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Biology subjects

Vreka, M.

Publications and source records attributed to Vreka, M..

4 recordsLinked to original sources

Tumor-secreted versican co-opts myeloid IKKβ during metastasis

The mechanisms tumor cells use to hijack the immune system are largely uncharted. Here we used bioluminescent nuclear factor (NF)-{kappa}B reporter mice and macrophages to discover that metastatic tumors trigger NF-{kappa}B activation in host macrophages, dependent on mutant KRAS signaling and delivered via secretory versican. Versican activates NF-{kappa}B in tumor-associated macrophages via inhibitor of NF-{kappa}B kinase (IKK) {beta}, resulting in release of interleukin (IL)-1{beta} into the tumor microenvironment. Versican silencing in cancer cells or conditional IKK{beta} deletion in macrophages prevents myeloid NF-{kappa}B activation and metastasis. Versican is overexpressed and/or mutated in human cancers and metastatic effusions with KRAS mutations, predicts poor survival, can aid in the development of diagnostic platforms for pleural metastasis, and is druggable via toll-like receptor (TLR) 1/2 inhibition. The data indicate a cardinal role for tumor-derived versican in establishing cross-talk with macrophage IKK{beta} during metastasis and may foster the development of new therapies and diagnostic tools.

cancer biology↗

KRAS signalling in malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) arises from mesothelial cells lining the pleural cavity of asbestos-exposed individuals and rapidly leads to the development of pleural effusion and death. MPM harbours loss-of-function mutations in genes like BAP1, NF2, CDKN2A, and TP53, but isolated deletion of these genes alone in mice does not cause MPM and mouse models of the disease are sparse. Here we show that a significant proportion of human MPM harbour point mutations and copy number alterations in the KRAS proto-oncogene. These mutations are likely pathogenic, since ectopic expression of mutant KRASG12D in the pleural mesothelium of conditional mice causes MPM. Murine MPM cell lines derived from these tumours carry the initiating KRASG12D lesions, secondary Bap1 alterations, and human MPM-like gene expression profiles. Moreover, they are transplantable and actionable by KRAS inhibition. Our results indicate that KRAS mutations likely play an important and underestimated role in MPM, which warrants further exploration.

physiology↗

Organ-restricted vascular delivery of nanoparticles for lung cancer therapy

Nanomedicines hold immense promise for a number of devastating diseases due to the ability to custom-design both the carrier and cargo. However, their clinical implementation has been hampered by physicochemical and biological barriers and off-target deposition which impair cell specific targeting, especially in internal organs. This study reports a new delivery approach using organ-restricted vascular delivery to allow for direct administration and recirculation of stimuli-responsive nanoparticles to promote cellular uptake into an organ of interest. Using this technique, nanoparticles reach the interior of dense tumors and are selectively taken up by lung cancer cells. Importantly, this surgical approach is essential as the same nanoparticles do not reach lung tumor cells upon systemic or intratracheal administration. Organ-restricted vascular delivery thus opens up new avenues for optimized nanotherapies for cancer and other diseases.

pharmacology and toxicology↗

Dual airway and alveolar contributions to adult lung homeostasis and carcinogenesis

Lung adenocarcinoma (LUAD) and chronic lung diseases caused by smoking and environmental noxious agents are the deadliest diseases worldwide, sharing a partially charted pathobiology of dysfunctional alveolar repair. Here we sought to identify the respiratory epithelial dynamics and molecular signatures participating in adult lung maintenance and chemical carcinogenesis. We employed novel mouse models of respiratory epithelial marking and ablation, a battery of pulmonary toxins and carcinogens, experimental protocols of carcinogen-induced LUAD, tobacco carcinogen-induced LUAD cell lines, and human transcriptomic data and identified a prominent involvement of airway molecular programs in alveolar maintenance and carcinogen-induced LUAD. The airway-specific transcriptomic signature was redistributed to the alveoli after toxic and carcinogenic insults and resulted in marked contributions of airway-labeled cells to injury-recovered alveoli and LUAD. Airway cells maintained Kras mutations and therefore possibly contributed to lung cancer initiation, while LUAD were spatially linked to neighboring airways. Transcriptomic profiling of carcinogen-induced murine and human LUAD revealed enrichment in airway signatures, while ablation of airway cells distorted alveolar structure and function and protected mice from LUAD development. Collectively, these results indicate that airway cells and/or transcriptomic signatures are essential for alveolar maintenance and LUAD development.

cancer biology↗