Search

Fig. S1. Supplementary data for Fig. 1 Fig. S2. Supplementary drug sensitivity data to ALK inhibitors in KTOR1 and KTOR1-RE. Fig. S3. Supplementary results of the phosphoproteome analysis Fig. S4. Saracatinib sensitized KTOR1-RE cells to crizotinib Fig. S5. Combined knockdown of MET and SRC inhibited proliferation and induces apoptosis Fig. S6. Supplementary data for Fig. 6 Table S1. Primer sequences for direct sequence of ALK exons Table S2. Primer sequences for detection and sequence of EML4-ALK rearrangement Table S3. Primer sequences for qRT-PCR

Supplementary Figure S1-S6 and Table S1-S3

Alectinib is used as a first-line treatment for anaplastic lymphoma kinase (ALK)-rearranged non–small cell lung cancer (NSCLC). Whereas other ALK inhibitors have been reported to be involved in resistance to ATP-binding cassette (ABC) transporters, no data are available regarding the association between resistance to alectinib and ABC-transporters. To investigate whether ABC-transporters contribute to alectinib resistance, ABC-transporter expression in alectinib-resistant cell lines derived from a patient with ALK-rearranged NSCLC and from H2228 lung cancer cells was evaluated and compared with that in each parent cell type. ATP-binding cassette subfamily C member 11 (ABCC11) expression was significantly increased in alectinib-resistant cell lines compared with that in alectinib-sensitive lines. ABCC11 inhibition increased sensitivity to alectinib in vitro. ABCC11-overexpressing cells were established by transfection of an ABCC11 expression vector into H2228 cells, while control cells were established by transfecting H2228 cells with an empty vector. ABCC11-overexpressing cells exhibited decreased sensitivity to alectinib compared with that of control cells in vitro. Moreover, the tumor growth rate following alectinib treatment was higher in ABCC11-overexpressing cells than that in control cells in vivo. In addition, the intracellular alectinib concentration following exposure to 100 nmol/L alectinib was significantly lower in the ABCC11-overexpressing cell line compared with that in control cells. This is the first preclinical evidence showing that ABCC11 expression may be involved in acquired resistance to alectinib.

Figure S1. Schematic representation of the ABCC11 expression vector. Figure S2. Sequence analysis of the tyrosine kinase coding region of anaplastic lymphoma kinase (ALK). Figure S3. Cell viability assay of alectinib in H2228 and H2228-AR1S cells under low-attachment conditions. Figure S4. Gene expression of the ABC transporters in the five cell types. Figure S5. Intracellular concentration of alectinib. Figure S6. Tumor images on day 11 of treatment. The tumor volume at 10 days after alectinib administration. Figure S7. ALK phosphorylation in KTOR1 and KOR1-RE cell exposed to alectinib for 3 hours as determined using immunoblotting. Figure S8. IC50 values of H2228 and H2228-AR1S cell lines in the presence of crizotinib, ceritinib, lorlatinib, and brigatinib. Table S1. Immunoblotting antibodies. Table S2. Primers used for ABC transporters purchased from Thermo Fisher Scientific. Table S3. siRNA oligonucleotides purchased from Thermo Fisher Scientific. Table S4. Primer sequences for direct sequencing of ALK exons. Table S5. IC50 for alectinib in H2228-AR1S cells transfected with negative control or ABCC11 siRNA. Table S6. IC50 for alectinib in KTOR1-RE cells transfected with negative control or ABCC11 siRNA.

The mechanisms responsible for the development of resistance to alectinib, a second-generation anaplastic lymphoma kinase (ALK) inhibitor, are still unclear, and few cell lines are currently available for investigating ALK-rearranged lung cancer. To identify the mechanisms underlying acquired resistance to alectinib, two patient-derived cell lines were established from an alectinib-naïve ALK-rearranged lung cancer and then after development of alectinib resistance. The properties acquired during treatments were detected by comparisons of the two cell lines, and then functional analyses were performed. Coactivation of c-Src and MET was identified after the development of alectinib resistance. Combinatorial therapy against Src and MET significantly restored alectinib sensitivity in vitro (17.2-fold). Increased apoptosis, reduction of tumor volume, and inhibition of MAPK and PI3K/AKT signaling molecules for proliferation and survival were observed when the three kinases (Src, MET, and ALK) were inhibited. A patient-derived xenograft from the alectinib-resistant cells indicated that combination therapy with a saracatinib and crizotinib significantly decreased tumor size in vivo. To confirm the generality, a conventional alectinib-resistant cell line model (H2228-AR1S) was established from NCI-H2228 cells (EML4-ALK variant 3a/b). In H2228-AR1S, combination inhibition of Src and MET also restored alectinib sensitivity. These data reveal that dual salvage signaling from MET and Src is a potential therapeutic target in alectinib-resistant patients.Implications:This study demonstrates the feasibility to elucidate personalized drug-resistance mechanisms from individual patient samples.

Data sets of the phosphoproteome analysis in KTOR1 and KTOR1-RE cells

ABCC11 sequence inserted into the vector

The mechanisms responsible for the development of resistance to alectinib, a second-generation anaplastic lymphoma kinase (ALK) inhibitor, are still unclear, and few cell lines are currently available for investigating ALK-rearranged lung cancer. To identify the mechanisms underlying acquired resistance to alectinib, two patient-derived cell lines were established from an alectinib-naïve ALK-rearranged lung cancer and then after development of alectinib resistance. The properties acquired during treatments were detected by comparisons of the two cell lines, and then functional analyses were performed. Coactivation of c-Src and MET was identified after the development of alectinib resistance. Combinatorial therapy against Src and MET significantly restored alectinib sensitivity in vitro (17.2-fold). Increased apoptosis, reduction of tumor volume, and inhibition of MAPK and PI3K/AKT signaling molecules for proliferation and survival were observed when the three kinases (Src, MET, and ALK) were inhibited. A patient-derived xenograft from the alectinib-resistant cells indicated that combination therapy with a saracatinib and crizotinib significantly decreased tumor size in vivo. To confirm the generality, a conventional alectinib-resistant cell line model (H2228-AR1S) was established from NCI-H2228 cells (EML4-ALK variant 3a/b). In H2228-AR1S, combination inhibition of Src and MET also restored alectinib sensitivity. These data reveal that dual salvage signaling from MET and Src is a potential therapeutic target in alectinib-resistant patients. Implications: This study demonstrates the feasibility to elucidate personalized drug-resistance mechanisms from individual patient samples.

Anaplastic lymphoma kinase (ALK) inhibitors, such as alectinib (ALC), have dramatic therapeutic effects on ALK-rearranged lung cancer, but cures are usually not achieved. We focused on tumor cells that survive ALK inhibitor administration and hypothesized that targeted therapy for these cells could provide complete remission. To explore survival factors, we established patient-derived cell lines and screened them using proteome analysis. Three ALK-rearranged ALC-sensitive cell lines (KTOR-1, KTOR-2, KTOR-3) were established from 3 patients; the 50% inhibitory concentrations (IC50)s for ALC were 24-65 nM. Comprehensive protein expression profiles of the 3 cells indicated that exposure to ALC significantly enriched proteins related to actin and extracellular matrix (ECM) adhesion. We focused on Yes-associated protein 1 (YAP1), which is activated by ECM adhesion and actin fiber accumulation. Nuclear localization of YAP1 (an activation marker of YAP1) was assessed using immunohistostaining. In KTOR1-3 and H2228 cells from an ALK-rearranged line purchased from ATCC, exposure to ALC in vitro promoted YAP1 accumulation in the nucleus. BALB/nu mice xenograft models of H2228 or KTOR1 were administered ALC (8 mg/kg/day, N=4) or a vehicle (N=4) for 7 days, and tumors were evaluated. In ALC-administered tumors, YAP1 was localized to the nucleus, which was rarely the case in vehicle-administered tumors. The expression of pro-apoptosis factors Mcl-1 and Bcl-xL also increased after exposure to ALC in vitro, but the increment was cancelled by YAP1 inhibition by siRNA or verteporfin (VER), a non-specific YAP1 inhibitor. Exposure to ALC with combinatorial YAP1 inhibition significantly increased Caspase 3/7 activity. To address the treatment effects of YAP1 inhibition, a YAP1-activated H2228 cell line (H2ARY) was established by exposing H2228 cells to 100-300 nM of ALC for 3 months and thorough subsequent cloning. The H2ARY had lower sensitivity to ALC in vitro than parental H2228 (IC50: 1.4 μM vs 315 nM, 96 h) and restored the sensitivity by YAP1 inhibition (208 nM with VER 1 μM, 312 nM with siYAP1). Twenty-four xenograft models (mean volume: 199 mm3) of H2ARY on BALB/nu mice were randomized (Day 0) into 4 treatment groups to receive ALC monotherapy (8 mg/kg daily, N=6), VER monotherapy (12.5 mg/kg twice a week, N=7), combination (N=7), or vehicle (N=5). On day 15, the tumor volume of the vehicle and VER monotherapy groups reached > 800 mm3, with no significant differences among the groups. On day 33, the tumors of the combination group were significantly smaller than those of the ALC monotherapy group (187 vs 761 mm3, P = 0.0125). Exposure to ALC-activated YAP1 may regulate anti-apoptotic activity by controlling the expression of Mcl-1 and Bcl-xL in ALK-rearranged lung cancer cells. This is the first evidence that combinatorial therapy against ALK and YAP1 could enhance ALK-rearranged tumor treatment. Citation Format: Takahiro Tsuji, Hiroaki Ozasa, Wataru Aoki, Shunsuke Aburaya, Tomoko Funazo, Koh Furugaki, Yasushi Yoshimura, Hitomi Ajimizu, Yuto Yasuda, Takashi Nomizo, Yuichi Sakamori, Hironori Yoshida, Mitsuyoshi Ueda, Young Hak Kim, Toyohiro Hirai. YAP1 mediates initial survival of alectinib therapy in ALK-rearranged lung cancer via pro-apoptotic protein regulation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 72.

Non-small cell lung cancer is known to have a poor prognosis. One reason for this is resistance to anticancer drugs. Various mechanisms for resistance to anticancer drugs have been reported. Herein we focus on ABCC11, an adenosine triphosphate (ATP)-binding cassette transporter. ABCC11 is ubiquitously expressed in various adult human tissues, including liver, lung, and kidney, and confers drug resistance to some cytotoxic agents such as 5-fluorouracil (5-FU), pemetrexed, and methotrexate. However, the association between ABCC11 and resistance to molecularly-targeted therapeutic drugs is still unknown. We hypothesized that alectinib, a molecularly-targeted therapeutic agent for anaplastic lymphoma kinase (ALK)-rearranged lung cancer, was a substrate for ABCC11. To evaluate the expression of ABCC11 in alectinib-resistant cells, an alectinib-resistant cell line model (AR1S) was established by exposing NCI-H2228, an ALK-rearranged cell line, to alectinib for 3 months. Patient-derived cell lines that were sensitive or resistant to alectinib were also established from a treatment-naïve patient (KTOR-1), and after disease progression (KTOR-1 RE). The protein expression of ABCC11 was increased in both alectinib-resistant cell lines (AR1S and KTOR-1 RE), compared to naïve cell lines (H2228 and KTOR-1). To investigate the role of ABCC11 in alectinib resistance, ABCC11 overexpression cell lines (OE-A and OE-B) were established by introducing an ABCC11 expression construct into H2228. A negative control cell line (mock) was established by introducing the control empty vector into H2228. The gene expression of ABCC11 in OE-A and OE-B was higher than that in mock (133-fold increase, P < 0.0001 and 109-fold increase, P < 0.0001 respectively), and the protein expression of ABCC11 was also higher in OE-A and OE-B. The IC50 for alectinib was higher in OE-A (8.0 times) and OE-B (10.8 times) compared to mock. ABCC11 was knocked down using siRNA in AR1S to evaluate alectinib susceptibility. Knockdown of ABCC11 improved the IC50 for alectinib, compared with a negative control (0.299-fold decrease). Next, the tumor responses to alectinib in OE-A and OE-B were evaluated in vivo. Xenograft models of OE-A, OE-B, and mock on BALB/nu mice were administered daily alectinib (8 mg/kg/day) or vehicle for 10 days. In mice administered alectinib (N = 6-7), the tumor shrinkage rate of OE-A (−23.6%) and OE-B (−34.3%) was significantly lower than that of mock (−76.8%). There results have provided the first of preclinical evidence that ABCC11 is involved in resistance to alectinib. Citation Format: Tomoko Yamamoto Funazo, Hiroaki Ozasa, Takahiro Tsuji, Koh Furugaki, Yasushi Yoshimura, Hitomi Ajimizu, Yuto Yasuda, Takashi Nomizo, Yuichi Sakamori, Hironori Yoshida, Young Hak Kim, Toyohiro Hirai. ABCC11 is involved in resistance to alectinib [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1271.

Purpose: We investigated the antitumor activity of the combination of two different humanized monoclonal human epidermal growth factor receptor (HER) 2 antibodies, pertuzumab and trastuzumab, for gastric cancer. Experimental Design: Tumor mouse xenograft models were used to examine antitumor activity. Cell proliferation was examined using crystal violet staining. HER family proteins' expression was analyzed by ELISA and immunohistochemistry. Phosphorylated proteins and heterodimers were detected by Western blotting and in situ proximity ligation assay (PLA), respectively. Apoptosis activity was examined by caspase 3/7 activity. Antibody-dependent cellular cytotoxicity (ADCC) activity was detected by xCELLigence. Microvessel density was examined by CD31 staining. Results: Pertuzumab in combination with trastuzumab showed significant antitumor activity compared with each monotherapy in NCI-N87, an HER2-positive human gastric cancer xenograft model. The efficacy was stronger than that of the maximum effective dose with each monotherapy. Similar antitumor activity was shown in 4-1ST, another HER2-positive gastric cancer model, but not in MKN-28, an HER2-negative model. Combining pertuzumab with trastuzumab enhanced cell growth inhibition and apoptosis activity by inhibiting EGFR-HER2 heterodimerization and the phosphorylation of these receptors and their downstream factors. This effect was also seen in HER2-HER3 signaling. Furthermore, pertuzumab in combination with trastuzumab potentiated the ADCC activity of those antibodies and reduced tumor microvessel density. Conclusions: We showed the significantly enhanced efficacy of pertuzumab combining with trastuzumab for HER2 overexpressing gastric cancer through the potentiation of cell growth inhibition, apoptosis activity, cell killing activity by ADCC, and antiangiogenic activity. This study suggests the clinical benefit of combination therapy with pertuzumab and trastuzumab for patients with HER2-positive gastric cancers. Clin Cancer Res; 17(15); 5060–70. ©2011 AACR.

Conventional drug-resistant cancer cell line models have contributed to the elucidation of drug-resistant mechanisms. However, whether or not these models reflect patients in clinical settings is often controversial. We herein report a patient-derived drug resistant model system named the “clinical paired resistant model”. This model consists of 2 cell lines derived from a treatment-naïve patient (drug sensitive cell line model) and again after disease progression (drug resistant cell line model). The clinical paired resistant model of alectinib, the second generation ALK inhibitor, revealed the properties that cancer cells acquired during treatment using phosphoproteome and immunoblotting analyses; the proto-oncogene protein tyrosine kinase Src and hepatocyte growth factor receptor MET were activated after the development of alectinib resistance. No secondary mutations were detected in the coding region of ALK tyrosine kinase in the alectinib resistant model. In this alectinib-resistant model, the inhibition of Src and MET using saracatinib and PHA-665752 significantly restored alectinib sensitivity in vitro (17.2-fold change in IC50). Downstream signaling molecules for proliferation and survival, phosphorylation of Akt and ERK1/2, were inhibited and caspase 3/7 activity was significantly increased when the cells were treated with all three inhibitors (saracatinib, PHA-665752, and alectinib). Combined knockdown of SRC and MET restored alectinib sensitivity and inhibited downstream signaling in combination with ALK inhibition using alectinib, suggesting that the dual salvage signaling of MET and Src conferred alectinib resistance. A xenograft generated from our paired resistant model (N=5-6, in each group) indicated that combination therapy with a saracatinib and crizotinib, the first generation ALK inhibitor which also inhibits MET, significantly decreased tumor size in vivo as compared with saracatinib or crizotinib monotherapy. We also established a conventional alectinib resistant cell line model in vitro by exposing NCI-H2228 cells (EML4-ALK variant 3a/b) to 300 nM of alectinib for 3 months and found MET and Src were also activated in the model. Our clinical paired resistant model permits the detection of drug-resistant mechanisms without exploring the common characteristics of numerous drug-resistant patients. Our results demonstrate that MET and Src are potential therapeutic targets in patients with alectinib resistance and that the clinical paired resistant model may be a new strategy to elucidate drug-resistant mechanisms in relatively rare cancers. Citation Format: Takahiro Tsuji, Hiroaki Ozasa, Takashi Nomizo, Tomoko Funazo, Yuto Yasuda, Yuichi Sakamori, Hironori Yoshida, Kiyoshi Uemasu, Hitomi Ajimizu, Ryoko Okutani, Shunsuke Aburaya, Wataru Aoki, Mitsuyoshi Ueda, Koh Furugaki, Yasushi Yoshimura, Toyohiro Hirai, Young Hak Kim. A clinical paired resistant model elucidated novel dual salvage signaling that confers alectinib resistance in ALK-rearranged lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1830.