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Background: MiRNAs are non-coding RNA molecules and its function is the regulation of gene expression. In cancer, the deregulation of miRNAs allows them to act as oncogenes or tumor suppressors. From an analysis of the expression of miRNAs in breast cancer (BC) in The Cancer Genome Atlas (TCGA), it was identified that miR-1307-3p is significantly overexpressed in the tumor tissue compared to healthy tissue from patients. So far, in BC, it has only been reported that this miRNA inhibits SMYD4 and that it is involved in resistance to cisplatin through its effect on Mdm4. In this project we propose to identify the role of miR-1307-3p in proliferation, migration, invasion, angiogenesis, and possible targets involved in these processes in BC cells. Methods: RT-qPCR was used to evaluate basal levels of miR-1307-3p in the BC cell lines MDA-MB-231 and MCF-7, and the human epithelial breast MCF-10A cells. Later, we determined the effect of miR-1307-3p on proliferation, migration, and invasion in MDA-MB-231 and MCF-7, and angiogenesis in the HUVEC endothelial cells. All assays were carried out using the miR-1307-3p inhibitor. Finally, nine miRNA-target prediction databases were analyzed to identify potential miR-1307-3p target genes, and their expression was analyzed by RT-qPCR in a designed 384-well plate. Results: We found that miR-1307-3p is overexpressed in MDA-MB-231 and MCF-7, compared to MCF-10A cells. We also identified that transfection with the miR-1307-3p inhibitor causes a significant decrease in the processes of proliferation, migration, invasion, and angiogenesis, when compared with untreated or negative control transfected cells. For its part, prediction databases analysis allowed us to identify 19 potential targets of miR-1307-3p. Finally, by RT-qPCR, the overexpression of 3 and the downregulation of 2 genes were confirmed. Conclusions: MiR-1307-3p is overexpressed in BC cells. Furthermore, miR-1307-3p induces the processes of proliferation, migration and invasion in BC cells, and angiogenesis in HUVEC cells. These observations suggest that miR-1307-3p can acts as an onco-miRNA. In addition, the expression of 5 of the predicted target genes were altered by miR-1307-3p inhibitor. Further analysis to validate the implication of this miR-1307-3p targets are needed to understand its importance in BC. Citation Format: José Roberto Estupiñan Jimenez, Valeria Villarreal-García, Ricardo Noriega, Recep Bayraktar, Diana Reséndez-Pérez, Cristina Rodríguez-Padilla, José Manuel Vázquez-Guillén, Fermín Mar-Aguilar, Gabriel Lopez-Berestein, Pablo E. Vivas-Mejía, Vianey Gonzalez-Villasana. Functional effect of miR-1307-3p on breast cancer progression [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-22-04.

Background: Breast cancer (BC) is the most diagnosed cancer in women worldwide. MicroRNAs (miRNAs) are involved in different processes of BC and their deregulation can cause them to act as oncogenes or tumor suppressors, participating in cancer progression or also as therapeutic target. Using The Cancer Genome Atlas (TCGA) database, we found that miR-660-5p is significantly overexpressed and associated with poor survival in patients with this pathology. Moreover, it is reported that miR-660-5p can induce BC progression through transcription factor CP2 (TFCP2) and the down regulation of tet-eleven translocation 2 (TET2). In this project, we propose to identify the role of miR-660-5p in proliferation, migration, invasion, angiogenesis, and possible targets involved in these processes in BC cell lines. Methods: Basal levels of miR-660-5p were determined in BC cells MDA-MB-231 and MCF-7, and in human epithelial breast cells MCF-10A by RT-qPCR. The effect of miR-660-5p was evaluated on proliferation, migration, and invasion processes using MDA-MB-231 and MCF-7 cells. HUVEC cells were used to assess angiogenesis. All cell lines were transfected with miR-660-5p inhibitor. Analysis of nine miRNA-target prediction databases was made to identify targets of miR-660-5p. We selected the target genes predicted by at least three of these programs, and their expression was evaluated by RT-qPCR in a customized 384-well plate. Results: We found that miR-660-5p is significantly upregulated in MDA-MB-231 and MCF-7, compared to MCF-10A cells. In addition, we observed a significant decrease in proliferation, migration, and invasion of BC cells transfected with miR-660-5p inhibitor, compared to non-treated cells and miRNA inhibitor negative control treated cells. Similarly, we observed a significant decrease in angiogenesis of HUVEC cells transfected with miR-660-5p inhibitor. Furthermore, of all the miR-660-5p targets identified by prediction databases 21 were selected, and of these, 7 were observed upregulated and 1 downregulated. Conclusions: The results show that miR-660-5p is upregulated and involved in proliferation, migration, invasion, and angiogenesis of BC, which may lead us to suggest that this miRNA act as an onco-miRNA. In addition, seven potential miR-660-5p target genes were identified, but further validation assays are needed to clarify their implication in this disease. Citation Format: Valeria Villarreal-García, José Roberto Estupiñan Jimenez, Ricardo Noriega, Recep Bayraktar, Diana Reséndez-Pérez, Cristina Rodríguez-Padilla, José Manuel Vázquez-Guillén, Gabriel Lopez-Berestein, Pablo E. Vivas-Mejía, Vianey Gonzalez-Villasana. Effect of miR-660-5p in breast cancer progression [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-22-03.

Supplementary Figures 1-7. Supplementary Figure 1. (A) Capan-2 animal protocol. Supplementary Figure 2. Effects of the combination of ZA with nab-paclitaxel on the mRNA levels of alpha-SMA and Rap1A in vivo. Supplementary Figure 3. (A) Reduction of pancreatic tumor volume by Gem alone or ZA alone. Supplementary Figure 4. Cell viability assessed by MTS assay. Supplementary Figure 5. Isobologram analysis. Supplementary Figure 6. Combination of ZA with nab-paclitaxel decrease fibronectin levels in vitro and laminin levels in vivo. Supplementary Figure 7. Mechanistic association of ZA and nab-paclitaxel.

Despite being among the most common oncogenes in human cancer, to date, there are no effective clinical options for inhibiting KRAS activity. We investigated whether systemically delivered KRAS siRNAs have therapeutic potential in KRAS-mutated cancer models. We identified KRAS siRNA sequences with notable potency in knocking down KRAS expression. Using lung and colon adenocarcinoma cell lines, we assessed antiproliferative effects of KRAS silencing in vitro. For in vivo experiments, we used a nanoliposomal delivery platform, DOPC, for systemic delivery of siRNAs. Various lung and colon cancer models were used to determine efficacy of systemic KRAS siRNA based on tumor growth, development of metastasis, and downstream signaling. KRAS siRNA sequences induced >90% knockdown of KRAS expression, significantly reducing viability in mutant cell lines. In the lung cancer model, KRAS siRNA treatment demonstrated significant reductions in primary tumor growth and distant metastatic disease, while the addition of CDDP was not additive. Significant reductions in Ki-67 indices were seen in all treatment groups, whereas significant increases in caspase-3 activity were only seen in the CDDP treatment groups. In the colon cancer model, KRAS siRNA reduced tumor KRAS and pERK expression. KRAS siRNAs significantly reduced HCP1 subcutaneous tumor growth, as well as outgrowth of liver metastases. Our studies demonstrate a proof-of-concept approach to therapeutic KRAS targeting using nanoparticle delivery of siRNA. This study highlights the potential translational impact of therapeutic RNA interference, which may have broad applications in oncology, especially for traditional “undruggable” targets. Mol Cancer Ther; 13(12); 2876–85. ©2014 AACR.

Supplementary figure 1 provides a schematic of DOPC:siRNA nanoliposomal preparation, and Supplementary figure 2 shows tumor volumetric measurements of the A549 orthotopic lung cancer therapeutic experiment described in the main figure 2.

Supplementary Figure Legends, Materials and Methods, and Table 1. Supplementary Figure Legends, Supplementary Material and Methods for RNA isolation, cDNA synthesis, and quantification of RNA species, Supplementary Table 1. Primer Sequences.

Supplementary Figure Legends (Figures 1-6)

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.

Dose-response curves for MEC1 and MEC2 cells treated with fludarabine.

Supplementary Table S1 Clinical characteristics of two chronic lymphocytic leukemia patient datasets; Supplementary Table S2 Clinical characteristics of two lung cancer patient datasets; Supplementary Table S3 Clinical characteristics of the ALL dataset; Supplementary Table S4 Integrated function and pathway analysis on 248 experimentally validated targets of miR-155; Supplementary Table S5 Univariate and multivariate analyses of survival with patient characteristics and miR-155 and TP53 expression as categorical and continuous variables in different patient cohorts; Supplementary Table S6 Estimate of Cox model and multivariate Cox model, as well as the HR estimated based on the model for miR-155 high and TP53 low vs. miR-155 low and TP53 high.

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.

Clinical correlation of miR-155 expression with survival in leukemia. Kaplan-Meier survival analysis for patients expressing high levels of miR-155 vs. low levels of miR-155 in two CLL cohorts, CLL - NEJM (A) and CLL - Italy (B), and in one ALL cohort, ALL - MDACC (C).

Supplementary Figures 1-6. Supplementary Figure S1: In vivo and in vitro effects of ZA on apoptosis. Supplementary Figure S2: Nab-paclitaxel inhibits tube formation.Supplementary Figure S3: RPPA analysis in HeyA8 MDR treated with ZA. Supplementary Figure S4: Functional changes induced by ZA in HeyA8 MDR. Supplementary Figure S5: ZA decreases angiogenic factors. Supplementary Figure S6: ZA inhibits cell invasion

In vivo orthotopic lung cancer model for the role of miR-155 in chemoresistance. (A) Injection and treatment schedule for CDDP (green arrows) and anti-miR negative control (NC) or anti-miR-155 liposomal nanoparticles (red stars) for four different treatment groups: mice that were injected with A549-LVEV cells and untreated (group 1), injected with A549-LVEV cells and treated with anti-miR-NC and CDDP (group 2), injected with A549-155LV cells and treated with anti-miR-NC and CDDP (group 3), and injected with A549-155LV cells and treated with anti-miR-155 and CDDP (group 4). (B) Representative pictures of dissected mice belonging to each of the treatment groups described in panel A of this Figure. Tumor nodules are marked by dotted white circles. (C-D) Graphs of the primary tumor size (C) and aggregate mass of nodules in mediastinum (D) of the four treatment groups mentioned above. (E) In situ hybridization for miR-155 for each of the four treatment groups mentioned above. (F) Immunohistochemical analysis for Ki-67 (proliferation) and CD31 (angiogenesis), as well as the TUNEL assay (apoptosis) and TP53 immunostaining for each of the four treatment groups mentioned above.

Clinical correlation of miR-155 and TP53 expression with survival in the lung adenocarcinoma - TCGA dataset when distinguishing between TP53 wild-type and TP53 mutated samples. (A-B) Kaplan-Meier survival analysis for patients expressing high levels of miR-155 vs. low levels of miR-155 in samples that express wild-typeTP53 or harbor TP53 mutations that do not affect TP53 function (A), and in samples expressing mutated TP53 that affects TP53 function (B). (C-D) Kaplan-Meier survival analysis for patients expressing high levels of miR-155 and low levels of TP53 vs. low levels of miR-155 and high levels of TP53 in samples that express wild-type TP53 or harbor TP53 mutations that do not affect TP53 function (C), and in samples expressing mutated TP53 that affects TP53 function (D).

Purpose: VEGF-targeted therapies have modest efficacy in cancer patients, but acquired resistance is common. The mechanisms underlying such resistance are poorly understood.Experimental Design: To evaluate the potential role of immune cells in the development of resistance to VEGF blockade, we first established a preclinical model of adaptive resistance to anti-VEGF therapy. Additional in vitro and in vivo studies were carried out to characterize the role of macrophages in such resistance.Results: Using murine cancer models of adaptive resistance to anti-VEGF antibody (AVA), we found a previously unrecognized role of macrophages in such resistance. Macrophages were actively recruited to the tumor microenvironment and were responsible for the emergence of AVA resistance. Depletion of macrophages following emergence of resistance halted tumor growth and prolonged survival of tumor-bearing mice. In a macrophage-deficient mouse model, resistance to AVA failed to develop, but could be induced by injection of macrophages. Downregulation of macrophage VEGFR-1 and VEGFR-3 expression accompanied upregulation of alternative angiogenic pathways, facilitating escape from anti-VEGF therapy.Conclusions: These findings provide a new understanding of the mechanisms underlying the modest efficacy of current antiangiogenesis therapies and identify new opportunities for combination approaches for ovarian and other cancers. Clin Cancer Res; 23(22); 7034–46. ©2017 AACR.

S Figure 1 (A) C57BL/6 mice that received intra-peritoneal injections of IG10 cells were randomly assigned to one of two groups (control or B20 treatment). S Figure 2 (A) Bar graph represents the CD11b+/F4/80+ macrophages in tumor tissue by FACS analysis. S Figure 3 Anti-VEGF therapyââ,¬â€œresistant macrophages have heightened viability, migration, and invasion. S Figure 4 (A) Bar graph represents the percentage of viability of B20 treated macrophages. S Figure 5. VEGFR1-positive macrophages increase the effectiveness of anti-VEGF therapy.

Table S1

MicroRNAs (miRNAs) are short, non-coding, single-strand RNA molecules that act as regulators of gene expression in plants and animals. In 2012, the first evidence was found that plant miRNAs could enter the bloodstream through the digestive tract. Since then, there has been an ongoing discussion about whether miRNAs from the diet are transferred to blood, accumulate in tissues, and regulate gene expression. Different research groups have tried to replicate these findings, using both plant and animal sources. Here, we review the evidence for and against the transfer of diet-derived miRNAs from plants, meat, milk and exosome and their assimilation and putative molecular regulation role in the consuming organism. Some groups using both miRNAs from plant and animal sources have claimed success, whereas others have not shown transfer. In spite of the biological barriers that may limit miRNA transference, several diet-derived miRNAs can transfer into the circulating system and targets genes for transcription regulation, which adds arguments that miRNAs can be absorbed from the diet and target specific genes by regulating their expression. However, many other studies show that cross-kingdom transfer of exogenous miRNAs appears to be insignificant and not biologically relevant. The main source of controversy in plant studies is the lack of reproducibility of the findings. For meat-derived miRNAs, studies concluded that the miRNAs can survive the cooking process; nevertheless, our evidence shows that the bovine miRNAs are not transferred to human bloodstream. The most important contributions and promising evidence in this controversial field is the transference of milk miRNAs in exosomes and the finding that plant miRNAs in beebread regulate honeybee caste development, and cause similar changes when fed to Drosophila. MiRNAs encapsulated in exosomes ensure their stability and resistance in the harsh conditions presented in milk, bloodstream, and gastrointestinaltract to reinforce the idea of transference. Regardless of the model organism, the idea of source of miRNAs, or the approach—bioinformatics or in vivo—the issue of transfer of miRNAs from the diet remains in doubt. Our understanding of the cross-kingdom talk of miRNAs needs more research to study the transfer of “xenomiRs” from different food sources to complement and expand what we know so far regarding the interspecies transfer of miRNAs.

Despite substantial improvements in the treatment strategies, ovarian cancer is still the most lethal gynecological malignancy. Identification of drug treatable therapeutic targets and their safe and effective targeting is critical to improve patient survival in ovarian cancer. AXL receptor tyrosine kinase (RTK) has been proposed to be an important therapeutic target for metastatic and advanced-stage human ovarian cancer. We found that AXL-RTK expression is associated with significantly shorter patient survival based on the The Cancer Genome Atlas patient database. To target AXL-RTK, we developed a chemically modified serum nuclease-stable AXL aptamer (AXL-APTAMER), and we evaluated its in vitro and in vivo antitumor activity using in vitro assays as well as two intraperitoneal animal models. AXL-aptamer treatment inhibited the phosphorylation and the activity of AXL, impaired the migration and invasion ability of ovarian cancer cells, and led to the inhibition of tumor growth and number of intraperitoneal metastatic nodules, which was associated with the inhibition of AXL activity and angiogenesis in tumors. When combined with paclitaxel, in vivo systemic (intravenous [i.v.]) administration of AXL-aptamer treatment markedly enhanced the antitumor efficacy of paclitaxel in mice. Taken together, our data indicate that AXL-aptamers successfully target in vivo AXL-RTK and inhibit its AXL activity and tumor growth and progression, representing a promising strategy for the treatment of ovarian cancer.

Purpose: VEGF-targeted therapies have modest efficacy in cancer patients, but acquired resistance is common. The mechanisms underlying such resistance are poorly understood. Experimental Design: To evaluate the potential role of immune cells in the development of resistance to VEGF blockade, we first established a preclinical model of adaptive resistance to anti-VEGF therapy. Additional in vitro and in vivo studies were carried out to characterize the role of macrophages in such resistance. Results: Using murine cancer models of adaptive resistance to anti-VEGF antibody (AVA), we found a previously unrecognized role of macrophages in such resistance. Macrophages were actively recruited to the tumor microenvironment and were responsible for the emergence of AVA resistance. Depletion of macrophages following emergence of resistance halted tumor growth and prolonged survival of tumor-bearing mice. In a macrophage-deficient mouse model, resistance to AVA failed to develop, but could be induced by injection of macrophages. Downregulation of macrophage VEGFR-1 and VEGFR-3 expression accompanied upregulation of alternative angiogenic pathways, facilitating escape from anti-VEGF therapy. Conclusions: These findings provide a new understanding of the mechanisms underlying the modest efficacy of current antiangiogenesis therapies and identify new opportunities for combination approaches for ovarian and other cancers. Clin Cancer Res; 23(22); 7034–46. ©2017 AACR.

Hepatocellular carcinoma (HCC) is the most common form of liver cancer. The number of cases is increasing and the trend for the next few years is not encouraging. HCC is usually detected in the advanced stages of the disease, and pharmacological therapies are not entirely effective. For this reason, it is necessary to search for new therapeutic options. The objective of this work was to evaluate the effect of the drugs isotretinoin and thalidomide on c-MYC expression and cancer-related proteins in an HCC cellular model. The expression of c-MYC was measured using RT-qPCR and western blot assays. In addition, luciferase activity assays were performed for the c-MYC promoters P1 and P2 using recombinant plasmids. Dose-response-time analyses were performed for isotretinoin or thalidomide in cells transfected with the c-MYC promoters. Finally, a proteome profile analysis of cells exposed to these two drugs was performed and the results were validated by western blot. We demonstrated that in HepG2 cells, isotretinoin and thalidomide reduced c-MYC mRNA expression levels, but this decrease in expression was linked to the regulation of P1 and P1-P2 c-MYC promoter activity in isotretinoin only. Thalidomide did not exert any effect on c-MYC promoters. Also, isotretinoin and thalidomide were capable of inducing and repressing proteins associated with cancer. In conclusion, isotretinoin and thalidomide down-regulate c-MYC mRNA expression and this is partially due to P1 or P2 promoter activity, suggesting that these drugs could be promising options for modulating the expression of oncogenes and tumor suppressor genes in HCC.

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.

Background Human papillomavirus (HPV) is recognized as an important risk factor for laryngeal carcinogenesis. Although HPV-16 and 18 have been strongly implicated, the presence of other high-risk HPV (HR-HPV) genotypes or the coinfection with Epstein-Barr virus (EBV) or Merkel cell polyomavirus (MCPV) may increase the risk, but their etiological association has not been definitively established. Methods We characterized the genotype-specific HPV and the frequency of EBV and MCPV infections through the detection of their DNA in 195 laryngeal specimens of squamous cell carcinoma (SCC) histologically confirmed. Results HPV DNA was detected in 93 (47.7%) specimens. HPV-11 was the most frequent with 68 cases (73.1%), and HPV-52 was the most frequently HR-HPV found with 51 cases, which corresponds to 54.8% of all HPV-positive specimens. EBV DNA was detected in 54 (27.7%) tumor tissue specimens of which 25 (46.3%) were in coinfection with HPV. MCPV DNA was detected only in 11 (5.6%) cases of which 5 (45.4%) were in coinfection with an HR-HPV. No association between the presence of DNA of the three examined viruses and the patient smoking habits, alcohol consumption, age, the keratinization status, differentiation grade, or localization of the tumor in the larynx were found. Discussion HPV-52 was the most prevalent HR-HPV, which may suggest that this and other genotypes in addition to HPV-16 and 18 could be considered for prophylaxis. However, further studies including non-cancer larynx cases and the evaluation of other molecular markers and viral co-infection mechanisms are needed to determine the role of the different HR-HPV genotypes, EBV, and MCPV in the etiology of SCC of the larynx.

miR-145, miR-155, and miR-382 have been proposed as noninvasive biomarkers to distinguish breast cancer patients from healthy individuals. However, it is unknown if these three miRNAs are secreted by exosomes. Thus, we hypothesized that miR-145, miR-155, and miR-382 in breast cancer patients are present in exosomes. We isolated exosomes from serum of breast cancer patients and healthy donors, then we characterized them according to their shape, size, and exosome markers by scanning electron microscopy, atomic force microscopy, nanoparticle tracking analysis (NTA), and Western blot and determined the exosome concentration in all samples by NTA. Later, exosomal small RNA extraction was done to determine the expression levels of miR-145, miR-155, and miR-382 by qRT-PCR. We observed a round shape of exosomes with a mean size of 119.84 nm in breast cancer patients and 115.4 nm in healthy donors. All exosomes present the proteins CD63, Alix, Tsg, CD9, and CD81 commonly used as markers. Moreover, we found a significantly high concentration of exosomes in breast cancer patients with stages I, III, and IV compared to healthy donors. We detected miR-145, miR-155, and miR-382 in the exosomes isolated from serum of breast cancer patients and healthy donors. Our results show that the exosomes isolated from the serum of breast cancer patients and healthy donors contains miR-145, miR-155, and miR-382 but not in a selective manner in breast cancer patients. Moreover, our data support the association between exosome concentration and the presence of breast cancer, opening the possibility to study how miRNAs packaged into exosomes play a role in BC progression.

Increased adrenergic signaling facilitates tumor progression, but the underlying mechanisms remain poorly understood. We examined factors responsible for stress-mediated effects on monocyte/macrophage recruitment into the tumor microenvironment, and the resultant effects on tumor growth. In vitro, MCP1 was significantly increased after catecholamine exposure, which was mediated by cAMP and PKA. Tumor samples from mice subjected to daily restraint stress had elevated MCP1 gene and protein levels, increased CD14+ cells, and increased infiltration of CD68+ cells. hMCP1 siRNA-DOPC nanoparticles significantly abrogated daily restraint stress-induced tumor growth and inhibited infiltration of CD68+ and F4/80+ cells. In ovarian cancer patients, elevated peripheral blood monocytes and tumoral macrophages were associated with worse overall survival. Collectively, we demonstrate that increased adrenergic signaling is associated with macrophage infiltration and mediated by tumor cell-derived MCP1 production.

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.

Despite being among the most common oncogenes in human cancer, to date, there are no effective clinical options for inhibiting KRAS activity. We investigated whether systemically delivered KRAS siRNAs have therapeutic potential in KRAS-mutated cancer models. We identified KRAS siRNA sequences with notable potency in knocking down KRAS expression. Using lung and colon adenocarcinoma cell lines, we assessed antiproliferative effects of KRAS silencing in vitro. For in vivo experiments, we used a nanoliposomal delivery platform, DOPC, for systemic delivery of siRNAs. Various lung and colon cancer models were used to determine efficacy of systemic KRAS siRNA based on tumor growth, development of metastasis, and downstream signaling. KRAS siRNA sequences induced >90% knockdown of KRAS expression, significantly reducing viability in mutant cell lines. In the lung cancer model, KRAS siRNA treatment demonstrated significant reductions in primary tumor growth and distant metastatic disease, while the addition of CDDP was not additive. Significant reductions in Ki-67 indices were seen in all treatment groups, whereas significant increases in caspase-3 activity were only seen in the CDDP treatment groups. In the colon cancer model, KRAS siRNA reduced tumor KRAS and pERK expression. KRAS siRNAs significantly reduced HCP1 subcutaneous tumor growth, as well as outgrowth of liver metastases. Our studies demonstrate a proof-of-concept approach to therapeutic KRAS targeting using nanoparticle delivery of siRNA. This study highlights the potential translational impact of therapeutic RNA interference, which may have broad applications in oncology, especially for traditional “undruggable” targets. Mol Cancer Ther; 13(12); 2876–85. ©2014 AACR.

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.

Purpose Bisphosphonates have been shown to inhibit and deplete macrophages. The effects of bisphosphonates on other cell types in the tumor microenvironment have been insufficiently studied. Here, we sought to determine the effects of bisphosphonates on ovarian cancer angiogenesis and growth via their effect on the microenvironment, including macrophage, endothelial and tumor cell populations. Experimental Design Using in vitro and in vivo models, we examined the effects of clodronate on angiogenesis and macrophage density, and the overall effect of clodronate on tumor size and metastasis. Results Clodronate inhibited the secretion of pro-angiogenic cytokines by endothelial cells and macrophages, and decreased endothelial migration and capillary tube formation. In treated mice, clodronate significantly decreased tumor size, number of tumor nodules, number of tumor-associated macrophages and tumor capillary density. Conclusions Clodronate is a potent inhibitor of tumor angiogenesis. These results highlight clodronate as a potential therapeutic for cancer.

Growing understanding of the role of the tumor microenvironment in angiogenesis has brought monocyte-derived cells into focus. Monocyte subpopulations are an increasingly attractive therapeutic target in many pathologic states, including cancer. Before monocyte-directed therapies can be fully harnessed for clinical use, understanding of monocyte-driven angiogenesis in tissue development and homeostasis, as well as malignancy, is required. Here, we provide an overview of the mechanisms by which monocytic subpopulations contribute to angiogenesis in tissue and tumor development, highlight gaps in our existing knowledge, and discuss opportunities to exploit these cells for clinical benefit. Cancer Res; 74(5); 1287–93. ©2014 AACR.

Elevated cyclooxygenase-2 (COX-2) expression in breast tumors is associated with a lower survival rate in patients with estrogen receptor α (ERα)-positive tumors. We hypothesized that COX-2 reduces the survival rate of breast cancer patients with ERα-positive tumors since COX-2 increases the invasiveness of ERα-positive breast tumors and decreases tumor sensitivity to tamoxifen. Previously, we demonstrated that COX-2 stimulates the activity of protein kinase C (PKC) to increase the invasiveness of ERα-positive MCF-7 breast cancer cells and to decrease the sensitivity of MCF-7 cells to tamoxifen. High levels of COX-2 are associated with the activation of the mitogen-activated protein kinase (MAPK) family and the Akt kinase. However, it is not known whether these kinases mediate COX-2-induced invasive activity and tamoxifen resistance. In the present study, we report that COX-2 utilizes PKC to enhance the phosphorylation of Jun N-terminal kinases (JNKs), but not that of other MAPK family members or Akt. Inhibition aimed at JNKs reduced COX-2-induced invasion but not COX-2-induced tamoxifen resistance. We conclude that JNKs are essential for induced cell invasion by COX-2, but not tamoxifen resistance, in ERα-positive breast cancer cells.

Purpose: RNA interference has the potential to specifically knockdown the expression of target genes and thereby transform cancer therapy. However, lack of effective delivery of siRNA has dramatically limited its in vivo applications. We have developed a multistage vector (MSV) system, composed of discoidal porous silicon particles loaded with nanotherapeutics, that directs effective delivery and sustained release of siRNA in tumor tissues. In this study, we evaluated therapeutic efficacy of MSV-loaded EphA2 siRNA (MSV/EphA2) with murine orthotopic models of metastatic ovarian cancers as a first step toward development of a new class of nanotherapeutics for the treatment of ovarian cancer. Experimental Design: Tumor accumulation of MSV/EphA2 and sustained release of siRNA from MSV were analyzed after intravenous administration of MSV/siRNA. Nude mice with metastatic SKOV3ip2 tumors were treated with MSV/EphA2 and paclitaxel, and therapeutic efficacy was assessed. Mice with chemotherapy-resistant HeyA8 ovarian tumors were treated with a combination of MSV/EphA2 and docetaxel, and enhanced therapeutic efficacy was evaluated. Results: Treatment of SKOV3ip2 tumor mice with MSV/EphA2 biweekly for 6 weeks resulted in dose-dependent (5, 10, and 15 μg/mice) reduction of tumor weight (36%, 64%, and 83%) and number of tumor nodules compared with the control groups. In addition, tumor growth was completely inhibited when mice were treated with MSV/EphA2 in combination with paclitaxel. Furthermore, combination treatment with MSV/EphA2 and docetaxel inhibited growth of HeyA8-MDR tumors, which were otherwise resistant to docetaxel treatment. Conclusion: These findings indicate that MSV/EphA2 merits further development as a novel therapeutic agent for ovarian cancer. Clin Cancer Res; 19(7); 1806–15. ©2013 AACR.

Obesity is a significant risk factor for post-menopausal women to develop and die from breast cancer. Leptin, an adipokine is produced in high levels in obese individuals, and its receptor is overexpressed in breast tumors and lymph node metastases. Previously, we demonstrated that leptin stimulates breast cancer cell invasion, which is correlated with breast cancer metastasis. Programmed cell death 4 (PDCD4) has been shown to block cancer cell invasion. However, whether PDCD4 blocks leptin-induced breast cancer cell invasion is not known. Here, we report the novel findings that leptin failed to induce invasion in MCF-7 breast cancer cells overexpressing PDCD4 (MCF-7/PDCD4). Tissue inhibitor of metalloproteinase-2 (TIMP-2) was essential to the anti-invasive effect of PDCD4, as leptin stimulated the invasion of MCF-7/PDCD4 cells pretreated with TIMP-2 siRNA. Furthermore, TIMP-2 knockdown allowed leptin to augment phosphorylation of extracellular signal-regulated kinases 1,2 and signal transducer and activator of transcription 3, but not that of Jun N-terminal kinases. These data indicate that PDCD4 utilizes TIMP-2 to exert its anti-invasive effect by suppressing leptin-induced activation of extracellular signal-regulated kinases 1,2 and signal transducer and activator of transcription 3. Novel therapeutic strategies aiming at enhancing PDCD4 expression in breast tumors may be able to stop obesity-related breast tumor progression and prolong the life of patients.

Increased adrenergic signaling is known to promote tumor progression, but the underlying mechanisms remain poorly understood. Tumor associated macrophages (TAMs) are key components of the tumor microenvironment that contribute to pro-inflammatory processes and tumor growth. Recently, it has been reported that patients with higher levels of adrenergic signaling have higher counts of MMP-9-producing TAMs. Here, we examined factors responsible for stress-mediated effects on monocyte/macrophage recruitment into the tumor microenvironment and the resultant effects on tumor growth. Conditioned media from norepinephrine- or epinephrine-treated ADRB positive SKOV3ip1 ovarian cancer cells had significantly increased levels of pro-inflammatory cytokines, such as MCP1, fractalkine, IL6, IL8 and VEGF. MCP1, a key modulator of monocyte/macrophage recruitment, gene and protein levels were significantly increased in vitro after catecholamine exposure, which was mediated by cAMP and PKA, while this effect was abrogated by a beta-blocker. SKOV3ip1 tumor samples from mice, subjected to daily restraint stress, had elevated MCP1 gene and protein expression levels, increased CD14+ cells, and increased infiltration of CD68+ cells. Both, propranolol, a non-specific beta-blocker, and hMCP1 siRNA packaged in DOPC nanoparticles significantly abrogated daily restraint stress-induced tumor growth and inhibited infiltration of CD68+ and F4/80+ cells. Of patient samples evaluated (n = 462), 28% had elevated absolute peripheral blood monocyte (>0.7 × 106/μL) and 43% had high peripheral blood monocytes when measured as the percent of white blood cell content (>8%). Elevated peripheral blood monocytes and increased CD68+ cells (>15/hpf) in samples from ovarian cancer patients were significantly associated with advanced disease and worse overall survival. In summary, increased adrenergic signaling is associated with enhanced macrophage infiltration mediated by tumor cell-derived MCP1 production. Citation Format: Guillermo N. Armaiz-Pena, Vianey Gonzalez-Villasana, Archana S. Nagaraja, Cristian Rodriguez-Aguayo, Piotr Dorniak, Rebecca Previs, Nouara Sadaoui, Rebecca Stone, Koji Matsuo, Heather J. Dalton, Susan K. Lutgendorf, Anil K. Sood, Gabriel Lopez-Berestein. Adrenergic regulation of MCP-1 leads to enhanced macrophage recruitment and ovarian carcinoma growth. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2359. doi:10.1158/1538-7445.AM2015-2359

Introduction: Despite being amongst the most common oncogenes in human cancer, to date there are no effective clinical options for inhibiting KRAS activity. We investigated whether systemically delivered KRAS siRNAs using biocompatible nanoparticles has therapeutic potential in KRAS mutated lung and colorectal cancer models. Methods: We identified two KRAS siRNA sequences with notable potency in knocking-down KRAS expression independent of nucleotide substitution. Using human lung (A549; KRASG12S) and colon (HCP1; KRASG12D) adenocarcinoma cell lines, we assessed anti-proliferative effects of KRAS silencing with MTT assays in vitro. For in vivo experiments, we used a nano-liposomal delivery platform, DOPC, for systemic delivery of siRNAs. We used luciferase-labeled A549 cells to create an orthotopic lung cancer model in athymic nude mice. One week after cell injection, we began weekly IVIS imaging and treatments to assess efficacy of systemic KRAS siRNA with and without cisplatin (CDDP) chemotherapy. Proliferation and apoptosis indices were assessed using Ki-67 and caspase-3 IHC, respectively. Using a patient-derived xenograft colon cancer cell line, HCP1, we performed several in vivo experiments to assess KRAS siRNA effects on down-stream signaling, primary tumor growth, and experimental metastasis. Results: For both KRAS siRNA sequences, greater than 90% knock-down of KRAS was observed by western blot; ∼40-60% reductions in cell viability was observed in both A549 and HCP1 (p Discussion: Our studies demonstrate a proof-of-concept approach to therapeutic KRAS targeting using nanoparticle delivery of siRNA. This study highlights the potential translational impact of therapeutic RNA interference, which may have broad applications in oncology, especially for traditional “undruggable” targets. Citation Format: Chad Pecot, Sherry Wu, Seth Bellister, Rajat Bhattacharya, Anshumaan Maharaj, Cristian Rodriguez-Aguayo, Vianey Gonzalez-Villasana, Rajesha Rupaimoole, Gabriel Lopez-Berestein, Lee M. Ellis, Anil Sood. Therapeutic KRAS silencing in lung and colon cancer models. [abstract]. In: Proceedings of the AACR Special Conference on RAS Oncogenes: From Biology to Therapy; Feb 24-27, 2014; Lake Buena Vista, FL. Philadelphia (PA): AACR; Mol Cancer Res 2014;12(12 Suppl):Abstract nr B47. doi: 10.1158/1557-3125.RASONC14-B47

Background. Posttranscriptional regulation is a critical control point for the expression of genes that promote or retard tumor growth. The mRNA-binding protein hnRNP A1 is required for the processing of miR-18a, an inhibitor of k-ras expression. In this study we hypothesized that downmodulation of hnRNP A1 by miR-25 and miR-15a controls the expression of miR-18a and k-ras by modulating nuclear and cytoplasmic miRNA processing at the posttranscriptional level. Methods. In this study, we determined the expression of hnRNP A1 at mRNA and protein levels in three parental ovarian cancer cells lines (Skov3ip1, HeyA8, and A2780) and their chemotherapy-resistant derivatives (Skov3-TR, HeyA8 MDR, and A2780 cp20). We also predicted in silico which miRNAS can target hnRNP A1 and confirmed the miRNA expression by real-time PCR. Moreover, we inhibited miR-25 and mir-15a to determine their tumorigenic potential in vitro. We also correlated the expression of miR-25 and miR-15a and/or miR-18a and k-ras expression in the TCGA data. Results. Downregulation of hnRNP A1 at the RNA and protein levels was observed in the taxane-resistant cell lines but not in the cisplatin-resistant cell line. Furthermore, we predicted in silico that miR-25and miR-15a can target hnRNP A1 and confirmed the overexpression of these microRNAs in SKOV3-TR (5- and 3-fold, respectively) and HeyA8 MDR (3-fold) by real-time PCR. We also analyzed overall survival, trying to find a correlation between k-ras and miR-15a (high 23.77, low 33.97 months), k-ras and miR-25 (high 16.95, low 35.21 months), and the combination of k-ras, miR-25, and miR18a (k-ras high, miR25 high, mir18a low, 20.73 months; k-ras low, miR25 low, mir18a high, 31.49 months). Comparison of these data with a validation set yielded similar results. Conclusion. These results underscore the importance of a previously uncharacterized circuit of posttranscriptional regulation between miR-25 or -15a and RNA-binding protein hnRNP A1 that regulates miR-18a and k-ras expression. This circuit represents a unique opportunity for novel therapeutics approaches. Citation Format: Cristian Rodriguez-Aguayo, Paloma Monroig, Maria I. Almeida, Cristina Ivan, Vianey Gonzalez-Villasana, Maitri Y. Shah, Anil K. Sood, George Calin, Gabriel Lopez-Berestein. Downregulation of hnRNP A1 by miRNAs as a new mechanism of survival 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 539. doi:10.1158/1538-7445.AM2014-539

Introduction: Despite being one of the first known oncogenes in human cancer, to date there are no effective therapeutic options for inhibiting KRAS. We investigated whether systemically delivered KRAS siRNA using biocompatible nanoparticles has therapeutic potential in lung cancer models. Methods: We identified two KRAS siRNA sequences with notable potency in knocking-down KRAS expression, which were combined for the in vivo experiments. Using a lung adenocarcinoma cell line (A549) with a KRAS mutation (G12S), we assessed anti-proliferative affects of KRAS silencing with MTT assays. Using luciferase-labeled A549 cells in athymic nude mice, we created an orthotopic lung cancer model in the left lower lung and performed weekly IVIS imaging beginning one week after injection. We used a nanoliposomal delivery platform, DOPC, for systemic delivery of siRNAs. Mice were randomly distributed into the following treatment groups (n=10 mice per group): 1) Control (NC) siRNA, 2) KRAS siRNA, 3) NC siRNA+cisplatin (CDDP), 4) KRAS siRNA +CDDP. One week after cell line injection, treatment began and continued for 4 weeks. At the end of the experiment mice were sacrificed, necropsied, and tumors were stained and evaluated for Ki-67 and caspase-3 by immunohistochemistry. Results: For both KRAS siRNA sequences, greater than 90% knock-down of KRAS was seen by western blot; which individually resulted in a 38% and 61% reduction in A549 cell viability (p=0.001 and p Discussion: Here, we demonstrate a proof-of-concept approach to therapeutic KRAS targeting using nanoparticle delivery of siRNA. This study highlights the potential translational impact of therapeutic RNA interference, which may have broad applications in oncology. Citation Format: Chad V. Pecot, Anshumaan Maharaj, Sherry Wu, Cristian Rodriguez-Aguayo, Vianey Gonzalez-Villasana, Rajesh Rupaimoole, Behrouz Zand, Thiru Arumugam, Gabriel Lopez, Anil Sood. Silencing the elephant in the room: therapeutic KRAS targeting with siRNA. [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 938. doi:10.1158/1538-7445.AM2013-938

RNA interference has the potential to specifically knock down the expression of target genes, and thereby transform cancer therapy. However, lack of effective delivery of small inhibitory RNA (siRNA) has dramatically limited its in vivo applications. We have developed a multistage vector (MSV) system, composed of discoidal porous silicon particles loaded with siRNA oligos packaged in dioleoyl phosphatidylcholine (DOPC) nanoliposomes, that directs effective delivery and sustained release of siRNA in tumor tissues. Tumor accumulation of siRNA was observed after i.v. administration of MSV/siRNA, and sustained release of siRNA from DMSV maintained high levels of siRNA in tumor for over one week after a single dose of DMSV/siRNA. Treatment of SKOV3ip2 tumor mice with DMSV carrying siRNA oligos specific for the human EphA2 gene (MSV/EphA2) biweekly for 6 weeks resulted in dose-dependent (5, 10 and 15 μg/mice) reduction of tumor weight (36%, 64%, and 83%) and number of tumor nodules compared with the control groups. In addition, tumor growth was completely inhibited when mice were treated with MSV/EphA2 in combination with paclitaxel. Furthermore, combination treatment with MSV/EphA2 and docetaxel inhibited growth of HeyA8-MDR tumors, which were otherwise resistant to docetaxel treatment. Taken together, MSV/EphA2 merits further development as a therapeutic approach for ovarian cancer. Citation Format: Cristian Rodriguez-Aguayo, Haifa Shen, Vianey Gonzalez-Villasana, Guodong Zhang, Xiaoyong Deng, Burcu Aslan, Xuewu Liu, Jason Sakamoto, Arturo Chavez-Reyes, Hee-Dong Han, Anil K. Sood, Mauro Ferrari1, Gabriel Lopez-Berestein. Enhancing chemotherapy response with sustained EphA2 silencing using multistage vector delivery . [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 3269. doi:10.1158/1538-7445.AM2013-3269

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

The use of small interfering RNA (siRNA) technology has rapidly become an attractive revolutionary tool in silencing gene expression and holds potential as a therapeutic strategy in cancer and other diseases. However, for siRNA-based therapeutics to become a reality, an efficient method for in vivo systemic delivery is needed. Here, we demonstrate effective and sustained delivery of siRNA using mesoporous silicon particles (MSP). We first developed a novel variant of multistage MSP by tuning the size and shape properties, which can load dioleoyl phosphatidylcholine (DOPC) nanoliposomes containing siRNA. To test this concept, we targeted EphA2 oncoprotein, which is highly overexpressed in most cancers such as breast, lung, pancreas and ovarian carcinoma. MSP incorporated with EphA2 siRNA-DOPC (MSP-siEphA2-DOPC) resulted in effective gene silencing for up to 15 days after single i.v. injection into mice bearing either SKOV3ip1 or HeyA8.MDR ovarian tumors in the peritoneal cavity. In addition, with a single injection of MSP-siEphA2-DOPC given every 15 days during 6 weeks of treatment, there was significant reduction (83%, P** 0.0032, 64%, P* 0.028, 36%, P, ns 0.0032) of tumor weight and number of nodules in a dose dependent manner (15,10 and 5 µg/mice) respectively compared with control groups. Furthermore, when we administrated MSP-siEphA2-DOPC in combination with either paclitaxel or docetaxel, we observed 87% and 91% tumor reduction compared to the control group respectively. Taken together, MSP-siEphA2-DOPC provides a new approach for sustained release of siRNA into disease sites without repetition of injection. 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 5684. doi:1538-7445.AM2012-5684