Spatial and single-cell colocalisation analysis reveals MDK-mediated immunosuppressive environment with regulatory T cells in colorectal carcinogenesis

BACKGROUND

Cell-cell interaction factors that facilitate the progression of adenoma to sporadic colorectal cancer (CRC) remain unclear, thereby hindering patient survival.

METHODS

We performed spatial transcriptomics on five early CRC cases, which included adenoma and carcinoma, and one advanced CRC. To elucidate cell-cell interactions within the tumour microenvironment (TME), we investigated the colocalisation network at single-cell resolution using a deep generative model for colocalisation analysis, combined with a single-cell transcriptome, and assessed the clinical significance in CRC patients.

FINDINGS

CRC cells colocalised with regulatory T cells (Tregs) at the adenoma-carcinoma interface. At early-stage carcinogenesis, cell-cell interaction inference between colocalised adenoma and cancer epithelial cells and Tregs based on the spatial distribution of single cells highlighted midkine (MDK) as a prominent signalling molecule sent from tumour epithelial cells to Tregs. Interaction between MDK-high CRC cells and SPP1+ macrophages and stromal cells proved to be the mechanism underlying immunosuppression in the TME. Additionally, we identified syndecan4 (SDC4) as a receptor for MDK associated with Treg colocalisation. Finally, clinical analysis using CRC datasets indicated that increased MDK/SDC4 levels correlated with poor overall survival in CRC patients.

INTERPRETATION

MDK is involved in the immune tolerance shown by Tregs to tumour growth. MDK-mediated formation of the TME could be a potential target for early diagnosis and treatment of CRC.

FUNDING

Japan Society for the Promotion of Science (JSPS) Grant-in-Aid for Science Research; OITA Cancer Research Foundation; AMED under Grant Number; Japan Science and Technology Agency (JST); Takeda Science Foundation; The Princess Takamatsu Cancer Research Fund.

MDK induces temozolomide resistance in glioblastoma by promoting cancer stem-like properties

Glioblastoma (GBM) is the most frequently observed and aggressive type of high-grade malignant glioma. Temozolomide (TMZ) is the primary agent for GBM treatment. However, TMZ resistance remains a major challenge. In this study, we report that MDK is overexpressed in GBM, which leads to enhanced proliferation, apoptosis inhibition, increased invasion and TMZ resistance in GBM cells. It was also determined that MDK could significantly improve the stem-like properties of GBM cells. Mechanistically, MDK enhanced p-JNK through Notch1 and subsequently increased the expression of stemness markers, such as CD133 and Nanog, thereby promoting TMZ resistance. Finally, xenograft experiments and clinical sample analysis also demonstrated that MDK knockdown could significantly inhibit tumor growth in vivo, and the expression of MDK was positively correlated with Notch1, p-JNK and CD133. This study revealed that MDK induces TMZ resistance by improving the stem-like properties of GBM by upregulating the Notch1/p-JNK signaling pathway, which provides a possible target for therapeutic intervention of GBM, especially in TMZ-resistant GBM with high MDK expression.

Midkine promotes glioblastoma progression via PI3K-Akt signaling

Background

Our previous bioinformatics-based study found that midkine (MDK) was associated with poor prognosis of glioblastoma (GBM). However, the mechanism of MDK in GBM remains elusive.

Methods

A public GBM-related dataset and GBM tissues from our center were used validate the aberrant expression of MDK in GBM at the RNA and protein levels. The relationship between MDK expression and survival of GBM patients was also explored through survival analysis. Subsequently, we identified MDK-related GBM-specific genes using differential expression analysis. Functional enrichment analyses were performed to reveal their potential biological functions. CCK-8, 5-ethynyl-2′-deoxyuridine, and Matrigel-transwell assays were performed in GBM cell lines in which MDK was knocked out or overexpressed in order assess the effects of MDK on proliferation, migration, and invasion of GBM cells. Western blotting was performed to detect candidate proteins.

Results

Our study showed MDK is a promising diagnostic and prognostic biomarker for GBM because it is highly expressed in the disease and it is associated with poor prognosis. MDK is involved in various cancer-related pathways, such as PI3K-Akt signaling, the cell cycle, and VEGF signaling. A comprehensive transcriptional regulatory network was constructed to show the potential pathways through which MDK may be involved in GBM. In vitro, Overexpression of MDK augmented proliferation, migration, and invasion of GBM cell lines, whereas suppression of MDK led to the opposite effects. Furthermore, our study confirmed that MDK promotes the progression of GBM by activating the PI3K-Akt signaling pathway.

Conclusions

Our present study proposes that MDK promotes GBM by activating the PI3K-Akt signaling pathway, and it describes a potential regulatory network involved.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02212-3.

Comparison of diagnostic accuracy of Midkine and AFP for detecting hepatocellular carcinoma: a systematic review and meta-analysis

Objective: Midkine (MDK) has been proposed as one of the most promising markers for hepatocellular carcinoma (HCC). This meta-analysis was conducted to compare the diagnostic accuracy of MDK and α-fetoprotein (AFP) for HCC.

Methods: We systematically searched PubMed/MEDLINE, Ovid/EMBASE, and the Cochrane Library for all relevant studies up to 18 May 2019. The Revised Quality Assessment for Studies of Diagnostic Accuracy tool (QUADAS-2) was used to assess the methodological quality of the included studies. The sensitivity, specificity, and the area under the curve (AUC) of MDK and AFP for detecting HCC were pooled using random-effects model.

Results: Seventeen studies from five articles with a total of 1122 HCC patients and 2483 controls were included. The summary estimates using MDK and AFP for detecting HCC were as follows: sensitivity, 85 vs 52%, specificity, 82 vs 94%, and AUC, 0.90 vs 0.83. The summary estimates using MDK and AFP for detecting hepatitis virus-related HCC as follows: sensitivity, 93 vs 74%, specificity, 85 vs 97%, and AUC, 0.95 vs 0.97. The summary estimates using MDK and AFP for detecting early-stage HCC were as follows: sensitivity, 83.5 vs 44.4%, specificity, 81.7 vs 84.8%, and AUC, 0.87 vs 0.52. The summary estimates using MDK for detecting AFP-negative HCC as follows: sensitivity, 88.5%, specificity, 83.9%, and AUC, 0.91.

Conclusion: MDK is more accurate than AFP in diagnosing HCC, especially for early-stage HCC and AFP-negative HCC. Both MDK and AFP had excellent diagnostic performance for hepatitis virus-related HCC.

Most-Probable-Number-Based Minimum Duration of Killing Assay for Determining the Spectrum of Rifampicin Susceptibility in Clinical Mycobacterium tuberculosis Isolates

Accurate antibiotic susceptibility testing is essential for successful tuberculosis treatment. Recent studies have highlighted the limitations of MIC-based phenotypic susceptibility methods in detecting other aspects of antibiotic susceptibilities in bacteria. Duration and peak of antibiotic exposure, at or above the MIC required for killing the bacterial population, has emerged as another important factor for determining antibiotic susceptibility. This is broadly defined as antibiotic tolerance.

Accurate antibiotic susceptibility testing is essential for successful tuberculosis treatment. Recent studies have highlighted the limitations of MIC-based phenotypic susceptibility methods in detecting other aspects of antibiotic susceptibilities in bacteria. Duration and peak of antibiotic exposure, at or above the MIC required for killing the bacterial population, has emerged as another important factor for determining antibiotic susceptibility. This is broadly defined as antibiotic tolerance. Antibiotic tolerance can further facilitate the emergence of antibiotic resistance. Currently, there are limited methods to quantify antibiotic tolerance among clinical M. tuberculosis isolates. In this study, we develop a most-probable-number (MPN)-based minimum duration of killing (MDK) assay to quantify the spectrum of M. tuberculosis rifampicin susceptibility within subpopulations based on the duration of rifampicin exposure required for killing the bacterial population. MDK₉₀–₉₉ and MDK_99.99 were defined as the minimum duration of antibiotic exposure at or above the MIC required for killing 90 to 99% and 99.99% of the initial (pretreatment) bacterial population, respectively. Results from the rifampicin MDK assay applied to 28 laboratory and clinical M. tuberculosis isolates showed that there is variation in rifampicin susceptibility among isolates. The rifampicin MDK_99/99.99 time for isolates varied from less than 2 to 10 days. MDK was correlated with larger subpopulations of M. tuberculosis from clinical isolates that were rifampicin tolerant. Our study demonstrates the utility of MDK assays to measure the variation in antibiotic tolerance among clinical M. tuberculosis isolates and further expands clinically important aspects of antibiotic susceptibility testing.

MicroRNA-188 inhibits biological activity of lung cancer stem cells through targeting MDK and mediating the Hippo pathway

New Findings

What is the central question of this study?

The aim was to investigate the function of microRNA‐188 in the biological characteristics of lung cancer stem cells and the molecular mechanisms involved.

What is the main finding and its importance?

This study highlights a new molecular mechanism involving microRNA‐188, MDK and the Hippo signalling pathway that plays a suppressive role in biological activity of lung cancer stem cells. This finding might offer new insights into gene‐based therapy for lung cancer.

Abstract

MicroRNAs (miRNAs) have been implicated in lung cancer and reported as new promising diagnostic and therapeutic tools for cancer control. Here, we investigated the action of microRNA‐188 (miR‐188) in lung cancer stem cells. We first tested miR‐188 expression in clinical samples of lung cancer patients, and a low expression profile of miR‐188 was found. Next, we analysed the role of miR‐188 in lung cancer stem cells with cell growth assays. To verify the in vitro results, we used a xenograft model to validate the capability of miR‐188 in tumorigenesis. Overexpression of miR‐188 reduced viability and metastasis of cancer stem cells. Similar results were reproduced in vivo, where overexpression of miR‐188 retarded tumour growth in mice. We also identified MDK as a target of miR‐188, and overexpression of MDK was found in lung cancer samples. Overexpressed MDK promoted the malignant behaviours of lung cancer stem cells. In addition, the Hippo pathway was found to be inactivated in lung cancer tissues, presenting as increased levels of YAP and TAZ. Suppression of the Hippo pathway also enhanced lung cancer stem cell activity and promoted the growth of xenograft tumours. To sum up, our results reveal that miR‐188 inhibits the malignant behaviours of lung cancer stem cells and the growth of xenograft tumours. This study might offer new insights into gene‐based therapies for cancer.

The Long Noncoding RNA ZFAS1 Potentiates the Development of Hepatocellular Carcinoma via the microRNA-624/MDK/ERK/JNK/P38 Signaling Pathway

Background

A long noncoding RNA (lncRNA), ZNFX1 antisense RNA 1 (ZFAS1), was increased in multiple cancers, including hepatocellular carcinoma (HCC), resulting in malignancy development and progression. However, the mechanisms involving the interaction between ZFAS1 and microRNA-624 (miRNA-624) remain largely unknown. Therefore, the goal of this study was to probe the functional role of ZFAS1 in the development of HCC and its underlying mechanism.

Methods

Firstly, differentially expressed lncRNAs in HCC tissues were screened out by microarray. Subsequently, the prognostic effect of ZFAS1 patients with HCC was analyzed by the Kaplan-Meier analysis and The Cancer Genome Atlas database. ZFAS1 regulation on miRNA-624 was determined after si-ZFAS1 and/or miRNA-624 inhibitor were transfected into HepG2 and SMMC7721 cell lines. Finally, the effects of ZFAS1 on the growth and metastasis of HCC were observed by in vivo tumorigenesis and metastasis tests.

Results

ZFAS1 was overexpressed in HCC tissues and cells and indicated worse prognosis and shorter survival in patients with HCC. Silencing of ZFAS1 inhibited the malignancy of HCC cells, but miR-624 inhibitor could partially reverse the repressive role of si-ZFAS1. Moreover, ZFAS1 induced the extracellular-regulated protein kinases/c-Jun N-terminal kinase (ERK/JNK)/P38 pathway by binding to midkine (MDK) through miR-624, thus promoting the occurrence of HCC.

Conclusion

Collectively, ZFAS1 depletion inhibited the occurrence of HCC by downregulating the MDK/ERK/JNK/P38 pathway through restoring miR-624 expression. Inhibition of ZFAS1 may act as an innovative target to suppress occurrence in HCC.

MiR-326 targets MDK to regulate the progression of cardiac hypertrophy through blocking JAK/STAT and MAPK signaling pathways

Cardiac hypertrophy is a heart reaction to the increase of cardiac load, with the characteristics of increased expression of cardiac hypertrophy markers, enhanced protein synthesis, and enlarged cell area. However, molecular mechanisms in cardiac hypertrophy are still poorly substantiated. It has been reported that miRNAs can modulate human diseases, among which miR-326 has been reported as a biological regulator in human cancers, but its role in cardiac hypertrophy is rarely explored. This study focused on the exploration of the potential of miR-326 in cardiac hypertrophy. Our data revealed the downregulation of miR-326 in the TAC-induced hypertrophic mice and the Ang II-induced hypertrophic H9c2 cells. Functionally, miR-326 attenuated the effect of Ang II on cardiac hypertrophy in vitro. In addition, miR-326 negatively regulated JAK/STAT and MAPK signaling pathways. Mechanistically, miR-326 targeted and inhibited MDK to induce JAK/STAT and MAPK pathways. Rescue assays certified that miR-326 attenuated cardiac hypertrophy through targeting MDK and inhibiting JAK/STAT and MAPK signaling pathways. In brief, our study unveiled that miR-326 targets MDK to regulate the progression of cardiac hypertrophy through blocking JAK/STAT and MAPK signaling pathways, indicating that targeting miR-326 as a potential approach for cardiac hypertrophy treatment.

Exosomal miR-9 inhibits angiogenesis by targeting MDK and regulating PDK/AKT pathway in nasopharyngeal carcinoma

Background

Exosomes are small vesicles containing a wide range of functional proteins, mRNA and miRNA. Exosomal miRNAs from cancer cells play crucial roles in mediating cell-cell communication and tumor-microenvironment cross talk, specifically in enabling metastasis and promoting angiogenesis. We focused on miR-9 that was identified as a tumor suppressor previously in nasopharyngeal carcinoma (NPC) tumorigenesis.

Methods

Differential centrifugation, transmission electron microscopy and nanoparticle tracking analysis were used to isolate and identify exosomes. Quantitative PCR and western blotting analysis were used to detect miR-9, pri-miR-9, CD63, TSG101, MDK, P70S6K P-Ser424 and PDK1 P-Ser241 expression. Laser confocal microscopy was used to trace exosomal miR-9 secreted by NPC cells into HUVECs. The effect of exosomal miR-9 on cell migration and tube formation of HUVECs in vivo and vitro was assessed by using migration assay, tube formation assay and matrigel plug assay, respectively. Bioinformatics analysis and luciferase reporter assay were utilized to confirm the binding of exosomal miR-9 to the 3′untranslated region (3′-UTR) of MDK, while Phosphorylation Array was performed to identify AKT Pathway in HUVECs treated with exosomal miR-9. Furthermore, Immunohistochemistry (IHC) and in situ hybridization (ISH) was used to detected miR-9, CD31 and MDK expression in human NPC tumor samples.

Results

NPC cells transfected with miR-9-overexpressing lentivirus, released miR-9 in exosomes. Exosomal miR-9 directly suppressed its target gene - MDK in endothelial cells. Mechanistic analyses revealed that exosomal miR-9 from NPC cells inhibited endothelial tube formation and migration by targeting MDK and regulating PDK/AKT signaling pathway. Additionally, the level of MDK was upregulated in NPC tumor samples and was positively correlated with microvessel density. Notably, the level of exosomal miR-9 was positively correlated with overall survival, and MDK overexpression was positively associated with poor prognosis in NPC patients, suggesting the clinical relevance and prognostic value of exosomal miR-9 and MDK.

Conclusions

Taken together, our data identify an extracellular anti-angiogenic role for tumor-derived, exosome-associated miR-9 in NPC tumorigenesis and prompt further investigation into exosome-based therapies for cancer treatment.

Electronic supplementary material

The online version of this article (10.1186/s13046-018-0814-3) contains supplementary material, which is available to authorized users.

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.