Identification of cytokeratin24 as a tumor suppressor for the management of head and neck cancer

Proteome Profiling of Brain Vessels in a Mouse Model of Cerebrovascular Pathology

Cerebrovascular pathology that involves altered protein levels (or signaling) of the transforming growth factor beta (TGFβ) family has been associated with various forms of age-related dementias, including Alzheimer disease (AD) and vascular cognitive impairment and dementia (VCID). Transgenic mice overexpressing TGFβ1 in the brain (TGF mice) recapitulate VCID-associated cerebrovascular pathology and develop cognitive deficits in old age or when submitted to comorbid cardiovascular risk factors for dementia. We characterized the cerebrovascular proteome of TGF mice using mass spectrometry (MS)-based quantitative proteomics. Cerebral arteries were surgically removed from 6-month-old-TGF and wild-type mice, and proteins were extracted and analyzed by gel-free nanoLC-MS/MS. We identified 3602 proteins in brain vessels, with 20 demonstrating significantly altered levels in TGF mice. For total and/or differentially expressed proteins (p ≤ 0.01, ≥ 2-fold change), using multiple databases, we (a) performed protein characterization, (b) demonstrated the presence of their RNA transcripts in both mouse and human cerebrovascular cells, and (c) demonstrated that several of these proteins were present in human extracellular vesicles (EVs) circulating in blood. Finally, using human plasma, we demonstrated the presence of several of these proteins in plasma and plasma EVs. Dysregulated proteins point to perturbed brain vessel vasomotricity, remodeling, and inflammation. Given that blood-isolated EVs are novel, attractive, and a minimally invasive biomarker discovery platform for age-related dementias, several proteins identified in this study can potentially serve as VCID markers in humans.

Construction of a CCL20-centered circadian-signature based prognostic model in cervical cancer

BACKGROUND

Rather low vaccination rates for Human papillomavirus (HPV) and pre-existing cervical cancer patients with limited therapeutic strategies ask for more precise prognostic model development. On the other side, the clinical significance of circadian clock signatures in cervical cancer lacks investigation.

METHODS

Subtypes classification based upon eight circadian clock core genes were implemented in TCGA-CESC through k-means clustering methods. Afterwards, KEGG, GO and GSEA analysis were conducted upon differentially expressed genes (DEGs) between high and low-risk groups, and tumor microenvironment (TME) investigation by CIBERSORT and ESTIMATE. Furthermore, a prognostic model was developed by cox and lasso regression methods, and verified in GSE44001 by time-dependent receiver-operating characteristic curve (ROC) analysis. Lastly, FISH and IHC were used for validation of CCL20 expression in patients' specimens and U14 subcutaneous tumor models were built for TME composition.

RESULTS

We successfully classified cervical patients into high-risk and low-risk groups based upon circadian-oscillation-signatures. Afterwards, we built a prognostic risk model composed of GJB2, CCL20 and KRT24 with excellent predictive value on patients' overall survival (OS). We then proposed metabolism unbalance, especially for glycolysis, and immune related pathways to be major enriched signatures between the high-risk and low-risk groups. Then, we proposed an 'immune-desert'-like suppressive myeloid cells infiltration pattern in high-risk group TME and verified its resistance to immunotherapies. Finally, CCL20 was proved positively correlated with real-world patients' stages and induced significant less CD8⁺ T cells and more M2 macrophages infiltration in mouse model.

CONCLUSIONS

We unraveled a prognostic risk model based upon circadian oscillation and verified its solidity. Specifically, we unveiled distinct TME immune signatures in high-risk groups.

Effect of the Rho-Kinase/ROCK Signaling Pathway on Cytoskeleton Components

The mechanical properties of cells are important in tissue homeostasis and enable cell growth, division, migration and the epithelial-mesenchymal transition. Mechanical properties are determined to a large extent by the cytoskeleton. The cytoskeleton is a complex and dynamic network composed of microfilaments, intermediate filaments and microtubules. These cellular structures confer both cell shape and mechanical properties. The architecture of the networks formed by the cytoskeleton is regulated by several pathways, a key one being the Rho-kinase/ROCK signaling pathway. This review describes the role of ROCK (Rho-associated coiled-coil forming kinase) and how it mediates effects on the key components of the cytoskeleton that are critical for cell behaviour.

Impact of Secretion-Active Osteoblast-Specific Factor 2 in Promoting Progression and Metastasis of Head and Neck Cancer

Treatment success of head and neck cancer (HNC) is still hampered by tumor relapse due to metastases. Our study aimed to identify biomarkers by exploiting transcriptomics profiles of patient-matched metastases, primary tumors, and normal tissue mucosa as well as the TCGA HNC cohort data sets. Analyses identified osteoblast-specific factor 2 (OSF-2) as significantly overexpressed in lymph node metastases and primary tumors compared to normal tissue. High OSF-2 levels correlate with metastatic disease and reduced overall survival of predominantly HPV-negative HNC patients. No significant correlation was observed with tumor localization or therapy response. These findings were supported by the fact that OSF-2 expression was not elevated in cisplatin-resistant HNC cell lines. OSF-2 was strongly expressed in tumor-associated fibroblasts, suggesting a tumor microenvironment-promoting function. Molecular cloning and expression studies of OSF-2 variants from patients identified an evolutionary conserved bona fide protein secretion signal (1MIPFLPMFSLLLLLIVNPINA21). OSF-2 enhanced cell migration and cellular survival under stress conditions, which could be mimicked by the extracellular administration of recombinant protein. Here, OSF-2 executes its functions via ß1 integrin, resulting in the phosphorylation of PI3K and activation of the Akt/PKB signaling pathway. Collectively, we suggest OSF-2 as a potential prognostic biomarker and drug target, promoting metastases by supporting the tumor microenvironment and lymph node metastases survival rather than by enhancing primary tumor proliferation or therapy resistance.

IsoMAG-An Automated System for the Immunomagnetic Isolation of Squamous Cell Carcinoma-Derived Circulating Tumor Cells

BACKGROUND

detailed information about circulating tumor cells (CTCs) as an indicator of therapy response and cancer metastasis is crucial not only for basic research but also for diagnostics and therapeutic approaches. Here, we showcase a newly developed IsoMAG IMS system with an optimized protocol for fully automated immunomagnetic enrichment of CTCs, also revealing rare CTC subpopulations.

METHODS

using different squamous cell carcinoma cell lines, we developed an isolation protocol exploiting highly efficient EpCAM-targeting magnetic beads for automated CTC enrichment by the IsoMAG IMS system. By FACS analysis, we analyzed white blood contamination usually preventing further downstream analysis of enriched cells.

RESULTS

1 µm magnetic beads with tosyl-activated hydrophobic surface properties were found to be optimal for automated CTC enrichment. More than 86.5% and 95% of spiked cancer cells were recovered from both cell culture media or human blood employing our developed protocol. In addition, contamination with white blood cells was minimized to about 1200 cells starting from 7.5 mL blood. Finally, we showed that the system is applicable for HNSCC patient samples and characterized isolated CTCs by immunostaining using a panel of tumor markers.

CONCLUSION

Herein, we demonstrate that the IsoMAG system allows the detection and isolation of CTCs from HNSCC patient blood for disease monitoring in a fully-automated process with a significant leukocyte count reduction. Future developments seek to integrate the IsoMAG IMS system into an automated microfluidic-based isolation workflow to further facilitate single CTC detection also in clinical routine.

Profiling Cisplatin Resistance in Head and Neck Cancer: A Critical Role of the VRAC Ion Channel for Chemoresistance

Treatment success of head and neck cancers (HNSCC) is often hindered by tumor relapses due to therapy resistances. This study aimed at profiling cisplatin resistance mechanisms and identifying biomarkers potentially suitable as drug targets and for patient stratification. Bioinformatic analyses of suggested resistance factors in a cohort of 565 HNSCC patients identified the VRAC ion channel as a clinically relevant indicator for recurrent diseases following radiochemotherapy (p = 0.042). Other drug import/export transporters, such as CTR1, OCT1, or MRP1, were found to be less relevant. To experimentally verify VRAC's critical role for cisplatin resistance, we used CRISPR/Cas9 knockout resulting in cisplatin-resistant HNSCC cells, which could be resensitized by VRAC expression. Next-generation sequencing further underlined VRAC's importance and identified VRAC-regulated signaling networks, potentially also contributing to cisplatin resistance. CTR1, OCT1, or MRP1 did not contribute to increased cisplatin resistance. In addition to two-dimensional HNSCC models, three-dimensional tumor spheroid cultures confirmed VRAC's unique role for cisplatin sensitivity. Here, resistance correlated with DNA damage and downstream apoptosis. The cisplatin specificity of the identified VRAC pathway was verified by testing paclitaxel and doxorubicin. Our results were independently confirmed in naturally occurring, cisplatin-resistant HNSCC cancer cell models. Collectively, we here demonstrate VRAC's role for cisplatin resistance in HNSCC and its relevance as a potential drug target and/or prognostic biomarker for chemotherapy resistance.