Tumor microenvironment: The role of the tumor stroma in cancer
ABSTRACT The tumor microenvironment, composed of non-cancer cells and their stroma, has become recognized as a major factor influencing the growth of cancer. The microenvironment has been implicated in the regulation of cell growth, determining metastatic potential and possibly determining location of metastatic disease, and impacting the outcome of therapy. While the stromal cells are not malignant per se, their role in supporting cancer growth is so vital to the survival of the tumor that they have become an attractive target for chemotherapeutic agents. In this review, we will discuss the various cellular and molecular components of the stromal environment, their effects on cancer cell dynamics, and the rationale and implications of targeting this environment for control of cancer. Additionally, we will emphasize the role of the bone marrow-derived cell in providing cells for the stroma.
- SourceAvailable from: Vikas Patil
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- "The tumor–stroma interaction is a complex process comprising of multiple cell types like macrophages and endothelial cells besides tumor cells . Our results show that CRP does not have any direct effect on tumor cells, microglial cells and endothelial cells. "
ABSTRACT: Glioblastoma (GBM) is the most common malignant adult primary brain tumor. We profiled 724 cancer-associated proteins in sera of healthy individuals (n=27) and GBM (n=28) using antibody microarray. While 69 proteins exhibited differential abundance in GBM sera, a three-marker panel (LYAM1, BHE40 and CRP) could discriminate GBM sera from that of healthy donors with an accuracy of 89.7% and p<0.0001. The high abundance of C-reactive protein (CRP) in GBM sera was confirmed in 264 independent samples. High level of CRP protein was seen in GBM but without a change in transcript levels suggesting a non-tumoral origin. Glioma-secreted Interleukin 6 (IL6) was found to induce hepatocytes to secrete CRP, involving JAK-STAT pathway. The culture supernatant from CRP-treated microglial cells induced endothelial cell survival under nutrient-deprivation involving CRP-FcγRIII signaling cascade. Transcript profiling of CRP-treated microglial cells identified Interleukin 1β (IL1β) present in the microglial secretome as the key mediator of CRP-induced endothelial cell survival. IL1β neutralization by antibody-binding or siRNA-mediated silencing in microglial cells reduced the ability of the supernatant from CRP-treated microglial cells to induce endothelial cell survival. Thus our study identifies a serum based three-marker panel for GBM diagnosis and provides leads for developing targeted therapies. Biological significance A complex antibody microarray based serum marker profiling identified a three-marker panel- LYAM1, BHE40 and CRP as an accurate discriminator of glioblastoma sera from that of healthy individuals. CRP protein is seen in high levels without a concomitant increase of CRP transcripts in glioblastoma. Glioma-secreted IL6 induced hepatocytes to produce CRP in a JAK-STAT signaling dependent manner. CRP induced microglial cells to release IL1β which in turn promoted endothelial cell survival. This study, besides defining a serum panel for glioblastoma discrimination, identified IL1β as a potential candidate for developing targeted therapy. Copyright © 2015. Published by Elsevier B.V.Journal of proteomics 07/2015; 128. DOI:10.1016/j.jprot.2015.07.026 · 3.89 Impact Factor
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- "Accompanied with atypical matrix composition, various types of cells, including fibroblast, vascular, glial, smooth muscle, epithelial, fat, and immune cells, infiltrate into tumor stroma, a process which further contributes to the altered tissue architecture of tumor tissue . Among these cells, cancer-associated fibroblasts play a crucial role in accelerating tumor progression through multiple mechanisms for cell viability, immune evasion, and epithelial–mesenchymal transition   . "
ABSTRACT: Cancer-associated fibroblasts play a crucial role in accelerating tumor progression, but there is a knowledge gap regarding the chemotactic signal activated in a tumor microenvironment. In this study, the expression of type IV collagen was knocked down using a lentiviral-mediated short hairpin RNA strategy. Although there was no obvious effect on cell growth in vitro, silencing the Col4-α1 gene decreased the tumorigenicity of B16F10 in C57BL/6 mice, which was accompanied by a reduction in the infiltration of alpha-smooth muscle actin-positive (α-SMA(+)) fibroblasts. Silencing the Col4-α1 gene or disrupting integrin engagement by blocking the antibody reduced the expression of platelet-derived growth factor A (PDGF-A), a potent chemotactic factor for fibroblasts. Furthermore, ectopic expression of the autoclustering integrin mutant significantly stimulated PDGF-A expression in murine B16F10 and human U118MG and Huh7 cells. PDGF-A-specific sh-RNA and neutralizing anti-PDGF-A antibody effectively inhibited the transwell migration of fibroblasts. Adding recombinant PDGF-A back to shCol cell-conditioned media restored the fibroblast-attraction ability indicating that PDGF-A is a major chemotactic factor for fibroblasts in the current study model. The integrin-associated PDGF-A production correlated with the activation of Src and ERK. High type IV collagen staining intensity colocalized with elevated PDGF-A expression was observed in tumor tissues obtained from hepatoma and glioma patients. The integrin signal pathway was activated by collagen engagement through Src and ERK, leading to enhanced PDGF-A production, which serves as a key regulator of fibroblast recruitment. Copyright © 2015 Elsevier B.V. All rights reserved.Biochimica et Biophysica Acta (BBA) - Molecular Cell Research 02/2015; 1853(5). DOI:10.1016/j.bbamcr.2015.02.004 · 5.02 Impact Factor
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- "Despite the advances in the field of anticancer drug discovery, the statistics are noteworthy; in 2012, 14.1 million new cases of cancer were diagnosed worldwide, with 8.2 million deaths . Thus, there is still a necessity for the development of new therapies and the tumor microenvironment is an important source of multiple targets for cancer therapy, including inflammation . "
ABSTRACT: Despite the advances in anticancer drug discovery field, the worldwide cancer incidence is remarkable, highlighting the need for new therapies focusing on both cancer cell and its microenvironment. The tumor microenvironment offers multiple targets for cancer therapy, including inflammation. Nowadays, almost 75% of the anticancer agents used in chemotherapy are derived from natural products, and plants are an important source of new promising therapies. Continuing our research on Piper umbellatum species, here we describe the anticancer (in vitro antiproliferative activity and in vivo Ehrlich solid tumor model) and anti-inflammatory (carrageenan-induced paw edema and peritonitis models) activities of a standardized dichloromethane extract (SDE) from P. umbellatum leaves, containing 23.9% of 4-nerolidylcatechol. SDE showed in vitro and in vivo antiproliferative activity, reducing Ehrlich solid tumor growth by 38.7 and 52.2% when doses of 200 and 400 mg/kg, respectively, were administered daily by oral route. Daily treatments did not produce signals of toxicity. SDE also reduced paw edema and leukocyte migration on carrageenan-induced inflammation models, suggesting that the anticancer activity of SDE from Piper umbellatum leaves could involve antiproliferative and anti-inflammatory effects. These findings highlight P. umbellatum as a source of compounds against cancer and inflammation.Evidence-based Complementary and Alternative Medicine 01/2015; 2015(Article ID 948737):8 pages. DOI:10.1155/2015/948737 · 1.88 Impact Factor