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1.
Sci Rep ; 11(1): 23627, 2021 12 08.
Article in English | MEDLINE | ID: mdl-34880268

ABSTRACT

Cachexia is a muscle wasting syndrome occurring in many advanced cancer patients. Cachexia significantly increases cancer morbidity and mortality. Cardiac atrophy and contractility deficits have been observed in patients and in animal models with cancer cachexia, which may contribute to cachexia pathophysiology. However, underlying contributors to decreased in vivo cardiac contractility are not well understood. In this study, we sought to distinguish heart-intrinsic changes from systemic factors contributing to cachexia-associated cardiac dysfunction. We hypothesized that isolated heart and cardiac myocyte functional deficits underlie in vivo contractile dysfunction. To test this hypothesis, isolated heart and cardiac myocyte function was measured in the colon-26 adenocarcinoma murine model of cachexia. Ex vivo perfused hearts from cachectic animals exhibited marked contraction and relaxation deficits during basal and pacing conditions. Isolated myocytes displayed significantly decreased peak contraction and relaxation rates, which was accompanied by decreased peak calcium and decay rates. This study uncovers significant organ and cellular-level functional deficits in cachectic hearts outside of the catabolic in vivo environment, which is explained in part by impaired calcium cycling. These data provide insight into physiological mechanisms of cardiomyopathy in cachexia, which is critical for the ultimate development of effective treatments for patients.


Subject(s)
Cachexia/physiopathology , Calcium/metabolism , Heart Failure/etiology , Myocardial Contraction , Myocytes, Cardiac/pathology , Neoplasms, Experimental/physiopathology , Animals , Body Weight , Cachexia/complications , Cell Line, Tumor , Humans , Male , Mice , Muscular Atrophy/metabolism , Myocytes, Cardiac/metabolism , Neoplasms, Experimental/complications , Organ Size
2.
Int J Mol Sci ; 22(23)2021 Nov 30.
Article in English | MEDLINE | ID: mdl-34884748

ABSTRACT

Intramedullary spinal cord tumors are a rare and understudied cancer with poor treatment options and prognosis. Our prior study used a combination of PDGF-B, HRAS, and p53 knockdown to induce the development of high-grade glioma in the spinal cords of minipigs. In this study, we evaluate the ability of each vector alone and combinations of vectors to produce high-grade spinal cord gliomas. Eight groups of rats (n = 8/group) underwent thoracolumbar laminectomy and injection of lentiviral vector in the lateral white matter of the spinal cord. Each group received a different combination of lentiviral vectors expressing PDGF-B, a constitutively active HRAS mutant, or shRNA targeting p53, or a control vector. All animals were monitored once per week for clinical deficits for 98 days. Tissues were harvested and analyzed using hematoxylin and eosin (H&E) and immunohistochemical (IHC) staining. Rats injected with PDGF-B+HRAS+sh-p53 (triple cocktail) exhibited statistically significant declines in all behavioral measures (Basso Beattie Bresnahan scoring, Tarlov scoring, weight, and survival rate) over time when compared to the control. Histologically, all groups except the control and those injected with sh-p53 displayed the development of tumors at the injection site, although there were differences in the rate of tumor growth and the histopathological features of the lesions between groups. Examination of immunohistochemistry revealed rats receiving triple cocktail displayed the largest and most significant increase in the Ki67 proliferation index and GFAP positivity than any other group. PDGF-B+HRAS also displayed a significant increase in the Ki67 proliferation index. Rats receiving PDGF-B alone and PDGF-B+ sh-p53 displayed more a significant increase in SOX2-positive staining than in any other group. We found that different vector combinations produced differing high-grade glioma models in rodents. The combination of all three vectors produced a model of high-grade glioma more efficiently and aggressively with respect to behavioral, physiological, and histological characteristics than the rest of the vector combinations. Thus, the present rat model of spinal cord glioma may potentially be used to evaluate therapeutic strategies in the future.


Subject(s)
Glioma/etiology , Lentivirus/genetics , Spinal Cord Neoplasms/etiology , Animals , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Cell Proliferation , Genetic Vectors , Glioma/pathology , Glioma/physiopathology , Mutation , Neoplasms, Experimental/etiology , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Oncogene Proteins/genetics , Oncogene Proteins/metabolism , Platelet-Derived Growth Factor/genetics , Platelet-Derived Growth Factor/metabolism , RNA, Small Interfering/administration & dosage , RNA, Small Interfering/genetics , Rats , Rats, Sprague-Dawley , Spinal Cord Neoplasms/pathology , Spinal Cord Neoplasms/physiopathology , Tumor Suppressor Protein p53/antagonists & inhibitors , Tumor Suppressor Protein p53/genetics , Tumor Suppressor Protein p53/metabolism , ras Proteins/genetics , ras Proteins/metabolism
3.
Int J Mol Sci ; 22(14)2021 Jul 19.
Article in English | MEDLINE | ID: mdl-34299314

ABSTRACT

Signal transducer and activator of transcription 1 (STAT1) acts as a tumor suppressor molecule in colitis-associated colorectal cancer (CAC), particularly during the very early stages, modulating immune responses and controlling mechanisms such as apoptosis and cell proliferation. Previously, using an experimental model of CAC, we reported increased intestinal cell proliferation and faster tumor development, which were consistent with more signs of disease and damage, and reduced survival in STAT1-/- mice, compared with WT counterparts. However, the mechanisms through which STAT1 might prevent colorectal cancer progression preceded by chronic inflammation are still unclear. Here, we demonstrate that increased tumorigenicity related to STAT1 deficiency could be suppressed by IL-17 neutralization. The blockade of IL-17 in STAT1-/- mice reduced the accumulation of CD11b+Ly6ClowLy6G+ cells resembling granulocytic myeloid-derived suppressor cells (MDSCs) in both spleen and circulation. Additionally, IL-17 blockade reduced the recruitment of neutrophils into intestinal tissue, the expression and production of inflammatory cytokines, and the expression of intestinal STAT3. In addition, the anti-IL-17 treatment also reduced the expression of Arginase-1 and inducible nitric oxide synthase (iNOS) in the colon, both associated with the main suppressive activity of MDSCs. Thus, a lack of STAT1 signaling induces a significant change in the colonic microenvironment that supports inflammation and tumor formation. Anti-IL-17 treatment throughout the initial stages of CAC related to STAT1 deficiency abrogates the tumor formation possibly caused by myeloid cells.


Subject(s)
Colitis-Associated Neoplasms/etiology , Granulocytes/pathology , Interleukin-17/physiology , STAT1 Transcription Factor/physiology , Animals , Antibodies, Neutralizing/administration & dosage , Colitis-Associated Neoplasms/pathology , Colitis-Associated Neoplasms/physiopathology , Disease Progression , Female , Granulocytes/immunology , Interleukin-17/antagonists & inhibitors , Interleukin-17/immunology , Mice , Mice, Inbred BALB C , Mice, Knockout , Myeloid-Derived Suppressor Cells/immunology , Myeloid-Derived Suppressor Cells/pathology , Neoplasms, Experimental/etiology , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , STAT1 Transcription Factor/deficiency , STAT1 Transcription Factor/genetics , Tumor Microenvironment/immunology
4.
Nat Commun ; 11(1): 4653, 2020 09 16.
Article in English | MEDLINE | ID: mdl-32938923

ABSTRACT

Cancer cells demand excess nutrients to support their proliferation, but how tumours exploit extracellular amino acids during systemic metabolic perturbations remain incompletely understood. Here, we use a Drosophila model of high-sugar diet (HSD)-enhanced tumourigenesis to uncover a systemic host-tumour metabolic circuit that supports tumour growth. We demonstrate coordinate induction of systemic muscle wasting with tumour-autonomous Yorkie-mediated SLC36-family amino acid transporter expression as a proline-scavenging programme to drive tumourigenesis. We identify Indole-3-propionic acid as an optimal amino acid derivative to rationally target the proline-dependency of tumour growth. Insights from this whole-animal Drosophila model provide a powerful approach towards the identification and therapeutic exploitation of the amino acid vulnerabilities of tumourigenesis in the context of a perturbed systemic metabolic network.


Subject(s)
Dietary Sugars/adverse effects , Muscle, Skeletal/drug effects , Muscle, Skeletal/physiopathology , Neoplasms, Experimental/physiopathology , Proline/metabolism , Amino Acid Transport Systems/genetics , Amino Acid Transport Systems/metabolism , Animals , Animals, Genetically Modified , Carcinogenesis , Drosophila Proteins/genetics , Drosophila Proteins/metabolism , Drosophila melanogaster/genetics , Drosophila melanogaster/metabolism , Fibroblast Growth Factors/genetics , Fibroblast Growth Factors/metabolism , Gene Expression Profiling , Hemolymph/drug effects , Hemolymph/metabolism , Larva , Muscle Weakness/chemically induced , Muscle Weakness/pathology , Muscular Atrophy/chemically induced , Muscular Atrophy/pathology , Neoplasms, Experimental/etiology , Nuclear Proteins/genetics , Receptor Protein-Tyrosine Kinases/metabolism , Trans-Activators/genetics , YAP-Signaling Proteins , ras Proteins/genetics
5.
Int J Mol Sci ; 21(19)2020 Sep 23.
Article in English | MEDLINE | ID: mdl-32977526

ABSTRACT

Seizures are common in patients with high-grade gliomas (30-60%) and approximately 15-30% of glioblastoma (GB) patients develop drug-resistant epilepsy. Reliable animal models are needed to develop adequate treatments for glioma-related epilepsy. Therefore, fifteen rats were inoculated with F98 GB cells (GB group) and four rats with vehicle only (control group) in the right entorhinal cortex. MRI was performed to visualize tumor presence. A subset of seven GB and two control rats were implanted with recording electrodes to determine the occurrence of epileptic seizures with video-EEG recording over multiple days. In a subset of rats, tumor size and expression of tumor markers were investigated with histology or mRNA in situ hybridization. Tumors were visible on MRI six days post-inoculation. Time-dependent changes in tumor morphology and size were visible on MRI. Epileptic seizures were detected in all GB rats monitored with video-EEG. Twenty-one days after inoculation, rats were euthanized based on signs of discomfort and pain. This study describes, for the first time, reproducible tumor growth and spontaneous seizures upon inoculation of F98 cells in the rat entorhinal cortex. The development of this new model of GB-related epilepsy may be valuable to design new therapies against tumor growth and associated epileptic seizures.


Subject(s)
Brain Neoplasms , Electroencephalography , Epilepsy , Glioma , Neoplasms, Experimental , Animals , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Brain Neoplasms/physiopathology , Cell Line, Tumor , Epilepsy/metabolism , Epilepsy/pathology , Epilepsy/physiopathology , Glioma/metabolism , Glioma/pathology , Glioma/physiopathology , Male , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Rats , Rats, Inbred F344
6.
J Clin Invest ; 130(5): 2286-2300, 2020 05 01.
Article in English | MEDLINE | ID: mdl-32250339

ABSTRACT

Seizures often herald the clinical appearance of gliomas or appear at later stages. Dissecting their precise evolution and cellular pathogenesis in brain malignancies could inform the development of staged therapies for these highly pharmaco-resistant epilepsies. Studies in immunodeficient xenograft models have identified local interneuron loss and excess glial glutamate release as chief contributors to network disinhibition, but how hyperexcitability in the peritumoral microenvironment evolves in an immunocompetent brain is unclear. We generated gliomas in WT mice via in utero deletion of key tumor suppressor genes and serially monitored cortical epileptogenesis during tumor infiltration with in vivo electrophysiology and GCAMP7 calcium imaging, revealing a reproducible progression from hyperexcitability to convulsive seizures. Long before seizures, coincident with loss of inhibitory cells and their protective scaffolding, gain of glial glutamate antiporter xCT expression, and reactive astrocytosis, we detected local Iba1+ microglial inflammation that intensified and later extended far beyond tumor boundaries. Hitherto unrecognized episodes of cortical spreading depolarization that arose frequently from the peritumoral region may provide a mechanism for transient neurological deficits. Early blockade of glial xCT activity inhibited later seizures, and genomic reduction of host brain excitability by deleting MapT suppressed molecular markers of epileptogenesis and seizures. Our studies confirmed xenograft tumor-driven pathobiology and revealed early and late components of tumor-related epileptogenesis in a genetically tractable, immunocompetent mouse model of glioma, allowing the complex dissection of tumor versus host pathogenic seizure mechanisms.


Subject(s)
Brain Neoplasms , Brain , CRISPR-Cas Systems , Glioblastoma , Neoplasms, Experimental , Seizures , Synaptic Transmission , Animals , Brain/metabolism , Brain/pathology , Brain/physiopathology , Brain Neoplasms/genetics , Brain Neoplasms/metabolism , Brain Neoplasms/pathology , Brain Neoplasms/physiopathology , Gene Deletion , Glioblastoma/genetics , Glioblastoma/metabolism , Glioblastoma/pathology , Glioblastoma/physiopathology , Mice , Mice, Knockout , Neoplasms, Experimental/genetics , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Seizures/genetics , Seizures/metabolism , Seizures/pathology , Seizures/physiopathology
7.
Cell Rep ; 27(11): 3305-3314.e13, 2019 06 11.
Article in English | MEDLINE | ID: mdl-31189113

ABSTRACT

Lymphatic vessels (LVs) are important in the regulation of tissue fluid homeostasis and the pathogenesis of tumor progression. We investigated the innervation of LVs and the response to agonists and antagonists of the autonomic nervous system in vivo. While skin-draining collecting LVs express muscarinic, α1- and ß2-adrenergic receptors on lymphatic endothelial cells and smooth muscle cells, intestinal lacteals express only ß-adrenergic receptors and muscarinic receptors on their smooth muscle cells. Quantitative in vivo near-infrared imaging of the exposed flank-collecting LV revealed that muscarinic and α1-adrenergic agonists increased LV contractility, whereas activation of ß2-adrenergic receptors inhibited contractility and initiated nitric oxide (NO)-dependent vasodilation. Tumor-draining LVs were expanded and showed a higher innervation density and contractility that was reduced by treatment with atropine, phentolamine, and, most potently, isoproterenol. These findings likely have clinical implications given the impact of lymphatic fluid drainage on intratumoral fluid pressure and thus drug delivery.


Subject(s)
Autonomic Nervous System/physiology , Lymphatic Vessels/physiology , Neoplasms, Experimental/physiopathology , Animals , Autonomic Nervous System/physiopathology , Calcium/metabolism , Cells, Cultured , Endothelial Cells/metabolism , Humans , Lymphatic Vessels/cytology , Lymphatic Vessels/metabolism , Lymphatic Vessels/physiopathology , Male , Mice , Mice, Inbred C57BL , Muscle Contraction , Myocytes, Smooth Muscle/metabolism , Nitric Oxide/metabolism , Receptors, Adrenergic/metabolism
8.
J Muscle Res Cell Motil ; 40(1): 59-65, 2019 03.
Article in English | MEDLINE | ID: mdl-30945134

ABSTRACT

The present study aimed to determine the impact of colon 26 adenocarcinoma (C26)-induced cancer cachexia on skeletal muscle mitochondrial respiration and content. Twelve male CD2F1 mice were injected with C26-cells (tumor bearing (TB) group), whereas 12 age-matched mice received PBS vehicle injection (non-tumor bearing (N-TB) group). Mitochondrial respiration was studied in saponin-permeabilized soleus myofibers. TB mice showed lower body weight (~ 20%) as well as lower soleus, gastrocnemius-plantaris complex and tibialis anterior masses versus N-TB mice (p < 0.05). Soleus maximal state III mitochondrial respiration was 20% lower (10 mM glutamate, 5 mM malate, 5 mM adenosine diphosphate; p < 0.05) and acceptor control ratio (state III/state II) was 15% lower in the TB vs. N-TB (p < 0.05), with the latter suggesting uncoupling. Lower VDAC protein content suggested reduced mitochondrial content in TB versus N-TB (p < 0.05). Skeletal muscle in C26-induced cancer cachexia exhibits reductions in: maximal mitochondrial respiration capacity, mitochondrial coupling and mitochondrial content.


Subject(s)
Adenocarcinoma , Cachexia , Colonic Neoplasms , Mitochondria, Muscle , Muscle, Skeletal , Neoplasms, Experimental , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Adenocarcinoma/physiopathology , Animals , Cachexia/metabolism , Cachexia/pathology , Cachexia/physiopathology , Cell Line, Tumor , Colonic Neoplasms/metabolism , Colonic Neoplasms/pathology , Colonic Neoplasms/physiopathology , Male , Mice , Mitochondria, Muscle/metabolism , Mitochondria, Muscle/pathology , Muscle, Skeletal/metabolism , Muscle, Skeletal/pathology , Muscle, Skeletal/physiopathology , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology
9.
Sci Rep ; 8(1): 13038, 2018 08 29.
Article in English | MEDLINE | ID: mdl-30158566

ABSTRACT

Although Ras genes are frequently mutated in human tumors, these mutations are uncommon in breast cancer. However, many breast tumors show evidences of Ras pathway activation. In this manuscript, we have analyzed and characterized mouse mammary tumors generated by random Sleeping Beauty transposon mutagenesis and identify ERAS -a member of the RAS family silenced in adult tissues- as a new gene involved in progression and malignancy of breast cancer. Forced expression of ERAS in human non-transformed mammary gland cells induces a process of epithelial-to-mesenchymal transition and an increase in stem cells markers; these changes are mediated by miR-200c downregulation. ERAS expression in human tumorigenic mammary cells leads to the generation of larger and less differentiated tumors in xenotransplant experiments. Immunohistochemical, RT-qPCR and bioinformatics analysis of human samples show that ERAS is aberrantly expressed in 8-10% of breast tumors and this expression is associated with distant metastasis and reduced metastasis-free survival. In summary, our results reveal that inappropriate activation of ERAS may be important in the development of a subset of breast tumors. These findings open the possibility of new specific treatments for this subset of ERAS-expressing tumors.


Subject(s)
Breast Neoplasms/physiopathology , Oncogene Protein p21(ras)/metabolism , Animals , Breast Neoplasms/pathology , Carcinogenesis , Cell Differentiation , Cells, Cultured , Epithelial Cells/physiology , Epithelial-Mesenchymal Transition , Humans , Mice , Neoplasm Transplantation , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Oncogene Protein p21(ras)/genetics , Transplantation, Heterologous
10.
PLoS One ; 13(7): e0200548, 2018.
Article in English | MEDLINE | ID: mdl-30011306

ABSTRACT

This study was designed to characterize morphologic stages during neuroma development post amputation with an eye toward developing better treatment strategies that intervene before neuromas are fully formed. Right forelimbs of 30 Sprague Dawley rats were amputated and limb stumps were collected at 3, 7, 28, 60 and 90 Days Post Amputation (DPA). Morphology of newly formed nerves and neuromas were assessed via general histology and neurofilament protein antibody staining. Analysis revealed six morphological characteristics during nerve and neuroma development; 1) normal nerve, 2) degenerating axons, 3) axonal sprouts, 4) unorganized bundles of axons, 5) unorganized axon growth into muscles, and 6) unorganized axon growth into fibrotic tissue (neuroma). At early stages (3 & 7 DPA) after amputation, normal nerves could be identified throughout the limb stump and small areas of axonal sprouts were present near the site of injury. Signs of degenerating axons were evident from 7 to 90 DPA. From day 28 on, variability of nerve characteristics with signs of unorganized axon growth into muscle and fibrotic tissue and neuroma formation became visible in multiple areas of stump tissue. These pathological features became more evident on days 60 and 90. At 90 DPA frank neuroma formation was present in all stump tissue. By following nerve regrowth and neuroma formation after amputation we were able to identify 6 separate histological stages of nerve regrowth and neuroma development. Axonal regrowth was observed as early as 3 DPA and signs of unorganized axonal growth and neuroma formation were evident by 28 DPA. Based on these observations we speculate that neuroma treatment and or prevention strategies might be more successful if targeted at the initial stages of development and not after 28 DPA.


Subject(s)
Axons/pathology , Neoplasms, Experimental , Neuroma , Wounds and Injuries , Amputation Stumps/pathology , Amputation Stumps/physiopathology , Animals , Hindlimb , Male , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Neuroma/pathology , Neuroma/physiopathology , Rats , Rats, Sprague-Dawley , Time Factors , Wounds and Injuries/complications , Wounds and Injuries/pathology , Wounds and Injuries/physiopathology
11.
Ann N Y Acad Sci ; 1434(1): 139-148, 2018 12.
Article in English | MEDLINE | ID: mdl-29974961

ABSTRACT

Barrett's esophagus (BE) is clinically significant, as it is the only known precursor lesion for esophageal adenocarcinoma. To develop improved therapies for the treatment of BE, a greater understanding of the disease process at the molecular genetic level is needed. However, achieving a greater understanding will require improved preclinical models so that the disease process can be more closely studied and novel therapies can be tested. Our concise review highlights progress in the development of preclinical models for the study of BE and identifies the most suitable model in which to test novel therapies.


Subject(s)
Adenocarcinoma , Barrett Esophagus , Carcinogenesis , Esophageal Neoplasms , Neoplasms, Experimental , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Adenocarcinoma/physiopathology , Animals , Barrett Esophagus/metabolism , Barrett Esophagus/pathology , Barrett Esophagus/physiopathology , Carcinogenesis/metabolism , Carcinogenesis/pathology , Esophageal Neoplasms/metabolism , Esophageal Neoplasms/pathology , Esophageal Neoplasms/physiopathology , Humans , Neoplasms, Experimental/metabolism , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology
12.
J Pediatr Hematol Oncol ; 40(3): 208-215, 2018 04.
Article in English | MEDLINE | ID: mdl-29557918

ABSTRACT

We report the cardioprotective effects of moderate aerobic exercise from parallel pediatric murine models of doxorubicin (Doxo) exposure in non-tumor-bearing immune competent (NTB-IC) mice and tumor-bearing nude mice (TB-NM). In both models, animals at 4 weeks of age underwent Doxo treatment with or without 2 weeks of simultaneous exercise. In sedentary NTB-IC or TB-NM mice, Doxo treatment resulted in a statistically significant decrease in ejection fraction and fractional shortening compared with control animals. Interestingly, moderate aerobic exercise during Doxo treatment significantly mitigated decreases in ejection fraction and fractional shortening. In contrast, these protective effects of exercise were not observed when exercise was started after completion of Doxo treatments. Moreover, in the TB-NM model, Doxo caused a decrease in heart mass: tibia length and in body weight that was prevented by exercise, whereas NTB-IC mice exhibited no change in these measurements. Doxo delivery to the hearts of TB-NM was decreased by consistent moderate aerobic exercise before Doxo injection. These findings demonstrate the important but subtle differences in cardiotoxicity observed in different mouse models. Collectively, these results also strongly suggest that aerobic exercise during early-life Doxo exposure mitigates cardiotoxicity, possibly through altered delivery of Doxo to myocardial tissue.


Subject(s)
Antibiotics, Antineoplastic/toxicity , Cardiotoxicity/physiopathology , Doxorubicin/toxicity , Heart/drug effects , Physical Conditioning, Animal , Animals , Cardiotoxicity/etiology , Cardiotoxicity/prevention & control , Disease Models, Animal , Mice , Mice, Inbred C57BL , Mice, Nude , Neoplasms, Experimental/physiopathology
13.
Biochem Biophys Res Commun ; 493(1): 213-219, 2017 11 04.
Article in English | MEDLINE | ID: mdl-28899783

ABSTRACT

Currently, there are no effective therapeutic strategies targeting Kras driven cancers, and therefore, identifying new targeted therapies and overcoming drug resistance have become paramount for effective long-term cancer therapy. We have found that reducing expression of the palmitoyl transferase DHHC20 increases cell death induced by the EGFR inhibitor gefitinib in Kras and EGFR mutant cell lines, but not MCF7 cells harboring wildtype Kras. We show that the increased gefitinib sensitivity in cancer cells induced by DHHC20 inhibition is mediated directly through loss of palmitoylation on a previously identified cysteine residue in the C-terminal tail of EGFR. We utilized an EGFR point mutant in which the palmitoylated cysteine 1025 is mutated to alanine (EGFRC1025A), that results in receptor activation. Expression of the EGFR mutant alone in NIH3T3 cells does not increase sensitivity to gefitinib-induced cell death. However, when EGFRC1025A is expressed in cells expressing activated KrasG12V, EGFR inhibitor induced cell death is increased. Surprisingly, lung cancer cells harboring the EGFR inhibitor resistant mutation, T790M, become sensitive to EGFR inhibitor treatment when DHHC20 is inhibited. Finally, the small molecule, 2-bromopalmitate, which has been shown to inhibit palmitoyl transferases, acts synergistically with gefitinib to induce cell death in the gefitinib resistant cell line NCI-H1975.


Subject(s)
Cysteine/genetics , ErbB Receptors/antagonists & inhibitors , ErbB Receptors/genetics , Neoplasms, Experimental/physiopathology , Proto-Oncogene Proteins p21(ras)/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Apoptosis/drug effects , Cocarcinogenesis , Cysteine/metabolism , Dose-Response Relationship, Drug , Drug Resistance, Neoplasm , ErbB Receptors/metabolism , Gefitinib , Humans , Lipoylation/drug effects , Lipoylation/genetics , MCF-7 Cells , Membrane Proteins , Mutation , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/metabolism , Proto-Oncogene Proteins p21(ras)/genetics , Quinazolines/administration & dosage , Quinazolines/pharmacology
14.
Radiat Res ; 188(3): 335-341, 2017 09.
Article in English | MEDLINE | ID: mdl-28686544

ABSTRACT

The purpose of this study was to compare the biological effects of fractionated doses versus a single dose of high-LET carbon ions in bystander normal cells, and determine the effect on their progeny using the layered tissue co-culture system. Briefly, confluent human glioblastoma (T98G) cells received a single dose of 6 Gy or three daily doses of 2 Gy carbon ions, which were then seeded on top of an insert with bystander normal skin fibroblasts (NB1RGB) growing underneath. Cells were co-cultured for 6 h or allowed to grow for 20 population doublings, then harvested and assayed for different end points. A single dose of carbon ions resulted in less damage in bystander normal NB1RGB cells than the fractionated doses. In contrast, the progeny of bystander NB1RGB cells co-cultured with T98G cells exposed to fractionated doses showed less damage than progeny from bystander cells co-cultured with single dose glioblastoma cells. Furthermore, inhibition of gap junction communication demonstrated its involvement in the stressful effects in bystander cells and their progeny. These results indicate that dose fractionation reduced the late effect of carbon-ion exposure in the progeny of bystander cells compared to the effect in the initial bystander cells.


Subject(s)
Bystander Effect/physiology , Bystander Effect/radiation effects , Cell Survival/radiation effects , Dose Fractionation, Radiation , Fibroblasts/radiation effects , Neoplasms, Experimental/radiotherapy , Cell Line , Cell Survival/physiology , Dose-Response Relationship, Radiation , Fibroblasts/cytology , Fibroblasts/physiology , Heavy Ion Radiotherapy/methods , Humans , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Treatment Outcome
15.
Adv Healthc Mater ; 6(15)2017 Aug.
Article in English | MEDLINE | ID: mdl-28544639

ABSTRACT

The "Tumor microenvironment" (TME) is a complex, interacting system of the tumor and its surrounding environment. The TME has drawn more attention recently in attempts to overcome current drug resistance and the recurrence of cancer by understanding the cancer and its microenvironment systematically, beyond past reductionist approaches. However, a lack of experimental tools to dissect the intricate interactions has hampered in-depth research into the TME. Here, a biomimetic TME model using a microfluidic platform is presented, which enables the interaction between TME constituents to be studied in a comprehensive manner. Paracrine interactions of cocultured tumor cell lines (SK-OV-3, MKN-74, and SW620) with primary fibroblasts show marked morphological changes in the tumor cells, depending on the type of tumor cells, and, importantly, the composition of the extracellular matrix. Furthermore, this model allows direct observation of angiogenesis induced by the tumor-stroma interaction. Finally, reconstituting simultaneous angiogenesis and lymphangiogenesis induced by the tumor-stromal interaction with TME mimicking extrinsic factors is enabled. It is believed that the in vitro biomimetic model and the experimental concepts described will help to shed light on the complex biology of the TME.


Subject(s)
Batch Cell Culture Techniques/instrumentation , Biomimetic Materials/chemistry , Lab-On-A-Chip Devices , Neoplasms, Experimental/chemistry , Neoplasms, Experimental/physiopathology , Tissue Engineering/instrumentation , Tumor Microenvironment , Batch Cell Culture Techniques/methods , Cell Line, Tumor , Equipment Design , Equipment Failure Analysis , Humans , Materials Testing , Neoplasms, Experimental/pathology , Tissue Engineering/methods
16.
Adv Healthc Mater ; 6(15)2017 Aug.
Article in English | MEDLINE | ID: mdl-28471542

ABSTRACT

The efficient recognition and isolation of rare cancer cells holds great promise for cancer diagnosis and prognosis. In nature, pollens exploit spiky structures to realize recognition and adhesion to stigma. Herein, a bioinspired pollen-like hierarchical surface is developed by replicating the assembly of pollen grains, and efficient and specific recognition to target cancer cells is achieved. The pollen-like surface is fabricated by combining filtering-assisted assembly and soft lithography-based replication of pollen grains of wild chrysanthemum. After modification with a capture agent specific to cancer cells, the pollen-like surface enables the capture of target cancer cells with high efficiency and specificity. In addition, the pollen-like surface not only assures high viability of captured cells but also performs well in cell mixture system and at low cell density. This study represents a good example of constructing cell recognition biointerfaces inspired by pollen-stigma adhesion.


Subject(s)
Biomimetic Materials/chemistry , Cell Adhesion , Cell Separation/methods , Neoplasms, Experimental/pathology , Neoplasms, Experimental/physiopathology , Pollen/chemistry , Pollen/ultrastructure , Cell Line, Tumor , Humans , Materials Testing , Surface Properties
17.
Biotechnol Bioeng ; 114(8): 1865-1877, 2017 08.
Article in English | MEDLINE | ID: mdl-28369747

ABSTRACT

Angiogenesis marks the transformation of a benign local tumor into a life-threatening disease. Many in vitro assays are available on two-dimensional (2D) platforms, however, limited research has been conducted to investigate the behavior of tumors and endothelial cells (ECs) grown on three-dimensional (3D) platforms. This study provides a 3D co-culture spheroid of tumor cells with ECs to study the interplay between ECs and tumor cells. In a 3D co-culture with HepG2 hepatocellular carcinoma (HCC) cells, ECs differentiate to form tubule networks when in co-culture. Addition of angiogenic factors or angiogenesis inhibitors to the model system enhanced or inhibited endothelial differentiation in the 3D model, enabling investigations of the cellular signaling pathways utilized in HCC development. The 3D model demonstrated similar protein expression levels as a HCC xenograft, as well as exhibited upregulation of essential signaling proteins such as Akt/mTor in the 3D model, which is not reflected in the 2D model. The effects of several anti-angiogenic agents, such as sorafenib, sunitinib, and axitinib were analyzed in the 3D co-culture model by utilizing fluorescent proteins and a fluorescence resonance energy transfer (FRET)-based caspase-3 sensor in the ECs, which can detect apoptosis in real time. The apoptotic capability of a drug to inhibit angiogenesis in the 3D model can be easily distinguished via the FRET sensor, and dual screening of anti-angiogenesis and anti-tumor drugs can be achieved in a single step via the 3D co-culture model. In summary, a 3D co-culture model is constructed, where a HCC tumor microenvironment with a hypoxic core and true gradient penetration of drugs is achieved for drug screening purposes and in vitro studies utilizing a small HCC tumor. Biotechnol. Bioeng. 2017;114: 1865-1877. © 2017 Wiley Periodicals, Inc.


Subject(s)
Cell Proliferation , Coculture Techniques/methods , Endothelial Cells/pathology , Neoplasms, Experimental/pathology , Neovascularization, Pathologic/pathology , Tissue Engineering/methods , Cell Differentiation , Coculture Techniques/instrumentation , Hep G2 Cells , Humans , Neoplasms, Experimental/physiopathology , Neovascularization, Pathologic/physiopathology , Spheroids, Cellular/pathology , Tissue Engineering/instrumentation , Tumor Cells, Cultured
18.
J R Soc Interface ; 14(128)2017 03.
Article in English | MEDLINE | ID: mdl-28330985

ABSTRACT

While gliomas have been extensively modelled with a reaction-diffusion (RD) type equation it is most likely an oversimplification. In this study, three mathematical models of glioma growth are developed and systematically investigated to establish a framework for accurate prediction of changes in tumour volume as well as intra-tumoural heterogeneity. Tumour cell movement was described by coupling movement to tissue stress, leading to a mechanically coupled (MC) RD model. Intra-tumour heterogeneity was described by including a voxel-specific carrying capacity (CC) to the RD model. The MC and CC models were also combined in a third model. To evaluate these models, rats (n = 14) with C6 gliomas were imaged with diffusion-weighted magnetic resonance imaging over 10 days to estimate tumour cellularity. Model parameters were estimated from the first three imaging time points and then used to predict tumour growth at the remaining time points which were then directly compared to experimental data. The results in this work demonstrate that mechanical-biological effects are a necessary component of brain tissue tumour modelling efforts. The results are suggestive that a variable tissue carrying capacity is a needed model component to capture tumour heterogeneity. Lastly, the results advocate the need for additional effort towards capturing tumour-to-tissue infiltration.


Subject(s)
Brain Neoplasms , Glioma , Magnetic Resonance Imaging , Models, Biological , Animals , Brain Neoplasms/diagnostic imaging , Brain Neoplasms/physiopathology , Female , Glioma/diagnostic imaging , Glioma/physiopathology , Neoplasms, Experimental/diagnostic imaging , Neoplasms, Experimental/physiopathology , Rats , Rats, Wistar
19.
PLoS One ; 12(2): e0171559, 2017.
Article in English | MEDLINE | ID: mdl-28222111

ABSTRACT

BACKGROUND: Preclinical in vivo studies using small animals are considered crucial in translational cancer research and clinical implementation of novel treatments. This is of paramount relevance in radiobiology, especially for any technological developments permitted to deliver high doses in single or oligo-fractionated regimens, such as stereotactic ablative radiotherapy (SABR). In this context, clinical success in cancer treatment needs to be guaranteed, sparing normal tissue and preventing the potential spread of disease or local recurrence. In this work we introduce a new dose-response relationship based on relevant publications concerning preclinical models with regard to delivered dose, fractionation schedule and occurrence of biological effects on non-irradiated tissue, abscopal effects. METHODS: We reviewed relevant publications on murine models and the abscopal effect in radiation cancer research following PRISMA methodology. In particular, through a log-likelihood method, we evaluated whether the occurrence of abscopal effects may be related to the biologically effective dose (BED). To this aim, studies accomplished with different tumor histotypes were considered in our analysis including breast, colon, lung, fibrosarcoma, pancreas, melanoma and head and neck cancer. For all the tumors, the α / ß ratio was assumed to be 10 Gy, as generally adopted for neoplastic cells. RESULTS: Our results support the hypothesis that the occurrence rate of abscopal effects in preclinical models increases with BED. In particular, the probability of revealing abscopal effects is 50% when a BED of 60 Gy is generated. CONCLUSION: Our study provides evidence that SABR treatments associated with high BEDs could be considered an effective strategy in triggering the abscopal effect, thus shedding light on the promising outcomes revealed in clinical practice.


Subject(s)
Neoplasm Metastasis/radiotherapy , Neoplasms, Experimental/radiotherapy , Radiosurgery , Animals , Combined Modality Therapy , Dose Fractionation, Radiation , Dose-Response Relationship, Radiation , Female , Immunotherapy , Likelihood Functions , Male , Mice , Neoplasm Metastasis/physiopathology , Neoplasms, Experimental/physiopathology , Neoplasms, Experimental/therapy , Radiotherapy Dosage , Research Design , Tumor Burden
20.
Gen Physiol Biophys ; 36(2): 187-196, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28150586

ABSTRACT

Selenium and palladium containing compounds separately exert multifunctional effects on cells. While selenium containing compounds usually exert antioxidative properties, palladium(II) containing compounds are cytotoxic and prooxidative. Here we investigated biological effects of bicyclic seleno-hydantoin cis-7a-ethyl-5-methyl-5-phenylselanylmethyl-tetrahydro-pyrrolo[1,2-c]imidazole-1,3-dione (Hid-Se), and its palladium(II) complex, trans-bis-(cis-7a-ethyl-5-methyl-5-phenylselanylmethyl-tetrahydro-pyrrolo[1,2-c]imidazole-1,3-dionato) palladium(II) chloride ((Hid-Se)2Pd) on human colon HCT-116 and breast MDA-MB-231 cancer cell lines. Hid-Se and (Hid-Se)2Pd showed prooxidative and cytotoxic character. In all performed experiments (Hid-Se)2Pd proved to be more active, i.e. this substance exerted greater prooxidative effect, cytotoxicity and influence on cell migration potential. Even though Hid-Se and (Hid-Se)2Pd enhanced migration of HCT-116 cells, very important feature of these substances is the strong antimigratory potential on metastatic MDA-MB-231 cells.


Subject(s)
Cell Movement/drug effects , Cell Survival/drug effects , Neoplasms, Experimental/drug therapy , Neoplasms, Experimental/physiopathology , Palladium/administration & dosage , Selenium/administration & dosage , Antineoplastic Agents/administration & dosage , Dose-Response Relationship, Drug , Drug Compounding/methods , HCT116 Cells , Humans , Hydantoins/chemistry , Neoplasms, Experimental/pathology , Oxidants/administration & dosage , Palladium/chemistry , Reactive Oxygen Species/metabolism , Selenium/chemistry , Treatment Outcome
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