关于阿法替尼（Bibw 2992）耐药的一些理论和解决方案

请教老马，我爱人 HER1(-). HER2(+),VEGF(++)非小细胞肺癌腺癌 19外显子缺失 20突变，其他正常。易和特耐药。目前吃2992，后续该如何治疗

我妈妈易有效，换2992两个半月后耐药，现在299804中，一个月后来汇报情况。

Transformation to "high grade" neuroendocrine carcinoma as an acquired drug resistance mechanism in EGFR-mutant lung adenocarcinoma.
Popat S, Wotherspoon A, Nutting CM, Gonzalez D, Nicholson AG, O'Brien M.
SourceRoyal Marsden Hospital NHS Foundation Trust, London, and Surrey, UK. sanjay.popat@rmh.nhs.uk

Abstract
Several different acquired resistance mechanisms of EGFR mutant lung adenocarcinoma to EGFR-tyrosine kinase inhibitor (TKI) therapy have been described, most recently transformation to small cell lung carcinoma (SCLC). We describe the case of a 46-year-old female with relapsed EGFR exon 19 deletion lung adenocarcinoma treated with erlotinib, and on resistance, cisplatin-pemetrexed. Liver rebiopsy identified an afatinib-resistant combined SCLC and non-small cell carcinoma with neuroendocrine morphology, retaining the EGFR exon 19 deletion. This case highlights acquired EGFR-TKI resistance through transformation to the high-grade neuroendocrine carcinoma spectrum and that that such transformation may not be evident at time of progression on TKI therapy.
http://www.ncbi.nlm.nih.gov/pubmed/23312887

Abstract 5649: Investigational study of acquired resistance to the EGFR irreversible inhibitor afatinib (BIBW2992) in wild-type and EGFR-mutant NSCLC cell lines.
Angela Alama, Simona Coco, Zita Cavalieri, Anna Truini, Cristina Bruzzo, Mariella Dono, and Francesco Grossi
IRCCS A.O.U. San Martino-IST, Genoa, Italy.

Introduction: Non-small cell lung cancer (NSCLC) represents about 85% of all lung cancers. Almost 20% of NSCLC tumors harbor somatic activating mutations of the tyrosine kinase (TK) encoding domain in EGFR gene (exons 18-21). Patients with EGFR mutations treated with specific inhibitors of EGFR-TKI such as gefitinib and erlotinib demonstrated a significantly longer survival. Nevertheless, the majority of patients acquire resistance to these drugs within one year due to a second-site mutation in EGFR (T790M). The irreversible EGFR-TKI, afatinib, has been found to be effective in inhibiting the growth of NSCLC cells with the T790M mutation of EGFR. In this study, we generated different NSCLC cell lines resistant to afatinib to investigate the biological and molecular mechanisms of acquired resistance.

Methods: A dose-escalation study to establish afatinib-resistant cell lines was performed in 3 NSCLC cell lines with a different EGFR mutational status: A549 (EGFR-wild type); H-1650 (exon19 delE746-A750); H-1975 (exon21 L858R/exon20 T790M). EGFR exons (18-21) from parental and resistant cells were sequenced by Sanger method while the EGF pathway was studied by qPCR using TaqMan® Array EGF Pathway and relative expression values of 92 genes, compared to parental cells, were obtained by 2–ddCT. Concomitantly, protein expression of some relevant genes such as EGFR and AKT, both phosphorylated and unphosphorylated, were investigated by western blot (WB).

Results: All 3 cell lines exhibited different degree of drug resistance and actively proliferated under persistent afatinib pressure (A549: 8.5μM; H-1650: 1.0μM; H-1975: 5.0μM) as compared to parental cultures. WB reported active phosphorylation of EGFR and AKT in resistant cells regardless of EGFR mutational status. This behavior also persisted in absence of EGF stimulation and in cultures maintained in afatinib-free medium for over 2 months. However none of the resistant cell lines harbored new EGFR mutation in the 4 exons (18-21). Gene expression analysis showed an increase of some members of RAS (MRAS, KRAS) and Rho families and also PI3K regulatory subunit 1 (PIK3R1) in A549 and H1975 cells. Notably, SHC3 (Src homology 2 domain containing; transforming protein 3) was up-regulated about 60-fold in H1975 whereas proto-oncogene JUN showed a 6-fold increase in H1650. In addition EGF was down-modulated in both H1650 and H1975.

Conclusion: Silencing of EGF in resistant cells together with the EGFR and AKT phosphorylation, suggest that these cultures acquired a different way to activate the EGF pathway. Furthermore in H-1975 the markedly increase of SHC3, an adaptor immediately downstream of EGFR, leads to hypothesize that it could be implicated in the activation of EGFR. Further investigations of SHC3 involvement in EGF pathway activation as well as sequencing analysis of the whole EGFR gene are ongoing.

http://cancerres.aacrjournals.or ... etingAbstracts/5649

Following prolonged therapy with afatinib, many independent afatinib-resistant
http://caspasesignaling.com/foll ... fatinib-resistant-c
Right after prolonged treatment method with afatinib, many independent afatinib-resistant clones emerged that persisted and proliferated even within the presence of two ?M afatinib. From these, we established 14 various independent clones that acquired resistance to afatinib. A few of the drug responses with the representative resistant clones are CYP17 Inhibitors shown in Fig. 1B. To keep track of no matter if the acquisition of resistance was irreversible, we cultured all of these clones in standard development medium with no the RTK inhibitor. These clones remained resistant to afatinib soon after incubation in standard development medium for quite a few months , indicating that these cells underwent an irreversible alter, potentially involving chemically stable physical alterations in their genetic space. The signature exon 19 deletion of parental PC9 cells remained unaltered in all of the r . Full surgical resection of tumors or liver transplantation is only probable in a minority of patients; for patients with innovative condition, the prognosis is extremely poor, with an overall median survival of only some months. Response rates to classical chemotherapy are reduced, and also with combination regimens, long lasting remission has remained elusive . Thus, there is a solid need for added therapeutic possibilities.
Lately, rationally created, molecularly targeted medicines have grown to be out there. These agents are built to target growth or survival pathways hyper-activated in cancer cells. Tyrosine kinases are considered to become exceptional molecular oncology targets Dabigatran due to the fact they transduce growth and survival signals and therefore are hyper-activated in many, if not all, human malignancies . The ErbB receptor tyrosine kinase family members, comprising EGFR and ErbB2, -3, and -4, has become of central interest during the development of targeted anticancer strategies. Trastuzumab , a monoclonal antibody against ErbB2, is efficiently being utilized in individuals with ErbB2-overexpressing breast cancer, and overexpression of ErbB2 through gene amplification is really a excellent predictor of favorable response . Several preclinical and clinical research have addressed the efficacy of EGFR-targeting agents, including tyrosine kinase inhibitors , for example gefitinib and erlotinib , likewise as monoclonal anti-EGFR antibodies, like cetuximab, for that treatment of non-small cell lung cancer , head and neck cancer, colon carcinoma, glioblastoma, together with other tumors . Even though NSCLC sufferers with activating mutations inside the kinase domain of EGFR respond favorably to EGFR TKIs, top to their approval for this subset of malignancies, the molecular basis figuring out the response of tumor cells to EGFR-targeting drugs in other settings is only partially understood and it is talked about controversially.

The Role of STAT3 in De Novo Resistance to Afatinib
http://scienceindex.com/stories/ ... ce_to_Afatinib.html
The secondary T790M mutation in epidermal growth factor receptor (EGFR) is the major mechanism of acquired resistance to EGFR tyrosine kinase inhibitors (TKI) in non–small cell lung cancer (NSCLC). Although irreversible EGFR TKIs, such as afatinib or dacomitinib, have been introduced to overcome the acquired resistance, they showed a limited efficacy in NSCLC with T790M. Herein, we identified the novel de novo resistance mechanism to irreversible EGFR TKIs in H1975 and PC9-GR cells, which are NSCLC cells with EGFR T790M. Afatinib activated interleukin-6 receptor (IL-6R)/JAK1/STAT3 signaling via autocrine IL-6 secretion in both cells. Inhibition of IL-6R/JAK1/STAT3 signaling pathway increased the sensitivity to afatinib. Cancer cells showed stronger STAT3 activation and enhanced resistance to afatinib in the presence of MRC5 lung fibroblasts. Blockade of IL-6R/JAK1 significantly increased the sensitivity to afatinib through inhibition of afatinib-induced STAT3 activation augmented by the interaction with fibroblasts, suggesting a critical role of paracrine IL-6R/JAK1/STAT3 loop between fibroblasts and cancer cells in the development of drug resistance. The enhancement of afatinib sensitivity by inhibition of IL-6R/JAK1/STAT3 signaling was confirmed in in vivo PC9-GR xenograft model. Similar to afatinib, de novo resistance to dacomitinib in H1975 and PC9-GR cells was also mediated by dacomitinib-induced JAK1/STAT3 activation. Taken together, these findings suggest that IL-6R/JAK1/STAT3 signaling can be a potential therapeutic target to enhance the efficacy of irreversible EGFR TKIs in patients with EGFR T790M. Mol Cancer Ther; 11; 2254–64. ©2012 AACR.

Approved
Ruxolitinib against JAK1/JAK2 for psoriasis, myelofibrosis, and rheumatoid arthritis.approved by the U.S. Food and Drug Administration (FDA) in November 2011 for myelofibrosis.
Tofacitinib (tasocitinib; CP-690550) against JAK3 for psoriasis and rheumatoid arthritis.[7] US FDA approved in November 2012 for rheumatoid arthritis.
In clinical trials
Baricitinib (LY3009104, INCB28050) against JAK1/JAK2 starting phase IIb for rheumatoid arthritis
CYT387 against JAK2 for myeloproliferative disorders
Lestaurtinib against JAK2, for acute myelogenous leukemia (AML)
Pacritinib (SB1518) against JAK2 for relapsed lymphoma and advanced myeloid malignancies,[12] chronic idiopathic myelofibrosis (CIMF)
TG101348 against JAK2; phase I results for myelofibrosis are published

Overcoming the acquired resistance to Afatinib (BIBW2992) in HCC827, a non-small cell lung cancer cell line
Understanding of the pharmacological responses to drug treatment in cancer cells is essential for discovery and development of novel anticancer therapies. In this study, drug resistant cell lines, HCC827-BR1 and HCC827-BR2, were developed by treatment of HCC827 cells with escalating concentration of afatinib (BIBW2992). The CC50 of BIBW2992 in HCC827 ranges from 2 to 10 nM while the CC50s of BIBW2992 in HCC827-BR1 and HCC827-BR2 are approximately 10 uM. Gene expression analysis revealed that the epithelial-mesenchymal transition (EMT) may be involved in resistance to BIBW2992. The drug-resistant cells are more invasive as evaluated under in vitro assays. Results from this study have also identified that the drug-resistance cells are more sensitive to another kinase inhibitor; indicating that an oncogenic shift has occurred. When this drug is combined with BIBW2992 in treatment of HCC827 cells, much less colonies survived compared to cells treated by BIBW2992 alone. The clinical ramifications of these observations will be discussed.

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Glycolysis Inhibition Sensitizes Non–Small Cell Lung Cancer with T790M Mutation to Irreversible EGFR Inhibitors via Translational Suppression of Mcl-1 by AMPK Activation
http://mct.aacrjournals.org/content/12/10/2145.short?rss=1
The secondary EGF receptor (EGFR) T790M is the most common mechanism of resistance to reversible EGFR-tyrosine kinase inhibitors (TKI) in patients with non–small cell lung cancer (NSCLC) with activating EGFR mutations. Although afatinib (BIBW2992), a second-generation irreversible EGFR-TKI, was expected to overcome the acquired resistance, it showed limited efficacy in a recent phase III clinical study. In this study, we found that the inhibition of glycolysis using 2-deoxy-d-glucose (2DG) improves the efficacy of afatinib in H1975 and PC9-GR NSCLC cells with EGFR T790M. Treatment with the combination of 2DG and afatinib induced intracellular ATP depletion in both H1975 and PC9-GR cells, resulting in activation of AMP-activated protein kinase (AMPK). AMPK activation played a central role in the cytotoxicity of the combined treatment with 2DG and afatinib through the inhibition of mTOR. The alteration of the AMPK/mTOR signaling pathway by the inhibition of glucose metabolism induced specific downregulation of Mcl-1, a member of the antiapoptotic Bcl-2 family, through translational control. The enhancement of afatinib sensitivity by 2DG was confirmed in the in vivo PC9-GR xenograft model. In conclusion, this study examined whether the inhibition of glucose metabolism using 2DG enhances sensitivity to afatinib in NSCLC cells with EGFR T790M through the regulation of the AMPK/mTOR/Mcl-1 signaling pathway. These data suggest that the combined use of an inhibitor of glucose metabolism and afatinib is a potential therapeutic strategy for the treatment of patients with acquired resistance to reversible EGFR-TKIs due to secondary EGFR T790M. Mol Cancer Ther; 12(10); 2145–56. ©2013 AACR.