Experimental Cancer Models Research Articles

SelSA-1, a novel HDAC inhibitor demonstrates enhanced chemotherapeutic potential by redox modulation

Colorectal cancer (CRC) is a multistep disorder resulting from genetic and epigenetic genome changes. It is the third most common malignancy in developed nations accounting for roughly 600,000 deaths annually. Persistent gut inflammation, as observed in inflammatory bowel disease (IBD), is a key risk factor for CRC development. From an epigenetic viewpoint, the pharmacological inhibition of HDACs using HDAC inhibitors such as SAHA has emerged as a suitable anticancer strategy in the recent past. However, the clinical success of these strategies is limited and has risk factors associated with their uses. Thus, considering the critical involvement of epigenetic regulation of key molecular mechanisms in carcinogenesis as well as HDAC inhibitory and anti-tumorigenic properties of Selenium (Se), we aimed to explore the potentially safer and enhanced chemotherapeutic potential of a Se derivative of SAHA namely SelSA-1, in an experimental model of colitis-associated experimental cancer (CAC) model and mechanism involved therein. The in vitro study indicated improved efficiency, specificity, and better safety margin in terms of lower IC50 value of SelSA-1 than SAHA in both NIH3T3 (9.44 and 10.87 µM) and HCT 115 (5.70 and 7.49 µM) cell lines as well on primary colonocytes (5.61 and 6.30 µM) respectively. In an in vivo experimental model, SelSA-1 efficiently demonstrated amelioration of the multiple plaque lesions (MPLs), tumor burden/incidence, and modulation of various histological and morphological parameters. Further, redox-mediated alterations in apoptotic mediators suggested induction of cancer cell apoptosis by SelSA-1. These findings indicate the enhanced chemotherapeutic and pro-resolution effects of SelSA-1 in part mediated through redox modulation of multiple epigenetic and apoptotic pathways.

Liver resection modulates hepatic chemokine levels in breast cancer

BackgroundResection of metastatic hepatic tumors of breast cancer may result in the acceleration of hepatic and extrahepatic tumor progression due to the microenvironmental circulation of chemokines. This study aimed to investigate the effect of hepatectomy on a large panel of chemokines, liver regeneration, and myeloid cell levels in an experimental breast cancer model. MethodsThe 4T1 breast cancer cells were inoculated, and 30% to 40% hepatectomy was performed. Mice without tumors or only laparotomy (no hepatectomy) served as control groups. After 14 days (short-term) and 21 days (long-term), tissue samples were obtained from the regions near and distant from the resection site. Chemokine levels were evaluated by enzyme-linked immunosorbent assay arrays. Myeloid infiltration in the liver and the primary tumor and hepatic regeneration status were also histopathologically evaluated. ResultsThe levels of pro-tumorigenic chemokines such as CCL2, CCL3, CCL4, and CCL5 were elevated in hepatectomized tumor-bearing animals. This observation was consistent with the presence of hepatic metastases. Liver regeneration and myeloid cell infiltration showed significant differences between the tumor-bearing hepatectomized groups followed in the short and long term. ConclusionOur study showed elevation and variations in chemokines after hepatectomy, with a prominent increase in pro-tumorigenic chemokines. These results can be associated with the acceleration of metastasis after liver resection. However, further prospective studies are required to better define the impact of resection, which may transform the liver into a favorable site for metastasis.

Abstract 1710: Pharmacologic targeting or silencing of TRIP13 reduces progression of pancreatic ductal adenocarcinoma

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with a 5-year overall survival rate of < 9%. Thus, there is a need to identify key driver signaling molecules that regulate PDAC progression and to target them for therapeutic intervention. Thyroid receptor-interacting protein 13 (TRIP13), an enzyme of the AAA-ATPase family, participates in spindle assembly checkpoints, double-strand DNA repair, and development of drug resistance. Recently, a small-molecule inhibitor of TRIP13, DCZ0415, was evaluated in experimental models of multiple myeloma and colorectal cancer. However, the expression, oncogenic role, and targeting of TRIP13 in PDAC are unknown. Thus, we examined the expression and role of TRIP13 in PDAC and investigated if targeting it with DCZ0415 had an inhibitory effect on phenotypic features, tumor growth, metastasis, and immune modulation. Methods: Publicly available cancer OMICS datasets (TCGA and CPTAC) for TRIP13 expression were analyzed by using the UALCAN portal, and results were validated with human PDAC samples. To demonstrate the oncogenic role of TRIP13 in PDAC progression, we used silencing with shRNA or pharmacologic targeting by DCZ0415 and performed MTT, colony formation, wound healing, Transwell, and western blot assays in PDAC cell lines, and assessed tumor growth and metastasis in immunocompromised NSG mice. Immunostaining and western blotting were performed to ascertain the immuno-modulatory mechanism of DCZ0415 in an immunocompetent KPC murine model of PDAC. Results: In human PDACs, TRIP13 is overexpressed at the mRNA and protein levels, relative to adjacent normal pancreatic tissues. Silencing of TRIP13 with shRNA or DCZ0415 treatment of PDAC cells reduced their proliferation, migration, and invasion; induced G2/M cell cycle arrest; and, by modulating Bcl-2 family proteins, increased apoptosis. Furthermore, DCZ0415 treatment or silencing of TRIP13 increased E-cadherin and decreased N-cadherin and vimentin, suggesting its involvement in the epithelial-mesenchymal transition process. Genetic manipulation or pharmacologic targeting of TRIP13 also resulted in reduced expression of FGFR4 and pSTAT3, leading to lower levels of β-catenin, cyclin D1, LEF1, and TCF1, indicating inactivation of the Wnt/β-catenin pathway. In a syngeneic PDCA model, DCZ0415 induced an immune response by increasing granzyme B and perforin and by decreasing PD1. DCZ0415 treatment also facilitated immune cell infiltration, as evident from elevated staining of CD3 and CD4 cells. Conclusions: In sum, silencing of TRIP13 or treatment with DCZ0415 reduces PDAC progression by downregulating the FGFR4/STAT3/β-catenin pathway. DCZ0415 treatment also enhances anti-tumor immunity. These findings suggest that DCZ0415 can be developed as a therapeutic/immunostimulatory agent to improve treatment of PDAC patients expressing elevated levels of TRIP13. Citation Format: Farrukh Afaq, Sumit Agarwal, Prachi Bajpai, Hyung-Gyoon Kim, Sameer Al Diffalha, Shajan P. Sugandha, Moh'd Khushman, Sooryanarayana Varambally, Upender Manne. Pharmacologic targeting or silencing of TRIP13 reduces progression of pancreatic ductal adenocarcinoma [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 1710.

LCN2 secreted by tissue-infiltrating neutrophils induces the ferroptosis and wasting of adipose and muscle tissues in lung cancer cachexia

BackgroundCancer cachexia is a deadly wasting syndrome that accompanies various diseases (including ~ 50% of cancers). Clinical studies have established that cachexia is not a nutritional deficiency and is linked to expression of certain proteins (e.g., interleukin-6 and C-reactive protein), but much remains unknown about this often fatal syndrome.MethodsFirst, cachexia was created in experimental mouse models of lung cancer. Samples of human lung cancer were used to identify the association between the serum lipocalin 2 (LCN2) level and cachexia progression. Then, mouse models with LCN2 blockade or LCN2 overexpression were used to ascertain the role of LCN2 upon ferroptosis and cachexia. Furthermore, antibody depletion of tissue-infiltrating neutrophils (TI-Neu), as well as myeloid-specific-knockout of Lcn2, were undertaken to reveal if LCN2 secreted by TI-Neu caused cachexia. Finally, chemical inhibition of ferroptosis was conducted to illustrate the effect of ferroptosis upon tissue wasting.ResultsProtein expression of LCN2 was higher in the wasting adipose tissue and muscle tissues of experimental mouse models of lung cancer cachexia. Moreover, evaluation of lung cancer patients revealed an association between the serum LCN2 level and cachexia progression. Inhibition of LCN2 expression reduced cachexia symptoms significantly and inhibited tissue wasting in vivo. Strikingly, we discovered a significant increase in the number of TI-Neu in wasting tissues, and that these innate immune cells secreted high levels of LCN2. Antibody depletion of TI-Neu, as well as myeloid-specific-knockout of Lcn2, prevented ferroptosis and tissue wasting in experimental models of lung cancer cachexia. Chemical inhibition of ferroptosis alleviated tissue wasting significantly and also prolonged the survival of cachectic mice.ConclusionsOur study provides new insights into how LCN2-induced ferroptosis functionally impacts tissue wasting. We identified LCN2 as a potential target in the treatment of cancer cachexia.

Preclinical development of non-viral gene therapy for patients with advanced pancreatic cancer

Pancreatic cancer remains one of the greatest challenges in oncology for which therapeutic intervention is urgently needed. We previously demonstrated that the intra-tumoral gene transfer of somatostatin receptor 2, to combat tumor aggressiveness, or of deoxycytidine kinase and uridylate monophosphate kinase, to sensitize to gemcitabine chemotherapy, has anti-tumoral potential in experimental models of cancer. Here, we describe the development of the CYL-02 non-viral gene therapy product that comprises a DNA-plasmid encoding for the three aforementioned genes, which expression is targeted to tumor cells, and complexed with polyethyleneimine non-viral vector. We performed pre-clinical toxicology, bio-distribution, and therapeutic activity studies of CYL-02 in two rodent models of pancreatic cancer. We found that CYL-02 is safe, does not increase gemcitabine toxicity, is rapidly cleared from blood following intravenous administration, and sequestered in tumors following intra-tumoral injection. CYL-02 drives the expression of therapeutic genes in cancer cells and strongly sensitizes tumor cells to gemcitabine, both invitro and invivo, with significant inhibition of tumor cells dissemination. This study was instrumental for the later use of CYL-02 in patients with advanced pancreatic cancer, demonstrating that rigorous and thorough preclinical investigations are informative for the clinical transfer of gene therapies against this disease.

Potential cardioprotective and anticancer effects of carvedilol either free or as loaded nanoparticles with or without doxorubicin in solid Ehrlich carcinoma-bearing mice

AimThe aim of this study was to investigate the potential cardioprotective and anti-cancer effects of carvedilol (CAR) either free or as loaded nano-formulated with or without doxorubicin (DOX) in solid Ehrlich carcinoma (SEC)-bearing mice. It focused on assessment of cardiac damage, drug resistance, apoptosis, oxidative stress status, angiogenesis and proliferation. MethodsCAR was loaded into poly-D,L lactic-co-glycolic acid)PLGA(or Niosomes. SEC was induced in female albino mice as an experimental model of breast cancer. Seventy-two mice were randomly divided into 9 equal groups (Normal control, Untreated-SEC, SEC + DOX, SEC + CAR-free, SEC + CAR-PLGA, SEC + CAR-Niosomes, SEC + DOX + CAR-free, SEC + DOX + CAR-PLGA and SEC + DOX + CAR-Niosomes). Tumor volume and survival rate were recorded. On day 28 from tumor inoculation, mice were sacrificed, and blood samples were collected for determination of serum lactate dehydrogenase (LDH) and creatine kinase-MB (CK-MB). One part from tumor tissues was prepared for assessment of multidrug resistance protein-1 (MDR-1), caspase-3, reduced glutathione (GSH) and malondialdehyde (MDA), while the other part was processed for histopathological examination and immunohistochemical expression of vascular endothelial growth factor (VEGF) and Ki-67. ResultsThere was non-significant difference between CAR-free, CAR-PLGA and CAR-Niosomes as anticancer either alone or when combined with DOX. However, CAR-free demonstrated potential cardioprotective effects against cardiac damage mediated by cancer or DOX that have been enhanced using CAR-PLGA or CAR-Niosomes, but that of Niosomes outperformed them both. ConclusionCAR could be used as an adjuvant therapy with DOX, especially when nanoformualted with PLGA and even better with Niosomes, without compromising its cytotoxicity against cancer cells and preventing its cardiotoxic impacts.

Effects of glutamine and n-3 polyunsaturated fatty acid mixed lipid emulsion supplementation of parenteral nutrition on sepsis score and bacterial clearance in early experimental sepsis

Glutamine (GLN) and n-3 polyunsaturated fatty acids (n-3PUFAs) have been shown to potentially possess immune-modulating and disease-modifying properties in experimental and clinical critical illness when given with parenteral nutrition (PN). However, we recently showed in experimental cancer models that combinations of GLN/n-3 PUFA may antagonize benefits of either nutrient alone. Thus, our aim was to explore the effects of PN-containing GLN and n-3PUFA mixed lipid emulsion (MLE) alone and in combination in experimental sepsis. Adult male rats were exposed to cecal ligation and puncture (CLP) and sacrificed at 24h. Rats were infused with either normal saline (NS); PN+Intralipid (PNcont); PN+GLN; PN+n-3PUFA MLE; or PN+GLN/n-3PUFA MLE after CLP-sepsis for 23h. Animals were assessed at 24h for sepsis score, Gram (+) and Gram (-) bacterial load in blood, peritoneum, and bronchoalveolar lavage fluid (BALF). Rats treated with PN+GLN or PN+n-3PUFA showed significantly lower sepsis scores compared to NS and PNcont (all p≤0.016). Non-significant trends to improved sepsis scores was observed in rats treated with PN+GLN/n-3PUFA versus NS (p=0.067) or PNcont (p=0.093). Rats treated with PN+GLN, PN+n-3PUFA, or PN+GLN/n-3PUFA had significant improvement or trends to improved Gram (+) and Gram (-) bacterial loads in BALF versus NS (p≤0.05, PN+GLN and PN+GLN/n-3PUFA for Gram (+); p=0.057, PN+n-3PUFA for Gram (+); p≤0.05, n-3PUFA and PN+GLN/n-3PUFA for Gram (-)). No differences between groups in blood or peritoneal bacterial counts observed. This data describes initial evidence that nutritional-doses of GLN, n-3PUFA MLE, and GLN+n-3PUFA MLE in PN can improve bacterial load/clearance in sepsis. Further, improvements of sepsis score by PN+n-3PUFA MLE and PN+GLN was observed. Previously observed antagonism of benefits of PN-containing GLN or n-3PUFAs alone by combinations of these nutrients was not observed in experimental sepsis. These results suggest further research is needed into PN-strategies using GLN and/or n-3PUFA at nutritional-doses in sepsis.

Role of β-hydroxybutyrate as regulator of cell death pathway in experimental cancer model

Role of β-hydroxybutyrate as regulator of cell death pathway in experimental cancer model

Royal Jelly Nanoparticle Alleviates Experimental Model of Breast Cancer Through Suppressing Regulatory T Cells and Upregulating TH1 Cells.

Royal jelly, a natural product from bees' hypopharyngeal glands, is commonly used in biomedicine due to its antioxidant and anti-tumor activities. The aim of this study was to compare royal jelly in free form and loaded in layered double hydroxide (LDH) nanoparticle for the treatment of breast cancer with a focus on Th1 and T regulatory parameters in an animal model. Nanoparticles were produced using the coprecipitation method and characterized using DLS, FTIR, and SEM techniques. Forty female BALB/c mice were inoculated with 7.5 x 105 4T1 cells and treated with royal jelly in free and nanoparticle form. Clinical signs and tumor volume were assessed weekly. The effect of royal jelly products on the serum level of IFN-γ and TGF-β was measured by ELISA. In addition, the mRNA expression of these cytokines and Th1 and regulatory T cells' transcription factors (T-bet and FoxP3) was assessed by real-time PCR in the splenocytes of tumor-bearing mice. The physicochemical analysis of nanoparticles confirmed the synthesis of LDH nanoparticles and loading of royal jelly into the LDH structures (RJ-LDH). Animal studies showed that royal jelly and RJ-LDH significantly reduced the size of tumor in BALB/c mice. Additionally, treatment with RJ-LDH significantly inhibited TGF-β and increased IFN-γ production. The data also revealed that RJ-LDH inhibited the differentiation of regulatory T cells, while promoting Th1 cell differentiation via regulating their master transcription factors. These results indicated that royal jelly and RJ-LDH could inhibit breast cancer progression by in-hibiting regulatory T cells and expansion of Th1 cell. Furthermore, the current study demonstrated the therapeutic efficacy of royal jelly is enhanced by LDH nanoparticles; hence, RJ-LDH is significantly more efficient than Free-RJ in the treatment of breast cancer.

GK-1 Induces Oxidative Stress, Mitochondrial Dysfunction, Decreased Membrane Potential, and Impaired Autophagy Flux in a Mouse Model of Breast Cancer.

Breast cancer (BC) is the second most common cancer worldwide in women. During the last decades, the mortality due to breast cancer has progressively decreased due to early diagnosis and the emergence of more effective new treatments. However, human epidermal growth factor receptor 2 (HER2) and triple-negative breast cancer (TNBC) remain with poor prognoses. In our research group, we are proposing the GK-1 immunomodulatory peptide as a new alternative for immunotherapy of these aggressive tumors. GK-1 reduced the growth rate of established tumors and effectively reduced lung metastasis in the 4T1 experimental murine model of breast cancer. Herein, the effect of GK-1 on the redox state, mitochondrial metabolism, and autophagy of triple-negative tumors that can be linked to cancer evolution was studied. GK-1 decreased catalase activity, reduced glutathione (GSH) content and GSH/oxidized glutathione (GSSG) ratio while increased hydrogen peroxide (H2O2) production, GSSG, and protein carbonyl content, inducing oxidative stress (OS) in tumoral tissues. This imbalance between reactive oxygen species (ROS) and antioxidants was related to mitochondrial dysfunction and uncoupling, characterized by reduced mitochondrial respiratory parameters and dissipation of mitochondrial membrane potential (ΔΨm), respectively. Furthermore, GK-1 likely affected autophagy flux, confirmed by elevated levels of p62, a marker of autophagy flux. Overall, the induction of OS, dysfunction, and uncoupling of the mitochondria and the reduction of autophagy could be molecular mechanisms that underlie the reduction of the 4T1 breast cancer induced by GK-1.

Original experimental model of tuberculosis and lung cancer

BACKGROUND: The potential relationship between pulmonary tuberculosis and lung cancer has been the subject of intense interest over the past few decades. Nevertheless, the features of the pathogenesis of concomitant pathology remain poorly studied.
 AIM: The ain of the study to develop an experimental model of the concomitant pathology of tuberculosis and lung cancer.
 MATERIALS AND METHODS: The study was performed on mice of the C57BL/6 line at the age of two months in four groups: 1st intact mice (n = 12), 2nd mice without a tumor infected with tuberculosis (n = 24), 3rd tumor-bearing mice not infected with tuberculosis (n = 23), 4th tumor-bearing mice infected with tuberculosis (n = 24). Individual and group parameters were evaluated using the SPSS Statistica v23 software package.
 RESULTS: Tumor was developed at the site of primary transplantation in all mice from groups 3 and 4, which was confirmed by visual assessment and the results of histological examination. Tumor growth in the main group was significantly less than in the control group of the tumor, which may be due to intoxication against the background of tuberculosis infection. All infected mice from groups 2 and 4 developed pulmonary tuberculosis, confirmed by computed tomography of the lungs, bacteriological and histological examination of lung samples. Mycobacterial load in the lungs was the highest in animals with concomitant pathology of tuberculosis and tumor. The survival rate of mice was determined to a large extent by tumor growth rather than by the progression of tuberculosis infection.
 CONCLUSIONS: The results of the study indicate the possibility of creating an experimental biological model of the concomitant pathology of tuberculosis and lung cancer in mice. The features of the course of the concomitant pathology were revealed: Lewis lung epidermoid carcinoma develops more slowly in tuberculosis infected animals than in the tumor control group; the development of the tuberculosis process in mice with a tumor occurs more intensively than in the tuberculosis infection control group. The survival rate of mice with concomitant pathology is determined more by the intensity of tumor growth than by the progression of tuberculosis.

Biodistribution and kinetic characters of radiopharmaceutical medication based on biospecific antibodies to tumor-associated stroma elements and 177lutcium

Biodistribution and kinetics were studied of potentially target biospecific radiopharmaceutical medication for the treatment of malignant tumors of various histologic type and location with expression of cytotoxic T-lymphocyte membrane associated glycoprotein 4 and glucocorticoid Induced Tumor Necrosis Factor Receptor) 177Lu-DOTA-anti-CTLA4-GITR. Colorectal cancer experimental model has been successfully reproduced by means of murine large intestine experimental adenocarcinoma cells (AKATOL) СТ26 EGFR) direct transplantation. The model was characteristic of moderate growth rate and practically complete absence of metastatic spread. Immunohistochemical assay of tumor tissue has revealed satisfactory expression level of target antigens for the medication under study, i.e. cytotoxic T-lymphocyte associated protein 4 (CTLA4) as well as membrane receptor of tumor necrosis factor group (GITR). This medication 177Lu-DOTA-anti-CTLA4-GITR has been shown to store in the tumor tissue. Its major pathways out of the organism were through urinary system. On the other hand, the medication has also been demonstrated to store in non-target tissues, namely: kidneys, liver, large intestine. The results of this study may be used in preclinical studies of medications and serve as a basis for broader studies of 177Lu-DOTA-anti-CTLA4-GITR and its safety.

Establishment of experimental salivary gland cancer models using organoid culture and patient-derived xenografting

PurposeDepending on its histological subtype, salivary gland carcinoma (SGC) may have a poor prognosis. Due to the scarcity of preclinical experimental models, its molecular biology has so far remained largely unknown, hampering the development of new treatment modalities for patients with these malignancies. The aim of this study was to generate experimental human SGC models of multiple histological subtypes using patient-derived xenograft (PDX) and organoid culture techniques.MethodsTumor specimens from surgically resected SGCs were processed for the preparation of PDXs and patient-derived organoids (PDOs). Specimens from SGC PDXs were also processed for PDX-derived organoid (PDXO) generation. In vivo tumorigenicity was assessed using orthotopic transplantation of SGC organoids. The pathological characteristics of each model were compared to those of the original tumors using immunohistochemistry. RNA-seq was used to analyze the genetic traits of our models.ResultsThree series of PDOs, PDXs and PDXOs of salivary duct carcinomas, one series of PDOs, PDXs and PDXOs of mucoepidermoid carcinomas and PDXs of myoepithelial carcinomas were successfully generated. We found that PDXs and orthotopic transplants from PDOs/PDXOs showed similar histological features as the original tumors. Our models also retained their genetic traits, i.e., transcription profiles, genomic variants and fusion genes of the corresponding histological subtypes.ConclusionWe report the generation of SGC PDOs, PDXs and PDXOs of multiple histological subtypes, recapitulating the histological and genetical characteristics of the original tumors. These experimental SGC models may serve as a useful resource for the development of novel therapeutic strategies and for investigating the molecular mechanisms underlying the development of these malignancies.

Investigating the anti-tumoral effect of yarrow (Achillea milllefolium) on the mice in which ehrlich solid tumor is created.

In this study, BALB/c mice with Ehrlich solid tumors were used to examine the effect of Achillea millefolium L. (AM) extract on the Ehrlich ascites tumor (EAT) model, which is one of the experimental cancer models. Also known as yarrow and plant, AM has antioxidant, anti-inflammatory, antibacterial and antitumor properties. In our study, 57 male BALB/c type mice, 8-10weeks old, weighing 25-30g, were used. Mice were divided into two groups. Ehrlich Solid Tumor group: Negative Control Group (ENC), Positive Control Group (EPC), and Treatment Group (TG) (TNCAM-200mg/kg, TPCAM-400mg/kg). EPC and TG were given to EAT cells. Each EAT contained 1 × 106 (will be 6 out of 10: so:000000) EAT cells, 0.1ml of phosphate-buffered saline (PBS) was administered subcutaneously (s.c.) to the nape of mice. Then It was awaited for solid tumor formation. AM extract was administered intraperitoneally (i.p.) to TG for 17days to mice. AM extract was found to have a curative effect on areas of inflammation, bleeding, and necrosis in treatment groups treated with AM extract alone. The treatment groups showed nearly normal histological results compared to the positive control group. According to the results, the TPCAM-400mg/kg group had a more significant histological impact than the TNCAM-200mg/kg group. In terms of tumor growth, tumor length, tumor volume, and tumor weight, AM extract did not show significant effects. However, in the light of histological findings, promising results of AM were observed in mice in which Ehrlich Solid Tumor was formed.

A mouse model of lung cancer induced via intranasal injection for anticancer drug screening and evaluation of pathology.

The pathologies and lethality of lung cancers are associated with smoking, lifestyle, and genomic factors. Several experimental mouse models of lung cancer, including those induced via intrapulmonary injection and intratracheal injection, have been reported for evaluating the pharmacological effect of drugs. However, these models are not sufficient for evaluating the efficacy of drugs during screening, as these direct injection models ignore the native processes of cancer progression invivo, resulting in the inadequate pathological formation of lung cancer. In the present study, we developed a novel intranasal injection model of lung cancer simulating the native lung cancer pathology for anticancer drug screening. A mouse lung cancer cell line (Lewis lung carcinoma; LCC) was intranasally injected into mouse lungs, and injected cell number-dependent cancer proliferation was apparent in both the left and right lungs. Human non-small-cell lung cancer (NCI-H460) cells were also intranasally injected into nude mice and similarly showed injected cell number-dependent cancer growth. For the pharmacological evaluation of cisplatin, two different treatment frequencies were tested four times per month and twice a month. The intranasal injection model confirmed that cisplatin suppressed lung cancer progression to a greater extent under the more frequent treatment condition. In conclusion, these results indicated that our intranasal injection model is a powerful tool for investigating lung cancer pathology and may aid in the development of new anti-lung cancer agents.

Retroviral Replicating Vector Toca 511 (Vocimagene Amiretrorepvec) for Prodrug Activator Gene Therapy of Lung Cancer.

Therapeutic efficacy of retroviral replicating vector (RRV)-mediated prodrug activator gene therapy has been demonstrated in a variety of tumor models, but clinical investigation of this approach has so far been restricted to glioma and gastrointestinal malignancies. In the present study, we evaluated replication kinetics, transduction efficiency, and therapeutic efficacy of RRV in experimental models of lung cancer. RRV delivering GFP as a reporter gene showed rapid viral replication in a panel of lung cancer cells in vitro, as well as robust intratumoral replication and high levels of tumor transduction in subcutaneous and orthotopic pleural dissemination models of lung cancer in vivo. Toca 511 (vocimagene amiretrorepvec), a clinical-stage RRV encoding optimized yeast cytosine deaminase (yCD) which converts the prodrug 5-fluorocytosine (5-FC) to the active drug 5-fluorouracil (5-FU), showed potent cytotoxicity in lung cancer cells upon exposure to 5-FC prodrug. In vivo, Toca 511 achieved significant tumor growth inhibition following 5-FC treatment in subcutaneous and orthotopic pleural dissemination models of lung cancer in both immunodeficient and immunocompetent hosts, resulting in significantly increased overall survival. This study demonstrates that RRV can serve as highly efficient vehicles for gene delivery to lung cancer, and indicates the translational potential of RRV-mediated prodrug activator gene therapy with Toca 511/5-FC as a novel therapeutic strategy for pulmonary malignancies.

Ionizing Radiation and Estrogen Affecting Growth Factor Genes in an Experimental Breast Cancer Model.

Genes associated with growth factors were previously analyzed in a radiation- and estrogen-induced experimental breast cancer model. Such in vitro experimental breast cancer model was developed by exposure of the immortalized human breast epithelial cell line, MCF-10F, to low doses of high linear energy transfer (LET) α particle radiation (150 keV/μm) and subsequent growth in the presence or absence of 17β-estradiol. The MCF-10F cell line was analyzed in different stages of transformation after being irradiated with either a single 60 cGy dose or 60/60 cGy doses of alpha particles. In the present report, the profiling of differentially expressed genes associated with growth factors was analyzed in their relationship with clinical parameters. Thus, the results indicated that Fibroblast growth factor2 gene expression levels were higher in cells transformed by radiation or in the presence of ionizing radiation; whereas the fibroblast growth factor-binding protein 1gene expression was higher in the tumor cell line derived from this model. Such expressions were coincident with higher values in normal than malignant tissues and with estrogen receptor (ER) negative samples for both gene types. The results also showed that transforming growth factor alpha gene expression was higher in the tumor cell line than the tumorigenic A5 and the transformed A3 cell line, whereas the transforming growth factor beta receptor 3 gene expression was higher in A3 and A5 than in Tumor2 cell lines and the untreated controls and the E cell lines. Such gene expression was accompanied by results indicating negative and positive receptors for transforming growth factor alpha and the transforming growth factor beta receptor 3, respectively. Such expressions were low in malignant tissues when compared with benign ones. Furthermore, Fibroblast growth factor2, the fibroblast growth factor-binding protein 1, transforming growth factor alpha, the transforming growth factor beta receptor 3, and the insulin growth factor receptor gene expressions were found to be present in all BRCA patients that are BRCA-Basal, BRCA-LumA, and BRCA-LumB, except in BRCA-Her2 patients. The results also indicated that the insulin growth factor receptor gene expression was higher in the tumor cell line Tumor2 than in Alpha3 cells transformed by ionizing radiation only; then, the insulin growth factor receptor was higher in the A5 than E cell line. The insulin growth factor receptor gene expression was higher in breast cancer than in normal tissues in breast cancer patients. Furthermore, Fibroblast growth factor2, the fibroblast growth factor-binding protein 1, transforming growth factor alpha, the transforming growth factor beta receptor 3, and the insulin growth factor receptor gene expression levels were in stages 3 and 4 of breast cancer patients. It can be concluded that, by using gene technology and molecular information, it is possible to improve therapy and reduce the side effects of therapeutic radiation use. Knowing the different genes involved in breast cancer will make possible the improvement of clinical chemotherapy.

Inhibitory Effect of Dietary Defatted Rice Bran in an AOM/DSS-Induced Colitis-Associated Colorectal Cancer Experimental Animal Model

Defatted rice bran (DRB) is gaining immense popularity worldwide because of its nutritional and functional aspects. Emerging evidence suggests that DRB is a potential source of dietary fiber and phenolic compounds with numerous purported health benefits. However, less is known about its chemoprotective efficacy. In the present study, we determined and examined the nutrient composition of DRB and its chemopreventive effect on azoxymethane and dextran sulphate sodium (AOM/DSS)-induced colitis-associated colorectal cancer (CRC) in rats. The results showed the presence of several bioactive compounds, such as dietary fiber, phytic acid, and phenolic acids, in DRB. In addition, DRB supplementation reduced the progression of CRC symptoms, such as colonic shortening, disease activity index (DAI), and histopathological changes. Interestingly, a significant decrease was observed in total numbers of aberrant crypt foci (ACFs) and tumors with DRB supplementation. Furthermore, DRB supplementation suppressed the expression of pro-inflammatory cytokines (IL-6) and inflammatory mediators (NF-κB and COX-2) through the inactivation of the NF-κB signaling pathway. The administration of DRB revealed a negative effect on cancer cell proliferation by repressing the expression of nuclear β-catenin, cyclin D1, and c-Myc. These findings suggest that DRB supplementation mitigates chronic inflammation and cancer cell proliferation and delays tumorigenesis in rat AOM/DSS-induced colitis-associated CRC. Therefore, the establishment of DRB as a natural dietary food-derived chemopreventive agent has the potential to have a significant impact on cancer prevention in the global population.

Effect of Curcumin-Loaded Mesoporous Silica Nanoparticles on the Head and Neck Cancer Cell Line, HN5.

Curcumin is an active ingredient isolated from Curcuma longa. It has several pharmacological effects, including anticancer, anti-inflammatory, and antioxidant effects. Due to its low bioavailability, chemical structure instability, and easy oxidation, the application of curcumin has been limited. In this study, to overcome these limitations, curcumin-loaded mesoporous silica nanoparticles (Cur-MSN) were prepared, and the anticancerous effect of Cur-MSNs on head and neck cancer cells, HN5, was investigated. Transmission electron microscopy (TEM) revealed rod-shaped mesoporous nanoparticles with average particle size smaller than 100 nm. Higher cytotoxicity of Cur-MSNs was seen in treated cancer cells compared with free curcumin. The expression of Bcl-2 was significantly reduced in the presence of Cur-MSNs compared to the control (untreated HN5 cells) (p < 0.05). A 3.43-fold increase in the Bax/Bcl-2 ratio was seen in Cur-MSNs treated HN5 cells at the IC50. Cur-MSNs increased intracellular reactive oxygen species (ROS) production. Based on these novel results, we suggest that Cur-MSNs offer efficacy for cancer treatment and future studies should further characterize their properties in various experimental cancer models.

Cell Adhesion Molecules Affected by Ionizing Radiation and Estrogen in an Experimental Breast Cancer Model.

Cancer develops in a multi-step process where environmental carcinogenic exposure is a primary etiological component, and where cell–cell communication governs the biological activities of tissues. Identifying the molecular genes that regulate this process is essential to targeting metastatic breast cancer. Ionizing radiation can modify and damage DNA, RNA, and cell membrane components such as lipids and proteins by direct ionization. Comparing differential gene expression can help to determine the effect of radiation and estrogens on cell adhesion. An in vitro experimental breast cancer model was developed by exposure of the immortalized human breast epithelial cell line MCF-10F to low doses of high linear energy transfer α particle radiation and subsequent growth in the presence of 17β-estradiol. The MCF-10F cell line was analyzed in different stages of transformation that showed gradual phenotypic changes including altered morphology, increase in cell proliferation relative to the control, anchorage-independent growth, and invasive capability before becoming tumorigenic in nude mice. This model was used to determine genes associated with cell adhesion and communication such as E-cadherin, the desmocollin 3, the gap junction protein alpha 1, the Integrin alpha 6, the Integrin beta 6, the Keratin 14, Keratin 16, Keratin 17, Keratin 6B, and the laminin beta 3. Results indicated that most genes had greater expression in the tumorigenic cell line Tumor2 derived from the athymic animal than the Alpha3, a non-tumorigenic cell line exposed only to radiation, indicating that altered expression levels of adhesion molecules depended on estrogen. There is a significant need for experimental model systems that facilitate the study of cell plasticity to assess the importance of estrogens in modulating the biology of cancer cells.