scholarly journals Emergence of mTOR mutation as an acquired resistance mechanism to AKT inhibition, and subsequent response to mTORC1/2 inhibition

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Niamh Coleman ◽  
Vivek Subbiah ◽  
Shubham Pant ◽  
Keyur Patel ◽  
Sinchita Roy-Chowdhuri ◽  
...  
Keyword(s):  
Precision Medicine ◽  
Human Cancer ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
Treatment Strategies ◽  
Mechanisms Of Resistance ◽  
Mtor Inhibition ◽  
Improve Patient Selection ◽  
Subsequent Response ◽  
Phosphoinositide 3 Kinase

AbstractAcquired resistance to molecular targeted therapy is a significant challenge of the precision medicine era. The ability to understand these mechanisms of resistance may improve patient selection and allow for the development of rationally designed next-line or combination treatment strategies and improved patient outcomes. AKT is a critical effector of the phosphoinositide 3-kinase signaling cascade, one of the most commonly activated pathways in human cancer. Deregulation of signaling pathways, such as RAF/MEK/ERK are previously described mechanisms of resistance to AKT/PI3K inhibitors. Mutations in the mTOR gene, however, are exceedingly rare. We present a case of acquired mTOR resistance, following targeted AKT inhibition, and subsequent response to mTOR1/2 inhibitor in a patient with metastatic endometrial cancer, the first documented response to ATP-competitive mTOR inhibition in this setting. This case supports mTOR mutation as a mechanism of resistance, and underscores the importance of tumor molecular profiling, exemplifying precision medicine in action.

Radio-Susceptibility of Nasopharyngeal Carcinoma: Focus on Epstein- Barr Virus, MicroRNAs, Long Non-Coding RNAs and Circular RNAs

2020 ◽  
Vol 13 (3) ◽  
pp. 192-205 ◽  
Author(s):  
Fanghong Lei ◽  
Tongda Lei ◽  
Yun Huang ◽  
Mingxiu Yang ◽  
Mingchu Liao ◽  
...  
Keyword(s):  
Nasopharyngeal Carcinoma ◽  
Regulatory Networks ◽  
Epstein Barr Virus ◽  
Molecular Mechanisms ◽  
Acquired Resistance ◽  
Treatment Strategies ◽  
Circular Rnas ◽  
Barr Virus ◽  
Non Coding Rnas ◽  
Epstein Barr

Nasopharyngeal carcinoma (NPC) is a type of head and neck cancer. As a neoplastic disorder, NPC is a highly malignant squamous cell carcinoma that is derived from the nasopharyngeal epithelium. NPC is radiosensitive; radiotherapy or radiotherapy combining with chemotherapy are the main treatment strategies. However, both modalities are usually accompanied by complications and acquired resistance to radiotherapy is a significant impediment to effective NPC therapy. Therefore, there is an urgent need to discover effective radio-sensitization and radio-resistance biomarkers for NPC. Recent studies have shown that Epstein-Barr virus (EBV)-encoded products, microRNAs (miRNAs), long non-coding RNAs (lncRNAs) and circular RNAs (circRNAs), which share several common signaling pathways, can function in radio-related NPC cells or tissues. Understanding these interconnected regulatory networks will reveal the details of NPC radiation sensitivity and resistance. In this review, we discuss and summarize the specific molecular mechanisms of NPC radio-sensitization and radio-resistance, focusing on EBV-encoded products, miRNAs, lncRNAs and circRNAs. This will provide a foundation for the discovery of more accurate, effective and specific markers related to NPC radiotherapy. EBVencoded products, miRNAs, lncRNAs and circRNAs have emerged as crucial molecules mediating the radio-susceptibility of NPC. This understanding will improve the clinical application of markers and inform the development of novel therapeutics for NPC.

scholarly journals Transient Receptor Potential C 1/4/5 Is a Determinant of MTI-101 Induced Calcium Influx and Cell Death in Multiple Myeloma

Cells ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1490
Author(s):  
Osama M. Elzamzamy ◽  
Brandon E. Johnson ◽  
Wei-Chih Chen ◽  
Gangqing Hu ◽  
Reinhold Penner ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Cell Death ◽  
Transient Receptor Potential ◽  
Cyclic Peptide ◽  
Calcium Influx ◽  
Acquired Resistance ◽  
Treatment Strategies ◽  
Prognostic Indicators ◽  
Causative Role

Multiple myeloma (MM) is a currently incurable hematologic cancer. Patients that initially respond to therapeutic intervention eventually relapse with drug resistant disease. Thus, novel treatment strategies are critically needed to improve patient outcomes. Our group has developed a novel cyclic peptide referred to as MTI-101 for the treatment of MM. We previously reported that acquired resistance to HYD-1, the linear form of MTI-101, correlated with the repression of genes involved in store operated Ca2+ entry (SOCE): PLCβ, SERCA, ITPR3, and TRPC1 expression. In this study, we sought to determine the role of TRPC1 heteromers in mediating MTI-101 induced cationic flux. Our data indicate that, consistent with the activation of TRPC heteromers, MTI-101 treatment induced Ca2+ and Na+ influx. However, replacing extracellular Na+ with NMDG did not reduce MTI-101-induced cell death. In contrast, decreasing extracellular Ca2+ reduced both MTI-101-induced Ca2+ influx as well as cell death. The causative role of TRPC heteromers was established by suppressing STIM1, TRPC1, TRPC4, or TRPC5 function both pharmacologically and by siRNA, resulting in a reduction in MTI-101-induced Ca2+ influx. Mechanistically, MTI-101 treatment induces trafficking of TRPC1 to the membrane and co-immunoprecipitation studies indicate that MTI-101 treatment induces a TRPC1-STIM1 complex. Moreover, treatment with calpeptin inhibited MTI-101-induced Ca2+ influx and cell death, indicating a role of calpain in the mechanism of MTI-101-induced cytotoxicity. Finally, components of the SOCE pathway were found to be poor prognostic indicators among MM patients, suggesting that this pathway is attractive for the treatment of MM.

scholarly journals Metabolic Interplay between the Immune System and Melanoma Cells: Therapeutic Implications

Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 607
Author(s):  
Alice Indini ◽  
Francesco Grossi ◽  
Mario Mandalà ◽  
Daniela Taverna ◽  
Valentina Audrito
Keyword(s):  
Metabolic Pathways ◽  
Cancer Metabolism ◽  
Acquired Resistance ◽  
Treatment Strategies ◽  
Predictive Biomarkers ◽  
Treatment Resistance ◽  
Metastatic Potential ◽  
Biological Behavior ◽  
Therapeutic Implications ◽  
Systemic Treatments

Malignant melanoma represents the most fatal skin cancer due to its aggressive biological behavior and high metastatic potential. Treatment strategies for advanced disease have dramatically changed over the last years due to the introduction of BRAF/MEK inhibitors and immunotherapy. However, many patients either display primary (i.e., innate) or eventually develop secondary (i.e., acquired) resistance to systemic treatments. Treatment resistance depends on multiple mechanisms driven by a set of rewiring processes, which involve cancer metabolism, epigenetic, gene expression, and interactions within the tumor microenvironment. Prognostic and predictive biomarkers are needed to guide patients’ selection and treatment decisions. Indeed, there are no recognized clinical or biological characteristics that identify which patients will benefit more from available treatments, but several biomarkers have been studied with promising preliminary results. In this review, we will summarize novel tumor metabolic pathways and tumor-host metabolic crosstalk mechanisms leading to melanoma progression and drug resistance, with an overview on their translational potential as novel therapeutic targets.

scholarly journals Resistance Mechanisms of Multiresistant Pseudomonas aeruginosa Strains from Germany and Correlation with Hypermutation

2007 ◽  
Vol 51 (11) ◽  
pp. 4062-4070 ◽  
Author(s):  
B. Henrichfreise ◽  
I. Wiegand ◽  
W. Pfister ◽  
B. Wiedemann
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Efflux Pump ◽  
Acquired Resistance ◽  
Resistance Mechanisms ◽  
Type Ii ◽  
Mechanisms Of Resistance ◽  
Resistance Determinants ◽  
Class 1 ◽  
Mutator Strains ◽  
Multiresistant Strains

ABSTRACT In this study, we analyzed the mechanisms of multiresistance for 22 clinical multiresistant and clonally different Pseudomonas aeruginosa strains from Germany. Twelve and 10 strains originated from cystic fibrosis (CF) and non-CF patients, respectively. Overproduction of the efflux systems MexAB-OprM, MexCD-OprJ, MexEF-OprN, and MexXY-OprM was studied. Furthermore, loss of OprD, alterations in type II topoisomerases, AmpC overproduction, and the presence of 25 acquired resistance determinants were investigated. The presence of a hypermutation phenotype was also taken into account. Besides modifications in GyrA (91%), the most frequent mechanisms of resistance were MexXY-OprM overproduction (82%), OprD loss (82%), and AmpC overproduction (73%). Clear differences between strains from CF and non-CF patients were found: numerous genes coding for aminoglycoside-modifying enzymes and located, partially in combination with β-lactamase genes, in class 1 integrons were found only in strains from non-CF patients. Furthermore, multiple modifications in type II topoisomerases conferring high quinolone resistance levels and overexpression of MexAB-OprM were exclusively detected in multiresistant strains from non-CF patients. Correlations of the detected phenotypes and resistance mechanisms revealed a great impact of efflux pump overproduction on multiresistance in P. aeruginosa. Confirming previous studies, we found that additional, unknown chromosomally mediated resistance mechanisms remain to be determined. In our study, 11 out of 12 strains and 3 out of 10 strains from CF patients and non-CF patients, respectively, were hypermutable. This extremely high proportion of mutator strains should be taken into consideration for the treatment of multiresistant P. aeruginosa.

scholarly journals n-Butylidenephthalide Modulates Autophagy to Ameliorate Neuropathological Progress of Spinocerebellar Ataxia Type 3 through mTOR Pathway

2021 ◽  
Vol 22 (12) ◽  
pp. 6339
Author(s):  
Jui-Hao Lee ◽  
Si-Yin Lin ◽  
Jen-Wei Liu ◽  
Shinn-Zong Lin ◽  
Horng-Jyh Harn ◽  
...  
Keyword(s):  
Spinocerebellar Ataxia ◽  
Treatment Strategies ◽  
Spinocerebellar Ataxia Type ◽  
Treated Animal ◽  
Bafilomycin A1 ◽  
Spinocerebellar Ataxia Type 3 ◽  
Mtor Inhibition ◽  
Abnormal Accumulation ◽  
Type 3 ◽  
Unique Mechanism

Spinocerebellar ataxia type 3 (SCA3), a hereditary and lethal neurodegenerative disease, is attributed to the abnormal accumulation of undegradable polyglutamine (polyQ), which is encoded by mutated ataxin-3 gene (ATXN3). The toxic fragments processed from mutant ATXN3 can induce neuronal death, leading to the muscular incoordination of the human body. Some treatment strategies of SCA3 are preferentially focused on depleting the abnormal aggregates, which led to the discovery of small molecule n-butylidenephthalide (n-BP). n-BP-promoted autophagy protected the loss of Purkinje cell in the cerebellum that regulates the network associated with motor functions. We report that the n-BP treatment may be effective in treating SCA3 disease. n-BP treatment led to the depletion of mutant ATXN3 with the expanded polyQ chain and the toxic fragments resulting in increased metabolic activity and alleviated atrophy of SCA3 murine cerebellum. Furthermore, n-BP treated animal and HEK-293GFP-ATXN3-84Q cell models could consistently show the depletion of aggregates through mTOR inhibition. With its unique mechanism, the two autophagic inhibitors Bafilomycin A1 and wortmannin could halt the n-BP-induced elimination of aggregates. Collectively, n-BP shows promising results for the treatment of SCA3.

scholarly journals Cytotoxic Efficacy and Resistance Mechanism of a TRAIL and VEGFA-Peptide Fusion Protein in Colorectal Cancer Models

2021 ◽  
Vol 22 (6) ◽  
pp. 3160
Author(s):  
Michal Kopczynski ◽  
Malgorzata Statkiewicz ◽  
Magdalena Cybulska ◽  
Urszula Kuklinska ◽  
Katarzyna Unrug-Bielawska ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Lines ◽  
Transmembrane Protein ◽  
Acquired Resistance ◽  
Protein A ◽  
Resistance Mechanism ◽  
Receptor Expression ◽  
Human Colorectal Cancer ◽  
Protein Activity ◽  
Anticancer Efficacy

TNF-related apoptosis-inducing ligand (TRAIL) is a type II transmembrane protein capable of selectively inducing apoptosis in cancer cells by binding to its cognate receptors. Here, we examined the anticancer efficacy of a recently developed chimeric AD-O51.4 protein, a TRAIL fused to the VEGFA-originating peptide. We tested AD-O51.4 protein activity against human colorectal cancer (CRC) models and investigated the resistance mechanism in the non-responsive CRC models. The quantitative comparison of apoptotic activity between AD-O51.4 and the native TRAIL in nine human colorectal cancer cell lines revealed dose-dependent toxicity in seven of them; the immunofluorescence-captured receptor abundance correlated with the extent of apoptosis. AD-O51.4 reduced the growth of CRC patient-derived xenografts (PDXs) with good efficacy. Cell lines that acquired AD-O51.4 resistance showed a significant decrease in surface TRAIL receptor expression and apoptosis-related proteins, including Caspase-8, HSP60, and p53. These results demonstrate the effectiveness of AD-O51.4 protein in CRC preclinical models and identify the potential mechanism underlying acquired resistance. Progression of AD-O51.4 to clinical trials is expected.

scholarly journals Suppression of Autophagy Sensitizes Osteosarcoma to mTOR Inhibition

2020 ◽  
Author(s):  
Ke Zeng ◽  
Lei Jin ◽  
Xiao Yang ◽  
Zhengjie Yang ◽  
Guoxin Zhu
Keyword(s):  
Combination Therapy ◽  
Colony Formation ◽  
Resistance Mechanism ◽  
Osteosarcoma Cell ◽  
Osteosarcoma Cells ◽  
Mtor Inhibition ◽  
Major Health Problem ◽  
Induced Apoptosis ◽  
Autophagy Inhibition

Abstract Aim Osteosarcoma is some major health problem. We intended to investigate the role of Rapamycin and autophagy inhibition in the treatment of osteosarcoma. Method We conducted a series of in vitro studies using two osteosarcoma cell lines. Using genetic and pharmaceutical interventions we studied whether combined autophagy inhibition could sensitize osteosarcoma sales to a Rapamycin treatment. Proliferation, innovation, migration, and colony formation assays were performed. Results Osteosarcoma cells had low basal autophagy levels. Inhibition of mTOR only demonstrated moderate effects but induced increased autophagy levels, indicating possible resistance mechanism. Inhibition of both autophagy and mTOR axis synergistically inhibited proliferation, migration, invasion, and colony formation of osteosarcoma cells. The combination therapy induced apoptosis, which could be restored in part by NEC1. Conclusion Increased autophagy level was responsible for compromised effect of mTOR inhibition in osteosarcoma. Combination therapy using rapamycin and chloroquine held promise to the development of novel mortality.

scholarly journals The effect of CELLFOODTM on radiotherapy or combined chemoradiotherapy: preclinical evidence

2019 ◽  
Vol 11 ◽  
pp. 175883591987834
Author(s):  
Barbara Nuvoli ◽  
Bruno Amadio ◽  
Giancarlo Cortese ◽  
Serena Benedetti ◽  
Barbara Antoniani ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Tumour Growth ◽  
Human Cancer ◽  
Combined Treatment ◽  
Treatment Strategies ◽  
Phosphoglycerate Kinase ◽  
Immunohistochemical Analysis ◽  
Chemotherapy Treatment ◽  
Human Cancer Cell Lines

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.

scholarly journals Resistance mechanism for ibrutinib in marginal zone lymphoma

2019 ◽  
Vol 3 (4) ◽  
pp. 500-502 ◽  
Author(s):  
Narendranath Epperla ◽  
Arwa Y. Shana’ah ◽  
Dan Jones ◽  
Beth A. Christian ◽  
Sabarish Ayyappan ◽  
...  
Keyword(s):  
Marginal Zone ◽  
Acquired Resistance ◽  
Resistance Mechanism ◽  
Marginal Zone Lymphoma ◽  
First Case ◽  
Molecular Events ◽  
Key Points

Key Points The molecular events leading to primary and acquired resistance to ibrutinib in marginal zone lymphoma have not been studied. We describe the first case of MZL with acquired resistance to ibrutinib in which mutations in both BTK (C481S) and PLCG2 are documented.

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