Chromosomal 3q amplicon encodes essential regulators of secretory vesicles that drive secretory addiction in cancer.

Cancer cells exhibit heightened secretory states that drive tumor progression. Here, we identify a chromosome 3q amplicon that serves as a platform for secretory regulation in cancer. The 3q amplicon encodes multiple Golgi-resident proteins, including the scaffold Golgi integral membrane protein 4 (GOLIM4) and the ion channel ATPase Secretory Pathway Ca2+ Transporting 1 (ATP2C1). We show that GOLIM4 recruits ATP2C1 and Golgi phosphoprotein 3 (GOLPH3) to coordinate calcium-dependent cargo loading and Golgi membrane bending and vesicle scission. GOLIM4 depletion disrupts the protein complex, resulting in a secretory blockade that inhibits the progression of 3q-amplified malignancies. In addition to its role as a scaffold, GOLIM4 maintains intracellular manganese (Mn) homeostasis by binding excess Mn in the Golgi lumen, which initiates the routing of Mn-bound GOLIM4 to lysosomes for degradation. We show that Mn treatment inhibits the progression of multiple types of 3q-amplified malignancies by degrading GOLIM4, resulting in a secretory blockade that interrupts pro-survival autocrine loops and attenuates pro-metastatic processes in the tumor microenvironment. Potentially underlying the selective activity of Mn against 3q-amplified malignancies, ATP2C1 co-amplification increases Mn influx into the Golgi lumen, resulting in a more rapid degradation of GOLIM4. These findings show that functional cooperativity between co-amplified genes underlies heightened secretion and a targetable secretory addiction in 3q-amplified malignancies.

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 .).

Major Pathologic Response and Prognostic Score Predict Survival in Patients With Lung Cancer Receiving Neoadjuvant Chemotherapy.

Introduction: Complete pathologic response (CPR) is an acceptable surrogate for survival in clinical trials but it occurs infrequently in patients with NSCLC receiving neoadjuvant chemotherapy (NCT). Therefore, we studied the impact of major pathologic response (MPR) for predicting survival of patients with NSCLC receiving NCT. We also tested a newly reported scoring system-the prognostic score (PRSC)-which combines T category, lymph node status, and MPR status. Methods: We analyzed CPR and MPR, defined as 0% and less than or equal to 10% viable tumor cells, respectively, in 339 patients with NSCLC with various histologic types who had been treated with NCT followed by complete surgical resection. We evaluated the relationships between CPR, MPR, or PRSC and overall survival using the Kaplan-Meier method and Cox regression multivariate models, accounting for known prognostic factors, such as age, gender, histologic subtype, and pathologic stage. Results: Among all 339 patients, the Kaplan-Meier method revealed that patients with CPR and MPR had better survival. MPR identified a favorable group of patients who experienced survival similar to patients with CPR. Nevertheless, patients with no MPR had a significantly reduced probability of survival. Furthermore, univariate and multivariate Cox proportional hazards regression analysis revealed that MPR and PRSC were significantly associated with overall survival. Conclusions: Our data suggest that MPR can be used as an end point for overall survival in different histologic types for evaluation of therapeutic agents in clinical trials exploring NCT. We also confirmed that PRSC had a prognostic impact, differentiating patients into three prognostic groups, but not superior compared with MPR alone or the TNM8 systems.

Distinct Immune Gene Programs Associated with Host Tumor Immunity, Neoadjuvant Chemotherapy, and Chemoimmunotherapy in Resectable NSCLC.

PURPOSE: Our understanding of the immunopathology of resectable non-small cell lung cancer (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 were based on the location of CD8+ T cells (inflamed, cold, excluded), tumoral PD-L1 expression (<1% and ≥1%), and tumor-infiltrating lymphocytes (TIL). Immune programs and signatures were statistically analyzed on the basis of tumoral PD-L1 expression, immune phenotypes, and pathologic 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). Pathologic response to chemoimmunotherapy was positively associated with higher expression of genes involved in immune activation, chemotaxis, as well as T and natural killer cells (P < 0.05 for all). Among the three cohorts, chemoimmunotherapy-treated NSCLCs exhibited the 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 after neoadjuvant nivolumab or nivolumab with ipilimumab in patients with 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.

Epstein Barr virus-positive B-cell lymphoma is highly vulnerable to MDM2 inhibitors in vivo.

Epstein-Barr virus-positive (EBV-positive) B-cell lymphomas are common in immunocompromised patients and remain an unmet medical need. Here we report that MDM2 inhibitors (MDM2is) navtemadlin and idasanutlin have potent in vivo activity in EBV-positive B-cell lymphoma established in immunocompromised mice. Tumor regression was observed in all 5 EBV-positive xenograft-associated B-cell lymphomas treated with navtemadlin or idasanutlin. Molecular characterization showed that treatment with MDM2is resulted in activation of p53 pathways and downregulation of cell cycle effectors in human lymphoma cell lines that were either EBV-positive or had undetectable expression of BCL6, a transcriptional inhibitor of the TP53 gene. Moreover, treatment with navtemadlin resulted in tumor regression and prevented systemic dissemination of EBV-positive lymphoma derived from 2 juvenile patients with posttransplant lymphoproliferative diseases, including 1 whose tumor was resistant to virus-specific T-cell therapy. These results provide proof-of-concept for targeted therapy of EBV-positive lymphoma with MDM2is and the feasibility of using EBV infection or loss of BCL6 expression to identify responders to MDM2is.

Nodal immune flare mimics nodal disease progression following neoadjuvant immune checkpoint inhibitors in non-small cell lung cancer.

Radiographic imaging is the standard approach for evaluating the disease involvement of lymph nodes in patients with operable NSCLC although the impact of neoadjuvant immune checkpoint inhibitors (ICIs) on lymph nodes has not yet been characterized. Herein, we present an ad hoc analysis of the NEOSTAR trial (NCT03158129) where we observed a phenomenon we refer to as "nodal immune flare" (NIF) in which patients treated with neoadjuvant ICIs demonstrate radiologically abnormal nodes post-therapy that upon pathological evaluation are devoid of cancer and demonstrate de novo non-caseating granulomas. Abnormal lymph nodes are analyzed by computed tomography and 18F-fluorodeoxyglucose positron emission tomography/computer tomography to evaluate the size and the maximum standard uptake value post- and pre-therapy in NEOSTAR and an independent neoadjuvant chemotherapy cohort. NIF occurs in 16% (7/44) of patients treated with ICIs but in 0% (0/28) of patients after neoadjuvant chemotherapy. NIF is associated with an inflamed nodal immune microenvironment and with fecal abundance of genera belonging to the family Coriobacteriaceae of phylum Actinobacteria, but not with tumor responses or treatment-related toxicity. Our findings suggest that this apparent radiological cancer progression in lymph nodes may occur due to an inflammatory response after neoadjuvant immunotherapy, and such cases should be evaluated by pathological examination to distinguish NIF from true nodal progression and to ensure appropriate clinical treatment planning.

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.

Neoadjuvant nivolumab or nivolumab plus ipilimumab in operable non-small cell lung cancer: the phase 2 randomized NEOSTAR trial.

Ipilimumab improves clinical outcomes when combined with nivolumab in metastatic non-small cell lung cancer (NSCLC), but its efficacy and impact on the immune microenvironment in operable NSCLC remain unclear. We report the results of the phase 2 randomized NEOSTAR trial (NCT03158129) of neoadjuvant nivolumab or nivolumab + ipilimumab followed by surgery in 44 patients with operable NSCLC, using major pathologic response (MPR) as the primary endpoint. The MPR rate for each treatment arm was tested against historical controls of neoadjuvant chemotherapy. The nivolumab + ipilimumab arm met the prespecified primary endpoint threshold of 6 MPRs in 21 patients, achieving a 38% MPR rate (8/21). We observed a 22% MPR rate (5/23) in the nivolumab arm. In 37 patients resected on trial, nivolumab and nivolumab + ipilimumab produced MPR rates of 24% (5/21) and 50% (8/16), respectively. Compared with nivolumab, nivolumab + ipilimumab resulted in higher pathologic complete response rates (10% versus 38%), less viable tumor (median 50% versus 9%), and greater frequencies of effector, tissue-resident memory and effector memory T cells. Increased abundance of gut Ruminococcus and Akkermansia spp. was associated with MPR to dual therapy. Our data indicate that neoadjuvant nivolumab + ipilimumab-based therapy enhances pathologic responses, tumor immune infiltrates and immunologic memory, and merits further investigation in operable NSCLC.

Controversies and challenges in the pathologic examination of lung resection specimens after neoadjuvant treatment.

New therapy approaches in the treatment of surgically resectable non-small cell lung cancer (NSCLC) challenge the traditional handling and examination of pathology specimens. The increasingly common use of neoadjuvant therapies before surgical resection, due to advantages in novel drug administration, tolerance, and measurement of radiographic and pathologic response compared to adjuvant treatment, has the potential to alter the microscopic tumor appearance and its biology. Currently, many clinical trials use pathologic response as a surrogate endpoint of clinical efficacy, since the extent of residual viable tumor appears to correlate with outcome in patients treated with neoadjuvant chemotherapy. Consequently, pathologic assessment of the extent of residual viable tumor is of paramount importance. However, high level evidence-based guidelines on how to process and evaluate such specimens are lacking. Moreover, while pathologic response has been shown to be associated with survival after chemotherapy, its significance after immunotherapy remains to be determined. Additionally, many clinical trials do not routinely include pathologists in trial design, which may lead to non-standardized evaluation of pathologic response. Although recently, several algorithms have been proposed to address these issues, none of them represents evidence-based recommendations or is universally applied. Therefore, controversies and challenges continue to exist, raising concerns about the validity, reproducibility, and comparability of the results of many neoadjuvant clinical trials. Herein, we discuss the current difficulties in pathologic specimen evaluation following neoadjuvant therapy in NSCLC and propose potential approaches to overcome these challenges.

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.

Agreement on Major Pathological Response in NSCLC Patients Receiving Neoadjuvant Chemotherapy.

INTRODUCTION: We have suggested that major pathologic response (MPR) could serve as a surrogate endpoint for survival and provide rapid means of comparing different neoadjuvant treatment regimens. Here, we confirm that MPR is predictive of long-term overall survival (OS) in patients with non-small-cell lung cancer (NSCLC) who underwent neoadjuvant chemotherapy and surgical resection, to assess agreement on MPR between 2 observers, and to determine the minimum number of slides needed to obtain an accurate determination of MPR. PATIENTS AND METHODS: We identified 151 patients with NSCLC who had been treated with neoadjuvant chemotherapy followed by complete surgical resection from 2008 to 2012. Tissue specimens were retrospectively evaluated by 2 pathologists who had been blinded to patients' treatment and outcome. We assessed the relationships between MPR and OS, the levels of agreement between the pathologists, and determined the number of slides needed to obtain an accurate determination of MPR. RESULTS: Our results reveal that MPR examined by either observer 1 (experienced) or by observer 2 (trained) was significantly predictive of long-term OS after neoadjuvant chemotherapy. MPR was associated with long-term OS in patients with NSCLC undergoing neoadjuvant chemotherapy on multivariable analysis (hazard ratio 2.68; P = .01). The levels of agreement between 2 pathologists were high after direct in-person training by one pathologist or the other (R2 = 0.994). Our data suggest that at least 3 slides should be read to accurately determine MPR. CONCLUSIONS: MPR is significantly predictive of long-term OS in neoadjuvant chemotherapy-treated patients with NSCLC. MPR may serve as a surrogate endpoint for evaluating novel chemotherapies and immunotherapy response in biomarker-driven translational clinical trials.

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-XL/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.

Therapeutic targeting of the PI4K2A/PKR lysosome network is critical for misfolded protein clearance and survival in cancer cells.

The role of RNA-dependent protein kinase R (PKR) and its association with misfolded protein expression in cancer cells are unclear. Herein we report that PKR regulates misfolded protein clearance by preventing it release through exosomes and promoting lysosomal degradation of misfolded prion proteins in cancer cells. We demonstrated that PKR contributes to the lysosome function and regulates misfolded prion protein clearance. We hypothesized that PKR-associated lysosome function is critical for cancer but not normal cell survival, representing an effective approach for highly targeted cancer therapy. In screening a compound library, we identified two PKR-associated compounds 1 and 2 (Pac 1 and 2) did not affect normal cells but selectively induced cell death in cancer cells depending on their PKR expression status. Pac 1 significantly inhibited the growth of human lung and breast xenograft tumors in mice with no toxicity. Pac 1 binds to PI4K2A and disrupts the PKR/PI4K2A-associated lysosome complex, contributing to destabilization of cancer cell lysosomes and triggering cell death. We observed that PKR and PI4K2A play significant prognostic roles in breast cancer patients. These results demonstrate that targeting of a PI4K2A/PKR lysosome complex may be an effective approach for cancer therapy.

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.