Bioinformatic analysis reveals an exosomal miRNA-mRNA network in colorectal cancer

The facilitating effects of KRT80 on chemoresistance, lipogenesis, and invasion of esophageal cancer

Keratin 80 (KRT80) is a filament protein that makes up one of the major structural fibers of epithelial cells, and involved in cell differentiation and epithelial barrier integrity. Here, KRT80 mRNA expression was found to be higher in esophageal cancer than normal epithelium by RT-PCR and bioinformatics analysis (p < .05), opposite to KRT80 methylation (p < .05). There was a negative relationship between promoter methylation and expression level of KRT80 gene in esophageal cancer (p < .05). KRT80 mRNA expression was positively correlated with the differentiation, infiltration of immune cells, and poor prognosis of esophageal cancer (p < .05). KRT80 mRNA expression was positively linked to no infiltration of immune cells, the short survival time of esophageal cancers (p < .05). The differential genes of KRT80 mRNA were involved in fat digestion and metabolism, peptidase inhibitor, and intermediate filament, desosome, keratinocyte differentiation, epidermis development, keratinization, ECM regulator, complement cascade, metabolism of vitamins and co-factor (p < .05). KRT-80-related genes were classified into endocytosis, cell adhesion molecule binding, cadherin binding, cell-cell junction, cell leading edge, epidermal cell differentiation and development, T cell differentiation and receptor complex, plasma membrane receptor complex, external side of plasma membrane, metabolism of amino acids and catabolism of small molecules, and so forth (p < .05). KRT80 knockdown suppressed anti-apoptosis, anti-pyroptosis, migration, invasion, chemoresistance, and lipogenesis in esophageal cancer cells (p < .05), while ACC1 and ACLY overexpression reversed the inhibitory effects of KRT80 on lipogenesis and chemoresistance. These findings indicated that up-regulated expression of KRT80 might be involved in esophageal carcinogenesis and subsequent progression, aggravate aggressive phenotypes, and induced chemoresistance by lipid droplet assembly and ACC1- and ACLY-mediated lipogenesis.

miRNA‑mRNA network contributes to HBV‑related hepatocellular carcinoma via immune infiltration induced by GRB2

Chronic hepatitis B virus (HBV) infection is a critical causative factor in the tumorigenesis and progression of hepatocellular carcinoma (HCC). MicroRNAs (miRNAs) serve a critical role in the process of viral infection. However, there has been insufficient evaluation of HBV-associated miRNA-mRNA regulatory networks in HCC. The differential expression levels of miRNAs were compared in HBV-associated HCC tumor and normal tissues using the Gene Expression Omnibus database. The present study evaluated potential target genes of differentially expressed miRNAs using protein-protein interaction network, hub gene, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment and immune infiltration analysis. A total of five miRNAs and seven target genes were identified in the HBV-associated miRNA-mRNA network. miRNA-93 could positively regulate the growth factor receptor bound protein 2 (GRB2) gene, while there was a positive correlation between GRB2 and cancer immune infiltrate function in Tumor Immune Estimation Resource. Collectively, the present study investigated the miRNA-mRNA regulatory network in HCC with HBV infection and showed that miRNA-93 positively regulated immune infiltration-related GRB2. Restoring GRB2 may be a candidate strategy for the treatment of HBV-related HCC.

A comprehensive insight into the immunomodulatory role of MSCs-derived exosomes (MSC-Exos) through modulating pattern-recognition receptors (PRRs)

Mesenchymal stem cell-derived exosomes (MSC-Exos) are emerging as remarkable agents in the field of immunomodulation with vast potential for diagnosing and treating various diseases, including cancer and autoimmune disorders. These tiny vesicles are laden with a diverse cargo encompassing proteins, nucleic acids, lipids, and bioactive molecules, offering a wealth of biomarkers and therapeutic options. MSC-Exos exhibit their immunomodulatory prowess by skillfully regulating pattern-recognition receptors (PRRs). They conduct a symphony of immunological responses, modulating B-cell activities, polarizing macrophages toward anti-inflammatory phenotypes, and fine-tuning T-cell activity. These interactions have profound implications for precision medicine, cancer immunotherapy, autoimmune disease management, biomarker discovery, and regulatory approvals. MSC-Exos promises to usher in a new era of tailored therapies, personalized diagnostics, and more effective treatments for various medical conditions. As research advances, their transformative potential in healthcare becomes increasingly evident.

The promoting effects of Grin2d expression in tumorigenesis and the aggressiveness of esophageal cancer

Grin2d is an ionotropic NMDA receptor, a subunit of glutamate-dependent, and a facilitator of cellular calcium influx in neuronal tissue. In this study, we found that Grin2d expression was higher in esophageal cancer than in normal mucosa at both the mRNA and protein level using RT-PCR, bioinformatics analysis, and western blotting (p<0.05). Grin2d mRNA expression was positively correlated with old age, white race, heavy weight, distal location, adenocarcinoma, cancer with Barrett's lesion, or high-grade columnar dysplasia (p<0.05). The differential genes associated with Grin2d mRNA were involved in fat digestion and absorption, cholesterol metabolism, lipid transfer, lipoproteins, synaptic membranes, and ABC transporters (p<0.05). The Grin2d-related genes were classified into the following categories: metabolism of glycerolipids, galactose, and O-glycan, cell adhesion binding, actin binding, cadherin binding, the Hippo signaling pathway, cell-cell junctions, desmosomes, DNA-transcription activator binding, and skin development and differentiation (p<0.05). Grin2d immunoreactivity was positively correlated with distal metastasis and unfavorable overall survival in esophageal cancer (p<0.05). Grin2d overexpression promoted proliferation, migration, and invasion in esophageal cancer cells but blocked apoptosis (p<0.05) and increased the expression of PI3K, Akt and p-mTOR. Grin2d knockout caused the opposite effects. These findings indicated that upregulated Grin2d expression played an important role in esophageal carcinogenesis via the PI3K/Akt/mTOR pathway and might be a biological marker for aggressive tumor behavior and poor prognosis. Its silencing might represent a targeted therapy approach against esophageal cancer.

Prognostic value of long noncoding RNA LINC00924 in lung adenocarcinoma and its regulatory effect on tumor progression

PURPOSE

Long non-coding RNAs (lncRNAs) have been used in the study of tumor biomarkers in recent years. However, the prognostic role of lncRNA LINC00924 (LINC00924) in lung adenocarcinoma (LUAD) has not yet been concluded. Therefore, this study investigates the prognostic value of LINC00924 in LUAD and its regulatory effect on tumor progression.

PATIENTS AND METHODS

The LUAD tissues and adjacent normal tissues of 128 subjects were extracted, and the expressions of LINC00924 and miR-196a-5p in tissues and cells were detected by RT-qPCR. The prognostic value of LINC00924 in LUAD patients was obtained by Kaplan-Meier analysis and multivariate Cox regression test. The cell counting kit-8 (CCK-8) and Transwell assay were used to detect the effect of overexpression LINC00924 on LUAD cells.

RESULTS

In LUAD tissues and cells, LINC00924 expression was down-regulated and miR-196a-5p expression was up-regulated compared with the normal control group. High expression of LINC00924 inhibited the proliferation level, migration ability and invasion situation of LUAD cells, which was more conducive to the survival and prognosis of LUAD patients. Bioinformatics studies indicated that overexpression of LINC00924 inhibited the development of LUAD by targeting miR-196a-5p, while miR-196a-5p mimic effectively weakened the inhibition.

CONCLUSION

LINC00924 sponges of miR-196a-5p may be considered as a potential prognostic biomarker for LUAD.

Multi-omics pan-cancer study of SPTBN2 and its value as a potential therapeutic target in pancreatic cancer

SPTBN2 is a protein-coding gene that is closely related to the development of malignant tumors. However, its prognostic value and biological function in pan-cancer, especially pancreatic cancer (PAAD), have not been reported. In the present study, a novel exploration of the value and potential mechanism of SPTBN2 in PAAD was conducted using multi-omics in the background of pan-cancer. Via various database analysis, up-regulated expression of SPTBN2 was detected in most of the tumor tissues examined. Overexpression of SPTBN2 in PAAD and kidney renal clear cell cancer patients potentially affected overall survival, disease-specific survival, and progression-free interval. In PAAD, SPTBN2 can be used as an independent factor affecting prognosis. Mutations and amplification of SPTBN2 were detected, with abnormal methylation of SPTBN2 affecting its expression and the survival outcome of PAAD patients. Immunoassay results demonstrate that SPTBN2 was a potential biomarker for predicting therapeutic response in PAAD, and may influence the immunotherapy efficacy of PAAD by regulating levels of CD8 + T cells and neutrophil infiltration. Results from an enrichment analysis indicated that SPTBN2 may regulate the development of PAAD via immune pathways. Thus, SPTBN2 is a potential prognostic biomarker and immunotherapy target based on its crucial role in the development of PAAD.

5-methylcytosine-mediated upregulation of circular RNA 0102913 augments malignant properties of colorectal cancer cells through a microRNA-571/Rac family small GTPase 2 axis

Circular RNAs (circRNAs) are a class of stable non-coding RNAs that have emerged as key regulators in human diseases including cancer. This study investigates the role of circRNA_0102913 (circ_0102913) in malignant behavior of colorectal cancer (CRC) cells and the underpinning mechanisms. By analyzing CRC-related GSE197991, GSE159669, and GSE223001 datasets, we obtained circ_0102913 as an aberrantly upregulated circRNA in CRC. Increased circ_0102913 expression was detected in CRC tissues and cells. By querying multiple bioinformatics systems (circBank, Circular RNA Interactome, TargetScan, miRDIP, miRwalk, and miRDB), we identified microRNA-571 (miR-571) as a target of circ_0102913 and Rac family small GTPase 2 (RAC2) mRNA as a target of miR-571. Biotinylated-RNA pull-down and/or luciferase assays showed that circ_0102913 bound to miR-571 to restore the expression of RAC2 mRNA. Circ_0102913 silencing or miR-571 overexpression repressed proliferation, migration and invasion, and in vivo tumorigenesis abilities of CRC cells. However, the malignant properties of cells were restored by RAC2 overexpression. The increased circ_0102913 expression in CRC cells was attributed to increased 5-methylcytosine (m5C) modification levels. Silencing of NOP2/Sun RNA methyltransferase 5 reduced the m5C level and therefore reduced stability and expression of circ_0102913 expression in CRC cells. In conclusion, this study demonstrates that m5C-mediated upregulation of circ_0102913 augments malignant properties of CRC cells through a miR-571/RAC2 axis.

ZSWIM4 inhibition improves chemosensitivity in epithelial ovarian cancer cells by suppressing intracellular glycine biosynthesis

BACKGROUND

Zinc finger SWIM-type containing 4 (ZSWIM4) induces drug resistance in breast cancer cells. However, its role in epithelial ovarian cancer (EOC) remains unknown. In this study, we aimed to investigate the clinical significance of ZSWIM4 expression in EOC and develop new clinical therapeutic strategies for EOC.

METHODS

ZSWIM4 expression in control and EOC tumor tissues was examined using immunohistochemistry. Lentiviral transduction, Cell Counting Kit-8 assay, tumorsphere formation assay, flow cytometry, western blotting, and animal xenograft model were used to assess the role of ZSWIM4 in chemotherapy. Cleavage Under Targets and Tagmentation (CUT&Tag) assays, chromatin immunoprecipitation assays, and luciferase reporter assays were used to confirm FOXK1-mediated upregulation of ZSWIM4 expression. The mechanism by which ZSWIM4 inhibition improves chemosensitivity was evaluated using RNA-sequencing. A ZSWIM4-targeting inhibitor was explored by virtual screening and surface plasmon resonance analysis. Patient-derived organoid (PDO) models were constructed from EOC tumor tissues with ZSWIM4 expression.

RESULTS

ZSWIM4 was overexpressed in EOC tumor tissues and impaired patient prognoses. Its expression correlated positively with EOC recurrence. ZSWIM4 expression was upregulated following carboplatin treatment, which, in turn, contributed to chemoresistance. Silencing ZSWIM4 expression sensitized EOC cells to carboplatin treatment in vitro and in vivo. FOXK1 could bind to the GTAAACA sequence of the ZSWIM4 promoter region to upregulate ZSWIM4 transcriptional activity and FOXK1 expression increased following carboplatin treatment, leading to an increase in ZSWIM4 expression. Mechanistically, ZSWIM4 knockdown downregulated the expression of several rate-limiting enzymes involved in glycine synthesis, causing a decrease in intracellular glycine levels, thus enhancing intracellular reactive oxygen species production induced by carboplatin treatment. Compound IPN60090 directly bound to ZSWIM4 protein and exerted a significant chemosensitizing effect in both EOC cells and PDO models.

CONCLUSIONS

ZSWIM4 inhibition enhanced EOC cell chemosensitivity by ameliorating intracellular glycine metabolism reprogramming, thus providing a new potential therapeutic strategy for EOC.

MiR-92a-2-5p suppresses esophageal squamous cell carcinoma cell proliferation and invasion by targeting PRDX2

MicroRNAs (miRNAs) can function as negative regulators of gene expression by binding to the 3'-untranslated region (3'-UTR) of target genes. The aberrant expression of miRNAs in neoplasm is extensively associated with tumorigenesis and cancer progression, including esophageal squamous cell carcinoma (ESCC). Our previous investigation has identified the oncogenic roles of Peroxiredoxin2 (PRDX2) in ESCC progression; however, its upstream regulatory mechanism remains to be elucidated. By merging the prediction results from miRWalk2.0 and miRNA differential expression analysis results based on The Cancer Genome Atlas Esophageal Carcinoma (TCGA-ESCA) database, eight miRNA candidates were predicted to be the potential regulatory miRNAs of PRDX2, followed by further identification of miR-92a-2-5p as the putative miRNA of PRDX2. Subsequent functional studies demonstrated that miR-92a-2-5p can suppress ESCC cell proliferation and migration, as well as tumor growth in subcutaneous tumor xenograft models, which might be mediated by the suppression of AKT/mTOR and Wnt3a/β-catenin signaling pathways upon miR-92a-2-5p mimic transfection condition. These data revealed the tumor suppressive functions of miR-92a-2-5p in ESCC by targeting PRDX2.

KRT80 expression works as a biomarker and a target for differentiation in gastric cancer

Keratin 80 (KRT80) is a filament protein that participates in cell differentiation and the integrity of the epithelial barrier. Here, KRT80 expression was higher in gastric cancer compared with normal mucosa at both mRNA and protein levels by bioinformatic analysis, qRT-PCR and Western blot (p<0.05), however, the methylation of KRT80 was lower than in normal mucosa (p<0.05). There was a negative relationship between promoter methylation and expression level of KRT80 gene in gastric cancer (p<0.05). KRT80 mRNA and protein expression was positively correlated with the differentiation of gastric cancer (p<0.05), while KRT80 methylation was negatively associated with gastric cancer differentiation and p53 mutation (p<0.05). The expression of KRT80 mRNA was positively linked to the short survival time of gastric cancers (p<0.05). The differential genes of KRT80 mRNA were involved in ligand-receptor interaction, estrogen signal pathway, peptidase, filament and cytoskeleton, keratinocyte differentiation, vitamin D receptor, muscle contraction, and B cell-mediated immunity (p<0.05). KRT80-related genes were classified into cell adhesion and junction, cadherin binding, skin and epidermis development, and so forth (p<0.05). KRT80 knockdown suppressed proliferation, anti-apoptosis, anti-pyroptosis, migration, invasion and epithelial-mesenchymal transition in gastric cancer cells (p<0.05). These findings indicated that up-regulated expression of KRT80 played a crucial part in gastric carcinogenesis, and might be considered as a biological marker for aggressive behaviors and poor prognosis. Its silencing might be used as an approach of target therapy for gastric cancer patients.

Expression of long noncoding RNA MEG3 and microRNA-302b-3p in colon cancer: Correlation with clinical stage and value in predicing prognosis after surgical treatment

BACKGROUND

More and more long non-coding RNAs and microRNAs have been found to have significant changes in expression levels during the occurrence and development of tumors, which can affect the expression of tumor suppressor genes or oncogenes and play an important role in the proliferation and metastasis of cancer cells.

AIM

To investigate the correlation between the expression of long non-coding RNA maternal imprinted gene 3 (LncRNA MEG3) and microRNA (miR)-302b-3p in colon cancer and clinical stage and analyze their value in predicting the prognosis after surgical treatment.

METHODS

A total of 97 patients with colon cancer treated at Jinhua Hospital of TCM from January 2017 to March 2022 were selected to compare the expression of LncRNA MEG3 and miR-302b-3p in different tissues, analyze the correlation between the expression of LncRNA MEG3 and miR-302b-3p and clinical pathological characteristics, compare the recurrence in patients with different LncRNA MEG3 and miR-302b-3p expression, analyze the factors affecting the recurrence of colon cancer after surgery, and analyze the impact of the interaction between LncRNA MEG3 and miR-302b-3p on the recurrence of colon cancer. The predictive value of LncRNA MEG3 and miR-302b-3p expression for the recurrence of colon cancer after surgery was evaluated.

RESULTS

The expression of LncRNA MEG3 and miR-302b-3p in colon cancer tissues was lower than that in tumor-adjacent tissues (P < 0.05). The expression of LncRNA MEG3 and miR-302b-3p in colon cancer tissues was not correlated with sex, age, or tumor size (P > 0.05), but was correlated with tumor differentiation, clinical stage, and lymph node metastasis (P < 0.05). In colon cancer tissues, the recurrence rate in patients with high LncRNA MEG3 and miR-302b-3p expression was lower than that of patients with lower LncRNA MEG3 and miR-302b-3p expression (P < 0.05). Tumor differentiation degree, clinical stage, and lymph node metastasis were all identified to be risk factors for colon cancer recurrence, and LncRNA MEG3 and miR-302b-3p expression were protective factors for colon cancer recurrence (P < 0.05). The interaction analysis showed that the synergistic effect of simultaneous exposure to LncRNA MEG3 and miR-302b-3p was 15.888 times greater than the effect of exposure to either LncRNA MEG3 or miR-302b-3p alone, and when simultaneously exposing to both, 56.98% of the risk of colon cancer recurrence was attributed to their synergistic effect. The area under the curve (AUC) (95% confidence interval [CI]) of LncRNA MEG3 and miR-302b-3p in predicting the prognosis of colon cancer patients was 0.720 (0.620-0.807) and 0.767 (0.670-0.847), respectively, and that of the combined prediction was 0.892 (0.813-0.946), with a sensitivity and specificity of 92.31% and 83.33%, respectively, which were significantly higher than those of either LncRNA MEG3 or miR-302b-3p alone.

CONCLUSION

The down-regulated expression of LncRNA MEG3 and miR-302b-3p in colon cancer is related to clinical stage. Clinical detection of their expression can be used to determine the malignant degree of tumor and predict the prognosis of surgical treatment, thus providing reference for adjustment of clinical treatment plan.

Paper-based biosensors as point-of-care diagnostic devices for the detection of cancers: a review of innovative techniques and clinical applications

The development and rapid progression of cancer are major social problems. Medical diagnostic techniques and smooth clinical care of cancer are new necessities that must be supported by innovative diagnostic methods and technologies. Current molecular diagnostic tools based on the detection of blood protein markers are the most common tools for cancer diagnosis. Biosensors have already proven to be a cost-effective and accessible diagnostic tool that can be used where conventional laboratory methods are not readily available. Paper-based biosensors offer a new look at the world of analytical techniques by overcoming limitations through the creation of a simple device with significant advantages such as adaptability, biocompatibility, biodegradability, ease of use, large surface-to-volume ratio, and cost-effectiveness. In this review, we covered the characteristics of exosomes and their role in tumor growth and clinical diagnosis, followed by a discussion of various paper-based biosensors for exosome detection, such as dipsticks, lateral flow assays (LFA), and microfluidic paper-based devices (µPADs). We also discussed the various clinical studies on paper-based biosensors for exosome detection.

Construction of a fecal immune-related protein-based biomarker panel for colorectal cancer diagnosis: a multicenter study

Purpose

To explore fecal immune-related proteins that can be used for colorectal cancer (CRC) diagnosis.

Patients and methods

Three independent cohorts were used in present study. In the discovery cohort, which included 14 CRC patients and 6 healthy controls (HCs), label-free proteomics was applied to identify immune-related proteins in stool that could be used for CRC diagnosis. Exploring potential links between gut microbes and immune-related proteins by 16S rRNA sequencing. The abundance of fecal immune-associated proteins was verified by ELISA in two independent validation cohorts and a biomarker panel was constructed that could be used for CRC diagnosis. The validation cohort I included 192 CRC patients and 151 HCs from 6 different hospitals. The validation cohort II included 141 CRC patients, 82 colorectal adenoma (CRA) patients, and 87 HCs from another hospital. Finally, the expression of biomarkers in cancer tissues was verified by immunohistochemistry (IHC).

Results

In the discovery study, 436 plausible fecal proteins were identified. And among 67 differential fecal proteins (|log2 fold change| > 1, P< 0.01) that could be used for CRC diagnosis, 16 immune-related proteins with diagnostic value were identified. The 16S rRNA sequencing results showed a positive correlation between immune-related proteins and the abundance of oncogenic bacteria. In the validation cohort I, a biomarker panel consisting of five fecal immune-related proteins (CAT, LTF, MMP9, RBP4, and SERPINA3) was constructed based on the least absolute shrinkage and selection operator (LASSO) and multivariate logistic regression. The biomarker panel was found to be superior to hemoglobin in the diagnosis of CRC in both validation cohort I and validation cohort II. The IHC result showed that protein expression levels of these five immune-related proteins were significantly higher in CRC tissue than in normal colorectal tissue.

Conclusion

A novel biomarker panel consisting of fecal immune-related proteins can be used for the diagnosis of CRC.

Machine learning algorithms reveal potential miRNAs biomarkers in gastric cancer

Gastric cancer is the high mortality rate cancers globally, and the current survival rate is 30% even with the use of combination therapies. Recently, mounting evidence indicates the potential role of miRNAs in the diagnosis and assessing the prognosis of cancers. In the state-of-art research in cancer, machine-learning (ML) has gained increasing attention to find clinically useful biomarkers. The present study aimed to identify potential diagnostic and prognostic miRNAs in GC with the application of ML. Using the TCGA database and ML algorithms such as Support Vector Machine (SVM), Random Forest, k-NN, etc., a panel of 29 was obtained. Among the ML algorithms, SVM was chosen (AUC:88.5%, Accuracy:93% in GC). To find common molecular mechanisms of the miRNAs, their common gene targets were predicted using online databases such as miRWalk, miRDB, and Targetscan. Functional and enrichment analyzes were performed using Gene Ontology (GO) and Kyoto Database of Genes and Genomes (KEGG), as well as identification of protein-protein interactions (PPI) using the STRING database. Pathway analysis of the target genes revealed the involvement of several cancer-related pathways including miRNA mediated inhibition of translation, regulation of gene expression by genetic imprinting, and the Wnt signaling pathway. Survival and ROC curve analysis showed that the expression levels of hsa-miR-21, hsa-miR-133a, hsa-miR-146b, and hsa-miR-29c were associated with higher mortality and potentially earlier detection of GC patients. A panel of dysregulated miRNAs that may serve as reliable biomarkers for gastric cancer were identified using machine learning, which represents a powerful tool in biomarker identification.

Exosomes in Colorectal Cancer: From Physiology to Clinical Applications

Exosomes are nanosized vesicles that have been found to be involved in many diseases. Exosomes can mediate communication between cells in a variety of ways. Certain types of mediators derived from cancer cells can play a crucial role in the development of this pathology, promoting tumor growth, invasion, metastasis, angiogenesis, and immunomodulation. Exosomes in the bloodstream show promise as a future tool for detecting cancer at an early stage. The sensitivity and specificity of clinical exosome biomarkers need to be enhanced. Knowledge of exosomes is not only important for understanding the significance of cancer progression but also for providing clinicians with useful information for the diagnosis, treatment, and discovery of methods to prevent cancer from recurring. The widespread adoption of diagnostic tools based on exosomes may revolutionize cancer diagnosis and treatment. Tumor metastasis, chemoresistance, and immunity are all aided by exosomes. A potential new approach to cancer therapy involves preventing metastasis by inhibiting miRNA intracellular signaling and blocking the formation of pre-metastatic niches. For colorectal patients, exosomes represent a promising area of investigation for improving the diagnosis, treatment, and management. Reported data demonstrate that the serum expression level of certain exosomal miRNA is significantly higher in primary colorectal cancer patients. The present review discusses mechanisms and clinical implications of exosomes in colorectal cancer.

Recent Advances in the Study of Extracellular Vesicles in Colorectal Cancer

There has been significant progress in the study of extracellular vesicles (EVs) since the 2017 American Gastroenterological Association-sponsored Freston Conference "Extracellular Vesicles: Biology, Translation and Clinical Application in GI Disorders." The burgeoning interest in this field stems from the increasing recognition that EVs represent an understudied form of cell-to-cell communication and contain cargo replete with biomarkers and therapeutic targets. This short review will highlight recent advances in the field, with an emphasis on colorectal cancer. After a brief introduction to secreted particles, we will describe how our laboratory became interested in EVs, which led to refined methods of isolation and identification of 2 secreted nanoparticles. We will then summarize the cargo found in small EVs released from colorectal cancer cells and other cells in the tumor microenvironment, as well as those found in the circulation of patients with colorectal cancer. Finally, we will consider the continuing challenges and future opportunities in this rapidly evolving field.

Identification of gene signatures for COAD using feature selection and Bayesian network approaches

The combination of TCGA and GTEx databases will provide more comprehensive information for characterizing the human genome in health and disease, especially for underlying the cancer genetic alterations. Here we analyzed the gene expression profile of COAD in both tumor samples from TCGA and normal colon tissues from GTEx. Using the SNR-PPFS feature selection algorithms, we discovered a 38 gene signatures that performed well in distinguishing COAD tumors from normal samples. Bayesian network of the 38 genes revealed that DEGs with similar expression patterns or functions interacted more closely. We identified 14 up-DEGs that were significantly correlated with tumor stages. Cox regression analysis demonstrated that tumor stage, STMN4 and FAM135B dysregulation were independent prognostic factors for COAD survival outcomes. Overall, this study indicates that using feature selection approaches to select key gene signatures from high-dimensional datasets can be an effective way for studying cancer genomic characteristics.

SPTBN2, a New Biomarker of Lung Adenocarcinoma

Objectives

The roles played by β-III-spectrin, also known as spectrin beta, non-erythrocytic 2 (SPTBN2), in the occurrence and development of lung adenocarcinoma (LUAD) have not been previously examined. Our study aimed to reveal the relationship between the SPTBN2 expression and LUAD.

Materials and Methods

Twenty pairs of LUAD tissues and adjacent tissues were collected from patients diagnosed and treated at the Thoracic Surgery Department of The First Affiliated Hospital of Zhengzhou University from July 2019 to September 2020. RNA sequencing (RNA-seq) analysis determined that the expression of SPTBN2 was higher in LUAD samples than in adjacent normal tissues. The expression levels of SPTBN2 were examined in various databases, including the Cancer Cell Line Encyclopedia (CCLE), Gene Expression Omnibus (GEO), and Human Protein Atlas (HPA). The Search Tool for the Retrieval of Interacting Genes (STRING) online website was used to examine protein–protein interactions involving SPTBN2, and the results were visualized by Cytoscape software. The Molecular Complex Detection (MCODE) plug-in for Cytoscape software was used to identify functional modules of the obtained protein–protein interaction (PPI) network. Gene enrichment analysis was performed, and survival analysis was conducted using the Kaplan–Meier plotter. The online prediction website TargetScan was used to predict SPTBN2-targeted miRNA sequences by searching for SPTBN2 sequences. Finally, we verified the expression of SPTBN2 in the obtained tissue samples using real-time fluorescence quantitative polymerase chain reaction (RT-qPCR). The human lung cancer cell lines A549 and H1299 were selected for the transfection of small interfering RNA (siRNA) targeting SPTBN2 (si-SPTBN2), and the knockdown efficiency was evaluated by RT-qPCR. The cellular proliferation, migration, and invasion capacities of A549 and H1299 cells were determined using the cell counting kit-8 (CCK-8) proliferation assay; the wound-healing assay and the Transwell migration assay; and the Matrigel invasion assay, respectively.

Results

The expression of SPTBN2 in non–small cell lung cancer (NSCLC) ranked 13th among cancer cell lines based on the CCLE database. At the mRNA and protein levels, the expression levels of SPTBN2 were higher in LUAD tissues than in normal lung tissues. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis revealed that proteins related to SPTBN2 were enriched in apoptotic and phagosomal pathways. Kaplan–Meier survival analysis revealed that SPTBN2 expression was significantly related to the prognosis of patients with LUAD. The TargetScan database verified that miR-16 was a negative regulator of SPTBN2 mRNA expression. The results of the CCK-8 cell proliferation assay revealed that SPTBN2 knockdown significantly inhibited the cell proliferation abilities of A549 and H1299 cells. The wound-healing assay indicated that SPTBN2 knockdown resulted in reduced migration after 48 h compared with the control group. The Transwell migration and invasion test revealed that the migration and invasion abilities were greatly decreased by SPTBN2 knockdown compared with control conditions.

Conclusion

We uncovered a novel gene, SPTBN2, that was significantly upregulated in LUAD tissues relative to normal tissue expression. SPTBN2 is highly expressed in LUAD, positively correlated with poor prognosis, and can promote the proliferation, migration, and invasion of LUAD cells.

miR-126 in Extracellular Vesicles Derived from Hepatoblastoma Cells Promotes the Tumorigenesis of Hepatoblastoma through Inducing the Differentiation of BMSCs into Cancer Stem Cells

Background

Extracellular vesicles (EVs) can deliver miRNAs between cells and play a crucial role in hepatoblastoma progression. In this study, we explored the differentially expressed miRNAs related to tumor cell-derived EVs and the mechanism by which EVs regulate hepatoblastoma progression.

Methods

Bioinformatics analysis was performed to explore the differentially expressed miRNAs between the hepatoblastoma and adjacent normal tissues. TEM, NTA, and western blotting were conducted to identify EVs. The expression of miR-126-3p, miR-126-5p, miR-30b-3p, miR-30b-3p, SRY, IL-1α, IL-6, and TGF-β was detected by RT-qPCR. Immunofluorescence (IF) was used to analyze the expression of PKH67, and flow cytometry was applied to assess the ratio of CD44+ CD90+ CD133+ cells. ELISA was used to evaluate the levels of IL-6 and TGF-β. A xenograft mouse model was constructed to detect the function of EVs with downregulated miR-126. IHC was performed to calculate β-catenin levels in tumor tissues.

Results

miR-126 was upregulated in hepatoblastoma. EVs derived from hepatoblastoma cells significantly increased the ratio of CD44+ CD90+ CD133+ cells and increased the expression of IL-6, Oct4, SRY, and TGF-β in bone marrow mesenchymal stem cells (BMSCs), while EVs with downregulated miR-126 reversed these phenomena. miR-126 downregulation notably attenuated hepatoblastoma tumor growth and decreased the ratio of CD44+ CD90+ CD133+ cells and increased the expression of IL-6, Oct4, SRY, TGF-β, and β-catenin in tumor tissues of mice. Furthermore, EVs with downregulated miR-126 inhibited the differentiation of BMSCs into cancer stem cells.

Conclusions

Exosomal miR-126 derived from hepatoblastoma cells promoted the tumorigenesis of liver cancer through inducing the differentiation of BMSCs into cancer stem cells.

Keratin 80 regulated by miR-206/ETS1 promotes tumor progression via the MEK/ERK pathway in ovarian cancer

Introduction: Keratin 80 (KRT80) is a type II epithelial keratin protein that plays an important role in cell differentiation and tumor progression. However, its role and mechanisms in ovarian cancer remain unclear. Methods: The effect of KRT80 on the survival and prognosis of patients with ovarian cancer was determined using immunohistochemistry. Cell lines overexpressing KRT80 and with KRT80 knockdown were established to study its effect on the malignant behavior of ovarian cancer cells. Western blotting was used to detect changes in related molecules, and in the MEK/ERK signal transduction pathway. ChIP assay was used to confirm that ETS1 regulates KRT80 at the transcriptional level. A double luciferase assay was used to confirm the target of miR-206. Results: The expression levels of KRT80 were high in ovarian cancer tissue, and were related to survival and prognosis. KRT80 expression is an independent prognostic factor in patients with ovarian cancer. KRT80 overexpression promotes the proliferation of ovarian cancer cells, the transition from G1 phase to S phase, invasion, and migration. KRT80 overexpression increased the expression of BCL2/BAX, CyclinD1, MMP2, MMP9, and N-cadherin, decreased the expression of E-cadherin, and increased the phosphorylation of MEK and ERK. ETS1 binds to the upstream promoter sequence of KRT80 and regulates KRT80 expression at the transcriptional level. ETS1 is a direct target of miR-206 in ovarian cancer cells. Conclusion: KRT80 regulated by miR-206/ETS1 promotes tumor progression via the MEK/ERK pathway in ovarian cancer, and KRT80 may have applications as a screening biomarker and potential therapeutic target for ovarian cancer.

Expression Profile and Prognostic Value of Wnt Signaling Pathway Molecules in Colorectal Cancer

Colorectal cancer (CRC) is a heterogeneous disease with changes in the genetic and epigenetic levels of various genes. The molecular assessment of CRC is gaining increasing attention, and furthermore, there is an increase in biomarker use for disease prognostication. Therefore, the identification of different gene biomarkers through messenger RNA (mRNA) abundance levels may be useful for capturing the complex effects of CRC. In this study, we demonstrate that the high mRNA levels of 10 upregulated genes (DPEP1, KRT80, FABP6, NKD2, FOXQ1, CEMIP, ETV4, TESC, FUT1, and GAS2) are observed in CRC cell lines and public CRC datasets. Moreover, we find that a high mRNA expression of DPEP1, NKD2, CEMIP, ETV4, TESC, or FUT1 is significantly correlated with a worse prognosis in CRC patients. Further investigation reveals that CTNNB1 is the key factor in the interaction of the canonical Wnt signaling pathway with 10 upregulated CRC-associated genes. In particular, we identify NKD2, FOXQ1, and CEMIP as three CTNNB1-regulated genes. Moreover, individual inhibition of the expression of three CTNNB1-regulated genes can cause the growth inhibition of CRC cells. This study reveals efficient biomarkers for the prognosis of CRC and provides a new molecular interaction network for CRC.

Exosomes in the lung cancer microenvironment: biological functions and potential use as clinical biomarkers

Lung cancer is one of the most common malignant tumours worldwide. however, emerging immunotherapy and targeted therapies continue to show limited efficacy. In the search for new targets for lung cancer treatment, exosomes have become a major focus of research. Exosomes play an important role in the tumour microenvironment (TME) of lung cancer and affect invasion, metastasis, and treatment responses. This review describes our current understanding of the release of exosomes derived from different cells in the TME, the effects of exosomes on T/Tregs, myeloid-derived suppressor cells, tumour-associated macrophages, dendritic cells, and natural killer cells, and the role of exosomes in the endothelial–mesenchymal transition, angiogenesis, and cancer-associated fibroblasts. In particular, this review focuses on the potential clinical applications of exosomes in the lung cancer microenvironment and their prognostic and diagnostic value.