scholarly journals PTEN mutant NSCLC require ATM to suppress pro-apoptotic signalling and evade radiotherapy

2021 ◽  
Author(s):  
Thomas Fischer ◽  
Oliver Hartmann ◽  
Michaela Reissland ◽  
Cristian Prieto-Garcia ◽  
Kevin Klann ◽  
...  

Background: Despite advances in treatment of patients with non-small cell lung cancer, carriers of certain genetic alterations are prone to failure. One such factor frequently mutated, is the tumor suppressor PTEN. These tumors are supposed to be more resistant to radiation, chemo- and immunotherapy. Methods: Using CRISPR genome editing, we deleted PTEN in a human tracheal stem cell-like cell line as well generated primary murine NSCLC, proficient or deficient for Pten, in vivo. These models were used to verify the impact of PTEN loss in vitro and in vivo by immunohistochemical staining, western blot and RNA-Sequencing. Radiation sensitivity was assessed by colony formation and growth assays. To elucidate putative treatment options, identified via the molecular characterisation, PTEN pro- and deficient cells were treated with PI3K/mTOR/DNA-PK-inhibitor PI-103 or the ATM-inhibitors KU-60019 und AZD 1390. Changes in radiation sensitivity were assessed by colony-formation assay, FACS, western-blot, phospho-proteomic mass spectrometry and ex vivo lung slice cultures. Results: We demonstrate that loss of PTEN led to altered expression of transcriptional programs which directly regulate therapy resistance, resulting in establishment of radiation resistance. While PTEN-deficient tumor cells were not dependent on DNA PK for IR resistance nor activated ATR during IR, they showed a significant dependence for the DNA damage kinase ATM. Pharmacologic inhibition of ATM, via KU-60019 and AZD1390 at non-toxic doses, restored and even synergized with IR in PTEN-deficient human and murine NSCLC cells as well in a multicellular organotypic ex vivo tumor model. Conclusion: PTEN tumors are addicted to ATM to detect and repair radiation induced DNA damage. This creates an exploitable bottleneck. At least in cellulo and ex vivo we show that low concentration of ATM inhibitor is able to synergise with IR to treat PTEN-deficient tumors in genetically well-defined IR resistant lung cancer models.

2021 ◽  
Author(s):  
Thomas Fischer ◽  
Oliver Hartmann ◽  
Michaela Reissland ◽  
Cristian Prieto-Garcia ◽  
Kevin Klann ◽  
...  

Abstract BackgroundDespite advances in treatment of patients with non-small cell lung cancer, carriers of certain genetic alterations are prone to failure. One such factor frequently mutated, is the tumor suppressor PTEN. These tumors are supposed to be more resistant to radiation, chemo- and immunotherapy.ResultsWe demonstrate that loss of PTEN led to altered expression of transcriptional programs which directly regulate therapy resistance, resulting in establishment of radiation resistance. While PTEN-deficient tumor cells were not dependent on DNA‑PK for IR resistance nor activated ATR during IR, they showed a significant dependence for the DNA damage kinase ATM. Pharmacologic inhibition of ATM, via KU-60019 and AZD1390 at non-toxic doses, restored and even synergized with IR in PTEN-deficient human and murine NSCLC cells as well in a multicellular organotypic ex vivo tumor model.ConclusionPTEN tumors are addicted to ATM to detect and repair radiation induced DNA damage. This creates an exploitable bottleneck. At least in cellulo and ex vivo we show that low concentration of ATM inhibitor is able to synergise with IR to treat PTEN-deficient tumors in genetically well-defined IR resistant lung cancer models.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3617-3617
Author(s):  
Jan Dörr ◽  
Yong Yu ◽  
Bernd Dörken ◽  
Clemens A. Schmitt

Abstract Introduction: Premature senescence reflects an acutely inducible, irreversible growth arrest as a cellular response to stresses such as oncogenic activation and DNA damage, including chemotherapeutic anticancer agents. Senescence complements apoptosis as a tumor suppressive and therapeutic effector principle, but whether a selective disruption of the senescence machinery impairs treatment outcome is unknown. Moreover, function and fate of senescent tumor cells within the tumor site remain unclear. Here, we analyze the impact of defined genetic alterations, i.e. Bcl2 overexpression (blocking apoptosis), deletion of the histone H3 lysine 9 methyltransferase Suv39h1 (controlling senescence), and conditional expression of p53 (mediating both apoptosis and senescence), on therapy-induced senescence (TIS) in the Eμ-myc mouse lymphoma model with specific emphasis on immunological tumor-host and growth-modulating senescent/non-senescent cell interactions as a consequence of TIS in vitro and in vivo. Methods: Lymphoma cells (LCs) of various genetic backgrounds were retrovirally transduced with the bcl2 gene to study TIS in the absence of drug-induced apoptosis. Bcl2-protected LCs were treated with the DNA damaging anticancer agent adriamycin in vitro, or were exposed to the alkylating agent cyclophosphamide upon lymphoma formation in normal immunocompetent mice in vivo. TIS was detected by staining for senescence-associated β-galactosidase activity (SA-β-gal) and other senescence-related markers, including Ki67 and BrdU incorporation. To study tumor-host cell interactions, isolated normal splenocytes were co-incubated with proliferating or senescent LCs in vitro. Immunophenotyping was carried out with antibodies specific for macrophages, granulocytes, natural killer cells and T-lymphocytes. Cytokine production was measured by protein arrays. Results: Senescent LCs engage in cell-cell interactions with different immune cell subsets, in particular macrophages, granulocytes and T-cells in vitro. Fluorescence microscopy reveals that macrophages engulf LCs after they entered TIS. In vivo, TIS correlates with the quantitative attraction of immune cell populations to the tumor site and subsequent clearing of senescent cells. Ongoing mechanistic studies on underlying ligand/receptor interactions will be reported at the meeting. TIS cells exhibit a specific pro-inflammatory secretory profile whose functional impact on tumor and bystander cells is currently being investigated. Importantly, this profile is distinguishable from cytokine profiles of senescence-compromised Suv39h1- or p53-deficient lymphomas, and, thus, reflects a senescence - rather than a DNA damage-associated secretory response. Discussion: The study unveils a functional interaction of senescent LCs with different immune cell subsets in vitro and in vivo. The cytokine arrays show that senescent cells produce a specific secretory profile, which might stimulate immune cell attraction. Therefore, immune cells could be recruited to lymphomas in vivo specifically after TIS with the potential to clear senescent – and possibly non-senescent – cells from the tumor site. The data demonstrate genetically that senescence is a beneficial effector principle of DNA damaging chemotherapy and encourage further exploration of this program to limit cancer expansion in vivo.


Cancers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2517
Author(s):  
Pavel N. Lobachevsky ◽  
Nicholas W. Bucknell ◽  
Joel Mason ◽  
Diane Russo ◽  
Xiaoyu Yin ◽  
...  

Thoracic radiotherapy (RT) is required for the curative management of inoperable lung cancer, however, treatment delivery is limited by normal tissue toxicity. Prior studies suggest that using radiation-induced DNA damage response (DDR) in peripheral blood mononuclear cells (PBMC) has potential to predict RT-associated toxicities. We collected PBMC from 38 patients enrolled on a prospective clinical trial who received definitive fractionated RT for non-small cell lung cancer. DDR was measured by automated counting of nuclear γ-H2AX foci in immunofluorescence images. Analysis of samples collected before, during and after RT demonstrated the induction of DNA damage in PBMC collected shortly after RT commenced, however, this damage repaired later. Radiation dose to the tumour and lung contributed to the in vivo induction of γ-H2AX foci. Aliquots of PBMC collected before treatment were also irradiated ex vivo, and γ-H2AX kinetics were analyzed. A trend for increasing of fraction of irreparable DNA damage in patients with higher toxicity grades was revealed. Slow DNA repair in three patients was associated with a combined dysphagia/cough toxicity and was confirmed by elevated in vivo RT-generated irreparable DNA damage. These results warrant inclusion of an assessment of DDR in PBMC in a panel of predictive biomarkers that would identify patients at a higher risk of toxicity.


2020 ◽  
Author(s):  
Jianping Guo ◽  
Lei Yin ◽  
Xuezhong Zhang ◽  
Peng Su ◽  
Qiaoli Zhai

Abstract Background Peptidylarginine deiminase 4 (PADI4), an important modification enzyme of proteins, has received increased attention for its role in tumorigenesis of several human cancers. However, the effect of PADI4 on osteosarcoma remains largely unknown. Here, we evaluated the impact and mechanism of PADI4 on osteosarcoma proliferation. Methods Impact of PADI4 on proliferation of osteosarcoma cells is detected by the method of CCK8 and colony formation assay. Expression of PADI4 as well as Wnt/β-catenin and MEK/ERK signaling markers after knocking down or ectopically expressing PADI4 or PADI4 inhibitor treatment is investigated by Western blot and RT-PCR. Then we investigated relevance of the expression level of the PADI4 in osteosarcoma samples and paired normal tissues by Western blot and RT-PCR. To further confirm whether PADI4 affect osteosarcoma tumorigenesis in vivo, we performed tumor formation experiments in nude mice. Results Firstly, ectopically expressing PADI4 showed positive regulation on colony formation capacity of osteosarcoma cells. Secondly, PADI4 stimulated Wnt/β-catenin and MEK/ERK signaling in osteosarcoma cells. Thirdly, PADI4 is highly expressed in osteosarcoma samples compared with normal tissues. In vivo experiment also verified the positive effect of PADI4 on the growth of transplanted tumors in nude mice. Conclusions Taken together, our results revealed PADI4 promoted proliferation of osteosarcoma via Wnt/β-catenin and MEK/ERK signaling pathway. This study may expand our understanding of osteosarcoma tumorigenesis and identify PADI4 as a potential target for diagnosis and treatment of osteosarcoma.


2020 ◽  
Author(s):  
Jianping Guo ◽  
Lei Yin ◽  
Xuezhong Zhang ◽  
Peng Su ◽  
Qiaoli Zhai

Abstract Background: Peptidylarginine deiminase 4 (PADI4), an important modification enzyme of proteins, has received increased attention for its role in tumorigenesis of several human cancers. However, the effect of PADI4 on osteosarcoma remains largely unknown. Here, we evaluated the impact and mechanism of PADI4 on osteosarcoma proliferation.Methods: Impact of PADI4 on proliferation of osteosarcoma cells is detected by the method of CCK8 and colony formation assay. Expression of PADI4 as well as Wnt/β-catenin and MEK/ERK signaling markers after knocking down or ectopically expressing PADI4 or PADI4 inhibitor treatment is investigated by Western blot and RT-PCR. Then we investigated relevance of the expression level of the PADI4 in osteosarcoma samples and paired normal tissues by Western blot and RT-PCR. To further confirm whether PADI4 affects osteosarcoma tumorigenesis in vivo, we performed tumor formation experiments in nude mice.Results: Firstly, ectopically expressing PADI4 showed positive regulation on colony formation capacity of osteosarcoma cells. Secondly, PADI4 stimulated Wnt/β-catenin and MEK/ERK signaling in osteosarcoma cells. Thirdly, expression of PADI4 is higher in osteosarcoma samples compared with normal tissues. In vivo experiment also verified the positive effect of PADI4 on the growth of transplanted tumors in nude mice.Conclusions: Taken together, our results revealed PADI4 promoted proliferation of osteosarcoma via Wnt/β-catenin and MEK/ERK signaling pathway. This study may expand our understanding of osteosarcoma tumorigenesis and identify PADI4 as a potential target for diagnosis and treatment of osteosarcoma.


Author(s):  
Hossam Ebaid ◽  
Mohamed Habila ◽  
Iftekhar Hassan ◽  
Jameel Al-Tamimi ◽  
Mohamed S. Omar ◽  
...  

Background: Hepatotoxicity remains an important clinical challenge. Hepatotoxicity observed in response to toxins and hazardous chemicals may be alleviated by delivery of the curcumin in silver nanoparticles (AgNPs-curcumin). In this study, we examined the impact of AgNPs-curcumin in a mouse model of carbon tetrachloride (CCl4)-induced hepatic injury. Methods: Male C57BL/6 mice were divided into three groups (n=8 per group). Mice in group 1 were treated with vehicle control alone, while mice in Group 2 received a single intraperitoneal injection of 1 ml/kg CCl4 in liquid paraffin (1:1 v/v). Mice in group 3 were treated with 2.5 mg/kg AgNPs-curcumin twice per week for three weeks after the CCl4 challenge. Results: Administration of CCL4 resulted in oxidative dysregulation, including significant reductions in reduced glutathione and concomitant elevations in the level of malondialdehyde (MDA). CCL4 challenge also resulted in elevated levels of serum aspartate transaminase (AST) and alanine transaminase (ALT); these findings were associated with the destruction of hepatic tissues. Treatment with AgNPs-curcumin prevented oxidative imbalance, hepatic dysfunction, and tissue destruction. A comet assay revealed that CCl4 challenge resulted in significant DNA damage as documented by a 70% increase in nuclear DNA tail-length; treatment with AgNPs-curcumin inhibited the CCL4-mediated increase in nuclear DNA tail-length by 34%. Conclusion: Administration of AgNPs-curcumin resulted in significant antioxidant activity in vivo. This agent has the potential to prevent the hepatic tissue destruction and DNA damage that results from direct exposure to CCL4.


2019 ◽  
Vol 15 (36) ◽  
pp. 4127-4139 ◽  
Author(s):  
Yingli Yuan ◽  
Luguo Sun ◽  
Xu Wang ◽  
Jingxian Chen ◽  
Mingnan Jia ◽  
...  

Aim: To clarify the regulatory roles of GLDCV1, the first identified truncated glycine decarboxylase (GLDC), on cancer stem cells and tumorigenesis. Materials & methods: RT-PCR or RT-qPCR, immunoblotting and immunohistochemical staining were applied to assess gene expression. MTT, BrdU incorporation and colony formation assays were used to examine cell proliferation capacity. Soft agar colony formation and in vivo transplantation were applied to evaluate cellular transformation and tumorigenesis. Results & conclusion: Expression of GLDCV1 or GLDC was enhanced in non-small-cell lung cancer cell line and clinical samples. GLDCV1 overexpression induced MRC5 cell proliferation, transformation and tumorigenesis. Additionally, GLDCV1 increased lactate production and cancer stem cell marker expression and activated ERK and P38 pathways. Our study gained deeper insight into GLDC oncogene.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
J. Ellegood ◽  
S. P. Petkova ◽  
A. Kinman ◽  
L. R. Qiu ◽  
A. Adhikari ◽  
...  

Abstract Background One of the causal mechanisms underlying neurodevelopmental disorders (NDDs) is chromatin modification and the genes that regulate chromatin. AT-rich interactive domain 1B (ARID1B), a chromatin modifier, has been linked to autism spectrum disorder and to affect rare and inherited genetic variation in a broad set of NDDs. Methods A novel preclinical mouse model of Arid1b deficiency was created and validated to characterize and define neuroanatomical, behavioral and transcriptional phenotypes. Neuroanatomy was assessed ex vivo in adult animals and in vivo longitudinally from birth to adulthood. Behavioral testing was also performed throughout development and tested all aspects of motor, learning, sociability, repetitive behaviors, seizure susceptibility, and general milestones delays. Results We validated decreased Arid1b mRNA and protein in Arid1b+/− mice, with signatures of increased axonal and synaptic gene expression, decreased transcriptional regulator and RNA processing expression in adult Arid1b+/− cerebellum. During neonatal development, Arid1b+/− mice exhibited robust impairments in ultrasonic vocalizations (USVs) and metrics of developmental growth. In addition, a striking sex effect was observed neuroanatomically throughout development. Behaviorally, as adults, Arid1b+/− mice showed low motor skills in open field exploration and normal three-chambered approach. Arid1b+/− mice had learning and memory deficits in novel object recognition but not in visual discrimination and reversal touchscreen tasks. Social interactions in the male–female social dyad with USVs revealed social deficits on some but not all parameters. No repetitive behaviors were observed. Brains of adult Arid1b+/− mice had a smaller cerebellum and a larger hippocampus and corpus callosum. The corpus callosum increase seen here contrasts previous reports which highlight losses in corpus callosum volume in mice and humans. Limitations The behavior and neuroimaging analyses were done on separate cohorts of mice, which did not allow a direct correlation between the imaging and behavioral findings, and the transcriptomic analysis was exploratory, with no validation of altered expression beyond Arid1b. Conclusions This study represents a full validation and investigation of a novel model of Arid1b+/− haploinsufficiency throughout development and highlights the importance of examining both sexes throughout development in NDDs.


2021 ◽  
Vol 22 (2) ◽  
pp. 674
Author(s):  
Óscar Darío García-García ◽  
Marwa El Soury ◽  
David González-Quevedo ◽  
David Sánchez-Porras ◽  
Jesús Chato-Astrain ◽  
...  

Acellular nerve allografts (ANGs) represent a promising alternative in nerve repair. Our aim is to improve the structural and biomechanical properties of biocompatible Sondell (SD) and Roosens (RS) based ANGs using genipin (GP) as a crosslinker agent ex vivo. The impact of two concentrations of GP (0.10% and 0.25%) on Wistar rat sciatic nerve-derived ANGs was assessed at the histological, biomechanical, and biocompatibility levels. Histology confirmed the differences between SD and RS procedures, but not remarkable changes were induced by GP, which helped to preserve the nerve histological pattern. Tensile test revealed that GP enhanced the biomechanical properties of SD and RS ANGs, being the crosslinked RS ANGs more comparable to the native nerves used as control. The evaluation of the ANGs biocompatibility conducted with adipose-derived mesenchymal stem cells cultured within the ANGs confirmed a high degree of biocompatibility in all ANGs, especially in RS and RS-GP 0.10% ANGs. Finally, this study demonstrates that the use of GP could be an efficient alternative to improve the biomechanical properties of ANGs with a slight impact on the biocompatibility and histological pattern. For these reasons, we hypothesize that our novel crosslinked ANGs could be a suitable alternative for future in vivo preclinical studies.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuxin Qi ◽  
Wenping Yang ◽  
Shuang Liu ◽  
Fanjie Han ◽  
Haibin Wang ◽  
...  

Abstract Background Lung cancer is one of the important health threats worldwide, of which 5-year survival rate is less than 15%. Non-small-cell lung cancer (NSCLC) accounts for about 80% of all lung cancer with high metastasis and mortality. Methods Cisplatin loaded multiwalled carbon nanotubes (Pt-MWNTS) were synthesized and used to evaluate the anticancer effect in our study. The NSCLC cell lines A549 (cisplatin sensitive) and A549/DDP (cisplatin resistant) were used in our in vitro assays. MTT was used to determine Cancer cells viability and invasion were measured by MTT assay and Transwell assay, respectively. Apoptosis and epithelial-mesenchymal transition related marker proteins were measured by western blot. The in vivo anti-cancer effect of Pt-MWNTs were performed in male BALB/c nude mice (4-week old). Results Pt-MWNTS were synthesized and characterized by X-ray diffraction, Raman, FT-IR spectroscopy and scan electron microscopy. No significant cytotoxicity of MWNTS was detected in both A549/DDP and A549 cell lines. However, Pt-MWNTS showed a stronger inhibition effect on cell growth than free cisplatin, especially on A549/DDP. We found Pt-MWNTS showed higher intracellular accumulation of cisplatin in A549/DDP cells than free cisplatin and resulted in enhanced the percent of apoptotic cells. Western blot showed that application of Pt-MWNTS can significantly upregulate the expression level of Bax, Bim, Bid, Caspase-3 and Caspase-9 while downregulate the expression level of Bcl-2, compared with free cisplatin. Moreover, the expression level of mesenchymal markers like Vimentin and N-cadherin was more efficiently reduced by Pt-MWNTS treatment in A549/DDP cells than free cisplatin. In vivo study in nude mice proved that Pt-MWNTS more effectively inhibited tumorigenesis compared with cisplatin, although both of them had no significant effect on body weight. Conclusion Pt-MWNT reverses the drug resistance in the A549/DDP cell line, underlying its possibility of treating NSCLC with cisplatin resistance.


Sign in / Sign up

Export Citation Format

Share Document