MicroRNAs (miRNAs) are small noncoding RNAs that potentially play a critical role in tumorigenesis. Mounting evidence indicates that one specific miRNA: miR-320b is down regulated in numerous human cancers, including colorectal cancer (CRC); making the hypothesis that miR-320b may play a key role in tumorigenesis plausible. However, its role in carcinogenesis remains poorly defined. The goal of this study is to better clarify the role of miR-320b in tumor growth of CRC. Quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was conducted to detect the expression of miR-320b in CRC tissues and 5 CRC cell lines. The effect of miR-320b on cell proliferation was analyzed in vitro and in vivo. Furthermore, a luciferase reporter assay was performed to measure the target effects of miR-320b. Lastly, the messenger RNA (mRNA) and protein levels of the gene c-MYC were measured in CRC cell lines and tissues by qRT-PCR, and confirmed via Western blot and Immunohistochemical (IHC) staining. The results presented here showed that miR-320b expression was down regulated in both CRC tissues and cells. Overexpression of miR-320b in CRC cells was statistically correlated with a decrease of cell growth in vitro and in vivo, while c-MYC was identified as a target gene of miR-320b in CRC. Furthermore, it was found that up-regulation of c-Myc can attenuate the effects induced by miR-320b. Our identification of c-MYC as a target gene of miR-320b provides new insights into the pathophysiology of CRC proliferation, and identifies miR-320b as a novel therapeutic target for the treatment of CRC.

Colorectal cancer (CRC) is one of the most commonly diagnosed malignant tumors of the digestive tract. H2-calponin (CNN2), an actin cytoskeleton-binding protein, is an isoform of the calponin protein family whose role in CRC is still unknown. Research based on clinical samples showed the up-regulation of CNN2 in CRC and its association with tumor development, metastasis, and poor prognosis of patients. Both in vitro loss-of-function and gain-of-function experiments showed that CNN2 participates in CRC development through influencing malignant cell phenotypes. In vivo, xenografts formed by CNN2 knockdown cells also showed a slower growth rate and smaller final tumors. Furthermore, EGR1 was identified as a downstream of CNN2, forming a complex with CNN2 and YAP1 and playing an essential role in the CNN2-induced regulation of CRC development. Mechanistically, CNN2 knockdown down-regulated EGR1 expression through enhancing its ubiquitination, thus decreasing its protein stability in a YAP1-dependent manner. In summary, CNN2 plays an EGR1-dependent promotion role in the development and progression of CRC, which may be a promising therapeutic target for CRC treatment.

Colorectal cancer (CRC) remains a significant health challenge globally, demanding a comprehensive understanding of its molecular underpinnings for effective management. In this study, we investigated the role of Aldolase C (ALDOC), a glycolytic enzyme, in CRC pathogenesis. Transcriptomic analysis of CRC tissues from The Cancer Genome Atlas (TCGA) revealed a substantial upregulation of ALDOC, correlating with adverse clinical outcomes. Immunohistochemical (IHC) staining of locally collected patient-derived tissues corroborated these findings, demonstrating elevated ALDOC expression in tumor tissues, particularly in advanced stages. Functional studies elucidated the regulatory role of ALDOC in CRC cell phenotypes. ALDOC knockdown significantly inhibited cell proliferation, induced apoptosis, arrested cell cycle progression, and suppressed cell migration in vitro. Moreover, in vivo studies using xenograft models confirmed that ALDOC knockdown attenuated tumor growth. Mechanistically, ALDOC was found to interact with hypoxia-inducible factor 1 alpha (HIF1A) and enhance its transcriptional activity on phosphoglycerate kinase 1 (PGK1), a key glycolytic enzyme. Dual-luciferase reporter assays and chromatin immunoprecipitation experiments validated the ALDOC-mediated transcriptional activation of PGK1. Further functional rescue experiments revealed a synergistic interplay between ALDOC and PGK1 in regulating CRC cell phenotypes. Additionally, ALDOC was implicated in promoting aerobic glycolysis in CRC cells, potentially through PGK1 regulation. Collectively, our findings unveil ALDOC as a critical regulator of CRC pathogenesis, offering insights into its potential as a therapeutic target and highlighting the ALDOC/PGK1 axis as a promising avenue for further investigation in CRC.