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Background: Potential novel strategies for adverse event (AE) management of osimertinib therapy, including therapeutic drug monitoring and the use of biomarkers, have not yet been fully investigated. This study aimed to evaluate (1) the relationship between exposure to osimertinib, especially its active metabolites (AZ5104 and AZ7550), and AEs, and (2) the relationship between germline polymorphisms and AEs. Methods: We conducted a prospective, longitudinal observational study of 53 patients with advanced non-small cell lung cancer receiving osimertinib therapy from February 2019 to April 2022. A population pharmacokinetic model was developed to estimate the area under the serum concentration–time curve from 0 to 24 h (AUC0–24) of osimertinib and its metabolites. Germline polymorphisms were analyzed using TaqMan® SNP genotyping and CycleavePCR® assays. Results: There was a significant association between the AUC0–24 of AZ7550 and grade ≥ 2 paronychia (p = 0.043) or anorexia (p = 0.011) and between that of osimertinib or AZ5104 and grade ≥ 2 diarrhea (p = 0.026 and p = 0.049, respectively). Furthermore, the AUC0–24 of AZ5104 was significantly associated with any grade ≥ 2 AEs (p = 0.046). EGFR rs2293348 and rs4947492 were associated with severe AEs (p = 0.019 and p = 0.050, respectively), and ABCG2 rs2231137 and ABCB1 rs1128503 were associated with grade ≥ 2 AEs (p = 0.008 and p = 0.038, respectively). Conclusion: Higher exposures to osimertinib, AZ5104, and AZ7550 and polymorphisms in EGFR, ABCG2, and ABCB1 were related to higher severity of AEs; therefore, monitoring these may be beneficial for osimertinib AE management.

PURPOSE: Patients' values and priorities in their lives should be appreciated from an early phase of incurable diseases such as advanced cancer. However, studies examining these characteristics have been lacking. This study attempted to determine what patients with advanced lung cancer valued most, once they had been diagnosed, and any associated factors. METHODS: Patients with newly diagnosed advanced lung cancer (N = 248) were enrolled in a questionnaire survey conducted at 16 hospitals in Japan. Their priorities were assessed using a free-text response to the question what is the most important thing to you now? at the time of diagnosis and 3 months after diagnosis. The free-text responses were classified into 10 categories for quantification. The clinical characteristics associated with the category describing daily life were further examined. RESULTS: Free-text comments were obtained from 103 (44.0%) and 66 (42.6%) patients at the time of diagnosis and at 3 months, respectively. The most frequent categories were family (at diagnosis: 50.5%; at 3 months: 50.0%) and daily life (at diagnosis: 33.0%; at 3 months: 36.4%), followed by health (at diagnosis: 32.0%; at 3 months: 27.3%) at both time points. The patients mentioning daily life, the issues related to how to spend daily life, showed significantly higher total scores and functional well-being subscale scores on the Functional Assessment of Cancer Therapy-Lung scale at both time points and lower depression scores at diagnosis and lower anxiety scores at 3 months on the Hospital Anxiety and Depression Scale. CONCLUSION: Family and daily life were highly valued by patients with advanced lung cancer at diagnosis. A better quality of life and better mood were associated with mentioning daily life, which should be taken into account in care planning to maintain patients' involvement in daily life even with incurable diseases.

The optimal treatment for advanced non-small cell lung cancer (NSCLC) in very elderly patients is unclear. We aimed to evaluate their treatment in real-world clinical practice and identify suitable therapy that can improve their prognosis.The medical records of 132 Japanese patients aged 80 years and older with advanced NSCLCs who were enrolled at a university hospital and its 9 affiliates were retrospectively analyzed. Clinical characteristics and overall survival (OS) were compared based on the Eastern Cooperative Oncology Group Performance Status (ECOG PS) and biomarker statuses. Patients were defined as biomarker-positive if programmed death-ligand 1 tumor proportion score (PD-L1 TPS) was ≥ 50% or activating mutations were present in epidermal growth factor receptor, anaplastic lymphoma kinase, or c-ros oncogene 1. Finally, the factors contributing to better prognosis were explored in both PS 0 - 2 and PS 3 - 4 patient groups.The PS 0 - 2 patients showed a longer median OS than the PS 3 - 4 patients (5.5 vs. 1.6 months). PS 0 - 2 patients with positive biomarkers who received chemotherapy showed a significantly longer median OS than those without (18.1 vs. 3.7 months). Among the biomarker-negative/unknown PS 0 - 2 patients, the median OS showed no significant difference between those who received chemotherapy and those who did not (4.5 vs. 3.1 months). The multivariate analysis showed that treatment with tyrosine kinase inhibitors or immune checkpoint inhibitors was related to better prognoses in the PS 0 - 2 group.Biomarker-matched therapy is effective even in very elderly patients. Meanwhile, the effectiveness of chemotherapy for biomarker-negative/unknown PS 0 - 2 patients is questionable.

EGFR-mutated lung cancer accounts for a significant proportion of lung cancer cases worldwide. For these cases, osimertinib, a third-generation EGFR tyrosine kinase inhibitor, is extensively used as a first-line or second-line treatment. However, lung cancer cells acquire resistance to osimertinib in 1 to 2 years. Thus, a thorough clarification of resistance mechanisms to osimertinib is highly anticipated. Recent next-generation sequencing (NGS) of lung cancer samples identified several genetically defined resistance mechanisms to osimertinib, such as EGFR C797S or MET amplification. However, nongenetically defined mechanisms are not well evaluated. For a thorough clarification of osimertinib resistance, both genetic and nongenetic mechanisms are essential. By using our comprehensive protein phosphorylation array, we detected IGF1R bypass pathway activation after EGFR abolishment. Both of our established lung cancer cells and patient-derived lung cancer cells demonstrated IGF2 autocrine-mediated IGF1R pathway activation as a mechanism of osimertinib resistance. Notably, this resistance mechanism was not detected by a previously performed NGS, highlighting the essential roles of living cancer cells for a thorough clarification of resistance mechanisms. Interestingly, the immunohistochemical analysis confirmed the increased IGF2 expression in lung cancer patients who were treated with osimertinib and met the established clinical definition of acquired resistance. The findings highlight the crucial roles of cell-autonomous ligand expression in osimertinib resistance. Here, we report for the first time the IGF2 autocrine-mediated IGF1R activation as a nongenetic mechanism of osimertinib resistance in lung cancer at a clinically relevant level. Implications: Using comprehensive protein phosphorylation array and patient-derived lung cancer cells, we found that IGF2 autocrine-mediated IGF1R pathway activation is a clinically relevant and common mechanism of acquired resistance to osimertinib.

Background Accurate prognostic understanding in patients with advanced cancer is essential for shared decision making; however, patients may experience psychological burden through knowing the incurable nature of advanced cancer. It has been unclear how their prognostic understanding fluctuates and whether accurate prognostic understanding is associated with psychological distress from the time of diagnosis over time. Materials and Methods We longitudinally investigated prognostic understanding in 225 patients with newly diagnosed advanced lung cancer at 16 hospitals in Japan until 24 months after diagnosis. We examined associated factors with being consistently accurate in prognostic understanding, especially focusing on its association with psychological well-being. Results The proportion of patients with an inaccurate prognostic understanding remained approximately 20% over time with the presence of patients with inconsistent understanding. Patients with consistently accurate prognostic understanding showed a significantly lower Emotional Well-Being subscale score at both 3 and 6 months after diagnosis (p = .010 and p = .014, respectively). In multivariate analyses, being consistently accurate in prognostic understanding was significantly associated with female gender and higher lung cancer–specific symptom burden at 3 months (p = .008 and p = .005, respectively) and lower emotional well-being at 6 months (p = .006). Conclusion Although substantial proportions of patients with advanced lung cancer had inaccurate prognostic understanding from the time of diagnosis over time, patients with consistently accurate prognostic understanding experienced greater psychological burden. Our findings highlight the importance of continuous psychological care and support for patients who understand their severe prognosis accurately. Implications for Practice This study demonstrated that approximately 20% of patients with advanced lung cancer had an inaccurate understanding about their prognosis, not only at the time of diagnosis but also at the later time points. Being consistently accurate in prognostic understanding was significantly associated with elevated levels of psychological distress. Although accurate prognostic understanding is essential for decision making for treatment and advance care planning, health care providers should be aware of psychological burdens in patients that accept their severe prognosis accurately. Appropriate care and support for such patients are warranted from diagnosis over time.

EGFR-mutated lung cancer is a significant subgroup of non–small cell lung cancer. To inhibit EGFR-mediated signals, multiple EGFR tyrosine kinase inhibitors (EGFR-TKI) have been developed; however, approximately one third of patients with EGFR-mutated lung cancer do not respond to EGFR-TKIs. More effective inhibition of EGFR-mediated signals is therefore necessary. For cancers expressing mutated EGFR, including EGFR T790M, which confers resistance to first- (gefitinib and erlotinib) and second- (afatinib) generation EGFR-TKIs, the synergistic efficacy of afatinib and cetuximab combination therapy has been reported in preclinical and clinical studies; however, the mechanisms underlying this effect remain elusive. In this study, we evaluated the effects of multiple EGFR-TKIs on the EGFR monomer–dimer equilibrium by inducing dimerization-impairing mutations in cells expressing EGFR. Interestingly, we found that afatinib and dacomitinib exhibit a monomer preference: cells expressing dimerization-impaired EGFR mutants exhibited increased sensitivity to afatinib and dacomitinib relative to those with dimerization-competent EGFR mutants. Although EGFR-TKIs themselves induce dimerization of EGFR, the inhibition of dimerization by cetuximab overcame EGFR-TKI–induced dimerization. By shifting the monomer–dimer equilibrium toward monomer dominance using cetuximab, the effectiveness of afatinib and dacomitinib improved significantly. We report a novel and clinically relevant phenomenon, the monomer preference of EGFR-TKIs, which can explain the mechanism underlying the synergism observed in afatinib and cetuximab combination therapy. In addition, we propose the novel concept that monomer–dimer equilibrium is an important factor in determining EGFR-TKI efficacy. These findings provide novel insights into treatment strategies for EGFR-TKI–refractory non–small cell lung cancer.

Transdifferentiation of lung adenocarcinoma to small cell lung cancer (SCLC) has been reported in a subset of lung cancer cases that bear EGFR mutations. Several studies have reported the prerequisite role of TP53 and RB1 alterations in transdifferentiation. However, the mechanism underlying transdifferentiation remains understudied, and definitive additional events, the third hit, for transdifferentiation have not yet been identified. In addition, no prospective experiments provide direct evidence for transdifferentiation. In this study, we show that FGF9 upregulation plays an essential role in transdifferentiation. An integrative omics analysis of paired tumor samples from a patient with transdifferentiated SCLC exhibited robust upregulation of FGF9. Furthermore, FGF9 upregulation was confirmed at the protein level in four of six (66.7%) paired samples. FGF9 induction transformed mouse lung adenocarcinoma-derived cells to SCLC-like tumors in vivo through cell autonomous activation of the FGFR pathway. In vivo treatment of transdifferentiated SCLC-like tumors with the pan-FGFR inhibitor AZD4547 inhibited growth. In addition, FGF9 induced neuroendocrine differentiation, a pathologic characteristic of SCLC, in established human lung adenocarcinoma cells. Thus, the findings provide direct evidence for FGF9-mediated SCLC transdifferentiation and propose the FGF9–FGFR axis as a therapeutic target for transdifferentiated SCLC. Significance: This study demonstrates that FGF9 plays a role in the transdifferentiation of lung adenocarcinoma to small cell lung cancer.

BackgroundNot all non-small cell lung cancer (NSCLC) patients possess drug-targetable driver mutations, and response rates to immune checkpoint blockade therapies also remain unsatisfactory. Therefore, more effective treatments are still needed. Here, we report the results of a phase 2 clinical trial of adoptive cell therapy using zoledronate-expanded autologous Vγ9Vδ2 T-cells for treatment-refractory NSCLC.MethodsNSCLC patients who had undergone at least two regimens of standard chemotherapy for unresectable disease or had had at least one treatment including chemotherapy or radiation for recurrent disease after surgery were enrolled in this open-label, single-arm, multicenter, phase 2 study. After preliminary testing of Vγ9Vδ2 T-cell proliferation, autologous peripheral blood mononuclear cells were cultured with zoledronate and IL-2 to expand the Vγ9Vδ2 T-cells. Cultured cells (>1×109) were intravenously administered every 2 weeks for six injections. The primary endpoint of this study was progression-free survival (PFS), and secondary endpoints included overall survival (OS), best objective response rate (ORR), disease control rate (DCR), safety and immunomonitoring. Clinical efficacy was defined as median PFS significantly >4 months.ResultsTwenty-five patients (20 adenocarcinoma, 4 squamous cell carcinoma and 1 large cell carcinoma) were enrolled. Autologous Vγ9Vδ2 T-cell therapy was administered to all 25 patients, of which 16 completed the foreseen course of 6 injections of cultured cells. Median PFS was 95.0 days (95% CI 73.0 to 132.0 days); median OS was 418.0 days (179.0–479.0 days), and best overall responses were 1 partial response, 16 stable disease (SD) and 8 progressive disease. ORR and DCR were 4.0% (0.1%–20.4%) and 68.0% (46.5%–85.1%), respectively. Severe adverse events developed in nine patients, mostly associated with disease progression. In one patient, pneumonitis and inflammatory responses resulted from Vγ9Vδ2 T-cell infusions, together with the disappearance of a massive tumor.ConclusionsAlthough autologous Vγ9Vδ2 T-cell therapy was well tolerated and may have an acceptable DCR, this trial did not meet its primary efficacy endpoint.Trial registration numberUMIN000006128

EGFR mutation-positive patients with non–small cell lung cancer (NSCLC) respond well to treatment with EGFR–tyrosine kinase inhibitors (EGFR–TKI); however, treatment with EGFR–TKIs is not curative, owing to the presence of residual cancer cells with intrinsic or acquired resistance to this class of drugs. Additional treatment targets that may enhance the efficacy of EGFR–TKIs remain elusive. Using a CRISPR/Cas9-based screen, we identified the leucine-rich repeat scaffold protein SHOC2 as a key modulator of sensitivity to EGFR–TKI treatment. On the basis of in vitro assays, we demonstrated that SHOC2 expression levels strongly correlate with the sensitivity to EGFR–TKIs and that SHOC2 affects the sensitivity to EGFR–TKIs in NSCLC cells via SHOC2/MRAS/PP1c and SHOC2/SCRIB signaling. The potential SHOC2 inhibitor celastrol phenocopied SHOC2 depletion. In addition, we confirmed that SHOC2 expression levels were important for the sensitivity to EGFR–TKIs in vivo. Furthermore, IHC showed the accumulation of cancer cells that express high levels of SHOC2 in lung cancer tissues obtained from patients with NSCLC who experienced acquired resistance to EGFR–TKIs. These data indicate that SHOC2 may be a therapeutic target for patients with NSCLC or a biomarker to predict sensitivity to EGFR–TKI therapy in EGFR mutation-positive patients with NSCLC. Our findings may help improve treatment strategies for patients with NSCLC harboring EGFR mutations. Implications: This study showed that SHOC2 works as a modulator of sensitivity to EGFR–TKIs and the expression levels of SHOC2 can be used as a biomarker for sensitivity to EGFR–TKIs.

ABT‐263 (Navitoclax) is a BH3‐mimetic drugs targeting anti‐apoptotic B‐cell lymphoma‐2 (BCL‐2) family proteins, including BCL‐2, BCL‐xL, and BCL‐w, thereby inducing apoptosis. In small‐cell lung cancer (SCLC) cells, the response to ABT‐263 is associated with the expression of myeloid cell leukemia‐1 (MCL‐1) protein, however the efficacy of ABT‐263 in non‐small‐cell lung cancer (NSCLC) has not been thoroughly evaluated. There are currently no established biomarkers for predicting the efficacy of ABT‐263 treatment in NSCLC. We screened a panel of different NSCLC cell lines and found that ABT‐263 inhibited cell proliferation and induced apoptosis in Calu‐1, Calu‐3, and BID007 cells. Inconsistent with previous reports on SCLC, low levels of MCL‐1 did not predict the response to ABT‐263 in NSCLC cells, however we found that intracellular levels of reactive oxygen species (ROS) in cancer cells were associated with sensitivity to ABT‐263 in NSCLC cells. We also showed that increasing the level of intracellular ROS could enhance the sensitivity to ABT‐263 in NSCLC cells. In summary, we propose that the intracellular levels of ROS could be used as a potential novel biomarker for predicting a response to ABT‐263 in NSCLC. Furthermore, we show some evidence supporting the further assessment of ABT‐263 as a new therapeutic strategy in patients with NSCLC combined with agents regulating ROS levels. We believe that our findings and follow‐up studies on this matter would lead to novel diagnostic and treatment strategies in patients with NSCLC., This article clarified the potential relationship between intracellular ROS and sensitivity to BH3‐mimetic drug, ABT‐263 in non‐small‐cell lung cancer.

Background Prognostic understanding in advanced cancer patients and their caregivers may have an impact on the delivery of effective care. The aims of this study were to explore prognostic understanding at diagnosis in both patients with advanced lung cancer and their caregivers and to investigate correlates of their understanding. Subjects, Materials, and Methods A total of 193 patients with newly diagnosed advanced lung cancer and their 167 caregivers were enrolled at 16 hospitals in Japan. We assessed their perceptions of prognosis and goals of therapy and examined their associations with their sociodemographic characteristics, clinical status, quality of life, mood symptoms, and the status of disclosure of information by their treating physicians. Results One fifth of patients and caregivers (21.7% and 17.6%, respectively) mistakenly believed that the patients’ cancer was “completely curable.” Substantial proportions of them (16.9% and 10.3%, respectively) mistakenly believed that the primary goal of therapy was to remove all the cancer. Levels of anxiety and depression in both patients and caregivers were significantly higher among those who had accurate understanding of prognosis. In multivariate analyses, inaccurate perceptions of prognosis in patients were associated with sex, better emotional well-being, and lower lung cancer-specific symptom burden. Caregivers’ inaccurate perceptions of patients’ prognoses were associated with better performance status and better emotional well-being of patients. Conclusion Substantial proportions of advanced lung cancer patients and their caregivers misunderstood their prognosis. Interventions to improve their accurate prognostic understanding should be developed with careful attention paid to its associated factors. Implications for Practice This study demonstrated that substantial proportions of patients with newly diagnosed advanced lung cancer and their caregivers had misunderstandings about their prognosis. Accurate perceptions of prognosis, which are indispensable in the delivery of effective care, were associated with elevated levels of anxiety and depression in both patients and caregivers, warranting psychosocial care and support for them immediately after diagnosis. Inaccurate perceptions of prognosis in patients were associated with better emotional well-being and lower lung cancer-specific symptom burden. Illness understanding in caregivers was associated with patients’ physical and mental status. Those findings provide insight into how they obtain accurate illness understanding.

Background Osimertinib, a third-generation epidermal growth factor receptor-tyrosine kinase inhibitor, exerts remarkable effects against EGFR T790M resistance mutation-positive non-small cell lung cancer. Identifying T790M mutation by re-biopsy is essential before prescribing osimertinib. Tissue biopsy is the golden standard for this purpose, but several factors limit its success rate. The liquid biopsy with blood, using circulating tumor DNA, has been an alternative method. However, the true biological meaning and equivalence of liquid biopsy and tumor biopsy are still under investigation. Especially, the usefulness of serum samples to detect T790M mutation is not yet been known. Patients and methods We prospectively evaluated the sensitivity, specificity, and parallelism of the detection of EGFR mutations in tissue re-biopsy and liquid biopsy (plasma and serum), simultaneously, from June 2016 to May 2017. EGFR mutations in tumor re-biopsy were evaluated by COBAS ver2 and PNA-LNA PCR clamp method, and those in liquid biopsy were evaluated with COBAS ver2. Results Fifteen patients were enrolled. In 10 patients whose EGFR mutation was detected in liquid biopsy, the original EGFR mutation (exon 19 del or L858R) was detected in all patients. Detection of EGFR mutation by COBAS ver2 and by PNA-LNA method was almost the same in tissue re-biopsy. The detection rate of T790M was lower than that of the original EGFR mutation in liquid biopsy compared to that in tissue re-biopsy. The detection of T790M in serum exhibited a higher specificity (67%) and positive predictive value (50%) than that in plasma (50% and 40%, respectively). The detection sensitivity was similar in plasma and serum. Conclusion Plasma, serum, and tissue genotyping can have complementary roles for detecting EGFR-T790M using COBAS ver2. Repeated tests with different samples and different methods may improve accuracy of T790M detection and will lead to the maximum benefit for the patient.

Multiple epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKI) have been developed to effectively inhibit EGFR-derived signals in non–small cell lung cancer (NSCLC). In this study, we assessed the efficacy of EGFR-TKIs, including a novel third-generation inhibitor naquotinib (ASP8273), in clinically relevant EGFR mutations, including L858R, exon 19 deletion, L858R+T790M, exon 19 deletion+T790M with or without a C797S mutation, and several exon 20 insertion mutations. Using structural analyses, we also elucidated the mechanism of activation and sensitivity/resistance to EGFR-TKIs in EGFR exon 20 insertion mutations. The efficacy of naquotinib in cells with L858R, exon 19 deletion and exon 19 deletion+T790M was comparable with that of osimertinib. Interestingly, naquotinib was more potent than osimertinib for L858R+T790M. Additionally, naquotinib and osimertinib had comparable efficacy and a wide therapeutic window for cells with EGFR exon 20 insertions. Structural modeling partly elucidated the mechanism of activation and sensitivity/resistance to EGFR-TKIs in two EGFR exon 20 insertion mutants, A767_V769dupASV and Y764_V765insHH. In summary, we have characterized the efficacy of EGFR-TKIs for NSCLC using in vitro and structural analyses and suggested the mechanism of activation and resistance to EGFR-TKIs of EGFR exon 20 insertion mutations. Our findings should guide the selection of appropriate EGFR-TKIs for the treatment of NSCLC with EGFR mutations and help clarify the biology of EGFR exon 20 insertion mutations. Mol Cancer Ther; 17(4); 740–50. ©2018 AACR.

Third-generation epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs) were developed to overcome EGFR T790M-mediated resistance to first- and second-generation EGFR-TKIs. Third-generation EGFR-TKIs, such as osimertinib and nazartinib, are effective for patients with the EGFR T790M mutation. However, there are no direct comparison data to guide the selection of a third-generation EGFR-TKI for patients with different EGFR mutations. We previously established an in vitro model to estimate the therapeutic windows of EGFR-TKIs by comparing their relative efficacies against cells expressing mutant or wild type EGFRs. The present study used this approach to characterize the efficacy of third-generation EGFR-TKIs and compare them with that of other EGFR-TKIs. Treatment efficacy was examined using human lung cancer-derived cell lines and Ba/F3 cells, which were transduced with clinically relevant mutant EGFRs. Interestingly, mutation-related differences in EGFR-TKI sensitivity were observed. For classic EGFR mutations (exon 19 deletion and L858R, with or without T790M), osimertinib showed lower IC50 values and wider therapeutic windows than nazartinib. For less common EGFR mutations (G719S or L861Q), afatinib showed the lowest IC50 values. For G719S+T790M or L861Q+T790M, the IC50 values of osimertinib and nazartinib were around 100 nM, which was 10- to 100-fold higher than those for classic+T790M mutations. On the contrary, osimertinib and nazartinib showed similar efficacies in cells expressing EGFR exon 20 insertions. The findings highlight the diverse mutation-related sensitivity pattern of EGFR-TKIs. These data may help in the selection of EGFR-TKIs for non-small cell lung cancer patients harboring EGFR mutations.

Epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitors (EGFR-TKIs) are widely used for the treatment of non-small cell lung cancers (NSCLCs) harboring EGFR-activating mutations. However, lung cancer cells inevitably acquire resistance to these EGFR-TKIs. The majority of patients whose lung cancer acquires resistance to EGFR-TKIs are subjected to treatment using cytotoxic agents. The present study aimed to determine if lung cancer cells acquiring resistance to EGFR-TKIs also develop altered sensitivity to cytotoxic agents. It was revealed that lung cancer cells that had developed resistance to EGFR-TKIs had increased sensitivity to gemcitabine and vinorelbine compared with EGFR-TKI naïve cells. The expression levels of ATP-binding cassette (ABC) transporter genes, including ABCC3, ABCC5 and ABCG2, were observed to be commonly repressed in EGFR-TKI-resistant cells. In addition, two cases were identified in which gemcitabine and vinorelbine exerted marked responses to lung cancers that had acquired resistance to EGFR-TKIs, even with late-line treatment. Therefore, it was proposed that gemcitabine and vinorelbine may be effective agents for patients with lung cancer previously treated with EGFR-TKIs.

EGFR-mutated lung cancers account for a significant subgroup of non–small cell lung cancers overall. Third-generation EGFR tyrosine kinase inhibitors (TKI) are mutation-selective inhibitors with minimal effects on wild-type EGFR. Acquired resistance develops to these agents, however, the mechanisms are as yet uncharacterized. In this study, we report that the Src–AKT pathway contributes to acquired resistance to these TKI. In addition, amplification of EGFR wild-type alleles but not mutant alleles was sufficient to confer acquired resistance. These findings underscore the importance of signals from wild-type EGFR alleles in acquiring resistance to mutant-selective EGFR-TKI. Our data provide evidence of wild-type allele-mediated resistance, a novel concept of acquired resistance in response to mutation-selective inhibitor therapy in cancer treatment. Cancer Res; 77(8); 2078–89. ©2017 AACR.

Activation of the EGFR pathway is one of the mechanisms inducing acquired resistance to anaplastic lymphoma kinase (ALK) tyrosine kinase inhibitors (TKI) such as crizotinib and alectinib. Ceritinib is a highly selective ALK inhibitor and shows promising efficacy in non–small cell lung cancers (NSCLC) harboring the ALK gene rearrangement. However, the precise mechanism underlying acquired resistance to ceritinib is not well-defined. This study set out to clarify the mechanism in ALK-translocated lung cancer and to find the preclinical rationale overcoming EGFR pathway–induced acquired resistance to ALK-TKIs. To this end, ceritinib-resistant cells (H3122-CER) were established from the H3122 NSCLC cell line harboring the ALK gene rearrangement via long-term exposure to ceritinib. H3122-CER cells acquired resistance to ceritinib through EGFR bypass pathway activation. Furthermore, H3122 cells that became resistant to ceritinib or alectinib through EGFR pathway activation showed cross-resistance to other ALK-TKIs. Ceritinib and afatinib combination treatment partially restored the sensitivity to ceritinib. Implications: This study proposes a preclinical rationale to use ALK-TKIs and afatinib combination therapy for ALK-translocated lung cancers that have acquired resistance to ALK-TKIs through EGFR pathway activation. Mol Cancer Res; 15(1); 106–14. ©2016 AACR.

Alectinib is a highly selective ALK inhibitor and shows promising efficacy in non–small cell lung cancers (NSCLC) harboring the EML4-ALK gene rearrangement. The precise mechanism of acquired resistance to alectinib is not well defined. The purpose of this study was to clarify the mechanism of acquired resistance to alectinib in ALK-translocated lung cancer cells. We established alectinib-resistant cells (H3122-AR) from the H3122 NSCLC cell line, harboring the EML4-ALK gene rearrangement, by long-term exposure to alectinib. The mechanism of acquired resistance to alectinib in H3122-AR cells was evaluated by phospho-receptor tyrosine kinase (phospho-RTK) array screening and Western blotting. No mutation of the ALK-TK domain was found. Phospho-RTK array analysis revealed that the phosphorylation level of EGFR was increased in H3122-AR cells compared with H3122. Expression of TGFα, one of the EGFR ligands, was significantly increased and knockdown of TGFα restored the sensitivity to alectinib in H3122-AR cells. We found combination therapy targeting ALK and EGFR with alectinib and afatinib showed efficacy both in vitro and in a mouse xenograft model. We propose a preclinical rationale to use the combination therapy with alectinib and afatinib in NSCLC that acquired resistance to alectinib by the activation of EGFR bypass signaling. Mol Cancer Ther; 15(1); 162–71. ©2015 AACR.

Epidermal Growth Factor Receptor tyrosine kinase inhibitors (EGFR-TKI) have become the first line treatment for patients with EGFR mutated non-small cell lung cancer (NSCLC) as a result of multiple clinical trials demonstrating superior response and less toxicity as compared to conventional cytotoxic agents. However, despite the clinical experience among nearly two decades, it is well known that EGFR-TKI monotherapy cannot cure EGFR mutation-positive lung cancer patients due to the occurrence of drug resistance. While dramatic initial tumor shrinkage is shown in most patients with EGFR-TKI treatment, therapeutic resistance is often observed in 1-2 years. This is likely caused by the outgrowth of rare pre-existing resistant clones and/or small fraction of drug tolerant persister cells (DTPs) which survive and acquire resistance to EGFR-TKIs. Several previous studies have clarified the acquired resistance mechanisms to EGFR-TKIs, but little is known how the DTPs survive during the initial phase of drug exposure and rapidly adapt to EGFR-TKIs. Utilizing the genome wide CRISPR/Cas9 screening, we have previously reported that DTPs were capable to exploit endoplasmic reticulum stress to survive EGFR-TKI exposure (Terai, et al, Cancer Research 2018). Further analysis of this data identified multiple genes which could affect the initial drug response to EGFR-TKIs, including the scaffold protein coding gene, SHOC2. In our present study we focused on this unique protein and revealed its critical function as a modulator of drug response to EGFR-TKIs in lung cancer cells. We confirmed that depletion/overexpression of SHOC2 in PC9 cells, an EGFR-dependent NSCLC cell line, renders the cells sensitive/resistant to all 1st to 3rd generation EGFR-TKIs. We have also confirmed similar findings with another EGFR dependent NSCLC cell line named H1975. Reduction of phosphorylation levels of ERK1/2 induced by EGFR-TKIs were stronger in PC9 or H1975 cells with SHOC2 knockout, indicating that SHOC2 can facilitate ERK1/2 reactivation during EGFR-TKI treatment. The above data indicate that SHOC2 is essential for DTPs and its function is correlated with MAPK-ERK pathway activity. Celastrol, a candidate SHOC2 inhibitor, inhibited the emergence of DTPs and synergized with EGFR-TKIs. Additionally, we showed that SHOC2 depletion enhanced the growth inhibitory effect of osimertinib in vivo. Lastly, we confirmed the increased expression of SHOC2 in clinical human samples which experienced EGFR-TKI failure. Our findings could offer a new treatment strategy for NSCLC patients with EGFR mutation leading to the increase of the degree and duration of EGFR TKIs response. Citation Format: Hideki Terai, Junko Hamamoto, Tadashi Manabe, Katsura Emoto, Takeshi Masuda, Satoshi Kuronuma, Keigo Kobayashi, Keita Masuzawa, Shinnosuke Ikemura, Sohei Nakayama, Ichiro Kawada, Yusuke Suzuki, Osamu Takeuchi, Yukio Suzuki, Sumio Ohtsuki, Hiroyuki Yasuda, Kenzo Soejima, Koichi Fukunaga. SHOC2 is a critical modulator of the sensitivity to EGFR-TKI in non-small cell lung cancer cells [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 3081.

In non-small cell lung cancer (NSCLC), several somatic mutations such as EGFR and EML4-ALK have been identified in a significant subgroup of patients. Multiple clinical trials involving tyrosine kinase inhibitors (TKIs) have demonstrated significant improvement in the prognosis of lung cancer patients with these mutations. However, in clinic, lung cancer cells gradually acquire resistance to these inhibitors in a span of approximately 1 - 2 years. In TKI resistant lung cancer patients, next-generation sequencing of clinical samples from individual patients enables the detection of genetic alterations that contribute to drug resistance, such as EGFR T790M and EGFR C797S mutations. However, it does not always offer an appropriate treatment strategy for patients with acquired resistance. In contrast, the presence of living cancer cells allows researchers to biologically evaluate the roles of mutations or bypass pathways. For a thorough clarification of resistance mechanisms, living cancer cells, in addition to genomic information, are essential. In our report, we have established six patient-derived cancer cells (PDCs) from NSCLC patients who were treated with various TKIs and thereafter experienced disease progression. The success rate for PDCs was as high as 50% (6/12). Upon the established cell lines, 2 cases had EML4-ALK and the rest had EGFR mutation as an oncogene. After establishing the PDCs, TKI resistance was confirmed by MTS cell proliferation assay and 5 of 6 cases showed matched TKI resistance referring to the clinical background. To elucidate the adaptive resistant mechanisms in PDCs, Sanger sequence was performed and none of the gene mutations that have been previously reported to contribute to resistance to TKIs was detected. Next, to investigate the bypass pathway activation in these cell lines, we performed phospho-receptor tyrosine kinase (RTK) array screening. Interestingly, 4 of 5 cases showed activation of bypass RTK signaling and 3 of 4 cases obtained combined effectiveness with the additional RTK inhibitor. Furthermore, we have performed western blotting in 3 PDCs and detected that combination treatment attenuated the phosphorylation of the downstream molecules. In conclusion, by using PDCs, we have clarified the mechanism of acquired resistance and detected the treatment strategy to overcome these resistances. The findings suggest that PDCs may help develop precision medicine for TKI resistant patients. Citation Format: Tadashi Manabe, Hiroyuki Yasuda, Hideki Terai, Junko Hamamoto, Toshiki Ebisudani, Keigo Kobayashi, Keita Masuzawa, Shinnosuke Ikemura, Ichiro Kawada, Koichi Fukunaga, Kenzo Soejima. Establishment of patient-derived cancer cell lines to elucidate the resistant mechanism of tyrosine kinase inhibitors [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2991.

Lung cancer is the leading cause of cancer-associated deaths worldwide. Metabolic reprogramming facilitates the growth advantage of cancer cells and is a hallmark of cancer. Although multiple studies have investigated the cancer-specific metabolic status of lung cancer, it remains unclear. Aberrant fucosylation, which results from the deficiency or overexpression of fucosyltransferases, is also associated with a variety of cancers, including lung cancer. However, the role and regulatory mechanism(s) of fucosylation in lung cancer remain largely unknown. In order to elucidate the specific metabolic status of human lung cancer tissues, we performed metabolomics profiling of paired tumor and normal tissues from patients with non-small cell lung cancer (NSCLC) using both capillary electrophoresis mass-spectrometry (CE-MS) and imaging mass-spectrometry (I-MS). We used principle component analysis (PCA) to confirm that human lung cancer has distinctive metabolic patterns. We revealed upregulation of the GDP-L-fucose de novo pathway, which regulates the level of fucosylated glycoproteins, in lung cancer tissues compared to the adjacent non-malignant lung tissues. In order to elucidate the mechanisms by which fucosylation is increased in lung cancer tissues, gene expression of fucosyltransferases (FUT1-9) were evaluated. We confirmed that fucosyltransferase 3 (FUT3) expression was increased in a significant proportion of human primary lung adenocarcinoma samples and was correlated with sLeX expression. A fucosylation inhibitor, 6-alkynyl-fucose, inhibited the proliferation and invasion of lung cancer cell lines with high endogenous FUT3 expression in vitro. Exogenous FUT3-overexpressing lung cancer cells did not show increased proliferation, but showed significantly increased invasion and adhesion activities in vitro. In order to confirm whether FUT3 promoted metastasis of A549 cells in an experimental lung metastatic mouse model, A549 lung cancer cells expressing EGFP (A549-EGFP) and A549 lung cancer cells overexpressing FUT3 (A549-FUT3) were intravenously administered to BALB/C nude mice and the numbers of metastatic nodules in the lungs were counted after 8 weeks. In concordance with our observations in vitro, there was no significant difference in tumor growth between the A549-EGFP and A549-FUT3 treatments in vivo. Interestingly, injection of A549-FUT3 resulted in an increase in the number of lung metastases compared to the injection of A549-EGFP, suggesting that FUT3 is a positive regulator of cancer invasion and metastasis. Furthermore, high expression of FUT3 in lung cancer tissues predicted a poorer prognosis for patients with lung adenocarcinoma. These findings highlight the important roles of protein fucosylation in lung cancer progression and provide the preclinical rationale to target this pathway in lung cancer treatment. Citation Format: Keita Masuzawa, Hiroyuki Yasuda, Atsushi Matsuda, Hideki Terai, Yuki Sugiura, Junko Hamamoto, Daisuke Arai, Shizuko Kagawa, Katsura Emoto, Shinnosuke Ikemura, Ichiro Kawada, Kenzo Soejima, Koichi Fukunaga. The role of protein fucosylation in lung cancer progression [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 365.

Epidermal growth factor receptor (EGFR) mutation-positive lung cancer accounts for a significant subgroup of non-small cell lung cancers (NSCLC). Approximately 4-10% of EGFR mutations in NSCLC are EGFR exon 20 insertion mutations, which are reportedly associated with resistance to EGFR tyrosine kinase inhibitor (EGFR-TKI) treatment. NSCLC patients carrying these mutations are rarely treated with EGFR-TKIs. The purpose of this study was to evaluate the efficacy of afatinib or osimertinib plus cetuximab combination therapy in experimental NSCLC models with EGFR exon 20 insertion mutations.The EGFR mutations examined in this study were A763_Y764insFQEA, Y764_V765insHH, A767_V769dupASV, and D770_N771insNPG. Ba/F3 cells constitutively expressing wild type or mutated EGFR were used to determine the efficacy of afatinib or osimertinib plus cetuximab combination therapy in vitro. To determine the efficacy of the combination therapy in vivo, female BALB/c-nu mice were injected subcutaneously with 1 million Ba/F3 cells carrying EGFR A767_V769dupASV or Y764_V765insHH.We observed a mild but significant (P 0.05) additive effect of the combination therapy against several EGFR exon 20 insertion mutations in vitro. Regarding EGFR A767_V769dupASV and EGFR Y764_V765insHH, cetuximab and afatinib single treatment did not induce significant inhibition of tumor formation; however, afatinib plus cetuximab combination treatment induced significant (P 0.05) tumor growth inhibition without significant body weight loss or skin rash.The combination therapy induced a more potent inhibitory effect against several EGFR exon 20 insertion mutations than either therapy alone. Cetuximab can potentially increase the efficacy of afatinib or osimertinib in NSCLC with EGFR exon 20 insertion mutations.

Objective: Targeted therapy-induced facial skin toxicities may reduce overall quality of life (QoL) in cancer patients. We investigated whether facial skin toxicities affect QoL and attempted to identify factors related to QoL in patients with advanced/recurrent cancer. Methods: We performed a cross-sectional study in 34 outpatients with advanced/recurrent cancer showing targeted therapy-induced facial skin toxicities in Japan between November 2016 and February 2017. For measurement, we used the Kessler Psychological Distress Scale (K6), Mental Adjustment to Cancer (MAC) Scale, and Dermatology Life Quality Index (DLQI). Data were analyzed using Spearman's rank correlation coefficient. Results: Mean DLQI score in 34 patients was 4.59 (standard deviation ± 4.70), which was interpreted as a small effect on a patient's life. Acneiform rash was the most common skin condition noted, followed by xerosis, pruritus, and erythema. Analysis of DLQI scores revealed that symptoms and feelings was the domain most commonly affected among different domains constituting the DLQI. MAC analysis revealed that the fighting spirit score was the highest among MAC scales. We found that age, K6, and fatalism construct in MAC were significantly correlated with total DLQI scores (age: Spearman's ρ= −0.48, P = 0.004; K6: ρ= 0.58, P < 0.001; fatalism; ρ= −0.39, P = 0.025). Conclusions: This is the first study investigating targeted therapy-induced facial skin toxicities in cancer patients. Our results suggest potential negative effects of facial skin toxicities on overall QoL in patients with advanced/recurrent cancer in middle and early old age.

Stereotactic radiosurgery (SRS) using the Gamma Knife (GK) is now being increasingly utilized for the treatment of brain metastases. However, there are a few reported cases of SRS-induced brain neoplasms. We herein report the case of a Japanese woman with metastatic non-small cell lung cancer (NSCLC) harboring epidermal growth factor (EGFR)-mutations who was treated four times with a GK for brain metastases. She developed glioblastoma 5.7 years after the initial GK surgery. Radiation-induced secondary neoplasms generally appear after a latency period of several years. Advances in cancer therapy have improved the survival of patients with NSCLC, providing enough time for secondary neoplasms to appear after SRS.

This Phase II study was conducted to evaluate the efficacy and safety of S-1 and irinotecan combination therapy as a second-line treatment in patients with advanced non-small cell lung cancer.Irinotecan was administered at 60 mg/m(2) on Days 1 and 8. Oral S-1 was administered on Days 1-14 every 3 weeks at 80 mg/day for patients with a body surface area of1.25 m(2), 100 mg/day for patients with a body surface area of 1.25-1.5 m(2) and 120 mg/day for patients with a body surface area of1.5 m(2). The primary endpoint was response rate, while the secondary endpoints were progression-free survival, overall survival and safety.Thirty-one patients were enrolled in this study. The response and disease control rates were 6.5 and 58.1%, respectively. Progression-free survival and median survival time were 2.8 and 12.6 months, respectively. Grade 3-4 adverse events were reported for 29.0% of the patients. Hematological toxicities of Grade 3 or 4 included leukopenia (9.7%), neutropenia (9.7%), febrile neutropenia (3.2%), thrombopenia (3.2%) and anemia (6.5%). Non-hematological toxicities of Grade 3 or 4 included pneumonitis (6.5%), diarrhea, colitis, dyspnea, rash, oral mucositis, anorexia and pulmonary thromboembolism/deep vein thrombosis (3.2% each).S-1 and irinotecan combination therapy at the present dose and schedule exhibited only modest efficacy with mild toxicities in previously treated patients with non-small cell lung cancer. No further clinical investigation with current dose and schedules is warranted for patients with non-small cell lung cancer who failed first-line platinum-based doublet chemotherapy.

The number of elderly patients with advanced non-small cell lung cancer (NSCLC) is increasing. Although several studies have suggested the benefit of chemotherapy with a platinum doublet for elderly patients with advanced NSCLC, this treatment is still controversial in this age group. To evaluate the efficacy and tolerability of combination chemotherapy with biweekly paclitaxel and carboplatin for elderly patients with advanced NSCLC, we conducted a multicenter, non-randomized, open label, phase II trial. We recruited patients aged ≥70 years with clinical stage IIIB and IV NSCLC and ECOG performance status (PS) of 0–2. Patients received paclitaxel (90 mg/m2) and carboplatin (AUC = 2.5) on day 1 and 15, every 4 weeks. The primary endpoint was overall response rate (ORR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS), and safety. Sixty-five patients (median age 79 years; range 70–87 years) were enrolled. Forty-nine patients were men, and 48 were stage IV. The PS was 0, 1, and 2 in 28, 33, and 4 patients, respectively. The histological type of NSCLC was non-squamous in 69.3 % and squamous cell carcinoma in 30.7 % of patients. The median number of treatment cycles was 3 (range 1–6). The response rate was 29.4 % (95 % CI 18.7–43.0), and the disease control rate was 78.0 % (95 % CI 64.8–87.2). Median PFS and OS were 3.8 months (95 % CI 1.9–5.3) and 17.3 months (95 % CI 10.4–25.1), respectively. The most common grade 3 or 4 toxicities were neutropenia (27 %), leukopenia (15 %), infection (10 %), and anemia (8 %). The combination of biweekly paclitaxel and carboplatin was effective and well tolerated in elderly patients with advanced NSCLC.

Nivolumab, an immune checkpoint inhibitor, is now a standard treatment for previously treated advanced non-small-cell lung cancer based on the results from phase III clinical trials. We evaluated the real-world efficacy and safety of nivolumab in a nonselected population and identified the clinical characteristics that influence efficacy.A total of 142 patients with advanced non-small-cell lung cancer who were administered nivolumab at Keio University and affiliated hospitals in Japan from January to July 2016 were enrolled. The treatment efficacy and adverse events were retrospectively reviewed, and the clinical characteristics associated with the nivolumab response were evaluated using univariate and stratified analyses and the Cochran-Mantel-Haenszel test.The objective response rate was 17.0% (95% confidence interval [CI], 12.0%-24.0%), the median progression-free survival (PFS) was 58 days (95% CI, 50-67 days), and the proportion of patients with adverse events of any grade was 45.0%. EGFR/ALK mutation status was inversely associated with the treatment response (P .05), and the difference in PFS for the mutation-positive versus mutation-negative patients was statistically significant (49 vs. 63 days; hazard ratio, 1.9; 95% CI, 1.1-5.2; P = .029). Previous radiotherapy also had a positive association with the treatment response (P = .012).The objective response rate, PFS, and adverse event profiles were comparable to those observed in previous clinical trials. EGFR/ALK mutation-negative status and previous radiotherapy might be key clinical characteristics associated with a positive treatment response. Our findings could aid in the efficient immunotherapeutic management of lung cancer.

The aim of this study was to assess the efficacy and safety of erlotinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), as second- or third-line treatment for elderly Japanese patients with non-small-cell lung cancer (NSCLC). The patients eligible for this phase II trial were aged ≥70 years, had stage III/IV or recurrent NSCLC, and had previously received 1 or 2 chemotherapy regimens that did not include EGFR-TKIs. The patients received erlotinib at a dose of 150 mg/day. The primary endpoint was overall response rate (ORR), and the secondary endpoints were progression-free survival (PFS), overall survival (OS) and toxicity. A total of 38 patients with a median age of 76 years were enrolled. The majority of the patients were men (66%), had an Eastern Cooperative Oncology Group performance status of 1 (58%), stage IV disease (66%) and adenocarcinoma (74%). Of the 35 patients, 13 (34%) had tumors with EGFR mutations. The ORR was 26.3% (95% confidence interval: 12.1-40.5%) and the disease control rate was 47.4%. The median PFS was 3.7 months and the median OS was 17.3 months. The grade 3 adverse events observed included rash (13%), diarrhea (5%), interstitial pneumonitis (5%), anorexia (3%) and gastrointestinal bleeding (3%). Grade 4 or 5 adverse events were not observed. The median OS did not differ significantly between patients aged

Cytoskeletal and focal adhesion abnormalities are observed in several types of cancer, including lung cancer. We have previously reported that paxillin (PXN) was mutated, amplified, and overexpressed in a significant number of lung cancer patient samples, that PXN protein was upregulated in more advanced stages of lung cancer compared with lower stages, and that the PXN gene was also amplified in some pre-neoplastic lung lesions. Among the mutations investigated, we previously found that PXN variant A127T in lung cancer cells enhanced cell proliferation and focal adhesion formation and colocalized with the anti-apoptotic protein B Cell Lymphoma 2 (BCL-2), which is known to localize to the mitochondria, among other sites. To further explore the effects of activating mutations of PXN on mitochondrial function, we cloned and expressed wild-type PXN and variants containing the most commonly occurring PXN mutations (P46S, P52L, G105D, A127T, P233L, T255I, D399N, E423K, P487L, and K506R) in a GFP-tagged vector using HEK-293 human embryonic kidney cells. Utilizing live-cell imaging to systematically study the effects of wild-type PXN vs. mutants, we created a model that recapitulates the salient features of the measured dynamics and conclude that compared with wild-type, some mutant clones confer enhanced focal adhesion and lamellipodia formation (A127T, P233L, and P487L) and some confer increased association with BCL-2, Dynamin-related Protein-1 (DRP-1), and Mitofusion-2 (MFN-2) proteins (P233L and D399N). Further, PXN mutants, through their interactions with BCL-2 and DRP-1, could regulate cisplatin drug resistance in human lung cancer cells. The data reported herein suggest that mutant PXN variants play a prominent role in mitochondrial dynamics with direct implications on lung cancer progression and hence, deserve further exploration as therapeutic targets.

Purpose Bronchoscopic microsampling (BMS) is a novel and direct method with which to obtain epithelial lining fluid (ELF) from the lungs. Analysis of DNA hypermethylation of tumor suppressor genes (TSGs) is expected to be a sensitive tool for the early detection of lung cancer. It has been reported that the existence of EGFR mutations and EML4-ALK gene rearrangements are related to the sensitivity of corresponding kinase inhibitors. We aimed to evaluate the suitability of ELF as a sample for analyzing molecular changes specific for lung cancer. Patients and methods We collected ELF from 61 lung cancer patients by BMS from the airway close to the peripheral lung nodule and purified the nucleic acids. We performed methylation specific PCR in each ELF as well as matched serum and tumor tissue for TSGs for DNA methylation analysis. We also examined EGFR mutations and EML4-ALK rearrangement. Results The sensitivity for detecting DNA hypermethylation in ELF vs serum was 74.1% vs 18.5%. We found 60.1% of patients had at least one hypermethylation in ELF, while only 27.9% had it in serum. Of note, DNA hypermethylation was detected even in stage I patients (60.0%) and the detection rate was almost the same level in each stage. We also found the sensitivity for detecting EGFR mutation in ELF vs serum was 58.3% vs 8.3%. We detected an EML4-ALK fusion gene using ELF in one patient. Conclusions BMS is an alternative method to detect cancer specific genetic and epigenetic alterations and will be a useful complementary diagnostic tool for lung cancer. Summary Investigation of genetic and epigenetic changes associated with lung cancer has clinical importance for its diagnosis and management. The clinical usefulness of bronchoscopic microsampling (BMS) in lung cancer has not yet been evaluated. This study demonstrates that BMS could be useful for detecting lung cancer specific molecular changes and valuable for early diagnosis and determination of treatment options for lung cancer.

Introduction Epidermal growth factor receptor (EGFR) mutations are strong determinants of tumor response to EGFR tyrosine kinase inhibitors in non-small cell lung cancers (NSCLCs). Currently available methods of EGFR mutation detection rely on direct sequencing. Here, we describe the use of an alternative way to screen EGFR mutations. Methods A total of 109 frozen tumor specimens from NSCLC patients were obtained. For mutational analysis of EGFR exons 18, 19, and 21, reverse transcription-polymerase chain reaction was performed on the cDNA using original primers designed for restriction fragment length polymorphism (RFLP). Results EGFR mutations were detected in 37 patients (34%) by both RFLP and direct sequencing except one case in which it was detected only by RFLP. EGFR mutations were more frequently observed to be significant by multivariate analysis in patients with adenocarcinoma (OR = 5.56), no-smoking history (OR = 4.34), and 65-year-old or younger (OR = 2.64), but not in women (OR = 1.14). Among 37 patients, 18 were treated with gefitinib and 9 responded to the treatment. One patient without any mutation responded. Conclusion RFLP is a useful method for screening EGFR mutations and can also be applied to predicting the sensitivity of NSCLC patients to EGFR-tyrosine kinase inhibitors.

// Toshiyuki Hirano 1, * , Hiroyuki Yasuda 1 , Tetsuo Tani 1, * , Junko Hamamoto 1 , Ayano Oashi 1 , Kota Ishioka 1 , Daisuke Arai 1 , Shigenari Nukaga 1 , Masayoshi Miyawaki 1 , Ichiro Kawada 1 , Katsuhiko Naoki 2 , Daniel B. Costa 3 , Susumu S. Kobayashi 3 , Tomoko Betsuyaku 1 , Kenzo Soejima 1 1 Division of Pulmonary Medicine, Department of Medicine, Keio University, School of Medicine 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan 2 Keio Cancer Center, Keio University, School of Medicine 35 Shinanomachi, Shinjuku-ku, Tokyo, Japan 3 Division of Hematology/Oncology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA * These authors have contributed equally to this work Correspondence to: Hiroyuki Yasuda, e-mail: hiroyukiyasuda@a8.keio.jp Kenzo Soejima, e-mail: ksoejima@cpnet.med.keio.ac.jp Keywords: EGFR mutation, EGFR tyrosine kinase inhibitors, EGFR exon 20 insertion mutations, in vitro modeling, lung cancer Received: August 18, 2015 Accepted: October 03, 2015 Published: October 15, 2015 ABSTRACT EGFR mutated lung cancer accounts for a significant subgroup of non-small-cell lung cancer (NSCLC). Over the last decade, multiple EGFR tyrosine kinase inhibitors (EGFR-TKIs) have been developed to target mutated EGFR. However, there is little information regarding mutation specific potency of EGFR-TKIs against various types of EGFR mutations. The purpose of this study is to establish an in vitro model to determine the “therapeutic window” of EGFR-TKIs against various types of EGFR mutations, including EGFR exon 20 insertion mutations. The potency of 1 st (erlotinib), 2 nd (afatinib) and 3 rd (osimertinib and rociletinib) generation EGFR-TKIs was compared in vitro for human lung cancer cell lines and Ba/F3 cells, which exogenously express mutated or wild type EGFR . An in vitro model of mutation specificity was created by calculating the ratio of IC50 values between mutated and wild type EGFR. The in vitro model identified a wide therapeutic window of afatinib for exon 19 deletions and L858R and of osimertinib and rociletinib for T790M positive mutations. The results obtained with our models matched well with previously reported preclinical and clinical data. Interestingly, for EGFR exon 20 insertion mutations, most of which are known to be resistant to 1 st and 2 nd generation EGFR-TKIS, osimertinib was potent and presented a wide therapeutic window. To our knowledge, this is the first report that has identified the therapeutic window of osimertinib for EGFR exon 20 insertion mutations. In conclusion, this model will provide a preclinical rationale for proper selection of EGFR-TKIs against clinically-relevant EGFR mutations.

Purpose: Third-generation EGFR-tyrosine kinase inhibitors (TKIs) are mutation-specific inhibitors that generally have minimal effects on wild type protein. The mechanisms underlying acquired resistance to third-generation EGFR-TKIs remain relatively uncharacterized. The purpose of this study is to clarify the mechanisms of acquired resistance to third-generation EGFR-TKIs in order to improve the prognosis of lung cancer patients harboring EGFR mutations. Experimental design: We established third-generation EGFR-TKIs resistant cells using a dose-escalation method. The PC9 (EGFR E746-A750del) and H1975 (EGFR L858R+T790M) human NSCLC cell lines were cultured with rociletinib (CO-1686) or osimertinib (AZD9291) for several months. Their resistance to a third-generation EGFR-TKIs was confirmed by the MTS cell proliferation assay. To clarify the heterogeneity of potential resistance mechanisms, those resistant cell lines were subcloned to isolate resistant clones. DNA isolated from the parental and resistant cell clones was then subjected to whole exome sequencing. Copy number alterations and several genetic alterations potentially relevant to EGFR-TKIs sensitivity were detected. Results: We identified Src-AKT pathway contribute to acquired resistance. In addition, we identified that EGFR wild type allele, but not mutation allele, amplification induced acquired resistance. It mirrors the decreased inhibitory pressure for wild type EGFR by mutation-specific EGFR-TKIs. Conclusion: We provide evidence of wild type allele-mediated resistance, a novel concept of acquired resistance, occurring in response to mutation-specific inhibitor therapy in cancer treatment. 1833 /2600characters Citation Format: Keigo Kobayashi, Shigenari Nukaga, Hiroyuki Yasuda, Keita Masuzawa, Jyunko Hamamoto, Ichiro Kawada, Katsuhiko Naoki, Sachiyo Mimaki, Shingo Matsumoto, Koichi Goto, Katsuya Tsuchihara, Tomoko Betsuyaku, Kenzo Soejima. EGFR wild type allele amplification induces acquired resistance to mutation-specific EGFR tyrosine kinase inhibitors in non-small cell lung cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4111. doi:10.1158/1538-7445.AM2017-4111

e20577 Background: Nivolumab, an immune checkpoint inhibitor, is now approved as standard treatment for pre-treated advanced non-small cell lung cancer (NSCLC) based on the results from mega clinical trials with carefully selected patients. We sought to clarify the real-world efficacy and safety of nivolumab and to identify the clinical factors influencing the efficacy. Methods: This study enrolled 142 patients with pre-treated advanced NSCLC who had been administered nivolumab (3mg/kg, Q2W) from January to July 2016 at Keio University and affiliated hospitals in Japan. We retrospectively evaluated objective responses, adverse events (AEs), and analysed clinical factors associated with the response. Results: The overall response rate and disease control rate were 17% and 62%, respectively. The rate of any grade AEs was 45%, while the rate of grade 3-4 AEs was 13%. Among patient’s clinical factors such as age, gender, ECOG performance status, types of carcinoma, epidermal growth factor receptor ( EGFR)/ anaplastic lymphoma receptor tyrosine kinase (ALK) mutation status, smoking status, number of previous treatment lines, presence of central nervous system (CNS) metastasis and presence of prior radiotherapy, “ EGFR/ALK mutation negative” and “administration of prior radiotherapy” were independently associated with the good response to nivolumab treatment by multivariate logistic regression analysis (OR NA/ p < 0.01, OR 5.4/ p < 0.01, respectively). None of the 19 EGFR/ALK mutation positive patients showed response. Although a significant difference was not recognized between “current, former smokers” and “never smokers” (chi-square test, p = 0.1), a subsequent analysis showed smoking pack years (PY) was significantly higher in responders than in non-responders ( t-test, p = 0.035). Conclusions: The objective responses and the profiles of AEs confirmed in our study were similar to those observed in Checkmate 057/017 trials. We can use nivolumab safely regardless of age or number of treatment lines. EGFR/ALK mutation and presence of prior radiotherapy were key clinical factors statistically associated with the nivolumab efficacy.

Lung cancer is a heterogeneous disease encompassing a wide array of genetic abnormalities. The MET receptor tyrosine kinase is altered in many lung cancers, especially non–small cell lung cancer (NSCLC), and clinical trials of MET inhibitors that are under way are documenting cases of acquired resistance. On the basis of the evidence that the RON tyrosine kinase receptor can also be overexpressed in NSCLC, we evaluated the potent MET/RON dual kinase inhibitor LY2801653 in this setting. LY2801653 was more efficacious than the MET/ALK/RON/ROS inhibitor crizotinib with a distinct pattern of downstream signaling effects. Using the PamGene platform, we found that inhibition of MET and RON was associated with decreased phosphorylation of CBL, PI3K, and STAT3. In classic and orthotopic mouse xenograft models of lung cancer, LY2801653 decreased tumor growth, dramatically inhibiting mitotic events and angiogenesis. Taken together, our results argued that specific targeting of the MET/RON kinases could provide robust inhibition of cell proliferation and tumor outgrowth in multiple in vitro and in vivo models of NSCLC. These findings offer a robust preclinical proof of concept for MET/RON targeting by LY2801653 as a promising small-molecule modality to treat NSCLC. Cancer Res; 74(3); 884–95. ©2013 AACR.

症例は55歳の女性. 平成7年5月頃より喀痰, 咳嗽が出現し, 次第に労作時呼吸困難が増強することから近医を受診した. 胸部単純写真で右上・中肺野に広範な浸潤影を指摘され, TBLBにて肺腺癌と診断された. 化学療法は無効であったが, 経過とともに増加する多量の喀痰に対してインドメタシン吸入 (75rng/日) を開始したところ, 数日のうちに著明な喀痰の減少が認められた. 患者は肺癌の進行により死亡したが, これらの薬剤は患者のQOL改善に非常に有効であった.

Background: World-wide, esophageal cancer is a growing epidemic and patients frequently present with advanced disease that is surgically inoperable. Hence, chemotherapy is the predominate treatment. Cytotoxic platinum compounds are mostly used, but their efficacy is only moderate. Newer alkylating agents have shown promise in other tumor types, but little is known about their utility in esophageal cancer. Methods: We utilized archived human esophageal cancer samples and esophageal cancer cell lines to evaluate O-6-methylguanine-deoxyribonucleic acid methyltransferase (MGMT) hypermethylation status and determined sensitivity to the alkylating drug temozolomide (TMZ). Immunoblot analysis was performed to determine MGMT protein expression in cell lines. To assess and confirm the effect of TMZ treatment in a methylated esophageal cancer cell line in vivo , a mouse flank xenograft tumor model was utilized. Results: Nearly 71% (12/17) of adenocarcinoma and 38% (3/8) of squamous cell carcinoma (SCC) patient samples were MGMT hypermethylated. Out of four adenocarcinoma and nine SCC cell lines tested, one of each histology was hypermethylated. Immunoblot analyses confirmed that hypermethylated cell lines did not express the MGMT protein. In vitro cell viability assays showed the methylated Kyse-140 and FLO cells to be sensitive to TMZ at an IC 50 of 52-420 μM, whereas unmethylated cells Kyse-410 and SKGT-4 did not respond. In an in vivo xenograft tumor model with Kyse-140 cells, which are MGMT hypermethylated, TMZ treatment abrogated tumor growth by more than 60%. Conclusion: MGMT methylation may be an important biomarker in subsets of esophageal cancers and targeting by TMZ may be utilized to successfully treat these patients.

Esophageal cancer incidence is increasing and has few treatment options. In studying receptor tyrosine kinases associated with esophageal cancers, we have identified EPHB4 to be robustly overexpressed in cell lines and primary tumor tissues. In total, 94 squamous cell carcinoma, 82 adenocarcinoma, 25 dysplasia, 13 Barrett esophagus, and 25 adjacent or unrelated normal esophageal tissues were evaluated by immunohistochemistry. EPHB4 expression was significantly higher in all the different histologic categories than in adjacent normal tissues. In 13 esophageal cancer cell lines, 3 of the 9 SCC cell lines and 2 of the 4 adenocarcinomas expressed very high levels of EPHB4. An increased gene copy number ranging from 4 to 20 copies was identified in a subset of the overexpressing patient samples and cell lines. We have developed a novel 4-nitroquinoline 1-oxide (4-NQO)-induced mouse model of esophageal cancer that recapitulates the EPHB4 expression in humans. A specific small-molecule inhibitor of EPHB4 decreased cell viability in a time- and dose-dependent manner in 3 of the 4 cell lines tested. The small-molecule inhibitor and an EPHB4 siRNA also decreased cell migration (12%–40% closure in treated vs. 60%–80% in untreated), with decreased phosphorylation of various tyrosyl-containing proteins, EphB4, and its downstream target p125FAK. Finally, in a xenograft tumor model, an EPHB4 inhibitor abrogated tumor growth by approximately 60% compared with untreated control. EphB4 is robustly expressed and potentially serves as a novel biomarker for targeted therapy in esophageal cancers. Cancer Res; 73(1); 184–94. ©2012 AACR.

Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKI) show antitumor activity in a subset of non–small cell lung cancer (NSCLC) patients. However, the initial tumor response is followed by recurrence. Several studies have suggested the importance of other receptor tyrosine kinases (RTK) and downstream kinases as potential targets in the treatment of NSCLC. We used the multiple-RTK inhibitor AEE788, which inhibits EGFR, vascular endothelial growth factor receptor, and human epidermal growth factor receptor 2, with and without the downstream kinase inhibitor RAD001 (an inhibitor of mammalian target of rapamycin). AEE788 inhibited cell growth more effectively than did erlotinib in three NSCLC cell lines examined (A549, H1650, and H1975). However, in the EGFR-TKI–resistant cell line H1975 harboring T790M resistance mutation, cell growth inhibition by AEE788 was only mild, and the phosphorylation of its leading targets such as EGFR and vascular endothelial growth factor receptor 2 was not inhibited. In H1975, AEE788 induced significantly greater cell growth inhibition when combined with RAD001 than when used alone. This cooperative effect was not seen with the combination of erlotinib and RAD001. We found that c-Met was highly phosphorylated in this cell line, and the phosphorylated c-Met was inhibited effectively by AEE788. Using a phospho-RTK array, the phosphorylation of c-Met and insulin-like growth factor-I receptor was inhibited by AEE788. These results suggest that upstream RTK inhibitor overcomes the acquired resistance to EGFR-TKI when combined with downstream kinase inhibitor. Thus, the combined inhibition of upstream and downstream RTKs is a promising strategy for the treatment of NSCLC. Mol Cancer Res; 8(8); 1142–51. ©2010 AACR.

Background Alterations in the processing of the genetic information in carcinogenesis result from stable genetic mutations or epigenetic modifications. It is becoming clear that nucleosomal histones are central to proper gene expression and that aberrant DNA methylation of genes and histone methylation plays important roles in tumor progression. To date, several histone lysine methyltransferases (HKMTs) have been identified and histone lysine methylation is now considered to be a critical regulator of transcription. However, still relatively little is known about the role of HKMTs in tumorigenesis. Results We observed differential HKMT expression in a lung cancer model in which normal human bronchial epithelial (NHBE) cells expressing telomerase, SV40 large T antigen, and Ras were immortal, formed colonies in soft agar, and expressed specific HKMTs for H3 lysine 9 and 27 residues but not for H3 lysine 4 residue. Modifications in the H3 tails affect the binding of proteins to the histone tails and regulate protein function and the position of lysine methylation marks a gene to be either activated or repressed. In the present study, suppression by siRNA of HKMTs (EZH2, G9A, SETDB1 and SUV39H1) that are over-expressed in immortalized and transformed cells lead to reduced cell proliferation and much less anchorage-independent colony growth. We also found that the suppression of H3-K9, G9A and SUV39H1 induced apoptosis and the suppression of H3-K27, EZH2 caused G1 arrest. Conclusion Our results indicate the potential of these HKMTs in addition to the other targets for epigenetics such as DNMTs and HDACs to be interesting therapeutic targets.

Rationale: Recently, the importance of fibroblast growth factor (FGF) and its receptor (FGFR) signals has been emphasized in various types of cancer, including lung cancer. FGFs and FGFRs are reported to be related to drug resistance, cell proliferation, differentiation and motility. Among various FGFs, FGF9 is a developmentally important FGF associated with epithelial airway branching, and its expression is repressed in normal adult lungs. We have previously shown that FGF9 is highly expressed in NSCLC cells, and FGF9 expression was associated with poor prognosis of NSCLC patients. Furthermore, we reported that induction of FGF9 in adult lung results in the rapid formation of adenocarcinoma in specific gene engineered mouse model. However, the exact roles of FGF9 in lung epithelial cells remain elusive. Objectives: The objective of this study is to clarify the roles of FGF9 in lung epithelial cells. Methods: For in vitro experiments, a stable cell line with constitutive expression of FGF9 in MLE12 (a mouse lung alveolar type II cell line transformed by SV40 large T antigen) was established by retroviral infection. The effect of FGF9 on proliferation, colony formation capacity and downstream signaling was evaluated by MTS assay, softagar colony formation assay and Western blotting, respectively. For in vivo experiments, the cells were transplanted into immunodeficient mice subcutaneously, and the size of tumor was measured. To evaluate the efficacy of FGFR inhibitors for FGF9-driven lung cancers, AZD4547, selective FGFR inhibitor, was orally administered. For pathological characterization of the tumors, immunohistochemical staining was performed. Fifteen surgically-resected SCLC samples were obtained and the expression of FGF9 was evaluated by immunohistochemistry. Results: FGF9 has oncogenic ability in vitro and its effect may be exerted by the activation of MAPK pathway through FGFR1 and FGFR3 in MLE12 cells. Unexpectedly, pathological analysis revealed FGF9-driven tumors exhibited SCLC histology. Selective FGFR inhibitor, AZD4547 suppressed tumor growth of FGF9-driven MLE12 tumors. FGF9 is highly expressed in human SCLC samples (67%). Conclusions: These results suggest that FGF9 has roles of tumor initiation and progression in lung cancer, especially in SCLC. SCLC which highly expresses FGF9 may be a target of FGFR inhibitors. Citation Format: Kota Ishioka, Kenzo Sejima, Hiroyuki Yasuda, Junko Hamamoto, Ahmed Hegab, Tetsuo Tani, Aoi Kuroda, Daisuke Arai, Keiko Ohgino, Takashi Sato, Terai Hideki, Ichiro Kawada, Katsuhiko Naoki, Yuichiro Hayashi, Tomoko Betsuyaku. Oncogenic potential of FGF9 in 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 3916. doi:10.1158/1538-7445.AM2015-3916

Purpose: Alectinib is a highly selective ALK inhibitor and showed a striking efficacy in non-small cell lung cancers (NSCLC) harboring EML4-ALK gene rearrangement. Recently, it was reported that alectinib had an objective response rate of 93.5% in ALK positive patients in a clinical study. However, cancer cells usually acquire resistance to molecular-targeted drugs. The mechanisms of acquired resistance to alectinib are not yet well clarified. The purpose of this study is to clarify the mechanism of acquired resistance to alectinib in ALK translocated lung cancer cells. Experimental design: We have established alectinib resistant cells (H3122-AR) from H3122, which harbors EML4-ALK rearrangement, by long term exposure to alectinib. The mechanism of acquired resistance to alectinib in H3122-AR cells was evaluated in vitro by cDNA sequencing of ALK tyrosine kinase (TK) domain, or by phospho-RTK array to estimate activation of bypass pathway. The efficacy of combination therapy targeting ALK and EGFR was evaluated in vitro and in vivo by using alectinib, afatinib, or siRNA for EGFR. For in vivo experiment, we used mouse xenograft model. Human tumor samples were evaluated by immunohistochemistry. Results: No additional mutation in ALK TK domain was found by cDNA sequencing. Phospho-RTK array revealed that the phosphorylation level of EGFR was increased in H3122-AR cells compared with H3122 parental cells, which was subsequently confirmed by western blotting. We found no additional mutation in EGFR TK domain by cDNA sequencing. Among 5 ligands for EGFR, the expression of TGFα was significantly increased in H3122-AR cells compared with H3122 parental cells. We found the phosphorylation level of EGFR was decreased in TGFα gene knockdown, therefore TGFα and EGFR contributed to the acquired resistance to alectinib. The combination therapy targeting ALK and EGFR by using alectinib, afatinib in vitro and in vivo, or siRNA for EGFR in vitro showed efficacy. We found the increased phosphorylation of EGFR after long term ALK-TKI treatment was also detected in human tumor samples. Conclusion: Activation of EGFR signaling pathway through TGFα overexpression induces acquired resistance to alectinib in ALK-translocated lung cancer cells. Citation Format: Tetsuo Tani, Hiroyuki Yasuda, Junko Hamamoto, Aoi Kuroda, Daisuke Arai, Kota Ishioka, Keiko Ohgino, Ichiro Kawada, Katsuhiko Naoki, Hayashi Yuichiro, Tomoko Betsuyaku, Kenzo Soejima. Activation of EGFR bypass signaling through TGFα overexpression induces acquired resistance to alectinib in ALK-translocated lung cancer cells. [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 746. doi:10.1158/1538-7445.AM2015-746

Introduction: Many anti-tumor drugs have been developed, however, prognosis of NSCLC remains poor and new approaches for NSCLC treatment are expected. Lung is a unique organ whose epithelial cells are directly exposed to oxygen. Hyperoxia produces reactive oxygen species (ROS) and induces cell damage. Therefore we attempted to investigate the potential of hyperoxia as an anti-tumor treatment in NSCLC cells in this study. Methods: We used oxygen-concentration-adjustable incubators and validated effect of hyperoxia on various lung cancer cell lines in vitro. The effect of hyperoxia on cell proliferation, apoptosis and gene expression was evaluated using MTS assay, flowcytometry and cDNA microarray, respectively. Results: We found that the growth of lung cancer cell lines (A549, NCI-H1975) was inhibited by 50% of hyperoxia in a dose-dependent manner, while that of normal airway epithelial cells (NHBE, BEAS-2B) was not. Two independent pathway analysis using cDNA microarray revealed the activation of NF-kB and AMPK pathways, and the production of nitric oxide and ROS in hyperoxia (50%) treated lung cancer cell lines compared to untreated ones. The combined treatment with ABT-263, Bcl-2 inhibitor, and hyperoxia (50%) induced synergistic growth inhibition and apoptosis in NCI-H1975 and SK-MES-1 cells. Moreover, the combination of ABT-263 and activator of either ROS, NF-kB or AMPK also showed synergistic growth inhibition in those cells. Conclusions: Hyperoxia (50%) showed anti-tumor effect in NSCLC cell lines through the activation of NF-kB and AMPK pathways, and the production of ROS. The effect was augumented in combination with Bcl-2 inhibitor. Hyperoxia may be a treatment option for NSCLC patients. Citation Format: Junko Hamamoto, Hiroyuki Yasuda, Ichiro Nakachi, Michael G. Edwards, Masayoshi Miyawaki, Makoto Nishino, Aoi Kuroda, Tetsuo Tani, Daisuke Arai, Kota Ishioka, Ichiro Kawada, Katsuhiko Naoki, Tomoko Betsuyaku, Kenzo Soejima. Hyperoxia may be a treatment option for NSCLC. [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 3006. doi:10.1158/1538-7445.AM2015-3006

Rationale: ABT-263 (Navitoclax) is one of the BH3 mimetics targeting anti-apoptotic B-cell lymphoma-2 (Bcl-2) family proteins such as Bcl-2, Bcl-XL, and Bcl-w, thereby inducing apoptosis. It has been reported that the response to ABT-263 is associated with expressions of myeloid cell leukemia-1 (Mcl-1), an anti-apoptotic protein. Given its effectiveness as a single agent in preclinical studies, ABT-263 is currently being evaluated in clinical trials for small cell lung cancer (SCLC) and leukemia. However, the efficacy of ABT-263 in non-small cell lung cancer (NSCLC) has not been fully evaluated. We examined the effect of ABT-263 on cell proliferation of NSCLC cell lines and investigated the underlying mechanisms. Methods: The following 9 NSCLC cell lines were examined: SK-LU-1, A549, H358, Calu3, H3122, H1975, H460, H441, and BID007. The effects of ABT-263 in NSCLC cell lines were evaluated by MTS assay. Apoptosis was examined by flowcytometry using staining for annexin V and propidium iodide (PI), and also western blotting for cleaved PARP. Quantitative RT-PCR was carried out to assess the mRNA expression levels of anti-apoptotic genes and pro-apoptotic genes. Immunoprecipitation and western blotting were performed to compare the levels of anti-apoptotic and pro-apoptotic proteins between the sensitive and resistant cell lines. In addition, knockdown of Mcl-1 was performed by siRNA. Results: By screening 9 NSCLC cell lines using MTS assay, we found Calu3 and BID007were sensitive to ABT-263. We also confirmed that apoptosis was induced only in the ABT-263 sensitive lines but not in the ABT-263 resistant cell lines after ABT-263 treatment. However, the expression levels of Bcl-2 family proteins, including Mcl-1, did not differ significantly among the ABT-263 sensitive and resistant cell lines. Unlike the results in previous reports regarding SCLC, Mcl-1 was not decreased in the sensitive cell lines. The ABT-263 resistant cell lines became sensitive to ABT-263 after knockdown of Mcl-1 by siRNA, while the ABT-263 sensitive cell lines maintained the same sensitivity. Conclusion: We found that Calu3 and BID007 were sensitive to ABT-263. In the sensitive NSCLC cell lines, ABT-263 induces apoptosis irrespective of Mcl-1 expression levels. Citation Format: Aoi Kuroda, Keiko Ohgino, Hiroyuki Yasuda, Junko Hamamoto, Daisuke Arai, Kota Ishioka, Tetsuo Tani, Shigenari Nukaga, Ichiro Kawada, Katsuhiko Naoki, Kenzo Soejima, Tomoko Betsuyaku. ABT-263 is effective in a subset of non-small cell lung cancer cell lines. [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 4. doi:10.1158/1538-7445.AM2015-4