MicroRNA-331-3p inhibits epithelial-mesenchymal transition by targeting ErbB2 and VAV2 through the Rac1/PAK1/β-catenin axis in non-small-cell lung cancer

Molecular pathological approach to cancer epigenomics and its clinical application

Careful microscopic observation of histopathological specimens, accumulation of large numbers of high-quality tissue specimens, and analysis of molecular pathology in relation to morphological features are considered to yield realistic data on the nature of multistage carcinogenesis. Since the morphological hallmark of cancer is disruption of the normal histological structure maintained through cell-cell adhesiveness and cellular polarity, attempts have been made to investigate abnormalities of the cadherin-catenin cell adhesion system in human cancer cells. It has been shown that the CDH1 tumor suppressor gene encoding E-cadherin is silenced by DNA methylation, suggesting that a "double hit" involving DNA methylation and loss of heterozygosity leads to carcinogenesis. Therefore, in the 1990s, we focused on epigenomic mechanisms, which until then had not received much attention. In chronic hepatitis and liver cirrhosis associated with hepatitis virus infection, DNA methylation abnormalities were found to occur frequently, being one of the earliest indications that such abnormalities are present even in precancerous tissue. Aberrant expression and splicing of DNA methyltransferases, such as DNMT1 and DNMT3B, was found to underlie the mechanism of DNA methylation alterations in various organs. The CpG island methylator phenotype in renal cell carcinoma was identified for the first time, and its therapeutic targets were identified by multilayer omics analysis. Furthermore, the DNA methylation profile of nonalcoholic steatohepatitis (NASH)-related hepatocellular carcinoma was clarified in groundbreaking studies. Since then, we have developed diagnostic markers for carcinogenesis risk in NASH patients and noninvasive diagnostic markers for upper urinary tract cancer, as well as developing a new high-performance liquid chromatography-based diagnostic system for DNA methylation diagnosis. Research on the cancer epigenome has revealed that DNA methylation alterations occur from the precancerous stage as a result of exposure to carcinogenic factors such as inflammation, smoking, and viral infections, and continuously contribute to multistage carcinogenesis through aberrant expression of cancer-related genes and genomic instability. DNA methylation alterations at the precancerous stages are inherited by or strengthened in cancers themselves and determine the clinicopathological aggressiveness of cancers as well as patient outcome. DNA methylation alterations have applications as biomarkers, and are expected to contribute to diagnosis, as well as preventive and preemptive medicine.

HER2 Alterations in Non-Small Cell Lung Cancer: Biologico-Clinical Consequences and Interest in Therapeutic Strategies

Lung cancer stands as the first cause of death by cancer in the world. Despite the improvement in patients' outcomes in the past decades through the development of personalized medicine approaches, a substantial portion of patients remains ineligible for targeted therapies due to the lack of a "druggable" molecular target. HER2, a receptor tyrosine kinase member of the EGFR/ErbB family, is known to show oncogenic properties. In this review, we focus on the different HER2 dysregulation mechanisms that have been observed in non-small cell lung cancer (NSCLC): gene mutation, gene amplification, protein overexpression and protein hyper-phosphorylation, the latter suggesting that HER2 dysregulation can occur independently of any molecular aberration. These HER2 alterations inevitably have consequences on tumor biology. Here, we discuss how they are not only involved in abnormal proliferation and survival of cancer cells but also potentially in increased angiogenic properties, mesenchymal features and tumor immune escape. Finally, we review the impact of these HER2 alterations in various therapeutic approaches. While standard chemotherapy and groundbreaking immunotherapy seem rather ineffective for HER2-altered NSCLCs, the development of HER2-targeted therapies such as tyrosine kinase inhibitors, anti-HER2 antibodies and especially antibody-drug conjugates could provide new hopes for patients.

Characterization of MicroRNA expression profiles in the ovarian tissue of goats during the sexual maturity period

BACKGROUND

The ovary is an important reproductive organ in mammals, and its development directly affects the sexual maturity and reproductive capacity of individuals. MicroRNAs (miRNAs) are recognized as regulators of reproductive physiological processes in various animals and have been shown to regulate ovarian development through typical targeting and translational repression. However, little is known about the regulatory role of miRNAs in ovarian tissue development during sexual maturity in goats. To comprehensively profile the different physiological stages of sexual maturation in goats, we performed small-RNA sequencing of ovarian tissue samples collected at four specific time points (1 day after birth (D1), 2 months old (M2), 4 months old (M4), and 6 months old (M6)). In addition, we used ELISAs to measure serum levels of reproductive hormones to study their temporal changes.

RESULTS

The results showed that serum levels of gonadotropin-releasing hormone, follicle-stimulating hormone, luteinizing hormone, oestradiol, progesterone, oxytocin, and prolactin were lower in goats at the D1 stage than at the other three developmental stages (P < 0.05). The secretion patterns of these seven hormones show a similar trend, with hormone levels reaching their peaks at 4 months of age. A total of 667 miRNAs were detected in 20 libraries, and 254 differentially expressed miRNAs and 3 groups of miRNA clusters that had unique expression patterns were identified (|log2-fold change|> 1, FDR < 0.05) in the 6 comparison groups. RT‒qPCR was employed to confirm that the expression pattern of the 15 selected miRNAs was consistent with the Illumina sequencing results. Gene ontology analyses revealed significant enrichment of GO terms such as cell proliferation regulation, epithelial cell development, and amino acid transport, as well as important signaling pathways including the MAPK signaling pathway, the PI3K-Akt signaling pathway, and the oestrogen signaling pathway. Further miRNA‒mRNA regulation network analysis revealed that 8 differentially expressed miRNAs (chi-miR-1343, chi-miR-328-3p, chi-miR-877-3p, chi-miR-296-3p, chi-miR-128-5p, chi-miR-331-3p, chi-miR-342-5p and chi-miR-34a) have important regulatory roles in ovarian cell proliferation, hormone secretion and metabolism-related biological processes.

CONCLUSIONS

Overall, our study investigated the changes in serum hormone and miRNA levels in the ovaries. These data provide a valuable resource for understanding the molecular regulatory mechanisms of miRNAs in ovarian tissue during the sexual maturity period in goats.

Exosomal miR-331-3p derived from chemoresistant osteosarcoma cells induces chemoresistance through autophagy

BACKGROUND

Osteosarcoma is a common malignant bone tumor, and chemotherapy can effectively improve the prognosis. MicroRNA-331 (MiR-331) is associated with poor cancer outcomes. However, the role of miR-331 in osteosarcoma remains to be explored.

METHODS

Drug-resistant osteosarcoma cells were cultured, and their exosomes were purified. The secretion and uptake of exosomes by drug-resistant osteosarcoma and osteosarcoma cells were confirmed using a fluorescence tracking assay and Transwell experiments. The effects of drug-resistant exosomes on cell proliferation were determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. siRNA-Drosha and neutral sphingomyelinase inhibitor GW4869 were used to determine the transfer of miRNAs. qRT-PCR and western blotting were used to detect the role of autophagy in the regulation of drug-resistant cell-derived exosomal miR-331-3p.

RESULTS

Exosomal miR-331-3p levels in drug-resistant cells were higher than in exosomes from osteosarcoma cells. The exosomes secreted by the drug-resistant osteosarcoma cells could be absorbed by osteosarcoma cells, leading to acquired drug resistance in previously non-resistance cells. Inhibition of miRNAs resulted in reduced transmission of drug resistance transmission by exosomes. Exosomes from drug-resistant osteosarcoma cells transfected with siRNA-Drosha or treated by GW4869 could not enhance the proliferation of MG63 and HOS cells. Finally, miR-331-3p in the exosomes secreted by drug-resistant osteosarcoma cells could induce autophagy of osteosarcoma cells, allowing them to acquire drug resistance. The inhibition of miR-331-3p decreased drug resistance of osteosarcoma cells.

CONCLUSION

Exosomes secreted from chemoresistant osteosarcoma cells promote drug resistance through miR-331-3p and autophagy. Inhibition of miR-331-3p could be used to alleviate drug resistance in osteosarcoma.

Regulation and therapeutic potentials of microRNAs to non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common type of lung cancer, accounting for 80%-85% of total cases and leading to millions of deaths worldwide. Drug resistance is the primary cause of treatment failure in NSCLC, which urges scientists to develop advanced approaches for NSCLC treatment. Among novel approaches, the miRNA-based method has emerged as a potential approach as it allows researchers to modulate target gene expression. Subsequently, cell behaviors are altered, which leads to the death and the depletion of cancer cells. It has been reported that miRNAs possess the capacity to regulate multiple genes that are involved in various signaling pathways, including the phosphoinositide 3-kinase, receptor tyrosine kinase/rat sarcoma virus/mitogen-activated protein kinase, wingless/integrated, retinoblastoma, p53, transforming growth factor β, and nuclear factor-kappa B pathways. Dysregulation of these signaling pathways in NSCLC results in abnormal cell proliferation, tissue invasion, and drug resistance while inhibiting apoptosis. Thus, understanding the roles of miRNAs in regulating these signaling pathways may enable the development of novel NSCLC treatment therapies. However, a comprehensive review of potential miRNAs in NSCLC treatment has been lacking. Therefore, this review aims to fill the gap by summarizing the up-to-date information on miRNAs regarding their targets, impact on cancer-associated pathways, and prospective outcomes in treating NSCLC. We also discuss current technologies for delivering miRNAs to the target cells, including virus-based, non-viral, and emerging extracellular vesicle-based delivery systems. This knowledge will support future studies to develop an innovative miRNA-based therapy and select a suitable carrier to treat NSCLC effectively.

SYTL2 promotes metastasis of prostate cancer cells by enhancing FSCN1-mediated pseudopodia formation and invasion

BACKGROUND

Metastatic prostate cancer (mPCa) has a poor prognosis with limited treatment options. The high mobility of tumor cells is the key driving characteristic of metastasis. However, the mechanism is complex and far from clarified in PCa. Therefore, it is essential to explore the mechanism of metastasis and discover an intrinsic biomarker for mPCa.

METHODS

Transcriptome sequencing data and clinicopathologic features of PCa from multifarious public databases were used to identify novel metastatic genes in PCa. The PCa tissue cohort containing 102 formalin-fixed paraffin-embedded (FFPE) samples was used to evaluate the clinicopathologic features of synaptotagmin-like 2 (SYTL2) in PCa. The function of SYTL2 was investigated by migration and invasion assays and a 3D migration model in vitro and a popliteal lymph node metastasis model in vivo. We performed coimmunoprecipitation and protein stability assays to clarify the mechanism of SYTL2.

RESULTS

We discovered a pseudopodia regulator, SYTL2, which correlated with a higher Gleason score, worse prognosis and higher risk of metastasis. Functional experiments revealed that SYTL2 promoted migration, invasion and lymph node metastasis by increasing pseudopodia formation in vitro and in vivo. Furthermore, SYTL2 induced pseudopodia formation by enhancing the stability of fascin actin-bundling protein 1 (FSCN1) by binding and inhibiting the proteasome degradation pathway. Targeting FSCN1 enabled rescue and reversal of the oncogenic effect of SYTL2.

CONCLUSIONS

Overall, our study established an FSCN1-dependent mechanism by which SYTL2 regulates the mobility of PCa cells. We also found that the SYTL2-FSCN1-pseudopodia axis may serve as a pharmacological and novel target for treating mPCa.

Rac1: A Regulator of Cell Migration and A Potential Target for Cancer Therapy

Cell migration is crucial for physiological and pathological processes such as morphogenesis, wound repair, immune response and cancer invasion/metastasis. There are many factors affecting cell migration, and the regulatory mechanisms are complex. Rac1 is a GTP-binding protein with small molecular weight belonging to the Rac subfamily of the Rho GTPase family. As a key molecule in regulating cell migration, Rac1 participates in signal transduction from the external cell to the actin cytoskeleton and promotes the establishment of cell polarity which plays an important role in cancer cell invasion/metastasis. In this review, we firstly introduce the molecular structure and activity regulation of Rac1, and then summarize the role of Rac1 in cancer invasion/metastasis and other physiological processes. We also discuss the regulatory mechanisms of Rac1 in cell migration and highlight it as a potential target in cancer therapy. Finally, the current state as well as the future challenges in this area are considered. Understanding the role and the regulatory mechanism of Rac1 in cell migration can provide fundamental insights into Rac1-related cancer progression and further help us to develop novel intervention strategies for cancer therapy in clinic.

Potentially functional genetic variants of VAV2 and PSMA4 in the immune-activation pathway and non-small cell lung cancer survival

BACKGROUND

Lung cancer ranks the highest mortality among cancers, represented by a low 5-year survival rate. The function of the immune system has a profound influence on the development and progression of lung cancer. Thus genetic variants of the immune-related genes may serve as potential predictors of non-small cell lung cancer (NSCLC) survival.

METHODS

In the present study, we conducted a two-stage survival analysis in 1,531 NSCLC patients and assessed the associations between genetic variants in the immune-activation gene-set and overall survival (OS) of NSCLC. The validated variants were further subjected to functional annotation and in vitro experiments.

RESULTS

We identified 25 SNPs spanning 6 loci associated with NSCLC OS after multiple-testing corrections in all datasets, in which two variants, PSMA4 rs12901682 A>C and VAV2 rs12002767 C>T were shown to potentially affect lung cancer OS by cis-regulating the expression of the corresponding genes [(HR (95% CI) = 0.76 (0.65-0.89) and 1.36 (1.12-1.65), P=4.29E-04 and 0.002, respectively)].

CONCLUSION

Our findings provide new insights into the role of genetic variants in the immune-activation pathway genes in lung cancer progression.

LINC01063 functions as an oncogene in melanoma through regulation of miR-5194-mediated SOX12 expression

Melanoma is one of the most aggressive skin cancers and a major cause of cancer-linked deaths worldwide. As the morbidity and mortality of melanoma are increasing, it is necessary to elucidate the potential mechanism influencing melanoma progression. Tumor tissues and adjacent normal tissues (5 cm away from tumors) from 22 melanoma patients at the I-II stage and 39 patients at the III-VI stage were acquired. The expression of LINC01063 in melanoma was estimated by quantitative PCR. Functional assays were employed to investigate the function of LINC01063 in melanoma. Mechanism assays were adopted to explore the mechanism of LINC01063. LINC01063 knockdown impeded melanoma cell proliferation, migration, invasion, and epithelial-mesenchymal transition as well as melanoma tumor growth. Mechanistically, LINC01063 acted as an miR-5194 sponge to upregulate SOX12 expression. Finally, LINC01063 was tested to facilitate the malignant behaviors of melanoma cells via targeting miR-5194/SOX12. LINC01063 was significantly upregulated in melanoma. Specifically, LINC01063 displayed a higher level in patients at an advanced stage or with metastasis than those at an early stage or without metastasis. Our study revealed the oncogenic effects of LINC01063 on melanoma cell/tumor growth and its molecular mechanism involving miR-5194/SOX12, which might support LINC01063 to be the potential prognostic or therapeutic biomarker against melanoma.

The Mechanism of Rac1 in Regulating HCC Cell Glycolysis Which Provides Underlying Therapeutic Target for HCC Therapy

Aim

To explore the role of Rac1 on sorafenib resistance in hepatocellular carcinoma.

Methods

CCK-8, wound healing assay, Transwell, and cell cycle assay were used to detect the tumor cells development. Cell viability was assessed by MTT. The glycolytic pathway was revealed by cellular metabolism assays.

Result

We recovered that Rac1 upregulation was related to HCC patients' poorer prognosis. Forced expression of Rac1 promoted cell development and sorafenib chemoresistance in HCC cells. Rac1 inhibitor EHop-016 and sorafenib combination markedly prevented cell viability, G2/M phase cycle arrest, and apoptosis than single therapy. Furthermore, combination therapy decreased glycolysis in HCC cells. In vivo, the tumor growth was significantly prevented by combination therapy single therapy.

Conclusion

Our research declares that Rac1 inhibition could block sorafenib resistance in HCC by decreasing glycolysis, which would provide an underlying target for HCC therapy.

Engineered Exosomes Loaded with miR-563 Inhibit Lung Cancer Growth

The malignancy of lung cancer (LC) is serious in the world. Exosomes are well-known natural nanovesicles, which are reported to have the potential to carry functional miRNAs as natural carriers and deliver chemotherapeutic drugs. However, the safety and functions of the engineered exosomes for delivering miRNA for the treatment of LC remain to be evaluated. In this study, we found that miR-563 is related to lung cancer from GeneCard database. RT-qPCR and in situ hybridization (ISH) were used to assess miR-563 expression in clinical samples. We prepared and verified the engineered exosomes loaded with miR-563 both in vitro and in vivo. In vitro, flow cytometry, Western blot, and other experimental methods were performed to evaluate the antitumor effect of miR-563 loaded exosomes. In in vivo, the LC mouse model was used to observe the effect of the prepared exosomes. The safety of using this exosomes was accessed by liver function test, hematological analysis, and H&E staining in major organs of the mice. Our findings indicated that the miR-563 loaded engineered exosomes inhibit the A549 cells growth in vitro, by inhibiting the tumor cell proliferation, migration, and invasion and promoting apoptosis. In in vivo, these engineered exosomes were enriched in tumor tissue after injecting to LC model mice and impacted tumor tissue by inhibiting the tumor volume and tumor weight. Importantly, our study indicated that miR-563 loaded engineered exosomes have the potential for clinical application for LC treatment with acceptable safety profiles. Our findings indicate a novel potential therapeutic target for lung cancer patients by miR-563 loaded engineered exosomes.

Exosome-Associated circRNAs as Key Regulators of EMT in Cancer

Epithelial-to-mesenchymal transition (EMT) is a dynamic program of cell plasticity aberrantly reactivated in cancer. The crosstalk between tumor cells and the tumoral microenvironment (TME) has a pivotal importance for the induction of the EMT and the progression toward a malignant phenotype. Notably, exosomes are key mediators of this crosstalk as vehicles of specific molecular signals that include the class of circular RNAs (circRNAs). This review specifically focuses on the role of exosome-associated circRNAs as key regulators of EMT in cancer. The relevance of these molecules in regulating the intercellular communication in TME and tumor progression is highlighted. Moreover, the here-presented evidence indicates that exosome-associated circRNA modulation should be taken in account for cancer diagnostic and therapeutic approaches.

LINC01232 Promotes Metastasis and EMT by Regulating miR-506-5p/PAK1 Axis in Gastric Cancer

Background

Long non-coding RNA LINC01232 plays an important role in the progression of metastasis in several cancers. However, the function of LINC01232 in gastric cancer is limited. Authors aimed to investigate the role and mechanism of LINC01232 in the metastasis of gastric cancer.

Methods

The expression levels and correlation of LINC01232, miR-506-5p, and PAK1 were analyzed by GEPIA or ENCORI, and the abundance of LINC01232 and miR-506-5p was measured in tissues and cells via qRT-PCR, the location of LINC01232 in gastric cells was analyzed by nuclear and cytoplasmic fractionation, while the protein levels of PAK1, E-cadherin and vimentin were additionally quantified by Western blotting. Interactions between LINC01232, miR-506-5p, and PAK1 were detected through luciferase reporter assays, qRT-PCR and Western blotting. Cellular viability was evaluated through CCK8 assays, migration ability was measured by transwell assays, invasion ability was tested by wound healing experiment.

Results

LINC01232 was overexpressed in gastric cancer tissues and cells, and mainly located in nucleus. The inhibition of LINC01232 could suppress migration, invasion and EMT of gastric cancer cells. MiR-506-5p was downregulated in gastric cancer tissues and cells. LINC01232 sponged miR-506-5p to accelerate migration and EMT. PAK1 was certified to be a target of miR-506-5p, inhibition of PAK1 could interrupt LINC01232 overexpression-induced migration of gastric cancer cells.

Conclusion

The LINC01232/miR-506-5p/PAK1 axis promotes metastasis of gastric cancer cells.

Heterogeneity among tumors with acquired resistance to EGFR tyrosine kinase inhibitors harboring EGFR ‐T790M mutation in non‐small cell lung cancer cells

EGFR‐T790M mutation is a major mechanism underlying acquired resistance to first‐ and second‐generation EGFR tyrosine kinase inhibitors (EGFR‐TKIs) in lung cancer with mutated EGFR. However, differences in the biological characteristics of T790M tumors based on treatment regimens with each generation of EGFR‐TKI are not fully understood. We established cell lines with acquired resistance harboring EGFR‐T790M mutation derived from xenograft tumors treated with each generation of EGFR‐TKI and examined their biological characteristics with respect to third‐generation EGFR‐TKI osimertinib sensitivity. Second‐generation EGFR‐TKI dacomitinib‐resistant cells with T790M‐exhibited higher sensitivity to osimertinib than first‐generation EGFR‐TKI gefitinib‐resistant cells with T790M via inhibition of AKT and ERK signaling and promotion of apoptosis. Furthermore, gefitinib‐resistant cells showed enhanced intratumor heterogeneity accompanied by genomic instability and activation of alternative resistance mechanisms compared with dacomitinib‐resistant cells; this suggests that the maintenance of EGFR dependency after acquiring resistance might depend on the type of EGFR‐TKI. Our results demonstrate that the progression of tumor heterogeneity via both genetic and non‐genetic mechanisms might affect osimertinib sensitivity in tumors with acquired resistance harboring EGFR‐T790M mutation.

High Expression of VAV Gene Family Predicts Poor Prognosis of Acute Myeloid Leukemia

Objectives: VAV family genes (VAV1, VAV2, and VAV3) are associated with prognosis in various cancers; however, they have not been evaluated in acute myeloid leukemia (AML). In this study, the prognostic value of VAV expression in AML was evaluated by a single-center study in combination with bioinformatics analyses. Methods: The expression and prognostic value of VAVs in patients with AML were investigated using various databases, including GEPIA, CCLE, EMBL-EBI, UALCAN, cBioPortal, STRING, and DAVID. Blood samples from 35 patients with AML (non-M3 subtype) and 13 benigh individuals were collected at our center. VAV expression levels were detected by real-time quantitative PCR (RT-qPCR) and western blotting. Clinical data were derived from medical records. Results: Based on data from multiple databases, the expression levels of VAV1, VAV2, and VAV3 were significantly higher in AML than in control tissues (P < 0.05). RT-qPCR and western blotting results showed that VAV expression in mRNA and protein levels were higher in patients with AML that in the control group (P < 0.05). Complete remission rates were lower and risks were higher in patients with AML with high VAV1 expression than with low VAV1 expression (P < 0.05). High levels of VAV2, VAV3, and VAV1 were related to a poor overall survival, and this relationship was significant for VAV1 (P < 0.05). High expression levels of genes correlated with VAV1, such as SIPA1, SH2D3C, and HMHA1 were also related to a poor prognosis in AML. Functional and pathways enrichment analyses indicated that the contribution of the VAV family to AML may be mediated by the NF-κB, cAMP, and other pathways. Conclusion: VAVs were highly expressed in AML. In particular, VAV1 has prognostic value and is a promising therapeutic target for AML.

Baicalin Inhibits EMT through PDK1/AKT Signaling in Human Nonsmall Cell Lung Cancer

Background

Baicalin is a naturally occurring compound with anticancer, antioxidant, and anti-inflammatory properties. However, the mechanism underlying its anticancer activity on nonsmall cell lung cancer (NSCLC) remains unclear.

Methods

The effects of baicalin on the progression and metastasis of experimental NSCLC cell lines were studied in vitro and in vivo. Wound-healing and transwell assays were performed to evaluate the potency of baicalin and the motility and migration ability of NCI-H460 cells. Immunofluorescence assay, western blot assay, and immunohistochemistry test were conducted to investigate the inhibiting effect of baicalin on the epithelial-mesenchymal transition (EMT) of NSCLC.

Results

Baicalin inhibited the proliferation and migration of NCI-H446 human NSCLC cells in a dose-dependent manner, reduced the expression levels of phospho-3-phosphoinositide-dependent protein kinase 1 (p-PDK1) and phosphor-serine/threonine-protein kinase (p-AKT), reversed the levels of EMT markers, and inhibited the migration of NSCLC cells.

Conclusions

Baicalin impedes EMT by inhibiting the PDK1/AKT pathway in human NSCLC and thus may be an effective alternative treatment for carcinoma and a new candidate antimetastasis drug.

The epigenetic silencing of microRNA-433 facilitates the malignant phenotypes of non-small cell lung cancer by targeting CREB1

OBJECTIVE

MicroRNAs (miRNAs) play a big role in the regulation of non-small cell lung cancer (NSCLC) development. The objective of this study is to determine how DNA methylation regulates miR-433 in NSCLC.

METHODS

The degree of DNA methylation was determined, and the relevance of miR-433 and the features of NSCLC patients were assessed. The MiR-433 and CREB1 expressions were tested, and the biological characteristics of the NSCLC cells were determined. Subcutaneous tumorigenesis in nude mice and luciferase activity assays were performed.

RESULTS

MiR-433 was downregulated, and CREB1 was upregulated in the NSCLC tissues, and the methylating rate of the C-phosphate-G (CpG) island in the miR-433 promoter region was enhanced. MiR-433 was also downregulated, and CREB1 was upregulated in the NSCLC cells and there was a low degree of promoter methylation of miR-433 in the NSCLC cells after demethylation. Upregulated miR-433 or downregulated CREB1 repressed the cell vitality and colony formation abilities and increased the amount of apoptotic A549 cells. Moreover, upregulated miR-433 also decelerated tumor growth. Conversely, the H460 cells and xenografts with reduced miR-433 or overexpressed CREB1 had contrary results. CREB1 was found to be targeted by miR-433, as verified by a luciferase activity assay.

CONCLUSION

We found that DNA methylation can downregulate miR-433 in NSCLC, which promotes the malignant behaviors of NSCLC cells.

Hsa_circ_0004712 downregulation attenuates ovarian cancer malignant development by targeting the miR-331-3p/FZD4 pathway

Background

Circular RNAs (circRNAs) are gradually reported to be implicated in the development of malignant tumors, including ovarian cancer (OC). This paper intended to explore the function and action mechanism of hsa_circ_0004712 in OC.

Results

In our results, hsa_circ_0004712 was aberrantly overexpressed in OC tissues and cells. Downregulation of hsa_circ_0004712 impaired OC cell proliferation, colony formation, invasion and migration, and accelerated apoptosis. Hsa_circ_0004712 directly targeted miR-331-3p whose inhibitors reversed the effects of hsa_circ_0004712 downregulation. FZD4 was targeted by miR-331-3p, and hsa_circ_0004712 could positively regulated FZD4 expression by targeting miR-331-3p. The anti-tumor effects of miR-331-3p restoration were reversed by FZD4 overexpression. Downregulation of hsa_circ_0004712 also impaired tumor development in vivo by regulating miR-331-3p and FZD4.

Conclusion

In conclusion, hsa_circ_0004712 deficiency repressed OC development by mediating the miR-331-3p/FZD4 pathway, predicting that hsa_circ_0004712 was a promising biomarker for OC diagnosis and therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13048-021-00859-0.

MicroRNA-106b-5p inhibits growth and progression of lung adenocarcinoma cells by downregulating IGSF10

In this study, we investigated the mechanistic role and prognostic significance of IGSF10 in lung adenocarcinoma. Oncomine database analysis showed that IGSF10 expression was significantly reduced in most cancer types, including lung adenocarcinoma (LUAD). In the TCGA-LUAD dataset, IGSF10 expression correlated positively with proportions of tumor-infiltrated B cells, CD4⁺ T cells, CD8⁺ T cells, neutrophils, macrophages, and dendritic cells. Kaplan-Meier survival analysis showed that overall survival of patients with low IGSF10 expression was significantly shorter than those with high IGSF10 expression. MiRWalk2.0 database analysis and dual luciferase reporter assays confirmed that miR-106b-5p suppressed IGSF10 expression by binding to its 3’UTR. MiR-106b-5p levels inversely correlated with IGSF10 expression in the TCGA-LUAD dataset. Moreover, inhibition of miR-106b-5p significantly decreased in vitro proliferation, migration, and invasion by LUAD cells, whereas miR-106b-5p overexpression reversed those effects. These results demonstrate that IGSF10 is an independent prognostic factor for LUAD. Furthermore, miR-106b-5p suppressed IGSF10 expression in LUAD tissues by binding to its 3’UTR, which makes IGSF10 and miR-106b-5p potential prognostic biomarkers and therapeutic targets in LUAD patients.

Cooperative participation of epigenomic and genomic alterations in the clinicopathological diversity of gastric adenocarcinomas: significance of cell adhesion and epithelial-mesenchymal transition-related signaling pathways

The present study was conducted to clarify the cooperative significance of epigenomic and genomic abnormalities during gastric carcinogenesis. Using 21 samples of normal control gastric mucosa (C), 109 samples of non-cancerous gastric mucosa (N) and 105 samples of cancerous tissue (T) from 109 patients with primary gastric adenocarcinomas, genome-wide DNA methylation analysis was performed using Infinium assay. Among these samples, 66 paired N and corresponding T samples were subjected to whole-exome and single nucleotide polymorphism array analyses. As had been shown in our previous study, 109 patients were clustered clinicopathologically into least aggressive Cluster A (n = 20), most aggressive Cluster B1 (n = 20) and Cluster B2 (n = 69). Most DNA methylation alterations in each cluster had already occurred even in N samples compared with C samples, and DNA methylation alterations at the precancerous N stage were inherited by the established cancers themselves. Recurrent single nucleotide variants and insertions/deletions resulting in functional disruption of the proteins encoded by the ABCA10, BNC2, CDH1, CTNNB1, SMAD4 and VAV2 genes were specific to Cluster B1, whereas those of the APC, EGFR, ERBB2, ERBB3, MLH1 and MUC6 genes were specific to Cluster A. MetaCore pathway analysis revealed that the epigenomically affected TWIST1 gene and genomically affected CDH1, CTNNB1, MMP9, TLN2, ROCK1 and SMAD4 genes were accumulated in signaling pathways related to cell adhesion, cytoskeleton remodeling and epithelial–mesenchymal transition in Cluster B1. These data indicate that epigenomic alterations at the precancerous stage are important in gastric carcinogenesis and that epigenomic and genomic alterations cooperatively underlie the aggressiveness of gastric adenocarcinomas.

Rac1, A Potential Target for Tumor Therapy

RAS-related C3 botulinum toxin substrate 1 (Rac.1) is one of the important members of Rho GTPases. It is well known that Rac1 is a cytoskeleton regulation protein that regulates cell adhesion, morphology, and movement. Rac1 is highly expressed in different types of tumors, which is related to poor prognosis. Studies have shown that Rac1 not only participates in the tumor cell cycle, apoptosis, proliferation, invasion, migration and angiogenesis, but also participates in the regulation of tumor stem cell, thus promoting the occurrence of tumors. Rac1 also plays a key role in anti-tumor therapy and participates in immune escape mediated by the tumor microenvironment. In addition, the good prospects of Rac1 inhibitors in cancer prevention and treatment are exciting. Therefore, Rac1 is considered as a potential target for the prevention and treatment of cancer. The necessity and importance of Rac1 are obvious, but it still needs further study.

Genetic variants of DOCK2, EPHB1 and VAV2 in the natural killer cell-related pathway are associated with non-small cell lung cancer survival

Although natural killer (NK) cells are a known major player in anti-tumor immunity, the effect of genetic variation in NK-associated genes on survival in patients with non-small cell lung cancer (NSCLC) remains unknown. Here, in 1,185 with NSCLC cases of a discovery dataset, we evaluated associations of 28,219 single nucleotide polymorphisms (SNPs) in 276 NK-associated genes with their survival. These patients were from the reported genome-wide association study (GWAS) from the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial. We further validated the findings in an additional 984 cases from the Harvard Lung Cancer Susceptibility (HLCS) Study. We identified three SNPs (i.e., DOCK2 rs261083 G>C, VAV2 rs2519996 C>T and EPHB1 rs36215 A>G) to be independently associated with overall survival (OS) in NSCLC cases with adjusted hazards ratios (HRs) of 1.16 (95% confidence interval [CI] = 1.07-1.26, P = 3.34×10^-4), 1.28 (1.12-1.47, P = 4.57×10^-4) and 0.75 (0.67-0.83, P = 1.50×10^-7), respectively. Additional joint assessment of the unfavorable genotypes of the three SNPs showed significant associations with OS and disease-specific survival of NSCLC cases in the PLCO dataset (P _trend<0.0001 and <0.0001, respectively). Moreover, the survival-associated DOCK2 rs261083 C allele had a significant correlation with reduced DOCK2 transcript levels in lung adenocarcinoma (LUAD), while the rs36215 G allele was significantly correlated with reduced EPHB1 transcript levels in lymphoblastoid cell lines in the 1000 Genomes Project. These results revealed that DOCK2 and EPHB1 genetic variants may be prognostic biomarkers of NSCLC survival, likely via transcription regulation of respective genes.

miR-224 aggravates cancer-associated fibroblast-induced progression of non-small cell lung cancer by modulating a positive loop of the SIRT3/AMPK/mTOR/HIF-1α axis

Objectives: Cancer-associated fibroblast (CAF) is among the most important tumor-host microenvironment components by affecting tumor progression. This study explored the role of miR-224 in CAF-induced non-small cell lung cancer (NSCLC).

Materials and methods: A CAF-NSCLC cell co-culture model was established, and the miR-224 expression in CAF was detected by reverse transcription-polymerase chain reaction (RT-PCR). Gain- and loss- of experiments of miR-224 were implemented to verify the effects of CAF on NSCLC cell proliferation, invasion, and epithelial-mesenchymal transition (EMT), and endothelial cell (EC) angiogenesis. Overexpressing genetic or pharmacological interventions were performed to explore the potential mechanisms of Sirtuins 3/AMP-activated protein kinase/mammalian target of rapamycin/hypoxia-inducible factor-1α (SIRT3/AMPK/mTOR/HIF-1α).

Results: CAF enhanced the malignant phenotype of NSCLC cells and induced EC angiogenesis. miR-224 was significantly altered in CAFs. miR-224 up-regulation exacerbated NSCLC development mediated by CAFs, while miR-224 inhibition mostly reversed CAF-induced effects. Mechanistically, miR-224 targeted the 3’-untranslated regions (UTR) of SIRT3 mRNA, thereby inhibiting SIRT3/AMPK and activating mTOR/HIF-1α. Forced overexpression of SIRT3 up-regulated AMPK and inactivated mTOR/HIF-1α, while inhibiting HIF-1α markedly up-regulated SIRT3/AMPK and reduced mTOR phosphorylation. Interestingly, both Sirt1 overexpression and HIF-1α inhibition repressed miR-224 levels and miR-224-mediated promotive effects in NSCLC.

Conclusion: The miR-224-SIRT3/AMPK/mTOR/HIF-1α axis formed a positive feedback loop in modulating CAF-induced carcinogenic effects on NSCLC.

circ-ANXA7 facilitates lung adenocarcinoma progression via miR-331/LAD1 axis

Background

Lung adenocarcinoma (LUAD) is the most common histological subtype of lung cancer, with a poor prognosis. The roles of circular RNAs (circRNAs) in tumors have been initially clarified. In this study, we probed into the functions and underlying molecular mechanisms of circ-ANXA7 in LUAD.

Methods

According to circRNA microarray analysis based on 40 pairs of LUAD tissues and non-tumor tissues, a novel circ-ANXA7 was up-regulated in LUAD, which was verified in LUAD tissues and cells by RT-qPCR. Correlation between its expression and clinical features of LUAD was analyzed. When transfected with sh-circ-ANXA7, proliferation, invasion, and migration of LUAD cells were determined by a series of functional assays. Furthermore, tumor growth was investigated in nude mice injected with sh-circ-ANXA7. Dual luciferase report and gain and loss assays were used to confirm the relationships between circ-ANXA7 and miR-331, miR-331 and LAD1.

Results

circ-ANXA7 was up-regulated in LUAD tissues and cells. Its high expression promoted proliferation, migration, and invasion of LUAD cells as well as tumor growth. High circ-ANXA7 expression usually predicted a poorer prognosis for LUAD patients. Furthermore, circ-ANXA7 could accelerate proliferation and invasion of LUAD cells by targeting miR-331. miR-331 directly bound to the 3′-UTR of LAD1. LAD1 induced proliferation and invasion of LUAD cells, which was reversed after co-transfection with circ-ANXA7 knockdown. LAD1 expression could be an independent prognostic marker for LUAD by univariate and multivariate analysis.

Conclusions

Our research identified a novel circ-ANXA7 for LUAD, which could facilitate proliferation, migration, and invasion of LUAD cells by miR-331/ LAD1 axis. circ-ANXA7 could become a promising prognosis and treatment target for LUAD.

Alteration of Pituitary Tumor Transforming Gene 1 by MicroRNA-186 and 655 Regulates Invasion Ability of Human Oral Squamous Cell Carcinoma

Background: Pituitary tumor-transforming gene 1 (PTTG1) was recently shown to be involved in the progression as well as the metastasis of cancers. However, their expression and function in the invasion of oral squamous cell carcinoma (SCC) remain unclear. Methods: The expressions of PTTG1 and PTTG1-targeted miRNA in oral SCC cell lines and their invasion capability depended on PTTG1 expression were analyzed by quantitative RT-PCR, Western blots, the transwell insert system and Zymography. Results: Invasion abilities were decreased in oral SCC cells treated with siRNA-PTTG1. When PTTG1 were downregulated in oral SCC cells treated with microRNA-186 and -655 inhibited their invasion abilities via MMP-9 activity. Conclusions: These results indicate that alteration of expression of PTTG1 in oral SCC cells by newly identified microRNA-186 and -655 can regulate invasion activity. Therefore, these data offer new insights into further understanding PTTG1 function in oral SCC and should provide new strategies for diagnostic markers for oral SCC.

Construction and validation of a novel prognostic signature of microRNAs in lung adenocarcinoma

MicroRNA (miRNA, miR) has been reported to be highly implicated in a wide range of biological processes in lung cancer (LC), and identification of differentially expressed miRNAs between normal and LC samples has been widely used in the discovery of prognostic factors for overall survival (OS) and response to therapy. The present study was designed to develop and evaluate a miRNA-based signature with prognostic value for the OS of lung adenocarcinoma (LUAD), a common histologic subtype of LC. In brief, the miRNA expression profiles and clinicopathological factors of 499 LUAD patients were collected from The Cancer Genome Atlas (TCGA) database. Kaplan-Meier (K-M) survival analysis showed significant correlations between differentially expressed miRNAs and LUAD survival outcomes. Afterward, 1,000 resample LUAD training matrices based on the training set was applied to identify the potential prognostic miRNAs. The least absolute shrinkage and selection operator (LASSO) cox regression analysis was used to constructed a six-miRNA based prognostic signature for LUAD patients. Samples with different risk scores displayed distinct OS in K-M analysis, indicating considerable predictive accuracy of this signature in both training and validation sets. Furthermore, time-dependent receiver operating characteristic (ROC) analysis demonstrated the nomogram achieved higher predictive accuracy than any other clinical variables after incorporating the clinical information (age, sex, stage, and recurrence). In the stratification analysis, the prognostic value of this classifier in LUAD patients was validated to be independent of other clinicopathological variables, such as age, gender, tumor recurrence, and early stage. Gene set annotation analyses were also conducted through the Hallmark gene set and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, indicating target genes of the six miRNAs were positively related to various molecular pathways of cancer, such as hallmark UV response, Wnt signaling pathway and mTOR signaling pathway. In addition, fresh cancer tissue samples and matched adjacent tissue samples from 12 LUAD patients were collected to verify the expression of miR-582's target genes in the model, further revealing the potential relationship between SOX9, RASA1, CEP55, MAP4K4 and LUAD tumorigenesis, and validating the predictive value of the model. Taken together, the present study identified a robust signature for the OS prediction of LUAD patients, which could potentially aid in the individualized selection of therapeutic approaches for LUAD patients.

microRNAs Mediated Regulation of the Ribosomal Proteins and its Consequences on the Global Translation of Proteins

Ribosomal proteins (RPs) are mostly derived from the energy-consuming enzyme families such as ATP-dependent RNA helicases, AAA-ATPases, GTPases and kinases, and are important structural components of the ribosome, which is a supramolecular ribonucleoprotein complex, composed of Ribosomal RNA (rRNA) and RPs, coordinates the translation and synthesis of proteins with the help of transfer RNA (tRNA) and other factors. Not all RPs are indispensable; in other words, the ribosome could be functional and could continue the translation of proteins instead of lacking in some of the RPs. However, the lack of many RPs could result in severe defects in the biogenesis of ribosomes, which could directly influence the overall translation processes and global expression of the proteins leading to the emergence of different diseases including cancer. While microRNAs (miRNAs) are small non-coding RNAs and one of the potent regulators of the post-transcriptional gene expression, miRNAs regulate gene expression by targeting the 3' untranslated region and/or coding region of the messenger RNAs (mRNAs), and by interacting with the 5' untranslated region, and eventually finetune the expression of approximately one-third of all mammalian genes. Herein, we highlighted the significance of miRNAs mediated regulation of RPs coding mRNAs in the global protein translation.

Fentanyl Inhibits Lung Cancer Viability and Invasion via Upregulation of miR-331-3p and Repression of HDAC5

Purpose

Non-small cell lung cancer (NSCLC) accounts for more than 80% of lung cancer cases and remains the primary cause of cancer-related deaths worldwide. Fentanyl is a commonly utilized anesthetic during the process of tumor resection, and exhibits inhibitory effects on the progression of numerous cancer types, including pancreatic cancer, colorectal cancer and gastric cancer. However, the effects of fentanyl on the cell viability and invasion of NSCLC has not been investigated. Current study aimed to investigate the effects and the mechanisms underlying the effects of fentanyl on NSCLC.

Methods

The expression of μ-opioid receptor (MOR) was proved by flow cytometry. The expression of microRNA-331-3p (miR-331-3p) and histone deacetylase 5 (HDAC5) in NSCLC tissues and cell lines are evaluated by reverse transcription-quantitative PCR (RT-qPCR) and Western blot, respectively. Cell viability and invasion are measured by cell counting kit-8 (CCK-8) assay and transwell assay, respectively. The interaction between miR-331-3p and 3ʹ-untranslated region (UTR) of HDAC5 is predicted by TargetScan 7.1 (http://www.targetscan.org/vert_71/), validated by dual luciferase assay, RT-qPCR and Western blot.

Results

There was lower miR-331-3p expression and higher HDAC5 expression in NSCLC cell lines A549 and CALU-1 compared with BEAS-2B, which was reversed by fentanyl administration. miR-331-3p targeted 3ʹ-UTR of HDAC5 in NSCLC cell lines A549 and CALU-1. miR-331-3p inhibitor partially abrogated the inhibitory effects of fentanyl on NSCLC cell viability and invasion by targeting HDAC5. In addition, there was higher HDAC5 expression and lower miR-331-3p expression in tumor tissues which were isolated from patients with NSCLC compared to the adjacent normal tissues, and miR-331-3p was negatively correlated with HDAC5 in NSCLC tumor tissues.

Conclusion

Fentanyl inhibits the viability and invasion of NSCLC cells by induction of miR-331-3p and reduction of HDAC5.

Long Noncoding RNA PTPRG Antisense RNA 1 Reduces Radiosensitivity of Nonsmall Cell Lung Cancer Cells Via Regulating MiR-200c-3p/TCF4

Background:

PTPRG antisense RNA 1 has been well-documented to exert an oncogenic role in diverse neoplasms. However, the precise role of PTPRG antisense RNA 1 in regulating radiosensitivity of nonsmall cell lung cancer cells remains largely elusive.

Methods:

Expression levels of PTPRG antisense RNA 1 and miR-200c-3p in nonsmall cell lung cancer tissues and cells were detected by quantitative real-time polymerase chain reaction, while transcription factor 4 expression was examined by immunohistochemistry and Western blot. After nonsmall cell lung cancer cells were exposed to X-ray with different doses in vitro, Cell Counting Kit-8 assay and colony formation assay were conducted to determine the influence of PTPRG antisense RNA 1 on cell viability. Interaction between miR-200c-3p and PTPRG antisense RNA 1 as well as transcription factor 4 was investigated by dual luciferase reporter assay.

Result:

In nonsmall cell lung cancer tissues, the expressions of PTPRG antisense RNA 1 and transcription factor 4 were significantly upregulated, whereas the expression of miR-200c-3p was downregulated. It was also proved that PTPRG antisense RNA 1 and 3′-untranslated region of transcription factor 4 can bind to miR-200c-3p. Under X-ray irradiation, overexpressed PTPRG antisense RNA 1 could promote the viability and enhance the radioresistance of nonsmall cell lung cancer cells, and this effect was partially weakened by miR-200c-3p mimics. Transcription factor 4 was identified as a target gene of miR-200c-3p, which could be positively regulated by PTPRG antisense RNA 1.

Conclusion:

PTPRG antisense RNA 1 reduces the radiosensitivity of nonsmall cell lung cancer cells via modulating miR-200c-3p/TCF4 axis.

CHIP-mediated CIB1 ubiquitination regulated epithelial-mesenchymal transition and tumor metastasis in lung adenocarcinoma

CIB1 is a homolog of calmodulin that regulates cell adhesion, migration, and differentiation. It has been considered as an oncogene in many tumor cells; however, its role in lung adenocarcinoma (LAC) has not been studied. In this study, the expression levels of CIB1 in LAC tissues and adjacent normal tissues were examined by immunohistochemistry, and the relationship between CIB1 expression and patient clinicopathological characteristics was analyzed. The effects of CIB1 on epithelial–mesenchymal transition (EMT), migration, and metastasis of LAC cells were determined in vitro and vivo. Proteins interacting with CIB1 were identified using electrospray mass spectrometry (LS-MS), and CHIP was selected in the following assays. Carboxyl-terminus of Hsp70-interacting protein (CHIP) is a ubiquitin E3 ligase. We show that CHIP can degrade CIB1 via promoting polyubiquitination of CIB1 and its subsequent proteasomal degradation. Besides, lysine residue 10 and 65 of CIB1 is the ubiquitinated site of CIB1. Furthermore, CHIP-mediated CIB1 downregulation is critical for the suppression of metastasis and migration of LAC. These results indicated that CHIP-mediated CIB1 ubiquitination could regulate epithelial–mesenchymal and tumor metastasis in LAC.

The metastatic promoter DEPDC1B induces epithelial-mesenchymal transition and promotes prostate cancer cell proliferation via Rac1-PAK1 signaling

Metastasis is the major cause of prostate cancer (PCa)‐related mortality. Epithelial‐mesenchymal transition (EMT) is a vital characteristic feature that empowers cancer cells to adapt and survive at the beginning of metastasis. Therefore, it is essential to identify the regulatory mechanism of EMT in metastatic prostate cancer (mPCa) and to develop a novel therapy to block PCa metastasis. Here, we discovered a novel PCa metastasis oncogene, DEP domain containing 1B (DEPDC1B), which was positively correlated with the metastasis status, high Gleason score, advanced tumor stage, and poor prognosis. Functional assays revealed that DEPDC1B enhanced the migration, invasion, and proliferation of PCa cells in vitro and promoted tumor metastasis and growth in vivo. Mechanistic investigations clarified that DEPDC1B induced EMT and enhanced proliferation by binding to Rac1 and enhancing the Rac1‐PAK1 pathway. This DEPDC1B‐mediated oncogenic effect was reversed by a Rac1‐GTP inhibitor or Rac1 knockdown. In conclusion, we discover that the DEPDC1B‐Rac1‐PAK1 signaling pathway may serve as a multipotent target for clinical intervention in mPCa.

miR-331-3p Suppresses Cell Proliferation in TNBC Cells by Downregulating NRP2

PURPOSE

Triple-negative breast cancer is characterized by fast progression with high possible for metastasis and poor survival. Dysfunction of microRNAs plays an important role in the initiation and progression of cancer. Our previous microRNA-seq data indicated the downregulation of miR-331-3p in triple-negative breast cancer tissues compared with that of the noncancer tissues. However, the function of miR-331-3p in triple-negative breast cancer remains largely unknown. Herein, the involvement of miR-331-3p in triple-negative breast cancer was investigated and the therapeutic potential of miR-331-3p was also explored.

METHODS

Real-time quantitative polymerase chain reaction was performed to detect the expression of miR-331-3p in triple-negative breast cancer tissues and cell lines. The cell proliferation was determined by the cell counting kit-8 assay. Apoptosis of triple-negative breast cancer cells was examined by annexin V/propidium iodide staining. miRDB database was used to predict the potential targets of miR-331-3p. Western blot was performed to examine the expression of the target protein.

RESULTS

miR-331-3p was significantly downregulated in triple-negative breast cancer tissues and cell line. Lower miR-331-3p expression was significantly correlated with the tumor size, TNM stage, and lymph node metastasis of patients with triple-negative breast cancer. Functional experiments showed that the overexpression of miR-331-3p inhibited the proliferation and increased apoptosis of triple-negative breast cancer cells. Neuropilin-2 was identified as a target of miR-331-3p, which harbored binding site of miR-331-3p in its 3'-untranslated region. Overexpression of miR-331-3p decreased the messenger RNA and protein levels of neuropilin-2 in triple-negative breast cancer cells. Restoration of neuropilin-2 partially reversed the inhibitory effects of miR-331-3p on the proliferation of triple-negative breast cancer cells.

CONCLUSIONS

Our results demonstrated the novel function of miR-331-3p/neuropilin-2 signaling in regulating the malignant behaviors of triple-negative breast cancer cells, which suggested miR-331-3p as a potential target for the treatment of triple-negative breast cancer.

MiR-331-3p Links to Drug Resistance of Pancreatic Cancer Cells by Activating WNT/β-Catenin Signal via ST7L

Background:

Pancreatic cancer is an aggressive type of cancer with poor prognosis, short survival rate, and high mortality. Drug resistance is a major cause of treatment failure in the disease. MiR-331-3p has been reported to play an important role in several cancers. We previously showed that miR-331-3p is upregulated in pancreatic cancer and promotes pancreatic cancer cell proliferation and epithelial-to-mesenchymal transition–mediated metastasis by targeting ST7L. However, it is uncertain whether miR-331-3p is involved in drug resistance.

Methods:

We investigated the relationship between miR-331-3p and pancreatic cancer drug resistance. As part of this, microRNA mimics or inhibitors were transfected into pancreatic cancer cells. Quantitative polymerase chain reaction was used to detect miR-331-3p expression, and flow cytometry was used to detect cell apoptosis. The Cell Counting Kit-8 assay was used to measure the IC50 values of gemcitabine in pancreatic cancer cells. The expression of multidrug resistance protein 1, multidrug resistance-related protein 1, breast cancer resistance protein, β-Catenin, c-Myc, Cyclin D1, Bcl-2, and Caspase-3 was evaluated by Western blotting.

Results:

We confirmed that miR-331-3p is upregulated in gemcitabine-treated pancreatic cancer cells and plasma from chemotherapy patients. We also confirmed that miR-331-3p inhibition decreased drug resistance by regulating cell apoptosis and multidrug resistance protein 1, multidrug resistance-related protein 1, and breast cancer resistance protein expression in pancreatic cancer cells, whereas miR-331-3p overexpression had the opposite effect. We further demonstrated that miR-331-3p effects in drug resistance were partially reversed by ST7L overexpression. In addition, overexpression of miR-331-3p activated Wnt/β-catenin signaling in pancreatic cancer cells, and ST7L overexpression restored activation of Wnt/β-catenin signaling.

Conclusions:

Taken together, our data demonstrate that miR-331-3p contributes to drug resistance by activating Wnt/β-catenin signaling via ST7L in pancreatic cancer cells. These data provide a theoretical basis for new targeted therapies in the future.

Exosome-Reversed Chemoresistance to Cisplatin in Non-Small Lung Cancer Through Transferring miR-613

Introduction

Non-small lung cancer (NSCLC) is one of the most common malignant tumors in the world. Chemoresistance is the main reason of adverse effects leading to the death of patients; thus, it is important to discover the potential target of chemotherapeutic resistance.

Methods

The expression of differentially expressed miRNA was detected in BEAS-2B, A549 and A549/cisplatin (DDP) by qRT-PCR. Transmission electron microscopy (TEM) and exosome biomarkers were used to validate the extracted exosome. Cells incubated with miR-613 enriched exosomes were used to detect the function of exo-miR-613 in vitro. Then, exo-miR-613 was injected to mice treated with DDP to investigate the function role of exo-miR-613 in vivo.

Results

Comparing to BEAS-2B, the expression of miR-613 inA549 was significantly reduced, which was more obvious in A549/DDP. After incubated with exo-miR-613 and corresponding exo-negative control (NC), we found overexpression of miR-613 remarkably increased the inhibition of cell proliferation induced by cisplatin. Exo-miR-613 fused into cells to significantly enhance the inhibited effect of DDP on the proliferation, migration and showed a promotion on cell apoptosis and DNA damage. The in vivo study showed that exo-miR-613 significantly inhibited the tumor growth, and promote the sensitivity to DDP, probably by down-regulating the expressions of GJA1, TBP and EIF-4E in tumor cells and tissues.

Conclusion

Exo-miR-613 reversed chemoresistance to DDP in NSCLC cell to involve in the process of tumor progression, and might be a potential therapeutic strategy for NSCLC.

Disparities in Head and Neck Cancer: A Case for Chemoprevention with Vitamin D

Blacks experience disproportionate head and neck cancer (HNC) recurrence and mortality compared to Whites. Overall, vitamin D status is inversely associated to HNC pointing to a potential protective linkage. Although hypovitaminosis D in Blacks is well documented it has not been investigated in Black HNC patients. Thus, we conducted a prospective pilot study accessing vitamin D status in newly diagnosed HNC patients stratified by race and conducted in vitro studies to investigate mechanisms associated with potential cancer inhibitory effects of vitamin D. Outcome measures included circulating levels of vitamin D, related nutrients, and risk factor characterization as well as dietary and supplemental estimates. Vitamin D-based in vitro assays utilized proteome and microRNA (miR) profiling. Nineteen patients were enrolled, mean circulating vitamin D levels were significantly reduced in Black compared to White HNC patients, 27.3 and 20.0 ng/mL, respectively. Whites also supplemented vitamin D more frequently than Blacks who had non-significantly higher vitamin D from dietary sources. Vitamin D treatment of HNC cell lines revealed five significantly altered miRs regulating genes targeting multiple pathways in cancer based on enrichment analysis (i.e., negative regulation of cell proliferation, angiogenesis, chemokine, MAPK, and WNT signaling). Vitamin D further altered proteins involved in cancer progression, metastasis and survival supporting a potential role for vitamin D in targeted cancer prevention.

Overexpression of miR-331 Indicates Poor Prognosis and Promotes Progression of Breast Cancer

BACKGROUND

With the increasing number of cases of breast cancer every year, the exploration of novel biomarkers has drawn attention. miR-331 has been demonstrated to play a role in various cancers, but its role in breast cancer is still unknown.

METHODS

In this study, we included 121 patients with breast cancer treated at Affiliated Hospital of Weifang Medical University. Breast cancer tissues and adjacent normal tissues were collected during the surgery. The expression of miR-331 in breast cancer tissues and cell lines was detected by qRT-PCR assay. Then, with the help of Kaplan-Meier survival and Cox regression analyses, the role of miR-331 in the prognosis of breast cancer was analyzed. Finally, the effect of miR-331 on cell proliferation, migration, and invasion was investigated with CCK-8 assay and transwell assay.

RESULTS

miR-331 was significantly upregulated in breast cancer tissues compared with normal tissues. The overexpression of miR-331 was associated with lymph node metastasis, TNM stage, and poor prognosis. From the results of Cox regression analyses, it was found that miR-331 served as an independent indicator in the prognosis of breast cancer. In addition, miR-331 was also found to be upregulated in breast cancer cells, which promoted cell proliferation, migration, and invasion of breast cancer.

CONCLUSION

As shown from our data, miR-331 may be a potential prognostic biomarker in breast cancer. Moreover, the development and progression of breast cancer may involve miR-331. These findings suggest a novel therapeutic target for the treatment of breast cancer.

Inhibition of Rac1 reverses enzalutamide resistance in castration-resistant prostate cancer

Enzalutamide, an androgen receptor inhibitor, has been clinically approved for the treatment of metastatic castration-resistant prostate cancer (CRPC) in the United States. However, patients only benefit from enzalutamide for a short period of time as resistance may develop. Therefore, it is vital to develop a novel strategy to overcome enzalutamide resistance. Ras-related C3 botulinum toxin substrate 1 (Rac1), which is commonly upregulated in human cancer types, has been recognized as a key molecular component in tumorigenesis, invasion and metastasis. However, the role of Rac1 in enzalutamide-resistance in prostate cancer (PCa) remains unknown. In the present study, Rac1 was demonstrated to be upregulated in enzalutamide-resistant PCa cells, and Rac1 knockdown inhibited enzalutamide-resistant cell proliferation and colony formation. Western blotting results indicated that enzalutamide treatment downregulated the expression levels of JNK and activated transcription factor 2, as well as enhanced the Bax/Bcl-2 ratio and induced cleavage of poly-ADP ribose polymerase. Moreover, knockdown of Rac1 in MR49F cells significantly inhibited cell migration and invasion via the downregulation of Snail and the upregulation of E-cadherin. The results of a nude mouse xenograft tumor model using 22RV1 cells demonstrated that enzalutamide inhibited tumor growth after Rac1 knockdown dramatically, compared to vehicle and single treatment groups. Therefore, the present study provided novel evidence that Rac1 may serve a crucial role in enzalutamide resistance, and that targeting Rac1 may be a potential approach for the treatment of CRPC.

P21-Activated Kinase 1: Emerging biological functions and potential therapeutic targets in Cancer

The p21-Activated kinase 1 (PAK1), a member of serine-threonine kinases family, was initially identified as an interactor of the Rho GTPases RAC1 and CDC42, which affect a wide range of processes associated with cell motility, survival, metabolism, cell cycle, proliferation, transformation, stress, inflammation, and gene expression. Recently, the PAK1 has emerged as a potential therapeutic target in cancer due to its role in many oncogenic signaling pathways. Many PAK1 inhibitors have been developed as potential preclinical agents for cancer therapy. Here, we provide an overview of essential roles that PAK1 plays in cancer, including its structure and autoactivation mechanism, its crucial function from onset to progression to metastasis, metabolism, immune escape and even drug resistance in cancer; endogenous regulators; and cancer-related pathways. We also summarize the reported PAK1 small-molecule inhibitors based on their structure types and their potential application in cancer. In addition, we provide overviews on current progress and future challenges of PAK1 in cancer, hoping to provide new ideas for the diagnosis and treatment of cancer.

Downregulation of miR-125b-5p and Its Prospective Molecular Mechanism in Lung Squamous Cell Carcinoma

Background: To explore the clinical significance of miR-125b-5p and its potential mechanisms in lung squamous cell carcinoma (LUSC). Materials and Methods: An integrated analysis of data from in-house quantitative real-time polymerase chain reaction (qRT-PCR), microRNA-sequencing, and microarray assays to appraise the expression level of miR-125b-5p in LUSC tissues compared to adjacent noncancerous controls. The authors identified the candidate targets of miR-125b-5p and conducted functional analysis using computational biology strategies from gene ontology, the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis, disease ontology (DO), and protein-protein interaction (PPI) network analyses to investigate the prospective mechanisms. Results: According to qRT-PCR results, the expression level of miR-125b-5p was markedly decreased in LUSC tissues compared to noncancerous control tissues. Receiver operating characteristic and summary receiver operating characteristic analyses showed that miR-125b-5p had good specificity and sensitivity for distinguishing LUSC tissue from noncancerous lung tissue. The standard mean difference revealed that men and women with lower expression levels of miR-125b-5p may have a higher risk for LUSC. KEGG analysis and DO analysis intimated that target genes were evidently enriched in pyrimidine metabolism and pancreatic carcinoma. The PPI network of the top assembled KEGG pathway indicated that RRM2, UMPS, UCK2, and CTPS1 were regarded as crucial target genes for miR-125b-5p, and RRM2 was eventually deemed a key target. Conclusions: The authors' findings implicate a low expression level of miR-125b-5p in LUSC. A tumor-suppressive role of miR-125b-5p is proposed, based on its effects on LUSC tumor growth, clinical stage progression, and lymph node metastasis.

MicroRNA Regulation of the Small Rho GTPase Regulators-Complexities and Opportunities in Targeting Cancer Metastasis

The small Rho GTPases regulate important cellular processes that affect cancer metastasis, such as cell survival and proliferation, actin dynamics, adhesion, migration, invasion and transcriptional activation. The Rho GTPases function as molecular switches cycling between an active GTP-bound and inactive guanosine diphosphate (GDP)-bound conformation. It is known that Rho GTPase activities are mainly regulated by guanine nucleotide exchange factors (RhoGEFs), GTPase-activating proteins (RhoGAPs), GDP dissociation inhibitors (RhoGDIs) and guanine nucleotide exchange modifiers (GEMs). These Rho GTPase regulators are often dysregulated in cancer; however, the underlying mechanisms are not well understood. MicroRNAs (miRNAs), a large family of small non-coding RNAs that negatively regulate protein-coding gene expression, have been shown to play important roles in cancer metastasis. Recent studies showed that miRNAs are capable of directly targeting RhoGAPs, RhoGEFs, and RhoGDIs, and regulate the activities of Rho GTPases. This not only provides new evidence for the critical role of miRNA dysregulation in cancer metastasis, it also reveals novel mechanisms for Rho GTPase regulation. This review summarizes recent exciting findings showing that miRNAs play important roles in regulating Rho GTPase regulators (RhoGEFs, RhoGAPs, RhoGDIs), thus affecting Rho GTPase activities and cancer metastasis. The potential opportunities and challenges for targeting miRNAs and Rho GTPase regulators in treating cancer metastasis are also discussed. A comprehensive list of the currently validated miRNA-targeting of small Rho GTPase regulators is presented as a reference resource.

Hsa_circ_0038646 promotes cell proliferation and migration in colorectal cancer via miR-331-3p/GRIK3

Increasing evidence supports the essential roles of circular RNAs (circRNAs) and microRNAs (miRNAs/miRs) in different types of human cancer. For example, hsa_circ_0137008 functions as a sponge for mi-338-5p and inhibits the malignant phenotype in colorectal cancer. Furthermore, hsa_circ_RNA_0011780 downregulates FBXW7 by targeting miR-554a and suppressing the progression of non-small cell lung cancer. Thus far, only a single report has identified that the miRNA miR-331-3p exerts a pivotal effect on human colorectal cancer (CRC) evolution. However, both the up- and downstream regulatory mechanisms of miR-331-3p are unclear. In the present study, it was predicted via bioinformatics analysis that the circRNA, hsa_circ_0038646, and the glutamate receptor ionotropic kainate 3 (GRIK3) gene contain binding sites that can interact with miR-331-3p. Thus, hsa_circ_0038646/miR-331-3p/GRIK3 may be a novel therapeutic pathway for CRC. Reverse transcription-quantitative PCR and western blotting analyses were performed, as well as cell proliferation, luciferase reporter and Transwell migration assays. Hsa_circ_0038646 was overexpressed in both CRC cells and tissues, and this aberrant expression was positively related with increasing tumor grade. Knockdown of hsa_circ_0038646 significantly weakened human CRC cell proliferation and migration. It was shown that hsa_circ_0038646 can sponge miR-331-3p to suppress its expression, and that suppression of miR-331-3p can reverse the effects of hsa_circ_0038646 inhibition in CRC cells. It was determined that GRIK3 is a downstream target of miR-331-3p, and that hsa_circ_0038646 could increase the levels of GRIK3 by suppressing miR-331-3p in CRC cells. Restoring GRIK3 expression rescued the weakened CRC cell proliferation and migration following hsa_circ_0038646 knockdown. The present study indicated that hsa_circ_0038646 functions as a tumor promoter in CRC by increasing GRIK3 expression via sponging of miR-331-3p. The hsa_circ_0038646/miR-331-3p/GRIK3 axis may be a novel therapeutic and diagnostic target of CRC.

Long Non-Coding RNA Cancer Susceptibility 9 (CASC9) Up-Regulates the Expression of ERBB2 by Inhibiting miR-193a-5p in Colorectal Cancer

Background

Emerging studies have reported that long non-coding RNAs (lncRNAs) were crucial regulators in the progression of colorectal cancer (CRC). LncRNA susceptibility 9 (CASC9) was involved in several cancers; however, its role in CRC remains unknown.

Methods

RT-PCR was done to probe the expression of CASC9 and miR-193a-5p in CRC samples. CRC cell lines (HCT116 and SW480) were used as cell models. The biological influence of CASC9 on cancer cells was studied using CCK-8 assay, Transwell assay and TUNEL assay in vitro, and subcutaneous xenotransplanted tumor model in vivo. Interaction between CASC9 and miR-193a-5p was investigated by bioinformatics analysis, RT-PCR, and luciferase reporter assay. The expression level of the downstream gene of miR-193a-5p, erb-b2 receptor tyrosine kinase 2 (ERBB2), was tested by Western blot.

Results

CASC9 was significantly up-regulated in CRC samples, while miR-193a-5p was markedly down-regulated. Overexpression of CASC9 promoted viability, migration and invasion of CRC cells, while overexpression of miR-193a-5p had the opposite effect. CASC9 could down-regulate miR-193a-5p via sponging it, and there was a negative relevancy between CASC9 and miR-193a-5p in CRC samples. CASC9 also enhanced the expression levels of ERBB2, while this effect could be reversed by co-transfection with miR-193a-5p.

Conclusion

CASC9, an oncogenic lncRNA, was abnormally up-regulated in CRC tissues, and it could indirectly modulate the expression of ERBB2 via reducing the expression level of miR-193a-5p.

LncRNA SBF2-AS1 affects the radiosensitivity of non-small cell lung cancer via modulating microRNA-302a/MBNL3 axis

Background: Long non-coding RNAs (lncRNAs) have been reported to participate in many diseases including non-small cell lung cancer (NSCLC), thus our objective was to investigate the impact of lncRNA SBF2-AS1 modulating microRNA-302a (miR-302a) expression on radiosensitivity of NSCLC.Methods: The expression of SBF2-AS1, miR-302a and muscleblind-like 3 (MBNL3) in NSCLC tissues of the radiotherapy-sensitive and radiotherapy-resistant groups was tested. The radiosensitivity of parent and resistant strains (NCI-H1299 and NCI-H1299_R cells) was detected. Further, cells were treated with si-SBF2-AS1 and miR-302a mimics to determine their roles in proliferation and apoptosis of parent strain and resistant strain cells as well as transfected cells. The in-vivo growth capacity of the cells and the effect of radiotherapy on tumor size of NSCLC were detected.Results: Up-regulated SBF2-AS1 and MBNL3 and down-regulated miR-302a in NSCLC tissues of the radiotherapy resistant group. Overexpression of SBF2-AS1 and MBNL3 and low expression of miR-302a were witnessed in NCI-H1299_R cells. Down-regulated SBF2-AS1 or up-regulated miR-302a suppressed the proliferation while boosted the apoptosis of NCI-H1299 cells and decreased the radioresistance of the NCI-H1299_R cells. Silencing SBF2-AS1 or up-regulating miR-302a restrained tumor growth in vivo.Conclusion: Our study presents that high expression of miR-302a or inhibition of SBF2-AS1 can enhance the radiosensitivity and apoptosis of NSCLC cells through downregulation of MBNL3, which is a therapeutic target for NSCLC.

MicroRNA-877 inhibits cell proliferation and invasion in non-small cell lung cancer by directly targeting IGF-1R

MicroRNAs (miRNAs/miRs) are frequently differentially expressed in non-small cell lung cancer (NSCLC), and differential miRNAs expression may be closely associated with NSCLC genesis and development. Therefore, an in-depth investigation of the cancer-associated miRNAs that are crucial for NSCLC pathogenesis may provide effective therapeutic targets for patients with this aggressive malignant tumor type. The expression levels and roles of miR-877 have been well studied in hepatocellular carcinoma and renal cell carcinoma. However, the expression pattern and functions of miR-877 in NSCLC as well as associated underlying mechanisms, to the best of our knowledge, have not yet been investigated. The present study revealed that miR-877 expression was downregulated in NSCLC tissues and cell lines. Low miR-877 expression was significantly associated with TNM stage and distant metastasis in patients with NSCLC. Functional experiments demonstrated that recovery of miR-877 expression restricted the proliferation and invasion of NSCLC cells. In addition, bioinformatics analysis predicted insulin-like growth factor 1 receptor (IGF-1R) as a potential target of miR-877. Luciferase reporter assays, reverse transcription-quantitative PCR and western blot analysis further validated that IGF-1R was a direct target of miR-877 in NSCLC. Furthermore, IGF-1R expression was markedly upregulated in NSCLC tissues, and exhibited an inverse correlation with miR-877 expression. Additionally, IGF-1R overexpression reversed the inhibitory effects in NSCLC cells caused by miR-877 upregulation. These findings demonstrated that miR-877 attenuated NSCLC cell proliferation and invasion, at least partly, by downregulating IGF-1R expression, thereby providing an new candidate biomarker for the diagnosis and therapy of patients with NSCLC.

MicroRNA-331-3p inhibits epithelial-mesenchymal transition by targeting ErbB2 and VAV2 through the Rac1/PAK1/β-catenin axis in non-small-cell lung cancer

MicroRNAs have been reported to play critical roles in the regulation of non-small-cell cancer (NSCLC) development, but the role of microRNA (miR)-331-3p in NSCLC is still unclear. In this study, the expression levels of miR-331-3p in NSCLC tumor tissues and adjacent normal tissues were examined by quantitative RT-PCR, and the relationship between miR-331-3p expression and patient clinicopathological characteristics was analyzed. The effects of miR-331-3p on epithelial-mesenchymal transition (EMT), migration, and metastasis of NSCLC cells were determined in vitro and vivo. Direct functional targets of miR-331-3p were identified by luciferase reporter assay, western blot assay, immunohistochemical staining, and rescue assay. The downstream pathway regulated by miR-331-3p was identified by immunofluorescence, immunoprecipitation, and Rac1 activity examination. Our results showed that miR-331-3p was significantly downregulated in NSCLC tumor tissues and was correlated with clinicopathological characteristics, and miR-331-3p could be an independent prognostic marker for NSCLC patients. Furthermore, miR-331-3p significantly suppressed EMT, migration and metastasis of NSCLC cells in vitro and in vivo. Both ErbB2 and VAV2 were direct functional targets of miR-331-3p. The activities of Rac1, PAK1, and β-catenin were regulated by miR-331-3p through ErbB2 and VAV2 targeting. These results indicated that miR-331-3p suppresses EMT, migratory capacity, and metastatic ability by targeting ErbB2 and VAV2 through the Rac1/PAK1/β-catenin axis in NSCLC.