[Knockdown of IGF2BP2 inhibits colorectal cancer cell proliferation, migration and promotes tumor immunity by down-regulating MYC expression].

Objective To investigate the effect of insulin-like growth factor 2 mRNA binding protein 2 (IGF2BP2) on the proliferation, migration and tumor immune microenvironment of colorectal cancer cells and its possible molecular mechanism. Methods The Cancer Genome Atlas (TCGA) database was used to analyze the expression levels of IGF2BP2 and MYC in colorectal cancer and adjacent tissues. The expression of IGF2BP2 in HCT-116 and SW480 human colorectal cancer cells was silenced by RNA interference (RNAi), and the silencing effect was detected by quantitative real-time PCR. After knocking down IGF2BP2, colony formation assay, CCK-8 assay and 5-ethynyl-2'-deoxyuridine (EdU) assay were employed to detect cell colony formation and proliferation ability. TranswellTM assay was used to detect cell migration ability. Quantitative real-time PCR was used to detect the mRNA expression of IGF2BP2, MYC, tumor necrosis factor-α (TNF-α), transforming growth factor-ß (TGF-ß) and interleukin-10 (IL-10). The protein expression of IGF2BP2 and MYC was detected by western blot. The binding ability of IGF2BP2 and MYC in HCT-116 cells was detected by quantitative real-time PCR after RNA immunoprecipitation. Results The results of TCGA database showed that the expression of IGF2BP2 and MYC in colorectal cancer tissues was significantly higher than that in adjacent tissues, and the survival time of colorectal cancer patients with high expression of IGF2BP2 was shorter. After silencing IGF2BP2, the viability, proliferation and migration of HCT-116 and SW480 cells were decreased. The mRNA expression of MYC, TGF-ß and IL-10 in IGF2BP2 knockdown group was significantly decreased, while the expression of TNF-α mRNA was increased. The expression of MYC protein and the stability of MYC mRNA were significantly decreased. RIP-qPCR results showed that IGF2BP2 could bind to MYC mRNA. Conclusion Knockdown of IGF2BP2 inhibits colorectal cancer cell proliferation, migration and promotes tumor immunity by down-regulating MYC expression.

IGF2BP2 promotes colorectal cancer progression by upregulating the expression of TFRC and enhancing iron metabolism.

BACKGROUND: Colorectal cancer (CRC) is one of the most common malignant tumors of the digestive system, ranking third for morbidity and mortality worldwide. At present, no effective control method is available for this cancer type. In tumor cells, especially iron metabolization, is necessary for its growth and proliferation. High levels of iron are an important feature to maintain tumor growth; however, the overall mechanism remains unclear. METHODS: We used western blotting, immunohistochemistry (IHC) and real-time quantitative PCR to analyze the expression of IGF2BP2 in cell lines and tissues. Further, RNA-sequencing, RNA immunoprecipitation and methylated RNA immunoprecipitation experiments explored the specific binding of target genes. Moreover, the RNA stability assay was performed to determine the half-life of genes downstream of IGF2BP2. In addition, the Cell Counting Kit-8, colony formation assay, 5-ethynyl-2'-deoxyuridine assay and flow cytometry were used to evaluate the effects of IGF2BP2 on proliferation and iron metabolism. Lastly, the role of IGF2BP2 in promoting CRC growth was demonstrated in animal models. RESULTS: We observed that IGF2BP2 is associated with iron homeostasis and that TFRC is a downstream target of IGF2BP2. Further, overexpression of TFRC can rescue the growth of IGF2BP2-knockdown CRC cells. Mechanistically, we determined that IGF2BP2 regulates TFRC methylation via METTL4, thereby regulating iron metabolism and promoting CRC growth. Furthermore, using animal models, we observed that IGF2BP2 promotes CRC growth. CONCLUSION: IGF2BP2 regulates TFRC mRNA methylation via METTL4, thereby regulating iron metabolism and promoting CRC growth. Our study highlights the key roles of IGF2BP2 in CRC carcinogenesis and the iron transport pathways.

miR-145 inhibits aerobic glycolysis and cell proliferation of cervical cancer by acting on MYC.

Nearly half a million women are diagnosed with cervical cancer (CC) each year, with the incidence of CC stabilizing or rising in low-income and middle-income countries. Cancer cells use metabolic reprogramming to meet the needs of rapid proliferation, known as the Warburg effect, but the mechanism of the Warburg effect in CC remains unclear. microRNAs (miRNAs) have a wide range of effects on gene expression and diverse modes of action, and they regulate genes for metabolic reprogramming. Dysregulation of miRNA expression leads to metabolic abnormalities in tumor cells and promotes tumorigenesis and tumor progression. In this study, we found that miR-145 was negatively correlated with metabolic reprogramming-related genes and prevented the proliferation and metastasis of CC cell lines by impeding aerobic glycolysis. A dual-luciferase reporter assay showed that miR-145 can bind to the 3'-untranslated region (3'-UTR) of MYC. Chromatin Immunoprecipitation-quantitative real-time PCR indicated that MYC was involved in the regulation of glycolysis-related genes. In addition, miR-145 mimics significantly suppressed the growth of CC cell xenograft tumor, prolonged the survival time of mice, and dramatically silenced the expression of tumor proliferation marker Ki-67. Therefore, the results suggested that miR-145 affects aerobic glycolysis through MYC, which may be a potential target for the treatment of CC.