scholarly journals Necrotic debris and STING exert therapeutically relevant effects on tumor cholesterol homeostasis

2022 ◽  
Vol 5 (3) ◽  
pp. e202101256
Author(s):  
Sampath Katakam ◽  
Santosh Anand ◽  
Patricia Martin ◽  
Nicolo Riggi ◽  
Ivan Stamenkovic

Malignant tumors commonly display necrosis, which invariably triggers an inflammatory response that supports tumor growth. However, the effect on tumor cells of necrotic debris, or damage-associated molecular patterns (DAMPs) released by dying cells is unknown. Here, we addressed the effect of DAMPs on primary Ewing sarcoma (EwS) cells and cell lines grown in 3D (spheroids) and 2D culture. We show that DAMPs promote the growth of EwS spheroids but not 2D cultures and that the underlying mechanism implicates an increase in cholesterol load in spheroids. In contrast, stimulation of the nucleic acid sensor signaling platform STING by its ligand cyclic GMP-AMP decreases the tumor cell cholesterol load and reduces their tumor initiating ability. Overexpression of STING or stimulation with cyclic GMP-AMP opposes the growth stimulatory effect of DAMPs and synergizes with the cholesterol synthesis inhibitor simvastatin to inhibit tumor growth. Our observations show that modulation of cholesterol homeostasis is a major effect of necrotic cell debris and STING and suggest that combining STING agonists with statins may help control tumor growth.

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Linnan Yang ◽  
Feng Li ◽  
Yongsheng Cao ◽  
Qiang Liu ◽  
Guoxin Jing ◽  
...  

AbstractThe tumor immune microenvironment (TIME) has been demonstrated to be the main cause of cancer immunotherapy failure in various malignant tumors, due to poor immunogenicity and existence of immunosuppressive factors. Thus, establishing effective treatments for hostile TIME remodeling has considerable potential to enhance immune response rates for durable tumor growth retardation. This study aims to develop a novel nanocomposite, polyethyleneimine-modified dendritic mesoporous silica nanoparticles loaded with microRNA-125a (DMSN-PEI@125a) to synergistically enhance immune response and immunosuppression reversion, ultimately generating a tumoricidal environment. Our results showed that DMSN-PEI@125a exhibited excellent ability in cellular uptake by murine macrophages and the cervical cancer cell line TC-1, repolarization of tumor associated macrophages (TAMs) to M1 type in a synergistic manner, and promotion of TC-1 immunogenic death. Intratumor injection of DMSN-PEI@125a facilitated the release of more damage-related molecular patterns and enhanced the infiltration of natural killer and CD8+ T cells. Meanwhile, repolarized TAMs could function as a helper to promote antitumor immunity, thus inhibiting tumor growth in TC-1 mouse models in a collaborative manner. Collectively, this work highlights the multifunctional roles of DMSN-PEI@125a in generating an inflammatory TIME and provoking antitumor immunity, which may serve as a potential agent for cancer immunotherapy.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 555
Author(s):  
Soyoung Hur ◽  
Eungyeong Jang ◽  
Jang-Hoon Lee

Tumors are one of the most life-threatening diseases, and a variety of cancer treatment options have been continuously introduced in order to overcome cancer and improve conventional therapy. Orostachys japonica (O. japonica), which is a perennial plant belonging to the genus Orostachys of the Crassulaceae family, has been revealed to exhibit pharmacological properties against various tumors in numerous studies. The present review aimed to discuss the biological actions and underlying molecular mechanisms of O. japonica and its representative compounds—kaempferol and quercetin—against tumors. O. japonica reportedly has antiproliferative, anti-angiogenic, and antimetastatic activities against various types of malignant tumors through the induction of apoptosis and cell cycle arrest, a blockade of downstream vascular endothelial growth factor (VEGF)-VEGFR2 pathways, and the regulation of epithelial-to-mesenchymal transition. In addition, emerging studies have highlighted the antitumor efficacy of kaempferol and quercetin. Interestingly, it was found that alterations of the mitogen-activated protein kinase (MAPK) signaling cascades are involved in the pivotal mechanisms of the antitumor effects of O. japonica and its two compounds against cancer cell overgrowth, angiogenesis, and metastasis. In summary, O. japonica could be considered a preventive and therapeutic medicinal plant which exhibits antitumor actions by reversing altered patterns of MAPK cascades, and kaempferol and quercetin might be potential components that can contribute to the efficacy and underlying mechanism of O. japonica.


2021 ◽  
Vol 22 (3) ◽  
pp. 1407
Author(s):  
Hongxia Liu ◽  
Wang Zheng ◽  
Qianping Chen ◽  
Yuchuan Zhou ◽  
Yan Pan ◽  
...  

Nasopharyngeal carcinoma (NPC) is one of the most frequent head and neck malignant tumors and is majorly treated by radiotherapy. However, radiation resistance remains a serious obstacle to the successful treatment of NPC. The aim of this study was to discover the underlying mechanism of radioresistance and to elucidate novel genes that may play important roles in the regulation of NPC radiosensitivity. By using RNA-seq analysis of NPC cell line CNE2 and its radioresistant cell line CNE2R, lncRNA CASC19 was screened out as a candidate radioresistance marker. Both in vitro and in vivo data demonstrated that a high expression level of CASC19 was positively correlated with the radioresistance of NPC, and the radiosensitivity of NPC cells was considerably enhanced by knockdown of CASC19. The incidence of autophagy was enhanced in CNE2R in comparison with CNE2 and another NPC cell line HONE1, and silencing autophagy with LC3 siRNA (siLC3) sensitized NPC cells to irradiation. Furthermore, CASC19 siRNA (siCASC19) suppressed cellular autophagy by inhibiting the AMPK/mTOR pathway and promoted apoptosis through the PARP1 pathway. Our results revealed for the first time that lncRNA CASC19 contributed to the radioresistance of NPC by regulating autophagy. In significance, CASC19 might be a potential molecular biomarker and a new therapeutic target in NPC.


2021 ◽  
Vol 9 (12) ◽  
pp. e003495
Author(s):  
Laura A Mittmann ◽  
Florian Haring ◽  
Johanna B Schaubächer ◽  
Roman Hennel ◽  
Bojan Smiljanov ◽  
...  

BackgroundBeyond their fundamental role in homeostasis and host defense, neutrophilic granulocytes (neutrophils) are increasingly recognized to contribute to the pathogenesis of malignant tumors. Recently, aging of mature neutrophils in the systemic circulation has been identified to be critical for these immune cells to properly unfold their homeostatic and anti-infectious functional properties. The role of neutrophil aging in cancer remains largely obscure.MethodsEmploying advanced in vivo microscopy techniques in different animal models of cancer as well as utilizing pulse-labeling and cell transfer approaches, various ex vivo/in vitro assays, and human data, we sought to define the functional relevance of neutrophil aging in cancer.ResultsHere, we show that signals released during early tumor growth accelerate biological aging of circulating neutrophils, hence uncoupling biological from chronological aging of these immune cells. This facilitates the accumulation of highly reactive neutrophils in malignant lesions and endows them with potent protumorigenic functions, thus promoting tumor progression. Counteracting uncoupled biological aging of circulating neutrophils by blocking the chemokine receptor CXCR2 effectively suppressed tumor growth.ConclusionsOur data uncover a self-sustaining mechanism of malignant neoplasms in fostering protumorigenic phenotypic and functional changes in circulating neutrophils. Interference with this aberrant process might therefore provide a novel, already pharmacologically targetable strategy for cancer immunotherapy.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e15011-e15011
Author(s):  
A. V. Volkova ◽  
Rostorguev Eduard Evgenievich ◽  
Anna S. Goncharova ◽  
M. V. Mindar ◽  
Ekaterina V. Zaikina ◽  
...  

e15011 Background: Poor clinical effects of standard treatment for glioblastoma determine the need for the development of new therapeutic strategies. Aberrant functioning of the proteasome system, as well as activation of the HIF-1α signaling pathway, are characteristic of glial tumor cells; they can be considered as potential therapeutic targets in the treatment of malignant brain tumors. One of the possible options for improving the results of glioblastoma treatment may involve strategies for inhibiting the HIF-1α pathway. Bortezomib, a proteasome inhibitor, can block the biological effects of HIF-1α. Bortezomib showed a pronounced antitumor effect in in vitro testing on various models of solid malignant tumors, giving grounds for further studies of its effectiveness in vivo. Patient-derived xenograft (PDX) models are characterized by a variety of cell subclones and are therefore considered the most reliable tool for predicting therapeutic responses. Methods: A PDX model of glioblastoma was created in 20 Balb/c Nude mice implanted with a subcutaneously inoculated human glioblastoma. Temozolomide (0.5 mg/kg), bortezomib (0.25 mg/kg), or a combination of temozolomide and bortezomib were administered intraperitoneally daily for 21 days. The tumor histotype was confirmed by histological analysis (staining with hematoxylin and eosin). The antitumor effect was determined by the inhibition of tumor growth (ITG%), the volume of tumor nodes, and the index of tumor growth. Results: The highest value of the inhibition of tumor growth (ITG%) was registered in the group of animals receiving a combination of temozolomide and bortezomib – 85.38%. The values in the groups receiving temozolomide or bortezomib monotherapy were 57.32% and 63.11%, respectively. Conclusions: An analysis of the antitumor efficacy of bortezomib combined with temozolomide in human subcutaneous PDX-glioblastomas demonstrated their synergistic effect.


2020 ◽  
Author(s):  
Licheng Du ◽  
Fenghua Kong ◽  
Qing Yang ◽  
Yaqiong Li ◽  
Peikai Ding ◽  
...  

Abstract Background:Lymphogenous metastasis, one of the most common dissemination routes for ovarian carcinoma, predicts a poor prognosis and relates to most cancer-related death. Now there were no effective therapy and control methods for ovarian carcinoma. Hence, it is necessary to build an animal model of lymph node metastasis in ovarian cancer to seek for the tools to find effective treatments. Our purpose of this study was to investigate the tumor cell dissemination of ovarian carcinoma to the gradient lymph nodes of nude mice and its possible mechanism. Methods: The mice models of VEGF-D over-expressed were built and the tumor growth and sentinel lymph nodes were evaluated weekly, while the visible lymph nodes and tumor masses were excised for histological examination using HE examination. Then Evan’s Blue was conducted to observe the unveil lymphatic network. Subsequently, immunohistochemistry was performed to check the expression of relative genes. Meanwhile, microvessel counting was performed within the tumor tissues and measured using computer assisted morphometric analysis.Results: The over-expression of VEGF-D promoted the tumor growth of ovarian carcinoma, facilitated the hyperplasia of tumor lymphatic and increased the intratumoral lymphatic vessel density. Besides, the up-regulation of VEGF-D induced the expression of MMP-2, which might be the underlying mechanism for the lymph metastasis in ovarian cancer. Conclusion: It was a step-by-step progression from the inoculation of cancer cells, to the proliferation of the primary tumors, and then to the lymphatic metastases, in which VEGF-D and MMP-2 played vital roles.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chaoyun Pan ◽  
JiHoon Kang ◽  
Jung Seok Hwang ◽  
Jie Li ◽  
Austin C. Boese ◽  
...  

AbstractAgonists of glucocorticoid receptor (GR) are frequently given to cancer patients with platinum-containing chemotherapy to reduce inflammation, but how GR influences tumor growth in response to platinum-based chemotherapy such as cisplatin through inflammation-independent signaling remains largely unclear. Combined genomics and transcription factor profiling reveal that MAST1, a critical platinum resistance factor that reprograms the MAPK pathway, is upregulated upon cisplatin exposure through activated transcription factor GR. Mechanistically, cisplatin binds to C622 in GR and recruits GR to the nucleus for its activation, which induces MAST1 expression and consequently reactivates MEK signaling. GR nuclear translocation and MAST1 upregulation coordinately occur in patient tumors collected after platinum treatment, and align with patient treatment resistance. Co-treatment with dexamethasone and cisplatin restores cisplatin-resistant tumor growth, whereas addition of the MAST1 inhibitor lestaurtinib abrogates tumor growth while preserving the inhibitory effect of dexamethasone on inflammation in vivo. These findings not only provide insights into the underlying mechanism of GR in cisplatin resistance but also offer an effective alternative therapeutic strategy to improve the clinical outcome of patients receiving platinum-based chemotherapy with GR agonists.


2019 ◽  
Vol 18 ◽  
pp. 153473541984513 ◽  
Author(s):  
Masatoshi Kusuhara ◽  
Koji Maruyama ◽  
Hidee Ishii ◽  
Yoko Masuda ◽  
Kazutoshi Sakurai ◽  
...  

The environment is thought to affect outcomes in patients with cancer; however, this relationship has not been proven directly. Recently, an enriched environment, as a model of a positive environment, has been shown to suppress tumor growth by lowering leptin production through a pathway involving the hypothalamus/sympathetic nerve/leptin axis. We previously reported that a fragrant environment (FE) containing α-pinene suppressed tumor growth in mice; however, the underlying mechanism has not been elucidated. Accordingly, in this study, we investigated changes in the neuroendocrine and immune systems following exposure to an FE. Mice were exposed to α-pinene (5 h/day) for 4 weeks prior to tumor implantation with murine melanoma cells and 3 weeks after transplantation. In addition to the evaluation of tumor growth, the blood, spleen, and hypothalamus were collected 3 weeks after transplantation, and neuroendocrinological and immunological parameters were measured. Tumor size was ~40% smaller in mice exposed to FE. Moreover, plasma noradrenaline concentrations, which reflected sympathetic nervous activity, tended to increase, and leptin levels were significantly decreased in FE-exposed mice. Levels of stress hormones, such as plasma corticosterone and adrenaline, did not change in the 2 groups. In the hypothalamus, brain-derived neurotrophic factor protein levels and glucose-1-phosphate concentrations were decreased in the FE group. Additionally, numbers of B cells, CD4+ T cells, CD8+ T cells, and natural killer cells increased in the FE-exposed mice. These neurohormonal and immunological changes in the FE-exposed mice suggested that the FE may activate the hypothalamus/sympathetic nerve/leptin axis and immune system, thereby retarding tumor growth.


2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Ying Zheng ◽  
Bowen Zheng ◽  
Xue Meng ◽  
Yuwen Yan ◽  
Jia He ◽  
...  

Abstract Background Tongue squamous cell carcinoma (TSCC) is a most invasive cancer with high mortality and poor prognosis. It is reported that lncRNA DANCR has implications in multiple types of cancers. However, its biological role and underlying mechanism in TSCC progress are not well elucidated. Methods Our present study first investigated the function of DANCR on the proliferation, migration and invasion of TSCC cells by silencing or overexpressing DANCR. Further, the miR-135a-5p-Kruppel-like Factor 8 (KLF8) axis was focused on to explore the regulatory mechanism of DANCR on TSCC cell malignant phenotypes. Xenografted tumor growth using nude mice was performed to examine the role of DANCR in vivo. Results DANCR knockdown reduced the viability and inhibited the migration and invasion of TSCC cells in vitro, while ectopic expression of DANCR induced opposite effects. In vivo, the tumor growth and the expression of matrix metalloproteinase (MMP)-2/9 and KLF8 were also blocked by DANCR inhibition. In addition, we found that miR-135-5p directly targeted DANCR, which was negatively correlated with DANCR on TSCC progression. Its inhibition reversed the beneficial effects of DANCR silence on TSCC malignancies. Furthermore, the expression of KLF8 evidently altered by both DANCR and miR-135a-5p. Silencing KLF8 using its specific siRNA showed that KLF8 was responsible for the induction of miR-135a-5p inhibitor on TSCC cell malignancies and MMP-2/9 expression. Conclusions These findings, for the first time, suggest that DANCR plays an oncogenic role in TSCC progression via targeting miR-135a-5p/KLF8 axis, which provides a promising biomarker and treatment approach for preventing TSCC.


2019 ◽  
Vol 10 (11) ◽  
Author(s):  
Ying Yang ◽  
Nandan Wu ◽  
Yihui Wu ◽  
Haoting Chen ◽  
Jin Qiu ◽  
...  

Abstract Retinoblastoma (RB) is the most common primary intraocular malignancy in children. Intravitreal chemotherapy achieves favorable clinical outcomes in controlling RB vitreous seeds, which are a common reason for treatment failure. Thus, a novel, effective and safe intravitreal chemotherapeutic drug is urgently required. The malaria drug artesunate (ART) recently demonstrated remarkable anticancer effects with mild side effects. The purpose of this study is to investigate the anti-RB efficacy, the underlying mechanism and the intraocular safety of ART. Herein, we verified that ART inhibits RB cell viability and induces cell apoptosis in a dose- and time-dependent manner. Microarray analysis revealed that Kruppel-like factor 6 (KLF6) was upregulated after ART treatment, and this was further confirmed by real-time PCR and western blot assays. Silencing of KLF6 expression significantly reversed ART-induced RB cell growth inhibition and apoptosis. Furthermore, ART activated mitochondria-mediated apoptosis of RB cells, while silencing KLF6 expression significantly inhibited this effect. In murine xenotransplantation models of RB, we further confirmed that ART inhibits RB tumor growth, induces tumor cell apoptosis and upregulates KLF6 expression. In addition, KLF6 silencing attenuates ART-mediated inhibition of tumor growth in vivo. Furthermore, we proved that intravitreal injection of ART in Sprague-Dawley (SD) rats is safe, with no obvious retinal function damage or structural disorders observed by electrophysiology (ERG), fundal photographs, fundus fluorescein angiography (FFA) or optical coherence tomography (OCT) examinations. Collectively, our study revealed that ART induces mitochondrial apoptosis of RB cells via upregulating KLF6, and our results may extend the application of ART to the clinic as an effective and safe intravitreal chemotherapeutic drug to treat RB, especially RB with vitreous seeds.


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