Development of Competency-based Online Genomic Medicine Training (COGENT)

The fields of genetics and genomics have greatly expanded across medicine through the development of new technologies that have revealed genetic contributions to a wide array of traits and diseases. Thus, the development of widely available educational resources for all healthcare providers is essential to ensure the timely and appropriate utilization of genetics and genomics patient care. In 2020, the National Human Genome Research Institute released a call for new proposals to develop accessible, sustainable online education for health providers. This paper describes the efforts of the six teams awarded to reach the goal of providing genetic and genomic training modules that are broadly available for busy clinicians.

Evaluation of the Pink Luminous Breast LED-Based Technology Device as a Screening Tool for the Early Detection of Breast Abnormalities

Breast cancer is the leading cause of sex-specific female cancer deaths in the United States. Detection at earlier stages contributes to decreasing the mortality rate. The mammogram is the "Gold Standard" for breast cancer screening with an estimated sensitivity of 86.9% and a specificity of 88.9%. However, these values are negatively affected by the breast density considered a risk factor for developing breast cancer. Herein, we validate the novel LED-based medical device Pink Luminous Breast (PLB) by comparison with the mammogram using a double blinded approach. The PLB works by emitting a LED red light with a harmless spectrum of 640-800 nanometers. This allows the observation of abnormalities represented by dark or shadow areas. In this study, we evaluated the sensitivity and specificity of the PLB device as a screening tool for the early detection of breast abnormalities. Our results show that the PLB device has a high sensitivity (89.6%) and specificity (96.4%) for detecting breast abnormalities comparable to the adjusted mammogram values: 86.3 and 68.9%, respectively. The percentage of presence of breast density was 78.2% using PLB vs. 72.9% with the mammogram. Even with higher findings of breast density, the PLB is still capable of detecting 9.4% of calcifications compared to 6.2% in mammogram results and the reported findings for cysts, masses, or tumor-like abnormalities was higher using the PLB (6.5%) than the mammogram (5.6%). A 100% of the participants felt comfortable using the device without feeling pain or discomfort during the examination with 100% acceptability. The PLB positive validation shows its potential for routine breast screening at non-clinical settings. The PLB provides a rapid, non-invasive, portable, and easy-to-use tool for breast screening that can complement the home-based breast self-examination technique or the clinical breast examination. In addition, the PLB can be conveniently used for screening breasts with surgical implants. PLB provides an accessible and painless breast cancer screening tool. The PLB use is not intended to replace the mammogram for breast screening but rather to use it as an adjunct or complemental tool as part of more efficient earlier detection strategies contributing to decrease mortality rates.

Soy and Frequent Dairy Consumption with Subsequent Equol Production Reveals Decreased Gut Health in a Cohort of Healthy Puerto Rican Women

The U.S. Hispanic female population has one of the highest breast cancer (BC) incidence and mortality rates, while BC is the leading cause of cancer death in Puerto Rican women. Certain foods may predispose to carcinogenesis. Our previous studies indicate that consuming combined soy isoflavones (genistein, daidzein, and glycitein) promotes tumor metastasis possibly through increased protein synthesis activated by equol, a secondary dietary metabolite. Equol is a bacterial metabolite produced in about 20-60% of the population that harbor and exhibit specific gut microbiota capable of producing it from daidzein. The aim of the current study was to investigate the prevalence of equol production in Puerto Rican women and identify the equol producing microbiota in this understudied population. Herein, we conducted a cross-sectional characterization of equol production in a clinically based sample of eighty healthy 25-50 year old Puerto Rican women. Urine samples were collected and evaluated by GCMS for the presence of soy isoflavones and metabolites to determine the ratio of equol producers to equol non-producers. Furthermore, fecal samples were collected for gut microbiota characterization on a subset of women using next generation sequencing (NGS). We report that 25% of the participants were classified as equol producers. Importantly, the gut microbiota from equol non-producers demonstrated a higher diversity. Our results suggest that healthy women with soy and high dairy consumption with subsequent equol production may result in gut dysbiosis by having reduced quantities (diversity) of healthy bacterial biomarkers, which might be associated to increased diseased outcomes (e.g., cancer, and other diseases).

Ganoderma lucidum extract (GLE) impairs breast cancer stem cells by targeting the STAT3 pathway

The aggressive nature of triple negative breast cancer (TNBC) may be explained in part by the presence of breast cancer stem cells (BCSCs), a subpopulation of cells, which are involved in tumor initiation, progression, metastasis, recurrence, and therapy resistance. The signal transducer and activator of transcription 3 (STAT3) pathway participates in the development and progression of BCSCs, but its role in TNBC remains unclear. Here, we report that Ganoderma lucidum extract (GLE), a medicinal mushroom with anticancer activity, acts on BCSCs in vitro and in TNBC pre-clinical animal tumor models by downregulating the STAT3 pathway. We show that GLE significantly reduces TNBC cell viability, and down-regulates total and phosphorylated STAT3 expression. This is consistent with the reduction of OCT4, NANOG and SOX2 expression, reduction in the BCSC population by loss of the ALDH1 and CD44⁺/CD24^– population, the deformation of mammospheres, and the strong reduction in animal tumor volume and tumor weight. Analysis of the BCSC compartment in tumors revealed that GLE decreases the STAT3 pathway and the expression of OCT4, NANOG, and SOX2 in BCSCs. These findings demonstrate that the anti-cancer activity of GLE targets BCSCs of TNBC through the downregulation of the STAT3 pathway.

Characterization of a Dual Rac/Cdc42 Inhibitor MBQ-167 in Metastatic Cancer

The Rho GTPases Rac (Ras-related C3 botulinum toxin substrate) and Cdc42 (cell division control protein 42 homolog) regulate cell functions governing cancer malignancy, including cell polarity, migration, and cell-cycle progression. Accordingly, our recently developed Rac inhibitor EHop-016 (IC₅₀, 1,100 nmol/L) inhibits cancer cell migration and viability and reduces tumor growth, metastasis, and angiogenesis in vivo Herein, we describe MBQ-167, which inhibits Rac and Cdc42 with IC₅₀ values of 103 and 78 nmol/L, respectively, in metastatic breast cancer cells. Consequently, MBQ-167 significantly decreases Rac and Cdc42 downstream effector p21-activated kinase (PAK) signaling and the activity of STAT3, without affecting Rho, MAPK, or Akt activities. MBQ-167 also inhibits breast cancer cell migration, viability, and mammosphere formation. Moreover, MBQ-167 affects cancer cells that have undergone epithelial-to-mesenchymal transition by a loss of cell polarity and inhibition of cell surface actin-based extensions to ultimately result in detachment from the substratum. Prolonged incubation (120 hours) in MBQ-167 decreases metastatic cancer cell viability with a GI₅₀ of approximately 130 nmol/L, without affecting noncancer mammary epithelial cells. The loss in cancer cell viability is due to MBQ-167-mediated G₂-M cell-cycle arrest and subsequent apoptosis, especially of the detached cells. In vivo, MBQ-167 inhibits mammary tumor growth and metastasis in immunocompromised mice by approximately 90%. In conclusion, MBQ-167 is 10× more potent than other currently available Rac/Cdc42 inhibitors and has the potential to be developed as an anticancer drug, as well as a dual inhibitory probe for the study of Rac and Cdc42. Mol Cancer Ther; 16(5); 805-18. ©2017 AACR.

HIV-1 Gp120 clade B/C induces a GRP78 driven cytoprotective mechanism in astrocytoma

HIV-1 clades are known to be one of the key factors implicated in modulating HIV-associated neurocognitive disorders. HIV-1 B and C clades account for the majority of HIV-1 infections, clade B being the most neuropathogenic. The mechanisms behind HIV-mediated neuropathogenesis remain the subject of active research. We hypothesized that HIV-1 gp120 clade B and C proteins may exert differential proliferation, cell survival and NeuroAIDS effects in human astrocytoma cells via the Unfolded Protein Response, an endoplasmic reticulum- based cytoprotective mechanism. The differential effect of gp120 clade B and C was evaluated using for the first time a Tandem Mass Tag isobaric labeling quantitative proteomic approach. Flow cytometry analyses were performed for cell cycle and cell death identification. Among the proteins differentiated by HIV-1 gp120 proteins figure cytoskeleton, oxidative stress, UPR markers and numerous glycolytic metabolism enzymes. Our results demonstrate that HIV-1 gp120 B induced migration, proliferative and protective responses granted by the expression of GRP78, while HIV-1 gp120 C induced the expression of key inflammatory and pro-apoptotic markers. These novel findings put forward the first evidence that GRP78 is a key player in HIV-1 clade B and C neuropathogenic discrepancies and can be used as a novel target for immunotherapies.

Abstract 181: Discovery of novel targeted therapeutics for metastatic breast cancer

Metastatic disease is the primary cause of breast cancer mortality, due to the lack of effective therapy. The Rho GTPase Rac is integral for the promotion of cancer cell migration/invasion, proliferation, and survival. Since metastatic breast cancers often overexpress or exhibit high Rac activity, inhibition of Rac is a viable strategy against metastatic cancer. Recently, we characterized EHop-016, a small molecule that inhibits Rac activity of metastatic breast cancer cells with an IC50 of 1 µM. EHop-016 is 10-100 times more active than previously available Rac inhibitors, and is the first compound shown to inhibit the activation of Rac by the oncogenic GEF Vav. EHop-016 inhibits the activity of the Rac downstream effector p21 activated kinase (PAK), lamellipodia extension, and cell migration of metastatic breast cancer cells. We also reported that EHop-016 at ≥ 25 mg/kg Body Weight (BW) significantly reduced tumor growth, metastasis, and angiogenesis in a mouse model. However, our recent pharmacokinetic study of EHop-016 in a mouse model demonstrated that the bioavailability of Ehop-016 needs to be improved for further pharmacological development. Therefore our hypothesis is that improvement of the EHop-016 structure will provide probes with increased potency against Rac and, therefore, increased bioavailability. Herein we have tested several Ehop-016 derivatives for their effects on breast cancer cell viability and Rac activation. Using MTT assays we found that the Ehop-016 derivatives, HV-107 and HV-118, significantly inhibit the viability of metastatic breast cancer cell lines MDA-MB-231 and MDA-MB-435. The effects of HV-107 and HV-118 on the inhibition of Rac activation were tested by ELISA-based Rac activity assays and pulldown assays. Results show that at 250nM, HV-107 inhibits Rac activation by 55%, whereas HV-118 has a similar effect at 100nM in MDA-MB-231 and MDA-MB-435 cells. Taken together, our findings suggest HV-107 and HV-118 as promising Ehop-016 derivatives with potential as anti-metastatic agents, which should be further characterized.

This study was supported by awards from the Susan Komen for the Cure, NIH/NIMHHD U54MD008149, and the Puerto Rico Science and Technology Trust to SD; NIH/NCRR R25GM061838 to UPR MSC; NIH/NIMHHD RCMI 8G12MD007583RCMI, Title V PPOHA 031M10505 and Title V Cooperative P031S130068 from U.S. Department of Education to UCC; and PRINBRE (NIH/NIGMS P20GM103475-13) Pilot Project to LCP.

Citation Format: Cristina Del Valle, Eliud Hernández, Cornelis P. Vlaar, Luis A. Cubano, Suranganie Dharmawardhane, Linette Castillo-Pichardo. Discovery of novel targeted therapeutics for metastatic breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 181. doi:10.1158/1538-7445.AM2017-181

Targeting multiple pro-apoptotic signaling pathways with curcumin in prostate cancer cells

Curcumin, an extract from the turmeric rhizome (Curcuma longa), is known to exhibit anti-inflammatory, antioxidant, chemopreventive and antitumoral activities against aggressive and recurrent cancers. Accumulative data indicate that curcumin may induce cancer cell death. However, the detailed mechanism underlying its pro-apoptotic and anti-cancer effects remains to be elucidated. In the present study, we examined the signaling pathways triggered by curcumin, specifically, the exact molecular mechanisms of curcumin-induced apoptosis in highly metastatic human prostate cancer cells. The effect of curcumin was evaluated using for the first time in prostate cancer, a gel-free shotgun quantitative proteomic analysis coupled with Tandem Mass Tag isobaric labeling-based-signaling networks. Results were confirmed at the gene expression level by qRT-PCR and at the protein expression level by western blot and flow cytometry. Our findings revealed that curcumin induced an Endoplasmic Reticulum stress-mediated apoptosis in PC3. The mechanisms by which curcumin promoted cell death in these cells were associated with cell cycle arrest, increased reactive oxygen species, autophagy and the Unfolded Protein Response. Furthermore, the upregulation of ER stress was measured using key indicators of ER stress: Glucose-Regulated Protein 78, Inositol-Requiring Enzyme 1 alpha, Protein Disulfide isomerase and Calreticulin. Chronic ER stress induction was concomitant with the upregulation of pro-apoptotic markers (caspases 3,9,12) and Poly (ADP-ribose) polymerase. The downregulated proteins include anti-apoptotic and anti-tumor markers, supporting their curcumin-induced pro-apoptotic role in prostate cancer cells. Taken together, these data suggest that curcumin may serve as a promising anticancer agent by inducing a chronic ER stress mediated cell death and activation of cell cycle arrest, UPR, autophagy and oxidative stress responses.

A decade of viral mutations and associated drug resistance in a population of HIV-1+ Puerto Ricans: 2002-2011

Puerto Rico has one of the highest rates of HIV/AIDS seen for any US state or territory, and antiretroviral therapy has been a mainstay of efforts to mitigate the HIV/AIDS public health burden on the island. We studied the evolutionary dynamics of HIV-1 mutation and antiretroviral drug resistance in Puerto Rico by monitoring the population frequency of resistance-associated mutations from 2002 to 2011. Whole blood samples from 4,475 patients were analyzed using the TRUGENE HIV-1 Genotyping Kit and OpenGene DNA Sequencing System in the Immunoretrovirus Research Laboratory at Universidad Central del Caribe. Results show that 64.0% of female and 62.9% of male patients had HIV-1 mutations that confer resistance to at least one antiretroviral medication. L63P and M184V were the dominant mutations observed for the protease (PRO) and reverse transcriptase (RT) encoding genes, respectively. Specific resistance mutations, along with their associated drug resistance profiles, can be seen to form temporal clusters that reveal a steadily changing landscape of resistance trends over time. Both women and men showed resistance mutations for an average of 4.8 drugs over the 10-year period, further underscoring the strong selective pressure exerted by antiretrovirals along with the rapid adaptive response of HIV. Nevertheless, both female and male patients showed a precipitous decrease for overall drug resistance, and for PRO mutations in particular, over the entire course of the study, with the most rapid decrease in frequency seen after 2006. The reduced HIV-1 mutation and drug resistance trends that we observed are consistent with previous reports from multi-year studies conducted around the world. Reduced resistance can be attributed to the use of more efficacious antiretroviral drug therapy, including the introduction of multi-drug combination therapies, which limited the ability of the virus to mount rapid adaptive responses to antiretroviral selection pressure.

The proteome signature of the inflammatory breast cancer plasma membrane identifies novel molecular markers of disease

Inflammatory Breast Cancer (IBC) is the most lethal form of breast cancer with a 35% 5-year survival rate. The accurate and early diagnosis of IBC and the development of targeted therapy against this deadly disease remain a great medical challenge. Plasma membrane proteins (PMPs) such as E-cadherin and EGFR, play an important role in the progression of IBC. Because the critical role of PMPs in the oncogenic processes they are the perfect candidates as molecular markers and targets for cancer therapies. In the present study, Stable Isotope Labeling with Amino Acids in Cell Culture (SILAC) followed by mass spectrometry analysis was used to compare the relative expression levels of membrane proteins (MP) between non-cancerous mammary epithelial and IBC cells, MCF-10A and SUM-149, respectively. Six of the identified PMPs were validated by immunoblotting using the membrane fractions of non-IBC and IBC cell lines, compared with MCF-10A cells. Immunohistochemical analysis using IBC, invasive ductal carcinoma or normal mammary tissue samples was carried out to complete the validation method in nine of the PMPs. We identified and quantified 278 MPs, 76% of which classified as PMPs with 1.3-fold or higher change. We identified for the first time the overexpression of the novel plasminogen receptor, PLGRKT in IBC and of the carrier protein, SCAMP3. Furthermore, we describe the positive relationship between L1CAM expression and metastasis in IBC patients and the role of SCAMP3 as a tumor-related protein. Overall, the membrane proteomic signature of IBC reflects a global change in cellular organization and suggests additional strategies for cancer progression. Together, this study provides insight into the specialized IBC plasma membrane proteome with the potential to identify a number of novel therapeutic targets for IBC.

Abstract 3076: Characterization of an improved derivative of the Rac/PAK inhibitor EHop-016 in breast cancer

The expression and activities of the Rho GTPases Rac and Cdc42, and their downstream effector P21-activated kinase (PAK), have been correlated with metastatic cancer. Our published studies with the Rac/PAK inhibitor EHop-016 demonstrate the validity of using Rac inhibitors as anti metastatic cancer therapeutics. However, the relatively high effective concentrations (Rac activity IC50 1μM, tumor inhibition at 25 mg/kg body weight (BW)), and the moderate bioavailability (∼30%, t1/2 4.5h) of EHop-016 need improvement. Therefore, we developed EHop-016 derivatives and identified EHop-167 as a Rac inhibitor at nM concentrations. Unlike EHop-016, which does not substantially change breast cancer cell shape, but only reduces cell surface actin based invadopodia, EHop-167 induced a marked decrease in breast cancer cell polarity, cell surface extensions, and cell-extracellular matrix (ECM) attachments (focal adhesions). This phenotype of cell rounding and detachment in response to EHop-167 was demonstrated only by breast cancer cell lines that have undergone epithelial to mesenchymal transition, but not by epithelial breast cancer cells, or MCF-10A mammary epithelial cells. As assessed by pulldown assays and western blotting, Rac and PAK activities were reduced by 80-90% in response to 250 nM EHop-167, in the detached cells. As demonstrated by caspase assays, the cell rounding and detachment from the ECM ultimately resulted in anoikis (cell death due to loss of focal adhesions). Accordingly, Transwell assays of mesenchymal breast cancer cells following 250 nM Ehop-167 showed a ∼90% reduction in cell migration in the detached breast cancer cells, and a ∼60% inhibition in the attached cells. EHop-167 also reduced the mammosphere formation efficiency of metastatic cancer cells by 50%, indicating an inhibitory effect on cancer stem cells. To determine the in vivo efficacy of EHop-167, athymic nude mice, bearing mammary fatpad tumors of MDA-MB-435 metastatic cancer cells, were treated 3X a week with 0, 1, or 10 mg/kg BW EHop-167 for 50 days. Treatment with 1.0 mg/kg BW EHop-167 resulted in a 50% reduction in tumor growth, while 10.0 mg/kg BW EHop-167 induced an ∼95% reduction in tumor growth, compared to controls. Additionally, these mice did not show gross signs of toxicity or significant weight loss. Since the parental compound EHop-016 has no anticancer effects at similar concentrations, we conclude that EHop-167 is an improved Rac/PAK inhibitor that holds promise as an anti metastatic breast cancer therapeutic.

Citation Format: Linette Castillo-Pichardo, Tessa Humphries-Bickley, Ingrid Forrestier-Roman, Luis Borrero-Garcia, Fabiola Pagan Melendez, Eliud Hernandez, Cornelis Vlaar, Luis A. Cubano, Surangani Dharmawardhane. Characterization of an improved derivative of the Rac/PAK inhibitor EHop-016 in breast cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3076.

Novel KCNJ10 Gene Variations Compromise Function of Inwardly Rectifying Potassium Channel 4.1

TheKCNJ10gene encoding Kir4.1 contains numerous SNPs whose molecular effects remain unknown. We investigated the functional consequences of uncharacterized SNPs (Q212R, L166Q, and G83V) on homomeric (Kir4.1) and heteromeric (Kir4.1-Kir5.1) channel function. We compared these with previously characterized EAST/SeSAME mutants (G77R and A167V) in kidney-derived tsA201 cells and in glial cell-derived C6 glioma cells. The membrane potentials of tsA201 cells expressing G77R and G83V were significantly depolarized as compared with WTKir4.1, whereas cells expressing Q212R, L166Q, and A167V were less affected. Furthermore, macroscopic currents from cells expressing WTKir4.1 and Q212R channels did not differ, whereas currents from cells expressing L166Q, G83V, G77R, and A167V were reduced. Unexpectedly, L166Q current responses were rescued when co-expressed with Kir5.1. In addition, we observed notable differences in channel activity between C6 glioma cells and tsA201 cells expressing L166Q and A167V, suggesting that there are underlying differences between cell lines in terms of Kir4.1 protein synthesis, stability, or expression at the surface. Finally, we determined spermine (SPM) sensitivity of these uncharacterized SNPs and found that Q212R-containing channels displayed reduced block by 1 μmSPM. At 100 μmSPM, the block was equal to or greater than WT, suggesting that the greater driving force of SPM allowed achievement of steady state. In contrast, L166Q-Kir5.1 channels achieved a higher block than WT, suggesting a more stable interaction of SPM in the deep pore cavity. Overall, our data suggest that G83V, L166Q, and Q212R residues play a pivotal role in controlling Kir4.1 channel function.

Ganoderma lucidum Combined with the EGFR Tyrosine Kinase Inhibitor, Erlotinib Synergize to Reduce Inflammatory Breast Cancer Progression

The high incidence of resistance to Tyrosine Kinase Inhibitors (TKIs) targeted against EGFR and downstream pathways has increased the necessity to identify agents that may be combined with these therapies to provide a sustained response for breast cancer patients. Here, we investigate the therapeutic potential of Ganoderma lucidum extract (GLE) in breast cancer, focusing on the regulation of the EGFR signaling cascade when treated with the EGFR TKI, Erlotinib. SUM-149, or intrinsic Erlotinib resistant MDA-MB-231 cells, and a successfully developed Erlotinib resistant cell line, rSUM-149 were treated with increasing concentrations of Erlotinib, GLE, or their combination (Erlotinib/GLE) for 72h. Treatment effects were tested on cell viability, cell proliferation, cell migration and invasion. To determine tumor progression, severe combined immunodeficient mice were injected with SUM-149 cells and then treated with Erlotinib/GLE or Erlotinib for 13 weeks. We assessed the protein expression of ERK1/2 and AKT in in vitro and in vivo models. Our results show that GLE synergizes with Erlotinib to sensitize SUM-149 cells to drug treatment, and overcomes intrinsic and developed Erlotinib resistance. Also, Erlotinib/GLE decreases SUM-149 cell viability, proliferation, migration and invasion. GLE increases Erlotinib sensitivity by inactivating AKT and ERK signaling pathways in our models. We conclude that a combinatorial therapeutic approach may be the best way to increase prognosis in breast cancer patients with EGFR overexpressing tumors.

Abstract B20: Combination of Ganoderma lucidum extract and erlotinib decreases IBC progression

Inflammatory breast cancer (IBC) is a rare, and the most lethal and aggressive type of advanced breast cancer. Despite many efforts to increase IBC treatment efficacy, prognosis of this cancer is very grim. IBC cells and tissues overexpress epidermal growth factor receptor (EGFR), and this is a poor prognostic factor in this disease. Erlotinib is a small oral EGFR tyrosine kinase inhibitor that causes reverse inhibition of the EGFR tyrosine kinase domain. However, Erlotinib resistance can reduce the efficacy of this treatment. Our published results demonstrate that the extract of medicinal mushroom, Ganoderma lucidum (GLE), selectively decreases IBC cell viability. Our hypothesis is that the combination of GLE and Erlotinib will be more effective than their treatments alone, in reducing cancer cell viability and tumor progression via the EGFR signaling pathway. The IBC cell line, SUM149, was treated with Erlotinib and GLE at different concentrations for 72hrs to examine cell viability. To determine tumor progression, severe combined immunodeficient (SCID) mice were injected with SUM149 cells and then treated with Erlotinib alone, and in combination with GLE for 13 weeks. The expression of extracellular signal-regulated kinase (ERK)-1/2 and serine/threonine-specific protein kinase (AKT) of tumor samples were studied by Western Blot analysis, as the interaction of these signaling pathways are important in drug resistance effects and tumorigenesis. Our results show that SUM149 cells treated with Erlotinib and/or GLE decrease their viability in a dose-dependent manner. Moreover, using both treatments in combination at lower dosages than those alone results in reduced viability. In vivo results show that during weeks 8 to 13 of treatment, tumor volume in Erlotinib plus GLE treated mice was significantly lower when compared to tumor volume in Erlotinib treated mice. Also, Erlotinib alone and Erlotinib plus GLE treated mice displayed significantly reduced tumor weight when compared with their respective controls. Tumor lysate analysis shows that Erlotinib plus GLE treated mice have significant lower expression of total ERK-1/2 and total AKT in their tumors when compared with Erlotinib treated mice. Our results suggest that the combination of Erlotinib with GLE may be affecting the downstream EGFR signaling pathway. We conclude that a combinatorial therapeutic approach might be the best way to increase prognosis in IBC patients. This project was sponsored by NIH/NCI #1F31CA174307 to ISA, Title V PPOHA US Department of Education #P031M105050 to UCC, NIH/RCMI #G12MD007583 to UCC/MMM, NIH/INBRE #5P20 GM103475 to UPR/UCC/MMM, NIH/SC3 #SC3GM111171 to UCC/MMM and NIH/NIGMS R25GM110513 to UCC/LAC. The content is solely the responsibility of the authors and does not necessarily represent the official views of the supporting agencies.

Citation Format: Tiffany J. Rios-Fuller, Ivette J. Suarez-Arroyo, Mercedes Lacourt-Ventura, Geronimo Maldonado, Luis A. Cubano, Michelle M. Martinez-Montemayor. Combination of Ganoderma lucidum extract and erlotinib decreases IBC progression. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B20.

Abstract B202: Combined therapy of temozolomide and PF-562271, a PYK2 inhibitor, reduces glioma tumor growth and dispersal compare to temozolomide monotherapy

Microglia infiltrate majority of gliomas and release factors, which favor tumor growth and dispersal. Previously we demonstrated that microglia residing within the tumor stimulate glioma cell dispersal through the proline rich tyrosine kinase 2 (Pyk2) signaling cascade (Rolon-Reyes et al. 2015). We hypothesize that the use of pharmacological inhibitors of Pyk2 in applied therapy can significantly reduce the dispersal of tumor cells and improve the outcome of treatment.

In the present study, we investigated both in vitro and in vivo, the effect of the combined treatment of glioblastoma with temozolomide (TMZ) together with PF-562271 (a Pyk2 and FAK inhibitor), vs. TMZ monotherapy. Proliferation and migration assays were performed for a number of primary human glioma cell lines, as well as U87 and HS683cell lines in the presence and absence of microglia. Tumor size and invasion area were evaluated in brains of GL261 tumor bearing C57BL/6 mice for the assessment of the effectiveness of treatment.

Our data demonstrate that PF-562271 (16nM) and TMZ (100μM) given alone reduced in vitro migration and proliferation of glioma cells in the presence of microglia. PF-562271 (16nM) given in combination with TMZ at a concentration of just 10μM provided the same effect as TMZ 100 μM along, without reduction of efficacy. In vivo experiments demonstrated that oral administration of PF-562271 (twice/daily, 25 mg/kg, orally) reduced invasion of glioma cells at the tumor edge, while TMZ (50 mg/kg, once/day, orally) reduced the tumor growth. Combined treatment revealed significantly more prominent effect on both tumor growth and invasion compare to monotherapy.

These data indicate that the combination of TMZ and PF-562271 reduces both tumor growth and dispersal of tumor cells to surrounding areas. Moreover, in vitro experiments revealed a complex effect of these drugs on glioma cell proliferation and migration, allowing the reduction of the applied concentration of TMZ without the loss of its therapeutic effect.

This research was made possible by NIH grant numbers: 1SC2GM102040-01A1, 8G12MD007583-27, Title V PPOHA grant number P031M105050, NIH NIMH R25 MH055929 and RO1-CA18382701A1.

Citation Format: Kimberleve Rolon-Reyes, Luis A. Cubano, Alfredo Quiñones-Hinojosa, Lilia Kucheryavykh. Combined therapy of temozolomide and PF-562271, a PYK2 inhibitor, reduces glioma tumor growth and dispersal compare to temozolomide monotherapy. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr B202.

Abstract 5548: Reishi reduces the phosphorylation of STAT-3 in inflammatory breast cancer in vitro and in vivo models

Inflammatory Breast Cancer (IBC) is an aggressive form of breast cancer (BC) with symptoms that include a diffuse redness and swelling of the breast. Pathological findings indicate the presence of tumor emboli (tumor spheroids in vitro) invading the dermal lymphatics of the breast; a process considered to be responsible for the inflammatory phenotype seen in this disease. However, these tumors produce inflammatory mediators such interleukin-6 (IL-6), which may act as growth factors that contribute with cancer progression. Some consequences of IL-6 activation include the activation of the Janus Kinase-2/Signal Transducer and Activator of Transcription 3 (STAT-3) pathway that results in triggering invasion and metastasis processes. Our published data demonstrates that the medicinal mushroom, Ganoderma lucidum (Reishi), disintegrates tumor emboli, reduces tumor growth and modulates the abundance of proteins involved in invasion cascades. In the current study, we assessed the effects of Reishi on inflammatory markers focusing on the IL-6/JAK-2/STAT-3 pathway both in vitro and in vivo. SUM-149 IBC and SUM-102 non-IBC BC cells were treated with vehicle, or Reishi at different time points to determine cancer cell viability, invasion via three-dimensional culture assays and protein abundance via immunoblots. In vivo studies were carried out in female severe combined immunodeficient (SCID) mice that were injected with SUM-149 IBC cells in their lower right mammary fat pad and then treated with vehicle, 7mg/kgBW, or 14mg/kgBW Reishi for 10wk. Our data from the in vitro study suggests that Reishi reduces cancer cell viability, and Reishi has an immunomodulatory role in SUM-149 IBC cell line, demonstrated by its ability to reduce the secretion of IL-6 and reduced phosphorylation of STAT-3 in SUM-149 cells. Cell invasion studies show that Reishi reduces invasion in IBC cells. Interestingly, Reishi reduces SUM-102 BC cell viability; however it does not affect STAT-3 signaling in the cell line. Our in vivo results show that Reishi deceases tumor volume by 46 and 77%, when treated with 7mg/kgBW, or 14mg/kgBW Reishi, respectively. Moreover, the phosphorylation of STAT-3 in tumor lysates significantly decreases in a concentration dependent manner. Our data suggests that Reishi inactivates STAT-3 both in vitro and in vivo in IBC cells, thus Reishi may be used as a targeted therapeutic for women afflicted with IBC, for whom no direct therapeutics are currently available. This project was sponsored by Title V PPOHA US Department of Education #P031M105050, NIH/NIMHD # 8G12 MD 007583, NIH/NIGMS #P20 GM103475, NIH/NIMHD #U54 MD008149.

Note: This abstract was not presented at the meeting.

Citation Format: Michelle M. Martínez-Montemayor, Luis A. Cubano, Yaliz Loperena. Reishi reduces the phosphorylation of STAT-3 in inflammatory breast cancer in vitro and in vivo models. [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 5548. doi:10.1158/1538-7445.AM2015-5548

Abstract 5556: Enhancing response of Ganoderma lucidum (Reishi) and lapatinib in HER2+ inflammatory breast cancer cells

Inflammatory Breast Cancer (IBC) is an aggressive and unique form of breast cancer that develops rapidly. IBC, like non-IBC breast cancers, is a heterogeneous disease and can occur as any of the six molecular breast cancer subtypes. However, they are most commonly either triple negative; that is presenting with an absence of estrogen receptor (ER-), progesterone receptor (PR-) and the epidermal growth factor receptor 2 (HER2-) or ER-, PR- and HER2+ overexpressed. There is no specific IBC treatment; thus, it seems possible to find a therapeutic for this deadly disease. Our published data demonstrates that Ganoderma lucidum (Reishi) inhibits the viability of the triple negative IBC SUM149 cell line, but not of MCF10A noncancerous mammary epithelial cells. Subsequently, in this study, we aimed to investigate Reishi effects in the viability and molecular signaling of the ER-, PR-, HER2+ IBC cell lines SUM190, KPL-4 and IBC-3. Furthermore, we studied the effects of Reishi on IBC cells when treated in complement with the HER2 Tyrosine Kinase Inhibitor, lapatinib. The hypothesis for this study is that Reishi inhibits cancer cell viability and sensitizes IBC cells to lapatinib therapy and downregulates key proteins overexpressed in IBC. Herein, SUM190, KPL-4 and IBC-3 cells were treated with increasing concentrations of lapatinib and/or Reishi for 24 or 72h. The combination of lapatinib plus Reishi reduced cell viability of KPL-4 cells to 80% when treated with a concentration of 0.25 mg/mL of Reishi for 72h. Additionally, our data shows a reduction in cell viability of 70% in SUM190 cells treated with lapatinib plus Reishi for 72h. Also, Reishi and lapatinib downregulate the expression HER2 in KPL-4 cell after 72h of treatment. Our results provide evidence that Reishi inhibits cancer cell viability, highlighting the potential of Reishi as a natural anti-IBC-therapeutic. This project was sponsored by NIH/NCI #1F31 CA174307 to ISA, Title V PPOHA US Department of Education #P031M105050 to UCC/LAC, NIH/RCMI #G12 MD007583 to UCC/MMM, NIH/INBRE #5P20 GM103475 to UPR/UCC/MMM, NIH/NIMHD U54 MD008149 UH/MMM.

Citation Format: Yismeilin Feliz-Mosquea, Ivette Suarez-Arroyo, Yaliz Loperena, Luis A. Cubano, Michelle M. Martinez-Montemayor. Enhancing response of Ganoderma lucidum (Reishi) and lapatinib in HER2+ inflammatory breast cancer cells. [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 5556. doi:10.1158/1538-7445.AM2015-5556

Chemical profile and in vivo hypoglycemic effects of Syzygium jambos, Costus speciosus and Tapeinochilos ananassae plant extracts used as diabetes adjuvants in Puerto Rico

BACKGROUND

The increasing numbers of people who use plant-based remedies as alternative or complementary medicine call for the validation of less known herbal formulations used to treat their ailments. Since Puerto Rico has the highest rate of Type 2 diabetes within all the states and territories of the United States, and Puerto Ricans commonly use plants as diabetes adjuvants, it is important to study the plants' physiological effects, and identify their bioactive compounds to understand their role in modulation of blood glucose levels. We present the phytochemical profiles and hypoglycemic effects of Tapeinochilus ananassae, Costus speciosus and Syzygium jambos.

METHODS

Phytochemicals in methanolic and aqueous extracts were analyzed by thin layer chromatography (TLC). Alkaloids (Bromocresol green, λ=470 nm), flavonoids (AlCl3, λ=415 nm), saponins (DNS, λ=760 nm), tannins (FeCl3/K4Fe(CN)6, λ=395 nm) and phenolics (Folin-Ciocalteau, λ=765 nm) were quantified. Male C57BLKS/J (db/db) and C57BL/J (ob/ob) genetically obese mice were orally gavaged with aqueous extracts of lyophilized plant decoctions for 10 wks.

RESULTS

Our results show that T. ananassae had significantly greater amounts of flavonoids and tannins, while S. jambos showed the greatest concentration of phenolics and C. speciosus exhibited higher amounts of alkaloids. C57BLKS/J db/db treated with plant extracts show better glucose modulation when the extracts are administered in complement with an insulin injection. Finally, C57BL/J ob/ob mice on T. ananassae and S. jambos treatments show better blood glucose modulation over time.

CONCLUSION

These results document for the first time the chemical profile of T. ananassae and provide evidence for a potential anti-diabetic efficacy of T. ananassae and S. jambos.

Microglia Activate Migration of Glioma Cells through a Pyk2 Intracellular Pathway

Glioblastoma is one of the most aggressive and fatal brain cancers due to the highly invasive nature of glioma cells. Microglia infiltrate most glioma tumors and, therefore, make up an important component of the glioma microenvironment. In the tumor environment, microglia release factors that lead to the degradation of the extracellular matrix and stimulate signaling pathways to promote glioma cell invasion. In the present study, we demonstrated that microglia can promote glioma migration through a mechanism independent of extracellular matrix degradation. Using western blot analysis, we found upregulation of proline rich tyrosine kinase 2 (Pyk2) protein phosphorylated at Tyr579/580 in glioma cells treated with microglia conditioned medium. This upregulation occurred in rodent C6 and GL261 as well as in human glioma cell lines with varying levels of invasiveness (U-87MG, A172, and HS683). siRNA knock-down of Pyk2 protein and pharmacological blockade by the Pyk2/focal-adhesion kinase (FAK) inhibitor PF-562,271 reversed the stimulatory effect of microglia on glioma migration in all cell lines. A lower concentration of PF-562,271 that selectively inhibits FAK, but not Pyk2, did not have any effect on glioma cell migration. Moreover, with the use of the CD11b-HSVTK microglia ablation mouse model we demonstrated that elimination of microglia in the implanted tumors (GL261 glioma cells were used for brain implantation) by the local in-tumor administration of Ganciclovir, significantly reduced the phosphorylation of Pyk2 at Tyr579/580 in implanted tumor cells. Taken together, these data indicate that microglial cells activate glioma cell migration/dispersal through the pro-migratory Pyk2 signaling pathway in glioma cells.

Up-regulation of TREK-2 potassium channels in cultured astrocytes requires de novo protein synthesis: relevance to localization of TREK-2 channels in astrocytes after transient cerebral ischemia

Excitotoxicity due to glutamate receptor over-activation is one of the key mediators of neuronal death after an ischemic insult. Therefore, a major function of astrocytes is to maintain low extracellular levels of glutamate. The ability of astrocytic glutamate transporters to regulate the extracellular glutamate concentration depends upon the hyperpolarized membrane potential of astrocytes conferred by the presence of K+ channels in their membranes. We have previously shown that TREK-2 potassium channels in cultured astrocytes are up-regulated by ischemia and may support glutamate clearance by astrocytes during ischemia. Thus, herein we determine the mechanism leading to this up-regulation and assess the localization of TREK-2 channels in astrocytes after transient middle cerebral artery occlusion. By using a cell surface biotinylation assay we confirmed that functional TREK-2 protein is up-regulated in the astrocytic membrane after ischemic conditions. Using real time RT-PCR, we determined that the levels of TREK-2 mRNA were not increased in response to ischemic conditions. By using Western blot and a variety of protein synthesis inhibitors, we demonstrated that the increase of TREK-2 protein expression requires De novo protein synthesis, while protein degradation pathways do not contribute to TREK-2 up-regulation after ischemic conditions. Immunohistochemical studies revealed TREK-2 localization in astrocytes together with increased expression of the selective glial marker, glial fibrillary acidic protein, in brain 24 hours after transient middle cerebral occlusion. Our data indicate that functional TREK-2 channels are up-regulated in the astrocytic membrane during ischemia through a mechanism requiring De novo protein synthesis. This study provides important information about the mechanisms underlying TREK-2 regulation, which has profound implications in neurological diseases such as ischemia where astrocytes play an important role.

Paraoxon and Pyridostigmine Interfere with Neural Stem Cell Differentiation

Acetylcholinesterase (AChE) inhibition has been described as the main mechanism of organophosphate (OP)-evoked toxicity. OPs represent a human health threat, because chronic exposure to low doses can damage the developing brain, and acute exposure can produce long-lasting damage to adult brains, despite post-exposure medical countermeasures. Although the main mechanism of OP toxicity is AChE inhibition, several lines of evidence suggest that OPs also act by other mechanisms. We hypothesized that rat neural progenitor cells extracted on embryonic day 14.5 would be affected by constant inhibition of AChE from chronic exposure to OP or pyridostigmine (a reversible AChE blocker) during differentiation. In this work, the OP paraoxon decreased cell viability in concentrations >50 μM, as measured with the MTT assay; however, this effect was not dose-dependent. Reduced viability could not be attributed to blockade of AChE activity, since treatment with 200 µM pyridostigmine did not affect cell viability, even after 6 days. Although changes in protein expression patterns were noted in both treatments, the distribution of differentiated phenotypes, such as the percentages of neurons and glial cells, was not altered, as determined by flow cytometry. Since paraoxon and pyridostigmine each decreased neurite outgrowth (but did not prevent differentiation), we infer that developmental patterns may have been affected.

The Rac Inhibitor EHop-016 Inhibits Mammary Tumor Growth and Metastasis in a Nude Mouse Model

Metastatic disease still lacks effective treatments, and remains the primary cause of cancer mortality. Therefore, there is a critical need to develop better strategies to inhibit metastatic cancer. The Rho family GTPase Rac is an ideal target for anti-metastatic cancer therapy, because Rac is a key molecular switch that is activated by a myriad of cell surface receptors to promote cancer cell migration/invasion and survival. Previously, we reported the design and development of EHop-016, a small molecule compound, which inhibits Rac activity of metastatic cancer cells with an IC₅₀ of 1 μM. EHop-016 also inhibits the activity of the Rac downstream effector p21-activated kinase (PAK), lamellipodia extension, and cell migration in metastatic cancer cells. Herein, we tested the efficacy of EHop-016 in a nude mouse model of experimental metastasis, where EHop-016 administration at 25 mg/kg body weight (BW) significantly reduced mammary fat pad tumor growth, metastasis, and angiogenesis. As quantified by UPLC MS/MS, EHop-016 was detectable in the plasma of nude mice at 17 to 23 ng/ml levels at 12 h following intraperitoneal (i.p.) administration of 10 to 25 mg/kg BW EHop-016. The EHop-016 mediated inhibition of angiogenesis In Vivo was confirmed by immunohistochemistry of excised tumors and by In Vitro tube formation assays of endothelial cells. Moreover, EHop-016 affected cell viability by down-regulating Akt and Jun kinase activities and c-Myc and Cyclin D expression, as well as increasing caspase 3/7 activities in metastatic cancer cells. In conclusion, EHop-016 has potential as an anticancer compound to block cancer progression via multiple Rac-directed mechanisms.

Abstract 3212: Ganoderma lucidum (Reishi) chemosensitizes EGFR-overexpressing inflammatory breast cancer cells to erlotinib

Inflammatory Breast Cancer (IBC) is an aggressive cancer with a unique ability of forming tumor spheroids, which invade the dermal lymphatics causing the inflammatory phenotype. IBC cell lines and human tissues, overexpress Epidermal Growth Factor Receptor (EGFR), which has been associated with increasing IBC tumor growth rate, invasion and metastasis. Among the current therapeutic strategies for EGFR inhibition are the small molecule Tyrosine Kinase Inhibitors (TKIs). The high incidence of resistance to such therapies has greatly diminished their overall effectiveness, thus it seems feasible to identify agents that may be combined with these TKIs to provide a sustained response for IBC patients. For this reason, the purpose of this study is to investigate Reishi's therapeutic potential in IBC, focusing on the regulation of the EGFR signaling cascade and its contribution to the IBC cellular response when treated with the EGFR TKI, erlotinib. Our hypothesis is that Reishi sensitizes IBC cells to erlotinib therapy. EGFR-overexpressing SUM-149 IBC cells were treated with several concentrations of erlotinib, 0.025mg/mL Reishi, or both treatments simultaneously for 72h. Our results showed a synergistic effect when erlotinib and Reishi are used simultaneously after 72 hours of treatment. In order to study the molecular mechanism for the improved effects of the combination treatment we successfully developed an IBC erlotinib resistant cell line from the parental SUM-149 cells. Our data revealed that Reishi increases erlotinib sensitivity by inactivating AKT and extracellular signal-regulated kinase (ERK) signaling pathways. Taken together, our results provide evidence that Reishi chemosensitizes IBC cells to erlotinib therapy, highlighting its anti-IBC-therapeutic potential. This project was sponsored by NIH/NCI #1F31 CA174307 to ISA, Title V PPOHA US Department of Education #P031M105050 to UCC, NIH/RCMI #G12 MD007583 to UCC, NIH/INBRE #5P20 GM103475 to UPR/UCC and a research donation from the Commonwealth of Puerto Rico to UCC's University Center of Integral and Complementary Medicine (CUMIC)/MMM.

Citation Format: Ivette Suárez-Arroyo, Michael Moraskie, Luis A. Cubano, Michelle M. Martínez-Montemayor. Ganoderma lucidum (Reishi) chemosensitizes EGFR-overexpressing inflammatory breast cancer cells to erlotinib. [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 3212. doi:10.1158/1538-7445.AM2014-3212

Abstract 3219: Synergistic effect between Ganoderma lucidum (Reishi) and lapatinib in HER2+ inflammatory breast cancer cells

Inflammatory Breast Cancer (IBC) is the most lethal and rare form of breast cancer. It is characterized by rapid progression, local and distant metastases, younger age of onset, and lower overall survival compared with other breast cancers. Although IBC, like non-IBC breast cancers, is a heterogeneous disease and can occur as any of the five molecular breast cancer subtypes, they are most commonly either triple negative; or ER-, PR- and HER2+ overexpressed. There is no specific IBC treatment; thus, it seems feasible to find a therapeutic for this deadly disease. Our published data demonstrates that Ganoderma lucidum (Reishi) inhibits the viability of the triple negative IBC SUM149 cell line, but not of MCF10A noncancerous mammary epithelial cells. Consequently, in this study, we aimed to investigate Reishi effects in the viability of the ER-, PR-, HER2+ IBC cells lines SUM190 and KPL4. Also we studied the effects of Reishi on IBC cells when treated in complement with the HER2 Tyrosine Kinase Inhibitor, lapatinib (Tykerb®). Our hypothesis is that Reishi chemosensitizes IBC cells to lapatinib therapy. Herein, SUM190 and KPL-4 cells were treated with increasing concentrations of lapatinib and/or Reishi for 24 or 72h. Our results demonstrate that SUM190 and KPL-4 cells are sensitive to Reishi treatment. The combination of lapatinib plus Reishi reduced cell viability of SUM190 cells to 70% when treated with a concentration of 0.5mg/mL Reishi for 24h. Also, our data shows a reduction in cell viability of 94% in KPL-4 cells treated with lapatinib plus Reishi for 72h. We are currently directing our efforts to continue studying the contribution of Reishi in IBC cells when treated with lapatinib after 24 or 72h. Our results provide evidence that Reishi inhibits cancer cell viability and chemosensitizes IBC cells to lapatinib therapy, highlighting its anti-IBC-therapeutic potential. We thank Dr. Kurebayashi (Kawasaki Medical School, Japan) for providing KPL-4 cells. This project was sponsored by NIH/NCI #1F31CA174307 to ISA, Title V PPOHA US Department of Education #P031M105050 to UCC, NIH/RCMI #G12MD007583 to UCC, NIH/INBRE #5P20GM103475 to UPR/UCC and a research donation from the Commonwealth of Puerto Rico to UCC's University Center of Integral and Complementary Medicine (CUMIC)/MMM.

Citation Format: Yismeilin Feliz-Mosquea, Ivette Suárez-Arroyo, Luis A. Cubano, Michelle M. Martínez-Montemayor. Synergistic effect between Ganoderma lucidum (Reishi) and lapatinib in HER2+ inflammatory breast cancer cells. [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 3219. doi:10.1158/1538-7445.AM2014-3219

Abstract 3673: Role of IL-6 in inflammatory breast cancer and its modulation by Ganoderma lucid (Reishi)

Inflammatory Breast Cancer (IBC) is an aggressive and lethal form of breast cancer with symptoms that include a diffuse redness and swelling of the breast. These signs resemble an inflammation, which may suggest the involvement of both immunological and inflammatory processes in the pathogenesis of this disease. Unique pathological findings indicate the presence of tumor emboli invading the dermal lymphatics of the breast; a process considered to be responsible for the inflammatory phenotype. However, these tumors produce inflammatory mediators such interleukin-6 (IL-6), which may act as a growth factor to contribute to cancer progression. Thus, cancer cells stimulated with or that secrete IL-6 via an autocrine loop, auto-activate these pathways resulting in malignant features such as enhanced invasion and increased metastasis. Our published data demonstrates that the medicinal mushroom, Ganoderma lucidum (Reishi), disintegrates tumor emboli, and reduces tumor growth. We hypothesize that IL-6 enhances while Reishi reduces IBC progression via modulation of the JAK-2/STAT-3 pathway both in vitro and in vivo. SUM-149 wound-healing assays were performed to determine the migratory phenotype of IBC cells stimulated with IL-6 or treated with Reishi. Immunoblots of SUM-149 and KPL-4 IBC cell lysates were performed to detect the expression of the JAK-2/STAT-3 signaling pathway and its downstream effectors upon Reishi treatment. Cell fractioning was performed to delineate if the proteins affected by Reishi belong to the nuclear or cytoplasmic fraction of the cell. For in vivo studies, severe combined immunodeficient (SCID) mice were injected with SUM-149 IBC cells in their mammary fat pad and treated via oral gavage with various concentrations of Reishi for 10wk. Our data from the in vitro studies indicate that IL-6 causes wound closure after 24h, an effect prevented by Reishi. Additionally, our data suggests that Reishi has an immunomodulatory role, demonstrated by its ability to reduce the phosphorylation of the IL-6/JAK-2/STAT-3 pathway. Cell fractioning of SUM-149 and KPL-4 cells show a drastic reduction in the expression of proteins corresponding to the nuclear fraction of the cell when treated Reishi. Finally, our in vivo data show a dose dependent reduction by 3.0 and 5.5 fold in tumor volume, when mice where treated with 7mg/kg BW and 14mg/kg BW of Reishi, respectively. This data suggests that Reishi may be used as a targeted therapeutic for women afflicted with IBC, for whom no direct therapeutics are currently available. We thank Dr. Kurebayashi (Kawasaki Medical School, Japan) for providing KPL-4 cells. This project was sponsored by Title V PPOHA US Department of Education #P031M105050 to UCC, NIH/RCMI #G12 MD007583 to UCC, NIH/INBRE #P20 GM103475 to UPR/UCC and a research donation from the Commonwealth of Puerto Rico to UCC's University Center of Integral and Complementary Medicine (CUMIC)/MMM.

Citation Format: Yaliz Loperena-Alvarez, Luis A. Cubano, Michelle M. Martínez-Montemayor. Role of IL-6 in inflammatory breast cancer and its modulation by Ganoderma lucid (Reishi). [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 3673. doi:10.1158/1538-7445.AM2014-3673

Abstract A057: Therapeutic potential of genistein via targeting the microRNA miR-155 in breast cancer

We previously reported that dietary genistein significantly inhibits mammary tumor growth and metastasis of estrogen receptor (ER) (-) MDA-MB-435 metastatic cancer cells in immunocompromised mice. The purpose of the present study is to investigate the molecular mechanisms of genistein in ER (-) breast cancer cells. We report that at low physiologically relevant concentrations, genistein significantly inhibits cell growth and induces apoptosis in MDA-MB-435 and Hs578t breast cancer cells. To investigate the mechanism by which genistein regulates cancer cell viability, a panel of microRNAs (miRNAs) were tested for differential expression in response to genistein treatment. We found that miR-155, a designated oncomiR in breast cancer, is significantly downregulated by genistein in MDA-MB-435 and Hs578t cells. Concomitantly, pro-apoptotic and anti-cell proliferative miR-155 targets FOXO3, PTEN, casein kinase (CK1alpha), and p27 are upregulated by genistein. Moreover, the CK1alpha target beta catenin is downregulated in the MDA-MB-435 cells, thus further contributing to the anticancer effects of genistein by inhibiting wnt signaling. Stable ectopic expression of miR-155 in MDA-MB-435 and Hs578t cells decreases the inhibitory effect of genistein on cell viability, and abrogates the effect of genistein on apoptosis and expression of pro-apoptotic proteins. Therefore, genistein acts as a potential anti breast cancer therapeutic via downregulation of miR-155, a critical suppressor of apoptosis. This study was sponsored by United States Army/BCRP W81XWH-11-1-0199 (to CDP), NIH/NIGMS SC3GM084824 (to SD), NIH/NIGMS G12RR035051 (to UPR MSC), and NIH/NIGMS G12RR003035 and Title V PPOHA US Department of Education #P031M105050 (to UCC).

Citation Format: Columba de la Parra, Linette Castillo-Pichardo, Luis A. Cubano, George A. Calin, Suranganie Dharmawardhane. Therapeutic potential of genistein via targeting the microRNA miR-155 in breast cancer. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research: Genetics, Biology, and Clinical Applications; Oct 3-6, 2013; San Diego, CA. Philadelphia (PA): AACR; Mol Cancer Res 2013;11(10 Suppl):Abstract nr A057.

Unidirectional photoreceptor-to-Müller glia coupling and unique K+ channel expression in Caiman retina

Background

Müller cells, the principal glial cells of the vertebrate retina, are fundamental for the maintenance and function of neuronal cells. In most vertebrates, including humans, Müller cells abundantly express Kir4.1 inwardly rectifying potassium channels responsible for hyperpolarized membrane potential and for various vital functions such as potassium buffering and glutamate clearance; inter-species differences in Kir4.1 expression were, however, observed. Localization and function of potassium channels in Müller cells from the retina of crocodiles remain, hitherto, unknown.

Methods

We studied retinae of the Spectacled caiman (Caiman crocodilus fuscus), endowed with both diurnal and nocturnal vision, by (i) immunohistochemistry, (ii) whole-cell voltage-clamp, and (iii) fluorescent dye tracing to investigate K⁺ channel distribution and glia-to-neuron communications.

Results

Immunohistochemistry revealed that caiman Müller cells, similarly to other vertebrates, express vimentin, GFAP, S100β, and glutamine synthetase. In contrast, Kir4.1 channel protein was not found in Müller cells but was localized in photoreceptor cells. Instead, 2P-domain TASK-1 channels were expressed in Müller cells. Electrophysiological properties of enzymatically dissociated Müller cells without photoreceptors and isolated Müller cells with adhering photoreceptors were significantly different. This suggests ion coupling between Müller cells and photoreceptors in the caiman retina. Sulforhodamine-B injected into cones permeated to adhering Müller cells thus revealing a uni-directional dye coupling.

Conclusion

Our data indicate that caiman Müller glial cells are unique among vertebrates studied so far by predominantly expressing TASK-1 rather than Kir4.1 K⁺ channels and by bi-directional ion and uni-directional dye coupling to photoreceptor cells. This coupling may play an important role in specific glia-neuron signaling pathways and in a new type of K⁺ buffering.

Abstract 4727: Effects of Ganoderma lucidum on cytokine expression in Inflammatory Breast Cancer

Ganoderma lucidum (Reishi) is a medicinal mushroom used to treat among many diseases, hyperglycemia, inflammation and cancer. Our laboratory studies the effects Reishi, as an alternative approach to treat Inflammatory Breast Cancer (IBC). IBC is an aggressive form of breast cancer. IBC symptoms include a diffuse redness and swelling of the breast, which resembles inflammation and may suggest the involvement of both immunological and inflammatory processes in the pathogenesis of this disease. Pathological findings indicate the presence of tumor emboli invading the dermal lymphatics of the breast. In these tumors pro-inflammatory mediators such as interleukin-8 (IL-8), IL-6, and Monocyte Chemotactic Protein 1 (MCP-1) are produced to contribute to cancer progression. These proteins are regulators of the immune system but in the tumor microenvironment they can act as growth factors, allowing tumor cell survival, invasion and metastasis. Our published data demonstrates that Reishi disintegrates tumor emboli, reduces tumor growth and modulates the abundance of plasma membrane proteins involved in downstream signaling of invasion cascades. Herein, we are characterizing cytokine production in vitro and in vivo and their modulation upon Reishi treatment. SUM-149 conditioned media was analyzed via cytokine bead array to quantify cytokine production after 0 or 0.5mg/mL Reishi treatment at different time points. For in vivo studies, severe combined immunodeficient (SCID) mice were treated daily for two weeks with 0, 7, 14 or 28mg/kg BW of Reishi via oral gavage. At two weeks the mice were injected with SUM-149 IBC cells in their mammary fat pad and continued oral gavage treatment for an additional 14 weeks. Our in vitro study data shows that SUM-149 cells secrete IL-6 and IL-8 and that secretion of these cytokines, which are known to behave as growth factors, was decreased by 23% and 76% respectively after 48 hours of Reishi treatment. As of 10 weeks of the study, tumor size is reduced in all Reishi treated animals when compared with vehicles. Interestingly, Reishi shows a tendency to decrease the expression of MCP-1 and IL-6 in plasma, while a slight increase in TNF-α is observed. Our results show that Reishi has an immunomodulatory role, demonstrated by its ability to reduce cytokine production both in cells and in mice plasma. Reishi may be used as a targeted therapeutic for women afflicted with IBC, for whom no direct therapeutics are currently available. This project was sponsored by Title V PPOHA US Dept of Education #P031M105050 to UCC, NIH/RCMI #2G12RR003035 to UCC, NIH/INBRE #5P20RR016470 to UPR/UCC, NIH/NCRR #U54RR026139 to UPR/UCC, and a research donation from the Commonwealth of Puerto Rico to UCC-Centro Universitario de Medicina Integral y Complementaria (CUMIC) / MMM.

Citation Format: Yaliz Loperena-Alvarez, Luis A. Cubano, Michelle M. Martínez-Montemayor. Effects of Ganoderma lucidum on cytokine expression in Inflammatory Breast 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 4727. doi:10.1158/1538-7445.AM2013-4727

Abstract 2247: Ganoderma lucidum (Reishi) downregulates key proteins overexpressed in IBC and chemosensitizes EGFR-overexpressing cells to erlotinib

Inflammatory Breast Cancer (IBC) is a unique and aggressive cancer where tumor spheroids invade the dermal lymphatics causing the inflammatory phenotype. IBC cell lines and human tissues overexpress plasma membrane proteins such as E-cadherin and Epidermal Growth Factor Receptor (EGFR), which are associated with maintaining tumor spheroid integrity, increased IBC tumor growth rate, invasion and metastasis. Since IBC tumor cell emboli are more efficient at forming metastases and are more resistant to chemo and radiotherapy than single cells, it seems feasible to prevent IBC with a compound that has the ability to disintegrate the cell spheroids. Our published data shows that the medicinal mushroom, Ganoderma lucidum (Reishi), inhibits IBC progression via disintegration of tumor spheroids. Thus, we aimed to investigate Reishi's in vitro and in vivo therapeutic potential in IBC, focusing on the regulation of E-cadherin and EGFR and its contribution to the IBC cellular response when treated with the EGFR Tyrosine Kinase Inhibitor (TKI), erlotinib (commercially known as Tarceva®). Herein, we show that Reishi downregulates E-cadherin and EGFR abundance in vitro, significantly reduces tumor growth by 58%, and downregulates in vivo EGFR, and E-cadherin protein expression. Moreover, a synergistic effect is observed when erlotinib and Reishi are used simultaneously after 72 hours of treatment. Since Reishi downregulates the expression of E-cadherin and EGFR, our subsequent investigations will focus on the identification of PM proteins using stable isotope labeling with amino acids in cell culture (SILAC). Our results provide evidence that Reishi downregulates key proteins overexpressed in IBC, and chemosensitizes IBC cells to erlotinib therapy, highlighting its anti-IBC-therapeutic potential. This project was sponsored by Title V PPOHA US Dept of Education #P031M105050 to UCC, NIH/RCMI #2G12RR003035 to UCC, NIH/INBRE #5P20RR016470 to UPR/UCC, NIH/NCRR #U54RR026139 to UPR/UCC, and a research donation from the Commonwealth of Puerto Rico to UCC-Centro Universitario de Medicina Integral y Complementaria (CUMIC) / MMM.

Citation Format: Ivette Suarez-Arroyo, Raysa Rosario-Acevedo, Alexandra Aguilar-Pérez, Luis A. Cubano, Michelle M. Martínez-Montemayor. Ganoderma lucidum (Reishi) downregulates key proteins overexpressed in IBC and chemosensitizes EGFR-overexpressing cells to erlotinib. [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 2247. doi:10.1158/1538-7445.AM2013-2247

Abstract 4868: Dietary resveratrol promotes breast cancer progression in immunocompromised mice

Resveratrol, a polyphenol from grapes and red wine has been widely studied due to its beneficial effects against cardiovascular diseases and cancer. However, our group and others have provided evidence for a dual cancer promoting or inhibitory role for resveratrol in breast cancer, dependent on the concentration. Moreover, much of the reported inhibitory effects of resveratrol are from studies with high non-physiological concentrations. Herein, we investigated the effects of low (0.5 and 5 mg/kg body weight) and moderate concentrations (50 mg/kg body weight) of resveratrol on mammary tumor growth, using immunocompromised mice. Our findings suggest promotion of mammary tumor growth and metastasis by resveratrol at all concentrations tested in tumors derived from the low metastatic estrogen receptor (ER)α(-), ERβ(+) MDA-MB-231 and the highly metastatic ER(-) MDA-MB-435 cancer cell lines. Additionally, the activity of the migration/invasion regulator Rac, which we have previously shown to be regulated by resveratrol in vitro, was measured in tumors from resveratrol treated mice. Our results show a significant induction of tumoral Rac activity and a trend in increased expression of the Rac downstream effector PAK1, Akt, and jun kinase (JNK) following resveratrol treatment. Taken together, our findings implicate low concentrations of resveratrol in potential promotion of breast cancer. Because of this dual role of resveratrol on cancer progression, measuring circulating plasma levels of resveratrol becomes critical and could be used as a prognostic tool for resveratrol's responsiveness. Since, detection and quantification of low levels of resveratrol is limited by the sensitivity of existing methodologies, we developed a rapid UPLC-tandem MS method to quantify resveratrol from plasma. This method requires minimal sample preparation and allows the quantification of resveratrol in mouse plasma at lower levels and shorter retention times than those previously reported by similar methodologies. This study was supported by DoD/BCRP W81XWH-08-1-0258 to LCP, DoD/BCRP W81XWH-07-1-0330 to SD, the UCC Pilot Project Program, the UCC Postdoctoral Program sponsored by the PR Science, Technology and Research Trust, and the Title V PPOHA grant number PO31M105050 from U.S. Department of Education to UCC.

Citation Format: Linette Castillo-Pichardo, Luis A. Cubano, José F. Rodríguez-Orengo, Suranganie Dharmawardhane. Dietary resveratrol promotes breast cancer progression in immunocompromised mice. [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 4868. doi:10.1158/1538-7445.AM2013-4868

Abstract 1672: Ganoderma lucidum (Reishi) induces autophagy in inflammatory breast cancer cells to promote cell death

Autophagic cell death is an important physiological cell death process that is characterized by massive degradation of cellular contents by means of intracellular membrane/vesicle reorganization and lysosomal activity. Herein, we test the autophagy inducing effects of the medicinal mushroom Ganoderma lucidum (Reishi) in the inflammatory breast cancer (IBC) cell line, SUM-149. IBC is a rare, lethal and aggressive form of advanced breast cancer with poor prognosis and no targeted therapy. Because the mechanism is not well defined, some autophagic cell death events might be attributed to apoptosis. This death or survival mechanism depends on cell type and cells stress, since in such cases the induction of both, autophagy and other pro-death signals (i.e. BAX), occur in parallel. Our hypothesis is that Reishi induces autophagy in IBC cells to promote cell death. SUM-149 cells were treated with 0.5mg/mL of Reishi for 2h, 4h, 6h, 8h, 12h and 24h. Cells were lysed and equal total protein was western blotted against Beclin-1, Atg5, Atg12 and LC3B autophagy proteins. To confirm autophagy effects on cell viability, cells were treated with 3-methyladenine (3-MA), chloroquine (CQ) and PP242 with or without Reishi for 24 hours. Cells were fixed and stained with propidium iodide to assess viable nuclei. Herein we show that Reishi affects the expression of autophagy-associated molecules depending on treatment time. Reishi increases the expression of autophagy proteins in IBC. Moreover, the autophagy inhibitors increased cell viability after 24h, while cancer cell viability decreased when Reishi was added. Autophagy inducer PP242 alone and in combination with Reishi decreased cell viability and induced the expression of the pro-apoptotic protein, BAX. Thus, we demonstrate that Reishi induces autophagy, promoting cell death in IBC cells, as cancer cell viability is reduced, with a subsequent increase in pro-apoptotic protein expression when Reishi is added. Our findings are the first to show a novel mechanism responsible for the inhibition of IBC cell viability by Reishi demonstrating its potential for use in treatment of cancer. This project was sponsored by Title V PPOHA US Dept of Education #P031M105050 to UCC, NIH/RCMI #2G12RR003035 to UCC, NIH/INBRE #5P20RR016470 to UPR/UCC, NIH/NCRR #U54RR026139 to UPR/UCC, and a research donation from the Commonwealth of Puerto Rico to UCC-Centro Universitario de Medicina Integral y Complementaria (CUMIC) / MMM.

Citation Format: Raysa Rosario-Acevedo, Tiffany Rios, Ivette Suarez-Arroyo, Luis A. Cubano, Michelle M. Martínez-Montemayor. Ganoderma lucidum (Reishi) induces autophagy in inflammatory breast cancer cells to promote cell death. [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 1672. doi:10.1158/1538-7445.AM2013-1672

Anti-tumor effects of Ganoderma lucidum (reishi) in inflammatory breast cancer in in vivo and in vitro models

The medicinal mushroom Ganoderma lucidum (Reishi) was tested as a potential therapeutic for Inflammatory Breast Cancer (IBC) using in vivo and in vitro IBC models. IBC is a lethal and aggressive form of breast cancer that manifests itself without a typical tumor mass. Studies show that IBC tissue biopsies overexpress E-cadherin and the eukaryotic initiation factor 4GI (eIF4GI), two proteins that are partially responsible for the unique pathological properties of this disease. IBC is treated with a multimodal approach that includes non-targeted systemic chemotherapy, surgery, and radiation. Because of its non-toxic and selective anti-cancer activity, medicinal mushroom extracts have received attention for their use in cancer therapy. Our previous studies demonstrate these selective anti-cancer effects of Reishi, where IBC cell viability and invasion, as well as the expression of key IBC molecules, including eIF4G is compromised. Thus, herein we define the mechanistic effects of Reishi focusing on the phosphoinositide-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway, a regulator of cell survival and growth. The present study demonstrates that Reishi treated IBC SUM-149 cells have reduced expression of mTOR downstream effectors at early treatment times, as we observe reduced eIF4G levels coupled with increased levels of eIF4E bound to 4E-BP, with consequential protein synthesis reduction. Severe combined immunodeficient mice injected with IBC cells treated with Reishi for 13 weeks show reduced tumor growth and weight by ∼50%, and Reishi treated tumors showed reduced expression of E-cadherin, mTOR, eIF4G, and p70S6K, and activity of extracellular regulated kinase (ERK1/2). Our results provide evidence that Reishi suppresses protein synthesis and tumor growth by affecting survival and proliferative signaling pathways that act on translation, suggesting that Reishi is a potential natural therapeutic for breast and other cancers.

Dietary grape polyphenol resveratrol increases mammary tumor growth and metastasis in immunocompromised mice

Background

Resveratrol, a polyphenol from grapes and red wine has many health beneficial effects, including protection against cardiovascular and neurodegenerative diseases and cancer. However, our group and others have provided evidence for a dual cancer promoting or inhibitory role for resveratrol in breast cancer, dependent on estrogenic or antiestrogenic activities. Moreover, much of the inhibitory effects of resveratrol have been reported from studies with high non-physiological concentrations.

Methods

We investigated the effects of a range of concentrations (0.5, 5, 50 mg/kg body weight) of resveratrol on mammary tumor development post-initiation, using immunocompromised mice.

Results

Our findings suggest promotion of mammary tumor growth and metastasis by resveratrol at all concentrations tested in tumors derived from the low metastatic estrogen receptor (ER)α(-), ERβ(+) MDA-MB-231 and the highly metastatic ER(-) MDA-MB-435 cancer cell lines. Additionally, the activity of the migration/invasion regulator Rac, which we have previously shown to be regulated by resveratrol in vitro, was measured in tumors from resveratrol treated mice. Our results show a significant induction of tumoral Rac activity and a trend in increased expression of the Rac downstream effector PAK1 and other tumor promoting molecules following resveratrol treatment.

Conclusion

Taken together, our findings implicate low concentrations of resveratrol in potential promotion of breast cancer. Therefore, this study illuminates the importance of further delineating resveratrol’s concentration dependent effects, particularly in breast cancer, before it can be tested in the clinic or used as a dietary supplement for breast cancer patients.

Abstract A16: Molecular mechanisms of EGFR therapy resistance in breast cancer cells

The purpose of this study is to investigate molecular mechanisms of epidermal growth factor receptor (EGFR) therapy resistance using a syngeneic pair of gefitinib-sensitive and gefitinib-resistant breast cancer cells. Signaling from EGFRs is usually dysregulated in breast, as well as other cancers, where it is commonly associated with an aggressive phenotype and poor outcome. The initial success of targeted therapies for EGFR1 and HER2 has been marred by de novo or acquired resistance. Gefitinib, a small molecule tyrosine kinase inhibitor with high specificity towards EGFR, was proven to be effective for the treatment of non-small cell lung carcinoma (NSCLC). However, clinical trials of gefitinib as a breast cancer therapeutic have failed due to lack of response, probably due to resistance, and adverse toxic effects. We have developed a Gefitinib resistant variant of the gefitinib sensitive human breast cancer cell line SKBR3 (SKBR3 G.R.), with the objective of studying the involvement of micro (mi)-RNAs in therapy resistance. A partial screening of several miRNAs previously shown to be involved in therapy resistance was performed and miRNA (miR-)200a was identified as a downregulated miRNA in the SKBR3 G.R. cells. Members of the miR-200 family play a critical role in the suppression of epithelial-to-mesenchymal transition (EMT) by repressing key mRNAs involved in this process. Additionally, the miR-200 family can regulate tumor cell adhesion, migration, invasion and metastasis; and has been associated with EGFR inhibitor resistance. Herein, we have analyzed the protein expression of EGFR, phospho-EGFR, and miR-200 family targets Zeb1, β-catenin, and the ErbB receptor inhibitor-1 (ERRFI-1 or Mig6) by western blot analysis in SKBR3 and SKBR3 G.R. breast cancer cells. Our results show a significant increase in the expression of EGFR, Zeb1, and β-catenin; whereas, phospho-EGFR and Mig6 expression was significantly downregulated in SKBR3 G.R. cells when compared to parental cells. Therefore, Mig6 expression may not be regulated via miR-200 activity in these cells. Downregulation of Mig6 may explain the increased EGFR levels due to its role in EGFR internalization and subsequent degradation. Since SKBR3 cells are mesenchymal, they do not express E-cadherin, another Zeb1 target. Our results suggest that in cancer cells that have undergone EMT, decreased miR-200a levels, and thus, increased Zeb1 and β-catenin, a potent pro-cancer transcriptional activator in the absence of an E-cadherin axis, is a potential mechanism of Gefitinib resistance in aggressive breast cancer.

This study was supported by NIH/NIGMS SC3GM094824 to SD, the UCC Pilot Project Program, and the UCC Postdoctoral Program sponsored by the PR Science, Technology and Research Trust.

Abstract 2142: Dietary grape polyphenol resveratrol regulates Rac activity to increase mammary tumor growth and metastasis

Resveratrol is a natural compound from grapes and peanuts that is structurally similar to estrogen and can act as an estrogenic or antiestrogenic compound, depending on the concentration. In vitro, high concentrations of resveratrol can have proapoptotic, antigrowth, anti-inflammmatory, antiangiogenic, and anti-invasive properties in cancer cells. However, we reported that resveratrol at low, physiologically relevant, concentrations acts similar to estrogen and promotes breast cancer cell migration via actin cytoskeletal changes regulated by Rac; a small GTPase that plays a pivotal role in cancer cell migration/invasion, and thus, metastasis. Herein, we investigated the effects of dietary resveratrol on mammary tumor growth and metastasis in immunocompromised mouse models of cancer metastasis. Interestingly, our findings suggest promotion of mammary tumor growth and metastasis to lung, liver, and kidney by resveratrol in tumors derived from the low metastatic estrogen receptor (ER)α(−), ERα(+) MDA-MB-231 and the highly metastatic ER(-) MDA-MB-435 cancer cell lines. To determine the role of Rac in resveratrol-mediated mammary tumor progression, the activity of Rac was measured in tumors from resveratrol-treated mice. Our results show a significant increase in tumoral Rac activity, consistent with the concentration of resveratrol that induced the highest metastatic efficiency. Taken together, our findings demonstrate a cancer-promoting role for dietary concentrations of resveratrol in metastatic cancer via Rac activation. Therefore, this study illuminates the importance of further delineating resveratrol's concentration dependent molecular mechanisms, particularly in breast cancer, before it can be tested in the clinic or used as a dietary supplement for cancer patients. This study was supported by DoD/BCRP W81XWH-08-1-0258 to LCP, DoD/BCRP W81XWH-07-1-0330 to SD, the UCC Pilot Project Program, and the UCC Postdoctoral Program sponsored by the PR Science, Technology and Research Trust. The content is solely the responsibility of the authors and does not necessarily represent the official views of the Universidad Central del Caribe or the PR Science, Technology and Research Trust.

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 2142. doi:1538-7445.AM2012-2142

Abstract 1992: Ganoderma lucidum (Reishi) induces autophagy in inflammatory breast cancer by regulation of the mTOR signaling pathway

The control of cell growth by the mammalian target of rapamycin (mTOR) signaling pathway and autophagy are relevant to disease, as altered regulation of either pathway may result in tumorigenesis. Autophagy is a regulated pathway involving the lysosomal degradation of cytoplasmic components and organelles. Activation of the human autophagy-initiation kinase (ULK1) is directly controlled by mTOR and is a critical part of the autophagy machinery. In this study we test the autophagy inducing effects of the medicinal mushroom Ganoderma lucidum (Reishi) in the patient derived inflammatory breast cancer (IBC) cell line SUM-149 and in the non-cancerous mammary epithelial cell line MCF10A. IBC is a rare, lethal and aggressive form of locally advanced breast cancer that has a poor prognosis and no targeted therapy. Herein, we demonstrate that Reishi modulates the expression of autophagy related molecules depending on treatment time. At 2h post-Reishi treatment SUM-149 cells show that ULK1, Atg5, Atg12, Beclin1 and the microtubule-associated protein 1 light chain 3 (LC3) are α1.2 fold upregulated. Furthermore, autophagosomal structures were identified in SUM-149 but not in MCF10A Reishi treated cells. At 4h post-Reishi Atg5 and Atg12 (required for phagophore formation) are ∼1.5 fold upregulated, while at 6h LC3 expression (involved in autophagosome formation) is ∼2 fold upregulated compared to vehicle. We also show that autophagy induction in SUM-149 cells is mediated via downregulation of the PI3K/mTOR signaling pathway. Reishi downregulates PI3K (p85 and p110), mTOR phosphorylation and reduces the expression of Raptor, which is the regulatory subunit of mTORC1, the complex that directly regulates proteins involved in autophagy. Rictor, the regulatory subunit of the mTORC2 complex, which inhibits autophagy indirectly through Akt is also downregulated by Reishi. We demonstrate that Reishi has great potential to be used as an anti-IBC-therapeutic. This project was sponsored by Title V PPOHA grant number P031M105050 from the US Dept of Education to UCC, and NIH/RCMI 2G12RR003035 to UCC.

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 1992. doi:1538-7445.AM2012-1992

Abstract 1987: Ganoderma lucidum (Reishi) suppresses key protein synthesis initiation molecules in inflammatory breast cancer

Inflammatory breast cancer (IBC) is an aggressive and lethal type of breast cancer. IBC's lethality originates from its nature of invading the lymphatic system and to the absence of a palpable tumor mass. Pathogenic properties of IBC result in part from deregulation of the eukaryotic translation initiation factor (eIF4G), which is activated via the mammalian target of rapamycin (mTOR) pathway. Active mTOR signaling liberates eukaryotic translation initiation factor 4E (eIF4E) through the hierarchical phosphorylation of eIF4E binding protein (4E-BP). When hypophosphorylated, 4E-BP associates with eIF4E, preventing eIF4E from binding eIF4G, blocking the formation of the eIF4F translation initiation complex; thus, impeding protein translation. Therefore therapeutics that target eIF4G in IBC are of great interest. Ganoderma lucidum (Reishi) is a medicinal mushroom used to prevent and treat many diseases including cancer. We recently reported that Reishi inhibits eIF4G expression after 24h of treatment in the SUM-149 IBC patient derived cell line. Therefore, we investigated the therapeutic potential of Reishi mushroom in IBC cells in vitro and in vivo, focusing on the regulation of mTOR and direct downstream effectors: 4E-BP1 and the ribosomal protein p70S6K. Herein, we show that Reishi treatment of SUM-149 cells impacts protein synthesis initiation via inhibition of the mTOR pathway leading to hypophosphorylation of 4E-BP1. Accordingly, Reishi downregulates mTOR protein levels, 4E-BP1 phosphorylation, maintains eIF4E levels and decreases p70S6k and eIF4G expression, potentially leading to reduced eIF4F translation initiation complex levels after 6h of treatment. To further investigate Reishi's therapeutic effects in vivo, we studied IBC progression of SUM-149 subcutaneous tumors in severe combined immunocompromised (SCID) mice. Following tumor establishment, mice were gavaged every day with vehicle or Reishi at 28mg/kg BW for 13 weeks. Tumor progression was quantified by caliper measurements, followed by analysis of excised organs for protein expression. Results show that Reishi significantly reduced tumor growth by 58% compared to vehicle controls. Moreover, mTOR, eIF4E, eIF4G, E-cadherin, p4E-BP1 and p70S6k expression decreases in the SUM-149 tumors from mice treated with Reishi. Our results provide evidence that Reishi suppresses key molecules that are important for protein synthesis initiation in IBC, thus highlighting the potential of Reishi as a natural anti-IBC-therapeutic. This project was sponsored by Title V PPOHA grant number P031M105050 from the US Dept of Education to UCC, and NIH/RCMI 2G12RR003035 to UCC.

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 1987. doi:1538-7445.AM2012-1987

Characterization of EHop-016, novel small molecule inhibitor of Rac GTPase

The Rho GTPase Rac regulates actin cytoskeleton reorganization to form cell surface extensions (lamellipodia) required for cell migration/invasion during cancer metastasis. Rac hyperactivation and overexpression are associated with aggressive cancers; thus, interference of the interaction of Rac with its direct upstream activators, guanine nucleotide exchange factors (GEFs), is a viable strategy for inhibiting Rac activity. We synthesized EHop-016, a novel inhibitor of Rac activity, based on the structure of the established Rac/Rac GEF inhibitor NSC23766. Herein, we demonstrate that EHop-016 inhibits Rac activity in the MDA-MB-435 metastatic cancer cells that overexpress Rac and exhibits high endogenous Rac activity. The IC(50) of 1.1 μM for Rac inhibition by EHop-016 is ∼100-fold lower than for NSC23766. EHop-016 is specific for Rac1 and Rac3 at concentrations of ≤5 μM. At higher concentrations, EHop-016 inhibits the close homolog Cdc42. In MDA-MB-435 cells that demonstrate high active levels of the Rac GEF Vav2, EHop-016 inhibits the association of Vav2 with a nucleotide-free Rac1(G15A), which has a high affinity for activated GEFs. EHop-016 also inhibits the Rac activity of MDA-MB-231 metastatic breast cancer cells and reduces Rac-directed lamellipodia formation in both cell lines. EHop-016 decreases Rac downstream effects of PAK1 (p21-activated kinase 1) activity and directed migration of metastatic cancer cells. Moreover, at effective concentrations (<5 μM), EHop-016 does not affect the viability of transformed mammary epithelial cells (MCF-10A) and reduces viability of MDA-MB-435 cells by only 20%. Therefore, EHop-016 holds promise as a targeted therapeutic agent for the treatment of metastatic cancers with high Rac activity.

Ganoderma lucidum (Reishi) inhibits cancer cell growth and expression of key molecules in inflammatory breast cancer

Inflammatory breast cancer (IBC) is the most lethal and least understood form of advanced breast cancer. Its lethality originates from its nature of invading the lymphatic system and absence of a palpable tumor mass. Different from other metastatic breast cancer cells, IBC cells invade by forming tumor spheroids that retain E-cadherin-based cell-cell adhesions. Herein we describe the potential of the medicinal mushroom Ganoderma lucidum (Reishi) as an attractive candidate for anti-IBC therapy. Reishi contains biological compounds that are cytotoxic against cancer cells. We report the effects of Reishi on viability, apoptosis, invasion, and its mechanism of action in IBC cells (SUM-149). Results show that Reishi selectively inhibits cancer cell viability although it does not affect the viability of noncancerous mammary epithelial cells. Apoptosis induction is consistent with decreased cell viability. Reishi inhibits cell invasion and disrupts the cell spheroids that are characteristic of the IBC invasive pathology. Reishi decreases the expression of genes involved in cancer cell survival and proliferation (BCL-2, TERT, PDGFB), and invasion and metastasis (MMP-9), whereas it increases the expression of IL8. Reishi reduces BCL-2, BCL-XL, E-cadherin, eIF4G, p120-catenin, and c-Myc protein expression and gelatinase activity. These findings suggest that Reishi is an effective anti-IBC therapeutic.

Individual and combined soy isoflavones exert differential effects on metastatic cancer progression

To investigate the effects soy isoflavones in established cancers, the role of genistein, daidzein, and combined soy isoflavones was studied on progression of subcutaneous tumors in nude mice created from green fluorescent protein (GFP) tagged-MDA-MB-435 cells. Following tumor establishment, mice were gavaged with vehicle or genistein or daidzein at 10 mg/kg body weight (BW) or a combination of genistein (10 mg/kg BW), daidzein (9 mg/kg BW), and glycitein (1 mg/kg BW) three times per week. Tumor progression was quantified by whole body fluorescence image analysis followed by microscopic image analysis of excised organs for metastases. Results show that daidzein increased while genistein decreased mammary tumor growth by 38 and 33% respectively, compared to vehicle. Daidzein increased lung and heart metastases while genistein decreased bone and liver metastases. Combined soy isoflavones did not affect primary tumor growth but increased metastasis to all organs tested, which include lung, liver, heart, kidney, and bones. Phosphoinositide-3-kinase (PI3-K) pathway real time PCR array analysis and western blotting of excised tumors demonstrate that genistein significantly downregulated 10/84 genes, including the Rho GTPases RHOA, RAC1, and CDC42 and their effector PAK1. Daidzein significantly upregulated 9/84 genes that regulate proliferation and protein synthesis including EIF4G1, eIF4E, and survivin protein levels. Combined soy treatment significantly increased gene and protein levels of EIF4E and decreased TIRAP gene expression. Differential regulation of Rho GTPases, initiation factors, and survivin may account for the disparate responses of breast cancers to genistein and daidzein diets. This study indicates that consumption of soy foods may increase metastasis.

Implications of ER stress, the unfolded protein response, and pro- and anti-apoptotic protein fingerprints in human monocyte-derived dendritic cells treated with alcohol

BACKGROUND

Dendritic cells (DCs) are responsible for the activation of T cells and B cells. There is accumulating evidence that psychoactive substances such as alcohol can affect immune responses. We hypothesize that this occurs by modulating changes in proteins triggering a process known as unfolded protein response (UPR). This process protects cells from the toxic effects of misfolded proteins responsible for causing endoplasmic reticulum (ER) stress. Although much is known about ER stress, little is understood about the consequences of ethanol use on DC's protein expression.

METHODS

In this study, we investigated alterations in the proteins of human monocyte-derived dendritic cells (MDDC) treated with 0.1% of alcohol by two-dimensional (2D) gel electrophoresis followed by liquid chromatography-tandem mass spectrometry, protein identification, and confirmation at the gene expression level by qRT-PCR.

RESULTS

Proteomes of related samples demonstrated 32 differentially expressed proteins that had a 2-fold or greater change in expression (18 spots were up-regulated and 14 were down-regulated), compared to the control cultures (untreated cells). Alcohol significantly changed the expression of several components of the UPR stress-induced pathways that include chaperones, ER stress, antioxidant enzymes, proteases, alcohol dehydrogenase, cytoskeletal and apoptosis-regulating proteins. qRT-PCR analyses highlighted the enhanced expression of UPR and antioxidant genes that increased (18 hours) with alcohol treatment.

CONCLUSION

Results of these analyses provide insights into alcohol mechanisms of regulating DC and suggest that alcohol induced specifically the UPR in DC. We speculate that activation of a UPR by alcohol may protect the DC from oxidant injury but may lead to the development of alcohol-related diseases.

Prevalence of drug resistance and associated mutations in a population of Hiv-1+ Puerto Ricans in 2005

This is a continuation of our efforts to maintain a record of the evolution of HIV-1 infection in Puerto Rico by monitoring the expression levels of antiretroviral resistance-associated mutations. Samples from 2005 were analyzed (458: 270 males, 137 females, 51 anonymous), using the TRUGENE HIV-1 Genotyping Kit and the OpenGene DNA Sequencing System. Results show that 60.1% of males and 50.2% of females had HIV-1 with resistance to at least one medication. The average number of HIV mutations in males was 6.27, while the average number of HIV mutations in females was 5.49. The highest levels of resistance were to Zalcitabine, Lamivudine, and Stavudine. The reverse transcriptase mutations with the highest frequency of expression were M184V, K103N and D67N. Protease mutations with the highest rate of expression were L63P, M361 and L90M. Significant differences between men and women were recorded in the levels of HIV-1 expressed mutations and resistance.

Ischemia Increases TREK-2 Channel Expression in Astrocytes: Relevance to Glutamate Clearance

The extent of an ischemic insult is less in brain regions enriched in astrocytes suggesting that astrocytes maintain function and buffer glutamate during ischemia. Astrocytes express a wide variety of potassium channels to support their functions including TREK-2 channels which are regulated by polyunsaturated fatty acids, intracellular acidosis and swelling; conditions that pertain to ischemia. The present study investigated the possible involvement of TREK-2 channels in cultured cortical astrocytes during experimental ischemia (anoxia/hypoglycemia) by examining TREK-2 protein levels, channel activity and ability to clear glutamate. We found that TREK-2 protein levels were increased rapidly within 2 hrs of the onset of simulated ischemia. This increase corresponded to an increase in temperature-sensitive TREK-2-like channel conductance and the ability of astrocytes to buffer extracellular glutamate even during ischemia. Together, these data suggest that up-regulation of TREK-2 channels may help rescue astrocyte function and lower extracellular glutamate during ischemia.

Prevalence of drug resistance and associated mutations in HIV-positive Puerto Ricans: sex variations

INTRODUCTION

A cross sectional study was conducted from 2002-2004 to record the evolution of HIV-1 infection in Puerto Rico by monitoring the expression of antiretroviral resistance-associated mutations.

METHODS

Samples were analyzed by using the TRUGENE HIV-1 Genotyping Kit and the OpenGene DNA Sequencing System.

RESULTS

Mutations in the HIV-1 virus were detected in 92.7% of men and 94.8% of women. Of these, 75.1% of men and 72.4% of women had HIV-1 with resistance to at least one medication. The average number of HIV mutations was 6.1 in men and 5.3 in women. In 2002 and 2003, strains were most frequently resistant to the antiretroviral drugs zalcitabine, lamivudine and didanosine, while in 2004, strains were most frequently resistant to zalcitabine, lamivudine, and efavirenz. The most prevalent mutations in the reverse transcriptase gene were M184V, K103N, T215Y, and M41L. The most prevalent mutations in the protease gene were L63P, M361, L90M, A71V, and L101.

CONCLUSIONS

Significant differences between men and women were recorded in the levels of HIV-1 expressed mutations and resistance. When comparing these results with data from 2000 and 2001, results indicate that expression of resistant mutations has remained constant.

Estrogen and resveratrol regulate Rac and Cdc42 signaling to the actin cytoskeleton of metastatic breast cancer cells

Estrogen and structurally related molecules play critical roles in breast cancer. We reported that resveratrol (50 microM), an estrogen-like phytosterol from grapes, acts in an antiestrogenic manner in breast cancer cells to reduce cell migration and to induce a global and sustained extension of actin structures called filopodia. Herein, we report that resveratrol-induced filopodia formation is time-dependent and concentration-dependent. In contrast to resveratrol at 50 microM, resveratrol at 5 microM acts in a manner similar to estrogen by increasing lamellipodia, as well as cell migration and invasion. Because Rho GTPases regulate the extension of actin structures, we investigated a role for Rac and Cdc42 in estrogen and resveratrol signaling. Our results demonstrate that 50 microM resveratrol decreases Rac and Cdc42 activity, whereas estrogen and 5 microM resveratrol increase Rac activity in breast cancer cells. MDA-MB-231 cells expressing dominant-negative Cdc42 or dominant-negative Rac retain filopodia response to 50 microM resveratrol. Lamellipodia response to 5 microM resveratrol, estrogen, or epidermal growth factor is inhibited in cells expressing dominant-negative Rac, indicating that Rac regulates estrogen and resveratrol (5 microM) signaling to the actin cytoskeleton. These results indicate that signaling to the actin cytoskeleton by low and high concentrations of resveratrol may be differentially regulated by Rac and Cdc42.

Induction of a Soluble Anti-HIV-1 factor (s) with IFN-γ, IL-10, and β-Chemokine Modulating Activity by an Influenza-Bacterial Polyantigenic Mixture

Partial immune restoration may be obtained with highly active antiretroviral therapy (HAART), but specific anti-HIV-1 immune responses do not appear to improve substantially. We have demonstrated that a soluble factor(s) induced by a mixture of inactivated influenza and bacterial vaccines called polyantigenic immunomodulator (PAI), possesses strong immunoregulatory and anti-HIV-1 activities. In the present study, we show that culture fluids from both PAI-stimulated peripheral blood mononuclear cells (PBMC) and CD8+ T-cells of HIV-1 infected patients were able to suppress HIV-1 replication in an MHC-unrestricted fashion. The PAI-induced antiviral activity was eliminated when culture fluids were pre-heated at 100°C for 10 min. and it is associated with induction of IFN-γ, MIP-1α, MIP-1β, and RANTES production, but inhibition of IL-10. Furthermore, this induction is dependent on the immunological status (CD4:CD8 ratio) of the HIV-1 infected patient. Taken together, our results suggest that the MHC-unrestricted HIV-1 suppression that is induced by culture fluids from PAI-stimulated PBMC may result from the stimulation of immune cell subpopulations to produce a heat-labile antiviral soluble factor(s), which in turn modulate cytokine and β-chemokine production. The identification of this PAI-induced soluble factor(s) may have major therapeutic potential.

Immune cells under altered gravity conditions

Considerable research over the past three decades has been devoted to characterizing changes in the response of cells of the immune system to stimuli while exposed to altered gravity conditions. A consistent finding shows that mammalian cells subjected to conditions of spaceflight and the microgravity environment of space manifest a number of alterations in structure and function. Changes in cells flown on the space shuttle include reduction in growth activation and decline in growth rate in the total population. Other changes include chromosomal aberration, inhibited locomotion, altered cytokine production, changes in protein kinase C distribution, and increased apoptosis. Human lymphocytes respond poorly to mitogenic stimulation in microgravity and lymphoid cell lines are growth arrested. Recent research into the gene expression of immune cells under altered gravity conditions has provided insight into the possible pathways involved in adapting to gravity changes. Here we synthesize the findings of research related to changes in the immune response as a result of exposure to altered gravity conditions.

Saccharomyces cerevisiae gene expression changes during rotating wall vessel suspension culture

This study utilizes Saccharomyces cerevisiae to study genetic responses to suspension culture. The suspension culture system used in this study is the high-aspect-ratio vessel, one type of the rotating wall vessel, that provides a high rate of gas exchange necessary for rapidly dividing cells. Cells were grown in the high-aspect-ratio vessel, and DNA microarray and metabolic analyses were used to determine the resulting changes in yeast gene expression. A significant number of genes were found to be up- or downregulated by at least twofold as a result of rotational growth. By using Gibbs promoter alignment, clusters of genes were examined for promoter elements mediating these genetic changes. Candidate binding motifs similar to the Rap1p binding site and the stress-responsive element were identified in the promoter regions of differentially regulated genes. This study shows that, as in higher order organisms, S. cerevisiae changes gene expression in response to rotational culture and also provides clues for investigations into the signaling pathways involved in gravitational response.