Autosomal dominant polycystic kidney disease (ADPKD) is the most frequent genetic cause of renal failure. Here we identify miR-17 as a target for the treatment of ADPKD. We report that miR-17 is induced in kidney cysts of mouse and human ADPKD. Genetic deletion of the miR-17∼92 cluster inhibits cyst proliferation and PKD progression in four orthologous, including two long-lived, mouse models of ADPKD. Anti-miR-17 treatment attenuates cyst growth in short-term and long-term PKD mouse models. miR-17 inhibition also suppresses proliferation and cyst growth of primary ADPKD cysts cultures derived from multiple human donors. Mechanistically, c-Myc upregulates miR-17∼92 in cystic kidneys, which in turn aggravates cyst growth by inhibiting oxidative phosphorylation and stimulating proliferation through direct repression of Pparα. Thus, miR-17 family is a promising drug target for ADPKD, and miR-17-mediated inhibition of mitochondrial metabolism represents a potential new mechanism for ADPKD progression.

Polycystic kidney disease (PKD), the most common genetic cause of chronic kidney failure, is characterized by the presence of numerous, progressively enlarging fluid-filled cysts in the renal parenchyma. The cysts arise from renal tubules and are lined by abnormally functioning and hyperproliferative epithelial cells. Despite recent progress, no Food and Drug Administration-approved therapy is available to retard cyst growth. MicroRNAs (miRNAs) are short noncoding RNAs that inhibit posttranscriptional gene expression. Dysregulated miRNA expression is observed in PKD, but whether miRNAs are directly involved in kidney cyst formation and growth is not known. Here, we show that miR-17∼92, an oncogenic miRNA cluster, is up-regulated in mouse models of PKD. Kidney-specific transgenic overexpression of miR-17∼92 produces kidney cysts in mice. Conversely, kidney-specific inactivation of miR-17∼92 in a mouse model of PKD retards kidney cyst growth, improves renal function, and prolongs survival. miR-17∼92 may mediate these effects by promoting proliferation and through posttranscriptional repression of PKD genes Pkd1, Pkd2, and hepatocyte nuclear factor-1β. These studies demonstrate a pathogenic role of miRNAs in mouse models of PKD and identify miR-17∼92 as a therapeutic target in PKD. Our results also provide a unique hypothesis for disease progression in PKD involving miRNAs and regulation of PKD gene dosage.cilia | kinesin family member 3A | autosomal dominant polycystic kidney disease P olycystic kidney disease (PKD) is among the most common monogenic human diseases (1, 2). PKD is characterized by the presence of numerous fluid-filled cysts in the renal parenchyma. The cysts arise from renal tubules and are lined by abnormally functioning epithelial cells. The cyst epithelial cells secrete excessive fluid and display high rates of proliferation, which results in cyst expansion. The expanding cysts compress the surrounding normal nephrons, which cause renal failure. Based on the mode of inheritance, PKD is classified into autosomal dominant PKD (ADPKD) and autosomal recessive PKD (ARPKD). ADPKD is caused by mutations of PKD1 or PKD2, which encode polycystin-1 and polycystin-2, respectively. ARPKD is caused by mutations of polycystic kidney and hepatic disease 1 (PKHD1) which encodes fibrocystin (1, 3). Polycystin-1, polycystin-2, and fibrocystin localize to the primary cilium, a sensory organelle present on the apical surface of most cells in the body. Abnormalities of the primary cilium are linked to the pathogenesis of many forms of cystic kidney diseases, including PKD (1, 4, 5). Despite recent advances, no Food and Drug Administration-approved therapy is available for PKD patients.MicroRNAs (miRNAs) are noncoding RNAs that constitute the endogenous RNA interference pathway. miRNAs are transcribed as primary miRNAs (pri-miRNAs), which are sequentially processed by the enzymes Drosha and Dicer to produce mature miRNAs (6). Watson-Crick base pairing between nucleotides 2-8 (seed sequence) at the 5′ end of the matur...

Recent studies have shown that stromal fibroblasts have a more profound influence on the initiation and progression of carcinoma than was previously appreciated. This study aimed at investigating the reciprocal relationship between cancer cells and their associated fibroblasts at both the molecular and cellular level in oral squamous cell carcinoma (OSCC). To identify key molecular regulators expressed by carcinoma-associated fibroblasts (CAF) that promote cancer cell invasion, microarrays were performed by comparing cocultured OSCC cells and CAF with monoculture controls. Microarray and real-time PCR analysis identified marked upregulation of the chemokine (C-C motif) ligand 7 (CCL7) in cocultured CAF. ELISA showed an elevated level of CCL7 secretion from CAF stimulated by coculture with OSCC cells. CCL7 promoted the invasion and migration of OSCC cells, and the invasiveness was inhibited by treatment with CCL7 neutralizing antibody. OSCC cells were shown to express CCR1, CCR2 and CCR3, receptors for CCL7, by RT-PCR. In addition, treatment with anti-CCR1 or anti-CCR3 antibody inhibited CCL7-induced OSCC cell migration, implicating that CCL7 promotes cancer cell migration through CCR1 and CCR3 on OSCC cells. Cytokine antibody array analysis of the supernatant from OSCC cell culture revealed that interleukin-1a was an inducer of CCL7 secretion by CAF. This study confirms the reciprocal relationship of the molecular crosstalk regulating the invasion of OSCC and describes new potential targets for future therapy.Carcinomas are malignant neoplasms derived from epithelial cells and are surrounded by specialized stroma, which orchestrate with cancer cells to regulate disease progression. 1-3 Carcinoma-associated fibroblasts (CAF) have been recognized as prominent modifiers of cancer initiation and progression. 4,5 For instance, it has been previously demonstrated that human prostatic CAF induce tumor formation from initiated but nontumorigenic human prostatic epithelial cells. 6 CAF also facilitate the invasiveness of otherwise noninvasive cancer cells when coinjected into mice. 7 The putative proinvasive effects of CAF may be mediated through either direct heterotypic cellÀcell contacts 8 or diffusible molecules, such as inflammatory mediators, cytokines and chemokines. 9,10 Chemokines have been shown to play an important role in tumor biology by influencing tumor growth, invasion and metastasis. 11 Chemokines are a family of small, structurally related cytokines with chemoattractant and activation properties that are involved in inflammatory reactions. 12 They are classified mainly into the CC and CXC subfamilies, according to the location of the first 2 cysteine residues, and are produced by a range of cell types, including fibroblasts. Various types of cancer cells also express chemokines and chemokine receptors, 11,[13][14][15] and their autocrine and paracrine roles in cancer progression are receiving increasing attention. For example, the CXC chemokine, CXCL12 (stromal cell-derived factor 1), secreted by CAF, r...

M2-type TAMs are increasingly implicated as a crucial factor promoting metastasis. Numerous cell types dictate monocyte differentiation into M2 TAMs via a complex network of cytokine-based communication. Elucidating critical pathways in this network can provide new targets for inhibiting metastasis. In this study, we focused on cancer cells, CAFs, and monocytes as a major node in this network. Monocyte cocultures with cancer-stimulated CAFs were used to investigate differentiation into M2-like TAMs. Cytokine array analyses were employed to discover the CAF-derived regulators of differentiation. These regulators were validated in primary CAFs and bone marrow-derived monocytes. Orthotopic, syngeneic colon carcinoma models using cotransplanted CAFs were established to observe effects on tumor growth and metastasis. To confirm a correlation with clinical evidence, meta-analyses were employed using the Oncomine database. Our coculture studies identify IL6 and GM-CSF as the pivotal signals released from cancer cell-activated CAFs that cooperate to induce monocyte differentiation into M2-like TAMs. In orthotopic, syngeneic colon carcinoma mouse models, cotransplanted CAFs elevated IL6 and GM-CSF levels, TAM infiltration, and metastasis. These pathologic effects were dramatically reversed by joint IL6 and GM-CSF blockade. A positive correlation between GM-CSF and IL6 expression and disease course was observed by meta-analyses of the clinical data. Our studies indicate a significant reappraisal of the role of IL6 and GM-CSF in metastasis and implicate CAFs as the "henchmen" for cancer cells in producing an immunosuppressive tumor ecological niche. Dual targeting of GM-CSF and IL6 is a promising new approach for inhibiting metastasis. .

MicroRNAs (miRNAs) contribute to the regulation of early kidney development, but their role during later stages of renal tubule maturation is not well understood. Here, we found that ablation of the miRNA-processing enzyme Dicer from maturing renal tubules produces tubular and glomerular cysts in mice. Inactivation of Dicer is associated with downregulation of miR-200, a kidney-enriched miRNA family, and upregulation of the polycystic kidney disease gene Pkd1. Inhibition of miR-200 in cultured renal epithelial cells disrupted tubulogenesis and led to upregulation of Pkd1. Using bioinformatic and in vitro approaches, we found that miR-200b/c/429 induce post-transcriptional repression of Pkd1 through two conserved binding sites in the 39-Untranslated regions of Pkd1. Overexpression of PKD1 in renal epithelial cells was sufficient to disrupt tubulogenesis and produce cyst-like structures. In conclusion, miRNAs are essential for the maturation of renal tubules, and Pkd1 is a target of miR-200. These results also suggest that miRNAs may modulate PKD1 gene dosage and play a role in the initiation of cystogenesis.