Validation of the diagnostic utility of urinary midkine for the detection of bladder cancer

Midkine-Notch2 Pathway Mediates Excessive Proliferation of Airway Smooth Muscle Cells in Chronic Obstructive Lung Disease

Inflammation-induced proliferation of airway smooth muscle cells (ASMCs) and subsequent airway remodeling is a hallmark of chronic obstructive lung disease (COPD). The role of midkine (MK) in COPD is unclear. In this work, we explored the role of MK-Notch2 signaling in COPD by inhibiting the expression of MK using lentivirus shRNA in ASMCs in vitro and instillation of AAV9-MK in the airway of a COPD rat model in vivo. The results demonstrated that LPS decreased ASMC migration and proliferation, increased apoptosis and induced the expression of MK and Notch2 signaling molecules. Inhibition of MK exacerbated the changes in migration and proliferation but decreased the expression of MK and Notch2 signaling molecules. Rats treated with smoke fumigation and LPS showed features of COPD. The small airways of COPD rats were remodeled and lung function was significantly reduced. The expressions of TGF-β, ICAM-1, HA, MMP-9, PC-III, and LN in BALF and the expression of MK and Notch2 signaling molecules were significantly increased in the COPD rats compared with controls. Inhibition of MK reversed these changes. In conclusion, the MK-Notch2 pathway plays a key role in airway remodeling induced by ASMC proliferation. Targeting the MK-Notch2 pathway may be a new strategy for improving airway remodeling and preventing progressive decline of pulmonary function in COPD.

Serum midkine levels for the diagnosis and assessment of response to interventional therapy in patients with hepatocellular carcinoma

Objective

To explore the clinical significance of serum midkine (MDK) levels for the diagnosis of hepatocellular carcinoma (HCC) and evaluate the efficacy of interventional therapy.

Methods

Eighty-four patients with HCC were enrolled in this retrospective study. They received an interventional treatment. A follow-up was performed every 2 months, using magnetic resonance imaging, to determine whether the treatment should be continued. Serum alpha-fetoprotein (AFP) and MDK levels were measured at the first diagnosis and during the follow-ups, and the HCC detection rates based on the cutoff values of these two measurements were compared. The relationships between AFP and MDK and the clinical tumor characteristics and changes in APK and MDK before and after treatment were also compared using a rank sum test and χ² test, respectively. The prognostic significance of MDK for HCC was determined through regression analysis. A two-sided P ​< ​0.05 was considered statistically significant.

Results

MDK expression was detected in 95.24% of the cases. Subgroup analysis revealed MDK expression in 95.35%, 95.12%, 85.19%, 86.67%, and 83.33% of the AFP-positive, AFP-negative, stage A Barcelona clinic liver cancer (BCLC-A), BCLC-A/AFP-positive, and BCLC-A/AFP-negative cases, respectively. MDK expression after the interventional treatment (66.7%) was significantly lower than that before the treatment (95.2%). The mean post-treatment MDK level was 0.67 ​ng/mL in patients with a positive response to therapy as compared with 3.66 ​ng/mL in those with no positive response. All patients were followed up for 18 months, and those positive for MDK expression before the intervention were more likely to relapse than patients without MDK expression. Subgroup analysis revealed the highest recurrence rate for patients who were positive for MDK expression before and after treatment.

Conclusions

Serum MDK may serve as a powerful complement to AFP in the diagnosis of HCC. MDK measurement may improve the detection rate of BCLC-A and AFP-negative HCC. Serum MDK may help to determine the vascular invasion and poor clinical staging of HCC tumors. Patients with MDK-positive HCC before treatment may be more prone to postoperative tumor progression.

Noninvasive Urine-Based Tests to Diagnose or Detect Recurrence of Bladder Cancer

Liquid biopsies are increasingly used for the diagnosis and follow-up of cancer patients. Urine is a body fluid that can be used to detect cancers and others diseases. It is noninvasive and easy to collect. To detect Bladder Cancer (BC), cytology is the first assay used. It is an effective way to detect high grade BC but has a high rate of equivocal results, especially for low grade BC. Furthermore, cystoscopy is used to confirm cytology results and to determine cancer status. Cystoscopy is also effective but highly invasive, and not well accepted by patients, especially for BC follow-up. In this review we survey the numerous assays recently developed in order to diagnose BC at an early stage, and to facilitate the follow-up of patients. We discuss their effectiveness, ease of use, and applications. Finally, we discuss assays that, in the future, could improve the diagnosis and management of BC patients.

Discovery of Novel Protein Biomarkers in Urine for Diagnosis of Urothelial Cancer Using iTRAQ Proteomics

Urothelial carcinoma (UC) is the ninth most prevalent malignancy worldwide. Noninvasive and efficient biomarkers with high accuracy are imperative for the surveillance and diagnosis of UC. CKD patients were enrolled as a control group in this study for the discovery of highly specific urinary protein markers of UC. An iTRAQ-labeled quantitative proteomic approach was used to discover novel potential markers. These markers were further validated with 501 samples by ELISA assay, and their diagnostic accuracies were compared to those of other reported UC markers. BRDT, CYBP, GARS, and HDGF were identified as novel urinary UC biomarkers with a high discrimination ability in a population comprising CKD and healthy subjects. The diagnostic values of the four novel UC markers were better than that of a panel of well-known or FDA-approved urinary protein markers CYFR21.1, Midkine, and NUMA1. Three of our discovered markers (BRDT, HDGF, GARS) and one well-known marker (CYFR21.1) were finally selected and combined as a marker panel having AUC values of 0.962 (95% CI, 0.94-0.98) and 0.860 (95% CI, 0.83-0.89) for the discrimination between UC and normal groups and UC and control (healthy + CKD) groups, respectively.

Midkine (MDK) growth factor: a key player in cancer progression and a promising therapeutic target

Midkine is a heparin-binding growth factor, originally reported as the product of a retinoic acid-responsive gene during embryogenesis, but currently viewed as a multifaceted factor contributing to both normal tissue homeostasis and disease development. Midkine is abnormally expressed at high levels in various human malignancies and acts as a mediator for the acquisition of critical hallmarks of cancer, including cell growth, survival, metastasis, migration, and angiogenesis. Several studies have investigated the role of midkine as a cancer biomarker for the detection, prognosis, and management of cancer, as well as for monitoring the response to cancer treatment. Moreover, several efforts are also being made to elucidate its underlying mechanisms in therapeutic resistance and immunomodulation within the tumor microenvironment. We hereby summarize the current knowledge on midkine expression and function in cancer development and progression, and highlight its promising potential as a cancer biomarker and as a future therapeutic target in personalized cancer medicine.

The Role of Midkine in Arteriogenesis, Involving Mechanosensing, Endothelial Cell Proliferation, and Vasodilation

Mechanical forces in blood circulation such as shear stress play a predominant role in many physiological and pathophysiological processes related to vascular responses or vessel remodeling. Arteriogenesis, defined as the growth of pre-existing arterioles into functional collateral arteries compensating for stenosed or occluded arteries, is such a process. Midkine, a pleiotropic protein and growth factor, has originally been identified to orchestrate embryonic development. In the adult organism its expression is restricted to distinct tissues (including tumors), whereby midkine is strongly expressed in inflamed tissue and has been shown to promote inflammation. Recent investigations conferred midkine an important function in vascular remodeling and growth. In this review, we introduce the midkine gene and protein along with its cognate receptors, and highlight its role in inflammation and the vascular system with special emphasis on arteriogenesis, particularly focusing on shear stress-mediated vascular cell proliferation and vasodilatation.

Effect of midkine on gemcitabine resistance in biliary tract cancer

Gemcitabine-based chemotherapy is one of the most effective and commonly used chemotherapeutic regimens for biliary tract cancer (BTC). However, development of resistance to this drug limits its efficacy. The present study aimed to explore the effects of midkine (MDK) on the resistance of BTC cells to gemcitabine. Cell viability and proliferation were measured by a Cell Counting Kit-8 assay and 5-ethynyl-2′-deoxyuridine staining, respectively. Western blot analysis was used to detect the expression of E-cadherin and vimentin. The results indicated that BTC cell lines were more resistant to gemcitabine plus MDK compared with gemcitabine alone. In terms of the underlying mechanism, MDK promoted the epithelial to mesenchymal transition (EMT) of BTC cells and the enhancing effect of MDK on gemcitabine resistance was abrogated when the EMT was blocked with small interfering (si)RNA targeting Twist. In addition, MDK promoted the expression of Notch-1, while knockdown of Notch-1 by siRNA blocked the EMT process in the BTC cell lines. Taken together, these results indicated that MDK promoted gemcitabine resistance of BTC through inducing EMT via upregulating Notch-1. It was suggested that inhibition of the EMT is a promising strategy to overcome MDK-induced drug resistance.

Prognostic value of Midkine expression in patients with solid tumors: a systematic review and meta-analysis

Background

Accumulated studies have shown the important role of Midkine (MDK) protein in various solid tumors and indicated its correlation with patients' survival. This meta-analysis was performed to further explore the prognostic value of MDK expression in solid tumors.

Materials and Methods

We collected the literatures through searching PubMed, Embase and the Cochrane Library (last up to April 10, 2017) to assess the effect of MDK on survival in solid tumor patients. The STATA 12.0 software was used for the meta-analysis. Fixed-effects models or random-effects models were used to estimate the pooled hazard ratios (HRs) for overall survival (OS).

Results

A total of 2097 patients from 17 observational studies were summarized. High expression of MDK was notably associated with worse OS in solid tumor patients. (pooled HR = 1.96; 95% CI = 1.67-2.31). The subgroup analysis of tumor type demonstrated negative impact of elevated MDK on OS in most solid tumor patients (P < 0.05), while MDK had no relevance with OS in the patients with OSCC (pooled HR = 1.68; 95% CI = 0.84-3.36; P = 0.145) or HNSCC (pooled HR = 1.56; 95% CI = 0.96-2.51; P = 0.075).

Conclusions

The present meta-analysis clarifies that MDK is a potential prognostic biomarker in solid tumor patients. Future large-scale prospective clinical trials are needed to determine the prognostic value of MDK in solid tumor patients.