A novel small molecule STAT3 inhibitor, LY5, inhibits cell viability, colony formation, and migration of colon and liver cancer cells

Signal Transducer and Activator of Transcription 3 (STAT3) is persistently activated in human liver and colon cancer cells and is required for cancer cell viability, survival and migration. Therefore, inhibition of STAT3 signaling may be a viable therapeutic approach for these two cancers. We recently designed a non-peptide small molecule STAT3 inhibitor, LY5, using in silico site-directed Fragment-based drug design (FBDD). The inhibitory effect on STAT3 phosphorylation, cell viability, migration and colony forming ability by LY5 were examined in human liver and colon cancer cells. We demonstrated that LY5 inhibited constitutive Interleukin-6 (IL-6)-induced STAT3 phosphorylation, STAT3 nuclear translocation, decreased STAT3 downstream targeted gene expression and induced apoptosis in liver and colon cancer cells. LY5 had little effect on STAT1 phosphorylation mediated by IFN-γ. Inhibition of persistent STAT3 phosphorylation by LY5 also inhibited colony formation, cell migration, and decreased the viability of liver cancer and colon cancer cells. Furthermore, LY5 inhibited STAT3 phosphorylation and suppressed colon tumor growth in a mouse model in vivo. Our results suggest that LY5 is a potent STAT3 inhibitor and may be a potential drug candidate for liver and colon cancer therapy.

Increased Jab1/COPS5 is associated with therapeutic response and adverse outcome in lung cancer and breast cancer patients

Adjuvant chemotherapy has been established as standard treatment for advanced cancer among multidisciplinary therapies. A simple and instructive biomarker for therapeutic response and recurrence is needed to evaluate the therapeutic effect. Jab1/COPS5 level has been shown to be associated with tumor progression and poor outcomes in many types of cancer patients. This study aims to further evaluate the clinical and prognostic value of Jab1/COPS5 level as a biomarker in lung and breast cancer patients receiving adjuvant chemotherapy. In this study, data of 88 lung cancer and 76 breast cancer patients were retrospectively collected and analyzed to identify the relationship between the Jab1/COPS5 level and the clinical progression and outcome of these patients. Lung cancer patients with increased Jab1/COPS5 level tend to be non-responsive to chemotherapy. Relapsed breast cancer patients had an increased Jab1/COPS5 level and breast cancer patients with increased Jab1/COPS5 level had significantly shorter disease-free survival and overall survival. In a multivariate survival analysis, histological type and Jab1/COPS5 were associated with disease-free survival and overall survival. The Jab1/COPS5 level was found to be a possible biomarker for clinical response to chemotherapy in lung cancer patients and for postoperative relapse in breast cancer patients who received adjuvant chemotherapy. In conclusion, this study identified Jab1/COPS5 as novel prognostic markers for lung cancer and breast cancer.

Prognostic and clinicopathological significance of microRNA-494 overexpression in cancers: a meta-analysis

MicroRNA-494 was revealed as an attractive prognostic biomarker in recent studies. Nevertheless, the prognostic value of microRNA-494 in cancers remains controversial. Current meta-analysis aims to elucidate the precise predictive value of microRNA-494 in various cancers. Eligible studies were identified through multiple search strategies, the hazard ratios (HRs) and their confidence interval (CI) for patient prognostic outcomes were extracted and estimated. The pooled results of fifteen studies indicated that elevated expression of microRNA-494 implies a good overall survival of cancer patients (HR = 0.58, 95% CI: 0.36-0.91); While no significant association was found between the high expression of microRNA-494 and clinicopathological characteristic. Additionally, subgroup analysis revealed that overexpression of microRNA-494 predicted a worse overall survival in non-small cell lung cancer (HR = 2.35, 95% CI: 1.05-5.24) and colorectal cancer (HR = 2.59, 95% CI: 1.62-4.14). As per the subgroup analysis, the cancer type, the anatomy system classification and the ethnic background had influence on the overall survival result. Our findings indicate that elevated expression of microRNA-494 might predict a good overall survival in most cancers, while in non-small cell lung cancer and colorectal cancer, overexpression of microRNA-494 might predict a worse overall survival.

JAB1-STAT3 activation loop is associated with recurrence following 5-fluorouracil-based adjuvant chemotherapy in human colorectal cancer

Jun activation domain-binding protein 1 (JAB1) has been shown to have multiple roles in tumorigenesis, including the degradation of tumor suppressor proteins such as p53, Smad7, Runx3 and the cyclin-dependent kinase inhibitor p27Kip1, and the activation of oncogenic transcription factors, such as c-Jun and hypoxia-inducible factor-1α. In addition, our previous study revealed that JAB1 positively regulates signal transducer and activator of transcription 3 (STAT3) DNA-binding activity in human colon cancer cells. In turn, the oncogenic transcription factor STAT3 positively regulates JAB1 expression, indicative of a positive feedback loop. Furthermore, high JAB1 expression is associated with a poor prognosis in numerous malignant carcinomas. However, the association between JAB1 expression and prognosis in colorectal cancer remains unclear. The aim of the present study was to elucidate the association between JAB1 and STAT3 expression and recurrence in colorectal cancer. In the present study, it was found that high JAB1 expression in primary colorectal cancer tissues is an independent predictor of recurrence following 5-fluorouracil (5-FU)-based adjuvant chemotherapy in colorectal cancer patients, and that high expression of both JAB1 and STAT3 in primary colorectal cancer tissues is associated with a lower recurrence-free survival rate following 5-FU-based adjuvant chemotherapy compared to high expression of only JAB1 or STAT3. Overall, these results suggest that JAB1 is a novel predictive marker of recurrence following 5-FU-based adjuvant chemotherapy in colorectal cancer patients, and that the JAB1-STAT3 activation loop may be a potential therapeutic target in recurrent colorectal cancer following 5-FU-based adjuvant chemotherapy.

Stattic Enhances Radiosensitivity and Reduces Radio-Induced Migration and Invasion in HCC Cell Lines through an Apoptosis Pathway

Purpose

Signal transducer and activator of transcription factor 3 (STAT3) is involved in tumorigenesis, development, and radioresistance of many solid tumors. The aim of this study is to investigate the effects of stattic (an inhibitor of STAT3) on the radiosensitivity and radio-induced migration and invasion ability in hepatocellular carcinoma (HCC) cell lines.

Methods

HCC cells were treated with stattic, and cell survival rate was analyzed through CCK-8 assay. Radiosensitivity was evaluated using cloning formation analysis; STAT3, p-STAT3, and apoptosis related proteins were detected by western blot. Radio-induced migration and invasion ability in HCC cells were analyzed by wound-healing assay and transwell test.

Results

Stattic inhibits the expression of p-STAT3 and reduces cell survival in a dose-dependent manner in HCC cell lines, and the IC50 values for Hep G2, Bel-7402, and SMMC-7721 are 2.94 μM, 2.5 μM, and 5.1 μM, respectively. Cloning formation analysis shows that stattic enhances the radiosensitivity of HCC cells. Wound-healing assay and transwell test show that stattic inhibits radio-induced migration and invasion. Further study indicates that stattic promotes radio-induce apoptosis through regulating the expression of apoptosis related proteins in HCC cells.

Conclusion

Stattic enhances radiosensitivity and reduces radio-induced migration and invasion ability in HCC cells probably through apoptosis pathway.

p53: key conductor of all anti-acne therapies

This review based on translational research predicts that the transcription factor p53 is the key effector of all anti-acne therapies. All-trans retinoic acid (ATRA) and isotretinoin (13-cis retinoic acid) enhance p53 expression. Tetracyclines and macrolides via inhibiting p450 enzymes attenuate ATRA degradation, thereby increase p53. Benzoyl peroxide and hydrogen peroxide elicit oxidative stress, which upregulates p53. Azelaic acid leads to mitochondrial damage associated with increased release of reactive oxygen species inducing p53. p53 inhibits the expression of androgen receptor and IGF-1 receptor, and induces the expression of IGF binding protein 3. p53 induces FoxO1, FoxO3, p21 and sestrin 1, sestrin 2, and tumour necrosis factor-related apoptosis-inducing ligand (TRAIL), the key inducer of isotretinoin-mediated sebocyte apoptosis explaining isotretinoin's sebum-suppressive effect. Anti-androgens attenuate the expression of miRNA-125b, a key negative regulator of p53. It can thus be concluded that all anti-acne therapies have a common mode of action, i.e., upregulation of the guardian of the genome p53. Immortalized p53-inactivated sebocyte cultures are unfortunate models for studying acne pathogenesis and treatment.

Correlation of the expressions of IGF1R-RACK1-STAT3 and Bcl-xl in nasopharyngeal carcinoma with the clinicopathological features and prognosis of nasopharyngeal carcinoma

The aim of this study was to investigate the correlation of expression of IGF1R-RACK1-STAT3 and Bcl-xl in nasopharyngeal carcinoma (NPC) with the clinicopathological features and the prognosis of NPC. Our study selected 215 NPC tissues and 178 chronic nasopharyngitis tissues (control group). Positive expression rates of IGF1R, RACK1, STAT3, and Bcl-xl were tested by immunohistochemical method, and expression of IGF1R, RACK1, STAT3, Bcl-xl, Bcl-2, and Bax by western blotting. Correlation of IGF1R, RACK1, STAT3, and Bcl-xl with the clinicopathological features of NPC was analyzed. The correlation among those four expression was analyzed by Spearman. The survival of NPC and independent factors of prognosis were tested by Kaplan-Meier and COX proportional hazards model respectively. The NPC group had higher positive expression rates of IGF1R, RACK1, STAT3, and Bcl-xl, and elevated expression of IGF1R, RACK1, STAT3, Bcl-xl, Bcl-2, and Bax. The lymph node metastasis (LNM) group had higher positive expression rates of IGF1R and RACK1 when compared with the non-LNM group. Patients with stage III and IV had higher positive expression rates of IGF1R, RACK1, STAT3, and Bcl-xl. There was positive correlation between expression of IGF1R and RACK1, STAT3. Such correlation was found between RACK1 and STAT3. Patients with negative expression of IGF1R, RACK1, STAT3, and Bcl-xl had higher survival rates. The risky factors of poor prognosis of NPC were positive expression of IGF1R, RACK1, STAT3 and Bcl-xl, and LNM. IGF1R-RACK1-STAT3 and Bcl-xl expression correlated with the clinicopathological features and poor prognosis of NPC.

COPS5 inhibition arrests the proliferation and growth of serous ovarian cancer cells via the elevation of p27 level

The fifth component of the COP9 signalosome complex (COPS5), which plays an essential role in ubiquitin-mediated protein degradation, has been found as a prognostic biomarker for multiple cancers, however, the role of COPS5 in serous ovarian cancer (SOC) remain to be clarified. In this study, we found that COPS5 expression was significantly increased in SOC cells and tissues compared with those controls. Mechanistically, COPS5 and p27was proved to interact with each other, with COPS5 acts as a negative regulator of p27. SOC cells with COPS5 depletion were arrested in G1/G0-phase and exhibited a reduced proliferation ability and an increased cytoplasmic p27 expression. Whereas, the cells were stuck at S-phase accompanied with an elevation of nucleus p27 expression after knocking down COPS6 or blocking COPS5 by CSN5i-3. Furthermore, inhibition of COPS5 resulted in an elevation of Akt expression and sensitized SOC cells to Akt inhibitor MK2206. Suppression of COPS5 and Akt offers a potential strategy for the treatment of SOC.

Sumoylation in p27kip1 via RanBP2 promotes cancer cell growth in cholangiocarcinoma cell line QBC939

BACKGROUND

Cholangiocarcinoma is one of the deadly disease with poor 5-year survival and poor response to conventional therapies. Previously, we found that p27kip1 nuclear-cytoplasmic translocation confers proliferation potential to cholangiocarcinoma cell line QBC939 and this process is mediated by crm-1. However, no other post-transcriptional regulation was found in this process including sumoylation in cholangiocarcinoma.

RESULTS

In this study, we explored the role of sumoylation in the nuclear-cytoplasmic translocation of p27kip1 and its involvement of QBC939 cells' proliferation. First, we identified K73 as the sumoylation site in p27kip1. By utilizing plasmid flag-p27kip1, HA-RanBP2, GST-RanBP2 and His-p27kip1 and immunoprecipitation assay, we validated that p27kip1 can serve as the sumoylation target of RanBP2 in QBC939. Furthermore, we confirmed crm-1's role in promoting nuclear-cytoplasmic translocation of p27kip1 and found that RanBP2's function relies on crm-1. However, K73R mutated p27kip1 can't be identified by crm-1 or RanBP2 in p27kip1 translocation process, suggesting sumoylation of p27kip1 via K73 site is necessary in this process by RanBP2 and crm-1. Phenotypically, the overexpression of either RanBP2 or crm-1 can partially rescue the anti-proliferative effect brought by p27kip1 overexpression in both the MTS and EdU assay. For the first time, we identified and validated the K73 sumoylation site in p27kip1, which is critical to RanBP2 and crm-1 in p27kip1 nuclear-cytoplasmic translocation process.

CONCLUSION

Taken together, targeted inhibition of sumoylation of p27kip1 may serve as a potentially potent therapeutic target in the eradication of cholangiocarcinoma development and relapses.

The effects of microRNA-98 inhibits cell proliferation and invasion by targeting STAT3 in nasopharyngeal carcinoma

MicroRNA-98 (miR-98) is downregulated in many tumors, and is closely related to tumor progression. In addition, it shows anticarcinogenic functions in various tumor. However, few study show that the biological function and regulatory mechanisms of miR-98 in nasopharyngeal carcinoma (NPC) progression. The identification and its target genes which regulate by dysregulated miRNAs may strengthen our understanding of the molecular mechanisms of NPC. In this study, we observe that miR-98 is not only significantly reduced in NPC tissues, but also decreased markedly in NPC cell lines. Moreover, silencing miR-98 expression studies not only show miR-98 induced cell proliferation, migration and invasion in vitro, but also it promoted xenograft tumor growth in vivo in NPC. Furthermore, western blot assay was used to detected the level of STAT3 protein and we demonstrate that miR-98 regulate cells poliferation, migration and invasion through directly modulating functional target STAT3 by directly binding its 3'-UTR. These findings illustrate miR-98 as a anticarcinogenic functions through targeting STAT3, the miR-98/STAT3 pathway gives new clues for understanding NPC carcinogenesis and provides novel therapeutic targetsfor NPC.

Hyaluronic acid-functionalized bismuth oxide nanoparticles for computed tomography imaging-guided radiotherapy of tumor

The inherent radioresistance and inaccuracy of localization of tumors weaken the clinical implementation effectiveness of radiotherapy. To overcome these limitations, hyaluronic acid-functionalized bismuth oxide nanoparticles (HA-Bi₂O₃ NPs) were synthesized by one-pot hydrothermal method for target-specific computed tomography (CT) imaging and radiosensitization of tumor. After functionalization with hyaluronic acid, the Bi₂O₃ NPs possessed favorable solubility in water and excellent biocompatibility and were uptaken specifically by cancer cells overexpressing CD44 receptors. The as-prepared HA-Bi₂O₃ NPs exhibited high X-ray attenuation efficiency and ideal radiosensitivity via synergizing X-rays to induce cell apoptosis and arrest the cell cycle in a dose-dependent manner in vitro. Remarkably, these properties offered excellent performance in active-targeting CT imaging and enhancement of radiosensitivity for inhibition of tumor growth. These findings demonstrated that HA-Bi₂O₃ NPs as theranostic agents exhibit great promise for CT imaging-guided radiotherapy in diagnosis and treatment of tumors.

Prognostic value of microRNAs in gastric cancer: a meta-analysis

BACKGROUND

Previous articles have reported that expression levels of microRNAs (miRNAs) are associated with survival time of patients with gastric cancer (GC). A systematic review and meta-analysis was performed to study the outcome of it.

DESIGN

Meta-analysis.

METHODS

English studies estimating expression levels of miRNAs with any of survival curves in GC were identified up till March 19, 2017 through performing online searches in PubMed, EMBASE, Web of Science and Cochrane Database of Systematic Reviews by two authors independently. The pooled hazard ratios (HR) with 95% confidence intervals (CI) were used to estimate the correlation between miRNA expression and overall survival (OS).

RESULTS

Sixty-nine relevant articles about 26 miRNAs with 6148 patients were ultimately included. GC patients with high expression of miR-20b (HR=2.38, 95%CI=1.16-4.87), 21 (HR=1.77, 95%CI=1.01-3.08), 106b (HR=1.84, 95%CI=1.15-2.94), 196a (HR=2.66, 95%CI=1.94-3.63), 196b (HR=1.67, 95%CI=1.38-2.02), 214 (HR=1.84, 95%CI=1.27-2.67) or low expression of miR-125a (HR=2.06, 95%CI=1.26-3.37), 137 (HR=3.21, 95%CI=1.68-6.13), 141 (HR=2.47, 95%CI=1.34-4.56), 145 (HR=1.62, 95%CI=1.07-2.46), 146a (HR=2.60, 95%CI=1.63-4.13), 206 (HR=2.85, 95%CI=1.73-4.70), 218 (HR=2.61, 95%CI=1.74-3.92), 451 (HR=1.73, 95%CI=1.19-2.52), 486-5p (HR=2.45, 95%CI=1.65-3.65), 506 (HR=2.07, 95%CI=1.33-3.23) have significantly poor OS (P<0.05).

CONCLUSIONS

In summary, miR-20b, 21, 106b, 125a, 137, 141, 145, 146a, 196a, 196b, 206, 214, 218, 451, 486-5p and 506 demonstrate significantly prognostic value. Among them, miR-20b, 125a, 137, 141, 146a, 196a, 206, 218, 486-5p and 506 are strong biomarkers of prognosis in GC.

PAX2 maintains the differentiation of mouse oviductal epithelium and inhibits the transition to a stem cell-like state

Recent studies have provided evidence that the secretory cells of the fallopian tube (oviduct) are a probable origin for high-grade serous ovarian carcinoma. In addition to secretory cells, the fallopian tube epithelium consists of ciliated cells and CD44+ undifferentiated stem-like cells. Loss of PAX2 expression is recognized as an early event in epithelial transformation, but the specific role of PAX2 in this transition is unknown. The aim of this study was to define the role of PAX2 in oviductal epithelial (OVE) cells and its response to transforming growth factor β1 (TGFβ), characterizing specifically its potential involvement in regulating stem cell-like behaviors that may contribute to formation of cancer-initiating cells. Treatment of primary cultures of mouse OVE cells with TGFβ induced an epithelial-mesenchymal transition (EMT) associated with decreased expression of PAX2 and an increase in the fraction of cells expressing CD44. PAX2 knockdown in OVE cells and overexpression in ovarian epithelial cells confirmed that PAX2 inhibits stem cell characteristics and regulates the degree of epithelial differentiation of OVE cells. These results suggest that loss of PAX2, as occurs in serous tubal intraepithelial carcinomas, may shift secretory cells to a more mesenchymal phenotype associated with stem-like features.

Functionalized Selenium Nanosystem as Radiation Sensitizer of 125I Seeds for Precise Cancer Therapy

Although radiotherapy has been extensively applied in cancer treatment, external beam radiation therapy is still unable to avoid damage to adjacent normal tissues in the process of delivering a sufficient radiation dose to the tumor sites of patients. To overcome this limitation, chemoradiotherapy, as a combination of chemotherapy and radiotherapy of a radioactive seed, has been proposed to decrease the damage to tumor-surrounding tissues and enhance the radiosensitivity of solid tumors. In this study, we designed and synthesized folic acid-conjugated selenium nanoparticles (FA@SeNPs) as a cancer-targeting agent that could be synergistically enhanced by radioactive ¹²⁵I seeds to realize anticancer efficacy and inhibited colony formation ability. Interestingly, when compared with X-ray irradiation, ¹²⁵I seeds demonstrate a larger synergistic effect with the FA@SeNPs, drastically increasing reactive oxygen species overproduction to trigger apoptosis and influencing the cell cycle distribution in human breast cancer cells, inducing DNA damage and activating the mitogen-activated protein kinase and p53 signaling pathways. Moreover, this combination treatment demonstrates better in vivo antitumor activity and lower systemic toxicity. Therefore, this study demonstrates a new strategy for using functionalized SeNPs as a radiation sensitizer for ¹²⁵I seeds for cancer therapy.

Jab1/Csn5-Thioredoxin Signaling in Relapsed Acute Monocytic Leukemia under Oxidative Stress

Purpose: High levels of ROS and ineffective antioxidant systems contribute to oxidative stress, which affects the function of hematopoietic cells in acute myeloid leukemia (AML); however, the mechanisms by which ROS lead to malignant transformation in relapsed AML-M5 are not completely understood. We hypothesized that alterations in intracellular ROS would trigger AML-M5 relapse by activating the intrinsic pathway.Experimental Design: We studied ROS levels and conducted c-Jun activation domain-binding protein-1 (JAB1/COPS5) and thioredoxin (TRX) gene expression analyses with blood samples obtained from 60 matched AML-M5 patients at diagnosis and relapse and conducted mechanism studies of Jab1's regulation of Trx in leukemia cell lines.Results: Our data showed that increased production of ROS and a low capacity of antioxidant enzymes were characteristics of AML-M5, both at diagnosis and at relapse. Consistently, increased gene expression levels of TRX and JAB1/COPS5 were associated with low overall survival rates in patients with AML-M5. In addition, stimulating AML-M5 cells with low concentrations of hydrogen peroxide led to increased Jab1 and Trx expression. Consistently, transfection of ectopic Jab1 into leukemia cells increased Trx expression, whereas silencing of Jab1 in leukemia cells reduced Trx expression. Mechanistically, Jab1 interacted with Trx and stabilized Trx protein. Moreover, Jab1 transcriptionally regulated Trx. Furthermore, depletion of Jab1 inhibited leukemia cell growth both in vitro and in vivoConclusions: We identified a novel Jab1-Trx axis that is a key cellular process in the pathobiologic characteristics of AML-M5. Targeting the ROS/Jab1/Trx pathway could be beneficial in the treatment of AML-M5. Clin Cancer Res; 23(15); 4450-61. ©2017 AACR.

3-Bromopyruvate enhances TRAIL-induced apoptosis in human nasopharyngeal carcinoma cells through CHOP-dependent upregulation of TRAIL-R2

Past reports have shown that the sensitivity of cancer cells to TRAIL-induced apoptosis is related to their expression of TRAIL-death receptors on the cell surface. However, the level of TRAIL-death receptors expression on cancer cells is always low. Our previous research showed that nasopharyngeal carcinoma (NPC) cells have a poor sensitivity to low doses of TRAIL. Here, we evaluated combined treatment with the energy inhibitor 3-bromopyruvate (3BP) and TRAIL as a method to produce an increased apoptotic response in NPC cells. The results showed that 3BP and TRAIL together produced higher cytotoxicity and increased TRAIL-R2 expression in NPC cells compared with the effects of either 3BP or TRAIL alone. These findings led us to hypothesize that 3BP may sensitize NPC cells to TRAIL. 3BP is a metabolic blocker that inhibits hexokinase II activity, suppresses ATP production, and induces endoplasmic reticulum (ER) stress. Our results showed that 3BP also activated AMP-activated protein kinase, which we found to play an important role in the induction of ER stress by 3BP. Furthermore, the induction of TRAIL-R2 expression and the sensitization of the NPC cells to TRAIL by 3BP were reduced when we inhibited the expression of CHOP. Taken together, our results showed that a low dose of 3BP sensitized NPC cells to TRAIL-induced apoptosis by the upregulation of CHOP, which was mediated by the activation of AMP-activated protein kinase and ER stress. The results showed that 3BP is a promising candidate agent for enhancing the therapeutic response to TRAIL in NPC.

microRNA-494 is a potential prognostic marker and inhibits cellular proliferation, migration and invasion by targeting SIRT1 in epithelial ovarian cancer

Ovarian cancer is one of the most common types of gynecological malignancy worldwide, and is the fourth leading cause of cancer-associated mortality among women. Despite improvements in therapeutic treatments, the prognosis for epithelial ovarian cancer (EOC) remains poor, mainly due to the rapid growth and metastasis of ovarian cancer tumors. An increasing number of studies have indicated that microRNAs (miRNAs) are involved in the carcinogenesis and progression of human cancer, suggesting that miRNAs may be used in clinical prognosis and as a therapeutic target in EOC. The aim of the present study was to investigate the expression levels of miRNA-494 in EOC tissues and cell lines. The clinical significance of miRNA-494 in patients with EOC was also evaluated. The results demonstrated that miRNA-494 was significantly downregulated in EOC tissues and cell lines. Low expression levels of miRNA-494 were associated with poor prognostic features, including International Federation of Gynecology and Obstetrics stage, tumor size and lymph node metastasis. In vitro functional studies demonstrated that overexpression of miRNA-494 inhibited proliferation, migration and invasion in EOC cells. By contrast, knockdown of miRNA-494 enhanced cell growth, migration and invasion in EOC cells. Notably, sirtuin 1 (SIRT1) was identified as a direct target of miRNA-494 in EOC. Furthermore, MTT, cell migration and invasion assays verified that EOC cell proliferation, migration and invasion were completely restored with forced miRNA-494 expression and SIRT1 restoration. Together, these findings suggest that miRNA-494 is a potential prognostic marker, and may provide novel therapeutic regimens of targeted therapy for EOC.

MiR-130a-3p inhibits the viability, proliferation, invasion, and cell cycle, and promotes apoptosis of nasopharyngeal carcinoma cells by suppressing BACH2 expression

The aim of the present study was to explore the mechanism through which miR-130a-3p affects the viability, proliferation, migration, and invasion of nasopharyngeal carcinoma (NPC). Tissue samples were collected from the hospital department. NPC cell lines were purchased to conduct the in vitro and in vivo assays. A series of biological assays including MTT, Transwell, and wound healing assays were conducted to investigate the effects of miR-130a-3p and BACH2 on NPC cells. MiR-130a-3p was down-regulated in both NPC tissues and cell lines, whereas BACH2 was up-regulated in both tissues and cell lines. MiR-130a-3p overexpression inhibited NPC cell viability, proliferation, migration, and invasion but promoted cell apoptosis. The converse was true of BACH2, the down-regulation of which could inhibit the corresponding cell abilities and promote apoptosis of NPC cells. The target relationship between miR-130a-3p and BACH2 was confirmed. The epithelial-mesenchymal transition (EMT) pathway was also influenced by miR-130a-3p down-regulation. In conclusion, miR-130a-3p could bind to BACH2, inhibit NPC cell abilities, and promote cell apoptosis.

MicroRNA-508-5p suppresses metastasis in human gastric cancer by targeting S-phase kinase‑associated protein 2

S-phase kinase-associated protein 2 (SKP2), a potent oncogene was revealed to be upregulated in gastric cancer (GC) tissue samples, in which SKP2 was inversely correlated with microRNA (miR)‑508‑5p transcripts. In present study, the functional effect of miR‑508‑5p on SKP2 and its metastatic potential were investigated in SGC‑7901 GC cells. Significant downregulation of the miR‑508‑5p transcript was associated with the progression of GC. Furthermore, the overexpression of miR‑508‑5p was demonstrated to inhibit the proliferation, migration and invasion of SGC‑7901 cells, as well as induced cell apoptosis and cell cycle arrest at the G0/G1 phase in vitro. The overexpression of miR‑508‑5p was able to downregulate the expression of the SKP2 oncogene, through a mechanism by which miR‑508‑5p directly targeted the SKP2 gene. Thus, regulating transcriptional and post‑transcriptional SKP2 expression, as demonstrated using luciferase reporter assays, reverse transcription‑quantitative polymerase chain reaction analysis and immunoblotting assays. The results of the present study identified that miR‑508‑5p functionally affects the SKP2 gene and reduces metastatic potential in GC, suggesting a novel role of miR‑508‑5p in the regulation of SKP2 and cell cycle.

Niclosamide enhances the antitumor effects of radiation by inhibiting the hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway in human lung cancer cells

Lung cancer is one of the leading causes of cancer-associated mortality, worldwide. The overall survival rate remains low, but progress has been made in improving the diagnosis and treatment of lung cancer over the past decades. Niclosamide, a salicylanilide derivative used for the treatment of tapeworm infections, is safe, well tolerated, inexpensive and readily available. Previous studies have identified niclosamide as a potential anticancer agent. The present study demonstrated that niclosamide enhanced the effect of irradiation by inhibiting the hypoxia-inducible factor-1α/vascular endothelial growth factor signaling pathway. These findings suggest that niclosamide may be a promising candidate for clinical evaluation as part of a combined regimen for the treatment of non-small cell lung cancer.

Azelaic Acid Exerts Antileukemic Activity in Acute Myeloid Leukemia

Acute myeloid leukemia (AML) is an acute leukemia common in most adults; its prevalence intensifies with age. The overall survival of AML is very poor because of therapeutic resistance. Azelaic acid (AZA) is non-toxic, non-teratogenic, and non-mutagenic and its antitumor effect on various tumor cells is well established; Nonetheless, its therapeutic effects in AML cells are largely unknown. In this study, it was shown that AZA significantly inhibits the cell viability and induces apoptosis in AML cells in a dose-dependent manner. Additionally, AZA suppressed the expression of phosphorylated Akt, Jab1 and Trx, and this suppression was enhanced by treatment with Jab1 siRNA. Furthermore, AZA sensitized AML cells to Ara-c chemotherapy. The suppressive effect of AZA on tumor growth was examined in vivo by subcutaneously inoculated AML cells in a tumor model using nude mice. These findings indicate that AZA is useful as an effective ingredient in antineoplastic activity.

MicroRNA-494 improves functional recovery and inhibits apoptosis by modulating PTEN/AKT/mTOR pathway in rats after spinal cord injury

Multiple cellular, molecular, and biochemical changes contribute to the etiology and treatment outcome of contusion spinal cord injury (SCI). MicroRNAs (miRNAs) aberrant expression have been found after SCI in recent studies. However, little is known about the functional significance of the unique role of miRNAs in SCI. Here, we established a rat SCI model and performed the miRNA microarray to analyze miRNAs expression at different times post-SCI. Microarray data revealed that 14 miRNAs were upregulated and 46 miRNAs were downregulated by 2 times compared with sham rat spinal cords, and miR-494 was one of the miRNAs being most significantly downregulated. Subsequently, we investigated miR-494 function and found that upregulation of miR-494 by agomir-494 improves functional recovery, reduces lesion size and inhibits apoptotic cell in rats following SCI. Moreover, our data showed that miR-494 suppresses phosphatase and tensin homolog (PTEN), a negative regulator of AKT/mTOR pathway, through directly targeting its 3'-UTR in BV-2 cells. Most importantly, we demonstrated that overexpression of miR-494 activates AKT/mTOR signaling pathway via inhibiting PTEN expression in rat SCI model. These findings suggested that miR-494 harbored the protective effect after SCI by modulating PTEN/AKT/mTOR pathway in rats and it is a potential candidate for SCI therapeutics.

Improved detection of gene-microbe interactions in the mouse skin microbiota using high-resolution QTL mapping of 16S rRNA transcripts

BACKGROUND

Recent studies highlight the utility of quantitative trait locus (QTL) mapping for determining the contribution of host genetics to interindividual variation in the microbiota. We previously demonstrated that similar to the gut microbiota, abundances of bacterial taxa in the skin are significantly influenced by host genetic variation. In this study, we analyzed the skin microbiota of mice from the 15th generation of an advanced intercross line using a novel approach of extending bacterial trait mapping to both the 16S rRNA gene copy (DNA) and transcript (RNA) levels, which reflect relative bacterial cell number and activity, respectively.

RESULTS

Remarkably, the combination of highly recombined individuals and 53,203 informative SNPs allowed the identification of genomic intervals as small as <0.1 megabases containing single genes. Furthermore, the inclusion of 16S rRNA transcript-level mapping dramatically increased the number of significant associations detected, with five versus 21 significant SNP-bacterial trait associations based on DNA- compared to RNA-level profiling, respectively. Importantly, the genomic intervals identified contain many genes involved in skin inflammation and cancer and are further supported by the bacterial traits they influence, which in some cases have known genotoxic or probiotic capabilities.

CONCLUSIONS

These results indicate that profiling based on the relative activity levels of bacterial community members greatly enhances the capability of detecting interactions between the host and its associated microbes. Finally, the identification of several genes involved in skin cancer suggests that similar to colon carcinogenesis, the resident microbiota may play a role in skin cancer susceptibility and its potential prevention and/or treatment.

Epigenetic regulation of the extrinsic oncosuppressor PTX3 gene in inflammation and cancer

PTX3 is a component of the humoral arm of innate immunity and an extrinsic oncosuppressor gene taming tumor-promoting inflammation. Here, we show that two enhancers differently regulate PTX3 expression: enhancer 1, located 230 kb upstream of PTX3 promoter, mediated the action of inflammatory transcription factors; and enhancer 2, encompassing PTX3 second exon, was implicated in pre-initiation complex assembly. Polycomb repressive complex 2 silenced these regulatory elements and the promoter in basal condition. Enhancer 1 was epigenetically inactivated in early colorectal cancer (CRC) stages, while the promoter and enhancer 2 showed increasingly DNA methylation during CRC progression from adenomas to stage II and III CRC. Inhibition of DNA methylation rescued PTX3 expression in CRC. Finally, enhancer 1 acquired the binding of STAT3 in stage I CRC, and inhibition of STAT3 phosphorylation restored PTX3 activity and decreased enhancer 1 methylation. Thus, the expression of PTX3 is under the control of two enhancers, which emerge as important fine regulators of PTX3 expression in inflammation and cancer.

Overexpression of mir-183 and mir-494 promotes proliferation and migration in human breast cancer cell lines

Breast cancer (BC) is a leading cause of cancer-associated mortality in females worldwide. MicroRNAs (miRNAs or miRs), a type of non-coding RNA, have been reported to be important in the regulation of BC onset and progression. Several studies have implicated the role of miR-183 and miR-494 in different types of cancer. However, the biological functions of these miRNAs in BC remain largely unknown. In the present study, the expression of both miRNAs was assessed in the MDA-MB-231 and MDA-MB-468 BC cell lines. It was hypothesized that miR-183 and miR-494 serve an important role in regulating the expression of key genes associated with the metastatic phenotype of BC cells. To further understand their role, the expression of these miRNAs was restored in selected BC cell lines. Functional assays revealed that overexpression of miR-183 or miR-494 modulated the proliferation and migration of MDA-MB-231 and MDA-MB-468 cells in vitro. Additionally, retinoblastoma 1 (RB1) was identified to be a downstream target of both miRNAs by in silico analysis. Western blotting revealed that upregulation of miR-183 was associated with downregulation of RB1 protein in MDA-MB-231 cells. In conclusion, the present results support the hypothesis that miR-183 and miR-494 serve a pivotal role in BC metastasis, and that miR-183 may act as an oncogene by targeting RB1 protein in MDA-MB-231 cells.

Chimeric antigen receptor (CAR)-modified natural killer cell-based immunotherapy and immunological synapse formation in cancer and HIV

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells contribute to the body’s immune defenses. Current chimeric antigen receptor (CAR)-modified T cell immunotherapy shows strong promise for treating various cancers and infectious diseases. Although CAR-modified NK cell immunotherapy is rapidly gaining attention, its clinical applications are mainly focused on preclinical investigations using the NK92 cell line. Despite recent advances in CAR-modified T cell immunotherapy, cost and severe toxicity have hindered its widespread use. To alleviate these disadvantages of CAR-modified T cell immunotherapy, additional cytotoxic cell-mediated immunotherapies are urgently needed. The unique biology of NK cells allows them to serve as a safe, effective, alternative immunotherapeutic strategy to CAR-modified T cells in the clinic. While the fundamental mechanisms underlying the cytotoxicity and side effects of CAR-modified T and NK cell immunotherapies remain poorly understood, the formation of the immunological synapse (IS) between CAR-modified T or NK cells and their susceptible target cells is known to be essential. The role of the IS in CAR T and NK cell immunotherapies will allow scientists to harness the power of CAR-modified T and NK cells to treat cancer and infectious diseases. In this review, we highlight the potential applications of CAR-modified NK cells to treat cancer and human immunodeficiency virus (HIV), and discuss the challenges and possible future directions of CAR-modified NK cell immunotherapy, as well as the importance of understanding the molecular mechanisms of CAR-modified T cell- or NK cell-mediated cytotoxicity and side effects, with a focus on the CAR-modified NK cell IS.

Cul3 neddylation is crucial for gradual lipid droplet formation during adipogenesis

Cullin 3 (Cul3) belongs to the family of cullins (Cul1-7) providing the scaffold for cullin-RING ubiquitin (Ub) ligases (CRLs), which are activated by neddylation and represent essential E3 ligases of the Ub proteasome system. During adipogenic differentiation neddylated Cul3 accumulates in LiSa-2 preadipocytes. Downregulation of Cul3 and inhibition of neddylation by MLN4924 blocks the formation of lipid droplets (LDs), the lipid storage organelles and markers of adipogenesis. Neddylation of Cul3 coincides with an increase of Rab18, a GTPase associated with LDs. Immunoprecipitation and confocal fluorescence microscopy revealed physical association of Cul3 and Rab18 at the membrane of LDs. RhoA, a suppressor of adipogenesis decreased during differentiation. Our results in LiSa-2 cells, but also mouse embryonic fibroblasts revealed a connection between Cul3, Rab18 and RhoA. Downregulation of Cul3 led to a marked increase in RhoA protein expression after 6days of LiSa-2 cell differentiation, suggesting that Cul3 is involved in the regulation of RhoA stability.

Stat3 regulates centrosome clustering in cancer cells via Stathmin/PLK1

Cancer cells frequently have amplified centrosomes that must be clustered together to form a bipolar mitotic spindle, and targeting centrosome clustering is considered a promising therapeutic strategy. A high-content chemical screen for inhibitors of centrosome clustering identified Stattic, a Stat3 inhibitor. Stat3 depletion and inhibition in cancer cell lines and in tumours in vivo caused significant inhibition of centrosome clustering and viability. Here we describe a transcription-independent mechanism for Stat3-mediated centrosome clustering that involves Stathmin, a Stat3 interactor involved in microtubule depolymerization, and the mitotic kinase PLK1. Furthermore, PLK4-driven centrosome amplified breast tumour cells are highly sensitive to Stat3 inhibitors. We have identified an unexpected role of Stat3 in the regulation of centrosome clustering, and this role of Stat3 may be critical in identifying tumours that are sensitive to Stat3 inhibitors.

Structural Insight into Ubiquitin-Like Protein Recognition and Oligomeric States of JAMM/MPN+ Proteases

JAMM/MPN⁺ metalloproteases cleave (iso)peptide bonds C-terminal to ubiquitin (Ub) and ubiquitin-like protein (Ubl) domains and typically require association with protein partners for activity, which has limited a molecular understanding of enzyme function. To provide an insight, we solved the X-ray crystal structures of a catalytically active Pyrococcus furiosus JAMM/MPN⁺ metalloprotease (PfJAMM1) alone and in complex with a Ubl (PfSAMP2) to 1.7- to 1.9-Å resolution. PfJAMM1 was found to have a redox sensitive dimer interface. In the PfJAMM1-bound state of the SAMP2, a Ubl-to-Ub conformational change was detected. Surprisingly, distant homologs of PfJAMM1 were found to be closely related in 3D structure, including the interface for Ubl/Ub binding. From this work, we infer the molecular basis of how JAMM/MPN⁺ proteases recognize and cleave Ubl/Ub tags from diverse proteins and highlight an α2-helix structural element that is conserved and crucial for binding and removing the Ubl SAMP2 tag.

Curcumin exerts its antitumor activity through regulation of miR-7/Skp2/p21 in nasopharyngeal carcinoma cells

Curcumin, a natural polyphenol compound, exhibits tumor suppressive activity in a wide spectrum of cancers, including nasopharyngeal carcinoma cells. However, the exact molecular mechanisms governing this tumor suppressive activity remain elusive. Multiple studies have revealed that miRNAs are critically involved in tumorigenesis, indicating that targeting miRNAs could be a therapeutic strategy for treating human cancer. In the current study, we set out to determine whether curcumin regulates miR-7 expression in nasopharyngeal carcinoma cells. We found that curcumin inhibited cell growth, induced apoptosis, retarded cell migration and invasion, and triggered cell cycle arrest in the human nasopharyngeal carcinoma cell lines CNE1 and CNE2. Importantly, we observed that curcumin upregulated the expression of miR-7 and subsequently inhibited Skp2, a direct miR-7 target. Our results identified that upregulation of miR-7 by curcumin could benefit nasopharyngeal carcinoma patients.

Association of the rs1760944 polymorphism in the APEX1 base excision repair gene with risk of nasopharyngeal carcinoma in a population from an endemic area in South China

BACKGROUND

Apurinic/apyrimidinic endonuclease 1 (APEX1) plays a central role in the repair of oxidative DNA lesions via base excision repair, and polymorphism in the APEX1 gene may affect susceptibility to carcinogenesis.

METHODS

Here, we assessed possible relationships between single-nucleotide polymorphism at APEX1 rs1760944 and risk of nasopharyngeal carcinoma (NPC) in 477 NPC patients and 558 healthy controls from Guangxi province, which is the second largest NPC endemic area in South China.

RESULTS

Genotype frequencies in controls were in Hardy-Weinberg equilibrium. Logistic regression analysis identified the genotypes GT or GG as associated with significantly lower risk than the genotype TT (adjusted odds ratio [OR] 0.745, 95% confidence interval [CI] 0.573-0.970). This apparent protective effect of GT/GG was even greater among those with no smoking history (adjusted OR 0.679, 95%CI 0.494-0.934).

CONCLUSION

Our results suggest that APEX1 rs1760944 polymorphism may correlate with NPC susceptibility in a population from an endemic area in South China.

Folate-Functionalized Lipid Nanoemulsion to Deliver Chemo-Radiotherapeutics Together for the Effective Treatment of Nasopharyngeal Carcinoma

Aim of the investigation was to develop folate-functionalized lipid nanoemulsion (LNE) comprising chemo-radiotherapeutics for targeted delivery to nasopharyngeal carcinoma (NPC). Soy lecithin nanoemulsion of doxorubicin (Dox) and yittrium-90 (90Y) was prepared by nanoprecipitation using ultrasonic homogenization technique followed by folic acid conjugation. Nanoemulsion (Dox-LNE) was characterized as positively charged (zeta potential), spherical shape (transmission electron microscopy) nano-droplets of uniform size distribution (polydispersity index). No significant variation in parameters such as particle size, zeta potential, and polydispersity index was observed when the stability of Dox-LNE was assessed during long-term storage at room temperature and at 8000 rpm, 121°C temperature, and 5000 time dilution in water. In vitro release of Dox from Dox-LNE was observed to be controlled for at least 48 h. Folate decoration over Dox-LNE surface (FD-Dox-LNE) and incorporation of 90Y in FD-Dox-LNE (FD-Dox + 90Y-LNE) changed droplet size up to 50 nm; however, surface charge of Dox-LNE did not change significantly. FD-Dox + 90Y-LNE inhibited growth of cancerous cell line like CNE1 (folate receptor rich) in vitro and alleviated tumor volume in NPC-induced nude mice significantly as compared to Dox + 90Y-LNE. Massive necrosis and hemorrhage of CNE1 cells were observed by FD-Dox + 90Y-LNE (89.9%); however, inhibition of growth of nasal epithelial cells (RPMI 2650; folate deficient) by FD-Dox + 90Y-LNE and Dox + 90Y-LNE was observed to be 21.5 and 43.65%, respectively. The investigation highlights the vast utility of folate-decorated lipid emulsion in delivering chemo-radiotherapeutics to the specific NPC site. FD-Dox + 90Y-LNE might offer a cost-effective, safe, efficacious, and clinically pertinent option to the available therapeutics.

lncRNA C22orf32-1 contributes to the tumorigenesis of nasopharyngeal carcinoma

The mechanism of nasopharyngeal carcinoma (NPC) remains unclear. The present study investigated the abnormal expression of long non-coding (lnc)RNAs in NPC tissues and one NPC cell line to identify the involvement of lncRNAs in the tumorigenesis of NPC. Using a quantitative reverse transcription polymerase chain reaction (RT-qPCR), the expression of lncRNA C22orf32-1 in NPC tissues and an NPC cell line was verified. The effects of lncRNA C22orf32-1 on NPC cells were investigated with a cell proliferation assay, cell scratch assay, Transwell assay and a cell apoptosis assay. The expression levels of lncRNA C22orf32-1 in NPC tissues and an NPC cell line were upregulated. lncRNA C22orf32-1 promoted the proliferation, migration and invasion of NPC cells, and reduced the apoptosis of NPC cells. The data demonstrated that lncRNA C22orf32-1 may facilitate the tumorigenesis of NPC, and may be used for the early diagnosis and treatment of NPC.

Dual Functional Mesoporous Silicon Nanoparticles Enhance the Radiosensitivity of VPA in Glioblastoma

Radiotherapy is a critical strategy and standard adjuvant approach to glioblastoma treatment. One of the major challenges facing radiotherapy is to minimize radiation damage to normal tissue without compromising therapeutic effects on cancer cells. Various agents and numerous approaches have been developed to improve the therapeutic index of radiotherapy. Among them, radiosensitizers have attracted much attention because they selectively increase susceptibility of cancer cells to radiation and thus enhance biological effectiveness of radiotherapy. However, clinical translation of radiosensitizers has been severely limited by their potential toxicity to normal tissue. Recent advances in nanomedicine offer an opportunity to overcome this hindrance. In this study, a dual functional mesoporous silica nanoparticle (MSN) formulation of the valproic acid (VPA) radiosensitizer was developed, which specifically recognized folic acid-overexpressing cancer cells and released VPA conditionally in acidic turmeric microenvironment. The efficacy of this targeted and pH-responsive VPA nanocarrier was evaluated as compared to VPA treatment approach in two cell lines: rat glioma cells C6 and human glioma U87. Compared to VPA treatment, targeted VPA-MSNs not only potentiated the toxic effects of radiation and led to a higher rate of cell death but also enhanced inhibition on clonogenic assay. More interestingly, these effects were further accentuated by VPA-MSNs at low pH values. Western blot analysis showed that the effects were mediated via enhanced apoptosis-inducing effects. Our results suggest that the adjunctive use of VPA-MSNs may enhance the effectiveness of radiotherapy in glioma treatment by lowering the radiation doses required to kill cancer cells and thereby minimize collateral damage to healthy adjacent tissue.

IL-17A promotes the proliferation of human nasopharyngeal carcinoma cells through p300-mediated Akt1 acetylation

Interleukin (IL)-17A is a T helper (Th)17 cell-secreted cytokine that is able to induce various inflammatory responses. There is emerging evidence that IL-17A is generated in the cancer microenvironment of human nasopharyngeal carcinoma (NPC). However, the role of IL-17A in NPC remains unclear. Thus, the present study aimed to examine the direct influence of IL-17A stimulation on the proliferation of human NPC cells and identify the underlying molecular mechanisms. Furthermore, E1A binding protein p300 (p300)-mediated AKT serine/threonine kinase 1 (Akt1) acetylation and its role in regulating the proliferation of NPC cells was investigated. The results of the current study demonstrated that IL-17A stimulation in vitro increased the proliferation of human NPC cells. Furthermore, Akt1 acetylation was identified to be enhanced in human NPC cells induced by IL-17A. Additionally, p300 induction was demonstrated to be required for Akt1 acetylation in human NPC cells following exposure to IL-17A. Functionally, p300-mediated Akt1 acetylation contributed to the proliferation of human NPC cells stimulated by IL-17A. In conclusion, the results of the present demonstrate a novel activity of IL-17A that promotes human NPC cell proliferation via p300-mediated Akt1 acetylation. This may provide a potential strategy for the treatment of patients with NPC through the inhibition of IL-17A or its receptors.

Interplay of DNA methyltransferase 1 and EZH2 through inactivation of Stat3 contributes to β-elemene-inhibited growth of nasopharyngeal carcinoma cells

β-elemene, a compound extracted from Curcuma wenyujin plant, exhibits anticancer activity in many cancer types. However, the detailed mechanism by which β-elemene inhibits growth of nasopharyngeal carcinoma (NPC) cells remains unknown. We showed that β-elemene reduced phosphorylation of signal transducer and activator of transcription 3 (Stat3), and protein expressions of DNA methyltransferase 1 (DNMT1) and enhancer of zeste homolog 2 (EZH2). Exogenously expressed Stat3 antagonized the effect of β-elemene on DNMT1 and EZH2 expressions. Furthermore, overexpressions of DNMT1 and EZH2 reversed the effect of β-elemene on phosphorylation of Stat3 and cell growth inhibition. Intriguingly, exogenously expressed DNMT1 overcame β-elemene-inhibited EZH2 protein expression and promoter activity. On the contrary, silencing of EZH2 and DNMT1 genes feedback strengthened the effect of β-elemene on phosphorylation of Stat3. Consistent with this, β-elemene inhibited tumor growth, phosphorylation of Stat3, expressions of DNMT1 and EZH2 in a mouse xenograft model. Collectively, this study shows that β-elemene inhibits NPC cell growth via inactivation of Stat3, and reduces DNMT1 and EZH2 expressions. The interplay of DNMT1 and EZH2, and the mutual regulations among Stat3, EZH2 and DNMT1 contribute to the overall responses of β-elemene. This study uncovers a novel mechanism by which β-elemene inhibits growth of NPC cells.

Epigenetic modulation associated with carcinogenesis and prognosis of human gastric cancer

Gastric cancer (GC) is a leading cause of cancer-related death, particularly in Asia. Epidemiological and other clinical studies have identified an association between a number of risk factors, including Helicobacter pylori, and GC. A number of studies have also examined genetic changes associated with the development and progression of GC. When considering the clinical significance of the expression of a specific gene, its epigenetic modulation should be considered. Epigenetic modulation appears to be a primary driver of changes in gastric tissue that promotes carcinogenesis and progression of GC and other neoplasms. The role of epigenetic modulation in GC carcinogenesis and progression has been widely studied in recent years. In the present review, recent results of epigenetic modulation associated with GC and their effects on clinical outcome are examined, with particular respect to DNA methylation, histone modulation and non-coding RNA. A number of studies indicate that epigenetic changes in the expression of specific genes critically affect their clinical significance and further study may reveal epigenetic changes as the basis for targeted molecular therapy or novel biomarkers that predict GC prognosis or extension of this often fatal disease.

The miR-24-3p/p130Cas: a novel axis regulating the migration and invasion of cancer cells

MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression by suppressing translation or facilitating mRNA decay. Differential expression of miRNAs is involved in the pathogenesis of several diseases including cancer. Here, we investigated the role of-miR-24-3p as a downregulated miRNA in metastatic cancer. miR-24-3p was decreased in metastatic cancer and lower expression of miR-24-3p was related to poor survival of cancer patients. Consistently, ectopic expression of miR-24-3p suppressed the cell migration, invasion, and proliferation of MCF7, Hep3B, B16F10, SK-Hep1, and PC-3 cells by directly targeting p130Cas. Stable expression of p130Cas restored miR-24-3p-mediated inhibition of cell migration and invasion. These results suggest that miR-24-3p functions as a tumor suppressor and the miR-24-3p/p130Cas axis is a novel factor of cancer progression by regulating cell migration and invasion.

The long non-coding RNA LINC01013 enhances invasion of human anaplastic large-cell lymphoma

Anaplastic large-cell lymphoma (ALCL) is a rare type of highly malignant, non-Hodgkin lymphoma (NHL). Currently, only studies on the chimeric oncogene NPM-ALK have reported a link to ALCL progression. However, the specific molecular mechanisms underlying the invasion of ALCL are still unclear. Here, we sought to investigate differentially expressed, long non-coding RNAs (lncRNAs) in ALCL and their potential biological function. Our microarray analyses revealed that LINC01013, a novel non-coding RNA gene, was highly expressed in clinical specimens of ALCL and was significantly upregulated in invasive ALCL cell lines. Knockdown of LINC01013 suppressed tumor cell invasion; conversely, its overexpression enhanced tumor cell invasion. LINC01013-induced invasion was mediated by activation of the epithelial-to-mesenchymal transition (EMT)-associated proteins, snail and fibronectin. Specifically, LINC01013 induced snail, resulting in activation of fibronectin and enhanced ALCL cell invasion. Collectively, these findings support a potential role for LINC01013 in cancer cell invasion through the snail-fibronectin activation cascade and suggest that LINC01013 could potentially be utilized as a metastasis marker in ALCL.

Cyclooxygenase-2 expression is positively associated with lymph node metastasis in nasopharyngeal carcinoma

BACKGROUND

Accumulating evidence has demonstrated that cyclooxygenase-2 (COX-2) is involved in head and neck cancers, especially in nasopharyngeal carcinoma (NPC). However, the association between COX-2 expression and lymph node metastasis in NPC remains uncertain. This systematic review and meta-analysis meta-analysis investigated the relationship between COX-2 expression and lymph node metastasis and other signs of disease progression in NPC.

METHODS

Previously published studies assessing COX-2 expression and lymph node metastasis in NPC were identified in four English databases and three Chinese ones (Pubmed, Embase, Cochrane Database of Systematic Reviews, Web of Science, China National Knowledge Infrastructure, Wanfang, Vip Journal Integration Platform) up to November 2016. Quality of all eligible studies was assessed using the Newcastle-Ottawa Quality Assessment Scale (NOS). Pooled odds ratios (OR) and their 95% confidence intervals (95%CI) were calculated with fixed-effects or random-effects model to evaluate the effects of COX-2 expression on lymph node metastasis.

RESULTS

A total of 27 studies with 1797 NPC patients met the inclusion criteria. The expression of COX-2 was significantly higher in patients with nasopharyngeal carcinoma than those without the carcinoma, with a combined OR of 21.17 (95%CI = 15.02-29.85, I2 = 35.1%, Pheterogeneity = 0.070). A statistically significant association between COX-2 expression and lymph node metastasis in NPC patients, with an OR of 4.44 (95%CI = 3.46-5.70, I2 = 38.3%, Pheterogeneity = 0.024), and with other indicators of disease progression. Subgroup analyses based on COX-2 assay and staging criteria of TNM showed no significant heterogeneity.

CONCLUSIONS

The results suggest that expression of COX-2 is associated with lymph node metastasis and disease progression in NPC, indicating a potential role in evaluation of prognosis and in treatment decisions. COX-2 inhibitors have potential in the treatment of NPC that should be further investigated.

Inhibition of atherogenesis by the COP9 signalosome subunit 5 in vivo

Constitutive photomorphogenesis 9 (COP9) signalosome 5 (CSN5), an isopeptidase that removes neural precursor cell-expressed, developmentally down-regulated 8 (NEDD8) moieties from cullins (thus termed "deNEDDylase") and a subunit of the cullin-RING E3 ligase-regulating COP9 signalosome complex, attenuates proinflammatory NF-κB signaling. We previously showed that CSN5 is up-regulated in human atherosclerotic arteries. Here, we investigated the role of CSN5 in atherogenesis in vivo by using mice with myeloid-specific Csn5 deletion. Genetic deletion of Csn5 in Apoe^-/- mice markedly exacerbated atherosclerotic lesion formation. This was broadly observed in aortic root, arch, and total aorta of male mice, whereas the effect was less pronounced and site-specific in females. Mechanistically, Csn5 KO potentiated NF-κB signaling and proinflammatory cytokine expression in macrophages, whereas HIF-1α levels were reduced. Inversely, inhibition of NEDDylation by MLN4924 blocked proinflammatory gene expression and NF-κB activation while enhancing HIF-1α levels and the expression of M2 marker Arginase 1 in inflammatory-elicited macrophages. MLN4924 further attenuated the expression of chemokines and adhesion molecules in endothelial cells and reduced NF-κB activation and monocyte arrest on activated endothelium in vitro. In vivo, MLN4924 reduced LPS-induced inflammation, favored an antiinflammatory macrophage phenotype, and decreased the progression of early atherosclerotic lesions in mice. On the contrary, MLN4924 treatment increased neutrophil and monocyte counts in blood and had no net effect on the progression of more advanced lesions. Our data show that CSN5 is atheroprotective. We conclude that MLN4924 may be useful in preventing early atherogenesis, whereas selectively promoting CSN5-mediated deNEDDylation may be beneficial in all stages of atherosclerosis.

Stat3 contributes to cancer progression by regulating Jab1/Csn5 expression

Our previous studies demonstrated that Jab1/Csn5 overexpression is correlated with low survival rates in cancer patients, including nasopharyngeal carcinoma (NPC), breast cancer and hepatocellular carcinoma, and contributes to NPC's resistance to radiotherapy and cisplatin by regulating DNA damage and repair pathways. However, the molecular mechanism by which Jab1/Csn5 expression is upregulated in NPCs has yet to be determined. In the present study, we identified the upstream regulator of Jab1/Csn5 expression and demonstrated its role in intrinsic resistance of NPC cells to treatment with cisplatin. Signal transducer and activator of transcription-3 (Stat3) expression correlates with and contributes to Jab1/Csn5 transcription. Consistently, silencing of Stat3 in tumors reduced Jab1/Csn5 expression, thereby sensitizing NPC cells to cisplatin-induced apoptosis both in vitro and in vivo. Mechanistically, Stat3 transcriptionally regulated Jab1/Csn5. Furthermore, high mRNA expression levels of Stat3 or Jab1 in colon cancer, breast cancer and glioblastoma are associated with significantly shorter survival times from the R2 online database. These findings identify a novel Stat3-Jab1/Csn5 signaling axis in cancer pathogenesis with therapeutic and prognostic relevance.

Suppression of the Growth and Invasion of Human Head and Neck Squamous Cell Carcinomas via Regulating STAT3 Signaling and the miR-21/β-catenin Axis with HJC0152

Signal transducer and activator of transcription 3 (STAT3) is involved in the tumor growth and metastasis of human head and neck squamous cell carcinoma (HNSCC) and is therefore a target with therapeutic potential. In this study, we show that HJC0152, a recently developed anticancer agent and a STAT3 signaling inhibitor, exhibits promising antitumor effects against HNSCC both in vitro and in vivo via inactivating STAT3 and downstream miR-21/β-catenin axis. HJC0152 treatment efficiently suppressed HNSCC cell proliferation, arrested the cell cycle at the G₀-G₁ phase, induced apoptosis, and reduced cell invasion in both SCC25 and CAL27 cell lines. Moreover, HJC0152 inhibited nuclear translocation of phosphorylated STAT3 at Tyr705 and decreased VHL/β-catenin signaling activity via regulation of miR-21. Loss of function of VHL remarkably compromised the antitumor effect of HJC0152 in both cell lines. In our SCC25-derived orthotopic mouse models, HJC0152 treatment significantly abrogated STAT3/β-catenin expression in vivo, leading to a global decrease of tumor growth and invasion. With its favorable aqueous solubility and oral bioavailability, HJC0152 holds the potential to be translated into the clinic as a promising therapeutic strategy for patients with HNSCC. Mol Cancer Ther; 16(4); 578-90. ©2017 AACR.

Zoledronic acid reverses cisplatin resistance in nasopharyngeal carcinoma cells by activating the mitochondrial apoptotic pathway

Despite improvements to radiotherapeutic strategies, resistance to adjuvant chemotherapy remains the main problem underlying the low 5-year survival rate in patients with nasopharyngeal carcinoma (NPC). In the present study, the human NPC cell line HNE1 was exposed to gradually increasing concentrations of cisplatin (CDDP) in order to establish a drug-resistant sub-cell line, HNE1/CDDP. HNE1/CDDP cells exhibited multidrug resistance and a prolonged doubling time, as compared with the parent HNE1 cells. Furthermore, pretreatment with zoledronic acid (ZOL) appeared to resensitize the CDDP-resistant cells by inducing S-phase cell cycle arrest and the mitochondrial apoptotic pathway by upregulating the expression of B-cell lymphoma-2 (BCL-2)-associated X protein and caspase-9 and downregulating the expression of BCL-2. The results of the present study suggested that HNE1/CDDP cells are a stable, multidrug-resistant NPC cell line that may serve as an important tool for research in drug resistance. In addition, the application of ZOL may hold clinical therapeutic potential for the treatment of drug resistance in NPC.

Mutual regulation of microRNAs and DNA methylation in human cancers

microRNAs (miRNAs) and DNA methylation are the 2 epigenetic modifications that have emerged in recent years as the most critical players in the regulation of gene expression. Compelling evidence has indicated the roles of miRNAs and DNA methylation in modulating cellular transformation and tumorigenesis. miRNAs act as negative regulators of gene expression and are involved in the regulation of both physiologic conditions and during diseases, such as cancer, inflammatory diseases, and psychiatric disorders, among others. Meanwhile, aberrant DNA methylation manifests in both global genome changes and in localized gene promoter changes, which influences the transcription of cancer genes. In this review, we described the mutual regulation of miRNAs and DNA methylation in human cancers. miRNAs regulate DNA methylation by targeting DNA methyltransferases or methylation-related proteins. On the other hand, both hyper- and hypo-methylation of miRNAs occur frequently in human cancers and represent a new level of complexity in gene regulation. Therefore, understanding the mechanisms underlying the mutual regulation of miRNAs and DNA methylation may provide helpful insights in the development of efficient therapeutic approaches.