miRNA Targeting Angiogenesis as a Potential Therapeutic Approach in the Treatment of Colorectal Cancers

MicroRNA-34 and gastrointestinal cancers: a player with big functions

It is commonly assumed that gastrointestinal cancer is the most common form of cancer across the globe and is the leading contributor to cancer-related death. The intricate mechanisms underlying the growth of GI cancers have been identified. It is worth mentioning that both non-coding RNAs (ncRNAs) and certain types of RNA, such as circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and microRNAs (miRNAs), can have considerable impact on the development of gastrointestinal (GI) cancers. As a tumour suppressor, in the group of short non-coding regulatory RNAs is miR-34a. miR-34a silences multiple proto-oncogenes at the post-transcriptional stage by targeting them, which inhibits all physiologically relevant cell proliferation pathways. However, it has been discovered that deregulation of miR-34a plays important roles in the growth of tumors and the development of cancer, including invasion, metastasis, and the tumor-associated epithelial-mesenchymal transition (EMT). Further understanding of miR-34a's molecular pathways in cancer is also necessary for the development of precise diagnoses and effective treatments. We outlined the most recent research on miR-34a functions in GI cancers in this review. Additionally, we emphasize the significance of exosomal miR-34 in gastrointestinal cancers.

Perspectives of using microRNA-loaded nanocarriers for epigenetic reprogramming of drug resistant colorectal cancers

Epigenetic regulation by microRNAs (miRs) demonstrated a promising therapeutic potential of these molecules to regulate genetic activity in different cancers, including colorectal cancers (CRCs). The RNA-based therapy does not change genetic codes in tumor cells but can silence oncogenes and/or reactivate inhibited tumor suppressor genes. In many cancers, specific miRs were shown to promote or stop tumor progression. Among confirmed and powerful epigenetic regulators of colon carcinogenesis and development of resistance are onco-miRs, which include let-7, miR-21, miR-22, miR-23a, miR-27a, miR-34, miR-92, miR-96, miR-125b, miR-135b, miR-182, miR-200c, miR-203, miR-221, miR-421, miR-451, and others. Moreover, various tumor-suppressor miRs (miR-15b-5b, miR-18a, miR-20b, miR-22, miR-96, miR-139-5p, miR-145, miR-149, miR-197, miR-199b, miR-203, miR-214, miR-218, miR-320, miR-375-3p, miR-409-3p, miR-450b-5p, miR-494, miR-577, miR-874, and others) were found silenced in drug-resistant CRCs. Re-expression of tumor suppressor miR is complicated by the chemical nature of miRs that are not long-lasting compounds and require protection from the enzymatic degradation. Several recent studies explored application of miRs using nanocarrier complexes. This study critically describes the most successfully tested nanoparticle complexes used for intracellular delivery of nuclear acids and miRs, including micelles, liposomes, inorganic and polymeric NPs, dendrimers, and aptamers. Nanocarriers shield incorporated miRs and improve the agent stability in circulation. Attachment of antibodies and/or specific peptide or ligands facilitates cell-targeted miR delivery. Addressing in vivo challenges, a broad spectrum of non-toxic materials has been tested and indicated reliable advantages of lipid-based (lipoplexes) and polymer-based liposomes. Recent cutting-edge developments indicated that lipid-based complexes with multiple cargo, including several miRs, are the most effective approach to eradicate drug-resistant tumors. Focusing on CRC-specific miRs, this review provides a guidance and insights towards the most promising direction to achieve dramatic reduction in tumor growth and metastasis using miR-nanocarrier complexes.

Newcastle disease virus expressing an angiogenic inhibitor exerts an enhanced therapeutic efficacy in colon cancer model

Newcastle disease virus (NDV)-mediated gene therapy is a promising new approach for treatment of cancer but shows limited anti-angiogenesis. VEGF-Trap plays a vital role in anti-angiogenesis. To enhance the anti-tumor effect of NDV, VEGF-Trap gene was incorporated into the genome of rNDV in this study (named rNDV-VEGF-Trap). Results showed that rNDV-VEGF-Trap reduced cell growth ratio by 85.37% and migration ratio by 87.9% in EA.hy926 cells. In vivo studies, rNDV-VEGF-Trap reduced tumor volume and weight of CT26-bearing mice by more than 3 folds. Immunohistochemistry analysis of CD34 showed rNDV-VEGF-Trap significantly decreased the number of vascular endothelial cells in the tumor tissues. Moreover, Western blot analysis demonstrated that treatment with rNDV-VEGF-Trap significantly decreased the phosphorylation levels of AKT, ERK1/2 and STAT3 and increased the expression levels of P53, BAX and cleaved caspase-3 in the tumor tissue. In addition, to evaluate the toxicity of rNDV-VEGF-Trap, serum chemistries were analyzed. The results showed that rNDV-VEGF-Trap caused insignificant changes of creatinine levels, alanine aminotransferase and aspartate transaminase. Furthermore, administration of rNDV-VEGF-Trap did not cause the diarrhoea, decreased appetite, weight decrease and haemorrhage of the experimental mice. These data suggest that rNDV-VEGF-Trap exhibits an enhanced inhibition of CT26-bearing mice by enhancing anti-angiogenesis and apoptosis and may be a potential candidate for carcinoma therapy especially for colon cancer.

The dual role of microRNA-9 in gastrointestinal cancers: oncomiR or tumor suppressor?

microRNA are noncoding endogenous RNAs of ∼ 25-nucleotide, involved in RNA silencing and controlling of cell function. Recent evidence has highlighted the important role of various in the biology of human cancers. miR-9 is a highly conserved microRNA and abnormal regulation of miR-9 expression has various impacts on disease pathology. miR-9 may play a dual tumor-suppressive or oncomiR activity in several cancers. There have been conflicting reports concerning the role of miR-9 in gastrointestinal cancers. Several signaling pathways including PDK/AKT, Hippo, Wnt/β-catenin and PDGFRB axes are affected by miR-9 in suppressing proliferation, invasion and metastasis of tumor cells. Oncogenic miR-9 triggers migration, metastasis and clinic-pathological characteristics of patients with gastrointestinal malignancy by targeting various enzymes and transcription factors such as E-cadherin, HK2, LMX1A, and CDX2. On the other hand, long non-coding RNAs and circular RNAs can modulate miR-9 expression in human cancers. In this review, we aimed to summarize recent findings about the potential value of miR-9 in gastrointestinal tumors, that include: screening, prognostic and treatment.

Identification of cluster of differentiation molecule-associated microRNAs as potential therapeutic targets for gastrointestinal cancer immunotherapy

BACKGROUND

Cluster of differentiation molecules are markers of immune cells that have been identified as a potential immunotherapeutic target for cancer treatment. MicroRNAs are small non-coding RNAs that act as tumor suppressors or oncogenes whose importance in diagnosis, prognosis, and treatment of gastric and colorectal cancers has been widely reported. However, their association with cluster of differentiation molecules in gastrointestinal cancers has not been well studied. Therefore, our study aimed to analyze the relationship between microRNAs and cluster of differentiation molecules in gastrointestinal cancers, and to identify cluster of differentiation molecule-associated microRNAs as prognostic biomarkers for gastrointestinal cancer patients.

METHODS

Targetscan, Starbase, DIANA microT, and miRDB were used to investigate microRNA profiles that might be correlated with cluster of differentiation molecules in gastrointestinal cancers. Moreover, The Cancer Genome Atlas data analysis was used to investigate the association between cluster of differentiation molecules and microRNA expression in patients with gastric, colon, rectal, pancreatic, and esophageal cancers. The Kaplan-Meier plotter was used to identify the association between overall survival and cluster of differentiation molecule-associated microRNA expression in gastrointestinal cancer patients.

RESULTS

miR-200a, miR-559, and miR-1236 were negatively associated with CD86, CD81, and CD160, respectively, in almost all types of gastrointestinal cancers, which were further verified in the in vitro studies by transfecting microRNA mimics in gastric cancer, colon cancer, pancreatic, and esophageal cell lines.

CONCLUSION

Our study showed that miR-200a, miR-1236, and miR-559 are identified as cluster of differentiation-associated microRNAs in gastrointestinal cancers, providing a novel perspective to identify new therapeutic targets for cancer immunotherapy in gastrointestinal cancer patients.

Exosomes from microRNA-126 overexpressing mesenchymal stem cells promote angiogenesis by targeting the PIK3R2-mediated PI3K/Akt signalling pathway

microRNA‐126 (miR‐126), an endothelial‐specific miRNA, is associated with vascular homeostasis and angiogenesis. However, the efficiency of miR‐126‐based treatment is partially compromised due to the low efficiency of miRNA delivery in vivo. Lately, exosomes have emerged as a natural tool for therapeutic molecule delivery. Herein, we investigated whether exosomes derived from bone marrow mesenchymal stem cells (BMMSCs) can be utilized to deliver miR‐126 to promote angiogenesis. Exosomes were isolated from BMMSCs overexpressed with miR‐126 (Exo‐miR‐126) by ultracentrifugation. In vitro study, Exo‐miR‐126 treatment promoted the proliferation, migration and angiogenesis of human umbilical vein endothelial cells (HUVECs). Furthermore, the gene/protein expression of angiogenesis‐related vascular endothelial growth factor (VEGF) and angiotensin‐1 (Ang‐1) were up‐regulated after incubation with Exo‐miR‐126. Additionally, the expression level of phosphoinositol‐3 kinase regulatory subunit 2 (PIK3R2) showed an inverse correlation with miR‐126 in HUVECs. Particularly, the Exo‐miR‐126 treatment contributed to enhanced angiogenesis of HUVECs by targeting PIK3R2 to activate the PI3K/Akt signalling pathway. Similarly, Exo‐miR‐126 administration profoundly increased the number of newly formed capillaries in wound sites and accelerated the wound healing in vivo. The results demonstrate that exosomes derived from BMMSCs combined with miR‐126 may be a promising strategy to promote angiogenesis.

NT5DC2 knockdown inhibits colorectal carcinoma progression by repressing metastasis, angiogenesis and tumor-associated macrophage recruitment: A mechanism involving VEGF signaling

Colorectal cancer (CRC) is one of the most commonly diagnosed tumors among human worldwide. Angiogenesis and tumor-associated macrophage (TAM) recruitment are closely associated with CRC development. Nevertheless, the mechanisms revealing CRC progression are still not fully understood. 5'-Nucleotidase domain containing 2 (NT5DC2), a member of the NT5DC family, modulates various cellular events to mediate tumor growth, and thus serves as a disgnostic biomarker. Here, we explored the potential of NT5DC2 on tumor progression in CRC. We first found that NT5DC2 expression was significantly up-regulated in CRC tissues and cell lines. CRC patients with higher NT5DC2 expression showed poor overall survival. Furthermore, CRC cell lines stably transfected with shNT5DC2 lentivirus plasmids exhibited markedly reduced cell proliferation, migration and invasion compared with the negative control group. Hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor A (VEGF-A) expression levels were remarkably reduced in CRC cells with NT5DC2 deletion, along with evidently reduced tube formation in the HUVECs cultured in the collected conditional medium. The expression levels of CC chemokine ligand 2 (CCL2) and its receptor CCR2 were found to be greatly down-regulated in CRC cells transfected with shNT5DC2. Moreover, NT5DC2 knockdown markedly suppressed the activation of protein kinase-B/nuclear transcription factor κB (AKT/NF-κB) signaling in CRC cells. Furthermore, we found that NT5DC2 deletion obviously reduced the TAM recruitments through suppressing CCL2/CCR2 and AKT/NF-κB signaling pathways. Intriguingly, our in vitro experiments demonstrated that VEGF reduction was necessary for shNT5DC2-inhibited cell proliferation, migration, invasion, angiogenesis and TAM recruitment. In vivo studies also confirmed that NT5DC2 knockdown effectively reduced the tumor growth and VEGF expression in a xonegraft mouse model with CRC. Lung metastasis of CRC cells was also hindered by NT5DC2 deletion in vivo. Collectively, our results indicated a previously unrecognized NT5DC2/VEGF/CCL2 axis involved in CRC development and metastasis.

Mast Cells, microRNAs and Others: The Role of Translational Research on Colorectal Cancer in the Forthcoming Era of Precision Medicine

Colorectal cancer (CRC) is a heterogeneous disease, molecularly and anatomically, that develops in a multi-step process requiring the accumulation of several genetic or epigenetic mutations that lead to the gradual transformation of normal mucosa into cancer. In fact, tumorigenesis is extremely complex, with many immunologic and non-immunologic factors present in the tumor microenvironment that can influence tumorigenesis. In the last few years, a role for mast cells (MCs), microRNAs (miRNAs), Kirsten rat sarcoma (KRAS) and v-raf murine sarcoma viral oncogene homologue B (BRAF) in cancer development and progression has been suggested, and numerous efforts have been made to thoroughly assess their correlation with CRC to improve patient survival and quality of life. The identification of easily measurable, non-invasive and cost-effective biomarkers, the so-called "ideal biomarkers", for CRC screening and treatment remains a high priority. The aim of this review is to discuss the emerging role of mast cells (MCs), microRNAs (miRNAs), KRAS and BRAF as diagnostic and prognostic biomarkers for CRC, evaluating their influence as potential therapy targets in the forthcoming era of precision medicine.

Effect of Curcumin and Its Derivates on Gastric Cancer: Molecular Mechanisms

Gastric carcinoma is one of the most prevalent malignancies and is associated with a high mortality. Chemotherapy is the principal therapeutic option in the treatment of gastric cancer, but its success rate is restricted by severe side effects and the prevalence of chemo-resistance. Curcumin is a polyphenolic compound derived from turmeric that has potent antioxidant, anti-inflammatory and anti-tumor effects. There is accumulating evidence that curcumin may prevent gastric cancer through regulation of oncogenic pathways. Furthermore some curcumin analogues and novel formulation of curcumin appear to have anti-tumor activity. The aim of this review was to give an overview of the therapeutic potential of curcumin and its derivatives against gastric cancer in preclinical and clinical studies.

Effects of 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors on ageing: Molecular mechanisms

Human ageing is determined by degenerative alterations and processes with different manifestations such as gradual organ dysfunction, tissue function loss, increased population of aged (senescent) cells, incapability of maintaining homeostasis and reduced repair capacity, which collectively lead to an increased risk of diseases and death. The inhibitors of HMG-CoA reductase (statins) are the most widely used lipid-lowering agents, which can reduce cardiovascular morbidity and mortality. Accumulating evidence has documented several pleiotropic effects of statins in addition to their lipid-lowering properties. Recently, several studies have highlighted that statins may have the potential to delay the ageing process and inhibit the onset of senescence. In this review, we focused on the anti-ageing mechanisms of statin drugs and their effects on cardiovascular and non-cardiovascular diseases.