MiR-124 changes the sensitivity of lung cancer cells to cisplatin through targeting STAT3

Overexpression of miR-506-3p reversed doxorubicin resistance in drug-resistant osteosarcoma cells

Background and objective: Osteosarcoma is a common primary malignant tumor of bone, and doxorubicin is one of the most widely used therapeutic drugs. While the problem of doxorubicin resistance limits the long-term treatment benefits in osteosarcoma patients. The role of miRNAs and their target genes in osteosarcoma have become increasingly prominent. Currently, there is no report on miR-506-3p reversing doxorubicin resistance by targeting STAT3 in osteosarcoma. The purpose of this study was to investigate the molecular mechanism that overexpression of miR-506-3p reverses doxorubicin resistance in drug-resistant osteosarcoma cells. Methods: Doxorubicin-resistant osteosarcoma cells (U-2OS/Dox) were constructed by intermittent stepwise increasing stoichiometry. The target genes of miR-506-3p were predicted by bioinformatics approach and the targeting relationship between miR-506-3p and STAT3 was detected using dual luciferase reporter assay. U-2OS/Dox cells were treated with miR-506-3p overexpression and STAT3 silencing respectively. Then Western blot and RT-qPCR were used to detect the protein and mRNA expression levels of JAK2/STAT3 signaling pathway, drug-resistant and apoptotic associated molecules. The migration and invasion were assessed by cell scratch assay and transwell assay. The cell proliferative viability and apoptosis were investigated by CCK8 assay and flow cytometry assay. Results: U-2OS/Dox cells were successfully constructed with a 14.4-fold resistance. MiR-506-3p is directly bound to the 3'-UTR of STAT3 mRNA. Compared with U-2OS cells, the mRNA expression of miR-506-3p was reduced in U-2OS/Dox cells. Overexpression of miR-506-3p decreased the mRNA expression levels of JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and decreased the protein expression levels of p-JAK2, STAT3, MDR1/ABCB1, MRP1/ABCC1, Survivin and Bcl-2, and conversely increased Bax expression. It also inhibited the proliferation, migration and invasion of U-2OS/Dox cells and promoted cells apoptosis. The results of STAT3 silencing experiments in the above indicators were consistent with that of miR-506-3p overexpression. Conclusion: Overexpression of miR-506-3p could inhibit the JAK2/STAT3 pathway and the malignant biological behaviors, then further reverse doxorubicin resistance in drug-resistant osteosarcoma cells. The study reported a new molecular mechanism for reversing the resistance of osteosarcoma to doxorubicin chemotherapy and provided theoretical support for solving the clinical problems of doxorubicin resistance in osteosarcoma.

Collagen type 1 alpha 1 chain is a novel predictive biomarker of poor progression-free survival and chemoresistance in metastatic lung cancer

Background: Collagen type 1 alpha 1 chain (COL1A1) is an extracellular matrix protein comprising two alpha 1 chains and one alpha 2 chain. Our previous study identified that COL1A1 is the key gene during the development and progression of lung adenocarcinoma by multi-omics analysis. However, the clinical significance of COL1A1 expression in lung cancer samples remains largely unknown. Here, we aimed to evaluate the level of COL1A1 in lung cancer samples and correlate its level with the clinical outcome.

Methods:COL1A1 gene expression in lung cancer samples was analyzed using the Oncomine database (www.oncomine.org). A total of 308 lung cancer samples (208 formalin-fixed paraffin-embedded tissues and 100 blood samples) were assessed for protein expression of COL1A1. Immunohistochemistry staining and enzyme-linked immunosorbent assay were used to detect COL1A1 expression in tissues and serum, respectively.

Results: We identified an elevation of COL1A1 in mRNA level and gene amplification in lung cancer tissues compared with normal lung tissues. High COL1A1 expression was observed in lung cancer tissues and serum (P < 0.05), it was significantly correlated with the peripheral type tumor, the larger diameter of the tumor, the occurrence of lymph node metastases and distant metastases, a higher TNM stage, and smoking (P < 0.05). High COL1A1 expression was associated with poor progression-free survival (PFS) and chemoresistance in lung cancer patients (P < 0.05). Multivariable Cox-regression analysis showed that COL1A1 expression was an independent prognostic factor (P < 0.05). Furthermore, the area under the receiver operating characteristic (AUC) curve was 0.909 for the combined COL1A1 and carcinoembryonic antigen (CEA) measurement.

Conclusion: Our findings revealed that COL1A1 could be used as a novel diagnostic, prognostic, and chemoresistance biomarker of human lung cancer, and these results provide a potential therapeutic strategy for lung cancer patients.

Tumor Suppressive Effects of miR-124 and Its Function in Neuronal Development

MicroRNA-124 (miR-124) is strongly expressed in neurons, and its expression increases as neurons mature. Through DNA methylation in the miR-124 promoter region and adsorption of miR-124 by non-coding RNAs, miR-124 expression is known to be reduced in many cancer cells, especially with high malignancy. Recently, numerous studies have focused on miR-124 due to its promising tumor-suppressive effects; however, the overview of their results is unclear. We surveyed the tumor-suppressive effect of miR-124 in glial cell lineage cancers, which are the most frequently reported cancer types involving miR-124, and in lung, colon, liver, stomach, and breast cancers, which are the top five causes of cancer death. Reportedly, miR-124 not only inhibits proliferation and accelerates apoptosis, but also comprehensively suppresses tumor malignant transformation. Moreover, we found that miR-124 exerts its anti-tumor effects by regulating a wide range of target genes, most notably STAT3 and EZH2. In addition, when compared to the original role of miR-124 in neuronal development, we found that the miR-124 target genes that contribute to neuronal maturation share similarities with genes that cause cancer cell metastasis and epithelial-mesenchymal transition. We believe that the two apparently unrelated fields, cancer and neuronal development, can bring new discoveries to each other through the study of miR-124.

Elucidating Role of Reactive Oxygen Species (ROS) in Cisplatin Chemotherapy: A Focus on Molecular Pathways and Possible Therapeutic Strategies

The failure of chemotherapy is a major challenge nowadays, and in order to ensure effective treatment of cancer patients, it is of great importance to reveal the molecular pathways and mechanisms involved in chemoresistance. Cisplatin (CP) is a platinum-containing drug with anti-tumor activity against different cancers in both pre-clinical and clinical studies. However, drug resistance has restricted its potential in the treatment of cancer patients. CP can promote levels of free radicals, particularly reactive oxygen species (ROS) to induce cell death. Due to the double-edged sword role of ROS in cancer as a pro-survival or pro-death mechanism, ROS can result in CP resistance. In the present review, association of ROS with CP sensitivity/resistance is discussed, and in particular, how molecular pathways, both upstream and downstream targets, can affect the response of cancer cells to CP chemotherapy. Furthermore, anti-tumor compounds, such as curcumin, emodin, chloroquine that regulate ROS and related molecular pathways in increasing CP sensitivity are described. Nanoparticles can provide co-delivery of CP with anti-tumor agents and by mediating photodynamic therapy, and induce ROS overgeneration to trigger CP sensitivity. Genetic tools, such as small interfering RNA (siRNA) can down-regulate molecular pathways such as HIF-1α and Nrf2 to promote ROS levels, leading to CP sensitivity. Considering the relationship between ROS and CP chemotherapy, and translating these findings to clinic can pave the way for effective treatment of cancer patients.

AKT2 drives cancer progression and is negatively modulated by miR-124 in human lung adenocarcinoma

BACKGROUND

AKT2 is highly expressed in many human cancers, including non-small cell lung cancer (NSCLC). Accumulating evidence has also revealed that AKT2 can promote NSCLC cell proliferation and metastasis. However, the involved mechanism remains unclear. Herein, our study mainly explored the function of AKT2 during cancer progression and uncovered a new post-transcriptional mechanism of AKT2 expression in lung adenocarcinoma (LUAD).

METHODS

Quantitative real-time (qRT-PCR), western blot and immunohistochemistry (IHC) assays were performed to detect the expression of AKT2 and other proteins. Cell counting kit-8 (CCK-8), colony formation and EdU assays were performed to assess cell proliferation. Flow cytometry analysis was used to detect changes in the cell cycle and apoptosis. Transwell assays were used to evaluate cell migration and invasion. Additionally, a luciferase reporter assay and western blotting were employed to assess miR-124 targeting of AKT2. Xenograft mouse model was used to observe the role of miR-124/AKT2 axis on the occurrence and development of LUAD.

RESULTS

We showed that AKT2 was highly expressed in NSCLC tissues and closely related to the poor prognosis of LUAD patients. Moreover, AKT2 affected LUAD cell proliferation, migration and invasion by regulating the cell cycle and promoting the occurrence of epithelial-mesenchymal transition (EMT) and the expression of matrix metalloproteinases (MMPs). In addition, we demonstrated that miR-124 overexpression downregulated AKT2 expression by binding to the 3'-untranslated region (3'- UTR) of AKT2 and thus inhibited the occurrence and development of LUAD in vivo and in vitro.

CONCLUSIONS

Our results suggest that miR-124 overexpression can negatively regulate AKT2 and thus inhibit the progression of LUAD. Therefore, the miR-124/AKT2 axis may serve as a potential target for novel therapies for LUAD.

MiR-29b-3p Reverses Cisplatin Resistance by Targeting COL1A1 in Non-Small-Cell Lung Cancer A549/DDP Cells

Objective

To investigate the expression of miR-29b-3p in tissues and cells of non-small-cell lung cancer (NSCLC) and its effect on cisplatin resistance in NSCLC cells and its mechanism.

Methods

The mRNA expression of miR-29b-3p and COL1A1 in NSCLC tissue, cell line A549 and cisplatin-resistant cell line A549/DDP was detected by RT-qPCR. MiR-29b-3p Mimics was transfected into A549/DDP cells, and the cell viability, proliferation, apoptosis and related protein expression were detected by CCK-8, flow cytometry and Western blot. Also, luciferase reporter gene assay was used to verify the targeting relationship between miR-29b-3p and COL1A1. Moreover, COL1A1 overexpression lentivirus and miR-29b-3p mimics (Mimics+COL1A1) were simultaneously transfected into A549/DDP cells, and then the cell viability and related protein expression were measured.

Results

In NSCLC tissue and its cell line, miR-29b-3p was downregulated and COL1A1 was upregulated (P<0.05). After A549/DDP cell was transfected by mimics, its cell viability and proliferation rate decreased, apoptosis rate and the expression of tumor suppressor gene PTEN and apoptosis-related protein BAX were increased (P<0.05), which could be reversed by Mimics+COL1A1 co-transfection. Luciferase reporter gene assay indicated that COL1A1 was the target gene of miR-29b-3p.

Conclusion

All in all, miR-29b-3p can reverse the cisplatin resistance of A549/DDP cells by inhibiting the expression of COL1A1 gene and increasing the expression of PTEN and BAX.

Chronic Regulation of miR-124-3p in the Perilesional Cortex after Experimental and Human TBI

Traumatic brain injury (TBI) dysregulates microRNAs, which are the master regulators of gene expression. Here we investigated the changes in a brain-enriched miR-124-3p, which is known to associate with major post-injury pathologies, such as neuroinflammation. RT-qPCR of the rat tissue sampled at 7 d and 3 months in the perilesional cortex adjacent to the necrotic lesion core (aPeCx) revealed downregulation of miR-124-3p at 7 d (fold-change (FC) 0.13, p < 0.05 compared with control) and 3 months (FC 0.40, p < 0.05) post-TBI. In situ hybridization confirmed the downregulation of miR-124-3p at 7 d and 3 months post-TBI in the aPeCx (both p < 0.01). RT-qPCR confirmed the upregulation of the miR-124-3p target Stat3 in the aPeCx at 7 d post-TBI (7-fold, p < 0.05). mRNA-Seq revealed 312 downregulated and 311 upregulated miR-124 targets (p < 0.05). To investigate whether experimental findings translated to humans, we performed in situ hybridization of miR-124-3p in temporal lobe autopsy samples of TBI patients. Our data revealed downregulation of miR-124-3p in individual neurons of cortical layer III. These findings indicate a persistent downregulation of miR-124-3p in the perilesional cortex that might contribute to post-injury neurodegeneration and inflammation.

Promotion of miR-221-5p on the Sensitivity of Gastric Cancer Cells to Cisplatin and Its Effects on Cell Proliferation and Apoptosis by Regulating DDR1

Purpose

This research aimed to explore the role of miR-221-5p on the sensitivity of gastric cancer cells to cisplatin, and the proliferation and invasion of gastric cancer cells by regulating DDR1.

Patients and Methods

Altogether 69 patients who treated with radical gastrectomy from January 2014 to January 2016 were collected. With the agree of the patients, 69 gastric carcinoma and 69 adjacent tissues were taken, respectively, during the operation, and gastric carcinoma and human gastric mucosa cells were purchased. RT-PCR was used for detection of the expression level of miR-221-5p and DDR1. Wound healing assay and CCK-8 assay were used for exploration of the cell migration and viability. Western blot and double luciferase reporter gene were performed to determine the target gene of miR-221-5p.

Results

It was showed that miR-221-5p expression was decreased in GC tissues and cell lines. The high expression of miR-221-5p reduced the resistance of GC cells to cisplatin and inhibited the proliferation and migration of gastric cancer cells. The high expression of miR-221-5p promoted the proliferation, invasion and migration of GC cells. In addition, we found that DDR1 was a direct target gene of miR-221-5p in GC cells. We found that DDR1 expression increased in gastric carcinoma. Moreover, there was a negative correlation of DDR1 with the expression level of miR-221-5p. The increase of miR-221-5p increased the chemosensitivity of GC cells to cisplatin, and inhibited the proliferation, invasion, migration and EMT of GC cells by targeting DDR1.

Conclusion

The above research indicated that miR-221-5p may be a target for enhancing cisplatin chemotherapy sensitivity in gastric cancer patients.

Evaluation of the Role of hsa-mir-124 in Predicting Clinical Outcome in Breast Invasive Carcinoma Based on Bioinformatics Analysis

Purpose

Breast invasive carcinoma (BRCA) is the most common malignant tumor. MiR-124 plays a tumor-suppressive role in human cancer. However, the clinical significance of miR-124 in BRCA remains unclear. The aim of this study was to evaluate the association of hsa-mir-124 expression and the clinicopathological characteristics in BRCA using database analysis.

Methods

The clinical data and expression profiles of hsa-mir-124 were obtained from the cancer genome atlas for BRCA (TCGA_BRCA). Then, the prognostic value of hsa-mir-124 in BRCA was investigated using the Cox Regression test, and the association of hsa-mir-124 and pathology TNM stages and pathologic stages were measured by the Kruskal–Wallis test and Wilcox. test. In addition, the association of hsa-mir-124 and tumor molecular phenotypes was performed using the Chi-Square test.

Results

We found that the overall survival of patients with high expression of hsa-mir-124-1 and hsa-mir-124-2 was better than that of patients with low expression of hsa-mir-124-1 and hsa-mir-124-2. And the expression of hsa-mir-124-1, hsa-mir-124-2, and hsa-mir-124-3 was mainly enriched in T1/T2 stages, NO/N1 stages, and M0 stages. Then, the expression of hsa-mir-124-1, hsa-mir-124-2, and hsa-mir-124-3 was negatively associated with tumor lymph node metastasis. Moreover, the expression of hsa-mir-124 was associated with tumor molecular phenotype in breast invasive carcinoma.

Conclusion

Our findings indicated that hsa-mir-124 expressions were associated with overall survival, TNM stages, pathologic characteristics, and tumor molecular phenotype in BRCA via TCGA_BRCA database, providing a new biomarker and a potential therapeutic target for BRCA patients.