Erratum: A model system for antiviral siRNA therapeutics using exosome-based delivery.

[This corrects the article DOI: 10.1016/j.omtn.2022.08.011.].

A model system for antiviral siRNA therapeutics using exosome-based delivery.

Emerging viral diseases, such as Ebola, SARS, MERS, and the pathogen causing COVID-19, SARS-CoV-2, present a challenge for the development of therapeutics because of strict biosafety handling procedures and rapid mutation of their genomes. To facilitate the development of an adaptable and testable therapeutic model system, a colostrum exosome-based nanoparticle delivery system, EPM (exosome-PEI matrix), that overcomes stringent biosafety containment, was used to mimic the expression of viral proteins. This system would greatly expand the number of laboratories actively participating in the screening of potential therapeutics. EPM technology can deliver both plasmid DNA and siRNA to both simulate viral gene expression and screen potential antiviral siRNA therapeutics. Using this nanoplatform, three key SARS-CoV-2 proteins (the spike glycoprotein, nucleocapsid, and replicase) were expressed in vitro and in vivo. In vitro, several viral gene-targeting siRNAs were screened to determine knockdown efficiency, with some siRNA duplexes resulting in 80%-95% knockdown of corresponding protein expression. Moreover, in vivo experiments introducing the spike protein and nucleocapsid by EPM resulted in the production of antibodies against the viral antigen, measured up to 45 d after target delivery. Together, these findings support the efficacy of the EPM delivery system to establish a model for screening antiviral therapeutics-reduced biosafety level.

Berry anthocyanidins inhibit intestinal polyps and colon tumors by modulation of Src, EGFR and the colon inflammatory environment.

Colorectal cancer is the third most common form of cancer diagnosed and the third leading class for cancer-related deaths. Given the prevalence of colon cancer worldwide, further insight into developing novel and effective prevention and treatment strategies are warranted. The family of plant pigments known as the anthocyanins has been identified with a variety of health benefits including chemopreventive and therapeutic effects. A limitation to current clinical applications of anthocyanins is the high doses that are required. In order to overcome this limitation, we tested the active moiety, anthocyanidins for chemopreventive and therapeutic effects against colorectal cancer in vivo and in vitro. Treatment with native anthocyanidin mixture (Anthos) from bilberry yielded significant antiproliferative activity against colon cancer cells. Anthos treatment led to significant reductions in polyp and tumor counts in vivo. Reduced Src and EGFR phosphorylation was observed with Anthos treatment, which correlated with downstream targets such as PD-L1 and modulation of the colon inflammatory environment. These results provide a promising outlook on the impact of berry Anthos for the treatment and prevention of familial adenomatous polyposis and colorectal cancer. Results from this study also provide novel mechanistic insight into the chemopreventive and therapeutic activities of Anthos.

Anthocyanidins Inhibit Growth and Chemosensitize Triple-Negative Breast Cancer via the NF-κB Signaling Pathway.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. Due to the lack of drug-targetable receptors, chemotherapy is the only systemic treatment option. Although chemotherapeutic drugs respond initially in TNBC, many patients relapse and have a poor prognosis. Poor survival after metastatic relapse is largely attributed to the development of resistance to chemotherapeutic drugs. In this study, we show that bilberry-derived anthocyanidins (Anthos) can inhibit the growth and metastasis of TNBC and chemosensitize paclitaxel (PAC)-resistant TNBC cells by modulating the NF-κB signaling pathway, as well as metastatic and angiogenic mediators. Anthos administered orally significantly decreased MDA-MB-231 orthoxenograft tumor volume and led to lower rates of lymph node and lung metastasis, compared to control. Treatment of PAC-resistant MDA-MB-231Tx cells with Anthos and PAC in combination lowered the IC50 of PAC by nearly 20-fold. The combination treatment also significantly (p < 0.01) decreased the tumor volume in MDA-MB-231Tx orthoxenografts, compared to control. In contrast, Anthos and PAC alone were ineffective against MDA-MB-231Tx tumors. Our approach of using Anthos to inhibit the growth and metastasis of breast cancers, as well as to chemosensitize PAC-resistant TNBC, provides a highly promising and effective strategy for the management of TNBC.

Targeted Oral Delivery of Paclitaxel Using Colostrum-Derived Exosomes.

Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small-cell lung cancer (NSCLC) is the most common type accounting for 84% of all lung cancers. Paclitaxel (PAC) is a widely used drug in the treatment of a broad spectrum of human cancers, including lung. While efficacious, PAC generally is not well tolerated and its limitations include low aqueous solubility, and significant toxicity. To overcome the dose-related toxicity of solvent-based PAC, we utilized bovine colostrum-derived exosomes as a delivery vehicle for PAC for the treatment of lung cancer. Colostrum provided higher yield of exosomes and could be loaded with higher amount of PAC compared to mature milk. Exosomal formulation of PAC (ExoPAC) showed higher antiproliferative activity and inhibition of colony formation against A549 cells compared with PAC alone, and also showed antiproliferative activity against a drug-resistant variant of A549. To further enhance its efficacy, exosomes were attached with a tumor-targeting ligand, folic acid (FA). FA-ExoPAC given orally showed significant inhibition (>50%) of subcutaneous tumor xenograft while similar doses of PAC showed insignificant inhibition. In the orthotopic lung cancer model, oral dosing of FA-ExoPAC achieved greater efficacy (55% growth inhibition) than traditional i.v. PAC (24-32% growth inhibition) and similar efficacy as i.v. Abraxane (59% growth inhibition). The FA-ExoPAC given i.v. exceeded the therapeutic efficacy of Abraxane (76% growth inhibition). Finally, wild-type animals treated with p.o. ExoPAC did not show gross, systemic or immunotoxicity. Solvent-based PAC caused immunotoxicity which was either reduced or completely mitigated by its exosomal formulations. These studies show that a tumor-targeted oral formulation of PAC (FA-ExoPAC) significantly improved the overall efficacy and safety profile while providing a user-friendly, cost-effective alternative to bolus i.v. PAC and i.v. Abraxane.

Cumin Prevents 17ß-Estradiol-Associated Breast Cancer in ACI Rats.

Breast cancer (BC) is a leading cause of cancer deaths in women in less developed countries and the second leading cause of cancer death in women in the U.S. In this study, we report the inhibition of E2-mediated mammary tumorigenesis by Cuminum cyminum (cumin) administered via the diet as cumin powder, as well as dried ethanolic extract. Groups of female ACI rats were given either an AIN-93M diet or a diet supplemented with cumin powder (5% and 7.5%, w/w) or dried ethanolic cumin extract (1%, w/w), and then challenged with subcutaneous E2 silastic implants (1.2 cm; 9 mg). The first appearance of a palpable mammary tumor was significantly delayed by both the cumin powder and extract. At the end of the study, the tumor incidence was 96% in the control group, whereas only 55% and 45% animals had palpable tumors in the cumin powder and extract groups, respectively. Significant reductions in tumor volume (660 ± 122 vs. 138 ± 49 and 75 ± 46 mm3) and tumor multiplicity (4.21 ± 0.43 vs. 1.16 ± 0.26 and 0.9 ± 0.29 tumors/animal) were also observed by the cumin powder and cumin extract groups, respectively. The cumin powder diet intervention dose- and time-dependently offset E2-related pituitary growth, and reduced the levels of circulating prolactin and the levels of PCNA in the mammary tissues. Mechanistically, the cumin powder diet resulted in a significant reversal of E2-associated modulation in ERα, CYP1A1 and CYP1B1. Further, the cumin powder diet reversed the expression levels of miRNAs (miR-182, miR-375, miR-127 and miR-206) that were highly modulated by E2 treatment. We analyzed the composition of the extract by GC/MS and established cymene and cuminaldehyde as major components, and further detected no signs of gross or systemic toxicity. Thus, cumin bioactives can significantly delay and prevent E2-mediated mammary tumorigenesis in a safe and effective manner, and warrant continued efforts to develop these clinically translatable spice bioactives as chemopreventives and therapeutics against BC.

Exosome-mediated delivery of RNA and DNA for gene therapy.

Gene therapy promises to revolutionize biomedicine and personalized medicine by modulating or compensating the expression of abnormal genes. The biggest obstacle for clinical application is the lack of an effective, non-immunogenic delivery system. We show that bovine colostrum exosomes and polyethyleneimine matrix (EPM) delivers short interfering RNA (siRNA) or plasmid DNA (pDNA) for effective gene therapy. KRAS, a therapeutic focus for many cancers, was targeted by EPM-delivered KRAS siRNA (siKRAS) and inhibited lung tumor growth (>70%) and reduced KRAS expression (50%-80%). Aberrant p53 is another therapeutic focus for many cancers. EPM-mediated introduction of wild-type (WT) p53 pDNA (pcDNA-p53) resulted in p53 expression in p53-null H1299 cells in culture, subcutaneous lung tumor, and tissues of p53-knockout mice. Additionally, chemo-sensitizing effects of paclitaxel were restored by exogenous WT p53 in lung cancer cells. Together, this novel EPM technology represents an effective 'platform' for delivery of therapeutic nucleic acids to treat human disease.

Chemoprevention of Colorectal Cancer by Anthocyanidins and Mitigation of Metabolic Shifts Induced by Dysbiosis of the Gut Microbiome.

Diets rich in fat, smoking, as well as exposure to environmental pollutants and dysbiosis of gut microbiota, increase the risk of developing colorectal cancer. Much progress has been made in combating colorectal cancer. However, options for chemoprevention from environmental insult and dysbiosis of gut microbiota remain elusive. We investigated the influence of berry-derived anthocyanidins (Anthos), with and without encapsulating them in bovine milk-derived exosomes (ExoAnthos), on the chemoprevention of bacteria-driven colon tumor development. Anthos and ExoAnthos treatment of colon cancer cells showed dose-dependent decreases in cell viability. Calculated selectivity index (SI) values for Anthos and ExoAnthos suggest that both treatments selectively targeted cancer over normal colon cells. In addition, ExoAnthos treatment yielded higher SI values than Anthos. Anthos and ExoAnthos treatment of ApcMin/+ mice inoculated with enterotoxigenic Bacteriodes fragilis (ETBF) bacteria led to significant decreases in colon tumor numbers over mice receiving vehicle treatments. Western blot analysis of normal colon, colon tumor, and liver tissue lysates showed that mice inoculated with ETBF featured increased expression of phase I enzymes in normal colon tissue and decreased expression of phase II enzymes in liver tissue. Treatment with the Anthos and ExoAnthos reverted the modulation of phase I and phase II enzymes, respectively; no significant changes in phase II enzyme expression occurred in colon tumor tissue. Treatment of HCT-116 cells with the ubiquitous carcinogen, benzo[a]pyrene (B[a]P) led to similar modulation of phase I and II enzymes, which was partially mitigated by treatment with Anthos. These results provide a promising outlook on the impact of berry Anthos for prevention and treatment of bacteria- and B[a]P-driven colorectal cancer.

Milk exosomes - Natural nanoparticles for siRNA delivery.

Gene-silencing with targeted siRNAs has great potential as a therapeutic approach for various diseases including cancer. However, intracellular delivery of siRNA is challenging. We used bovine milk exosomes as a novel system for siRNA delivery. First, we demonstrated that exosomes can deliver endogenous RNA payloads into recipient cells. Next, we loaded siRNA against specific genes including VEGF, EGFR, AKT, MAPK, and KRAS. We utilized 5'-32P-labeled siKRAS as a tracer and found exosome loading with siRNA could be variable. We demonstrated that the siRNA of loaded exosomes is stable and resist degradation. Our results indicated that siRNAs against target genes ranged from 2 to 10-fold knockdown in expression levels in various cancers. Since mutated KRAS has been implicated in the development of various cancers including lung cancer, we tested a mutant-allele specific siRNA against KRASG12S, in A549 cells. We observed a dose-dependent anti-proliferative activity against A549 cells treated with exosomes carrying siKRASG12S. We observed significant inhibition of A549 tumor xenografts in animals treated with folic acid-functionalized exosomes carrying siKRAS. In summary, milk-derived exosomes represent a viable natural nano-carrier for the delivery of siRNA for therapeutic application against cancer.

Development of a goat model for evaluation of withaferin A: Cervical implants for the treatment of cervical intraepithelial neoplasia.

Cervical cancer is caused by human papillomavirus (HPV). The disease develops over many years through a series of precancerous lesions. Cervical cancer can be prevented by HPV-vaccination, screening and treatment of precancer before development of cervical cancer. The treatment of high-grade cervical dysplasia (CIN 2+) has traditionally been by cervical conization. Surgical procedures are associated with increased risk of undesirable side effects including bleeding, infection, scarring (stenosis), infertility and complications in later pregnancies. An inexpensive, non-invasive method of delivering therapeutics locally will be favorable to treat precancerous cervical lesions without damaging healthy tissue. The feasibility and safety of a sustained, continuous drug-releasing cervical polymeric implant for use in clinical trials was studied using a large animal model. The goat (Capra hircus), non-pregnant adult female Boer goats, was chosen due to similarities in cervical dimensions to the human. Estrus was induced with progesterone CIDR® vaginal implants for 14days followed by the administration of chorionic gonadotropins 48h prior to removal of the progesterone implants to relax the cervix to allow for the placement of the cervical implant. Cervical implants, containing 2% and 4% withaferin A (WFA), with 8 coats of blank polymer, provided sustained release for a long duration and were used for the animal study. The 'mushroom'-shaped cervical polymeric implant, originally designed for women required redesigning to be accommodated within the goat cervix. The cervical implants were well tolerated by the animals with no obvious evidence of discomfort, systemic or local inflammation or toxicity. In addition, we developed a new method to analyze tissue WFA levels by solvent extractions and LS/MS-MS. WFA was found to be localized to the target and adjacent tissues with 12-16ng WFA/g tissue, with essentially no detectable WFA in distant tissues. This study suggests that the goat is a good large animal model for the future development and evaluation of therapeutic efficacy of continuous local drug delivery by cervical polymeric implants to treat precancerous cervical lesions.

Exosomal delivery of berry anthocyanidins for the management of ovarian cancer.

Despite optimal diagnosis and early therapeutic interventions, the prognosis for ovarian cancer patients remains dismal because the efficacy of chemotherapy is limited by the development of resistance and off-site toxicity. Berry bioactives indicate preventive and therapeutic activities against various cancer types. Here, we examined the antiproliferative activity of berry anthocyanidins (Anthos) against drug-sensitive (A2780) and drug-resistant (A2780/CP70, OVCA432 and OVCA433) ovarian cancer cells. These drug-resistant ovarian cancer cell lines overexpress p-glycoproteins (PgP) and show >100-fold resistance to the chemotherapeutic drug cisplatin compared to A2780. We observed a dose-dependent growth inhibition of ovarian cancer cells with the Anthos. Furthermore, the treatment of drug-resistant ovarian cancer (OVCA433) cells with cisplatin in combination with the Anthos (75 µM) resulted in significantly higher cell killing. The cisplatin dose required to achieve this effect was 10 to 15-fold lower than the IC50 of cisplatin alone. However, many plant bioactives including Anthos face the challenge of poor oral bioavailability and stability. Recently, we have developed strategies to overcome these limitations by delivering Anthos via milk-derived exosomes. The exosomal Anthos (ExoAnthos) significantly enhanced the antiproliferative activity against the growth of ovarian cancer cells and inhibited tumor growth more efficiently compared to Anthos alone and a vehicle control. Often patients with cisplatin-resistant tumors retain sensitivity to paclitaxel (PAC). We prepared exosomal formulations of PAC (ExoPAC) for oral delivery as the systemic administration of PAC has severe side effects. ExoPAC delivered orally showed the same therapeutic efficacy as the free PAC delivered intraperitoneally. Finally, we report that the combination of the Anthos and PAC decreased the PgP level in a dose-dependent manner in OVCA432 cells. A significantly enhanced antitumor activity was observed with the combination of ExoPAC and ExoAnthos against A2780 tumor xenografts. Together, our data indicate that the berry Anthos are highly effective against ovarian cancer and that the milk exosomes serve as an excellent nano-carrier to enhance the drug's oral bioavailability for the management of ovarian cancer.

Exosomes for the Enhanced Tissue Bioavailability and Efficacy of Curcumin.

Exosomes are extracellular microvesicles with a particle size of 30-100 nm and carry a cargo of proteins, lipids, RNA, and DNA. Their properties of shuttling in-and-out of the cells suggest that these particles can be exploited as a nano drug carrier. In this manuscript, we show that curcumin can be delivered effectively using milk-derived exosomes. Curcumin when mixed with exosomes in the presence of 10% ethanol:acetonitrile (1:1) provided a drug load of 18-24%, and the formulation stored at - 80°C was stable for 6 months as determined by particle size analysis, drug load, and antiproliferative activity. The uptake of exosomes by cancer cells involved caveolae/clathrin-mediated endocytosis. Oral administration of exosomal curcumin (ExoCUR) in Sprague-Dawley rats demonstrated 3-5 times higher levels in various organs versus free agent. ExoCUR showed enhanced antiproliferative activity against multiple cancer cell lines including, breast, lung, and cervical cancer compared with the free curcumin. ExoCUR showed significantly higher anti-inflammatory activity measured as NF-κB activation in human lung and breast cancer cells. To determine in vivo antitumor activity, nude mice bearing the cervical CaSki tumor xenograft were treated with ExoCUR by oral gavage, curcumin diet, exosomes alone, and PBS as controls. While curcumin via dietary route failed to elicit any effect, exosomes had a modest (25-30%) tumor growth inhibition. However, ExoCUR showed significant inhibition (61%; p < 0.01) of the cervical tumor xenograft. No gross or systemic toxicity was observed in the rats administered with the exosomes or ExoCUR. These results suggest that exosomes can be developed as potential nano carriers for delivering curcumin which otherwise has encountered significant tissue bioavailability issues in the past.

Milk-derived exosomes for oral delivery of paclitaxel.

In this report milk-derived exosomes have been investigated for oral delivery of the chemotherapeutic drug paclitaxel (PAC) as an alternative to conventional i.v. therapy for improved efficacy and reduced toxicity. PAC-loaded exosomes (ExoPAC) were found to have a particle size of ~108 nm, a narrow particle size distribution (PDI ~0.190), zeta potential (~ -7 mV) and a practical loading efficiency of ~8%. Exosomes and ExoPAC exhibited excellent stability in the presence of simulated-gastrointestinal fluids, and during the storage at -80 °C. A sustained release of PAC was also observed up to 48 h in vitro using PBS (pH 6.8). Importantly, ExoPAC delivered orally showed significant tumor growth inhibition (60%; P<0.001) against human lung tumor xenografts in nude mice. Treatment with i.p. PAC at the same dose as ExoPAC, however, showed modest but statistically insignificant inhibition (31%). Moreover, ExoPAC demonstrated remarkably lower systemic and immunologic toxicities as compared to i.v. PAC.

Chemoprevention of Rat Mammary Carcinogenesis by Apiaceae Spices.

Scientific evidence suggests that many herbs and spices have medicinal properties that alleviate symptoms or prevent disease. In this study, we examined the chemopreventive effects of the Apiaceae spices, anise, caraway, and celery seeds against 17ß-estrogen (E2)-mediated mammary tumorigenesis in an ACI (August-Copenhagen Irish) rat model. Female ACI rats were given either control diet (AIN 93M) or diet supplemented with 7.5% (w/w) of anise, caraway, or celery seed powder. Two weeks later, one half of the animals in each group received subcutaneous silastic implants of E2. Diet intake and body weight were recorded weekly, and animals were euthanized after 3 and 12 weeks. E2-treatment showed significantly (2.1- and 3.4-fold) enhanced growth of pituitary gland at 3 and 12 weeks, respectively. All test spices significantly offset the pituitary growth by 12 weeks, except celery which was effective as early as three weeks. Immunohistochemical analysis for proliferative cell nuclear antigen (PCNA) in mammary tissues showed significant reduction in E2-mediated mammary cell proliferation. Test spices reduced the circulating levels of both E2 and prolactin at three weeks. This protection was more pronounced at 12 weeks, with celery eliciting the highest effect. RT-PCR and western blot analysis were performed to determine the potential molecular targets of the spices. Anise and caraway diets significantly offset estrogen-mediated overexpression of both cyclin D1 and estrogen receptor α (ERα). The effect of anise was modest. Likewise, expression of CYP1B1 and CYP1A1 was inhibited by all test spices. Based on short-term molecular markers, caraway was selected over other spices based on its enhanced effect on estrogen-associated pathway. Therefore, a tumor-end point study in ACI rats was conducted with dietary caraway. Tumor palpation from 12 weeks onwards revealed tumor latency of 29 days in caraway-treated animals compared with first tumor appearance at 92 days in control group. At the end of the study (25 weeks), the tumor incidence was 96% in the control group compared with only 70% in the caraway group. A significant reduction in tumor volume (661 ± 123 vs. 313 ± 81 mm³) and tumor multiplicity (4.2 ± 0.4 vs. 2.5 ± 0.5 tumors/animal) was also observed in the caraway group compared with the control group. Together, our data show dietary caraway can significantly delay and prevent the hormonal mammary tumorigenesis by modulating different cellular and molecular targets.

Exosomal formulation of anthocyanidins against multiple cancer types.

Over the last two decades, berries and berry bioactives, particularly anthocyanins and their aglycones anthocyanidins (Anthos) have demonstrated excellent anti-oxidant, anti-proliferative, apoptotic and anti-inflammatory properties. However, their physicochemical and pharmacokinetic limitations such as, low permeability, and poor oral bioavailability are considered as unfavorable properties for development as drugs. Therefore there is a need to develop systems for efficient systemic delivery and robust bioavailability. In this study we prepared nano-formulation of bilberry-derived Anthos using exosomes harvested from raw bovine milk. Exosomal formulation of Anthos enhanced antiproliferative and anti-inflammatory effects compared with the free Anthos against various cancer cells in vitro. Our data also showed significantly enhanced therapeutic response of exosomal-Anthos formulation compared with the free Anthos against lung cancer tumor xenograft in nude mice. The Anthos showed no signs of gross or systemic toxicity in wild-type mice. Thus, exosomes provide an effective alternative for oral delivery of Anthos that is efficacious, cost-effective, and safe, and this regimen can be developed as a non-toxic, widely applicable therapeutic agent.

Exosomal formulation enhances therapeutic response of celastrol against lung cancer.

Celastrol (CEL), a plant-derived triterpenoid, is a known inhibitor of Hsp90 and NF-κB activation pathways and has recently been suggested to be of therapeutic importance in various cancers. However, the molecular mechanisms of celastrol-mediated effects in lung cancer are not systematically studied. Moreover, it suffers from poor bioavailability and off-site toxicity issues. This study aims to study the effect of celastrol loaded into exosomes against two non-small cell-lung carcinoma (NSCLC) cell lines and explore the molecular mechanisms to determine the proteins governing the cellular responses. We observed that celastrol inhibited the proliferation of A549 and H1299 NSCLC cells in a time- and concentration-dependent manner as indexed by MTT assay. Mechanistically, CEL pre-treatment of H1299 cells completely abrogated TNFα-induced NF-κB activation and upregulated the expression of ER-stress chaperones Grp 94, Grp78, and pPERK. These changes in ER-stress mediators were paralleled by an increase in apoptotic response as evidenced by higher annexin-V/PI positive cells evaluated by FACS and immunoblotting which showed upregulation of the ER stress specific pro-apoptotic transcription factor, GADD153/CHOP and alteration of Bax/Bcl2 levels. Exosomes loaded with CEL exhibited enhanced anti-tumor efficacy as compared to free CEL against lung cancer cell xenograft. CEL did not exhibit any gross or systemic toxicity in wild-type C57BL6 mice as determined by hematological and liver and kidney function test. Together, our data demonstrate the chemotherapeutic potential of CEL in lung cancer and that exosomal formulation enhances its efficacy and reduces dose related toxicity.

Prevention of hormonal breast cancer by dietary jamun.

SCOPE: Syzygium cumini (jamun) is perhaps the only berry that has the diversity of anthocyanidins of blueberry and bilberry and the abundance of ellagitannins/ellagic acid of black raspberry. Here, we report the potential of jamun against 17ß-estrogen-mediated breast cancer and the role of miRNAs and other targets in disease inhibition. METHODS AND RESULTS: Female August-Copenhagen Irish rats were given AIN-93M diet or diet supplemented with jamun. Two weeks later, animals received 17ß-estradiol and were palpated weekly for the mammary tumors. At the end of 26 weeks, the jamun-diet significantly delayed the first tumor appearance by 21 days, and reduced the tumor incidence (65% versus 96%), tumor burden (313 ± 95 versus 661 ± 123 mm(3) ) and tumor multiplicity (1.8 ± 0.3 versus 4.2 ± 0.4 tumors/rat) compared to control. The experimental diet significantly reduced the estrogen-associated growth of pituitary prolactinomas, circulating prolactin and estradiol levels and offset estrogen-associated increases in mammary cell-proliferation, estrogen receptor-alpha (ER-α), and cyclinD1. miRNAs that were either overexpressed (miR-182 and miR-375) or underexpressed (miR-127 and miR-206) following estrogen-treatment were significantly protected by jamun diet. CONCLUSIONS: Together, our data show that jamun significantly offset estrogen-mediated alterations in mammary cell-proliferation, ER-α, cyclinD1, and candidate miRNAs, and that the modulation of these biomarkers correlated with a reduction in mammary carcinogenicity.

Bovine milk-derived exosomes for drug delivery.

Exosomes are biological nanovesicles that are involved in cell-cell communication via the functionally-active cargo (such as miRNA, mRNA, DNA and proteins). Because of their nanosize, exosomes are explored as nanodevices for the development of new therapeutic applications. However, bulk, safe and cost-effective production of exosomes is not available. Here, we show that bovine milk can serve as a scalable source of exosomes that can act as a carrier for chemotherapeutic/chemopreventive agents. Drug-loaded exosomes showed significantly higher efficacy compared to free drug in cell culture studies and against lung tumor xenografts in vivo. Moreover, tumor targeting ligands such as folate increased cancer-cell targeting of the exosomes resulting in enhanced tumor reduction. Milk exosomes exhibited cross-species tolerance with no adverse immune and inflammatory response. Thus, we show the versatility of milk exosomes with respect to the cargo it can carry and ability to achieve tumor targetability. This is the first report to identify a biocompatible and cost-effective means of exosomes to enhance oral bioavailability, improve efficacy and safety of drugs.

Potent Chemopreventive/Antioxidant Activity Detected in Common Spices of the Apiaceae Family.

Spices are used worldwide, particularly in the Asian and Middle Eastern countries, and considered protective against degenerative diseases, including cancer. Here, we report the efficacy of aqueous and non-aqueous extracts of 11 Apiaceae spices for free radical-scavenging activity and to inhibit cytochrome P450s in two separate reactions involving: 1) 4-hydroxy-17ß-estradiol (4E2), DNA, and CuCl2 and 2) 17ß-estradiol, rat liver microsomes, cofactors, DNA and CuCl2. Oxidative DNA adducts resulting from redox cycling of 4E2 were analyzed by (32)P-postlabeling. Aqueous (5 mg/ml) and non-aqueous extracts (6 mg/ml) substantially inhibited (83-98%) formation of DNA adducts in the microsomal reaction. However, in nonmicrosomal reaction, only aqueous extracts showed the inhibitory activity (83-96%). Adduct inhibition was also observed at five-fold lower concentrations of aqueous extracts of cumin (60%) and caraway (90%), and 10-fold lower concentrations of carrot seeds (76%) and ajowan (90%). These results suggests the presence of 2 groups of phytochemicals: polar compounds that have free radical-scavenging activity and lipophilic compounds that selectively inhibit P450 activity associated with estrogen metabolism. Because most of these Apiaceae spices are used widely with no known toxicity, the phytochemicals from the Apiaceae spices used in foods may be potentially protective against estrogen-mediated breast cancer.

Tanshinone IIA inhibits viral oncogene expression leading to apoptosis and inhibition of cervical cancer.

Human papilloma virus (HPV) is the well-established etiological factor of cervical cancer. E6 and E7 oncoproteins expressed by HPV are known to inactivate tumor suppressor proteins p53 and pRb, respectively. Tanshinone IIA (Tan IIA) is a diterpenoid naphthoquinone found in the traditional Chinese medicine Danshen (Salvia sp.). Tan IIA has been shown to possess anti-tumor activity against several cancer types. In this study we show that Tan IIA potently inhibited proliferation of the human cervical cancer CaSki, SiHa, HeLa and C33a cells. Mechanistically in HPV positive CaSki cells, Tan IIA was found to (i) downregulate expression of HPV E6 and E7 genes and modulate associated proteins E6AP and E2F1, (ii) cause S phase cell cycle arrest, (iii) induce accumulation of p53 and alter expression of p53-dependent targets, (iv) modulate pRb and related proteins, and (v) cause p53-mediated apoptosis by moderating Bcl2, Bax, caspase-3, and PARP cleavage expressions. In vivo, Tan IIA resulted in over 66% reduction in tumor volume of cervical cancer xenograft in athymic nude mice. Tan IIA treated tumor tissues had lower expression of proliferation marker PCNA and changes in apoptosis targets were in agreement with in vitro studies, further confirming reduced proliferation and involvement of multiple targets behind anti-cancer effects. This is the first demonstration of Tan IIA to possess significant anti-viral activity by repressing HPV oncogenes leading to inhibition of cervical cancer. Together, our data suggest that Tan IIA can be exploited as a potent therapeutic agent for the prevention and treatment of cervical and other HPV-related cancers.