Co-occurring gene alterations associated with efficacy of osimertinib in EGFR-mutated lung cancer: Based on a large-scale genomic screening project (LC-SCRUM-Asia)

9103

Background: Osimertinib is a standard drug for first-line treatment of patients with advanced non–small cell lung cancer (NSCLC) harboring EGFR mutations (mt). While tumor mutational burden (TMB)-high and co-occurring genetic alterations (alt) have been reported to be negatively associated with the efficacy of other EGFR-TKIs, the impact of co-occurring genetic alt with EGFR major mt on the efficacy of osimertinib remains unclear. Methods: In a multi-institutional genomic screening project (LC-SCRUM-Asia), we have analyzed lung cancer patients for genomic alt by a targeted next-generation sequencing (NGS) system, Oncomine Comprehensive Assay and Genexus/OPA. We retrospectively evaluated the association between the genomic profile and efficacy of first-line osimertinib for EGFR-mutated NSCLC based on the LC-SCRUM-Asia database. Results: Between March 2015 and January 2022, 12,705 NSCLC patients were enrolled in the LC-SCRUM-Asia database, and EGFR mt was detected in 2,232 patients. Of these, 324 patients, including 171 with ex19del (53%) and 153 with L858R (47%), received first-line treatment with osimertinib. The patient characteristics were as follows: median age, 69 years (range 31-97); females, 64%; never-smokers, 57%; adenocarcinoma, 97%; and performance status 0-1, 99%. The frequency of compound EGFR mt and TMB were higher in the L858R (LR) group than in the ex19del (Ex19) group (compound mt (%), 12 vs. 4; mean TMB (mt/Mb), 3.4 vs. 2.5). There were no differences in the frequencies of other co-occurring genetic alt between the two groups. Higher TMB, alt of genes encoding receptor tyrosine kinase (RTK), including FGFR1, RET, MET etc., and amp of cell-cycle related genes were significantly associated with shorter progression-free survival (PFS) in the entire group (median PFS: TMB > 3 vs. ≤3 mt/Mb = 11.4 vs. 17.1 months; p = 0.023; RTK gene alt+ vs. alt- = 9.7 vs. 15.2 months; p = 0.014; cell-cycle gene amp+ vs. amp- = 10.6 vs. 15.6 months, p = 0.001). EGFR subgroup analysis showed that a higher TMB was significantly associated with a shorter PFS in the LR group (> 3 vs. ≤3 mt/Mb = 10.0 vs. 17.1 months, p < 0.001), but not in the Ex19 group. On the other hand, alt of genes encoding RTK and amp of cell-cycle related genes were significantly associated with a shorter PFS in the Ex19 group (RTK gene alt+ vs. alt- = 8.4 vs. 17.8 months, p = 0.008; cell-cycle gene amp+ vs. amp- = 10.6 vs. 17.5 months, p = 0.003), but not in the LR group. Multivariate analysis identified RTK gene alt in the Ex19 group and higher TMB in the LR group as being independently associated with a shorter PFS. Conclusions: First-line osimertinib treatment was less effective in NSCLC patients harboring Ex19 with other RTK gene alt or LR with a higher TMB, indicating that co-occurring genetic alt affecting the efficacy of osimertinib differ between NSCLC patients harboring Ex19 and LR.

An MDM2 inhibitor achieves synergistic cytotoxic effects with adenoviruses lacking E1B55kDa gene on mesothelioma with the wild-type p53 through augmenting NFI expression

A majority of mesothelioma specimens were defective of p14 and p16 expression due to deletion of the INK4A/ARF region, and the p53 pathway was consequently inactivated by elevated MDM2 functions which facilitated p53 degradaton. We investigated a role of p53 elevation by MDM2 inhibitors, nutlin-3a and RG7112, in cytotoxicity of replication-competent adenoviruses (Ad) lacking the p53-binding E1B55kDa gene (Ad-delE1B). We found that a growth inhibition by p53-activating Ad-delE1B was irrelevant to p53 expression in the infected cells, but combination of Ad-delE1B and the MDM2 inhibitor produced synergistic inhibitory effects on mesothelioma with the wild-type but not mutated p53 genotype. The combination augmented p53 phosphorylation, activated apoptotic but not autophagic pathway, and enhanced DNA damage signals through ATM-Chk2 phosphorylation. The MDM2 inhibitors facilitated production of the Ad progenies through augmented expression of nuclear factor I (NFI), one of the transcriptional factors involved in Ad replications. Knocking down of p53 with siRNA did not increase the progeny production or the NFI expression. We also demonstrated anti-tumor effects by the combination of Ad-delE1B and the MDM2 inhibitors in an orthotopic animal model. These data collectively indicated that upregulation of wild-type p53 expression contributed to cytotoxicity by E1B55kDa-defective replicative Ad through NFI induction and suggested that replication-competent Ad together with augmented p53 levels was a therapeutic strategy for p53 wild-type mesothelioma.

Combination of a p53-activating CP-31398 and an MDM2 or a FAK inhibitor produces growth suppressive effects in mesothelioma with wild-type p53 genotype

A majority of mesothelioma had the wild-type p53 genotype but was defective of p53 functions primarily due to a genetic defect in INK4A/ARF region. We examined a growth suppressive activity of CP-31398 which was developed to restore the p53 functions irrespective of the genotype in mesothelioma with wild-type or mutated p53. CP-31398 up-regulated p53 levels in cells with wild-type p53 genotype but induced cell growth suppression in a p53-independent manner. In contrasts, nutlin-3a, an MDM2 inhibitor, increased p53 and p21 levels in mesothelioma with the wild-type p53 genotype and produced growth suppressive effects. We investigated a combinatory effect of CP-31398 and nutlin-2a and found the combination produced synergistic growth inhibition in mesothelioma with the wild-type p53 but not with mutated p53. Western blot analysis showed that the combination increased p53 and the phosphorylation levels greater than treatments with the single agent, augmented cleavages of PARP and caspase-3, and decreased phosphorylated FAK levels. Combination of CP-31398 and defactinib, a FAK inhibitor, also achieved synergistic inhibitory effects and increased p53 with FAK dephosphorylation levels greater than the single treatment. These data indicated that a p53-activating CP-31398 achieved growth inhibitory effects in combination with a MDM2 or a FAK inhibitor and suggested a possible reciprocal pathway between p53 elevation and FAK inactivation.

Clinico-pathological and genomic features of NRAS- or HRAS-mutated non-small cell lung cancer (NSCLC) identified in large-scale genomic screening project (LC-SCRUM-Asia)

9054

Background: RAS ( KRAS, NRAS and HRAS) is a targetable oncogene family in several cancers, including NSCLC, and the clinical development of various RAS-targeted therapies are ongoing. However, the clinical relevance of uncommon RAS mutations, such as NRAS and HRAS mutations, in NSCLC patients (pts) remains unclear. Methods: In a large-scale genomic screening project (LC-SCRUM-Asia), we have prospectively analyzed lung cancer pts for genomic alterations by a targeted next-generation sequencing (NGS) system, Oncomine Comprehensive Assay. We evaluated clinico-pathological and genomic characteristics in NRAS- or HRAS-mutated NSCLC pts comparing with those in KRAS-mutated pts based on the LC-SCRUM-Asia database. Results: Since March 2015 to December 2020, 9131 NSCLC pts were enrolled in the LC-SCRUM-Asia, and 8374 of them (92%) were successfully analyzed by NGS. The RAS mutation frequencies were 1134 KRAS (14%), 50 NRAS (0.6%), and 15 HRAS (0.2%). The most frequent variant of NRAS and HRAS mutations was Q61X (78%) and G13X (80%), respectively, whereas that of KRAS was G12X (84%). Patient characteristics were summarized in Table. Male was significantly frequent in NRAS- than in KRAS-group (p=0.03), and smokers were frequent in all the three groups (overall, 79%). The majority of NRAS (70%) and KRAS mutations (89%) were detected in adenocarcinoma (Ad), whereas 60% of HRAS mutations were in squamous cell carcinoma (Sq). Tumor mutation burden (TMB) was significantly higher in NRAS-mutated tumors than in KRAS-mutated tumors (p=0.03). Concomitant TP53 mutations were significantly frequent in HRAS-mutated pts than in KRAS-mutated pts (53% vs. 30%, p=0.05), and STK11 mutations were also tended to be frequent in HRAS-mutated pts than in KRAS-mutated pts (20 vs. 7%, p=0.10). Therapeutic efficacy of PD-1/PD-L1 inhibitors was not different among the three groups in the current follow-up data, but HRAS-mutated tumors did not respond to PD-1/PD-L1 inhibitors (response rate, 0%; median PFS, 1.6 months). Conclusions: NRAS- or HRAS-mutated NSCLCs were different from KRAS-mutated NSCLCs in clinico-pathological and genomic profiles. In particular, the immunotherapies were not effective for HRAS-mutated NSCLCs.[Table: see text]

Clinical value of PET/CT with carbon-11 4DST in the evaluation of malignant and benign lung tumors

OBJECTIVES

The aim of this study was to assess the clinical value of [¹¹C]4DST uptake in patients with lung nodules, including benign and malignant tumors, and to assess the correlation between [¹¹C]4DST uptake and proliferative activity of tumors in comparison with [¹⁸F]FDG uptake.

METHODS

Twenty-six patients (22 males and 4 females, mean age of 65.5-year-old) were analyzed in this prospective study. Patients underwent [¹¹C]4DST and [¹⁸F]FDG PET/CT imaging on the same day. Diagnosis of each lung nodule was confirmed by histopathological examination of tissue specimens at surgery, or during clinical follow-up after the PET/CT studies. To assess the utility of the semi-quantitative evaluation method, the SUV_max was calculated of [¹¹C]4DST and [¹⁸F]FDG uptake by the lesion. Proliferative activities of each tumor as indicated by the immunohistochemical Ki-67 index was also estimated using surgical specimens of patients. Then the relationship between the SUV_max of both PET/CT and the Ki-67 index was examined. Furthermore, the relationship between the uptake of [¹¹C]4DST or [¹⁸F]FDG and the histopathological findings, the clinical stage, and the clinical outcome of patients were also assessed.

RESULTS

There was a positive linear relationship between the SUV_max of [¹¹C]4DST images and the Ki-67 index (Correlation coefficients = 0.68). The SUV_max of [¹¹C]4DST in the 26 lung nodules were 1.65 ± 0.40 for benign lesions, 3.09 ± 0.83 for adenocarcinomas (P < 0.001 between benign and adenocarcinoma), and 2.92 ± 0.58 for SqCCs (P < 0.001 between benign and SqCC). Whereas, the SUVmax of [¹⁸F]FDG were 2.38 ± 2.27 for benign lesions, 6.63 ± 4.24 for adenocarcinomas (n.s.), and 7.52 ± 2.84 for SqCCs (n.s.). The relationship between TNM tumor stage and the SUV_max of [¹¹C]4DST were 2.54 ± 0.37 for T1, 3.48 ± 0.57 for T2, and 4.17 ± 0.72 for T3 (P < 0.005 between T1 and T2, and P < 0.001 between T1 and T3). In comparison with the TNM pathological stage, SUVmax of [¹¹C]4DST were 2.63 ± 0.49 for stage I, 3.36 ± 0.23 for stage II, 3.40 ± 1.12 for stage III, and 4.65 for stage IV (P < 0.05 between stages I and II). In comparison of the clinical outcome, the SUV_max of [¹¹C]4DST were 2.72 ± 0.56 for the no recurrence (No Rec.) group, 3.10 ± 0.33 for the recurrence-free with adjuvant chemotherapy after the surgery (the No Rec. Adjv. CTx. group) and 4.66 ± 0.02 for the recurrence group (Rec. group) (P < 0.001 between the No Rec and Rec. groups, and P < 0.005 between the No Rec. Adjv. CTx. and Rec. groups).

CONCLUSIONS

PET/CT with [¹¹C]4DST is as feasible for imaging of lung tumors as [¹⁸F]FDG PET/CT. For diagnosing lung tumors, [¹¹C]4DST PET is useful in distinguishing benign nodules from malignancies. [¹¹C]4DST uptake in lung carcinomas is correlated with the proliferative activity of tumors, indicating a promising noninvasive PET imaging of DNA synthesis in malignant lung tumors.

Large scale clinico-genomic analyses among patients with BRAF-mutated non-small cell lung cancers (NSCLC) identified by nationwide genomic screening project (LC-SCRUM-Japan)

9590

Background: BRAF mutations are functionally classified into three groups, comprisingV600-mutant kinase-activating monomers (class I), kinase-activating dimers (class II), kinase-inactivating heterodimers (class III). The difference of clinical outcomes and concomitant genetic alterations among the three classes in non-small cell lung cancers (NSCLC) are unclear. Methods: We have prospectively analyzed NSCLC patients (pts) for cancer-related genes by a next-generation sequencing system, Oncomine™ Comprehensive Assay, in a large-scale genome screening project in Japan (LC-SCRUM-Japan). The clinical characteristics and outcomes of pts with BRAF-mutated non-squamous (non-sq) NSCLC were comparatively evaluated among the three classes of BRAF mutations. Results: A total of 5166 non-sq NSCLC pts were enrolled into the LC-SCRUM-Japan from 2015 to 2019. BRAF mutations were detected in 176 pts (3%). Among the 176 pts, 153 (87%) were classified into the three classes according to the mutation variants, including 65 (42%) into class I, 52 (34%) into class II and 36 (24%) into class III. The remaining 23 were not classified into any of the three classes. Compared with class I, class II or class III was significantly associated with smoking (P = 0.02 and < 0.01, respectively). Concomitant RAS mutations were significantly more frequent in class II and class III than in class I (P < 0.01 and = 0.04, respectively). The frequency of concomitant STK11 mutations was significantly higher in class III than in others (P < 0.01, respectively). There was no significant difference in the frequency of other oncogene and tumor suppressor gene mutations among the three classes. In the 1st-line platinum-containing chemotherapies for advanced or recurrent cases, median progression-free survival (mPFS) of class III pts was shorter than class I or class II pts (4.2, 11.5 and 4.8 months, I vs III; P < 0.01, II vs III; P = 0.06). In the treatment with 2nd-4th line PD-1/PD-L1 inhibitors, mPFS was not significantly different among the three classes. Overall survival of class III pts was significantly shorter than class I pts (11.9 vs 35.2 months, P = 0.03). Conclusions: Concomitant gene mutations and clinical features are largely different among the BRAF mutation classes. Especially in class III, concomitant RAS and STK11 mutations are more frequent and clinical outcomes were significantly less favorable. These results suggest the need of novel therapeutic strategy based on the mutation class for BRAF-mutated lung cancers.

Phase II study of gedatolisib for small-cell lung cancer (SCLC) patients (pts) with genetic alterations in PI3K/AKT/mTOR pathway based on a large-scale nationwide genomic screening network in Japan (EAGLE-PAT/LC-SCRUM-Japan)

9064

Background: Development of targeted therapy for SCLC based on a large-scale genomic screening is an innovative challenge. Gedatolisib is a highly potent dual inhibitor of PI3K/mTOR and is expected to have an effect for tumors with PI3K/AKT/mTOR pathway alterations. SCLC harboring this pathway alterations is rare. Thus, we conducted a phase II study based on a nationwide genomic screening network in Japan (LC-SCRUM-Japan) to develop novel targeted therapies. Methods: SCLC pts with targetable genetic alterations were screened at 154 institutions in Japan. A multicenter, single-arm phase II study was conducted to evaluate the efficacy and safety of gedatolisib in advanced SCLC pts with genetic alterations in the PI3K/AKT/mTOR pathway. The primary endpoint was objective response rate (ORR). The planned sample size was 19 (threshold and expected ORR of 20% and 50%, one-sided alpha of 5%, and power of 80%). Results: 930 SCLC pts were screened from July 2015 to January 2020. Targetable genetic alterations were identified in 148 pts (16%), including 53 PI3K/AKT/mTOR (6%), 81 MYC family (9%), 10 EGFR (1%) and 15 KRAS (2%). A total of 12 pts with genetic alterations in the PI3K/AKT/mTOR pathway (5 PIK3CA, 6 PTEN, and 1 AKT1 mutation) were enrolled in the phase II study. The median age was 67 years (range 58-79), 7 pts were male and 5 pts received 2 or more prior chemotherapy (range 1-4). The ORR was 0% and disease control rate was 25%. The median progression-free survival (PFS) was 0.9 months (95% CI, 0.4 to 3.0). The median overall survival was 5.8 months (95% CI, 1.1 to NR). Treatment-related G3 adverse events (hypertension, hypoalbuminemia, oral mucositis, ALT increased and creatinine increased) were observed in 4 pts. One patient with PTEN I8fs mutation had a long duration of stable disease (PFS; 6.7 months). Conclusions: This Large-scale nationwide genomic screening network was effective to identify rare targetable genetic alterations and had a potential role to develop targeted therapies in SCLC. This phase II study didn’t show promising clinical benefit of gedatolisib for advanced SCLC pts with genetic alterations in the PI3K/AKT/mTOR pathway. The safety profile of gedatolisib was similar to that reported previously. Clinical trial information: UMIN000020585.

Therapeutic impact of mutation subtypes and concomitant STK11 mutations in KRAS–mutated non-small cell lung cancer (NSCLC): A result of nationwide genomic screening project (LC-SCRUM-Japan)

9589

Background: KRAS mutations are one of the common oncogene drivers in non-small cell lung cancer (NSCLC), and the development of several targeted drugs for KRAS-mutated NSCLC is now ongoing. However, the clinical impact of KRAS mutation subtypes or concomitant other gene mutations in NSCLC patients (pts) remains unclear. Methods: In a nationwide genomic screening project (LC-SCRUM-Japan), we have prospectively analyzed lung cancer pts for genetic alterations and tumor mutation burden (TMB) by next-generation sequencing system, and for PD-L1 expression by immunohistochemistry (22C3 antibody). The therapeutic efficacy and survival of KRAS-mutated non-squamous (non-sq) NSCLC pts were evaluated using a clinico-genomic database of the LC-SCRUM-Japan. Results: A total of 5166 non-sq NSCLC pts enrolled from 2015 to 2019. KRAS mutations were detected in 794 pts (15%; G12C/G12D/G12V/G12A/G13X/others = 232/186/165/66/61/84). Among the 794 pts, TMB and PD-L1 expression were analyzed in 128 and 79, respectively, and 218 received PD-1/PD-L1 inhibitors (IO) after 1st-line chemotherapy. The median age was 66 years (range, 29-89). 142 pts (65%) were male and 172 (78%) were smokers. Concomitant STK11 mutations were detected in 33 pts (15%) with no difference in the mutation frequency among KRAS mutation subtypes. KRAS G12C was significantly associated with high TMB (≥ 10 mut/Mb) (p = 0.03), and KRAS G12C or G12V with high PD-L1 expression (≥ 50%) (p = 0.02). In pts who received IO, median progression-free survival (mPFS) was significantly longer in pts with KRAS G12C or G12V than in those with other KRAS mutations (4.7 vs 2.0 months, hazard ratio (HR) 0.58 [95%CI 0.43-0.78], p < 0.01). Among pts with KRAS G12C or G12V, mPFS of IO was significantly shorter in pts with concomitant STK11 mutations than in those without (1.8 vs. 5.7 months, HR 1.97 [95%CI 1.06-3.41], p = 0.02). These correlations were not observed in platinum-containing chemotherapy (Plt-CTx). There were also no significant differences in IO and Plt-CTx efficacies between with and without other concomitant mutations, such as TP53, RB1, CDKN2A and PTEN mutations. Conclusions: Non-sq NSCLC pts with KRAS G12C/V were more sensitive to IO therapies than those with other KRAS mutations, but KRAS G12C/V-positive pts with concomitant STK11 mutations were less sensitive than those without. These results could be highly informative in the development of novel targeted therapies for KRAS-mutated NSCLC.

Genetic profiling and the response to RET inhibitors in RET fusion positive non-small cell lung cancer (NSCLC) identified by international genomic screening project (LC-SCRUM-Asia)

9557

Background: RET fusions are targetable oncogenic drivers in 1 – 2 % of NSCLC, yet no RET inhibitors are approved. Selective RET inhibitors, such as LOXO-292 and BLU-667, are currently in development. The impact of co-occurring mutation on outcome in RET-TKI therapy remains largely unknown. Methods: In an international genome screening project in Asia (LC-SCRUM-Asia), 161 cancer-related genes have been analyzed by a next-generation sequencing (NGS) system, Oncomine™ Comprehensive Assay. The therapeutic efficacy and survival of RET fusion+ NSCLC were evaluated using a large-scale clinicogenomic database in the LC-SCRUM-Japan. Results: From Feb 2013 to Dec 2019, a total of 7177 patients with non-squamous NSCLC were enrolled. RET fusion were detected in 167 patients (2.3 %). Median age was 61 years (range: 29 - 85), 60 % were female, 61 % were never-smokers, 99 % had adenocarcinoma, and 78 % had stage IIIB/IV disease. Based on our database, the median overall survival was 37 months. 62 patients received RET inhibitor therapy. RET fusions was identified by NGS assay (KIF5B-RET: 75, CCDC6-RET: 30, Others: 2) in 107 patients. Co-occurring genomic alterations were detected in 62 (58 %) patients, the median number of co-mutations was 1 (range 0 - 4). The most common co-occurring mutations in tumor involved TP53 (31; 29 %), STK11 (6; 6 %), CDKN2A (5; 5 %) and TSC2 (5; 5 %). In 23 patients treated with RET inhibitor (unapproved drugs), there was a strong association between co-occurring mutation and time to treatment discontinuation (TTD) in RET inhibitor therapy; HR 2.75 (95%CI 1.71 - 15.6, P = 0.0096). Conclusions: RET rearrangements continue to represent a rare but high unmet need disease. Co-occurring mutation was significantly associated with shorter TTD. Our data is the largest cohort of advanced-stage RET fusion+ NSCLC profiled by NGS to date. Co-occurring mutation should be evaluated in the development of novel targeted therapies for RET fusion+ NSCLC.

Impact of large-scale nationwide genomic screening project for small cell lung cancer (LC-SCRUM-Japan)

8559

Background: A variety of genetic analyses have been performed in small cell lung cancer (SCLC), however the clinical relevance of them remains unclear. We prospectively analyzed clinical samples of small-cell lung cancer using a nationwide genomic screening project (LC-SCRUM-Japan). Methods: Submitted tumor samples were subjected to a next-generation sequencing (NGS) system, Oncomine™ Comprehensive Assay, enabling the simultaneous analysis of 143 (ver.1) or 161 (ver.3) cancer-related genes. Results: From July 2015 to January 2019, 707 SCLC patients had been enrolled. The median age was 68 years. 77% were male and 94% were smokers. Among 588 samples completed analysis, we identified high prevalence of inactivating TP53/RB1 mutations in 426 (72%) /194 (33%) of cases, respectively. MYC/MYCL1/MYCN amplifications were detected in 21 (4%) /30 (5%) /9 (2%) of cases, respectively. This NGS analysis also showed that 32 (5%) of cases had well-known genetic alterations in receptor tyrosine kinase genes: 9 EGFR mutations, 9 KRAS mutations and 14 FGFR1 copy number gains. Mutations in the PI3K pathway were detected in 44 (7%) of the tumors. Among them, 8 cases enrolled in the investigator-initiated phase II study of gedatolisib (UMIN 000020585). Survival data was available in 463 patients receiving platinum-based chemotherapy. Multivariate analysis revealed that the presence of PIK3CA mutation (HR; 2.56; 95% CI 1.19 – 5.52; p = 0.016) and MYCN amplification (HR; 4.36; 95% CI 1.91 – 9.97; p < 0.001) were significantly associated with unfavorable survival. The frequency of amplifications in MYC family genes was higher in the samples obtained ≥ 90 days after the first-line platinum-based chemotherapy (18.1%) than in those < 90 days (8.1%, p = 0.01), suggesting MYC family amplification as one of the resistance mechanisms. Conclusions: This large-scale nationwide screening system is helpful for identifying therapeutically relevant genetic alterations, prognostic prediction, and exploring resistance mechanism in SCLC. Updated screening results will be presented at the 2019 ASCO Annual Meeting. Clinical trial information: UMIN000018656.

Therapeutic and prognostic impacts of specific gene alterations for squamous cell lung cancer: A result of nationwide genome screening in Japan (LC-SCRUM-Japan)

9060

Background: Various gene alterations occur during the development of squamous cell lung cancer (SqLC), but specific gene alterations for SqLC and their clinical significance remain unknown. Methods: In a nationwide genome screening project (LC-SCRUM-Japan), we have prospectively analyzed lung cancer patients for genetic alterations using a next-generation sequencing (NGS) system, Oncomine Comprehensive Assay, and have established a large-scale clinico-genomic database. Results: Since February 2013 to December 2018, a total of 6692 lung cancer patients (686 SqLCs, 5360 non-squamous non-small cell lung cancers [Non-sq] and 646 small cell lung cancers [SCLCs]) had been enrolled in the LC-SCRUM-Japan. The success rate of the NGS assay was 91%. Of 639 SqLCs analyzed, 274 (48%) had potentially targetable gene alterations, including 77 NFE2L2 (encoding NRF2) mut, 50 PIK3CA mut, 46 FGFR1 amp, 40 EGFRmut/amp, 36 PTEN mut, 23 KRAS mut, 6 AKT1 mut, 6 MET ex14skip, 5 ALK fusions, 2 FGFR3 fusions. Among the alterations detected, NFE2L2 mut and FGFR1 amp were significantly frequent in SqLC than Non-sq or SCLC (NFE2L2, 12.1% vs. 1.0% vs. 1.3%; p < 0.001, and FGFR1, 7.2% vs. 1.1% vs. 3.4%; p < 0.001). In advanced SqLC patients who received platinum-containing chemotherapies, the median progression-free survival (mPFS) was significantly shorter in NFE2L2-mutated patients (NRF2-type) than NFE2L2/FGFR1-negative patients (nonNF-type) (3.8 [95%CI, 2.9-5.1] vs. 4.5 [95%CI, 3.8-5.4] months, p = 0.03), and similarly, the mPFS of FGFR1-amplified patients (FGFR1-type) (3.5 months [95%CI, 1.5-4.9]) tended to be shorter than that of nonNF-type (p = 0.07), although the response rates were equivalent among the three types. NRF2-type also showed shorter overall survival (OS) than nonNF-type (median OS, 10.4 [95%CI, 6.9-22.3] vs. 16.6 [95%CI, 13.6-21.7] months, p = 0.10). Therapeutic efficacy of nivolumab or pembrolizumab was not different among these types in the current follow-up data. Conclusions: Our large scale genome screening identified specific gene alterations for SqLC and the alterations were associated with a less efficacy of chemotherapy and worse prognosis, suggesting the need for the development of genotype-directed therapeutic strategy for SqLC patients.

AMPK activation induced in pemetrexed-treated cells is associated with development of drug resistance independently of target enzyme expression

Pemetrexed (PEM) inhibits DNA and RNA synthesis and is currently one of the first‐line agents for mesothelioma. PEM suppresses the activities of several enzymes involved in purine and pyrimidine synthesis, and elevated activity of these enzymes in tumors is often linked with resistance to PEM. The agent also stimulates AMP‐activated protein kinase (AMPK) and consequently influences the mammalian target of rapamycin complex 1 (mTORC1) pathways. Nevertheless, it remains unclear whether PEM resistance is linked to the AMPK or mTORC1 pathways. Here, we established two independent PEM‐resistant mesothelioma cell lines in which expression of the PEM‐target enzymes was not elevated, and found that levels of phosphorylated AMPK and p70S6K and, to a lesser extent, levels of phosphorylated AKT and p53, were increased in these cells as compared with the respective parent cells. PEM stimulation also augmented phosphorylation of AMPK, p70S6K, AKT and p53 in most cases. An AMPK activator increased phosphorylation and PEM resistance in parental cells, and the inhibitor decreased the resistance of PEM‐resistant cells. In contrast, inhibitors for p70S6K and AKT did not influence PEM resistance; furthermore, increased levels of endogenous p53 did not affect PEM sensitivity. These data collectively indicate that constitutive activation of AMPK is associated with PEM resistance, and that this is unconnected with elevated DNA and RNA synthesis.

Japanese subgroup analysis of a phase III study of S-1 versus docetaxel in non-small cell lung cancer patients after platinum-based treatment: EAST-LC

Introduction

The East Asia S-1 Trial in Lung Cancer (EAST-LC) was a randomized phase III study conducted in East Asia that demonstrated the non-inferiority of S-1 to docetaxel in previously treated patients with advanced non-small cell lung cancer (NSCLC). Here, we reported the results of the Japanese subgroup treated with docetaxel 60 mg/m², the standard dosage in Japan.

Patients and methods

Patients were randomized 1:1 to receive either S-1 or docetaxel. The primary endpoint was overall survival (OS); the secondary endpoints included progression-free survival (PFS), response rate (RR), quality of life (QOL), and safety.

Results

Patient characteristics in the Japanese subgroup (n = 724) were similar to those in the overall EAST-LC population. Median OS was 13.4 months in the S-1 group and 12.6 months in the docetaxel group. In pemetrexed-pretreated patients, OS with S-1 was similar to that with docetaxel. Median PFS was 2.9 and 3.0 months in the S-1 and docetaxel groups, respectively. RR was 9.4% and 10.3% in the S-1 and docetaxel groups, respectively. The QOL of patients treated with S-1 was better compared with that of patients treated with docetaxel. Decreased appetite and diarrhea were more common in the S-1 group, whereas the frequency of neutropenia and febrile neutropenia was markedly higher in the docetaxel group.

Conclusions

This Japanese subgroup analysis showed that S-1 had similar efficacy to docetaxel in patients with previously treated advanced NSCLC. These results are similar to those of the overall EAST-LC population.

Electronic supplementary material

The online version of this article (10.1007/s10147-019-01396-z) contains supplementary material, which is available to authorized users.

A p53-stabilizing agent, CP-31398, induces p21 expression with increased G2/M phase through the YY1 transcription factor in esophageal carcinoma defective of the p53 pathway

Restoration of p53 functions is one of the therapeutic strategies for esophageal carcinoma which is often defective of the p53 pathway. We examined effects of CP-31398 which potentially increased expression of wild-type p53 or converted mutated p53 to the wild-type. We used 9 kinds of human squamous esophageal carcinoma cells with different p53 genotypes and examined expression of p53 and the related molecules in CP-31398-treated cells. Cisplatin, a DNA damaging agent, induced cleavages of PARP and caspase-3 without increase of p53 levels, indicating that the p53 down-stream pathway was disrupted in these cells. CP-31398 induced growth retardation but the cytotoxic effects were irrelevant to p53 genotype. CP-31398 influenced expression of p53 and the downstream molecules in a cell-dependent manner, but constantly increased p21 expression at the transcriptional level with decreased YY1 expression. Knockdown experiments with siRNA demonstrated that the CP-31398-mediated p21 up-regulation was unrelated with p53 expression but was associated with YY1 expression. We also showed that CP-31398-induced cell cycle changes including increase of G2/M populations was attributable to the up-regulated p21. These data collectively indicated that CP-31398 augmented endogenous p21 levels and induced cell cycle changes through regulation of YY1, and that YY1 was a novel target of CP-31398 in p53 dysfunctional cells.

Ceritinib Treatment for Carcinomatous Meningitis with a Secondary Mutation at I1171T in Anaplastic Lymphoma Kinase

The mechanisms underlying anaplastic lymphoma kinase (ALK) resistance have not been well investigated in clinical practice. We herein report the case of a lung cancer patient with carcinomatous meningitis who had an ALK I1171T resistance mutation revealed by direct DNA sequencing of the cerebrospinal fluid after treatment with cytotoxic chemotherapy, crizotinib, and alectinib. I1171T is considered to be sensitive to ceritinib. Although ceritinib was not effective initially, we chose ceritinib again after whole-brain radiotherapy and ventriculoperitoneal shunting. Although the response duration was short, spinal magnetic resonance imaging revealed a marked response. The identification of an acquired ALK resistance mutation will aid in choosing the optimum sequence therapy.

Heat shock protein 90 inhibitors augment endogenous wild-type p53 expression but down-regulate the adenovirally-induced expression by inhibiting a proteasome activity

Heat shock protein 90 (HSP90) inhibitors suppressed MDM4 functions which mediated p53 ubiquitination, and blocked a chaperon function which influenced expression of the client proteins. We examined cytotoxic effects of the inhibitors, 17-allylamino-17-demetheoxygeldanamycin (17-AAG) and 17-dimethylaminoethylamino-17-demethoxy-geldanamycin (17-DMAG), on mesothelioma and investigated combinatory effects of the inhibitors and adenoviruses expressing the wild-type p53 gene (Ad-p53). A majority of mesothelioma lacks p14 and p16 expression, which leads to defective p53 pathway despite bearing the wild-type p53 genotype. The HSP90 inhibitors up-regulated endogenous wild-type p53 expression and induced cell death. Furthermore, the inhibitors increased the endogenous p53 levels that were induced by cisplatin. Nevertheless, the HSP90 inhibitors suppressed Ad-p53-induced exogenous p53 expression primarily at a posttranscriptional level and inhibited the Ad-p53-mediated cell death. HSP90 inhibitors suppressed ubiquitination processes which were involved in p53 degradation, but a proteasome inhibitor, MG-132, prevented the HSP90 inhibitors-induced p53 down-regulation. In contrast, an inhibitor for HSP70 with a chaperon function, pifithrin-μ, did not produce the p53 down-regulation. The HSP90 inhibitors did not suppress expression of Ad receptor molecules but rather increased expression of green fluorescence protein transduced by the same Ad vector. These data collectively indicated that an HSP90 inhibitor possessed a divalent action on p53 expression, as an activator for endogenous wild-type p53 through inhibited ubiquitination and a negative regulator of exogenously over-expressed p53 through the proteasome pathway.

Augmented expression of cardiac ankyrin repeat protein is induced by pemetrexed and a possible marker for the pemetrexed resistance in mesothelioma cells

Background

Pemetrexed (PEM) is an anti-cancer agent targeting DNA and RNA synthesis, and clinically in use for mesothelioma and non-small cell lung carcinoma. A mechanism of resistance to PEM is associated with elevated activities of several enzymes involved in nucleic acid metabolism.

Methods

We established two kinds of PEM-resistant mesothelioma cells which did not show any increase of the relevant enzyme activities. We screened genes enhanced in the PEM-resistant cells with a microarray analysis and confirmed the expression levels with Western blot analysis. A possible involvement of the candidates in the PEM-resistance was examined with a WST assay after knocking down the expression with si-RNA. We also analyzed a mechanism of the up-regulated expression with agents influencing AMP-activated protein kinase (AMPK) and p53.

Results

We found that expression of cardiac ankyrin repeat protein (CARP) was elevated in the PEM-resistant cells with a microarray and Western blot analysis. Down-regulation of CARP expression with si-RNA did not however influence the PEM resistance. Parent and PEM-resistant cells treated with PEM increased expression of CARP, AMPK, p53 and histone H2AX. The CARP up-regulation was however irrelevant to the p53 genotypes and not induced by an AMPK activator. Augmented p53 levels with nutlin-3a, an inhibitor for p53 degradation, and DNA damages were not always associated with the enhanced CARP expression.

Conclusions

These data collectively suggest that up-regulated CARP expression is a potential marker for development of PEM-resistance in mesothelioma and that the PEM-mediated enhanced expression is not directly linked with immediate cellular responses to PEM.

Electronic supplementary material

The online version of this article (10.1186/s12935-017-0493-8) contains supplementary material, which is available to authorized users.

An image cytometric technique is a concise method to detect adenoviruses and host cell proteins and to monitor the infection and cellular responses induced

Background

Genetically modified adenoviruses (Ad) with preferential replications in tumor cells have been examined for a possible clinical applicability as an anti-cancer agent. A simple method to detect viral and cellular proteins is valuable to monitor the viral infections and to predict the Ad-mediated cytotoxicity.

Methods

We used type 5 Ad in which the expression of E1A gene was activated by 5′-regulatory sequences of genes that were augmented in the expression in human tumors. The Ad were further modified to have the fiber-knob region replaced with that derived from type 35 Ad. We infected human mesothelioma cells with the fiber-replaced Ad, and sequentially examined cytotoxic processes together with an expression level of the viral E1A, hexon, and cellular cleaved caspase-3 with image cytometric and Western blot analyses.

Results

The replication-competent Ad produced cytotoxicity on mesothelioma cells. The infected cells expressed E1A and hexon 24 h after the infection and then showed cleavage of caspase-3, all of which were detected with image cytometry and Western blot analysis. Image cytometry furthermore demonstrated that increased Ad doses did not enhance an expression level of E1A and hexon in an individual cell and that caspase-3-cleaved cells were found more frequently in hexon-positive cells than in E1A-positive cells. Image cytometry thus detected these molecular changes in a sensitive manner and at a single cell level. We also showed that an image cytometric technique detected expression changes of other host cell proteins, cyclin-E and phosphorylated histone H3 at a single cell level.

Conclusions

Image cytometry is a concise procedure to detect expression changes of Ad and host cell proteins at a single cell level, and is useful to analyze molecular events after the infection.

Electronic supplementary material

The online version of this article (10.1186/s12985-017-0888-0) contains supplementary material, which is available to authorized users.

Cytotoxicity of replication-competent adenoviruses powered by an exogenous regulatory region is not linearly correlated with the viral infectivity/gene expression or with the E1A-activating ability but is associated with the p53 genotypes

Background

Replication-competent adenoviruses (Ad) produced cytotoxic effects on infected tumors and have been examined for the clinical applicability. A biomarkers to predict the cytotoxicity is valuable in a clinical setting.

Methods

We constructed type 5 Ad (Ad5) of which the expression of E1A gene was activated by a 5′ regulatory sequences of survivin, midkine or cyclooxygenase-2, which were highly expressed in human tumors. We also produced the same replication-competent Ad of which the fiber-knob region was replaced by that of Ad35 (AdF35). The cytotoxicity was examined by a colorimetric assay with human tumor cell lines, 4 kinds of pancreatic, 9 esophageal carcinoma and 5 mesothelioma. Ad infectivity and Ad-mediated gene expression were examined with replication-incompetent Ad5 and AdF35 which expressed the green fluorescence protein gene. Expression of cellular receptors for Ad5 and AdF35 was also examined with flow cytometry. A transcriptional activity of the regulatory sequences was investigated with a luciferase assay in the tumor cells. We then investigated a possible correlation between Ad-mediated cytotoxicity and the infectivity/gene expression, the transcriptional activity or the p53 genotype.

Results

We found that the cytotoxicity was greater with AdF35 than with Ad5 vectors, but was not correlated with the Ad infectivity/gene expression irrespective of the fiber-knob region or the E1A-activating transcriptional activity. In contrast, replication-competent Ad produced greater cytotoxicity in p53 mutated than in wild-type esophageal carcinoma cells, suggesting a possible association between the cytotoxicity and the p53 genotype.

Conclusions

Sensitivity to Ad-mediated cytotoxic activity was linked with the p53 genotype but was not lineally correlated with the infectivity/gene expression or the E1A expression.

Electronic supplementary material

The online version of this article (10.1186/s12885-017-3621-x) contains supplementary material, which is available to authorized users.

A nationwide genomic screening project for small cell lung cancer in Japan (LC-SCRUM-Japan)

8518

Background: Recent genomic studies of small-cell lung cancer (SCLC) have identified promising therapeutic strategies for this highly lethal form of cancer. Thus, we established a nationwide lung cancer genomic screening project in Japan (LC-SCRUM-Japan) to identify SCLC patients harboring targetable genomic alterations for the development of novel targeted therapies. Methods: The samples were subjected to a next-generation sequencing (NGS) system, Oncomine™ Comprehensive Assay, enabling the simultaneous analysis of 143 cancer-related genes. Results: As of December 2016, 133 institutions were participating and 295 patients had been enrolled. The median age was 69 years (range, 14-90 years). Two hundred seventeen (74%) were male and most patients (93%) were smokers. Among 268 samples completed analysis, we identified high prevalence of inactivating TP53/RB1 mutations in 198 (74%) /82 (31) of cases, respectively. MYC/MYCL1/MYCN amplifications were detected in 10 (4%) /13 (5) /4 (1) of cases, respectively. The NGS analysis also showed that 62 (23%) of cases had at least one targetable genomic alterations, including 7 EGFR activating mutations (3%), 6 KRAS activating mutations (2%), and 8 FGFR1 copy number gains (3%). No case was positive for ALK or ROS1 fusions. Never-smokers (71% vs. 5%, p<0.001) were significantly frequent in the EGFR type compared to the others. The KRAS type showed significantly poor progression free survival (PFS) of the first-line chemotherapy compared to the others (median PFS 1.2 vs. 6.1 months, respectively; p<0.001). Mutations in the PI3K/AKT/mTOR pathway were detected in 22 (8%) of the tumors: 10 PIK3CA mutations (4%), 9 PTEN inactivating mutations (3%) and 3 TSC2 inactivating mutations (1%). Among them, a case with PTEN mutation was enrolled in the investigator initiated phase II study of gedatolisib named “EAGLE-PAT” (UMIN 000020585). Conclusions: We identified a series of targetable genomic alterations in SCLC. This nationwide screening system is helpful for identifying targetable genomic alterations and their clinical features, contributing to the development of novel targeted therapies for this disease. Updated screening results will be presented at the 2017 ASCO Annual Meeting.

Contribution to the development of precision medicine and clinical utility of nationwide lung cancer genomic screening in Japan (LC-SCRUM-Japan)

e20659

Background: A nationwide lung cancer genomic screening project in Japan (LC-SCRUM-Japan) was established in 2013. The objective of this project is to contribute to the development of precision medicine through the genomic biomarker screening, leading to improvement of patient prognoses. Methods: Advanced non-squamous non-small cell lung cancer (non-sq NSCLC) without EGFR mutations were eligible for inclusion. The tumors were analyzed for ALK/ROS1/RET fusions using RT-PCR and FISH. Since March 2015, the samples were further subjected to a next-generation sequencing (NGS) system, Oncomine™ Comprehensive Assay. Since April 2016, MET exon 14 skipping ( MET skip) was also analyzed by RT-PCR. The clinical course and prognosis of patients were monitored every 6 month. Results:As of December, 2016, 3206 patients from 242 institutions across Japan had been enrolled. The success rates for RT-PCR and NGS were 94% (3020/3206) and 91% (1523/1666), respectively. ALK/ROS1/RET fusions were detected in 65 (2%)/116 (4%)/84 (3%), respectively. The NGS assay showed that 753 tumors (49%) had actionable gene alterations, including 184 KRAS (12%), 92 ERBB2 (6%), 73 BRAF (5%), 42 PIK3CA (3%), 11 NRAS (0.7%), 7 MAP2K1 mutations (0.5%) and 5 FGFR2/3 fusions (0.3%). ERBB2/MET/FGFR1 amplifications were also detected in 36 (3%)/28 (2%)/11 (1%) cases, respectively. The frequency of MET skip was 4% (26/597). Through this screening, a total of 576 genotype-matched patients to clinical trials of targeted agents were identified, and 111 of them (19%) were enrolled into the trials. Of the 1523 patients analyzed by NGS, the monitoring data were available in 870 (57%). The patients with actionable gene alterations who received targeted agents (n = 100) showed significantly longer survivals than those who did not receive targeted agents (n = 358) or the patients without actionable gene alterations (n = 412) (median survival [95%CI], 5.1 [3.0-N.R.] vs. 3.3 [2.1-5.9] vs. 2.3 [1.9-2.9] years, respectively; p < 0.01). Conclusions: Our nationwide screening contributes to the development of precision medicine for non-sq NSCLC and could improve patient prognoses.

Clinical features of squamous cell lung cancer with targetable gene alterations in a nationwide genomic screening network in Japan (LC-SCRUM-Japan)

9057

Background: Molecular-targeted therapies for precision medicine in squamous cell lung cancer (SqLC) have not yet been established. To identify precise patients for targeted therapies and to reveal their clinical characteristics, we have operated clinical sequencing of advanced SqLCs in our nationwide genomic screening project in Japan (LC-SCRUM-Japan) since March 2015. Methods: As of December 2016, 190 institutions across Japan were participating and 263 advanced SqLC patients had been enrolled in this project. Submitted tumor samples were subjected to a next-generation sequencing system, Oncomine™ Comprehensive Assay, enabling the simultaneous analysis of 143 cancer-related genes. Results: The median age of the 263 patients was 74 years (range, 27-87 years). Two hundred thirty (87%) were male and most patients (97%) were smokers. Among 211 available samples, potentially targetable gene alterations were detected in 58 (27%). Based on these gene alterations, the patients were subdivided into 4 groups, consisting of 25 (12%) with genetic alterations of FGFR family (FGFR type; 23 FGFR1 amplifications, 1 FGFR2 amplification and 1 FGFR3 fusion), 20 (9%) with genetic alterations of the PI3K pathway (PI3K type; 10 PIK3CA mutations, 8 PTEN mutations and 2 AKT mutations), 15 (7%) with other oncogene alterations (KRAS/EGFR/ALK type; 10 KRAS mutations, 3 EGFR mutations and 2 ALK fusions) and others. Comparative analyses of clinical characteristics between the 4 types showed that brain metastases were significantly more frequent in the FGFR type than the others (24% vs. 5%, p = 0.0007), and females (40% vs. 11%, p = 0.0009) and never-smokers (21% vs. 3%, p = 0.0004) were significantly frequent in the KRAS/EGFR/ALK type compared to the others. The prognostic significance of these genetic alterations has not yet been evaluated because of short follow-up time (median, 8.5 months). Conclusions: A series of potentially targetable gene alterations have been identified in SqLC patients. The SqLC patients had distinct clinical features according to the molecular subtypes, and genotype-directed therapeutic strategy should be developed for the individual subtypes.

Metformin produces growth inhibitory effects in combination with nutlin-3a on malignant mesothelioma through a cross-talk between mTOR and p53 pathways

Background

Mesothelioma is resistant to conventional treatments and is often defective in p53 pathways. We then examined anti-tumor effects of metformin, an agent for type 2 diabetes, and combinatory effects of metformin and nutlin-3a, an inhibitor for ubiquitin-mediated p53 degradation, on human mesothelioma.

Methods

We examined the effects with a colorimetric assay and cell cycle analyses, and investigated molecular events in cells treated with metformin and/or nutlin-3a with Western blot analyses. An involvement of p53 was tested with siRNA for p53.

Results

Metformin suppressed cell growth of 9 kinds of mesothelioma including immortalized cells of mesothelium origin irrespective of the p53 functional status, whereas susceptibility to nutlin-3a was partly dependent on the p53 genotype. We investigated combinatory effects of metformin and nutlin-3a on, nutlin-3a sensitive MSTO-211H and NCI-H28 cells and insensitive EHMES-10 cells, all of which had the wild-type p53 gene. Knockdown of p53 expression with the siRNA demonstrated that susceptibility of MSTO-211H and NCI-H28 cells to nutlin-3a was p53-dependent, whereas that of EHMES-10 cells was not. Nevertheless, all the cells treated with both agents produced additive or synergistic growth inhibitory effects. Cell cycle analyses also showed that the combination increased sub-G1 fractions greater than metformin or nutlin-3a alone in MSTO-211H and EHMES-10 cells. Western blot analyses showed that metformin inhibited downstream pathways of the mammalian target of rapamycin (mTOR) but did not activate the p53 pathways, whereas nutlin-3a phosphorylated p53 and suppressed mTOR pathways. Cleaved caspase-3 and conversion of LC3A/B were also detected but it was dependent on cells and treatments. The combination of both agents in MSTO-211H cells rather suppressed the p53 pathways that were activated by nutrin-3a treatments, whereas the combination rather augmented the p53 actions in NCI-H28 and EHMES-10 cells.

Conclusion

These data collectively indicated a possible interactions between mTOR and p53 pathways, and the combinatory effects were attributable to differential mechanisms induced by a cross-talk between the pathways.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-017-3300-y) contains supplementary material, which is available to authorized users.

Retrospective analysis of lung cancer patients treated with supportive care alone

BACKGROUND

It is not uncommon for patients with lung cancer to receive supportive care alone. However, the clinical characteristics of these patients have not been fully studied. We conducted a retrospective study to identify the clinical characteristics of definitive lung cancer patients treated with supportive care alone.

METHODS

We retrospectively analyzed the percentage of and reasons for definitive lung cancer patients treated with supportive care alone at a regional cancer center. We also investigated the histological diagnostic approaches, palliative therapy types, primary treatment locations after hospital consultation, and places of death.

RESULTS

A total of 1,223 patients were histologically diagnosed as having lung cancer between 2011 and 2014. Of these, 160 (13%) patients were treated with supportive care alone. The primary reason for treatment with supportive care alone was a poor performance status (PS) in almost half of the patients. Overall, 40% of the patients received supportive care at home, and 17% were admitted to a palliative care unit (PCU). Death occurred at home for 17% of the patients and in the PCU for 42% of the patients.

CONCLUSION

This study revealed that 13% of histologically proven lung cancer patients were treated with supportive care alone, mostly because of a poor PS. Only 40% of these patients received home care, suggesting the need for a more accessible home care system for patients and their families.

Combination of a third generation bisphosphonate and replication-competent adenoviruses augments the cytotoxicity on mesothelioma

Background

Approximately 80 % of mesothelioma specimens have the wild-type p53 gene, whereas they contain homozygous deletions in the INK4A/ARF locus that encodes p14^ARF and the 16^INK4A genes. Consequently, the majority of mesothelioma is defective of the p53 pathways. We examined whether zoledronic acid (ZOL), a third generation bisphosphonate, and adenoviruses with a deletion of the E1B-55kD gene (Ad-delE1B55), which augments p53 levels in the infected tumors, could produce combinatory anti-tumor effects on human mesothelioma cells bearing the wild-type p53 gene.

Methods

Cytotoxicity of ZOL and Ad-delE1B55 was assessed with a WST assay. Cell cycle changes were tested with flow cytometry. Expression levels of relevant molecules were examined with western blot analysis to investigate a possible mechanism of cytotoxicity. Furthermore, the expressions of Ad receptors on target cells and infectivity were estimated with flow cytometry. Viral replication was assayed with the tissue culture infection dose method.

Results

A combinatory use of ZOL and Ad-delE1B55 suppressed cell growth and increased sub-G1 or S-phase populations compared with a single agent, depending on cells tested. The combinatory treatment up-regulated p53 levels and subsequently enhanced the cleavage of caspase-3, 8, 9 and poly (ADP-ribose) polymerase, but expression of molecules involved in autophagy pathways were inconsistent. ZOL-treated cells also increased Ad infectivity with a dose-dependent manner and augmented Ad replication although the expression levels of integrin molecules, one of the Ad receptors, were down-regulated.

Conclusions

These findings indicated that ZOL and Ad-delE1B55 achieved combinatory anti-tumor effects through augmented apoptotic pathways or increased viral replication.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-016-2483-y) contains supplementary material, which is available to authorized users.

An intrapleural administration of zoledronic acid for inoperable malignant mesothelioma patients: a phase I clinical study protocol

Background

The third generation of bisphosphonates is clinically in use for patients of osteoporosis or malignancy-linked hypercalcemia. The agents can also produce anti-tumor effects on bone metastasis of several types of tumors. We recently found that one of the agents achieved cytotoxicity to mesothelioma in vitro and in an orthotopic animal model. Mesothelioma is resistant to a number of chemotherapeutic agents, and suppression of local tumor growth is beneficial to the patients since metastasis to extra-thoracic organs is relatively infrequent until a late stage.

Methods/design

We demonstrated in an orthotopic mouse model that an intrapleural but not intravenous injection of zoledronic acid, one of the third generation bisphosphonates, at a clinically equivalent dose suppressed the tumor growth. Nevertheless, a high concentration of zoledronic acid administrated in the pleural cavity produced pleural adhesion. We also showed that zoledronic acid produced synergistic cytotoxic effects with cisplatin, the first-line chemotherapeutic agent for mesothelioma. We then planned to conduct a phase I clinical study to investigate any adverse effects and a possible clinical benefits produced by an intrapleural administration of zoledronic acid to mesothelioma patients who became resistant to the first-line chemotherapeutic agents. The clinical trial is a dose escalation study starting with 0.4, 1, 4, 8 and 16 mg per person since safety of administration of zoledronic acid into the pleural cavity remains unknown. Each dose group consists of three persons and the protocol allows to repeat administration of the same dose into the pleural cavity at a 4-weeks interval.

Discussion

We will conduct a possible combinatory study of intrapleural administration of zoledronic acid and systemic administration of the first-line agent to a chemotherapy-naïve patient based on the maximum tolerance dose of zoledronic acid determined by the present clinical trial. We propose that administration of bisphosphonates in a closed cavity is a treatment strategy for tumors developed in the cavity probably through the direct cytotoxic activity.

Trial registration: UMIN clinical trials registry, Japan. Register ID: UMIN8093.

Spectrum Analysis of Endobronchial Ultrasound Radiofrequency of Lymph Nodes in Patients With Lung Cancer

OBJECTIVE

The aim of this study was to analyze the spectral features of the radiofrequency of lymph nodes during endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) and to determine its diagnostic value for detecting metastatic nodes in patients with lung cancer.

METHODS

Ultrasound spectrums of lymph nodes during EBUS-TBNA were retrospectively analyzed. A linear regression of frequency spectrum and the ultrasonic spectral parameters midband-fit, slope, and intercept were calculated. Mean values for these parameters within lymph nodes were computed. The cutoff values for each parameter for distinguishing metastatic vs benign lymph nodes were first determined within the training set; these cutoff values were then applied to the testing set for validation.

RESULTS

Overall, 362 lymph nodes (112 metastatic, 250 benign) were analyzed as the training set, and 284 lymph nodes (74 metastatic, 210 benign) were evaluated as the testing set. In the training set, all of the parameters showed a significant difference between metastatic and benign lymph nodes (P < .001). The metastatic nodes tended to show low midband-fit, high slope, and low intercept. When midband-fit and intercept were combined, the diagnostic accuracy was maximized in the training set. In the testing set, the combination of intercept and slope produced the highest diagnostic accuracy, with the following outcomes: sensitivity, 79.7%; specificity, 84.3%; diagnostic accuracy, 83.1%; positive predictive value, 64.1%; and negative predictive value, 92.2%.

CONCLUSIONS

Metastatic lymph nodes possess unique ultrasonic spectrum features, and spectrum analysis can be used as a novel diagnostic tool for differentiating between benign and malignant nodes in patients with lung cancer.

Administration of DNA Encoding the Interleukin-27 Gene Augments Antitumour Responses through Non-adaptive Immunity

DNA-mediated immunization of a tumour antigen is a possible immunotherapy for cancer, and interleukin (IL)-27 has diverse functions in adaptive immunity. In this study, we examined whether IL-27 DNA administration enhanced antitumour effects in mice vaccinated with DNA encoding a putative tumour antigen, β-galactosidase (β-gal). An intramuscular injection of cardiotoxin before DNA administration facilitated the exogenous gene expression. In mice received β-gal and IL-27 DNA, growth of β-gal-positive P815 tumours was retarded and survival of the mice was prolonged. Development of β-gal-positive Colon 26 tumours was suppressed by vaccination of β-gal DNA and further inhibited by additional IL-27 DNA administration or IL-12 family cytokines. Nevertheless, a population of β-gal-specific CD8(+) T cells did not increase, and production of anti-β-gal antibody was not enhanced by IL-27 DNA administration. Spleen cells from mice bearing IL-27-expressing Colon 26 tumours showed greater YAC-1-targeted cytotoxicity although CD3(-)/DX5(+) natural killer (NK) cell numbers remained unchanged. Recombinant IL-27 enhanced YAC-1-targeted cytotoxicity of IL-2-primed splenic NK cells and augmented a phosphorylation of signal transducer and activator of transcription 3 and an expression of perforin. These data collectively indicate that IL-27 DNA administration activates NK cells and augments vaccination effects of DNA encoding a tumour antigen through non-adaptive immune responses.

Replication-competent adenoviruses with the type 35-derived fiber-knob region achieve reactive oxygen species-dependent cytotoxicity and produce greater toxicity than those with the type 5-derived region in pancreatic carcinoma

Pancreatic carcinoma is relatively resistant to chemotherapy and cell death induced by replication of adenoviruses (Ad) can be one of the therapeutic options. Transduction efficacy of conventional type 5 Ad (Ad5) is however low and the cytotoxic mechanism by replication-competent Ad was not well understood. We constructed replication-competent Ad5 of which the E1A promoter region was replaced with a transcriptional regulatory region of the midkine, the survivin or the cyclooxygenase-2 gene, all of which were expressed at a high level in human tumors. We also prepared replication-competent Ad5 that were activated with the same region but had the type 35 Ad-derived fiber-knob region (AdF35) to convert the major cellular receptor for Ad infection from the coxsackie adenovirus receptor to CD46 molecules. Replication-competent AdF35 that were activated with the exogenous region produced cytotoxic effects on human pancreatic carcinoma cells greater than the corresponding Ad5 bearing with the same regulatory region. Cells infected with the AdF35 showed cytopathic effects and increased sub-G1 fractions. Caspase-9, less significantly caspase-8 and poly (ADP-ribose) polymerase, but not caspase-3 was cleaved and expression of molecules involved in autophagy and caspase-independent cell death pathways remained unchanged. Nevertheless, H2A histone family member X molecules were phosphorylated, and N-acetyl-L-cystein, an inhibitor for reactive oxygen species, suppressed the AdF35-mediated cytotoxicity. These data indicated a novel mechanism of Ad-mediated cell death and suggest a possible clinical application of the fiber-knob modified Ad.

A combinatory use of adenoviruses expressing melanoma differentiation-associated gene-7 and replication-competent adenoviruses produces synergistic effects on pancreatic carcinoma cells

Type 5 adenoviruses expressing mda-7 gene (Ad-mda-7) induced cell death in various kinds of human tumors, but pancreatic carcinoma cells were relatively resistant to Ad-mda-7-mediated cytotoxicity. We then examined whether infection of Ad-mda-7 together with replication-competent Ad produced combinatory cytotoxic effects. We prepared replication-competent Ad, defective of the E1B55kDa gene or activated by a transcriptional regulatory region of the midkine or the survivin gene of which the expression was up-regulated in human tumors. Type 5 Ad bearing the exogenous regulatory region were further modified by replacing the fiber-knob region with that of type 35 Ad. Pancreatic carcinoma cells were infected with replication-incompetent Ad-mda-7 and the replication-competent Ad. Combinatory effects were examined with the CalcuSyn software and cell cycle analyses. Ad-mda-7 and the replication-competent Ad achieved cytotoxicity to pancreatic carcinoma. A combinatory use of Ad-mda-7 and either Ad defective of the E1B55kDa gene or Ad activated by the regulatory region produced synergistic cytotoxic effects. Cell cycle analyses demonstrated that the combination increased sub-G1 populations. These data collectively suggest that expression of MDA-7 augments cytotoxicity of replication-competent Ad and achieves adjuvant effects on Ad-mediated cell death.

A clinical protocol to inhibit the HGF/c-Met pathway for malignant mesothelioma with an intrapleural injection of adenoviruses expressing the NK4 gene

Background

The hepatocyte growth factor (HGF)/c-Met signal pathway is up-regulated in human mesothelioma and suppression of the HGF/c-Met signaling with a competitive inhibitor, NK4 homologous to HGF in the structure, produced anti-tumor effects to mesothelioma in a preclinical study. Mesothelioma is highly resistant to a number of chemotherapeutic agents but distant metastasis to extra-thoracic organs is relatively infrequent until the late stage.

Methods/design

We planned to conduct a clinical study of gene therapy with adenoviruses expressing the NK4 gene (Ad-NK4) to control the local tumor growth. The study is designed to inject Ad-NK4 into the intrapleural cavity with a dose escalation manner from 10¹⁰ to 10¹² virus particles per patient and to examine safety and possible clinical benefits. The clinical investigation is a first-in-human trial to use the NK4 gene and to block the HGF/c-Met pathway with gene medicine. We conducted in vivo animal experiments to examine the safety level as one of the preclinical studies, and showed that Ad DNA administered in the pleural cavity was detected in many parenchymal organs. Biochemical and pathological analyses showed that liver damages were the major adverse effects with little toxicity to other organs. These studies firstly demonstrated biodistribution and transgene expression after an intrapleural injection of Ad vectors in an animal study, which contrasts with an intravenous injection showing relatively rapid clearance of Ad-NK4.

Discussion

The clinical study can also provide information regarding production of NK4 protein and antibody against NK4, and inhibition levels of the HGF/c-Met pathway by detecting dephosphorylation of c-Met in mesothelioma cells. These data will be crucial to judge whether local production of NK4 molecules can be an anti-cancer strategy.

Trial registration: UMIN clinical trials registry, Japan. Register ID: UMIN15771

Considerations on the management of EGF receptor-TKIs for brain metastases in EGFR-mutant lung carcinoma patients

SUMMARY 

Approximately 20–30% of patients with NSCLC are present with brain metastases. The standard management for brain metastases is radiotherapy. Despite the administration of radiation therapy for brain metastases, the prognosis is still poor. The poor prognosis is related to the progression of extracranial lesions. Therefore, systemic therapy is important to improve survival of patients with brain metastases. EGF receptor-tyrosine kinase inhibitor (EGFR-TKI) is a standard treatment for advanced NSCLC patients with sensitive EGFR mutations and is also effective in controlling brain metastasis in such patients. Upfront EGFR-TKI therapy might be one of the treatment choices for EGFR-mutant NSCLC patients with asymptomatic brain metastases. However, it is unclear whether upfront EGFR-TKI or radiation therapy is more preferable. New EGFR-TKIs and combination with existing EGFR-TKIs and other drugs are being investigated for treatment options. Further investigations are required to determine the future direction for management of EGFR-mutant NSCLC patients with brain metastasis.

Endobronchial ultrasound-guided transbronchial needle aspiration in a patient with pericardial mesothelioma

Pericardial mesothelioma is a very rare pericardial tumor. Diagnosing pericardial disease can be challenging, and obtaining an antemortem diagnosis of pericardial mesothelioma is particularly difficult. We herein report the case of a 60-year-old man with pericardial mesothelioma diagnosed on endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA). Chest computed tomography showed a mass surrounding the pericardium, and EBUS-TBNA of the right inferior paratracheal and subcarinal stations was consequently performed. No uptake was noted on (18)F-fluorodeoxy glucose positron emission tomography, other than in the pericardial mass. The results of histological and immunohistochemical examinations indicated the features of malignant mesothelioma. We therefore diagnosed the patient with pericardial mesothelioma, which was subsequently confirmed at autopsy.

Frequency of brain metastases in non-small-cell lung cancer, and their association with epidermal growth factor receptor mutations

BACKGROUND

The brain is a frequent site of metastases from non-small-cell lung cancer (NSCLC). We analyzed the frequency of brain metastases (BMs) from NSCLC in the era of magnetic resonance images, and evaluated the correlation between epidermal growth factor receptor (EGFR) mutations and BMs among East Asian patients.

METHODS

Frequency, number, and size of BMs, and survival of 1,127 NSCLC patients were retrospectively reviewed. Mutation status of EGFR was evaluated in all cases, and its association with BMs was statistically evaluated.

RESULTS

EGFR mutations were found for 331 cases (29.4 %). BM was the cause of primary symptoms for 52 patients (4.6 %), and found before initiation of treatment for 102 other patients (9.1 %); In addition to these 154 patients, 107 patients (9.5 %) developed BMs, giving a total of 261 patients (23.2 %) who developed BMs from 1,127 with NSCLC. BM frequency was higher among EGFR-mutated cases (31.4 %) than EGFR-wild cases (19.7 %; odds ratio: 1.86; 95 % confidence interval (CI) 1.39-2.49; P < 0.001). BMs from EGFR-mutated NSCLC were small, but often became disseminated. EGFR mutations accounted for 39.9 % of BMs, but patient survival after BMs was significantly longer for EGFR-mutated cases than for EGFR-wild cases (hazard ratio: 2.23; 95 % CI 1.62-3.10; P < 0.001).

CONCLUSIONS

Patients with EGFR-mutated NSCLC were more likely to develop BMs, but apparently also survived longer after BMs.