Analysis of the Effcacy and Safety of Amivantamab in Non-small Cell Lung Cancer Patients with EGFR/MET Gene Abnormalities: A Single Center's Experience / 中国肺癌杂志

BACKGROUND@#Epidermal growth factor receptor (EGFR) and cellular-mesenchymal to epithelial transition factor (c-Met) are widely expressed on cancer cells. There is a synergistic effect of EGFR and HGF/c-Met pathways on proliferation, downstream activation of signal transduction and an additive effect. Studies show that combination of both signaling pathways could potentially be targeted in a synergistic fashion. Amivantamab, a bispecific monoclonal antibody targeting EGFR and c-Met, yielded robust and durable responses in a variety of clinicals trials. However, few researches have reported its efficacy in Chinese non-small cell lung cancer (NSCLC) patients. This study was conducted to evaluate the effectiveness and tolerance of Amivantamab in NSCLC patients with EGFR/MET gene abnormalities at Peking University Cancer Hospital.@*METHODS@#The study enrolled NSCLC patients who received Amivantamab in our hospital between August 2020 and December 2021, and analyzed the response, survival, and treatment-related adverse events.@*RESULTS@#Fifteen patients were enrolled in this research, and six of them received Amivantamab treatment and the other nine patients received Amivantamab plus Lazertinib treatment. The rates of partial response (PR), stable disease (SD), and progressive disease (PD) were 46.7% (7/15), 46.7% (7/15) and 6.7% (1/15), respectively. The overall response rate (ORR) and disease control rate (DCR) were 28.6% (2/7) and 100.0% (7/7) in seven patients with EGFR exon 20 insertion, respectively. The ORR and DCR were 40.0% (2/5) and 100.0% (5/5) in five post-osimertinib EGFR-mutant patients, respectively. After a median follow-up of 8.7 months, the median progression-free survival and overall survival were not reached. The most common treatment-related adverse events were rash (86.7%), paronychia (80.0%), and infusion-related reactions (60.0%), and most of them were graded as 1 to 2. Grade 3 to 4 adverse events included rash (33.3%), alanine aminotransferase elevation (13.3%), gamma-glutamyl transpeptidase elevation (13.3%), peripheral edema (6.7%), thromboembolism (6.7%), interstitial lung disease (6.7%), and thrombocytopenia (6.7%).@*CONCLUSIONS@#Amivantamab was effective in Chinese NSCLC patients with EGFR exon 20 insertion and post-Osimertinib EGFR-mutant patients, similar to the results of clinical trials conducted in western countries. Amivantamab was well tolerated and emphases should be put on adverse events such as rash, paronychia, and infusion-related reactions.

SMARCA2 deficiency in NSCLC: a clinicopathologic and immunohistochemical analysis of a large series from a single institution

BACKGROUND@#SMARCA2 (SWI/SNF Related, Matrix Associated, Actin Dependent Regulator of Chromatin, Subfamily A, Member 2) is an important ATPase catalytic subunit in the switch-sucrose nonfermenting (SWI/SNF) complex. However, its relationship with the pathological features of NSCLC and its prognosis remain unclear.@*METHODS@#We retrospectively reviewed 2390 patients with surgically resected NSCLC, constructed tissue microarrays (TMAs) and performed immunohistochemical assays. We analyzed the correlation of SAMRCA2 with clinicopathological features and evaluated its prognostic value.@*RESULTS@#Among 2390 NSCLC cases, the negative expression ratios of SAMRCA2, SMARCA4, ARID1A, ARID1B and INI1 were 9.3%, 1.8%, 1.2%, 0.4% and 0%, respectively. In NSCLC, male sex, T3 and T4 stage, moderate and poor differentiation, tumor ≥ 2 cm, Ki67 ≥ 15%, SOX-2 negative expression, middle lobe lesion and adenocarcinoma were relative risk factors affecting SMARCA2-negative expression. In lung adenocarcinomas, high-grade nuclei, histological morphology of acinar and papillary, solid and micropapillary and TTF-1-negative expression were relative risk factors affecting SMARCA2-negative expression. Kaplan-Meier survival analysis showed that the OS was shorter in the SMARCA2-negative group. Multivariate survival analysis revealed that SMARCA2-negative expression was an independent factor correlated with a poor prognosis in NSCLC.@*CONCLUSION@#In conclusion, SMARCA2-negative expression is an independent predictor of a poor outcome of NSCLC and is a potential target for NSCLC treatment.

Advances in Treatment of Non-small Cell Lung Cancer Harboring EGFR Exon 20 Insertion Mutations / 中国肺癌杂志

Epidermal growth factor receptor (EGFR) exon 20 insertion mutations are the third most prevalent activating EGFR mutation in non-small cell lung cancer (NSCLC), accounting for 5%-12% of all EGFR mutations in NSCLC cases. Patients harboring EGFR exon 20 insertion mutations exhibit similar clinical characteristics except for worse prognosis as compared to those with 'classic' EGFR mutations. EGFR exon 20 insertion mutations are considered as a heterogeneous class of alterations that cause different conformational changes in EGFR. The majority of mutations (almost 90% of cases) is positioned in the loop that immediately follows the C-terminal of the C-helix, and the most widely reported subtype of insertion mutations is D770_N771>ASVDN(A767_V769dupASV) with frequency of 21%-28%. NSCLC patients with EGFR exon 20 insertion mutations show primary drug resistance to previously approved EGFR tyrosine kinase inhibitors and are generally insensitive to conventional chemotherapy and immunotherapy. The recently approved targeted drugs Amivantamab and Mobocertinib shift the treatment paradigm for NSCLC patients harboring EGFR exon 20 insertion mutations. There are also several new compounds targeting NSCLC EGFR exon 20 insertion mutations are in development. In this article, we provide a through overview on the treatment development in EGFR exon 20 insertion mutant NSCLC.
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Research Advances of EGFR-TP53 Co-mutation in Advanced Non-small Cell Lung Cancer / 中国肺癌杂志

With the rapid development and wide application of next generation sequencing (NGS) technology, a series of researches have revealed that concurrent genetic alterations play an important role in the response and resistance of epidermal growth factor receptor (EGFR)-mutant NSCLC to EGFR-tyrosine kinase inhibitor (TKI). Besides, TP53 mutation is the most common co-mutation gene in EGFR-mutant NSCLC, which has been proved to confer a worse prognosis in EGFR-mutated patients treated with first, second and third generation of EGFR-TKIs. Currently, it is still being explored how to select the best treatment strategies for patients with concomitant presence of TP53 mutation in EGFR-mutant NSCLC. Here, we review the literature on recent research progress of TP53 concurrent mutation in EGFR-mutant advanced NSCLC.
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Effect of circ-SFMBT2 on the biological behavior of non-small cell lung cancer cells by targeting the miR-7-5p/ADAM10 axis / 中华医学遗传学杂志

OBJECTIVE@#To explore the effect of circ-SFMBT2 on the biological behavior of non-small cell lung cancer (NSCLC) cells and its regulatory role on the miR-7-5p/ADAM10 axis.@*METHODS@#qRT-PCR and Western blotting were used to determine the expression of circ-SFMBT2, miR-7-5p, and ADAM10 in NSCLC tissues and adjacent tissues. Pearson analysis was used to analyze the correlation between circ-SFMBT2 and miR-7-5p, and between miR-7-5p and ADAM10. In vitro cultured human bronchial epithelial-like cells (HBE) and lung cancer cell lines H1650, H460, A549, H1299. CCK-8 and EdU methods were used to assess the ability of cell proliferation. Plate experiment was used to detect the clone formation ability. Flow cytometry was used to detect the apoptosis rate. Transwell experiment was used to detect cell invasion ability. Dual luciferase reporter experiment detects the targeting relationship between circ-SFMBT2 and miR-7-5p, and between miR-7-5p and ADAM10. Transplanted tumor experiment in nude mice assessed the effect of knocking down circ-SFMBT2 on the growth of transplanted tumor. Immunohistochemical experiments were performed to detect the positive rates of ADAM10 and Ki67 proteins in transplanted tumor tissues.@*RESULTS@#The expression levels of circ-SFMBT2 and ADAM10 were increased in NSCLC tissues and cell lines, while decreased the expression of miR-7-5p. circ-SFMBT2 was negatively correlated with miR-7-5p, while miR-7-5p was negatively correlated with ADAM10. Silencing the overexpression of circ-SFMBT2 and miR-7-5p could inhibit cell proliferation, clone formation and invasion, and also promote apoptosis. circ-SFMBT2 could target miR-7-5p, and ADAM10 was the target gene of miR-7-5p. The combined effect of silencing circ-SFMBT2 and inhibition of miR-7-5p, as well as miR-7-5p overexpression and ADAM10 overexpression could promote cell proliferation, clone formation and invasion, and also suppress cell apoptosis. Silencing circ-SFMBT2 could inhibit the growth of transplanted tumors.@*CONCLUSION@#Silencing circ-SFMBT2 can suppress the proliferation, clone formation, invasion ability and induce apoptosis of NSCLC cells by regulating the miR-7-5p/ADAM10 axis.

Association of tumor mutation burden and epidermal growth factor receptor inhibitor history with survival in patients with metastatic stage III/IV non-small-cell lung cancer: A retrospective study

OBJECTIVES: Lung cancer is the leading cause of cancer-related deaths worldwide. However, factors associated with the survival of patients with advanced non-small-cell lung cancer (NSCLC) who received only hospice care are largely unclear. In this study, we aimed to determine the prognostic factors correlated with survival in patients with advanced NSCLC who had undergone hospice care only. METHODS: A total of 102 patients with recurrent stage III/IV NSCLC after traditional treatment failure were investigated. Survival was measured from the date of enrollment to December 2019 or the time of death. Tumor tissues were collected, and DNA sequencing was performed to identify somatic mutations. Data on clinical factors of patients were collected and analyzed by univariate and multivariate analyses. Overall survival analysis was conducted using the Kaplan-Meier method. RESULTS: The 6-month, 1-year, and 2-year overall survival rates of the 102 patients with metastatic NSCLC were 17.65%, 3.92%, and 0.98%, respectively. The median overall survival of the 102 patients was 3.15 months. Tumor location in the peripheral lung, epidermal growth factor receptor (EGFR) inhibitor history, low tumor mutation load, adenocarcinoma, and poor performance status score were associated with prolonged survival compared with tumor location in the central lung, no EGFR inhibitor history, high tumor mutation load, squamous cell carcinoma, and good performance status score (p=0.045, p=0.003, p=0.045, p=0.021, and p=0.0003, respectively). CONCLUSIONS: EGFR inhibitor treatment history and tumor mutation load are risk factors for the overall survival of patients with stage III/IV NSCLC who have undergone only hospice care. These results provide a critical clinical basis for further study of nontraditional anti-tumor responses induced by EGFR inhibitors.

Comprehensive functional annotation of susceptibility variants identifies genetic heterogeneity between lung adenocarcinoma and squamous cell carcinoma / 医学前沿

Although genome-wide association studies have identified more than eighty genetic variants associated with non-small cell lung cancer (NSCLC) risk, biological mechanisms of these variants remain largely unknown. By integrating a large-scale genotype data of 15 581 lung adenocarcinoma (AD) cases, 8350 squamous cell carcinoma (SqCC) cases, and 27 355 controls, as well as multiple transcriptome and epigenomic databases, we conducted histology-specific meta-analyses and functional annotations of both reported and novel susceptibility variants. We identified 3064 credible risk variants for NSCLC, which were overrepresented in enhancer-like and promoter-like histone modification peaks as well as DNase I hypersensitive sites. Transcription factor enrichment analysis revealed that USF1 was AD-specific while CREB1 was SqCC-specific. Functional annotation and gene-based analysis implicated 894 target genes, including 274 specifics for AD and 123 for SqCC, which were overrepresented in somatic driver genes (ER = 1.95, P = 0.005). Pathway enrichment analysis and Gene-Set Enrichment Analysis revealed that AD genes were primarily involved in immune-related pathways, while SqCC genes were homologous recombination deficiency related. Our results illustrate the molecular basis of both well-studied and new susceptibility loci of NSCLC, providing not only novel insights into the genetic heterogeneity between AD and SqCC but also a set of plausible gene targets for post-GWAS functional experiments.

Role of metabolic reprogramming in drug resistance to epidermal growth factor tyrosine kinase inhibitors in non-small cell lung cancer / 中南大学学报(医学版)

Epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) can effectively inhibit the growth of EGFR-dependent mutant non-small cell lung cancer (NSCLC). Unfortunately, NSCLC patients often develop severe drug resistance after long-term EGFR-TKI treatment. Studies have shown that the disorder of energy metabolism in tumor cells can induce EGFR-TKI resistance. Due to the drug action, gene mutation and other factors, tumor cells undergo metabolic reprogramming, which increases the metabolic rate and intensity of tumor cells, promotes the intake and synthesis of nutrients (such as sugar, fat and glutamine), forms a microenvironment conducive to tumor growth, enhances the bypass activation, phenotype transformation and abnormal proliferation of tumor cells, and inhibits the activity of immune cells and apoptosis of tumor cells, ultimately leading to drug resistance of tumor cells to EGFR-TKI. Therefore, targeting energy metabolism of NSCLC may be a potential way to alleviate TKI resistance.

Detection of epidermal growth factor receptor mutations in non-small cell lung cancer by immunohistochemistry / 中南大学学报(医学版)

OBJECTIVES@#To evaluate the sensitivity and specificity of immunohistochemistry (IHC) for detecting common epidermal growth factor receptor (EGFR) mutations in non-small cell lung cancer (NSCLC) and to estimate the cost-effectiveness of IHC testing.@*METHODS@#A total of 208 NSCLC patients were included in the trial, and the EGFR mutation status in the patients were detected by PCR and IHC. Two mutation-specific antibodies against the most common exon 19 deletion (clone SP111) and exon 21 L858R mutation (clone SP125) were tested by using automated immunostainer. A cost-effectiveness analysis model was built for the analysis of optimal detection scheme.@*RESULTS@#With a cutoff value of IHC 1+, the overall sensitivity and specificity of the IHC-based method compared with the PCR-based method were 81.7% (95% CI 72.4% to 89.0%) and 94.7% (95% CI 92.6% to 99.5%), respectively. EGFR 19del mutation was detected by SP111 antibody with a sensitivity of 65.9% (95% CI 49.4% to 79.9%) and specificity of 98.8% (95% CI 95.7% to 99.9%). EGFR L858R mutation was detected by SP125 antibody with a sensitivity of 94.2% (95% CI 84.1% to 98.8%) and specificity of 99.4% (95% CI 96.5% to 100%). The IHC and PCR cost ratio needed to be 1-to-3 or more in our patients to economically justify before the use of IHC.@*CONCLUSIONS@#The study confirms an excellent specificity with fairly good sensitivity of IHC and mutation-specific antibodies for common EGFR mutations. It is cost-effective to use IHC method to detect EGFR mutation first when the IHC and PCR cost ratio is 1-to-3 or more in Chinese populations.

Circ_0001666 promotes the proliferation and inhibits apoptosis of non-small cell lung cancer cells by targeting the miR-330-5p/HMGA2 axis / 生理学报

Many studies have shown that circular RNAs (circRNAs) play a key regulatory role in the whole biological process of tumors. The purpose of this study was to explore the biological function and molecular mechanism of circ_0001666 in non-small cell lung cancer (NSCLC), so as to provide new targets for the diagnosis and treatment of NSCLC. Gene expression profiles were downloaded from Gene Expression Omnibus (GEO, GSE101586) and the differential genes were obtained by using GEO2R analysis. The quantitative real time polymerase chain reaction (qRT-PCR) was used to detect the expression level of circ_0001666 in NSCLC cells. Cell counting kit-8 (CCK-8) and Annexin V-FITC apoptosis detection kit were respectively used to assess the cell proliferation and apoptosis, where circ_0001666 was knockdown in NSCLC cells. The targeted relationship among mircoRNA 330-5p (miR-330-5p), circ_0001666, and high mobility group A2 protein (HMGA2) was verified by bioinformatics prediction, dual-luciferase reporter gene, RNA immunoprecipitation (RIP) and RNA pull down assay. The results showed that the expression of circ_0001666 in NSCLC cells was significantly up-regulated than that in normal lung epithelial cells. Circ_0001666 knockdown reduced the cell viability and promoted the apoptosis of NSCLC cells, which could be reversed by miR-330-5p inhibitors. MiR-330-5p is the downstream target of circ_0001666 and can be adsorbed by circ_0001666. HMGA2 is a target gene of miR-330-5p, which can be indirectly regulated by circ_0001666. The results suggest that circ_0001666 promotes the proliferation and inhibits apoptosis of NSCLC cells via miR-330-5p/HMGA2 axis.

Response of Lung Adenocarcinoma Harbouring Sensitizing EGFR Mutation to the Fourth-line Combination Treatment of Pembrolizumab and Anlotinib / 中国肺癌杂志

45.7% of Chinese patients with advanced lung adenocarcinoma were reported to harbour sensitizing epidermal growth factor receptor (EGFR) mutations. Limited therapeutic options are left for non-small cell lung cancer (NSCLC) harbouring sensitizing EGFR mutations after failure of EGFR-tyrosine kinase inhibitor (TKI) therapy and chemotherapy, finding effective options for them is an unmet clinic need. Herein we reported a case that till January 12, 2021, an 82-year-old female with sensitizing EGFR-mutant advanced lung adenocarcinoma received a surprising progression-free survival (PFS) benefit of over 21 months from the combination therapy of pembrolizumab and anlotinib after her failure of treatments of osimertinib, chemotherapy and anlotinib-monotherapy.
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Osimertinib Re-challenge for EGFR-mutant NSCLC after Osimertinib-induced Interstitial Lung Disease: A Case Report / 中国肺癌杂志

Osimertinib-induced interstitial lung disease (ILD) is an uncommon, but fatal pulmonary toxicity in some patients. We report a case of a 64-year-old male with stage IV adeno-non-small cell lung cancer (NSCLC) harboring an exon 19 deletion in the epidermal growth factor receptor (EGFR) treated with osimertinib 80 mg/d for first-line targeted therapy. On day 60 after initiating treatment of osimertinib, the patient developed ILD. Osimertinib was discontinued immediately and oral prednisone 60 mg/d was initiated, ILD improved within 13 d. After balancing the risk and benefit, osimertinib was restarted concurrently with prednisone. The patient showed neither disease progression nor a recurrence of ILD for more than 16 months. Based on our case and literature review, retreatment with osimertinib under steroid coverage could be considered as an effective treatment option after careful risk-benefit assessment for patients with EGFR-mutant NSCLC.
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Progress in the Mechanism of Lymphangiogenesis and Lymphatic Metastasis of Non-small Cell Lung Cancer / 中国肺癌杂志

Lung cancer ranks the first cancer-related morbidity and mortality in China. Tumor metastasis always predicts the poor prognosis for patients. Moreover, lymphatic metastasis is one of the most significant predictors of poor prognosis in patients with non-small cell lung cancer (NSCLC) and lymphangiogenesis represents the bridge that functionally facilitates tumor lymphatic metastasis. In this review, we first discussed the molecular mechanisms of tumor-associated lymphangiogenesis and the interaction between tumor microenvironment and lymphatic endothelial cells, then, summarized the role of non-coding RNA in regulating tumor-associated lymphangiogenesis in recent frontier studies, with the aim to provide some novel insights on NSCLC-related lymphangiogenesis research, diagnosis and treatment.
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Advances in the Treatment of RET Fusion-positive Advanced Non-small Cell Lung Cancer / 中国肺癌杂志

Rearranged during transfection (RET) fusions are found in 0.7% to 2% of non-small cell lung cancer (NSCLC). Fusions between RET gene and other domains represent the distinct biological and clinicopathological subtypes of NSCLC. Recent years have witnessed the remarkable advancement of RET fusion-positive advanced NSCLC therapy. Conventional chemotherapy produced moderate clinical benefits. Prior to the introduction of targeted therapy or in the context of unavailability, platinum-based systemic regimens are initial therapy options. Immunotherapy predicted minimal response in the presence of RET fusions while currently available data have been scarce, and the single-agent immunotherapy or in combination with chemotherapy regimens are not recommended as initial systemic therapy in this population. The repurpose of multi-target kinase inhibitors in patients with RET fusion-positive NSCLC showed encouraging therapeutic activity, with only cabozantinib and vandetanib being recommended as initial or subsequent options under certain circumstances. However, there are still unmet clinical needs. Pralsetinib and selpercatinib have been developed as tyrosine kinase inhibitors (TKI) selectively targeting RET variation of fusions or mutations, and both agents significantly improved the prognosis of patients with RET fusion-positive NSCLC. Pralsetinib and selpercatinib have been established as preferred first-line therapy or subsequent therapy options. As observed with other TKIs treatment, resistance has also been associated with RET targeted inhibition, and the acquired resistance eventually affect the long-term therapeutic effectiveness, leading to limited subsequent treatment options. Therefore, it is essential to identify resistance mechanisms to TKI in RET fusion-positive advanced NSCLC to help reveal and establish new strategies to overcome resistance. Here, we review the advances in the treatment of RET fusion-positive advanced NSCLC.
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Effects of Pigment Epithelium-derived Factor and Its Peptides on Proliferation, Apoptosis and Migration of Non-small Cell Lung Cancer / 中国肺癌杂志

BACKGROUND@#The anti-tumor effect of pigment epithelium-derived factor (PEDF) has been widely confirmed. However, the anti-tumor effect of its peptides is rarely reported. This study aims to investigate the effects of PEDF and its peptides on the apoptosis and migration of non-small cell lung cancer (NSCLC).@*METHODS@#In this study, A549 cells and H1299 cells were selected as the research object, and the cells were divided into normal group, PEDF treatment group, 34 peptide treatment group, 44 peptide treatment group and 34+44 peptide treatment group by administering different drugs at the same concentration to the cells. The proliferation activity of cells in each group was detected by CCK-8 method; the migration ability of cells was detected by scratch test; the expression levels of apoptosis related proteins such as protein kinase 3 (RIP3) and cleaved-caspase-3 were detected by Western blot; the expression levels of epithelial mesenchymal transition (EMT) markers in each group, such as cadherin (E-cadherin) and α-smooth muscle actin (α-SMA) were detected by Western blot; the apoptosis rate of each group was detected by flow cytometry.@*RESULTS@#The results of CCK-8 showed that PEDF and its peptides could inhibit cell proliferation, and the inhibitory effect of 34+44 peptide was the strongest (P<0.05); Observation under the microscope found that PEDF and its peptides can inhibit the proliferation and mesenchymal transformation of A549 cells and H1299 cells, and the inhibitory effect of the 34+44 peptide group is the most obvious; Western blot indicated that compared with other groups, the expressions of cleaved-caspase-3 and RIP3 in 34+44 peptide group were significantly higher (P<0.05), and the expressions of EMT protein E-cadherin were higher, the expression of α-SMA decreased (P<0.05); The results of flow cytometry showed that the apoptosis rate of 34+44 peptide group was significantly higher than those of other groups (P<0.05); The scratch test showed that compared with all the other groups, the healing rate of 34+44 peptide group was the lowest (P<0.05).@*CONCLUSIONS@#34+44 combination peptide can better promote the apoptosis of NSCLC, inhibit the migration of NSCLC, and thereby inhibit the growth of NSCLC.

Current Advance in Targeted Treatment and Immunotherapy for BRAF-mutant Advanced Non-small Cell Lung Cancer / 中国肺癌杂志

With the development of precision medicine, therapies of targeting driver genes have significantly prolonged survival in advanced non-small cell lung cancer (NSCLC) patients. Among them, BRAF gene mutation is relatively rare, and the traditional regimen follows the treatment plan of NSCLC without driver gene mutation, which is far from meeting the clinical needs. In recent years, targeted therapy for NSCLC patients with BRAF V600E mutations has shown good efficacy when we are still exploring the better targeted therapies for other BRAF-mutated subtypes. Immunotherapy also showed positive antitumor activity in V600E and non-V600E subtypes of BRAF-mutated NSCLC. This article reviewed the progress of immunological and targeted therapy for patients with BRAF-mutated NSCLC.
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Research Progress of Epigenetic Mechanism in Acquired Resistance of Targeted Therapy in Non-small Cell Lung Cancer / 中国肺癌杂志

Patients with oncogenic driver alterations of non-small cell lung cancer (NSCLC) can benefit from targeted therapy, but acquired resistance is inevitable ultimately. Epigenetic modifications, including DNA methylation, histone modifications, non-coding RNA-mediated regulate and chromatin remodeling, are important mechanisms of acquired resistance in targeted therapy of NSCLC. In recent years, studies have found that epigenetic modifications can effectively reverse drug resistance. Targeted therapy combined with epigenetic modifications may become a promising therapeutic strategy. Here, we review the progress of epigenetic mechanism in acquired resistance of targeted therapy in NSCLC, hoping to provide ideas for screening dominant population and overcoming resistance.
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The effect and mechanism of sphingosine kinase-1 knockdown on non-small cell lung cancer cell proliferation and mitochondrial apoptotic pathway / 生理学报

The purpose of the present study was to investigate the effect and potential mechanism of knockdown of sphingosine kinase-1 (SPHK1) on the proliferation, cell cycle and apoptosis of non-small cell lung cancer (NSCLC) cells. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) was used to detect SPHK1 mRNA expression in human healthy lung fibroblasts (MRC-5 cells) and four NSCLC cell lines. Then, A549 and H1299 cells were transfected with SPHK1-shRNA and corresponding negative control. CCK-8, Annexin V-FITC/PI dual staining and cell cycle assay were performed to evaluate cell proliferation, apoptosis and cell cycle distribution, respectively. JC-1 mitochondrial membrane potential measurement kit was adopted to measure mitochondrial membrane potential. Western blot was used to detect the protein expression levels of cell cycle and mitochondrial apoptotic pathway-related proteins, as well as MEK/ERK signaling pathway. The results showed that the mRNA expression of SPHK1 in NSCLC cells was higher than that in MRC-5 cells. SPHK1-shRNA significantly inhibited the proliferation of A549 and H1299 cells, blocked the cell cycle in G0/G1 phase, and promoted cell apoptosis through the mitochondrial pathway. Compared with the control group, the expression of p-MEK and p-ERK proteins in the SPHK1-shRNA group was significantly down-regulated. Moreover, MEK/ERK inhibitor could dramatically suppress cell proliferation and promote cell apoptosis. These results suggest that SPHK1 knockdown can inhibit the proliferation of NSCLC cells and might promote mitochondrial apoptotic pathway by inhibiting MEK/ERK signaling pathway.

Research Progress in Hepatocyte Growth Factor/Mesenchymal-epithelial Transition Factor Signaling Pathway:Effects and Mechanisms on Resistance to Targeted Therapy for Non-small Cell Lung Cancer / 中国医学科学院学报

Targeted therapy is an important therapeutic method for advanced non-small cell lung cancer with driver gene alteration.However,resistance to targeted therapy will inevitably happen in clinical practice,which has become a major issue demanding prompt solution.Studies have demonstrated that bypass resistance mediated by the activation of hepatocyte growth factor(HGF)/mesenchymal-epithelial transition factor(MET)signaling pathway is a common cause of resistance to targeted therapy.Presently,relevant studies have accumulated rich experience in the specific mechanisms.To be brief,HGF/MET is an important target for overcoming the resistance to targeted therapy and promises to be a leading biomarker for judging and observing the occurrence of resistance.This paper introduces the recent studies concerning the effects and mechanisms of HGF/MET signaling pathway on resistance to targeted therapy.