Drug use and relapse involve learned associations between drug-associated environmental cues and drug effects. Extinction procedures in the clinic can suppress conditioned responses to drug cues, but the extinguished responses typically reemerge after exposure to the drug itself (reinstatement), the drug-associated environment (renewal), or the passage of time (spontaneous recovery). We describe a memory retrieval-extinction procedure that decreases conditioned drug effects and drug seeking in rat models of relapse, and drug craving in abstinent heroin addicts. In rats, daily retrieval of drug-associated memories 10 minutes or 1 hour but not 6 hours before extinction sessions attenuated drug-induced reinstatement, spontaneous recovery, and renewal of conditioned drug effects and drug seeking. In heroin addicts, retrieval of drug-associated memories 10 minutes before extinction sessions attenuated cue-induced heroin craving 1, 30, and 180 days later. The memory retrieval-extinction procedure is a promising nonpharmacological method for decreasing drug craving and relapse during abstinence.

As an economic crop, pepper satisfies people's spicy taste and has medicinal uses worldwide. To gain a better understanding of Capsicum evolution, domestication, and specialization, we present here the genome sequence of the cultivated pepper Zunla-1 (C. annuum L.) and its wild progenitor Chiltepin (C. annuum var. glabriusculum). We estimate that the pepper genome expanded ∼0.3 Mya (with respect to the genome of other Solanaceae) by a rapid amplification of retrotransposons elements, resulting in a genome comprised of ∼81% repetitive sequences. Approximately 79% of 3.48-Gb scaffolds containing 34,476 protein-coding genes were anchored to chromosomes by a high-density genetic map. Comparison of cultivated and wild pepper genomes with 20 resequencing accessions revealed molecular footprints of artificial selection, providing us with a list of candidate domestication genes. We also found that dosage compensation effect of tandem duplication genes probably contributed to the pungent diversification in pepper. The Capsicum reference genome provides crucial information for the study of not only the evolution of the pepper genome but also, the Solanaceae family, and it will facilitate the establishment of more effective pepper breeding programs.de novo genome sequence | genome expansion | Solanaceae evolution

Tumor-associated macrophages (TAMs) are associated with tumor progression and metastasis. Here, we demonstrate for the first time that legumain, a member of the asparaginyl endopeptidase family functioning as a stress protein, overexpressed by TAMs, provides an ideal target molecule. In fact, a legumain-based DNA vaccine served as a tool to prove this point, as it induced a robust CD8 + T cell response against TAMs, which dramatically reduced their density in tumor tissues and resulted in a marked decrease in proangiogenic factors released by TAMs such as TGF-b, TNF-a, MMP-9, and VEGF. This, in turn, led to a suppression of both tumor angiogenesis and tumor growth and metastasis. Importantly, the success of this strategy was demonstrated in murine models of metastatic breast, colon, and non-small cell lung cancers, where 75% of vaccinated mice survived lethal tumor cell challenges and 62% were completely free of metastases. In conclusion, decreasing the number of TAMs in the tumor stroma effectively altered the tumor microenvironment involved in tumor angiogenesis and progression to markedly suppress tumor growth and metastasis. Gaining better insights into the mechanisms required for an effective intervention in tumor growth and metastasis may ultimately lead to new therapeutic targets and better anticancer strategies. IntroductionA novel antitumor strategy is immunization against molecules overexpressed by tumor-associated macrophages (TAMs) and thereby remodel the tumor microenvironment that attracts these macrophages and mediates their function (1, 2). TAMs consist primarily of a polarized M2 (F4/80 + /CD206 + ) macrophage population with little cytotoxicity for tumor cells because of their limited production of NO and proinflammatory cytokines (3). TAMs also possess poor antigen-presenting capability and effectively suppress T cell activation. In fact, these macrophages of M2 phenotype actually promote tumor cell proliferation and metastasis by secreting a wide range of growth and proangiogenic factors as well as metalloproteinases and by their involvement in signaling circuits that regulate the function of fibroblasts in the tumor stroma (4). In recent studies, anti-TAM effects induced by small molecule inhibitors contributed to tumor suppression (5, 6). For example, the antineoplastic agent Yondelis has a selective cytotoxic effect on TAMs, thereby significantly reducing their production of IL-6 and CCL2, which, in turn, contribute to growth suppression of inflammation-associated human tumors (7). Another such example is provided by a biphosphonate compound, zoledronic acid, that suppresses MMP-9 secretion by TAMs, thereby inhibiting tumor metalloproteinase activity and diminishing the association of VEGF with its tyrosine kinase receptors on proliferating endothelial cells (8). In a different experimental model, the chemokine CCL5 was shown to be key in the recruitment of TAMs, and an antagonist of this chemokine reduced the tumor infiltrate and slowed tumor growth (9). Hence, although the therapeutic ta...

BackgroundLocal inflammation associated with solid tumors commonly results from factors released by tumor cells and the tumor stroma, and promotes tumor progression. Cancer associated fibroblasts comprise a majority of the cells found in tumor stroma and are appealing targets for cancer therapy. Here, our aim was to determine the efficacy of targeting cancer associated fibroblasts for the treatment of metastatic breast cancer.Methodology/Principal FindingsWe demonstrate that cancer associated fibroblasts are key modulators of immune polarization in the tumor microenvironment of a 4T1 murine model of metastatic breast cancer. Elimination of cancer associated fibroblasts in vivo by a DNA vaccine targeted to fibroblast activation protein results in a shift of the immune microenvironment from a Th2 to Th1 polarization. This shift is characterized by increased protein expression of IL-2 and IL-7, suppressed recruitment of tumor-associated macrophages, myeloid derived suppressor cells, T regulatory cells, and decreased tumor angiogenesis and lymphangiogenesis. Additionally, the vaccine improved anti-metastatic effects of doxorubicin chemotherapy and enhanced suppression of IL-6 and IL-4 protein expression while increasing recruitment of dendritic cells and CD8+ T cells. Treatment with the combination therapy also reduced tumor-associated Vegf, Pdgfc, and GM-CSF mRNA and protein expression.Conclusions/SignificanceOur findings demonstrate that cancer associated fibroblasts promote tumor growth and metastasis through their role as key modulators of immune polarization in the tumor microenvironment and are valid targets for therapy of metastatic breast cancer.

Cancers with dysfunctional mutations in BRCA1 or BRCA2, most commonly associated with some breast cancers, are deficient in the DNA damage repair pathway called homologous recombination (HR), which makes them exquisitely vulnerable to poly(ADP-ribose) polymerase (PARP) inhibitors, such as olaparib. This functional state and therapeutic sensitivity is referred to as “BRCAness”. Pharmaceutical induction of BRCAness could expand the use of PARP inhibitors to other tumor types. For example, BRCA mutations are present in only a small proportion of prostate cancer (PCa) patients. We found that castration-resistant PCa (CRPC) cells increased expression of a set of HR-associated genes, including BRCA1, RAD54L and RMI2. Androgen-targeted therapy is typically not effective in CRPC patients. However, the androgen receptor (AR) inhibitor enzalutamide suppressed the expression of those HR genes, thus creating HR deficiency and BRCAness in CRPC cells. In a manner dependent on these gene expression effects, a “lead-in” treatment strategy, in which enzalutamide was followed by the combination of enzalutamide and olaparib, promoted DNA damage-induced cell death and inhibited clonal proliferation of PCa cells in culture and suppressed the growth of PCa xenografts in mice. Thus, our study suggests that anti-androgen and PARP inhibitor combination therapy may be effective for patients with CRPC, and that pharmaceutically-induced BRCAness may expand the clinical use of PARP inhibitors.

Immunotherapy is regarded as the most promising treatment for cancers. Various cancer immunotherapies, including adoptive cellular immunotherapy, tumor vaccines, antibodies, immune checkpoint inhibitors, and small-molecule inhibitors, have achieved certain successes. In this review, we summarize the role of macrophages in current immunotherapies and the advantages of targeting macrophages. To better understand and make better use of this type of cell, their development and differentiation characteristics, categories, typical markers, and functions were collated at the beginning of the review. Therapeutic strategies based on or combined with macrophages have the potential to improve the treatment efficacy of cancer therapies.

The cancer stem cell (CSC) hypothesis has gained significant recognition as a descriptor of tumorigenesis. Additionally, tumor-associated macrophages (TAMs) are known to promote growth and metastasis of breast cancer. However, it is not known whether TAMs mediate tumorigenesis through regulation of breast CSCs. Here, we report that TAMs promote CSC-like phenotypes in murine breast cancer cells by upregulating their expression of Sox-2. These CSC-like phenotypes were characterized by increased Sox-2, Oct-4, Nanog, AbcG2, and Sca-1 gene expression, in addition to increased drug-efflux capacity, resistance to chemotherapy, and increased tumorigenicity in vivo. Downregulation of Sox-2 in tumor cells by siRNA blocked the ability of TAMs to induce these CSC-like phenotypes and inhibited tumor growth in vivo. Furthermore, we identified a novel epidermal growth factor receptor (EGFR)/signal transducers and activators of transcription 3 (Stat3)/Sox-2 paracrine signaling pathway between macrophages and mouse breast cancer cells that is required for macrophage-induced upregulation of Sox-2 and CSC phenotypes in tumor cells. We showed that this crosstalk was effectively blocked by the small molecule inhibitors AG1478 or CDDO-Im against EGFR and Stat3, respectively. Therefore, our report identifies a novel role for TAMs in breast CSC regulation and establishes a rationale for targeting the EGFR/Stat3/Sox-2 signaling pathway for CSC therapy. STEM CELLS 2013;31:248-258 Disclosure of potential conflicts of interest is found at the end of this article.

Background Conditioned fear memories can be updated by extinction during reconsolidation, and this effect is specific to the reactivated conditioned stimulus (CS). However, a traumatic event can be associated with several cues, and each cue can potentially trigger recollection of the event. In the present study, we introduced a technique to target all diverse cues associated with an aversive event that causes fear. Methods In the human experiments, the subjects underwent modified fear conditioning, in which they were exposed to an unconditioned stimulus (US) or unreinforced CS to reactivate the memory and then underwent extinction, spontaneous recovery, and reinstatement. In the animal experiments, rats underwent contextual fear conditioning under a similar protocol as the used in the human experiments. We also explored the molecular alterations after US reactivation in rats. Results We found that presentation of a lower-intensity US following extinction disrupted the associations between the different CSs and reactivated US in both humans and rats. This disruptive effect persisted for at least 6 months in humans and was selective to the reactivated US. This procedure was also effective for remote memories in both humans and rats. Compared with the CS, the US induced stronger endocytosis of AMPA glutamate receptors 1 and 2 and stronger activation of protein kinase A, p70S6 kinase, and cyclic adenosine monophosphate response element binding protein in the dorsal hippocampus in rats. Conclusions These findings demonstrate that a modified US retrieval-extinction strategy may have a potential impact on therapeutic approaches to prevent the return of fear.