Significant Reduction In Tumor Weight Research Articles

Preclinical Pharmacokinetics in Tumors and Normal Tissues of the Antigene PNA Oligonucleotide MYCN-Inhibitor BGA002.

Although MYCN has been considered an undruggable target, MYCN alterations confer poor prognosis in many pediatric and adult cancers. The novel MYCN-specific inhibitor BGA002 is an antigene peptide nucleic acid oligonucleotide covalently bound to a nuclear localization signal peptide. In the present study, we characterized the pharmacokinetics (PK) of BGA002 after single and repeated administration to mice using a novel specific enzyme-linked immunosorbent assay. BGA002 concentrations in plasma showed linear PK, with dose proportional increase across the tested dose levels and similar exposure between male and female and between intravenous and subcutaneous route of administration. Repeated dosing resulted in no accumulation in plasma. Biodistribution up to 7 days after single subcutaneous administration of [14C]-radiolabeled BGA002 showed broad tissues and organ distribution (suggesting a potential capability to reach primary tumor and metastasis in several body sites), with high concentrations in kidney, liver, spleen, lymph nodes, adrenals, and bone marrow. Remarkably, we demonstrated that BGA002 concentrates in tumors after repeated systemic administrations in three mouse models with MYCN amplification (neuroblastoma, rhabdomyosarcoma, and small-cell lung cancer), leading to a significant reduction in tumor weight. Taking into account the available safety profile of BGA002, these data support further evaluation of BGA002 in patients with MYCN-positive tumors.

Single-cell transcriptome sequencing to explore the infiltration and disappearance of NK cells in liver cancer.

e14520 Background: The emergence of tumor immunotherapy such as immune checkpoint blocking has greatly promoted the development of Hepatocellular carcinoma (HCC) treatment. However, the response rate of HCC patients to immunotherapy is not high, and the probability of adverse reactions is high. Natural killer (NK) cells play a crucial role in inhibiting the proliferation and metastasis of tumor cells and are expected to become a new hope for tumor therapy. Methods: The HCC single-cell transcriptome atlas was constructed by using the tumor tissues, adjacent tissues, peripheral blood of HCC patients. To emulate the hypoxic state within the tumor, NK cells were treated with rotenone, and the post-rotenone treatment changes of NK cells in transcriptome levels were evaluated using qPCR. The proliferation, apoptosis, and cytotoxicity of NK cells were assessed via flow cytometry. The study also investigated the role of c-Jun N-terminal protein kinase (JNK) in NK cell function by applying the JNK inhibitor tanzisertib (CC-930) in vitro. The impact of JNK inhibition on the tumor-killing potential of NK cells was examined in vivo using tumor-bearing mice NCG (NOD/ShiLtJ-Prkdcem26Cd52Il2rgem26Cd22/Gpt). Results: Analysis of the source of NK cell subsets found that the specific NK cells in tumor tissues were tissue-resident NK cells (trNK). Both RNA velocity analysis and pseudo-time sequence analysis suggested that trNK cells differentiated from PBMC-1 NK cells. Upon treatment of PBMC-1 NK cells with Tanzisertib, we observed inhibition of NK cell apoptosis. Through the subcutaneous tumor formation experiment of NCG mice, Tanzisertib-treated NK cells were transferred into tumor-bearing mice. Notably, we observed a significant reduction in tumor weight (Before treatment: 0.19g, 0.19g, 0.22g, 0.24g, 0.26g, 0.27g; After treatment: 0.16g, 0.17g, 0.17g, 0.19g, 0.21g, 0.23g; P value = 0.049). TUNEL assay confirmed a significant increase number of apoptotic cells within the tumor and an increased number of infiltrated NK cells. Conclusions: The NK cells in HCC tumors are likely derived from the infiltration of NK cells in peripheral blood. Importantly, the inhibition of JNK function can significantly inhibit the apoptosis of NK cells and enhance the killing ability of NK cells against tumor cells in vivo.

Abstract 1589: Integrated multiomics analysis revealed the significance of Transgelin in driving pancreatic cancer-associated fibroblast-mediated cancer progression

Abstract Pancreatic ductal adenocarcinoma (PDAC) is primarily characterized by a desmoplastic reaction, mainly consisting of cancer-associated fibroblasts (CAFs). In order to investigate the heterogeneity of CAFs, we initially conducted single-cell Assay for Transposase-Accessible Chromatin with high-throughput sequencing (scATAC-seq) using pancreas tissue from 12-week-old KPC (K-rasLSL.G12D/+; Trp53R172H/+; Pdx-1-Cre) PDAC mouse models. We identified three clusters enriched with myofibroblast CAF (myCAF) gene markers and one cluster enriched with inflammatory CAF (iCAF) gene markers. Next, we performed single-cell RNA sequencing (scRNA-seq) on pancreas tissues from KPC mice. scRNA-seq revealed four distinct fibroblast clusters, each exhibiting characteristic gene expression profiles of normal fibroblasts, iCAF, myCAF and antigen-presenting CAF (apCAF). These findings suggest that CAFs in the myCAF cluster identified in scATAC-seq may have potential to differentiate into either myCAFs or other CAF subtypes based on certain cues. Next, we focus on the expression of myCAF marker genes, particularly two commonly used markers, Tagln and Acta2. Among myCAFs, two subtypes were identified: Tagln-positive and Acta2-positive CAFs, and Tagln-negative and Acta2-positive CAFs. To confirm our findings, we conducted Immunohistochemical analysis (IHC) on KPC pancreas samples. We observed CAFs that were positive for both Talng and αSMA exclusively in close proximity to tumor cells. Fibroblast expressing only αSMA mostly located in normal area. Tagln is known as an actin-binding protein and plays an important role in activated fibroblasts. Orthotopic PDAC mouse models using Tagln homozygous knockout mice showed a significant reduction in tumor weight compared to the wild-type mice (P = 0.0076). Indeed, we found that high TAGLN expression in PDAC samples was associated with poor survival, as demonstrated by the analysis of the TCGA dataset. These data suggest that myCAFs expressing TAGLN contribute to the promotion of PDAC growth. Targeting stromal TAGLN might be a potential therapeutic strategy to counteract PDAC progression. Citation Format: Keiko Shinjo, Xingxing Wang, Kohei Kumegawa, Reo Maruyama, Shinji Mii, Yoshiteru Murofushi, Miho Suzuki, Atsushi Enomoto, Yutaka Kondo. Integrated multiomics analysis revealed the significance of Transgelin in driving pancreatic cancer-associated fibroblast-mediated cancer progression [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 1589.

Photo-enhanced catalytic activity enabled by core–shell nanozymes for combination breast cancer therapy

Enhanced catalytic therapy of triple-negative 4T1 breast tumors through the application of photo-enhanced peroxidase (POD)-like and catalase (CAT)-like activities combined with chemotherapy could be enabled by core–shell nanozymes. Therefore, the dual POD and CAT-like activities of the core–shell iron oxide (Fe3O4)-@gold (IO@Au) nanozymes loaded with epirubicin (EPI) were evaluated in this study for photo-enhanced combination therapy. The core–shell nanozymes induced oxidative stress and apoptosis, and these effects were enhanced upon application of PDT, as demonstrated by ROS and caspase-3 activity assays. Additionally, it was shown that by reducing the expression of HIF-1α gene and upregulation of caspase-3 gene, core–shell nanozymes with and without PDT were able to induce a significant reduction in tumor weight, when compared to free EPI. The bio-distribution of the drug-loaded into core–shell nanozymes showed a higher accumulation of the EPI in the 4T1 breast tumor when compared to samples treated with free EPI. Overall core–shell nanozymes with catalytic-like activity can be used as potential platforms for photo-enhanced combination therapy.

Toxicity and antitumor activity of the water-soluble lectin from Moringa oleifera Lam. Seeds (WSMoL) in sarcoma 180-bearing mice

WSMoL, a water-soluble lectin from the seeds of Moringa oleifera, present several biological activities. This work aimed to evaluated the toxicity and antitumor activity of WSMoL. To analyze toxicity, it was determined hematological, biochemical and histological parameters; consumption of water and feed as well as the weight of the animals. Antitumor analysis included evaluation of tumor weight, histology and cytokine levels. Acute toxicity assay revealed 60% mortality of animals treated with lectin at 200 mg/kg i. p. At 100 mg/kg i. p., the animals showed a decreased food and water consumption as well weight gain in comparison with control. However, no animal died and there were no alterations in blood parameters or histological analysis. Antitumor activity evaluated at safe doses (2.5, 5 and 10 mg/kg) showed a significant reduction in tumor weight. Tumor photomicrographs evidenced that WSMoL treatment reduced dissemination of tumor cells. WSMoL (5 and 10 mg/kg) significantly enhance the immune function in the tumor environment as showed by increased the levels of pro-inflammatory (TNF-α, IFN-γ, IL-2, IL-6, and IL-17) and anti-inflammatory (IL-4 and IL-10) cytokines. In conclusion, WSMoL showed in vivo antitumor activity in mice bearing sarcoma 180 tumor, probably by increase the immune response against the tumor.

A novel dopamine receptor D2 antagonist (ONC206) potentiates the effects of olaparib in endometrial cancer

ABSTRACT Poly ADP-ribose polymerase (PARP) inhibitors are effective therapies for cancer patients with homologous recombination (HR) deficient tumors. The imipridone ONC206 is an orally bioavailable dopamine receptor D2 antagonist and mitochondrial protease ClpP agonist that has anti-tumorigenic effects in endometrial cancer via induction of apoptosis, activation of the integrated stress response and modulation of PI3K/AKT signaling. Both PARP inhibitors and imipridones are being evaluated in endometrial cancer clinical trials but have yet to be explored in combination. In this manuscript, we evaluated the effects of the PARP inhibitor olaparib in combination with ONC206 in human endometrioid endometrial cancer cell lines and in a genetically engineered mouse model of endometrial cancer. Our results showed that simultaneous exposure of endometrial cancer cells to olaparib and ONC206 resulted in synergistic anti-proliferative effects and increased cellular stress and apoptosis in both cell lines, compared to either drug alone. The combination treatment also decreased expression of the anti-apoptotic protein Bcl-2 and reduced phosphorylation of AKT and S6, with greater effects compared to either drug alone. In the transgenic model of endometrial cancer, the combination of olaparib and ONC206 resulted in a more significant reduction in tumor weight in obese and lean mice compared to ONC206 alone or olaparib alone, together with a considerably decreased Ki-67 and enhanced H2AX expression in obese and lean mice. These results suggest that this novel dual therapy may be worthy of further exploration in clinical trials.

Prophylactic antineoplastic activity of Toxoplasma gondii RH derived antigen against ehrlich solid carcinoma with evidence of shared antigens by comparative immunoblotting

BackgroundWith cancer cases escalation, an urgent request to develop novel combating strategies arise. Pathogen-based cancer-immunotherapy is getting more consideration. Autoclaved parasitic antigens seem promising candidates, taking steadily their first steps. Our aim was to examine the prophylactic antineoplastic activity of autoclaved Toxoplasma vaccine (ATV) and to test for the shared antigen theory between Toxoplasma gondii and cancer cells.MethodsMice were immunized with ATV followed by Ehrlich solid carcinoma (ESC) inoculation. Tumor weight, volume, histopathology, and immunohistochemistry for CD8+ T cells, Treg cells and VEGF were assessed. In addition, the proposed shared antigen theory between parasites and cancer was also verified using SDS-PAGE and immunoblotting.ResultsResults revealed powerful prophylactic activity of ATV with 13.3% inhibition of ESC incidence, significant reduction in tumor weight and volume in ATV vaccinated mice. Immunologically, significantly higher CD8+T cells and lower FOXP3+ Treg cells surrounded and infiltrated ESC in ATV immunized mice with higher CD8+T/Treg cells ratio and significant antiangiogenic effect. Moreover, SDS-PAGE and immunoblotting showed four shared bands between Ehrlich carcinoma and ATV of approximate molecular weights 60, 26, 22 and 12.5 KDa.ConclusionExclusively, we demonstrated a prophylactic antineoplastic activity of autoclaved Toxoplasma vaccine against ESC. Moreover, to the best of our knowledge this is the first report highlighting the existence of cross-reactive antigens between Toxoplasma gondi parasite and cancer cells of Ehrlich carcinoma.

Abstract 6001: Epigenetic regulation of BARD1 confers resistance to anti-VEGF therapy in ovarian cancer

Abstract Introduction: Vascular endothelial growth factor (VEGF) is a key promoter of angiogenesis and disease progression in epithelial ovarian cancer (OC). Bevacizumab, a humanized anti-VEGF monoclonal antibody, is approved for treatment of patients with ovarian and other cancers. Despite the wide use of anti-VEGF therapy for cancer treatment, most patients develop resistant disease. Therefore, new combinations/strategies are needed to reduce adaptive resistance to anti-VEGF antibody (AVA) therapy. Our aim is to determine the potential role of epigenetic changes in AVA-adaptive resistance. We identified and characterized epigenetic changes in BARD1, a tumor suppressor, at the emergence of AVA resistance. Methods: To define epigenetic changes during AVA therapy induced resistance, we performed series of in vitro (methylation array, RNA sequencing) and in vivo (orthotopic OC (PDX-MDA-OVCA1, immunocompetent-IG10, and immunocompromised-SKOV3) and fibrosarcoma-HT1080, an inherently VEGF resistant model) experiments. The biological effects of DNA methylation agent (5`-Azacytidine; 5`-Aza) with B20 (murine anti-VEGF antibody) treatment were subsequently tested using in vivo models. Results: To determine whether 5`-Aza can enhance the efficacy of AVA therapy and overcome resistance to AVA in OC, we established AVA-resistant SKOV3 model. In AVA-resistant mice treated with B20 + 5`-Aza, there was a statistically significant reduction in tumor weight (p=0.03). Next, we performed a Human 450k methylation and mRNA arrays from xenografts of SKOV3 tumors. Based on both analyses, we demonstrated that BARD1 was one of the top candidate which was highly expressed (p=0.02) and less methylated (p<0.05) in the combination of B20 and 5`-Aza group compared to B20 alone. Our data also showed that BARD1 expression was restored in the combination therapy. The sequential treatment with 5`-Aza reverted the resistance towards the AVA therapy in SKOV3 model. Furthermore, the combination of B20 and 5`-Aza significantly decreased tumor weight in SKOV3 (p=0.005), IG10 (p<0.05), MDA-OVCA1 (p=0.01), and HT1080 (p<0.05). BARD1 expression levels were substantially increased in combination therapy compared to the B20 alone group (>4-fold, p=0.006). Tumor weight and BARD1 expression were inversely correlated. To determine the biological significance of BARD1, we knockdown BARD1 using Tet-inducible shRNA system. Our data showed a significant reduction in tumor weight in the BARD1 knockdown group in SKOV3 model (p=0.021). RNA-sequencing of BARD1 knockdown showed an enrichment of the angiogenesis pathway. Moreover, BARD1 expression levels were decreased in hypoxic conditions both in vitro and in vivo. Conclusion: Our findings indicate a previously unrecognized role for BARD1 in mediating resistance to AVA therapy. Use of epigenetic drugs to control the expression of tumor suppressor genes may enhance the efficacy of AVA therapy in OC. Citation Format: Emine Bayraktar, Cristian Rodriguez-Aguayo, Sudhir Kumar, Elaine Stur, Lingegowda S. Mangala, Stephen Baylin, Gabriel Lopez-Berestein, Sunila Pradeep, Anil K. Sood. Epigenetic regulation of BARD1 confers resistance to anti-VEGF therapy in ovarian cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6001.

What’s next after bevaciumab resistance? Targeting metabolic vulnerabilities in ovarian cancer (022)

What’s next after bevaciumab resistance? Targeting metabolic vulnerabilities in ovarian cancer (022)

Carbopol thickened nanoemulsions of chemotherapeutics to treat DMBA-induced breast cancer

Breast cancer is the most frequent invasive malignancy in women globally. The goal of this study was to prepare mitoxantrone and 4-methyl umbelliferone nanoemulsions followed by hydrogel preparation viz. MTO-NE-Gel and 4-MU-NE-Gel and characterized for various parameters like visual assessment, pH, rheology, ex vivo studies, and in vivo studies in 7,12-dimethylbenz(a)anthracene-induced breast cancer in swiss albino mice. The pH, viscosity, and spreadability were found to be 5.62±0.05, 13107 cP ±658, and 5.3 g.cm/s ±0.28 for 4-MU-NE-Gel and 5.75±0.03, 13025 cP ±705, and 4.06 g.cm/s ±0.45 for MTO-NE-Gel. The percent cumulative amount of drug permeated for 4-MU suspension, MTO Solution,4-MU-NE-Gel, and MTO-NE-Gel were found to be 51.26% ±5.22, 15.54% ±3.91, 89.093% ± 6.8, and 97.242%±4.51 respectively after 8 h which was significantly higher in hydrogel formulations. The outcome of pharmacodynamic studies reveals a significant reduction in tumor weight and tumor volume for MTO-NE-Gel and 4-MU-NE-Gel treated mice as compared to MTO-Gel and 4-MU-sus-Gel. Histopathological evaluation of mammary tumors indicates improvement in the tissue anatomical features and a significant decreasing trend in levels of tumor marker CA15-3 was also observed. Based on the promising results of this investigation,,,

Abstract 2484: Hyperpolarized magnetic resonance spectroscopy assessment of the metabolic effects of glutaminase inhibitor therapy in an ovarian cancer model

Abstract Introduction: Ovarian cancer accounts for more deaths than any other cancer of the female reproductive system despite advances in targeted drugs such as anti-VEGF antibody (AVA). Additionally, resistance to AVA therapy is nearly ubiquitous given the occurrence of metabolic adaptations such as a dependence on glutamine metabolism via the enzyme glutaminase. Objectives: To examine the metabolic vulnerability of AVA-resistant cancer with glutaminase inhibitor (GLSi) therapy and to test the utility of hyperpolarized magnetic resonance spectroscopy (HP-MRS) for assessing changes in lactate metabolism associated with GLSi treatment following injection of hyperpolarized [1-13C] pyruvate. Methods: We used a well-characterized SKOV3ip1 orthotopic mouse model of high-grade serous ovarian cancer with adaptive resistance to AVA (bevacizumab) treatment. Following three weeks of GLSi and bevacizumab treatment, we performed HP-MRS imaging to directly and non-invasively compare metabolic changes between the treatment groups of bevacizumab monotherapy versus a combined treatment of bevacizumab plus GLSi therapy. Upon injection of hyperpolarized [1-13C] pyruvate, we quantitatively assessed a normalized lactate ratio (nLac), defined as the 13C resonance signal of lactate divided by the sum of the pyruvate and lactate signals, sixty seconds after injection. GLSi treatment effect was subsequently compared between GLSi monotherapy, bevacizumab monotherapy and control mice receiving no therapy. This was performed via gross necropsy to assess disease burden and quantification of tumor weight and nodule number. Results: Significance analysis microarrays (SAM) of bevacizumab treated tumors from the mouse models revealed greater glutamine and glutamate abundance in all tissues suggestive of a glutamine dependence in AVA resistant tumors that could be susceptible to glutaminase inhibition. The in vivo HP-MRS provided a direct and non-invasive investigation of pyruvate metabolism of tumors in situ. Our analysis indicated that the pyruvate-to-lactate conversion was significantly reduced in vivo by GLSi treatment (0.337 vs 0.178, p=0.0002), suggestive of therapeutic efficacy of GLSi in the setting of AVA-resistant tumors. Consistent with this, we observed a statistically significant reduction in tumor weight (0.05g vs 0.62g and 0.64g, p<0.01) and tumor nodule number (n=3.3 vs n=12.8 and n=13.9, p<0.05) in mice treated with a combination of bevacizumab and GLSi compared to the control group, or GLSi monotherapy, respectively. Conclusions: Using HP-MRS in vivo, we directly monitored metabolic changes occurring after GLSi treatment. These findings are consistent with the notion of glutamine dependence being an important resistance mechanism to AVA therapy and imply potential future use of HP-MRS in monitoring therapeutic efficacy in a clinical realm. Citation Format: Deanna Glassman, Mark S. Kim, Prasanta Dutta, Charles V. Kingsley, Emine Bayraktar, Yutuan Wu, Elaine Stur, Lingegowda S. Mangala, Katherine Foster, Sanghoon Lee, Timothy A. Yap, Shannon N. Westin, Pratip Bhattacharya, Anil K. Sood. Hyperpolarized magnetic resonance spectroscopy assessment of the metabolic effects of glutaminase inhibitor therapy in an ovarian cancer model [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2484.

GPx8 regulates apoptosis and autophagy in esophageal squamous cell carcinoma through the IRE1/JNK pathway

Glutathione peroxidase 8 (GPx8) belongs to a family of enzymes that have a critical role in controlling levels of reactive oxygen species (ROS). GPX family members have been associated with several cancers. Here, we examined the role of GPx8 in esophageal squamous cell carcinoma (ESCC). Immunohistochemical staining and western blot analysis were used to study the clinical significance of GPx8 in ESCC tissue. GPx8 was further evaluated in cells by MTT assay and colony formation. RT-PCR, western blot, immunofluorescence staining, TUNEL assay, TEM, and flow cytometry were used to assess the molecular mechanism underlying endoplasmic reticulum (ER) stress associated with GPx8 in ESCC cells. Xenografted tumor growth was used to assess the in vivo role of GPx8. We found that GPx8 was overexpressed in both ESCC cell lines and tumor tissue. GPx8 knockdown significantly suppressed ESCC proliferation and induced autophagy and apoptosis in ESCC cell lines, whereas GPx8 overexpression led to increased proliferation and inhibition of apoptosis. GPx8-mediated inhibition of apoptosis was associated with the ER stress pathway through inositol-requiring enzyme 1 (IRE1) and Jun N-terminal kinase (JNK). Knockdown of GPx8 in xenograft models of ESCC resulted in a significant reduction in tumor weight and volume, which was further reduced with IRE1 or JNK inhibitors. Our study suggests that GPx8 regulates apoptosis and autophagy in ESCC through the IRE1/JNK pathway in response to ER stress. Targeting this pathway might be a potential therapeutic strategy for ESCC.

VEGFR-Mediated Cytotoxic Activity of Pulicaria undulata Isolated Metabolites: A Biological Evaluation and In Silico Study.

Natural products play a remarkable role not only in the synthesis, design, and discovery of new drugs but also as the most prominent source of drugs and bioactive substances. Adding to the search for new sources of safe innovative antitumor drugs, here we reported a phytochemical study on Pulicaria undulata which revealed promising antiangiogenic agents. Six compounds were isolated and identified as xanthoxyline (1), stigmasterol (2), oleanolic acid (3), salvigenin (4), rhamnetin (5) and dihydroquercetin-4′-methyl ether (6) using nuclear magnetic resonance (NMR) spectroscopic techniques. Compound 3 and 4 are first reported in Pulicaria genus. Both the extract and isolated compounds were evaluated for in vitro antiproliferative activity against breast cancer cell line (MCF-7). In vivo antiproliferative activity against Ehrlich’s ascites carcinoma (EAC) were also assessed. The P. undulata extract and isolates showed significant reduction in tumor weight, decreased both serum vascular endothelial growth factor B (VEGF-B) levels and vascular endothelial growth factor receptor 2 (VEGFR-2) expression significantly compared to the control EAC group, suggesting an antiangiogenic activity through the inhibition of VEGF signaling. Besides, they displayed reduction in CD34 expression, confirming their antiangiogenic effect. Moreover, the potential affinity of isolated compounds to human estrogen nuclear receptor-alpha (hER-α), the most recognized modulator of VEGFR-2 expression, was virtually estimated through molecular modeling studies. The most promising activity profiles were assigned to the investigated flavonoids, compounds 4–6, as well as the alkyl-phenylketone, compound 1. Additionally, these four top active compounds showed respective high to intermediate docking scores while possessing preferential binding with hER-α critical pocket residues. Based on the provided data, these isolated compounds illustrated promising inhibitors of VEGF-stimulated angiogenesis, which could be a possible mechanism for their anticancer activity.

Antitumor Effects of Ethanol Extract from Ventilago leiocarpa Benth on Sarcoma 180 Tumor-Bearing Mice and Possible Immune Mechanism.

To explore the antitumor effects of ethanol extract from Ventilago leiocarpa Benth (EEVLB) on sarcoma 180 (S180) tumor-bearing mice and the potential mechanism. Sixty mice were randomly assigned to 6 groups according to a random number table: normal group, model group, 5-fluorouracil (5-FU) group (0.02 g·kg-1), and high-, medium-, low-dose EEVLB groups (100, 84, and 56 g of raw material·kg-1 body weight, respectively), with 10 mice each group. All treatments were given once daily for 10 consecutive days. Effects of EEVLB on inhibiting tumor growth and immune function in mice were evaluated among all groups after the treatments by detecting tumor inhibition rate, organ index, serum levels of interleukin (IL)-2, -6, -10, CD3+CD4+ T lymphocytes, CD4+/CD8+ ratio, caspase-3 and Bcl-2. EEVLB with different concentrations achieved inhibition of tumor growth in vivo, wherein the high-dose group showed the most significant reduction in tumor weight and increased apoptosis of tumor cells (P<0.05). In addition, both net weight gain and spleen index of mice showed uptrend in EEVLB treatment groups (P<0.05). Besides, serum levels of IL-2 and IL-6, percentages of CD3+CD4+ T lymphocytes and ratio of CD4+/CD8+ in peripheral blood were elevated in high- and medium-dose EEVLB groups compared with the model group (P<0.05). Also, upregulation of caspase-3 and downregulation of Bcl-2 were observed at protein levels in the high-dose EEVLB group (P<0.01). EEVLB exhibits promising antitumor activity in vivo. This effect might be due to activation of apoptotic signaling pathway, increase of cytokine levels and enhancement of immune function in tumor-bearing mice.

Abstract 2658: PFKFB3 inhibition reprograms malignant pleural mesothelioma to glycolytic stress-induced macropinocytosis and ER stress as independent binary adaptive responses

Abstract The metabolic signatures of cancer cells are often associated with elevated glycolysis which promotes alteration in cellular bioenergetics. 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), a critical control point in the glycolytic pathway has emerged as a potential anti-cancer target associated with many aspects of neoplastic progression. Pharmacological (PFK158 treatment) and genetic inhibition of PFKFB3 activity, decreases glucose uptake, ATP production, and lactate dehydrogenase activity and inhibits cell proliferation in vitro by arresting the cells in the G0/G1 phase induced cell death in malignant pleural mesothelioma (MPM). It induces an early response of increased macropinocytosis and drastic endosomal vacuolization to overcome the nutrient stress both in sarcomatoid (H28) and epithelioid (EMMeso) MPM cells. Inhibition of PFKFB3 leads to the activation of the endocytic Rac1-Rab5-Rab7 pathway resulting in a unique form of cell death called “methuosis”. Transmission Electron Microscopy analysis showed that pharmacological and genetic inhibition of PFKFB3 activity leads to the formation of nascent macropinocytotic vesicles, which rapidly coalesced to form large vacuoles with compromised lysosomal function. Confocal microscopy revealed F-actin and α-tubulin disassembly leading to the disruption of cell structure integrity. In parallel, PFKFB3 expression inversely modulates endoplasmic reticulum (ER) stress in MPM. Pharmacological and genetic inhibition of PFKFB3 led to an escalation in ER activity and aggravated ER stress mostly by upregulating BiP and GADD153 expression levels. However, EHT1864, a Rac1 inhibitor, could not rescue MPM cells from ER stress, suggesting that the activation of macropinocytosis and ER stress are a result of two independent PFKFB3 modulated adaptive responses. Both immunofluorescence microscopy and co-immunoprecipitation analyses revealed that the two crucial biomolecules of each pathway, Rac1 and Calnexin, interact with each other only at the later stages of PFKFB3 inhibition. Finally, PFK158, in a combination of with CBPt, demonstrated a significant reduction in tumor weight in mesothelin overexpressed EMMeso xenograft model. Since most cancer cells exhibit an increased glycolytic rate, these results provide evidence for PFK158, in combination with standard chemotherapy, may have a potential in the treatment of MPM. Citation Format: Sayantani Sarkar Bhattacharya, Ling Jin, Debarshi Roy, Deokbeom Jung, Prabhu Thirusangu, Yinan Xiao, Julie Staub, Julian Molina, Viji Shridhar. PFKFB3 inhibition reprograms malignant pleural mesothelioma to glycolytic stress-induced macropinocytosis and ER stress as independent binary adaptive responses [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 2658.

CD11b hyperactivation improves response to immunotherapy in pancreatic cancer

Introduction: Survival in pancreatic cancer (PC) remains low and development of effective clinical approaches is critical. Modern strategies including immunotherapy show minimal efficacy in human PC. One way to improve response to immunotherapy is to reprogram the tumor microenvironment which includes desmoplastic-stroma and abundant immunosuppressive myeloid-infiltrate. We utilize a novel strategy of hyper-activating CD11b-receptor using a small molecule agonist, ADH-503. ADH-503 binds to CD11b-receptor, preventing its binding to ligand ICAM-1 which prevents leukocyte trans-endothelial migration. We hypothesize that CD11b hyper-activation will reprogram myeloid response and improve immunotherapeutic efficacy in PC. Methods: We utilized genetic (KPC: p48-Cre; LSL-KrasG12D; Trp53flox/flox) and orthotopic models of murine PC models to evaluate the effect of ADH-503 on tumor-growth and immune-infiltrates by flow-cytometry and immunohistochemistry. Results: To determine the effect of CD11b hyper-activation in PC, we treated tumor bearing mice with ADH-503 for 10 days and observed significant reduction in tumor-weight. Analysis of myeloid cells showed that monocytes, granulocytes and macrophages were significantly reduced by ADH-503. Simultaneously there was a decrease in regulatory T-cells and increase in CD8+ T-cell numbers, activation and proliferation. We observed a significant change in gene expression profiles of tumor infiltrating macrophages with ADH-503-therapy, suggesting macrophage re-polarization. In orthotopic models, which are extremely resistant to immunotherapy, combination of ADH-503+/-anti-PD1 and ADH-503+/-41BB, showed significant regression of tumor-growth, suggesting improved efficacy in combination with immunotherapy. Conclusions: Our data suggest that combination of CD11b hyper-activation and immunotherapy has the potential to overcome the barrier to T-cell infiltration and may be a useful strategy in the treatment of PC.

Targeting HSP60 by subcutaneous injections of jetPEI/HSP60-shRNA destabilizes cytoplasmic survivin and inhibits hepatocellular carcinoma growth.

Heat shock protein 60 (HSP60) overexpresses in various types of cancer, but its expression levels and functions in hepatocellular carcinoma (HCC) are still in dispute. We aim to clarify this issue and examine whether HSP60 could be a therapeutic target for HCC. We found drastically enhanced cell apoptosis and suppressed cell proliferation in two HCC cell lines with HSP60-silencing, and also indicated survivin was involved in this regulatory process in vitro and in vivo. However, HSP60-silencing in normal human hepatocytes only resulted in a minimal reduction of cell proliferation but without effects on cell apoptosis. We also showed HSP60 interacted with cytosolic but not mitochondrial survivin by immunoprecipitation assay. A rigorous method was used to standardize quantification from immunoblot assay to obtain more precise expression levels of HSP60 and survivin. The expression of HSP60 and survivin positively correlated in both cancerous and non-cancerous liver tissues (P < 0.001) after analyzing 145 surgically removed HCC tissues. A total of 56.6% of HCC patients overexpressed HSP60 in cancerous tissues, and 40.0% under-expressed HSP60. Higher expression of HSP60 and survivin in non-cancerous tissues both correlated with shorter overall survival (P = 0.029 and P < 0.001, respectively). Finally, we evaluated the therapeutic potential of HSP60 using extraneous delivery of jetPEI/shHSP60 complexes. The treatment results showed significant reduction of tumor weight by 44.3% (P < 0.05), accompanied by under-expression of survivin. These studies suggested that HSP60 not only served as a prognostic marker but also served as a novel therapeutic target for HCC.

Comparison of fusion protein and DC vaccine in inhibition of mouse B16F10 melanoma tumor

Dendritic cell (DC) vaccine and fusion protein vaccine have been put into clinical use in cancer immunotherapy. This study compared DC vaccine and fusion protein vaccine directly in their capability of inducing specific immune response. We used mouse Granulocyte Macrophage-Colony Stimulating Factor (mGM-CSF) fused with gastrin-releasing peptide (GRP) and Gonadotrophin Releasing Hormone (GnRH) respectively to obtain mGM-CSF/GRP6 (mG6) and mGM-CSF/mGGn (mGGn) fusion proteins. We prepared fusion protein vaccine and DC vaccine including mG6 protein vaccine (6P), mGGn protein vaccine (nP), mG6 DC vaccine (6D) and mGGn DC vaccine (nD), then the two proteins were mixed to prepare combination proteins vaccine (6nP) and DC vaccine (6nD). After that, C57BL/6 mice were injected with B16F10 cell line to build melanoma tumor model, and were immunized with vaccines to produce antibodies to inhibit and destruct melanoma tumor cells. The discoveries showed that anti- mGM-CSF-GRP6 and anti- mGM-CSF-mGGn antibody vaccines were successfully created as expected; this was deduced from significant inhibition of melanoma tumor in vivo and significant reduction of tumor weight and volume. The effects of DC groups were better than that of the protein groups and the combination of vaccines were more effective than vaccine given separately. Our results indicate that using combination vaccine provides a new strategy to inhibit melanoma tumor growth but a complete cure of melanoma needs further investigations.

Abstract 3065: High-throughput screen identifies HSP90 as a potential therapeutic target in models of advanced CRPC

Abstract Castrate resistant prostate cancer (CRPC) remains the primary cause of mortality for prostate cancer (PCa) patients. Several therapies are currently approved for use against CRPC, consisting mostly of androgen receptor (AR) signaling inhibitors and toxic anti-microtubule chemotherapeutics that do not score long-term durable responses. Recent deep-sequencing analysis studies have elucidated the complex and heterogeneous landscape of CRPC, highlighting the necessity to develop effective targeted therapies against specific CRPC subtypes or therapies effective against numerous subtypes of CRPC. PTEN and p53 are two of the most frequently altered genes in CRPC, and are associated with therapy resistance and a poor clinical prognosis. The objective of this study was to identify and subsequently validate therapeutic targets against models of advanced PCa, specifically in the absence of PTEN and p53. Using non-biased high throughput screening technology, we identified HSP90 inhibitors to be potent and efficacious against a model of PTEN/p53 null PCa. HSP90 is a critical regulator of prostate cancer cell signaling homeostasis, and recently developed second generation compounds targeting HSP90 are effective against genotypically heterogeneous panels of cancer cell lines and have favorable safety parameters in the clinic. Screening results and subsequent validation efforts in vitro identified ganetespib as the most potent HSP90 inhibitor, with efficacy that translated into established human PCa cells lines. Ganetespib also displayed strongly inhibitory activity against PTEN/p53 null progenitor cells, a plastic subpopulation of PCa believed to be partly responsible for therapy resistance. In vivo, ganetespib completely inhibited progression of PIN to invasive adenocarcinoma in the Pten/Tp53 null PCa mouse model, leading to a significant reduction in tumor weight. Expanding from the mouse model to clinically predictive PDX-derived LuCaP models of human PCa, we found that ganetespib displayed a range of activity against a genotypically diverse array of 11 LuCaP organoids ex vivo. Furthermore, the PTEN null/p53 altered LuCaP 136 displayed a robust response to ganetespib in vivo, with ganetespib causing a significant reduction in tumor growth. Mechanistic interrogation in vitro, ex vivo, and in vivo revealed ganetespib induced effects to be multifactorial and model specific, with unifying trends being inactivation of PI3K signaling and modulation of cell cycle regulatory proteins. In all, these data indicate that inhibition of HSP90 is a novel therapeutic to treat advanced PCa via multifactorial perturbation of growth regulatory pathways. Citation Format: Keith H. Jansson, John Tucker, Lauren Stahl, Caitlyn Fuller, Michael Beshiri, John K. Simmons, Supreet Agarwal, Lei Fang, Aian Neil Alilin, Ross Lake, Crystal Tran, Paul G. Hynes, Jacob Cawley, JuanJuan Yin, Xiaohu Zhang, Rajarshi Guha, Shelley Hoover, R. Mark Simpson, Holly Nguyen, Eva Corey, Craig Thomas, David Proia, Kathleen Kelly. High-throughput screen identifies HSP90 as a potential therapeutic target in models of advanced CRPC [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 3065. doi:10.1158/1538-7445.AM2017-3065

Styrene maleic acid-encapsulated paclitaxel micelles: antitumor activity and toxicity studies following oral administration in a murine orthotopic colon cancer model.

Oral administration of paclitaxel (PTX), a broad spectrum anticancer agent, is challenged by its low uptake due to its poor bioavailability, efflux through P-glycoprotein, and gastrointestinal toxicity. We synthesized PTX nanomicelles using poly(styrene-co-maleic acid) (SMA). Oral administration of SMA-PTX micelles doubled the maximum tolerated dose (60 mg/kg vs 30 mg/kg) compared to the commercially available PTX formulation (PTX [Ebewe]). In a murine orthotopic colon cancer model, oral administration of SMA-PTX micelles at doses 30 mg/kg and 60 mg/kg reduced tumor weight by 54% and 69%, respectively, as compared to the control group, while no significant reduction in tumor weight was observed with 30 mg/kg of PTX (Ebewe). In addition, toxicity of PTX was largely reduced by its encapsulation into SMA. Furthermore, examination of the tumors demonstrated a decrease in the number of blood vessels. Thus, oral delivery of SMA-PTX micelles may provide a safe and effective strategy for the treatment of colon cancer.