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1.
Acad Radiol ; 2024 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-39227217

RESUMO

RATIONALE AND OBJECTIVES: Immune checkpoint inhibitors (ICIs) have improved lung cancer prognosis; however, ICI-related interstitial lung disease (ILD) is fatal and difficult to predict. Herein, we hypothesized that pre-existing lung inflammation on radiological imaging can be a potential risk factor for ILD onset. Therefore, we investigated the association between high uptake in noncancerous lung (NCL) on 18F- FDG-PET/CT and ICI-ILD in lung cancer. METHODS: Patients with primary lung cancer who underwent FDG-PET/CT within three months prior to ICI therapy were retrospectively included. Artificial intelligence was utilized for extracting the NCL regions (background lung) from the lung contralateral to the primary tumor. FDG uptake by the NCL was assessed via the SUVmax (NCL-SUVmax), SUVmean (NCL-SUVmean), and total glycolytic activity (NCL-TGA)defined as NCL-SUVmean×NCL volume [mL]. NCL-SUVmean and NCL-TGA were calculated using the following four SUV thresholds: 0.5, 1.0, 1.5, and 2.0. RESULTS: Of the 165 patients, 28 (17.0%) developed ILD. Univariate analysis showed that high values of NCL-SUVmax, NCL-SUVmean2.0 (SUV threshold=2.0), and NCL-TGA1.0 (SUV threshold=1.0) were significantly associated with ILD onset (all p = 0.003). Multivariate analysis adjusted for age, tumor FDG uptake, and pre-existing interstitial lung abnormalities revealed that a high NCL-TGA1.0 (≥149.45) was independently associated with ILD onset (odds ratio, 6.588; p = 0.002). Two-year cumulative incidence of ILD was significantly higher in the high NCL-TGA1.0 group than in the low group (58.4% vs. 14.4%; p < 0.001). CONCLUSION: High uptake of NCL on FDG-PET/CT is correlated with ICI-ILD development, which could serve as a risk stratification tool before ICI therapy in primary lung cancer.

2.
Transl Lung Cancer Res ; 11(9): 1858-1865, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36248339

RESUMO

Background: Although the addition of immune checkpoint inhibitors (ICIs) to platinum-doublet chemotherapy has improved the efficacy of first-line therapy in extensive-disease small cell lung cancer (SCLC) patients, the best treatment option for patients with recurrent SCLC has not yet been determined. We conducted a retrospective study to evaluate the efficacy and safety of amrubicin (AMR) therapy after treatment with ICIs. Methods: We retrospectively assessed patients with recurrent SCLC who received AMR after chemoimmunotherapy at the Niigata Lung Cancer Treatment Group from August 2019 to February 2021. Results: This analysis included 30 patients. The median progression-free survival (PFS) and overall survival (OS) were 3.8 (95% CI: 2.7-4.2) and 10 (95% CI: 7.4-14.8) months, respectively. The median PFS and OS did not significantly differ between the sensitive and refractory groups [PFS; 3.1 (95% CI: 1.1-4.0) vs. 4.2 (95% CI: 2.3-4.8) months, P=0.1142, OS; 10.0 (95% CI: 5.2-14.8) vs. 10.4 (95% CI: 3.8-NE) months, P=0.5525]. The most common adverse event was grade ≥3 neutropenia, which occurred in 22 of 30 patients (73%), and 2 patients (7%) discontinued AMR due to adverse events. Conclusions: AMR after chemoimmunotherapy shows good clinical efficacy and safety in patients with recurrent SCLC.

3.
Transl Lung Cancer Res ; 11(7): 1359-1368, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35958345

RESUMO

Background: This multicenter, open-label, single-arm phase II study [Niigata Lung Cancer Treatment Group (NLCTG) 1302] was conducted to evaluate the efficacy and safety of nanoparticle albumin-bound paclitaxel (nab-paclitaxel) monotherapy for previously treated patients with advanced non-small cell lung cancer (NSCLC). We also investigated chemotherapy-induced peripheral neuropathy (CIPN) to evaluate the quality of life (QOL). Methods: Sixty-five patients with advanced NSCLC from 14 participating institutions who had previously undergone one or two cytotoxic chemotherapy regimens were enrolled in this study. The patients received 100 mg/m2 nab-paclitaxel intravenously on days 1, 8, and 15, every 4 weeks. The primary endpoint was overall objective response rate. CIPN symptoms were prospectively assessed using the Patient Neurotoxicity Questionnaire (PNQ) and Common Terminology Criteria for Adverse Events (CTCAE). Results: The overall response rate (ORR) was 18.5% [95% confidence interval (CI): 10.9-29.6%], and the median progression-free survival (PFS) was 3.4 (95% CI: 2.5-4.3) months. Median overall survival (OS) was 8.6 (95% CI: 7.1-10.2) months. The most common non-hematologic grade ≥3 adverse events were infection (7.7%) and hyponatremia (4.6%). Neutropenia was the most common grade 3 or 4 adverse event (30.8%), and febrile neutropenia developed in 6.2% patients. The PNQ and CTCAE scores for motor peripheral neuropathy were low (kappa =0.10). Conclusions: The primary endpoint was achieved. Nab-paclitaxel was well tolerated and showed anti-tumor activity in patients with previously treated NSCLC. This study demonstrates a low degree of concordance in CIPN grading between physicians and patients. Trial Registration: University hospital Medical Information Network Clinical Trial Registry (ID: UMIN000012343).

4.
Transl Lung Cancer Res ; 11(1): 43-52, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35242626

RESUMO

BACKGROUND: Procalcitonin (PCT) is a serological marker whose utility has been established in infectious disease areas. Although serum calcitonin is a prognostic predictor in patients with medullary thyroid carcinoma, the clinical usefulness of PCT remains unclear in lung cancer patients. METHODS: As a discovery cohort, we retrospectively analyzed consecutive patients with non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) who received first-line chemotherapy at our institution, and PCT blood levels were measured. As the validation cohort, PCT blood levels were prospectively evaluated in SCLC patients before first-line chemotherapy. The correlation between a PCT increase and prognosis was examined in the discovery and validation cohorts. RESULTS: Twenty-three SCLC patients and 26 NSCLC patients were enrolled as the discovery cohort, and 30 SCLC patients were enrolled as the validation cohort. The PCT level in SCLC patients was significantly higher than that in NSCLC patients. The PCT level was not associated with WBC count and weakly associated with the CRP level. In both the discovery and validation cohorts, the median survival time was significantly shorter in SCLC patients with PCT-high than in SCLC patients with PCT-normal (discovery; 11.7 vs. 89.7 months, P<0.005, validation; 9.6 vs. 22.6 months, P<0.005). CONCLUSIONS: It may be difficult to differentiate bacterial infections in SCLC patients by PCT, as PCT is elevated even in SCLC patients without infectious diseases. This is the first study to prospectively verify that pretreatment PCT levels have a significant negative correlation with prognosis in SCLC patients.

5.
Cancers (Basel) ; 15(1)2022 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-36612200

RESUMO

Anaplastic lymphoma kinase (ALK)-positive lung cancer is a rare cancer that occurs in approximately 5% of non-small-cell lung cancer (NSCLCs) patients. Despite the excellent efficacy of ALK-tyrosine kinase inhibitor in ALK-positive NSCLCs, most patients experience resistance. We conducted a phase II study to investigate the combination of alectinib with bevacizumab in ALK-positive NSCLC patients after failure of alectinib. In this study, ALK-positive nonsquamous NSCLC patients previously treated with alectinib received bevacizumab 15 mg/kg on day 1 every 3 weeks and alectinib 600 mg/day until disease progression. The primary endpoints were progression-free survival (PFS) and the safety of alectinib and bevacizumab. The secondary endpoints included overall survival (OS) and correlation of circulating tumor DNA and plasma proteins with PFS. Of the 12 patients treated, the median PFS was 3.1 months (95% CI 1.2-16.1), and the median OS was 24.1 months (95% CI 8.3-not estimable). The EML4-ALK fusion gene in circulating tumor DNA was significantly correlated with shorter PFS (1.2 months vs. 11.4 months, HR 5.2, p = 0.0153). Two patients experienced grade 3 adverse events; however, none of the patients required dose reduction. Although the primary endpoint was not met, alectinib combined with bevacizumab showed clinical efficacy in ALK-positive patients.

6.
Cancer Immunol Immunother ; 71(6): 1357-1369, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34657194

RESUMO

Lymphodepleting cytotoxic regimens enhance the antitumor effects of adoptively transferred effector and naïve T cells. Although the mechanisms of antitumor immunity augmentation by lymphodepletion have been intensively investigated, the effects of lymphodepletion followed by T cell transfer on immune checkpoints in the tumor microenvironment remain unclear. The current study demonstrated that the expression of immune checkpoint molecules on transferred donor CD4+ and CD8+ T cells was significantly decreased in lymphodepleted tumor-bearing mice. In contrast, lymphodepletion did not reduce immune checkpoint molecule levels on recipient CD4+ and CD8+ T cells. Administration of anti-PD-1 antibodies after lymphodepletion and adoptive transfer of T cells significantly inhibited tumor progression. Further analysis revealed that transfer of both donor CD4+ and CD8+ T cells was responsible for the antitumor effects of a combination therapy consisting of lymphodepletion, T cell transfer and anti-PD-1 treatment. Our findings indicate that a possible mechanism underlying the antitumor effects of lymphodepletion followed by T cell transfer is the prevention of donor T cell exhaustion and dysfunction. PD-1 blockade may reinvigorate exhausted recipient T cells and augment the antitumor effects of lymphodepletion and adoptive T cell transfer.


Assuntos
Linfócitos T CD8-Positivos , Neoplasias , Transferência Adotiva , Animais , Humanos , Imunoterapia Adotiva , Camundongos , Neoplasias/terapia , Receptor de Morte Celular Programada 1 , Microambiente Tumoral
7.
Front Oncol ; 11: 704475, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34631533

RESUMO

OBJECTIVES: Although immune checkpoint inhibitors (ICIs) have been shown to improve overall survival (OS) in advanced non-small-cell lung cancer (NSCLC) patients, ICIs sometimes cause various types of immune-related adverse events (irAEs), which lead to the interruption of ICI treatment. This study aims to evaluate the clinical significance of the continuation of ICIs in NSCLC patients with irAEs and to assess the safety and efficacy of the readministration of ICIs after their discontinuation due to irAEs. METHODS: We retrospectively identified patients with advanced NSCLC who were treated with first- to third-line anti-programmed cell death-1 (PD-1) therapy from January 2016 through October 2017 at multiple institutions belonging to the Niigata Lung Cancer Treatment Group. Progression-free survival (PFS) and OS from the initiation of ICI treatment were analyzed in patients with and without irAEs, with and without ICI interruption, and with and without ICI readministration. A 6-week landmark analysis of PFS and OS was performed to minimize the lead-time bias associated with time-dependent factors. RESULTS: Of 231 patients who received anti-PD-1 antibodies, 93 patients (40%) developed irAEs. Of 84 eligible patients with irAEs, 32 patients (14%) continued ICIs, and OS was significantly longer in patients who continued ICIs than that in patients who discontinued ICIs [not reached (95% CI: NE-NE) vs. not reached (95% CI: 22.4-NE); p = 0.025]. Of 52 patients who discontinued ICIs, 14 patients (6.1%) readministered ICIs, and OS in patients with ICI readministration was significantly longer than that in patients without ICI readministration [not reached (95% CI: NE-NE) vs. not reached (95% CI: 8.4-NE); p = 0.031]. CONCLUSION: The current study demonstrated that both the continuation and readministration of ICIs after irAE occurrence improved OS compared to the permanent interruption of ICIs in NSCLC patients with ICI-related irAEs.

8.
Transl Lung Cancer Res ; 10(7): 3132-3143, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34430353

RESUMO

BACKGROUND: Although immune checkpoint inhibitors (ICIs) are effective for advanced non-small cell lung cancer (NSCLC), ICIs may cause interstitial lung disease (ILD), which results in treatment discontinuation and is sometimes fatal. Despite the high incidence of ICI-related ILD, there are few cancer treatment options for patients. This study aimed to evaluate the safety and efficacy of subsequent systemic cancer therapy in NSCLC patients with ICI-related ILD. METHODS: We retrospectively assessed NSCLC patients who received programmed cell death-1 (PD-1) inhibitors as first- to third-line therapy at participating institutions of the Niigata Lung Cancer Treatment Group from January 2016 to October 2017. RESULTS: This analysis included 231 patients, 32 (14%) of whom developed ICI-related ILD. Of these patients, 16 (7%) received subsequent systemic cancer treatments. The median overall survival (OS) tended to be longer in the systemic cancer therapy group than in the no systemic cancer therapy group [22.2 months (95% CI: 1-NE) vs. 4.5 months (95% CI: 1-NE); P=0.067]. ICI-related ILD recurred in half of the patients who received systemic cancer therapy, and the median OS tended to be shorter in patients with recurrent ICI-related ILD [22.0 months (95% CI: 1-NE) vs. 7.0 months (95% CI: 1-NE); P=0.3154]. CONCLUSIONS: According to the current study, systemic cancer treatment is effective in patients with ICI-related ILD; however, its safety is uncertain because of the high risk of ICI-related ILD recurrence and poor survival outcome following ILD recurrence.

9.
Sci Rep ; 11(1): 750, 2021 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-33437029

RESUMO

Cisplatin, one of the most active anticancer agents, is widely used in standard chemotherapy for various cancers. Cisplatin is more poorly tolerated than other chemotherapeutic drugs, and the main dose-limiting toxicity of cisplatin is its nephrotoxicity, which is dose-dependent. Although less toxic methods of cisplatin administration have been established, cisplatin-induced nephrotoxicity remains an unsolved problem. Megalin is an endocytic receptor expressed at the apical membrane of proximal tubules. We previously demonstrated that nephrotoxic drugs, including cisplatin, are reabsorbed through megalin and cause proximal tubular cell injury. We further found that cilastatin blocked the binding of cisplatin to megalin in vitro. In this study, we investigated whether cilastatin could reduce cisplatin-induced nephrotoxicity without influencing the antitumor effects of cisplatin. Nephrotoxicity was decreased or absent in mice treated with cisplatin and cilastatin, as determined by kidney injury molecule-1 staining and the blood urea nitrogen content. Combined with cilastatin, a twofold dose of cisplatin was used to successfully treat the mice, which enhanced the antitumor effects of cisplatin but reduced its nephrotoxicity. These findings suggest that we can increase the dose of cisplatin when combined with cilastatin and improve the outcome of cancer patients.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Neoplasias do Colo/tratamento farmacológico , Insuficiência Renal/prevenção & controle , Animais , Apoptose , Proliferação de Células , Cilastatina/administração & dosagem , Cisplatino/administração & dosagem , Neoplasias do Colo/metabolismo , Neoplasias do Colo/patologia , Feminino , Taxa de Filtração Glomerular , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Camundongos Endogâmicos NOD , Camundongos SCID , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
10.
Cells ; 9(11)2020 11 03.
Artigo em Inglês | MEDLINE | ID: mdl-33153169

RESUMO

Ribosomal RNA (rRNA), the most abundant non-coding RNA species, is a major component of the ribosome. Impaired ribosome biogenesis causes the dysfunction of protein synthesis and diseases called "ribosomopathies," including genetic disorders with cancer risk. However, the potential role of rRNA gene (rDNA) alterations in cancer is unknown. We investigated germline and somatic single-nucleotide variants (SNVs) in the rDNA promoter region (positions -248 to +100, relative to the transcription start site) in 82 lung adenocarcinomas (LUAC). Twenty-nine tumors (35.4%) carried germline SNVs, and eight tumors (9.8%) harbored somatic SNVs. Interestingly, the presence of germline SNVs between positions +1 and +100 (n = 12; 14.6%) was associated with significantly shorter recurrence-free survival (RFS) and overall survival (OS) by univariate analysis (p < 0.05, respectively), and was an independent prognostic factor for RFS and OS by multivariate analysis. LUAC cell line PC9, carrying rDNA promoter SNV at position +49, showed significantly higher ribosome biogenesis than H1650 cells without SNV. Upon nucleolar stress induced by actinomycin D, PC9 retained significantly higher ribosome biogenesis than H1650. These results highlight the possible functional role of SNVs at specific sites of the rDNA promoter region in ribosome biogenesis, the progression of LUAC, and their potential prognostic value.


Assuntos
Adenocarcinoma de Pulmão/genética , Povo Asiático/genética , Mutação em Linhagem Germinativa/genética , Neoplasias Pulmonares/genética , Polimorfismo de Nucleotídeo Único/genética , Regiões Promotoras Genéticas , RNA Ribossômico/genética , Idoso , Sequência de Bases , Linhagem Celular Tumoral , Dactinomicina/farmacologia , Bases de Dados Genéticas , Feminino , Loci Gênicos , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Recidiva Local de Neoplasia/patologia , Modelos de Riscos Proporcionais , Reprodutibilidade dos Testes , Análise de Sobrevida
11.
PLoS One ; 12(8): e0183976, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28854279

RESUMO

The adoptive transfer of effector T cells combined with lymphodepletion has demonstrated promising antitumor effects in mice and humans, although the availability of tumor-specific T cells is limited. We and others have also demonstrated that the transfer of polyclonal naïve T cells induces tumor-specific effector T cells and enhances antitumor immunity after lymphodepletion. Because tumors have been demonstrated to induce immunosuppressive networks and regulate the function of T cells, obtaining a sufficient number of fully functional naïve T cells that are able to differentiate into tumor-specific effector T cells remains difficult. To establish culture methods to obtain a large number of polyclonal T cells that are capable of differentiating into tumor-specific effector T cells, naïve T cells were activated with anti-CD3 mAbs in vitro. These cells were stimulated with IL-2 and IL-7 for the CD8 subset or with IL-7 and IL-23 for the CD4 subset. Transfer of these hyperexpanded T cells after lymphodepletion showed significant antitumor efficacy, and tumor-specific effector T cells were primed from these expanded T cells in tumor-bearing hosts. Moreover, these ex vivo-expanded T cells maintained T cell receptor diversity and showed long-term persistence of memory against specific tumors. Further analyses revealed that combination therapy consisting of vaccination with dendritic cells that were co-cultured with irradiated whole tumor cells and the transfer of ex vivo-expanded T cells significantly enhanced antitumor immunity. These results indicate that the transfer of ex vivo-expanded polyclonal T cells can be combined with other immunotherapies and augment antitumor effects.


Assuntos
Transferência Adotiva/métodos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/transplante , Neoplasias/terapia , Animais , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Proliferação de Células , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/transplante , Feminino , Interleucina-2/imunologia , Interleucina-23/imunologia , Interleucina-7/imunologia , Ativação Linfocitária , Depleção Linfocítica , Camundongos Endogâmicos C57BL , Neoplasias/imunologia , Receptores de Antígenos de Linfócitos T/imunologia
12.
BMC Cancer ; 16: 222, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26979596

RESUMO

BACKGROUND: Nephrotoxicity is the major side effect that limits the dose of cisplatin that can be safely administered, and it is a clinical problem in cancer patients who received cisplatin combination chemotherapy. Recent evidence has demonstrated that patients with chronic kidney disease (CKD) have an increased risk of developing acute kidney injury (AKI). The present study was conducted to evaluate the prevalence of CKD risk factors in patients who received cisplatin and to assess the correlation between CKD risk factors and cisplatin-induced AKI. METHODS: We retrospectively analyzed 84 patients treated with cisplatin combination chemotherapy for thoracic malignancies. AKI was defined as a decrease in the estimated glomerular filtration rate (eGFR) > 25% from base line, an increase in the serum creatinine (sCre) level of > 0.3 mg/dl or ≥ 1.5 times the baseline level. RESULTS: Eighty of the 84 patients (95.2%) had at least one risk factor for CKD. All enrolled patients received cisplatin with hydration, magnesium supplementation and mannitol. Cisplatin-induced AKI was observed in 18 patients (21.4%). Univariate analysis revealed that cardiac disease and use of non-steroidal anti-inflammatory drugs (NSAIDs) were associated with cisplatin-induced nephrotoxicity (odds ratios [OR] 6 and 3.56, 95% confidence intervals [CI] 1.21-29.87 and 1.11-11.39, p = 0.04 and p = 0.04, respectively). Multivariate analysis revealed that cisplatin nephrotoxicity occurred significantly more often in patients with both risk factors (OR 13.64, 95% CI 1.11-326.83, p = 0.04). Patients with more risk factors for CKD tended to have a greater risk of developing cisplatin-induced AKI. CONCLUSIONS: We should consider avoiding administration of cisplatin to patients with CKD risk factors, particularly cardiac disease and NSAID use.


Assuntos
Injúria Renal Aguda/patologia , Cisplatino/efeitos adversos , Insuficiência Renal Crônica/patologia , Neoplasias Torácicas/tratamento farmacológico , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/tratamento farmacológico , Adulto , Idoso , Anti-Inflamatórios não Esteroides/administração & dosagem , Cisplatino/administração & dosagem , Creatinina/sangue , Quimioterapia Combinada , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência Renal Crônica/tratamento farmacológico , Fatores de Risco , Neoplasias Torácicas/complicações , Neoplasias Torácicas/patologia
13.
Gan To Kagaku Ryoho ; 42(7): 847-9, 2015 Jul.
Artigo em Japonês | MEDLINE | ID: mdl-26197747

RESUMO

Pneumatosis cystoides intestinalis (PCI) is a relatively rare condition, characterized by subserosal or submucosal air within the bowel wall. Herein, we report a rare case of PCI secondary to treatment with an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI). A 71-year-old man, who had received gefitinib therapy for 2 years and 5 months for lung adenocarcinoma with metastases to the bones and brain, presented with abdominal pain, diarrhea, and vomiting. Computed tomography of the abdomen revealed intramural air in the small bowel, free air in the abdomen, and moderate ascites. A diagnosis of PCI was made, and the patient was managed conservatively by discontinuing gefitinib treatment, because his vital signs were stable and there was no sign of peritonitis. The patient's symptoms gradually improved, and follow-up CT after 1 week revealed that the initial findings had almost completely resolved. Clinicians should note that treatment with gefitinib might cause PCI.


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/efeitos adversos , Neoplasias Pulmonares/tratamento farmacológico , Pneumatose Cistoide Intestinal/induzido quimicamente , Quinazolinas/efeitos adversos , Adenocarcinoma de Pulmão , Idoso , Antineoplásicos/uso terapêutico , Diarreia/etiologia , Gefitinibe , Humanos , Masculino , Pneumatose Cistoide Intestinal/diagnóstico por imagem , Quinazolinas/uso terapêutico , Tomografia Computadorizada por Raios X , Vômito/etiologia
14.
PLoS One ; 9(10): e111019, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25343452

RESUMO

The specific mechanisms how lung cancer cells harboring epidermal growth factor receptor (EGFR) activating mutations can survive treatment with EGFR-tyrosine kinase inhibitors (TKIs) until they eventually acquire treatment-resistance genetic mutations are unclear. The phenotypic diversity of cancer cells caused by genetic or epigenetic alterations (intratumor heterogeneity) confers treatment failure and may foster tumor evolution through Darwinian selection. Recently, we found DDX3X as the protein that was preferentially expressed in murine melanoma with cancer stem cell (CSC)-like phenotypes by proteome analysis. In this study, we transfected PC9, human lung cancer cells harboring EGFR exon19 deletion, with cDNA encoding DDX3X and found that DDX3X, an ATP-dependent RNA helicase, induced CSC-like phenotypes and the epithelial-mesenchymal transition (EMT) accompanied with loss of sensitivity to EGFR-TKI. DDX3X expression was associated with upregulation of Sox2 and increase of cancer cells exhibiting CSC-like phenotypes, such as anchorage-independent proliferation, strong expression of CD44, and aldehyde dehydrogenase (ALDH). The EMT with switching from E-cadherin to N-cadherin was also facilitated by DDX3X. Either ligand-independent or ligand-induced EGFR phosphorylation was inhibited in lung cancer cells that strongly expressed DDX3X. Lack of EGFR signal addiction resulted in resistance to EGFR-TKI. Moreover, we found a small nonadherent subpopulation that strongly expressed DDX3X accompanied by the same stem cell-like properties and the EMT in parental PC9 cells. The unique subpopulation lacked EGFR signaling and was highly resistant to EGFR-TKI. In conclusion, our data indicate that DDX3X may play a critical role for inducing phenotypic diversity, and that treatment targeting DDX3X may overcome primary resistance to EGFR-TKI resulting from intratumor heterogeneity.


Assuntos
RNA Helicases DEAD-box/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Receptores ErbB/genética , Heterogeneidade Genética , Neoplasias Pulmonares/genética , Mutação/genética , Inibidores de Proteínas Quinases/farmacologia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Humanos , Immunoblotting , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/patologia , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Fenótipo , Fosforilação/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , beta Catenina/metabolismo
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