IntroductionOsimertinib is an irreversible EGFR tyrosine kinase inhibitor approved for the first-line treatment of patients with metastatic NSCLC harboring EGFR exon 19 deletions or L858R mutations. Patients treated with osimertinib invariably develop acquired resistance by mechanisms involving additional EGFR mutations, MET amplification, and other pathways. There is no known involvement of the oncogenic MUC1-C protein in acquired osimertinib resistance.MethodsH1975/EGFR (L858R/T790M) and patient-derived NSCLC cells with acquired osimertinib resistance were investigated for MUC1-C dependence in studies of EGFR pathway activation, clonogenicity, and self-renewal capacity.ResultsWe reveal that MUC1-C is up-regulated in H1975 osimertinib drug-tolerant persister cells and is necessary for activation of the EGFR pathway. H1975 cells selected for stable osimertinib resistance (H1975-OR) and MGH700-2D cells isolated from a patient with acquired osimertinib resistance are found to be dependent on MUC1-C for induction of (1) phospho (p)-EGFR, p-ERK, and p-AKT, (2) EMT, and (3) the resistant phenotype. We report that MUC1-C is also required for p-EGFR, p-ERK, and p-AKT activation and self-renewal capacity in acquired osimertinib-resistant (1) MET-amplified MGH170-1D #2 cells and (2) MGH121 Res#2/EGFR (T790M/C797S) cells. Importantly, targeting MUC1-C in these diverse models reverses osimertinib resistance. In support of these results, high MUC1 mRNA and MUC1-C protein expression is associated with a poor prognosis for patients with EGFR-mutant NSCLCs.ConclusionsOur findings reveal that MUC1-C is a common effector of osimertinib resistance and is a potential target for the treatment of osimertinib-resistant NSCLCs.
Abstract Background: Programmed cell death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) play a major role in suppressing the immune system by forming the PD-1/PD-L1 complex, which transmits an inhibitory signal to reduce T-cell activity. PD-L1 is often expressed in various malignant tumors. On the other hand, PD-1 is generally observed in activated lymphocytes and myeloid-derived dendritic cells. Of the malignant cells, only Jurkat cells (under special conditions) and angioimmunoblastic T-cell lymphoma tissue cells express PD-1 on their surface. Purpose: To clarify whether PD-1/PD-L1 complex participates in the immunotolerance on small-cell lung cancer (SCLC) cells. Materials and methods: We examined the expression levels of PD-1 and PD-L1 on the cell surface of SCLC cell lines using flowcytometry and reverse transcription polymerase chain reaction. Subsequently, the soluble PD-L1 (sPD-L1) concentration was measured using enzyme-linked immunosorbent assay, and the cell growth inhibitory effect of IFN-γ was determined by direct cell counting using a hemocytometer and Trypan blue staining. Results: Among the four SCLC cell lines examined, only SBC-3 cells expressed both PD-1 and PD-L1. The sPD-L1 concentrations in culture medium gradually increased according to cell growth. Although IFN-γ alone inhibited the growth of SBC-3 cells, PD-L1 expression on the cell surface was not induced by IFN-γ. Conclusions: We demonstrated that both PD-1 and PD-L1 molecules are co-expressed on the surface of SCLC cells. Although the biological implications of this remain unclear, we speculate that PD-1 and its ligand on the SCLC cells may participate in the growth inhibition of tumor cells as is reported in cytotoxic T cells. Citation Format: Hiromichi Yamane, Hideko Isozaki, Nobuaki Ochi, Kenichiro Kudo, Yoshihiro Honda, Tomoko Yamagishi, Toshio Kubo, Katsuyuki Kiura, Nagio Takigawa. Both programmed cell death protein 1 and programmed death-ligand 1 molecules can be expressed on the cell surface of small-cell lung cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1323. doi:10.1158/1538-7445.AM2015-1323
Abstract Background: Osimertinib is an irreversible EGFR tyrosine kinase inhibitor approved for the first-line treatment of patients with metastatic NSCLC harboring EGFR exon 19 deletions or L858R mutations. Patients treated with osimertinib invariably develop acquired resistance by mechanisms involving additional EGFR mutations, MET amplification and other pathways. There is no known involvement of the oncogenic MUC1-C protein in acquired osimertinib resistance. Methods: H1975/EGFR(L858R/T790M) and patient-derived NSCLC cells with acquired osimertinib resistance (EMT, MET amplified, C797S mutation, or PCBP2-BRAF fusion) were investigated for MUC1-C dependence in studies of EGFR pathway activation, clonogenicity and self-renewal capacity. Results: We demonstrate that MUC1-C is upregulated in H1975 osimertinib drug tolerant persister (DTP) cells and is necessary for activation of the EGFR pathway. H1975 cells selected for stable osimertinib resistance (H1975-OR) and MGH700-2D cells isolated from a patient with acquired osimertinib resistance are shown to be dependent on MUC1-C for induction of (i) p-EGFR, p-ERK and p-AKT, (ii) EMT, and (iii) the resistant phenotype. We report that MUC1-C is also required for p-EGFR, p-ERK and p-AKT activation and self-renewal capacity in acquired osimertinib-resistant (i) MET amplified MGH170-1D #2 cells, (ii) MGH121 Res#2/EGFR(T790M/C797S) cells, and (iii) MGH845-1R5/EGFR(19del)/PCBP2-BRAF fusion cells. Importantly, targeting MUC1-C in these diverse models reverses osimertinib resistance. To extend these results, we established MET amplified MGH170-1D #2 tumors in mice and found that treatment with GO-203 inhibitor, which is a cell-penetrating peptide that blocks MUC1-C homodimerization, nuclear localization, and function, results in more pronounced inhibition and that the GO-203+osimertinib combination is more effective than either agent alone. In support of these results, high MUC1 expression is associated with poor prognosis for patients with EGFR mutant NSCLCs and those treated with osimertinib. Conclusions: Our findings demonstrate that MUC1-C is a common effector of osimertinib resistance and is a potential target for the treatment of osimertinib resistant NSCLCs. Citation Format: Naoki Haratake, Hiroki Ozawa, Yoshihiro Morimoto, Nami Yamashita, Tatsuaki Daimon, Atrayee Bhattacharya, Keyi Wang, Ayako Nakashoji, Hideko Isozaki, Aaron Hata, Donald Kufe. MUC1-C is a common driver of acquired osimertinb resistance in NSCLC [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr B089.
e19140 Background: Crizotinib, which is capable of blocking MET, ALK and ROS1, has been demonstrated the superior efficacy on first and second line therapy for advanced/metastatic patients with NSCLC harboring EML4-ALK fusion gene compared with chemotherapy. Alectinib, selective ALK inhibitor also has been showed dramatic response rate, long response duration and acceptable toxic profile (Lancet Oncol 14, 2013: 590-98). Two randomized clinical trials comparing alectinib with crizotinib in a first-line setting are ongoing. Alectinib would be a key drug of ALK-positive lung cancer treatment in the future. However, subsequent resistance to alectinib is expected after its approval. Thus, we need consider the therapeutic strategy to overcome the resistance to alectinib in advance. To elucidate the mechanisms of alectinib-resistance, we established resistant cell line and analyzed. Methods: Two alectinib-resistant ABC-11/CHR NSCLC cell lines from ABC-11 harboring EML4-ALK fusion genes were established by continuous exposure to alectinib. We characterized the resistant cell lines using MTT assay, Western blotting, immunohistochemistry, polymerase chain reaction, fluorescent in situ hybridization, phospho-receptor tyrosine kinase array, RNA array, ELISA and xenograft models. Results: ABC-11/CHR cells showed 17-fold more resistant than parent cells to alectinib by MTT assay. The resitant cells were activated MET with increment of its ligand (hepatocyte growth factor) as an autocrine action. Because crizotinib could inhibit MET as well as ALK, ABC-11/CHR cells were sensitive to the drug both in vitro and in vivo. Conclusions: We found that activation of MET caused to acquired resistance to alectinib. MET inhibitor combined with AKK inhibitor was effective on such case. Thus, ALK positive NSCLC patients with refractory to alectinib might have benefits from crizotinib.
Abstract Background The second-generation anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitor (TKI), alectinib, demonstrated high response rate, long response duration and a favorable toxic profile in patients with ALK-rearranged advanced non-small cell lung cancer in a phase II study (Lancet Oncol 14:590-8, 2013). However, even this promising drug is predicted to develop acquired resistance. Therefore, we investigated the mechanisms of resistance using two alectinib-resistant cell lines. Methods We established alectinib-resistant cell lines, H2228/CHR and ABC-11/CHR, from H2228 (EML4-ALK fusion genes variant 3a/b E6) and ABC-11 (EML4-ALK fusion genes variant 3b E6) respectively, by continuous exposure to alectinib. They were characterized using MTT assay, Western blotting, receptor tyrosine kinase array, ELISA, FISH, RT-PCR, and xenograft models. Results H2228/CHR and ABC-11/CHR cells were 117- and 40-fold more resistant than the parental lines, respectively, and maintained downstream AKT and ERK phosphorylation even in the presence of 10 μM alectinib. There were no ALK secondary mutations in those resistant cell lines. H2228/CHR lost the EML4-ALK fusion gene, and exhibited increased activation of insulin-like growth factor-1 receptor (IGF-1R) and human epidermal growth factor receptor 3 (HER3) with overexpression of the HER3 ligand neuregulin 1. Accordingly, pharmacologic inhibition of IGF-1R and HER3 signaling overcame the resistance. In ABC-11/CHR, MET was activated by stimulated hepatocyte growth factor (HGF) autocrine signaling. We found HGF gene translocation underlying the HGF autocrine system. Anti-HGF antibody suppressed the MET activation and combined treatment with alectinib and anti-HGF antibody or a MET inhibitor suppressed downstream signaling in ABC-11/CHR cells. Finally, crizotinib, which targets both ALK and MET, most effectively inhibited the growth of ABC-11/CHR both in vitro and in vivo. Conclusions We identified novel alectinib resistance mechanisms caused by the activation of alternative tyrosine kinase receptors. Our findings provide new insights into constructing a therapeutic strategy for ALK-positive lung cancer. Citation Format: Hideko Isozaki, Eiki Ichihara, Masayuki Yasugi, Nagio Takigawa, Kadoaki Ohashi, Toshio Kubo, Takashi Ninomiya, Nobuaki Ochi, Daisuke Minami, Kenichiro Kudo, Yuka Kato, Hiroe Kayatani, Tomoki Tamura, Kiichiro Ninomiya, Toshio Higo, Tsuyoshi Makimoto, Akiko Sato, Katsuyuki Hotta, Kunio Matsumoto, Toshiaki Sendo, Mitsune Tanimoto, Katsuyuki Kiura. Activating alternative receptor tyrosine kinases induced alectinib-resistance in ALK rearranged non-small cell lung cancer cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2103.
The far-infrared spectra of bicyclo(3.1.0.)hexane, 3-oxabicyclo(3.1.0.)hexane, and 3,6-dioxabicyclo(3.1.0.)hexane exhibit series of Q branches in the frequency range 250–125 cm−1, like those observed for 6-oxabicyclo(3.1.0.)hexane (cyclopentene oxide) by Carreira and Lord (J. Chem. Phys. 51, 2735 (1969)). The Q branches are interpreted as single quantum jumps of a one-dimensional ring-puckering vibration governed by a potential function of the form V(cm−1) = A(Z4 + BZ2 + CZ3), where Z is a reduced ring-puckering coordinate.The potential parameters for bicyclo(3.1.0.)hexane are A, 24.31 cm−1; B, 26.67; C, 9.63; for 3-oxabicyclo(3.1.0.)hexane, 27.77 cm−1, 20.63, 7.84; and for 3,6-dioxabicyclo(3.1.0.)hexane, 25.25 cm−1, 17.23, 7.33. They were determined by an iterative least-squares fit to the observed four, seven, and nine Q branches, respectively. These potential functions all have only a single minimum, implying a single stable conformation. The dipole moment, μrms, for 3,6-dioxabicyclo(3.1.0.)hexane in benzene solution was determined to be 2.50 D, clearly indicating that the stable conformation is the boat form. The boat conformation had been determined to be the stable form for cyclopentene oxide from a microwave study by Lafferty (J. Mol. Spectrosc. 36, 84 (1970)). There is no direct evidence for the preferred conformation of the remaining two molecules but consideration of torsional interactions about the 1–2 and 4–5 bonds as well as the similarity of the spectra and potential functions for these molecules suggests that the boat conformation is the stable form of all of these molecules.
