Feifei Pu

Effect of microRNA-101 on proliferation and apoptosis of human osteosarcoma cells by targeting mTOR.

Studies have proved that microRNA-101 (miR-101) functions as a tumor suppressor and is associated with growth and apoptosis of various human cancers. However, the role of miR-101 in osteosarcoma and the possible mechanism by which miR-101 affects the tumor growth and apoptosis have not been fully elucidated. In this study, we found that the expression of miR-101 was down-regulated in osteosarcoma tissues and Saos-2 cell line as compared with that in adjacent non-neoplastic bone tissues and the osteoblastic cell line. To better characterize the role of miR-101 in osteosarcoma, we used a gain-of-function analysis by transfecting human osteosarcoma cell line Saos-2 with chemically synthesized miR-101 mimics. The results showed that overexpression of miR-101 inhibited the proliferation and promoted the apoptosis of Saos-2 cells. Meanwhile, bioinformatic analysis demonstrated that mTOR gene was a direct target of miR-101. Overexpression of miR-101 significantly decreased the expression of mTOR at both mRNA and protein levels in Saos-2 cells, consequently inhibiting Saos-2 cells proliferation and promoting cells apoptosis in an mTOR-dependent manner. Taken together, these data suggest that miR-101 may act as a tumor suppressor, which is commonly downregulated in both osteosarcoma tissues and cells. mTOR plays an important role in mediating miR-101 dependent biological functions in osteosarcoma. Reintroduction of miR-101 may be a novel therapeutic strategy by down-regulating mTOR expression.SummaryStudies have proved that microRNA-101 (miR-101) functions as a tumor suppressor and is associated with growth and apoptosis of various human cancers. However, the role of miR-101 in osteosarcoma and the possible mechanism by which miR-101 affects the tumor growth and apoptosis have not been fully elucidated. In this study, we found that the expression of miR-101 was down-regulated in osteosarcoma tissues and Saos-2 cell line as compared with that in adjacent non-neoplastic bone tissues and the osteoblastic cell line. To better characterize the role of miR-101 in osteosarcoma, we used a gain-of-function analysis by transfecting human osteosarcoma cell line Saos-2 with chemically synthesized miR-101 mimics. The results showed that overexpression of miR-101 inhibited the proliferation and promoted the apoptosis of Saos-2 cells. Meanwhile, bioinformatic analysis demonstrated that mTOR gene was a direct target of miR-101. Overexpression of miR-101 significantly decreased the expression of mTOR at both mRNA and protein levels in Saos-2 cells, consequently inhibiting Saos-2 cells proliferation and promoting cells apoptosis in an mTOR-dependent manner. Taken together, these data suggest that miR-101 may act as a tumor suppressor, which is commonly downregulated in both osteosarcoma tissues and cells. mTOR plays an important role in mediating miR-101 dependent biological functions in osteosarcoma. Reintroduction of miR-101 may be a novel therapeutic strategy by down-regulating mTOR expression.

High Birth Weight Increases the Risk for Bone Tumor: A Systematic Review and Meta-Analysis

There have been several epidemiologic studies on the relationship between high birth weight and the risk for bone tumor in the past decades. However, due to the rarity of bone tumors, the sample size of individual studies was generally too small for reliable conclusions. Therefore, we have performed a meta-analysis to pool all published data on electronic databases with the purpose to clarify the potential relationship. According to the inclusion and exclusion criteria, 18 independent studies with more than 2796 cases were included. As a result, high birth weight was found to increase the risk for bone tumor with an Odds Ratio (OR) of 1.13, with the 95% confidence interval (95% CI) ranging from 1.01 to 1.27. The OR of bone tumor for an increase of 500 gram of birth weight was 1.01 (95% CI 1.00–1.02; p = 0.048 for linear trend). Interestingly, individuals with high birth weight had a greater risk for osteosarcoma (OR = 1.22, 95% CI 1.06–1.40, p = 0.006) than those with normal birth weight. In addition, in the subgroup analysis by geographical region, elevated risk was detected among Europeans (OR = 1.14, 95% CI 1.00–1.29, p = 0.049). The present meta-analysis supported a positive association between high birth weight and bone tumor risk.

The synergistic anticancer effect of cisplatin combined with Oldenlandia diffusa in osteosarcoma MG-63 cell line in vitro.

Background Oldenlandia diffusa (OD) is a well-known traditional Chinese medicine, which is used to prevent and treat many disorders, especially cancers. However, its role in osteosarcoma has not been well understood. Here, we used OD and cisplatin individually and combined in osteosarcoma MG-63 cell to explore whether OD could induce cellular apoptosis and suppress the ability of proliferation and invasion of osteosarcoma MG-63 cell. Methods The changes of cellular shape were analyzed by optical microscopy. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide assay was used to analyze cell survival rate in vitro. Flow cytometry was performed to detect cell cycle and cell death. Scratch migration assay was used to evaluate cell migration and invasion. Western blot was performed to determine the expression levels of pro-apoptotic and anti-apoptotic protein. Results In this study, we found that the survival rate reduced significantly in the combined group compared with the individual group and control group. The apoptosis-inducing effect of combined application was much more significant than that of individual application. The invasion ability of combined application was significantly lower than that of the individual application. In the combined group, there were high expression levels of pro-apoptotic protein and low expression of anti-apoptotic protein. Cell-cycle analysis showed a change in the cell-cycle distribution and arrested cells in G2-M phase. Conclusion In this study, we found that OD inhibited proliferation and induced apoptosis in the human osteosarcoma MG-63 cell line in a time-dependent and dose-dependent manner. In addition, OD displayed inhibitory activity on MG-63 cell proliferation and invasion and the study also showed that OD activity might be mediated by caspase activation. These data suggest that OD might represent a novel, efficient candidate agent for further experimentation in osteosarcoma treatment.

Edaravone ameliorates compression-induced damage in rat nucleus pulposus cells

Aims: Edaravone is a strong free radical scavenger most used for treating acute ischemic stroke. In this study we investigated the protective effects and underlying mechanisms of edaravone on compression‐induced damage in rat nucleus pulposus (NP) cells. Materials and methods: Cell viability was determined using MTT assay methods. NP cell apoptosis was measured by Hoechst 33,258 staining and Annexin V/PI double staining. Intracellular reactive oxygen species (ROS), mitochondrial membrane potential (MMP), and intracellular calcium ([Ca2 +]i) were determined by fluorescent probes DCFH‐DA, JC‐1 and Fluo‐3/AM, respectively. Apoptosis‐related proteins (cleaved caspase‐3, cytosolic cytochrome c, Bax and Bcl‐2) and extracellular matrix proteins (aggrecan and collagen II) were analyzed by western blot. Key findings: Edaravone attenuated the compression‐induced decrease in viability of NP cells in a dose‐dependent manner. 33,258 and Annexin V/PI double staining showed that edaravone protected NP cells from compression‐induced apoptosis. Further studies confirmed that edaravone protected NP cells against compression‐induced mitochondrial pathway of apoptosis by inhibiting overproduction of ROS, collapse of MMP and overload of [Ca2 +]i. In addition, edaravone promoted the expression of aggrecan and collagen II in compression‐treated NP cells. Significance: These results strongly indicate that edaravone ameliorates compression‐induced damage in rat nucleus pulposus cells. Edaravone could be a potential new drug for treatment of IDD.

Palliative Surgery in Treating Painful Metastases of the Upper Cervical Spine: Case Report and Review of the Literature.

AbstractIncreased incidence of upper cervical metastases and higher life expectancy resulted in higher operative rates in patients. The purpose of this study was to explore the methods and the clinical outcomes of palliative surgery for cervical spinal metastases.A systematic review of a 15-case series of upper cervical metastases treated with palliative surgery was performed. All cases underwent palliative surgery, including anterior tumor resection and internal fixation in 3 cases, posterior tumor resection and internal fixation in 10 cases, and combined anterior and posterior tumor resection and internal fixation in 2 cases. Patients were followed-up clinically and radiologically after the operation, and visual analog scale (VAS) and activities of daily living scores were calculated. In addition, a literature review was performed and patients with upper cervical spine metastases were analyzed.The mean follow-up period was 12.5 months (range, 3–26 months) in this consecutive case series. The pain was substantially relieved in 93.3% (14/15) of the patients after the operation. The VAS and Japanese Orthopedic Association scores showed improved clinical outcomes, from 7.86 ± 1.72 and 11.13 ± 2.19 preoperatively to 2.13 ± 1.40 and 14.26 ± 3.03 postoperatively, respectively. The mean survival time was 9.5 months (range, 5–26 months). Dural tear occurred in 1 patient. Wound infections, instrumentation failure, and postoperative death were not observed. Among our cases and other cases reported in the literature, 72% of the patients were treated with simple anterior or posterior operation, and only 12% of the patients (3/25) underwent complex combined anterior and posterior operation.Metastatic upper cervical spine disease is not a rare occurrence. Balancing the perspective of patients on palliative surgery concerning the clinical benefits of operation versus its operative risks can assist the decision for surgery.

In vitro effect of microRNA-107 targeting Dkk-1 by regulation of Wnt/β-catenin signaling pathway in osteosarcoma

Background: The aim of the study was to explore the effects of microRNA-107 (miR-107) by targeting Dkk-1 on osteosarcoma (OS) via the Wnt/&bgr;-catenin signaling pathway. Methods: OS and adjacent tissues were collected from 67 patients diagnosed with OS. Expressions of miR-107, Dkk-1, LRP5, &bgr;-catenin, and c-Myc were detected by the quantitative real-time polymerase chain reaction (qRT-PCR) and Western blotting. The dual-luciferase reporter gene assay was performed to observe the relationship between miR-107 and Dkk-1.Transfected cells were divided into different investigating groups designated as Inhibitor, Mimic, siRNA, Inhibitor + siRNA, negative control (NC), and blank groups. qRT-PCR and Western blotting were used to detect expressions of miR-107, Dkk-1, &bgr;-catenin, Bcl-2, c-Myc, Caspase-3, and PARP. Cell counting kit-8 (CCK-8), flow cytometry (FCM), colony-formation efficiency (CFE), and subcutaneous tumorigenicity assays were all utilized for to determine cell proliferation, apoptosis, colony-forming, and tumorigenic abilities. Results: Dkk-1 is the target gene of miR-107. Decreased expressions of miR-107, LRP5, &bgr;-catenin, and c-Myc, and increased expressions of Dkk-1 were found in OS tissues. The Mimic and siRNA groups exhibited decreased proliferation rates, colony-forming abilities, and tumorigenicity and increased apoptosis rates, whereas the inhibitor group showed opposite trends when compared to the blank group. On the other hand, expressions of miR-107, LRP5, &bgr;-catenin, c-Myc, Caspase-3, and PARP were all elevated in the mimic group, whereas expressions of Dkk-1 and Bcl-2 were reduced; opposite trends were observed in the inhibitor group. Conclusion: We conclude that miR-107 is likely to inhibit the occurrence and development of OS by down-regulating Dkk-1 via the Wnt/&bgr;-catenin signaling pathway, providing us with a new therapeutic target for the treatment of OS.

association between GSTP1 polymorphisms and prognosis of osteosarcoma in patients treated with chemotherapy: a meta-analysis

Objective The aim of this study was to evaluate the relationship between GSTP1 polymorphisms and prognosis of osteosarcoma in patients treated with chemotherapy, by performing a meta-analysis. Methods The studies of effects of GSTP1 gene polymorphisms on osteosarcoma survival after chemotherapy were collected. STATA (version 12.0) was used to perform data synthesis. Results Six studies involving 898 participants were included. A meta-analysis was performed on studies in GSTP1 313A>G(rs1695) assessing the association between tumor response and the polymorphisms in GSTP1 (AA vs AG, AA vs GG), the pooled odds ratios (ORs) were 2.06 (95% confidence interval [CI]: 1.48–2.86, P=0.628, I2=0.0%). There was significant association between the polymorphisms in GSTP1 (AA vs AG, AA vs GG) and the events that happened, the pooled ORs were 1.86 (95% CI: 1.14–3.06, P=0.034, I2=58.6%), and there was significant association between the polymorphisms in GSTP1 (AA vs AG, AA vs GG) and survival times (overall survival and progression-free survival) in osteosarcoma patients treated with chemotherapy, and the pooled ORs were 2.14 (95% CI: 1.51–3.04, P=0.675, I2=0.0%) and 2.77 (95% CI: 1.56–4.91, P=0.347, I2=9.3%), respectively. Two studies assessed the association of polymorphisms in GSTP1 I105V (IIe/IIe vs IIe/Val, IIe/IIe vs Val/Val) with overall survival in human osteosarcoma. The pooled ORs were 1.20 (95% CI: 0.64–2.27, P=0.010, I2=73.5%). The study showed an insignificant difference in overall survival for the polymorphisms in GSTP1 (IIe/IIe vs IIe/Val, IIe/IIe vs Val/Val). Conclusion This meta-analysis indicated that GSTP1 polymorphisms might influence osteosarcoma risk and suggests that GSTP1 polymorphisms may be an important risk factor for osteosarcoma.

Presacral Tarlov Cyst as an Unusual Cause of Abdominal Pain: New Case and Literature Review

BACKGROUND A presacral Tarlov cyst is an unusual cause of abdominal pain. The unusual location of a presacral Tarlov cyst can lead to misdiagnosis and inappropriate treatment. To guide appropriate diagnosis and treatment, we reviewed causes, clinical presentations, radiologic features, and management options of this extremely rare lesion. METHODS We performed an English-language literature search using PubMed to identify reports of patients with presacral Tarlov cysts. The diagnosis was based on classic radiologic signs. Seven patients described in 7 publications met the inclusion criteria and were analyzed in conjunction with 3 new patients described by our team. RESULTS A congenital arachnoidal defect may be the primary causative factor of a presacral Tarlov cyst. Lumbosacral pain, leg pain, and bowel and bladder dysfunction are common clinical complaints, while abdominal pain is uncommon. Myelography and magnetic resonance imaging are considered useful diagnostic techniques. Myelography provided the definitive diagnosis for 33% of the patients, and magnetic resonance imaging was diagnostic for 67%. Surgical interventions may be appropriate for symptomatic presacral lesions. Two patients who received conservative treatment continued to experience their presenting symptoms, whereas 7 patients who underwent surgical treatment experienced favorable outcomes. CONCLUSIONS Although extremely rare, presacral Tarlov cysts should be suspected in patients with abdominal pain, especially when pain occurs along with other neurologic symptoms. This review provides a systematic description of this rare disease, which may be helpful in guiding the appropriate diagnosis and treatment.

Functional variants of TIM-3/HAVCR2 3′UTR in lymphoblastoid cell lines

Aim: Variants of TIM-3/HAVCR2 3′UTR miRNA binding sites are significantly associated with cancer; however, roles in post-transcriptional regulation have not been elucidated. Methods: The regulatory and coding region single nucleotide polymorphisms (SNPs) of TIM-3/HAVCR2 were identified using an online database. Single nucleotide polymorphism Function Prediction was used to predict potential functional relevance of miRNA binding sites. Results: The analysis indicated rs9313439, rs4704846, rs3087616 and rs1036199 affect possible miRNA binding sites in TIM-3/HAVCR2 3′UTR. We used additional data on genotypes and limited minor allele frequency >5% in the HapMap populations. Only rs3087616 and rs4704846 were significantly associated with TIM-3/HAVCR2. Conclusion: Both rs3087616 and rs4704846 could be putative variants mediating post-transcriptional regulation of the TIM-3/HAVCR2. Deeper understanding of how 3′UTR variants influence the activity by TIM-3/HAVCR2 for therapy against cancer.

TRAIL-R1 as a novel surface marker for circulating giant cell tumor of bone

Giant cell tumor of bone (GCT), which frequently occurs in the patients’ spine, is relatively prevalent in Chinese population. A group of GCT invades into vessels and appears to be circulating tumor cells (CTCs) responsible for the distal metastasis of the primary tumor. So far the cell surface markers of GCT have not been determined. In the current study, we aimed to identify a novel CTC marker with higher specificity in GCT. TRAIL-R1+ cells were purified from GCT cell lines. The TRAIL-R1+ cells were compared with total GCT cells for tumor sphere formation, chemo-resistance, tumor formation in nude mice, and frequency of developing distal metastases. We found that TRAIL-R1+ GCT cells appeared to be highly enriched for CTCs in GCT. Compared to total GCT cells, TRAIL-R1+ GCT cells generated significantly more tumor spheres in culture, were higher chemo-resistant, and had a higher frequency of being detected in the circulation after subcutaneous transplantation as well as development of distal metastases. Thus, we conclude that TRAIL-R1+ may be a novel CTC marker in GCT. Selective elimination of TRAIL-R1+ GCT cells may improve the current GCT therapy.