益气祛痰解毒方通过调控FRMD6 抑制非小细胞肺癌进展的作用机制研究

探究益气祛痰解毒方对非小细胞肺癌（non-small cell lung cancers,NSCLC）细胞的抑制作用和相关分子机制。方法 构建FRMD6（FERM domain-containing protein 6, FRMD6）敲低PC9细胞株。将PC9细胞分为对照组,shNC组,shFRMD6组,益气祛痰解毒方+shNC组,益气祛痰解毒方+shFRMD6组。采用实时定量PCR（qRT-PCR）检测各组PC9细胞的FRMD6表达水平变化;应用CCK-8法检测各组PC9细胞增殖率;采用Annexin V-FITC/PI法检测试各组PC9细胞凋亡情况;利用Transwell实验检测各组PC9细胞侵袭能力;利用Western blot检测各组FRMD6, c-MET, p-PI3K, PI3K, p-Akt和Akt蛋白表达的变化。结果 CCK8检测结果表明,与对照组相比,益气祛痰解毒方对PC9细胞增殖具有显著抑制效果（P < 0.05）;qRT-PCR和Western blot结果显示,发现益气祛痰解毒方可以上调FRMD6表达。进一步进行qRT-PCR和Western blot结果表明FRMD6敲低PC9细胞株构建成功;益气祛痰解毒方处理能够抑制PC9细胞增殖、侵袭,并促进细胞凋亡;同时,与shNC组相比,益气祛痰解毒方+shNC组均可显著抑制PC9细胞增殖、侵袭并促进细胞凋亡（P < 0.05）。Western blot结果发现,益气祛痰解毒方+shNC组相较于shNC组的c-MET、p-PI3K和p-Akt表达明显降低,说明使用益气祛痰解毒方处理可抑制c-MET/PI3K/AKT通路;此外,与shFRMD6组相比,益气祛痰解毒方+shFRMD6组c-MET、p-PI3K和p-Akt表达显著下调,敲低FRMD6表达会显著减弱益气祛痰解毒方对c-MET/PI3K/AKT通路的抑制作用。结论 益气祛痰解毒方能够抑制肺癌PC9细胞增殖、降低侵袭能力和促进细胞凋亡,其分子机制可能通过FRMD6调控c-MET/PI3K/AKT通路来实现。     

Discovery of novel exceptionally potent and orally active c-MET PROTACs for the treatment of tumors with MET alterations

Various c-mesenchymal-to-epithelial transition (c-MET) inhibitors are effective in the treatment of non-small cell lung cancer; however, the inevitable drug resistance remains a challenge, limiting their clinical efficacy. Therefore, novel strategies targeting c-MET are urgently required. Herein, through rational structure optimization, we obtained novel exceptionally potent and orally active c-MET proteolysis targeting chimeras (PROTACs) namely D10 and D15 based on thalidomide and tepotinib. D10 and D15 inhibited cell growth with low nanomolar IC₅₀ values and achieved picomolar DC₅₀ values and >99% of maximum degradation (D_max) in EBC-1 and Hs746T cells. Mechanistically, D10 and D15 dramatically induced cell apoptosis, G1 cell cycle arrest and inhibited cell migration and invasion. Notably, intraperitoneal administration of D10 and D15 significantly inhibited tumor growth in the EBC-1 xenograft model and oral administration of D15 induced approximately complete tumor suppression in the Hs746T xenograft model with well-tolerated dose-schedules. Furthermore, D10 and D15 exerted significant anti-tumor effect in cells with c-MET^Y1230H and c-MET^D1228N mutations, which are resistant to tepotinib in clinic. These findings demonstrated that D10 and D15 could serve as candidates for the treatment of tumors with MET alterations.     

A Phase II Study of Telisotuzumab Vedotin in Patients With c–MET-positive Stage IV or Recurrent Squamous Cell Lung Cancer (LUNG-MAP Sub-study S1400K,NCT03574753)

IntroductionLung-MAP S1400K was designed to evaluate the response to telisotuzumab vedotin, an antibody-drug conjugate targeting c-MET, in patients with c-MET–positive squamous cell carcinoma (SCC).Patients and MethodsPatients with previously treated SCC with c-MET–positive tumors (H score ≥ 150, Ventana SP44 assay) were enrolled into 2 cohorts: Cohort 1 (immune checkpoint inhibitor-naive) and Cohort 2 (immune checkpoint inhibitor refractory). Telisotuzumab vedotin 2.7 mg/kg was administered intravenously every 3 weeks until disease progression or unacceptable toxicity. Response assessments were performed every 6 weeks. The primary endpoint was response by Response Evaluation Criteria in Solid Tumors (RECIST) v1.1. Secondary endpoints included progression-free survival, overall survival, response within cohort, duration of response, and toxicities. Interim analysis was planned after 20 evaluable patients, with ≥ 3 responses needed to continue enrollment.ResultsForty-nine patients (14% of screened patients) were assigned to S1400K, 28 patients enrolled (15 in Cohort 1 and 13 in Cohort 2), and 23 were eligible. S1400K closed on December 21, 2018 owing to lack of efficacy. Two responses (response rate of 9%; 95% confidence interval, 0%-20%) were reported in cohort 1 (1 complete and 1 unconfirmed partial response), whereas 10 patients had stable disease, with a disease control rate of 52%. The median overall and progression-free survival was 5.6 and 2.4 months, respectively. There were 3 grade 5 events (2 pneumonitis, in Cohort 2, and 1 bronchopulmonary hemorrhage, in Cohort 1).ConclusionTelisotuzumab vedotin failed to meet the pre-specified response needed to justify continuing enrollment to S1400K. Pneumonitis was an unanticipated toxicity observed in patients with SCC.     

Upfront molecular testing in patients with advanced gastro-esophageal cancer: Is it time yet?

Introduction

Targeting HER2 has improved outcomes in metastatic GE (mGE) cancer. In this study, we aim to explore the feasibility of molecular profiling in patients with refractory mGE cancer in routine clinical practice.

Methods

Archival formalin-fixed, paraffin-embedded (FFPE) samples for patients with mGE were analyzed with commercially available targeted next generation sequencing (NGS) and/or FISH for MET amplification. We also reviewed the patients'' medical records for concurrent HER 2 testing.

Results

Tumor samples from 99 patients with mGE cancer were analyzed as follows: NGS (N = 56), FISH for MET amplification (N = 65), IHC and/or FISH for HER2 (N = 87). Of patients who underwent NGS, 50/56 (89%) had at least one actionable molecular alteration. The most notable actionable alterations included cell cycle abnormalities (58%), HER2 amplification (30%), PI3KCA mutation (14%), MCL1 amplification (11%), PTEN loss (9%), CDH1 mutation (2%) and MET amplification (5%). Ninety-two percent (12/13) of patients with HER2 amplification by NGS were positive for HER2 by IHC and/or FISH. In contrast, only 12/18 (66%) patients positive for HER2 by IHC and/or FISH demonstrated HER2 amplification by NGS.

Conclusion

Comprehensive molecular testing is feasible in clinical practice and provides a platform for screening patients for molecularly guided clinical trials and available targeted therapies.     

Foretinib inhibits angiogenesis,lymphangiogenesis and tumor growth of pancreatic cancer in vivo by decreasing VEGFR-2/3 and TIE-2 signaling

Foretinib, a multiple kinase inhibitor undergoing clinical trials, could suppress the activity of hepatocyte growth factor (HGF) receptor c-MET and vascular endothelial growth factor receptor-2 (VEGFR-2). In addition, Foretinib may inhibit two critical lymphangiogenic signaling receptors VEGFR-3 and TIE-2. However, the effect of Foretinib on lymphatic endothelial cells (LECs) in vitro and lymphangiogenesis in vivo is still unknown. We found Foretinib decreased basal- and HGF-induced c-MET activity at low concentrations. However, Foretinib only reduced the proliferation of pancreatic cancer cells at high concentration reflecting the intrinsic chemoresistance of pancreatic cancer cells. Foretinib inhibited VEGF-A, VEGF-C and Angiopoetin-2 (ANG-2)-stimulated tube formation and sprouting of LECs by reducing VEGFR-2, VEGFR-3 and TIE-2 activation and increased apoptosis of LECs. In xenograft animal study, Foretinib suppressed tumor growth by inhibiting proliferation, angiogenesis and lymphangiogenesis. Additionally, Foretinib inhibited angiogenesis and lymphangiogenesis more significantly and exhibited low detrimental effect in orthotopic animal study. Collectively, we suggested that Foretinib simultaneously inhibits cancer cells and LECs to reduce pancreatic tumor growth in vivo and demonstrated for the first time that Foretinib suppresses angiogenesis and lymphangiogenesis by blocking VEGFR-2/3 and TIE-2 signaling.     

肺金生方抗非小细胞肺癌EGFR-TKIs耐药性的分子机制研究

目的探讨肺金生方抗非小细胞肺癌(NSCLC)酪氨酸磷酸酶抑制剂(TKIs)靶向药物耐药的作用及分子机制。方法选用NSCLC细胞系HCC827,按0.01、0.05、0.10、0.50和1.0μM浓度梯度诱导构建吉非替尼耐药细胞株,采用CCK8法检测耐药株是否构建成功,采用荧光定量PCR(q-PCR)检测耐药株c-MET扩增水平。20只BALB/c裸鼠按随机数字表法分成空白对照组、吉非替尼组、肺金生方组和肺金生方+吉非替尼组,每组5只。按每只4×10~7/200μL将吉非替尼耐药细胞株注射于裸鼠后肢皮下,构建皮下移植瘤模型。四组均腹腔注射生理盐水,吉非替尼组给予吉非替尼50mg/kg灌胃;肺金生方组给予肺金生方剂量53.6g/kg灌胃;肺金生方+吉非替尼组给予吉非替尼50mg/kg+肺金生方剂量53.6g/kg联合灌胃给药。给药频次每2天1次,连续给药4周。CCK8法检测耐药HCC827 GR细胞增殖率,流式细胞技术检测耐药HCC827 GR细胞凋亡率,Western blot检测耐药HCC827 GR细胞p-EGFR、p-MET、p-AKT、p-ERK1/2表达水平。结果与空白对照组比较,吉非替尼组裸鼠皮下移植瘤瘤重无差异[(1.34±0.16)g比(1.41±0.13)g,P>0.05],肺金生方组裸鼠皮下移植瘤瘤重明显减轻[(0.77±0.28)g比(1.41±0.13)g,P<0.01],吉非替尼+肺金生方组裸鼠皮下移植瘤明显小于肺金生方组和吉非替尼组[(0.34±0.16)g比(0.77±0.28)g、(1.34±0.16)g,P均<0.01];肺金生方单用或与吉非替尼联用能够明显抑制耐药HCC827 GR细胞的增殖能力[(43.45±4.47)%、(24.25±5.21)%比(100.00±2.14)%,P均<0.01];肺金生方组、吉非替尼+肺金生方组细胞凋亡率显著高于空白对照组[(7.40±0.56)%、(12.80±0.72)%比(3.05±0.54)%,P均<0.01];肺金生方组、吉非替尼+肺金生方组c-MET和p-c-MET表达水平明显降低,并明显抑制下游AKT/ERK1/2磷酸化水平。结论肺金生方或和吉非替尼联用能有效抑制吉非替尼耐药皮下移植瘤的生长,抑制耐药细胞的增殖并促进凋亡,其作用机制可能与下调c-MET蛋白表达以及下游AKT/ERK1/2磷酸化水平有关。     

非小细胞肺癌人群中c-MET基因的扩增检测

目的：c-MET基因扩增是非小细胞肺癌对EGFR TKIs（吉非替尼或厄罗替尼）产生耐药的主要机制之一。本研究探讨没有接受TKIs治疗与TKIs治疗后耐药的NSCLC中c-MET基因的扩增是否存在差异。方法:获得55例术后非小细胞肺癌（NSCLC）的肿瘤组织（基线组）以及23例对TKIs耐药的肿瘤组织（耐药组）后,通过激光显微切割筛选癌细胞后提取基因组DNA,实时荧光定量PCR TaqMan探针法检测所有标本的c-MET基因的拷贝数。 结果:1.基线组和耐药组的临床病理特征均与c-MET基因的扩增无关。2.基线组中c-MET基因扩增阳性率为5.5% (3/55);耐药组的c-MET基因扩增阳性率为21.7% (5/23)。两组之间有统计学差异（Fisher精确概率法,P=0.045）。3.在7例获得TKI治疗前后肿瘤组织的NSCLC中,TKI治疗前没有出现c-MET的基因扩增,TKI治疗后有2例患者出现了c-MET的基因扩增（2/7）。TKI治疗前后的c-MET基因扩增差异无统计学意义。结论:NSCLC的临床病理特征不能预测c-MET基因扩增;在没有接受EGFR TKIs治疗的NSCLC中,c-MET基因扩增仅为少见事件。但经过吉非替尼或厄罗替尼治疗后出现耐药情况NSCLC中,部分患者的c-MET基因出现扩增。     

C-MET inhibitors for advanced non-small cell lung cancer

Introduction: The role of the c-mesenchymal-epithelial transition factor (c-MET) signaling pathway in tumor progression and invasion has been extensively studied. C-MET inhibitors have shown anti-tumor activity in NSCLC both in preclinical and in clinical trials. However, given the molecular heterogeneity of NSCLC, it is likely that only a specific subset of NSCLC patients will benefit from c-MET inhibitors. Emerging data also suggest that MET inhibitors in combination with EGFR-TKIs (epidermal growth factor receptor tyrosine kinase inhibitors) may have a role in therapy for both EGFR-TKI resistant and EGFR-TKI naïve patients. The challenges ahead are in the identification of the molecular subtypes that benefit most.

Areas covered: This review summarizes the current understanding of c-MET biology in relation to studies evaluating c-MET inhibitors in the treatment of NSCLC.

Expert opinion: MET inhibitors have the potential to benefit subsets of NSCLC patients with specific genetic alterations. Exon-14 skipping mutations appear so far to be the most promising molecular subset that is sensitive to MET inhibitors, whereas overexpression, amplification and point mutations of MET seem more challenging subgroups to target. Combination with other target agents, such as EGFR inhibitors, may represent a promising therapeutic strategy in specific areas (e.g. EGFR-TKI resistance).