Weijun Qin

MicroRNA Let-7a Inhibits Proliferation of Human Prostate Cancer Cells In Vitro and In Vivo by Targeting E2F2 and CCND2

Background Previous work has shown reduced expression levels of let-7 in lung tumors. But little is known about the expression or mechanisms of let-7a in prostate cancer. In this study, we used in vitro and in vivo approaches to investigate whether E2F2 and CCND2 are direct targets of let-7a, and if let-7a acts as a tumor suppressor in prostate cancer by down-regulating E2F2 and CCND2. Methodology/Principal Findings Real-time RT-PCR demonstrated that decreased levels of let-7a are present in resected prostate cancer samples and prostate cancer cell lines. Cellular proliferation was inhibited in PC3 cells and LNCaP cells after transfection with let-7a. Cell cycle analysis showed that let-7a induced cell cycle arrest at the G1/S phase. A dual-luciferase reporter assay demonstrated that the 3′UTR of E2F2 and CCND2 were directly bound to let-7a and western blotting analysis further indicated that let-7a down-regulated the expression of E2F2 and CCND2. Our xenograft models of prostate cancer confirmed the capability of let-7a to inhibit prostate tumor development in vivo. Conclusions/Significance These findings help to unravel the anti-proliferative mechanisms of let-7a in prostate cancer. Let-7a may also be novel therapeutic candidate for prostate cancer given its ability to induce cell-cycle arrest and inhibit cell growth, especially in hormone-refractory prostate cancer.

Near-infrared fluorescent probes in cancer imaging and therapy: an emerging field

Near-infrared fluorescence (NIRF) imaging is an attractive modality for early cancer detection with high sensitivity and multi-detection capability. Due to convenient modification by conjugating with moieties of interests, NIRF probes are ideal candidates for cancer targeted imaging. Additionally, the combinatory application of NIRF imaging and other imaging modalities that can delineate anatomical structures extends fluorometric determination of biomedical information. Moreover, nanoparticles loaded with NIRF dyes and anticancer agents contribute to the synergistic management of cancer, which integrates the advantage of imaging and therapeutic functions to achieve the ultimate goal of simultaneous diagnosis and treatment. Appropriate probe design with targeting moieties can retain the original properties of NIRF and pharmacokinetics. In recent years, great efforts have been made to develop new NIRF probes with better photostability and strong fluorescence emission, leading to the discovery of numerous novel NIRF probes with fine photophysical properties. Some of these probes exhibit tumoricidal activities upon light radiation, which holds great promise in photothermal therapy, photodynamic therapy, and photoimmunotherapy. This review aims to provide a timely and concise update on emerging NIRF dyes and multifunctional agents. Their potential uses as agents for cancer specific imaging, lymph node mapping, and therapeutics are included. Recent advances of NIRF dyes in clinical use are also summarized.

CD147, MMP-1, MMP-2 and MMP-9 Protein Expression as Significant Prognostic Factors in Human Prostate Cancer

Aim: CD147 and MMPs have been demonstrated to be involved in tumor invasion and angiogenesis. The aim of this study was to analyze the clinicopathological significance of CD147, MMP-1, MMP-2 and MMP-9 expression in human prostate cancer (PCa) and to evaluate their involvement in the progression of PCa. Methods: CD147, MMP-1, MMP-2 and MMP-9 expression was assessed in paraffin-embedded specimens collected from 62 cases of PCa and 15 cases of benign prostatic hyperplasia (BPH) by immunohistochemistry. Spearman’s correlation was applied to determine possible relationships between CD147, MMP-1, MMP-2 and MMP-9 expression and PCa. The association of CD147 and MMP-2 protein expression with the clinicopathological characteristics and the prognosis of PCa was subsequently assessed. Results: CD147was expressed in 51/62 (82.3%) PCa patients and in 2/15 (13.3%) BPH cases. MMP-1, MMP-2 and MMP-9 expression was significantly higher in PCa tissue than in BPH tissue. Using Spearman analysis, a significant positive correlation between CD147 and MMP-1, MMP-2 and MMP-9 expression was found (p <0.05). CD147 and MMP-2 expression was correlated with TMN grade and Gleason score. Patients with concurrent expression of CD147+ and MMP-2+ had the lowest survival (p <0.01). Conclusion: The results suggest that concurrent expression of CD147 and MMP may be an important characteristic of PCa which may help in the prediction of PCa progression.

CD147 and VEGF Expression in Advanced Renal Cell Carcinoma and Their Prognostic Value

Aim: To investigate the clinicopathologic characteristics of extracellular matrix (ECM) metalloproteinase inducer (CD147) and vascular endothelial growth factor (VEGF) expression in advanced renal cell carcinoma (RCC), and to evaluate the clinical significance of these two markers in the prognosis of advanced RCC. Methods: CD147 and VEGF expression in paraffin-embedded specimens gathered from 53 patients with advanced RCC and 12 healthy controls were detected by the method of immunohistochemistry. The Spearman correlation was calculated between the expression levels of CD147 and VEGF in advanced RCC tissues. The association of CD147 and VEGF expression with the clinicopathologic features and prognosis of advanced RCC was subsequently assessed. Results: CD147 and VEGF were positively expressed in 47/53 (88.7%) and 45/53 (84.9%) of patients with advanced RCC, respectively. Positive expression of CD147 (p= 0.02) and VEGF (p< 0.01) was significantly correlated with TNM stage of advanced RCC. A significant correlation was found between the expression of CD147 and VEGF in advanced RCC (r= 0.629, p= 0.04). Additionally, tumor CD147 and tumor VEGF expressions were significantly associated with the prognosis of advanced RCC patients. The survival rate of the patients with CD147−/VEGF− expression was the lowest (p< 0.01), and conjoined expressions of CD147−/VEGF− and CD147+/VEGF+ were independent prognostic indicators of advanced RCC (both p< 0.01). Conclusion: The expression of CD147 or VEGF may be an important feature of advanced RCC. A combined detection of CD147/VEGF coexpression may benefit us in the prediction of the prognosis of advanced RCC.

CD147 expression indicates unfavourable prognosis in prostate cancer.

Extracellular matrix metalloproteinase inducer (EMMPRIN, also named as CD147) is a multifunctional membrane glycoprotein over-expressed in many kinds of human solid tumors. It has been demonstrated to be involved in tumor invasion and angiogenesis. The aim of this study was to analyze the clinicopathological characteristics of the expression of CD147 in human prostate cancer (PCa), and to evaluate its clinical significance in the histologic classification and prognosis of PCa. CD147 protein expression in paraffin-embedded specimens gathered from 62 cases of PCa and 30 cases of benign prostatic hyperplasia (BPH) were detected by the method of immunohistochemistry. The association of CD147 protein expression with the clinicopathological characteristics and with the prognosis of PCa was subsequently assessed. CD147 expression were positively expressed in 51/62 (82.3%) of PCa and 4/30 (13.3%) of BPH cases, respectively. The positive expression rate of CD147 in PCa tissues was significantly higher than that in BPH. The positive expression of CD147 was dramatically associated with TNM grade (p < 0.001), the depth of the prostatic wall invasion (p = 0.008), GLEASON Score (p = 0.001) and Histologic grade (p = 0.001). The patients with CD147 expression were associated with a poor prognosis of PCa (p = 0.01) and the survival rate of the patients with a strong positive expression of CD147 was the lowest (p = 0.01). The results suggest that the expression of CD147 may be an important feature of PCa and the detection of its expression may benefit us in the prediction of the prognosis of PCa.

Adaptive Induction of Growth Differentiation Factor 15 Attenuates Endothelial Cell Apoptosis in Response to High Glucose Stimulus

Growth differentiation factor 15 (GDF15), a direct target gene of p53, is a multifunctional member of the TGF-β/BMP superfamily. GDF15 can be induced and is implicated as a key secretory cytokine in response to multiple cellular stimuli. Accumulating evidence indicates that GDF15 is associated with the development and prognosis of diabetes mellitus, while whether GDF15 can be induced by high glucose is unknown. In the present study, we revealed that high glucose could induce GDF15 expression and secretion in cultured human umbilical vein endothelial cells in a ROS- and p53-dependent manner. Inhibition of high glucose-induced GDF15 expression by siRNA demonstrated that adaptively induced GDF15 played a protective role against high glucose-induced human umbilical vein endothelial cell apoptosis via maintaining the active state of PI3K/Akt/eNOS pathway and attenuating NF-κB/JNK pathway activation. The protective effects of GDF15 were probably achieved by inhibiting ROS overproduction in high glucose-treated human umbilical vein endothelial cells in a negative feedback manner. Our results suggest that high glucose can promote GDF15 expression and secretion in human umbilical vein endothelial cells, which in turn attenuates high glucose-induced endothelial cell apoptosis.

IR-780 Dye for Near-Infrared Fluorescence Imaging in Prostate Cancer

Background The aim of this study was to investigate near-infrared fluorescence (NIRF) imaging as a novel imaging modality that allows for early detection of cancer and real-time monitoring to acquire related information. IR-780 iodide, a lipophilic dye, accumulates selectively in breast cancer cells and drug-resistant human lung cancer cells, with a peak emission at 780 nm that can be easily detected by the NIRF imaging system. The application of IR-780 for prostate cancer imaging was thoroughly investigated to further expand its clinical value. Material/Methods The impact of IR-780 on the survival of prostate cancer cells PC-3 and LNCaP as well as normal prostate epithelial cells RWPE-1 was determined. Duration of IR-780 dye staining was optimized in PC-3 cells. The involvement of specific OATP1B3 inhibitor in the selective accumulation of IR-780 was investigated. IR-780 for prostate cancer imaging was carried out in athymic nude mouse models and, acute toxicity of IR-780 was evaluated. Results IR-780 incubation resulted in a dose-dependent inhibition to cell proliferation. Mean fluorescence intensity of prostate cancer cells peaked at 20-min IR-780 incubation. Specific uptake of IR-780 dye in prostate cancer cells was mainly through the function of OATP1B3. We also demonstrated that NIRF dye effectively identified the subcutaneous prostate cancer xenografts, subsequently confirmed by histological examination. There was no significant impact on the physical activity, weight, and tissue histology of BABL/C mice with 10-fold imaging dose of 1-month IR-780 dye administration. Conclusions NIRF imaging using IR-780 dye is a feasible and practicable method for prostate cancer detection, with potential tumor-killing ability, although more investigations are needed before clinical translation.

Bispecific Antibodies as a Development Platform for New Concepts and Treatment Strategies

With the development of molecular cloning technology and the deep understanding of antibody engineering, there are diverse bispecific antibody formats from which to choose to pursue the optimal biological activity and clinical purpose. The single-chain-based bispecific antibodies usually bridge tumor cells with immune cells and form an immunological synapse because of their relatively small size. Bispecific antibodies in the IgG format include asymmetric bispecific antibodies and homodimerized bispecific antibodies, all of which have an extended blood half-life and their own crystalline fragment (Fc)-mediated functions. Besides retargeting effector cells to the site of cancer, new applications were established for bispecific antibodies. Bispecific antibodies that can simultaneously bind to cell surface antigens and payloads are a very ideal delivery system for therapeutic use. Bispecific antibodies that can inhibit two correlated signaling molecules at the same time can be developed to overcome inherent or acquired resistance and to be more efficient angiogenesis inhibitors. Bispecific antibodies can also be used to treat hemophilia A by mimicking the function of factor VIII. Bispecific antibodies also have broad application prospects in bone disorders and infections and diseases of the central nervous system. The latest developments of the formats and application of bispecific antibodies will be reviewed. Furthermore, the challenges and perspectives are summarized in this review.

α-linolenic acid inhibits human renal cell carcinoma cell proliferation through PPAR-γ activation and COX-2 inhibition

ω-3 fatty acids have potential anticancer effects, and consuming food rich in ω-3 fatty acids reduces the human renal cell carcinoma (RCC) risk. However, the direct effect of ω-3 fatty acids on RCC in vitro is unknown. In the present study, the effects of α-linolenic acid (ALA), an ω-3 fatty acid, were observed on cell proliferation in the RCC cell line OS-RC-2. The activity and gene expression levels of peroxisome proliferator-activated receptor-γ (PPAR-γ) and cyclooxygenase-2 (COX-2) in the OS-RC-2 cells were measured by ELISA and real-time RT-PCR, respectively, following ALA treatment. ALA (20–80 μM) dose-dependently suppressed the proliferation of the OS-RC-2 cells. PPAR-γ activity and gene expression were significantly increased by ALA at 20 and 40 μM. COX-2 activity and gene expression levels were significantly decreased by ALA from 20 μM. Use of purely the PPAR-γ agonist, rosiglitazone, decreased the proliferation of the OS-RC-2 cells, while ALA induced further suppression of cell proliferation in the presence of rosiglitazone. The COX-2 inhibitor N-(3-Pyridyl)indomethacinamide induced further suppression of cell proliferation in the presence of rosiglitazone. N-(3-Pyridyl)indomethacinamide also suppressed the proliferation of the OS-RC-2 cells. In the presence of N-(3-Pyridyl)indomethacinamide, ALA and rosiglitazone further inhibited OS-RC-2 cell proliferation. In conclusion, ALA inhibits the cell proliferation of the OS-RC-2 human RCC cell line. PPAR-γ activation and COX-2 inhibition serve as two signaling pathways for the inhibitory effects of ALA on RCC cell proliferation.

Near‑infrared fluorescence imaging of prostate cancer using heptamethine carbocyanine dyes

Near-infrared fluorescence (NIRF) imaging is an attractive novel modality for the detection of cancer. A previous study defined two organic polymethine cyanine dyes as ideal NIRF probes, IR-783 and its derivative MHI-148, which have excellent optical characteristics, superior biocompatibility and cancer targeting abilities. To investigate the feasibility of NIRF dye-mediated prostate cancer imaging, dye uptake and subcellular co-localization were investigated in PC-3, DU-145 and LNCaP human prostate cancer cells and RWPE-1 normal prostate epithelial cells. Different organic anion transporting peptide (OATP) inhibitors were utilized to explore the potential role of the OATP subtype, including the nonspecific OATP inhibitor bromosulfophthalein, the OATP1 inhibitor 17β-estradiol, the selective OATP1B1 inhibitor rifampicin and the selective OATP1B3 inhibitor cholecystokinin octapeptide. NIRF dyes were also used for the simulated detection of circulating tumor cells and the rapid detection of prostate cancer in human prostate cancer tissues and prostate cancer xenografts in mouse models. The results revealed that the cancer-specific uptake of these organic dyes in prostate cancer cells occurred primarily via OATP1B3. A strong NIRF signal was detected in prostate cancer tissues, but not in normal tissues that were stained with IR-783. Prostate cancer cells were recognized with particular NIR fluorescence in isolated mononuclear cell mixtures. The results of the present study demonstrated that NIRF dye-mediated imaging is a feasible and practicable method for prostate cancer detection, although further investigative studies are required before clinical translation.