Cancer-associated fibroblasts (CAFs) are a key component of the tumour microenvironment with diverse functions, including matrix deposition and remodelling, extensive reciprocal signalling interactions with cancer cells and crosstalk with infiltrating leukocytes. As such, they are a potential target for optimizing therapeutic strategies against cancer. However, many challenges are present in ongoing attempts to modulate CAFs for therapeutic benefit. These include limitations in our understanding of the origin of CAFs and heterogeneity in CAF function, with it being desirable to retain some antitumorigenic functions. On the basis of a meeting of experts in the field of CAF biology, we summarize in this Consensus Statement our current knowledge and present a framework for advancing our understanding of this critical cell type within the tumour microenvironment. Extracellular matrix (ECM).The structural network of secreted proteins and glycosaminoglycans that provides structure to tissue. Angiogenesis The formation of new blood vessels. Mesenchyme A type of tissue composed of loosely associated cells surrounded by extracellular matrix. Mesoderm one of three fundamental layers of tissue formed early in development and the predominant source of fibroblastic lineages.

Obesity has been linked to the increased risk and aggressiveness of many types of carcinoma. A state of chronic inflammation in adipose tissue (AT), resulting in genotoxic stress, may contribute to carcinogenesis and cancer initiation. Evidence that AT plays a role in cancer aggressiveness is solid and mounting. During cancer progression, tumor cells engage in a metabolic symbiosis with adjacent AT. Mature adipocytes provide adipokines and lipids to cancer cells, while stromal and immune cells from AT infiltrate carcinomas and locally secrete paracrine factors within the tumor microenvironment. This review focuses on the crosstalk between AT and tumor cells that promotes tumor growth and increases cellular lipid metabolism, metastasis, and chemoresistance.

Prostate cancer antigen 3 (PCA3) is the most specific prostate cancer biomarker but its function remains unknown. Here we identify PRUNE2, a target protein-coding gene variant, which harbors the PCA3 locus, thereby classifying PCA3 as an antisense intronic long noncoding (lnc)RNA. We show that PCA3 controls PRUNE2 levels via a unique regulatory mechanism involving formation of a PRUNE2/PCA3 double-stranded RNA that undergoes adenosine deaminase acting on RNA (ADAR)-dependent adenosine-to-inosine RNA editing. PRUNE2 expression or silencing in prostate cancer cells decreased and increased cell proliferation, respectively. Moreover, PRUNE2 and PCA3 elicited opposite effects on tumor growth in immunodeficient tumor-bearing mice. Coregulation and RNA editing of PRUNE2 and PCA3 were confirmed in human prostate cancer specimens, supporting the medical relevance of our findings. These results establish PCA3 as a dominant-negative oncogene and PRUNE2 as an unrecognized tumor suppressor gene in human prostate cancer, and their regulatory axis represents a unique molecular target for diagnostic and therapeutic intervention.S everal lines of evidence demonstrate that long noncoding RNAs (lncRNAs) are functional in carcinogenesis through regulatory mechanisms such as promoter looping, alternative splicing, antisense gene silencing, transcriptional regulation, and DNA repair, thus potentially serving as tumor markers. A few lncRNA species have emerged as potential prostate cancer biomarkers such as prostate cancer gene expression marker-1 (PCGEM1) and prostate cancer noncoding RNA1 (PRNCR1), which enhance androgen receptor (AR)-dependent gene activation, and prostate cancer-associated ncRNA transcript-1 (PCAT1), which silences BRCA2 via posttranscriptional homologous recombination (1). Notably, the most specific biomarker in human prostate cancer identified to date is an lncRNA, prostate cancer antigen 3 (PCA3, also known as PCA3 DD3 or DD3 PCA3 ), which is up-regulated in human prostate cancer (2). Since its discovery more than 15 y ago, PCA3 has been extensively investigated (3) and has been approved for clinical applications to aid the diagnosis of prostate cancer in both the European Union and the United States. Paradoxically-despite its striking clinical specificity-the inherent cellular role of the lncRNA PCA3 in human prostate cancer, if any, remains completely unknown (1). Here we report a unique biological function for PCA3. Within a single functional genetic unit, we show that PCA3 is an antisense intronic lncRNA that down-regulates an as yet unrecognized tumor suppressor gene, a human homolog of the Drosophila prune gene, PRUNE2, through a process that involves RNA editing mediated by a supramolecular complex containing adenosine deaminase acting on RNA (ADAR) family members. We propose a working model in which PCA3 acts as a dominant-negative oncogene in prostate cancer and show consistent results in therapeutic preclinical models and in patient-derived human samples. Therefore, the molecular interaction of PRUNE2...

White adipose tissue (WAT) is becoming widely used in regenerative medicine/cell therapy applications, and its physiological and pathological importance is increasingly appreciated. WAT is a complex organ composed of differentiated adipocytes, stromal mesenchymal progenitors known as adipose stromal cells (ASC), as well as endothelial vascular cells and infiltrating leukocytes. Two-dimensional (2D) culture that has been typically used for studying adipose cells does not adequately recapitulate WAT complexity. Improved methods for reconstruction of functional WAT ex vivo are instrumental for understanding of physiological interactions between the composing cell populations. Here, we used a three-dimensional (3D) levitation tissue culture system based on magnetic nanoparticle assembly to model WAT development and growth in organoids termed adipospheres. We show that 3T3-L1 preadipocytes remain viable in spheroids for a long period of time, while in 2D culture, they lose adherence and die after reaching confluence. Upon adipogenesis induction in 3T3-L1 adipospheres, cells efficiently formed large lipid droplets typical of white adipocytes in vivo, while only smaller lipid droplet formation is achievable in 2D. Adiposphere-based coculture of 3T3-L1 preadipocytes with murine endothelial bEND.3 cells led to a vascular-like network assembly concomitantly with lipogenesis in perivascular cells. Adipocyte-depleted stromal vascular fraction (SVF) of mouse WAT cultured in 3D underwent assembly into organoids with vascular-like structures containing luminal endothelial and perivascular stromal cell layers. Adipospheres made from primary WAT cells displayed robust proliferation and complex hierarchical organization reflected by a matricellular gradient incorporating ASC, endothelial cells, and leukocytes, while ASC quickly outgrew other cell types in adherent culture. Upon adipogenesis induction, adipospheres derived from the SVF displayed more efficient lipid droplet accumulation than 2D cultures. This indicates that 3D intercellular signaling better recapitulates WAT organogenesis. Combined, our studies show that adipospheres are appropriate for WAT modeling ex vivo and provide a new platform for functional screens to identify molecules bioactive toward individual adipose cell populations. This 3D methodology could be adopted for WAT transplantation applications and aid approaches to WAT-based cell therapy.

White adipose tissue (WAT) overgrowth in obesity is linked with increased aggressiveness of certain cancers. Adipose stromal cells (ASCs) can become mobilized from WAT, recruited by tumours and promote cancer progression. Mechanisms underlying ASC trafficking are unclear. Here we demonstrate that chemokines CXCL1 and CXCL8 chemoattract ASC by signalling through their receptors, CXCR1 and CXCR2, in cell culture models. We further show that obese patients with prostate cancer have increased epithelial CXCL1 expression. Concomitantly, we observe that cells with ASC phenotype are mobilized and infiltrate tumours in obese patients. Using mouse models, we show that the CXCL1 chemokine gradient is required for the obesity-dependent tumour ASC recruitment, vascularization and tumour growth promotion. We demonstrate that αSMA expression in ASCs is induced by chemokine signalling and mediates the stimulatory effects of ASCs on endothelial cells. Our data suggest that ASC recruitment to tumours, driven by CXCL1 and CXCL8, promotes prostate cancer progression.

The yeast two-hybrid method (or interaction trap) is a powerful technique for detecting protein interactions. The procedure is performed using transcriptional activation of a dual reporter system in yeast to identify interactions between a protein of interest (the bait protein) and the candidate proteins for interaction. The method can be used to screen a protein library for interactions with a bait protein or to test for association between proteins that are expected to interact based on prior evidence. Interaction mating facilitates the screening of a library with multiple bait proteins.

Summary Brown adipose tissue (BAT) plays an important role in mammalian thermoregulation. The component of BAT mitochondria that permits this function is the inner membrane carrier protein uncoupling protein 1 (UCP1). To the best of our knowledge, no studies have directly quantified UCP1 function in human BAT. Further, whether human and rodent BAT have comparable thermogenic function remains unknown. We employed high-resolution respirometry to determine the respiratory capacity, coupling control, and most importantly, UCP1 function of human supraclavicular BAT and rodent interscapular BAT. Human BAT was sensitive to the purine nucleotide GDP, providing the first direct that human BAT mitochondria have thermogenically functional UCP1. Further, our data demonstrate that human and rodent BAT have similar UCP1 function per mitochondrion. These data indicate that human and rodent BAT are qualitatively similar in terms of UCP1 function.

Obesity is a prognostic risk factor in the progression of prostate cancer (PCa), however, the molecular mechanisms involved are unclear. In this study, we provide preclinical proof of concept for the role of a pro-inflammatory CXCL12-CXCR4/CXCR7 signaling axis in an obesity-driven mouse model of HiMyc prostate cancer. Analysis of the stromal vascular fraction (SVF) from periprostatic white adipose tissue (ppWAT) from obese HiMyc mice at 6 months of age revealed a dramatic increase in mRNAs encoding various chemokines, cytokines, growth factors and angiogenesis mediators, with CXCL12 among the most significantly upregulated genes. Immunofluorescence staining of ventral prostate tissue from obese HiMyc mice revealed high levels of CXCL12 in the stromal compartment as well as high staining for CXCR4 and CXCR7 in the epithelial compartment of tumors. PCa cell lines derived from HiMyc tumors (HMVP2 and derivative cell lines) displayed increased protein expression of both CXCR4 and CXCR7 compared to protein lysates from a non-tumorigenic prostate epithelial cell line (NMVP cells). CXCL12 treatment stimulated migration and invasion of HMVP2 cells but not NMVP cells. These effects of CXCL12 on HMVP2 cells were inhibited by the CXCR4 antagonist AMD3100 as well as knockdown of either CXCR4 or CXCR7. CXCL12 treatment also produced rapid activation of STAT3, NFkB, and MAPK signaling in HMVP2 cells which was again attenuated by either AMD3100 or knockdown of CXCR4 or CXCR7. Collectively, these data suggest that CXCL12 secreted by stromal cells activates invasiveness of PCa cells and may play a role in driving tumor progression in obesity. Targeting the CXCL12-CXCR4/CXCR7 axis could lead to novel approaches for offsetting the effects of obesity on PCa progression.