Let-7c-5p Inhibits Cell Proliferation and Migration and Promotes Apoptosis via the CTHRC1/AKT/ERK Pathway in Esophageal Squamous Cell Carcinoma

Genome-wide RNA-seq, DNA methylation and small RNA-seq analysis unraveled complex gene regulatory networks in psoriasis pathogenesis

Psoriasis is a complex inflammatory skin disease characterized by reversible albeit relapsing red scaly plaques in the skin of a patient. In addition to the genetic predisposition, involvement of epigenetic and non-coding RNAs have also been liked with the disease. Nevertheless, any comprehensive study involving transcriptomic, small-RNA and DNA methylation at the genomic level from same patients is lacking. To investigate the complex regulation of molecular pathways in psoriasis, we carried out multi-omics integrative analysis of RNA-sequencing, small RNA-sequencing and DNA methylation profiling from the psoriatic and adjacent normal skin tissues. Our multi-omics analysis identified the genes and biological processes regulated either independently or in combination by DNA methylation and microRNAs. We identified miRNAs that specifically regulated keratinocyte hyper-proliferation, and cell cycle progression and checkpoint signaling in psoriasis. On contrary, DNA methylation was found to be more predominant in regulating immune and inflammatory responses, another causative factor in psoriasis pathogenesis. Many characteristic pathways in psoriasis e.g., Th17 cell differentiation and JAK-STAT signaling, were found to be regulated by both miRNAs and DNA methylation. We carried out functional characterization of a downregulated miRNA hsa-let-7c-5p, predicted to target upregulated genes in psoriasis involved in cell cycle processes, Th17 cell differentiation and JAK-STAT signaling pathways. Overexpression of hsa-let-7c-5p in keratinocytes caused the downregulation of its target genes, resulting in reduced cell proliferation and migration rates, demonstrating potential of miRNAs in regulating psoriasis pathogenesis. In conclusion, our findings identified distinct and shared gene-networks regulated by DNA methylation and miRNAs of a complex disease with reversible phenotype.

Arntl-induced upregulation of DUSP1 inhibits tumor progression in esophageal squamous cell carcinoma by inactivating ERK signaling

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a primary histological type of esophageal carcinoma with high morbidity. Aryl hydrocarbon receptor nuclear translocator-like (ARNTL) is a circadian clock gene associated with the progression of multiple tumors. However, its roles and mechanisms in ESCC remain unknown.

METHODS

ARNTL expression was analyzed using TCGA database and detected using qRT-PCR, and ARNTL-related pathways were analyzed through GSEA. Cell functional behaviors were assessed in vitro by measuring cell viability, proliferation, and apoptosis. Cell growth in the murine model was investigated through xenograft model and immunofluorescence assays of PCNA and Ki67. The downstream targets of ARNTL were analyzed through sequencing and identified via luciferase report, ChIP, and RNA pull-down analyses. Dual-specificity protein phosphatase-1 (DUSP1) expression was analyzed using GEO datasets and measured using qRT-PCR and western blotting. Protein expression was examined via western blotting.

RESULTS

ARNTL expression was decreased in esophageal carcinoma and associated with histological types, and elevated expression of ARNTL repressed ESCC cell viability and proliferation and facilitated cell apoptosis. ARNTL upregulation reduced tumor cell growth in murine models and decreased PCNA and Ki67 levels. Furthermore, DUSP1 was downregulated upon ARNTL silencing in ESCC. ARNTL could bind and positively regulate DUSP1 transcription. Additionally, DUSP1 silencing reversed the influences of ARNTL upregulation on cell viability, proliferation, and apoptosis in ESCC cells. ARNTL attenuated the activation of the ERK signaling by decreasing ERK phosphorylation through upregulation of DUSP1.

CONCLUSION

ARNTL hinders cell growth and contributes to cell apoptosis by inactivating ERK signaling through transcriptional upregulation of DUSP1 in ESCC.

Let-7c-5p Targeting CHD7 Hinders Cervical Cancer Migration and Invasion by Regulating Cell Adhesion

Cervical cancer is one of the most common cancers worldwide. Many studies have reported the involvement of various miRNAs in cervical cancer progression. Our study was centered at investigating how let-7c-5p affected cervical cancer migration and invasion by regulating cell adhesion and its molecular mechanism. Bioinformatics was used for the analysis on differentially expressed mRNAs in cervical cancer and the prediction of their upstream regulatory miRNAs. Immunohistochemistry was performed to assess the expression of CHD7 in cervical cancer tissue. qRT-PCR was performed for examining how much let-7c-5p and CHD7 were expressed. Dual-luciferase assay was performed to verify the regulatory relationship between CHD7 and let-7c-5p. The CCK-8 and transwell assays helped in detecting cell viability, invasion and migration. The ability by which cells adhered to each other was detected by employing cell adhesion assay. In addition, the expression levels of the proteins related to cell adhesion and CHD7 were detected by Western blot. A remarkable high expression-level of CHD7 was discovered in cervical cancer tissues and cells. The cell viability, migration and invasiveness could be suppressed by the knockdown of CHD7 which could also attenuate the expression of cell adhesion-related proteins. Bioinformatics analysis showed that CHD7 had an upstream regulatory gene, miRNA-let-7c-5p, which was markedly lowly expressed in cervical cancer tissues and cells. To validate the binding relationship between CHD7 and let-7c-5p, dual-luciferase assay was performed. Rescue experiments revealed that the cancer-inhibiting effect of let-7c-5p in cervical cancer could be reversed by overexpressed CHD7. let-7c-5p regulates cell adhesion and attenuates cervical cancer migration and invasiveness by targeting CHD7. It indicates that the involvement of let-7c-5p/CHD7 axis is of significance in cervical cancer progression, which opens up new possibilities for us to develop novel clinical treatments for cervical cancer.

Let-7c-5p Down Regulates the Proliferation of Colorectal Cancer Through the MAPK-ERK-Signaling Pathway

Colorectal cancer (CRC) is one of the most prevalent and life-threatening cancers. Rapid cell proliferation is the leading cause of cancer-related death in CRC. MicroRNAs (miRNAs) have been identified to play essential roles in the proliferation of CRC. Differential expression of let-7c-5p in CRC was assessed using a GEO dataset, and confirmed through RT-qPCR using CRC subject tissues. Let-7c-5p-overexpressing HCT8 cell line was constructed by transfecting let-7c-5p. Bioinformatics analysis identified that DUSP7 is the target gene of let-7c-5p. Further experimental assays, including Cell Counting Kit-8 (CCK8), EdU staining, cell colony, and Western Blot assays, confirmed the target genes and pathway of let-7c-5p. Receiver operator characteristic curve (ROC) analysis was performed to evaluate the diagnostic value of let-7c-5p for CRC. Finally, survival analysis was performed to determine the effect of DUSP7 and let-7c-5p on the prognosis of CRC patients. RT-qPCR analysis showed that the expression level of let-7c-5p was significantly increased in CRC subject tissues compared to the adjacent tissue. Overexpression of let-7c-5p promoted cell proliferation in HCT8 cell line. Furthermore, the MAPK-ERK pathway's protein expression of p-ERK1/2 was downregulated, while the ratio of Bcl-2/Bax was increased by let-7c-5p transfection in HCT 8. ROC analysis demonstrated that the expressive level of let-7c-5p had higher diagnostic value for CRC. Survival curve analysis indicated that high expression of DUSP7 and low expression of let-7c-5p were associated with poor prognosis in CRC patients. The findings suggest that let-7c-5p exerts an antitumor function by inhibiting the DUSP7-mediated MAPK-ERK pathway. Both DUSP7 and let-7c-5p have the potential to serve as prognostic biomarkers in CRC patients.

LINC00665 promotes glycolysis in lung adenocarcinoma cells via the let-7c-5p/HMMR axis

Lung adenocarcinoma (LUAD) is one of the most lethal and common malignancies. The energy metabolism of LUAD is a critical factor affecting its malignant progression, and research on this topic can aid in the development of novel cancer treatment targets. Bioinformatics analysis of the expression of long non-coding RNA (lncRNA) LINC00665 in LUAD was performed. Downstream regulatory molecules of LINC00665 were predicted using the StarBase database. We used quantitative reverse transcription polymerase chain reaction and western blot to measure the expression at mRNA and protein levels, respectively. The effects of the LINC00665/let-7c-5p/HMMR axis on cell viability in vitro were tested by CCK-8 assay. The regulatory effects on glycolysis were analyzed by extracellular acidification rate, oxygen consumption rate, glucose uptake, adenosine triphosphate production, and lactate production. The predicted competitive endogenous RNA mechanism between LINC00665 and let-7c-5p/HMMR was verified by a dual-luciferase reporter gene assay. LINC00665 was upregulated in LUAD. Silencing LINC00665 inhibited tumor proliferation and reduced the glycolytic activity of tumor cells. Additionally, the expression of LINC00665 had a negative correlation with that of let-7c-5p, while the expression of HMMR was remarkably inhibited by let-7c-5p. HMMR could affect the development of LUAD by influencing glycolytic capacity. Mechanistically, LINC00665 acted as a molecular sponge to absorb let-7c-5p and targeted HMMR. Transfection of let-7c-5p inhibitor or overexpression of HMMR plasmid could reverse the inhibition in proliferation and glycolysis of LUAD cells induced by silencing of LINC00665. In summary, this study demonstrated that the LINC00665/let-7c-5p/HMMR regulatory axis promoted the tumorigenesis of LUAD by enhancing aerobic glycolysis, suggesting that this regulatory axis was an effective target for inhibiting LUAD progression and providing theoretical support for the development of new drugs for LUAD.

Let-7c-5p down-regulates immune-related CDCA8 to inhibit hepatocellular carcinoma

OBJECTIVE

The aim of this study is to investigate the effect of let-7c-5p on the malignant behaviors of hepatocellular carcinoma (HCC) and its specific molecular pathway.

METHODS

Differential expression and survival analysis of let-7c-5p were obtained from The Cancer Genome Atlas database, and then its expression level was preliminarily verified through qPCR. The effect of let-7c-5p on the malignant phenotype of HCC cells was subsequently evaluated using CCK-8, transwell, wound healing, and flow cytometry assays. Downstream mRNA regulated by let-7c-5p was identified and confirmed by ENCORI database, dual-luciferase reporter, and western blot assays. The immunocorrelation of genes was evaluated by Xiantao tool, and TIMER and TISIDB databases.

RESULTS

The expression level of let-7c-5p in HCC was obviously reduced, which was found to be closely associated with the short survival time of HCC patients. Cell phenotypic experiments showed that let-7c-5p inhibited proliferation, invasion, and migration and promoted apoptosis of HCC cells. Dual-luciferase reporter and western blot analysis demonstrated that CDCA8 is a downstream mRNA of let-7c-5p and is negatively regulated by it. Rescue experiment revealed that CDCA8 reversed the effect of let-7c-5p on the malignant phenotype of HCC cells. Furthermore, analysis of the public database revealed that CDCA8 is related to some immune cells and immunomodulators, and that it may participate in the regulation of some immune pathways and immune functions.

CONCLUSION

Let-7c-5p has been proved to suppress HCC by down-regulating immune-related CDCA8, which will help understand the pathogenesis of HCC and develop drugs for its treatment.

Iron Oxide Nanoparticles Conjugated to Thiosemicarbazone Reduce the Survival of Cancer Cells by Increasing the Gene Expression of MicroRNA let-7c in Lung Cancer A549 Cells

BACKGROUND

Cancer cells have a higher demand for iron to grow and proliferate. A new complex of iron nanoparticles and thiosemicarbazones was synthesized. Confirmation tests included UV-visible, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transform infrared (FTIR), X-ray diffraction (XRD) and zeta potential.

METHODS

MTT assay, flow cytometry and qRT-PCR were used to investigate anti-proliferative effect, amount of apoptosis and the effect of Fe3 O4 @Glu/BTSC on changes in gene expression of microRNA let-7c (let-7c), respectively. The specifications of Fe3 O4 @ Glu/BTSC were confirmed at 5 nm.

RESULTS

Fe3O4@Glu/BTSC was more effective than BTSC and Fe3 O4 on A549 cells (IC50=166.77 µg/mL) but its effect on healthy cells was smaller (CC50=189.15 µg/mL). The drug selectivity index (SI) was calculated to be 1.13. The initial apoptosis rate was 46.33% for Fe3 O4 @Glu/BTSC, 28.27% for BTSC and 26.02% for Fe3 O4 . BTSC and BTSC@Fe3 O4 inhibited the cell cycle progression in the Sub-G1 and S phases. let-7c expression was 6.9 times higher in treated cells compared to the control group. The expression rate was 2.2 with BTSC compared to the control group and 1.6 times for Fe3 O4.

CONCLUSION

Fe3 O4 @Glu/BTSC has proper anti-proliferative effects against lung cancer cells by increasing the expression of let-7c and inhibiting the cell cycle with the apoptosis activation pathway.

Circ_HECTD1 regulates cerebral ischemia injury via mechanisms involving the regulation of let-7c-5p/ROCK1 axis

BACKGROUND

Ischemia is the main cause of cerebral ischemic stroke with a high mortality rate, and it is affected by the dysfunction of circular RNAs. The underlying molecular mechanisms of circ_HECTD1 were explored in cerebral ischemia stroke.

METHODS

PC-12 cells were treated with oxygen-glucose deprivation/reoxygenation (OGD/R) as the cell model of cerebral ischemia model. The expression levels of circ_HECTD1, let-7c-5p, and Rho-associated coiled-coil-containing protein kinase 1 (ROCK1) were determined by quantitative real-time PCR in PC-12 cells. The proliferation ability of PC-12 cells was assessed by 5-ethynyl-2'-deoxyuridine and 3-(4,5-dimethylthizol-2-yl)-2,5-diphenyltetrazolium bromide assays. The protein expression levels were quantified by western blot analysis. Flow cytometry was performed to analyze cell apoptosis. Lactate dehydrogenase concentration was assessed by a commercialized kit. Dual-luciferase reporter assay was used to confirm the interaction relationships among circ_HECTD1, let-7c-5p and ROCK1.

RESULTS

Circ_HECTD1 was upregulated in OGD/R-treated PC-12 cells. The results also showed that cell proliferation was decreased and apoptosis was increased in OGD/R-treated PC-12 cells, which was overturned by the inhibition of circ_HECTD1. Let-7c-5p was a target of circ_HECTD1, and the protective effects of circ_HECTD1 knockdown on OGD/R-treated PC-12 cells were canceled after co-transfection with let-7c-5p inhibitor. We found that ROCK1 was a potential target of let-7c-5p. Let-7c-5p -mediated the effects on the proliferation and apoptosis of OGD/R-treated PC-12 cells by targeting ROCK1.

CONCLUSION

Circ_HECTD1 was implicated in the development of cerebral ischemia stroke. Knockdown of circ_HECTD1 protected against cerebral ischemia injury in OGD/R-treated PC-12 cells depending on the regulation of let-7c-5p/ROCK1 axis.

Pan-cancer analysis combined with experiments predicts CTHRC1 as a therapeutic target for human cancers

BACKGROUND

The function of collagen triple helix repeat containing 1 (CTHRC1) as an oncogene has been reported in a growing number of publications. Bioinformatics methods represent a beneficial approach to examine the mechanism and function of the CTHRC1 gene in the disease process of cancers from a pan-cancer perspective.

METHODS

In this study, using the online databases UCSC, NCBI, HPA, TIMER2, Oncomine, GEPIA, UALCAN, cBioPortal, COSMIC, MEXPRESS, STRING, CCLE, LinkedOmics, GTEx, TCGA, CGGA, and SangerBox, we focused on the relationship between CTHRC1 and tumorigenesis, progression, methylation, immunity, and prognosis. qPCR was used to detect CTHRC1 expression in glioma tissues and cell lines.

RESULTS

The pan-cancer analysis showed that CTHRC1 was overexpressed in most tumors, and a significant correlation was observed between CTHRC1 expression and the prognosis of patients with cancer. CTHRC1 genetic alterations occur in diverse tumors and are associated with tumor progression. Levels of CTHRC1 promoter methylation were decreased in most cancer tissues compared with normal tissues. In addition, CTHRC1 coordinated the activity of ICP genes through diverse signal transduction pathways, was also associated with immune cell infiltration and the tumor microenvironment, and potentially represented a promising immunotherapy target. We identified CTHRC1-related genes across cancers using the GEPIA2 tool. The single-gene GO analysis of CTHRC1 across cancers showed that it was involved in some signaling pathways and biological processes, such as the Wnt signaling pathway, cell migration, and positive regulation of protein binding. The expression and function of CTHRC1 were also further verified in glioma tissues and cell lines.

CONCLUSIONS

CTHRC1 is overexpressed in various cancer types and functions as an important oncogene that may promote tumorigenesis and development through different mechanisms. CTHRC1 may represent an important therapeutic target for human cancers.

Lack of Conserved miRNA Deregulation in HPV-Induced Squamous Cell Carcinomas

Squamous cell carcinomas (SCCs) in the anogenital and head and neck regions are associated with high-risk types of human papillomaviruses (HR-HPV). Deregulation of miRNA expression is an important contributor to carcinogenesis. This study aimed to pinpoint commonly and uniquely deregulated miRNAs in cervical, anal, vulvar, and tonsillar tumors of viral or non-viral etiology, searching for a common set of deregulated miRNAs linked to HPV-induced carcinogenesis. RNA was extracted from tumors and nonmalignant tissues from the same locations. The miRNA expression level was determined by next-generation sequencing. Differential expression of miRNAs was calculated, and the patterns of miRNA deregulation were compared between tumors. The total of deregulated miRNAs varied between tumors of different locations by two orders of magnitude, ranging from 1 to 282. The deregulated miRNA pool was largely tumor-specific. In tumors of the same location, a low proportion of miRNAs were exclusively deregulated and no deregulated miRNA was shared by all four types of HPV-positive tumors. The most significant overlap of deregulated miRNAs was found between tumors which differed in location and HPV status (HPV-positive cervical tumors vs. HPV-negative vulvar tumors). Our results imply that HPV infection does not elicit a conserved miRNA deregulation in SCCs.

Interleukin-18 promotes the antitumor ability of natural killer cells in colorectal cancer via the miR-574-3p/TGF-β1 axis

Interleukin (IL)-18 has a clear antitumor effect; however, its mechanisms of action are not understood in patients with colorectal cancer (CRC). Here, we investigated the potential mechanism of IL-18 in CRC. The results showed that IL-18 treatment alone had no effect on HCT116 cells apoptosis, whereas IL-18 in the presence of natural killer (NK) cells resulted in apoptosis and inhibition of cells proliferation in vitro. Profiling of miRNA expression following coculture with NK cells and treatment with IL-18 resulted in significant downregulation of miR-574-3p expression and upregulated expression of the target gene transforming growth factor beta 1 (TGF-β1). miR-574-3p binds to TGF-β1, and miR-574-3p overexpression increased the proliferation and decreased the apoptotic rate of HCT116 cells in NK cells coculture with IL-18 treatment; overexpression of TGF-β1 restored the effect of miR-574-3p overexpression. The miRNA profile of HCT116 undergoes significant alteration before and after coculturing with NK cells and treatment with IL-18. IL-18 alone did not affect HCT116 cells apoptosis but did promote the antitumor ability of NK cells in coculture with HCT116 cells via the miR-574-3p/TGF-β1 axis. Our study suggested that IL-18 can be a new potential target for cancer immunotherapy for CRC.