Abstract
Radioresistance is a major problem encountered in the treatment of non-small cell lung cancer (NSCLC). Aberrant microRNA (miRNA) expression contributes to multiple cancer-associated ...signaling pathways and profoundly influences effects of radiotherapy (RT) in cancers. MicroRNA-145-5p (miR-145) is recognized as a tumor suppresser in NSCLC. However, the roles of miR-145 during radiotherapy of NSCLC are largely unknown. The present study aimed to investigate the function and underlying mechanism of miR-145 in modulation of radiosensitivity in NSCLC. We generated radioresistant H460 and A549 subclones, named H460R and A549R, respectively, and found that irradiation (IR) could suppress the expression levels of miR-145 in radioresistant NSCLC cells. Furthermore, overexpression of miR-145 could sensitize radioresistant NSCLC cells to IR, whereas knockdown of miR-145 in NSCLC cells acted the converse manner. Mechanically, miR-145 was able to directly target 3′UTR of tropomodulin 3 (TMOD3) mRNA and decrease the expression of TMOD3 at the levels of mRNA and protein. Additionally, we confirmed that miR-145 could enhance the radiosensitivity of radioresistant NSCLC cells by targeting TMOD3 in vitro and in vivo, and could be used as a target in clinical treatment of NSCLC. Collectively, restoration of miR-145 expression increases the radiosensitivity of radioresistant NSCLC cells by suppression of TMOD3, and miR-145 can act as a new radiosensitizer for NSCLC therapy.
IR can decrease the expression of miR-145, leading to the up-regulation of TMOD3 and radioresistance in NSCLC cells; however, the overexpression of miR-145 can enhance the radiosensitivity of radioresistant NSCLC cells by inactivating TMOD3. We provide a new approach for NSCLC radiosensitizing.
Ultrathin SWCNT transparent and conductive films on flexible and transparent substrates are prepared via repeatedly halving the directly grown SWCNT films and flexible and transparent supercapacitors ...with excellent performance were fabricated.
The aim of this study was to investigate the underlying mechanism whereby HBx modulates the targeting of
by
to enhance hepatocarcinogenesis.
We employed an integrated approach of bioinformatics ...analysis and molecular experiments in hepatoma cells, HBV transgenic mice, and clinical liver cancer tissues to investigate the role of HBx-regulated
in the development of liver cancer.
In this study, we report that the HBx-mediated tumor suppressor
modulates hepatocarcinogenesis during the host-HBV interaction. The expression levels of
were lower in clinical HBV-positive liver cancer tissues and liver tissues of HBV-transgenic mice. Interestingly, HBx inhibited
expression by inducing the methylation of CpG islands in its promoter. Accordingly, we tested the hypothesis that HBx enhanced hepatocarcinogenesis by increasing the expression of target genes of
. Moreover, we identified nucleolar spindle-associated protein 1 (
) as one of the target genes of
. NUSAP1 was expressed at high levels in liver cancer tissues. Interestingly, HBx up-regulated NUSAP1 by suppressing
. Functionally,
significantly inhibited the proliferation of hepatoma cells by depressing NUSAP1 levels
and
.
Thus, we conclude that the targeting of
mRNA by the tumor suppressor
is controlled by HBx-modulated promoter methylation during the host-virus interaction, leading to hepatocarcinogenesis. Our findings provide new insights into the mechanism by which HBx-mediated miRNAs modulate hepatocarcinogenesis.
Background
To identify radio‐responsive genes and explore the biological function of encoded proteins in non‐small cell lung cancer (NSCLC).
Methods
Radio‐responsive genes in irradiated H460 cells ...were screened from microarray data deposited in the Gene Expression Omnibus (GEO) database. A quantitative real time polymerase chain reaction assay was used to detect the expression of candidate radio‐responsive genes in irradiated cells. CCK‐8 assay, EDU assay, clone formation assay, immunofluorescence and flow cytometry were conducted to evaluate the biological function of B cell translocation gene 2 (BTG2) in NSCLC.
Results
Bioinformatic analysis using GES20549 showed that BTG2 was a radio‐responsive gene in irradiated H460 cells. The mRNA expression level of BTG2 was lower in H460 cells compared with that in BEAS‐2B normal lung epithelial cells. BTG2 expression was elevated upon IR exposure, in a dose‐dependent but not a time‐dependent manner. CCK‐8 and EDU assays revealed that BTG2 overexpression inhibited the growth rate of irradiated cells. Clone formation showed that elevated BTG2 promoted DNA damage of irradiated H460 cells. The number of γ‐H2AX foci induced by DNA damage was also markedly increased upon BTG2 overexpression. Flow cytometry showed that BTG2 increased IR‐induced cell apoptosis.
Conclusions
BTG2 may be a novel radio‐responsive factor and a promising therapeutic target for radiotherapy of NSCLC.
Radiation upregulated BTG2 expression in H460 cells in a dose‐dependent manner. BTG2 overexpression could inhibit the growth rate of irradiated cells, enhance the degree of radiation‐induced DNA damage, and promote radiation‐induced cell apoptosis in vitro.
We have reported that the oncoprotein hepatitis B X-interacting protein (HBXIP) is able to promote migration of breast cancer cells. Fibroblast growth factor 4 (FGF4) is a multipotent growth factor ...and is highly expressed in various human cancers. However, the regulatory mechanism of FGF4 in breast cancer remains poorly understood. In the present study, we report that HBXIP is able to up-regulate FGF4 to enhance the migration of breast cancer cells. Immunohistochemistry staining showed that HBXIP and FGF4 were highly expressed in clinical metastatic lymph nodes of breast tumor. The expression levels of HBXIP were positively related to those of FGF4 in clinical breast cancer tissues. Then, we validated that HBXIP up-regulated the expression of FGF4 at the levels of promoter, mRNA and protein by luciferase reporter gene assays, reverse transcription-polymerase chain reaction and Western blot analysis. Moreover, we found that HBXIP was able to activate FGF4 promoter through transcriptional factor Sp1 by luciferase reporter gene assays. Chromatin immunoprecipitation assays confirmed that HBXIP coactivated Sp1 to stimulate FGF4 promoter. In function, we showed that HBXIP promoted breast cancer cell migration through FGF4 by wound healing and transwell cell migration assays. Thus, we conclude that the oncoprotein HBXIP up-regulates FGF4 through activating transcriptional factor Sp1 to promote the migration of breast cancer cells. Therapeutically, HBXIP may serve as a novel target in breast cancer.
•The highly expression of FGF4 is relevant to that of HBXIP in clinical breast cancer tissues.•FGF4 is up-regulated by HBXIP at transcriptional level in breast cancer cells.•HBXIP increases the expression level of FGF4 via activating transcriptional factor Sp1.•HBXIP enhances breast cancer cells migration through FGF4.
Radiotherapy is mainly a traditional treatment for breast cancer; however, the key genes and pathways in breast cancer associated with irradiation are not clear. In this study, we aimed to explore ...the messenger RNA expression changes between preradiation and postradiation breast cancer. The gene expression data set (GSE59733) was downloaded from Gene Expression Omnibus database. According to |log2FC (fold change) | ≥ 1 and with false discovery rate adjusted P value <.05, differentially expressed genes (DEGs) were screened and annotated by R programming software. The protein–protein interaction (PPI) network was conducted through STRING database, and subnetworks and hub genes were extracted by plug-in in Cytoscape. A total of 82 DEGs (74 upregulated and 8 downregulated genes) were identified. These DEGs mainly enriched in an intrinsic apoptotic signaling pathway and G-protein-coupled receptor binding. What’s more, tumor necrosis factor signaling pathway and interleukin 17 signaling pathway abnormally activated in postradiation tumor samples. Two characteristic subnetworks and 3 hub genes (FOS, CCL2, and CXCL12) were strongly distinguished in PPI network. Moreover, the expression level of the hub genes was confirmed in irradiated MCF-7 cell and SUM-159 cell using quantitative real-time polymerase chain reaction assay. These findings imply that these hub genes may play momentous function in breast cancer to irradiation.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Background
Radiotherapy is an effective therapeutic approach widely used clinically in non‐small cell lung cancer (NSCLC), but radioresistance remains a major challenge. New and effective ...radiosensitizing approaches are thus urgently needed. The activation of DNA‐sensing cyclic GMP‐AMP synthase (cGAS)‐stimulator of interferon genes (STING) pathway has become an attractive therapeutic target, but the relationship between activation of cGAS‐STING pathway and radiosensitization of NSCLC cells remains unknown.
Methods
Considering low expression of cGAS‐STING pathway genes in NSCLC, including STING, we used an activator (STING agonist, dimeric amidobenzimidazole diABZI) of cGAS‐STING pathway and increased activation factor (DNA double strand breaks) of cGAS‐STING pathway to respectively reinforce the activation of cGAS‐STING pathway in NSCLC cells. We then investigated the effect of increased activation of cGAS‐STING pathway on the proliferation of H460 and A549 cells by CCK‐8 and colony formation assays, and revealed the underlying mechanism.
Results
We found that both diABZI and the increased DNA double strand breaks could sensitize NSCLC cells to irradiation. Mechanically, our results showed that the increased activation of cGAS‐STING pathway enhanced radiosensitivity by promoting apoptosis in NSCLC cells.
Conclusion
Taken together, we concluded that diABZI could be used as a radiosensitizer in NSCLC cells, and targeting the activation of cGAS‐STING pathway has a potential to be a new approach for NSCLC radiosensitizing.
Both diABZI (STING agonist) and A12B4C3 (inhibition of DNA repair) reinforce the activation of cGAS‐STING pathway. The increased activation of cGAS‐STING pathway enhances the radiosensitivity of NSCLC cells by promoting apoptosis.
Radioresistance is a major challenge in lung cancer radiotherapy, and new radiosensitizers are urgently needed. Estrogen receptor β (ERβ) is involved in the progression of non-small cell lung cancer ...(NSCLC), however, the role of ERβ in the response to radiotherapy in lung cancer remains elusive. In the present study, we investigated the mechanism underlying ERβ-mediated transcriptional activation and radioresistance of NSCLC cells.
Quantitative real-time PCR, western blot and immunohistochemistry were used to detect the expression of CLPTM1L, ERβ and other target genes. The mechanism of CLPTM1L in modulation of radiosensitivity was investigated by chromatin immunoprecipitation assay, luciferase reporter gene assay, immunofluorescence staining, confocal microscopy, coimmunoprecipitation and GST pull-down assays. The functional role of CLPTM1L was detected by function assays in vitro and in vivo.
CLPTM1L expression was negatively correlated with the radiosensitivity of NSCLC cell lines, and irradiation upregulated CLPTM1L in radioresistant (A549) but not in radiosensitive (H460) NSCLC cells. Meanwhile, IR induced the translocation of CLPTM1L from the cytoplasm into the nucleus in NSCLC cells. Moreover, CLPTM1L induced radioresistance in NSCLC cells. iTRAQ-based analysis and cDNA microarray identified irradiation-related genes commonly targeted by CLPTM1L and ERβ, and CLPTM1L upregulated ERβ-induced genes CDC25A, c-Jun, and BCL2. Mechanistically, CLPTM1L coactivated ERβ by directly interacting with ERβ through the LXXLL NR (nuclear receptor)-binding motif. Functionally, ERβ silencing was sufficient to block CLPTM1L-enhanced radioresistance of NSCLC cells in vitro. CLPTM1L shRNA treatment in combination with irradiation significantly inhibited cancer cell growth in NSCLC xenograft tumors in vivo.
The present results indicate that CLPTM1L acts as a critical coactivator of ERβ to promote the transcription of its target genes and induce radioresistance of NSCLC cells, suggesting a new target for radiosensitization in NSCLC therapy. Video Abstract.
N6-Methyladenosine (m6A) is a prevalent modification present in the mRNAs of higher eukaryotes. YTH domain family 2 (YTHDF2), an m6A “reader” protein, can recognize mRNA m6A sites to mediate mRNA ...degradation. However, the regulatory mechanism of YTHDF2 is poorly understood. To this end, we investigated the post-transcriptional regulation of YTHDF2. Bioinformatics analysis suggested that the microRNA miR-145 might target the 3′-untranslated region (3′-UTR) of YTHDF2 mRNA. The levels of miR-145 were negatively correlated with those of YTHDF2 mRNA in clinical hepatocellular carcinoma (HCC) tissues, and immunohistochemical staining revealed that YTHDF2 was closely associated with malignancy of HCC. Interestingly, miR-145 decreased the luciferase activities of 3′-UTR of YTHDF2 mRNA. Mutation of predicted miR-145 binding sites in the 3′-UTR of YTHDF2 mRNA abolished the miR-145-induced decrease in luciferase activity. Overexpression of miR-145 dose-dependently down-regulated YTHDF2 expression in HCC cells at the levels of both mRNA and protein. Conversely, inhibition of miR-145 resulted in the up-regulation of YTHDF2 in the cells. Dot blot analysis and immunofluorescence staining revealed that the overexpression of miR-145 strongly increased m6A levels relative to those in control HCC cells, and this increase could be blocked by YTHDF2 overexpression. Moreover, miR-145 inhibition strongly decreased m6A levels, which were rescued by treatment with a small interfering RNA-based YTHDF2 knockdown. Thus, we conclude that miR-145 modulates m6A levels by targeting the 3′-UTR of YTHDF2 mRNA in HCC cells.
Radioresistance is a major challenge in lung cancer radiotherapy (RT), and consequently, new radiosensitizers are urgently needed. MicroRNAs (miRNAs) have been demonstrated to participate in many ...important cellular processes including radiosensitization. MiR-365 is dysregulated in non-small cell lung cancer (NSCLC) and is able to restrain the development of NSCLC. However, the relationship between miR-365 and radiosensitivities of NSCLC cells remains largely unknown. Here we reveal that overexpression of miR-365 is able to enhance the radiosensitivity of NSCLC cells through targeting CDC25A. We found that the expression level of miR-365 was positively correlated with the radiosensitivity of NSCLC cell lines. Furthermore, our results showed that overexpression of miR-365 could sensitize A549 cells to the irradiation. However, knockdown of miR-365 in H460 cells could act the converse manner. Mechanically, miR-365 was able to directly target 3′UTR of cell division cycle 25A (CDC25A) mRNA and reduce the expression of CDC25A at the levels of mRNA and protein. And we confirmed that miR-365 could increase the radiosensitivity of NSCLC cells by targeting CDC25A using in vitro and in vivo assays. Taken together, restoration of miR-365 expression enhances the radiosensitivity of NSCLC cells by suppressing CDC25A, and miR-365 could be used as a radiosensitizer for NSCLC therapy.
•MiR-365 is positively correlated with the radiosensitivity of NSCLC cells.•MiR-365 suppresses CDC25A through directly targeting its 3′UTR in NSCLC cells.•MiR-365 increases the radiosensitivity of NSCLC cells through targeting CDC25A.
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