MiR-765 functions as a tumour suppressor and eliminates lipids in clear cell renal cell carcinoma by downregulating PLP2

The role of miR-765 in human cancers

MicroRNAs, a collection of short noncoding RNAs, are promising biomarkers for identifying cancer in its early stages and tracking the effectiveness of treatment. This is due to their critical role in regulating gene expression and other vital biological functions via cell-level epigenetic mechanisms. This review brings together data on the molecular and clinical effects of miR-765 on different types of cancer. Significant variation in miR-765 levels has been observed in a variety of cancer types, suggesting that it could have an oncogene or tumor suppressor role. A number of pathways, including PLP2/Notch, VEGFA/Akt1, PDX1, KLK4, RUNX2, DPF3, EMP3, APE1, ERK/EMT axis, and others, are impacted by the inclusion of miR-765 in their analysis. MiR-765 is an essential biomarker that shows promise as a diagnostic tool for various types of cancer. The latest research has identified them as reliable predictive markers for detecting tumor development at an early stage. Based on our study, miR-765 shows promising potential as a biomarker for prognosis in multiple types of cancer. Specifically, we suggest that miR-765 could be an early detection marker for tumor development, progression, and metastasis.

Hsa_circ_0086414/transducer of ERBB2 (TOB2) axis-driven lipid elimination and tumor suppression in clear cell renal cell cancer via perilipin 3

BACKGROUND

Renal cell cancer (RCC) is characterized by abnormal lipid accumulation. However, the specific mechanism by which such lipid deposition is eliminated remains unclear. Circular RNAs (circRNAs) widely regulate various biological processes, but the effect of circRNAs on lipid metabolism in cancers, especially clear cell renal cell carcinoma (ccRCC), remains poorly understood.

METHODS

The downregulated circRNA, hsa_circ_0086414, was identified from high-throughput RNA-sequencing data of human ccRCC and pair-matched normal tissues. The target relationship between circRNA_0086414 and miR-661, and the transducer of ERBB2 (TOB2) was predicted using publicly available software programs and verified by luciferase reporter assays. The clinical prognostic value of TOB2 was evaluated by bioinformatic analysis. The expression levels of circRNA_0086414, miR-661, TOB2, and perilipin 3 (PLIN3) were measured by quantitative reverse-transcription polymerase chain reaction or western blot analysis. Cell Counting Kit-8, transwell assays, and xenograft models were employed to assess the biological behaviors of the hsa_circ_0086414/TOB2 axis. Oil Red staining and triglyceride assay was conducted to assess lipid deposition.

RESULTS

Herein, we identified a downregulated circRNA, hsa_circ_0086414. Functionally, the restored hsa_circ_0086414 inhibited ccRCC proliferation, metastasis, and lipid accumulation in vitro and in vivo. Furthermore, the downregulated TOB2 predicted adverse prognosis and promoted cancer progression and lipid deposition in ccRCC. Mechanically, the binding of hsa_circ_0086414 to miR-661, as a miRNA sponge, upregulates the expression of TOB2, wielding an anti-oncogene effect. Importantly, the restored hsa_circ_0086414/TOB2 axis significantly contributed to the elimination of lipid deposition by inhibiting the lipid metabolism regulator PLIN3 in ccRCC cells.

CONCLUSIONS

Our data highlight the importance of the hsa_circ_0086414/TOB2/PLIN3 axis as a tumor suppressor and lipid eliminator in ccRCC. The positive modulation of the hsa_circ_0086414/TOB2 axis might lead to the development of novel treatment strategies for ccRCC.

Use of Droplet Digital Polymerase Chain Reaction to Identify Biomarkers for Differentiation of Benign and Malignant Renal Masses

Several microRNAs (miRNAs) have been identified as cell-free biomarkers for detecting renal cell carcinoma (RCC). Droplet digital polymerase chain reaction (ddPCR) is a unique technology for nucleic acid quantification. It has the potential for superior precision, reproducibility, and diagnostic performance in identifying circulating miRNA biomarkers compared to conventional quantitative real-time PCR (qRT-PCR). This study aims to evaluate the performance of ddPCR compared to qRT- PCR in identifying miRNA biomarkers that differentiate malignant from benign renal masses. Potential biomarkers of RCC were identified from a literature review. RNA was extracted from the plasma of 56 patients. All the samples underwent analysis via ddPCR as well as qRT-PCR, and expression levels were recorded for the following miRNAs: miR-93, -144, -210, -221, and -222. Tumors were grouped into low-grade ccRCC, high-grade ccRCC, papillary RCC, and benign masses (primarily angiomyolipoma). The miRNA miR-210 (p = 0.034) and the combination of miRs-210 and miR-222 (p = 0.003) were expressed at significantly higher rates among those with RCC than those with benign masses, as measured by ddPCR. Using the combination of miR-210 and miR-222, ddPCR identified significant differences between the subgroups: papillary RCC versus benign (p = 0.03), low-grade ccRCC versus benign (p = 0.026), and high-grade ccRCC versus benign (p = 0.002). The only significant difference between these subgroups using qRT-PCR was between high-grade ccRCC and benign (p = 0.045). All the AUCs were significant when comparing each RCC subgroup with benign for both PCR technologies. Using a combination of miR-210 and miR-222, ddPCR identified significant differences between benign and malignant renal masses that were not identified as significant by conventional qRT-PCR.

Liquid Biopsy: A New Avenue for the Diagnosis of Kidney Disease: Diabetic Kidney Disease, Renal Cancer, and IgA Nephropathy

Kidney diseases are some of the most common healthcare problems. As the population of elderly individuals with concurrent health conditions continues to rise, there will be a heightened occurrence of these diseases. Due to the renal condition being one of the longevity predictors, early diagnosis of kidney dysfunction plays a crucial role. Currently, prevalent diagnostic tools include laboratory tests and kidney tissue biopsies. New technologies, particularly liquid biopsy and new detection biomarkers, hold promise for diagnosing kidney disorders. The aim of this review is to present modern diagnostic methods for kidney diseases. The paper focuses on the advances in diagnosing three common renal disorders: diabetic kidney disease, renal cancer, and immunoglobulin A nephropathy. We highlight the significance of liquid biopsy and epigenetic changes, such as DNA methylation, microRNA, piRNAs, and lncRNAs expression, or single-cell transcriptome sequencing in the assessment of kidney diseases. This review underscores the importance of early diagnosis for the effective management of kidney diseases and investigates liquid biopsy as a promising approach.

Targeting lipid biosynthesis on the basis of conventional treatments for clear cell renal cell carcinoma: A promising therapeutic approach

A variety of cancer cells exhibit dysregulated lipid metabolism, characterized by excessive intracellular lipid accumulation, and clear cell renal cell carcinoma (ccRCC) is the most typical disease with these characteristics. As the most common malignancy of all renal cell carcinomas (RCCs), ccRCC is typically characterized by a large accumulation of lipids and glycogen in the cytoplasm and a nucleus that is squeezed by the accumulated lipid droplets and localized to the marginal areas within the cytoplasm. This lipid accumulation has been found to be critically involved in the maintenance of malignant features observed in various cancers. Firstly, it maintains the persistent proliferative and metastasis properties of cancer cells. Secondly, it acts as a buffer against lipid peroxidation, preventing lipid peroxidation-induced ferroptosis. Moreover, lipids can diminish the sensitivity of cancer cells to radiotherapy. As ccRCC is a type of cancer with high lipid synthesis, targeting lipid synthesis-related genes in cancer cells may be a promising therapeutic modality for single treatment or in combination with radiotherapy, chemotherapy, and immunotherapy. This may revolutionize the choice of treatment modality for ccRCC patients. In this review, we concentrate on the current status and progress of research on lipid biosynthesis in ccRCC and the potential applications of targeting lipid synthesis to treat ccRCC. At last, we propose perspective and future research directions for targeting inhibition of lipid biosynthesis in combination with conventional therapeutic approaches for the treatment of ccRCC, which will help to evolve the therapeutic model.

Reduced Proteolipid Protein 2 promotes endoplasmic reticulum stress-related apoptosis and increases drug sensitivity in acute myeloid leukemia

BACKGROUND

The Proteolipid Protein 2 (PLP2), a protein in the Endoplasmic Reticulum (ER) membrane, has been reported to be highly expressed in various tumors. Previous studies have demonstrated that the reduced PLP2 can induce apoptosis and autophagy through ER stress-related pathways, leading to a decreased proliferation and aggressiveness. However, there is no research literature on the role of PLP2 in Acute Myeloid Leukemia (AML).

METHODS

PLP2 expression, clinical data, genetic mutations, and karyotype changes from GEO, TCGA, and timer2.0 databases were analyzed through the R packages. The possible functions and pathways of cells were explored through GO, KEGG, and GSEA enrichment analysis using the clusterProfiler R package. Immuno-infiltration analysis was conducted using the Cibersort algorithm and the Xcell R package. RT-PCR and western blot techniques were employed to identify the PLP2 expression, examine the knockdown effects in THP-1 cells, and assess the expression of genes associated with endoplasmic reticulum stress and apoptosis. Flow cytometry was utilized to determine the apoptosis and survival rates of different groups.

RESULTS

PLP2 expression was observed in different subsets of AML and other cancers. Enrichment analyses revealed that PLP2 was involved in various tumor-related biological processes, primarily apoptosis and lysosomal functions. Additionally, PLP2 expression showed a strong association with immune cell infiltration, particularly monocytes. In vitro, the knockdown of PLP2 enhanced endoplasmic reticulum stress-related apoptosis and increased drug sensitivity in THP-1 cells.

CONCLUSIONS

PLP2 could be a novel therapeutic target in AML, in addition, PLP2 is a potential endoplasmic reticulum stress regulatory gene in AML.

miR-765 targeting PDX1 impairs pancreatic β-cell function to induce type 2 diabetes

Type 2 diabetes (T2DM) is a chronic metabolism disorder with a symptom as pancreatic β-cell dysfunction. In this study, the bioinformatics analysis identified the key regulators (PDX1 and miR-765) in T2DM. By qRT-PCR and western blotting, miR-765 with high expression and PDX1 with low expression were observed in blood samples from T2DM patients and the T2DM cell model. Together with GSIS assay, CCK-8, TUNEL assay, glycolysis assay, and mitochondrial respiration assay, miR-765 overexpression impaired insulin secretion cell viability, glycolysis, and mitochondrial respiration, while enhanced cell apoptosis in pancreatic β-cell. The Luciferase reporter, RIP, and RNA pull-down assays showed that PDX1 was the target gene of miR-765 in pancreatic β-cell. Besides, the negative effect of miR-765 on pancreatic β-cell could be overturned by PDX1 overexpression. In conclusion, we confirmed that miR-765 could cause a detrimental effect on pancreatic β-cell survival and function by targeting PDX1, which might provide new insight for T2DM therapy.

PLP2 Could Be a Prognostic Biomarker and Potential Treatment Target in Glioblastoma Multiforme

Objective

This study aimed to discern the association between PLP2 expression, its biological significance, and the extent of immune infiltration in human GBM.

Methods

Utilizing the GEPIA2 and TCGA databases, we contrasted the expression levels of PLP2 in GBM against normal tissue. We utilized GEPIA2 and LinkedOmics for survival analysis, recognized genes co-expressed with PLP2 via cBioPortal and GEPIA2, and implemented GO and KEGG analyses. The STRING database facilitated the construction of protein-protein interaction networks. We evaluated the relationship of PLP2 with tumor immune infiltrates using ssGSEA and the TIMER 2.0 database. An IHC assay assessed PLP2 and PDL-1 expression in GBM tissue, and the Drugbank database aided in identifying potential PLP2-targeting compounds. Molecular docking was accomplished using Autodock Vina 1.2.2.

Results

PLP2 expression was markedly higher in GBM tissues in comparison to normal tissues. High PLP2 expression correlated with a decrease in overall survival across two databases. Functional analyses highlighted a focus of PLP2 functions within leukocyte. Discrepancies in PLP2 expression were evident in immune infiltration, impacting CD4+ T cells, neutrophils, myeloid dendritic cells, and macrophages. There was a concomitant increase in PLP2 and PD-L1 expression in GBM tissues, revealing a link between the two. Molecular docking with ethosuximide and praziquantel yielded scores of -7.441 and -4.295 kcal/mol, correspondingly.

Conclusion

PLP2's upregulation in GBM may adversely influence the lifespan of GBM patients. The involvement of PLP2 in pathways linked to leukocyte function is suggested. The positive correlation between PLP2 and PD-L1 could provide insights into PLP2's role in glioma modulation. Our research hints at PLP2's potential as a therapeutic target for GBM, with ethosuximide and praziquantel emerging as potential treatment candidates, especially emphasizing the potential of these compounds in GBM treatment targeting PLP2.

MicroRNA-765 is upregulated in myelodysplastic syndromes and induces apoptosis via PLP2 inhibition in leukemia cells

Background

Epigenetic studies, particularly research on microRNA (miRNA), have flourished. The abnormal expression of miRNA contributes to the development of hematologic malignancies. miR-765 has been reported to inhibit cell proliferation by downregulating proteolipid protein 2 (PLP2), which causes apoptosis. We investigated miR-765 dysregulation in myelodysplastic syndromes (MDS).

Methods

We compared the expression profiles of miR-765 in 65 patients with MDS and 11 controls. Cell proliferation and apoptosis assays were performed to determine the in vitro effects of miR-765 on leukemia cells transfected with the miR-765 mimic. Reverse transcription quantitative PCR (RT-qPCR) and western blotting were performed to examine the targets of miR-765.

Results

We found that miR-765 levels were upregulated 10.2-fold in patients with MDS compared to controls. In refractory cytopenia with multilineage dysplasia, the percentage of patients with elevated miR-765 levels was significantly higher than in other forms of MDS. Experiments with leukemia cells revealed that transfection with a miR-765 mimic inhibited cell proliferation and induced apoptosis. RT-qPCR and western blotting demonstrated that the target of miR-765 was PLP2.

Conclusion

These findings imply that upregulation of miR-765 induces apoptosis via downregulation of PLP2 and may have a role in MDS pathogenesis.

Chasing the Role of miRNAs in RCC: From Free-Circulating to Extracellular-Vesicle-Derived Biomarkers

Renal cell carcinoma (RCC) is the second most common cancer of the urinary system. The current therapeutic strategies are based on partial or total nephrectomy and/or targeted therapies based on immune checkpoint inhibitors to which patients are often refractory. Preventive and screening strategies do not exist and the few available biomarkers for RCC are characterized by a lack of sensitivity, outlining the need for novel noninvasive and sensitive biomarkers for early diagnosis and better disease monitoring. Blood liquid biopsy (LB) is a non- or minimally invasive procedure for a more representative view of tumor heterogeneity than a tissue biopsy, potentially allowing the real-time monitoring of cancer evolution. Growing interest is focused on the extracellular vesicles (EVs) secreted by either healthy or tumoral cells and recovered in a variety of biological matrices, blood included. EVs are involved in cell-to-cell crosstalk transferring their mRNAs, microRNAs (miRNAs), and protein content. In particular, transferred miRNAs may regulate tumorigenesis and proliferation also impacting resistance to apoptosis, thus representing potential useful biomarkers. Here, we present the latest efforts in the identification of circulating miRNAs in blood samples, focusing on the potential use of EV-derived miRNAs as RCC diagnostic and prognostic markers.

Identification of fatty acid metabolism-based molecular subtypes and prognostic signature to predict immune landscape and guide clinical drug treatment in renal clear cell carcinoma

Three subtypes of samples were generated based on genes involved in fatty acid metabolism in The Cancer Genome Atlas (TCGA)-RCC patients using a non-negative matrix factorization (NMF) algorithm. 32 co-expressed modules were identified using WCGNA. We constructed a four-gene signature in our training set using least absolute shrinkage selection operator regression analysis and verified it in our testing and overall sets. A relevant study analysis in clinical trials was conducted, which showed the model had good stability and potential application value for predicting outcomes. We analyzed the immune microenvironment using MCPcounter, CIBERSORT, quanTIseq, TIMER and ESTIMATE algorithms, and the result indicated risk was positively related to T cells, B-lineage, and fibroblasts and negatively correlated with monocytic lineage, myeloid dendritic cells, neutrophils, and endothelial cells, and CPT1B was positively related to T cells, CD8 + T cells, Cytotoxic lymphocytes and NK cells, and negatively correlated with myeloid dendritic cells, fibroblasts, endothelial cells. Tumor mutation burden was positively related to risk score and the expression of CPT1B using the R packages corrplot, circlize. Through the R package pRRophetic, drug sensitivity tests showed that the low-risk score group would benefit more from sunitinib and less from pazopanib, sorafenib, temsirolimus, gemcitabine and doxorubicin than the high-risk score group. We performed the relevant basic assay validation for CPT1B, and the proliferation ability of RCC cells was inhibited after the knockdown of protein expression of CPT1B. In conclusion, we established a four-gene model that can predict outcomes of RCC with potential applications in diagnosis and treatment.

Combining expression of RNF43 and infiltration level of CD163+ tumor associated macrophage predicts prognosis of clear cell renal cell carcinoma

Searching for reliable indicators for evaluating prognosis diagnosed with clear cell renal cell carcinoma (ccRCC) is crucial for improving clinical therapies. However, current researches have looked mainly at the prognostic value of a single intratumoral indicator, neglecting tumor-infiltrating immune cells (TIICs) in the microenvironment. This study examined whether the integration of Ring finger protein 43 (RNF43) expression and CD163⁺ tumor-associated macrophage (TAM) infiltration in combination with clinical indexes forecast ccRCC patient outcome with relatively high accuracy. Firstly, the expression of RNF43 and CD163 were detected with immunohistochemistry. Totally, 346 ccRCC patients were random separated evenly into training and validation datasets to make further analyses. We found that RNF43 expression was negatively correlated with infiltration level of CD163⁺ TAM in ccRCC, which was closely associated with the TNM stage and outcome of these patients. The multiple regression analysis demonstrated that RNF43, CD163, and TNM stage could function as independent risk factors in overall survival (OS) and progression-free survival (PFS) prediction of ccRCC. Furthermore, a better postoperative prognosis index for ccRCC patients was obtained by combining RNF43 and CD163⁺ TAMs, which assessed with time-dependent C-index analyses and a nomogram. Consequently, combining RNF43 and CD163⁺ TAMs along with TNM stage acquired robust accuracy in forecasting outcome of patients with ccRCC. In conclusion, combining intratumoral RNF43 expression, CD163⁺ TAM infiltration, and TNM stage could significantly enhance the veracity in forecasting postoperative outcomes.

Long noncoding RNA Mhrt alleviates angiotensin II-induced cardiac hypertrophy phenotypes by mediating the miR-765/Wnt family member 7B pathway

Long noncoding RNAs (lncRNAs) are known to participate in the pathological process of cardiac hypertrophy. This study aimed to investigate the function of the lncRNA, myosin heavy-chain associated RNA transcript (Mhrt), in cardiac hypertrophy and its possible mechanism of action. Adult mouse cardiomyocytes were treated with angiotensin II (Ang II) and transfected with Mhrt; cardiac hypertrophy was evaluated by estimating atrial natriuretic peptide, brain natriuretic peptide, and beta-myosin heavy-chain levels, and cell surface area by reverse transcription-quantitative polymerase chain reaction, western blotting, and immunofluorescence staining. The interaction between the Mhrt/Wnt family member 7B (WNT7B) and miR-765 was assessed using a luciferase reporter assay. Rescue experiments were performed by analyzing the role of the miR-765/WNT7B pathway underlying the function of Mhrt. The results indicated that Ang II induced hypertrophy of cardiomyocytes; however, overexpression of Mhrt alleviated the Ang II-induced cardiac hypertrophy. Mhrt acted as a sponge for miR-765 to regulate the expression of WNT7B. Rescue experiments revealed that the inhibitory effect of Mhrt on myocardial hypertrophy was abolished by miR-765. Additionally, the knockdown of WNT7B reversed the suppression of myocardial hypertrophy induced by downregulating miR-765. Taken together, Mhrt alleviated cardiac hypertrophy by targeting the miR-765/WNT7B axis.

Long noncoding RNA long intergenic non-protein-coding RNA 173 contributes to nasopharyngeal carcinoma progression by regulating microRNA-765/Gremlin 1 pathway

BACKGROUND

Long intergenic non-protein-coding RNA 173 (LINC00173) executes vital functions in various cancers. Nevertheless, its role and expression in nasopharyngeal carcinoma (NPC) have yet to be investigated. Here, we investigated its effects on the malignancy characteristics of NPC and elucidated the potential molecular mechanism of LINC00173 in NPC progression.

METHODS

Quantitative real-time reverse transcription-PCR (qRT-PCR) and immunoblotting were conducted to estimate the LINC00173, microRNA-765 (miR-765), and Gremlin 1 (GREM1) expressions in NPC cells and tissues. Cell counting kit-8 (CCK8), colony formation, and wound healing experiments were done to evaluate the proliferation, growth, and migration of NPC cells, respectively. The tumorous growth of NPC cells in vivo was assessed through the xenograft tumor experiment. Furthermore, the interactions among miR-765, LINC00173, and GREM1 were investigated through bioinformatics analyses, luciferase reporter and RNA immunoprecipitation chip assays.

RESULTS

An upregulated LINC00173 expression was found in NPC cell lines and tissues. The functional experiments uncovered that its downregulation repressed NPC cell proliferation, growth, and migration. In addition, LINC00173 knockdown hampered the NPC cells' tumorous growth in vivo. These effects could partially be reversed by downregulating miR-765. GREM1 is a downstream target of miR-765. GREM1 knockdown could repress the proliferation, growth, and migration of NPC cells. Nonetheless, these anti-tumor effects could be abolished by miR-765 downregulation. Mechanistically, LINC00173 increased the expression of GREM1 by binding with miR-765.

CONCLUSIONS

LINC00173 functions as an oncogenic factor by binding with miR-765 to promote the progression of NPC via GREM1 upregulation. This study provides a novel insight into the molecular mechanisms involved in NPC progression.

SLC17A9-PTHLH-EMT axis promotes proliferation and invasion of clear renal cell carcinoma

SLC17A9 is a vesicular ATP transport protein that plays an important role in determining cell functions and the onset and progression of different diseases. In this study, SLC17A9 was initially identified as a potential diagnostic and prognostic risk biomarker for clear cell renal cell carcinoma (ccRCC). Then, the aberrant expression levels of SLC17A9 were confirmed in both the cell lines and clinical tissues. Mechanistically, SLC17A9 could upregulate the expression of PTHLH, thus promoting epithelial-mesenchymal transition (EMT) in ccRCC. Functionally, SLC17A9 knockdown inhibited the proliferation, migration, and invasion activity of renal cancer cells, whereas its overexpression led to stronger cell viability and more malignant phenotype in vitro. The overexpression of SLC17A9 in vivo could significantly contribute to the growth of tumors. Finally, we found that SLC17A9 might be related to the drug resistance of vorinostat. Cumulatively, this study demonstrated that the SLC17A9-PTHLH-EMT axis could promote the progression of ccRCC.

KDELR2-KIF20A axis facilitates bladder cancer growth and metastasis by enhancing Golgi-mediated secretion

Background

Bladder cancer (BCa) is a fatal form of cancer worldwide associated with a poor prognosis. Identifying novel drivers of growth and metastasis hold therapeutic potential for the disease. Transport homeostasis between the endoplasmic reticulum and Golgi and the secretion of matrix metalloproteinases (MMPs) mediated by Golgi have been reported to be closely associated with tumor progression. However, to date, mechanistic studies remain limited.

Results

Here, we identified KDELR2 as a potential risk factor with prognostic value in patients with BCa, especially those harbouring the KDELR2 amplification. In addition, we found that KDELR2 is a regulator of BCa cell proliferation and tumorigenicity based on bioinformatic analysis with functional studies. Mechanistically, we revealed that KDELR2 could regulate the expression of KIF20A, thus stimulating the expression of MMP2, MMP9 and MKI67. Functionally, the overexpression of KDELR2 and KIF20A markedly promoted proliferation, migration, and invasion in vitro and enhanced tumor growth in vivo, while knockdown of KDELR2 and KIF20A exerted the opposite effects. And the overexpression of KDELR2 also enhanced lymph node metastasis in vivo.

Conclusions

Collectively, our findings clarified a hitherto unexplored mechanism of KDELR2-KIF20A axis in increasing Golgi-mediated secretion of MMPs to drive tumor progression in BCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12575-022-00174-y.

Profile of TREM2-Derived circRNA and mRNA Variants in the Entorhinal Cortex of Alzheimer’s Disease Patients

Genetic variants in TREM2, a microglia-related gene, are well-known risk factors for Alzheimer’s disease (AD). Here, we report that TREM2 originates from circular RNAs (circRNAs), a novel class of non-coding RNAs characterized by a covalent and stable closed-loop structure. First, divergent primers were designed to amplify circRNAs by RT-PCR, which were further assessed by Sanger sequencing. Then, additional primer sets were used to confirm back-splicing junctions. In addition, HMC3 cells were used to assess the microglial expression of circTREM2s. Three candidate circTREM2s were identified in control and AD human entorhinal samples. One of the circRNAs, circTREM2_1, was consistently amplified by all divergent primer sets in control and AD entorhinal cortex samples as well as in HMC3 cells. In AD cases, a moderate negative correlation (r = −0.434) was found between the global average area of Aβ deposits in the entorhinal cortex and circTREM2_1 expression level. In addition, by bioinformatics tools, a total of 16 miRNAs were predicted to join with circTREM2s. Finally, TREM2 mRNA corresponding to four isoforms was profiled by RT-qPCR. TREM2 mRNA levels were found elevated in entorhinal samples of AD patients with low or intermediate ABC scores compared to controls. To sum up, a novel circRNA derived from the TREM2 gene, circTREM2_1, has been identified in the human entorhinal cortex and TREM2 mRNA expression has been detected to increase in AD compared to controls. Unraveling the molecular genetics of the TREM2 gene may help to better know the innate immune response in AD.

M2-Polarization-related CNTNAP1 gene might be a novel immunotherapeutic target and biomarker for clear cell renal cell carcinoma

Clear cell renal carcinoma (ccRCC) is one of the most common malignancies, characterized by high mortality rate in urology. Unfortunately, reliable biomarkers for ccRCC diagnosis and prognosis remain lacking. Contactin Associated Protein 1 (CNTNAP1) has yet to be thoroughly investigated in cancer, especially its relationship with immune infiltration or clinical outcomes of ccRCC. Here, we explored the Cancer Genome Atlas Kidney Clear Cell Carcinoma database (TCGA-KIRC) for prognostic significance, differential expression, and probable mechanism of CNTNAP1. The aberrant CNTNAP1 expression was also validated by international Cancer Genome Consortium (ICGC) and ccRCC clinic samples. We used Database for Annotation, Visualization, and Integrated Discovery (DAVID) to performed the GO & KEGG enrichment. TIMER database was further utilized to assess its correlation with immune infiltration in ccRCC. The the CellMiner database was used to analyse the relationship between CNTNAP1 expression and drug sensitivity. Results showed CNTNAP1 was upregulated in TCGA-KIRC, ICGC and clinic samples. And CNTNAP1 expression was positively related to infiltration levels of cancer-associated fibroblast, regulatory T cells, and Myeloid-derived suppressor cells, while negatively related to eosinophils. Furthermore, we observed CNTNAP1 was appreciably positively associated with alternatively activated macrophage (M2) in ccRCC. Finally, high CNTNAP1 expression was negatively correlated with Nilotinib, Crizotinib, Eribulin mesylate, and Vinorelbine. Collectively, these results strongly suggest that CNTNAP1 might act as an immunotherapeutic target and a promising novel biomarker for ccRCC.

The Downregulation of Prognosis- and Immune Infiltration-Related Gene CYFIP2 Serves as a Novel Target in ccRCC

Background

Increasing evidence indicated that the aberrant expression of the cytoplasmic FMR1-interacting protein (CYFIP) family might possess critical role and potential functions in cancer. But the role of CYFIP2 in clear cell renal cell carcinoma (ccRCC) is still uncharacteristic.

Methods

We investigated the Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) database for the expression profile, clinicopathological variables, clinical prognosis information, and promoter methylation levels of CYFIPs in ccRCC. The aberrant CYFIP2 protein expression was validated by the Human Protein Atlas (HPA) and Clinical Proteomic Tumor Analysis Consortium (CPTAC). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to uncover CYFIP2 mRNA levels in 28 pairs of ccRCC cancer tissues. Kaplan–Meier analysis, univariate and multivariate Cox proportional hazard regression were performed to assess CYFIPs’ prognosis value. Gene set enrichment analysis (GSEA) was used to determined hallmark functions, gene ontology of CYFIP2. TIMER database was utilized to assess the correlation with immune infiltration in ccRCC.

Results

Results showed CYFIP2 was downregulated in ccRCC, relative to paired normal tissues in TCGA-KIRC database and 28 pairs of clinical samples (P < 0.0001). Similarly, a decreased CYFIP2 protein expression was confirmed by ccRCC tissues. The results showed CYFIP2 was negatively regulated by promoter DNA methylation. Survival analysis results showed CYFIP2 could be an independent biomarker for ccRCC and its reduction predicted a poor overall survival (OS) and disease-free survival (DFS). GSEA showed CYFIP2 was involved in metabolic pathways and epithelial–mesenchymal transition (EMT). Immune infiltration analysis revealed that a list of immune markers was significantly correlated with CYFIP2 expression especially with CD4+ cells and CD8+ cells in ccRCC.

Conclusion

These results show that CYFIP2 was downregulated in ccRCC patients and predicted an unfavorable prognosis. CYFIP2 might be a potential novel prognostic molecule, and related to immune infiltration, the metabolism, as well as EMT process in ccRCC. CYFIP2 could act as tumor suppressor gene in ccRCC and positive modulation of CYFIP2 might lead to development of a novel strategy for ccRCC treatment.

MicroRNAs in Body Fluids: A More Promising Biomarker for Clear Cell Renal Cell Carcinoma

Renal cell carcinoma (RCC) is the second most common cancer of the urinary system, accounting for approximately 10–15% of kidney cancers in the world. Clear cell renal cell carcinoma (ccRCC) is the most common RCC subtype with the highest mortality. Surgical resection or puncture of tumor tissue is still an important clinical treatment and diagnosis of ccRCC, but its high recurrence rate and poor prognosis often lead to the short survival period of patients. Hence, the development of novel molecular biomarkers is of great clinical importance. miRNAs are endogenous non-coding small RNAs with a length of 19–24 nt. A growing number of studies have reported that miRNAs, as proto-oncogenes or tumor suppressor genes, play a key role in the development of ccRCC and might be effective diagnostic and prognostic biomarkers. In addition, miRNAs can also predict the efficacy of treatment drug, thus improving the accuracy of clinical medication. Furthermore, non-invasive detection of miRNAs or extracellular vesicles (EV) in body fluids has better convenience and repeatability, which shows remarkable advantages compared with tissue detection. In this review, we summarized the typical miRNAs reported in recent years and place emphasis on evaluating miRNAs in different body fluids to provide reference for the clinical diagnosis and prognosis of ccRCC in the future.

LncRNA RP11-465B22.8 triggers esophageal cancer progression by targeting miR-765/KLK4 axis

LncRNAs play an important role in tumorigenesis and progression; however, the function and mechanisms of lncRNAs in esophageal cancer (EC) remain largely unclear. In this study, we screened the differentially expressed lncRNAs in EC by using RNA-seq and one of the most upregulated lncRNAs, lncRNA RP11-465B22.8, was further characterized. LncRNA RP11-465B22.8 was upregulated in EC tissues and high lncRNA RP11-465B22.8 expression was associated with poor survival of EC patients. Ectopic expression of lncRNA RP11-465B22.8 enhanced the proliferation, migration, and invasion of EC cells, whereas knockdown of lncRNA RP11-465B22.8 led to the opposite effects. Mechanistically, lncRNA RP11-465B22.8 sponged miR-765 to increase the expression of KLK4. Moreover, LncRNA RP11-465B22.8 could be delivered from EC cells to macrophages via exosomes and subsequently induced M2 macrophage-induced cell migration and invasion. Our findings revealed a novel lncRNA RP11-465B22.8/miR-765/KLK4 pathway in EC and indicated that lncRNA RP11-465B22.8 might be a potential target for EC therapy.

Biomarker Screening and Prognostic Significance Analysis for Renal Cell Carcinoma

Background

Studies report that conventional treatment of clear cell renal cell carcinoma (ccRCC) is effective, but several advanced patients present with poor prognosis. The current study explored potential new tumor markers and therapeutic targets in advanced ccRCC.

Methods

Biomarker gene expression of ccRCC was retrieved from GEO database and the Cancer Genome Atlas Kidney Clear Cell Carcinoma (TCGA-KIRC) database. Gene ontology (GO) analysis and protein–protein interaction (PPI) networks of biomarker genes were constructed using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool. Kaplan–Meier analysis and receiver operating characteristic curve (ROC) analysis were performed to explore the prognostic and diagnostic roles of these genes. Gene set enrichment analysis (GSEA) analysis was used to determine hallmark functions of the biomarker genes. qRT-PCR was used to verify the reliability of the analysis results in tumor tissues.

Results

A total of 21 upregulated genes were identified between advanced ccRCC and early ccRCC (grade III+IV vs grade I+II). Gene ontology analysis showed that the 21 upregulated genes were mainly implicated in biological processes including metabolic and lipid transport. The findings showed that 7 out of the 21 genes were significantly upregulated in 72-paired samples retrieved from the TCGA-KIRC. High expression of 5 genes indicated a poor prognosis of overall survival and disease-free survival in KIRC. Three genes effectively distinguished renal cancer tissue and adjacent renal tissues in a total of 533 ccRCC samples. GSEA showed that the 3 biomarkers were significantly enriched in epithelial–mesenchymal transition, G2M checkpoint, and angiogenesis. The results of qRT-PCR showed that STEAP3, IBSP, and AQP9 had a significant identification effect in ccRCC.

Conclusion

The findings showed that 3 biomarkers were significantly upregulated in advanced ccRCC and could be used for diagnosis, prediction, and potential novel therapeutic targets for progression of ccRCC.

Epigenetic Biomarkers of Renal Cell Carcinoma for Liquid Biopsy Tests

Renal cell carcinomas (RCC) account for 2–3% of the global cancer burden and are characterized by the highest mortality rate among all genitourinary cancers. However, excluding conventional imagining approaches, there are no reliable diagnostic and prognostic tools available for clinical use at present. Liquid biopsies, such as urine, serum, and plasma, contain a significant amount of tumor-derived nucleic acids, which may serve as non-invasive biomarkers that are particularly useful for early cancer detection, follow-up, and personalization of treatment. Changes in epigenetic phenomena, such as DNA methylation level, expression of microRNAs (miRNAs), and long noncoding RNAs (lncRNAs), are observed early during cancer development and are easily detectable in biofluids when morphological changes are still undetermined by conventional diagnostic tools. Here, we reviewed recent advances made in the development of liquid biopsy-derived DNA methylation-, miRNAs- and lncRNAs-based biomarkers for RCC, with an emphasis on the performance characteristics. In the last two decades, a mass of circulating epigenetic biomarkers of RCC were suggested, however, most of the studies done thus far analyzed biomarkers selected from the literature, used relatively miniature, local, and heterogeneous cohorts, and suffered from a lack of sufficient validations. In summary, for improved translation into the clinical setting, there is considerable demand for the validation of the existing pool of RCC biomarkers and the discovery of novel ones with better performance and clinical utility.

miR-765 Acts as a Tumor Promoter and Indicates Poor Prognosis in Non-Small Cell Lung Cancer

PURPOSE

Non-small cell lung cancer (NSCLC) is one of the leading causes of cancer-related death worldwide with poor prognosis. Accumulating evidence indicates that miR-765 is an important regulator in the progression and prognosis of various cancers. In this study, the function in the progression and prognosis of NSCLC was investigated.

PATIENTS AND METHODS

The expression of miR-765 in NSCLC was analyzed by qRT-PCR. The effect of miR-765 on cell proliferation, migration, and invasion of NSCLC was evaluated by CCK8 and Transwell assay. Kaplan-Meier analysis and Cox regression analysis were employed to assess the prognostic value of miR-765.

RESULTS

The results demonstrated the significant upregulation of miR-765 in NSCLC tissues and cell lines relative to normal tissues and cells. High miR-765 expression was significantly correlated with the TNM stage of patients. Patients with high miR-765 expression showed a poorer prognosis than that of patients with low miR-765 expression. Cox analysis indicated that miR-765 could be considered as an independent prognostic factor for NSCLC. Additionally, the upregulation of miR-765 was revealed to promote NSCLC cell proliferation, migration, and invasion by targeting BMP6.

CONCLUSION

The overexpression of miR-765 in NSCLC was associated with TNM stage and poor prognosis of patients. miR-765 served as a tumor promoter of NSCLC by regulating BMP6. These findings provide a potential biomarker and therapeutic target for the prognosis and treatment of NSCLC.

Circulating microRNAs from the Molecular Mechanisms to Clinical Biomarkers: A Focus on the Clear Cell Renal Cell Carcinoma

microRNAs (miRNAs) are emerging as relevant molecules in cancer development and progression. MiRNAs add a post-transcriptional level of control to the regulation of gene expression. The deregulation of miRNA expression results in changing the molecular circuitry in which miRNAs are involved, leading to alterations of cell fate determination. In this review, we describe the miRNAs that are emerging as innovative molecular biomarkers from liquid biopsies, not only for diagnosis, but also for post-surgery management in cancer. We focus our attention on renal cell carcinoma, in particular highlighting the crucial role of circulating miRNAs in clear cell renal cell carcinoma (ccRCC) management. In addition, the functional deregulation of miRNA expression in ccRCC is also discussed, to underline the contribution of miRNAs to ccRCC development and progression, which may be relevant for the identification and design of innovative clinical strategies against this tumor.

CircRNA_2646 functions as a ceRNA to promote progression of esophageal squamous cell carcinoma via inhibiting miR-124/PLP2 signaling pathway

MicroRNA-124 (miR-124) has been predicted as a tumor suppressor in esophageal squamous cell carcinoma (ESCC). However, factors contributing to miR-124 reduction remain unclear. Circular RNAs (circRNAs) are a new family of non-coding RNAs with gene regulatory potential via interacting with miRNAs. We predicted three circRNAs, including CircRNA_14359, CircRNA_2646, and CircRNA_129, that could interact with miR-124 by bioinformatics analysis and determined their expressions in ESCC tissues and adjacent normal tissues. We found that CircRNA_2646 was up-regulated in ESCC, negatively correlated with the expression of miR-124 and positively associated with TNM stage and lymph node metastasis of ESCC. Luciferase reporter assay showed that CircRNA_2646 interacted with miR-124 in ESCC Eca109 and TE-1 cells. Moreover, ectopical overexpression of CircRNA_2646 accelerated cell proliferation, migration, invasion, and epithelial-to-mesenchymal transition (EMT), but restoration of miR-124 abrogated these functions and promoted Bcl-2-dependent cell apoptosis. Furthermore, it was found that the oncogene Proteolipid Protein 2 (PLP2) was the target gene of miR-124. In Eca109 and TE-1 cells, restoration of miR-124 decreased the level of PLP2 and inhibited PLP2-induced cell proliferation, migration, invasion, and EMT, but enhanced cell apoptosis. The in vivo study confirmed that CircRNA_2646 promoted ESCC development by repressing miR-124 and activating PLP2. Taken together, we identified that CircRNA_2646 functioned as an inhibitor in miR-124 signaling pathway in ESCC for carcinogenesis and could be a promising target for ESCC therapy.

A Review of Recent Research on the Role of MicroRNAs in Renal Cancer

Renal cell carcinoma (RCC) is a most common type of urologic neoplasms; it accounts for 3% of malignant tumors, with high rates of relapse and mortality. The most common types of renal cancer are clear cell carcinoma (ccRCC), papillary renal cell carcinoma (pRCC), and chromophobe renal carcinoma (chRCC), which account for 90%, 6–15%, and 2–5%, respectively, of all renal malignancies. Although surgical resection, chemotherapy, and radiotherapy are the most common treatment method for those diseases, their effects remain dissatisfactory. Furthermore, recent research shows that the treatment efficacy of checkpoint inhibitors in advanced RCC patients is widely variable. Hence, patients urgently need a new molecular biomarker for early diagnosis and evaluating the prognosis of RCC. MicroRNAs (miRNAs) belong to a family of short, non-coding RNAs that are highly conserved, have long half-life evolution, and post-transcriptionally regulate gene expression; they have been predicted to play crucial roles in tumor metastasis, invasion, angiogenesis, proliferation, apoptosis, epithelial-mesenchymal transition, differentiation, metabolism, cancer occurrence, and treatment resistance. Although some previous papers demonstrated that miRNAs play vital roles in renal cancer, such as pathogenesis, diagnosis, and prognosis, the roles of miRNAs in kidney cancer are still unclear. Therefore, we reviewed studies indexed in PubMed from 2017 to 2020, and found several studies suggesting that there are more than 82 miRNAs involved in renal cancers. The present review describes the current status of miRNAs in RCC and their roles in progression, diagnosis, therapy targeting, and prognosis of RCC.

Long non-coding RNA LINC01137 contributes to oral squamous cell carcinoma development and is negatively regulated by miR-22-3p

PURPOSE

Long noncoding RNAs (lncRNAs) are emerging as key regulators in cancer initiation and progression. LINC01137 is a recently identified lncRNA of which the functional role in the development of oral squamous cell carcinoma (OSCC) has not been determined yet.

METHODS

We analyzed the expression of LINC01137 using a microarray-based OSCC gene expression dataset (GSE31056), and validated the results obtained using RT-qPCR in 26 pairs of primary OSCC tumor tissues and adjacent non-tumor tissues. The proliferative and invasive effects of LINC01137 on OSCC cells were determined using CCK-8, colony formation and transwell assays, respectively. Targeted binding between miR-22-3p and LINC01137 was verified using a dual luciferase reporter assay.

RESULTS

We found that LINC01137 was significantly upregulated in primary OSCCs. LINC01137 knockdown inhibited OSCC cell proliferation, migration and invasion, whereas LINC01137 overexpression induced opposite effects. LINC01137 upregulation along with p53 inhibition enhanced the malignant transformation of oral cells. In addition, we found that miR-22-3p can directly target LINC01137 through interaction with a putative miR-22-3p-binding site present within the LINC01137 sequence. A significant negative correlation was observed between LINC01137 and miR-22-3p expression in primary OSCC specimens. Exogenous overexpression of miR-22-3p markedly reduced the endogenous expression level of LINC01137 in OSCC cells. Additional functional assays showed that miR-22-3p overexpression enhanced the inhibitory effect of siRNA-mediated LINC01137 silencing on OSCC cell proliferation, migration and invasion, whereas miR-22-3p inhibition had the opposite effect.

CONCLUSIONS

Our results indicate that LINC01137 functions as an oncogenic lncRNA in OSCC. miR-22-3p can directly target LINC01137 and negatively regulate its expression and function.

CD45RO-CD8+ T cell-derived exosomes restrict estrogen-driven endometrial cancer development via the ERβ/miR-765/PLP2/Notch axis

Rationale: Estrogen-dependent cancers (e.g., breast, endometrial, and ovarian cancers) are among the leading causes of morbidity and mortality in women worldwide. Recently, exosomes released by tumor-infiltrating CD8⁺ T cells have been under the spotlight in the field of cancer immunotherapy. Our study aims at elucidating the underlying mechanisms of the crosstalk between estrogen signaling and CD8⁺ T cells, and possible intervention values in uterine corpus endometrial cancer (UCEC).

Methods: Micro RNA-seq was conducted to screen differentially expressed micro RNA in UCEC. Bioinformatic analysis was processed to predict the target of miR-765. RNA silencing or overexpressing and pharmacologic inhibitors were used to assess the functions of ERβ/miR-765/PLP2/Notch axis in UCEC cell proliferation and invasion in vivo and in vitro. In vivo imaging was performed to evaluate the metastasis of tumor in mice. Combined fluorescent in situ hybridization for miR-765 and immunofluorescent labeling for CD8 was carried out to prove the co-localization between miR-765 and CD8⁺ T cells. Exosomes derived from CD45RO^-CD8⁺ T cells were isolated to detect the regulatory effects on UCEC.

Results: miR-765 is characterized as the most downregulated miRNA in UCEC, and there is a negative correlation between miR-765 and Proteolipid protein 2 (PLP2) in UCEC lesion. Estrogen significantly down-regulates miR-765 level, and facilitates the development of UCEC by estrogen receptor (ER) β. Mechanistically, this process is mediated through the miRNAs (e.g., miR-3584-5p, miR-7-5p, miR-150-5p, and miR-124-3p) cluster-controlled regulation of the PLP2, which further regulates Ki-67 and multiple epithelial-mesenchymal transition (EMT)-related molecules (e.g, E-cadherin and Vimentin) in a Notch signaling pathway-dependent manner. Interestingly, the selective ER degrader Fulvestrant alleviates estrogen-mediated miR-765/PLP2 expression regulation and UCEC development in ERβ-dependent and -independent manners. Additionally, CD45RO^-CD8⁺ T cell-derived exosomes release more miR-765 than that from CD45RO⁺CD8⁺ T cells. In therapeutic studies, these exosomes limit estrogen-driven disease development via regulation of the miR-765/PLP2 axis.

Conclusions: This observation reveals novel molecular mechanisms underlying estrogen signaling and CD8⁺ T cell-released exosomes in UCEC development, and provides a potential therapeutic strategy for UCEC patients with aberrant ERβ/miR-765/PLP2/Notch signaling axis.

Bromodomain-containing protein 4 silencing by microRNA-765 produces anti-ovarian cancer cell activity

Bromodomain-containing protein 4 (BRD4) overexpression promotes ovarian cancer progression, and represents an important therapeutic oncotarget. This current study identified microRNA-765 (miR-765) as a novel BRD4-targeting miRNA. We showed that miR-765 directly associated with and silenced BRD4. In primary ovarian cancer cells and established cell lines (SKOV3 and CaOV3), ectopic overexpression of miR-765 inhibited cancer cell proliferation, migration and invasion, and induced apoptosis activation. In contrast, miR-765 inhibition by its anti-sense induced BRD4 upregulation to promote ovarian cancer cell proliferation, migration and invasion. Significantly, miR-765 overexpression-induced anti-ovarian cancer cell activity was largely attenuated by restoring BRD4 expression through an UTR-null BRD4 construct. Moreover, CRISPR/Cas9-induced BRD4 knockout (KO)inhibited proliferation and activated apoptosis in ovarian cancer cells. BRD4 KO in ovarian cancer cells abolished the functional impact of miR-765. miR-765 expression levels were downregulated in human ovarian cancer tissues and cells, correlating with the upregulation of BRD4 mRNA. Collectively, BRD4 silencing by miR-765produces significant anti-ovarian cancer cell activity. miR-765 could be further tested for its anti-ovarian cancer potential.

Identification of HIPK3 as a potential biomarker and an inhibitor of clear cell renal cell carcinoma

Invasion and metastasis are the main causes of poor prognosis in patients with clear cell renal cell carcinoma (ccRCC). The homeodomain interacting protein kinases (HIPKs) can regulate cell proliferation and apoptosis. Little is known about the prognostic role of HIPKs in ccRCC. Here we use Kaplan-Meier survival analysis and multivariate analysis to analyze the correlation of overall survival (OS) and disease–free survival (DFS). ROC curves analyzed the relationship between clinicopathological parameters and HIPK3 expression in ccRCC. Univariate analysis and multivariate analysis confirmed that the expression of HIPK3 was associated with OS (HR, 0.701; P=0.041) and DFS (HR, 0.630; P=0.012). Low HIPK3 expression was a poor prognostic factor and HIPK3 expression was significantly down-regulated in ccRCC cancer tissues when compared with normal renal tissues. In vitro cell results also confirmed that HIPK3 over-expression could inhibit tumor growth and malignant characteristics. The results indicate that low expression of HIPK3 in ccRCC tissues is significantly associated with poor survival rates in tumor patients, and HIPK3 may be used as a valuable biomarker and inhibitor of ccRCC.

Exosomal linc-FAM138B from cancer cells alleviates hepatocellular carcinoma progression via regulating miR-765

Exosomes are small vesicles with a diameter of 30-150 nm secreted by cells, which can be used as signal carriers to transfer nucleic acids, proteins, lipids and other functional substances to the recipient cells and play a role in cell communication. Hepatocellular carcinoma is the fourth most common cause of cancer-related death worldwide. Studies have shown that long non-coding RNAs (lncRNAs) are involved in the development and progression of many types of tumors. Our present study found that linc-FAM138B was reduced in HCC tissues and cell lines, low expression of linc-FAM138B indicated a poor prognosis in HCC patients. Interestingly, linc-FAM138B could be packaged into cancer cells. And exo-FAM138B inhibited the proliferation, migration and invasion of HCC cells. Furthermore, linc-FAM138B sponged miR-765 levels. And exo-si-FAM138B promoted HCC progression, while deletion of miR-765 reversed the role of exo-si-FAM138B. In vivo tumorigenesis experiments showed that exo-FAM138B suppressed HCC growth via modulating miR-765. In conclusion, exo-linc-FAM138B secreted by cancer cells inhibited HCC development via targeting miR-765, which provided a new idea and perspective for in-depth understanding of the complex signal regulation in HCC process.

MicroRNA Signature in Renal Cell Carcinoma

Renal cell carcinoma (RCC) includes 2.2% of all diagnosed cancers and 1.8% of cancer-related mortalities. The available biomarkers or screening methods for RCC suffer from lack of sensitivity or high cost, necessitating identification of novel biomarkers that facilitate early diagnosis of this cancer especially in the susceptible individuals. MicroRNAs (miRNAs) have several advantageous properties that potentiate them as biomarkers for cancer detection. Expression profile of miRNAs has been assessed in biological samples from RCC patients. Circulatory or urinary levels of certain miRNAs have been proposed as markers for RCC diagnosis or follow-up. Moreover, expression profile of some miRNAs has been correlated with response to chemotherapy, immunotherapy or targeted therapeutic options such as sunitinib. In the current study, we summarize the results of studies that assessed the application of miRNAs as biomarkers, therapeutic targets or modulators of response to treatment modalities in RCC patients.

Identification of a Novel Signature and Construction of a Nomogram Predicting Overall Survival in Clear Cell Renal Cell Carcinoma

Background

Clear cell renal cell carcinoma (ccRCC) is the most common subtype of renal cell carcinoma (RCC), which accounts for majority of RCC-related deaths. It is clearly essential to further identify more novel prognostic signatures and therapeutic targets.

Material and Methods

We identified differentially expressed genes (DEGs) between ccRCC and adjacent normal tissues in GEO database using a Robust Rank Aggregation (RRA) method. An mRNA signature (mRNASig) based on DEGs was developed using Cox and LASSO analysis in the TCGA database and validated in the ICGC database. Afterward, the influence of mRNASig mRNAs on the immune microenvironment in ccRCC was explored using comprehensive bioinformatics analysis.

Results

A total of 957 robust DEGs were identified using the RRA method. mRNASig comprised CEP55, IFI44, NCF4, and TCIRG1 and was developed and validated to identify high-risk patients who had poorer prognosis than low-risk patients. A nomogram was also constructed based on mRNASig, AJCC stage, and tumor grade. The mRNASig were closely related to a variety of tumor-infiltrating lymphocytes, especially including CD8+ T cells, activated CD4+ memory T cells, regulatory T cells, activated NK cells, and resting NK cells. The mRNASig were also correlated positively with the expression of CTLA4, LAG3, PDCD1, TIGIT, and HAVCR2.

Conclusion

We developed and validated mRNASig to assist clinicians in making personalized treatment decisions. Furthermore, CEP55, IFI44, NCF4, and TCIRG1 may be novel potential targets for future treatment of ccRCC.

Silencing miR-454 suppresses cell proliferation, migration and invasion via directly targeting MECP2 in renal cell carcinoma

Renal cell cancer (RCC) is one of the most common malignant tumors of the urinary system. MicroRNA-454 (miR-454) has been reported to play an important role in various cancer progressions, such as hepatocellular carcinoma, breast cancer and glioblastoma. Nevertheless, its effect on RCC still remains unknown. We aimed to investigate the biological function and underlying mechanisms of miR-454 in RCC. The expressions of miR-454 and MECP2 in RCC tissues were assessed using data from TCGA database and our own clinical samples. Functional experiments Cell Counting Kit-8 (CCK-8), colony formation, wound healing and Transwell assays were applied to detect the effects of miR-454 and MECP2 in RCC. The interaction between miR-454 and MECP2 was assessed by western blot and luciferase reporter assays. MiR-454 was upregulated in RCC tissues and cell lines compared with matched adjacent normal tissues and the normal kidney tubular epithelial cell line HK-2. MiR-454 inhibition and methyl-CpG binding protein 2 (MECP2) overexpression could both decrease the proliferative, migrative and invasive abilities of RCC cells. Higher expression of miR-454 predicted a poor overall survival (OS) (HR: 1.8; P < 0.05), while MECP2 level was positively related with RCC OS (HR: 0.55; P < 0.05) and disease-free survival (HR: 0.56; P < 0.05). Mechanistically, we showed that miR-454 could directly target the downstream gene MECP2. Our findings indicated that miR-454 accelerates RCC progression via suppressing MECP2 expression, which may provide a novel potential target of RCC treatment in the future.

LncRNA MAFG-AS1 Accelerates Cell Migration, Invasion and Aerobic Glycolysis of Esophageal Squamous Cell Carcinoma Cells via miR-765/PDX1 Axis

Background

LncRNA dysregulation is implicated in esophageal squamous cell carcinoma (ESCC) progression; However, the precise role and function of lncRNA MAFG-AS1 in ESCC remains unknown.

Materials and Methods

Expressions of MAFG-AS1, miR-765, PDX1, GLUT1 and LDH-A were detected via qRT-PCR or/and Western blot in ESCC tissues and cell lines. CCK-8, transwell and glycolysis assays were used to investigate the effects of MAFG-AS1 on ESCC cell proliferation, migration, invasion and aerobic glycolysis after knockdown or overexpression of MAFG-AS1, and bioinformatics analyses, RNA pull-down and dual luciferase reporter systems were applied to investigate the interaction between MAFG-AS1, miR-765 and PDX1.

Results

MAFG-AS1 was significantly up-modulated in ESCC tissues and cell lines. MAFG-AS1 significantly accelerated ESCC cell proliferation, migration, invasion and aerobic glycolysis. MAFG-AS1 competitively adsorbed miR-765, while miR-765 negatively modulated the expression of PDX1. miR-765 and PDX1 participated in the promotive effects of MAFG-AS1 on cell migration, invasion and aerobic glycolysis in ESCC cells.

Conclusion

Our research indicates that the MAFG-AS1/miR-765/PDX1 axis accelerates ESCC cell proliferation, migration, invasion and aerobic glycolysis.

A novel circRNA, circNUP98, a potential biomarker, acted as an oncogene via the miR-567/ PRDX3 axis in renal cell carcinoma

In recent years, plenty of studies found that circular RNAs (circRNAs) were essential players in the initiation and progression of various cancers including the renal cell carcinoma (RCC). However, the knowledge about the circRNAs in carcinogenesis is still limited. Dysregulated expression of circNUP98 in RCC tissues was identified by the circular RNA microarray. RT‐PCR was performed to measure the expression of circNUP98 in 78 pairs of RCC tissues and adjacent normal tissues. Survival analysis was conducted to explore the association between the expression of circNUP98 and the prognosis of RCC. The function and underlying mechanisms of circSMC3 in RCC cells were investigated by RNAi, CCK‐8, Western blotting, bioinformatic analysis, ChIP assay, circRIP assay and dual luciferase reporter assay. CircNUP98 was up‐regulated in both RCC tissues and cell lines, and high expression of circNUP98 was correlated with poor prognosis of RCC patients. Silencing of circSMC3 inhibited the proliferation and promoted the apoptosis in a caspase‐dependent manner in RCC cells. Mechanistically, we revealed that silencing of circ NUP98 inhibited RCC progression by down‐regulating of PRDX3 via up‐regulation of miR‐567. Furthermore, STAT3 was identified as an inducer of circ NUP98 in RCC cells. CircNUP98 acts as an oncogene by a novel STAT3/circ NUP98/miR‐567/PRDX3 axis, which may provide a potential biomarker and therapeutic target for the treatment of RCC.

Hsa_circ_0085576 promotes clear cell renal cell carcinoma tumorigenesis and metastasis through the miR-498/YAP1 axis

There is emerging evidence that circular RNAs (circRNAs) act as important regulators in various cancers. It is less clear, however, what role circRNA plays in the tumorigenesis and metastasis of clear cell renal cell carcinoma (ccRCC). In this study, using bioinformatics analysis and a series of experimental analysis, we characterized a novel circRNA, hsa_circ_0085576 was up-regulated in ccRCC tissues and cell lines. High hsa_circ_0085576 expression was significantly correlated with tumor size, clinical stage, and metastasis status and poorer survival. Knockdown of hsa_circ_0085576 notably inhibited cell proliferation, migration, invasion, whereas enhanced cell apoptosis of ccRCC cells, in vitro. In contrast, overexpression of hsa_circ_0085576 had the opposite effects. Moreover, hsa_circ_0085576 silencing significantly suppressed tumor growth and metastasis, whereas overexpression of hsa_circ_0085576 had the opposite effects, in vivo, Our results further showed that hsa_circ_0085576 acted as a competitive endogenous RNAs to interact with microRNA-498, to attenuate its repressive effect on target gene Yes-associated protein 1 (YAP1). Finally, functional studies revealed that inhibition of hsa_circ_0085576 suppressed cell growth and metastasis by regulating miR-498/YAP1 signaling, in ccRCC cells. Based on these findings, hsa_circ_0085576 may represent a valuable prognostic biomarker and a potential therapeutic target to curb the tumorigenesis and metastasis of ccRCC.

PLP2 Expression as a Prognostic and Therapeutic Indicator in High-Risk Multiple Myeloma

Multiple myeloma (MM) is a devastating cancer with a highly heterogeneous outcome. Because of the heterogeneity of myeloma cells, risk stratification is important for making therapeutic regimens. Nevertheless, no immunohistochemical predictive and prognostic marker has been constructed yet. In the present study, we explored the prognostic value of proteolipid protein 2 (PLP2) in MM patients using immunohistochemistry (IHC). We assessed PLP2 expression in bone marrow (BM) biopsy specimens obtained from 87 newly diagnosed MM (NDMM) patients. Correlations between PLP2 expression and clinicopathological features were analyzed. PLP2 expression was present in high-risk MM patients, which was increased with disease progression and poor prognosis. PLP2 was increasing in parallel with high beta-2 microglobulin (β2-MG) and lactate dehydrogenase (LDH). Furthermore, MM patients with low PLP2 expression could achieve a favorable treatment response. PLP2 may be a novel biomarker for prognostic prediction and a therapeutic target for anti-MM treatments.

Long Noncoding RNA LINC00173 Contributes to the Growth, Invasiveness and Chemo-Resistance of Colorectal Cancer Through Regulating miR-765/PLP2 Axis

Background

Long noncoding RNA has been involved in tumorigenesis of colorectal cancer (CRC). This study aimed to illustrate the functions and mechanisms of LINC00173 in CRC progression.

Methods

The expression of LINC00173 in CRC tissues and cell lines were analyzed via qRT-PCR. Kaplan-Meier curve was used to determine survival rate. Luciferase reporter assay was conducted to evaluate the interactions among LINC00173, miR-765 and PLP2 (proteolipid protein 2). CCK8 assay, EdU assay, transwell assay and xenograft assay were performed to examine the effect of LINC00173/miR-765/PLP2 axis on proliferation, migration and invasion. The Ki67 expression level in tumors tissues was detected through immunofluorescence assay.

Results

LINC00173 expression was markedly upregulated in CRC tissues and cells. High expression level of LINC00173 in CRC patients was correlated with poor prognosis. LINC00173 knockdown inhibited proliferation, migration, invasion and chemo-resistance of CRC cells in vitro. LINC00173 downregulation delayed CRC growth in vivo. LINC00173 interacted with miR-765 to promote PLP2 expression.

Conclusion

Our results demonstrated that LINC00173 plays an important oncogenic role in CRC via modulating miR-765/PLP2 axis. And LINC00173 may be a potential prognostic biomarker and therapeutic target for CRC.