bims-stacyt 2020-01-12 papers

Front Oncol. 2019 ;9 1359

Ping-Pong-Tumor and Host in Pancreatic Cancer Progression.

Metastasis is the main cause of high pancreatic cancer (PaCa) mortality and trials dampening PaCa mortality rates are not satisfying. Tumor progression is driven by the crosstalk between tumor cells, predominantly cancer-initiating cells (CIC), and surrounding cells and tissues as well as distant organs, where tumor-derived extracellular vesicles (TEX) are of major importance. A strong stroma reaction, recruitment of immunosuppressive leukocytes, perineural invasion, and early spread toward the peritoneal cavity, liver, and lung are shared with several epithelial cell-derived cancer, but are most prominent in PaCa. Here, we report on the state of knowledge on the PaCIC markers Tspan8, alpha6beta4, CD44v6, CXCR4, LRP5/6, LRG5, claudin7, EpCAM, and CD133, which all, but at different steps, are engaged in the metastatic cascade, frequently via PaCIC-TEX. This includes the contribution of PaCIC markers to TEX biogenesis, targeting, and uptake. We then discuss PaCa-selective features, where feedback loops between stromal elements and tumor cells, including distorted transcription, signal transduction, and metabolic shifts, establish vicious circles. For the latter particularly pancreatic stellate cells (PSC) are responsible, furnishing PaCa to cope with poor angiogenesis-promoted hypoxia by metabolic shifts and direct nutrient transfer via vesicles. Furthermore, nerves including Schwann cells deliver a large range of tumor cell attracting factors and Schwann cells additionally support PaCa cell survival by signaling receptor binding. PSC, tumor-associated macrophages, and components of the dysplastic stroma contribute to perineural invasion with signaling pathway activation including the cholinergic system. Last, PaCa aggressiveness is strongly assisted by the immune system. Although rich in immune cells, only immunosuppressive cells and factors are recovered in proximity to tumor cells and hamper effector immune cells entering the tumor stroma. Besides a paucity of immunostimulatory factors and receptors, immunosuppressive cytokines, myeloid-derived suppressor cells, regulatory T-cells, and M2 macrophages as well as PSC actively inhibit effector cell activation. This accounts for NK cells of the non-adaptive and cytotoxic T-cells of the adaptive immune system. We anticipate further deciphering the molecular background of these recently unraveled intermingled phenomena may turn most lethal PaCa into a curatively treatable disease.

Keywords: cancer-initiating cell markers; exosomes; immunosuppression; metabolism; metastasis; pancreatic cancer; perineural invasion; stellate cells

DOI: https://doi.org/10.3389/fonc.2019.01359

Cancer Res. 2020 Jan 07. pii: canres.1934.2019. [Epub ahead of print]

miR-149 suppresses breast cancer metastasis by blocking paracrine interactions with macrophages.

Ismael Sánchez-González, Anja Bobien, Christian Molnar, Simone Schmid, Michaela Strotbek, Melanie Boerries, Hauke Busch, Monilola A Olayioye.

Paracrine activation of cells contained in the tumor microenvironment promotes tumor progression and metastasis. In breast cancer, malignant cells recruit and educate macrophages into a M2 tumor-promoting phenotype that supports the metastatic spread of cancer cells. Here, we show that miR-149 functions as a metastasis-suppressing microRNA in breast cancer cells by limiting colony-stimulating factor-1 (CSF1)-dependent recruitment and M2 polarization of macrophages. In lymph node-positive, triple-negative breast cancer (TNBC) tissues, low miR-149 expression correlated with reduced macrophage infiltration and patient survival. By directly targeting CSF1, miR-149 expression in TNBC cell lines (MDA-MB-231 and BT-549) inhibited the recruitment of human monocytic THP-1 cells and primary human macrophages. Furthermore, in macrophages co-cultured with MDA-MB-231 cells expressing miR-149, epidermal growth factor (EGF) and amphiregulin expression levels were strongly reduced, resulting in reduced EGF receptor activation in the cancer cells. In vivo, lung metastases developing from orthotopic MDA-MB-231 tumors were reduced by 75% by miR-149 expression and this was associated with impaired M2 macrophage infiltration of the primary tumors. These data suggest that miR-149 downregulation functionally contributes to breast tumor progression by recruiting macrophages to the tumor and facilitating CSF1 and EGF receptor crosstalk between cancer cells and macrophages.

DOI: https://doi.org/10.1158/0008-5472.CAN-19-1934

Front Oncol. 2019 ;9 1399

Contribution of Angiogenesis to Inflammation and Cancer.

Dolores Aguilar-Cazares, Rodolfo Chavez-Dominguez, Angeles Carlos-Reyes, César Lopez-Camarillo, Olga N Hernadez de la Cruz, Jose S Lopez-Gonzalez.

During carcinogenesis, advanced tumors are surrounded by both stromal and immune cells, which support tumor development. In addition, inflammation and angiogenesis are processes that play important roles in the development of cancer, from the initiation of carcinogenesis, tumor in situ and advanced stages of cancer. During acute inflammation, vascular hyperpermeability allows inflammatory mediators and immune response cells, including leukocytes and monocytes/macrophages, to infiltrate the site of damage. As a factor that regulates vascular permeability, vascular endothelial growth factor (VEGF) also plays a vital role as a multifunctional molecule and growth factor. Furthermore, stromal and immune cells secrete soluble factors that activate endothelial cells and favor their transmigration to eliminate the aggressive agent. In this review, we present a comprehensive view of both the relationship between chronic inflammation and angiogenesis during carcinogenesis and the participation of endothelial cells in the inflammatory process. In addition, the regulatory mechanisms that contribute to the endothelium returning to its basal permeability state after acute inflammation are discussed. Moreover, the manner in which immune cells participate in pathological angiogenesis release pro-angiogenic factors that contribute to early tumor vascularization, even before the angiogenic switch occurs, is also examined. Also, we discuss the role of hypoxia as a mechanism that drives the acquisition of tumor hallmarks that make certain cancers more aggressive. Finally, some combinations of therapies that inhibit the angiogenesis process and that may be a successful strategy for cancer patients are indicated.

Keywords: angiogenesis; cancer; carcinogenesis; inflammation; metastasis; vascular hyperpermeability; vasculogenic mimicry

DOI: https://doi.org/10.3389/fonc.2019.01399

Cancer Res. 2020 Jan 08. pii: canres.2080.2019. [Epub ahead of print]

Tumor Cell-Derived IL-1β Promotes Desmoplasia and Immune Suppression in Pancreatic Cancer.

Shipra Das, Beny Shapiro, Emily A Vucic, Sandra Vogt, Dafna Bar-Sagi.

Pancreatic ductal adenocarcinoma (PDA) is an aggressive malignancy typified by a highly stromal and weakly immunogenic tumor microenvironment that promotes tumor evolution and contributes to therapeutic resistance. Here, we demonstrate that PDA tumor cell-derived pro-inflammatory cytokine, interleukin-1β (IL-1β) is essential for the establishment of the pro-tumorigenic PDA microenvironment. Tumor cell-derived IL-1β promoted the activation and secretory phenotype of quiescent pancreatic stellate cells (PSC) and established an immunosuppressive milieu mediated by M2 macrophages, MDSCs, CD1dhiCD5+ regulatory B cells and Th17 cells. Loss of tumor cell-derived IL-1 signaling in tumor stroma enabled intra-tumoral infiltration and activation of CD8+ cytotoxic T cells, attenuated growth of pancreatic neoplasia and conferred survival advantage to PDA bearing mice. Accordingly, antibody-mediated neutralization of IL-1β significantly enhanced the anti-tumor activity of α-PD-1, and was accompanied by increased tumor infiltration of CD8+ T cells. Tumor cell expression of IL-1β in vivo was driven by microbial-dependent activation of toll-like receptor 4 (TLR4) signaling and subsequent engagement of the NLRP3 inflammasome. Collectively, these findings identify a hitherto unappreciated role for tumor cell-derived IL-1β in orchestrating an immune modulatory program that supports pancreatic tumorigenesis.

DOI: https://doi.org/10.1158/0008-5472.CAN-19-2080

Am J Physiol Cell Physiol. 2020 Jan 08.

CC and CXC chemokines, major regulators of tumor progression and the tumor microenvironment.

Andreas Bikfalvi, Clotilde Billottet.

Chemokines are a family of soluble cytokines that act as chemoattractants to guide the migration of cells, in particular of immune cells. However, chemokines are also involved in cell proliferation, differentiation and survival. Chemokines are associated with a variety of human diseases including chronic inflammation, immune dysfunction, cancer and metastasis. This review discusses the expression of CC and CXC chemokines in the tumor microenvironment and their supportive and inhibitory roles in tumor progression, angiogenesis, metastasis and tumor immunity. We also specially focus on the diverse roles of CXC chemokines (CXCL9-11, CXCL4 and its variant CXCL4L1) and their two chemokine receptor CXCR3 isoforms, CXCR3-A and CXCR3-B. These two distinct isoforms have divergent roles in tumors, either promoting (CXCR3-A) or inhibiting (CXCR3-B) tumor progression. Their effects are mediated not only directly in tumor cells but also indirectly via the regulation of angiogenesis and tumor immunity. A full comprehension of their mechanisms of action is critical to further validate these chemokines and their receptors as biomarkers or therapeutic targets in cancer.

Keywords: angiogenesis; cancer; chemokines; tumor immunity; tumor invasion

DOI: https://doi.org/10.1152/ajpcell.00378.2019

Cancer Lett. 2020 Jan 07. pii: S0304-3835(20)30003-3. [Epub ahead of print]

Dysregulation Of Metabolic Enzymes In Tumor And Stromal Cells: Role In Oncogenesis And Therapeutic Opportunities.

Mohammad Aslam Khan, Haseeb Zubair, Shashi Anand, Sanjeev Kumar Srivastava, Seema Singh, Ajay Pratap Singh.

Altered cellular metabolism is a hallmark of cancer. Metabolic rewiring in cancer cells occurs due to the activation of oncogenes, inactivation of tumor suppressor genes, and/or other adaptive changes in cell signaling pathways. Furthermore, altered metabolism is also reported in tumor-corrupted stromal cells as a result of their interaction with cancer cells or due to their adaptation in the dynamic tumor microenvironment. Metabolic alterations are associated with dysregulation of metabolic enzymes and tumor-stromal metabolic crosstalk is vital for the progressive malignant journey of the tumor cells. Therefore, several therapies targeting metabolic enzymes have been evaluated and/or are being investigated in preclinical and clinical studies. In this review, we discuss some important metabolic enzymes that are altered in tumor and/or stromal cells, and focus on their role in supporting tumor growth. Moreover, we also discuss studies carried out in various cancers to target these metabolic abnormalities for therapeutic exploitation.

DOI: https://doi.org/10.1016/j.canlet.2020.01.003