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Purpose Preclinical evidence suggests that natural killer cell (NK-cell) function and myokines facilitate the protective effects of exercise for breast cancer prevention. Since higher-intensity exercise acutely promotes greater mobilization and larger changes in NK-cell cytotoxicity than lower-intensity, high-intensity interval training (HIIT) might offer increased immune protection compared to moderate-intensity continuous-training (MICT). This study compared a 12-week HIIT program to a 12-week MICT program and usual care on changes in resting NK-cell function and circulating myokines among women at high risk for breast cancer. Methods Thirty-three women were randomized to HIIT, MICT, or usual care, for a supervised exercise intervention. Blood was collected at baseline and end-of-study. The cytotoxic activity of CD3−/CD56+ NK-cells against the K562 target cell line in vitro was determined by flow cytometry. Circulating myokines (IL-15, IL-6, irisin, OSM, osteonectin, IL-7) were assessed with luminex multiplex assays and ELISA. One-way ANOVA and paired sample t-tests assessed between- and within-group differences, respectively. Pearson correlation coefficients determined relationships between baseline fitness and change variables. Results Significant differences were not observed between groups for change in NK-cell function or circulating myokines (p > 0.05). Significant correlations were only observed for baseline peak aerobic capacity (ml/kg/min) and change in NK-cell-specific lysis (r = − 0.43, p = 0.02) and hemacytotoxicity for the total sample (r = − 0.46, p = 0.01). Conclusion Our findings suggest that exercise intensity may not significantly impact change in resting NK-cell function and circulating myokines among women at high risk for breast cancer. Structured exercise training may have a larger impact on NK-cell function in those with lower levels of cardiorespiratory fitness. Clinical trial registration: NCT02923401; Registered on October 4, 2016

Background Type II diabetes mellitus (DM2) is a significant risk factor for cancers, including breast cancer. However, a proper diabetic breast cancer mouse model is not well‐established for treatment strategy design. Additionally, the precise diabetic signaling pathways that regulate cancer growth remain unresolved. In the present study, we established a suitable mouse model and demonstrated the pathogenic role of diabetes on breast cancer progression. Methods We successfully generated a transgenic mouse model of human epidermal growth factor receptor 2 positive (Her2+ or ERBB2) breast cancer with DM2 by crossing leptin receptor mutant (Leprdb/+) mice with MMTV‐ErbB2/neu) mice. The mouse models were administrated with antidiabetic drugs to assess the impacts of controlling DM2 in affecting tumor growth. Magnetic resonance spectroscopic imaging was employed to analyze the tumor metabolism. Results Treatment with metformin/rosiglitazone in MMTV‐ErbB2/Leprdb/db mouse model reduced serum insulin levels, prolonged overall survival, decreased cumulative tumor incidence, and inhibited tumor progression. Anti‐insulin resistance medications also inhibited glycolytic metabolism in tumors in vivo as indicated by the reduced metabolic flux of hyperpolarized 13C pyruvate‐to‐lactate reaction. The tumor cells from MMTV‐ErbB2/Leprdb/db transgenic mice treated with metformin had reprogrammed metabolism by reducing levels of both oxygen consumption and lactate production. Metformin decreased the expression of Myc and pyruvate kinase isozyme 2 (PKM2), leading to metabolism reprogramming. Moreover, metformin attenuated the mTOR/AKT signaling pathway and altered adipokine profiles. Conclusions MMTV‐ErbB2/Leprdb/db mouse model was able to recapitulate diabetic HER2+ human breast cancer. Additionally, our results defined the signaling pathways deregulated in HER2+ breast cancer under diabetic condition, which can be intervened by anti‐insulin resistance therapy., Our results define the signaling pathways deregulated in HER2+ breast cancer under diabetic condition, which can be intervened by anti‐insulin resistance therapy.

The ability of a receptor to preferentially activate only a subset of available downstream signal cascades is termed biased signaling. Although comprehensively recognized for the G protein–coupled receptors (GPCR), this process is scarcely explored downstream of receptor tyrosine kinases (RTK), including the cancer-relevant insulin-like growth factor-1 receptor (IGF1R). Successful IGF1R targeting requires receptor downregulation, yet therapy-mediated removal from the cell surface activates cancer-protective β-arrestin–biased signaling (β-arr-BS). As these overlapping processes are initiated by the β-arr/IGF1R interaction and controlled by GPCR-kinases (GRK), we explored GRKs as potential anticancer therapeutic targets to disconnect IGF1R downregulation and β-arr-BS. Transgenic modulation demonstrated that GRK2 inhibition or GRK6 overexpression enhanced degradation of IGF1R, but both scenarios sustained IGF1–induced β-arr-BS. Pharmacologic inhibition of GRK2 by the clinically approved antidepressant, serotonin reuptake inhibitor paroxetine (PX), recapitulated the effects of GRK2 silencing with dose- and time-dependent IGF1R downregulation without associated β-arr-BS. In vivo, PX treatment caused substantial downregulation of IGF1R, suppressing the growth of Ewing's sarcoma xenografts. Functional studies reveal that PX exploits the antagonism between β-arrestin isoforms; in low ligand conditions, PX favored β-arrestin1/Mdm2-mediated ubiquitination/degradation of IGF1R, a scenario usually exclusive to ligand abundancy, making PX more effective than antibody-mediated IGF1R downregulation. This study provides the rationale, molecular mechanism, and validation of a clinically feasible concept for “system bias” targeting of the IGF1R to uncouple downregulation from signaling. Demonstrating system bias as an effective anticancer approach, our study reveals a novel strategy for the rational design or repurposing of therapeutics to selectively cross-target the IGF1R or other RTK. Significance: This work provides insight into the molecular and biological roles of biased signaling downstream RTK and provides a novel “system bias” strategy to increase the efficacy of anti–IGF1R-targeted therapy in cancer.

Myelofibrosis (MF) is a myeloproliferative neoplasm characterized by cytopenia and extramedullary hematopoiesis, resulting in splenomegaly. Multiple pathological mechanisms (e.g., circulating cytokines and genetic alterations, such as JAKV617F mutation) have been implicated in the etiology of MF, but the molecular mechanism causing resistance to JAK2V617F inhibitor therapy remains unknown. Among MF patients who were treated with the JAK inhibitor ruxolitinib, we compared noncoding RNA profiles of ruxolitinib therapy responders versus nonresponders and found miR-543 was significantly upregulated in nonresponders. We validated these findings by reverse transcription–quantitative PCR. in this same cohort, in 2 additional independent MF patient cohorts from the United States and Romania, and in a JAK2V617F mouse model of MF. Both in vitro and in vivo models were used to determine the underlying molecular mechanism of miR-543 in MF. Here, we demonstrate that miR-543 targets the dioxygenases ten-eleven translocation 1 (TET1) and 2 (TET2) in patients and in vitro, causing increased levels of global 5-methylcytosine, while decreasing the acetylation of histone 3, STAT3, and tumor protein p53. Mechanistically, we found that activation of STAT3 by JAKs epigenetically controls miR-543 expression via binding the promoter region of miR-543. Furthermore, miR-543 upregulation promotes the expression of genes related to drug metabolism, including CYP3A4, which is involved in ruxolitinib metabolism. Our findings suggest miR-543 as a potentially novel biomarker for the prognosis of MF patients with a high risk of treatment resistance and as a potentially new target for the development of new treatment options The work in GAC’s laboratory was partly supported by NIH/National Center for Advancing Translational Sciences grant UH3TR00943-01, the NIH/National Cancer Institute (NCI) grant 1 R01 CA182905-01, U54 grant UPR/MDACC Partnership for Excellence in Cancer Research 2016 Pilot Project, Team Department of Defense grant CA160445P1, a Ladies Leukemia League grant, a Chronic Lymphocytic Leukemia Moonshot Flagship project, a Sister Institution Network Fund 2017 grant, and the Estate of C. G. Johnson, Jr. EFM was supported in part by award number P50 CA140388 from the NCI and by the NIH Clinical Research Loan Repayment Program. AMS was supported by Fundação para a Ciência e a Tecnologia through fellowship SFRH/BD/85968/2012. ZJZ’s work was supported by grants from the MPN Foundation and the Oklahoma Center for the Advancement of Science and Technology. DG, MPD, and IBN were supported in part by a Programul Opera¿ional Competitivitate grant nr35/01.09.2016, ID 37_796, titled “Clinical and economical impact of personalized targeted anti-mi-croRNA therapies in reconverting lung cancer chemoresistance” (CANTEMIR). NSDA was supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo, BEPE 2016/09349-4.

ObjectiveTo investigate the function of a novel primate-specific long non-coding RNA (lncRNA), named FLANC, based on its genomic location (co-localised with a pyknon motif), and to characterise its potential as a biomarker and therapeutic target.DesignFLANC expression was analysed in 349 tumours from four cohorts and correlated to clinical data. In a series of multiple in vitro and in vivo models and molecular analyses, we characterised the fundamental biological roles of this lncRNA. We further explored the therapeutic potential of targeting FLANC in a mouse model of colorectal cancer (CRC) metastases.ResultsFLANC, a primate-specific lncRNA feebly expressed in normal colon cells, was significantly upregulated in cancer cells compared with normal colon samples in two independent cohorts. High levels of FLANC were associated with poor survival in two additional independent CRC patient cohorts. Both in vitro and in vivo experiments demonstrated that the modulation of FLANC expression influenced cellular growth, apoptosis, migration, angiogenesis and metastases formation ability of CRC cells. In vivo pharmacological targeting of FLANC by administration of 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine nanoparticles loaded with a specific small interfering RNA, induced significant decrease in metastases, without evident tissue toxicity or pro-inflammatory effects. Mechanistically, FLANC upregulated and prolonged the half-life of phosphorylated STAT3, inducing the overexpression of VEGFA, a key regulator of angiogenesis.ConclusionsBased on our findings, we discovered, FLANC as a novel primate-specific lncRNA that is highly upregulated in CRC cells and regulates metastases formation. Targeting primate-specific transcripts such as FLANC may represent a novel and low toxic therapeutic strategy for the treatment of patients.

BackgroundDiabetes mellitus type 2 (DM2) is a modifiable risk factor associated with pancreatic carcinogenesis and tumor progression on the basis of epidemiology studies, but the biological mechanisms are not completely understood. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating these epidemiologic phenomena. Our hypothesis is that DM2 accelerates pancreatic cancer growth and that metformin treatment has a beneficial impact.MethodsTo determine the effect of glucose and insulin in pancreatic cancer proliferation, we used conditioned media to mimic DM2 conditions. Also, we studied the effect of anti-diabetic drugs, particularly metformin and rosiglitazone on pancreatic cancer growth. We established orthotopic/syngeneic (Leprdb/db) mouse cancer models to evaluate the effect of diabetes on pancreatic tumor growth and aggressiveness.ResultsOur results showed that diabetes promotes pancreatic tumor growth. Furthermore, enhanced tumor growth and aggressiveness (e.g. epithelial–mesenchymal transition) can be explained by functional transcriptomic and metabolomic changes in the mice with diabetes, namely via activation of the AKT/mTOR pathway. Metformin treatment suppressed the diabetes-induced AKT/mTOR pathway activation and tumor growth. The metabolic profile determined by mass spectrum showed important changes of metabolites in the pancreatic cancer derived from diabetic mice treated with metformin.ConclusionsDiabetes mellitus type 2 has critical effects that promote pancreatic cancer progression via transcriptomic and metabolomic changes. Our animal models provide strong evidence for the causal relationship between diabetes and accelerated pancreatic cancers. This study sheds a new insight into the effects of metformin and its potential as part of therapeutic interventions for pancreatic cancer in diabetic patients.

Purpose: The oncogenic miR-155 is upregulated in many human cancers, and its expression is increased in more aggressive and therapy-resistant tumors, but the molecular mechanisms underlying miR-155-induced therapy resistance are not fully understood. The main objectives of this study were to determine the role of miR-155 in resistance to chemotherapy and to evaluate anti-miR-155 treatment to chemosensitize tumors. Experimental Design: We performed in vitro studies on cell lines to investigate the role of miR-155 in therapy resistance. To assess the effects of miR-155 inhibition on chemoresistance, we used an in vivo orthotopic lung cancer model of athymic nude mice, which we treated with anti-miR-155 alone or in combination with chemotherapy. To analyze the association of miR-155 expression and the combination of miR-155 and TP53 expression with cancer survival, we studied 956 patients with lung cancer, chronic lymphocytic leukemia, and acute lymphoblastic leukemia. Results: We demonstrate that miR-155 induces resistance to multiple chemotherapeutic agents in vitro, and that downregulation of miR-155 successfully resensitizes tumors to chemotherapy in vivo. We show that anti-miR-155-DOPC can be considered non-toxic in vivo. We further demonstrate that miR-155 and TP53 are linked in a negative feedback mechanism and that a combination of high expression of miR-155 and low expression of TP53 is significantly associated with shorter survival in lung cancer. Conclusions: Our findings support the existence of an miR-155/TP53 feedback loop, which is involved in resistance to chemotherapy and which can be specifically targeted to overcome drug resistance, an important cause of cancer-related death. Clin Cancer Res; 23(11); 2891–904. ©2016 AACR.

It is becoming apparent that spatio-temporally controlled patterns of DNA methylation and histone modifications ensure that each cell in the body gets differentiated into its required cell fate during normal development. It is a well-coordinated and tightly synchronized unidirectional process that involves stepwise gene silencing associated with developmental stages, as well as the activation of tissue-specific programming of genes. However, dysregulations in epigenetic modifications can severely disturb normal developmental pathways, thus leading to cancer development and progression. Furthermore, increasing lists of research publications are examining tumor suppressor and oncogenic miRNAs, which are epigenetically modified in different cancers, as well as upregulated long non-coding RNAs acting as miRNA sponges.

Background Progression of conventional urothelial carcinoma of the bladder to a tumor with unique microscopic features referred to as micropapillary carcinoma is coupled with aggressive clinical behavior signified by a high propensity for metastasis to regional lymph nodes and distant organs resulting in shorter survival. Objective To analyze the expression profile of micropapillary cancer and define its molecular features relevant to clinical behavior. Design, setting, and participants We retrospectively identified 43 patients with micropapillary bladder cancers and a reference set of 89 patients with conventional urothelial carcinomas and performed whole-genome expression messenger RNA profiling. Outcome measurements and statistical analysis The tumors were segregated into distinct groups according to hierarchical clustering analyses. They were also classified according to luminal, p53-like, and basal categories using a previously described algorithm. We applied Ingenuity Pathway Analysis software (Qiagen, Redwood City, CA, USA) and gene set enrichment analysis for pathway analyses. Cox proportional hazards models and Kaplan-Meier methods were used to assess the relationship between survival and molecular subtypes. The expression profile of micropapillary cancer was validated for selected markers by immunohistochemistry on parallel tissue microarrays. Results and limitations We show that the striking features of micropapillary cancer are downregulation of miR-296 and activation of chromatin-remodeling complex RUVBL1. In contrast to conventional urothelial carcinomas that based on their expression can be equally divided into luminal and basal subtypes, micropapillary cancer is almost exclusively luminal, displaying enrichment of active peroxisome proliferator-activated receptor γ and suppression of p63 target genes. As with conventional luminal urothelial carcinomas, a subset of micropapillary cancers exhibit activation of wild-type p53 downstream genes and represent the most aggressive molecular subtype of the disease with the shortest survival. The involvement of miR-296 and RUVBL1 in the development of micropapillary bladder cancer was identified by the analyses of correlative associations of genome expression profiles and requires mechanistic validation. Conclusions Micropapillary cancer evolves through the luminal pathway and is characterized by the activation of miR-296 and RUVBL1 target genes. Patient summary Our observations have important implications for prognosis and for possible future development of more effective therapies for micropapillary bladder cancer.

The pervasive role of microRNAs (miRNAs) in cancer pathobiology drives the introduction of new drug development approaches such as miRNA inhibition. In order to advance miRNA-therapeutics, meticulous screening strategies addressing specific tumor targets are needed. Small molecule inhibitors represent an attractive goal for these strategies. In this study, we devised a strategy to screen for small molecule inhibitors that specifically inhibit, directly or indirectly, miR-10b (SMIRs) which is overexpressed in metastatic tumors. We found that the multi-tyrosine kinase inhibitor linifanib could significantly inhibit miR-10b and reverse its oncogenic function in breast cancer and liver cancer both in vitro and in vivo. In addition, we showed that the efficacy of linifanib to inhibit tyrosine kinases was reduced by high miR-10b levels. When the level of miR-10b is high, it can “hijack” the linifanib and reduce its kinase inhibitory effects in cancer resulting in reduced anti-tumor efficacy. In conclusion, our study describes an effective strategy to screen for small molecule inhibitors of miRNAs. We further propose that miR-10b expression levels, due to the newly described “hijacking” effect, may be used as a biomarker to select patients for linifanib treatment.

Breast cancer represents one of the most common forms of cancer in women worldwide, with an increase in the number of newly diagnosed patients in the last decade. The role of fatty acids, particularly of a diet rich in ω-3 and ω-6 polyunsaturated fatty acids (PUFAs), in breast cancer development is not fully understood and remains controversial due to their complex mechanism of action. However, a large number of animal models and cell culture studies have demonstrated that high levels of ω-3 PUFAs have an inhibitory role in the development and progression of breast cancer, compared to ω-6 PUFAs. The present review focused on recent studies regarding the correlation between dietary PUFAs and breast cancer development, and aimed to emphasize the main molecular mechanisms involved in the modification of cell membrane structure and function, modulation of signal transduction pathways, gene expression regulation, and antiangiogenic and antimetastatic effects. Furthermore, the anticancer role of ω-3 PUFAs through the modulation of microRNA expression levels was also reviewed.

The regulation of microRNA (miRNA) biogenesis, function and degradation involves a range of mechanisms, including interactions with RNA-binding proteins. The potential contribution of regulatory miRNAs to the expression of these RNA interactor proteins that could control other miRNAs expression is still unclear. Here we demonstrate a regulatory circuit involving oncogenic and tumor-suppressor miRNAs and an RNA-binding protein in a chemotherapy-resistant ovarian cancer model. We identified and characterized miR-15a-5p and miR-25-3p as negative regulators of hnRNPA1 expression, which is required for the processing of miR-18a-3p, an inhibitor of the K-RAS oncogene. The inhibition of miR-25-3p and miR-15a-5p decreased the proliferation, motility, invasiveness and angiogenic potential and increased apoptosis when combined with docetaxel. Alteration of this regulatory circuit causes poor overall survival outcome in ovarian cancer patients. These results highlight miR-15a-5p and miR-25-3p as key regulators of miR-18a-3p expression and its downstream target K-RAS, through direct modulation of hnRNPA1 expression. Our results demonstrate the therapeutic potential of inhibiting miR-25-3p and miR-15a-5p and the use of miR-18a-3p/KRAS ratio as a prominent outcome prognostic factor.

Previously we have reported that metastatic melanoma cell lines and tumor specimens have reduced expression of ADAR1 and consequently are impaired in their ability to perform A-to-I microRNA (miRNA) editing. The effects of A-to-I miRNAs editing on melanoma growth and metastasis are yet to be determined. Here we report that miR-378a–3p is undergoing A-to-I editing only in the non-metastatic but not in metastatic melanoma cells. The function of the edited form is different from its wild-type counterpart. The edited form of miR-378a-3p preferentially binds to the 3′-UTR of the PARVA oncogene and inhibits its expression, thus preventing the progression of melanoma towards the malignant phenotype. Indeed, edited miR-378a-3p but not its WT form inhibits melanoma metastasis in vivo. These results further emphasize the role of RNA editing in melanoma progression., In melanoma, reduced ADAR1 impairs A-to-I microRNA editing. Here, the authors show that miR-378a-3p undergoes this editing in non-metastatic cells and the edited form of miR-378a-3p binds to the PARVA oncogene, inhibiting its expression and preventing melanoma progression and metastasis.

Obesity is associated with an increased risk of developing breast cancer and is also associated with worse clinical prognosis. The mechanistic link between obesity and breast cancer progression remains unclear, and there has been no development of specific treatments to improve the outcome of obese cancer patients. Here we show that obesity-associated NLRC4 inflammasome activation/ interleukin (IL)-1 signalling promotes breast cancer progression. The tumour microenvironment in the context of obesity induces an increase in tumour-infiltrating myeloid cells with an activated NLRC4 inflammasome that in turn activates IL-1β, which drives disease progression through adipocyte-mediated vascular endothelial growth factor A (VEGFA) expression and angiogenesis. Further studies show that treatment of mice with metformin inhibits obesity-associated tumour progression associated with a marked decrease in angiogenesis. This report provides a causal mechanism by which obesity promotes breast cancer progression and lays out a foundation to block NLRC4 inflammasome activation or IL-1β signalling transduction that may be useful for the treatment of obese cancer patients., Obesity is associated with higher breast cancer risk and poor prognosis. Here, the authors show that obesity promotes breast cancer through the recruitment of macrophages with activated NLRC4 inflammasome, which activate IL-1β production, resulting in VEGFA expression in adipocytes and angiogenesis.

Although recent studies have shown that adenosine-to-inosine (A-to-I) RNA editing occurs in microRNAs (miRNAs), the effects of A-to-I miRNAs editing on melanoma growth and metastasis are yet to be determined. Previously we have reported that metastatic melanoma cell lines and tumor specimens have reduced expression of ADAR1 and consequently are impaired in their ability to perform A-to-I microRNA (miRNA) editing. Here we report that miR-378a-3p is undergoing A-to-I editing only in the non-metastatic but not in metastatic melanoma cells. The function of the edited form is different from its wild-type counterpart. The edited form of miR-378a-3p preferentially binds to the 3'UTR of the PARVA oncogene and inhibits its expression, thus preventing the progression of melanoma towards the malignant phenotype. Indeed, edited miR- 378a-3p but not its WT form inhibits melanoma metastasis in vivo. These results further emphasize the role of RNA editing in melanoma progression. Citation Format: Einav Shoshan, Guermarie Velazquez-Torres, Enrique Fuentes-Mattei, Cristina Ivan, Menashe Bar-Eli. A-to-I miR-378a-3p editing prevents melanoma progression via regulation ofPARVA expression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr LB-384.

Adrenocortical carcinoma is a rare malignancy with poor prognosis and limited response to chemotherapy. Hepatocyte growth factor (HGF) and its receptor cMET augment cancer growth and resistance to chemotherapy, but their role in adrenocortical carcinoma has not been examined. In this study, we investigated the association between HGF/cMET expression and cancer hallmarks of adrenocortical carcinoma. Transcriptomic and immunohistochemical analyses indicated that increased HGF/cMET expression in human adrenocortical carcinoma samples was positively associated with cancer-related biologic processes, including proliferation and angiogenesis, and negatively correlated with apoptosis. Accordingly, treatment of adrenocortical carcinoma cells with exogenous HGF resulted in increased cell proliferation in vitro and in vivo while short hairpin RNA–mediated knockdown or pharmacologic inhibition of cMET suppressed cell proliferation and tumor growth. Moreover, exposure of cells to mitotane, cisplatin, or radiation rapidly induced pro-cMET expression and was associated with an enrichment of genes (e.g., CYP450 family) related to therapy resistance, further implicating cMET in the anticancer drug response. Together, these data suggest an important role for HGF/cMET signaling in adrenocortical carcinoma growth and resistance to commonly used treatments. Targeting cMET, alone or in combination with other drugs, could provide a breakthrough in the management of this aggressive cancer. Cancer Res; 75(19); 4131–42. ©2015 AACR.

SummaryBiomarkers for predicting prognosis are critical to treating colorectal cancer (CRC) patients. We found that CSN6, a subunit of COP9 signalosome, is overexpressed in CRC samples and that CSN6 overexpression is correlated with poor patient survival. Mechanistic studies revealed that CSN6 is deregulated by epidermal growth factor receptor (EGFR) signaling, in which ERK2 binds directly to CSN6 Leu163/Val165 and phosphorylates CSN6 at Ser148. Furthermore, CSN6 regulated β-Trcp and stabilized β-catenin expression by blocking the ubiquitin-proteasome pathway, thereby promoting CRC development. High CSN6 expression was positively correlated with ERK2 activation and β-catenin overexpression in CRC samples, and inhibiting CSN6 stability with cetuximab reduced colon cancer growth. Taken together, our study’s findings indicate that the deregulation of β-catenin by ERK2-activated CSN6 is important for CRC development.

Summary Extensive reprogramming of cellular energy metabolism is a hallmark of cancer. Despite its importance, the molecular mechanism controlling this tumour metabolic shift remains not fully understood. Here we show that 14-3-3σ regulates cancer metabolic reprogramming and protects cells from tumourigenic transformation. 14-3-3σ opposes tumour-promoting metabolic programs by enhancing c-Myc poly-ubiquitination and subsequent degradation. 14-3-3σ demonstrates the suppressive impact on cancer glycolysis, glutaminolysis, mitochondrial biogenesis and other major metabolic processes of tumours. Importantly, 14-3-3σ expression levels predict overall and recurrence-free survival rates, tumour glucose uptake and metabolic gene expression in breast cancer patients. Thus, these results highlight that 14-3-3σ is an important regulator of tumour metabolism, and loss of 14-3-3σ expression is critical for cancer metabolic reprogramming. We anticipate that pharmacologically elevating the function of 14-3-3σ in tumours could be a promising direction for targeted anti-cancer metabolism therapy development in future.

Ovarian cancer is a highly metastatic disease, but no effective strategies to target this metastatic process currently are known. Here, an integrative computational analysis of The Cancer Genome Atlas ovarian cancer dataset coupled with experimental validation identified a novel zinc finger transcription factor ZNF304 as one of the key factors for ovarian cancer metastasis. High tumoral ZNF304 expression was associated with poor overall survival in ovarian cancer patients. Through reverse phase protein array analysis, we demonstrated that ZNF304 promotes multiple proto-oncogenic pathways important for cell survival, migration, and invasion. ZNF304 transcriptionally regulates β1 integrin, which subsequently regulates Src/focal adhesion kinase and paxillin and prevents anoikis. In vivo delivery of ZNF304 siRNA by a novel dual assembly nanoparticle led to sustained gene silencing for 14 days, increased anoikis, and reduced tumor growth in orthotopic mouse models of ovarian cancer. Taken together, ZNF304 is a novel transcriptional regulator of β1 integrin, promotes cancer cell survival, and protects against anoikis in ovarian cancer.

Summary Cullin-RING ubiquitin ligases (CRL) are critical in ubiquitinating Myc, while COP9 signalosome (CSN) controls neddylation of Cullin in CRL. The mechanistic link between Cullin neddylation and Myc ubiquitination/degradation is unclear. Here we show that Myc is a target of the CSN subunit 6 (CSN6)–Cullin signaling axis and that CSN6 is a positive regulator of Myc. CSN6 enhanced neddylation of Cullin-1 and facilitated auto-ubiquitination/degradation of Fbxw7, a component of CRL involved in Myc ubiquitination, thereby stabilizing Myc. Csn6 haplo-insufficiency decreased Cullin-1 neddylation but increased Fbxw7 stability to compromise Myc stability and activity in an Eµ-Myc mouse model, resulting in decelerated lymphomagenesis. We found that CSN6 overexpression, which leads to aberrant expression of Myc target genes, is frequent in human cancers. Together, these results define a mechanism for the regulation of Myc stability through the CSN-Cullin-Fbxw7 axis and provide insights into the correlation of CSN6 overexpression with Myc stabilization/activation during tumorigenesis.

Purpose: Zoledronic acid is being increasingly recognized for its antitumor properties, but the underlying functions are not well understood. In this study, we hypothesized that zoledronic acid inhibits ovarian cancer angiogenesis preventing Rac1 activation. Experimental Design: The biologic effects of zoledronic acid were examined using a series of in vitro [cell invasion, cytokine production, Rac1 activation, reverse-phase protein array, and in vivo (orthotopic mouse models)] experiments. Results: There was significant inhibition of ovarian cancer (HeyA8-MDR and OVCAR-5) cell invasion as well as reduced production of proangiogenic cytokines in response to zoledronic acid treatment. Furthermore, zoledronic acid inactivated Rac1 and decreased the levels of Pak1/p38/matrix metalloproteinase-2 in ovarian cancer cells. In vivo, zoledronic acid reduced tumor growth, angiogenesis, and cell proliferation and inactivated Rac1 in both HeyA8-MDR and OVCAR-5 models. These in vivo antitumor effects were enhanced in both models when zoledronic acid was combined with nab-paclitaxel. Conclusions: Zoledronic acid has robust antitumor and antiangiogenic activity and merits further clinical development as ovarian cancer treatment. Clin Cancer Res; 21(9); 2127–37. ©2015 AACR.

Background Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor–positive (ER+) breast cancer, but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiologic phenomenon. Methods We analyzed transcriptomic profiles of pretreatment biopsies from a prospective cohort of 137 ER+ breast cancer patients. We generated transgenic (MMTV-TGFα;A y /a) and orthotopic/syngeneic (A y /a) obese mouse models to investigate the effect of obesity on tumorigenesis and tumor progression and to determine biological mechanisms using whole-genome transcriptome microarrays and protein analyses. We used a coculture system to examine the impact of adipocytes/adipokines on breast cancer cell proliferation. All statistical tests were two-sided. Results Functional transcriptomic analysis of patients revealed the association of obesity with 59 biological functional changes (P < .05) linked to cancer hallmarks. Gene enrichment analysis revealed enrichment of AKT-target genes (P = .04) and epithelial–mesenchymal transition genes (P = .03) in patients. Our obese mouse models demonstrated activation of the AKT/mTOR pathway in obesity-accelerated mammary tumor growth (3.7- to 7.0-fold; P < .001; n = 6–7 mice per group). Metformin or everolimus can suppress obesity-induced secretion of adipokines and breast tumor formation and growth (0.5-fold, P = .04; 0.3-fold, P < .001, respectively; n = 6–8 mice per group). The coculture model revealed that adipocyte-secreted adipokines (eg, TIMP-1) regulate adipocyte-induced breast cancer cell proliferation and invasion. Metformin suppress adipocyte-induced cell proliferation and adipocyte-secreted adipokines in vitro. Conclusions Adipokine secretion and AKT/mTOR activation play important roles in obesity-accelerated breast cancer aggressiveness in addition to hyperinsulinemia, estrogen signaling, and inflammation. Metformin and everolimus have potential for therapeutic interventions of ER+ breast cancer patients with obesity.

Background Angiogenesis, the formation of new blood vessels from pre-existing vasculature, is a complex and crucial process for tumor growth and development of metastasis. Rac1, a member of the Rho GTPase family, plays a central role in angiogenesis through regulation of endothelial cell migration, tube formation, adhesion, invasion, and proliferation. In this study we hypothesized that zoledronic acid (ZA) inhibits ovarian cancer angiogenesis through the inactivation of Rac1. Methods We treated HeyA8 MDR and Ovcar-5 cells with ZA to assess its effects on cell invasion, proliferation, expression of matrix metalloproteinases (MMPs; Milliplex assay) and angiogenic factors. We also determined Rac1 activation by pull-down assay. HeyA8 MDR and Ovcar-5 orthotopic murine models of ovarian cancer were assessed for expression of CD31 and Ki-67, Rac1 activation, and apoptosis by immunohistochemistry after treatment with ZA, nanoparticle, albumin-bound paclitaxel (nab-paclitaxel), or a combination. Results In vitro, we observed inhibition of HeyA8 MDR and Ovcar-5 cell invasion and proliferation by ZA. Moreover, ZA decreased the secretion of MMP-7 and vascular endothelial growth factor C (VEGF-C) in HeyA8 MDR cells and MMP-9, MMP-10, VEGF-C, granulocyte-colony stimulating factor, endothelin-1, follistatin, interleukin-8, placenta growth factor, fibroblast growth factor-1, and hepatocyte growth factor in Ovcar-5 cells. Furthermore, ZA inactivated Rac1 in both cells lines. In vivo, ZA decreased the number of nodules and tumor weight, inhibited angiogenesis and cell proliferation, and increased apoptosis in both HeyA8 MDR and Ovcar-5 animal models. These in vivo antitumor effects were enhanced in both models when ZA was combined with nab-paclitaxel. Conclusion ZA inhibits ovarian cancer angiogenesis through the inactivation of Rac1, suggesting that ZA combined with paclitaxel could be a novel therapeutic approach to ovarian cancer angiogenesis. Citation Format: Viany Gonzalez-Villasana, Cristian Rodriguez-Aguayo, Enrique Fuentes-Mattei, Sunila Pradeep, Cristina Ivan, Anil K. Sood, Gabriel Lopez-Berestein. Zoledronic acid inhibits angiogenesis through Rac1 inactivation in ovarian cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2992. doi:10.1158/1538-7445.AM2014-2992

Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor-positive (ER+) breast cancer (BC), but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiological phenomenon. Transcriptomic profiles of pretreatment biopsies from a prospective cohort of 137 ER+ BC patients were analyzed. Transgenic and an orthotopic/syngeneic obese mouse models were created to phenocopy obese patients and evaluate the effect of obesity on breast carcinogenesis and tumor progression, and to explore further direct mechanisms. We used co-culture system to examine the impact of adipocytes and adipokines on BC cell proliferation. Functional transcriptomic analysis of patients revealed the association of obesity with many of the functional changes linked to cancer hallmarks. Our transgenic and orthotopic/syngeneic obese-mouse models recapitulated the functional transcriptomic landscape of obesity-associated changes seen in human patients and demonstrated the role of the Akt/mTOR pathway in obesity-induced breast carcinogenesis and tumor progression. Metformin and everolimus can suppress obesity-induced adipokines secretion and breast tumor formation and growth. An in vitro co-culture model revealed that adipocyte-secreted adipokines (e.g., TIMP-1) regulate adipocyte-induced BC cell proliferation and invasion. Metformin suppress adipocytes-induced cell proliferation and adipocytes-secreted adipokines in vitro. In conclusion, the patients' data provided evidence for the mechanistic involvement of adipokines in addition to estrogen, insulin and IGF-1 signaling in the link between obesity and ER+ BC. Our animal experiments provide strong evidence for the role of obesity on the accelerated breast carcinogenesis and obesity-induced tumor growth by activation of the Akt/mTOR signaling. Metformin and everolimus may be use as alternatives therapeutic interventions for BC patients with obesity. Citation Format: Enrique Fuentes-Mattei, Guermarie Velazquez-Torres, Liem Phan, Fanmao Zhang, Ping-Chieh Chou, Ji-Hyun Shin, Hyun-Ho Choi, Jiun-Sheng Chen, Ruiying Zhao, Jian Chen, Chris Gully, Colin Carlock, Yuan Qi, Ya Zhang, Yun Wu, Francisco Esteva, Yongde Luo, Wallace L. McKeehan, Joe E. Ensor, Gabriel N. Hortobagyi, Lajos Pusztai Pusztai, W. Fraser Symmans, Mong-Hong Lee, Sai-Ching J. Yeung. Obesity induces changes in adipokines profile and activates Akt/mTOR signaling accelerating breast carcinogenesis and tumor growth. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 3927. doi:10.1158/1538-7445.AM2014-3927

Obesity increases the risk of cancer death among postmenopausal women with estrogen receptor-positive (ER+) breast cancer, but the direct evidence for the mechanisms is lacking. The purpose of this study is to demonstrate direct evidence for the mechanisms mediating this epidemiologic phenomenon. Transcriptomic profiles of pretreatment biopsies from a prospective cohort of 137 ER+ breast cancer patients were analyzed. A transgenic and an orthotopic/syngeneic obese mouse models were created to phenocopy obese patients and evaluate the effect of obesity on breast carcinogenesis and tumor progression, and to explore further direct mechanisms. Functional transcriptomic analysis of untreated human ER+ breast cancer revealed that obesity was associated with increased insulin signaling among others. Many of the functional changes in obese patients were linked to cancer hallmarks. Obese mouse models recapitulated the functional transcriptomic landscape of obesity-associated changes seen in human ER+ breast cancer and demonstrated the role of the Akt/mTOR pathway in obesity-induced breast carcinogenesis and tumor progression. Functional transcriptomic analysis identified 85 biological functions common to humans and mice. An in vitro co-culture model revealed that adipocyte-secreted adipokines (e.g., TIMP-1) regulate adipocyte-induced breast cancer cell proliferation and invasion. The human transcriptomic data provided direct evidence for the roles of hyperinsulinemia, estrogen signaling, adipokine secretion, and inflammation in the link between obesity and ER+ breast cancer. Our animal experiments provide strong evidence for the causal relationship between obesity and accelerated carcinogenesis and cancer progression and for potential therapeutic interventions by blocking these signaling pathways. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-01-04.

Pancreatic cancer (PC) is characterized by a prominent stromal reaction. Recently, the contribution of the stromal elements to the initiation and progression of the disease has come to be appreciated. In this context, targeting this tumor microenvironment represents a potential strategy to improve the delivery and efficacy of chemotherapeutic agents leading a better prognosis for the patients. Pancreatic stellate cells (PSC) have been recognized as the principal cells responsible for the production of fibrosis in pancreatic cancer. In the current study, we observed that PSC possess α-naphthyl acetate esterase (ANAE) activity, which is a specific marker enzyme for monocytes and macrophages, these cells can be differentiated/activated in a similar fashion as a monocytes/macrophages, suggesting that PSC behave in a similar fashion as macrophages, and hence can be treated as such. Based on these data we targeted PSC in vitro and in vivo by using bisphosphonates (BPs) that are macrophages inhibitors. BPs inhibited proliferation and inactivated PSC in vitro through inhibition of protein prenylation, and increased cell apoptosis and cell cycle arrest in G1. Furthermore, BPs inactivated PSC, inhibited tumor growth (p Citation Format: Vianey Gonzalez-Villasana, Cristian Rodriguez-Aguayo, Thiru Arumugam, Zobeida Cruz-Monserrate, Defeng Deng, Enrique Fuentes-Mattei, Rosa F. Hwang, Huamin Wang, Guillermo N. Armaiz Pena, Burcu Aslan, Yolanda Gutierrez-Puente, Anil K. Sood, Craig Logsdon, Gabriel Lopez-Berestein. Targeting pancreatic stellate cells (PSC) to treat pancreatic cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4959. doi:10.1158/1538-7445.AM2013-4959

Aurora B (AurB) is a mitotic checkpoint kinase that plays a pivotal role in the cell cycle, ensuring correct chromosome segregation and normal progression through mitosis. Tumor suppressor p53 is a genome guardian and an important negative regulator of the cell cycle. Although overexpression of AurB and loss or degradation of p53 have been described in many types of human cancers, it is not known whether AurB and p53 are coordinately regulated during the cell cycle. Recently has been shown that NIR, which is a transcriptional co-repressor of histone acetyltransferase activity, interact with and suppress p53 via interaction with AurB. Our results show that AurB directly interacts with p53 in a NIR-independent matter. To prove direct molecular interaction between AurB and p53 in whole cells, we employed the method of bimolecular fluorescent complementation (BiFC). AurB-p53 interaction occurs at the nucleus in interphase and at the centromeres in prometaphase of mitosis. We observed that AurB-p53 interaction co-localized with Survivin and CENP-A, suggesting that AurB and p53 interact at the centromeres. Our results also show that Aurora B phosphorylates p53 to accelerate p53's degradation through the polyubiquitination-proteasome pathway, thus functionally suppressing the expression of p53 target genes involved in cell cycle inhibition and apoptosis. Inhibition of Aurora B in cancer cells with wild-type p53 increased p53 protein level and expression of p53 target genes to inhibit tumor growth. Together, these results give a new insight of a novel mechanism of p53 inactivation during the cell cycle and imply that oncogenic hyperactivation or overexpression of AurB may compromise p53's tumor suppressor function. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr LB-283. doi:1538-7445.AM2012-LB-283