5 research outputs found
EGFR λμ°λ³μ΄λ₯Ό κ°λ NSCLCνμμμ 3μΈλ EGFR TKIμΈ λ λΌμ (λ μ΄μ ν°λ)μ λν μλ‘μ΄ λ΄μ± κΈ°μ , βEGFR/BRAF fusionβ μ λν μ°κ΅¬
EGFR-TKI is an established first-line therapy for NSCLC with activating EGFR mutations. Lazertinib (YH25448), 3rd-generation EGFR-TKI, has been reported as an outstanding drug that had similar efficacy as osimertinib which was investigated as a first-in-class drug. Apart from its significant clinical benefits, it inevitably triggers an acquired drug resistance. Diverse resistance mechanisms to 3rd-generation EGFR TKI have been reported including loss of EGFR T790M, acquirement of EGFR C797S mutation, Met amplification, activation of other bypass pathway. However, a large part of the resistance mechanisms remains unknown so far. To explore the mechanism of resistance to lazertinib, I established lazertinib-resistant cell lines with four NSCLC cells including the patient-derived cell line (PDC), patient-derived tumor xenograft cell line (PDTC) and ATCC cell lines. I found that the EGFR/BRAF fusion mRNA and protein were specifically upregulated in an established lazertinib-resistant cell line. Consistently, I detected the EGFR/BRAF fusion gene expression in patient-derived xenografts obtained from patients who experienced acquired resistance to lazertinib. Most notably, combination treatment of lazertinib and MEK inhibitor obviously overcame lazertinib-acquired resistance with EGFR/BRAF fusion in vitro and in vivo. These findings indicate that the combination therapy of EGFR and MEK inhibitors might be a promising therapeutic option for overcoming lazertinib-acquired resistant NSCLC patients with EGFR/BRAF fusion gene in clinic.
μ μΈκ³μ μΌλ‘ νμμ μ κ΄λ ¨ μ¬λ§μ μ£Όμ μμΈ μ€ νλμ
λλ€. λΉμ μΈν¬ νμ (NSCLC) μ€μμ ννΌ μ±μ₯ μΈμ μμ©μ²΄ (EGFR) λμ°λ³μ΄λ νμ μμΈμ μλΉ λΆλΆμ μ°¨μ§ν©λλ€. μ΄μ λ°λΌ EGFR λμ°λ³μ΄λ₯Ό κ°λ NSCLC νμμμ moleculartargeted therapy μΈ EGFR tyrosine kinase inhibitors (TKIs) μ λν μ°κ΅¬κ° νλ°ν΄μ‘μ΅λλ€. EGFR TKI λ EGFR λμ°λ³μ΄λ₯Ό νμ±ννλ NSCLC μ λν΄ ν립λ first-line therapy μ
λλ€. NSCLC μμ EGFR λμ°λ³μ΄μ μ½ 85 %λ₯Ό μ°¨μ§νλ Exon 19 deletion κ³Ό Exon 21 missense mutation (L858R) μ 1 μΈλ λ° 2 μΈλ EGFR TKI μ λ°μν©λλ€. μ΄κΈ°μ μ’μ μΉλ£ν¨κ³Όμλ λΆκ΅¬νκ³ λλΆλΆμ νμλ μΉλ£ 9-13 κ°μ ν λΆκ°νΌνκ² disease progression μ΄ μ§νλκ² λ©λλ€. νμμ μ½ 50-60 %λ 1 μΈλ λ° 2 μΈλ EGFR TKI μ λν νμ²μ λ΄μ± κΈ°μ μΌλ‘μ¨ T790M λμ°λ³μ΄λ₯Ό κ°κ² λλ©°, μ΄μ λ°λΌ 3 μΈλ EGFR TKI κ° T790M λμ°λ³μ΄ NSCLC μ νκ² νμ¬ κ°λ°λμμ΅λλ€. Lazertinib μ 3 μΈλ EGFR TKI μ€ νλμ΄λ©° T790M λ΄μ± λμ°λ³μ΄λ‘ νμ±νλ EGFR μ μ νμ μΌλ‘ μ°¨λ¨ν©λλ€. λν Lazertinib μ μμ I / II μ dose-escalation μ°κ΅¬μμ νλ₯ν μΉλ£ν¨κ³Όλ₯Ό 보μκ³ , νμ¬ EGFR λμ°λ³μ΄λ₯Ό κ°λ locally advanced νΉμ metastatic NSCLC νμμμ first-line treatment λ‘μ¨μ lazertinib μ ν¨λ₯κ³Ό μμ μ±μ νκ°νκΈ° μν΄ μ§νμ€μΈ μμ 3 μ μ°κ΅¬κ° μ§ν μ€μ
λλ€. Lazertinib μ μμμμ λ°μ΄λ ν¨κ³Όλ₯Ό 보μμ§λ§ νμ°μ μΌλ‘ λ€λ₯Έ EGFR TKIμ λ§μ°¬κ°μ§λ‘ λ΄μ±μ κ°κ² λ κ²μ
λλ€. Lazertinib μ λν λ΄μ± κΈ°μ μ μ‘°μ¬νκΈ° μν΄, 6 κ°μ μ΄μμ κΈ°κ° λμ ATCC, PDC, PDX cell line μμ lazertinib μ λν λ΄μ± μΈν¬μ£Όλ₯Ό λ§λ€μμ΅λλ€. κΈ°μ‘΄μ μΈν¬μ£Όμ λΉκ΅νμ¬ λ§λ€μ΄μ§ λ΄μ±μΈν¬μ£Ό(YH1R)μμ μλ‘μ΄ μκΈ°λ genetic level, molecular level, drug screening μ μΈκ°μ§ μΈ‘λ©΄μμ μ°κ΅¬λ₯Ό μ§ννμμ΅λλ€. κ·Έ κ²°κ³Ό RNA-seq λΆμμ ν΅ν΄ genetic alteration, gene expression level μ νμΈνλ κ³Όμ μμ νκ²μ λ°κ΅΄νμμ΅λλ€. PC9GR_YH1R μΈν¬μ£Όμμ μλ‘μ΄ EGFR / BRAF fusion transcript λ₯Ό λ°κ²¬νμκ³ , EGFR / BRAF fusion mRNA λ° protein μ΄ lazertinib λ΄μ± μΈν¬μ£Όμμ νΉμ΄μ μΌλ‘ λ°νλμμ΅λλ€. ν₯λ―Έλ‘κ²λ EGFR / BRAF fusion gene μ΄ lazertinib μ λν λ΄μ±μ κ°λ νμλ‘λΆν° μ»μ νμ μ λ μν(PDTX)μμ λν λ°κ²¬λμμ΅λλ€. λ§μ§λ§μΌλ‘ lazertinib κ³Ό MEK inhibitor μ λ³μ© μΉλ£κ° EGFR/BRAF fusion μ κ°λ lazertinib resistant model μμ resistant λ₯Ό 극볡ν μ μλ€λ κ²μ in vitro λ° in vivo study λ₯Ό ν΅ν΄ μ¦λͺ
νμμ΅λλ€. λ³Έ μ°κ΅¬λ₯Ό ν΅ν΄ lazertinib μ λν νμ²μ λ΄μ±μ κ°μ§ NSCLC μΈν¬μμ lazertinib μ λ΄μ±κΈ°μ μΌλ‘μ μλ‘μ΄ EGFR / BRAF fusion gene μ λ°κ²¬νμ΅λλ€. λν lazertinib μΌλ‘ νλν λ΄μ± NSCLC model μμ κ°λ ₯ν ν μ’
μ ν¨κ³Όλ₯Ό 보μ¬μ€ lazertinib κ³Ό trametinib μ λ³μ© μΉλ£λ₯Ό μ μν©λλ€. μ΄λ¬ν λ°κ²¬μ EGFR κ³Ό MEK inhibitor μ λ³μ© μλ²μ΄ μμμμ lazertinib μ μν λ΄μ±μ κ°λ NSCLC νμλ₯Ό μν μ λ§ν μΉλ£ μ΅μ
μΌ μ μμμ λνλ
λλ€.openμ
μΆμν¨λͺ¨μμ νμ ν κ²½λ‘μ λ°λ₯Έ μ νΈμμ΄-μ μ’ν¨μ λ§λ¬Όλ¦Ό κΈ°μμ μ°¨μ΄ λΆμ
νμλ
Όλ¬Έ(μμ¬)--μμΈλνκ΅ λνμ :μμ°κ³Όνλν μλͺ
κ³ΌνλΆ,2020. 2. κΉνμ.In yeast, 30% of proteome is targeted to the endoplasmic reticulum (ER) as the first stage secretory pathway. The translocation into ER could be separated into three steps: delivery from the cytosol to ER surface, an engagement of substrate and translocon, and after initiation of translocation.
This study focused on the early stage docking process. To explain the dynamics of translocation, the head-in and inversion model and looped conformation model have been suggested. Thus, the purpose of this study is examining the suitability of models. For this, I classified the signal sequences depended on which model signals sequences followed. The test substrates were derived from CPY from modifying the length of N-region and the hydrophobicity of signal sequence.
I sought that Sec62 dependent and SRP independent signal sequences were inhibited their translocation by long N-region, and the positive charge rescued translocation of them. The translocation of SRP dependent signal sequences was originally not affected by the length of N-region. However, when the positive charge of N-region was eliminated, translocation of SRP dependent signal sequences shown Sec62 and Sec71/72 dependence and were affected by N-region length.
Therefore, these were suggested that 1) post-translocational substrate follows the head-in and inversion model, which is easily affected by the length of N-region, and 2) co-translocational substrate follows two models alternatively pursuant to charge distribution around the signal sequence.
Furthermore, the effects of N-region length and charge distribution were generally occurred at the other natural signal sequences, not only for CPY and its derivatives.μΆμν¨λͺ¨μ λ§ λ¨λ°±μ§κ³Ό λΆλΉ λ¨λ°±μ§μ λΆλΉκ²½λ‘μ 첫 λ¨κ³λ‘ μν¬μ²΄λ‘ ν₯νλ©° μ΄λ μ 체 ν¨λͺ¨ λ¨λ°±μ§μ²΄μ μ½ 30%λ₯Ό μ리νλ€. λ°λΌμ μν¬μ²΄λ‘μ μ μ’λ₯Ό ꡬμ±νλ μΈ λ¨κ³; μΈν¬μ§μμ ν©μ±λ λ¨λ°±μ§μ΄ μν¬μ²΄λ‘ κ·Όμ νλ λ¨κ³, λ¨λ°±μ§μ μλ―Έλ
Έ λ§λ¨μ΄ μ μν¨μ 볡ν©μ²΄ SECκ³Ό μνΈμμ©μ μμνλ λ¨κ³, μ μ’κ° λ³Έκ²©μ μΌλ‘ μ§νλλ λ¨κ³ κ°κ°μ μ΄ν΄ν νμκ° μλ€.
μ΄ μ°κ΅¬λ μ μ’ κ·Ήμ΄κΈ°μ μ μ’ν¨μμ μ μ’κΈ°μ§μ΄ μνΈμμ©μ μμνλ κ³Όμ μ μ΄μ μ λ§μΆκ³ μλ€. μμ μ°κ΅¬λ‘λΆν° μ§μ§-μμ λͺ¨λΈκ³Ό κ³ λ¦¬ λͺ¨ν λ κ°μ§κ° μ μλμ΄μλ€. λ°λΌμ μ΄λ² μ°κ΅¬μ λͺ©μ μ λ λͺ¨λΈμ΄ μ ν©νμ§ νμΈνλ κ²μ΄λ€. μ΄λ₯Ό μν΄ κ°κ°μ λͺ¨λΈμ λ°λ₯΄λ κΈ°μ§μ λΆλ₯νμ¬ λΉκ΅νκ³ μλ€. λͺ¨λΈ κΈ°μ§μ CPYμ μλ―Έλ
Έ λ§λ¨μ κΈΈμ΄, μ νΈμμ΄ μμμ±μ λ³ννμ¬ μ€λΉνμλ€.
μ΄λ₯Ό ν΅ν΄ Sec62μ μμ‘΄μ μ΄κ³ SRPμ λΉμμ‘΄μ μΈ μ νΈμμ΄μ μλ―Έλ
Έ λ§λ¨μ κΈΈμ΄κ° μ¦κ°ν μλ‘ μ μ’κ° λλ €μ§λ©°, μμ νμ μν΄ μ μ’ μλκ° ν볡λλ κ²μ κ΄μ°°νμλ€. SRP μμ‘΄μ μΈ μ νΈμμ΄μ μ μ’λ μλ―Έλ
Έ λ§λ¨μ κΈΈμ΄μ 무κ΄νμλ€. κ·Έλ¬λ μλ―Έλ
Έ λ§λ¨μ μμ νλ₯Ό μμ μ Sec62, Sec71/72μ μμ‘΄μ μΌλ‘ λ³νμΌλ©°, μλ―Έλ
Έ λ§λ¨μ κΈΈμ΄μλ μν₯μ λ°μλ€. λ°λΌμ λ²μνμ μ’μ κΈ°μ§μ μλ―Έλ
Έ λ§λ¨ κΈΈμ΄μ μν₯μ λ°κΈ° μ¬μ΄ μ§μ§-μμ λͺ¨λΈμ λ°λ₯΄κ³ , λ²μμ€μ μ’μ κΈ°μ§μ μ νλΆν¬μ λ°λΌ μ νΈμμ΄μ μ΄κΈ° λ°©ν₯μ΄ κ²°μ λλ€κ³ ν΄μνμλ€.
λμκ° CPY μ νΈμμ΄ λΏ μλλΌ λ€λ₯Έ λ¨λ°±μ§μ μ νΈμμ΄μ λν΄μλ κΈ΄ μλ―Έλ
Έ λ§λ¨κ³Ό μ νΈμμ΄ μ£Όλ³μ μ νλΆν¬κ° μ μ’μ λ―ΈμΉλ μν₯μ΄ λ³΄νΈμ μμ 보μλ€.Abstract 1
Table of Contents 2
LIST OF FIGURES AND TABLES 3
INTRODUCTION 4
I.1 Study Background 5
I.1.1 Protein translocation across the secretory pathway 5
I.1.2 Subcomplexes of the SEC translocon 8
I.1.3 Two routes into the ER: conventional distinction 10
I.1.4 The orientation of a signal sequence 10
I.1.5 The signal sequence docking models: a head-in and inversion and a looped conformation 13
I.1.6 Remaining problems 14
1.2. Purpose of Research 14
METHODS 15
M.1 Yeast strains 16
M.2 Plasmid construction 16
M.3 Prediction of N-length and hydrophobicity of signal sequences 16
M.4 Prediction of N-length and hydrophobicity of signal sequences 17
M.5 Western blot 17
M.6 Autoradiographic pulse-labelling and chase of proteins 17
RESULTS 20
R.1 The extension of N-region inhibited SRP independent secretory proteins but not to SRP dependent
hydrophobic signal sequences 21
R.2 The length of N-region is critical to inhibit the translocation of SRP independent CPY signal sequences than the charge, secondary structure, and mature part of preproteins. 25
R.3 The charge distribution along N-region modulates the temporal translocation rate than the initial engagement of SRP independent signal sequences 28
R.4 Translocation of weakly positive charge-biased signal sequences required Sec62, Sec71/72 even if they were SRP dependent 31
DISCUSSION 35
μ΄λ‘ 42Maste
Synthesis of Zeolite ZSM-10 and Catalytic Evaluation of Pt/K-ZSM-10 for n-Hexane Aromatization.
MasterThe synthesis of zeolite ZSM-10 with the MOZ topology and the catalytic properties of platinum supported K+ exchanged of ZSM-10 (Pt/K-ZSM-10) for the aromatization of n-hexane are presented. When the 1,4-diazocyclo[2,2,2]octane (1,4-dimethyl DABCO) hydroxide is used as an organic structure-directing agent together with K+, crystallization of pure ZSM-10 is very sensitive not only to the Si/Al molar ratio, but also to the concentration of K2O in the synthesis mixture. The physicochemical properties of Pt/K-ZSM-10 and its catalytic properties for the aromatization of n-hexane are compared with those obtained from Pt/K-L, which is the commercialized catalyst for this process. Although, when Pt loading level was fixed to be ca. 1.0 wt%, Pt/K-ZSM-10 and Pt/K-L shows comparable Pt dispersion levels, Pt/K-ZSM-10 was found to show the lower n-hexane aromatization activity, due to Pt clusters easily migrate to the external surface of the zeolite catalyst. The overall characterization and catalytic results of this work demonstrate that nanocrystallity of ZSM-10 is one of the most crucial factors influencing location of platinum and thus n-hexane activity