Cheng-Xiong Xu

Decreased Expression of miR216a Contributes to Non–Small-Cell Lung Cancer Progression

Purpose: The aim of the present study is to investigate the role and mechanism of miR216a in non–small-cell lung cancer (NSCLC). Experimental Design: The expression of miR216a in NSCLC cell lines and from NSCLC patient specimens was measured by real-time qRT-PCR. The correlation between gene expression and patient survival was analyzed using Kaplan–Meier methods. The effects of miR216a on NSCLC cell growth and metastasis were examined both in vitro and in vivo by overexpressing or inhibiting miR216a. Finally, the effect of miR216a on chemoresistance was investigated by MTT assay and flow cytometry. Results: miR216a expression was downregulated in specimens from patients with NSCLC compared with corresponding nontumor lung tissues. Clinical data indicate that decreased miR216a expression is inversely correlated with cancer stage, metastasis, and poor survival in patients with NSCLC. Our data also show that overexpression of miR216a suppresses NSCLC cell growth and metastasis, and enhances cisplatin-induced cell growth inhibition and apoptosis. In contrast, inhibition of miR216a stimulates NSCLC cell growth and metastasis, and suppresses cisplatin-induced cell growth inhibition and apoptosis. Furthermore, we demonstrate that miR216a exerts its role by directly targeting eIF4B and ZEB1. Conclusion: Our findings suggest that miR216a is a cancer suppressor miRNA and that overexpression of miR216a is a novel NSCLC treatment strategy. In addition, our clinical data indicate that miR216a may be a useful biomarker for predicting NSCLC progression. Clin Cancer Res; 20(17); 4705–16. ©2014 AACR.

MiR-34c inhibits osteosarcoma metastasis and chemoresistance

AbstractnnStudies have shown that miR-34c is associated with metastasis and the chemoresponse of several cancers, but its role in osteosarcoma (OS) is unclear. Here, we investigated the role and mechanism of miR-34c in OS metastasis and chemoresponse. In this study, we found that the expression of miR-34c was significantly decreased in specimens from OS patients with a poor chemoresponse or metastasis compared to those with a good chemoresponse and no metastasis. The inhibition of miR-34c significantly stimulated OS cell invasion and chemoresistance in vitro. In contrast, restoring miR-34c significantly inhibited OS cell invasion and chemoresistance. Furthermore, we identified Notch1 and lymphoid enhancer-binding factor 1 (LEF1) as target genes of miR-34c in OS cells and demonstrated that Notch1 and LEF1 have a major role in the effects of miR-34c on OS cell chemosensitivity and metastasis. Taken together, our data indicate that miR-34c suppresses OS metastasis and chemoresistance by targeting Notch1 and LEF1. Restoring miR-34c may have important implications for the development of strategies for inhibiting metastasis and overcoming OS cell resistance to chemotherapy.

Effects of endostar combined multidrug chemotherapy in osteosarcoma.

Angiogenesis is closely related to tumor development and metastasis. Osteosarcoma is an angiogenesis-dependent tumor, and studies have shown that chemotherapy often induces angiogenesis. Endostatin is a broad spectrum angiogenesis inhibitor and, while pre-clinical trials have shown that the combination of endostatin with chemotherapy can enhance anti-tumor effects, this effect has not yet been shown in clinical trials. Here, we aimed to evaluate the clinical efficacy of endostar (ES, human recombinant endostatin) combined with chemotherapy in the treatment of osteosarcoma patients. A total of 116 newly diagnosed patients with osteosarcoma were enrolled in this study. All patients received 4cycles of chemotherapy with (54 cases) or without (62 cases) ES. ES was administered intravenously at a dose of 15mg/day for 2weeks during each cycle of chemotherapy. The tumors were removed by surgery after 2cycles of chemotherapy treatment, and their histologic response to chemotherapy was evaluated. Immunohistochemistry was used to measure VEGF and CD 31 expression. Chemotherapy increased VEGF expression and the presence of microvessels in osteosarcoma tissues compared with pre-chemotherapy. No significant difference was observed in the histologic response between the ES treatment and non-treatment groups. However, ES treatment significantly inhibited the chemotherapy-induced VEGF expression and presence of microvessels. The ES treatment did not affect the overall survival rate but did increase the event-free survival rate and decreased the occurrence of metastases. In conclusion, our results indicate that antiangiogenic therapy using ES has the potential to prevent the progression of metastases.

IL-17A stimulates the progression of giant cell tumors of bone.

Purpose: Giant cell tumors of bone (GCTB) exhibit aggressive bone lytic behavior. Studies have shown that interleukin 17A (IL-17A) is involved pathologic bone resorption in various skeletal disorders. Thus, we have investigated the role of IL-17A in GCTBs. Experimental Design: We evaluated the progression of GCTBs using Campanacci grading and Enneking staging systems in 74 patients with GCTB. The expression of IL-17A and the IL-17A receptor A (IL-17RA) was assessed in GCTB tissues and in both multinucleated giant cells (MNGC) and stromal cells cultured in vitro using immunostaining and reverse transcription PCR (RT-PCR). The effects of IL-17A on the osteolytic activity of the MNGCs and the proliferation of the stromal cells were investigated using the “pit” formation and MTT assays, respectively. The effects of IL-17A on the expression of proosteolytic factors were examined in primary cultured MNGCs and stromal cells using RT-PCR, Western blotting, and gene expression microarrays. Results: In GCTBs, we detected abundant levels of IL-17A, which were associated with tumor extension and grade. IL-17A is predominantly produced by MNGCs, whereas IL-17RA is expressed by both MNGCs and stromal cells in GCTBs. In the MNGCs, the IL-17A increased the mRNA expression of IL-17A and proosteolytic enzymes, and also enhanced osteolytic ability. In the stromal cells, the IL-17A stimulated cellular proliferation and the expression of proosteolytic factors, including RANKL through myc and STAT3, respectively. In addition, IL-17A stimulated in vivo tumor growth and the extent of angiogenesis in GCTBs. Conclusion: IL-17A stimulates the progression of GCTBs and might represent a useful candidate marker for progression and as a therapeutic target for GCTBs. Clin Cancer Res; 19(17); 4697–705. ©2013 AACR.

miR-491 Inhibits Osteosarcoma Lung Metastasis and Chemoresistance by Targeting αB-crystallin

Dysregulated microRNAs (miRNAs) play an important role in osteosarcoma (OS) progression. In the present study, we investigate the clinical significance of serum miR-491 level and the potential role of miR-491 in OS lung metastasis and chemoresistance. Clinical data show that the level of miR-491 was decreased in serum from OS patients compared with healthy control subjects, and that a decreased serum miR-491 level is correlated with increased metastasis, poor chemoresponse, and lower survival rate in OS patients. Inxa0vitro and inxa0vivo experiments show that overexpression of miR-491 suppresses OS cell lung metastasis, whereas it enhances cisplatin (CDDP)-induced tumor growth inhibition and apoptosis. In contrast, inhibition of miR-491 stimulates OS cell lung metastasis and suppresses CDDP-induced tumor growth inhibition and apoptosis. Furthermore, we demonstrate that miR-491 exerts its role by directly targeting αB-crystallin (CRYAB) in OS. Our findings suggest that serum level of miR-491 has potential as a biomarker for predicting OS progression and prognosis of OS patients. Additionally, restoration of miR-491 may be a novel strategy for inhibiting OS lung metastasis and overcoming OS cell resistance to chemotherapy.

miR-424 acts as a tumor radiosensitizer by targeting aprataxin in cervical cancer

Previous studies have shown that some dysregulated miRNAs are involved in radioresistance of tumor cells. Here, we identified significantly decreased miR-424 expression in radioresistant cervical cancer cells and specimens from cervical cancer patients with radioresistance compared to their radiosensitive parental cells and specimens from radiosensitive patients, respectively. Ectopic expression of miR-424 significantly increased radiation-induced DNA damage, cell apoptosis and G2/M cell cycle arrest in radioresistant cervical cancer cells. Notably, miR-424 agomiR treatment can sensitize radioresistant cervical cancer cells to radiation in a xenograft model. Furthermore, we demonstrated that miR-424 regulated radiosensitivity by directly targeting aprataxin. Taken together, these findings suggest that miR-424 acts as a radiosensitizing miRNA and reveal a new therapeutic strategy for radioresistant cervical cancers.

miR-135b Stimulates Osteosarcoma Recurrence and Lung Metastasis via Notch and Wnt/β-Catenin Signaling

Cancer stem cells (CSCs) play an important role in osteosarcoma (OS) metastasis and recurrence, and both Wnt/β-catenin and Notch signaling are essential for the development of the biological traits of CSCs. However, the mechanism that underlies the simultaneous hyperactivation of both Wnt/β-catenin and Notch signaling in OS remains unclear. Here, we report that expression of miR-135b correlates with the overall and recurrence-free survival of OS patients, and that miR-135b has an activating effect on both Wnt/β-catenin and Notch signaling. The overexpression of miR-135b simultaneously targets multiple negative regulators of the Wnt/β-catenin and Notch signaling pathways, including glycogen synthase kinase-3 beta (GSK3β), casein kinase 1a (CK1α), and ten-eleven translocation 3 (TET3). Therefore, upregulated miR-135b promotes CSC traits, lung metastasis, and tumor recurrence in OS. Notably, antagonizing miR-135b potently inhibits OS lung metastasis, cancer cell stemness, CSC-induced tumor formation, and recurrence in xenograft animal models. These findings suggest that miR-135b mediates the constitutive activation of Wnt/β-catenin and Notch signaling, and that the inhibition of miR-135b is a novel strategy to inhibit tumor metastasis and prevent CSC-induced recurrence in OS.

miR-124 Inhibits Lung Tumorigenesis Induced by K-ras Mutation and NNK

Dysregulated miRNAs play important role in K-ras mutation or smoking caused lung tumorigenesis. Here, we investigate the role and mechanism of miR-124 in K-ras mutation or smoking-caused lung tumorigenesis and evaluate the therapeutic potential of miR-124 agomiR in K-ras mutation or smoking-caused lung cancer treatment. Our data show that smoking suppresses miR-124 expression, and decreased miR-124 expression is inversely correlated with the p-Akt level and predicts poor overall survival in non-small-cell lung cancer (NSCLC) patients. The overexpression of miR-124 suppressed NSCLC growth by inhibiting the Akt pathway by targeting Akt1 and Akt2. In addition, the systemic delivery of miR-124 agomiR dramatically suppressed tumorigenesis in both NNK-induced lung cancer model and K-rasLA1 transgenic mice by increasing apoptosis and inhibiting cell proliferation. Our findings suggest that smoking inhibits the expression of miR-124, and decreased miR-124 contributes to Akt activation, thereby promoting NSCLC progression. Our findings also represent a novel potential therapeutic strategy for lung cancer.

miR-125a promotes the progression of giant cell tumors of bone by stimulating IL-17A and β-Catenin expression

Giant cell tumors of bone (GCTBs) exhibit high recurrence and aggressive bone lytic behavior; but, the mechanism of GCTB progression is largely unknown. In GCTB, we detected abundant levels of miR-125a, which were associated with tumor extension, grade, and recurrence. miR-125a stimulates stromal cell tumorigenicity and growth in vivo by promoting the expression of interleukin-17A (IL-17A) and β-catenin. In contrast, inhibition of miR-125a suppressed stromal cell tumorigenicity and growth. Then, we found that miR-125a stimulates IL-17A by targeting TET2 and Foxp3, and it stimulates β-catenin expression by targeting APC and GSK3β in stromal cells. Furthermore, we identified that IL-17A stimulates miR-125a by activating nuclear factor κB (NF-κB) signaling in stromal cells. Finally, our data show that simultaneous inhibition of IL-17A signaling and miR-125a more significantly inhibits stromal cell growth than miR-125a inhibition alone. miR-125a stimulates the progression of GCTB, and it might represent a useful candidate marker for progression. Simultaneously blocking miR-125a and IL-17A might represent a new therapeutic strategy for GCTB.

A high risk of osteosarcoma in individuals who are homozygous for the p.D104N in endostatin

The D104N polymorphism (p.D104N) in endostatin has been previously identified in many types of cancer, and this polymorphism is believed to be a phenotypic modulator in some tumors. However, it is unknown whether endostatin p.D104N affects the risk and progression of osteosarcoma (OS). Here, we analyzed the p.D104N endostatin variant in 236 patients with OS and 418 healthy individuals. Similar frequencies of wild type and heterozygous p.104DN endostatin were observed in controls and OS patients. Interestingly, the frequency of the homozygous p.D104N (p.104NN) genotype was higher in OS patients group compared to control group, suggesting that individuals with p.104NN endostatin have a significantly increased risk for OS. In addition, OS patients with p.104NN endostatin had a shorter survival time and a higher rate of metastasis than OS patients with wild type endostatin. Animal experiments revealed that overexpression of p.104NN endostatin did not significantly inhibit OS lung metastasis. Interestingly, administration of endostatin dramatically inhibited OS lung metastasis in the p.104NN endostatin xenograft model. Together, these results suggest that p.104NN of endostatin is associated with the risk of OS and demonstrates predictive significance for clinical outcome in OS patients. In addition, endostatin therapy may be necessary for OS patients harboring p.104NN endostatin.