The miR-4732-5p/XPR1 axis suppresses the invasion, metastasis, and epithelial-mesenchymal transition of lung adenocarcinoma via the PI3K/Akt/GSK3β/Snail pathway

Non-coding RNAs and regulation of the PI3K signaling pathway in lung cancer: Recent insights and potential clinical applications

Lung cancer (LC) is one of the most common causes of cancer-related death worldwide. It has been demonstrated that the prognosis of current drug treatments is affected by a variety of factors, including late stage, tumor recurrence, inaccessibility to appropriate treatments, and, most importantly, chemotherapy resistance. Non-coding RNAs (ncRNAs) contribute to tumor development, with some acting as tumor suppressors and others as oncogenes. The phosphoinositide 3-kinase (PI3Ks)/AKT serine/threonine kinase pathway is one of the most important common targets of ncRNAs in cancer, which is widely applied to modulate the cell cycle and a variety of biological processes, including cell growth, mobility survival, metabolic activity, and protein production. Discovering the biology of ncRNA-PI3K/AKT signaling may lead to advances in cancer diagnosis and treatment. As a result, we investigated the expression and role of PI3K/AKT-related ncRNAs in clinical characteristics of lung cancer, as well as their functions as potential biomarkers in lung cancer diagnosis, prognosis, and treatment.

Xenotropic and polytropic retrovirus receptor 1 (XPR1) promotes progression of papillary thyroid carcinoma via the BRAF-ERK1/2-P53 signaling pathway

BACKGROUND

Papillary thyroid carcinoma (PTC) is the most common type of thyroid cancer. Xenotropic and polytropic retrovirus receptor 1 (XPR1), identified as a cellular receptor, plays roles in many pathophysiological processes. However, the underlying function and molecular mechanisms of XPR1 in PTC remain unclear. Therefore, this study aimed to elucidate the role of XPR1 in the process of PTC and the potential mechanisms.

METHODS

RNA-sequencing was performed for gene differential expression analysis in PTC patients' tissues. Immunohistochemical assay, real-time PCR, and western blotting assay were used to determine the expression of XPR1, BRAF, and P53 in PTC tissues. The function of XPR1 on the progression of PTC was explored using in vitro and in vivo experiments. The molecular mechanism of XPR1 was investigated using gene silencing, ELISA, immunofluorescence, western blotting, and real-time PCR assays.

RESULTS

We found that XPR1 was markedly upregulated in PTC tissues compared to adjacent noncancerous tissues, suggesting that high expression of XPR1 could be correlated with poor patient disease-free survival in PTC. In addition, the expression of BRAF and P53 in PTC tissues was substantially higher than in adjacent noncancerous tissues. Silencing of XPR1 reduced the proliferation, migration, and invasion capacities of TPC-1 cells in vitro and effectively inhibited the tumorigenecity of PTC in vivo. More importantly, silencing of XPR1 in TPC-1 cells significantly decreased the expression of XPR1, BRAF, and P53 both in vitro and in vivo. Interestingly, we demonstrated that XPR1 may positively activate the BRAF-ERK-P53 signaling pathway, further promoting PTC progression.

CONCLUSION

The findings reveal a crucial role of XPR1 in PTC progression and prognosis via the BRAF-ERK1/2-P53 signaling pathway, providing potential therapeutic targets for treating PTC.

RBM15-mediated m6A modification of XPR1 promotes the malignant progression of lung adenocarcinoma

Lung adenocarcinoma (LUAD) is a leading cause of cancer-related deaths worldwide. The poor prognosis of LUAD is attributed to its aggressive biological behavior and resistance to conventional therapies. Xenotropic and polytropic retrovirus receptor 1 (XPR1), a member of the XPR family, has been implicated in the pathogenesis of various malignancies, including LUAD. However, the regulatory mechanism of XPR1 in LUAD remains elusive. The study employed immunohistochemistry (IHC) and western blotting to analyze the protein expression of XPR1, RNA binding motif protein 15 (RBM15) and nuclear proliferation marker (ki-67) in LUAD tissues and cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the mRNA expression of XPR1, glutathione peroxidase 4 (GPX4), solute carrier family 7 member 11 (SLC7A11), and RBM15. Cell proliferation was assessed using a CCK-8 assay, colony-formation assay, and 5-Ethynyl-2'-deoxyuridine assay. Cell invasion and apoptosis were evaluated through transwell assay and flow cytometry, respectively. Caspase 3 activity and Fe2+ levels were determined using colorimetric assays. Reactive oxygen species (ROS) levels were analyzed by flow cytometry. The dual-luciferase reporter assay and m6A RNA immunoprecipitation assay were performed to investigate the association between RBM15 and XPR1. An actinomycin D assay was conducted to analyze the effect of RBM15 silencing on XPR1 mRNA stability. A subcutaneous xenograft mouse model was established to validate the role of RBM15 and XPR1 in regulating the malignant behaviors of LUAD cells. Both XPR1 and RBM15 expression levels were upregulated in LUAD tissues and cells. Knockdown of XPR1 inhibited the proliferation and invasion of LUAD cells, while promoting cell apoptosis, oxidative stress, and ferroptosis. RBM15 was identified to stabilize XPR1 mRNA through m6A modification in LUAD cells. Overexpression of XPR1 attenuated the effects of RBM15 silencing on both A549 and PC-9 cells. Moreover, RBM15 silencing delayed tumor growth by regulating XPR1 in vivo. RBM15-mediated m6A modification of XPR1 promoted the malignant progression of lung adenocarcinoma. These findings provide new insights into the molecular mechanism underlying the pathogenesis of LUAD and suggest potential therapeutic strategies for the treatment of this devastating disease.

Identification of Tumor Suppressive miR-144-5p Targets: FAM111B Expression Accelerates the Malignant Phenotypes of Lung Adenocarcinoma

Accumulating evidence suggests that the passenger strands microRNAs (miRNAs) derived from pre-miRNAs are closely involved in cancer pathogenesis. Analysis of our miRNA expression signature of lung adenocarcinoma (LUAD) and The Cancer Genome Atlas (TCGA) data revealed that miR-144-5p (the passenger strand derived from pre-miR-144) was significantly downregulated in LUAD tissues. The aim of this study was to identify therapeutic target molecules controlled by miR-144-5p in LUAD cells. Ectopic expression assays demonstrated that miR-144-5p attenuated LUAD cell aggressiveness, e.g., inhibited cell proliferation, migration and invasion abilities, and induced cell cycle arrest and apoptotic cells. A total of 18 genes were identified as putative cancer-promoting genes controlled by miR-144-5p in LUAD cells based on our in silico analysis. We focused on a family with sequence similarity 111 member B (FAM111B) and investigated its cancer-promoting functions in LUAD cells. Luciferase reporter assay showed that expression of FAM111B was directly regulated by miR-144-5p in LUAD cells. FAM111B knockdown assays showed that LUAD cells significantly suppressed malignant phenotypes, e.g., inhibited cell proliferation, migration and invasion abilities, and induced cell cycle arrest and apoptotic cells. Furthermore, we investigated the FAM111B-mediated molecular networks in LUAD cells. Identifying target genes regulated by passenger strands of miRNAs may aid in the discovery of diagnostic markers and therapeutic targets for LUAD.

Tumor-derived CircRNA_102191 promotes gastric cancer and facilitates M2 macrophage polarization

BACKGROUND

Gastric cancer is a common malignant tumor of the digestive tract and the fourth leading cause of death from cancer-related diseases. In recent years, many studies have found that circular RNAs play an important role in cancer. Tumor-associated macrophages (TAMs) are also critical for tumor progression.

OBJECTIVE

This study examined the role of circRNA_102191 in gastric cancer progression.

METHODS

The relative mRNA levels were determined by qRT-PCR. Western blotting and ELISA were used to detect the protein levels. In vitro proliferation was assessed using CCK8 and clonogenic assays. The migration and invasion of cell lines were assessed by transwell-based assays. The interactions between molecules were detected using a luciferase reporter assay. M0 macrophages were induced with PMA. M1 macrophages were induced with LPS and IFN-γ, and M2 macrophages were induced with IL-4.

RESULTS

The expression of circRNA_102191 was enhanced significantly in gastric cancer cell lines and clinical tumor tissues. CircRNA_102191 promotes gastric cancer cell progression by regulating miR-493-3p and its downstream target gene XPR1. CircRNA_102191 can enhance the EMT process of gastric cancer cells by promoting the M2 polarization of macrophages.

CONCLUSION

CircRNA_102191 promotes the biological function of gastric cancer cells by regulating the miR-493-3p/XPR1 axis and M2 macrophage polarization.

miR‑4732‑5p promotes ovarian cancer mobility by targeting MCUR1

MicroRNAs (miRNAs/miRs) play critical roles in tumor progression. However, the role of miR-4732 and its underlying molecular mechanism in ovarian cancer (OC) remain unclear. In the present study, the high expression of miR-4732 was confirmed to be associated with the mortality of patients with OC following surgery, according to The Cancer Genome Atlas Ovarian Cancer database (TCGA-OV). Additionally, the expression of miR-4732 was positively associated with an increased tendency to exhibit an early TNM stage (IIA, IIB and IIC) of OC, indicating its promotional role in the early stages of tumorigenesis. By performing in vitro gain-of-function experiments, the transient transfection of IGROV1 cells with miR-4732-5p mimics enhanced cell viability according to Cell Counting Kit-8 assay, and cell migration and invasion in Transwell assays. However, though the application of loss-of-function experiments, the transient transfection of IGROV1 cells with miR-4732-5p inhibitors hindered cell viability, cell migration and invasion in vitro. Mitochondrial calcium uniporter regulator 1 (MCUR1) was validated as a downstream direct target of miR-4732-5p through bioinformatics analysis, western blotting and luciferase assays. Therefore, the results of the present study provide evidence that miR-4732-5p may promote OC cell mobility through the direct targeting of the tumor suppressor, MCUR1.

miR-4732-3p prevents lung cancer progression via inhibition of the TBX15/TNFSF11 axis

Aim: Possible roles of miRNAs in cancer treatment have been highly studied. This study aimed to elucidate the role of miR-4732-3p in lung cancer. Methods: Bioinformatics analysis was conducted to predict miR-4732-3p-related mRNA targets in lung cancer. Following interaction determination between miR-4732-3p and TBX15 as well as between TBX15 and TNFSF11, their in vitro and in vivo roles were assayed. Results: miR-4732-3p negatively targeted TBX15, which upregulated TNFSF11 by enhancing the activity of the TNFSF11 promoter. Overexpression of miR-4732-3p or silencing of TBX15 or TNFSF11 inhibited the malignant phenotype of lung cancer cells and reduced tumorigenicity in vivo. Conclusion: Overall, this study highlighted the inhibitory role of miR-4732-3p in lung cancer progression through the TBX15/TNFSF11 axis.

Gene Expression in Bronchial Epithelial Cell Responses to Vanadium Exposure

Vanadium exposure has the adverse effect on lung function in human, whereas the detailed mechanisms of vanadium exposure-induced pulmonary toxicity are limited. Hence, the present study aimed to investigate the hub genes and signaling pathways related to sodium metavanadate (SMV)-induced pulmonary toxicity. The transcript expression profile GSE36684 downloaded from Gene Expression Omnibus contained eight human bronchial epithelial cell (HBEC) samples including five SMV-treated and three control HBEC samples. Totally 455 differentially expressed genes (DEGs) were screened, especially 201 and 254 genes were up- and down-regulated in the HBECs treated with SMV. Gene ontology analysis suggested that the DEGs were mainly involved in signal transduction, the response to drug, cell proliferation, adhesion, and migration. Pathway analysis demonstrated that the DEGs were primarily participated in NF-κB, Wnt, MAPK, and PI3K-Akt signaling pathways. Moreover, the hub genes, including ITGA5, ITGB3, ITGA2, LAMC2, MMP2, and ITGA4, might contribute to SMV-induced pulmonary toxicity. Our study improves the understanding of the molecular mechanisms by which SMV induced the pulmonary toxicity.

ECM1 regulates the resistance of colorectal cancer to 5-FU treatment by modulating apoptotic cell death and epithelial-mesenchymal transition induction

5-Fluorouracil (5-FU) chemoresistance is a persistent impediment to the efficient treatment of many types of cancer, yet the molecular mechanisms underlying such resistance remain incompletely understood. Here we found CRC patients resistant to 5-FU treatment exhibited increased extracellular matrix protein 1 (ECM1) expression compared to CRC patients sensitive to this chemotherapeutic agent, and higher levels of ECM1 expression were correlated significantly with shorter overall survival and disease-free survival. 5-FU resistant HCT15 (HCT15/FU) cells expressed significantly higher levels of ECM1 relative to parental HCT15 cells. Changes in ECM1 expression altered the ability of both parental and HCT15/FU cells to tolerate the medication in vitro and in vivo via processes associated with apoptosis and EMT induction. From a mechanistic perspective, knocking down and overexpressing ECM1 in HCT15/FU and HCT15 cell lines inhibited and activated PI3K/AKT/GSK3β signaling, respectively. Accordingly, 5-FU-induced apoptotic activity and EMT phenotype changes were affected by treatment with PI3K/AKT agonists and inhibitors. Together, these data support a model wherein ECM1 regulates CRC resistance to 5-FU via PI3K/AKT/GSK3β pathway-mediated modulation of apoptotic resistance and EMT induction, highlighting ECM1 as a promising target for therapeutic intervention for efforts aimed at overcoming chemoresistance in CRC patients.

Platycodin D sensitizes KRAS-mutant colorectal cancer cells to cetuximab by inhibiting the PI3K/Akt signaling pathway

Cetuximab is a monoclonal antibody against epidermal growth factor receptor that blocks downstream signaling pathways of receptor tyrosine kinases, including Ras/Raf/MAPK and PI3K/Akt, thereby inhibiting tumor cell proliferation and inducing cancer cell apoptosis. Owing to KRAS mutations, the effectiveness of cetuximab is usually limited by intrinsic drug resistance. Continuous activation of the PI3K/Akt signaling pathway is another reason for cetuximab resistance. Platycodin-D, a bioactive compound isolated from the Chinese herb Platycodon grandiflorum, regulates Akt in different trends based on tissue types. To investigate whether platycodin-D can sensitize KRAS-mutant colorectal cancer cells to cetuximab by inhibiting the PI3K/Akt signaling pathway, HCT116 and LoVo cells were treated with cetuximab and platycodin-D. LY294002 and SC79 were used to regulate Akt to further evaluate whether platycodin-D sensitizes cells to cetuximab by inhibiting Akt. Our results confirmed that platycodin-D increased the cytotoxic effects of cetuximab, including inhibition of growth, migration, and invasion, via downregulation of PI3K and Akt phosphorylation in HCT116 and LoVo cells both in vitro and in vivo. Given these data, platycodin-D may sensitize KRAS-mutant colorectal cancer cells to cetuximab via inhibition of the PI3K/Akt signaling pathway.

Overexpression of hsa_circ_0061817 Can Inhibit the Proliferation and Invasion of Lung Cancer Cells Based on Active Compounds

Objective

This study was aimed at investigating the expression level of hsa_circ_0061817 in lung adenocarcinoma cells and its effect on cell proliferation and invasion and the possible mechanism of hsa_circ_0061817 in lung adenocarcinoma.

Methods

The overexpression plasmids of hsa_circ_0061817 (OE-hsacirc_0061817) were transfected into human lung A549 cells and mouse LLC-LUC cells, respectively. The cell viability was detected by CCK-8, and the cell proliferation was detected by cell clone formation assay and EdU assay. Transwell test was used to detect the ability of cell invasion, and apoptosis was detected by flow cytometry. WB was applied to determine the expression of apoptosis and epithelial mesenchymal transition- (EMT-) related proteins and also target proteins for observation the effect of OE-hsa_circ_0061817 on the growth of A549 cells in nude mice. Bioinformatics method was used to predict the binding microRNA (miRNA) of hsa_circ_0061817 and construct the regulatory network of competitive endogenous RNA (ceRNA) and functional analysis of miRNA target genes.

Results

Compared with PLO-ciR group, the cell viability, proliferation, and invasive ability of A549 and LLC-LUC were significantly reduced in OE-hsa_circ_00061817 group, while the apoptosis increased in OE-hsa_circ_00061817 group compared to PLO-ciR group. WB results showed that the expression of caspase 3, caspase 7, caspase 9, and E-cadherin increased significantly, while the expression levels of vimentin and N-cadherin decreased severely. Most importantly, OE-hsa_circ_00061817 inhibited the growth of A549 tumor-bearing nude mice. According to TargetScan and mirBase databases, hsa_circ_0061817 may competitively bind hsa_mir-181b-3p, hsa-mir-337-3p, hsa-mir-421, and hsa-mir-548d-3p. The results of functional enrichment showed that miRNA target genes were involved in many cancer-related biological processes, including negative regulation of apoptosis, gene expression, transcriptional imbalance in cancer, transforming growth factor-β, and P53 signal pathway.

Conclusions

Over expression of hsa_circ_0061817 inhibits the proliferation of lung adenocarcinoma A549 and LLC-LUC cells and may reduce the invasive ability of lung adenocarcinoma cells by weakening the process of EMT, which provides a new target for the prevention and treatment of lung adenocarcinoma.