scholarly journals Bcl-2/Bcl-xL inhibitor ABT-263 overcomes hypoxia-driven radioresistence and improves radiotherapy

2021 ◽  
Vol 12 (7) ◽  
Author(s):  
Violetta Ritter ◽  
Franziska Krautter ◽  
Diana Klein ◽  
Verena Jendrossek ◽  
Justine Rudner

AbstractHypoxia, a characteristic of most human solid tumors, is a major obstacle to successful radiotherapy. While moderate acute hypoxia increases cell survival, chronic cycling hypoxia triggers adaptation processes, leading to the clonal selection of hypoxia-tolerant, apoptosis-resistant cancer cells. Our results demonstrate that exposure to acute and adaptation to chronic cycling hypoxia alters the balance of Bcl-2 family proteins in favor of anti-apoptotic family members, thereby elevating the apoptotic threshold and attenuating the success of radiotherapy. Of note, inhibition of Bcl-2 and Bcl-xL by BH3-mimetic ABT-263 enhanced the sensitivity of HCT116 colon cancer and NCI-H460 lung cancer cells to the cytotoxic action of ionizing radiation. Importantly, we observed this effect not only in normoxia, but also in severe hypoxia to a similar or even higher extent. ABT-263 furthermore enhanced the response of xenograft tumors of control and hypoxia-selected NCI-H460 cells to radiotherapy, thereby confirming the beneficial effect of combined treatment in vivo. Targeting the Bcl-2 rheostat with ABT-263, therefore, is a particularly promising approach to overcome radioresistance of cancer cells exposed to acute or chronic hypoxia with intermittent reoxygenation. Moreover, we found intrinsic as well as ABT-263- and irradiation-induced regulation of Bcl-2 family members to determine therapy sensitivity. In this context, we identified Mcl-1 as a resistance factor that interfered with apoptosis induction by ABT-263, ionizing radiation, and combinatorial treatment. Collectively, our findings provide novel insights into the molecular determinants of hypoxia-mediated resistance to apoptosis and radiotherapy and a rationale for future therapies of hypoxic and hypoxia-selected tumor cell fractions.

2018 ◽  
Vol 19 (12) ◽  
pp. 3974 ◽  
Author(s):  
Qin Wang ◽  
Zhijuan Sun ◽  
Liqing Du ◽  
Chang Xu ◽  
Yan Wang ◽  
...  

Colorectal cancer is the most commonly reported gastrointestinal malignancy, with a recent, rapid increase of the annual incidence all over the world. Enhancing the radiosensitivity of cancer cells while preserving the health of normal cells is one of the most important tasks in clinical radiobiology. However, resistance to radiotherapy for colorectal cancer greatly decreases the therapeutic outcome. Melatonin (N-acetyl-5-methoxytryptamine), a natural secretory product that the pineal gland in the brain normally produces, has been reported to have anticancer properties. In the study, we investigated the combination of melatonin with radiotherapy as a treatment for colorectal cancer. We firstly explored the anti-tumor activity of melatonin combined with ionizing radiation (IR) against colorectal carcinoma in vitro. It was found that melatonin effectively inhibited human colorectal carcinoma cell line HCT 116 cellular proliferation, colony formation rate and cell migration counts following IR. Increasing the radiosensitivity of colorectal cancer cells by melatonin treatment was found to be associated with cell cycle arrest in the G2/M phase, downregulation of proteins involved in DNA double-strand break repair and activation of the caspase-dependent apoptotic pathway. Moreover, we also investigated the combined effect of IR and melatonin on colorectal tumor in vivo. Results from a tumor xenograft showed that melatonin plus IR treatment significantly suppressed tumor cell growth compared with melatonin or IR alone, resulting in a much higher tumor inhibition rate for the combined treatment. The data suggested that melatonin combined with IR could improve the radiosensitivity of colorectal cancer and thus enhance the therapeutic effect of the patients, implying melatonin could function as a potential sensitizer in tumor radiotherapy.


2021 ◽  
Vol 22 (18) ◽  
pp. 9762
Author(s):  
Junko Takahashi ◽  
Shinsuke Nagasawa ◽  
Motomichi Doi ◽  
Masamichi Takahashi ◽  
Yoshitaka Narita ◽  
...  

To treat malignant glioma, standard fractionated radiotherapy (RT; 60 Gy/30 fractions over 6 weeks) was performed post-surgery in combination with temozolomide to improve overall survival. Malignant glioblastoma recurrence rate is extremely high, and most recurrent tumors originate from the excision cavity in the high-dose irradiation region. In our previous study, protoporphyrin IX physicochemically enhanced reactive oxygen species generation by ionizing radiation and combined treatment with 5-aminolevulinic acid (5-ALA) and ionizing radiation, while radiodynamic therapy (RDT) improved tumor growth suppression in vivo in a melanoma mouse model. We examined the effect of 5-ALA RDT on the standard fractionated RT protocol using U251MG- or U87MG-bearing mice. 5-ALA was orally administered at 60 or 120 mg/kg, 4 h prior to irradiation. In both models, combined treatment with 5-ALA slowed tumor progression and promoted regression compared to treatment with ionizing radiation alone. The standard fractionated RT protocol of 60 Gy in 30 fractions with oral administration of 120 and 240 mg/kg 5-ALA, the human equivalent dose of photodynamic diagnosis, revealed no significant increase in toxicity to normal skin or brain tissue compared to ionizing radiation alone. Thus, RDT is expected to enhance RT treatment of glioblastoma without severe toxicity under clinically feasible conditions.


2019 ◽  
Vol 116 (8) ◽  
pp. 2961-2966 ◽  
Author(s):  
Xiaowei Wu ◽  
Qingyu Luo ◽  
Pengfei Zhao ◽  
Wan Chang ◽  
Yating Wang ◽  
...  

Chemoresistance is a severe outcome among patients with ovarian cancer that leads to a poor prognosis. MCL1 is an antiapoptotic member of the BCL-2 family that has been found to play an essential role in advancing chemoresistance and could be a promising target for the treatment of ovarian cancer. Here, we found that deubiquitinating enzyme 3 (DUB3) interacts with and deubiquitinates MCL1 in the cytoplasm of ovarian cancer cells, which protects MCL1 from degradation. Furthermore, we identified that O6-methylguanine-DNA methyltransferase (MGMT) is a key activator of DUB3 transcription, and that the MGMT inhibitor PaTrin-2 effectively suppresses ovarian cancer cells with elevated MGMT-DUB3-MCL1 expression both in vitro and in vivo. Most interestingly, we found that histone deacetylase inhibitors (HDACis) could significantly activate MGMT/DUB3 expression; the combined administration of HDACis and PaTrin-2 led to the ideal therapeutic effect. Altogether, our results revealed the essential role of the MGMT-DUB3-MCL1 axis in the chemoresistance of ovarian cancer and identified that a combined treatment with HDACis and PaTrin-2 is an effective method for overcoming chemoresistance in ovarian cancer.


2019 ◽  
Vol 11 ◽  
pp. 175883591987834
Author(s):  
Barbara Nuvoli ◽  
Bruno Amadio ◽  
Giancarlo Cortese ◽  
Serena Benedetti ◽  
Barbara Antoniani ◽  
...  

Background: Based on previous observations that the nutraceutical CELLFOOD™ (CF), the ‘physiological modulator’ that aimed to make oxygen available ‘on demand’, inhibits the growth of cancer cells, this study was designed to investigate the role of CF in the regulation of hypoxia-inducible factor 1 alpha (HIF1α) and its correlated proteins, phosphoglycerate kinase 1 and vascular endothelial growth factor. Our idea was that CF, acting on HIF1α, in combination with current anticancer therapies could improve their effectiveness. Methods: To evaluate the effect of CF in association with radiotherapy and chemotherapy, different human cancer cell lines and mice with mesothelioma were analysed by tumour growth, clonogenic assay, western blot and immunohistochemical analysis. Results: CF in combination with radiation with or without cisplatin increases the death rate of cancer cells. In vivo, 70% of mice treated with CF before the mesothelioma graft did not show any tumour growth, indicating a possible preventive effect of CF. Moreover, in mouse mesothelioma xenografts, CF improves the effect of radiotherapy also in combination with chemotherapy treatment. Immunohistochemical analysis of tumour explants showed that HIF1α expression was reduced by the combination of CF and radiotherapy treatment and even more by the combination of CF and radiotherapy and chemotherapy treatment. Mechanistically, CF increases the fraction of oxygenated cells, making the radiotherapy more effective with a greater production of reactive oxygen species (ROS) that in turn, reduce the HIF1α expression. This effect is amplified by further increase in ROS from chemotherapy. Conclusions: Collectively, results from preclinical trials suggest that CF could be a useful intervention to improve the efficacy of radiotherapy or combined treatment strategies and could be a promising treatment modality to counteract cancer.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Wen-Shan Xu ◽  
Yuan-Ye Dang ◽  
Jia-Jie Guo ◽  
Guo-Sheng Wu ◽  
Jin-Jian Lu ◽  
...  

Furanodiene (FUR) is a natural terpenoid isolated fromCurcumae Rhizoma, a well-known Chinese medicinal herb that presents antiproliferation activities in several cancer cell lines. In this study, we demonstrated that FUR concentration dependently inhibits the cell proliferation of A549, NIH-H1299, and 95-D lung cancer cells.β-elemene, another terpenoid isolated fromCurcumae Rhizoma, exhibited weaker antiproliferative effects in A549 and NIH-H1299 cells and activities similar to FUR in 95-D cells. FUR significantly inhibited colony formation in A549 and 95-D cells and upregulated both the mRNA and protein expression levels of binding immunoglobulin protein (BIP) and C/EBP homologous protein (CHOP), indicating that endoplasmic reticulum (ER) stress is induced. FUR treatment led to the accumulation of CHOP in the nucleus, which further confirms induction of ER stress. Furthermore, combined treatment of FUR with paclitaxel showed significant synergetic activities in NIH-H1299 and 95-D cells, suggesting its potential roles in combination therapy. These findings provide a basis for the further study of the anticancer effectsin vivoand the internal mechanisms of FUR.


2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14565-e14565
Author(s):  
D. Sharma ◽  
B. B. Knight ◽  
R. Yacoub ◽  
T. Liu ◽  
L. Taliaferro-Smith ◽  
...  

e14565 Background: The outcome for patients with breast cancer has been significantly improved by the use of targeted agents. The prognosis of triple negative (TN) breast cancers, which do not express hormone receptors (ER, PR) or Her2, is poor, because of an aggressive clinical course and lack of targeted therapeutic agents. Epigenetic silencing of specific genes has been observed in breast cancer and some of these genes are more important due to available targeted therapies such as ER. Since all endocrine therapies are designed to block ER function in some way, the identification of new therapies or strategies that could sensitize TN breast cancers to existing endocrine therapy could provide a revolutionary means of treating this aggressive subtype of cancer Methods: We examined the efficacy of combined treatment of HDAC inhibitor LBH589 and DNMT inhibitor decitabine to regenerate ER and PR in TN breast cancer cells using RT-PCR and immunoblotting. Changes in growth and proliferation of TN breast cancer cells in response to LBH589 and decitabine treatment were determined by XTT, BrdU incorporation and colony formation assay. Changes in apoptotic proteins were determined by western blotting. Athymic nude mice were used to establish pre-clinical models for TN breast cancer cells and effectiveness of combined treatment of LBH589 and decitabine was determined. Tumors biopsies were analyzed for ER and PR re-expression by western blot analysis and immunohistochemistry at the end of the treatment. Results: Combined treatment of LBH589 and decitabine resulted in re-expression of ER and PR in TN breast cancers in vitro and in vivo. Although re-expression of ER and PR were noted following LBH589 treatment alone, re-expression was more robust with the combination. TN breast cancer cells showing re-expressed ER can be targeted with tamoxifen. Tamoxifen inhibits growth of TN breast cancer cells re- expressing ER by triggering apoptosis. Conclusions: The importance of epigenetic events such as DNA methylation and HDAC inhibition in tumor progression is becoming increasingly evident. A trial evaluating the ability of LBH589 and decitabine to re- express ER, which can then be targeted by tamoxifen, is planned in patients with metastatic TN breast cancer. No significant financial relationships to disclose.


Oncotarget ◽  
2016 ◽  
Vol 7 (51) ◽  
pp. 84286-84298 ◽  
Author(s):  
Annelies Gonnissen ◽  
Sofie Isebaert ◽  
Chad M McKee ◽  
Rüveyda Dok ◽  
Karin Haustermans ◽  
...  

Author(s):  
Haiyong Zhang ◽  
Jing Wu ◽  
Jinqiu Yuan ◽  
Huafu Li ◽  
Yawei Zhang ◽  
...  

Abstract Background Oxaliplatin is one of the most commonly used chemotherapeutic agent for the treatment of various cancers, including gastric cancer. It has, however, a narrow therapeutic index due to its toxicity and the occurrence of drug resistance. Hence, it is of great significance to develop novel therapies to potentiate the anti-tumor effect and reduce the toxicity of oxaliplatin. In our previous study, we demonstrated that ethaselen (BBSKE), an inhibitor of thioredoxin reductase, effectively inhibited the growth of gastric cancer cells and promoted apoptosis in vitro. In the present study, we investigated whether BBSKE can potentiate the anti-tumor effect of oxaliplatin in gastric cancer in vivo and vitro. Methods Cellular apoptosis and ROS levels were analyzed by flow cytometry. Thioredoxin reductase 1 (TrxR1) activity in gastric cancer cells, organoid and tumor tissues was determined by using the endpoint insulin reduction assay. Western blot was used to analyze the expressions of the indicated proteins. Nude mice xenograft models were used to test the effects of BBSKE and oxaliplatin combinations on gastric cancer cell growth in vivo. In addition, we also used the combined treatment of BBSKE and oxaliplatin in three cases of gastric cancer Patient-Derived organoid (GC-PDO) to detect the anti-tumor effect. Results We found that BBSKE significantly enhanced oxaliplatin-induced growth inhibition in gastric cancer cells by inhibiting TrxR1 activity. Because of the inhibition of TrxR1 activity, BBSKE synergized with oxaliplatin to enhance the production of ROS and activate p38 and JNK signaling pathways which eventually induced apoptosis of gastric cancer cells. In vivo, we also found that BBSKE synergized with oxaliplatin to suppress the gastric cancer tumor growth in xenograft nude mice model, accompanied by the reduced TrxR1 activity. Remarkably, we found that BBSKE attenuated body weight loss evoked by oxaliplatin treatment. We also used three cases of GC-PDO and found that the combined treatment of BBSKE and oxaliplatin dramatically inhibited the growth and viability of GC-PDO with increased ROS level, decreased TrxR1 activity and enhanced apoptosis. Conclusions This study elucidates the underlying mechanisms of synergistic effect of BBSKE and oxaliplatin, and suggests that the combined treatment has potential value in gastric cancer therapy.


2019 ◽  
Vol 184 (Supplement_1) ◽  
pp. 644-651 ◽  
Author(s):  
Rupak Pathak ◽  
Vidya Prasanna Kumar ◽  
Martin Hauer-Jensen ◽  
Sanchita Purohit Ghosh

Abstract Ionizing radiation exposure is a major concern for active military service members, as well as civilian population. Considering that the exposure is not predictable, it is imperative that strategies to counteract radiation damage must be discovered. Recent in vitro studies performed in our laboratory demonstrated that the vitamin E analog gamma-tocotrienol (GT3) in combination with cholesterol-lowering drugs (Statins), synergistically induced endothelial thrombomodulin, an anticoagulant with radio-protective efficacy. It was hypothesized that the combination of treatment with both GT3 along with Statins would provide better radiation protection in vivo than each drug individually. CD2F1 mice were injected subcutaneously with either vehicle or single dose of GT3 (200 mg/kg body weight) 24 hours before irradiation followed by oral or subcutaneous administration of various doses of simvastatin (25, 50, and 100 mg/kg body weight) before exposure to lethal doses (11.5 and 12 Gy) of Cobalt-60 (60Co) gamma-irradiation. The combined treatment group exhibited enhanced radiation lethality protection substantially, accelerated white blood cell recovery, and augmented restoration of bone marrow cellularity when compared to the animals treated with either drug exclusively. This information clearly suggests that combined treatment could be used as a safeguard for military personnel from exposure to harmful ionizing radiation.


Sign in / Sign up

Export Citation Format

Share Document