Head and neck squamous cancer progression is marked by CLIC4 attenuation in tumor epithelium and reciprocal stromal upregulation of miR-142-3p, a novel post-transcriptional regulator of CLIC4

Crosstalk between tumor and stroma modifies CLIC4 cargo in extracellular vesicles

Mouse models of breast cancer have revealed that tumor-bearing hosts must express the oxidoreductase CLIC4 to develop lung metastases. In the absence of host CLIC4, primary tumors grow but the lung premetastatic niche is defective for metastatic seeding. Primary breast cancer cells release EVs that incorporate CLIC4 as cargo and circulate in plasma of wildtype tumor-bearing hosts. CLIC4-deficient breast cancer cells also form tumors in wildtype hosts and release EVs in plasma, but these EVs lack CLIC4, suggesting that the tumor is the source of the plasma-derived EVs that carry CLIC4 as cargo. Paradoxically, circulating EVs are also devoid of CLIC4 when CLIC4-expressing primary tumors are grown in CLIC4 knockout hosts. Thus, the incorporation of CLIC4 (and perhaps other factors) as EV cargo released from tumors involves specific signals from the surrounding stroma determined by its genetic composition. Since CLIC4 is also detected in circulating EVs from human breast cancer patients, future studies will address its association with disease.

Host CLIC4 expression in the tumor microenvironment is essential for breast cancer metastatic competence

The TGF-β-regulated Chloride Intracellular Channel 4 (CLIC4) is an essential participant in the formation of breast cancer stroma. Here, we used data available from the TCGA and METABRIC datasets to show that CLIC4 expression was higher in breast cancers from younger women and those with early-stage metastatic disease. Elevated CLIC4 predicted poor outcome in breast cancer patients and was linked to the TGF-β pathway. However, these associations did not reveal the underlying biological contribution of CLIC4 to breast cancer progression. Constitutive ablation of host Clic4 in two murine metastatic breast cancer models nearly eliminated lung metastases without reducing primary tumor weight, while tumor cells ablated of Clic4 retained metastatic capability in wildtype hosts. Thus, CLIC4 was required for host metastatic competence. Pre- and post-metastatic proteomic analysis identified circulating pro-metastatic soluble factors that differed in tumor-bearing CLIC4-deficient and wildtype hosts. Vascular abnormalities and necrosis increased in primary tumors from CLIC4-deficient hosts. Transcriptional profiles of both primary tumors and pre-metastatic lungs of tumor-bearing CLIC4-deficient hosts were consistent with a microenvironment where inflammatory pathways were elevated. Altogether, CLIC4 expression in human breast cancers may serve as a prognostic biomarker; therapeutic targeting of CLIC4 could reduce primary tumor viability and host metastatic competence.

Current Insights and Advancements in Head and Neck Cancer: Emerging Biomarkers and Therapeutics with Cues from Single Cell and 3D Model Omics Profiling

Head and neck cancer (HNC) is among the ten leading malignancies worldwide, with India solely contributing one-third of global oral cancer cases. The current focus of all cutting-edge strategies against this global malignancy are directed towards the heterogeneous tumor microenvironment that obstructs most treatment blueprints. Subsequent to the portrayal of established information, the review details the application of single cell technology, organoids and spheroid technology in relevance to head and neck cancer and the tumor microenvironment acknowledging the resistance pattern of the heterogeneous cell population in HNC. Bioinformatic tools are used for study of differentially expressed genes and further omics data analysis. However, these tools have several challenges and limitations when analyzing single-cell gene expression data that are discussed briefly. The review further examines the omics of HNC, through comprehensive analyses of genomics, transcriptomics, proteomics, metabolomics, and epigenomics profiles. Patterns of alterations vary between patients, thus heterogeneity and molecular alterations between patients have driven the clinical significance of molecular targeted therapies. The analyses of potential molecular targets in HNC are discussed with connotation to the alteration of key pathways in HNC followed by a comprehensive study of protein kinases as novel drug targets including its ATPase and additional binding pockets, non-catalytic domains and single residues. We herein review, the therapeutic agents targeting the potential biomarkers in light of new molecular targeted therapies. In the final analysis, this review suggests that the development of improved target-specific personalized therapies can combat HNC's global plight.

Salivary exosomal microRNAs as biomarkers for head and neck cancer detection-a literature review

Background

MicroRNAs (miRs) are small, non-coding mRNA molecules which regulate cellular processes in tumorigenesis. miRs were discovered in extracellular environment and biological fluids, carrying marks of head and neck squamous cell carcinoma (HNSCC). They were also identified in abundance in salivary exosomes, in which they are protected by exosome lipid barrier against enzymatic injuries and therefore, the accuracy of exosomal miR-based cancer detection increase. This systematic review aimed to reveal and inventorize the most reliable exosomal miRNAs in saliva samples which can be used as novel biomarkers for early detection of HNSCC.

Materials and methods

A systematic literature search, according to PRISMA guideline, was performed on Pubmed and Google Academic libraries, based on specific keywords. Original articles published between 2010 and 2021 were selected. The quality of each paper was assessed using the Quality Evaluation Scoring Tool.

Results

At the end of selection process, five studies met the inclusion criteria. These studies analyzed twelve salivary exosomal miRs, presenting different methods of exosome and miR identification for HNSCC detection. A comprehensive explanation of the miR pathways of action was drawn and illustrated in this review.

Conclusion

Exosomal miRs are promising biomarkers for oral cavity and oropharyngeal cancer detection. miR-10b-5p, miR-486-5p, miR-24-3p and miR-200a stand as the most useful ones in saliva sample examination.

Intravitreal injection of anti-miRs against miR-142-3p reduces angiogenesis and microglia activation in a mouse model of laser-induced choroidal neovascularization

Age-related macular degeneration (AMD) is a worldwide leading cause of blindness affecting individuals over 50 years old. The most aggressive form, wet AMD, is characterized by choroidal neovascularization (CNV) and inflammation involving microglia recruitment. By using a laser-induced CNV mouse model, we provide evidence for a key role played by miR-142-3p during CNV formation. MiR-142-3p was overexpressed in murine CNV lesions and its pharmacological inhibition decreased vascular and microglia densities by 46% and 30%, respectively. Consistently, miR-142-3p overexpression with mimics resulted in an increase of 136% and 126% of blood vessels and microglia recruitment. Interestingly, miR-142-3p expression was linked to the activation state of mouse microglia cells as determined by morphological analysis (cell solidity) through a computational method. In vitro, miR-142-3p overexpression in human microglia cells (HMC3) modulated microglia activation, as shown by CD68 levels. Interestingly, miR142-3p modulation also regulated the production of VEGF-A, the main pro-angiogenic factor. Together, these data strongly support the unprecedented importance of miR-142-3p-dependent vascular-inflammation axis during CNV progression, through microglia activation.

Conserved cysteine dioxidation enhances membrane interaction of human Cl- intracellular channel 5

The human chloride intracellular channel (hCLIC) family is thought to transition between globular and membrane-associated forms by exposure of a hydrophobic surface. However, the molecular identity of this surface, and the triggering events leading to its exposure, remain elusive. Here, by combining biochemical and structural approaches, together with mass spectrometry (MS) analyses, we show that hCLIC5 is inherently flexible. X-ray crystallography revealed the existence of a globular conformation, while small-angle X-ray scattering showed additional elongated forms consisting of exposure of the conserved hydrophobic inter-domain interface to the bulk phase. Tryptophan fluorescence measurements demonstrated that the transition to the membrane-associated form is enhanced by the presence of oxidative environment and lipids. Using MS, we identified a dose-dependent oxidation of a highly conserved cysteine residue, known to play a key role in the structurally related omega-class of glutathione-S-transferases. Hydrogen/deuterium exchange MS analysis revealed that oxidation of this cysteine facilitates the exposure of the conserved hydrophobic inter-domain interface. Together, our results pinpoint an oxidation of a specific cysteine residue as a triggering mechanism initializing the molecular commitment for membrane interaction in the CLIC family.