Metadherin is an apoptotic modulator in prostate cancer through miR-342-3p regulation

Quercetin Inhibits Tumorigenesis of Colorectal Cancer Through Downregulation of hsa_circ_0006990

Quercetin can significantly inhibit the progression of colorectal cancer (CRC). However, its specific mechanism remains largely unclear. In this study, we aimed to explore the correlation among quercetin, tumour-associated macrophages (TAMs) and circular RNAs (circRNAs) in the progression of CRC and to present a novel strategy for the treatment of CRC. In this study, we revealed that quercetin could suppress the autophagy of M2-TAMs and induced their differentiation into M1-TAMs, by which quercetin significantly reversed the inhibition of M2-TAMS on CRC cell apoptosis and the promotion of M2-TAMS on CRC cell proliferation. Moreover, quercetin could promote the expression of downregulated hsa_circ_0006990 in CRC cells co-cultured with M2-TAMs, and the overexpression of hsa_circ_0006990 significantly reversed the anti-tumour effect of quercetin on CRC. Furthermore, we found quercetin can notably suppress the progression of CRC via mediation of the hsa_circ_0006990/miR-132-3p/MUC13 axis. In conclusion, our results suggested that quercetin inhibits the tumorigenesis of CRC via inhibiting the polarisation of M2 macrophages and downregulating hsa_circ_0006990. Our study provides useful insights for those exploring new methods of treating CRC.

Metadherin (MTDH) overexpression significantly correlates with advanced tumor grade and stages among colorectal cancer patients

BACKGROUND

Colorectal cancer is the 4th leading cause of cancer related deaths affecting both men and women worldwide. In the present study, any probable role of MTDH mRNA expression in CRC tumorigenesis was explored using both discovery and validation cohorts.

METHODS AND RESULTS

After prior ethical and biosafety approvals, tumor tissue samples along with their adjacent controls were collected for this study from Pakistani patients diagnosed with colorectal cancer. RNA was isolated using Trizol reagent, followed by cDNA synthesis. Transcript analysis of MTDH was performed by using qPCR. Moreover, genome-wide expression of MTDH was also determined through micro-array data analysis using BRB-array tools software. MTDH expression was significantly high in tumor tissue samples (p < 0.05) compared to their respective controls. Likewise, results of microarray analysis also revealed overamplification of MTDH in tumor samples as compared to controls. Expression of MTDH was also found to be positively correlated with KI-67 index (p < 0.05) and were observed to be significantly upregulated in advance tumor grade (p < 0.05) and stage (p < 0.05). However, no association of MTDH overexpression with age and gender could be established.

CONCLUSION

Hence, it can be concluded that MTDH is a core element that plays a pivotal role in colorectal tumorigenesis irrespective of patient's age and gender. Molecular insight into the tumor microenvironment revealed MTDH as a niche, representing distinctive framework for cancer progression, thus, making it an innovative target strategy for colorectal cancer treatment.

MiR-524 suppressed the progression of oral squamous cell carcinoma by suppressing Metadherin and NF-κB signaling pathway in OSCC cell lines

OBJECTIVES

The aim of the present study was to explore the functional role of miR-524 in oral squamous cell carcinoma (OSCC) and determine its underlying mechanism.

MATERIALS AND METHODS

Tumor tissues and adjacent tissues were obtained from 55 patients with OSCC (20 females and 35 males) with a mean age of 54 years (range from 24 to 72 years). Additionally, OSCC cell lines culture was used and Reverse transcription‑quantitative PCR (RT-qPCR) was applied to measure the expression of miR-524 in OSCC tissues and cells. The protein density of Metadherin (MTDH) in OSCC tissues was detected by Immunohistochemistry (IHC) assay. MiR-524 mimic was employed to investigate the impact of miR-524 on proliferation, migration, and invasion using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay and transwell assays. The dual luciferase reporter assay was utilized to investigate the interaction between MTDH and miR-524 expression. Cells transfected with miR-524 mimic and pcDNA-MTDH were subjected to western blot to investigate the role of NF-κB signaling in miR-524/MTDH axis mediated cell proliferation, migration, and invasion.

RESULTS

MiR-524 expression was decreased significantly in OSCC tissues compared to adjacent tissues, and closely related to clinical stage, tumor size, and lymph node metastasis. Over-expression of miR-524 suppressed the proliferation, migration, and invasion of OSCC cells. Luciferase reporter assay results demonstrated that MTDH was the target gene of miR-524. Over-expression of miR-524 reduced MTDH expression and inhibited NF-κB signaling pathway. Rescue experiments revealed that over-expression of MTDH partially reversed the efficacy of miR-524 mimic on OSCC cells.

CONCLUSIONS

These results indicated that miR-524 inhibits the activation of NF-κB signaling pathway via inhibiting MTDH, resulting in the suppression of cell proliferation, migration, and invasion.

LncRNA LINC00210 regulated radiosensitivity of osteosarcoma cells via miR-342-3p/GFRA1 axis

BACKGROUND

Radiotherapy is an effective strategy for preventing cancer metastasis, including osteosarcoma. However, cancer radioresistance limits the efficiency of radiotherapy. Therefore, it is essential to investigate the mechanism of osteosarcoma radioresistance.

METHODS

The osteosarcoma tissues and adjacent healthy tissues were collected from 53 osteosarcoma patients. The expression of LINC00210, miR-342-3p, and GFRA1 mRNA were determined using qRT-PCR. Cell viability, cell apoptosis, and cell surviving fraction were determined by MTT assay, flow cytometry, and colony formation assay, respectively. Western blot was performed to detect the protein levels. Luciferase assay was conducted to verify the relationship between LINC00210, miR-342-3p, and GFRA1.

RESULTS

LINC00210 and GFRA1 were up-regulated, and miR-342-3p was down-regulated in osteosarcoma tissues and cells. The expression of LINC00210 in osteosarcoma was negatively related to miR-342-3p expression and positively associated with GFRA1. Besides, there was a negative correlation between LINC00210 and GFRA1 expression in osteosarcoma. Also, LINC00210 and GFRA1 were up-regulated, and miR-342-3p was down-regulated in osteosarcoma cells exposed to 4 Gy irradiation treatment. Furthermore, either LINC00210 knockdown or miR-342-3p overexpression enhanced the radiosensitivity of osteosarcoma cells. Moreover, LINC00210 increased GFRA1 expression via sponging miR-342-3p. Additionally, LINC00210 knockdown improved the radiosensitivity of osteosarcoma cells by regulating GFRA1 expression via sponging miR-342-3p.

CONCLUSION

LINC00210 modulated the radiosensitivity of osteosarcoma cells via the miR-342-3p/GFRA1 axis, making LINC00210 a novel target for improving radiotherapy efficiency in osteosarcoma.

CircSAMD4A regulates cell progression and epithelial‑mesenchymal transition by sponging miR‑342‑3p via the regulation of FZD7 expression in osteosarcoma

Osteosarcoma (OS) is a primary malignant tumor with a complex etiology. Therefore, research into the pathogenesis of osteosarcoma is considered a priority. Circular RNAs play important roles in cell metabolism and in the immune response and are closely associated with cancer treatment. However, research into the association of circular RNAs with osteosarcoma is limited. In the present study, CircSAMD4A was validated by RT‑qPCR and agarose gel electrophoresis. CircSAMD4A and miR‑342‑3p expression was detected by RT‑qPCR. The relative protein expression levels were measured by western blot analysis. MTT assay and flow cytometry were used to detect cell cytotoxicity and apoptosis, respectively. Transwell assay was applied to assess cell migration and invasion. Dual‑luciferase reporter assay was used to determine the association among CircSAMD4A, Frizzled‑7 (FZD7) and miR‑342‑3p. In vivo, subcutaneous tumor formation assay was performed in an experiment with nude mice. The results revealed that the expression levels of CircSAMD4A and FZD7 were upregulated, while those of miR‑342‑3p were downregulated in OS tissues and cells. The inhibition of CircSAMD4A suppressed cell progression and epithelial‑mesenchymal transition (EMT), and promoted cell apoptosis in OS. The reduction of miR‑342‑3p reversed the effects of CircSAMD4A downregulation on cell cytotoxicity, migration, invasion, apoptosis and EMT in OS, while FZD7 overexpression blocked the effect of miR‑342‑3p upregulation on OS progression. The suppressive effect of sh‑CircSAMD4A on tumor growth was thus verified in OS. Overall, the present study demonstrated that CircSAMD4A affected cell cytotoxicity, invasion, apoptosis, migration and EMT by regulating the miR‑342‑3p/FDZ7 axis in OS, thereby providing a novel regulatory mechanism and a potential therapeutic target for OS.

Phenethyl Isothiocyanate Suppresses Stemness in the Chemo- and Radio-Resistant Triple-Negative Breast Cancer Cell Line MDA-MB-231/IR Via Downregulation of Metadherin

Resistance to chemotherapy and radiation therapy is considered a major therapeutic barrier in breast cancer. Cancer stem cells (CSCs) play a prominent role in chemo and radiotherapy resistance. The established chemo and radio-resistant triple-negative breast cancer (TNBC) cell line MDA-MB-231/IR displays greater CSC characteristics than the parental MDA-MB-231 cells. Escalating evidence demonstrates that metadherin (MTDH) is associated with a number of cancer signaling pathways as well as breast cancer therapy resistance, making it an attractive therapeutic target. Kaplan–Meier plot analysis revealed a correlation between higher levels of MTDH and shorter lifetimes in breast cancer and TNBC patients. Moreover, there was a positive correlation between the MTDH and CD44 expression levels in The Cancer Genome Atlas breast cancer database. We demonstrate that MTDH plays a pivotal role in the regulation of stemness in MDA-MB-231/IR cells. Knockdown of MTDH in MDA-MB-231/IR cells resulted in a reduction in the CSC population, aldehyde dehydrogenase activity, and major CSC markers, including β-catenin, CD44⁺, and Slug. In addition, MTDH knockdown increased reactive oxygen species (ROS) levels in MDA-MB-231/IR cells. We found that phenethyl isothiocyanate (PEITC), a well-known pro-oxidant phytochemical, suppressed stemness in MDA-MB-231/IR cells through ROS modulation via the downregulation of MTDH. Co-treatment of PEITC and N-Acetylcysteine (a ROS scavenger) caused alterations in PEITC induced cell death and CSC markers. Moreover, PEITC regulated MTDH expression at the post-transcriptional level, which was confirmed using cycloheximide, a protein synthesis inhibitor.

miR‑342 inhibits glioma cell proliferation by targeting GPRC5A

Accumulating evidence suggests that microRNAs (miRNAs) play a key role in the biological behaviors and progression of glioma. However, the function and bio-molecular mechanisms of miR-342 in glioma remain largely unclear. In the present study, reverse transcription quantitative-polymerase chain reaction and western blotting were performed to determine the mRNA and protein expression levels of the factors investigated. MTT assay was performed to examine the proliferation rates. Luciferase reporter assay was performed to test the binding between miRNA-342 and its putative target. Data indicated that miR-342 expression was markedly decreased in human glioma tissues and cell line U87, and reduced miR-342 expression significantly promoted cell proliferation. In order to explore the mechanisms, G-protein coupled receptor family C group 5 member A (GPRC5A) was identified as a target of miR-342 and depletion of GPRC5A suppressed cell proliferation. Our findings demonstrated that miR-342 regulates the cell proliferation of glioma by targeting GPRC5A, which indicates that miR-342 is a target of interest regarding the treatment of refractory glioma, and it may provide a promising prognostic and therapeutic strategy for glioma treatment.

Metadherin: A Therapeutic Target in Multiple Cancers

Altered expression of many genes and proteins is essential for cancer development and progression. Recently, the affected expression of metadherin (MTDH), also known as AEG-1 (Astrocyte Elevated Gene 1) and Lyric, has been implicated in various aspects of cancer progression and metastasis. Elevated expression of MTDH/AEG-1 has been reported in many cancers including breast, prostate, liver, and esophageal cancers, whereas its expression is low or absent in non-malignant tissues. These expression studies suggest that MTDH may represent a potential tumor associated antigen. MTDH also regulates multiple signaling pathways including PI3K/Akt, NF-κB, Wnt/β-catenin, and MAPK which cooperate to promote the tumorigenic and metastatic potential of transformed cells. Several microRNA have also been found to be associated with the increased MTDH expression in different cancers. Increased MTDH levels were linked to the tumor chemoresistance making it an attractive novel therapeutic target. In this review, we summarize data on MTDH function in various cancers.