The role of von Willebrand factor in breast cancer metastasis

ADAMTS-13 Prevents VWF-Mediated Gastric Cancer Metastasis

BACKGROUND

Gastric cancer invades local tissue extensively and metastasizes through the circulation to remote organs. Patients with metastasized gastric cancer have poor clinical outcomes. The vasculature in the cancer niche is developed poorly, thus allowing cancer cells to be released into the circulation. However, it is poorly understood how cancer cells adhere to and transmigrate through the fully developed endothelium in remote organs and what key adhesive ligands are involved in the process. Here, we report results from a study designed to investigate the role of hyperadhesive VWF (von Willebrand factor) in promoting the pulmonary metastasis of gastric cancer.

METHODS

We used mouse models to investigate the roles of hyperadhesive VWF in the pulmonary metastasis of gastric cancer. The findings from these mouse models were validated through in vitro experiments that specifically examined how VWF promoted gastric cancer-derived extracellular vesicles to activate endothelial cells and analyzed established databases of patients with gastric cancer.

RESULTS

VWF in cancer-bearing mice became hyperadhesive and mediated the adhesion of gastric cancer-derived extracellular vesicles to the endothelium, where gastric cancer-derived extracellular vesicles caused endothelial permeability and promoted the transmigration of cancer cells to the interstitial tissue of the lungs. Reducing VWF adhesive activity by the metalloprotease ADAMTS-13 (A disintegrin and metalloprotease with thrombospondin type motifs, type 13) prevented the pulmonary metastasis of gastric cancer cells in mice. We further validated the findings in mice through targeted in vitro experiments and by associating VWF with the outcomes of patients with gastric cancer through established databases of patients with gastric cancer using bioinformatics tools.

CONCLUSIONS

We show how VWF becomes hyperadhesive to promote the pulmonary metastasis of gastric cancer through its interaction with gastric cancer-derived extracellular vesicles and that the hyperadhesive activity of VWF is reduced by ADAMTS-13 to prevent the metastasis.

Tumour cell-induced platelet aggregation in breast cancer: Scope of metal nanoparticles

Breast cancer is a major cause of cancer-related mortality among the female population worldwide. Among the various factors promoting breast cancer metastasis, the role of cancer-cell platelet interactions leading to tumour cell-induced platelet aggregation (TCIPA) has garnered significant attention recently. Our state-of-the-art literature review verifies the implications of metal nanoparticles in breast cancer research and TCIPA-specific breast cancer metastasis. We have evaluated in vitro and in vivo research data as well as clinical investigations within the scope of this topic presented in the last ten years. Nanoparticle-based drug delivery platforms in cancer therapy can combat the growing concerns of multi-drug resistance, the alarming rates of chemotherapy-induced toxicities and cancer progression. Metal nanoparticles conjugated with chemotherapeutics can outperform their free drug counterparts in achieving targeted drug delivery and desired drug concentration inside the tumour tissue with minimal toxic effects. Existing data highlights the potential of metal nanoparticles as a promising tool for targeting the platelet-specific interactions associated with breast cancer metastasis including TCIPA.

Identification of cancer-associated fibroblast subtypes and prognostic model development in breast cancer: role of the RUNX1/SDC1 axis in promoting invasion and metastasis

In this study, we identified cancer-associated fibroblast (CAF) molecular subtypes and developed a CAF-based prognostic model for breast cancer (BRCA). The heterogeneity of cancer-associated fibroblasts (CAFs) and their significant involvement in the advancement of BRCA were discovered employing single-cell RNA sequencing. Notably, we discovered that the RUNX1/SDC1 axis enhances BRCA cell invasion and metastasis. RUNX1 transcriptionally upregulates SDC1, which facilitates extracellular matrix remodeling and promotes tumor cell migration. This finding highlights the vital contribution of CAFs to the tumor microenvironment and provides new potential targets for therapeutic intervention. The predictive model showcased remarkable precision in anticipating patient outcomes and could guide personalized treatment strategies.

Experimental and in silico analysis of LINC01279 expression in tumor of patients with breast cancer

Breast cancer (BC) is characterized by the increase of malignant cells in the breast. The malignant cells begin in the lining of the breast milk glands or ducts (ductal epithelium). BC is the most frequent cancer in women, but it may also occur in males. Long non-coding RNAs (lncRNA) have been demonstrated to control the development and incidence of cancer. However, some lncRNAs experience potential changes in BC, but their role has not been well studied. LINC01279 is known as a valuable biomarker in gastric cancer but has not yet been studied in BC. Changes in LINC01279 expression levels in BC samples were investigated by microarray. Q-PCR was also used to evaluate the expression of LINC01279 in the tumor and normal adjacent samples of 30 BC patients. The LINC01279 co-expressed gene module was discovered using weighted gene correlation network analysis (WGCNA) on the relevant dataset. The top ten hub genes were determined using gene ontology (GO) functional enrichments on the co-expressed gene module. The results of the bioinformatics study showed an increase in LINC01279 expression levels (log2FC = 3.228749561, adj.P.Val = 1.69E - 12) in tumor samples compared to normal marginal tissue. Q-PCR results also showed a significant increase in LINC01279 expression (P-value = 0.0005) in tumor samples. WGCNA analysis identified that the black module is the LINC01279 co-expressed module, and functional annotation analysis of black module genes enriched in significant cancer-related pathways and processes, including cell growth and/or maintenance, regulation of immune response, regulation of cell proliferation, and epithelial-to-mesenchymal transition (EMT). Regarding the real-time PCR results, the analysis of expression patterns has illuminated a distinct association between the heightened expression levels of LINC01279, and the stages of cancer progression as well as the metastatic potential of tumors. However, intriguingly, our observations have failed to reveal any statistically significant correlations between the relative expression of LINC01279 and tumor grade classification, or the presence of ER, PR, and HER2 biomarkers. The present study could provide a new perspective on the molecular regulatory. Processes associated with BC pathogenic mechanisms are linked to the LINC01279, although further research is needed on the possible role of this lncRNA in BC.

Systematic screening of protein-coding gene expression identified VWF as a potential key regulator in anthracycline-based chemotherapy-exacerbated metastasis of breast cancer

BACKGROUND

Breast cancer is the most commonly diagnosed cancer worldwide. Although major treatments represented by chemotherapy have shown effectiveness at the initial period, recurrence and metastasis still occur later after treatments. The alternation of the tumor microenvironment by chemotherapy is confirmed as a trigger of the elevated proliferation and migration of the remaining tumor cells.

METHODS

Using bioinformatic methods, differential gene expression analysis was used to determine DEGs between post-chemotherapy and pre-chemotherapy samples of breast cancer patients, followed by survival analysis and ELISA analysis of the potential key genes. An in vitro model of 2 breast cancer cells lines was used to demonstrate the role of VWF in the evasion and migration of breast cancer cells, using cell migration, evasion and wound healing assays, PCR and molecular docking analysis.

RESULTS

19 hub genes were further identified using GO and KEGG pathway analyses and WGCNA. The 5 secreted protein-coding genes with reported carcinogenesis effects (VWF, SVEP1, DPT, ADIPOQ, and LPL) were further analyzed in breast cancer patients and VWF was identified as a potential key regulator in the anthracycline-based chemotherapy-exacerbated metastasis. It was further confirmed that anthracycline-based chemotherapeutics doxorubicin exacerbated VWF upregulation and the evasion and migration of breast cancer cells. Based on molecular docking analysis and previous study, berberine was used as an inhibitor of VWF, and showed an effective inhibition of the doxorubicin-exacerbated VWF upregulation, migration and evasion in breast cancer.

CONCLUSIONS

Doxorubicin-exacerbated evasion and migration through VWF upregulation. Berberine as an inhibitor of VWF was able to reversed the doxorubicin-exacerbated VWF upregulation and evasion and migration in breast cancer cells.

FOXK2 amplification promotes breast cancer development and chemoresistance

Oncogene activation through DNA amplification or overexpression is a crucial driver of cancer initiation and progression. The FOXK2 gene, located on chromosome 17q25, encodes a transcription factor with a forkhead DNA-binding domain. Analysis of genomic datasets reveals that FOXK2 is frequently amplified and overexpressed in breast cancer, correlating with poor patient survival. Knockdown of FOXK2 significantly inhibited breast cancer cell proliferation, migration, anchorage-independent growth, and delayed tumor growth in a xenograft mouse model. Additionally, inhibiting FOXK2 sensitized breast cancer cells to chemotherapy. Co-overexpression of FOXK2 and mutant PI3KCA transformed non-tumorigenic MCF-10A cells, suggesting a role for FOXK2 in PI3KCA-driven tumorigenesis. CCNE2, PDK1, and ESR1 were identified as transcriptional targets of FOXK2 in MCF-7 cells. Small-molecule inhibitors of CCNE2/CDK2 (dinaciclib) and PDK1 (dichloroacetate) exhibited synergistic anti-tumor effects with PI3KCA inhibitor (alpelisib) in vitro. Inhibition of FOXK2 by dinaciclib synergistically enhanced the anti-tumor effects of alpelisib in a xenograft mouse model. Collectively, these findings highlight the oncogenic function of FOXK2 and suggest that FOXK2 and its downstream genes represent potential therapeutic targets in breast cancer.

Identifying the key hub genes linked with lung squamous cell carcinoma by examining the differentially expressed and survival genes

Lung Squamous Cell Carcinoma is characterised by significant alterations in RNA expression patterns, and a lack of early symptoms and diagnosis results in poor survival rates. Our study aimed to identify the hub genes involved in LUSC by differential expression analysis and their influence on overall survival rates in patients. Thus, identifying genes with the potential to serve as biomarkers and therapeutic targets. RNA sequence data for LUSC was obtained from TCGA and analysed using R Studio. Survival analysis was performed on DE genes. PPI network and hub gene analysis was performed on survival-relevant genes. Enrichment analysis was conducted on the PPI network to elucidate the functional roles of hub genes. Our analysis identified 2774 DEGs in LUSC patient datasets. Survival analysis revealed 511 genes with a significant impact on patient survival. Among these, 20 hub genes-FN1, ACTB, HGF, PDGFRB, PTEN, SNAI1, TGFBR1, ESR1, SERPINE1, THBS1, PDGFRA, VWF, BMP2, LEP, VTN, PXN, ABL1, ITGA3 and ANXA5-were found to have lower expression levels associated with better patient survival, whereas high expression of SOX2 correlated with longer survival. Enrichment analysis indicated that these hub genes are involved in critical cellular and cancer-related pathways. Our study has identified six key hub genes that are differentially expressed and exhibit significant influence over LUSC patient survival outcomes. Further, in vitro and in vivo studies must be conducted on the key genes for their utilisation as therapeutic targets and biomarkers in LUSC.

Numerical study of ultra-large von Willebrand factor multimers in coagulopathy

An excessive von Willebrand factor (VWF) secretion, coupled with a moderate to severe deficiency of ADAMTS13 activity, serves as a linking mechanism between inflammation to thrombosis. The former facilitates platelet adhesion to the vessel wall and the latter is required to cleave VWF multimers. As a result, the ultra-large VWF (UL-VWF) multimers released by Weibel-Palade bodies remain uncleaved. In this study, using a computational model based on first principles, we quantitatively show how the uncleaved UL-VWF multimers interact with the blood cells to initiate microthrombosis. We observed that platelets first adhere to unfolded and stretched uncleaved UL-VWF multimers anchored to the microvessel wall. By the end of this initial adhesion phase, the UL-VWF multimers and platelets make a mesh-like trap in which the red blood cells increasingly accumulate to initiate a gradually growing microthrombosis. Although high-shear rate and blood flow velocity are required to activate platelets and unfold the UL-VWFs, during the initial adhesion phase, the blood velocity drastically drops after thrombosis, and as a result, the wall shear stress is elevated near UL-VWF roots, and the pressure drops up to 6 times of the healthy condition. As the time passes, these trends progressively continue until the microthrombosis fully develops and the effective size of the microthrombosis and these flow quantities remain almost constant. Our findings quantitatively demonstrate the potential role of UL-VWF in coagulopathy.

Integrative epigenome-transcriptome analysis unravels cancer-specific over-expressed genes potentially regulating immune microenvironment in clear cell renal cell carcinoma

BACKGROUND

Clear cell Renal Cell Carcinoma (ccRCC) is the frequently diagnosed histological life-threatening tumor subtype in the urinary system. Integrating multi-omics data is emerging as a tool to provide a comprehensive view of biology and disease for better therapeutic interventions.

METHOD

We have integrated freely available ccRCC data sets of genome-wide DNA methylome, transcriptome, and active histone modification marks, H3K27ac, H3K4me1, and H3K4me3 specific ChIP-seq data to screen genes with higher expression. Further, these genes were filtered based on their effect on survival upon alteration in expression.

RESULTS

The six multi-omics-based identified genes, RUNX1, MSC, ADA, TREML1, TGFA, and VWF, showed higher expression with enrichment of active histone marks and hypomethylated CpG in ccRCC. In continuation, the identified genes were validated by an independent dataset and showed a correlation with nodal and metastatic status. Furthermore, gene ontology and pathway analysis revealed that immune-related pathways are activated in ccRCC patients.

CONCLUSIONS

The network analysis of six overexpressed genes suggests their potential role in an immunosuppressive environment, leading to tumor progression and poor prognosis. Our study shows that the multi-omics approach helps unravel complex biology for patient subtyping and proposes combination strategies with epi-drugs for more precise immunotherapy in ccRCC.

Small Extracellular Vesicle-Derived vWF Induces a Positive Feedback Loop between Tumor and Endothelial Cells to Promote Angiogenesis and Metastasis in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a hypervascular malignancy by which its growth and dissemination are largely driven by the modulation of tumor-derived small extracellular vesicles (sEVs). Proteomic profiling of circulating sEVs of control individuals and HCC patients identifies von Willibrand factor (vWF) to be upregulated progressively along HCC stages. Elevated sEV-vWF levels are found in a larger cohort of HCC-sEV samples and metastatic HCC cell lines compared to their respective normal counterparts. Circulating sEVs of late-stage HCC patients markedly augment angiogenesis, tumor-endothelial adhesion, pulmonary vascular leakiness, and metastasis, which are significantly compromised by anti-vWF antibody. The role of vWF is further corroborated by the enhanced promoting effect of sEVs collected from vWF-overexpressing cells. sEV-vWF modulates endothelial cells through an elevated level of vascular endothelial growth factor A (VEGF-A) and fibroblast growth factor 2 (FGF2). Mechanistically, secreted FGF2 elicits a positive feedback response in HCC via the FGFR4/ERK1 signaling pathway. The co-administration of anti-vWF antibody or FGFR inhibitor significantly improves the treatment outcome of sorafenib in a patient-derived xenograft mouse model. This study reveals mutual stimulation between HCC and endothelial cells by tumor-derived sEVs and endothelial angiogenic factors, facilitating angiogenesis and metastasis. It also provides insights into a new therapeutic strategy involving blocking tumor-endothelial intercellular communication.

Quantifiable peptide library bridges the gap for proteomics based biomarker discovery and validation on breast cancer

Mass spectrometry (MS) based proteomics is widely used for biomarker discovery. However, often, most biomarker candidates from discovery are discarded during the validation processes. Such discrepancies between biomarker discovery and validation are caused by several factors, mainly due to the differences in analytical methodology and experimental conditions. Here, we generated a peptide library which allows discovery of biomarkers in the equal settings as the validation process, thereby making the transition from discovery to validation more robust and efficient. The peptide library initiated with a list of 3393 proteins detectable in the blood from public databases. For each protein, surrogate peptides favorable for detection in mass spectrometry was selected and synthesized. A total of 4683 synthesized peptides were spiked into neat serum and plasma samples to check their quantifiability in a 10 min liquid chromatography-MS/MS run time. This led to the PepQuant library, which is composed of 852 quantifiable peptides that cover 452 human blood proteins. Using the PepQuant library, we discovered 30 candidate biomarkers for breast cancer. Among the 30 candidates, nine biomarkers, FN1, VWF, PRG4, MMP9, CLU, PRDX6, PPBP, APOC1, and CHL1 were validated. By combining the quantification values of these markers, we generated a machine learning model predicting breast cancer, showing an average area under the curve of 0.9105 for the receiver operating characteristic curve.

Tumor educated platelet: the novel BioSource for cancer detection

Platelets, involved in the whole process of tumorigenesis and development, constantly absorb and enrich tumor-specific substances in the circulation during their life span, thus called "Tumor Educated Platelets" (TEPs). The alterations of platelet mRNA profiles have been identified as tumor markers due to the regulatory mechanism of post-transcriptional splicing. Small nuclear RNAs (SnRNAs), the important spliceosome components in platelets, dominate platelet RNA splicing and regulate the splicing intensity of pre-mRNA. Endogenous variation at the snRNA levels leads to widespread differences in alternative splicing, thereby driving the development and progression of neoplastic diseases. This review systematically expounds the bidirectional tumor-platelets interactions, especially the tumor induced alternative splicing in TEP, and further explores whether molecules related to alternative splicing such as snRNAs can serve as novel biomarkers for cancer diagnostics.

Vascular endothelial-derived Von Willebrand factor inhibits lung cancer progression through the αvβ3/ERK1/2 axis

Lung cancer remains a common malignant tumor causing death due to the rapid industrialization and serious pollution of the environment. The Von Willebrand Factor (vWF) protein is an endothelial marker and is widely used to diagnose cancer and other inflammations, however its exact mechanism of action remains largely unexplored. In particular, how it plays two opposing roles in tumor development is not clear. Our study aimed to the impact of endothelial-derived vWF on tumor development by co-culturing human umbilical vein endothelial cells (HUVECs) with lung cancer cells (95D and A549). A knockdown of endothelial-derived vWF assisted lung cancer cell in proliferation, migration and inhibited apoptosis in vitro, while overexpression of endothelial-derived vWF inhibited the proliferation, migration and induced apoptosis of lung cancer cells. The results of further experiments indicated that the vWF secreted by endothelial cells could affect lung cancer cell migration and apoptosis via its binding to integrin αvβ3 on the surface of lung cancer cells. Furthermore, a novel finding was the fact that endothelial-derived vWF inhibited lung cancer cell apoptosis by phosphorylating ERK1/2. At the same time, we established experimental lung metastasis model and xenograft model in normal mice and vWF^-/- mice, and found that knockout of vWF in mice significantly promoted lung cancer growth and metastasis. In conclusion, our research found that endothelial-derived vWF could directly combine to αvβ3 on the exterior of A549 and 95D, thereby mediating lung cancer proliferation, migration and apoptosis and inhibiting the development of lung cancer.

Extracellular vesicles, hyperadhesive von willebrand factor, and outcomes of gastric cancer: a clinical observational study

Von Willebrand factor (VWF) is an adhesive ligand critical for maintaining hemostasis. However, it has also been increasingly recognized for its role in cancer development because it has been shown to mediate the adhesion of cancer cells to endothelial cells, promote the epithelial-mesenchymal transition, and enhance angiogenesis. We have previously shown that gastric cancer cells synthesize VWF, which mediates the interaction between the cancer and endothelial cells to promote cancer growth. Here, we report results from a clinical observational study that demonstrate the association of VWF in plasma and on the surface of extracellular vesicles (EVs) with the pathological characteristics of gastric cancer. We found that patients with gastric cancer had elevated and intrinsically hyperadhesive VWF in their peripheral blood samples. VWF was detected on the surface of EVs from cancer cells, platelets, and endothelial cells. Higher levels of these VWF-bound EVs were associated with cancer aggression and poor clinical outcomes for patients. These findings suggest that VWF⁺ EVs from different cell types serve collectively as a new class of biomarkers for the outcome assessment of gastric cancer patients.

Efficacy of digital breast tomosynthesis combined with magnetic resonance imaging in the diagnosis of early breast cancer

BACKGROUND

The incidence and mortality rate of breast cancer in China rank 120^th and 163^rd, worldwide, respectively. The incidence of breast cancer is on the rise; the risk increases with age but is slightly reduced after menopause. Early screening, diagnosis, and timely determination of the best treatment plan can ensure clinical efficacy and prognosis.

AIM

To evaluate the clinical value of magnetic resonance imaging (MRI) combined with digital breast tomosynthesis (DBT) in diagnosing early breast cancer and the effect of breast-conserving surgery by arc incision.

METHODS

This study was divided into two parts. Firstly, 110 patients with early breast cancer confirmed by pathological examination and 110 with benign breast diseases diagnosed simultaneously in Changzhi People’s Hospital of Shanxi Province and Shanxi Dayi Hospital from May 2019 to September 2020 were included in the breast cancer group and the benign group, respectively. Both groups underwent DBT and MRI examination, and the pathological results were used as the gold standard to evaluate the effectiveness of the combined application of DBT and MRI in the diagnosis of early breast cancer. Secondly, according to the operation method, 110 patients with breast cancer were divided into either a breast-conserving group (69 patients) or a modified radical mastectomy group (41 patients). The surgical effect, cosmetic effect, and quality of life of the two groups were compared.

RESULTS

Among the 110 cases of breast cancer, 66 were of invasive ductal carcinoma (60.00%), and 22 were of ductal carcinoma in situ (20.00%). Among the 110 cases of benign breast tumors, 55 were of breast fibromas (50.00%), and 27 were of breast adenosis (24.55%). The sensitivity, specificity, and area under the curve (AUC) of DBT in the differential diagnosis of benign and malignant breast tumors were 73.64%, 84.55%, and 0.791, respectively. The sensitivity, specificity, and AUC of MRI in the differential diagnosis of benign and malignant breast tumors were 84.55%, 85.45%, and 0.850, respectively. The sensitivity, specificity, and AUC of DBT combined with MRI in the differential diagnosis of benign and malignant breast tumors were 97.27%, 93.64%, and 0.955, respectively. The blood loss, operation time and hospitalization time of the breast-conserving group were significantly lower than those of the modified radical treatment group, and the difference was statistically significant (P < 0.05). After 3 mo of observation, the breast cosmetic effect of the breast-conserving group was better than that of the modified radical group, and the difference was statistically significant (P < 0.05). Before surgery, the quality-of-life scores of the breast-conserving and modified radical mastectomy groups did not differ (P > 0.05). Three months after surgery, the quality-of-life scores in both groups were higher than those before surgery (P < 0.05), and the quality-of-life score of the breast-conserving group was higher than that of the modified radical group (P < 0.05). In the observation of tumor recurrence rate two years after the operation, four patients in the breast-conserving group and one in the modified radical treatment group had a postoperative recurrence. There was no significant difference in the recurrence rate between the two groups (χ² = 0.668, P = 0.414 > 0.05).

CONCLUSION

MRI combined with DBT in diagnosing early breast cancer can significantly improve the diagnostic efficacy compared with the two alone. Breast-conserving surgery leads to better cosmetic breast effects and reduces the impact of surgery on postoperative quality of life.

Cancer Stem Cells and the Tumor Microenvironment: Targeting the Critical Crosstalk through Nanocarrier Systems

The physiological state of the tumor microenvironment (TME) plays a central role in cancer development due to multiple universal features that transcend heterogeneity and niche specifications, like promoting cancer progression and metastasis. As a result of their preponderant involvement in tumor growth and maintenance through several microsystemic alterations, including hypoxia, oxidative stress, and acidosis, TMEs make for ideal targets in both diagnostic and therapeutic ventures. Correspondingly, methodologies to target TMEs have been investigated this past decade as stratagems of significant potential in the genre of focused cancer treatment. Within targeted oncotherapy, nanomedical derivates-nanocarriers (NCs) especially-have emerged to present notable prospects in enhancing targeting specificity. Yet, one major issue in the application of NCs in microenvironmental directed therapy is that TMEs are too broad a spectrum of targeting possibilities for these carriers to be effectively employed. However, cancer stem cells (CSCs) might portend a solution to the above conundrum: aside from being quite heavily invested in tumorigenesis and therapeutic resistance, CSCs also show self-renewal and fluid clonogenic properties that often define specific TME niches. Further scrutiny of the relationship between CSCs and TMEs also points towards mechanisms that underly tumoral characteristics of metastasis, malignancy, and even resistance. This review summarizes recent advances in NC-enabled targeting of CSCs for more holistic strikes against TMEs and discusses both the current challenges that hinder the clinical application of these strategies as well as the avenues that can further CSC-targeting initiatives. Central role of CSCs in regulation of cellular components within the TME.

Heparan sulfate dependent binding of plasmatic von Willebrand factor to blood circulating melanoma cells attenuates metastasis

Heparan sulfate (HS), a highly negatively charged glycosaminoglycan, is ubiquitously present in all tissues and also exposed on the surface of mammalian cells. A plethora of molecules such as growth factors, cytokines or coagulation factors bear HS binding sites. Accordingly, HS controls the communication of cells with their environment and therefore numerous physiological and pathophysiological processes such as cell adhesion, migration, and cancer cell metastasis. In the present work, we found that HS exposed by blood circulating melanoma cells recruited considerable amounts of plasmatic von Willebrand factor (vWF) to the cellular surface. Analyses assisted by super-resolution microscopy indicated that HS and vWF formed a tight molecular complex. Enzymatic removal of HS or genetic engineering of the HS biosynthesis showed that a reduced length of the HS chains or complete lack of HS was associated with significantly reduced vWF encapsulation. In microfluidic experiments, mimicking a tumor-activated vascular system, we found that vWF-HS complexes prevented vascular adhesion. In line with this, single molecular force spectroscopy suggested that the vWF-HS complex promoted the repulsion of circulating cancer cells from the blood vessel wall to counteract metastasis. Experiments in wild type and vWF knockout mice confirmed that the HS-vWF complex at the melanoma cell surface attenuated hematogenous metastasis, whereas melanoma cells lacking HS evade the anti-metastatic recognition by vWF. Analysis of tissue samples obtained from melanoma patients validated that metastatic melanoma cells produce less HS. Transcriptome data further suggest that attenuated expression of HS-related genes correlate with metastases and reduced patients' survival. In conclusion, we showed that HS-mediated binding of plasmatic vWF to the cellular surface can reduce the hematogenous spread of melanoma. Cancer cells with low HS levels evade vWF recognition and are thus prone to form metastases. Therefore, therapeutic expansion of the cancer cell exposed HS may prevent tumor progression.

The genomic landscape of pediatric renal cell carcinomas

Pediatric renal cell carcinomas (RCC) differ from their adult counterparts not only in histologic subtypes but also in clinical characteristics and outcome. However, the underlying biology is still largely unclear. For this reason, we performed whole-exome and transcriptome sequencing analyses on a cohort of 25 pediatric RCC patients with various histologic subtypes, including 10 MiT family translocation (MiT) and 10 papillary RCCs. In this cohort of pediatric RCC, we find only limited genomic overlap with adult RCC, even within the same histologic subtype. Recurrent somatic mutations in genes not previously reported in RCC were detected, such as in CCDC168, PLEKHA1, VWF, and MAP3K9. Our papillary pediatric RCCs, which represent the largest cohort to date with comprehensive molecular profiling in this age group, appeared as a distinct genomic subtype differing in terms of gene mutations and gene expression patterns not only from MiT-RCC but also from their adult counterparts.

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WES and RNA-seq of 25 pediatric RCCs with various histologic subtypes

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Detected only limited genomic overlap with adult RCC

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Revealed recurrent somatic mutations in genes not previously reported in RCC

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Discovery of a CRK-PITPNA fusion gene in a pediatric papillary RCC

The Intriguing Connections between von Willebrand Factor, ADAMTS13 and Cancer

von Willebrand factor (VWF) is a complex and large protein that is cleaved by ADAMTS13 (a disintegrin and metalloproteinase with thrombospondin type 1 motif, member 13), and together they serve important roles in normal hemostasis. Malignancy can result in both a deficiency or excess of VWF, leading to aberrant hemostasis with either increased bleeding or thrombotic complications, as respectively seen with acquired von Willebrand syndrome and cancer-associated venous thromboembolism. There is emerging evidence to suggest VWF also plays a role in inflammation, angiogenesis and tumor biology, and it is likely that VWF promotes tumor metastasis. High VWF levels have been documented in a number of malignancies and in some cases correlate with more advanced disease and poor prognosis. Tumor cells can induce endothelial cells to release VWF and certain tumor cells have the capacity for de novo expression of VWF, leading to a proinflammatory microenvironment that is likely conducive to tumor progression, metastasis and micro-thrombosis. VWF can facilitate tumor cell adhesion to endothelial cells and aids with the recruitment of platelets into the tumor microenvironment, where tumor/platelet aggregates are able to form and facilitate hematogenous spread of cancer. As ADAMTS13 moderates VWF level and activity, it too is potentially involved in the pathophysiology of these events. VWF and ADAMTS13 have been explored as tumor biomarkers for the detection and prognostication of certain malignancies; however, the results are underdeveloped and so currently not utilized for clinical use. Further studies addressing the basic science mechanisms and real word epidemiology are required to better appreciate the intriguing connections between VWF, ADAMTS13 and malignancy. A better understanding of the role VWF and ADAMTS13 play in the promotion and inhibition of cancer and its metastasis will help direct further translational studies to aid with the development of novel cancer prognostic tools and treatment modalities.

Platelet Membrane: An Outstanding Factor in Cancer Metastasis

In addition to being biological barriers where the internalization or release of biomolecules is decided, cell membranes are contact structures between the interior and exterior of the cell. Here, the processes of cell signaling mediated by receptors, ions, hormones, cytokines, enzymes, growth factors, extracellular matrix (ECM), and vesicles begin. They triggering several responses from the cell membrane that include rearranging its components according to the immediate needs of the cell, for example, in the membrane of platelets, the formation of filopodia and lamellipodia as a tissue repair response. In cancer, the cancer cells must adapt to the new tumor microenvironment (TME) and acquire capacities in the cell membrane to transform their shape, such as in the case of epithelial−mesenchymal transition (EMT) in the metastatic process. The cancer cells must also attract allies in this challenging process, such as platelets, fibroblasts associated with cancer (CAF), stromal cells, adipocytes, and the extracellular matrix itself, which limits tumor growth. The platelets are enucleated cells with fairly interesting growth factors, proangiogenic factors, cytokines, mRNA, and proteins, which support the development of a tumor microenvironment and support the metastatic process. This review will discuss the different actions that platelet membranes and cancer cell membranes carry out during their relationship in the tumor microenvironment and metastasis.