miR-532-5p is a prognostic marker and suppresses cells proliferation and invasion by targeting TWIST1 in epithelial ovarian cancer.

OBJECTIVE: Dysregulated miR-532-5p has been observed in epithelial ovarian cancer (EOC). However, the potential biological function and clinical significance have not been fully explained. The study aimed to investigate the prognostic value and potential role of miR-532-5p in EOC. PATIENTS AND METHODS: MiR-532-5p and Twist homolog 1 (TWIST1) mRNA expression were examined using quantitative real-time PCR. The correlation of miR­532-5p expression with clinicopathological factors was statistically analyzed. Kaplan-Meier analysis and Cox proportional hazards regression models were explored to reveal the correlations of miR-532-5p expression with survival of patients. Cell Counting Kit-8, colony formation and transwell invasion assays were performed to evaluate the effects of miR-532-5p on cell proliferation and invasion, respectively. MiR­532-5p target genes were confirmed using luciferase activity, RT-PCR and Western blot assays. RESULTS: We found that miR-532-5p was significantly decreased in EOC tissue and cell lines, and its expression levels were highly correlated with grade (p = 0.011), FIGO stage (p = 0.004) and distant metastasis (p = 0.008). In addition, overall patient survival for those with high miR-532-5p expression was significantly longer than those patients with low miR-532-5p expression (p = 0.0058). Multivariate regression analysis identified miR-532-5p down-regulation as an independent unfavorable prognostic factor in EOC patients. Function assays showed that overexpression of miR-532-5p inhibited proliferation, colony formation and invasion of EOC cells. Mechanistic investigations confirmed TWIST1 as a direct target of miR-532-5p. Further in vitro assay indicated that restored expression of TWIST1 dampened miR-532-5p-mediated suppression of tumor progression. CONCLUSIONS: Our data suggested that miR-532-5p may act not only as a novel prognostic marker, but also as a potential target for molecular therapy of EOC.

Role of the CKIP1 gene in proliferation and apoptosis of the human lung cancer cell line H1299.

Casein kinase 2 interacting protein 1 (CKIP1) is a specific interacting protein of the casein kinase 2 (CK2) α subunit, and, by binding CK2 and other proteins, functions as an adaptor to regulate a series of cellular functions. Previous studies suggested that CKIP1 might play an important role in regulating oncogenic activities. However, few studies examining the function of CKIP1 in cancer cells have been performed. The present study aimed to investigate the role of CKIP1 in lung cancer. CKIP1 mRNA expression was detected in 5 human lung cancer cell lines (H-125, H1299, LTEP-A-2, SPC-A-1, and NCL-H446) by semi-quantitative RT-PCR, and in 10 noncancerous lung tissues and 30 non-small lung cancer tissues by real-time quantitative PCR. A lentivirus-mediated small interfering RNA (siRNA) was used to knock down CKIP1 expression in the H1299 cell line. To elucidate the impact of CKIP1 downregulation on H1299 cells, cell proliferation, DNA synthesis, and cell cycle distribution and apoptosis were measured by high content screening assay, BrdU incorporation, and flow cytometric analyses, respectively. CKIP1 mRNA was highly expressed both in H1299 cells and lung cancer tissues. We found that downregulation of CKIP1 resulted in suppression of proliferation and colony-forming ability of H1299 cells, and led to S phase cell cycle arrest and G2 phase promotion, as well as a significant enhancement of H1299 cell apoptosis. Our study indicated that high expression levels of CKIP1 were associated with the development of lung cancer, and that CKIP1 knockdown may block tumor cell growth mainly by promoting cell apoptosis.

High-speed atomic force microscope based on an astigmatic detection system.

High-speed atomic force microscopy (HS-AFM) enables visualizing dynamic behaviors of biological molecules under physiological conditions at a temporal resolution of 1s or shorter. A small cantilever with a high resonance frequency is crucial in increasing the scan speed. However, detecting mechanical resonances of small cantilevers is technically challenging. In this study, we constructed an atomic force microscope using a digital versatile disc (DVD) pickup head to detect cantilever deflections. In addition, a flexure-guided scanner and a sinusoidal scan method were implemented. In this work, we imaged a grating sample in air by using a regular cantilever and a small cantilever with a resonance frequency of 5.5 MHz. Poor tracking was seen at the scan rate of 50 line/s when a cantilever for regular AFM imaging was used. Using a small cantilever at the scan rate of 100 line/s revealed no significant degradation in the topographic images. The results indicate that a smaller cantilever can achieve a higher scan rate and superior force sensitivity. This work shows the potential for using a DVD pickup head in future HS-AFM technology.