Studies Of Agents Research Articles

Development of a Benzophenone-Free Red Propolis Extract and Evaluation of Its Efficacy against Colon Carcinogenesis.

Brazilian red propolis has attracted attention for its pharmacological properties. However, signs of toxicity were recently observed in long-term studies using the hydroalcoholic extract of red propolis (RPHE), likely due to polyprenylated benzophenones. This study aimed to develop a benzophenone-free red propolis extract (BFRP) and validate an HPLC-PDA method to quantify its main constituents: isoliquiritigenin, vestitol, neovestitol, medicarpine, and 7-O-methylvestitol. BFRP's toxicity was assessed in zebrafish larvae through a vibrational startle response assay (VSRA) and morphological analysis. Genotoxicity was evaluated using the micronucleus test in rodents, and the extract's effects on chemically induced preneoplastic lesions in rat colon were studied. An HPLC-PDA method was used to quantify BFRP's main compounds. BFRP primarily contained vestitol (128.24 ± 1.01 μg/mL) along with isoliquiritigenin, medicarpin, neovestitol, and 7-O-methylvestitol. Zebrafish larvae exposed to 40 µg/mL of BFRP exhibited toxicity, higher than the 10 µg/mL for RPHE, though no morphological differences were found. Fluorescent staining in the notochord, branchial arches, and mouth was observed in larvae treated with both BFRP and RPHE. No genotoxic or cytotoxic effects were observed up to 2000 mg/kg in rodents, with no impact on hepatotoxicity or nephrotoxicity markers. Chemoprevention studies showed a 41.6% reduction in preneoplastic lesions in rats treated with 6 mg/kg of BFRP. These findings indicate that BFRP is a safe, effective propolis-based extract with potential applications for human health, demonstrating reduced toxicity and chemopreventive properties.

In Vivo Chemosuppressive Effects of Kolaviron on 7,12-Dimethylbenzanthracene-Induced Mammary Lesions are Associated with Changes in Levels of Estrogen Receptor-α, CYP 1A1, Proinflammatory Cytokines, and Alterations to Metabolic Pathways Implicated in Mammary Carcinogenesis.

Garcinia kola is a medicinal food commonly consumed in Sub-Sahara Africa, for which Kolaviron (KV) is the active portion. As a follow-up to our earlier chemopreventive studies, we investigated the chemotherapeutic effects of KV on experimentally induced mammary carcinogenesis in female Wistar rats. Mammary carcinogenesis was induced using 80 mg/kg of 7,12-dimethylbenzanthracene (DMBA) administered by oral gavage. One hundred-fifty days post-DMBA induction, estrogen receptor-α (ER-α) levels were determined in the experimental rats before treatment with KV commenced. Treatment was done using 50, 100, and 200 mg/kg KV thrice a week for 4 weeks, after which the experiment was terminated. Significantly higher levels of estrogen receptor-α, CYP 1A1, malondialdehyde, formation of lobular neoplastic cells, epithelial hyperplasia, lymphocyte infiltration, and increased cytokine (interleukin-6 and tumor necrosis factor-α) activity were observed in DMBA-induced rats, which were attenuated in KV-treated rats. Tyrosine metabolism was exclusively enriched in DMBA-induced rats in contrast to KV-treated rats. Collectively, the results point to the chemotherapeutic potential of KV.

Establishment of a Mesoamerican-Caribbean South-South Research Platform: Challenges in the Meriva (Curcuminoids) Gastric Cancer Chemoprevention Trial.

Gastric adenocarcinoma (GAC) is the fourth leading global cause of cancer mortality and leading infection-associated cancer. High-incidence regions of GAC include Latin America and Eastern Asia. Immigrants from high-incidence regions maintain their GAC risk. GAC is a major U.S. cancer disparity, and its incidence rates are 2 to 10 times higher in non-White populations. Emerging guidelines recommend 3-year surveillance endoscopy for patients with high-risk gastric premalignant conditions (GPMC). Clinical trials of GPMC chemoprevention agents are lacking. We conducted a NCI Division of Cancer Prevention-funded, phase II placebo-controlled chemoprevention trial in patients with GPMCs (atrophic gastritis and intestinal metaplasia) with a highly bioavailable preparation of curcuminoids (Meriva). The trial sites in Puerto Rico and rural Honduras had important characteristics: (i) representative Caribbean and Mesoamerican populations, linked to large U.S. immigrant populations; (ii) high prevalence of Helicobacter pylori infection and GPMCs; (iii) the absence of turmeric and curcuminoids in local diets; and (iv) proven bidirectional collaboration with U.S. academic institutions. H. pylori-negative patients with GPMCs were randomized to the study drug (500 mg po bid) or placebo for 180 days (NCT02782949), with primary outcomes based upon histologic parameters. Principal study challenges included (i) an international regulatory environment; (ii) research infrastructure strengthening, particularly in Central America; (iii) participant recruitment in Honduras, wherein only 10% to 15% are H. pylori negative; (iv) the COVID-19 pandemic; and (v) natural disasters (three hurricanes). There were no losses to follow-up related to the pandemic or natural disasters. In conclusion, the south-south partnership provides a model for chemoprevention and translational studies in Latino populations with prevalent cancers, such as GAC.

Investigation of the synergistic photocatalytic activity of a ternary ZrTiO4/TiO2/Mn3O4 (ZTM) nanocomposite in a typical water treatment process

Because of the exploration of the increase in the aqueous environment caused by various organic pollutants, an urgent need is sensed to develop novel photocatalysts with high efficiency. Here, ZrTiO4/TiO2/Mn3O4 (ZTM) was in-situ synthesized and relatively well-characterized by XRD, FTIR, UV–Vis DRS, EIS, TG/DTG, TPD, SEM, TEM, and BET characterization techniques. Diffraction data showed the crystallite sizes of about 22 and 13 nm obtained by the Scherrer and Williamson-Hall formulas, respectively, with a d-spacing of about 0.21 nm. Then, the composite catalyst was applied in the photodegradation of Metoclopramide (MCP) and showed a boosted photocatalytic activity concerning ZrTiO4, TiO2, and Mn3O4 alone. The effective surface area of 105, 54, and 93 m2/g were obtained in BET analysis of ZTM, Mn3O4, and TiO2. ZTM, Mn3O4, TiO2, and ZrTiO4 band gap energies were obtained via the DRS spectra as 2.22, 1.88, 3.05, and 3.31 eV The scavenging agent's study confirmed that hydroxyl radical and photoinduced electrons have higher roles in the MCP photodegradation process, accordingly confirmed by a sequential direct Z-scheme charge transfer mechanism in the composite.

Salvia officinalis L. exerts oncostatic effects in rodent and in vitro models of breast carcinoma.

Introduction: Based on extensive data from oncology research, the use of phytochemicals or plant-based nutraceuticals is considered an innovative tool for cancer management. This research aimed to analyze the oncostatic properties of Salvia officinalis L. [Lamiaceae; Salviae officinalis herba] using animal and in vitro models of breast carcinoma (BC). Methods: The effects of dietary administered S. officinalis in two concentrations (0.1%/SAL 0.1/and 1%/SAL 1/) were assessed in both syngeneic 4T1 mouse and chemically induced rat models of BC. The histopathological and molecular evaluations of rodent carcinoma specimens were performed after the autopsy. Besides, numerous in vitro analyses using two human cancer cell lines were performed. Results and Conclusion: The dominant metabolites found in S. officinalis propylene glycol extract (SPGE) were representatives of phenolics, specifically rosmarinic, protocatechuic, and salicylic acids. Furthermore, the occurrence of triterpenoids ursolic and oleanolic acid was proved in SPGE. In a mouse model, a non-significant tumor volume decrease after S. officinalis treatment was associated with a significant reduction in the mitotic activity index of 4T1 tumors by 37.5% (SAL 0.1) and 31.5% (SAL 1) vs. controls (set as a blank group with not applied salvia in the diet). In addition, salvia at higher doses significantly decreased necrosis/whole tumor area ratio by 46% when compared to control tumor samples. In a rat chemoprevention study, S. officinalis at a higher dose significantly lengthened the latency of tumors by 8.5 days and significantly improved the high/low-grade carcinomas ratio vs. controls in both doses. Analyses of the mechanisms of anticancer activities of S. officinalis included well-validated prognostic, predictive, and diagnostic biomarkers that are applied in both oncology practice and preclinical investigation. Our assessment in vivo revealed numerous significant changes after a comparison of treated vs. untreated cancer cells. In this regard, we found an overexpression in caspase-3, an increased Bax/Bcl-2 ratio, and a decrease in MDA, ALDH1, and EpCam expression. In addition, salvia reduced TGF-β serum levels in rats (decrease in IL-6 and TNF-α levels were with borderline significance). Evaluation of epigenetic modifications in rat cancer specimens in vivo revealed a decline in the lysine methylations of H3K4m3 and an increase in lysine acetylation in H4K16ac levels in treated groups. Salvia decreased the relative levels of oncogenic miR21 and tumor-suppressive miR145 (miR210, miR22, miR34a, and miR155 were not significantly altered). The methylation of ATM and PTEN promoters was decreased after S. officinalis treatment (PITX2, RASSF1, and TIMP3 promoters were not altered). Analyzing plasma metabolomics profile in tumor-bearing rats, we found reduced levels of ketoacids derived from BCAAs after salvia treatment. In vitro analyses revealed significant anti-cancer effects of SPGE extract in MCF-7 and MDA-MB-231 cell lines (cytotoxicity, caspase-3/-7, Bcl-2, Annexin V/PI, cell cycle, BrdU, and mitochondrial membrane potential). Our study demonstrates the significant chemopreventive and treatment effects of salvia haulm using animal or in vitro BC models.

Duguetia confinis Engl. & Diels (Annonaceae) inhibitory and cytotoxic effects on breast adenocarcinoma growth both in vitro and in vivo

BackgroundBreast cancer is ranked as the most common malignant tumor in women globally with ∼ 2.3 million new cases (11.7 %) diagnosed in 2020. The multiple drawbacks associated with treatments, prompt researchers and patients to search for alternative therapy. Plants continue to offer encouraging leads, in particular those of the Annonaceae family, to which belongs Duguetia confinis, used by Cameroonian traditional healers to fight cancers. This study was aimed at investigating the effect of Duguetia confinis against human breast cancer cells. This was carried out by investigating the cytotoxicity, underlying mechanism of action and chemopreventive potential of D. confinis on 7,12-dimethylbenz(a)anthracene (DMBA)-induced breast cancer. MethodsTo achieve this goal, the ethanolic extract of the bark of D. confinis was prepared and assayed for its ability to inhibit cell growth, cell proliferation and clone formation. Furthermore, cell death mechanisms, cell cycle progression and anti-metastatic potential were investigated. The in vivo study consisted in a once-off administration of 50 mg/kg BW DMBA (in olive oil, s.c) from the 10th day after pretreatment with D. confinis extract (50 and 100 mg/kg BW) or standards [tamoxifen (3.3 mg/kg) and letrozole (1 mg/kg)] or leaf extract of Annona muricata L. (200 mg/kg as pharmacological control). Normal and negative controls received vehicle (3 % ethanol). The treatment of animals was done for 20 weeks, followed by the assessment of the incidence, burden and volume of tumors, breast cancer biomarker (CA 15-3), antioxidant status, inflammatory status and histopathology profile. The LD50 of D. confinis extract was estimated according to OECD guideline 423. ResultsD. confinis displayed cytotoxicity at 80 μg/mL on all the tested breast cancer cell lines. It induced apoptosis and caused a blockade at G0/G1; S-phase of MDA-MB 231 cells, thus, suggesting anticancer potential. A significant concentration-dependent antimetastatic potential was observed with D. confinis extract at 50 (p < 0.05) and 100 (p < 0.01) μg/mL, evidenced by a reduction in cell migration, chemotaxis and increased adhesion to extracellular matrix. With respect to the chemopreventive study, D. confinis was able to prevent the onset of breast adenocarcinoma in Wistar rats by preventing the growth of tumor mass and volume, as well as the histopathological severity of the disease. This was achieved through the modulation of antioxidant parameters (SOD, CAT, MDA) and inflammatory parameters (IL-12, IL-6, INF- gamma, TNF). Also, the LD50 of D. confinis extract was greater than 2000 mg/kg, indicating low acute toxicity and thus, favorable for therapeutic use. ConclusionIn summary, this study outlines for the first time the beneficial effect of D. confinis as a plant candidate in the fight against breast cancer just like other species of the Annonaceae family. However, further research studies are still warranted regarding its bioactive components, and in depth investigation of its anticancer mechanism of action are also needed.

Hydrogel-Embedded Precision-Cut Lung Slices Model Lung Cancer Premalignancy Ex Vivo.

Lung cancer is the leading global cause of cancer-related deaths. Although smoking cessation is the best prevention, 50% of lung cancer diagnoses occur in people who have quit smoking. Research into treatment options for high-risk patients is constrained to rodent models, which are time-consuming, expensive, and require large cohorts. Embedding precision-cut lung slices (PCLS) within an engineered hydrogel and exposing this tissue to vinyl carbamate, a carcinogen from cigarette smoke, creates an in vitro model of lung cancer premalignancy. Hydrogel formulations are selected to promote early lung cancer cellular phenotypes and extend PCLS viability to six weeks. Hydrogel-embedded PCLS are exposed to vinyl carbamate, which induces adenocarcinoma in mice. Analysis of proliferation, gene expression, histology, tissue stiffness, and cellular content after six weeks reveals that vinyl carbamate induces premalignant lesions with a mixed adenoma/squamous phenotype. Putative chemoprevention agents diffuse through the hydrogel and induce tissue-level changes. The design parameters selected using murine tissue are validated with hydrogel-embedded human PCLS and results show increased proliferation and premalignant lesion gene expression patterns. This tissue-engineered model of human lung cancer premalignancy is the foundation for more sophisticated ex vivo models that enable the study of carcinogenesis and chemoprevention strategies.

Chemopreventive Measurements and Oxidative Stress Effects of Terpenoid-rich Canarium odontophyllum Miq. Leaf Extract (TRCO) in Ultraviolet B-Induced In-Vitro Skin Carcinogenesis Model

The most common type of cancer found in the human outer and middle skin layers is keratinocyte carcinoma, often known as non-melanoma skin cancer. Although it can be aggressive, skin cancer is generally not fatal. This study aims to measure the chemopreventive and oxidative stress effects of terpenoid-rich Canarium odontophyllum Miq.’s leaf extract (TRCO) in the UVB-induced skin carcinogenesis model. The model involving human keratinocytes (HaCaT) was adapted with optimisations with pretreatment of 500 µg/ml TRCO (TRCO500) &amp; 1000 µg/ml TRCO (TRCO1000). The HaCaT oncogenic transformation model's repetitive UVB exposure resulted in altered cell shape, according to our findings. Pretreatment of TRCO1000 significantly reduced tumour protein p53 (TP53) and marker of proliferation KI-67 (KI67) expression in UVB-induced HaCaT. Treatment with TRCO resulted in an overall reduction in oxidative stress. TRCO pretreatment showed reduced lipid peroxides, LPO and significantly reduced protein carbonyls. In conclusion, the promising results of this chemopreventive study using TRCO on this in-vitro skin carcinogenesis model suggested that it is worthwhile to conduct further isolations and assessments of terpenoids from C. odontophyllum Miq. leaf as a possible chemoprevention agent.

Pre-clinical lung squamous cell carcinoma mouse models to identify novel biomarkers and therapeutic interventions.

Primary lung carcinoma or lung cancer (LC) is classified into small-cell or non-small-cell (NSCLC) lung carcinoma. Lung squamous cell carcinoma (LSCC) is the second most common subtype of NSCLC responsible for 30% of all LCs, and its survival remains low with only 24% of patients living for five years or longer post-diagnosis primarily due to the advanced stage of tumors at the time of diagnosis. The pathogenesis of LSCC is still poorly understood and has hampered the development of effective diagnostics and therapies. This review highlights the known risk factors, genetic and epigenetic alterations, miRNA biomarkers linked to the development and diagnosis of LSCC and the lack of therapeutic strategies to target specifically LSCC. We will also discuss existing animal models of LSCC including carcinogen induced, transgenic and xenograft mouse models, and their advantages and limitations along with the chemopreventive studies and molecular studies conducted using them. The importance of developing new and improved mouse models will also be discussed that will provide further insights into the initiation and progression of LSCC, and enable the identification of new biomarkers and therapeutic targets.

Toxicological and chemoprevention studies of Brazilian brown propolis from Araucaria sp

ABSTRACT Brazilian brown propolis (BBP) is a natural product derived predominantly from the south region of Brazil, where Araucaria forests are dominant. Despite its potential as a source of bioactive compounds with leishmanicidal, anti-inflammatory, nociceptive, and antimicrobial properties, BBP has not been comprehensively studied compared to green propolis. Therefore, this study aimed to determine the safety and chemopreventive potential of BBP. The cytotoxicity attributed to BBP was assessed using two different assays, while the Salmonella/microsome assay was employed to evaluate mutagenicity. The acute toxicity attributed to BBP was determined using a zebrafish model, while the chemopreventive potential was investigated utilizing Chinese hamster lung (V79) cell lines. Data demonstrated that BBP exerted cytotoxic effects at concentrations greater than or equal to 10 µg/ml and did not exhibit mutagenicity in Salmonella typhimurium strains TA98 and TA100. However, at the highest concentration tested (4000 µg/plate), BBP induced a significant increase in revertant colonies in S. typhimurium TA102 strain. The LC50 equivalent to 8.83 mg/L was obtained in the acute toxicity evaluation in zebrafish. BBP also showed antigenotoxic effect by significantly reducing chromosomal damage induced by the mutagen doxorubicin in V79 cell cultures at a concentration of 2.5 μg/ml. Compared to Brazilian green and red propolis, BBP exhibited greater toxicity. On the other hand, at lower concentrations, BBP displayed chemopreventive potential, which may be associated with the antioxidant capacity of the extract. These findings contribute to a better understanding of the biological properties and potential applications of BBP in treating various diseases.

A Polyherbal Formulation Habb-e-Ustukhuddus Induces Apoptosis and Inhibits Cell Migration in Lung and Breast Cancer Cells without Any Toxicity in Mice.

A polyherbal medicine, Habb-e-Ustukhuddus (HU), is used for its anti-inflammatory properties. However, the anticancer and chemopreventive properties of HU were not known, and Therefore, investigated in the present study. Cancer cells were treated with 50-400 µg/ml HU and MTT, trypan blue, and clonogenic assays were performed. Propidium iodide (PI) staining, annexin V-FITC assay, and JC-1 staining were done for cell cycle progression, apoptosis, and mitochondrial membrane potential, respectively, using flow cytometry. Immunoblotting, cell migration and invasion assays were performed. Chemical characterization of HU was done through GC-MS and HPLC analyses. C57BL/6 mice were used to assess the in vivo toxicity of HU. While evaluating the anticancer activity, the methanolic extract of HU (50-400 µg/ml) strongly inhibited the growth and survival (P<0.05-0.001) of lung and breast cancer cells and increased the cell population in the sub-G1 phase of the cell cycle. HU caused apoptotic death of cancer cells (P<0.05-0.001), which was associated with the depolarization of mitochondrial membrane potential (Δψ) (P<0.001) and an increase in Bax to Bcl-2 protein ratio. Further, HU inhibited the invasion and migration of cancer cells, which was accompanied by an increase in the epithelial marker, E-cadherin, and a decrease in the mesenchymal marker, vimentin. The HU characterization by GC-MS and HPLC analyses showed the abundance of bioactive compounds including flavonoids and alkaloids. In the chemopreventive study, the oral administration of methanolic extract of the formulation HU (50 and 100 mg/kg body weight) to mice did not cause any toxicity and significantly increased the specific activities of hepatic drug metabolizing phase I and phase II enzymes, which suggested for its detoxification potential of xenobiotic compounds. Together, these results demonstrated the anticancer potential HU, without any apparent toxicity in mice, and thus HU could be further explored for its clinical utility in cancer control.

Willingness of women at increased genetic and non-genetic risk of breast cancer to participate in intervention trials to prevent cancer.

e24190 Background: The factors that influence willingness to participate (WTP) in breast cancer (BC) prevention trials are not well understood. WTP in BC prevention trials was examined in patients at increased risk of BC considering intervention and participant characteristics. Methods: Women self-identifying as being at increased risk for BC were recruited to a cross-sectional study of WTP in BC prevention trials. 78% (87 of 112) of participants completed ≥50% of a 29 item Likert Scale questionnaire about WTP in BC prevention trials that varied in intervention type and intensity, duration, time commitment, study procedures, and side effects of medications. Responses were dichotomized into “more willing” (“a lot” and “moderately”) versus “less willing” (“some,” “a little,” and “not at all”). A chi-square test was used to determine if responses differed between participants based on intervention and participant characteristics. Results: General WTP in BC ‘prevention’ studies was high at 79% “more willing”, including 67% and 72%, respectively, for unspecified physical activity and diet behavior change interventions. WTP differed significantly for diet-based behavior change interventions by type and duration; WTP was significantly lower for 12- versus 3-month interventions for both eliminating foods (28% versus 53% “more willing”, p = 0.0007) and for engaging in intermittent fasting (30% versus 45% “more willing”, p = 0.042). For physical activity, WTP decreased with duration of the intervention with 28% fewer WTP for one hour of low intensity exercise/day when compared to 30 minutes (p &lt; 0.0001). For medications, less than half of participants (46%) expressed being “more willing” to participate, and WTP decreased significantly when possible side effects were presented (81% “less willing”) with 95% “less willing” for medications with a rare risk of serious side effects. WTP was influenced by BC risk gene mutation status, with higher proportions among gene carriers compared to non-gene carriers (59% versus 21% “more willing,” p = 0.0013), including WTP in medication chemoprevention studies (38% versus 8% “more willing,” p = 0.002). Conclusions: WTP in BC prevention trials of behavior change is high among patients at elevated risk of BC but for all women was found to be significantly negatively influenced by greater time commitment and duration of intervention beyond a few months. WTP in studies of medication is lower compared to behavior change, and very low for medications with any side effects. Overall, WTP is greater in women with known genetic risk. This study suggests that WTP may be influenced by how patients perceive their level of risk. These results also suggest that despite interest in behavior change prevention, patients may not fully recognize the relationship between sustained behavior change and potential for prevention benefit.

Precision Cut Lung Slices as a Preclinical Model for Non-Small Cell Lung Cancer Chemoprevention.

PCLS could be a new model for premalignancy and chemoprevention research, and this work evaluates the model with tissue from prevention-relevant genetic and carcinogen exposed in vivo mouse models, in addition to evaluating chemoprevention agents.

Malaria knowledge, attitude, and practice among communities involved in a seasonal malaria chemoprevention study in Nanyumbu and Masasi districts, Tanzania.

Utilization of malaria interventions is influenced by, among other things, the level of knowledge and attitude that the community has toward the infection as well as the available interventions. This study assessed malaria knowledge, attitudes, and practices on malaria infection and interventions in Masasi and Nanyumbu districts, Tanzania. A community-based cross-sectional survey was conducted between August and September 2020, among the heads of households having at least one under-five child. Information on knowledge, attitudes, and practices on malaria infection and interventions was gathered from the heads of the households using a structured questionnaire. The knowledge level was classified into low, moderate, and high. Attitudes were classified into positive and negative, whereas the practices were classified into good and poor. Children aged between 3 and 59 months were screened for malaria infection using a malaria rapid diagnostic test (mRDT). The proportion of the households' heads with high level of knowledge was the primary outcome. Proportions were compared using Chi-square or fisher's test, and logistic regression analysis was used as appropriate. A total of 1,556 household heads were interviewed, 1,167 (75.00%) were male, and according to marital status, 1,067 (68.57%) were couples. All the household heads had some knowledge of malaria, but 47.33% (736/1,555) and 13.83% (215/1,555) of them had moderate and high knowledge, respectively. The level of knowledge on malaria was significantly influenced by gender [adjusted odds ratio (aOR) = 0.72, 95.00% confidence interval (CI) = 0.56-0.94, p = 0.017], level of education (aOR = 1.50, 95.00% CI = 1.04-2.16, p = 0.03), and the occupation of the household head (aOR = 1.90, 95.00% CI = 1.22-2.96, p = 0.004). Majority of the households [83.87% (1,305/1,556)] had bed nets hanging on the sleeping spaces. Of the household heads possessing bed nets, 85.10% (514/604), 79.62% (586/736), and 95.35% (205/215) of them had a low, moderate, and high level of knowledge on malaria infection, respectively (trend x 2 = 31.53, p < 0.001). The majority [95.04% (1,474/1,551)] of the household heads perceived sleeping under the bed net to be beneficial. Furthermore, 15.56% (94/604), 14.67% (108/736), and 7.44% (16/215) of the household heads with low, moderate, and high knowledge, respectively, had children with malaria infection (trend x 2 = 9.172, p = 0.01). The study population had a good level of knowledge about malaria infection, and a good attitude toward malaria interventions, and the majority of them were using bed nets.

Acteoside from Conandron ramondioides Reduces Microcystin-LR Cytotoxicity by Inhibiting Intracellular Uptake Mediated by OATP1B3.

The hepatotoxin microcystin-LR is a strong inhibitor of serine/threonine protein phosphatase (PP) 1 and PP2A. The onset of its cytotoxicity depends on its selective uptake via the hepatocyte uptake transporters, organic anion transporting polypeptide (OATP) 1B1 and OATP1B3. Understanding and preventing the cytotoxicity of microcystin-LR is crucial to maintain human health. This chemoprevention study demonstrates that the herbal plant extract of iwajisha (20 µg/mL) reduced microcystin-LR cytotoxicity in OATP1B3-expressing cells by approximately six times. In addition, 20 µM acteoside, which is one of the major compounds in iwajisha, reduced microcystin-LR cytotoxicity by approximately 7.4 times. Acteoside could also reduce the cytotoxicity of other compounds, such as okadaic acid and nodularin, which are both substrates of OATP1B3 and inhibitors of PP1/PP2A. To investigate the mechanism by which the cytotoxicity of microcystin-LR is attenuated by acteosides, microcystin-LR and microcystin-LR-binding proteins in cells were examined after microcystin-LR and acteosides were co-exposed. Thus, acteoside noncompetitively inhibited microcystin-LR uptake by OATP1B3-expressing cells. Furthermore, acteoside inhibited the intracellular interaction of microcystin-LR with its binding protein(s), including the 22 kDa protein. Furthermore, using immunoblot analysis, acteoside induced the phosphorylation of extracellular signal-regulated kinase (ERK), which is one of the survival signaling molecules. These results suggest that acteoside reduces microcystin-LR cytotoxicity through several mechanisms, including the inhibition of microcystin-LR uptake via OATP1B3, and decreased interaction between microcystin-LR and its binding protein(s), and that ERK signaling activation contributes to the attenuation effect of acteoside against microcystin-LR cytotoxicity.

A novel Bayesian adaptive design incorporating both primary and secondary endpoints for randomized IIB chemoprevention study of women at increased risk for breast cancer

BackgroundOur randomized controlled clinical trial will explore the potential of bazedoxifene plus conjugated estrogen to modulate breast tissue-based risk biomarkers as a surrogate for breast cancer risk reduction. This paper investigates the statistical design features of the trial and the rationale for the final choice of its design. Group sequential designs are a popular design approach to allow a trial to stop early for success or futility, potentially saving time and money over a fixed trial design. While Bayesian adaptive designs enjoy the same properties as group sequential designs, they have the added benefit of using prior information as well as inferential interpretation conditional on the data. Whether a frequentist or Bayesian trial, most adaptive designs have interim analyses that allow for early stopping, typically utilizing only the primary endpoint. A drawback to this approach is that the study may not have enough data for adequate comparisons of a single, key secondary endpoint. This can happen, for example, if the secondary endpoint has a smaller effect than the primary endpoint.MethodsIn this paper, we investigate a trial design called two-endpoint adaptive, which stops early only if a criterion is met for primary and secondary endpoints. The approach focuses the final analysis on the primary endpoint but ensures adequate data for the secondary analysis. Our study has two arms with a primary (change in mammographic fibroglandular volume) and secondary endpoint (change in mammary tissue Ki-67).ResultsWe present operating characteristics including power, trial duration, and type I error rate and discuss the value and risks of modeling Bayesian group sequential designs with primary and secondary endpoints, comparing against alternative designs. The results indicate that the two-endpoint adaptive design has better operating characteristics than competing designs if one is concerned about having adequate information for a key secondary endpoint.DiscussionOur approach balances trial speed and the need for information on the single, key secondary endpoint.

Abstract A016: Successful design and execution of two gastric cancer chemoprevention trials in Central America and Puerto Rico

Abstract Gastric adenocarcinoma (GAC) is the third leading global cause of cancer mortality and leading infection-associated cancer. The high incidence regions are Latin America, East Asia, and Eastern Europe. In the U.S., GAC represents a major cancer disparity, double the incidence rates in all non-white populations, the opposite of Barrett’s Esophagus and EAC. Immigrants from high incidence regions maintain the risk profile of their nations of origin. In a paradigm shift, recent guidelines now recommend surveillance endoscopy (eg, 3 years) for patients with high-risk gastric premalignant conditions (GPMCs). Clinical trials of chemoprevention agents for patients with GPMCs are lacking. We conducted two independent, NCI DCP funded, phase II placebo-controlled chemoprevention trials in patients with GPMCs (intestinal metaplasia, atrophic gastritis). The oral agents were curcumin and eflornithine (DFMO). A highly bioavailable preparation of curcumin was used. The RCTs were conducted in Puerto Rico and rural Honduras, with important characteristics: (1) representative of Caribbean and Mesoamerican populations and linked to large U.S. immigrant populations; (2) high prevalence of H. pylori infection and GPMCs; (3) absence of turmeric and curcuminoids in the local diets; (4) proven bidirectional collaboration with academic institutions in the U.S. In the curcumin trial (NCT02782949) H. pylori negative patients were randomized to study drug or placebo for 6 months. In the eflornithine study (NCT02794428), H. pylori positive and negative subjects were randomized to study drug or placebo for 18 months, with endoscopy at baseline, and 6. 18, and 24 months. The primary outcomes were based upon changes in histologic parameters at 6 months. Principal study challenges included: (1) International and bilingual regulatory environment; (2) Strengthening of the research infrastructure, particularly in Central America; (3) Participant recruitment, eg, in the curcumin RCT in Honduras wherein only 10-15% are H. pylori negative; (4) The Covid-19 pandemic; (5) Natural disasters (3 hurricanes). In Conclusion: Eflornithine and curcumin RCTs have been successfully completed, despite important challenges in implementation and execution. No losses to follow-up were encountered related to the pandemic or natural disasters. The south-south partnership may provide a model for chemoprevention and translational studies in Latino populations with prevalent cancers such as GAC. Citation Format: Eleazar Montalvan-Sanchez, Maria Gonzalez-Pons, Dalton Norwood, Ricardo Dominguez, Keith Wilson, Marcia Cruz-Correa, Douglas Morgan. Successful design and execution of two gastric cancer chemoprevention trials in Central America and Puerto Rico [abstract]. In: Proceedings of the Second Biennial NCI Meeting: Translational Advances in Cancer Prevention Agent Development (TACPAD); 2022 Sep 7-9. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_2): Abstract nr A016.

Abstract A019: Targeting STAT3 for lung cancer prevention

Abstract Former smokers have an elevated risk of lung cancer and account for a large proportion of newly diagnosed lung cancer. Former smokers with airway dysplasia have received modest benefit in randomized chemoprevention trials, while active smokers have not. More effective chemoprevention agents for former smokers at risk for lung cancer are needed. We previously reported that a cyclic double-stranded DNA oligonucleotide STAT3 decoy (CS3D) administered intravenously (IV) had strong anti-tumor effects in lung cancer xenograft models and was also effective as a chemoprevention agent using a tobacco carcinogen (NNK)-induced lung cancer mouse model that mimics “ex-smokers”. CS3D prevents the binding of activated STAT3 dimers to the promoter of target genes and induces p-STAT3 degradation. Our goal was to develop a clinically applicable direct delivery method of CS3D to the lungs. Using fluorescently tagged CS3D, we evaluated the feasibility and determined the optimal dosing schedule of CS3D administered intratracheally (IT, a mimic of human inhalation) compared to IV in mice. IT delivery 3 times/week provided a high initial drug level that was cleared from the lungs within a few hours, while IV dosing provided lower initial drug levels but persisted up to 8 hrs, with CS3D accumulation over time in the lungs. While the pharmacodynamic effect was also greater with systemic dosing, IT delivery produced inhibition of the STAT3 pathway. Phosphorylated STAT3, VEGF, IL6 and Ki67 expression in NNK-induced lung preneoplasias was down-modulated by IT CS3D delivery after 4 weeks of treatment compared to the mutant oligonucleotide (CS3M), confirming our previous findings with IV delivery. We also demonstrated that CS3D delivered IT altered the pulmonary environment by promoting a pro-inflammatory, anti-tumor response in myeloid cells of the lung directly, or by acting on tumor and stromal components to establish an immune-reactive tumor-microenvironment. No toxicities were found during IT or IV treatment and no organ abnormalities were detected by either regimen. A long-term chemoprevention study of CS3D delivered IT in the ex-smoker lung cancer murine model is underway. Our findings suggest that blocking STAT3 may be a useful strategy for lung cancer prevention, and may involve both inhibition of oncogenic signaling and enhanced anti-tumor immunity. Citation Format: Jill M. Siegfried, Adam C. Soloff, Autumn Gaither Davis, Amy A. Powers, Seth H. Eisenberg, Laura P. Stabile. Targeting STAT3 for lung cancer prevention [abstract]. In: Proceedings of the Second Biennial NCI Meeting: Translational Advances in Cancer Prevention Agent Development (TACPAD); 2022 Sep 7-9. Philadelphia (PA): AACR; Can Prev Res 2022;15(12 Suppl_2): Abstract nr A019.

Resveratrol inhibits development of colorectal adenoma via suppression of LEF1; comprehensive analysis with connectivity map.

Although many chemopreventive studies on colorectal tumors have been reported, no effective and safe preventive agent is currently available. We searched for candidate preventive compounds against colorectal tumor comprehensively from United States Food and Drug Administration (FDA)-approved compounds by using connectivity map (CMAP) analysis coupled with in vitro screening with colorectal adenoma (CRA) patient-derived organoids (PDOs). We generated CRA-specific gene signatures based on the DNA microarray analysis of CRA and normal epithelial specimens, applied them to CMAP analysis with 1309 FDA-approved compounds, and identified 121 candidate compounds that should cancel the gene signatures. We narrowed them down to 15 compounds, and evaluated their inhibitory effects on the growth of CRA-PDOs in vitro. We finally identified resveratrol, one of the polyphenolic phytochemicals, as a compound showing the strongest inhibitory effect on the growth of CRA-PDOs compared with normal epithelial PDOs. When resveratrol was administered to ApcMin/+ mice at 15 or 30 mg/kg, the number of polyps (adenomas) was significantly reduced in both groups compared with control mice. Similarly, the number of polyps (adenomas) was significantly reduced in azoxymethane-injected rats treated with 10 or 100 mg/resveratrol compared with control rats. Microarray analysis of adenomas from resveratrol-treated rats revealed the highest change (downregulation) in expression of LEF1, a key molecule in the Wnt signaling pathway. Treatment with resveratrol significantly downregulated the Wnt-target gene (MYC) in CRA-PDOs. Our data demonstrated that resveratrol can be the most effective compound for chemoprevention of colorectal tumors, the efficacy of which is mediated through suppression of LEF1 expression in the Wnt signaling pathway.

Validation of a novel model of ovarian carcinogenesis: Digital spatial profiling of premalignant fallopian tube lesions in the MADM mouse and the potential impact on primary prevention of epithelial ovarian cancer (124)

Validation of a novel model of ovarian carcinogenesis: Digital spatial profiling of premalignant fallopian tube lesions in the MADM mouse and the potential impact on primary prevention of epithelial ovarian cancer (124)