Sensitivity analysis of EGFR L861Q mutation to six tyrosine kinase inhibitors

Purpose: Lung cancer is one of the most common carcinomas with the highest mortality in the world. Non-small cell lung carcinoma has a large proportion of epidermal growth factor receptor (EGFR) mutations, of which rare EGFR mutations account for about 10%–20%. Currently, tyrosine kinase inhibitors (TKIs) therapy is a standard treatment for patients with non-small cell lung carcinoma with EGFR mutations. To date, the toxicological effects of the EGFR L861Q variant (less than 2%) have been rarely reported, so further investigation of its sensitivity to six first-in-class TKIs is of great clinical interest.MethodsIn this study, two EGFR L861Q variants cell lines (EGFR L861Q variant and EGFR L861Q + exon 19 deletion variant) were established by CRISPR-Cas9 gene-editing technology. The steady-state plasma concentrations of six TKIs (gefitinib/erlotinib/icotinib, the first generation; dacomitinib/afatinib, the second generation; and osimertinib, the third generation) were tested, respectively. The change of cell viability, proliferation, cloning ability, mitochondrial membrane potential and apoptosis were detected by MTT assay, EdU staining assay, colony formation assay, mitochondrial membrane potential and apoptosis test. TUNEL and Annexin V / PI staining were used to detect cell apoptosis, and flow cytometry was employed to explore the sensitivity of two variants to six TKIs.ResultsOur study indicated that the six TKIs inhibited the viability of the two cell lines in a time-dependent manner, and the inhibitory time of six TKIs on proliferation was different between the two cell lines. The proliferation and cloning ability of two cell lines were inhibited by six TKIs. The cytoskeleton morphology, microfilament structure and distribution of the two cell lines were changed by six TKIs. (AU)

LncRNA MALAT1 Promotes Lung Cancer Proliferation and Gefitinib Resistance by Acting as a miR-200a Sponge / LncRNA MALAT1 promueve la profileración de las células tumorales de pulmón y su resistencia a gefitinib actuando como esponja para miR-200a

Introduction: Lung cancer is a major public health problem, as the second causes of cancer related death worldwide, with relatively low survival rates, and accessible drug resistance. Long non-coding RNAs (LncRNAs) have been identified as activator in lung cancer with elusive mechanisms. We aimed to detect the regulation of LncRNA MALAT1 in the proliferation and gefitinib resistance in lung cancer cells. Methods: MALAT1 in A549 and HCC 1299 human lung adenocarcinoma cell lines was silenced by shRNA or overexpressed using plasmid, and the cell viability and cell proliferation were evaluated by MTT assay and soft agar colony formation assay. RNA levels were detected by RT-PCR, and the protein expression was measured by western blot. The binding between MALAT1 and miR-200a was validated by luciferase reporter assays using pSi-Chech 2 vectors. Results: The cell viability and proliferation of A549 cells transfected with MALAT1 shRNA were significantly lower than the control. The MALAT1 expression in gefitinib resistant A549 cells was upregulated. miR-200a significantly inhibited the fluorescence of pSi-Check 2 vector with MALAT1 gene, suggesting the direct binding between MALAT1 and miR-200a. In addition, LncRNA MALAT1 promotes ZEB1 expression in A549 cells. Conclusion: Our study showed that MALAT1 promoted the proliferation and gefitinib resistance of lung cancer cells by sponging miR-200a, which regulates expression of ZEB1 in the A549 cells. This MALAT1/miR-200a axis could serve as new therapeutic target for lung cancer treatment

Introducción: El cáncer de pulmón es un importante problema de salud pública. Constituye la segunda causa de muerte por cáncer en el mundo y se asocia a tasas de supervivencia relativamente bajas y a resistencia a fármacos accesibles. Los RNA largos no-codificantes (lncRNA) se han identificado como activadores en el cáncer de pulmón con mecanismos aún no esclarecidos. El objetivo de este estudio fue detectar la regulación del LncRNA MALAT1 en la proliferación y la resistencia de las células tumorales de pulmón. Métodos: La expresión de MALAT1 se silenció con un shRNA o se sobreexpresó mediante el uso de un plásmido en las líneas celulares de adenocarcinoma pulmonar humano A459 y HCC. La viabilidad celular y la proliferación se evaluaron mediante un ensayo MTT y el ensayo de formación de colonias en agar blando. Los niveles de RNA se detectaron con RT-PCR y los niveles de proteína se midieron con Western Blot. La unión entre MALAT1 y miR-200a se validó gracias a un ensayo de luciferasa utilizando vectores pSi-Chech 2. Resultados: La viabilidad y la proliferación de las células A549 transfectadas con el shRNA contra MALAT1 resultaron significativamente más bajas que en el control. Se produjo un incremento en la expresión de MALAT1 en las células A549 resistentes a gefitinib. MiR-200a inhibió significativamente la fluorescencia del vector pSi-Check 2 que contenía el gen MALAT1, sugiriendo la unión directa entre MALAT1 y miR-200a. Además, el LncRNA de MALAT1 promovió la expresión de ZEB1 en las células A549. Conclusión: Nuestro estudio demuestra que MALAT1 promovió la proliferación y resistencia a gefitinib en células tumorales de pulmón actuando como "esponja" de miR-200a, que regula la expresión de ZEB1 en células A549

Presentación radiológica atípica de un adenocarcinoma de pulmón / An Atypical Radiological Presentation of Lung Adenocarcinoma

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