MicroRNA-934 facilitates cell proliferation, migration, invasion and angiogenesis in colorectal cancer by targeting B-cell translocation gene 2

A Phase II Exploratory Study to Identify Biomarkers Predictive of Clinical Response to Regorafenib in Patients with Metastatic Colorectal Cancer Who Have Failed First-Line Therapy

Single-agent regorafenib is approved in Canada for metastatic colorectal cancer (mCRC) patients who have failed previous lines of therapy. Identifying prognostic biomarkers is key to optimizing therapeutic strategies for these patients. In this clinical study (NCT01949194), we evaluated the safety and efficacy of single-agent regorafenib as a second-line therapy for mCRC patients who received it after failing first-line therapy with an oxaliplatin or irinotecan regimen with or without bevacizumab. Using various omics approaches, we also investigated putative biomarkers of response and resistance to regorafenib in metastatic lesions and blood samples in the same cohort. Overall, the safety profile of regorafenib seemed similar to the CORRECT trial, where regorafenib was administered as ≥ 2 lines of therapy. While the mutational landscape showed typical mutation rates for the top five driver genes (APC, KRAS, BRAF, PIK3CA, and TP53), KRAS mutations were enriched in intrinsically resistant lesions. Additional exploration of genomic-phenotype associations revealed several biomarker candidates linked to unfavorable prognoses in patients with mCRC using various approaches, including pathway analysis, cfDNA profiling, and copy number analysis. However, further research endeavors are necessary to validate the potential utility of these promising genes in understanding patients' responses to regorafenib treatment.

The ATF2/miR-3913-5p/CREB5 axis is involved in the cell proliferation and metastasis of colorectal cancer

Various miRNAs have been shown to participate in the tumor progression and development of colorectal cancer (CRC). However, the role of miR-3913-5p in CRC are yet to be clearly defined. In the present study, we determine that miR-3913-5p is downregulated in CRC cell lines and CRC tissues. Exogenous miR-3913-5p expression weakens the CRC cells growth, migration and invasion. Mechanistically, miR-3913-5p directly targets the 3'UTR of CREB5. Overexpression of CREB5 reverses the suppression of CRC cells proliferation, migration and invasion induced by miR-3913-5p. Furthermore, ATF2 negatively regulates the transcription of miR-3913-5p by binding to its promoter. CREB5 can cooperate with ATF2. CREB5 is required for ATF2 in regulating miR-3913-5p. Finally, inverse correlations can be found between the expressions of miR-3913-5p and CREB5 or ATF2 in CRC tissues. Thus, a plausible mechanism of ATF2/miR-3913-5p/CREB5 axis regulating CRC progression is elucidated. Our findings suggest that miR-3913-5p functions as a tumor suppressor in CRC. ATF2/miR-3913-5p/CREB5 axis might be a potential therapeutic target against CRC progression.

Metastasis organotropism in colorectal cancer: advancing toward innovative therapies

Distant metastasis remains a leading cause of mortality among patients with colorectal cancer (CRC). Organotropism, referring to the propensity of metastasis to target specific organs, is a well-documented phenomenon in CRC, with the liver, lungs, and peritoneum being preferred sites. Prior to establishing premetastatic niches within host organs, CRC cells secrete substances that promote metastatic organotropism. Given the pivotal role of organotropism in CRC metastasis, a comprehensive understanding of its molecular underpinnings is crucial for biomarker-based diagnosis, innovative treatment development, and ultimately, improved patient outcomes. In this review, we focus on metabolic reprogramming, tumor-derived exosomes, the immune system, and cancer cell-organ interactions to outline the molecular mechanisms of CRC organotropic metastasis. Furthermore, we consider the prospect of targeting metastatic organotropism for CRC therapy.

Heterogeneous nuclear ribonucleoprotein U-actin complex derived from extracellular vesicles facilitates proliferation and migration of human coronary artery endothelial cells by promoting RNA polymerase II transcription

Coronary artery disease (CAD) represents a fatal public threat. The involvement of extracellular vesicles (EVs) in CAD has been documented. This study explored the regulation of embryonic stem cells (ESCs)-derived EVs-hnRNPU-actin complex in human coronary artery endothelial cell (HCAEC) growth. Firstly, in vitro HCAEC hypoxia models were established. EVs were extracted from ESCs by ultracentrifugation. HCAECs were treated with EVs and si-VEGF for 24 h under hypoxia, followed by assessment of cell proliferation, apoptosis, migration, and tube formation. Uptake of EVs by HCAECs was testified. Additionally, hnRNPU, VEGF, and RNA Pol II levels were determined using Western blotting and CHIP assays. Interaction between hnRNPU and actin was evaluated by Co-immunoprecipitation assay. HCAEC viability and proliferation were lowered, apoptosis was enhanced, wound fusion was decreased, and the number of tubular capillary structures was reduced under hypoxia, whereas ESC-EVs treatment counteracted these effects. Moreover, EVs transferred hnRNPU into HCAECs. EVs-hnRNPU-actin complex increased RNA Pol II level on the VEGF gene promoter and promoted VEGF expression in HCAECs. Inhibition of hnRNPU or VEGF both annulled the promotion of EVs on HCAEC growth. Collectively, ESC-EVs-hnRNPU-actin increased RNA Pol II phosphorylation and VEGF expression, thus promoting HCAEC growth.

Elevated BTG2 improves the radiosensitivity of non-small cell lung cancer (NSCLC) through apoptosis

BACKGROUND

To identify radio-responsive genes and explore the biological function of encoded proteins in non-small cell lung cancer (NSCLC).

METHODS

Radio-responsive genes in irradiated H460 cells were screened from microarray data deposited in the Gene Expression Omnibus (GEO) database. A quantitative real time polymerase chain reaction assay was used to detect the expression of candidate radio-responsive genes in irradiated cells. CCK-8 assay, EDU assay, clone formation assay, immunofluorescence and flow cytometry were conducted to evaluate the biological function of B cell translocation gene 2 (BTG2) in NSCLC.

RESULTS

Bioinformatic analysis using GES20549 showed that BTG2 was a radio-responsive gene in irradiated H460 cells. The mRNA expression level of BTG2 was lower in H460 cells compared with that in BEAS-2B normal lung epithelial cells. BTG2 expression was elevated upon IR exposure, in a dose-dependent but not a time-dependent manner. CCK-8 and EDU assays revealed that BTG2 overexpression inhibited the growth rate of irradiated cells. Clone formation showed that elevated BTG2 promoted DNA damage of irradiated H460 cells. The number of γ-H2AX foci induced by DNA damage was also markedly increased upon BTG2 overexpression. Flow cytometry showed that BTG2 increased IR-induced cell apoptosis.

CONCLUSIONS

BTG2 may be a novel radio-responsive factor and a promising therapeutic target for radiotherapy of NSCLC.

MicroRNA-486-5p functions as a diagnostic marker for carotid artery stenosis and prevents endothelial dysfunction through inhibiting inflammation and oxidative stress

Carotid artery stenosis (CAS) can cause ischemic stroke, and clinical intervention for CAS is critical clinically. The purpose of this study was to explore the expression changes of microRNA-486-5p in the serum of patients with CAS and its possible mechanism. Ninety-one cases with asymptomatic CAS were recruited, and serum levels of miR-486-5p were measured using RT-qPCR. The diagnostic ability was evaluated by drawing the receiver operating characteristic (ROC) curve. Human aortic endothelial cells (HAECs) were treated with oxidized low-density lipoprotein (oxLDL) to establish cell model, and cell proliferation and apoptosis were tested. The markers of cell inflammation and oxidative stress were detected via ELISA. The target gene was analyzed using bioinformatics analysis combined with luciferase reporting assay. CAS cases exhibited significantly low serum miR-486-5p levels in comparison with the control group and can identify asymptomatic CAS. Serum miR-486-5p manifested a negative correlation with the degree of carotid stenosis. Underexpression of miR-486-5p was also detected in ox-LDL treated HAECs. OxLDL treatment contributes to inflammatory response and oxidative stress of HAECs; however, these adverse impacts caused by ox-LDL were reversed by miR-486-5p upregulation. NFAT5 was confirmed to be the target gene of miR-486-5p in HAECs. MiR-486-5p serves as a promising biomarker for the early identification of CAS. Overexpression of miR-486-5p can prevent endothelial dysfunction, and the mechanism might be related to anti-inflammation and anti-oxidation via targeting NFAT5.

Expression and methylation status of BTG2, PPP1CA, and PEG3 genes in colon adenocarcinoma cell lines: promising treatment targets

Aim

This study investigated the association between methylation status and expression levels of BTG2, PPP1CA, and PEG3 genes in colon cancer.

Background

Aberrant DNA methylation is one of the most important epigenetic modifications in the development of cancer. Evidence indicates that hypermethylation of various tumor suppressor genes could be a potential mechanism of colon tumorigenesis.

Methods

The expression levels of BTG2, PPP1CA, and PEG3 genes were evaluated in HT-29/219, HCT116, SW48, SW742, SW480, and LS180 cell lines using quantitative Real-Time PCR. The methylation status of BTG2 and PPP1CA was determined by methylation-specific PCR (MSP) method, and the methylation pattern of PEG3 was evaluated by bisulfite sequencing PCR (BSP). To investigate the effect of methylation on the expression of these genes, all colon cancer cell lines were treated by 5-Azacitidine (5-Aza) and/or Trichostatin A (TSA).

Results

The expression levels of BTG2, PPP1CA, and PEG3 were highly heterogeneous and quantitatively correlated to their promoter methylation status in the studied colon cancer cell lines. Treatment by 5-Aza and/or TSA increased the expression of the above-named genes in colon cancer cell lines.

Conclusion

Overall, it seems that BTG2, PPP1CA, and PEG3 act as tumor suppressor genes in colon cancer, and methylation is a potential mechanism for their loss of expression. Therefore, these genes may be considered as suitable targets for demethylation approaches and, eventually, colon cancer treatment. Combined treatment by 5-Aza and TSA may be a promising therapeutic strategy for colon cancer treatment. Further studies may contribute to confirm these results.