Magic and mystery of microRNA-32.

MicroRNAs (miRNAs) are a group of endogenous, small (∼22 nts in length) noncoding RNA molecules that function specifically by base pairing with the mRNA of genes and regulate gene expression at the post-transcriptional level. Alterations in miR-32 expression have been found in numerous diseases and shown to play a vital role in cell proliferation, apoptosis, oncogenesis, invasion, metastasis and drug resistance. MiR-32 has been documented as an oncomiR in the majority of related studies but has been also verified as a tumour suppressor miRNA in conflicting reports. Moreover, it has a crucial role in metabolic and cardiovascular disorders. This review provides an in-depth look into the most recent finding regarding miR-32, which is involved in the expression, regulation and functions in different diseases, especially tumours. Additionally, this review outlines novel findings suggesting that miR-32 may be useful as a noninvasive biomarker and as a targeted therapeutic in several diseases.

Highly expressed lncRNA FOXD3-AS1 promotes non-small cell lung cancer progression via regulating miR-127-3p/mediator complex subunit 28 axis.

OBJECTIVE: The present study aimed to determine the expression of long non-coding RNA (lncRNA) FOXD3 antisense RNA 1 (FOXD3-AS1) in lung cancer tissues and to explore its underlying mechanisms in mediating non-small cell lung cancer (NSCLC) progression. MATERIALS AND METHODS: Gene expression levels were determined by quantitative real-time PCR; lung cancer cell proliferation and invasion were determined by in vitro functional assays; protein levels were determined by Western blot assay; xenograft nude mice model was used to evaluate the in vivo tumor growth of lung cancer cells; Luciferase reporter assay determined the interactions among FOXD3-AS1, miR-127-3p, and mediator complex subunit 28 (MED28). RESULTS: Data mining and analysis of the clinical sample showed that FOXD3-AS1 expression was significantly up-regulated in lung cancer tissues. In vitro functional assays demonstrated that FOXD3-AS1 overexpression promoted NSCLC cell proliferation and invasion, while FOXD3-AS1 knockdown exerted tumor-suppressive effects on NSCLC cells. Moreover, FOXD3-AS1 interacted with miR-127-3p by acting as a competing endogenous RNA to suppress miR-127-3p expression, while miR-127-3p repressed MED28 expression by targeting MED28 3' untranslated region in NSCLC cells. Mechanistically, the oncogenic effects of FOXD3-AS1 overexpression were significantly attenuated by miR-127-3p overexpression and MED28 knockdown in NSCLC cells. In the xenograft mice model, FOXD3-AS1 knockdown suppressed in vivo tumor growth of A549 cells, and also up-regulated miR-127-3p expression and repressed MED28 expression in the xenograft tumors. In the clinical aspect, the downregulation of miR-127-3p and up-regulation of MED28 were respectively detected in lung cancer tissues. CONCLUSIONS: Our findings provided new evidence that the FOXD3-AS1 regulated NSCLC progression via targeting the miR-127-3p/MED28 axis.

Disrupting G6PD-mediated Redox homeostasis enhances chemosensitivity in colorectal cancer.

Glucose-6-phosphate dehydrogenase (G6PD) is a key enzyme that generates NADPH to maintain reduced glutathione (GSH), which scavenges reactive oxygen species (ROS) to protect cancer cell from oxidative damage. In this study, we mainly investigate the potential roles of G6PD in colorectal cancer (CRC) development and chemoresistance. We discover that G6PD is overexpressed in CRC cells and patient specimens. High expression of G6PD predicts poor prognosis and correlated with poor outcome of oxaliplatin-based first-line chemotherapy in patients with CRC. Suppressing G6PD decreases NADPH production, lowers GSH levels, impairs the ability to scavenge ROS levels, and enhances oxaliplatin-induced apoptosis in CRC via ROS-mediated damage in vitro. In vivo experiments further shows that silencing G6PD with lentivirus or non-viral gene delivery vector enhances oxaliplatin anti-tumor effects in cell based xenografts and PDX models. In summary, our finding indicated that disrupting G6PD-mediated NADPH homeostasis enhances oxaliplatin-induced apoptosis in CRC through redox modulation. Thus, this study indicates that G6PD is a potential prognostic biomarker and a promising target for CRC therapy.

[Clinical outcomes of single-level lumbar spondylolisthesis by minimally invasive transforaminal lumbar interbody fusion with bilateral tubular channels].

Objective: To evaluate the clinical effectiveness of minimally invasive transforaminal lumbar interbody fusion (MIS-TLIF) for single-level lumbar spondylolisthesis treatment with bilateral Spotlight tubular channels. Methods: A total of 21 patients with lumbar spondylolisthesis whom underwent MIS-TLIF via bilateral Spotlight tubular channels were retrospectively analyzed from October 2014 to November 2015. The 21 patients included 11 males and 10 females ranged from 35 to 82 years (average aged 60.7 years). In term of spondylolisthesis category, there were 18 cases of degenerative spondylolisthesis and 3 cases of isthmic spondylolisthesis. With respect to spondylolisthesis degree, 17 cases were grade Ⅰ° and 4 cases were grade Ⅱ°. Besides, 17 cases at L(4-5) and 4 cases at L(5)-S(1)were categorized by spondylolisthesis levels. Operation duration, blood loss, postoperative drainage and intraoperative exposure time were recorded, functional improvement was defined as an improvement in the Oswestry Disability Index (ODI), Visual Analog Scale (VAS) was also employed at pre and post-operation (3 months and the last follow-up), to evaluate low back and leg pain. Furthermore, to evaluate the recovery of the intervertebral foramen and of lumbar sagittal curvature, average height of intervertebral space, Cobb angles of lumbar vertebrae and operative segments, spondylolisthesis index were measured. At the last follow-up, intervertebral fusion was assessed using Siepe evaluation criteria and the clinical outcome was assessed using the MacNab scale. Radiographic and functional outcomes were compared pre- and post-operation using the paired T test to determine the effectiveness of MIS-TLIF. Statistical significance was defined as P<0.05. Results: All patients underwent a successful MIS-TLIF surgery. The operation time (235.2±30.2) mins, intraoperative blood loss (238.1±130.3) ml, postoperative drainage (95.7±57.1) ml and intraoperative radiation exposure (47.1±8.8) were recorded. Different significance between 3 months post-operative follow-up and pre-operation was exhibited (P<0.01) in respects of lumbar VAS (t=11.1, P<0.01) and leg VAS (t=17.8, P<0.01). Moreover, final follow-up compared with pre-operation, and final follow-up compared with 3 months post-operative follow-up, VAS scores were also statistical difference (P<0.01). At the final follow-up, there were significant differences compared with pre-operation in ODI scores (t=30.1, P<0.01). Comparison between 3 months post-operative follow-up and pre-operation, statistical distinctions were demonstrated (P<0.05) in terms of mean height of intervertebral space (t=-10.9, P<0.01), the Cobb angles of lumbar vertebrae (t=-2.4, P<0.05), operative segments Cobb angles (t=-5.2, P<0.01) and Lumbar spondylolisthesis incidence (t=17.1, P<0.01). In addition, there was statistical difference between final follow-up and pre-operation (P<0.05) as well. For instance, mean height of intervertebral space (t=-10.5, P<0.01), the Cobb angles of lumbar vertebrae (t=-2.7, P<0.05), operative segments Cobb angles (t=-4.2, P<0.01) and Lumbar spondylolisthesis incidence (t=18.6, P<0.01) were involved. All spondylolisthesis vertebrae were restored completely. Lastly, at the last follow-up, 12 cases of grade 1 and 7 cases of grade 2 fusion were present as determined by the Siepe evaluation criteria. McNab scale assessment classified 17 patients having excellent clinical outcome, 3 patients in good and 1 patient having a better clinical outcome. Conclusion: MIS-TLIF with bilateral Spotlight tubular channels is a safe and effective approach for single segment lumbar spondylolisthesis.

Metabolic regulation of cancer cell side population by glucose through activation of the Akt pathway.

Side population (SP) cells within tumors are a small fraction of cancer cells with stem-like properties that can be identified by flow cytometry analysis based on their high ability to export certain compounds such as Hoechst 33342 and chemotherapeutic agents. The existence of stem-like SP cells in tumors is considered as a key factor contributing to drug resistance, and presents a major challenge in cancer treatment. Although it has been recognized for some time that tumor tissue niches may significantly affect cancer stem cells (CSCs), the role of key nutrients such as glucose in the microenvironment in affecting stem-like cancer cells and their metabolism largely remains elusive. Here we report that SP cells isolated from human cancer cells exhibit higher glycolytic activity compared to non-SP cells. Glucose in the culture environment exerts a profound effect on SP cells as evidenced by its ability to induce a significant increase in the percentage of SP cells in the overall cancer cell population, and glucose starvation causes a rapid depletion of SP cells. Mechanistically, glucose upregulates the SP fraction through ATP-mediated suppression of AMPK and activation of the Akt pathway, leading to elevated expression of the ATP-dependent efflux pump ABCG2. Importantly, inhibition of glycolysis by 3-BrOP significantly reduces SP cells in vitro and impairs their ability to form tumors in vivo. Our data suggest that glucose is an essential regulator of SP cells mediated by the Akt pathway, and targeting glycolysis may eliminate the drug-resistant SP cells with potentially significant benefits in cancer treatment.

The correlation between vertebral wedge-shaped changes in X-ray imaging at supine and standing positions and the efficacy of operative treatment of thoracolumbar spinal fracture in the elderly.

STUDY DESIGN: By analyzing a large number of surgical patients, we identified the roles of wedge-shaped changes in related surgeries. OBJECTIVES: To illustrate the relevance of vertebral wedge-shaped changes in X-ray imaging at supine and standing positions in patients with percutaneous kyphoplasty as well as the postoperative effect. SETTING: All patient data were collected from a hospital in China. METHODS: Between June 2006 and May 2010, 77 surgical patients (9 men and 68 women) with wedge-shaped compression fractures were retrospectively analyzed. Patients were divided into group A (ΔWR2.5%) and group B (ΔWR<2.5%) according to the dynamic changes in the percentage of vertebral body wedge-shaped variable ratio (WR) at supine and standing positions. The intensity of back pain in different positions pre- and postoperatively was evaluated with a visual analog pain scale (VAS). RESULTS: The WRs in both standing and supine positions were significantly reduced by kyphoplasty in both groups A and B. In agreement with the improvement in WRs, the VAS was significantly decreased in three positions for patients in group A and in turning over and standing position for patients in group B. With respect to ΔWR changes, group B revealed significantly lower values compared with group A preoperatively (P<0.001), but there was no significant difference between groups A and B postoperatively and at 1-month follow-up (P=0.179 and P=0.558, respectively). CONCLUSIONS: Improvement in symptoms after kyphoplasty is better in patients with wedge-shaped changes in supine and standing positions, and the efficacy of height restoration of the spine would be better in unstable vertebrae by balloon dilatation.

Potential role of AQP1 and VEGF in the development of malignant pleural effusion in mice.

Recent studies have revealed the important role of aquaporin-1 (AQP1) in tumor cell migration and angiogenesis. However, the function of AQP1 in malignant pleural effusion has not been well characterized. We established a mouse model to examine the role of AQP1 and vascular endothelial growth factor (VEGF) in the development of malignant pleural effusion. We showed that elevated expressions of AQP1 mRNA and VEGF protein were associated with increased volume of malignant pleural effusion. These results suggest that AQP1 and VEGF play important roles in the development of malignant pleural effusion in mice, which may help us find new strategies for the prevention and treatment of malignant pleural effusion.

Reversion of the neoplastic phenotype of human glioblastoma cells by connexin 43 (cx43).

Connexins (cx), structural components of gap junction, are believed to play a role in the regulation of cell proliferation and suppression of the neoplastic phenotype. We used human brain glioblastoma tumor cells as a model system to test this hypothesis. Western blot and reverse transcription-PCR analysis indicate that the expression levels of the gap junction protein connexin 43 (cx43) are profoundly decreased in several human brain tumor cell lines examined. Transfection of human cx43 into human glioblastoma cell lines U251 and T98G profoundly reduces cell proliferation in monolayer culture, in soft agar, and in athymic nude mice. Surprisingly, these effects are not associated with the establishment of gap junction communication in cx43 transfected cells. We conclude that the loss of cx43 expression may play a role in the development of human gliomas and that cx43 acts as a tumor suppressor gene to human glioblastoma.

Suppression of human fibrosarcoma cell growth by transcription factor, Egr-1, involves down-regulation of Bcl-2.

Previously, we showed that the transcription factor Egr-1 suppressed the proliferation of v-sis transformed NIH3T3 cells and also a number of human tumor cells. Here, we investigate the possible mechanisms responsible for this function. We show that transfected Egr-1 in human fibrosarcoma cells HT1080 leads to down-regulation of Bcl-2. Transient CAT transfection assays reveal that expression of Egr-1 suppresses Bcl-2 promoter activity in a dose-dependent manner. Furthermore, overexpression of Bcl-2 in Egr-1-expressing HT1080 cells enhanced cell proliferation in monolayer culture and increased anchorage-independent growth. Our results suggest that suppression of tumor cell proliferation by Egr-1 may be at least partially mediated through the down-regulation of Bcl-2.