Midkine mRNA level in peripheral blood mononuclear cells is a novel biomarker for primary non-small cell lung cancer: a prospective study

[Expression of circRNA_051778 in Lung Adenocarcinoma-Associated Malignant and Tuberculous Pleural Effusions and Its Clinical Significance]

Objective

To investigate the expression and clinical significance of circular RNA (circRNA) 051778 in lung adenocarcinoma-malignant pleural effusion (LA-MPE) and tuberculous pleural effusion (TPE).

Methods

This is a cross-sectional study. A total of 212 patients were recruited from the Jiangxi Chest Hospital between October 2018 and September 2019, and their pleural effusion samples and/or plasma samples were collected. The exosomal circRNA profile was sketched by circRNA microarray. Differentially expressed circRNAs (DECs) were verified by droplet digital PCR. In addition, a putative circRNA-miRNA-mRNA network was constructed, and Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were performed to predict the functions of the DECs. The diagnostic value of circRNA_051778 was evaluated by binary logistic regression and receiver operating characteristic curve.

Results

The expression level of circRNA_051778 in the LA-MPE samples was (3.92±0.48) copies/100 ng cDNA, while that in the TPE samples was (21.53±2.22) copies/100 ng cDNA. Compared to that in the TPE samples, circRNA_051778 was significantly downregulated in the LA-MPE samples (P<0.001). The potential targets of circRNA_051778 were enriched in positive regulation of GTPase activity, cytoplasm, protein binding, and cancer-related pathways. The area under the curve (AUC) for the combined assessment of circRNA_051778 with liquid-based thin-layer cytology (TCT), erythrocyte sedimentation rate (ESR), and tuberculosis antibody (TBA) was 0.98 (95% confidence interval: 0.97-1.00), with the sensitivity being 88.0% and the specificity being 100.0%.

Conclusion

Exosomal circRNA_051778 is downregulated in LA-MPE. According to the findings from the GO and KEGG analyses, exosomal circRNA_051778 may play a role in cancer development and has the potential to serve as a marker for differential diagnostic of LA-MPE and TPE when it is used in combination with TCT, ESR, and TBA.

PBMCs: a new source of diagnostic and prognostic biomarkers

There are various types of molecular biomarkers that are derived from distinct starting materials. Although many indirect biomarkers are found in blood, their detection remains a challenging issue because of the high degree of fragmentation, minute quantity and a vast amount of non-specific background. The present review points out the sensitivity and specificity of peripheral blood mononuclear cells (PBMCs) as an intact source of biomarkers in a variety of diseases. Multiple recent studies that have used PBMCs as a source of biomarkers reveal the alteration of mRNAs/microRNAs (miRNAs) signature and methylation profile in many kinds of disorders; for instance, dysregulation of mRNAs/miRNAs in schizophrenia, diabetes and different types of cancers and change in the methylation status of LINE-1 in neoplasms. In conclusion with a strong probability, PBMCs mimic conditions of some tissues which are in contact with them like the tumour cells, hence providing a non-invasive and suitable source of biomarkers.

Available active surveillance follow-up protocols for small renal mass: a systematic review

PURPOSE

To evaluate follow-up strategies for active surveillance of renal masses and to assess contemporary data.

METHODS

We performed a comprehensive search of electronic databases (Embase, Medline, and Cochrane). A systematic review of the follow-up protocols was carried out. A total of 20 studies were included.

RESULT

Our analysis highlights that most of the series used different protocols of follow-up without consistent differences in the outcomes. Most common protocol consisted in imaging and clinical evaluation at 3, 6, and 12 months and yearly thereafter. Median length of follow-up was 42 months (range 1-137). Mean age was 74 years (range 67-83). Of 2243 patients 223 (10%) died during the follow-up and 19 patients died of kidney cancer (0.8%). The growth rate was the most used parameter to evaluate disease progression eventually triggering delayed intervention. Maximal axial diameter was the most common method to evaluate growth rate. CT scan is the most used, probably because it is usually more precise than kidney ultrasound and more accessible than MRI. Performing chest X-ray at every check does not seem to alter the clinical outcome during AS.

CONCLUSION

The minimal cancer-specific mortality does not seem to correlate with the follow-up scheme. Outside of growth rate and initial size, imaging features to predict outcome of RCC during AS are limited. Active surveillance of SRM is a well-established treatment option. However, standardized follow-up protocols are lacking. Prospective, randomized, trials to evaluate the best follow-up strategies are pending.

Midkine Is a Potential Urinary Biomarker for Non-Invasive Detection of Bladder Cancer with Microscopic Hematuria

BACKGROUND

To determine the role of Midkine (MDK) in non-invasive detection of bladder cancer (Bca) and the relationship with Ki67.

METHODS

Sixty-five Bca patients and 55 non-Bca patients or healthy volunteers were enrolled and voided urine samples were prospectively obtained on the first day of enrollment. Tissue samples were collected by surgery. MDK and Ki67 expressions were analyzed by immunohistochemistry and Western Blot (WB). Specificity and sensitivity of MDK mRNA testing in the detection of Bca were determined by Receiver Operating Characteristic curve (ROC). The relationship between MDK and Ki67 was also assessed.

RESULTS

MDK was overexpressed in Bca tissues than that in the non-cancer tissues. The specificity and sensitivity for MDK mRNA testing in urine in the identification of Bca was 80% and 72.3%. MDK detected 85.7% of high-grade tumors, 87.5% of muscle-invasive tumors and 79.4% of tumors larger than 3 cm in patients without gross hematuria. Microscopic hematuria may even increase the detection rate of Bca by MDK testing. Furthermore, the correlation of MDK and Ki67 was found positive.

CONCLUSION

MDK was overexpressed in Bca tissues and positively correlated with Ki67. MDK might be a potential biomarker for the detection of Bca, especially for those without gross hematuria but with microscopic hematuria.

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.

Midkine is up-regulated in both cancerous and inflamed bowel, reflecting lymph node metastasis in colorectal cancer and clinical activity of ulcerative colitis

Midkine is a multifunctional cytokine and growth factor displaying proinflammatory and pro-tumorigenic activity. Its association with bowel diseases has not been fully elucidated. Our purpose was to delineate midkine expression pattern by RT-qPCR in inflamed/cancerous bowel (n=208) and whole blood (n=150) in colorectal cancer (CRC), Crohn's disease (CD), and ulcerative colitis (UC) and to evaluate midkine dynamics in early postoperative period following colorectal surgery. The expression of midkine was significantly up-regulated in stage III CRC and independently associated with lymph node metastasis. The expression of midkine in whole blood was up-regulated solely in N1 CRC. Midkine expression in cancer-free tissue (CRC) was also elevated and dependent on CRC advancement. In IBD, inflammation increased the bowel expression of midkine solely in UC, in a manner proportional to the disease clinical activity. Large and small bowel differed with respect to the expression of midkine in quiescent tissue (higher in small bowel) and to its correlation pattern with chemokines (in a large bowel) and angiogenic factors and cell cycle regulators (in a small bowel). Circulating midkine and its expression in whole blood dropped directly following colorectal surgery; however, the concentration of midkine in serum was restored on postoperative day three. Midkine is involved in bowel inflammation in UC and lymph node metastasis in CRC, rendering midkine an attractive target for their treatment. Owing to midkine elevation in early postoperative period and its overexpression in tumor-adjacent tissue, targeting midkine might be considered also as a prevention of CRC recurrence following curative tumor resection.

MDK Protein Overexpression Correlates with the Malignant Status and Prognosis of Non-small Cell Lung Cancer

BACKGROUND AND AIMS

Midkine (MDK) is a heparin-binding growth factor and is overexpressed in various types of human cancer. However, little is known about the clinical significance of MDK in non-small cell lung cancer (NSCLC). The aim of this study was to measure MDK protein levels in patients with NSCLC and to explore its clinical significance.

METHODS

The expression status of MDK in NSCLC at Gene Expression Omnibus (GEO accession number: GSE19804) was observed. The expression of MDK mRNA and protein was examined in NSCLC tissues and normal lung tissues through real-time PCR and Western blot. Meanwhile, the relationship of MDK protein expression levels with clinical characteristics of 186 NSCLC patients was analyzed by immunohistochemistry.

RESULTS

MDK expression was increased in NSCLC tissues compared with paired normal lung tissues in microarray data (GSE19804). MDK mRNA and protein expression were obviously increased in NSCLC tissues than in paired adjacent normal lung tissues. Using immunohistochemistry, MDK protein overexpression was positively correlated with status of clinical stage, T classification, N classification, and M classification in NSCLC patients. In survival analysis, patients with higher MDK protein expression had a significantly shorter overall survival time than did patients with lower MDK protein expression. Multivariate analysis indicated that the MDK protein overexpression was an independent poor prognostic indicator for patients with NSCLC.

CONCLUSIONS

MDK plays an important role in NSCLC progression and prognosis and may act as a convincing prognostic indicator for NSCLC patients.

The clinical and prognostic significance of midkine in breast cancer patients

Midkine overexpression has been shown to be a tumor biomarker in several types of human cancer, but little is known about the clinical significance of midkine in breast cancer patients. The aim of this study was to analyze the expression of midkine in breast cancer and its correlation with clinicopathological characteristics, including breast cancer patient's survival. The expression status of midkine in breast cancer from Gene Expression Omnibus (GEO accession number: GDS3853) was observed initially. Furthermore, the expression of midkine messenger RNA (mRNA) and protein was examined in breast cancer and normal mammary tissues through real-time PCR and immunohistochemistry. Moreover, the relationship of midkine protein expression with clinical characteristics of 170 breast cancer patients was analyzed by immunohistochemistry. In our results, midkine was up-expressed in breast cancer tissues compared with normal mammary tissues in microarray data (GDS3853). Midkine mRNA and protein expression was significantly increased in breast cancer tissues than in normal mammary tissues. By immunohistochemistry, high levels of midkine protein were positively associated with the status of clinical stage, T classification, N classification, and M classification in breast cancer patients. Furthermore, midkine overexpression was an independent poor prognostic indicator for the survival of patients with breast cancer. In conclusion, overexpression of midkine protein serves as an unfavorable prognostic biomarker in breast cancer patients.

Transcriptional factor specificity protein 1 (SP1) promotes the proliferation of glioma cells by up-regulating midkine (MDK)

Midkine (MDK) expression is associated with the proliferation of many cancers, including glioma. However, the upstream signaling that leads to MDK accumulation remains elusive. This study investigates the molecular mechanism that induces MDK overexpression in human glioma. The Repository for Molecular Brain Neoplasia Data was analyzed to identify potential MDK regulators. Expression of MDK and specificity protein 1 (SP1) was compared in glioma specimens. Chromatin immunoprecipitation assay was used to confirm the transcriptional regulation. MDK-force-expressed, SP1-silenced glioma cells were used to test rescue effects in vitro and in vivo. MDK and SP1 expression in gliomas was significantly higher than in adjacent tissues and was positively correlated in glioma clinical samples and cell lines. The promoter of the human MDK gene has a putative SP1 binding site. SP1 binds to the promoter of the MDK gene and directly regulates MDK expression. MDK or SP1 gene silencing inhibited the proliferation of glioma cells and reduced the tumor volume in nude mice. Overexpression of MDK in SP1-silenced cells could partially rescue the SP1 inhibition effects in vivo and in vitro. SP1 directly up-regulated the expression of MDK, and the SP1-MDK axis cooperated in glioma tumorigenesis.

Overexpression of Wilms tumor 1 gene as a negative prognostic indicator in acute myeloid leukemia

Chromosomal aberrations are useful in assessing treatment options and clinical outcomes of acute myeloid leukemia (AML) patients. However, 40 ∼ 50% of the AML patients showed no chromosomal abnormalities, i.e., with normal cytogenetics aka the CN-AML patients. Testing of molecular aberrations such as FLT3 or NPM1 can help to define clinical outcomes in the CN-AML patients but with various successes. Goal of this study was to test the possibility of Wilms' tumor 1 (WT1) gene overexpression as an additional molecular biomarker. A total of 103 CN-AML patients, among which 28% had overexpressed WT1, were studied over a period of 38 months. Patient's response to induction chemotherapy as measured by the complete remission (CR) rate, disease-free survival (DFS) and overall survival (OS) were measured. Our data suggested that WT1 overexpression correlated negatively with the CR rate, DFS and OS. Consistent with previous reports, CN-AML patients can be divided into three different risk subgroups based on the status of known molecular abnormalities, i.e., the favorable (NPM1(mt)/no FLT3(ITD)), the unfavorable (FLT3(ITD)) and the intermediate risk subgroups. The WT1 overexpression significantly reduced the CR, DFS and OS in both the favorable and unfavorable groups. As the results, patients with normal WT1 gene expression in the favorable risk group showed the best clinical outcomes and all survived with complete remission and disease-free survival over the 37 month study period; in contrast, patients with WT1 overexpression in the unfavorable risk group displayed the worst clinical outcomes. WT1 overexpression by itself is an independent and negative indicator for predicting CR rate, DFS and OS of the CN-AML patients; moreover, it increases the statistical power of predicting the same clinical outcomes when it is combined with the NPM1(mt) or the FLT3(ITD) genotypes that are the good or poor prognostic markers of CN-AML.