Surgical outcomes after chemotherapy plus nivolumab and chemotherapy plus nivolumab and ipilimumab in patients with non-small cell lung cancer

OBJECTIVE

Chemotherapy plus nivolumab is the standard of care neoadjuvant treatment for patients with resectable stage IB to IIIA non-small cell lung cancer. The influence of dual checkpoint blockade with chemotherapy on surgical outcomes remains unknown. We aimed to determine operative complexity and perioperative outcomes associated with neoadjuvant chemotherapy and nivolumab with or without ipilimumab.

METHODS

A total of 44 patients with stage IB (≥4 cm) to IIIA non-small cell lung cancer were treated on sequential platform arms of the NEOSTAR trial. A total of 22 patients were treated with nivolumab + chemotherapy, and 22 patients were treated with ipilimumab + nivolumab + chemotherapy. The safety of surgical resection after neoadjuvant therapy was estimated using 30-day complication rates. Operative reports and surgeons' narratives were evaluated to determine procedural complexity and operative conduct.

RESULTS

All 22 of 22 patients (100%) treated with nivolumab + chemotherapy underwent surgical resection: 20 R0 (90.9%), 17 (77.3%) lobectomies, 1 wedge resection, 2 segmentectomies, and 2 pneumonectomies. The majority, 21 of 22 (95%), were performed by thoracotomy. A total of 13 of 22 (59.1%) were rated as challenging resections. A total of 4 of 22 patients (18.2%) experienced grade 3 or greater Clavien-Dindo complication. A total of 20 of 22 patients (90.9%) treated with ipilimumab + nivolumab + chemotherapy underwent surgical resection: 19 R0 (95%), 18 (90%) lobectomies, 1 pneumonectomy, and 1 segmentectomy. A total of 16 of 20 (80%) resections were performed via thoracotomy, 3 of 20 (15%) via robotics, and 1 of 20 (5%) via thoracoscopy. A total of 9 of 20 (45%) resections were considered challenging. A total of 4 of 20 patients (20%) experienced grade 3 or greater Clavien-Dindo complication.

CONCLUSIONS

Surgical resections are feasible and safe, with high rates of R0 after neoadjuvant chemotherapy and nivolumab with or without ipilimumab. Overall, approximately half of cases (22/42, 52.3%) were considered to be more challenging than a standard lobectomy.

Modulation of the proteostasis network promotes tumor resistance to oncogenic KRAS inhibitors

Despite substantial advances in targeting mutant KRAS, tumor resistance to KRAS inhibitors (KRASi) remains a major barrier to progress. Here, we report proteostasis reprogramming as a key convergence point of multiple KRASi-resistance mechanisms. Inactivation of oncogenic KRAS down-regulated both the heat shock response and the inositol-requiring enzyme 1α (IRE1α) branch of the unfolded protein response, causing severe proteostasis disturbances. However, IRE1α was selectively reactivated in an ER stress-independent manner in acquired KRASi-resistant tumors, restoring proteostasis. Oncogenic KRAS promoted IRE1α protein stability through extracellular signal-regulated kinase (ERK)-dependent phosphorylation of IRE1α, leading to IRE1α disassociation from 3-hydroxy-3-methylglutaryl reductase degradation (HRD1) E3-ligase. In KRASi-resistant tumors, both reactivated ERK and hyperactivated AKT restored IRE1α phosphorylation and stability. Suppression of IRE1α overcame resistance to KRASi. This study reveals a druggable mechanism that leads to proteostasis reprogramming and facilitates KRASi resistance.

Neoadjuvant chemotherapy plus nivolumab with or without ipilimumab in operable non-small cell lung cancer: the phase 2 platform NEOSTAR trial

Neoadjuvant ipilimumab + nivolumab (Ipi+Nivo) and nivolumab + chemotherapy (Nivo+CT) induce greater pathologic response rates than CT alone in patients with operable non-small cell lung cancer (NSCLC). The impact of adding ipilimumab to neoadjuvant Nivo+CT is unknown. Here we report the results and correlates of two arms of the phase 2 platform NEOSTAR trial testing neoadjuvant Nivo+CT and Ipi+Nivo+CT with major pathologic response (MPR) as the primary endpoint. MPR rates were 32.1% (7/22, 80% confidence interval (CI) 18.7-43.1%) in the Nivo+CT arm and 50% (11/22, 80% CI 34.6-61.1%) in the Ipi+Nivo+CT arm; the primary endpoint was met in both arms. In patients without known tumor EGFR/ALK alterations, MPR rates were 41.2% (7/17) and 62.5% (10/16) in the Nivo+CT and Ipi+Nivo+CT groups, respectively. No new safety signals were observed in either arm. Single-cell sequencing and multi-platform immune profiling (exploratory endpoints) underscored immune cell populations and phenotypes, including effector memory CD8⁺ T, B and myeloid cells and markers of tertiary lymphoid structures, that were preferentially increased in the Ipi+Nivo+CT cohort. Baseline fecal microbiota in patients with MPR were enriched with beneficial taxa, such as Akkermansia, and displayed reduced abundance of pro-inflammatory and pathogenic microbes. Neoadjuvant Ipi+Nivo+CT enhances pathologic responses and warrants further study in operable NSCLC. (ClinicalTrials.gov registration: NCT03158129 .).

Abstract 6152: Distinct immune gene programs associated with host tumor immunity, neoadjuvant chemotherapy and chemoimmunotherapy in resectable NSCLC

Background: Our understanding of the immunopathology of early-stage NSCLC is still limited. While neoadjuvant immunotherapeutic strategies have recently shown anti-tumor effects in resectable NSCLC, their mechanisms remain inadequately understood. Here, we explore immune programs that inform of tumor immunity and response to neoadjuvant chemotherapy and chemoimmunotherapy in localized NSCLC.

Methods: Targeted immune gene sequencing using the HTG Precision Immuno-Oncology panel was performed in localized NSCLCs from three cohorts based on treatment: naïve (n=190), neoadjuvant chemotherapy (n=38) and neoadjuvant chemoimmunotherapy (n=21). Three tumor immune microenvironment (TIME) phenotypes (inflamed, cold, excluded) were derived based on CD8+ T cell infiltration. Signatures of immune cell abundance and immune genes were statistically compared based on tumoral PD-L1 expression, immune phenotypes, associated with pathological response, and were cross-compared across the three cohorts.

Results: PD-L1 positive tumors exhibited increased signature scores for various lymphoid and myeloid cell subsets (both, p<0.05). TIME phenotypes exhibited disparate frequencies by stage, PD-L1 expression, and mutational burden. Inflamed NSCLCs displayed overall significantly heightened levels of immune signatures with the excluded group representing an intermediate state. A signature of cytotoxic T cells was associated with favorable survival in neoadjuvant chemotherapy-treated NSCLCs (p<0.05). Major pathological response to chemoimmunotherapy was positively associated with CD8 T cells (p<0.05) and Th1 cells were significantly reduced post-chemoimmunotherapy (p<0.001). Among the three cohorts, chemoimmunotherapy-treated NSCLCs exhibited highest scores for various immune cell subsets including T effector and B cells (both, p<0.05).

Conclusions: Our findings highlight immune gene programs that may underlie host tumor immunity and response to neoadjuvant chemotherapy and chemoimmunotherapy in early-stage NSCLC.

Citation Format: Pedro Rocha, Jiexin Zhang, Raquel Laza-Briviesca, Alberto Cruz-Bermúdez, Katsuhiro Yoshimura, Carmen Behrens, Apar Pataer, Edwin Parra-Cuentas, Cara Haymaker, Junya Fujimoto, Stephen Swisher, John Heymach, Don L. Gibbons, J Jack Lee, Boris Sepesi, Tina Cascone, Luisa M. Solis, Mariano Provencio, Ignacio I. Wistuba, Humam Kadara. Distinct immune gene programs associated with host tumor immunity, neoadjuvant chemotherapy and chemoimmunotherapy in resectable NSCLC [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6152.

Molecular parameters impacting the success rate of a lung cancer PDX model

e20592

Background: Patient-derived xenograft (PDX) models can provide renewable cancer tissue resources, are being increasingly utilized for the molecular characterizations of cancers and preclinical studies on drug activities, and have the potential to advance biomarker identification. Previous research has demonstrated that PDX tumors preserve the histologic and morphologic characteristics and gene expression and mutation patterns of primary tumors, and correlate to patient survival. Tumor histological subtypes and differentiation grades are known to contribute to the success of PDX intake, but little is known about how molecular features associate with the success of PDX engraftment or whether PDX preserves subclonal architecture of primary tumors. Methods: To fill this void, we analyzed 252 primary tumor samples from the SPORE/ICON project at MD Anderson Cancer Center that were used for generating PDXs and had comprehensive genomic, transcriptomic, and immune profiling data available to evaluate the parameters impacting the intake success of lung cancer PDXs. In order to establish the impact of molecular features on PDX intake success we also assessed the fidelity of PDX in representing the molecular features of this cohort of primary tumors. Results: Only 36% of the primary tumors in this study successfully generated a PDX, with Squamous Cell Carcinoma PDX demonstrating an intake rate of 67% and Adenocarcinoma PDX demonstrating an intake rate of 21%. Genomic architecture derived from whole exome sequencing showed not only 43% (38-48%) of mutations shared, but also similar clonal architecture between primary tumors and PDX. Higher copy number aberration burden, high tumor purity and low immune infiltration in primary tumors were found to be associated with successful intake of PDX. Transcriptomics revealed 6,103 genes differentially expressed between primary tumors with successful PDX intake versus those which were unsuccessful. Pathway analysis of these genes indicated that inhibition of cell proliferation, signaling, and migration as well as DNA replication, recombination and repair were associated with PDX intake failure regardless of histology. Conclusions: These findings indicate that PDX intake success is regulated by molecular features and multiomic evaluation of lung cancer primary tumors can be used as a marker for determining which samples to use for PDX model generation.

Distinct immune gene programs associated with host tumor immunity, neoadjuvant chemotherapy and chemoimmunotherapy in resectable NSCLC

PURPOSE

Our understanding of the immunopathology of resectable NSCLC is still limited. Here, we explore immune programs that inform of tumor immunity and response to neoadjuvant chemotherapy and chemoimmunotherapy in localized NSCLC.

EXPERIMENTAL DESIGN

Targeted immune gene sequencing using the HTG Precision Immuno-Oncology panel was performed in localized NSCLCs from three cohorts based on treatment: naïve (n=190), neoadjuvant chemotherapy (n=38) and neoadjuvant chemoimmunotherapy (n=21). Tumor immune microenvironment (TIME) phenotypes based on the location of CD8+ T cells (inflamed, cold, excluded), tumoral PD-L1 expression (<1% and {greater than or equal to}1%), and tumor infiltrating lymphocytes (TILs). Immune programs and signatures were statistically analyzed based on tumoral PD-L1 expression, immune phenotypes, pathological response and were cross-compared across the three cohorts.

RESULTS

PD-L1 positive tumors exhibited increased signature scores for various lymphoid and myeloid cell subsets (p<0.05). TIME phenotypes exhibited disparate frequencies by stage, PD-L1 expression, and mutational burden. Inflamed and PD-L1+/TILs+ NSCLCs displayed overall significantly heightened levels of immune signatures, with the excluded group representing an intermediate state. A cytotoxic T cell signature was associated with favorable survival in neoadjuvant chemotherapy-treated NSCLCs (p<0.05). Pathological response to chemoimmunotherapy was positively associated with higher expression of genes involved in immune activation, chemotaxis, as well as T and NK cells (p<0.05 for all). Among the three cohorts, chemoimmunotherapy-treated NSCLCs exhibited highest scores for various immune cell subsets including T effector and B cells (p<0.05).

CONCLUSIONS

Our findings highlight immune gene programs that may underlie host tumor immunity and response to neoadjuvant chemotherapy and chemoimmunotherapy in resectable NSCLC.

Surgical Outcomes Following Nivolumab or Nivolumab Plus Ipilimumab In Non-Small Cell Lung Cancer

BACKGROUND

Surgical outcomes for non-small cell lung cancer after neoadjuvant immune checkpoint inhibitors continue to be debated. We assessed perioperative outcomes of patients treated with Nivolumab or Nivolumab plus Ipilimumab (NEOSTAR) and compared them with patients treated with chemotherapy or previously untreated patients with stage I-IIIA non-small cell lung cancer.

METHODS

Forty-four patients with stage I to IIIA non-small cell lung cancer (American Joint Committee on Cancer Staging Manual, seventh edition) were randomized to nivolumab (N; 3 mg/kg intravenously on days 1, 15, and 29; n = 23) or nivolumab with ipilimumab (NI; I, 1 mg/kg intravenously on day 1; n = 21). Curative-intent operations were planned between 3 and 6 weeks after the last dose of neoadjuvant N. Patients who completed resection upfront or after chemotherapy from the same time period were used as comparison.

RESULTS

In the N arm, 21 (91%) were resected on-trial, 1 underwent surgery off-trial, and one was not resected (toxicity-related). In the NI arm, 16 (76%) resections were performed on-trial, one off-trial, and 4 were not resected (none toxicity-related). Median time to operation was 31 days, and consisted of 2 (5%) pneumonectomies, 33 (89%) lobectomies, and 1 (3%) each of segmentectomy and wedge resection. The approach was 27 (73%) thoracotomy, 7 (19%) thoracoscopy, and 3 (8%) robotic-assisted. Conversion occurred in 17% (n = 2/12) of minimally invasive cases. All 37 achieved R0 resection. Pulmonary, cardiac, enteric, neurologic, and wound complications occurred in 9 (24%), 4 (11%), 2 (5%), 1 (3%), and 1 (3%) patient, respectively. The 30- and 90-day mortality rate was 0% and 2.7% (n = 1), respectively. Postoperative complication rates were comparable with lung resection upfront or after chemotherapy.

CONCLUSIONS

Operating after neoadjuvant N or NI is overall safe and effective and yields perioperative outcomes similar to those achieved after chemotherapy or upfront resection.

962 Integrative immunomics highlight the immunomodulatory impact of neoadjuvant chemotherapy and immune-based treatments in resected non-small-cell lung cancer

Background

How neoadjuvant chemo-immunotherapy modulates tumor immune composition and response is not completely understood. We interrogate immunomodulation of neoadjuvant platinum-based chemotherapy (C), nivolumab (N), and N-plus-C (NC) and their connections to therapeutic efficacy in resected non-small cell lung cancer (NSCLC) by integrating immunomic data from the ImmunogenomiC PrOfiling of NSCLC (ICON) study and NEOSTAR trial cohorts.

Methods

In NEOSTAR (NCT03158129), patients with stage I-IIIA (single N2) resectable NSCLC (AJCC7th) received N (3 mg/kg IV, D1,15,29); patients with stage IB(≥4cm)-IIIA (single N2) resectable NSCLC received NC (N 360 mg IV plus C, D1,22,43 for 3 cycles, every 3 weeks) before surgery; major pathologic response (MPR) was the primary endpoint. In ICON, patients with stage IB(≥4cm)-IIIA resectable NSCLC received C before surgery. Surgically resected tumor samples underwent immune profiling via flow cytometry (n=16,13,9 for C,N,NC), immunohistochemistry (IHC;n=0,18,14), and multiplexed immunofluorescence (mIF;n=28,16,10). Treatment-associated immunomodulation and associations with therapeutic efficacy were analyzed using: 1) a shared nearest neighbors-based network we developed linking measurements across datasets; 2) MetaCyto, a specialized cytometry analysis method for identifying cell subsets by clustering.

Results

We holistically explored the immunomic data by integration across cohorts. Through hierarchical regression of the integrated data, we determined the overall effect of a given treatment controlling for the presence or absence of the other treatment.

We examined C’s effects across all cohorts controlling for N. Across all patients, regardless of MPR, C is associated with immunosuppression, increasing PD1+ T cell (CD45+CD3+) populations: regulatory (CD4+CD25+FOXP3+), helper (CD4+), and effector (CD8+) (effect size(ES):1.48,1.61,1.26;q<0.05). C also decreases proliferative (Ki67+) populations: helper and effector T cells as well as NK (CD45+CD3-CD56+) cells (ES:-1.27,-1.43;-1.36;q<0.05). In patients without MPR (i.e., non-responding patients), immunosuppression appears heightened by increased Ki67+ regulatory T cells (ES:1.86;q<0.05).

Conversely, we examined N’s effects across all cohorts controlling for C. Across all patients, regardless of MPR, N is associated with immune activation, increasing ICOS+ T cell populations: regulatory, helper, and effector (ES:1.29,1.29,1.47;q<0.05). Comparing N and NC reveals that adding C may drive exhaustion by increasing TIM3+ regulatory, helper and effector T cells (ES:1.16,1.17,1.23;q<0.05), an effect more pronounced in non-responding patients (ES:1.31,1.33,1.35;q<0.05).

Conclusions

We report the first integrated examination of the immunomodulatory effect of neoadjuvant C and N. C is associated with immunosuppression while N with immune activation; together, N appears to lessen C’s suppressive effects. Incorporation of transcriptomics into this integrated network of flow cytometry, mIF, and IHC immune profiling data is ongoing to augment translational insights for neoadjuvant chemo/immunotherapies.

Pathological nodal disease defines survival outcomes in patients with lung cancer with tumour major pathological response following neoadjuvant chemotherapy

OBJECTIVES

Major pathological response (MPR) is prognostic of outcomes for patients with non-small-cell lung cancer following neoadjuvant chemotherapy and is used as the primary end point in neoadjuvant immunotherapy trials. We studied the influence of pathological nodal disease on patterns and timing of recurrence among patients with MPR.

METHODS

Patients treated with neoadjuvant chemotherapy for stages I-III non-small-cell lung cancer were identified. Surgical specimens were histopathologically examined for tumour viability, categorized as ≤10% viability (MPR) or >10% (NoMPR). Overall survival and disease-free survival were evaluated with emphasis upon MPR and pathological nodal disease.

RESULTS

Among 307 patients, 58 (19%) had MPR within primary tumour and 42 (14%) had MPRypN0. In the MPR group, the frequency of cN0 and cN+ disease was 18 (31%) and 40 (69%); similarly, the frequency of ypN0, ypN1 and ypN2 was 72% (42/58), 16% (9/58) and 12% (7/58), respectively. When evaluating only those with MPR, recurrence rates among those with MPRypN0, MPRypN1 and MPRypN2 were 33% (14/42), 44% (4/9) and 71% (5/7) (P = 0.16). The median time-to-recurrence in MPRypN0, MPRypN1 and MPRypN2 was 40, 10 and 14 months (P = 0.006). Distant recurrences were less common among those with MPRypN0 [MPRypN0, 26% (11/42); MPRypN1, 44% (4/9); MPRypN2, 71% (5/7); P = 0.047]. Though the median disease-free survival was prolonged among those with MPR vs NoMPR (120 vs 25 months, P < 0.0001), only those with MPRypN0 had prolonged disease-free survival in comparison to other groups upon pairwise comparisons, while MPRypN+ experienced no benefit.

CONCLUSIONS

MPRypN0 represents the most favourable surrogate end point following neoadjuvant chemotherapy. Patients with ypN1-2 are at the risk of early recurrence regardless of primary tumour MPR, warranting intensive surveillance and consideration for additional adjuvant therapy. We highlight that MPRypN0 is the most rigorous end point and should be considered as a surrogate end point in future neoadjuvant trials.

Impact of genomic aberrations and additional therapies on survival outcomes of patients with operable non-small cell lung cancer (NSCLC) from the NEOSTAR study

8542

Background: The NEOSTAR study compared nivolumab (N) vs. nivolumab plus ipilimumab (NI) with major pathological response (MPR; ≤10% viable tumor) as primary outcome. We report updated rates of treatment failure (TF), including in patients whose tumors harbored genomic aberrations, and outcomes of additional treatments. Methods: Patients (pts) with stage I-IIIA resectable NSCLC (AJCC 7th) were randomized to either neoadjuvant N or NI followed by surgery (n = 44). TF was defined as radiographic and/or biopsy-proven recurrence from primary lung cancer and/or death (treatment or cancer-related). Additional systemic therapy at recurrence included immuno-oncology (IO)-based therapy (IO or chemo-IO), targeted therapy (TT), or chemotherapy. Disease control rate (DCR) was defined as the proportion of pts with radiographic objective responses and stable disease at first restaging. Cox proportional hazards model was used to associate baseline characteristics and time to TF. Results: A total of 44 randomized pts were evaluated, the median follow-up was 35 months (mts) as of February 4, 2021. Among the 12 TF pts (12/44, 27%), 42% (5/12) did not undergo surgery on trial, 9 (9/44, 20%) experienced recurrence and 6 (6/44, 14%) died (1 non-cancer-related, 5 cancer-related). TF was less likely in smokers vs. never smokers (hazard ratio = 0.20, 95% confidence interval = 0.06-0.65, p = 0.007). Among pts with pathological specimen resected on trial, MPR was achieved in 40% (12/30) of non-TF pts. Only 1 (1/7, 14%) TF pt achieved MPR, but died of a non-cancer related cause. TF-free survival rate at 2 years was 92% in MPR and 78% in non-MPR pts. Eight (8/9, 89%) pts had tumors with canonical oncodriver aberrations (5 EGFR mutations, 1 with STK11+ KRAS Q61H mutations, 1 ALK translocation and 1 RET fusions). Of the 9 recurrences, 44% (4/9) were treated with IO therapy, and all 7 pts with targetable aberrations were treated with TT (3 after retreatment with IO therapies). Of the 4 pts retreated with IO therapy, duration between end of neoadjuvant and retreatment were 20, 17, 23, and 19 mts. Duration from retreatment until progression (PD) were 1, 1, and 2 mts, respectively. Last pt was treated without PD for 2 mts but switched to TT due to discovery of genomic aberration. IO retreatment achieved 25% DCR (1/4). In comparison, the DCR for TT treated pts was 71% (5/7, p = 0.242). Median time to treatment was 21 mts, and median time to PD was not reached. Among 32 non-TF pts, 12 had genomic analysis and 7 aberrations were found in 6 pts (2 STK11, 2 ERBB2, 1 STK11 + 1 KRAS G12C, and 1 KRAS G12C mutation). Conclusions: A 27% TF rate was observed after neoadjuvant IO. TF was less likely to occur in smokers and MPR pts, and 42% of TF pts did not undergo curative-intent surgery on trial. Genomic aberrations were common in pts with recurrence (89%), and treatment with TT achieved 71% DCR vs. 25% DCR with IO-based retreatment. Clinical trial information: NCT: 03158129.

Evaluation of Pathologic Response in Lymph Nodes of Patients With Lung Cancer Receiving Neoadjuvant Chemotherapy

INTRODUCTION

Major pathologic response (MPR), defined as residual viable tumor of less than or equal to 10%, currently serves as a surrogate end point for survival for patients with resectable NSCLC after neoadjuvant chemotherapy. However, the significance of pathologic response in lymph nodes harboring metastatic tumors in such patients remains uncertain. Therefore, we studied the effect of neoadjuvant chemotherapy on resected positive lymph nodes and determined if the degree of pathologic response in the lymph nodes alone (LN-MPR) or in combination with that of the primary tumor (PT-MPR) was able to predict the outcome.

METHODS

A total of 75 patients with NSCLC who underwent neoadjuvant chemotherapy and completed surgical resection were included in this study. Tissue specimens were retrospectively evaluated by two pathologists blinded to the patients' treatments and outcomes. Specimens were reviewed for the degree of pathologic response in the primary tumor and in any involved lymph nodes. The prognostic performance of LN-MPR alone or in combination with PT-MPR with respect to overall survival (OS) was evaluated using the Kaplan-Meier method and Cox regression model.

RESULTS

LN-MPR was significantly predictive of long-term OS after neoadjuvant chemotherapy. A combination of PT-MPR with LN-MPR was significantly associated with outcome and allowed stratification of patients into three prognostic groups (p = 0.001).

CONCLUSIONS

LN-MPR in isolation is a reliable predictor of OS in patients with NSCLC receiving neoadjuvant chemotherapy. A combination of LN-MPR with PT-MPR seems to correlate well with the outcome and can be used to predict prognosis in this patient population.

KRT-232 and navitoclax enhance trametinib's anti-Cancer activity in non-small cell lung cancer patient-derived xenografts with KRAS mutations

Activating mutations of the KRAS gene are one of the major genomic alterations associated with tumorigenesis of non-small cell lung cancer (NSCLC). Thus far, treatment of KRAS-mutant NSCLC remains an unmet medical need. We determined the in vivo treatment responses of 13 KRAS mutant and 14 KRAS wild type NSCLC patient-derived xenografts (PDXs) to agents that target known NSCLC vulnerabilities: the MEK inhibitor trametinib, the MDM2 inhibitor KRT-232, and the BCL-X_L/BCL-2 inhibitor navitoclax. The results showed that the tumor regression rate after single agent therapy with KRT-232, trametinib and navitoclax was 11%, 10% and 0%, respectively. Combination therapies of trametinib plus KRT-232 and trametinib plus navitoclax led to improved partial response rates over single-agent activity in a subset of PDX models. Tumor regression was observed in 23% and 50% of PDXs after treatment with trametinib plus KRT-232 and trametinib plus navitoclax, respectively. The disease control rates in KRAS-mutant PDXs tested were 90%-100% after treatment with trametinib plus KRT-232 or plus navitoclax. A correlation analysis of treatment responses and genomic and proteomic biomarkers revealed that sensitivity to KRT-232 was significantly associated with TP53 wild-type or STK11 mutant genotypes (P<0.05). The levels of several proteins, including GSK3b, Nrf2, LKB1/pS334, and SMYD3, were significantly associated with sensitivity to trametinib plus navitoclax. Thus, the combination of trametinib plus KRT-232 or navitoclax resulted in improved efficacy compared with the agents alone in a subgroup of NSCLC PDX model with KRAS mutations. Expanded clinical trials of these targeted drug combinations in NSCLC are warranted.

277 Combined neoadjuvant chemo-immunotherapy therapy achieves superior downstaging of resectable non-small cell lung cancer as compared to chemotherapy, mono or dual immunotherapy

Background

Tumor and nodal downstaging following neoadjuvant therapy in resectable non-small cell lung cancer (NSCLC) are important markers of therapeutic response associated with favorable prognosis. We studied the impact of four different systemic neoadjuvant therapies on tumor, nodal and overall pathological downstaging of surgically resectable I-IIIA NSCLC (AJCC 7th edition).

Methods

Our study cohorts consisted of NSCLC patients treated with three cycles of neoadjuvant platinum doublet chemotherapy from 2001–2012 (N=302, 84%), and patients treated on the NEOSTAR study (NCT03158129) who received neoadjuvant nivolumab (N=21,6%), nivolumab plus ipilimumab (N=16, 4%), or platinum doublet chemotherapy plus nivolumab (N=22, 6%). Clinical and pathological (yp) T and N staging were evaluated for downstaging and upstaging; differences were assessed using Fisher’s exact test.

Results

Following neoadjuvant platinum doublet chemotherapy, nivolumab, nivolumab plus ipilimumab and platinum doublet chemotherapy plus nivolumab, the rates of clinical-to-pathological ypT downstaging were 26% (N=79), 29% (N=6), 38% (N=6) and 59% (N=13), respectively, p =0.012 (table 1). The rates of clinical-to-pathological ypN downstaging in patients with clinical N1 or N2 disease with each therapy were 55% (N=96), 50% (N=3), 50% (N=2), and 42% (N=5) respectively, p =0.862. Overall clinical-to-pathological (ypT and/or ypN) downstaging rates were 38% (N=114), 38% (N=8), 38% (N=6), and 68% (N=15) respectively, p=0.048. The proportions of patients being overall upstaged following each therapy were 28% (N=85), 38% (N=8), 38% (N=6) and 14% (N=3), respectively, p=0.251. These results suggest superior downstaging effect and clinically meaningful lower upstaging probability of combined platinum doublet chemotherapy plus nivolumab as compared to other neoadjuvant regimens.

Abstract 277 Table 1

Response to Chemotherapy, Immunotherapy, and Combination Therapy

Conclusions

The combination of neoadjuvant platinum doublet chemotherapy with nivolumab achieves the most robust tumor and overall pathological downstaging and decreases the probability of upstaging at surgery. Whether the overall downstaging effect results in improved survival will be determined with longer follow-up, in conjunction with results from ongoing phase III neoadjuvant chemo-immunotherapy trials.

Trial Registration

NCT03158129

Ethics Approval

This study was approved by the University of Texas MD Anderson Institutional Review Board with a waiver of informed consent, protocol 2020-0337.

EF2-kinase targeted cobalt-ferrite siRNA-nanotherapy suppresses BRCA1-mutated breast cancer

Aim: To investigate the role of EF2K in BRCA1-mutated breast cancer. Materials & methods: We developed silica coated cobalt-ferrite (CoFe) nanoparticles for in vivo delivery of small interfering RNAs (siRNAs) into BRCA1-mutated breast cancer. Results: Expression of EF2K is highly upregulated in the majority (78.5%) of BRCA1-mutated patients and significantly associated with poor patient survival and metastasis. Silencing of EF2K reduced cell proliferation, migration and invasion of the cancer cells. In vivo therapeutic targeting of EF2K by CoFe-siRNA-nanoparticles leads to sustained EF2K gene knockdown and suppressed tumor growth in orthotopic xenograft models of BRCA1-mutated breast cancer. Conclusion: EF2K is a potential novel molecular target in BRCA1-mutated tumors and CoFe-based siRNA nanotherapy may be used as a novel approach to target EF2K.

Tumor characteristics associated with engraftment of patient-derived non-small cell lung cancer xenografts in immunocompromised mice

BACKGROUND

Patient-derived xenograft (PDX) models increasingly are used in translational research. However, the engraftment rates of patient tumor samples in immunodeficient mice to PDX models vary greatly.

METHODS

Tumor tissue samples from 308 patients with non-small cell lung cancer were implanted in immunodeficient mice. The patients were followed for 1.5 to approximately 6 years. The authors performed histological analysis of PDXs and some residual tumor tissues in mice with failed PDX growth at 1 year after implantation. Quantitative polymerase chain reaction and enzyme-linked immunoadsorbent assay were performed to measure the levels of Epstein-Barr virus genes and human immunoglobulin G in PDX samples. Patient characteristics were compared for PDX growth and overall survival as outcomes using Cox regression analyses. Disease staging was based on the 7th TNM staging system.

RESULTS

The overall engraftment rate for PDXs from patients with non-small cell lung cancer was 34%. Squamous cell carcinomas had a higher engraftment rate (53%) compared with adenocarcinomas. Tumor samples from patients with stage II and stage III disease and from larger tumors were found to have relatively high engraftment rates. Patients whose tumors successfully engrafted had worse overall survival, particularly those individuals with adenocarcinoma, stage III or stage IV disease, and moderately differentiated tumors. Lymphoma formation was one of the factors associated with engraftment failure. Human CD8-positive and CD20-positive cells were detected in residual samples of tumor tissue that failed to generate a PDX at 1 year after implantation. Human immunoglobulin G was detected in the plasma of mice that did not have PDX growth at 14 months after implantation.

CONCLUSIONS

The results of the current study indicate that the characteristics of cancer cells and the tumor immune microenvironment in primary tumors both can affect engraftment of a primary tumor sample.

Glutathione reductase (GSR) gene deletion and chromosome 8 aneuploidy in primary lung cancers detected by fluorescence in situ hybridization

Our recent study demonstrated that cancer cells with compromised glutathione homeostasis, including reduced expression of the glutathione reductase (GSR) gene, were selectively killed by inhibition of thioredoxin reductase. The human GSR gene is located on chromosome 8p, a region often lost in lung and other cancers. However, whether GSR is altered in primary lung cancer remains unknown. To analyze alterations of GSR in lung cancer, we performed fluorescence in situ hybridization with probes for GSR and the chromosome 8 centromere (CEP8) in 45 surgical specimens of primary lung cancer, including 24 lung adenocarcinomas, 10 squamous cell carcinomas, 8 neuroendocrine cancers, and 3 small cell lung cancers. Twenty-five surgically resected normal lung tissue specimens from these lung cancer patients were used as a controls. The signal ratio of GSR to CEP8 per cell was used to identify gain or loss of GSR. GSR loss was detected in 6 of 24 (25%) adenocarcinoma specimens and 5 of 10 (50%) squamous cell carcinoma specimens, but not in neuroendocrine cancer or small cell lung cancer specimens. We also found that 19 of 45 (42%) specimens had chromosome 8 aneuploidy (more or less than 2 signals for CEP8), including 8 with both aneuploidy and GSR deletion. Chromosome 8 aneuploidy was detected in all types of lung cancer analyzed. Univariate and multivariable logistic regression analyses indicated that male patients had an increased risk of GSR deletion (hazard ratio [HR] = 4.77, 95% confidence interval [CI] = 1.00-22.86, P = 0.051), and patients who had undergone preoperative radiation therapy or had a self-reported history of cigarette smoking had an increased risk of chromosome 8 aneuploidy (preoperative radiation: HR = 18.63, 95% CI = 0.90-384.17, P = 0.058; smoking: HR = 7.59, 95% CI = 0.86-66.75, P = 0.068), although the p values did not reach significance. Because GSR deficiency and chromosome 8 aneuploidy have implications in targeted therapy and/or immunotherapy for cancer, they might serve as predictive biomarkers for precision therapy of lung cancers.

Patient-derived tumor immune microenvironments in patient-derived xenografts of lung cancer

Background

Because patient-derived xenografts (PDXs) are grown in immunodeficient mouse strains, PDXs are regarded as lacking an immune microenvironment. However, whether patients’ immune cells co-exist in PDXs remains uncharacterized.

Methods

We cultured small pieces of lung PDX tissue in media containing human interleukin-2 and characterized the proliferated lymphocytes by flow cytometric assays with antibodies specific for human immune cell surface markers. Presence of immune cells in PDXs was also determined by immunohistochemical staining.

Results

Human tumor-infiltrating lymphocytes (TILs) were cultured from nine of 25 PDX samples (36%). The mean time of PDX growth in immunodeficient mice before obtaining TILs in culture was 113 days (range 63–292 days). The TILs detected in PDXs were predominantly human CD8⁺ T cells, CD4⁺ T cells, or CD19⁺ B cells, depending on cases. DNA fingerprint analysis showed that the TILs originated from the same patients as the PDXs. Further analysis of two PDX-derived CD8⁺ T cells showed that they were PD-1⁻, CD45RO⁺, and either CD62L⁺ or CD62L⁻, suggesting they were likely memory T cells. Immunohistochemical staining showed that human T cells (CD8⁺ or CD4⁺), B cells (CD19⁺), and macrophages (CD68⁺) were present in stroma or intraepithelial cancer structures and that human PD-L1 was expressed in stromal cells. Moreover, the patient-derived immune cells in PDX can be passaged to the F2 generation and may migrate to spleens of PDX-bearing mice.

Conclusions

Patient-derived immune cells co-exist in early passages of PDXs in some lung cancer PDX models. The CD8⁺ cells from PDXs were likely memory T cells. These results suggest that PDXs can be used for evaluating the functionality of immune components in tumor microenvironments.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1704-3) contains supplementary material, which is available to authorized users.

Abstract 4527: Major pathologic response and biomarker predict survival in lung cancer patients receiving neoadjuvant chemotherapy

In a previous study, we determined that major pathologic response (MPR) as indicated by the percentage of residual viable tumor cells predicted overall survival (OS) in patients with non-small cell lung cancer (NSCLC) who received neoadjuvant chemotherapy. In this study, we assessed whether 2 gene and 5 protein biomarkers could predict MPR and OS in 98 NSCLC patients receiving neoadjuvant chemotherapy. We assessed whether gene mutation status or protein expression was associated with MPR or OS. We observed that KRAS mutation tended to be associated with OS (p = 0.06), but EGFR mutation was not associated with OS. We found that patients with high RAD51 expression levels had a poorer prognosis than did those with low RAD51 expression. We also observed that RAD51 expression was associated with MPR. MPR and RAD51 expression were associated with OS in univariate and multivariate analyses (p = 0.04 and p = 0.02, respectively). Combination of MPR with RAD51 is a significant predictor of prognosis in NSCLC patients who received neoadjuvant chemotherapy. No association of MPR or VEGFR2, EZH2, ERCC1, RAD51, or PKR expression with KRAS or EGFR mutation was found. We demonstrated that MPR or RAD51 expression was associated with OS in NSCLC patients receiving neoadjuvant chemotherapy. Prediction of a patient's prognosis could be improved by combined assessment of MPR and RAD51 expression.

Citation Format: Apar Pataer, Ruping Shao, Arlene M. Correa, Ignacio I. Wistuba, Stephen G. Swisher. Major pathologic response and biomarker predict survival in lung cancer patients receiving neoadjuvant chemotherapy [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 4527.

Effect of neoadjuvant chemotherapy on the immune microenvironment in non-small cell lung carcinomas as determined by multiplex immunofluorescence and image analysis approaches

Background

The clinical efficacy observed with inhibitors of programed cell death 1/programed cell death ligand 1 (PD-L1/PD-1) in cancer therapy has prompted studies to characterize the immune response in several tumor types, including lung cancer. However, the immunological profile of non–small cell lung carcinoma (NSCLC) treated with neoadjuvant chemotherapy (NCT) is not yet fully characterized, and it may be therapeutically important. The aim of this retrospective study was to characterize and quantify PD-L1/PD-1 expression and tumor-associated immune cells (TAICs) in surgically resected NSCLCs from patients who received NCT or did not receive NCT (non-NCT).

Methods

We analyzed immune markers in formalin-fixed, paraffin-embedded tumor tissues resected from 112 patients with stage II/III NSCLC, including 61 non-NCT (adenocarcinoma [ADC] = 33; squamous cell carcinoma [SCC] = 28) and 51 NCT (ADC = 31; SCC = 20). We used multiplex immunofluorescence to identify and quantify immune markers grouped into two 6-antibody panels: panel 1 included AE1/AE3, PD-L1, CD3, CD4, CD8, and CD68; panel 2 included AE1/AE3, PD1, granzyme B, FOXP3, CD45RO, and CD57.

Results

PD-L1 expression was higher (> overall median) in NCT cases (median, 19.53%) than in non-NCT cases (median, 1.55%; P = 0.022). Overall, density of TAICs was higher in NCT-NSCLCs than in non-NCT-NSCLCs. Densities of CD3+ cells in the tumor epithelial compartment were higher in NCT-ADCs and NCT-SCCs than in non-NCT-ADCs and non-NCT-SCCs (P = 0.043). Compared with non-NCT-SCCs, NCT-SCCs showed significantly higher densities of CD3 + CD4+ (P = 0.019) and PD-1+ (P < 0.001) cells in the tumor epithelial compartment. Density of CD68+ tumor-associated macrophages (TAMs) was higher in NCT-NSCLCs than in non-NCT-NSCLCs and was significantly higher in NCT-SCCs than in non-NCT-SCCs. In NCT-NSCLCs, higher levels of epithelial T lymphocytes (CD3 + CD4+) and epithelial and stromal TAMs (CD68+) were associated with better outcome in univariate and multivariate analyses.

Conclusions

NCT-NSCLCs exhibited higher levels of PD-L1 expression and T-cell subset regulation than non-NCT-NSCLCs, suggesting that NCT activates specific immune response mechanisms in lung cancer. These results suggest the need for clinical trials and translational studies of combined chemotherapy and immunotherapy prior to surgical resection of locally advanced NSCLC.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0368-0) contains supplementary material, which is available to authorized users.

Major pathologic response and RAD51 predict survival in lung cancer patients receiving neoadjuvant chemotherapy

In a previous study, we determined that major pathologic response (MPR) as indicated by the percentage of residual viable tumor cells predicted overall survival (OS) in patients with non-small-cell lung cancer (NSCLC) who received neoadjuvant chemotherapy. In this study, we assessed whether two genes and five protein biomarkers could predict MPR and OS in 98 patients with NSCLC receiving neoadjuvant chemotherapy. We collected formalin-fixed, paraffin-embedded specimens of resected NSCLC tumors from 98 patients treated with neoadjuvant chemotherapy. We identified mutations in KRAS and EGFR genes using pyrosequencing and examined the expression of protein markers VEGFR2, EZH2, ERCC1, RAD51, and PKR using immunohistochemistry. We assessed whether gene mutation status or protein expression was associated with MPR or OS. We observed that KRAS mutation tended to be associated with OS (P = .06), but EGFR mutation was not associated with OS. We found that patients with high RAD51 expression levels had a poorer prognosis than did those with low RAD51 expression. We also observed that RAD51 expression was associated with MPR. MPR and RAD51 expression were associated with OS in univariate and multivariate analyses (P = .04 and P = .02, respectively). Combination of MPR with RAD51 is a significant predictor of prognosis in patients with NSCLC who received neoadjuvant chemotherapy. We demonstrated that MPR or RAD51 expression was associated with OS in patients with NSCLC receiving neoadjuvant chemotherapy. Prediction of a patient's prognosis could be improved by combined assessment of MPR and RAD51 expression.

Cationic liquid crystalline nanoparticles for the delivery of synthetic RNAi-based therapeutics

RNA interference (RNAi)-based therapeutics have been used to silence the expression of targeted pathological genes. Small interfering RNA (siRNAs) and microRNA (miRNAs) inhibitor have performed this function. However, short half-life, poor cellular uptake, and nonspecific distribution of small RNAs call for the development of novel delivery systems to facilitate the use of RNAi. We developed a novel cationic liquid crystalline nanoparticle (CLCN) to efficiently deliver synthetic siRNAs and miRNAs. CLCNs were prepared by using high-speed homogenization and assembled with synthetic siRNA or miRNA molecules in nuclease-free water to create CLCN/siRNA or miRNA complexes. The homogeneous and stable CLCNs and CLCN-siRNA complexes were about 100 nm in diameter, with positively charged surfaces. CLCNs are nontoxic and are taken up by human cells though endocytosis. Significant inhibition of gene expression was detected in transiently transfected lung cancer H1299 cells treated with CLCNs/anti-GFP complexes 24 hours after transfection. Biodistribution analysis showed that the CLCNs and CLCNs-RNAi complexes were successfully delivered to various organs and into the subcutaneous human lung cancer H1299 tumor xenografts in mice 24 hours after systemic administration. These results suggest that CLCNs are a unique and advanced delivery system capable of protecting RNAi from degradation and of efficiently delivering RNAi in vitro and in vivo.

Taxane-Platin-Resistant Lung Cancers Co-develop Hypersensitivity to JumonjiC Demethylase Inhibitors

Although non-small cell lung cancer (NSCLC) patients benefit from standard taxane-platin chemotherapy, many relapse, developing drug resistance. We established preclinical taxane-platin-chemoresistance models and identified a 35-gene resistance signature, which was associated with poor recurrence-free survival in neoadjuvant-treated NSCLC patients and included upregulation of the JumonjiC lysine demethylase KDM3B. In fact, multi-drug-resistant cells progressively increased the expression of many JumonjiC demethylases, had altered histone methylation, and, importantly, showed hypersensitivity to JumonjiC inhibitors in vitro and in vivo. Increasing taxane-platin resistance in progressive cell line series was accompanied by progressive sensitization to JIB-04 and GSK-J4. These JumonjiC inhibitors partly reversed deregulated transcriptional programs, prevented the emergence of drug-tolerant colonies from chemo-naive cells, and synergized with standard chemotherapy in vitro and in vivo. Our findings reveal JumonjiC inhibitors as promising therapies for targeting taxane-platin-chemoresistant NSCLCs.

Accumulation of RNA-dependent protein kinase (PKR) in the nuclei of lung cancer cells mediates radiation resistance

We have previously demonstrated that radiation induced cell death in PKR (−/−) deficient mouse embryo fibroblasts (MEFs) but not in PKR (+/+) wild type MEFs. Our study indicated that PKR can also be involved in survival pathways following radiation therapy through activation of the AKT survival pathways in these MEFs is mediated in part through PKR. The role of PKR on radiation sensitivity in cancer cells has not been evaluated. In this study, we demonstrated that radiation treatment causes nuclear translocation of PKR in human lung cancer cells. The transduction of lung cancer cells with a dominant negative adenoviral PKR vector blocks nuclear translocation of PKR and leads to the reversal of radiation resistance. Plasmid transduction of lung cancer cells with nuclear targeted wild type PKR vectors also increased radiation resistance. This effect is selectively abrogated by plasmid transduction of dominant negative PKR vectors which restore radiation sensitivity. These findings suggest a novel role for PKR in lung cancer cells as a mediator of radiation resistance possibly through translocation of the protein product to the nucleus.

Induction Cisplatin Docetaxel Followed by Surgery and Erlotinib in Non-Small Cell Lung Cancer

BACKGROUND

Data from meta-analyses support the use of induction or adjuvant platinum-based chemotherapy for locally advanced non-small cell lung cancers (NSCLCs). This phase 2 study assessed the role of induction cisplatin and docetaxel followed by surgery in patients with resectable stage I to III NSCLCs, followed by 12 months of adjuvant erlotinib.

METHODS

Patients with resectable stage I to III NSCLCs received cisplatin 80 mg/m2, docetaxel 75 mg/m2 every 21 days for 3 cycles, followed by surgery, followed by adjuvant erlotinib for 12 months. The primary endpoint included safety. Long-term efficacy outcomes and exploratory analysis of intermediary endpoints are also reported (NCT00254384).

RESULTS

Forty-seven eligible patients received a median of 3 cycles of induction treatment, 37 underwent surgical resection, and only 21 received adjuvant erlotinib. Two patients died in the perioperative period (1 sepsis during chemotherapy, 1 acute respiratory distress syndrome postoperatively). Most common grade 3 to 5 toxicities during chemotherapy included hypokalemia (8%), infection (7%), and granulocytopenia (25%). During adjuvant erlotinib, 14% of patients experienced grade 2 rash. Median overall survival was 3.4 years. Major pathologic responses in the primary tumor were observed in 19% (7 of 37) of patients and correlated with improved long-term overall survival. Complete pathologic response in mediastinal/hilar nodes also correlated with superior survival.

CONCLUSIONS

Induction cisplatin and docetaxel was well tolerated. Adjuvant erlotinib did not improve outcomes compared with historical controls. Major pathologic response predicted for improved long-term survival and is a suitable intermediary endpoint for future phase 2 studies.

Abstract 2934: Neoadjuvant chemotherapy influence changes of the immune response in non-small cell lung carcinomas immune response in non-small cell lung carcinomas

Background: The clinical efficacy observed with PD-1/PD-L1 inhibitors in non-small cell lung carcinoma (NSCLC) has prompted to characterize the immune response in lung tumors treated with chemotherapy. The aim of this study was to determine the changes of the immune microenvironment in surgically resected NSCLCs from patients who received and did not receive neo-adjuvant chemotherapy.

Methods: We studied formalin-fixed and paraffin embedded (FFPE) tumor tissues from 112 stage II/III resected NSCLC, including 61 chemotherapy-naïve (adenocarcinoma, ADC=33; squamous cell carcinoma, SCC=28) and 51 chemotherapy-treated (ADC=31; SCC=20) tumors. mIF was performed using the Opal 7-color fIHC Kit™, scanning in the Vectra™ multispectral microscope and analyzed using the inForm™ software (Perkin Elmer, Waltham, MA). The markers studied were grouped in two 6-antibody panels: Panel 1, AE1/AE3 pancytokeratins, PD-L1 (clone E1L3N), CD3, CD4, CD8 and CD68; and Panel 2, AE1/AE3, PD1, Granzyme B, FOXP3, CD45RO and CD57.

Results: Positive PD-L1 expression (&gt;5%) in malignant cells (MCs) was detected in 48% (n=53/112) of NSCLCs. Overall, chemotherapy-treated tumors showed significantly higher percentages of MCs expressing PD-L1 (median, 19.52%) than chemotherapy-naïve cases (median, 1.54%; P=0.008). Higher densities of lymphocytes expressing CD3+ (P=0.021), CD4+ (P=0.05), CD57 (P&lt;0.001), CD45RO+ (P=0.019), and PD-1 (P=0.016) were detected in chemotherapy-treated NSCLCs compared with chemo-naïve tumors. In contrast, lower densities of FOXP3+ regulatory T cells and CD68+ macrophages but not statistical significant were detected in chemotherapy-naïve tumors when compared with chemotherapy-treated cases. Following chemotherapy ADCs exhibited significantly higher levels of CD57+ (P=0.008) and high density of PD-1 expressing by CD45RO+ cells (P=0.016) than chemotherapy-naïve tumors. Chemotherapy-treated SCCs demonstrated higher density of TAMs CD68+, CD57+,CD45RO+ and PD-1 cells than chemotherapy-naïve tumors (P&lt;0.05). In chemotherapy-treated cancers, lower levels of CD4+ helper T cells was associated with worse overall survival (OS; P=0.04) in univariate analysis. In chemotherapy-treated ADC patients, lower levels of CD68-positive (P=0.010) and higher levels of FOXP3-positive cells correlated with worse OS (P=0.044).

Conclusions: Neo-adjuvant chemotherapy-treated NSCLCs exhibited higher levels of PD-L1 expression and T cell subsets regulation compared to chemotherapy-naïve tumors, suggesting that chemotherapy activates specific immune response mechanisms in lung cancer. These results provide an inclination towards the design of clinical trials combining neo-adjuvant chemotherapy and immunotherapy prior to surgical resection of locally advanced NSCLC. (Supported by CPRIT MIRA and UT Lung SPORE grants, and MD Anderson Moon Shot Program).

Citation Format: Edwin Roger Cuentas, Carmen Behrens, Jaime Rodriguez-Canales, Mei Jiang, Apar Pataer, Arelene Correa, Stephen Swisher, Boris Sepesi, Annikka Weissferdt, Neda Kalhor, Jiexin Zhang, Jack Lee, John Heymach, Cesar Moran, Jianjun Zhang, Don Gibbons, Ignacio Wistuba. Neoadjuvant chemotherapy influence changes of the immune response in non-small cell lung carcinomas immune response in non-small cell lung carcinomas [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 2934. doi:10.1158/1538-7445.AM2017-2934

Abstract 5717: PKR promotes EphA2 and other proteins degradation and is predictor of survival in lung cancer

Relative expression of PKR and EphA2 was a significant predictor of survival in non-small cell lung cancer. To study the PKR-regulated protein, we evaluated expression of 149 proteins in lung cancer cells by reverse-phase protein assay (RPPA) after induction of PKR. Expression of several proteins (EphA2, IRS1, Chk1 and c-Raf and paxillin) was inhibited by PKR. In validating the downregulated proteins by western blot analysis, we observed that PKR reduced EphA2, IRS1, Chk1 and paxillin protein expression. We next investigated the involvement of the proteasomes and lysosomes in PKR-induced protein degradation. Human lung cancer H1299 and A549 cells were transfected with Ad-PKR for 48 h in the presence or absence of the proteasome inhibitor MG132 or lysosome inhibitor (3MA: 3-methyladenine). We observed that MG132 prevented PKR-induced IRS1 and Chk1 degradation, but not PKR-induced EphA2 and paxillin degradation in these cells. However, we found that 3MA prevented PKR-induced EphA2 and paxillin degradation in these cells. These data suggest that PKR is involved in proteasome as well as lysosome function. To study the involvement of autophagy pathway in PKR mediated protein degradation, we evaluated proteins which known involved in autophagy by Western blotting after induction of PKR on these cancer cells. We observed slightly decrease of LC-3, ATG5 and Beclin1 in these cancer cells after induction of PKR. Our data suggest that PKR may directly involve in in lysosome function.

Citation Format: Apar Pataer, Ruping Shao, Bulent Ozpolat, Bingliang Fang, Stephen G. Swisher. PKR promotes EphA2 and other proteins degradation and is predictor of survival in lung cancer [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 5717. doi:10.1158/1538-7445.AM2017-5717

Abstract 2261: PKR and Jagged1 associated with lymph node metastasis in lung cancer

In the current study, we analyzed the association between lymph node metastasis and over 50 biomarkers in 319 NSCLC patients. We observed that tumor location and the protein expressions of Jagged1 and RNA-dependent protein kinase (PKR) have significantly association with the lymph node metastasis. We further investigated the mechanism of interaction between Jagged1 and PKR, and demonstrated that induction of PKR promotes Jagged1 protein degradation through proteasome system in lung cancer cells. We also found that combination of Jagged1 with PKR improved prognostic value in all stages NSCLC patients. However, combination of Jagged1 with PKR did not improve lymph node metastatic value. Taken together, our data suggest that PKR and Jagged1 are independent markers for predicting lymph node metastasis, and PKR may reduce lymph node metastasis partly by promote Jagged1 proteins degradation in NSCLC patients.

Citation Format: Apar Pataer, Chuncheng Hao, Arlene M. Correa, Annikka Weissferdt, Carmen Behrens, Ignacio I. Wistuba, Stephen G. Swisher. PKR and Jagged1 associated with lymph node metastasis in lung cancer. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2261.

RNA-dependent protein kinase (PKR) depletes nutrients, inducing phosphorylation of AMP-activated kinase in lung cancer

We have demonstrated that RNA-dependent protein kinase (PKR) and its downstream protein p-eIF2α are independent prognostic markers for overall survival in lung cancer. In the current study, we further investigate the interaction between PKR and AMPK in lung tumor tissue and cancer cell lines. We examined PKR protein expression in 55 frozen primary lung tumor tissues by Western blotting and analyzed the association between PKR expression and expresson of 139 proteins on tissue samples examined previously by Reverse Phase Protein Array (RPPA) from the same 55 patients. We observed that biomarkers were either positively (phosphorylated AMP-activated kinase^T172 [p-AMPK]) or negatively (insulin receptor substrate 1, meiotic recombination 11, ATR interacting protein, telomerase, checkpoint kinase 1, and cyclin E1) correlated with PKR. We further confirmed that induction of PKR with expression vectors in lung cancer cells causes activation of the AMPK protein independent of the LKB1, TAK1, and CaMKKβ pathway. We found that PKR causes nutrient depletion, which increases AMP levels and decreases ATP levels, causing AMPK phosphorylation. We further demonstrated that inhibiting AMPK expression with compound C or siRNA enhanced PKR-mediated cell death. We next explored the combination of PKR and p-AMPK expression in NSCLC patients and observed that expression of p-AMPK predicted a poor outcome for adenocarcinoma patients with high PKR expression and a better prognosis for those with low PKR expression. These findings were consistent with our in vitro results. AMPK might rescue cells facing metabolic stresses, such as ATP depletion caused by PKR. Our data indicate that PKR causes nutrient depletion, which induces the phosphorylation of AMPK. AMPK might act as a protective response to metabolic stresses, such as nutrient deprivation.

Recent developments regarding the use of thieno[2,3-d]pyrimidin-4-one derivatives in medicinal chemistry, with a focus on their synthesis and anticancer properties

It is generally understood that the antitumor properties of synthetic heterocyclic compounds are among the most powerful properties that can be made use in medicinal chemistry. More specifically, their substantial cytotoxic effects against different types of human tumor cells, in addition to their roles as enzymes or receptors for various kinase inhibitors, make them critically important. In recent years, thieno[2,3-d]pyrimidin-4-one derivatives (TPs), which are analogs of quinazoline alkaloids, have frequently attracted the interest of medicinal chemistry researchers due to their promising anticancer properties. The present study is a review of the latest advances (i.e., since 2006) in TP derivative-related research, with a focus on how such derivatives are synthesized and on their anticancer activities.

Abstract 1908: Evaulate biomarkers in NSCLC tumors receiving neoadjuvant chemotherapy

In previous study, we have evaluated the ability of histopathologic response criteria to predict overall survival (OS) and disease free survival (DFS) and observed that the percentage of residual viable tumor cells were associated with OS and DFS in 192 NSCLC patients receiving neoadjuvant chemotherapy. In current study, we examined the selected protein biomarkers by IHC in surgical specimens of 98 NSCLC patients receiving neoadjuvant chemotherapy. All NSCLC patients treated with neoadjuvant chemotherapy received a platinum and taxane-based. For IHC analysis of protein markers, we selected candidate biomarkers (VEGFR2, EZH2, ERCC1 and Rad51) on the basis of the literature. Next, the results of VEGFR2, EZH2, ERCC1 and Rad51 expression were analyzed with regard to pathologic response and overall survival time of the patients. The surgical pathologic stage, percentage of viable tumor cells and Rad51 were associated with OS in 98 NSCLC patients receiving neoadjuvant chemotherapy in univariate and multivariate analysis. We found that patients with high-level expression of Rad51 had a poorer prognosis than did those with low-level expression. We observed that Rad51 expression was associated with pathologic response (viable tumor cells). However, there is no association between VEGFR2, EZH2, or ERCC1 expression and pathologic response (viable tumor cells). We further examined K-Ras and EGFR Mutation in these NSCLC tumors receiving neoadjuvant chemotherapy. We analyzed the hotsport mutations in K-Ras gene (Codon 12 and 13) and EGFR gene (Exon 19 and 21) by pyrosequencing and confirmed by direct sequencing method in 98 NSCLC tumors receiving neoadjuvant chemotherapy. We observed both methods had similar results on these patients’ samples. The L858R mutation results in an amino acid substitution at position 858 in EGFR, from a leucine (L) to an arginine (R). This mutation occurs within exon 21, which encodes part of the kinase domain,We found K-Ras mutation tended to be associated with OS, but not EGFR mutation. There is no association between percentage of viable tumor cells, VEGFR2, EZH2, ERCC1, Rad51 expression and K-Ras or EGFR mutation.

Citation Format: Apar Pataer, Ruping Shao, Arlene M. Correa, Carmen Behrens, Jack A. Roth, Ignacio I. Wistuba, Stephen G. Swisher. Evaulate biomarkers in NSCLC tumors receiving neoadjuvant chemotherapy. [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 1908. doi:10.1158/1538-7445.AM2015-1908

Gene mutations in primary tumors and corresponding patient-derived xenografts derived from non-small cell lung cancer

Molecular annotated patient-derived xenograft (PDX) models are useful for the preclinical investigation of anticancer drugs and individualized anticancer therapy. We established 23 PDXs from 88 surgical specimens of lung cancer patients and determined gene mutations in these PDXs and their paired primary tumors by ultradeep exome sequencing on 202 cancer-related genes. The numbers of primary tumors with deleterious mutations in TP53, KRAS, PI3KCA, ALK, STK11, and EGFR were 43.5%, 21.7%, 17.4%, 17.4%, 13.0%, and 8.7%, respectively. Other genes with deleterious mutations in ≥3 (13.0%) primary tumors were MLL3, SETD2, ATM, ARID1A, CRIPAK, HGF, BAI3, EP300, KDR, PDGRRA and RUNX1. Of 315 mutations detected in the primary tumors, 293 (93%) were also detected in their corresponding PDXs, indicating that PDXs have the capacity to recapitulate the mutations in primary tumors. Nevertheless, a substantial number of mutations had higher allele frequencies in the PDXs than in the primary tumors, or were not detectable in the primary tumor, suggesting the possibility of tumor cell enrichment in PDXs or heterogeneity in the primary tumors. The molecularly annotated PDXs generated from this study could be useful for future translational studies.

Abstract 4739: Nutrient depletion caused by PKR induces phosphorylation of AMPK in lung cancer

We have demonstrated that RNA-dependent protein kinase (PKR) and its downstream protein p-eIF2α are independent prognostic markers for survival in lung cancer. In the current study, we aimed to elucidate PKR's specific role in lung cancer. We examined PKR and p-PKR protein expression in 60 frozen primary lung tumor tissues by Western blot analysis and analyzed the association between PKR/p-PKR expression and expression of 139 proteins examined previously by reverse phase protein array in tissue samples from the same 60 patients. We demonstrated several biomarkers that were either positively (p-AMPK) or negatively (IRS1, p-IGF1R, MRE11, ATRIP, telomerase, CHK1, and cyclin E1) correlated with PKR and p-PKR. We confirmed that induction of PKR or p-PKR with expression vectors in lung cancer cells caused phospholation of the AMP-activated protein kinase (AMPK) protein; phospholation was independent of the LKB1, CaMKKβ, and TAK1 pathways. We observed that AMPK phosphorylation was caused by the elevated levels of AMP and decreased levels of ATP resulting from PKR-mediated nutrient depletion. Inhibition of AMPK expression by compound C or siRNA enhanced PKR-mediated cell death. We next investigated the combination of PKR and p-AMPK expression in non-small cell lung cancer patients; we observed that high expression of p-AMPK predicted worse prognosis in patients with high PKR expression but better prognosis in patients with low PKR expression. The p-AMPK may be required for cancer cell survival in patients with high PKR expression and may inhibit cancer cell growth in patients with low PKR expression. In summary, our data indicate that PKR-mediated nutrient depletion induces phosphorylation of AMPK, which is required for lung cancer cell survival.

Citation Format: Apar Pataer, Chengcheng Guo, Ruping Shao, Arlene M. Correa, Carmen Behrens, Bingliang Fang, Jack A. Roth, Ignacio I. Wistuba, Stephen G. Swisher. Nutrient depletion caused by PKR induces phosphorylation of AMPK in lung cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 4739. doi:10.1158/1538-7445.AM2014-4739

Pathological response after neoadjuvant chemotherapy in resectable non-small-cell lung cancers: proposal for the use of major pathological response as a surrogate endpoint

Improvements in outcomes for patients with resectable lung cancers have plateaued. Clinical trials of resectable non-small-cell lung cancers with overall survival as the primary endpoint require a decade or longer to complete, are expensive, and limit innovation. A surrogate for survival, such as pathological response to neoadjuvant chemotherapy, has the potential to improve the efficiency of trials and expedite advances. 10% or less residual viable tumour after neoadjuvant chemotherapy, termed here major pathological response, meets criteria for a surrogate; major pathological response strongly associates with improved survival, is reflective of treatment effect, and captures the magnitude of the treatment benefit on survival. We support the incorporation of major pathological response as a surrogate endpoint for survival in future neoadjuvant trials of resectable lung cancers. Additional prospective studies are needed to confirm the validity and reproducibility of major pathological response within individual histological and molecular subgroups and with new drugs.

Insulin-like growth factor binding protein-2 level is increased in blood of lung cancer patients and associated with poor survival

Background

We recently showed that IGFBP2 is overexpressed in primary lung cancer tissues. This study aims to determine whether IGFBP2 is elevated in blood samples of lung cancer patients and whether its level is associated with clinical outcomes.

Methodology/Principal Findings

Plasma IGFBP2 levels were determined blindly by enzyme-linked immunosorbent assay in 80 lung cancer patients and 80 case-matched healthy controls for comparison. We analyzed blood samples for IGFBP2 levels from an additional 84 patients with lung cancer and then tested for associations between blood IGFBP2 levels and clinical parameters in all 164 lung cancer patients. All statistical tests were two-sided and differences with p<0.05 were considered significant. The mean plasma concentration of IGFBP2 in lung cancer patients was significantly higher than that in healthy controls (388.12±261.00 ng/ml vs 219.30±172.84 ng/ml, p<0.001). IGFBP2 was increased in all types of lung cancer, including adenocarcinoma, squamous cell cancer, and small-cell cancer, regardless of patients’ age, sex, or smoking status. IGFBP2 levels were mildly but significantly associated with tumor size and were significantly higher in stage IV than stage I or III disease. A multivariate analysis showed that lung cancer patients whose blood IGFBP2 was higher than 160.9 ng/ml had a poor survival outcome, with a hazard ratio of 8.76 (95% CI 1.12-68.34, p=0.038 after adjustment for tumor size, pathology, and stage). The median survival time for patients with blood IGFBP2 >160.9 ng/ml is 15.1 months; whereas median survival time was 128.2 months for the patients whose blood IGFBP2 was ≤160.9 ng/ml (p =0.0002).

Conclusions/Significance

Blood IGFBP2 is significantly increased in lung cancer patients. A high circulating level of IGFBP2 is significantly associated with poor survival, suggesting that blood IGFBP2 levels could be a prognostic biomarker for lung cancer.

Abstract 1734: Prognostic significance of combinations of RNA-dependent protein kinase and EphA2 biomarkers for NSCLC

RNA-dependent protein kinase (PKR) is an independent prognostic variable in patients with non-small cell lung cancer (NSCLC). In the present study, we investigated the correlation between PKR and 25 other biomarkers for NSCLC, identified the markers that could further improve the prognostic significance of PKR, and elucidated the mechanisms of interaction between these markers and PKR. Tissue microarray samples obtained from 218 lung cancer patients were stained with an anti-PKR antibody and antibodies against 25 biomarkers. Immunohistochemical expression was scored and used for Kaplan-Meier survival analysis. The interaction between PKR and EphA2 in NSCLC cell lines was examined. We found that PKR was associated with EphA2 and that the prognostic information regarding NSCLC provided by the combination of PKR and EphA2 (P/E) was significantly more accurate than that provided by either marker alone. The 5-year overall survival rate in PKRlow/EphA2high patients (20%) was significantly lower than that of PKRhigh/EphA2low patients (74%), PKRhigh/EphA2high patients (55%), and PKRlow/EphA2low patients (55%) (P &lt; 0.0001). We also found that the PKR:EphA2 (P/E) ratio was significantly associated with prognosis (P &lt; 0.0001). Univariate and multivariate Cox analyses revealed that this P/E combination or ratio was an independent predictor of overall survival. In addition, induction of PKR expression reduced EphA2 protein expression levels in NSCLC cell lines. PKR/EphA2 is a significant predictor of prognosis for NSCLC. PKR/EphA2 may be a promising approach to improving screening efficiency and predicting prognosis in NSCLC patients.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 1734. doi:1538-7445.AM2012-1734

Aberrant expression of proteins involved in signal transduction and DNA repair pathways in lung cancer and their association with clinical parameters

BACKGROUND

Because cell signaling and cell metabolic pathways are executed through proteins, protein signatures in primary tumors are useful for identifying key nodes in signaling networks whose alteration is associated with malignancy and/or clinical outcomes. This study aimed to determine protein signatures in primary lung cancer tissues.

METHODOLOGY/ PRINCIPAL FINDINGS

We analyzed 126 proteins and/or protein phosphorylation sites in case-matched normal and tumor samples from 101 lung cancer patients with reverse-phase protein array (RPPA) assay. The results showed that 18 molecules were significantly different (p<0.05) by at least 30% between normal and tumor tissues. Most of those molecules play roles in cell proliferation, DNA repair, signal transduction and lipid metabolism, or function as cell surface/matrix proteins. We also validated RPPA results by Western blot and/or immunohistochemical analyses for some of those molecules. Statistical analyses showed that Ku80 levels were significantly higher in tumors of nonsmokers than in those of smokers. Cyclin B1 levels were significantly overexpressed in poorly differentiated tumors while Cox2 levels were significantly overexpressed in neuroendocrinal tumors. A high level of Stat5 is associated with favorable survival outcome for patients treated with surgery.

CONCLUSIONS/ SIGNIFICANCE

Our results revealed that some molecules involved in DNA damage/repair, signal transductions, lipid metabolism, and cell proliferation were drastically aberrant in lung cancer tissues, and Stat5 may serve a molecular marker for prognosis of lung cancers.

The role of PKR/eIF2α signaling pathway in prognosis of non-small cell lung cancer

BACKGROUND

In this study, we investigated whether PKR protein expression is correlated with mRNA levels and also evaluated molecular biomarkers that are associated with PKR, such as phosphorylated PKR (p-PKR) and phosphorylated eIF2α (p-eIF2α).

METHODOLOGY AND FINDINGS

We determined the levels of PKR protein expression and mRNA in 36 fresh primary lung tumor tissues by using Western blot analysis and real-time reverse-transcriptase PCR (RT-PCR), respectively. We used tissue microarrays for immunohistochemical evaluation of the expression of p-PKR and p-eIF2α proteins. We demonstrated that PKR mRNA levels are significantly correlated with PKR protein levels (Spearman's rho = 0.55, p<0.001), suggesting that PKR protein levels in tumor samples are regulated by PKR mRNA. We also observed that the patients with high p-PKR or p-eIF2α expression had a significantly longer median survival than those with little or no p-PKR or p-eIF2α expression (p = 0.03 and p = 0.032, respectively). We further evaluated the prognostic effect of combined expression of p-PKR plus PKR and p-eIF2α plus PKR and found that both combinations were strong independent prognostic markers for overall patient survival on stage I and all stage patients.

CONCLUSIONS

Our findings suggest that PKR protein expression may controlled by transcription level. Combined expression levels of PKR and p-PKR or p-eIF2α can be new markers for predicting the prognosis of patients with NSCLC.

Abstract 2250: PKR signaling pathway plays an important role in prognosis for non-small cell lung cancer

The role of RNA-dependent protein kinase (PKR) in antiviral defence mechanisms and in cellular differentiation, growth, and apoptosis is well known, but the role of PKR in human lung cancer remains poorly understood. To explore the role of PKR in human lung cancer, we evaluated PKR's expression in tissue microarray specimens from both non-small cell lung cancer (NSCLC) and normal human bronchial epithelium tissue. The NSCLC cells showed lower levels of PKR expression than normal bronchial epithelium cells did. We also found a significant association between lower levels of PKR expression and lymph node metastasis. We found that loss of PKR expression is correlated with a more aggressive behavior, and that a high PKR expression predicts a subgroup of patients with a favorable outcome. Univariate and multivariate Cox proportional hazards regression models showed that a lower level of PKR expression was significantly associated with shorter survival in NSCLC patients. We further validated and confirmed that PKR to be a powerful prognostic factor in TMA-2 lung cancer (HR=0.22, P&lt;0.0001). We also observed that the patients with high p-PKR or p-eIF2a expression had a significantly longer median survival than those with little or no p-PKR or p-eIF2a expression (P = 0.03 and P = 0.032, respectively). Combined expression of PKR and p-PKR or PKR and p-eIF2a increased patient survival (P = 0.001). Combined expression levels of PKR and p-PKR or p-eIF2a can be new markers for predicting the prognosis of patients with NSCLC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2250. doi:10.1158/1538-7445.AM2011-2250

Enhancement of adenoviral MDA-7-mediated cell killing in human lung cancer cells by geldanamycin and its 17-allyl- amino-17-demethoxy analogue

Our previous studies demonstrated that adenovirus-mediated overexpression of melanoma differentiation-associated gene-7 (Ad-mda7) leads to rapid induction of double-stranded RNA-dependent protein kinase (PKR) and activation of its downstream targets, resulting in apoptosis induction in human lung cancer cells. Here, we report that Ad-mda7 and the benzoquinone ansamycin geldanamycin (GA) interact in a highly synergistic manner to induce cell death in human lung cancer cells. Co-administration of Ad-mda7 and GA did not modify expression of MDA-7, and was not associated with further PKR induction and activation; instead the enhanced cytotoxicity of this combination was associated with inactivation of AKT by GA. By surface staining using anti-E-cadherin monoclonal antibody and flow cytometry, we found that treatment with the combination of Ad-mda7 and GA increased E-cadherin levels in these cancer cells. Ad-mda7 and GA cotreatment also inhibited lung cancer cell motility by increasing the beta-catenin/E-cadherin association. Moreover, combination of GA derivative 17-allyl-amino, 17-demethoxygeldanamycin (17AAG), with Ad-mda7 resulted in enhancement of cell death in A549 and H460 human lung cancer cells.

Genetic deletion of PKR abrogates TNF-induced activation of IkappaBalpha kinase, JNK, Akt and cell proliferation but potentiates p44/p42 MAPK and p38 MAPK activation

Double-stranded RNA-dependent protein kinase (PKR), a ubiquitously expressed serine/threonine kinase, has been implicated in the regulation or modulation of cell growth through multiple signaling pathways, but how PKR regulates tumor necrosis factor (TNF)-induced signaling pathways is poorly understood. In the present study, we used fibroblasts derived from PKR gene-deleted mice to investigate the role of PKR in TNF-induced activation of nuclear factor-kappaB (NF-kappaB), mitogen-activated protein kinases (MAPKs) and growth modulation. We found that in wild-type mouse embryonic fibroblast (MEF), TNF induced NF-kappaB activation as measured by DNA binding but deletion of PKR abolished this activation. This inhibition was associated with suppression of inhibitory subunit of NF-kappaB (IkappaB)alpha kinase (IKK) activation, IkappaBalpha phosphorylation and degradation, p65 phosphorylation and nuclear translocation, and NF-kappaB-dependent reporter gene transcription. TNF-induced Akt activation needed for IKK activation was also abolished by deletion of PKR. NF-kappaB activation was diminished in PKR-deleted cells transfected with TNF receptor (TNFR) 1, TNFR-associated death domain and TRAF2 plasmids; NF-kappaB activated by NF-kappaB-inducing kinase, IKK or p65, however, was minimally affected. Among the MAPKs, it was interesting that whereas TNF-induced c-Jun N-terminal kinase (JNK) activation was abolished, activation of p44/p42 MAPK and p38 MAPK was potentiated in PKR-deleted cells. TNF induced the expression of NF-kappaB-regulated gene products cyclin D1, c-Myc, matrix metalloproteinase-9, survivin, X-linked inhibitor-of-apoptosis protein (IAP), IAP1, Bcl-x(L), A1/Bfl-1 and Fas-associated death domain protein-like IL-1beta-converting enzyme-inhibitory protein in wild-type MEF but not in PKR-/- cells. Similarly, TNF induced the proliferation of wild-type cells, but this proliferation was completely suppressed in PKR-deleted cells. Overall, our results indicate that PKR differentially regulates TNF signaling; IKK, Akt and JNK were positively regulated, whereas p44/p42 MAPK and p38 MAPK were negatively regulated.

mda-7 gene transfer sensitizes breast carcinoma cells to chemotherapy, biologic therapies and radiotherapy: correlation with expression of bcl-2 family members

Current therapies used in the treatment of breast cancer are limited by systemic toxicity, rapid drug metabolism and intrinsic and acquired drug resistance. We have previously shown that adenoviral-mediated transfer of the melanoma differentiation-associated gene-7 (mda-7) elicits growth inhibition and apoptosis in various tumor types. Here, we evaluate the effects of Ad-mda7, alone and in combination with other therapies, against a panel of nine breast tumor cell lines and their normal counterparts; we report selective Ad-mda7-mediated p53-independent growth inhibition, G2/M cell cycle arrest, and apoptosis. In vivo, Ad-mda7 induced p53-independent tumor growth inhibition (P<0.004) in multiple xenograft models. We then evaluated the combination of Ad-mda7 with agents commonly used to treat breast cancer: radiotherapy (XRT), Tamoxifen, Taxotere, Adriamycin, and Herceptin. These agents exhibit diverse modes of action, including formation of bulky adducts, inhibition of DNA replication (Adriamycin, XRT), damage to microtubules (Taxotere), nonsteroidal estrogen antagonists (Tamoxifen), or Her2/neu receptor blockade (Herceptin). Treated with conventional anticancer drugs or radiation, MDA-7-expressing cells display additive or synergistic cytotoxicity and apoptosis that correlates with decreased BCL-2 expression and BAX upregulation. In vivo, animals that received Ad-mda7 and XRT underwent significant reduction of tumor growth (P<0.002). This is the first report of the synergistic effects of Ad-mda7 combined with chemotherapy or radiotherapy on human breast carcinoma cells.

Induction of apoptosis in human lung cancer cells following treatment with amifostine and an adenoviral vector containing wild-type p53

Adenoviral delivery of the p53 gene is a potential therapeutic approach for the treatment of lung cancer. Furthermore, amifostine is a cytoprotective agent and recent reports have described its potentiation of chemotherapy's antitumor activity in lung cancer. Therefore, we wished to investigate the ability of amifostine both alone and in combination with p53-based therapy to induce apoptosis, and to understand the mechanisms by which this apoptosis occurs. Using p53 null and wild-type p53 human lung cancer cells and normal human bronchial epithelial cells, we evaluated the effects of amifostine on proliferation and apoptosis. We then analyzed Adp53 in combination with amifostine and performed isobologram analysis. Expression of p53, p21(WAF1), Bax, Bak, bcl-2, as well as total and phosphorylated Cdc2 in the absence and presence of olomoucine, a phosphorylated Cdc2 kinase inhibitor, was then determined. Amifostine-induced apoptosis in human lung cancer cells in a dose-dependent fashion. The combination of amifostine and Adp53 significantly enhanced, with a supra-additive effect, the inhibition of proliferation of lung cancer cells. This enhancement of apoptosis by amifostine was associated with activation of p53 and dephosphorylation of Cdc2 proteins. Notably, olomoucine effectively prevented amifostine and/or Adp53-induced Cdc2 kinase activation and subsequent apoptosis. Our data shows that amifostine alone can induce apoptosis of human lung cancer cells, and that the combination of Adp53 with amifostine resulted in significantly higher levels of apoptosis. In addition, it appears that Cdc2 kinase plays an important role in the induction of apoptosis by amifostine and Adp53.

Adenovirus-mediated Bak gene transfer induces apoptosis in mesothelioma cell lines

OBJECTIVE

Conventional treatment for mesothelioma is largely ineffective. We therefore evaluated the novel approach of adenoviral gene transfer of the proapoptotic Bcl-2 family member Bak in mesothelioma cancer cell lines, which are sensitive and resistant to adenoviral p53.

METHODS

Binary adenoviral Bak (Ad/GT-Bak and Ad/GV16) and LacZ (Ad/GT-LacZ and Ad/GV16) vectors were used for transduction of the mesothelioma cell lines I-45 (p53 resistant) and REN (p53 sensitive). Protein levels were determined by Western blotting. Apoptosis was assessed by morphologic changes, caspase-3 cleavage, and fluorescence-activated cell sorter analysis of subdiploid populations. Cell viability was determined with the XTT assay. Statistical analysis was performed with analysis of variance and the Student t test.

RESULTS

High levels of Bak gene transfer were seen after coadministration of Ad/GT-Bak and Ad/GV16 in both mesothelioma cell lines. Apoptosis was induced 24 hours after Bak but not LacZ gene transfer ([Bak: I-45, 36%; REN, 25%] vs [LacZ: I-45, 1%; REN, 3%], P <.05]) in p53-sensitive (REN) and p53-resistant (I-45) cell lines. Cellular viability was significantly decreased 48 to 72 hours after Bak gene transfer compared with control vector in both cell lines (72 hours: Bak I-45, 1.4% +/- 1.0%, and Bak REN, 4.7% +/- 1%, vs Lac-Z I-45, 83% +/- 3%, and Lac-Z REN, 100% +/- 1%; P <.05).

CONCLUSIONS

Adenovirus-mediated overexpression of the Bak gene induces apoptosis and decreased cellular viability in p53-sensitive and p53-resistant mesothelioma cells. These data suggest that the gene transfer of proapoptotic Bcl-2 family members may represent a novel gene therapy strategy to treat mesothelioma.