Glioblastoma multiforme (GBM) is a common and aggressive malignant brain cancer with a mean survival time of approximately 15 months after initial diagnosis. Currently, the standard-of-care (SOC) ...treatment for this disease consists of radiotherapy (RT) with concomitant and adjuvant temozolomide (TMZ). We sought to develop an orthotopic preclinical model of GBM and to optimize a protocol for non-invasive monitoring of tumor growth, allowing for determination of the efficacy of SOC therapy using a targeted RT strategy combined with TMZ. A strong correlation (r = 0.80) was observed between contrast-enhanced (CE)-CT-based volume quantification and bioluminescent (BLI)-integrated image intensity when monitoring tumor growth, allowing for BLI imaging as a substitute for CE-CT. An optimized parallel-opposed single-angle RT beam plan delivered on average 96% of the expected RT dose (20, 30 or 60 Gy) to the tumor. Normal tissue on the ipsilateral and contralateral sides of the brain were spared 84% and 99% of the expected dose, respectively. An increase in median survival time was demonstrated for all SOC regimens compared to untreated controls (average 5.2 days, p < 0.05), but treatment was not curative, suggesting the need for novel treatment options to increase therapeutic efficacy.
Cancer is the second leading cause of death worldwide and the global cancer burden rises rapidly. The risk factors for cancer development can often be attributed to lifestyle factors, of which an ...unhealthy diet is a major contributor. Dietary fat is an important macronutrient and therefore a crucial part of a well-balanced and healthy diet, but it is still unclear which specific fatty acids contribute to a healthy and well-balanced diet in the context of cancer risk and prognosis. In this review, we describe epidemiological evidence on the associations between the intake of different classes of fatty acids and the risk of developing cancer, and we provide preclinical evidence on how specific fatty acids can act on tumor cells, thereby modulating tumor progression and metastasis. Moreover, the pro- and anti-inflammatory effects of each of the different groups of fatty acids will be discussed specifically in the context of inflammation-induced cancer progression and we will highlight challenges as well as opportunities for successful application of fatty acid tailored nutritional interventions in the clinic.
Non-alcoholic steatohepatitis (NASH) is characterized by liver steatosis and inflammation. Currently, the underlying mechanisms leading to hepatic inflammation are not fully understood and ...consequently, therapeutic options are poor. Non-alcoholic steatohepatitis (NASH) and atherosclerosis share the same etiology whereby macrophages play a key role in disease progression. Macrophage function can be modulated via activation of receptor-ligand binding of Notch signaling. Relevantly, global inhibition of Notch ligand Delta-Like Ligand-4 (DLL4) attenuates atherosclerosis by altering the macrophage-mediated inflammatory response. However, the specific contribution of macrophage DLL4 to hepatic inflammation is currently unknown. We hypothesized that myeloid DLL4 deficiency in low-density lipoprotein receptor knock-out (Ldlr-/-) mice reduces hepatic inflammation. Irradiated Ldlr-/- mice were transplanted (tp) with bone marrow from wild type (Wt) or DLL4f/fLysMCre+/0 (DLL4del) mice and fed either chow or high fat, high cholesterol (HFC) diet for 11 weeks. Additionally, gene expression was assessed in bone marrow-derived macrophages (BMDM) of DLL4f/fLysMCreWT and DLL4f/fLysMCre+/0 mice. In contrast to our hypothesis, inflammation was not decreased in HFC-fed DLL4del-transplanted mice. In line, in vitro, there was no difference in the expression of inflammatory genes between DLL4-deficient and wildtype bone marrow-derived macrophages. These results suggest that myeloid DLL4 deficiency does not contribute to hepatic inflammation in vivo. Since, macrophage-DLL4 expression in our model was not completely suppressed, it can't be totally excluded that complete DLL4 deletion in macrophages might lead to different results. Nevertheless, the contribution of non-myeloid Kupffer cells to notch signaling with regard to the pathogenesis of steatohepatitis is unknown and as such it is possible that, DLL4 on Kupffer cells promote the pathogenesis of steatohepatitis.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Small animal models are crucial to link molecular discoveries and implementation
of clinically relevant therapeutics in oncology. Using these models requires
noninvasive imaging techniques to monitor ...disease progression and therapy
response. Micro–computed tomography (CT) is less studied for the in vivo
monitoring of murine intracranial tumors and traditionally suffers from poor
soft tissue contrast, whereas bioluminescence imaging (BLI) is known for its
sensitivity but is not frequently employed for quantifying tumor volume. A
widely used orthotopic glioblastoma multiforme (GBM) tumor model was applied in
nude mice, and tumor growth was evaluated by BLI and contrast-enhanced microCT
imaging. A strong correlation was observed between CT volume and BLI-integrated
intensity (Pearson coefficient (r) = .85, p =
.0002). Repeated contouring of contrast-enhanced microCT-delineated tumor
volumes achieved an intraobserver average pairwise overlap ratio of 0.84 and an
average tumor volume coefficient of variance of 0.11. MicroCT-delineated tumor
size was found to correlate with tumor size obtained via histologic analysis
(Pearson coefficient (r) = .88, p = .005). We
conclude that BLI intensity can be used to derive tumor volume but that the use
of both contrast-enhanced microCT and BLI provides complementary tumor growth
information, which is particularly useful for modern small animal irradiation
devices that make use of microCT and BLI for treatment planning, targeting, and
monitoring.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To increase the potential of attenuated Salmonella as gene delivery vectors for cancer treatment, we developed a hypoxia-inducible promoter system to limit gene expression specifically to the tumor. ...This approach is envisaged to not only increase tumor specificity, but also to target those cells that are most resistant to conventional therapies. We demonstrate that the exponential growth of the attenuated bacteria is identical under normoxia and hypoxia. A hypoxia-inducible promoter (HIP-1) was created from a portion of the endogenous Salmonella pepT promoter and was shown to drive reporter gene expression under both acute and chronic hypoxia, but not under normoxia. Genetic engineering of the TATA- and FNR-box within HIP-1 allowed fine tuning of gene induction, resulting in hypoxic induction factors of up to 200-fold. Finally, we demonstrate that HIP-1 can drive hypoxia-mediated gene expression in bacteria which have colonized human tumor xenografts in mouse models. Expression of both GFP and RFP under control of HIP-1 demonstrated an ~15-fold increase relative to a constitutive promoter when tumors were made hypoxic. Moreover, the use of a constitutive promoter resulted in reporter gene expression in both tumors and normal tissues, whereas reporter gene expressing using HIP-1 was confined to the tumor.
Abstract Background Percutaneous radiotherapy (RT) may cause a range of acute and late side effects of the skin within the irradiated area. In rare cases radiotherapy can cause bullous pemphigoid ...(BP). BP is reported to occur mainly within irradiated fields following radiation treatment. Exceptionally, BP may arise during RT. It is unclear which mechanism exactly triggers BP following megavoltage irradiation and whether there is a potential association with hormonal anticancer treatment. Methods A systematic literature based review was performed. Publications reporting histologically confirmed BP and a treatment with RT were retrieved based on a standardized query using electronic databases. A standardized quality assessment was applied. Results Out of 306 potentially relevant publications 21 were identified to be relevant and included in this review. An association between RT and BP was reported in 27 patients. The majority developed BP after RT and a median dose of 50 Gy. Four patients developed BP during RT after a minimal dose of 20 Gy. Conclusions BP induced by RT was observed predominantly in patients with breast cancer. In all reported cases, there is a clear relationship with RT. Therefore, BP may be considered as RT-induced side effect. RT can induce a BP following a minimal dose of 20 Gy. New biological agents may play a role in the future treatment of BP.
Low profile high value target: The role of OxLDL in cancer Bitorina, Albert V.; Oligschlaeger, Yvonne; Shiri-Sverdlov, Ronit ...
Biochimica et biophysica acta. Molecular and cell biology of lipids,
December 2019, 2019-12-00, Letnik:
1864, Številka:
12
Journal Article
Recenzirano
Odprti dostop
Unhealthy Western-type diet and physical inactivity are highly associated with the current obesity epidemic and its related metabolic diseases such as atherosclerosis and non-alcoholic ...steatohepatitis. In addition, increasing evidence indicates that obesity is also a major risk factor for several types of common cancers. Recent studies have provided correlative support that disturbed lipid metabolism plays a role in cancer risk and development, pointing towards parallels in metabolic derangements between metabolic diseases and cancer. An important feature of disturbed lipid metabolism is the increase in circulating low-density lipoproteins, which can be oxidized (oxLDL). Elevated oxLDL and the level of its receptors have been positively associated with increased risk of various types of cancer. This review discusses the pro-oncogenic role of oxLDL in tumor development, progression and potential therapies, and provides insights into the underlying mechanisms.
•OxLDL is a key metabolic link between obesity and cancer•OxLDL is an inducer of carcinogenesis•OxLDL promotes cancer proliferation, stimulates epithelial-to-mesenchymal transition and metastasis•OxLDL adversely affects chemosensitivity•OxLDL and its receptors are promising targets in cancer treatment
In their paper "Intratumoral injection of Clostridium novyi-NT spores induces antitumor responses", Roberts et al. describe the induction of antitumor responses following local spore administration ...of an attenuated C. novyi strain (C. novyi-NT). Stereotactic intratumoral spore injection led to significant survival advantages in a murine orthotopic brain model and local bacterial treatment produced robust responses in a set of spontaneous canine soft tissue carcinomas. Their preclinical findings in both models, provided the basis for a phase 1 investigational clinical study in patients with solid tumors that were either refractory to standard treatment or without an available standard treatment available (NCT01924689). The results of the first patient enrolled in this trial, a 53-year-old female with a retroperitoneal leiomyosarcoma, are described. Next to the non-armed C. novyi-NT described in this paper, very potent genetically modified Clostridium expressing anti-cancer therapeutic genes are also being developed. Are treatments with these non-pathogenic clostridia a viable alternative cancer treatment?
Summary
Coronaviruses are constantly circulating in humans, causing common colds and mild respiratory infections. In contrast, infection with the novel severe acute respiratory syndrome coronavirus 2 ...(SARS‐CoV‐2), responsible for coronavirus disease‐2019 (COVID‐19), can cause additional severe complications, particularly in patients with obesity and associated metabolic disturbances. Obesity is a principal causative factor in the development of the metabolic syndrome; a series of physiological, biochemical, clinical, and metabolic factors that increase the risk of obesity‐associated diseases. “Metabolically unhealthy” obesity is, in addition to metabolic disturbances, also associated with immunological disturbances. As such, patients with obesity are more prone to develop serious complications from infections, including those from SARS‐CoV‐2. In this review, we first describe how obesity and related metabolic disturbances increase the risk of SARS‐CoV‐2 infection. Then, mechanisms contributing to COVID‐19 complications and poor prognosis in these patients are discussed. Finally, we discuss how obesity potentially reduces long‐term COVID‐19 vaccination efficacy. Despite encouraging COVID‐19 vaccination results in patients with obesity and related metabolic disturbances in the short‐term, it is becoming increasingly evident that long‐term COVID‐19 vaccination efficacy should be closely monitored in this vulnerable group.
Abstract Background and purpose Hypoxia is a hallmark of solid cancers and associated with metastases and treatment failure. During tumor progression epithelial cells often acquire mesenchymal ...features, a phenomenon known as epithelial-to-mesenchymal transition (EMT). Intratumoral hypoxia has been linked to EMT induction. We hypothesized that signals from the tumor microenvironment such as growth factors and tumor oxygenation collaborate to promote EMT and thereby contribute to radioresistance. Materials and methods Gene expression changes under hypoxia were analyzed using microarray and validated by qRT-PCR. Conversion of epithelial phenotype upon hypoxic exposure, TGFβ addition or oncogene activation was investigated by Western blot and immunofluorescence. Cell survival following ionizing radiation was assayed using clonogenic survival. Results Upon hypoxia, TGFβ addition or EGFRvIII expression, MCF7, A549 and NMuMG epithelial cells acquired a spindle shape and lost cell–cell contacts. Expression of epithelial markers such as E-cadherin decreased, whereas mesenchymal markers such as vimentin and N-cadherin increased. Combining hypoxia with TGFβ or EGFRvIII expression, lead to more rapid and pronounced EMT-like phenotype. Interestingly, E-cadherin expression and the mesenchymal appearance were reversible upon reoxygenation. Mesenchymal conversion and E-cadherin loss were associated with radioresistance. Conclusions Our findings describe a mechanism by which the tumor microenvironment may contribute to tumor radioresistance via E-cadherin loss and EMT.
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