MiR-519d reduces the 5-fluorouracil resistance in colorectal cancer cells by down-regulating the expression of CCND1

High Expression of F-Box Protein 43 Is Associated With Poor Prognosis and Adjuvant Chemotherapy Resistance in Colorectal Cancer

BACKGROUND

The F-box protein 43 (FBXO43), also referred to as endogenous meiotic inhibitor 2 (EMI2), has been linked to the advancement of various types of cancer, such as hepatocellular carcinoma, breast cancer, cholangiocarcinoma, and gastric cancer. Nevertheless, the precise function of FBXO43 in colorectal cancer (CRC) remains unclear. This study employed data from The Cancer Genome Atlas (TCGA) and clinical specimens to analyze the expression, prognostic value, and chemotherapeutic advantages of FBXO43 in CRC.

METHODS

Level 3 RNA sequencing data pertaining to 631 cases of colon and rectal adenocarcinomas (COAD-READ) were downloaded from TCGA. The data were utilized to analyze the expression, prognosis, and related signal pathways of FBXO43. The expression of FBXO43 in clinical samples was subsequently confirmed through the use of real-time quantitative polymerase chain reaction (qPCR) and immunohistochemistry (IHC). Lastly, a tissue microarray (TMA) consisting of 120 cases of CRC and corresponding normal tissues was established to investigate the relationship between FBXO43 and survival outcomes.

RESULTS

Results from both the TCGA analysis and clinical samples indicated that FBXO43 was significantly upregulated in CRC tissues in comparison to normal tissues. Moreover, high level of FBXO43 was found to be relevant to malignant clinical features, such as differentiation, lymph node metastasis, and pathological stage, as well as unfavorable prognosis in CRC patients. Subgroup analysis further demonstrated that FBXO43 could be an effective parameter for stratifying low-risk CRC patients. Notably, survival analysis showed that patients with high level of FBXO43 had worse overall survival (OS) and disease-free survival (DFS) following adjuvant chemotherapy, and FBXO43 was distinctly upregulated in chemotherapy-resistant patients' primary CRC tissues.

CONCLUSIONS

FBXO43 was upregulated and associated with poor prognosis of CRC; patients with high expression of FBXO43 may not be benefit from adjuvant chemotherapy.

A Crosstalk between Diet, Microbiome and microRNA in Epigenetic Regulation of Colorectal Cancer

A still growing interest between human nutrition in relation to health and disease states can be observed. Dietary components shape the composition of microbiota colonizing our gastrointestinal tract which play a vital role in maintaining human health. There is a strong evidence that diet, gut microbiota and their metabolites significantly influence our epigenome, particularly through the modulation of microRNAs. These group of small non-coding RNAs maintain cellular homeostasis, however any changes leading to impaired expression of miRNAs contribute to the development of different pathologies, including neoplastic diseases. Imbalance of intestinal microbiota due to diet is primary associated with the development of colorectal cancer as well as other types of cancers. In the present work we summarize current knowledge with particular emphasis on diet-microbiota-miRNAs axis and its relation to the development of colorectal cancer.

5-Fluorouracil: A Narrative Review on the Role of Regulatory Mechanisms in Driving Resistance to This Chemotherapeutic Agent

5-fluorouracil (5-FU) is among the mostly administrated chemotherapeutic agents for a wide variety of neoplasms. Non-coding RNAs have a central impact on the determination of the response of patients to 5-FU. These transcripts via modulation of cancer-related pathways, cell apoptosis, autophagy, epithelial-mesenchymal transition, and other aspects of cell behavior can affect cell response to 5-FU. Modulation of expression levels of microRNAs or long non-coding RNAs may be a suitable approach to sensitize tumor cells to 5-FU treatment via modulating multiple biological signaling pathways such as Hippo/YAP, Wnt/β-catenin, Hedgehog, NF-kB, and Notch cascades. Moreover, there is an increasing interest in targeting these transcripts in various kinds of cancers that are treated by 5-FU. In the present article, we provide a review of the function of non-coding transcripts in the modulation of response of neoplastic cells to 5-FU.

A Direct and Sensitive Method for Determination of 5-Fluorouracil in Colorectal Cancer Cells: Evaluating the Effect of Stromal Cell on Drug Resistance of Cancer Cells

Fibroblasts in the stroma play a critical role in tumor evolution. In this study, we assessed the influence of colonic fibroblasts on colon cancer cells treated with 5-fluorouracil (5-FU), and mouse colon cancer cell lines MC38 and colonic fibroblasts NIH3T3 were used in this study. A sensitive and rapid UHPLC-MS/MS method for the quantitation of 5-FU from the cell and their medium has been successfully developed and validated. The cells were lysed with methanol, and the mixture was evaporated and then redissolved to extract intracellular 5-FU. The analysis was performed on UHPLC-MS/MS using an Atlantis T3-C18 column (3 μm, 2. 1 ∗ 100 mm) and gradient elution with acetonitrile and 0.1% formic acid in water. Method validation included the following parameters: the matrix effect range 88.82%-93.64% and the recovery range 93.52%-94.56%. The intraday and interday precision and accuracy were <11% and within ±6%, and the stability, specificity, carry-over, dilution effect, and linearity all conformed to the criteria. The method was applied to detect the concentration of 5-FU inside cells and cell culture medium. The preliminary results present that NIH3T3 could enhance the drug resistance of MC38 to 5-FU with a decreased intracellular concentration of 5-FU in MC38, which showed a positive relationship with NIH3T3 number.

LncRNA BLACAT1/miR-519d-3p/CREB1 Axis Mediates Proliferation, Apoptosis, Migration, Invasion, and Drug-Resistance in Colorectal Cancer Progression

BACKGROUND

Colorectal cancer (CRC) is a common severe disease around the world. The merging papers reported that long noncoding RNAs (lncRNAs) took part in the diversified pathological processes of CRC. This study aimed to uncover the role and the potential mechanism of lncRNA bladder cancer-associated transcript 1 (BLACAT1) in CRC progression.

METHODS

LncRNA BLACAT1, micro-519d-3p (miR-519d-3p), and cAMP-responsive element binding protein 1 (CREB1) levels were detected by quantitative real-time polymerase chain reaction (qRT-PCR) in CRC tissues and cells. The bio-functional effects were examined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), flow cytometry assay, and transwell assay. The susceptibility testing was determined by oxaliplatin (OXA) administration. The potential binding sites between miR-519d-3p and BLACAT1 or CREB1 were predicted by online software starBase and confirmed by dual-luciferase reporter analysis. The relative proteins expression in CRC cells was determined by Western blot analysis. Xenograft tumor model was used to evaluate biological function of BLACAT1 in vivo.

RESULTS

The expression of BLACAT1 was promoted in CRC tissues and cells, and correlated to the TNM (tumor, node, metastasis) stage, distant metastasis, and overall survival rate. Silencing of BLACAT1 limited the proliferation, migration, and invasion, facilitated the apoptosis, and re-sensitized OXA-resistance in CRC cells. MiR-519d-3p was a target of BLACAT1. Furthermore, miR-519d-3p deletion reversed the positive effects of BLACAT1 deletion on CRC cells. Moreover, our data showed that miR-519d-3p directly targeted CREB1 and BLACAT1 sponged miR-519d-3p to regulate CREB1 expression. Besides, CREB1 disrupted the bio-functional results above from BLACAT1 suppression. Additionally, BLACAT1 knockdown promoted CRC cells sensitivity to OXA in vivo.

CONCLUSION

BLACAT1 mediated the progression of CRC and OXA-resistance by miR-519d-3p/CREB1 axis.

Long non-coding RNA LINC00460 predicts poor survival and promotes cell viability in pancreatic cancer

Emerging evidence has demonstrated that long non-coding RNAs (lncRNAs) possess great potential as vital biomarkers and powerful therapeutic targets in various diseases. In the present study, differentially expressed transcripts in pancreatic cancer (PC) were identified, and a competing endogenous RNA (ceRNA) network was constructed using The Cancer Genome Atlas database. An independent cohort consisting of 59 patients with PC was used to validate the clinical value of the identified lncRNA. Cell viability and colony formation assays were used to evaluate the biological functions of the lncRNA in PC cells. The present bioinformatic analysis revealed that LINC00460 was upregulated in PC samples with a prognostic significance. In the ceRNA network, it potentially targeted the microRNA-503/cyclin D1 axis. The results of real-time quantitative PCR confirmed that LINC00460 was significantly upregulated in cancer tissues and was associated with poor survival of patients with PC. The expression levels of LINC00460 were significantly associated with tumor size, but not with age, sex, differentiation, lymph node metastasis, vascular invasion and tumor stage. Through univariate and multivariate analysis, LINC00460 was characterized as an independent prognostic biomarker for PC. Further in vitro experiments demonstrated that suppressing LINC00460 using small interfering RNA inhibited viability and colony formation of PC cells. In summary, LINC00460 may be an independent prognostic biomarker for PC and may serve as an oncogenic lncRNA that promotes PC cell growth. Further in-depth exploration is required to reveal the specific biological mechanism of LINC00460 in PC cells.

MicroRNA‑628‑5p inhibits cell proliferation and induces apoptosis in colorectal cancer through downregulating CCND1 expression levels

MicroRNA (miR)-628-5p serves as an antitumor gene in a variety of cancers; however, the role of miR-628-5p in colorectal cancer remains largely unclear. The purpose of this study was to investigate the role and mechanism of miR-628-5p in colorectal cancer. Reverse transcription-quantitative PCR (RT-qPCR), colony formation assays and flow cytometric analysis were used to determine the expression levels of miR-628-5p in colorectal cancer tissues and cell lines, and the proliferative ability of colorectal cancer cells. TargetScan version 7.2 and dual-luciferase reporter assay were performed to predict and confirm miR-628-5p target genes. The expression levels of cyclin D1 (CCND1) and related genes were determined using RT-qPCR or/and western blotting analysis. miR-628-5p mimics and CCND1 plasmids were used to overexpress miR-628-5p and CCND1; it was demonstrated that the expression levels of miR-628-5p were significantly downregulated in colorectal cancer tissues and cell lines. miR-628-5p mimic-transfected cells inhibited the proliferation and induced apoptosis of HT-29 cells. CCND1, a downstream effector of miR-628-5p, promoted the proliferation and suppressed apoptosis of HT-29 cells, and the effects were reversed by miR-628-5p mimics. In conclusion, the present study suggested that colorectal cancer progression may be regulated through the miR-628-5p/CCND1 axis, and miR-628-5p could be used as a potential diagnostic and prognostic biomarker for colorectal cancer.

miR-1271 enhances the sensitivity of colorectal cancer cells to cisplatin

The high mortality of colorectal cancer (CRC) is likely caused by early invasion and metastasis. The chemoresistance of tumor cells is the critical reason for treatment failure. The present study aimed to develop targeted solutions to overcome chemotherapy drug resistance in CRC. CCK-8 assay was used to examine SW480 cell viability. SW480 cell apoptosis was examined using flow cytometry. The present study demonstrated that the expression of miR-1271 was significantly decreased in CRC tumors and cell lines compared with control tissues. Furthermore, the expression of microRNA (miR)-1271 was increased and decreased following the transfection of miR-1271 mimics and an inhibitor, respectively. Furthermore, miR-1271 regulated mammalian target of rapamycin (mTOR) expression by directly binding to the mTOR 3'-untranslated region and the relative luciferase activity of mTOR was decreased following miR-1271 overexpression. The results of the present study indicate that miR-1271 may be a potential target for anti-CRC therapy, particularly in the sensitivity of chemotherapeutic drugs. miR-1271 may therefore enhance the sensitivity of CRC cells to chemotherapy drugs and provide a novel approach for the gene therapy of CRC.