCL14, but not CXCL16 as potential biomarkers of colorectal cancer

Experts emphasize that colorectal cancer (CRC) incidence and mortality are increasing. That is why its early detection is of the utmost importance. Patients with cancer diagnosed in earlier stages have a better prognosis and a chance for faster implementation of treatment. Consequently, it is vital to search for new parameters that could be useful in its diagnosis. Therefore, we evaluated the usefulness of CXCL5, CXCL14 and CXCL16 in serum of 115 participants (75 CRC patients and 40 healthy volunteers). Concentrations of all parameters were measured using Luminex. CRP (C-reactive protein) levels were determined by immunoturbidimetry, while levels of classical tumor markers were measured using CMIA (Chemiluminescence Microparticle Immunoassay). Concentrations of CXCL5 were statistically higher in the CRC group when compared to healthy controls. The diagnostic sensitivity, specificity, positive and negative predictive value, and area under the ROC curve (AUC) of CXCL5 and CXCL14 were higher than those of CA 19-9. Obtained results suggest the usefulness of CXCL5 and CXCL16 in the determination of distant metastases and differentiation between TNM (Tumor-Node-Metastasis) stages, as well as the usefulness of CXCL14 and CRP combination in CRC detection (primary or recurrence). However, further studies concerning their role in CRC progression are crucial to confirm and explain their diagnostic utility and clinical application as biomarkers.

Gibson T, McCain S, Stone BC, Gill T, Pickett BE. Pathway2Targets: an open-source pathway-based approach to repurpose therapeutic drugs and prioritize human targets

Background

Recent efforts to repurpose existing drugs to different indications have been accompanied by a number of computational methods, which incorporate protein-protein interaction networks and signaling pathways, to aid with prioritizing existing targets and/or drugs. However, many of these existing methods are focused on integrating additional data that are only available for a small subset of diseases or conditions.

Methods

We have designed and implemented a new R-based open-source target prioritization and repurposing method that integrates both canonical intracellular signaling information from five public pathway databases and target information from public sources including OpenTargets.org. The Pathway2Targets algorithm takes a list of significant pathways as input, then retrieves and integrates public data for all targets within those pathways for a given condition. It also incorporates a weighting scheme that is customizable by the user to support a variety of use cases including target prioritization, drug repurposing, and identifying novel targets that are biologically relevant for a different indication.

Results

As a proof of concept, we applied this algorithm to a public colorectal cancer RNA-sequencing dataset with 144 case and control samples. Our analysis identified 430 targets and ~700 unique drugs based on differential gene expression and signaling pathway enrichment. We found that our highest-ranked predicted targets were significantly enriched in targets with FDA-approved therapeutics for colorectal cancer (p-value < 0.025) that included EGFR, VEGFA, and PTGS2. Interestingly, there was no statistically significant enrichment of targets for other cancers in this same list suggesting high specificity of the results. We also adjusted the weighting scheme to prioritize more novel targets for CRC. This second analysis revealed epidermal growth factor receptor (EGFR), phosphoinositide-3-kinase (PI3K), and two mitogen-activated protein kinases (MAPK14 and MAPK3). These observations suggest that our open-source method with a customizable weighting scheme can accurately prioritize targets that are specific and relevant to the disease or condition of interest, as well as targets that are at earlier stages of development. We anticipate that this method will complement other approaches to repurpose drugs for a variety of indications, which can contribute to the improvement of the quality of life and overall health of such patients.

MicroRNA-363-3p inhibits colorectal cancer progression by targeting interferon-induced transmembrane protein 1

BACKGROUND

The molecular mechanisms of colorectal cancer development and progression are far from being elucidated.

AIM

To investigate the role of microRNA-363-3p (miR-363-3p) in the progression of colorectal cancer.

METHODS

Real-time polymerase chain reaction was performed to detect miRNA expression in human colorectal cancer tissues and paired normal colorectal tissues. PITA 6 was utilized to predict the targets of miR-363-3p. Dual-luciferase reporter system was used to validate the target of miR-363-3p. Plate colony formation assay and wound-healing assay were performed to evaluate cancer cells' clonogenic survival ability and migration ability, respectively. Cell proliferation was examined by cell counting kit-8 assay. Immunohistochemical staining was used to determine the expression level of interferon-induced transmembrane protein 1 (IFITM1) in colorectal cancer tissues and adjacent tissues. The TCGA and GTEx databases were used to compare the expression levels of IFITM1 mRNA in colorectal cancer tissues and normal colorectal tissues and analyze the correlation between the expression levels of IFITM1 mRNA and overall survival and disease-free survival of patients. A colorectal cancer cell line with a deficiency of IFITM1 was constructed, and the regulation effect of IFITM1 on the clonogenic growth of colorectal cancer cells was clarified.

RESULTS

MiR-363-3p was decreased in colorectal cancer tissues compared to normal colorectal tissues. IFITM1 was characterized as a direct target of miR-363-3p. Overexpression of miR-363-3p led to decreased clonogenic survival, proliferation, and migration of colorectal cancer cells, which could be reversed by forced IFITM1 expression.

CONCLUSION

MiR-363-3p can constrain clonogenic survival, proliferation, and migration of colorectal cancer cells via targeting IFITM1.

Up-regulated Circular RNAs in Colorectal Cancer: New Entities for Therapy and Tools for Identification of Therapeutic Targets

Patients with disseminated colorectal cancer have a dismal prognosis with a 5-year survival rate of only 13%. In order to identify new treatment modalities and new targets, we searched the literature for up-regulated circular RNAs in colorectal cancer which induce tumor growth in corresponding preclinical in vivo models. We identified nine circular RNAs that mediate resistance against chemotherapeutic agents, seven that up-regulate transmembrane receptors, five that induce secreted factors, nine that activate signaling components, five which up-regulate enzymes, six which activate actin-related proteins, six which induce transcription factors and two which up-regulate the MUSASHI family of RNA binding proteins. All of the circular RNAs discussed in this paper induce the corresponding targets by sponging microRNAs (miRs) and can be inhibited by RNAi or shRNA in vitro and in xenograft models. We have focused on circular RNAs with demonstrated activity in preclinical in vivo models because the latter is an important milestone in drug development. All circular RNAs with in vitro activity only data are not referenced in this review. The translational impact of inhibition of these circular RNAs and of the identified targets for treatment of colorectal cancer (CRC) are discussed.

Circ_0002111 modulates the growth process of papillary thyroid carcinoma cells by targeting the miR-363-3p/HMGB1 axis

Previous studies have suggested that circular RNAs (circRNAs) are engaged in the progression of papillary thyroid carcinoma (PTC). However, the mechanism of circ_0002111 in PTC is still unclear. In this study, quantitative real-time PCR was carried out to measure the expressions of circ_0002111, microRNAs (miRNAs) and high-mobility group box 1 (HMGB1). Immunohistochemistry assay and western blot were applied for the determination of protein levels. The assays of 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide and thymidine analog 5-ethynyl-2'-deoxyuridine were deployed to assess PTC cell viability and proliferation, respectively. Besides, the capacities of cell apoptosis, invasion and angiogenesis were determined by flow cytometry, transwell and tube formation assays, respectively. Moreover, the interaction between miR-363-3p and circ_0002111 or HMGB1 was confirmed using a dual-luciferase reporter assay. Lastly, we established a xenograft model for the examination of the function of circ_0002111 in vivo. It was found that the expression of circ_0002111 was enhanced in PTC tissues and cells. Silencing circ_0002111 apparently retarded the viability, proliferation, invasion and tube formation, as well as expedited the apoptosis of PTC cells. Besides, circ_0002111 knockdown impeded the growth of the tumor in vivo. For mechanism analysis, circ_0002111 adjusted the expression of HMGB1 by sponge adsorption of miR-363-3p. Moreover, miR-363-3p inhibitor regained the influence of cellular malignant phenotype caused by circ_0002111 knockdown. Additionally, miR-363-3p overexpression impacted the cell functions by targeting HMGB1 in PTC. Thus, silencing circ_0002111 constrained the progression of PTC by the miR-363-3p/HMGB1 axis, which perhaps provided a novel idea of the therapeutic in PTC.

CircCTNNA1 is Upregulated in Mantle Cell Lymphoma and Predicts Poor Survival by Sponging miR-34a to Increase Cell Proliferation

Background

It was reported that circular RNA (circRNA) circCTNNA1 plays an oncogenic role in colorectal cancer, while its role in mantle cell lymphoma (MCL) is unknown. This study aimed to explore the role of circCTNNA1 in MCL.

Methods

Samples of B lymphocytes were collected from 56 MCL patients and 56 healthy controls. The expression of circCTNNA1 and miR-34a in these samples were determined by RT-qPCR. The direct interaction between circCTNNA1 and miR-34a in MCL cells was detected using RNA-RNA pulldown assay. Overexpression assays were performed to study the interactions between circCTNNA1 and miR-34a. Cell proliferation was assessed with BrdU assay.

Results

The results showed that circCTNNA1 was upregulated in MCL and high expression levels of circCTNNA1 predicted the poor survival of MCL patients. MiR-34a was downregulated in MCL and inversely correlated with circCTNNA1. CircCTNNA1 was predicted to interact with miR-34a, and the interaction between them was confirmed by RNA pull-down assay. Interestingly, overexpression of circCTNNA1 and miR-34a did not affect the expression of each other. Cell proliferation analysis showed that overexpression of circCTNNA1 reversed the inhibitory effects of overexpression of miR-34a on cell proliferation.

Conclusion

Upregulation of circCTNNA1 in MCL predicts poor survival of patients and it may sponge miR-34a to promote cancer cell proliferation.

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.

Circular noncoding RNA circ_0007334 sequestrates miR-577 to derepress KLF12 and accelerate colorectal cancer progression

Colorectal cancer (CRC) is a prevalent malignant tumor with a poor prognosis. Circular RNA (circRNA) circ_0007334 is related to cell proliferation in CRC. This study is designed to explore the role and mechanism of circ_0007334 in CRC progression. Circ_0007334, microRNA-577 (miR-577) and kruppel-like factor 12 (KLF12) levels were measured by real-time quantitative PCR (RT-qPCR). Exosomes were detected by a transmission electron microscope and nanoparticle tracking analysis (NTA). CD63, TSG101, matrix metallopeptidase-2 (MMP-2), MMP-9, VEGFA and KLF12 protein levels were examined by western blot assay. The binding relationship between miR-577 and circ_0007334 or KLF12 was predicted by circRNA interactome or Starbase and verified by a dual-luciferase reporter and RNA immunoprecipitation (RIP) assays. Cell viability, colony number, migration, invasion and angiogenesis were detected by cell counting kit-8 (CCK-8), colony formation, wound healing, transwell and tube formation assays. The biological role of circ_0007334 was examined by the xenograft tumor model in vivo. Circ_0007334 and KLF12 were increased, and miR-577 was decreased in CRC tissues and cells. Also, circ_0007334 expression was upregulated in CRC cell-derived exosomes. Circ_0007334 deficiency repressed cell viability, colony formation, migration, invasion, and angiogenesis in CRC cells. Mechanically, circ_0007334 could regulate KLF12 expression by sponging miR-577. Circ_0007334 downregulation or exosomal circ_0007334 silencing blocked CRC tumor growth in vivo. These results presented that circ_0007334 deficiency exerts a tumor-suppressor by the miR-577/KLF12 axis in CRC, and indicated that exosomal circ_0007334 could hinder CRC tumor growth and angiogenesis in vivo. Our findings provided a novel therapeutic strategy for CRC.

Hsa_circ_0001361 facilitates the progress of lung adenocarcinoma cells via targeting miR-525-5p/VMA21 axis

Background

Lung adenocarcinoma (LUAD) is a common subtype of lung cancer with high recurrence rate and fatality. Circ_0001361 has been recognized as key regulators in various malignancies, but its roles in LUAD remain ambiguous.

Methods

Circ_0001361, miR-525-5p, and VMA21 levels were assessed by RT-qPCR. The growth and metastasis of LUAD cells were detected by MTT, colony formation, wound scratch, and transwell assays, respectively. The interaction between circ_0001361/VMA21 and miR-525-5p was detected by dual luciferase, RNA immunoprecipitation, and RNA pull-down assays. VMA21 protein level was detected by Western blotting. Nude mouse xenograft model was established to determine the role of circ_0001361 in tumor growth in vivo.

Results

Circ_0001361 was up-regulated, while miR-525-5p was down-regulated in LUAD tissues and cells. Functional experiments demonstrated that circ_0001361 drove LUAD cell growth and metastasis. Mechanistically, circ_0001361 functioned as a sponge of miR-525-5p to up-regulate downstream target VMA21 level. MiR-525-5p/VMA21 axis was involved in circ_0001361-mediated malignant phenotypes of LUAD cells. Finally, inhibition of circ_0001361 restrained in vivo xenograft tumor growth via regulating miR-525-5p/VMA21 axis.

Conclusion

Our findings elucidate that circ_0001361 facilitates the tumorigenesis and development of LUAD through miR-525-5p/VMA21 axis, providing evidence for circ_0001361 as a potential prognosis biomarker and therapeutic target for clinical treatment of LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03045-4.

LncRNA FBXL19-AS1 promotes proliferation and metastasis of cervical cancer through upregulating COL1A1 as a sponge of miR-193a-5p

BACKGROUND

Cervical cancer (CC) is one of the most common and malignant tumors in women. In this study, we aim to explore the role and mechanism of F-box and leucine rich repeat protein 19 antisense RNA 1 (FBXL19-AS1), a novel long-chain non coding RNA (lncRNA) with marked roles in a variety of tumors, in regulating the proliferation and metastasis of CC.

METHODS

The expression of FBXL19-AS1, miR-193a-5p and COL1A1 were detected by RT-PCR and western blot. Gain- and loss-of functional assays of FBXL19-AS1 and miR-193a-5p were performed in CC cell lines in vitro or in vivo. The proliferation, migration, invasion, apoptosis and epithelial-mesenchymal transition (EMT) of CC cells were determined.

RESULTS

FBXL19-AS1 and COL1A1 were significantly up-regulated in CC tissues, while miR-193a-5p was significantly down-regulated. Overexpression of FBXL19-AS1 significantly promoted the proliferation, migration, invasion, EMT and growth of CC cells and inhibited apoptosis, while knockdown of FBXL19-AS1 had the opposite effects. On the other hand, miR-193a-5p inhibited the proliferation and metastasis of CC cells. Mechanistically, FBXL19-AS1 functioned as a competitive endogenous RNA (ceRNA) and inhibited the expression of miR-193a-5p, which targeted at the 3'-UTR site of COL1A1 and negatively regulated COL1A1 expression.

CONCLUSIONS

FBXL19-AS1 promotes the proliferation and metastasis of CC cells by sponging miR-193a-5p and up-regulating COL1A1.

Comprehensive analysis of the prognosis and immune infiltration for CXC chemokines in colorectal cancer

The C-X-C motif (CXC) chemokines are a family of chemotactic molecules that have been identified as potential prognostic markers and prospective therapeutic targets for many kinds of cancer types. Increasing evidence shows that CXC chemokines are associated with the progression of colorectal cancer (CRC); however, the correlations of CXC chemokines with prognostic and immune infiltrates in CRC remain to be clarified. In this study, we analyzed the mRNA expression level, prognostic data and immune infiltrates of CXC chemokines in CRC patients from the Gene Expression Profiling Interactive Analysis, Oncomine, cBioPortal and databases using GeneMANIA, STRING, DAVID 6.8, and TIMER. Our results showed that CXCL1/2/3/4/5/8/9/10/11/13/14/16 were significantly overexpressed in CRC tissues. Furthermore, expression of CXCL1/2/3/9/10/11 was associated with tumor stage in CRC. A significant association was also identified between the co-expression of CXCL16 with EGFR, KRAS and NRAS. In addition, the survival analysis suggested that high CXCL2/3/8/9/10/11/14 expression is correlated with clinical outcomes of CRC patients. Moreover, a significant association was observed between the CXCL8/9/10/11 expression and immune infiltration in colonic and rectal adenocarcinoma. Overall, CXC chemokines are not only implicated as prognostic biomarkers for CRC patients, but may also influence the immune status of CRC tissues.

Oncogenic Functions and Clinical Significance of Circular RNAs in Colorectal Cancer

Colorectal cancer (CRC) is ranked as the second most commonly diagnosed disease in females and the third in males worldwide. Therefore, the finding of new more reliable biomarkers for early diagnosis, for prediction of metastasis, and resistance to conventional therapies is an important challenge in overcoming the disease. The current review presents circular RNAs (circRNAs) with their unique features as potential prognostic and diagnostic biomarkers in CRC. The review highlights the mechanism of action and the role of circRNAs with oncogenic functions in the CRC as well as the association between their expression and clinicopathological characteristics of CRC patients. The comprehension of the role of oncogenic circRNAs in CRC pathogenesis is growing rapidly and the next step is using them as suitable new drug targets in the personalized treatment of CRC patients.