Tweety homolog 3 promotes colorectal cancer progression through mutual regulation of histone deacetylase 7.

Colorectal cancer (CRC) is one of the leading cancers worldwide, with metastasis being a major cause of high mortality rates among patients. In this study, dysregulated gene Tweety homolog 3 (TTYH3) was identified by Gene Expression Omnibus database. Public databases were used to predict potential competing endogenous RNAs (ceRNAs) for TTYH3. Quantitative real-time polymerase chain reaction, western blot, and immunohistochemistry were utilized to analyze TTYH3 and histone deacetylase 7 (HDAC7) levels. Luciferase assays confirmed miR-1271-5p directly targeting the 3' untranslated regions of TTYH3 and HDAC7. In vitro experiments such as transwell and human umbilical vein endothelial cell tube formation, as well as in vivo mouse models, were conducted to assess the biological functions of TTYH3 and HDAC7. We discovered that upregulation of TTYH3 in CRC promotes cell migration by affecting the Epithelial-mesenchymal transition pathway, which was independent of its ion channel activity. Mechanistically, TTYH3 and HDAC7 functioned as ceRNAs, reciprocally regulating each other's expression. TTYH3 competes for binding miR-1271-5p, increasing HDAC7 expression, facilitating CRC metastasis and angiogenesis. This study reveals the critical role of TTYH3 in promoting CRC metastasis through ceRNA crosstalk, offering new insights into potential therapeutic targets for clinical intervention.

Recent Advances in Antitumor Dendritic Cell Vaccines.

Background: Dendritic cells (DCs) are the most important antigen-presenting cells in the body and play a key role in antigen recognition, uptake, processing, and presentation and mediate nonspecific immunity and specific immunity. Purpose: To summarize the main findings that DC vaccines are a new immunotherapy scheme combining the strengths of tumor antigens and DCs that can boost the body's identification and clearance of tumors. Methods: In this review, the authors focus on the biological characteristics of DCs, recent advances in the understanding of antitumor mechanisms, and the classification of DC vaccines. Results: The current progress of DC-based vaccine immunotherapy for common tumors with high morbidity or mortality in China were systematically summarize. Conclusions: The DC vaccines combining the strengths of tumor antigens will provide directions to explore reasonable, safe, and effective combination immunotherapy strategies for tumors in the future.

Delivery of miR-3529-3p using MnO2 -SiO2 -APTES nanoparticles combined with phototherapy suppresses lung adenocarcinoma progression by targeting HIGD1A.

BACKGROUND: The present study aimed to investigate the function of miR-3529-3p in lung adenocarcinoma and MnO2 -SiO2 -APTES (MSA) as a promising multifunctional delivery agent for lung adenocarcinoma therapy. METHODS: Expression levels of miR-3529-3p were evaluated in lung carcinoma cells and tissues by qRT-PCR. The effects of miR-3529-3p on apoptosis, proliferation, metastasis and neovascularization were assessed by CCK-8, FACS, transwell and wound healing assays, tube formation and xenografts experiments. Luciferase reporter assays, western blot, qRT-PCR and mitochondrial complex assay were used to determine the targeting relationship between miR-3529-3p and hypoxia-inducible gene domain family member 1A (HIGD1A). MSA was fabricated using MnO2 nanoflowers, and its heating curves, temperature curves, IC50, and delivery efficiency were examined. The hypoxia and reactive oxygen species (ROS) production was investigated by nitro reductase probing, DCFH-DA staining and FACS. RESULTS: MiR-3529-3p expression was reduced in lung carcinoma tissues and cells. Transfection of miR-3529-3p could promote apoptosis and suppress cell proliferation, migration and angiogenesis. As a target of miR-3529-3p, HIGD1A expression was downregulated, through which miR-3529-3p could disrupt the activities of complexes III and IV of the respiratory chain. The multifunctional nanoparticle MSA could not only efficiently deliver miR-3529-3p into cells, but also enhance the antitumor function of miR-3529-3p. The underlying mechanism may be that MSA alleviates hypoxia and has synergistic effects in cellular ROS promotion with miR-3529-3p. CONCLUSIONS: Our results establish the antioncogenic role of miR-3529-3p, and demonstrate that miR-3529-3p delivered by MSA has enhanced tumor suppressive effects, probably through elevating ROS production and thermogenesis.

The protective role of HMGB1 in affecting the balance between autophagy and pyroptosis to maintain neutrophils homeostasis during ß-glucan-induced mice lung inflammation.

Fungal contamination is omnipresent, and inhalation of fungi-contaminated organic dust leads to hypersensitivity pneumonitis (HP), in which neutrophils played a pivotal role. Existing studies have suggested that cell homeostasis is crucial for the pathogenesis of the inflammatory disease. Although HMGB1 has been shown to contribute to suppressing HP, there is a lack of studies on its mechanisms, especially the regulation of neutrophil homeostasis. This study aims to investigate how HMGB1 regulates neutrophil function by affecting neutrophil homeostasis, and then affects lung inflammation induced by ß-glucan, the exposure marker of fungi. Our results showed that deficient HMGB1 led to neutrophil death by disrupting the balance between autophagy and pyroptosis after ß-glucan treatment. And HMGB1 deficiency exacerbated the ß-glucan-induced lung inflammation and neutrophil dysfunction both in vivo and in vitro. Furthermore, HMGB1 contributed to remodeling neutrophil function by restricting autophagy and aggravating pyroptosis ß-glucan exposure. Our funding suggested that HMGB1 deficiency could break the balance between autophagy and pyroptosis towards pyroptosis to cause neutrophil dysfunction during the exacerbated inflammatory response, which provides insights into the pathogenesis of HP and the potential biological targets for its treatment. DATA AVAILABILITY: The datasets used during the current study are available from the corresponding author on reasonable request.

HMGB1 could restrict 1,3-ß-glucan induced mice lung inflammation by affecting Beclin1 and Bcl2 interaction and promoting the autophagy of epithelial cells.

Fungi were microorganisms that are ubiquitous in a variety of environments. Inhalation of fungi-contaminated organic dust led to hypersensitivity pneumonitis and might eventually cause irreversible pulmonary fibrosis. Studies showed that maintaining the homeostasis of epithelial cells was vital for defending the exogenous fungi invasion. HMGB1-dependent autophagy played a critical role in maintaining cell homeostasis in multiple inflammatory diseases. However, the actual role of HMGB1-dependent autophagy in hypersensitivity pneumonitis was unclear. In our study, mice were exposed to 0.3 mg/50 µL 1,3-ß-glucan solution by intratracheal instillation to set up the lung inflammation model. To investigate the role of HMGB1-dependent autophagy in 1,3-ß-glucan induced lung inflammation, AAV-sh-HMGB1 was intratracheally injected to silence HMGB1 in the lung. Our finding suggested that silencing HMGB1 could aggravate the 1,3-ß-glucan induced lung inflammation by inhibiting the autophagy of epithelial cells. And ubiquitination of Beclin1 contributed to decreasing the interaction of Beclin1 and Bcl2, which might be a key regulatory mechanism of HMGB1 on 1,3-ß-glucan induced autophagy.

Downregulation of long noncoding RNA HOTAIRM1 promotes monocyte/dendritic cell differentiation through competitively binding to endogenous miR-3960.

Myeloid differentiation is controlled by a multilayered regulatory circuitry consisting of various elements, including histone modifications, transcription factors, and posttranscriptional regulators such as miRNAs, long noncoding RNAs, and circular RNAs. However, the molecular mechanism underlying this biological process remains unclear. In this study, through epigenetic profiling analysis using chromatin immunoprecipitation (ChIP) followed by sequencing (ChIP-seq), we identified an lncRNA, HOTAIRM1, with a critical role in myeloid development. Further ChIP-chip analysis showed obvious H3K4me3 and H3K27me3 histone modification peak changes in the promoter region of HOTAIRM1 during the process of monocyte to dendritic cell (DC) differentiation. In line with this observation, HOTAIRM1 RNA expression was downregulated when monocytes differentiated into DCs. Moreover, we found that HOTAIRM1 RNA was regulated by epigenetic factors such as RBBP4 and RBBP7. Mechanistically, we found that the silencing of HOTAIRM1 caused changes in the expression of several monocyte differentiation markers such as CD14 and B7H2. In addition, based on the "competing endogenous RNA" hypothesis, we discovered miR-3960 targeting both HOTAIRM1 and the DC differentiation repression gene, HOXA1, by most possibly constructing a potential competing endogenous RNA network. Increased miR-3960 expression could downregulate both of these two long RNAs and finally lead peripheral blood cells to differentiate into DCs. In summary, our study demonstrates that HOTAIRM1 competitively binds to miR-3960 and finally regulates the process of hematopoiesis, which reveals a novel regulatory mechanism of lncRNA function.

Epigenetic Component p66a Modulates Myeloid-Derived Suppressor Cells by Modifying STAT3.

STAT3 plays a critical role in myeloid-derived suppressor cell (MDSC) accumulation and activation. Most studies have probed underlying mechanisms of STAT3 activation. However, epigenetic events involved in STAT3 activation are poorly understood. In this study, we identified several epigenetic-associated proteins such as p66a (Gatad2a), a novel protein transcriptional repressor that might interact with STAT3 in functional MDSCs, by using immunoprecipitation and mass spectrometry. p66a could regulate the phosphorylation and ubiquitination of STAT3. Silencing p66a promoted not only phosphorylation but also K63 ubiquitination of STAT3 in the activated MDSCs. Interestingly, p66a expression was significantly suppressed by IL-6 both in vitro and in vivo during MDSC activation, suggesting that p66a is involved in IL-6-mediated differentiation of MDSCs. Indeed, silencing p66a could promote MDSC accumulation, differentiation, and activation. Tumors in mice injected with p66a small interfering RNA-transfected MDSCs also grew faster, whereas tumors in mice injected with p66a-transfected MDSCs were smaller as compared with the control. Thus, our data demonstrate that p66a may physically interact with STAT3 to suppress its activity through posttranslational modification, which reveals a novel regulatory mechanism controlling STAT3 activation during myeloid cell differentiation.

MicroRNA-200c Promotes Suppressive Potential of Myeloid-Derived Suppressor Cells by Modulating PTEN and FOG2 Expression.

Myeloid-derived suppressor cells (MDSCs) constitute one of the major populations that potently suppress anti-tumor immune responses and favor tumor growth in tumor microenvironment. However, the mechanism(s) regulating the differentiation and suppressive function of tumor-associated MDSCs remain(s) unclear. Here, we identified a microRNA-200c (miR-200c), whose expression was dramatically induced by tumor-derived factors. Meanwhile, we also demonstrated that GM-CSF was a main inducer of miR-200c in tumor environment, and miR-200c in turn promoted the expansion and immune suppressive activity of MDSCs via targeting phosphatase and tensin homolog (PTEN) and friend of Gata 2 (FOG2), which can lead to STAT3 and PI3K/Akt activation. Finally, we examined in vivo suppressive function of miR-200c transfected MDSCs and found that miR-200c could remarkably promote tumor growth via modifying MDSCs. Thus, GM-CSF induced miR-200c in tumor environment plays a critical role in governing the expansion and functions of tumor-associated MDSCs and serves as a potential target in immunotherapy against tumor.

MicroRNA-22 impairs anti-tumor ability of dendritic cells by targeting p38.

Dendritic cells (DCs) play a critical role in triggering anti-tumor immune responses. Their intracellular p38 signaling is of great importance in controlling DC activity. In this study, we identified microRNA-22 (miR-22) as a microRNA inhibiting p38 protein expression by directly binding to the 3' untranslated region (3'UTR) of its mRNA. The p38 down-regulation further interfered with the synthesis of DC-derived IL-6 and the differentiation of DC-driven Th17 cells. Moreover, overexpression of miR-22 in DCs impaired their tumor-suppressing ability while miR-22 inhibitor could reverse this phenomenon and improve the curative effect of DC-based immunotherapy. Thus, our results highlight a suppressive role for miR-22 in the process of DC-invoked anti-tumor immunity and that blocking this microRNA provides a new strategy for generating potent DC vaccines for patients with cancer.

miR-511 induces the apoptosis of radioresistant lung adenocarcinoma cells by triggering BAX.

Radioresistance is one of the main reasons for the failure of radiotherapy in lung cancer. The present study was conducted to identify the role of miR-511 in suppressing the growth of radioresistant lung adenocarcinoma cells. First, a radioresistant A549/R cell line was generated after prolonged exposure to X-rays for 68 Gy (2 Gy/day, 5 days/week) and the radioresistance was confirmed by wound healing assay. Next, oncogenic TRIB2 was found to be upregulated in the radioresistant A549/R cells when compared to that of the control A549 cells as determined by western blot analysis. As the upstream miRNA, quantitative PCR showed that miR-511 expression was decreased in the radioresistant A549/R cells. Overexpression of miR-511 in miR-511-transfected A549/R cells inhibited cell growth and increased the number of apoptotic cells when compared with the control treatment. Flow cytometric analysis further demonstrated that the growth suppressive effect of miR-511 on A549/R cells was mediated by regulation of the cell cycle, most likely due to a block in the G1-S transition. Finally, our results showed that the expression of BAX was lower in the radioresistant A549/R cells when compared with that in the control A549 cells. After downregulation of TRIB2 by miR-511 treatment, BAX expression was obviously increased in the miR-511-transfected apoptotic A549/R cells when compared to that in the NC-treated or control cultures. In summary, our results revealed that miR-511 regulates the growth of radioresistant A549/R cells by increasing BAX expression through TRIB2, which suggests that miR-511 may be a potential therapeutic molecule for the treatment of radioresistant lung adenocarcinoma.

miR-99 inhibits cervical carcinoma cell proliferation by targeting TRIB2.

MicroRNAs (miRNAs) have significant roles in cell processes, including proliferation, apoptosis and stress responses. To investigate the involvement of miR-99 in the inhibition of HeLa cell proliferation, an miR-99 gene expression vector (pU6.1/miR-99), which overexpressed miR-99 in HeLa cells after transient transfection, was constructed. The expression of miR-99 was detected by qPCR. Cell proliferation and apoptosis were analyzed by cell viability, proliferation and apoptosis assays, as well as by electron microscopy. The results showed that overexpression of miR-99 in HeLa cells increased the HeLa cell mortality rate. Moreover, miR-99 overexpression was able to markedly inhibit HeLa cell proliferation according to the 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The cell apoptosis rate was significantly higher in pU6.1/miR-99-treated cells compared with that in the control cultures. Increases in intracellular electron density, as well as the proportion of nuclear plasma, blebbing phenomena and apoptotic bodies were observed in pU6.1/miR-99-treated cells compared with control cultures according to electron microscopy analysis. The Tribbles 2 (TRIB2) 3'-untranslated region was also observed to be targeted by miR-99 and the results further demonstrated that miR-99 was able to negatively regulate TRIB2 expression in HeLa cells The results indicate that miR-99 acts as a tumor suppressor gene in HeLa cells, establishing a theoretical basis for its application in cancer therapeutics.

Downregulation of tumstatin expression by overexpression of ornithine decarboxylase.

Tumor angiogenesis, a pivotal process for cancer growth and metastasis, requires both upregulation of pro­angiogenic molecules and downregulation of anti­angiogenic molecules. Anti-angiogenesis therapy represents a promising way for cancer treatment. Tumstatin, a novel endogenous angiogenesis inhibitor, inhibits endothelial cell proliferation, pathological angiogenesis and tumor growth. Ornithine decarboxylase (ODC), overexpressed in various cancers, is associated with cell transformation, tumor invasion and angiogenesis. We found that the expression of tumstatin was suppressed in ODC-overexpressing human cancer cells and renal carcinoma tissues. We presumed that ODC overexpression may downregulate the expression of tumstatin. To be able to test this hypothesis, we generated HEK293 cells that overexpress ODC (ODC transfectants) and characterized the following experimental groups: PBS-treated group, mock transfectants, ODC transfectants, ODC transfectants transfected with pcDNA-ODCr (an antisense ODC-expressing plasmid) group and putrescine-treated group. The effect of ODC overexpression on tumstatin expression was examined by reverse transcriptase-polymerase chain reaction (RT-PCR), western blot analysis and dual luciferase reporter assay. ODC-overexpressing cells and putrescine-treated cells showed suppressed tumstatin mRNA and protein expression, and decreased tumstatin gene promoter activity. Thus, ODC overexpression suppresses the expression of tumstatin, which may provide fundamental evidence for the combination of anti-angiogenic therapy and conventional therapy for cancer treatment.

Cisplatin upregulates MSH2 expression by reducing miR-21 to inhibit A549 cell growth.

miR-21 can act as an oncogene. MSH2 has been reported that it involved in the DNA mismatch repair (MMR) system and overexpression of MSH2 can induce cell apoptosis. We predicted that MSH2-3'-untranslated region (3'-UTR) was targeted by miR-21 using microRNA analysis softwares. To further explore the roles of miR-21 and MSH2 in A549 cells, we constructed pcDNA-GFP-msh-UTR vector (including MSH2-3'-UTR) to transfect A549 cells with miR-21, GFP positive cells were estimated under a fluorescence microscopy and by flow cytometry. We found miR-21 could obviously downregulate the expression of MSH2, which was further proved by western blotting. Moreover, we treated A549 cells with cisplatin and found that cisplatin could inhibit A549 cell growth in vitro and in vivo. We also found that cisplatin could downregulate miR-21 expression, while increase MSH2 expression in A549 cells. Our results demonstrated that cisplatin could upregulate the expression of MSH2 through downregulating miR-21 to inhibit A549 cell proliferation, which provides new gene targets for drug design or cancer therary.

Downregulation of ornithine decarboxylase by pcDNA-ODCr inhibits gastric cancer cell growth in vitro.

Ornithine decarboxylase (ODC), the first rate-limiting enzyme of polyamine biosynthesis, was found to be associated with cell growth, proliferation and transformation. ODC gene expression in gastric cancer was increased and its level was positively correlated with the degree of malignity of gastric mucosa and development of gastric lesions. In order to evaluate the therapeutic effects of antisense RNA of ODC on gastric cancer, an antisense RNA of ODC expressing plasmid pcDNA-ODCr which delivered a 120 bp fragment complementary to the initiation codon of ODC gene was constructed and transfected to gastric cancer cells SGC7901 and MGC803. Expression of ODC in gastric cancer cells was determined by western blot. Cell proliferation was assessed by MTS assay. Cell cycle was analyzed by flow cytometry and Matrigel assay was performed to assess the ability of gastric cancer cell invasiveness. The results showed that the ODC gene expression in gastric cancer cells transfected with the pcDNA-ODCr was downregulated efficiently. Tumor cell proliferation was suppressed significantly, and cell cycle was arrested at G1 phase. Gastric cancer cells had reduced invasiveness after gene transfer. Our study suggested that antisense RNA of ODC expressing plasmid pcDNA-ODCr had antitumor activity by inhibiting the expression of ODC, and downregulation of ODC expression using a gene therapy approach might be a novel therapeutic strategy for gastric cancer.

Effects of eukaryotic expression plasmid encoding human tumstatin gene on endothelial cells in vitro.

BACKGROUND: Tumstatin is a novel endogenous angiogenesis inhibitor which is widely studied using purified protein. The current study evaluates the antiangiogenic effects of tumstatin-overexpression plasmid in vitro, reveals the mechanism underlying the vascular endothelial cell growth inhibition and searches for a novel method administering tumstatin persistently. METHODS: The eukaryotic expression plasmid pcDNA-tumstatin encoding tumstatin gene was constructed and transfected to human umbilical vein endothelial cell ECV304 and human renal carcinoma cell ACHN. Expression of tumstatin in the two cell lines was determined by RT-PCR and Western blotting. Vascular endothelial cell proliferation was assessed by CCK-8 assay and cell cycle was analyzed by flow cytometry. To investigate the mechanism by which pcDNA-tumstatin inhibited vascular endothelial cell proliferation in vitro, cyclin D1 protein was detected by Western blotting. RESULTS: DNA sequence confirmed that pcDNA-tumstatin was successfully constructed. RT-PCR and Western blotting indicated that tumstatin could express in the two cell lines effectively. After tumstatin gene transfer, ECV304 cell growth was significantly inhibited and the cell cycle was arrested in G1 phase. And Western blotting showed that pcDNA-tumstatin decreased the level of cyclin D1 protein. CONCLUSIONS: Overexpression of tumstatin mediated by pcDNA 3.1 (+) specially inhibited vascular endothelial cells by arresting vascular endothelial cell in G1 phase resulting from downregulation of cyclin D1 and administration of tumstatin using a gene therapy might be a novel strategy for cancer therapy.

The expression of tumstatin is down-regulated in renal carcinoma.

Tumstatin is the 28 kDa NC1 domain of the alpha3 chain of type IV collagen that inhibits pathological angiogenesis and suppresses endothelial cell proliferation and tumor growth. In the present paper, we expressed and purified recombinant human tumstatin protein and then prepared the anti-tumstatin polyclonal antibody. To investigate the expression of tumstatin in renal carcinoma, tumstatin protein was detected by western blotting using the prepared anti-tumstatin antibody and tumstatin mRNA levels were assayed by RT-PCR. The results showed that the expression of tumstatin gene was down-regulated in renal carcinoma tissues and cells. Our study suggests that as a novel endogenous angiogenesis inhibitor, tumstatin gene expression may be a marker for diagnosis, therapy and prognosis of renal carcinoma.

Adenovirus vector-mediated upregulation of spermidine /spermine N1-acetyltransferase impairs human gastric cancer growth in vitro and in vivo.

Spermidine/spermine N(1)-acetyltransferase (SSAT) is the rate-limiting step in polyamine catabolism. In a previous study, we constructed a recombinant adenovirus, Ad-SSAT, which can express human SSAT. In the present study, we investigated the effect of upregulated and downregulated SSAT on gastric cancer cells. We found that upregulated SSAT could inhibit the growth of MGC803 and SGC7901 cells, whereas adverse results were found with downregulated SSAT. We further analyzed cell cycle profiles and the expression levels of the major cell cycle regulatory proteins of S phase. The results showed that the growth inhibition was caused by S phase arrest. Ad-SSAT suppressed the expression of cyclin A and nuclear factor E2F1 in MGC803 and SGC7901 cells. We observed the E2F promoter activity caused by Ad-SSAT using a reporter gene assay. We also investigated the antitumorigenicity of upregulated SSAT by Ad-SSAT using a SGC7901 xenograft model in nude mice. Our results suggest that the upregulation of SSAT by Ad-SSAT infection inhibited the growth of gastric cancer in vitro and in vivo. Ad-SSAT arrested gastric cancer cells in S phase, which was mediated through downregulation of the cyclin A-E2F signaling pathway.