Selective up-regulation of CDK2 is critical for TLR9 signaling stimulated proliferation of human lung cancer cell

USP52 inhibits cell proliferation by stabilizing PTEN protein in non-small cell lung cancer

Non-small cell lung cancer (NSCLC) is the most common subtype of lung cancer. Ubiquitination is closely related to the development of lung cancer. However, the biological importance of newly discovered ubiquitin-specific peptidase (USP) 52 (USP52) in NSCLC remained unclear. Here, our findings identify USP52 as a novel tumor suppressor of NSCLC, the low expression of USP52 predicts a poor prognosis for NSCLC patients. The present study demonstrates that USP52 inhibits cancer cell proliferation through down-regulation of cyclin D1 (CCND1) as well as AKT/mTOR signaling pathway inhibition. Meanwhile, USP25 also suppresses NSCLC progression via enhancing phosphatase and tensin homolog (PTEN) stability in cancer cells, which further indicates the significance/importance of USP52 in NSCLC suppression.

TLR9 induces colitis-associated colorectal carcinogenesis by regulating NF-κB expression levels

Chronic colorectal inflammation has been associated with colorectal cancer (CRC); however, its exact molecular mechanisms remain unclear. The present study aimed to investigate the effect of Toll-like receptor 9 (TLR9) on the development of colitis-associated CRC (CAC) through its regulation of the NF-κB signaling pathway. By using a CAC mouse model and immunohistochemistry, the present study discovered that the protein expression levels of TLR9 were gradually upregulated during the development of CRC. In addition, the expression levels of TLR9 were revealed to be positively correlated with NF-κB and Ki67 expression levels. In vitro, inhibiting TLR9 expression levels using chloroquine decreased the cell viability, proliferation and migration of the CRC cell line HT29, and further experiments indicated that this may occur through downregulating the expression levels of NF-κB, proliferating cell nuclear antigen and Bcl-xl. In conclusion, the findings of the present study suggested that TLR9 may serve an important role in the development of CAC by regulating NF-κB signaling.

Modified Genomic Self-DNA Influences In Vitro Survival of HT29 Tumor Cells via TLR9- and Autophagy Signaling

In relation of immunobiology, the consequence of the crosstalk between TLR9-signaling and autophagy is poorly documented in HT29 cancer cells. To assess the TLR9-mediated biologic effects of modified self-DNA sequences on cell kinetics and autophagy response HT29 cells were incubated separately with intact genomic (g), hypermethylated (m), fragmented (f), and hypermethylated/fragmented (m/f) self-DNAs. Cell viability, apoptosis, cell proliferation, colonosphere-formation were determined. Moreover, the relation of TLR9-signaling to autophagy response was assayed by real-time RT-PCR, immunocytochemistry and transmission electron microscopy (TEM). After incubation with g-, m-, and m/f-DNAs cell viability and proliferation decreased, while apoptosis increased. F-DNA treatment resulted in an increase of cell survival. Methylation of self-DNA resulted in decrease of TLR9 expression, while it did not influence the positive effect of DNA fragmentation on MyD88 and TRAF6 overexpression, and TNFα downregulation. Fragmentation of DNA abrogated the positive effect of methylation on IRAK2, NFκB and IL-8 mRNA upregulations. In case of the autophagy genes and proteins, g- and f-DNAs caused significant upregulation of Beclin1, Atg16L1, and LC3B. According to TEM analyses, autophagy was present in each group of tumor cells, but to a varying degree. Incubation with m-DNA suppressed tumor cell survival by inducing features of apoptotic cell death, and activated mitophagy. F-DNA treatment enhanced cell survival, and activated macroautophagy and lipophagy. Colonospheres were only present after m-DNA incubation. Our data provided evidence for a close existing interplay between TLR9-signaling and the autophagy response with remarkable influences on cell survival in HT29 cells subjected to modified self-DNA treatments.

Paclitaxel-loaded nanobubble targeted to pro-gastrin-releasing peptide inhibits the growth of small cell lung cancer

Objective

The aim of this work was to study the effects of paclitaxel-loaded nanobubbles targeting pro-gastrin-releasing peptide, designated as paclitaxel targeting nanobubbles, on small cell lung cancer (SCLC).

Methods

Paclitaxel targeting nanobubbles were prepared by Thin-film hydration method. Subsequently, the prepared nanomaterials were tested for their in vitro effects on SCLC H446 cells proliferation, apoptosis and motility using the CCK-8 assay, flow cytometry and cell scratch test. Next, the potential molecular regulatory mechanisms of the prepared nanomaterials on H446 cells were evaluated by RT-PCR, Western blot and immunohistochemical detection. Finally, the in vivo effects of the constructed nanomaterials were assessed on SCLC tumor using tumor-burdened nude mice models.

Results

Paclitaxel targeting nanobubbles significantly inhibited SCLC cell proliferation and migration, and promoted cell apoptosis. Moreover, the expression levels of Bcl-2, survivin, CDK2 and MMP-2 significantly decreased in SCLC cells treated with paclitaxel targeting nanobubbles, whereas the expression of caspase-3 and Rb were increased. There was a notable decrease in tumor size in vivo in SCLC nude mice models treated with paclitaxel targeting nanobubbles.

Conclusion

Paclitaxel targeting nanobubbles effectively inhibited the proliferation, migration and invasion of SCLC cells and induced SCLC cells apoptosis. Hence, these nanobubbles show potential in SCLC-targeted drug treatment application.

TLR9 signaling activation at different stages in colorectal cancer and NF-kappaB expression

Background

The relationship of inflammation and tumor is becoming more and more important in the study on the pathogenesis of colorectal cancer. The role of TLR9-mediated immune inflammation reaction in the process is not currently clear. The purpose of the study was to discuss the correlation of TLR9 signal activation with tumor progression by detecting the expression of TLR9 and its downstream molecule NF-kappaB in colorectal cancer tissues at different stages.

Methods

TLR9 expression in colorectal cancer tissues was detected by immunohistochemical streptavidin-perosidase method and Western blot.

Results

The result showed that the high expression of TLR9 was correlated with tumor poorly differentiation, invasion and liver metastasis, the abnomal increasing levels of CEA in blood. With the signal activation, the levels of TLR9 protein raised more in advanced colorectal cancer than in early colorectal cancer. Afterward, we found that the activation of specific expression of TLR9 signal was related to histologic origin. TLR9-C expression displayed in both advanced cancer and para-carcinoma tissues, and TLR9-R protein was predominat in partial sigmoid and rectal cancer tissues. With the differential expression of TLR9, the levels of its downstream molecule NF-kappaB protein increased in colon cancer tissues and decreased in rectal cancer tissues.

Conclusion

The results confirmed that TLR9 signaling activation participated in the clinical process of colorectal cancer and influenced NF-kappaB expression.

Emerging landscape of circular RNAs in lung cancer

Lung cancer, the leading cause of cancer deaths worldwide, is characterized with malignant cell growth. Advances in next-generation sequencing has helped us further understand RNA and identify novel circular RNAs (circRNAs) that may be useful in the early diagnosis and treatment of lung cancer. Similar to other noncoding RNAs, circRNAs present diverse biological functions in normal and disease states, including various types of cancers. This review focuses mainly on the poorly understood functions of circRNA in lung cancer. This paper also summarizes the recent advances in circRNA biogenesis, analyzes the role of circRNAs in cancers, and discusses the potential mechanisms of circRNAs in lung cancer.

Roles of toll-like receptors: From inflammation to lung cancer progression

Lung cancer is among the most common malignant tumors worldwide, and is characterized by a low survival rate compared with other cancers. Toll-like receptors (TLRs) are highly conserved in evolution and widely expressed on immune cells, where they serve an important role in the innate immune system by evoking inflammatory responses. Evasion of immune destruction is an important hallmark in the development of cancer. There is an established association between chronic inflammation and cancer, with TLRs serving important roles in the immune response against tumor cells. Recently, TLRs have been identified on tumor cells, where their activation may orchestrate the downstream signaling pathways that serve crucial functions in tumorigenesis and tumor progression. The present review summarizes the roles of TLRs as sensors on lung cancer cells that regulate lung cancer progression with regard to cell growth and invasion, angiogenesis and cancer stem cell behavior. This aimed to provide theoretical support for the development of therapies that target TLR signaling pathways for the treatment of lung cancer.

Non-small-cell lung cancer pathological subtype-related gene selection and bioinformatics analysis based on gene expression profiles

Lung cancer is one of the most common malignant diseases and a major threat to public health on a global scale. Non-small-cell lung cancer (NSCLC) has a higher degree of malignancy and a lower 5-year survival rate compared with that of small-cell lung cancer. NSCLC may be mainly divided into two pathological subtypes, adenocarcinoma and squamous cell carcinoma. The aim of the present study was to identify disease genes based on the gene expression profile and the shortest path analysis of weighted functional protein association networks with the existing protein-protein interaction data from the Search Tool for the Retrieval of Interacting Genes. The gene expression profile (GSE10245) was downloaded from the National Center for Biotechnology Information Gene Expression Omnibus database, including 40 lung adenocarcinoma and 18 lung squamous cell carcinoma tissues. A total of 8 disease genes were identified using Naïve Bayesian Classifier based on the Maximum Relevance Minimum Redundancy feature selection method following preprocessing. An additional 21 candidate genes were selected using the shortest path analysis with Dijkstra's algorithm. The AURKA and SLC7A2 genes were selected three and two times in the shortest path analysis, respectively. All those genes participate in a number of important pathways, such as oocyte meiosis, cell cycle and cancer pathways with Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. The present findings may provide novel insights into the pathogenesis of NSCLC and enable the development of novel therapeutic strategies. However, further investigation is required to confirm these findings.

Radiosensitization by CpG ODN7909 in an epidermoid laryngeal carcinoma Hep-2 cell line

Objective

To evaluate the radiosensitivity effect of CpG oligodeoxyribonucleotide (ODN) 7909 on human epidermoid cancer strain-2 (Hep-2) cells in vitro and discuss the potential for improved radiotherapy treatment in patients with laryngeal squamous cell carcinoma.

Methods

Toll-like receptor (TLR) 9 expression was assessed in Hep-2 cells using Western blots and reverse transcription polymerase chain reaction. Cell Counting Kit-8 was used to detect Hep-2 cell viability at 24 and 48 h following treatment with different CpG ODN7909 concentrations. Cellular colonization was evaluated using microscopy. Cell cycle distribution and apoptosis rate was determined with flow cytometry. Interleukin (IL)-12 and tumour necrosis factor (TNF)-α concentrations were detected by enzyme-linked immunosorbent assay.

Results

Hep-2 cells were found to express TLR9, and CpG ODN7909 treatment suppressed Hep-2 cell viability in a dose- and time-dependent manner. Cell survival curve analyses revealed a sensitivity enhancement ratio of the mean death dose of 1.225 for CpG ODN7909 plus irradiation versus irradiation alone. Furthermore, the population of Gap 2/mitotic-phase cells, apoptosis rate and secreted IL-12 and TNF-α levels were significantly increased in Hep-2 cells treated with CpG ODN7909 plus irradiation versus IR alone.

Conclusion

CpG ODN7909 enhanced the radiosensitivity of Hep-2 cells in vitro.

IL-1 Receptor-Associated Kinase Signaling and Its Role in Inflammation, Cancer Progression, and Therapy Resistance

Chronic inflammation has long been associated with the development of cancer. Among the various signaling pathways within cancer cells that can incite the expression of inflammatory molecules are those that activate IL-1 receptor-associated kinases (IRAK). The IRAK family is comprised of four family members, IRAK-1, IRAK-2, IRAK-3 (also known as IRAK-M), and IRAK-4, which play important roles in both positively and negatively regulating the expression of inflammatory molecules. The wide array of inflammatory molecules that are expressed in response to IRAK signaling within the tumor microenvironment regulate the production of factors which promote tumor growth, metastasis, immune suppression, and chemotherapy resistance. Based on published reports we propose that dysregulated activation of the IRAK signaling pathway in cancer cells contributes to disease progression by creating a highly inflammatory tumor environment. In this article, we present both theoretical arguments and reference experimental data in support of this hypothesis.

Screening on human hepatoma cell line HepG-2 nucleus and cytoplasm protein after CDK2 silencing by RNAi

The activation of phase-specific cyclin-dependent kinases is associated with ordered cell cycle transitions. Among the mammalian Cdks, Cdk2 is essential for liver cancer cell proliferation. The related cycling protein CDK2 was analyzed by 2D-gel and MALDI-TOF/TOF MS mass assay in liver cancer cells, which CDK2 was silenced. The results showed four significantly different spots in cell ribonucleoprotein (similar to ribosomal protein S12, chaperonin 10-related protein, beta-actin and zinc finger protein 276) and four in plasmosin (aldolase A protein, hCG, anonymous protein and tubulin, gamma complex associated protein 2). In the plasmosin, aldolase A catalyzes the production of tublin and actin. Together they regulate the cell cycle and arrest the cell in the S phage. In the cell ribonucleoprotein, proteins with homology to ribosomal protein S12 and chaperonin 10 play a similar role in cell cycle regulation.

Role of toll-like receptors in lung cancer

Lung cancer is a leading cause of death world-wide and the long-term survival rate for patients with lung cancer is one of the lowest for any cancer. Toll-like receptors (TLRs), evolutionarily conserved innate, are expressed in a wide variety of tissues and cell types, and they play key role in the innate immune system. TLRs have been found to be expressed by some kinds of tumor cells. However, what is the biological function of TLRs on tumor cells and whether human lung cancer cells can express TLRs remain to be fully understood. This review was performed to sum up the role of TLRs in lung cancer.

The stimulatory activity of plasma in patients with advanced non-small cell lung cancer requires TLR-stimulating nucleic acid immunoglobulin complexes and discriminates responsiveness to chemotherapy

Background

Therapeutic options for patients with non-small cell lung cancer (NSCLC) are often restricted to systemic chemotherapy. However, the molecular and cellular processes during chemotherapy of advanced NSCLC patients still remain unclear. Here we investigated the stimulatory activity of plasma in advanced NSCLC patients and its correlation with chemotherapy.

Methods

Whole blood samples from advanced NSCLC patients were collected before the first, second, and third cycle of chemotherapy. Plasma was isolated following centrifugation of whole blood. PBMCs were isolated from whole-blood specimens by Ficoll-Hypaque density gradient centrifugation. Immune complexes (ICs) were isolated from NSCLC plasma using the IgG Purification Kit. qRT-PCR was used to detect a broad array of cytokines and chemokines.

Results

The plasma in advanced NSCLC patients was endowed with stimulatory activity and capable of inducing proinflammatory cytokines. Both nucleic acids and immunoglobulin components were required for the stimulatory activity of NSCLC plasma. In consistent, TLR8 and TLR9 conferred the stimulatory activity of plasma in NSCLC patients. Of note, we revealed the decreased stimulatory activity of plasma in patients who responded to chemotherapy.

Conclusions

Our findings demonstrated that the plasma of advanced NSCLC patients required TLR-stimulating nucleic acid immunoglobulin complexes and could discriminate the responsiveness to chemotherapy, which might provide a novel mechanism by which the proinflammatory immune response was induced and a potential new biomarker for evaluating responsiveness to chemotherapy in NSCLC patients.

Fengycin inhibits the growth of the human lung cancer cell line 95D through reactive oxygen species production and mitochondria-dependent apoptosis

To investigate the antitumor activity and action mechanism of fengycin using the human lung cancer cell line 95D. The antitumor activity of fengycin was tested in vitro and in vivo. Reactive oxygen species production, Ca(2+) uptake, and mitochondrial membrane potential loss induced by fengycin in 95D cells were measured by flow cytometry and a laser confocal microscope. Lactate dehydrogenase release and caspase activity in fengycin-treated 95D cells were assayed using cytotoxicity detection kits. Apoptosis triggered by fengycin was identified by 4,6-diamidino-2-phenylindole (DAPI) staining and flow cytometry. The effects of fengycin on cell-cycle and apoptosis-related proteins were evaluated by quantitative reverse-transcription PCR and western blot. Treatment with fengycin not only significantly decreased cell proliferation in various cancer cell lines including 95D but inhibited the growth of xenografted 95D cells in nude mice. Fengycin also induced reactive oxygen species production and Ca(2+) uptake, as well as lactate dehydrogenase release and mitochondrial membrane potential loss. Further experiments showed that fengycin could trigger apoptosis in 95D cells and cause cell-cycle arrest at the G0/G1 stage by downregulating cyclin D1 and cyclin-dependent kinase 4 (CDK4). While investigating caspase activity and the expression of apoptosis-related proteins, fengycin was found to induce apoptosis in 95D cells through the mitochondrial pathway, evidenced by increased caspase activity, Bax expression, and cytochrome c release into the cytoplasm, as well as decreased Bcl-2 levels. Fengycin can inhibit the growth of the cancer cell line 95D by regulating the cell cycle and promoting apoptosis, suggesting that it may have potential as an anticancer treatment.

TLR9 signaling repressed tumor suppressor miR-7 expression through up-regulation of HuR in human lung cancer cells

Background

Our recent evidence showed that Toll like receptor 9 (TLR9) signaling could enhance the growth and metastatic potential of human lung cancer cells through repressing microRNA-7 (miR-7) expression. Human antigen R (HuR) has been involved in stabilizing multiple mRNAs in cellular biology. However, whether HuR also contributed to the altered expression of miR-7 in TLR9 signaling stimulated human lung cancer cells remains to be elucidated.

Methods

The expression of HuR in human lung cancer 95D cells treated with TLR9 agonist CpG Oligonucleotides (ODNs) was detected by Real-time PCR and Western blot assay. To explore the possible role of HuR on miR-7 expression, eukaryotic expression vector encoding HuR was transiently transfected into 95D cells and then the expression of miR-7 was detected by Real-time PCR assay. Moreover, RNA interference, western blot, Real-time PCR, MTT assay, BrdU labeling, invasion assay and scratch assay were employed to examine the disrupt effect of HuR on miR-7 expression in human lung cancer cells treated with CpG ODNs. Finally, inhibitors for PI3K, Akt or Erk respectively, and western blot were performed to explore the possible signaling pathway related to HuR expression in CpG ODNs treated human lung cancer cells.

Results

Our data showed that TLR9 agonist CpG ODNs could induce the expression of HuR in human lung cancer cells. Moreover, overexpression of HuR could reduce the expression of miR-7 in lung cancer cells. Notably, down-regulation of HuR using RNA interference restored miR-7 expression in CpG ODNs treated lung cancer cells, accompanied by enhanced growth and metastatic potential. Finally, CpG ODNs could induce HuR expression through Akt pathway.

Conclusion

Our findings indicated that HuR could act as regulator in regulating TLR9 signaling associated biological effect in human lung cancer cells, which might be helpful for the understanding of the potential role of HuR in tumor biology.

MicroRNA-7–regulated TLR9 signaling–enhanced growth and metastatic potential of human lung cancer cells by altering the phosphoinositide-3-kinase, regulatory subunit 3/Akt pathway

This article reports that TLR9 signaling can reduce intrinsic microRNA-7 (miR-7) expression in human lung cancer cells and that overexpression of miR-7 can significantly inhibit TLR9 signaling–enhanced growth and metastatic potential of lung cancer cells in vitro and in vivo.

Recent evidence shows that microRNAs (miRNAs) contribute to the biological effects of Toll-like receptor (TLR) signaling on various cells. Our previous data showed that TLR9 signaling could enhance the growth and metastatic potential of human lung cancer cells. However, the potential role of miRNAs in the effects of TLR9 signaling on tumor biology remains unknown. In this paper, we first report that TLR9 signaling could reduce intrinsic miR-7 expression in human lung cancer cells. Furthermore, overexpression of miR-7 can significantly inhibit TLR9 signaling–enhanced growth and metastatic potential of lung cancer cells in vitro and in vivo. Notably, we identify phosphoinositide-3-kinase, regulatory subunit 3 (PIK3R3) as a novel target molecule of miR-7 in lung cancer cells by Western blotting and luciferase report assay. Further study shows that miR-7 inhibits the effects of TLR9 signaling on lung cancer cells through regulation of the PIK3R3/Akt pathway. These data suggest that miR-7 could act as a fine-tuner in regulating the biological effects of TLR9 signaling on human lung cancer cells, which might be helpful to the understanding of the potential role of miRNAs in TLR signaling effects on tumor biology.

MicroRNA-574-5p was pivotal for TLR9 signaling enhanced tumor progression via down-regulating checkpoint suppressor 1 in human lung cancer

Accumulating data suggested that functional expression of Toll-like receptors (TLRs) in tumor cells was involved in tumor progression. Our previous study demonstrated that TLR9 signaling could enhance the tumor progression of human lung cancer cells in vitro and in vivo. We further showed that miR-574-5p was the mostly up-regulated miRNA in human lung cancer cells under TLR9 signaling by miRNA array analysis. Here we characterized the potential role of miRNA-574-5p in enhanced tumor progression induced by TLR9 signaling in human lung cancer. We confirmed that TLR9 signaling effectively elevated the expression of miR-574-5p in human lung cancer cells. Notably, we found that down-regulation of miRNA-574-5p using miR-574-5p inhibitor in vitro or miR-574-5p sponge in vivo significantly abrogated the enhanced tumor progression induced by TLR9 signaling. Further studies showed that miR-574-5p was an important player associated with enhanced tumor progression of human lung cancer cells. Notably, we identified checkpoint suppressor 1 (Ches1) as the dominant direct target for miRNA-574-5p to confer the TLR9 signaling enhanced tumor progression. We revealed that over-expression of Ches1 significantly inhibited the cell cycle entry of human lung cancer cells. Finally, we revealed that the expression of miR-574-5p was positively correlated with TLR9 and reversely correlated with Ches1 in lung cancer patients. Our findings not only facilitated the further understanding of the crosstalk between miRNAs and TLRs in tumor biology, but also provided novel potential candidates for treatment of cancer.

HMGB1 was a pivotal synergistic effecor for CpG oligonucleotide to enhance the progression of human lung cancer cells

High-mobility group box 1 (HMGB1) has been implicated in a variety of biologically important processes, including transcription, DNA repair, differentiation, development, and extracellular signaling. However, the potential role of HMGB1 in tumor biology still remains intractable. Our previous study showed that TLR9 response to CpG oligonucleotide (ODN) in 95D human lung cancer cells could enhance their growth and invasive potential in vitro and in vivo. Here we found that CpG ODN stimulation to 95D cells induced the secretion of HMGB1 in a dose dependent manner. We further showed that blockade of extracellular HMGB1 using A box peptide and ethyl pyruvate significantly abrogated the CpG ODN enhanced progression of 95D cells. Interestingly, we found that HMGB1 alone or acted synergistic with CpG ODN could enhance the progression of 95D cells. Notably, we revealed that RAGE and TLR4 were critical for HMGB1 to exert the synergistic function. We observed a MyD88-dependent upregulation of matrix metalloproteinase (MMP) 2, MMP9 and cyclin-dependent kinase (CDK) 2 in 95D cells in response to HMGB1. These findings might further our understanding of TLR9 signaling in tumor biology and be helpful for developing HMGB1-based strategy against lung cancer.

Increased Toll-like receptor 9 expression indicates adverse prognosis in oesophageal adenocarcinoma

AIMS

Toll-like receptor 9 (TLR-9) is a cellular DNA receptor that has been linked previously to invasion in various cancers. The aim of this study was to investigate TLR-9 expression and its possible association with prognosis in oesophageal adenocarcinoma.

METHODS AND RESULTS

Immunohistochemical TLR-9 expression was graded in clinical specimens (n = 76) of oesophageal adenocarcinoma. The TLR-9 immunostaining intensity was compared with tumour grade, stage and indicators of proliferation, apoptosis and tumour vascular supply. High TLR-9 expression correlated with advanced tumour stage, tumour unresectability, poor differentiation and high proliferation. Strong immunoreactivity of TLR-9 also indicated poor overall survival.

CONCLUSIONS

High TLR-9 expression is associated with poor differentiation, a high proliferation rate and disseminated disease. Accordingly, increased TLR-9 expression may contribute to the growth and metastatic properties of oesophageal adenocarcinoma.

Toll-like receptor signaling pathways--therapeutic opportunities

Toll-like receptors (TLRs) are transmembrane proteins acting mainly as sensors of microbial components. Triggering TLRs results in increased expression of multiple inflammatory genes, which then play a protective role against infection. However, aberrant activation of TLR signaling has a significant impact on the onset of cancer, allergy, sepsis and autoimmunity. Various adaptor proteins, including MyD88, IRAKs, TIRAP, TRIF, and TRAM, are involved in specific TLR signaling pathways. This article reviews the role of these molecules in TLR signaling, and discusses the impact of this pathway on various disease scenarios. Given their important role in infectious and non-infectious disease settings, TLRs and their signaling pathways emerge as attractive targets for therapeutics.