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It is estimated that more than 6 million pet dogs are diagnosed with cancer annually in the USA. Both primary care and specialist veterinarians are frequently called upon to provide clinical care that improves the quality and/or quantity of life for affected animals. Because these cancers develop spontaneously in animals that often share the same environment as their owners, have intact immune systems and are of similar size to humans, and because the diagnostic tests and treatments for these cancers are similar to those used for management of human cancers, canine cancer provides an opportunity for research that simultaneously helps improve both canine and human health care. This is especially true in the field of radiation oncology, for which there is a rich and continually evolving history of learning from the careful study of pet dogs undergoing various forms of radiotherapy. The purpose of this review article is to inform readers of the potential utility and limitations of using dogs in that manner; the peer-reviewed literature will be critically reviewed, and current research efforts will be discussed. The article concludes with a look toward promising future directions and applications of this pet dog "model."

Late recurrences in postmenopausal women with hormone receptor-positive breast cancers remain an important challenge. Avoidance or delayed development of resistance represents the main objective in extended endocrine therapy (ET). In animal models, resistance was reversed with restoration of circulating estrogen levels during interruption of letrozole treatment. This phase III, randomized, open-label Study of Letrozole Extension (SOLE) studied the effect of extended intermittent letrozole treatment in comparison with continuous letrozole. In parallel, the SOLE estrogen substudy (SOLE-EST) analyzed the levels of estrogen during the interruption of treatment. SOLE enrolled 4884 postmenopausal women with hormone receptor-positive, lymph node-positive, operable breast cancer between December 2007 and October 2012 and among them, 104 patients were enrolled in SOLE-EST. They must have undergone local treatment and have completed 4-6 years of adjuvant ET. Patients were randomized between continuous letrozole (2.5 mg/day orally for 5 years) and intermittent letrozole treatment (2.5 mg/day for 9 months followed by a 3-month interruption in years 1-4 and then 2.5 mg/day during all of year 5). Intention-to-treat population included 4851 women in SOLE (n = 2425 in the intermittent and n = 2426 in the continuous letrozole groups) and 103 women in SOLE-EST (n = 78 in the intermittent and n = 25 in the continuous letrozole groups). After a median follow-up of 84 months, 7-year disease-free survival (DFS) was 81.4% in the intermittent group and 81.5% in the continuous group (hazard ratio: 1.03, 95% confidence interval: 0.91-1.17). Reported adverse events were similar in both groups. Circulating estrogen recovery was demonstrated within 6 weeks after the stop of letrozole treatment. Extended adjuvant ET by intermittent administration of letrozole did not improve DFS compared with continuous use, despite the recovery of circulating estrogen levels. The similar DFS coupled with previously reported quality-of-life advantages suggest intermittent extended treatment is a valid option for patients who require or prefer a treatment interruption. • Disease-free survival after 7 years was similar with extended intermittent or continuous letrozole in breast cancer. • Circulating estrogen level was restored 6 weeks after interruption of extended letrozole treatment. • Extended intermittent letrozole treatment is safe for postmenopausal women with hormone receptor-positive breast cancers. • Results coupled with reported quality-of-life data should be reassuring for patients who need to interrupt extended therapy. [ABSTRACT FROM AUTHOR]

Background: Cancer-associated fibroblasts (CAFs) are recruited to the tumor microenvironment (TME) and are critical drivers of breast cancer (BC) malignancy. Circulating tumor cells (CTCs) travel through hematogenous routes to establish metastases. CTCs circulate both individually and, more rarely, in clusters with other cell types. Clusters of CTCs have higher metastatic potential than single CTCs. Previously, we identified circulating CAFs (cCAFs) in patients with BC and found that while healthy donors had no CTCs or cCAFs, both were present in most Stage IV patients. cCAFs circulate individually, as cCAF–cCAF homotypic clusters, and in heterotypic clusters with CTCs. Methods: In this study, we evaluate CTCs, cCAFs, and heterotypic cCAF-CTC clusters in patients with stage I–IV BC. We evaluate the association of heterotypic clusters with BC disease progression and metastasis in a spontaneous mouse model. Using previously established primary BC and CAF cell lines, we examine the metastatic propensity of heterotypic cCAF-CTC clusters in orthotopic and tail vein xenograft mouse models of BC. Using an in vitro clustering assay, we determine factors that may be involved in clustering between CAF and BC cells. Results: We report that the dissemination of CTCs, cCAFs, and clusters is an early event in BC progression, and we find these clusters in all clinical stages of BC. Furthermore, cCAFs-CTC heterotypic clusters have a higher metastatic potential than homotypic CTC clusters in vivo. We also demonstrate that the adhesion and stemness marker CD44, found on a subset of CTCs and CAF cells, is involved in heterotypic clustering of these cells. Conclusion: We identify a novel subset of circulating tumor cell clusters that are enriched with stromal CAF cells in BC patient blood and preclinical mouse models of BC metastasis. Our data suggest that clustering of CTCs with cCAFs augments their metastatic potential and that CD44 might be an important mediator of heterotypic clustering of cCAFs and BC cells. [ABSTRACT FROM AUTHOR]

This review provides a summary of known molecular alterations in commonly used cancer models and strives to stipulate how they may affect ambient mass spectrometry profiles. Immortalized cell lines are known to accumulate mutations, and xenografts derived from cell lines are known to contain tumour microenvironment elements from the host animal. While the use of human specimens for mass spectrometry profiling studies is highly encouraged, patient-derived xenografts with low passage numbers could provide an alternative means of amplifying material for ambient MS research when needed. Similarly, genetic preservation of patient tissue seen in some organoid models, further verified by qualitative proteomic and transcriptomic analyses, may argue in favor of organoid suitability for certain ambient profiling studies. However, to choose the appropriate model, pre-evaluation of the model's molecular characteristics in the context of the research question(s) being asked will likely provide the most appropriate strategy to move research forward. This can be achieved by performing comparative ambient MS analysis of the disease model of choice against a small amount of patient tissue to verify concordance. Disease models, however, will continue to be useful tools to orthogonally validate metabolic states of patient tissues through controlled genetic alterations that are not possible with patient specimens. [ABSTRACT FROM AUTHOR]

Epithelial ovarian cancer (EOC) is the leading cause of gynecological cancer-related mortality in the developed world. EOC is a heterogeneous disease represented by several histological and molecular subtypes. Therefore, exploration of relevant preclinical animal models that consider the heterogenic nature of EOC is of great importance for the development of novel therapeutic strategies that can be translated clinically to combat this devastating disease. In this review, we discuss recent progress in the development of preclinical mouse models for EOC study as well as their advantages and limitations. [ABSTRACT FROM AUTHOR]

Background/Aim: The in vivo effect of abiraterone on bone mineral density (BMD) in addition to androgen deprivation therapy was examined using a murine model. Materials and Methods: The mice were separated into the following groups: control, abiraterone, castration, and castration+abiraterone. The percentage change in the ratio of bone to tissue volume (BV/TV), number of osteoblasts and osteoclasts, and the serum level of bone markers were compared on day 21. Results: The BV/TV ratio of the abiraterone, castration, and castration+abiraterone groups was lower than that of the control group. However, the change in the BV/TV ratio in the castration+abiraterone group was not significantly different from that in the castration group. There was no significant difference in the serum TRAP5b level and the number of osteoclasts and osteoblasts between the castration+abiraterone and the castration groups. Conclusion: The addition of abiraterone to castration did not affect BMD in the murine model. [ABSTRACT FROM AUTHOR]

Background/Aim: Periostin (POSTN) has a significant role in proliferation and migration of tumour cells as well as tumour progression. This study aimed to determinate POSTN expression in cancer cells in malignant and benign tumours of the mammary gland in female dogs. Materials and Methods: All together 83 cancers, 24 adenomas and 7 unchanged fragments of the mammary glands of bitches were investigated. Immunohistochemistry was performed using anti-POSTN, Ki-67 and HER2 antibodies. Results: POSTN expression was observed in cancer cells in 31.3% of malignancies and 12.5% of benign tumours. A significantly positive correlation between expression of POSTN in cancer cells and the degree of histological malignancy, expression of Ki-67 antigen and expression of POSTN in CAFs was found. Conclusion: The obtained results suggest the possible participation of POSTN in the process of carcinogenesis and progression of mammary tumors in bitches. [ABSTRACT FROM AUTHOR]

Background/Aim: The discovery of the nude mouse model enabled the experimental growth of humanpatient tumors. However, the low establishment rate of tumors in nude and other immunodeficient strains of mice has limited wide-spread clinical use. Materials and Methods: In order to increase the establishment rate of surgical specimens of patient tumors, we transplanted tumors to nude mice subcutaneously along with large amounts of surrounding tissue of the tumor. Results: The new transplantation method increased the establishment rate in nude mice to 66% compared to the old method of implanting the surgical tumor specimen with surrounding tissue removed (14%). High stage and presence of metastasis in the patient donor are positively correlated to tumor engraftment in nude mice. Conclusion: The new method can potentially allow most cancer patients who undergo surgery or biopsy to have their own mouse model for drug-sensitivity testing. [ABSTRACT FROM AUTHOR]

Background/Aim: Fucoxanthin (Fx) is a potent anticancer carotenoid, demonstrated by mouse cancer models. We recently showed the decrease of salivary glycine could represent an attenuation of tumor microenvironment (TME) formation in an azoxymethane/dextran sodium sulfate (AOM/DSS) colon cancer mouse model. However, it remains unclear whether the salivary glycine is an indicator for continuous TME suppression of Fx in the mice. Materials and Methods: In the present study, we time-dependently analyzed salivary metabolites in AOM/DSS mice, and investigated candidate markers to evaluate the continuous inhibition of colonic TME formation and carcinogenesis in the mice with and without Fx. Results: Fx attenuated the incidence and/or multiplicity of colonic lesions developed in AOM/DSS mice. The number of apoptosis-like cleaved caspase-3high cells was significantly increased, and colonic cancer stem cell-like CD44high/EpCAMhigh cells and cancerassociated fibroblast-like αSMAhigh cells were significantly decreased in colon mucosal tissue by Fx administration. [ABSTRACT FROM AUTHOR]

Background/Aim: The visualization of hepatic segments with indocyanine green (ICG) fluorescence can aid in anatomic liver resection. The present study aimed to develop a method to specifically label an hepatic segment in a nude mouse model with liver metastasis. Materials and Methods: An orthotopic mouse model was established by surgical orthotopic implantation (SOI) of a patient-derived colon-cancer liver metastasis in the left lobe of the liver. Three weeks after SOI, the left Glissonean pedicle was ligated and 10 μg ICG was administrated intravenously. Images were obtained with the Pearl Trilogy Imaging System. Results: All mice expressed an 800 nm signal from ICG on the right lobe of the liver. The left lobe of the liver, in which the tumor was located, showed no fluorescence and had ischemia due to successful ligation of the Glissonean pedicle. Conclusion: The ligation of the Glissonean pedicle enables specific liver-segment labeling with ICG, which has potential clinical application for liver metastasectomy. [ABSTRACT FROM AUTHOR]

Background/Aim: A more realistic mouse model of bladder cancer is necessary to develop effective drugs for the disease. Tumor models enhanced by bright fluorescent-reporter genes to follow the disease in real-time would enhance the ability to accurately predict the efficacy of various therapeutics on this particularly-malignant human cancer. Materials and Methods: A highly-fluorescent green fluorescent protein (GFP)- expressing bladder cancer model was orthotopically established in nude mice using the UM-UC-3 human bladder-cancer cell line (UM-UC-3-GFP). Fragments from a subcutaneous tumor of UM-UC-3-GFP were surgically implanted into the nude mouse bladder. Non-invasive and intra-vital fluorescence imaging was obtained with a simple imaging box. Results: The GFP-expressing orthotopic bladder tumor was imaged in realtime non-invasively as well as intra-vitally, with the two methods correlating at r=0.99. Conclusion: This is the first noninvasive-fluorescence-imaging orthotopic model of bladder cancer and can be used for rapidly screening novel effective agents for this recalcitrant disease. [ABSTRACT FROM AUTHOR]

Background/Aim: Surgical orthotopic implantation (SOI) is used to establish patient-derived orthotopic xenograft (PDOX) and other orthotopic mouse models. Orthotopic liver models can be challenging, as the liver parenchyma is prone to bleeding. The present report describes a sutureless method to implant tumors in the liver that reduces bleeding and procedural time. Materials and Methods: Human HCC cell-line (Huh-7-GFP) and CM2, a patient-derived coloncancer liver metastasis, were used for sutureless SOI of tumor fragments in the liver of nude mice. A small cavity was formed on the liver surface. A solitary tumor fragment was implanted in the cavity without suturing to create hemostasis. Results: Six weeks after sutureless SOI, the tumor volume of Huh-7-GFP (n=5) was 584.41±147.64 mm3 and the tumor volume of CM2 (n=5) was 1336.54±1038.20 mm3. The engraftment rate was 100%. Conclusion: This novel method for establishing orthotopic liver-implantation mouse models is suitable for studies of liver cancer and liver metastases due to its simple procedure and potential high engraftment rate. [ABSTRACT FROM AUTHOR]

Cancer vaccine development has proven challenging with the exception of some virally induced cancers for which prophylactic vaccines exist. Currently, there is only one FDA approved vaccine for the treatment of prostate cancer and as such prostate cancer continues to present a significant unmet medical need. In this study, we examine the effectiveness of a therapeutic cancer vaccine that combines the ISCOMATRIX™ adjuvant (ISCOMATRIX) with the Toll-like receptor 3 agonist, polyinosinic–polycytidylic acid (Poly I:C), and Flt3L, FMS-like tyrosine kinase 3 ligand. We employed the TRAMP-C1 (transgenic adenocarcinoma of the mouse prostate) model of prostate cancer and the self-protein mPAP (prostatic acid phosphatase) as the tumor antigen. ISCOMATRIX™–mPAP–Poly I:C–Flt3L was delivered in a therapeutic prime-boost regime that was consistently able to achieve complete tumor regression in 60% of animals treated and these tumor-free animals were protected upon rechallenge. Investigations into the underlying immunological mechanisms contributing to the effectiveness of this vaccine identified that both innate and adaptive responses are elicited and required. NK cells, CD4+ T cells and interferon-γ were all found to be critical for tumor control while tumor infiltrating CD8+ T cells became disabled by an immunosuppressive microenvironment. There is potential for broader application of this cancer vaccine, as we have been able to demonstrate effectiveness in two additional cancer models; melanoma (B16-OVA) and a model of B cell lymphoma (Eµ-myc-GFP-OVA). [ABSTRACT FROM AUTHOR]

Aims: To explore the role of IL-5 in eosinophils induction and cytokine modulation on the development of colitis-associated colorectal cancer mouse model (CA-CRC). Methods and Material: A plasmid carrying the mouse IL-5 gene (IL-5 transgenesis) was injected to the mice with concurrently induction of CA-CRC mouse model, Then (CA-CRC) development, cytokine gene expression, cell dynamics in tumor vicinity and peritoneal cavity were analysed. Results: A protumorigenic role of IL-5 was shown on early stages of CRC development as mice experienced severe physical symptoms including: rectal bleeding, diarrhea and significant reduction in body weight gain. Late findings of IL-5 transgenesis revealed higher tumor rates (89.0% vs 50%), significantly higher tumor count (15.1±7.2 vs 7.3±10.6 per colon), higher average tumor size (9.1±5.2 vs 4.4±6.5 mm), higher invasiveness index and shorter colon length. Microscopic examination of tumors revealed the presence of higher plasma cell count but lower eosinophils in AOM-DSS-pIL-5 treated group when compared to AOM-DSS group. Cytokine gene expression pointed out to the downregulation of IL-10 and TGF-β and the overexpression of IFN-γ in both tumor bearing groups compared to pIL-5 group. IL-5 treatment of AOM-DSS mice resulted in insignificant reduction in IL-5 gene expression in colon tissue that was associated with lower eosinophil count in the peritoneal cavity wash. Conclusions: Immunomodulatory effect of early IL-5 expression in the CA-CRC and its role in the early migration of eosinophils to colon epithelia during colitis development raised the colitis severity and induced higher polyp rate formation and consequently higher tumor load. [ABSTRACT FROM AUTHOR]

Targeted inhibition of the c‐Jun N‐terminal kinases (JNKs) has shown therapeutic potential in intrahepatic cholangiocarcinoma (CCA)‐related tumorigenesis. However, the cell‐type‐specific role and mechanisms triggered by JNK in liver parenchymal cells during CCA remain largely unknown. Here, we aimed to investigate the relevance of JNK1 and JNK2 function in hepatocytes in two different models of experimental carcinogenesis, the dethylnitrosamine (DEN) model and in nuclear factor kappa B essential modulator (NEMO)hepatocyte‐specific knockout (Δhepa) mice, focusing on liver damage, cell death, compensatory proliferation, fibrogenesis, and tumor development. Moreover, regulation of essential genes was assessed by reverse transcription polymerase chain reaction, immunoblottings, and immunostainings. Additionally, specific Jnk2 inhibition in hepatocytes of NEMOΔhepa/JNK1Δhepa mice was performed using small interfering (si) RNA (siJnk2) nanodelivery. Finally, active signaling pathways were blocked using specific inhibitors. Compound deletion of Jnk1 and Jnk2 in hepatocytes diminished hepatocellular carcinoma (HCC) in both the DEN model and in NEMOΔhepa mice but in contrast caused massive proliferation of the biliary ducts. Indeed, Jnk1/2 deficiency in hepatocytes of NEMOΔhepa (NEMOΔhepa/JNKΔhepa) animals caused elevated fibrosis, increased apoptosis, increased compensatory proliferation, and elevated inflammatory cytokines expression but reduced HCC. Furthermore, siJnk2 treatment in NEMOΔhepa/JNK1Δhepa mice recapitulated the phenotype of NEMOΔhepa/JNKΔhepa mice. Next, we sought to investigate the impact of molecular pathways in response to compound JNK deficiency in NEMOΔhepa mice. We found that NEMOΔhepa/JNKΔhepa livers exhibited overexpression of the interleukin‐6/signal transducer and activator of transcription 3 pathway in addition to epidermal growth factor receptor (EGFR)‐rapidly accelerated fibrosarcoma (Raf)‐mitogen‐activated protein kinase kinase (MEK)‐extracellular signal‐regulated kinase (ERK) cascade. The functional relevance was tested by administering lapatinib, which is a dual tyrosine kinase inhibitor of erythroblastic oncogene B‐2 (ErbB2) and EGFR signaling, to NEMOΔhepa/JNKΔhepa mice. Lapatinib effectively inhibited cystogenesis, improved transaminases, and effectively blocked EGFR‐Raf‐MEK‐ERK signaling. Conclusion: We define a novel function of JNK1/2 in cholangiocyte hyperproliferation. This opens new therapeutic avenues devised to inhibit pathways of cholangiocarcinogenesis. [ABSTRACT FROM AUTHOR]

It is estimated that more than 6 million pet dogs are diagnosed with cancer annually in the USA. Both primary care and specialist veterinarians are frequently called upon to provide clinical care that improves the quality and/or quantity of life for affected animals. Because these cancers develop spontaneously in animals that often share the same environment as their owners, have intact immune systems and are of similar size to humans, and because the diagnostic tests and treatments for these cancers are similar to those used for management of human cancers, canine cancer provides an opportunity for research that simultaneously helps improve both canine and human health care. This is especially true in the field of radiation oncology, for which there is a rich and continually evolving history of learning from the careful study of pet dogs undergoing various forms of radiotherapy. The purpose of this review article is to inform readers of the potential utility and limitations of using dogs in that manner; the peer-reviewed literature will be critically reviewed, and current research efforts will be discussed. The article concludes with a look toward promising future directions and applications of this pet dog “model.”

Chronic lymphocytic leukemia (CLL) is associated with an accumulation of oligoclonal CD8+ effector T-cells, which control leukemia progression in mice, but gradually acquire a dysfunctional phenotype along with disease progression. Exhaustion of CD8+ T-cells is characterized by increased expression of inhibitory receptors like PD-1, decreased proliferation, and reduced effector function such as cytokine production, which reduces anti-tumor control. Despite the accumulation of exhausted PD-1+ CD8+ T-cells in secondary lymphoid organs of CLL patients, immune checkpoint blockade as a means to reinvigorate anti-tumor T-cell activity has not shown the expected efficacy. This highlights the need for a better understanding of T-cell exhaustion in CLL. Here, we uncover the transcriptional program of T-cell exhaustion in CLL by comparing naïve with dysfunctional effector CD8+ T-cells with high PD-1 expression from mice after adoptive transfer of Eµ-TCL1 leukemic cells. Our data provide clear evidence for activation-induced dysfunction of CD8+ T-cells in the CLL microenvironment and assess the heterogeneity in the expression of functionally relevant proteins in specific clusters of CD8+ T-cells at a single-cell level. [ABSTRACT FROM AUTHOR]

It is estimated that more than 6 million pet dogs are diagnosed with cancer annually in the USA. Both primary care and specialist veterinarians are frequently called upon to provide clinical care that improves the quality and/or quantity of life for affected animals. Because these cancers develop spontaneously in animals that often share the same environment as their owners, have intact immune systems and are of similar size to humans, and because the diagnostic tests and treatments for these cancers are similar to those used for management of human cancers, canine cancer provides an opportunity for research that simultaneously helps improve both canine and human health care. This is especially true in the field of radiation oncology, for which there is a rich and continually evolving history of learning from the careful study of pet dogs undergoing various forms of radiotherapy. The purpose of this review article is to inform readers of the potential utility and limitations of using dogs in that manner; the peer-reviewed literature will be critically reviewed, and current research efforts will be discussed. The article concludes with a look toward promising future directions and applications of this pet dog "model." [ABSTRACT FROM AUTHOR]

Drosophila provides an inexpensive and quantitative platform for measuring whole animal drug response. A complementary approach is virtual screening, where chemical libraries can be efficiently screened against protein target(s). Here, we present a unique discovery platform integrating structure-based modeling with Drosophila biology and organic synthesis. We demonstrate this platform by developing chemicals targeting a Drosophila model of Medullary Thyroid Cancer (MTC) characterized by a transformation network activated by oncogenic dRetM955T. Structural models for kinases relevant to MTC were generated for virtual screening to identify unique preliminary hits that suppressed dRetM955T-induced transformation. We then combined features from our hits with those of known inhibitors to create a ‘hybrid’ molecule with improved suppression of dRetM955T transformation. Our platform provides a framework to efficiently explore novel kinase inhibitors outside of explored inhibitor chemical space that are effective in inhibiting cancer networks while minimizing whole body toxicity. [ABSTRACT FROM AUTHOR]

Immune checkpoint inhibitors are currently tested in different combinations in patients with advanced hepatocellular carcinoma (HCC). Nivolumab, an anti-PD-1 agent, has gained approval in the second-line setting in the USA. Epigenetic drugs have immune-mediated antitumor effects that may improve the activity of immunotherapy agents. Our aim was to study the therapeutic efficacy of checkpoint inhibitors (anti-CTLA-4 and anti-PD-1 antibodies) in combination with the histone deacetylase inhibitor (HDACi) Belinostat. In a subcutaneous Hepa129 murine HCC model, we demonstrated that Belinostat improves the antitumor activity of anti-CTLA-4 but not of anti-PD-1 therapy. This effect correlated with enhanced IFN-γ production by antitumor T-cells and a decrease in regulatory T-cells. Moreover, the combination induced early upregulation of PD-L1 on tumor antigen-presenting cells and late expression of PD-1 on tumor-infiltrating effector T-cells, suggesting the suitability of PD-1 blockade. Indeed, Belinostat combined with the simultaneous blockade of CTLA-4 and PD-1 led to complete tumor rejection. These results provide a rationale for testing Belinostat in combination with checkpoint inhibitors to enhance their therapeutic activity in patients with HCC. [ABSTRACT FROM AUTHOR]

Cancer is a multistep disease driven by the activation of specific oncogenic pathways concomitantly with the loss of function of tumor suppressor genes that act as sentinels to control physiological growth. The conservation of most of these signaling pathways in Drosophila , and the ability to easily manipulate them genetically, has made the fruit fly a useful model organism to study cancer biology. In this review we outline the basic mechanisms and signaling pathways conserved between humans and flies responsible of inducing uncontrolled growth and cancer development. Second, we describe classic and novel Drosophila models used to study different cancers, with the objective to discuss their strengths and limitations on their use to identify signals driving growth cell autonomously and within organs, drug discovery and for therapeutic approaches. [ABSTRACT FROM AUTHOR]

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the leading causes of cancer‐related mortality. Despite significant advances made in the treatment of other cancers, current chemotherapies offer little survival benefit in this disease. Pancreaticoduodenectomy offers patients the possibility of a cure, but most will die of recurrent or metastatic disease. Hence, preventing metastatic disease in these patients would be of significant benefit. Using principal component analysis (PCA), we identified a LOX/hypoxia signature associated with poor patient survival in resectable patients. We found that LOX expression is upregulated in metastatic tumors from Pdx1‐Cre KrasG12D/+Trp53R172H/+ (KPC) mice and that inhibition of LOX in these mice suppressed metastasis. Mechanistically, LOX inhibition suppressed both migration and invasion of KPC cells. LOX inhibition also synergized with gemcitabine to kill tumors and significantly prolonged tumor‐free survival in KPC mice with early‐stage tumors. This was associated with stromal alterations, including increased vasculature and decreased fibrillar collagen, and increased infiltration of macrophages and neutrophils into tumors. Therefore, LOX inhibition is able to reverse many of the features that make PDAC inherently refractory to conventional therapies and targeting LOX could improve outcome in surgically resectable disease.

Abstract Hepatocellular carcinoma (HCC) is a fatal oncogenic disorder with few therapeutic options. Novel therapeutic strategy with combination of a selective CDK4/6 inhibitor palbociclib (PAL) with a tyrosine kinase inhibitor (TKI) sorafenib (SOR) is reported to impair tumour growth and significantly increased survival in various preclinical models of HCC. In the current work a sensitive and rapid UHPLC–QTOF-MS method was established for the concurrent quantification of PAL and SOR in rat plasma using ibrutinib as internal standard (IS). Chromatographic separation was carried out on an Agilent Poroshell EC C18 (50 mm × 3 mm, 2.7 μm) using gradient mobile phase consisting of 0.1% formic acid and acetonitrile. Flow rate of 0. 45 mL/min with a run time of 5 min was used for separation. A simple sample preparation approach of protein precipitation was used in the current study. The mass spectrometric analysis of selective ions at [M + H]+ m / z 448.2455 for PAL, m / z 465.0936 for SOR and m / z 441.2034 for IS was monitored with extracted ion chromatography. The LC-MS method meets the regulatory bio-analytical guidelines, exhibited good sensitivity and linearity over the range of 1.0–2000.0 ng/mL for PAL and SOR. The pharmacokinetic parameters of PAL remained unchanged when SOR was co-administered with PAL. The study pointed out that the co-intake of PAL with SOR resulted in a slight increment of C max (11.21%) and AUC (7.95%) levels of SOR when co-administered with PAL when compared to individual oral intake in SD rats. The current method provides a modern rapid and sensitive tool for pharmacokinetic studies of PAL and SOR in a pre-clinical set up. Graphical abstract Unlabelled Image Highlights • First UHPLC-QTOF-MS method for the simultaneous quantification of palbociclib (PAL) and sorafenib (SOR) in rat plasma • Simple sample processing method • The method was specific, precise, accurate and linear from 1.0 to 2000.0 ng/mL • The safety of co-administration of PAL and SOR was studied. • Application to pharmacokinetics and drug interaction studies in SD rats. [ABSTRACT FROM AUTHOR]

Objective: We have previously demonstrated the effect of alpha-2-macroglobulin (α2M) in the remediation of radiation-induced cellular damage. Here, we investigated the protective effects of α2M in a preclinical rat model of jaw osteoradionecrosis (ORN).Methods: Eighteen rats were divided randomly into three groups: the control group, the radiation therapy (RT) alone group, and the radiated mandibles pretreated with α2M (α2M + RT) group. One month after radiation, all left molar teeth were extracted. After another 3 months, the animals were sacrificed and body weight, histopathology, microcomputed tomography and immunofluorescence were evaluated in all groups.Results: The RT group showed serious alopecia, bone exposure, inflammation, necrosis, fibrosis, and the absence of new bone formation within the socket. The α2M + RT group exhibited less alopecia than the RT group and slight inflammation and fibrosis in the bone marrow cavity. The cortical bone was similar to normal bone tissue. Interestingly, compared with RT group, serum superoxide dismutase levels in the α2M + RT group increased at the 1th day (P = 0.037), 14th day (P = 0.012), while reactive oxygen species levels clearly decreased at the 1th day (P< 0.001), 14th day (P = 0.007), and 28th day (P = 0.013).Conclusions: A clinically translational model of jaw ORN was successfully established and the application of α2M prior to radiation protected the bone from being injured by the radiation, possibly related to oxidative stress. [ABSTRACT FROM AUTHOR]

There is a growing need to quantitate or "score" lesions in mouse models of human disease, for correlation with human disease and to establish their clinical relevance. Several standard semiquantitative scoring schemes have been adapted for nonneoplastic lesions; similarly, the pathologist must carefully select an approach to score mouse models of cancer. Genetically engineered mouse models with a continuum of precancerous and cancerous lesions and xenogeneic models of various derivations present unique challenges for the pathologist. Important considerations include experimental design, understanding of the human disease being modeled, standardized classification of lesions, and approaches for semiquantitative and/or quantitative scoring in the model being evaluated. Quantification should be considered for measuring the extent of neoplasia and expression of tumor biomarkers. Semiquantitative scoring schemes have been devised that include severity, frequency, and distribution of lesions. Although labor-intensive, scoring mouse models of cancer provides numerical data that enable statistical analysis and greater translational impact. [ABSTRACT FROM AUTHOR]

The activation of TP53 is well known to exert tumor suppressive effects. We have detected a primate-specific adrenal androgen-mediated tumor suppression system in which circulating DHEAS is converted to DHEA specifically in cells in which TP53 has been inactivated. DHEA is an uncompetitive inhibitor of glucose-6-phosphate dehydrogenase (G6PD), an enzyme indispensable for maintaining reactive oxygen species within limits survivable by the cell. Uncompetitive inhibition is otherwise unknown in natural systems because it becomes irreversible in the presence of high concentrations of substrate and inhibitor. In addition to primate-specific circulating DHEAS, a unique, primate-specific sequence motif that disables an activating regulatory site in the glucose-6-phosphatase (G6PC) promoter was also required to enable function of this previously unrecognized tumor suppression system. In human somatic cells, loss of TP53 thus triggers activation of DHEAS transport proteins and steroid sulfatase, which converts circulating DHEAS into intracellular DHEA, and hexokinase which increases glucose-6-phosphate substrate concentration. The triggering of these enzymes in the TP53-affected cell combines with the primate-specific G6PC promoter sequence motif that enables G6P substrate accumulation, driving uncompetitive inhibition of G6PD to irreversibility and ROS-mediated cell death. By this catastrophic 'kill switch' mechanism, TP53 mutations are effectively prevented from initiating tumorigenesis in the somatic cells of humans, the primate with the highest peak levels of circulating DHEAS. TP53 mutations in human tumors therefore represent fossils of kill switch failure resulting from an age-related decline in circulating DHEAS, a potentially reversible artifact of hominid evolution. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the anticancer potential and cytotoxicity of some freshwater cyanobacterial extracts on Human Colon Carcinoma (HT29), Rat Brain Glioma (C6), Human Cervix Carcinoma (HeLa), Human Lung Carcinoma (A549), Human Breast Adenocarcinoma (MCF7), Human Liver Hepatocellular Carcinoma (Hep3B) cancerous cells, African Green Monkey Kidney cells (Vero), and Human Amnion cells (FL). Methods: Chroococus minutus, Geitlerinema carotinosum, Nostoc linckia and Anabaena oryzae were collected from different freshwater habitats and identified. Each cyanobacterium was extracted with methanol. Antiproliferative activities of the cyanobacterial extracts were evaluated by [3-(4, 5- dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide] (MTT) using HT29, C6, HeLa, A549, MCF7, Hep3B, Vero, and FL cell lines. Cytotoxicity was determined by lactate dehydrogenase (LDH) assay. Results: The cyanobacterial extracts showed varying antiproliferative and cytotoxic effects on cancer cells. G. carotinosum and N. linckia had significant inhibitory effect on C6 cell lines with half-maximal inhibitory (IC50) levels of 112.69 and 121.48 µg/mL, respectively. TGI values for G. carotinosum and N. linckia were 65.07 and 70.61 µg/mL, respectively. LC50 values for these two cyanobacteria were 386.64 and 760.55 µg/mL, respectively. In addition, cyanobacterium A. oryzae displayed excellent antiproliferative effect on MCF7 cancer cells (GI50 = 2.04 µg/mL). The extracts displayed the cytostatic effect on the cell lines. Conclusion: G. carotinosum, N. linckia and A. oryzae exhibit significant activity on various cancer cells. Hence these cyanobacteria may offer promise as anticancer agents. [ABSTRACT FROM AUTHOR]

Abstract Optical imaging technologies improve clinical diagnostic accuracy of early gastric cancer (EGC). However, there was a lack of imaging agents exhibiting molecular specificity for EGCs. Here, we employed the dye labeled human heavy-chain ferritin (HFn) as imaging nanoprobe, which recognizes tumor biomarker transferrin receptor 1 (TfR1), to enable specific EGC imaging using confocal laser endomicroscopy (CLE). TfR1 expression was initially examined in vitro in gastric tumor cells and in vivo through whole-body fluorescence and CLE imaging in tumor-bearing mice. Subsequently, dye labeled HFn was topically applied to resected human tissues for EGC detection. CLE analysis of TfR1-targeted fluorescence imaging allowed distinction of neoplastic from non-neoplastic tissues (P < 0.0001), and TfR1 expression level was found to correlate with EGC differentiation degrees (P < 0.0001). Notably, the CLE evaluation correlated well with the immunohistochemical findings (κ-coefficient: 0.8023). Our HFn-nanoprobe-based CLE increases the accuracy of EGC detection and enables visualization of tumor margins and endoscopic resection. Graphical abstract We developed a fluorescently labeled human heavy-chain ferritin (HFn) nanoparticle, which was incorporated by transferrin receptor positive tumor cells in a threshold-dependent manner. Targeted imaging using fluorescently labeled HFn is feasible with confocal laser endomicroscopy (CLE) on human gastric tumor bearing mice. Targeted imaging can also be observed in endoscopic specimens of early gastric cancer (EGC) patients with high specificity and sensitivity. The fluorescence intensity of HFn examined using CLE correlated well with the grade of EGCs confirmed by the histology. The fluorescently labeled HFn possesses potential clinical application for EGC detection. Unlabelled Image Highlights • We developed a novel fluorescently labeled human heavy chain ferritin nanoparticle (HFn), which was incorporated by transferrin receptor positive tumor cells in a threshold-dependent manner. • Targeted imaging using fluorescently labeled HFn is feasible with confocal laser endomicroscopy (CLE) on human gastric tumor bearing mice. • Targeted imaging can also be observed in endoscopic specimens of EGC patients with high specificity and sensitivity. • The fluorescence intensity of HFn examined using CLE correlated well with the grade of EGCs confirmed by the immunohistochemistry and histology results. • The fluorescently labeled HFn possesses potential clinical application for EGC detection. [ABSTRACT FROM AUTHOR]

Abstract Advances in in vivo stability and preferential tumor uptake of cancer nanomedicine are warranted for effective chemotherapy. Here, we describe a novel nanoformulation using an unconventional polymeric tubule-forming phospholipid, DC 8,9 PC. We report that DC 8,9 PC transitions to stable vesicles (LNPs) in the presence of PEGylated lipid (DSPE-PEG2000); the resulting DC 8,9 PC:DSPE-PEG2000 LNPs efficiently included a hydrophobic PDT drug, HPPH. Remarkably, these LNPs incorporated unusually high DSPE-PEG2000 concentrations; LNP 10 -HPPH and LNP 20 -HPPH (10 & 20 mol% PEGylated lipid, respectively) exhibited >90% serum stability at 37 °C. Increased PEGylation in the LNPs correlated with enhanced tumor accumulation in intravenously injected HT29 tumor mouse xenographs. Colon-26 bearing BALB/c mice, intravenously injected with LNP 20 -HPPH showed superior PDT efficacy and animal survival (no tumor recurrence up to 100 days) as compared to a formulation currently used in clinical trials. Taken together, we present a simple stealth binary lipid nanosystem with enhanced efficiency of tumor accumulation and superior therapeutic efficacy. Graphical Abstract Inclusion of a PEG lipid in a non-bilayer forming polymeric lipid, DC8,9PC results in the formation of nano-sized vesicles (LNPs), not reported earlier. These vesicles efficiently incorporate a hydrophobic drug (HPPH) and remain stable upon storage at room temperature, as well as in the presence of serum components. The HPPH-loaded LNPs exhibit better tumor accumulation and show enhanced tumor cure in comparison to currently used formulation in clinical trials for this drug for its PDT efficacy. Unlabelled Image [ABSTRACT FROM AUTHOR]

Abstract Understanding the molecular features responsible for the plasma kinetics of surface-modified polyamido amine (PAMAM) dendrimers is critical to explore novel biomedical applications for these nanomaterials. In this report, polyethylene glycol (PEG) and folic acid (FA) were employed to obtain partially-substituted PAMAM dendrimers as model biocompatible nanomaterials with different size, charge and surface functionality. Cytotoxicity assays on HEK cells at 1-500 μM concentration confirmed that PEG and FA incorporation increased the cell viability of PAMAM-based nanomaterials. Measurements of plasma kinetics in vivo revealed that PEG-PAMAM has an extended circulation time in mice blood (71.7 min) over native PAMAM (53.3 min) and FA-PAMAM (41.8 min). Molecular dynamics simulations revealed a direct relationship between circulation time and dendrimer size, thus providing valuable evidence to increase understanding about the modulation of functional properties of PAMAM-based systems through surface modification, and to guide future efforts on the rational design of novel biomedical nanomaterials. Graphical Abstract Measurements of plasma kinetics in vivo revealed that the blood retention times of PAMAM-based nanomaterials are related to size, charge and hydrophobicity of the surface functional groups. Unlabelled Image [ABSTRACT FROM AUTHOR]

The use of existing mouse models in cancer research is of utmost importance as they aim to explore the casual link between candidate cancer genes and carcinogenesis as well as to provide models to develop and test new therapies. However, faster progress in translating mouse cancer model research into the clinic has been hampered due to the limitations of these models to better reflect the complexities of human tumors. Traditionally, immunocompetent and immunodeficient mice with syngeneic and xenografted tumors transplanted subcutaneously or orthotopically have been used. These models are still being widely employed for many different types of studies, in part due to their widespread availability and low cost. Other types of mouse models used in cancer research comprise transgenic mice in which oncogenes can be constitutively or conditionally expressed and tumor-suppressor genes silenced using conventional methods, such as retroviral infection, microinjection of DNA constructs, and the so-called "gene-targeted transgene" approach. These traditional transgenic models have been very important in studies of carcinogenesis and tumor pathogenesis, as well as in studies evaluating the development of resistance to therapy. Recently, the clustered regularly interspaced short palindromic repeats (CRISPR)-based genome editing approach has revolutionized the field of mouse cancer models and has had a profound and rapid impact on the development of more effective systems to study human cancers. The CRISPR/Cas9-based transgenic models have the capacity to engineer a wide spectrum of mutations found in human cancers and provide solutions to problems that were previously unsolvable. Recently, humanized mouse xenograft models that accept patient-derived xenografts and CD34+ cells were developed to better mimic tumor heterogeneity, the tumor microenvironment, and cross-talk between the tumor and stromal/immune cells. These features make them extremely valuable models for the evaluation of investigational cancer therapies, specifically new immunotherapies. Taken together, improvements in both the CRISPR/Cas9 system producing more valid mouse models and in the humanized mouse xenograft models resembling complex interactions between the tumor and its environment might represent one of the successful pathways to precise individualized cancer therapy, leading to improved cancer patient survival and quality of life. [ABSTRACT FROM AUTHOR]

Aberrant miRNA expression has been detected in various tumor tissues, which may be considered as a marker for early cancer diagnosis. One miRNA has multiple downstream target genes, which can be regulated by multiple upstream other miRNAs. Hence, this dynamic regulation is likely characterized by volatility, and thus, finding the appropriate time point for tests becomes essential for the use of miRNAs as an early marker of tumor diagnosis. In this study, we established a chronic liver cancer progression model in mice by using low doses of the harmful substance microcystin-LR (MC-LR). On the basis of miRNAs microarray assay, we further tested seven miRNAs that showed characteristic expression changes in pre-hepatocarcinogenesis. Our results showed that the levels of four miRNAs (miR-122-5p, miR-125-5p, miR-199a-5p, and miR-503-5p) decreased dramatically, whereas those of two miRNAs (miR-222-5p and miR-590-5p) increased significantly in the early stages, which were all accompanied by an increase in atypia of hepatocytes. MiR-490-5p was a sensitive molecular, suitable only for evaluation of pathological changes in young mice. Therefore the combination the seven of miRNAs for a set may prove to be an effective method in healthy assessment of environmental toxicants for detection of hepatocarcinogenesis caused by hazardous materials. [ABSTRACT FROM AUTHOR]

The purpose of this study was to investigate some possible mechanisms underlying the in vitro antitumor activity of tea tree oil (TTO) on human and mouse breast cancer cells (MCF-7 and 4T1, respectively) and its cytotoxicity on fibroblasts (HFF-1) and on peripheral blood mononuclear cells (PBMCs). TTO High-Resolution Gas Chromatography (HRGC) showed seventeen main constituents, such as Terpinen-4-ol, γ-Terpinene, and α-Terpinene. High TTO concentrations (≥ 600 μg/mL) showed a remarkable antitumor activity, decreasing cell viability and cell proliferation of MCF-7 and 4T1 cells. TTO at 300 μg/mL increased the number of MCF-7 cells in the early stages of apoptosis and increased the BAX/BCL-2 genes ratio. TTO, mainly at 300 μg/mL, decreased cell growth and arrested MCF-7 cells in the S phase of the cell cycle. Lower antitumor concentrations (≤300 μg/mL) evaluated in MCF-7 and 4T1 cells were not cytotoxic to PBMCs and HFF-1. Also, TTO (300 μg/mL) was able to induce cell proliferation in fibroblasts after 72 h, indicating non-cytotoxic effect in these cells. TTO exhibited in vitro antitumor effect on MCF-7 and 4T1 cells by decreasing cell viability and modulating apoptotic pathways and cell cycle arrestment of MCF-7 cells. In this sense, our study provides new perspectives on the potential use of TTO for the development of new alternative therapies to treat topically locally advanced breast cancer (LABC). [ABSTRACT FROM AUTHOR]

β-2-himachalen-6-ol (HC), a novel sesquiterpene derived from Lebanese wild carrot, was shown to possess a remarkable anticancer activity. The present study investigates the in vitro anticancer activity of HC and its effect on papillomas induced using a DMBA/TPA skin carcinogenesis mouse model. HaCaT-ras II-4 epidermal squamous cell viability was assessed using WST-1 kit. Cell cycle was analyzed by flow cytometry, and pro/anti-apoptotic proteins were measured using western blot. Mice papillomas were induced by DMBA and promoted with TPA for 18 weeks. At week 12, animals were divided into four groups: HC topically treated (5%Top), HC intraperitoneally treated (25 mg/kg; HC25), Cisplatin treated (2.5 mg/kg), and control (DMSO treated). Papilloma yield, volume, histology, and mice weight and liver function were assessed. HC treatment decreased significantly cell survival (IC 50  = 7 and IC 90  = 40 μg/ml) and increased significantly cells undergoing late apoptosis and necrosis. It also significantly decreased the levels of pro-caspase-3, p53, Bcl-2, p-Erk/Erk and p-Akt/Akt and increased p21 and Bax proteins. Treatment with HC25, HC5%Top or Cisplatin showed a significant decrease in papilloma yield and volume. Only Cisplatin treatment caused a significant decrease in body weight and increase in serum ALT. In conclusion, β-2-himachalen-6-ol induced significant tumor shrinkage, an effect partly mediated via promoting apoptosis through inhibition of the MAPK/ERK and PI3K/AKT pathways, with no significant toxicity to laboratory mice. [ABSTRACT FROM AUTHOR]

Model systems for oral cancer research have progressed from tumor epithelial cell cultures to in vivo systems that mimic oral cancer genetics, pathological characteristics, and tumor-stroma interactions of oral cancer patients. In the era of cancer immunotherapy, it is imperative to use model systems to test oral cancer prevention and therapeutic interventions in the presence of an immune system and to discover mechanisms of stromal contributions to oral cancer carcinogenesis. Here, we review in vivo mouse model systems commonly used for studying oral cancer and discuss the impact these models are having in advancing basic mechanisms, chemoprevention, and therapeutic intervention of oral cancer while highlighting recent discoveries concerning the role of immune cells in oral cancer. Improvements to in vivo model systems that highly recapitulate human oral cancer hold the key to identifying features of oral cancer initiation, progression, and invasion as well as molecular and cellular targets for prevention, therapeutic response, and immunotherapy development. [ABSTRACT FROM AUTHOR]

Chronic inflammation is a major risk factor for colorectal cancer. The p38/MAPKAP Kinase 2 (MK2) kinase axis controls the synthesis of proinflammatory cytokines that mediate both chronic inflammation and tumor progression. Blockade of this pathway has been previously reported to suppress inflammation and to prevent colorectal tumorigenesis in a mouse model of inflammation-driven colorectal cancer, by mechanisms that are still unclear. Here, using wholeanimal and tissue-specific MK2 KO mice, we show that MK2 activity in the myeloid compartment promotes tumor progression by supporting tumor neoangiogenesis in vivo. Mechanistically, we demonstrate that MK2 promotes polarization of tumor-associated macrophages into protumorigenic, proangiogenic M2-like macrophages. We further confirmed our results in human cell lines, where MK2 chemical inhibition in macrophages impairs M2 polarization and M2 macrophage-induced angiogenesis. Together, this study provides a molecular and cellular mechanism for the protumorigenic function of MK2. [ABSTRACT FROM AUTHOR]

Reliable animal models are required for the in vivo study of the molecular mechanisms and effects of chemotherapeutic drugs in hepatocarcinoma. In vivo tracing techniques based on firefly luciferase (FLuc) may optimize the non-invasive monitoring of experimental animals. The present study established a murine Hepa1-6-FLuc cell line that stably expressed a retrovirus-delivered FLuc protein gene. The cell morphology, proliferation, migration and invasion ability of Hepa1-6-FLuc cells were the same as that of the Hepa1-6 cells, and thus is suitable to replace Hepa1-6 cells in the construction of hepatocarcinoma animal models. No differences in subcutaneous tumor mass and its pathomorphology from implanted Hepa1-6-FLuc cells were observed compared with Hepa1-6 control tumors. Bioluminescence imaging indicated that the Luc signal of the Hepa1-6-FLuc cells was consistently strengthened with increases in tumor mass; however, the Luc signal of Hepa1-6-AdFLuc became weaker and eventually disappeared during tumor development. Therefore, compared with the transient expression by adenovirus, stable expression of the FLuc gene in Hepa1-6 cells may better reflect cell proliferation and survival in vivo, and provide a reliable source for the establishment of hepatocarcinoma models. [ABSTRACT FROM AUTHOR]

The PERK-eIF2α pathway is activated in aggressive prostate cancer and associated with patient outcome, providing a therapeutic target for the disease. Stressing out prostate cancer: As tumors grow, they undergo a variety of metabolic changes that facilitate their proliferation. Protein synthesis is one of the cellular processes that is altered in cancer cells, because its continued activation helps drive cancer growth. This is not a benign adaptation, however, and unchecked up-regulation of protein synthesis can be toxic to the cells because it promotes cellular stress. As Nguyen et al. discovered, prostate cancer cells with a specific combination of mutations can override this stress by activating a protein called eIF2α, which protects them from excessive protein synthesis. To target this pathway, the authors identified an inhibitor of eIF2α that blocks this protective mechanism and has therapeutic activity against aggressive and otherwise untreatable prostate cancer. Oncogenic lesions up-regulate bioenergetically demanding cellular processes, such as protein synthesis, to drive cancer cell growth and continued proliferation. However, the hijacking of these key processes by oncogenic pathways imposes onerous cell stress that must be mitigated by adaptive responses for cell survival. The mechanism by which these adaptive responses are established, their functional consequences for tumor development, and their implications for therapeutic interventions remain largely unknown. Using murine and humanized models of prostate cancer (PCa), we show that one of the three branches of the unfolded protein response is selectively activated in advanced PCa. This adaptive response activates the phosphorylation of the eukaryotic initiation factor 2–α (P-eIF2α) to reset global protein synthesis to a level that fosters aggressive tumor development and is a marker of poor patient survival upon the acquisition of multiple oncogenic lesions. Using patient-derived xenograft models and an inhibitor of P-eIF2α activity, ISRIB, our data show that targeting this adaptive brake for protein synthesis selectively triggers cytotoxicity against aggressive metastatic PCa, a disease for which presently there is no cure. [ABSTRACT FROM AUTHOR]

Background: Probiotics are believed to have properties that lower the risk of colon cancer. However, the mechanisms by which they exert their beneficial effects are relatively unknown.Aim: To assess the impact of probiotics in preventing induction of colon carcinogenesis in rats.Methods: The rats were divided into six groups viz., normal control, Lactobacillus plantarum (AdF10)-treated, Lactobacillus rhamnosus GG (LGG)-treated, 1,2-dimethylhydrazine (DMH)-treated, L. plantarum (AdF10) + DMH-treated and L. rhamnosus GG (LGG) + DMH-treated. Both the probiotics were supplemented daily at a dose of 2 × 1010 cells per day. DMH at a dose of 30 mg/kg body weight was administered subcutaneously twice a week for the first 4 weeks and then once every week for a duration of 16 weeks. Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase as protein expression of genes involved in apoptosis were assessed during DMH-induced colon carcinogenesis in rats.Results: DMH treatment decreased the activity of GSH, GPx, GST, SOD and catalase. However, AdF10 and LGG supplementation to DMH-treated rats significantly increased the activity of these enzymes. Further, DMH treatment revealed alterations in the protein expressions of various genes involved in the p53-mediated apoptotic pathway such as p53, p21, Bcl-2, Bax, caspase-9 and caspase-3, which, however, were shifted towards normal control levels upon simultaneous supplementation with probiotics.Conclusion: The present study suggests that probiotics can provide protection against oxidative stress and apoptotic-related protein disregulation during experimentally induced colon carcinogenesis. [ABSTRACT FROM AUTHOR]

Toca 511, a retroviral replicating vector (RRV), uses an internal ribosomal entry site (IRES) to express an optimized yeast cytosine deaminase (yCD2), which converts 5-fluorocytosine to 5-fluorouracil. This configuration is genetically stable in both preclinical mouse models and human clinical trials. However, the use of IRES (∼600 bp) restricts choices of therapeutic transgenes due to limits in RRV genome size. This study replaced IRES with 2A peptides derived from picornaviruses with or without a GSG linker. The data show that GSG-linked 2A (g2A) peptide resulted in higher polyprotein separation efficiency than non-GSG linked 2A peptide. The study also shows that RRV can tolerate insertion of two separate 2A peptides to allow expression of two transgenes without compromising the assembly and function of the virus in addition to insertion of a single 2A peptide to confirm genetic stability with yCD2, green fluorescent protein, and HSV-1 thymidine kinase. In a parallel comparison of the RRV-IRES-yCD2 and RRV-g2A-yCD2 configurations, the study shows the yCD2 protein expressed from RRV-g2A-yCD2 has higher activity, resulting in a higher survival benefit in an intracranial tumor mouse model. These data enable a wider range of potential product candidates that could be developed using the RRV platform. [ABSTRACT FROM AUTHOR]

The laboratory mouse is widely considered as a valid and affordable model organism to study human disease. Attempts to improve the relevance of murine models for the investigation of human pathologies led to the development of various genetically engineered, xenograft and humanized mouse models. Nevertheless, most preclinical studies in mice suffer from insufficient predictive value when compared with cancer biology and therapy response of human patients. We propose an innovative strategy to improve the predictive power of preclinical cancer models. Combining (i) genomic, tissue engineering and regenerative medicine approaches for rational design of mouse models with (ii) rapid prototyping and computational benchmarking against human clinical data will enable fast and nonbiased validation of newly generated models. [ABSTRACT FROM AUTHOR]

A genetically engineered Salmonella typhimurium strain that may be applied in the medically useful therapeutic strategy of using bacterial agents to target breast cancer in a tumor‑bearing nude mouse model has been previously reported. Furthermore, immune cell accumulation in breast tumor types has been observed, particularly distributed in regions surrounding the bacteria. M2 macrophages are associated with breast cancer aggressiveness, whereas M1 macrophages are prone to devouring bacteria and killing cancer cells. Therefore, this engineered tumor‑targeting salmonella strain was used in an attempt to reverse the phenotype of M2 macrophages into the M1 phenotype. Subsequent to the co‑culture of M2 macrophages with the bacteria for a short time, >50% of the M2 macrophages were invaded by bacteria. These M2 macrophages exhibited a decreased expression of mannose receptor (an M2 phenotypic marker) and increased expression of human leukocyte antigen‑antigen D related (an M1 phenotypic marker). The results of the present study indicated that differentiated M2 macrophages may be redirected into the M1 phenotype following exposure to the engineered bacteria stimulus. This effect may be a potential mechanism by which bacteria retard tumor growth. Thus, this engineered bacterium may be a useful candidate for targeting and redirecting M2 macrophages into the M1 phenotype. [ABSTRACT FROM AUTHOR]

Lung is one of the most common sites for bladder cancer to metastasize. Although the involvement of the epithelial‑to‑mesenchymal transition (EMT) in bladder cancer progression has been established, the mechanism of EMT induction remains unclear. In order to investigate this, T24‑parental (P) and T24‑lung (L) bladder cancer cells were obtained from primary tumors and lung metastatic sites of an animal model with orthotopic spontaneous metastatic bladder cancer, according to a protocol previously described. Compared with T24‑P cells, mesenchymal‑like T24‑L cells exhibited an increased ability in tumor invasion and metastasis, as well as an increased expression of hypoxia‑inducible factor (HIF)‑1α, zinc finger E‑box‑binding homeobox 1 (ZEB1), vimentin and N‑cadherin and lower level of cytokeratin 18 were observed. Mechanistically, it was identified that HIF‑1α increases ZEB1 expression and subsequently regulates the expression of EMT‑related genes in both HIF‑1α knocking down by siRNA and gain‑in HIF‑1α by hypoxia culture cell models. In addition, the expression of HIF‑1α and ZEB1 in bladder cancer tissues were increased compared with normal bladder epithelial tissues, as well as significantly increased in the high‑grade, invasive and metastatic bladder cancer tissues compared with low‑grade, superficial and non‑metastatic bladder cancer tissues by using immune‑histochemical staining assay. Notably, the protein level of HIF‑1α was positively associated with that of ZEB1 in bladder cancer tissues. Results from the present study indicate that HIF‑1α promotes ZEB1 expression and EMT in the T24‑L human bladder cancer lung metastasis animal model, suggesting that HIF‑1α serves an important function in the metastasis of bladder cancer, and HIF‑1α and ZEB1 may be potential targets for inhibiting bladder metastasis in the future. [ABSTRACT FROM AUTHOR]

Tumor vascular normalization involved in immune response is beneficial to the chemotherapy of tumors. Recombinant human endostatin (Endostar), an angiogenesis inhibitor, has been demonstrated to be effective in hepatocellular cancer (HCC). However, its vascular normalization in HCC and the role of the immune response in angiogenesis were unclear. In the present study, effects of Endostar on tumor vascular normalization were evaluated in hepatoma 22 (H22) tumor‑bearing mice. Endostar was able to inhibit the proliferation and infiltration of tumor cells and improve α‑fetoprotein, tumor necrosis factor‑α and cyclic adenosine 5'‑phosphate levels in the serum of H22‑bearing mice, as well as the protein expression levels of the immune factors interferon‑γ and cluster of differentiation (CD)86 in liver tissue. Endostar also exhibited more marked downregulation of the levels of vascular endothelial growth factor, CD31, matrix metalloproteinase (MMP)‑2, MMP‑9 and interleukin‑17 during day 3‑9 treatment, resulting in short‑term normalization of tumor blood vessels. The period of vascular normalization was 3‑9 days. The results of the present study demonstrated that Endostar was able to induce the period of vascular normalization, contributing to a more efficacious means of HCC treatment combined with other chemotherapy, and this effect was associated with the immune response. It may be concluded that Endostar inhibited immunity‑associated angiogenesis behaviors of vascular endothelial cells in response to HCC. The results of the present study provided more reasonable possibility for the combination therapy of Endostar for the treatment of HCC. [ABSTRACT FROM AUTHOR]

Prognosis of pancreatic cancer is poor, thus the development of novel therapeutic drugs is necessary. During preclinical studies, appropriate models are essential for evaluating drug efficacy. The present study sought to determine the ideal pancreatic cancer mouse model for reliable preclinical testing. Such a model could accurately reflect human pancreatic cancer phenotypes and predict future clinical trial results. Systemic pathology analysis was performed in an orthotopic transplantation model to prepare model mice for use in preclinical studies, mimicking the progress of human pancreatic cancer. The location and the timing of inoculated cancer cell metastases, pathogenesis and cause of fatality were analyzed. Furthermore, the efficacy of gemcitabine, a key pancreatic cancer drug, was evaluated in this model where liver metastasis and peritoneal dissemination occur. Results indicated that the SUIT‑2 orthotopic pancreatic cancer model was similar to the phenotypic sequential progression of human pancreatic cancer, with extra‑pancreatic invasion, intra‑peritoneal dissemination and other hematogenous organ metastases. Notably, survival was prolonged by administering gemcitabine to mice with metastasized pancreatic cancer. Furthermore, the detailed effects of gemcitabine on the primary tumor and metastatic tumor lesions were pathologically evaluated in mice. The present study indicated the model accurately depicted pancreatic cancer development and metastasis. Furthermore, the detailed effects of pancreatic cancer drugs on the primary tumor and on metastatic tumor lesions. We present this model as a potential new standard for new drug development in pancreatic cancer. [ABSTRACT FROM AUTHOR]

Spontaneous tumors regression has been associated with microbial infection for 100s of years and inspired the use of bacteria for anticancer therapy. Dr. William B. Coley (1862-1936), a bone- sarcoma surgeon, was a pioneer in treating his patients with both live bacterial-based and mixture of heat-killed bacteria known as "Coley's toxins." Unfortunately, Coley was forced to stop his work which interrupted this field for about half a century. Currently, several species of bacteria are being developed against cancer. The bacterial species, their genetic background and their infectious behavior within the tumor microenvironment are thought to be relevant factors in determining their anti-tumor effectiveness in vivo. In this perspective article we will update the most promising results achieved using bacterial therapy (alone or combined with other strategies) in clinically-relevant animal models of cancer and critically discuss the impact of the bacterial variants, route of administration and mechanisms of bacteria-cancercell interaction. We will also discuss strategies to apply this information using modern mouse models, molecular biology, genetics and imaging for future bacterial therapy of cancer patients. [ABSTRACT FROM AUTHOR]

Background: Clear cell carcinoma (CCC) of the cervix is a rarely seen malignant tumor which is classified in adenocarcinomas of the endometrium. It is responsible for 2.15-3.0% of endometrial tumors. The diagnosis is difficult and is still controversial in uterine carcinomas. Macroscopically, masses were protruding to endometrial surface. However, the definitive diagnosis was carried by microscopical evaluation. The cells contain clear cytoplasm. The cells are seen in this pattern because there is either glycogenation or secretoric activity in the cells. Case: In the present case, clinicopathologic and immunohistochemical findings of clear cell carcinoma of the cervix were defined in a 3 year-old spayed Golden retriever bitch. Previously spayed bitch, which had vaginal discharge for the last month-long, was submitted to the Department of Obstetrics and Gynecology, Ankara University, Faculty of Veterinary Medicine. In the general clinical examination, vaginoscopy was performed and vaginal cytology was obtained from smear. The source of discharge was detected as cervix uteri. In vaginal cytologic examination, erythrocyte, neutrophile and superficial cells were observed. In abdominal ultrasonography, a hypoechoic mass was detected at cranial part of the urinary bladder. To evaluate the general health condition of the dog, total blood counting and serum biochemistry were analyzed in addition to assessing its hormone prophlye. Estrogen and progesterone levels were evaluated. Estradiol (E2) level was measured as 23 pg/mL and progesterone level was measured as 1.96 ng/mL from collected serum. The cervical mass in diameters of 3x4x2.5 cm was removed in operation. In macroscopical examination, it had spherical and regularly shape. After the macroscopical examination, tissue samples were fixed in 10% buffered formalin. Then, the samples stained with Haematoxylin-Eosin (H&E), Masson's trichrome and PAS stainings, respectively. At the macroscopic and histological examinations, the mass was diagnosed as clear cell carcinoma. Immunohistochemically, the tumor was stained with CK19 a-SMA, vimentin, desmin, TGF-ß, VEGF, CEA, ER and PR markers. Other markers gave moderate to severe reactions in exception for no or weak ER and PR positivities. In direction of these results, clear cell carcinoma of cervix had been found remarkably due to first description in a spayed bitch on the basis of knowledge. Discussion: Clear cell carcinoma (CCC) is one type of the endometrial carcinomas. It is frequently known to have aggressive behavior and unfavorable prognosis. In human counterparts, clear cell carcinoma is frequently reoccurred in caudoabdominal and pelvic region even after being removed. The occurrence of clear cell carcinoma has highly increased with diethylstilbestrol usage during pregnancy. The situation on uterine carcinoma is nearly same in domestic animals. It is related to prolonged estrogenism. In this case, the bitch has been under prolong exposure to estrogenic effect. Indeed the estradiol level was high when compared to spayed female. Also, it is thought that the reason of high estradiol level does not depend on the ovarian remnant. It is believed this situation may be relevant to exogen hormone usage. Vaginal smear confirmed erythrocyte (due to bleeding), predominantly superficial cells to it's under estrogenic effect even despite being spayed. [ABSTRACT FROM AUTHOR]

Background: The companion animal market has changed over the years. The number of people living in small apartments has increased; as a result, the demand for small pets such as exotics, fish, and small rodents has also increased due to their smaller space requirements and ease of handling and care. Pets help relieve anxiety and stress in people suffering from social issues. Small rodents are usually bred in specific cages with cellulose or wood shaving bedding, and fed with commercially available diets. Small rodent clinics struggle due to the lack of scientific reports on some diseases and therapies. To date, the oncology literature is too limited to develop better diagnosis and treatment methods. Here, we report three cases of squamous cell carcinoma in the mandibular region of Chinese hamsters (Cricetulus griseus). Case: Three adult male hamsters averaging 1.5 years old, from different pet stores, bred under home conditions by different owners in Sergipe, Brazil, were brought to the Dr. Vicente Borelli Hospital at Pio X University for exotic veterinary care. Each animal had been bred alone in a specific breeding cage. Each had a history of apathy, loss of appetite, and rapid deformity of the facial region. Radiographs showed areas of bone involvement and extensive injury, with partial resorption of the left ramus and angle of the mandibular region. Due to the location of the tumor mass, the clinical status, and limitations in systemic treatment, euthanasia was recommended for each animal. After anamnesis, the animals were subjected to clinical assessment. A firm and well-circumscribed mass was identified on palpation. In case A, it compromised the left mandible from the angle to the body and extended to the maxillary soft tissues and left superior lips. In case B, it extended from the ramus to the symphysis on the left side and to the maxillary region, similar to case A. In case C, it extended on both sides of the mandible symphysis, with no alterations in the maxillary soft tissues. Following clinical examination, each animal underwent laterolateral and dorsoventral radiographic examination; no images were suggestive of pulmonary metastasis. However, an expansive mandibular lesion with partial resorption, suggestive of bone neoplasia, was detected. The animals were dehydrated and in clinical distress, and euthanasia was recommended. Histopathological examination of samples from the tumor sites revealed moderate cellular and nuclear pleomorphism and proliferation of neoplastic keratinocytes, suggestive of squamous cell carcinoma, a malignant tumor of epidermal keratinocytes with a highly invasive and aggressive nature. Discussion: The number of reports in the literature of cancer in small rodent companion animals has lead us to believe that neoplasms in these animals are misdiagnosed and/or that their prevalence is underreported. The literature describes that the tumor incidence in hamsters is 3-40%, and that the incidence is higher in male rodents. This incidence range increases the analysis of cancer in these animals from rare to middle-frequent what do not contribute to the animals' clinics and to small rodent therapeutics. Differential diagnosis of squamous cell carcinoma and other tumor types should be addressed, especially osteosarcomas. Histopathological examination is essential to clarify the etiopathogenesis. [ABSTRACT FROM AUTHOR]

Arginine and α-tocopherol succinate (α-TOS) double grafted N-trimethyl chitosan chloride (TMC) nanoparticles (TAS NPs) were designed and developed for effective co-delivery of doxorubicin (DOX) and Survivin shRNA-expressing pDNA (iSur-pDNA). With DOX loading into the hydrophobic core and iSur-pDNA combining to the hydrophilic shell, TAS/DOX/pDNA NPs demonstrated favorable structural stability and sustained release properties in vitro . With the special non-clathrin-dependent endocytosis, TAS/DOX/pDNA NPs presented higher cellular uptake and mainly distributed in ER and Golgi rather than lysosomes following internalization. The in vitro nuclear localization, gene silencing efficiency, cell apoptosis, and growth inhibition of tumor cells were significantly promoted by arginine modification. In the tumor-bearing mice model, TAS/DOX/pDNA NPs possessed the maximum antitumor efficiency as compared with single delivery of DOX or iSur-pDNA. Particularly, blank TAS NPs were selectively be toxic to tumor cells as evidenced by their capabilities to inhibit proliferation and induce apoptosis of tumor cells. The promising tumor treatment of TAS/DOX/pDNA NPs via a multiple synergistic manner arising from DOX and pDNA as well as the vectors would provide a potential strategy for a dual-delivery system to improve their therapeutic efficacies. [ABSTRACT FROM AUTHOR]

Phospholipase D (PLD) activity has been proposed to facilitate multiple steps in cancer progression including growth, metabolism, angiogenesis, and mobility. The canonical enzymes PLD1 and PLD2 enact their diverse effects through hydrolyzing the membrane lipid phosphatidylcholine to generate the second messenger and signaling lipid phosphatidic acid (PA). However, the widespread expression of PLD1 and PLD2 in normal tissues and the additional distinct enzymatic mechanisms through which PA can be generated have produced uncertainty regarding the optimal settings in which PLD inhibition might ameliorate cancer. Recent studies in mouse model systems have demonstrated that inhibition or elimination of PLD activity reduces tumor growth and metastasis. One mechanism proposed for this outcome involves proliferative signaling mediated by receptor tyrosine kinases (RTK) and G protein-coupled receptors (GPCR), which is attenuated when downstream PLD signal propagation is suppressed. The reduced proliferative signaling has been reported to be compounded by dysfunctional energetic metabolism in the tumor cells under conditions of nutrient deprivation. Moreover, cancer cells lacking PLD activity display inefficiencies across multiple steps of the metastatic cascade, limiting the tumor's lethal spread. Using PLD isoform knockout mice, recent studies have reported on the net effects of inhibition and ablation in multiple cancer models through examining the role of PLD in the non-tumor cells comprising the stroma and microenvironment. The promising results of such in vivo studies, combined with the apparent low toxicity of highly-specific and potent inhibitors, highlights PLD as an attractive target for therapeutic inhibition in cancer. We discuss here the array of anti-tumor effects produced by PLD inhibition and ablation in cancer models with a focus on animal studies. [ABSTRACT FROM AUTHOR]