Rapid and effective differentiation between normal and cancer cells is an important challenge for the diagnosis and treatment of tumors. Here, we describe an array-based system for identification of ...normal and cancer cells based on a "chemical nose/tongue" approach that exploits subtle changes in the physicochemical nature of different cell surfaces. Their differential interactions with functionalized nanoparticles are transduced through displacement of a multivalent polymer fluorophore that is quenched when bound to the particle and fluorescent after release. Using this sensing strategy we can rapidly (minutes/seconds) and effectively distinguish (i) different cell types; (ii) normal, cancerous and metastatic human breast cells; and (iii) isogenic normal, cancerous and metastatic murine epithelial cell lines.
The majority of human solid tumours do not metastasize when grown subcutaneously in immunocompromised mice; this includes patient-derived xenograft (PDX) models. However, orthotopic implantation of ...intact tumour tissue can lead to metastasis that mimics that seen in patients. These patient-derived orthotopic xenograft (PDOX) models have a long history and might better recapitulate human tumours than PDX models.
ICAM‐1 is a cell surface glycoprotein and an adhesion receptor that is best known for regulating leukocyte recruitment from circulation to sites of inflammation. However, in addition to vascular ...endothelial cells, ICAM‐1 expression is also robustly induced on epithelial and immune cells in response to inflammatory stimulation. Importantly, ICAM‐1 serves as a biosensor to transduce outside‐in‐signaling via association of its cytoplasmic domain with the actin cytoskeleton following ligand engagement of the extracellular domain. Thus, ICAM‐1 has emerged as a master regulator of many essential cellular functions both at the onset and at the resolution of pathologic conditions. Because the role of ICAM‐1 in driving inflammatory responses is well recognized, this review will mainly focus on newly emerging roles of ICAM‐1 in epithelial injury‐resolution responses, as well as immune cell effector function in inflammation and tumorigenesis. ICAM‐1 has been of clinical and therapeutic interest for some time now; however, several attempts at inhibiting its function to improve injury resolution have failed. Perhaps, better understanding of its beneficial roles in resolution of inflammation or its emerging function in tumorigenesis will spark new interest in revisiting the clinical value of ICAM‐1 as a potential therapeutic target.
Review of established and emerging physiologic functions of ICAM‐1 in health and disease.
Calcium (Ca(2+)) regulates a plethora of cellular functions including hallmarks of cancer development such as cell cycle progression and cellular migration. Receptor-regulated calcium rise in ...nonexcitable cells occurs through store-dependent as well as store-independent Ca(2+) entry pathways. Stromal interaction molecules (STIM) and Orai proteins have been identified as critical constituents of both these Ca(2+) influx pathways. STIMs and Orais have emerged as targets for cancer therapeutics as their altered expression and function have been shown to contribute to tumorigenesis. Recent data demonstrate that they play a vital role in development and metastasis of a variety of tumor types including breast, prostate, cervical, colorectal, brain, and skin tumors. In this review, we will retrospect the data supporting a key role for STIM1, STIM2, Orai1, and Orai3 proteins in tumorigenesis and discuss the potential of targeting these proteins for cancer therapy.
Cancer-derived exosomes are considered a major driver of cancer-induced pre-metastatic niche formation at foreign sites, but the mechanisms remain unclear. Here, we show that miR-25-3p, a ...metastasis-promoting miRNA of colorectal cancer (CRC), can be transferred from CRC cells to endothelial cells via exosomes. Exosomal miR-25-3p regulates the expression of VEGFR2, ZO-1, occludin and Claudin5 in endothelial cells by targeting KLF2 and KLF4, consequently promotes vascular permeability and angiogenesis. In addition, exosomal miR-25-3p from CRC cells dramatically induces vascular leakiness and enhances CRC metastasis in liver and lung of mice. Moreover, the expression level of miR-25-3p from circulating exosomes is significantly higher in CRC patients with metastasis than those without metastasis. Our work suggests that exosomal miR-25-3p is involved in pre-metastatic niche formation and may be used as a blood-based biomarker for CRC metastasis.
TGF-β plays a prominent role as an inducer of epithelial-mesenchymal transitions (EMTs) during development and wound healing and in disease conditions such as fibrosis and cancer. During these ...processes EMT occurs together with changes in cell proliferation, differentiation, communication, and extracellular matrix remodeling that are orchestrated by multiple signaling inputs besides TGF-β. Chief among these inputs is RAS-MAPK signaling, which is frequently required for EMT induction by TGF-β. Recent work elucidated the molecular basis for the cooperation between the TGF-β-SMAD and RAS-MAPK pathways in the induction of EMT in embryonic, adult and carcinoma epithelial cells. These studies also provided direct mechanistic links between EMT and progenitor cell differentiation during gastrulation or intra-tumoral fibrosis during cancer metastasis. These insights illuminate the nature of TGF-β driven EMTs as part of broader processes during development, fibrogenesis and metastasis.
Metastasis resistant to therapy is the major cause of death from cancer. Despite almost 200 years of study, the process of tumor metastasis remains controversial. Stephen Paget initially identified ...the role of host-tumor interactions on the basis of a review of autopsy records. His "seed and soil" hypothesis was substantiated a century later with experimental studies, and numerous reports have confirmed these seminal observations. An improved understanding of the metastatic process and the attributes of the cells selected by this process is critical for the treatment of patients with systemic disease. In many patients, metastasis has occurred by the time of diagnosis, so metastasis prevention may not be relevant. Treating systemic disease and identifying patients with early disease should be our goal. Revitalized research in the past three decades has focused on new discoveries in the biology of metastasis. Even though our understanding of molecular events that regulate metastasis has improved, the contributions and timing of molecular lesion(s) involved in metastasis pathogenesis remain unclear. Review of the history of pioneering observations and discussion of current controversies should increase understanding of the complex and multifactorial interactions between the host and selected tumor cells that contribute to fatal metastasis and should lead to the design of successful therapy.
Metastasis is powered by disseminated cancer cells that re-create a full-fledged tumor in unwelcoming tissues, away from the primary site. How cancer cells moving from a tumor into the circulation ...manage to infiltrate distant organs and initiate metastatic growth is of interest to cancer biologists and clinical oncologists alike. Recent findings have started to define the sources, phenotypic properties, hosting niches, and signaling pathways that support the survival, self-renewal, dormancy, and reactivation of cancer cells that initiate metastasis: metastatic stem cells. By dissecting the biology of this process, vulnerabilities are being exposed that could be exploited to prevent metastasis.
This review discusses the current understanding of sources, lethal challenges, hosting niches, and vital pathways that enable the persistence and progression of metastatic stem cells.
Abstract Pancreatic ductal adenocarcinoma (PDAC) is an extremely aggressive malignancy, characterized by a high metastatic burden, already at the time of diagnosis. The metastatic potential of PDAC ...is one of the main reasons for the poor outcome next to lack of significant improvement in effective treatments in the last decade. Key mutated driver genes, such as activating KRAS mutations, are concordantly expressed in primary and metastatic tumors. However, the biology behind the metastatic potential of PDAC is not fully understood. Recently, large-scale omic approaches have revealed new mechanisms by which PDAC cells gain their metastatic potency. In particular, genomic studies have shown that multiple heterogeneous subclones reside in the primary tumor with different metastatic potential. The development of metastases may be correlated to a more mesenchymal transcriptomic subtype. However, for cancer cells to survive in a distant organ, metastatic sites need to be modulated into pre-metastatic niches. Proteomic studies identified the influence of exosomes on the Kuppfer cells in the liver, which could function to prepare this tissue for metastatic colonization. Phosphoproteomics adds an extra layer to the established omic techniques by unravelling key functional signaling. Future studies integrating results from these large-scale omic approaches will hopefully improve PDAC prognosis through identification of new therapeutic targets and patient selection tools. In this article, we will review the current knowledge on the biology of PDAC metastasis unravelled by large scale multi-omic approaches.
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