RESUMEN
Esophageal squamous cell carcinoma (ESCC) possesses a poor prognosis and treatment outcome. Dysregulated metabolism contributes to unrestricted growth of multiple cancers. However, abnormal metabolism, such as highly activated pentose phosphate pathway (PPP) in the progression of ESCC remains largely unknown. Herein, we report that high-mobility group AT-hook 1 (HMGA1), a structural transcriptional factor involved in chromatin remodeling, promoted the development of ESCC by upregulating the PPP. We found that HMGA1 was highly expressed in ESCC. Elevated HMGA1 promoted the malignant phenotype of ESCC cells. Conditional knockout of HMGA1 markedly reduced 4-nitroquinoline-1-oxide (4NQO)-induced esophageal tumorigenesis in mice. Through the metabolomic analysis and the validation assay, we found that HMGA1 upregulated the non-oxidative PPP. With the transcriptome sequencing, we identified that HMGA1 upregulated the expression of transketolase (TKT), which catalyzes the reversible reaction in non-oxidative PPP to exchange metabolites with glycolytic pathway. HMGA1 knockdown suppressed the PPP by downregulating TKT, resulting in the reduction of nucleotides in ESCC cells. Overexpression of HMGA1 upregulated PPP and promoted the survival of ESCC cells by activating TKT. We further characterized that HMGA1 promoted the transcription of TKT by interacting with and enhancing the binding of transcription factor SP1 to the promoter of TKT. Therapeutics targeting TKT with an inhibitor, oxythiamine, reduced HMGA1-induced ESCC cell proliferation and tumor growth. Together, in this study, we identified a new role of HMGA1 in ESCCs by upregulating TKT-mediated activation of PPP. Our results provided a new insight into the role of HMGA1/TKT/PPP in ESCC tumorigenesis and targeted therapy.
Asunto(s)
Progresión de la Enfermedad , Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Proteína HMGA1a , Vía de Pentosa Fosfato , Transcetolasa , Regulación hacia Arriba , Humanos , Animales , Transcetolasa/metabolismo , Transcetolasa/genética , Carcinoma de Células Escamosas de Esófago/patología , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/metabolismo , Proteína HMGA1a/metabolismo , Proteína HMGA1a/genética , Neoplasias Esofágicas/patología , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Ratones , Regulación hacia Arriba/genética , Línea Celular Tumoral , Regulación Neoplásica de la Expresión Génica , Proliferación Celular , Ratones Desnudos , Factor de Transcripción Sp1/metabolismo , Factor de Transcripción Sp1/genéticaRESUMEN
Esophageal carcinoma is amongst the prevalent malignancies worldwide, characterized by unclear molecular classifications and varying clinical outcomes. The PI3K/AKT/mTOR signaling, one of the frequently perturbed dysregulated pathways in human malignancies, has instigated the development of various inhibitory agents targeting this pathway, but many ESCC patients exhibit intrinsic or adaptive resistance to these inhibitors. Here, we aim to explore the reasons for the insensitivity of ESCC patients to mTOR inhibitors. We assessed the sensitivity to rapamycin in various ESCC cell lines by determining their respective IC50 values and found that cells with a low level of HMGA1 were more tolerant to rapamycin. Subsequent experiments have supported this finding. Through a transcriptome sequencing, we identified a crucial downstream effector of HMGA1, FKBP12, and found that FKBP12 was necessary for HMGA1-induced cell sensitivity to rapamycin. HMGA1 interacted with ETS1, and facilitated the transcription of FKBP12. Finally, we validated this regulatory axis in in vivo experiments, where HMGA1 deficiency in transplanted tumors rendered them resistance to rapamycin. Therefore, we speculate that mTOR inhibitor therapy for individuals exhibiting a reduced level of HMGA1 or FKBP12 may not work. Conversely, individuals exhibiting an elevated level of HMGA1 or FKBP12 are more suitable candidates for mTOR inhibitor treatment.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Proteína HMGA1a , Inhibidores mTOR , Proteína Proto-Oncogénica c-ets-1 , Proteína 1A de Unión a Tacrolimus , Animales , Humanos , Ratones , Línea Celular Tumoral , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas de Esófago/metabolismo , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Carcinoma de Células Escamosas de Esófago/genética , Carcinoma de Células Escamosas de Esófago/patología , Proteína HMGA1a/metabolismo , Proteína HMGA1a/genética , Ratones Desnudos , Inhibidores mTOR/farmacología , Inhibidores mTOR/uso terapéutico , Proteína Proto-Oncogénica c-ets-1/metabolismo , Proteína Proto-Oncogénica c-ets-1/genética , Transducción de Señal/efectos de los fármacos , Sirolimus/farmacología , Sirolimus/uso terapéutico , Proteína 1A de Unión a Tacrolimus/metabolismo , Proteína 1A de Unión a Tacrolimus/genética , Serina-Treonina Quinasas TOR/metabolismoRESUMEN
Chemotherapy is a primary treatment for esophageal squamous cell carcinoma (ESCC). Resistance to chemotherapeutic drugs is an important hurdle to effective treatment. Understanding the mechanisms underlying chemotherapy resistance in ESCC is an unmet medical need to improve the survival of ESCC. Herein, we demonstrate that ferroptosis triggered by inhibiting high mobility group AT-hook 1 (HMGA1) may provide a novel opportunity to gain an effective therapeutic strategy against chemoresistance in ESCC. HMGA1 is upregulated in ESCC and works as a key driver for cisplatin (DDP) resistance in ESCC by repressing ferroptosis. Inhibition of HMGA1 enhances the sensitivity of ESCC to ferroptosis. With a transcriptome analysis and following-up assays, we demonstrated that HMGA1 upregulates the expression of solute carrier family 7 member 11 (SLC7A11), a key transporter maintaining intracellular glutathione homeostasis and inhibiting the accumulation of malondialdehyde (MDA), thereby suppressing cell ferroptosis. HMGA1 acts as a chromatin remodeling factor promoting the binding of activating transcription factor 4 (ATF4) to the promoter of SLC7A11, and hence enhancing the transcription of SLC7A11 and maintaining the redox balance. We characterized that the enhanced chemosensitivity of ESCC is primarily attributed to the increased susceptibility of ferroptosis resulting from the depletion of HMGA1. Moreover, we utilized syngeneic allograft tumor models and genetically engineered mice of HMGA1 to induce ESCC and validated that depletion of HMGA1 promotes ferroptosis and restores the sensitivity of ESCC to DDP, and hence enhances the therapeutic efficacy. Our finding uncovers a critical role of HMGA1 in the repression of ferroptosis and thus in the establishment of DDP resistance in ESCC, highlighting HMGA1-based rewiring strategies as potential approaches to overcome ESCC chemotherapy resistance. Schematic depicting that HMGA1 maintains intracellular redox homeostasis against ferroptosis by assisting ATF4 to activate SLC7A11 transcription, resulting in ESCC resistance to chemotherapy.
Asunto(s)
Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Ferroptosis , Animales , Ratones , Carcinoma de Células Escamosas de Esófago/tratamiento farmacológico , Carcinoma de Células Escamosas de Esófago/genética , Neoplasias Esofágicas/tratamiento farmacológico , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Proteína HMGA1a/genética , Resistencia a Antineoplásicos/genética , Ferroptosis/genética , Proteína HMGA1b , Línea Celular TumoralRESUMEN
Intestinal dysbiosis frequently occurs in abdominal radiotherapy and contributes to irradiation (IR)-induced intestinal damage and inflammation. Akkermansia muciniphila (A. muciniphila) is a recently characterized probiotic, which is critical for maintaining the dynamics of the intestinal mucus layer and preserving intestinal microbiota homeostasis. However, the role of A. muciniphila in the alleviation of radiation enteritis remains unknown. In this study, we reported that the abundance of A. muciniphila was markedly reduced in the intestines of mice exposed to abdominal IR and in the feces of patients who received abdominal radiotherapy. Abundance of A. muciniphila in feces of radiotherapy patients was negatively correlated with the duration of diarrhea in patients. Administration of A. muciniphila substantially mitigated IR-induced intestinal damage and prevented mouse death. Analyzing the metabolic products of A. muciniphila revealed that propionic acid, a short-chain fatty acid secreted by the microbe, mediated the radioprotective effect. We further demonstrated that propionic acid bound to G-protein coupled receptor 43 (GRP43) on the surface of intestinal epithelia and increased histone acetylation and hence enhanced the expression of tight junction proteins occludin and ZO-1 and elevated the level of mucins, leading to enhanced integrity of intestinal epithelial barrier and reduced radiation-induced intestinal damage. Metformin, a first-line agent for the treatment of type II diabetes, promoted intestinal epithelial barrier integrity and reduced radiation intestinal damage through increasing the abundance of A. muciniphila. Together, our results demonstrated that A. muciniphila plays a critical role in the reduction of abdominal IR-induced intestinal damage. Application of probiotics or their regulators, such as metformin, could be an effective treatment for the protection of radiation exposure-damaged intestine.
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Diabetes Mellitus Tipo 2 , Microbioma Gastrointestinal , Metformina , Humanos , Ratones , Animales , Intestinos , Verrucomicrobia/metabolismoRESUMEN
Background: Emerging evidence reveals that SARS-CoV-2 possesses the capability to disrupt the gastrointestinal (GI) homeostasis, resulting in the long-term symptoms such as loss of appetite, diarrhea, gastroesophageal reflux, and nausea. In the current review, we summarized recent reports regarding the long-term effects of COVID-19 (long COVID) on the gastrointestine. Objective: To provide a narrative review of abundant clinical evidence regarding the development and management of long-term GI symptoms in COVID-19 patients. Results: Long-term persistent digestive symptoms are exhibited in a majority of long-COVID patients. SARS-CoV-2 infection of intestinal epithelial cells, cytokine storm, gut dysbiosis, therapeutic drugs, psychological factors and exacerbation of primary underlying diseases lead to long-term GI symptoms in COVID-19 patients. Interventions like probiotics, prebiotics, fecal microbiota transplantation, and antibiotics are proved to be beneficial in preserving intestinal microecological homeostasis and alleviating GI symptoms. Conclusion: Timely diagnosis and treatment of GI symptoms in long-COVID patients hold great significance as they may contribute to the mitigation of severe conditions and ultimately lead to the improvement of outcomes of the patients.
RESUMEN
Short-chain fatty acids (SCFAs) are the main metabolites produced by bacterial fermentation of dietary fibre in the gastrointestinal tract. The absorption of SCFAs is mediated by substrate transporters, such as monocarboxylate transporter 1 and sodium-coupled monocarboxylate transporter 1, which promote cellular metabolism. An increasing number of studies have implicated metabolites produced by microorganisms as crucial executors of diet-based microbial influence on the host. SCFAs are important fuels for intestinal epithelial cells (IECs) and represent a major carbon flux from the diet, that is decomposed by the gut microbiota. SCFAs play a vital role in multiple molecular biological processes, such as promoting the secretion of glucagon-like peptide-1 by IECs to inhibit the elevation of blood glucose, increasing the expression of G protein-coupled receptors such as GPR41 and GPR43, and inhibiting histone deacetylases, which participate in the regulation of the proliferation, differentiation, and function of IECs. SCFAs affect intestinal motility, barrier function, and host metabolism. Furthermore, SCFAs play important regulatory roles in local, intermediate, and peripheral metabolisms. Acetate, propionate, and butyrate are the major SCFAs, they are involved in the regulation of immunity, apoptosis, inflammation, and lipid metabolism. Herein, we review the diverse functional roles of this major class of bacterial metabolites and reflect on their ability to affect intestine, metabolic, and other diseases. Video Abstract.
Asunto(s)
Butiratos , Ácidos Grasos Volátiles , Propionatos , Tracto Gastrointestinal , ApoptosisRESUMEN
Abdominal irradiation (IR) destroys the intestinal mucosal barrier, leading to severe intestinal infection. There is an urgent need to find safe and effective treatments to reduce IR-induced intestinal injury. In this study, we reported that metformin protected mice from abdominal IR-induced intestinal injury by improving the composition and diversity of intestinal flora. The elimination of intestinal microbiota (Abx) abrogated the protective effects of metformin on irradiated mice. We further characterized that treatment of metformin increased the murine intestinal abundance of Lactobacillus, which mediated the radioprotective effect. The administration of Lactobacillus or fecal microbiota transplantation (FMT) into Abx mice considerably lessened IR-induced intestinal damage and restored the radioprotective function of metformin in Abx mice. In addition, applying the murine intestinal organoid model, we demonstrated that IR inhibited the formation of intestinal organoids, and metformin alone bore no protective effect on organoids after IR. However, a combination of metformin and Lactobacillus or Lactobacillus alone displayed a strong radioprotection on the organoid formation. We demonstrated that metformin/Lactobacillus activated the farnesoid X receptor (FXR) signaling in intestinal epithelial cells and hence upregulated tight junction proteins and mucins in intestinal epithelia, increased the number of goblet cells, and augmented the mucus layer thickness to maintain the integrity of intestinal epithelial barrier, which eventually contributed to reduced radiation intestinal injury. In addition, we found that Lactobacillus abundance was significantly increased in the intestine of patients receiving metformin while undergoing abdominal radiotherapy and the abundance was negatively correlated with the diarrhea duration of patients. In conclusion, our results demonstrate that metformin possesses a protective effect on IR-induced intestinal injury by upregulating the abundance of Lactobacillus in the intestine.
RESUMEN
The mammalian gastrointestinal tract is colonized with a majority of gut microbes, affecting host metabolism and homeostasis. Gut microbiota plays a vital role in nutrient exchange, signaling transduction between intestinal epithelial cells, and resistance to pathogen invasion. Gut microbiota is divided into mucus layer bacteria and intestinal lumen bacteria based on the colonization distribution. Akkermansia muciniphila (A. muciniphila) prefers to colonize in the intestinal mucus layer, and specifically degrades mucins to produce short-chain fatty acids, providing energy for the host and promoting colonization of the bacterium itself. Degradation of mucins prompts the host to compensate for the production of more mucins, thereby maintaining the dynamics of these proteins. In the intestinal micro-ecosystem, A. muciniphila is non-pathogenic, and its colonization with suitable abundance contributes to the development of immune system, thus promoting intestinal health. The mechanisms by which A. muciniphila bears a protective role in the host intestine are currently unclear. In this review, we summarize the microenvironment for the colonization of A. muciniphila, physiological characteristics and pathophysiological impact of A. muciniphila on intestinal diseases, such as irritable bowel syndrome, inflammatory bowel diseases, and intestinal tumors. We also provided updates for current studies on signals that A. muciniphila enhances intestinal barrier integrity and regulates immune response. Together, we conclude that A. muciniphila is a promising probiotic, which could be a microbial target for the treatment of multiple intestinal diseases.
Asunto(s)
Ecosistema , Enfermedades Inflamatorias del Intestino , Akkermansia , Animales , Ácidos Grasos Volátiles/metabolismo , Humanos , Mamíferos , Mucinas/metabolismo , Verrucomicrobia/metabolismoRESUMEN
Human papillomaviruses (HPVs) cause a subset of head and neck squamous cell carcinomas (HNSCCs). Previously, we demonstrated that HPV16 oncogene E6 or E6/E7 transduction increases the abundance of O-linked ß-N-acetylglucosamine (O-GlcNAc) transferase (OGT), but OGT substrates affected by this increase are unclear. Here, we focus on the effects of O-GlcNAcylation on HPV-positive HNSCCs. We found that upon HPV infection, Unc-51-like kinase 1 (ULK1), an autophagy-initiating kinase, is hyper-O-GlcNAcylated, stabilized, and linked with autophagy elevation. Through mass spectrometry, we identified that ULK1 is O-GlcNAcylated at Ser409, which is distinct from the previously reported Thr635/Thr754 sites. It has been demonstrated that PKCα mediates phosphorylation of ULK1 at Ser423, which attenuates its stability by shunting ULK1 to the chaperone-mediated autophagy (CMA) pathway. Using biochemical assays, we demonstrate that ULK1 Ser409Ser410 O-GlcNAcylation antagonizes its phosphorylation at Ser423. Moreover, mutations of Ser409A and its neighboring site Ser410A (2A) render ULK1 less stable by promoting interaction with the CMA chaperone HSC70 (heat shock cognate 70 kDa protein). Furthermore, ULK1-2A mutants attenuate the association of ULK1 with STX17, which is vital for the fusion between autophagosomes and lysosomes. Analysis of The Cancer Genome Atlas (TCGA) database reveals that ULK1 is upregulated in HPV-positive HNSCCs, and its level positively correlates with HNSCC patient survival. Overall, our work demonstrates that O-GlcNAcylation of ULK1 is altered in response to environmental changes. O-GlcNAcylation of ULK1 at Ser409 and perhaps Ser410 stabilizes ULK1, which might underlie the molecular mechanism of HPV-positive HNSCC patient survival.
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Acetilglucosamina , Homólogo de la Proteína 1 Relacionada con la Autofagia , Autofagia Mediada por Chaperones , Neoplasias de Cabeza y Cuello , Péptidos y Proteínas de Señalización Intracelular , Infecciones por Papillomavirus , Proteína Quinasa C-alfa , Carcinoma de Células Escamosas de Cabeza y Cuello , Acetilglucosamina/metabolismo , Homólogo de la Proteína 1 Relacionada con la Autofagia/genética , Homólogo de la Proteína 1 Relacionada con la Autofagia/metabolismo , Estabilidad de Enzimas , Glicosilación , Neoplasias de Cabeza y Cuello/metabolismo , Neoplasias de Cabeza y Cuello/virología , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética , Péptidos y Proteínas de Señalización Intracelular/metabolismo , N-Acetilglucosaminiltransferasas/metabolismo , Infecciones por Papillomavirus/metabolismo , Proteína Quinasa C-alfa/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/virologíaRESUMEN
Deficiency in T cell-mediated adaptive immunity, such as low CD8+ T cell infiltration, inhibits the immune surveillance, promotes malignant transformation, and facilitates tumor growth. Microbiota dysbiosis diminishes the immune system and contributes to the occurrence of cancer. However, the impact of oral dysbiosis on the occurrence and molecular mechanisms of oropharyngeal cancer (OPC) remains largely unknown. In the current study, we used 4-nitroquinoline-1-oxide (4NQO) to mimic tobacco-related carcinogenesis to generate a murine OPC model and determine the role of microbiota changes in OPC tumorigenesis. Our results showed that the oral flora composition of mice was deregulated during the tumorigenesis of OPC. The abundance of Streptococcus, Veillonella, Muribacter, Rodentibacter, and Gemella was increased, whereas the dominant genus Lactobacillus was gradually decreased with disease progression. We further demonstrated that infiltration of CD8+ T lymphocytes was markedly reduced due to the reduction of Lactobacillus. Supplementation of Lactobacillus increased the infiltration of CD8+ T cells, promoted the expression of IFN-γ and granzyme B, and lessened the OPC progression. Analyzing the metabolites of the Lactobacillus, we demonstrated that Lactobacillus enhanced the anti-tumor immune response by producing acetate in OPC development. Administration of acetate to mice could increase the expression of IFN-γ and IFN-γ-inducible chemokines in tumor tissues by activating GPR43 to promote the infiltration of CD8+ T lymphocytes and substantially delay the development of OPC. Together, our data suggest that dysbiosis of oral microbiota promotes the tumorigenesis of OPC through downregulation of cytotoxic T lymphocytes. Lactobacillus and its metabolite acetate improve the tumor microenvironment, which could be applied in the treatment of OPC.
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Abdominal irradiation (IR) may destroy the intestinal mucosal barrier, leading to severe intestinal infection and multiple organ dysfunction syndromes. The role of intestinal microbiota in the development of IR-induced intestinal injury remains largely unknown. Herein, we reported that abdominal IR altered the composition of the microbiota and reduced the abundance and diversity of the gut microbiome. Alterations of bacteria, in particular reduction of Lactobacillus, played a critical role in IR-induced intestinal injury. Fecal microbiota transplant (FMT) from normal mice or administration of Lactobacillus plantarum to intestinal microbiota-eliminated mice substantially reduced IR-induced intestinal damage and prevented mice from IR-induced death. We further characterized that L. plantarum activated the farnesoid X receptor (FXR) - fibroblast growth factor 15 (FGF15) signaling in intestinal epithelial cells and hence promoted DNA-damage repair. Application of GW4064, an activator of FXR, to microbiota eliminated mice markedly mitigated IR-induced intestinal damage, reduced intestinal epithelial cell death and promoted the survival of IR mice. In contrast, suppression of FXR with Gly-ß-MCA, a bile acid and an intestine-selective and high-affinity FXR inhibitor, abrogated L. Plantarum-mediated protection on the ileum of IR mice. Taken together, our findings not only provide new insights into the role of intestinal flora in radiation-induced intestinal injury but also shed new light on the application of probiotics for the protection of radiation-damaged individuals.
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Microbioma Gastrointestinal , Lactobacillus plantarum , Animales , Ácidos y Sales Biliares , Microbioma Gastrointestinal/fisiología , Mucosa Intestinal/metabolismo , Intestinos , Ratones , Ratones Endogámicos C57BLRESUMEN
BACKGROUND: Treatment of Crohn's disease (CD) remains to be a challenge due to limited insights for its pathogenesis. We aimed to determine the role of O-Linked ß-N-acetylglucosamine (O-GlcNAc) in the development of CD and evaluate therapeutic effects of O-GlcNAc inhibitors on CD. METHODS: O-GlcNAc in intestinal epithelial tissues of CD, adherent-invasive Escherichia coli (AIEC) LF82-infected cells and mice was determined by immunoblot and immunohistochemistry. AIEC LF82 and dextran sulfate sodium were administrated into C57BL/6 mice for estabolishing inflammatory bowel disease model and for therapeutic study. FINDINGS: O-GlcNAc was increased in intestinal epithelial tissues of CD patients and AIEC LF82-infected mice. Infection of AIEC LF82 up-regulated the level of UDP-GlcNAc and increased O-GlcNAc in human colon epithelial HCT116 and HT-29 cells. We identified that IKKß and NF-κB were O-Glycosylated in AIEC LF82-treated cells. Mutations of IKKß (S733A) and p65 (T352A) abrogated the O-GlcNAc in IKKß and NF-κB and inhibited AIEC LF82-induced activation of NF-κB. Application of 6-diazO-5-oxO-L-norleucine, an agent that blocks the production of UDP-GlcNAc and inhibits O-GlcNAc, inactivated NF-κB in AIEC LF82-infected cells, enhanced the formation of autophagy, promoted the removal of cell-associated AIEC LF82, alleviated intestinal epithelial inflammation, and improved the survival of the colitis mice. INTERPRETATION: Intestinal inflammation in CD is associated with increased O-GlcNAc modification, which is required for NF-κB activation and suppression of autophagy. Targeting O-GlcNAc could be an effective therapy for inflammatory bowel disease. FUNDING: National Natural Science Foundation of China (Nos. 81573087 and 81772924) and International Cooperation Foundation of Jilin Province (20190701006GH).
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Acetilglucosamina/metabolismo , Enfermedad de Crohn/metabolismo , FN-kappa B/metabolismo , Procesamiento Proteico-Postraduccional , Acetilación , Animales , Autofagia , Femenino , Células HCT116 , Células HT29 , Humanos , Mucosa Intestinal/metabolismo , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide. Mutations of TP53 may reach 70% - 85% in HNSCC patients without human papillomavirus (HPV) infection. Recurrence rate remains particularly high for HNSCC patients with mutations in the TP53 gene although patients are responsive to surgery, irradiation, and chemotherapy early in the treatment. p53-Reactivation and Induction of Massive Apoptosis-1 (PRIMA-1) and its methylated analogue PRIMA-1Met (also known as APR-246) are quinuclidine compounds that rescue the DNA-binding activity of mutant p53 (mut-p53) and restore the potential of wild-type p53. In the current report, we demonstrated that inhibition of poly (ADP-ribose) polymerase-1 (PARP-1) with 6(5H)-phenanthridinone (PHEN) and N-(6-Oxo-5,6-dihydrophenanthridin-2-yl)-(N, N-dimethylamino) acetamide hydrochloride (PJ34) sensitizes UMSCC1, UMSCC14, and UMSCC17A, three HNSCC cell lines to the treatment of APR-246. PHEN enhances APR-246-induced apoptosis, but not programmed necrosis or autophagic cell death in HNSCC cells. The PARP-1 inhibition-induced sensitization of HNSCC cells to APR-246 is independent of TP53 mutation. Instead, PARP-1 inhibition promotes APR-246-facilitated inactivation of thioredoxin reductase 1 (TrxR1), leading to ROS accumulation and DNA damage. Overexpression of TrxR1 or application of antioxidant N-acetyl-L-cysteine (NAC) depletes the ROS increase, reduces DNA damage, and decreases cell death triggered by APR-246/PHEN in HNSCC cells. Thus, we have characterized a new function of PARP-1 inhibitor in HNSCC cells by inactivation of TrxR1 and elevation of ROS and provide a novel therapeutic strategy for HNSCC by the combination of PARP-1 inhibitors and APR-246.
RESUMEN
TP53 mutations frequently occur in head and neck squamous cell carcinoma (HNSCC) patients without human papillomavirus infection. The recurrence rate for these patients is distinctly high. It has been actively explored to identify agents that target TP53 mutations and restore wild-type (WT) TP53 activities in HNSCC. PRIMA-1 (p53-reactivation and induction of massive apoptosis-1) and its methylated analogue PRIMA-1Met (also called APR-246) were found to be able to reestablish the DNA-binding activity of p53 mutants and reinstate the functions of WT p53. Herein we report that piperlongumine (PL), an alkaloid isolated from Piper longum L., synergizes with APR-246 to selectively induce apoptosis and autophagic cell death in HNSCC cells, whereas primary and immortalized mouse embryonic fibroblasts and spontaneously immortalized non-tumorigenic human skin keratinocytes (HaCat) are spared from the damage by the co-treatment. Interestingly, PL-sensitized HNSCC cells to APR-246 are TP53 mutation-independent. Instead, we demonstrated that glutathione S-transferase pi 1 (GSTP1), a GST family member that catalyzes the conjugation of GSH with electrophilic compounds to fulfill its detoxification function, is highly expressed in HNSCC tissues. Administration of PL and APR-246 significantly suppresses GSTP1 activity, resulting in the accumulation of ROS, depletion of GSH, elevation of GSSG, and DNA damage. Ectopic expression of GSTP1 or pre-treatment with antioxidant N-acetyl-L-cysteine (NAC) abrogates the ROS elevation and decreases DNA damage, apoptosis, and autophagic cell death prompted by PL/APR-246. In addition, administration of PL and APR-246 impedes UMSCC10A xenograft tumor growth in SCID mice. Taken together, our data suggest that HNSCC cells are selectively sensitive to the combination of PL and APR-246 due to a remarkably synergistic effect of the co-treatment in the induction of ROS by suppression of GSTP1.
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Carcinoma de Células Escamosas/patología , Dioxolanos/farmacología , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Gutatión-S-Transferasa pi/metabolismo , Neoplasias de Cabeza y Cuello/patología , Quinuclidinas/farmacología , Proteína p53 Supresora de Tumor/metabolismo , Animales , Apoptosis , Biomarcadores de Tumor/genética , Biomarcadores de Tumor/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Estudios de Casos y Controles , Proliferación Celular , Quimioterapia Combinada , Femenino , Estudios de Seguimiento , Gutatión-S-Transferasa pi/genética , Neoplasias de Cabeza y Cuello/genética , Neoplasias de Cabeza y Cuello/metabolismo , Humanos , Masculino , Ratones , Ratones SCID , Pronóstico , Células Tumorales Cultivadas , Proteína p53 Supresora de Tumor/genética , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Liver kinase B1 (LKB1) functions as a tumor suppressor encoded by STK11, a gene that mutated in Peutz-Jeghers syndrome and in sporadic cancers. Previous studies showed that LKB1 participates in IR- and ROS-induced DNA damage response (DDR). However, the impact of LKB1 mutations on targeted cancer therapy remains unknown. Herein, we demonstrated that LKB1 formed DNA damage-induced nuclear foci and co-localized with ataxia telangiectasia mutated kinase (ATM), γ-H2AX, and breast cancer susceptibility 1 (BRCA1). ATM mediated LKB1 phosphorylation at Thr 363 following the exposure of cells to ionizing radiation (IR). LKB1 interacted with BRCA1, a downstream effector in DDR that is recruited to sites of DNA damage and functions directly in homologous recombination (HR) DNA repair. LKB1 deficient cells exhibited delayed DNA repair due to insufficient HR. Notably, LKB1 deficiency sensitized cells to poly (ADP-ribose) polymerase (PARP) inhibitors. Thus, we have demonstrated a novel function of LKB1 in DNA damage response. Cancer cells lacking LKB1 are more susceptible to DNA damage-based therapy and, in particular, to drugs that further impair DNA repair, such as PARP inhibitors.
Asunto(s)
Daño del ADN , Resistencia a Antineoplásicos , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Proteínas Serina-Treonina Quinasas/metabolismo , Quinasas de la Proteína-Quinasa Activada por el AMP , Proteínas de la Ataxia Telangiectasia Mutada/metabolismo , Proteína BRCA1/metabolismo , Línea Celular Tumoral , Reparación del ADN , Recombinación Homóloga , Humanos , Fosforilación , Unión Proteica , Transporte de ProteínasRESUMEN
BACKGROUND AND AIMS: Intrahepatic lithiasis is a common disease in southeast Asia [Sheen-Chen and Chou, Acta Chir Scand 156:387-390, 1990], and a difficult problem of biliary surgery. There is no established method of treating patients with intrahepatic stones [Uchiyama et al., Arch Surg 137:149-533, 2002]. In recent years, resection of the affected liver lobe or segment is the best therapeutic option to completely remove the source of recurrent infection. The need for endoscopic treatment modalities is evident because hepatic resections are combined with a high morbidity and mortality rate [Andersson et al., HPB Surg 2:145-147, 1990; Adamek et al., Scand J Gastroenterol 34:1157-1161, 1999]. Hepatic resection only fit the cases in which the stones localized in one lobe or segment, while it doesn't fit the cases which have polystones in left and right biliary tract. Duodenoscope can only get the stones in the common bile duct and cannot deal with the intrahepatic lithiasis. The management of intrahepatic lithiasis can only be treated by intraoperative or postoperative choledochoscope. For big stones or compact stones, lithotripsy should be applied. But the laser lithotripsy and the electrohydraulic lithotripsy can cause serious complications such as perforation of bile duct. It needs a safer and more reliable treatment for intrahepatic lithiasis. The aim of our work is to study the lithotrity treatment of intrahepatic lithiasis by using helix hydro-jet under Video Choledochoscope. MATERIALS AND METHODS: From March 31, 2003 to October 20, 2004, 30 intrahepatic stone patients were treated. Eighteen of them were women and 12 were men, with ages ranging from 35 to 80 years (mean, 58 years). According to B ultrasound and computed tomography (CT) scan report, there were five cases of intrahepatic lithiasis and common bile duct stones, 25 cases of left and right hepatic duct stones, and one case with giant intrahepatic stone (1.5 x 1.5 x 1.2 cm). Intraoperative or postoperative choledochoscopic helix hydro-jet lithotripsy was applied through a video choledochoscope. For the patients to have the intraoperative choledochoscopic helix hydro-jet lithotripsy, they should be diagnosed correctly by B ultrasound or CT scan. The biliary tract reconstruction by spiral CT scan is as helpful as MRCP or ERCP for clinical diagnosis. For the patients to have the postoperative choledochoscopic helix hydro-jet lithotripsy, they should be diagnosed correctly by T-tube cholangiography and BUS and CT scan. All patients should be verified without stones remaining in the bile duct after lithotripsy by choledochoscopic examination and T-tube cholangiography, and should be examined by BUS again after 6 months to 1 year. We decide whether complications occurred by observation of symptoms and signs after choledochoscopy and lithotripsy. RESULTS: Seventy-five intrahepatic stones with diameter ranging from 0.6 to 1.5 cm were successfully fragmentized in 30 patients using of helix hydro-jet lithotripsy. These fragmentized stones mainly are bilirubin stones. The lithotripsy was carried for 45 times and the procedure needs 1-1.5 h. Helix hydro-jet lithotripsy are used in 16 cases during operation and 12 cases after operation; two cases during operation and after operation. Intrahepatic calculosis was cleaned out completely and verified by postoperative choledochoscope examination and postoperative T-tube cholangiography examination. No complications were observed. CONCLUSION: Helix hydro-jet lithotripsy under video choledochoscope is a safe and effective method for the removal of intrahepatic stone. No bile duct damnified and perforation was observed. The procedure is without pain and heat, and the pressure can be adjusted easily. The research provides a new way of using the helix hydro-jet, and a new way of curing the intrahepatic lithiasis.