Down-regulation of microRNA-224 -inhibites growth and epithelial-to-mesenchymal transition phenotype -via modulating SUFU expression in bladder cancer cells

The emerging role of noncoding RNAs in the Hedgehog signaling pathway in cancer

Hedgehog (HH), a conserved signaling pathway, is involved in embryo development, organogenesis, and other biological functions. Dysregulation and abnormal activation of HH are involved in tumorigenesis and tumor progression. With the emergence of interest in noncoding RNAs, studies on their involvement in abnormal regulation of biological processes in tumors have been published one after another. In this review, we focus on the crosstalk between noncoding RNAs and the HH pathway in tumors and elaborate the mechanisms by which long noncoding RNAs and microRNAs regulate or are regulated by HH signaling in cancer. We also discuss the interaction between noncoding RNAs and the HH pathway from the perspective of cancer hallmarks, presenting this complex network as concisely as possible and organizing ideas for cancer diagnosis and treatment.

Noncoding RNAs related to the hedgehog pathway in cancer: clinical implications and future perspectives

Cancer is a type of malignant affliction threatening human health worldwide; however, the molecular mechanism of cancer pathogenesis remains to be elusive. The oncogenic hedgehog (Hh) pathway is a highly evolutionarily conserved signaling pathway in which the hedgehog-Patched complex is internalized to cellular lysosomes for degradation, resulting in the release of Smoothened inhibition and producing downstream intracellular signals. Noncoding RNAs (ncRNAs) with diversified regulatory functions have the potency of controlling cellular processes. Compelling evidence reveals that Hh pathway, ncRNAs, or their crosstalk play complicated roles in the initiation, metastasis, apoptosis and drug resistance of cancer, allowing ncRNAs related to the Hh pathway to serve as clinical biomarkers for targeted cancer therapy. In this review, we attempt to depict the multiple patterns of ncRNAs in the progression of malignant tumors via interactions with the Hh crucial elements in order to better understand the complex regulatory mechanism, and focus on Hh associated ncRNA therapeutics aimed at boosting their application in the clinical setting.

Primary cilia presence and implications in bladder cancer progression and invasiveness

Urothelial bladder cancer is the tenth most common cancer worldwide. It is divided into muscle and non-muscle invading bladder cancer. Primary cilia have been related to several cancer hallmarks such as proliferation, epithelial-to-mesenchymal transition (EMT) or tumoral progression mainly through signaling pathways as Hedgehog (Hh). In the present study, we used immunohistochemical and ultrastructural techniques in human tissues of healthy bladder, non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) to study and clarify the activation of epithelial-to-mesenchymal transition and Hedgehog signaling pathway and the presence of primary cilia. Thus, we found a clear correlation between EMT and Hedgehog activation and bladder cancer stage and progression. Moreover, we identified the presence of primary cilia in these tissues. Interestingly, we found that in NMIBC, some ciliated cells cross the basement membrane and localized in lamina propria, near blood vessels. These results show a correlation between EMT beginning from urothelial basal cells and primary cilia assembly and suggest a potential implication of this structure in tumoral migration and invasiveness (likely in a Hh-dependent way). Hence, primary cilia may play a fundamental role in urothelial bladder cancer progression and suppose a potential therapeutic target.

miR-224 targets BTRC and promotes cell migration and invasion in colorectal cancer

Our study aims to investigate the impact of miR-224 on cell migration and invasion in colorectal cancer (CRC) as well as its molecular mechanisms. The results showed that miR-224 was significantly upregulated in CRC compared to normal tissues via the TCGA database. Overexpression of miR-224 promoted CRC cell migration and invasion, while inhibition of miR-224 demonstrated the opposite result via transwell assays. In addition, we found that BTRC was a target gene of miR-224 through the miRecords database and dual-luciferase assay, while western blot together with RT-qPCR showed that inhibition of miR-224 led to elevated BTRC expression in protein level but not in mRNA level, and also decreased the expression of β-catenin. In reference to the Human Protein Atlas, BTRC protein expression was higher in normal tissues than in CRC tissues. In conclusion, miR-224 regulates its target BTRC protein expression and its related Wnt/β-catenin pathway. Its impact on cell migration and invasion in CRC cells suggested that miR-224 could be a prospective therapeutic target for early-stage non-metastatic CRC.

LIFR-AS1 modulates Sufu to inhibit cell proliferation and migration by miR-197-3p in breast cancer

Numerous evidence has recently demonstrated that long non-coding RNAs (lncRNAs) play vital roles in the oncogenesis and development of a wide range of human neoplasms. Leukemia inhibitory factor receptor antisense RNA 1 (LIFR-AS1), a novel cancer-related lncRNA, has been reported to be under-expressed in breast cancer and associated with poor prognosis. However, the exact role of LIFR-AS1 in breast cancer remains largely unclear. The present study aimed to investigate the biological role of LIFR-AS1 in breast cancer and clarify the potential molecular mechanisms. In the present study, we found that LIFR-AS1 was significantly down-regulated in both tissues and cell lines. Furthermore, over-expression of LIFR-AS1 inhibited breast cancer cell proliferation, colony formation, migration and invasion, whereas knockdown of LIFR-AS1 promoted breast cancer cell proliferation, colony formation, migration and invasion. Moreover, LIFR-AS1 was observed to up-regulate suppressor of fused gene (Sufu) expression by competitively binding to miR-197-3p in breast cancer cells. Notably, miR-197-3p inhibitor reversed the promoting effects of LIFR-AS1 knockdown on breast cancer cell proliferation, colony formation, migration and invasion. Additionally, LIFR-AS1 knockdown promoted tumor growth in vivo. To sum up, our results imply the tumor-suppressing role of LIFR-AS1 in breast cancer.

EVI1 promotes epithelial-to-mesenchymal transition, cancer stem cell features and chemo-/radioresistance in nasopharyngeal carcinoma

BACKGROUND

Aberrant EVI1 expression is frequently reported in cancer studies; however, its role in nasopharyngeal carcinoma (NPC) has not been examined in detail. The aim of the present study is to investigate the involvement of EVI1 in progression and prognosis of NPC.

METHODS

RT-PCR, immunohistochemistry and western blot assays were used to examine the expression of EVI1 in NPC tissues and cell lines. Fluorescence in situ hybridization assay was used to examine the amplification of EVI1 in NPC tissues. The biological effect of EVI1 was determined by both in vitro and in vivo studies. The dual-luciferase reporter assay was performed to confirm that EVI1 bind at E-cadherin andβ-catenin promoters. The ChIP, EMSA, and coimmunoprecipitation combined with mass spectrometry assays were used to analyze the EVI1 regulated proteins.

RESULTS

EVI1 expression level was up-regulated in NPC tissues and cell lines. EVI1 was amplificated in NPC tissues. We observed that EVI1 down-regulation decreased the cell proliferation and invasive capacity of NPC cells in vitro and in vivo. EVI1, snail, and HDAC1 formed a co-repressor complex to repress E-cadherin expression and ultimately contributed to epithelial mesenchymal transition (EMT) phenotype in NPC cells. In another way, EVI1 directly bound at β-catenin promoter and activated its expression. β-catenin mediated EVI1's function on cancer stem cells (CSCs) properties. EVI1 up-regulation predicted unfavorable prognosis and contributed to chemo/radio-resistance in NPC cells. Finally, we constructed arsenic trioxide-loaded nanoparticles (ALNPs) and revealed that ALNPs exerted anti-tumor effect in NPC cells.

CONCLUSIONS

Our data indicated that EVI1 played an oncogenic role in NPC growth and metastasis and that EVI1 might serve as a novel molecular target for the treatment of NPC.

Epigenetic Mechanisms Influencing Epithelial to Mesenchymal Transition in Bladder Cancer

Bladder cancer is one of the most incident neoplasms worldwide, and its treatment remains a significant challenge, since the mechanisms underlying disease progression are still poorly understood. The epithelial to mesenchymal transition (EMT) has been proven to play an important role in the tumorigenic process, particularly in cancer cell invasiveness and metastatic potential. Several studies have reported the importance of epigenetic mechanisms and enzymes, which orchestrate them in several features of cancer cells and, specifically, in EMT. In this paper, we discuss the epigenetic enzymes, protein-coding and non-coding genes, and mechanisms altered in the EMT process occurring in bladder cancer cells, as well as its implications, which allows for improved understanding of bladder cancer biology and for the development of novel targeted therapies.

Anti-tumor activity and the mechanism of a green tea (Camellia sinensis) polysaccharide on prostate cancer

In this study, a homogeneous polysaccharide (GTP), with a molecular weight of 7.0 × 10⁴ Da, was isolated from Green tea, which was only composed of glucose. The antitumor effects of GTP on prostate cancer (PC) cell line along with the possible mechanism was examined. First, we investigate the potential role of microRNA-93 (miR-93) in PC progression. Our results showed that miR-93 was significantly upregulated in human PC tissues and several PC cell lines, and its overexpression was correlated with poor survival in PC patients. Furthermore, functional analysis showed that miR-93 overexpression promoted the migration, invasion and proliferation of PC-3 cells transfected with miR-93 mimics, while its knockdown displayed an opposite result in DU145 cells following miR-93 inhibitor transfection. Additionally, in vivo tumorigenic studies on nude mice confirmed that miR-93 mimic treatment accelerated the growth of PC-3 xenograft tumors. As expected, GTP (25, 50 and 100 μg/ml) inhibited growth of PC-3 cells via inducing apoptosis, which was achieved by elevation of bax/bcl-2 ratio and caspae-3 protein expression, as well as a decrease of miR-93. Thus, miR-93 may be a potential therapeutic target by GTP for PC therapy.

LncRNA-TUSC7/miR-224 affected chemotherapy resistance of esophageal squamous cell carcinoma by competitively regulating DESC1

BACKGROUND

This study aims to clarify the underlying mechanism for the tumor suppressive function of lnc TUSC7 in chemotherapy resistance of esophageal squamous cell carcinoma (ESCC).

METHODS

TUSC7, miR-224 and DESC1 expressions in ESCC tissues and cells were detected by qRT-PCR. Protein level of DESC1, EGFR and p-AKT were observed by Western blot. Overall survival was calculated using the Kaplan-Meier method. Dual-luciferase reporter gene assay and RIP assay were used to comfirm TUSC7 binding to miR-224, and miR-224 binding to DESC1. Cell proliferation, apoptosis, and colony formation was detected by MTT, Flow Cytometry and Colony formation assays.

RESULTS

TUSC7 was downregulated in ESCC tissues and cells, and low TUSC7 indicated worse overall survival. The analysis of bioinformatics softwares showed that TUSC7 specifically bound to miR-224, and we proved miR-224 was upregulated in ESCC and negatively correlated with TUSC7 expression. Overexpression of TUSC7/inhibition of miR-224 suppressed cell proliferation, colony formation and chemotherapy resistance of ESCC cells, and promoted cell apoptosis. In addition, we confirmed that miR-224 specifically bound to DESC1, and negatively correlated with DESC1. TUSC7 suppressed the proliferation and chemotherapy resistance of ESCC cells by increasing DESC1 expression via inhibiting miR-224. We also confirmed DESC1 inhibited chemotherapy resistance of ESCC cells via EGFR/AKT. Finally, in vivo experiments demonstrated that overexpression of TUSC7 decreased tumor growth and chemotherapy resistance.

CONCLUSION

These findings suggested TUSC7 suppressed chemotherapy resistance of ESCC by downregulating miR-224 to modulate DESC1/EGFR/AKT pathway.