[Research progress of the resistance mechanism of non-small cell lung cancer to EGFR-TKIs]

Effect of almonertinib on the proliferation, invasion, and migration in non-small cell lung cancer cells

OBJECTIVES

Lung cancer is one of the most common malignant tumors in the world, and its lethality ranks the first among many malignant tumors. For non-small cell lung cancer (NSCLC) patients, due to the high mortality rate, the overall 5-year survival rate is less than 15%. When NSCLC undergoes local invasion, the 5-year survival rate is only 20%, and it is even lower when distant metastasis occurs up to 4%. Almonertinib is an innovative drug independently researched and developed by China with independent intellectual property rights. As an epidermal growth factor receptor tyrosine kinase inhibitor, almonertinib is mainly used for locally advanced or metastatic NSCLC patients with epidermal growth factor receptor (EGFR) T790M mutation. This study aims to investigate the effects of almonertinib on the proliferation, invasion and migration of NSCLC cells in vitro.

METHODS

NSCLC cells H1975 and PC-9 were cultured in vitro. The effects of almonertinib on the proliferation, apoptosis, invasion, and migration of H1975 and PC-9 cells were detected by CCK-8 assay, apoptotic assay and Transwell assay. The expression of invasion and migration related proteins was detected by Western blotting.

RESULTS

The CCK-8 experiment showed that almonertinib inhibited the proliferation of H1975 and PC-9 cells in a time- and dose-dependent manner. The IC50 values in PC-9 cells at 24 and 48 h were 5.422 and 1.302 µmol/L, respectively. The IC50 values in H1975 cells at 24 and 48 h were 4.803 and 2.094 µmol/L, respectively. Almonertinib (1, 2, 4, 8 µmol/L)-treated PC-9 and H1975 cells for 24 h resulted in apoptosis rate at (8.82±3.22)%, (9.53±4.24)%, (13.62±3.69)%, (42.10±1.76)% and (9.81±0.90)%, (10.51±1.49)%, (15.34±3.50)%, (28.97±2.57)%, respectively. The transwell experiment showed that almonertinib inhibited the invasion and migration of H1975 and PC-9 cells. Western blotting showed that compared with the control group, the expression levels of MMP-9, MMP-2 and vimentin protein in PC-9 and H1975 cells in 1, 2 and 4 µmol/L almonertinib treatment group were significantly lower, and the expression level of E-cadherin protein was significantly higher (all P<0.05). The experimental results of nude mice showed that compared with the control group and the positive control ositinib (AZD9291) group, the tumor growth was significantly inhibited, the weight of nude mice, the tumor volume and the tumor mass were significantly reduced in the almonertinib treatment group (all P<0.05).

CONCLUSIONS

Almonertinib can inhibit the proliferation, invasion, and migration of NSCLCH1975 and PC-9 cells in vitro and vivo, and promote the apoptosis of H1975 and PC-9 cells. The underlying mechanism may be related to the inhibition of tumor cell epithelial mesenchymal transformation and metalloproteinase expression.

Chinese Medicine Combined With EGFR-TKIs Prolongs Progression-Free Survival and Overall Survival of Non-small Cell Lung Cancer (NSCLC) Patients Harboring EGFR Mutations, Compared With the Use of TKIs Alone

Objective: To explore the efficacy comparison between epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) combined with traditional Chinese medicine (TCM) and single EGFR-TKIs for advanced non-small cell lung cancer (NSCLC). Methods: A total of 91 NSCLC patients with EGFR mutation were divided into an experimental group and a control group (in a ratio of 2:1) to receive TCM and EGFR-TKIs (61 cases) or single EGFR-TKIs (30 cases). Patients in the control group took EGFR-TKIs and those in the experimental group took EGFR-TKIs plus TCM. We analyzed the progression-free survival (PFS), overall survival (OS), disease control rate (DCR), and treatment-related adverse events of two groups. Results: The mPFS of the experimental group and the control group was 12.3 and 8.9 months (P = 0.02), respectively, and the mOS of the experimental group and the control group was 28.2 and 24.2 months (P = 0.02), respectively. Subgroup analysis showed that for the patients with exon 19 deletion mutation (19DEL), mPFS between experimental group and control group was 12.7 and 10.1 months, respectively (P = 0.12). For exon 21 deletion mutation (L858R), the PFS of two groups was 10.8 vs. 8.2 months, respectively (P = 0.03). The subgroup analysis also showed that, for the patients with exon 19 deletion mutation, mOS between the experimental group and the control group was 30.3 and 28.7 months, respectively (P = 0.19). For exon 21 deletion mutation, the mOS of two groups was 25.5 vs. 21.3 months, respectively (P = 0.01). The DCR of the experimental group and the control group was 93.3% and 80.1%, respectively (P = 0.77). Grade 3-4 treatment-related adverse events were less common with the experimental group (11.48%) than the control group (26.67%). Conclusion: For NSCLC patients with EGFR mutation, EGFR-TKIs combined with TCM had a certain effect to prolong mPFS and mOS, compared with the use of EGFR-TKIs alone, especially for the patients with L858R. This conclusion has a significant effect on improving the survival of NSCLC patients after EGFR-TKIs resistance. It deserves further study.

[EGFR tyrosine kinase inhibitor HS-10296 induces autophagy and apoptosis in triplenegative breast cancer MDA-MB-231 cells]

OBJECTIVE

To investigate the inhibitory effect of epidermal growth factor receptor tyrosine kinase inhibitor (EGFRTKI) HS-10296 on the proliferation of triple-negative breast cancer (TNBC) MDA-MB-231 cells and explore the possible molecular mechanism.

METHODS

MDA-MB-231 cells were treated with HS-10296 for 24, 48, or 72 h, and CCK-8 assay was used to assess the changes in the cell viability. The inhibitory effect of HS-10296 on cell proliferation was determined by clonogenic assay. JC-1 and flow cytometry were employed for analyzing the cell apoptosis, and the ultrastructure of the cells was observed under electron microscope. After pretreatment with autophagy inhibitor chloroquine (CQ), MDA-MB-231 cells were divided into control group, CQ treatment group, HS-10296 (4 and 6 μmol/L) treatment groups and combined treatment groups, and the sensitivity of the treated cells to HS-10296 was determined using CCK-8 assay. The effects of HS-10296 on EGFR pathway and apoptosis- and autophagy-related proteins in MDA-MB-231 cells were investigated using Western blotting.

RESULTS

HS-10296 significantly inhibited the proliferation of MDA-MB-231 cells with IC₅₀ values at 24, 48 and 72 h of 8.393, 2.777 and 2.016 μmol/L, respectively. JC-1 and flow cytometry showed that HS-10296 induced obvious apoptosis of MDA-MB-231 cells, which showed an apoptosis rate of (21.63 ± 2.97)% following treatment with 8 μmol/L HS-10296. Autophagy vesicles were observed in the cells treated with HS-10296 under electron microscope. In MDA-MB-231 cells pretreated with CQ, inhibition of autophagy significantly enhanced HS-10296-induced cell death. Western blotting showed that the apoptosis-related protein caspase-3 was activated after HS-10296 treatment to cut its substrate PARP. The expression of autophagy-related protein light chain 3B (LC3B) was significantly enhanced after HS-10296 treatment (P &lt; 0.01), which also resulted in inhibited phosphorylation of EGFR and AKT proteins in the cells.

CONCLUSIONS

HS-10296 can inhibit the proliferation and induce autophagy and apoptosis of MDA-MB-231 cells by inhibiting the EGFR/PI3K/AKT signaling pathway.

Role of endothelin receptor type B (EDNRB) in lung adenocarcinoma

BACKGROUND

The five-year survival rate of lung adenocarcinoma patients (LUAD) is very low,and the methods of predicting survival are a great obstacle for LUAD therapies. Endothelin receptor type B (EDNRB) gene is associated with tumorigenesis. In this study, we aimed to evaluate the predictive value of EDNRB on LUAD.

METHODS

Survival analyses was performed to assess the correlation between EDNRB expression and survival of LUAD patients from the Cancer Genome Atlas (TCGA) and the Chinese Glioma Genome Atlas (CGGA) datasets. Gene set enrichment analysis (GSEA) was conducted to illustrate possible biological functions of EDNRB. Laboratory methods were used to verify the function of EDNRB in LUAD.

RESULTS

The TCGA results showed that a low expression of EDNRB was found in LUAD patients which led to poor outcome and worse survival, compared with the high expression in GSEA results which suggested that expression of EDNRB might be associated with regulation of the ERK pathway. Laboratory results suggested that EDNRB could inhibit the proliferation and migration of LUAD H1299 cells.

CONCLUSIONS

EDNRB is a potential prognostic marker for LUAD patients and might exert its functions by regulating the ERK pathway in LUAD.

Advances in studies of tyrosine kinase inhibitors and their acquired resistance

Protein tyrosine kinase (PTK) is one of the major signaling enzymes in the process of cell signal transduction, which catalyzes the transfer of ATP-γ-phosphate to the tyrosine residues of the substrate protein, making it phosphorylation, regulating cell growth, differentiation, death and a series of physiological and biochemical processes. Abnormal expression of PTK usually leads to cell proliferation disorders, and is closely related to tumor invasion, metastasis and tumor angiogenesis. At present, a variety of PTKs have been used as targets in the screening of anti-tumor drugs. Tyrosine kinase inhibitors (TKIs) compete with ATP for the ATP binding site of PTK and reduce tyrosine kinase phosphorylation, thereby inhibiting cancer cell proliferation. TKI has made great progress in the treatment of cancer, but the attendant acquired acquired resistance is still inevitable, restricting the treatment of cancer. In this paper, we summarize the role of PTK in cancer, TKI treatment of tumor pathways and TKI acquired resistance mechanisms, which provide some reference for further research on TKI treatment of tumors.

[Gene Expression and Clinical Characteristics of Molecular Targeted Therapy in Non-small Cell Lung Cancer Patients in Shandong]

BACKGROUND

Molecular targeted therapy has gradually become an important treatment for lung cancer, the aim of this research is to analyze the clinicopathologic features associated with the gene mutation status of epidermal growth factor receptor (EGFR), echinoderm microtubule-associated protein-like 4-anaplastic lymphoma kinase (EML4-ALK), ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) and Kirsten rat sarcoma viral oncogene (KRAS) in non-small cell lung cancer (NSCLC) patients and determine the most likely populations to benefit from molecular target therapy treatment.

METHODS

The mutation status of EGFR, EML4-ALK fusion gene, ROS1 and KARS gene were determined by Real-time PCR, the relationship between clinical pathologic features and concomitant gene were analyzed with χ2 test by SPSS software 19.0.

RESULTS

A total of 514 specimens from Shandong tumor hospital were collected from NSCLC patients between January 2014 and May 2016. The total mutation rate of EGFR gene was 36.70%, major occurred in exon 19 (36.61%) and exon 21 (51.36%), respectively, and EGFR mutations usually occurred in female, non-smoking and adenocarcinoma patients (P<0.05). The total rearrangements rate of EML4-ALK fusion gene was 9.37%, EML4-ALK fusion gene usually occurred in younger age (≤60 yr) and non-smoking patients (P<0.05). Mutations were not related to gender and pathological type (P>0.05). ROS1 fusion gene was detected in 136 cases, the positive rate was 3.67%, all patients were 60 years old, and the difference was statistically significant (P<0.05). Only 23 samples were tested KARS gene mutations, two of them were positive and the positive rate was 8.70%. They all occurred in non-smoker and adenocarcinoma patients. No mutation was detected to coexist in EGFR, EML4-ALK and KARS gene mutation.

CONCLUSIONS

EGFR, EML4-ALK, ROS1 and KRAS defines different molecular subset of NSCLC with distinct characteristic, which provides a new option for the clinical treatment of patients with NSCLC.

[The reversing and molecular mechanisms of miR-503 on the drug-resistance to cisplatin in A549/DDP cells]

背景与目的

临床上肺癌细胞往往出现对顺铂的耐药性，因此探讨肿瘤细胞的耐药机制，开发新的逆转耐药性的方法，对提高临床患者的受益有十分重要的意义。miRNA可通过其调控的目标基因，对多种与肿瘤细胞失控生长、抗凋亡、迁移和侵袭，甚至是肿瘤细胞对药物治疗的应答产生调控作用。本实验旨在探讨miR-503对肺癌顺铂耐药细胞株A549/DDP的耐药性逆转及其相关作用机制。

方法

应用MTS法检测miR-503对A549/DDP细胞顺铂耐受性的影响，流式细胞术检测肿瘤细胞凋亡率以及胞内罗丹明-123（Rhodamine-123, Rh-123）含量的变化，Western blot法和Real time PCR检测肿瘤细胞多药耐药蛋白MDR1、MRP1、Survivin和Bcl-2蛋白表达，以及Akt磷酸化的变化，应用双萤光报告基因技术检测细胞NF-κB和AP-1转录活性。

结果

与对照细胞组相比较，miR-503转染A549/DDP细胞株后，可明显增加细胞对顺铂的敏感性，使耐药逆转倍数增加为2.48倍，Rh-123含量升高2.49倍，细胞凋亡率提高10.3倍；在转录水平检测发现，与对照组相比较，miR-503转染的细胞中MDR1、MRP1、ERCC1、Survivin及Bcl-2等与肿瘤耐药相关基因的mRNA表达水平明显下调，而RhoE mRNA表达水平则明显升高（P < 0.05）；进一步在蛋白水平亦证实MDR1、MRP1、ERCC1、Survivin、Bcl-2以及p-Akt的表达明显下降，RhoE的表达明显上升。

结论

miR-503可逆转A549/DDP对顺铂的耐药性，这一作用可能与抑制药物外排，负调控肿瘤耐药相关蛋白的表达，促进细胞凋亡有关。