In silico analysis and prediction of transcription factors of the proteins interacting with astrocyte elevated gene-1

AEG-1 as a Novel Therapeutic Target in Colon Cancer: A Study from Silencing AEG-1 in BALB/c Mice to Large Data Analysis

BACKGROUND

Astrocyte elevated gene-1 (AEG-1) is overexpressed in various malignancies. Exostosin-1 (EXT-1), a tumor suppressor, is an intermediate for malignant tumors. Understanding the mechanism behind the interaction between AEG-1 and EXT-1 may provide insights into colon cancer metastasis.

METHODS

AOM/DSS was used to induce tumor in BALB/c mice. Using an in vivo-jetPEI transfection reagent, transient transfection of AEG-1 and EXT-1 siRNAs were achieved. Histological scoring, immunohistochemical staining, and gene expression studies were performed from excised tissues. Data from the Cancer Genomic Atlas and GEO databases were obtained to identify the expression status of AEG-1 and itsassociation with the survival.

RESULTS

In BALB/c mice, the AOM+DSS treated mice developed necrotic, inflammatory and dysplastic changes in the colon with definite clinical symptoms such as loss of goblet cells, colon shortening, and collagen deposition. Administration of AEG-1 siRNA resulted in a substantial decrease in the disease activity index. Mice treated with EXT-1 siRNA showed diffusely reduced goblet cells. In vivo investigations revealed that PTCH-1 activity was influenced by upstream gene AEG-1, which in turn may affect EXT-1 activity. Data from The Cancer Genomic Atlas and GEO databases confirmed the upregulation of AEG-1 and downregulation of EXT-1 in cancer patients.

CONCLUSIONS

This study revealed that AEG-1 silencing might alter EXT-1 expression indirectly through PTCH-1, influencing cell-ECM interactions, and decreasing dysplastic changes, proliferation and invasion.

RNA-Interference-Mediated miR-122-Based Gene Regulation in Colon Cancer, a Structural In Silico Analysis

The role of microRNA 122 (miR-122) in colorectal cancer (CRC) has not been widely investigated. In the current study, we aimed to identify the prominent gene and protein interactors of miR122 in CRC. Based on their binding affinity, these targets were chosen as candidate genes for the creation of miR122-mRNA duplexes. Following this, we examined the miRNA-mediated silencing mechanism using the gene-silencing complex protein Argonaute (AGO). Public databases, STRING, and GeneMANIA were utilized to identify major proteins and genes interacting with miR-122. DAVID, PANTHER, UniProt, FunRich, miRwalk, and KEGG were used for functional annotation, pathway enrichment, binding affinity analysis, and expression of genes in different stages of cancer. Three-dimensional duplexes of hub genes and miR-122 were created using the RNA composer, followed by molecular interaction analysis using molecular docking with the AGO protein. We analyzed, classified, and scrutinized 93 miR-122 interactors using various bioinformatic approaches. A total of 14 hub genes were categorized as major interactors of miR-122. The study confirmed the role of various experimentally documented miR-122 interactors such as MTDH (Q86UE4), AKT1 (P31749), PTPN1 (P18031), MYC (P01106), GSK3B (P49841), RHOA (P61586), and PIK3CG (P48736) and put forth several novel interactors, with AKT3 (Q9Y243), NCOR2 (Q9Y618), PIK3R2 (O00459), SMAD4 (P61586), and TGFBR1 (P36897). Double-stranded RNA duplexes of the strongest interactors were found to exhibit higher binding affinity with AGO. In conclusions, the study has explored the role of miR-122 in CRC and has identified a closely related group of genes influencing the prognosis of CRC in multiple ways. Further, these genes prove to be targets of gene silencing through RNA interference and might serve as effective therapeutic targets in understanding and 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.

Emerging Role and Clinicopathological Significance of AEG-1 in Different Cancer Types: A Concise Review

Tumor breakthrough is driven by genetic or epigenetic variations which assist in initiation, migration, invasion and metastasis of tumors. Astrocyte elevated gene-1 (AEG-1) protein has risen recently as the crucial factor in malignancies and plays a potential role in diverse complex oncogenic signaling cascades. AEG-1 has multiple roles in tumor growth and development and is found to be involved in various signaling pathways of: (i) Ha-ras and PI3K/AKT; (ii) the NF-κB; (iii) the ERK or mitogen-activated protein kinase and Wnt or β-catenin and (iv) the Aurora-A kinase. Recent studies have confirmed that in all the hallmarks of cancers, AEG-1 plays a key functionality including progression, transformation, sustained angiogenesis, evading apoptosis, and invasion and metastasis. Clinical studies have supported that AEG-1 is actively intricated in tumor growth and progression which includes esophageal squamous cell, gastric, colorectal, hepatocellular, gallbladder, breast, prostate and non-small cell lung cancers, as well as renal cell carcinomas, melanoma, glioma, neuroblastoma and osteosarcoma. Existing studies have reported that AEG-1 expression has been induced by Ha-ras through intrication of PI3K/AKT signaling. Conversely, AEG-1 also activates PI3K/AKT pathway and modulates the defined subset of downstream target proteins via crosstalk between the PI3K/AKT/mTOR and Hedgehog signaling cascade which further plays a crucial role in metastasis. Thus, AEG-1 may be employed as a biomarker to discern the patients of those who are likely to get aid from AEG-1-targeted medication. AEG-1 may play as an effective target to repress tumor development, occlude metastasis, and magnify the effectiveness of treatments. In this review, we focus on the molecular mechanism of AEG-1 in the process of carcinogenesis and its involvement in regulation of crosstalk between the PI3K/AKT/mTOR and Hedgehog signaling. We also highlight the multifaceted functions, expression, clinicopathological significance and molecular inhibitors of AEG-1 in various cancer types.