Disease control in patients with non-small cell lung cancer using pemetrexed: Investigating the best treatment strategy

BACKGROUND

Pemetrexed (PEM) is the primary chemotherapy for non-small cell lung cancer (NSCLC), showing potential for long-term disease stability in certain cases. However, studies examining disease control with PEM therapy are lacking. This study aimed to pinpoint clinical traits in patients with NSCLC responding well to PEM therapy, predict factors influencing disease control, and suggest optimal treatment approaches.

METHODS

A retrospective analysis of patients with NSCLC treated with PEM was performed to compare patients who achieved disease control after treatment with those who did not.

RESULTS

Of 73 patients, 56 (76.7%) achieved disease control with PEM therapy. In the disease control group, a significantly higher proportion of patients exhibited good performance status (PS) and received PEM doses without reduction after the second cycle. Multivariate analysis identified bevacizumab (Bev) noncompliance, PEM dose reduction, and thyroid transcription factor-1 (TTF-1) negativity as significant independent risk factors for disease progression during PEM therapy. Additionally, overall survival was significantly longer in the disease control group (p < 0.001).

CONCLUSIONS

Our findings indicated that maintaining the dose of PEM after the second treatment cycle in patients with NSCLC, along with concurrent use of Bev and the presence of TTF-1 positivity, could enhance disease control rates and extend survival.

Efficacy and safety of intrathecal pemetrexed for TKI-failed leptomeningeal metastases from EGFR+ NSCLC: an expanded, single-arm, phase II clinical trial

BACKGROUND

This study aimed to evaluate the efficacy and safety of intrathecal pemetrexed (IP) for treating patients with leptomeningeal metastases (LM) from non-small-cell lung cancer (NSCLC) who progressed from epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI) treatment in an expanded, prospective, single-arm, phase II clinical study (ChiCTR1800016615).

PATIENTS AND METHODS

Patients with confirmed NSCLC-LM who progressed from TKI received IP (50 mg, day 1/day 5 for 1 week, then every 3 weeks for four cycles, and then once monthly) until disease progression or intolerance. Objectives were to assess overall survival (OS), response rate, and safety. Measurable lesions were assessed by investigator according to RECIST version 1.1. LM were assessed according to the Response Assessment in Neuro-Oncology (RANO) criteria.

RESULTS

The study included 132 patients; 68% were female and median age was 52 years (31-74 years). The median OS was 12 months (95% confidence interval 10.4-13.6 months), RANO-assessed response rate was 80.3% (106/132), and the most common adverse event was myelosuppression (n = 42; 31.8%), which reversed after symptomatic treatment. The results of subgroup analysis showed that absence of brain parenchymal metastasis, good Eastern Cooperative Oncology Group score, good response to IP treatment, negative cytology after treatment, and patients without neck/back pain/difficult defecation had longer survival. Gender, age, previous intrathecal methotrexate/cytarabine, and whole-brain radiotherapy had no significant influence on OS.

CONCLUSIONS

This study further showed that IP is an effective and safe treatment method for the EGFR-TKI-failed NSCLC-LM, and should be recommended for these patients in clinical practice and guidelines.

Use of Novel National Data Sets to Monitor Chemotherapy Use and Outcomes: A Retrospective Cohort Study of Non-Small-Cell Lung Cancer in Aotearoa New Zealand

PURPOSE

Te Aho o Te Kahu, the New Zealand Cancer Control Agency, is establishing a systemic anticancer therapy (SACT) database (Anti-Cancer Therapy-Nationally Organized Workstream [ACT-NOW]) which can be linked to other national health data collections. In this article, we explore the application of ACT-NOW data in the monitoring of uptake and outcomes after the public funding of pemetrexed in Aotearoa New Zealand.

METHODS

We used the ACT-NOW collection to identify patients with advanced nonsquamous non-small-cell lung cancer, who were treated with first-line platinum-based doublet chemotherapy over an 8-year period. Data were extracted for a period of 4 years before and 4 years after the national funding of pemetrexed (November 1, 2017). Treatments were classified as historical platinum doublet (cisplatin or carboplatin with gemcitabine, vinorelbine, paclitaxel, or docetaxel) or platinum pemetrexed doublet (cisplatin or carboplatin with pemetrexed). The primary outcome was the proportion of patients receiving each treatment type, before and after November 1, 2017. To prototype linkage to outcomes data, we evaluated hospitalization and 1-year overall survival (OS) rates by treatment.

RESULTS

A total of 331 patients were included from four cancer centers. All patients (116 of 116) who were treated with first-line platinum-based doublet chemotherapy between November 2013 and November 2017 received historical platinum doublet chemotherapy. After the introduction of pemetrexed, between November 2017 and November 2021, 94% (203 of 215) were treated with platinum pemetrexed doublet chemotherapy and 6% (12 of 215) with historical platinum doublet chemotherapy. Linkage to outcomes data for 1-year OS, hospitalization rates, and lengths of stay outcome data were achievable.

CONCLUSION

The ACT-NOW data set has the potential to facilitate evaluation of the impact of national-level SACT funding decisions on prescribing practice and specific patient outcomes. Our results support the use of these data to inform resource planning and quality improvement.

MiR-320a upregulation contributes to the effectiveness of pemetrexed by inhibiting the growth and invasion of human lung cancer cell line (Calu-6)

BACKGROUND

Lung cancer is a common and deadly disease. Chemotherapy is the most common treatment, which inhibits cancer cell growth. Pemetrexed (PMX) is often used with other drugs. Environmental stress can affect regulatory non-coding RNAs such as MicroRNAs that modify gene expression. This study investigates the effect of PMX on the hsa-miR-320a-3p expression in the Calu-6 lung cancer cell line.

METHODS AND RESULT

Calu-6 cells were cultured in an incubator with 37 °C, 5% CO2, and 98% humidity. The MTT test was performed to determine the concentration of PMX required to inhibit 50% of cell growth. To examine growth inhibition and apoptosis, release of lactate dehydrogenase (LDH), cell assays and caspase 3 and 7 enzyme activity were used. Finally, molecular studies were conducted to compare the expression of hsa-miR-320a-3p and genes including VDAC1, DHFR, STAT3, BAX and BCL2 before and after therapy.

RESULTS

According to a study, it has been observed that PMX therapy significantly increases LDH release after 24 h. The study found that PMX's IC50 on Calu-6 is 8.870 µM. In addition, the treated sample showed higher expression of hsa-miR-320a-3p and BAX, while the expression of VDAC1, STAT3, DHFR and BCL2 decreased compared to the control sample.

CONCLUSION

According to the findings of the current research, hsa-miR-320a-3p seems to have the potential to play an important role in the development of novel approaches to the treatment of lung cancer.

A novel lncRNA-hidden polypeptide regulates malignant phenotypes and pemetrexed sensitivity in A549 pulmonary adenocarcinoma cells

The advance of high-throughput sequencing enhances the discovery of short ORFs embedded in long non-coding RNAs (lncRNAs). Here, we uncovered the production and biological activity of lncRNA-hidden polypeptides in lung adenocarcinoma (LUAD). In the present study, bioinformatics was used to screen the lncRNA-hidden polypeptides in LUAD. Analysis of protein expression was done by western blot or immunofluorescence assay. The functions of the polypeptide were determined by detecting its effects on cell viability, proliferation, migration, invasion, and pemetrexed (PEM) sensitivity. The protein interactors of the polypeptide were analyzed by mass spectrometry after Co-immunoprecipitation (Co-IP) assay. The results showed that the lncRNA LINC00954 was confirmed to encode a novel polypeptide LINC00954-ORF. The polypeptide had tumor-suppressor features in A549 cells by repressing cell growth, motility and invasion. Moreover, the polypeptide enhanced PEM sensitivity and suppressed growth in A549/PEM cells. The protein interactors of this polypeptide had close correlations with RNA processing, amide metabolic process, translation, RNA binding, RNA transport, and DNA replication. As a conclusion, the LINC00954-ORF polypeptide embedded in lncRNA LINC00954 possesses tumor-suppressor features in A549 and PEM-resistant A549 cells and sensitizes PEM-resistant A549 cells to PEM, providing evidence that the LINC00954-ORF polypeptide is a potential anti-cancer agent in LUAD.

Survivin degradation by bergenin overcomes pemetrexed resistance

PURPOSE

Chemoresistance is a primary factor for treatment failure and tumor recurrence in non-small cell lung cancer (NSCLC) patients. The oncoprotein survivin is commonly upregulated in human malignancies and is associated with poor prognosis, but its effect on carcinogenesis and chemoresistance in NSCLC is not yet evident, and to explore an effective inhibitor targeting survivin expression is urgently needed.

METHODS

The protumor characteristics of survivin and antitumor activities of bergenin in NSCLC cells were examined by MTS, colony formation assays, immunoblot, immunohistochemistry, and in vivo xenograft development.

RESULTS

Survivin was upregulated in non-small cell lung cancer (NSCLC) tissues, while its depletion inhibited NSCLC tumorigenesis. The current study focused on bergenin, identifying its effective antitumor effect on NSCLC cells both in vivo and in vitro. The results showed that bergenin could inhibit cell proliferation and induce the intrinsic pathway of apoptosis via downregulating survivin. Mechanistically, bergenin reduced the phosphorylation of survivin via inhibiting the Akt/Wee1/CDK1 signaling pathway, thus resulting in enhanced interaction between survivin and E3 ligase Fbxl7 to promote survivin ubiquitination and degradation. Furthermore, bergenin promoted chemoresistance in NSCLC cells re-sensitized to pemetrexed treatment.

CONCLUSIONS

Survivin overexpression is required for maintaining multiple malignant phenotypes of NSCLC cells. Bergenin exerts a potent antitumor effect on NSCLC via targeting survivin, rendering it a promising agent for the treatment of NSCLC.

Gastrodin destabilizes survivin and overcomes pemetrexed resistance

Survivin is a bifunctional protein that plays crucial roles in tumorigenesis. In the present study, we discovered that the natural product gastrodin suppressed the cell viability and colony formation of non-small cell lung cancer (NSCLC) cell lines A549, HCC827, and H460 in a dose-dependent manner. In addition, gastrodin enhanced the protein levels of cleaved-caspase 3 by activating the endogenous mitochondrial apoptosis pathway. Gastrodin inhibits protein kinase B (Akt)/WEE1/cyclin-dependent kinase 1 (CDK1) signaling to downregulate survivin Thr34 phosphorylation. Survivin Thr34 dephosphorylation caused by gastrodin interfered with the binding of ubiquitin-specific protease 19 (USP19), which eventually destabilized survivin. We revealed that the growth of NSCLC xenograft tumors was markedly suppressed by gastrodin in vivo. Furthermore, gastrodin overcomes pemetrexed resistance in vivo or in vitro. Our results suggest that gastrodin is a potential antitumor agent by reducing survivin in NSCLC.

Cellular responses after (neratinib plus pemetrexed) exposure in NSCLC cells

We previously demonstrated that neratinib interacted with pemetrexed to kill non-small cell lung cancer (NSCLC) cells. From developing other drug combinations, we observed that several days following exposure, cells activated survival mechanisms to counteract drug toxicity. The present studies attempted to define mechanisms that evolve to reduce the efficacy of neratinib and pemetrexed. Neratinib and pemetrexed synergized to kill NSCLC cells expressing wild-type RAS proteins, mutant KRAS (G12S; Q61H; G12A and G12C) or mutant NRAS (Q61K) or mutant ERBB1 (L858R; L858R T790M and exon 19 deletion). Neratinib and pemetrexed interacted in a greater than additive fashion to kill after 24 h, and after a further 24 h culture in the absence of drugs. Mutant KRAS G12V was more cytoprotective than either activated MEK1 or activated AKT. Knockdown of mutant KRAS reduced drug combination killing at the 48 h timepoint. Despite culture for 24 h in the absence of the drugs, the expression and activities of ERBB1, ERBB2 and ERBB4 remained significantly lower as did the activities of mammalian target of rapamycin (mTOR) C1 and mTORC2. The drug combination reduced KRAS and NRAS levels for 24 h, however, in the absence of the drugs, RAS levels had normalized by 48 h. Expression of Beclin1 and ATG5 remained elevated and of MCL1 and BCL-XL lower. No evolutionary activations of survival signaling by ERBB3, c-KIT, c-MET or PDGFRβ or in intracellular signaling pathways were observed. These findings argue against the development of 'early' resistance mechanisms after neratinib and pemetrexed exposure. Future studies will be required to understand how NSCLC cells become resistant to neratinib and pemetrexed.

ONCOS-102 plus pemetrexed and platinum chemotherapy in malignant pleural mesothelioma: a randomized phase 2 study investigating clinical outcomes and the tumor microenvironment

BACKGROUND

ONCOS-102, an oncolytic adenovirus expressing granulocyte-macrophage colony-stimulating factor, can alter the tumor microenvironment to an immunostimulatory state. Combining ONCOS-102 with standard-of-care chemotherapy for malignant pleural mesothelioma (MPM) may improve treatment outcomes.

METHODS

In this open-label, randomized study, patients with unresectable MPM received intratumoral ONCOS-102 (3×1011 virus particles on days 1, 4, 8, 36, 78, and 120) and pemetrexed plus cisplatin/carboplatin (from day 22), or pemetrexed plus cisplatin/carboplatin alone. The primary endpoint was safety. Overall survival (OS), progression-free survival, objective response rate, and tumor immunologic activation (baseline and day 36 biopsies) were also assessed.

RESULTS

In total, 31 patients (safety lead-in: n=6, randomized: n=25) were enrolled. Anemia (15.0% and 27.3%) and neutropenia (40.0% and 45.5%) were the most frequent grade ≥3 adverse events (AEs) in the ONCOS-102 (n=20) and chemotherapy-alone (n=11) cohorts. No patients discontinued ONCOS-102 due to AEs. No statistically significant difference in efficacy endpoints was observed. There was a numerical improvement in OS (30-month OS rate 34.1% vs 0; median OS 20.3 vs 13.5 months) with ONCOS-102 versus chemotherapy alone in chemotherapy-naïve patients (n=17). By day 36, ONCOS-102 was associated with increased T-cell infiltration and immune-related gene expression that was not observed in the control cohort. Substantial immune activation in the tumor microenvironment was associated with survival at month 18 in the ONCOS-102 cohort.

CONCLUSIONS

ONCOS-102 plus pemetrexed and cisplatin/carboplatin was well tolerated by patients with MPM. In injected tumors, ONCOS-102 promoted a proinflammatory environment, including T-cell infiltration, which showed association with survival at month 18.

Warburg effect enhanced by AKR1B10 promotes acquired resistance to pemetrexed in lung cancer-derived brain metastasis

BACKGROUND

Resistance to pemetrexed (PEM), a rare chemotherapeutic agent that can efficiently cross the blood-brain barrier, limits the therapeutic efficacy for patients with lung cancer brain metastasis (BM). Aldo-keto reductase family 1 B10 (AKR1B10) was recently found to be elevated in lung cancer BM. The link between AKR1B10 and BM-acquired PEM is unknown.

METHODS

PEM drug-sensitivity was assessed in the preclinical BM model of PC9 lung adenocarcinoma cells and the BM cells with or without AKR1B10 interference in vitro and in vivo. Metabolic reprogramming of BM attributed to AKR1B10 was identified by chromatography-mass spectrometry (GC-MS) metabolomics, and the mechanism of how AKR1B10 mediates PEM chemoresistance via a way of modified metabolism was revealed by RNA sequencing as well as further molecular biology experimental approaches.

RESULTS

The lung cancer brain metastatic subpopulation cells (PC9-BrM3) exhibited significant resistance to PEM and silencing AKR1B10 in PC9-BrM3 increased the PEM sensitivity in vitro and in vivo. Metabolic profiling revealed that AKR1B10 prominently facilitated the Warburg metabolism characterized by the overproduction of lactate. Glycolysis regulated by AKR1B10 is vital for the resistance to PEM. In mechanism, AKR1B10 promoted glycolysis by regulating the expression of lactate dehydrogenase (LDHA) and the increased lactate, acts as a precursor that stimulates histone lactylation (H4K12la), activated the transcription of CCNB1 and accelerated the DNA replication and cell cycle.

CONCLUSIONS

Our finding demonstrates that AKR1B10/glycolysis/H4K12la/CCNB1 promotes acquired PEM chemoresistance in lung cancer BM, providing novel strategies to sensitize PEM response in the treatment of lung cancer patients suffering from BM.

Effect of Chemotherapeutics on In Vitro Immune Checkpoint Expression in Non-Small Cell Lung Cancer

Objectives: Immune checkpoint (ICP) expression in tumor cells could directly or indirectly affect the results of immunotherapy. ICP ligands on tumor cells usually bind their immune cell receptors to inhibit the activity, resulting in tumor immune escape. Thus, the purpose of this study was to ascertain the impact of various chemotherapeutic drugs on ICP expression in non-small cell lung cancer (NSCLC) cell lines with different pathological subtypes to provide a basis for the development of a superior regimen of chemotherapy combined with ICP blockade. Methods: Several first-line chemotherapy agents (cisplatin, carboplatin, paclitaxel, gemcitabine, vinorelbine, and pemetrexed) were selected to treat different NSCLC cell lines (squamous carcinoma H1703, adenocarcinoma A549, and large cell cancer H460) for 72 hours, and then the changes in ICP expression in the tumor cells were observed through flow cytometry. Results: Cisplatin, carboplatin, and paclitaxel upregulated the expressions of programmed cell death ligand 1 (PD-L1) and programmed cell death ligand 2 (PD-L2) in A549 and H460 cell lines. Meanwhile, vinorelbine and pemetrexed upregulated PD-L1 and PD-L2 in H1703, A549, and H460 cell lines. Paclitaxel, gemcitabine, vinorelbine, and pemetrexed significantly upregulated the expressions of both galectin-9 and high-mobility group box protein 1 (HMGB1) in the A549 cell line. Cisplatin and paclitaxel significantly upregulated the expressions of major histocompatibility complex-II (MHC-II), galectin-3, α-synuclein, and fibrinogen-like protein 1 (FGL1) in A549 and H460 cell lines. In addition, cisplatin and vinorelbine significantly upregulated the expressions of both CD155 and CD112 in the H460 cell line. Vinorelbine upregulated MHC-I in all three cell lines. Conclusion: Chemotherapy agents have different effects on the expression of ICP ligands in tumor cells with different pathological types, and this may affect the efficacy of combined immunotherapy. These results provide a theoretical basis for further selection and optimization of the combination of chemotherapy and immunotherapy.

Schedule-Dependent Treatment Increases Chemotherapy Efficacy in Malignant Pleural Mesothelioma

Malignant pleural mesothelioma (MPM) is a rare but aggressive thoracic malignancy with limited treatment options. One of the standard treatments for MPM is chemotherapy, which consists of concurrent treatment with pemetrexed and cisplatin. Pemetrexed limits tumor growth by inhibiting critical metabolic enzymes involved in nucleotide synthesis. Cisplatin causes direct DNA damage, such as intra-strand and inter-strand cross-links, which are repaired by the nucleotide excision repair pathway, which depends on relatively high nucleotide levels. We hypothesized that prolonged pretreatment with pemetrexed might deplete nucleotide pools, thereby sensitizing cancer cells to subsequent cisplatin treatment. The MPM cell lines ACC-MESO-1 and NCI-H28 were treated for 72 h with pemetrexed. Three treatment schedules were evaluated by initiating 24 h of cisplatin treatment at 0 h (concomitant), 24 h, and 48 h relative to pemetrexed treatment, resulting in either concomitant administration or pemetrexed pretreatment for 24 h or 48 h, respectively. Multicolor flow cytometry was performed to detect γH2AX (phosphorylation of histone H2AX), a surrogate marker for the activation of the DNA damage response pathway. DAPI staining of DNA was used to analyze cell cycle distribution. Forward and side scatter intensity was used to distinguish subpopulations based on cellular size and granularity, respectively. Our study revealed that prolonged pemetrexed pretreatment for 48 h prior to cisplatin significantly reduced long-term cell growth. Specifically, pretreatment for 48 h with pemetrexed induced a cell cycle arrest, mainly in the G2/M phase, accumulation of persistent DNA damage, and induction of a senescence phenotype. The present study demonstrates that optimizing the treatment schedule by pretreatment with pemetrexed increases the efficacy of the pemetrexed-cisplatin combination therapy in MPM. We show that the observed benefits are associated with the persistence of treatment-induced DNA damage. Our study suggests that an adjustment of the treatment schedule could improve the efficacy of the standard chemotherapy regimen for MPM and might improve patient outcomes.

Biology and therapeutic applications of the proton-coupled folate transporter

INTRODUCTION

The proton-coupled folate transporter (PCFT; SLC46A1) was discovered in 2006 as the principal mechanism by which folates are absorbed in the intestine and the causal basis for hereditary folate malabsorption (HFM). In 2011, it was found that PCFT is highly expressed in many tumors. This stimulated interest in using PCFT for cytotoxic drug targeting, taking advantage of the substantial levels of PCFT transport and acidic pH conditions commonly associated with tumors.

AREAS COVERED

We summarize the literature from 2006 to 2022 that explores the role of PCFT in the intestinal absorption of dietary folates and its role in HFM and as a transporter of folates and antifolates such as pemetrexed (Alimta) in relation to cancer. We provide the rationale for the discovery of a new generation of targeted pyrrolo[2,3-d]pyrimidine antifolates with selective PCFT transport and inhibitory activity toward de novo purine biosynthesis in solid tumors. We summarize the benefits of this approach to cancer therapy and exciting new developments in the structural biology of PCFT and its potential to foster refinement of active structures of PCFT-targeted anti-cancer drugs.

EXPERT OPINION

We summarize the promising future and potential challenges of implementing PCFT-targeted therapeutics for HFM and a variety of cancers.

The New Microtubule-Targeting Agent SIX2G Induces Immunogenic Cell Death in Multiple Myeloma

Microtubule-targeting agents (MTAs) are effective drugs for cancer treatment. A novel diaryl [1,2]oxazole class of compounds binding the colchicine site was synthesized as cis-restricted-combretastatin-A-4-analogue and then chemically modified to have improved solubility and a wider therapeutic index as compared to vinca alkaloids and taxanes. On these bases, a new class of tricyclic compounds, containing the [1,2]oxazole ring and an isoindole moiety, has been synthetized, among which SIX2G emerged as improved MTA. Several findings highlighted the ability of some chemotherapeutics to induce immunogenic cell death (ICD), which is defined by the cell surface translocation of Calreticulin (CALR) via dissociation of the PP1/GADD34 complex. In this regard, we computationally predicted the ability of SIX2G to induce CALR exposure by interacting with the PP1 RVxF domain. We then assessed both the potential cytotoxic and immunogenic activity of SIX2G on in vitro models of multiple myeloma (MM), which is an incurable hematological malignancy characterized by an immunosuppressive milieu. We found that the treatment with SIX2G inhibited cell viability by inducing G2/M phase cell cycle arrest and apoptosis. Moreover, we observed the increase of hallmarks of ICD such as CALR exposure, ATP release and phospho-eIF2α protein level. Through co-culture experiments with immune cells, we demonstrated the increase of (i) CD86 maturation marker on dendritic cells, (ii) CD69 activation marker on cytotoxic T cells, and (iii) phagocytosis of tumor cells following treatment with SIX2G, confirming the onset of an immunogenic cascade. In conclusion, our findings provide a framework for further development of SIX2G as a new potential anti-MM agent.

Trojan-Horse Diameter-Reducible Nanotheranostics for Macroscopic/Microscopic Imaging-Monitored Chemo-Antiangiogenic Therapy

Although nanotheranostics have displayed striking potential toward precise nanomedicine, their targeting delivery and tumor penetration capacities are still impeded by several biological barriers. Besides, the current antitumor strategies mainly focus on killing tumor cells rather than antiangiogenesis. Enlightened by the fact that the smart transformable self-targeting nanotheranostics can enhance their targeting efficiency, tumor penetration, and cellular uptake, we herein report carrier-free Trojan-horse diameter-reducible metal-organic nanotheranostics by the coordination-driven supramolecular sequential co-assembly of the chemo-drug pemetrexed (PEM), transition-metal ions (Fe^III), and antiangiogenesis pseudolaric acid B. Such nanotheranostics with both a high dual-drug payload efficiency and outstanding physiological stability are responsively decomposed into numerous ultra-small-diameter nanotheranostics under stimuli of the moderate acidic tumor microenvironment and then internalized into tumor cells through tumor-receptor-mediated self-targeting, synergistically enhancing tumor penetration and cellular uptake. Besides, such nanotheranostics enable visualization of self-targeting capacity under the macroscopic monitor of computed tomography/magnetic resonance imaging, thereby realizing efficient oncotherapy. Moreover, tumor microvessels are precisely monitored by optical coherence tomography angiography/laser speckle imaging during chemo-antiangiogenic therapy in vivo, visually verifying that such nanotheranostics possess an excellent antiangiogenic effect. Our work will provide a promising strategy for further tumor diagnosis and targeted therapy.

A Novel Molecular Target in EGFR-mutant Lung Cancer Treated With the Combination of Osimertinib and Pemetrexed

BACKGROUND/AIM

Synergistic effects of epidermal growth factor receptor tyrosine kinase inhibitors and chemotherapy have been reported. Here, we evaluated the therapeutic potential of combining osimertinib with pemetrexed and investigated the molecular mechanisms.

MATERIALS AND METHODS

We analyzed the antitumor effects of osimertinib± pemetrexed in PC-9 and H1975 cells. Gene expression on exposure to osimertinib±pemetrexed was assessed in these cultured cells. Cell lines resistant to osimertinib±pemetrexed were established to explore mechanisms of resistance.

RESULTS

Osimertinib+pemetrexed treatment delayed the emergence of resistance relative to monotherapy in vitro and in vivo. Expression of the anti-apoptotic gene PLK1 was down-regulated in PC-9 and H1975 exposed to osimertinib+ pemetrexed, whereas it was up-regulated in resistant cells. Furthermore, inhibition of PLK1 induced apoptosis and inhibited proliferation of resistant cells.

CONCLUSION

Blocking PLK1 contributes to mediating the synergistic anti-proliferative effect of osimertinib+pemetrexed. PLK1 over-expression may be a critical mechanism for acquired resistance to osimertinib+pemetrexed.

EGFR-targeted pemetrexed therapy of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare malignancy with poor prognosis, for which chemotherapy with pemetrexed (PEM) is among the few clinical treatments. PEM suffers, however, fast clearance, moderate drug exposure, and dose-limiting toxicities. Here, we report on epidermal growth factor receptor (EGFR)-targeted disulfide-crosslinked biodegradable chimaeric polymersomes (EGFR-CPs) to firmly load PEM and boost chemotherapy of MPM. EGFR-CPs encapsulating 8.7-16.4 wt.% PEM (EGFR-CPs-PEM) showed diameters of 62-65 nm and reduction-responsive drug release property. EGFR-CPs-PEM was more efficiently taken up by EGFR-overexpressed MSTO-211H cells, inducing about 4.7-fold enhanced anticancer activity compared with non-targeted CPs-PEM control. Intriguingly, the in vivo experiments in MSTO-211H xenograft mouse model revealed that EGFR-CPs-PEM brought about superior tumor deposition and penetration to CPs-PEM, and significantly more potent tumor repression than CPs-PEM and free PEM. This polymersome-enabled EGFR-targeted delivery of PEM offers an appealing therapeutic strategy for MPM.

L-Type Amino Acid Transporter 1 Regulates Cancer Stemness and the Expression of Programmed Cell Death 1 Ligand 1 in Lung Cancer Cells

The l-type amino acid transporter 1 (LAT1) is a membranous transporter that transports neutral amino acids for cells and is dysregulated in various types of cancer. Here, we first observed increased LAT1 expression in pemetrexed-resistant non-small cell lung cancer (NSCLC) cells with high cancer stem cell (CSC) activity, and its mRNA expression level was associated with shorter overall survival in the lung adenocarcinoma dataset of the Cancer Genome Atlas database. The inhibition of LAT1 by a small molecule inhibitor, JPH203, or by RNA interference led to a significant reduction in tumorsphere formation and the downregulation of several cancer stemness genes in NSCLC cells through decreased AKT serine/threonine kinase (AKT)/mammalian target of rapamycin (mTOR) activation. The treatment of the cell-permeable leucine derivative promoted AKT/mTOR phosphorylation and reversed the inhibitory effect of JPH203 in the reduction of CSC activity in pemetrexed-resistant lung cancer cells. Furthermore, we observed that LAT1 silencing caused the downregulation of programmed cell death 1 ligand 1 (PD-L1) on lung cancer cells. The PD-L1⁺/LAT1⁺ subpopulation of NSCLC cells displayed great CSC activity with increased expression of several cancer stemness genes. These data suggest that LAT1 inhibitors can serve as anti-CSC agents and could be used in combination with immune checkpoint inhibitors in lung cancer therapy.

Maintenance treatment of combination with bevacizumab vs single agent for advanced non-squamous non-small cell lung cancer: A systematic review and meta-analysis

BACKGROUND

When the patients of advanced non-squamous non-small cell lung cancer (NSCLC) have achieved remission by induction therapy, it is controversial that combination with bevacizumab is used as maintenance therapy. Pemetrexed is a classic drug for maintenance therapy, is bevacizumab the superiority to pemetrexed is also unclear. This meta-analysis aims to evaluate the effectiveness and safety of advanced non-squamous NSCLC in the maintenance treatment.

METHOD

From the establishment as of December 6, 2020, PubMed, Embase, and Cochrane electronic databases were searched and the American Society of Clinical Oncology, European Society of Medical Oncology, and National Comprehensive Cancer Network databases in the past 10 years. The application of combination with bevacizumab, pemetrexed was studied in clinical trials of maintenance treatment for advanced NSCLC. The extracted data include progression-free survival (PFS), overall survival (OS), and grade 3-4 adverse events (AE).

RESULTS

Seven clinical trials we screened, 6 were phase III RCTs, and a cohort trial, including 3298 patients. Compared with bevacizumab and pemetrexed, PFS of combination with bevacizumab was significantly improved (hazard ratio [HR] = 0.71, 95% confidence interval [CI] = 0.65-0.77, P < .00001), but OS was not improved (HR = 0.93, 95% CI = 0.85-1.01, P = .10). Compared with bevacizumab and pemetrexed, no significant difference of PFS (HR = 0.87, 95% CI = 0.69-1.09, P = .21), and OS (HR = 0.87, 95% CI = 0.72-1.05, P = .15) was found. A higher incidence of grade 3-4 AE occurred in combination with bevacizumab (odds ratio = 1.63, 95% CI = 1.35-1.97, P < .00001).

CONCLUSIONS

PFS was significantly improved in patients with advanced non-squamous NSCLC who use bevacizumab combination with single-agent as maintenance treatment, but it does not translate into the advantages of OS; compared with bevacizumab, no PFS and OS benefits were found. A higher incidence of grade 3-4 AE occurred in combination with bevacizumab than pemetrexed and bevacizumab.

Osimertinib-resistant NSCLC cells activate ERBB2 and YAP/TAZ and are killed by neratinib

We performed additional mechanistic analyses to redefine neratinib biology and determined the mechanisms by which the multi-kinase inhibitor neratinib interacted with the thymidylate synthase inhibitor pemetrexed to kill NSCLC cells expressing either mutant KRAS (G12S; Q61H; G12A; G12C) or mutant NRAS (Q61K) or mutant ERBB1 (L858R; L858R T790M; exon 19 deletion). Neratinib rapidly reduced KRASG12V and RAC1G12V nanoclustering which was followed by KRASG12V, but not RAC1G12V, being extensively mislocalized away from the plasma membrane. This correlated with reduced levels of, and reorganized membrane localization of phosphatidylserine and cholesterol. Reduced nanoclustering was not associated with inactivation of ERBB1, Merlin or Ezrin. The drug combination killed cells expressing mutant KRAS, NRAS or mutant ERBB1 proteins. Afatinib or osimertinib resistant cells were killed with a similar efficacy to non-resistant cells. Compared to osimertinib-resistant cells, sensitive cells had less ERBB2 Y1248 phosphorylation. In osimertinib resistant H1975 cells, the drug combination was less capable of inactivating AKT, mTOR, STAT3, STAT5, ERK1/2 whereas it gained the ability to inactivate ERBB3. In resistant H1650 cells, the drug combination was less capable of inactivating JAK2 and STAT5. Sensitive cells exhibited elevated basal phosphorylation of YAP and TAZ. In resistant cells, portions of YAP and TAZ were localized in the nucleus. [Neratinib + pemetrexed] increased phosphorylation of YAP and TAZ, caused their nuclear exit, and enhanced ERBB2 degradation. Thus, neratinib targets an unidentified protein whose functional inhibition directly results in RAS inactivation and tumor cell killing. Our data prove that, albeit indirectly, oncogenic RAS proteins are druggable by neratinib.

Folate transporter dynamics and therapy with classic and tumor-targeted antifolates

There are three major folate uptake systems in human tissues and tumors, including the reduced folate carrier (RFC), folate receptors (FRs) and proton-coupled folate transporter (PCFT). We studied the functional interrelationships among these systems for the novel tumor-targeted antifolates AGF94 (transported by PCFT and FRs but not RFC) and AGF102 (selective for FRs) versus the classic antifolates pemetrexed, methotrexate and PT523 (variously transported by FRs, PCFT and RFC). We engineered HeLa cell models to express FRα or RFC under control of a tetracycline-inducible promoter with or without constitutive PCFT. We showed that cellular accumulations of extracellular folates were determined by the type and levels of the major folate transporters, with PCFT and RFC prevailing over FRα, depending on expression levels and pH. Based on patterns of cell proliferation in the presence of the inhibitors, we established transport redundancy for RFC and PCFT in pemetrexed uptake, and for PCFT and FRα in AGF94 uptake; uptake by PCFT predominated for pemetrexed and FRα for AGF94. For methotrexate and PT523, uptake by RFC predominated even in the presence of PCFT or FRα. For both classic (methotrexate, PT523) and FRα-targeted (AGF102) antifolates, anti-proliferative activities were antagonized by PCFT, likely due to its robust activity in mediating folate accumulation. Collectively, our findings describe a previously unrecognized interplay among the major folate transport systems that depends on transporter levels and extracellular pH, and that determines their contributions to the uptake and anti-tumor efficacies of targeted and untargeted antifolates.

Akt kinase LANCL2 functions as a key driver in EGFR-mutant lung adenocarcinoma tumorigenesis

Epidermal growth factor receptor (EGFR) is a key oncogene in lung adenocarcinoma (LUAD). Resistance to EGFR tyrosine kinase inhibitors is a major obstacle for EGFR-mutant LUAD patients. Our gene chip array, quantitative polymerase chain reaction validation, and shRNA-based high-content screening identified the Akt kinase lanthionine synthetase C-like protein 2 (LANCL2) as a pro-proliferative gene in the EGFR-mutant LUAD cell line PC9. Therefore, we investigated whether LANCL2 plays a role in promoting cell proliferation and drug resistance in EGFR-mutant LUAD. In silico clinical correlation analysis using the Cancer Genome Atlas Lung Adenocarcinoma dataset revealed a positive correlation between LANCL2 and EGFR expression and an inverse relationship between LANCL2 gain-of-function and survival in LUAD patients. The EGFR-mutant LUAD cell lines PC9 and HCC827 displayed higher LANCL2 expression than the non-EGFR-mutant cell line A549. In addition, LANCL2 was downregulated following gefitinib+pemetrexed combination therapy in PC9 cells. LANCL2 knockdown reduced proliferation and enhanced apoptosis in PC9, HCC827, and A549 cells in vitro and suppressed murine PC9 xenograft tumor growth in vivo. Notably, LANCL2 overexpression rescued these effects and promoted gefitinib + pemetrexed resistance in PC9 and HCC827 cells. Pathway analysis and co-immunoprecipitation followed by mass spectrometry of differentially-expressed genes in LANCL2 knockdown cells revealed enrichment of several cancer signaling pathways. In addition, Filamin A and glutathione S-transferase Mu 3 were identified as two novel protein interactors of LANCL2. In conclusion, LANCL2 promotes tumorigenic proliferation, suppresses apoptosis, and promotes gefitinib+pemetrexed resistance in EGFR-mutant LUAD cells. Based on the positive association between LANCL2, EGFR, and downstream Akt signaling, LANCL2 may be a promising new therapeutic target for EGFR-mutant LUAD.

Simultaneous Single Cell Gene Expression and EGFR Mutation Analysis of Circulating Tumor Cells Reveals Distinct Phenotypes in NSCLC

While cancer cell populations are known to be highly heterogeneous within a tumor, the current gold standard of tumor profiling is through a tumor biopsy. These biopsies are invasive and prone to missing these clones due to spatial heterogeneity, and this bulk analysis approach can miss information from rare subpopulations. To noninvasively investigate tumor cell heterogeneity, a streamlined workflow is developed to scrutinize rare cells, such as circulating tumor cells (CTCs), for simultaneous analysis of mutations and gene expression profiles at the single cell level. This powerful workflow overcomes low-input limitations of single cell analysis techniques. The utility of this multiplexed workflow to unravel inter- and intra-patient heterogeneity is demonstrated using non-small-cell lung cancer (NSCLC) CTCs (n = 58) from six epidermal growth factor receptor (EGFR) mutant positive NSCLC patients. CTCs are isolated using a high-throughput microfluidic technology, the Labyrinth, and their EGFR mutation status and gene expression profiles are characterized.

Tumor-associated macrophage-derived inflammatory cytokine enhances malignant potential of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is an asbestos-related aggressive malignant neoplasm. Due to the difficulty of achieving curative surgical resection in most patients with MPM, a combination chemotherapy of cisplatin and pemetrexed has been the only approved regimen proven to improve the prognosis of MPM. However, the median overall survival time is at most 12 mo even with this regimen. There has been therefore a pressing need to develop a novel chemotherapeutic strategy to bring about a better outcome for MPM. We found that expression of interleukin-1 receptor (IL-1R) was upregulated in MPM cells compared with normal mesothelial cells. We also investigated the biological significance of the interaction between pro-inflammatory cytokine IL-1β and the IL-1R in MPM cells. Stimulation by IL-1β promoted MPM cells to form spheroids along with upregulating a cancer stem cell marker CD26. We also identified tumor-associated macrophages (TAMs) as the major source of IL-1β in the MPM microenvironment. Both high mobility group box 1 derived from MPM cells and the asbestos-activated inflammasome in TAMs induced the production of IL-1β, which resulted in enhancement of the malignant potential of MPM. We further performed immunohistochemical analysis using clinical MPM samples obtained from patients who were treated with the combination of platinum plus pemetrexed, and found that the overexpression of IL-1R tended to correlate with poor overall survival. In conclusion, the interaction between MPM cells and TAMs through a IL-1β/IL-1R signal could be a promising candidate as the target for novel treatment of MPM (Hyogo College of Medicine clinical trial registration number: 2973).

Propensity score-weighted analysis of chemotherapy after PD-1 inhibitors versus chemotherapy alone in patients with non-small cell lung cancer (WJOG10217L)

BACKGROUND

Studies have suggested that chemotherapy after immune checkpoint inhibitors may confer an improved response for non-small cell lung cancer (NSCLC). However, potential selection bias in such studies has not been addressed. We therefore applied propensity score analysis to investigate the efficacy of chemotherapy after PD-1 inhibitor treatment (CAP) compared with chemotherapy alone.

METHODS

We conducted a retrospective observational cohort study for patients treated at 47 institutions across Japan between April 1, 2014 and July 31, 2017. Eligible patients had advanced or recurrent NSCLC who have undergone chemotherapy. Patients subsequently treated with chemotherapy (docetaxel with or without ramucirumab, S-1 or pemetrexed) either after PD-1 inhibitor therapy (CAP cohort) or alone (control cohort) were included. The primary end point was objective response rate (ORR). Inverse probability weighting (IPW) was applied to adjust for potential confounding factors.

RESULTS

A total of 1439 patients (243 and 1196 in the CAP and control cohorts, respectively) was available for unadjusted analysis. Several baseline characteristics-including age, histology, EGFR or ALK genetic alterations, and brain metastasis-differed significantly between the two cohorts. After adjustment for patient characteristics with the IPW method, ORR was 18.9% for the CAP cohort and 11.0% for the control cohort (ORR ratio 1.71; 95% CI 1.19 to 2.46; p=0.004). IPW-adjusted Kaplan-Meier curves showed that median progression-free survival (PFS) for the CAP and control cohorts was 2.8 and 2.7 months (IPW-adjusted HR 0.95; 95% CI 0.80 to 1.12; p=0.55), and median overall survival (OS) was 9.2 and 10.4 months (IPW-adjusted HR 1.05; 95% CI 0.86 to 1.28; p=0.63), respectively.

CONCLUSIONS

After accounting for selection bias by propensity score analysis, CAP showed a significantly higher ORR compared with chemotherapy alone, with the primary end point of ORR being achieved. However, these results did not translate into a PFS or OS advantage, suggesting that prior administration of PD-1 inhibitors may result in a synergistic antitumor effect with subsequent chemotherapy, but that such an effect is transient. CAP therefore does not appear to achieve durable tumor control or confer a lasting survival benefit.

Synergistic anticancer effect of combined use of Trichosanthes kirilowii with cisplatin and pemetrexed enhances apoptosis of H1299 non-small-cell lung cancer cells via modulation of ErbB3

BACKGROUND

Lung cancer is one of the most common malignancies worldwide. To treat lung cancer, various anticancer drugs were developed and tested, but they failed because of drug resistance. In the present study, we tested herbal medicines, such as TK and CuD, as anticancer drugs to decrease side effects and resistance.

METHODS

Cell viability was measured by an MTT assay. Analysis of cell cycle arrest was performed by flow cytometry. Induction of apoptosis by cucurbitacin D was measured by an annexin V-FITC/PI assay. We performed RTK kit analysis. Levels of p-ErbB3, p-STAT3, p-NF-κB, and caspases were measured by western blot analysis. Nuclear staining of ErbB3 was measured by immunocytochemistry. Transcriptional activity of STAT3 and NF-κB was detected by STAT3 and NF-κB luciferase reporter gene assays.

RESULTS

We found a synergistic effect of TK with CDDP and PXD in primary culture of human NSCLC tumor cells. The combination of CDDP/PXD and TK or CuD inhibited the proliferation of H1299 cells. The combination of CDDP/PXD and TK or CuD induced sub-G1 and G2/M cell cycle arrest in H1299 cells. The combination of CDDP/PXD and TK or CuD induced apoptosis, regulated apoptotic molecules, caused morphological changes and inhibited colony formation in H1299 cells. We found that TK suppresses p-ErbB3 expression and signaling. The combination of CDDP/PXD and TK or CuD inhibited p-AKT, p-Erk, and p-JNK signaling and suppressed Stat3 and NF-κB transcriptional activity in H1299 cells. More importantly, the combination of CDDP/PXD and TK or CuD inhibited p-ErbB3 and downstream molecules in H1299 cells. The combination of CDDP/PXD and TK or CuD inhibited ErbB2/ErbB3 dimerization. Our results clearly demonstrate that the synergistic effect of CDDP/PXD and TK or CuD inhibits cell growth and induces apoptosis by inhibiting ErbB3 signaling.

CONCLUSION

The combination of CDDP/PXD and TK or CuD decreases cell proliferation and induces apoptosis by inhibiting ErbB3 signaling in H1299 lung cancer cells. TK or CuD could be useful as a compound to treat lung cancer. Additionally, targeting ErbB3 may also be useful for treating lung cancer.

Circular RNA CDR1-AS contributes to pemetrexed and cisplatin chemoresistance through EGFR/PI3K signaling pathway in lung adenocarcinoma

Recent studies found circRNAs were involved in tumorigenesis and became new tumor biomarkers and therapeutic targets in lung adenocarcinoma (LUAD), which played a critical role in various biological processes and had been implicated in resistance to chemotherapeutic drugs. However, the role of CDR1-AS in chemoresistance of LUAD to pemetrexed (PTX) and cisplatin (CDDP) is poorly understood. Here, we found that CDR1-AS was up-regulated in LUAD tissues and cell lines, its high-expression was relevant to smoking history, T stage and neoadjuvant chemotherapy (PTX and CDDP) of LUAD patients. CDR1-AS was an independent prognostic biomarker for LUAD patients. CDR1-AS was highly expressed in PTX and CDDP resistant LUAD tissues and cell line (A549/CR). Silence of CDR1-AS re-sensitized A549/CR cells to PTX and CDDP. CDR1-AS was closely related with EGFR/PI3K signaling pathway in A549/CR cells. The activating of EGFR/PI3K pathway mostly restored the effecting of CDR1-AS silence on PTX and CDDP sensitivity in A549/CR cells, CDR1-AS contributed to PTX and CDDP chemoresistance through EGFR/PI3K signaling pathway in LUAD. In conclusion, the CDR1-AS is high-expressed in LUAD and is an independent prognostic biomarker for LUAD patients. The high-expression of CDR1-AS is related with the PTX and CDDP insensitivity of LUAD patients, CDR1-AS promotes PTX and CDDP chemoresistance through EGFR/PI3K signaling pathway in LUAD.

Afatinib Overcomes Pemetrexed-Acquired Resistance in Non-Small Cell Lung Cancer Cells Harboring an EML4-ALK Rearrangement

Background: The aim of this study is to elucidate the mechanisms of acquired resistance to pemetrexed in echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) rearranged non-small cell lung cancer. Methods: We analyzed the sensitivity to pemetrexed and the expression patterns of various proteins after pemetrexed treatment in the cell lines, A549, NCI-H460, NCI-H2228 harboring EML4-ALK variant 3, and NCI-H3122 harboring EML4-ALK variant 1. Pemetrexed-resistant cell lines were also generated through long-term exposure to pemetrexed. Results: The EML4-ALK variant 1 rearranged NCI-H3122 was found to be more sensitive than the other cell lines. Cell cycle analysis after pemetrexed treatment showed that the fraction of cells in the S phase increased in A549, NCI-H460, and NCI-H2228, whereas the fraction in the apoptotic sub-G₁ phase increased in NCI-H3122. The pemetrexed-resistant NCI-H3122 cell line showed increased expression of EGFR and HER2 compared to the parent cell line, whereas A549 and NCI-H460 did not show this change. The pan-HER inhibitor afatinib inhibited this alternative signaling pathway, resulting in a superior cytotoxic effect in pemetrexed-resistant NCI-H3122 cell lines compared to that in the parental cells line. Conclusion: The activation of EGFR-HER2 contributes to the acquisition of resistance to pemetrexed in EML4-ALK rearranged non-small cell lung cancer. However, the inhibition of this alternative survival signaling pathway with RNAi against EGFR-HER2 and with afatinib overcomes this resistance.

Tumor Microenvironment Responsive Shape-Reversal Self-Targeting Virus-Inspired Nanodrug for Imaging-Guided Near-Infrared-II Photothermal Chemotherapy

Tumor microenvironment responsive multimodal synergistic theranostic strategies can significantly improve the therapeutic efficacy while avoiding severe side effects. Inspired by the fact that special morphology could enhance photothermal conversion efficiency (PCE) and cellular delivery, we developed an acidic tumor microenvironment responsive shape-reversal metal-organic virus-inspired nanodrug for enhancing near-infrared (NIR)-II PCE, increasing cell adhesion, and activating tumor targeting. First, a NIR-I fluorescence probe (IR825), a chemo-drug (pemetrexed, PEM), and a rare-earth metal ion (Nd(III)) were chosen to synthesize a virus-like nanodrug via coordination-driven assembly. Then, the spike-like surface of the nanodrug was further camouflaged by an acidity-sensitive poly(ethylene glycol) "shell" to create virus-core and sphere-shell hierarchical nanoassemblies, which could efficiently prevent immune clearance and prolong systemic circulation. Interestingly, the acidic tumor microenvironment could trigger the shell detachment of nanoassemblies for shape reversal to produce a virus-like surface followed by re-exposure of PEM to synergistically amplify the cellular internalization while enhancing NIR-II PCE. By utilizing the shell-detached virus-like nanodrug core, the tumor microenvironment specific enhanced NIR-II photothermal chemotherapy can be realized under the precise guidance of fluorescence/photoacoustic imaging, thereby achieving complete tumor elimination without recurrence in a single treatment cycle. We envision that integrating the tumor microenvironment responsive ability with  "sphere-to-virus" shape reversal will provide a promising strategy for biomimetic targeted cancer therapy.

A Randomized, Double-Blinded, Phase II Trial of Carboplatin and Pemetrexed with or without Apatorsen (OGX-427) in Patients with Previously Untreated Stage IV Non-Squamous-Non-Small-Cell Lung Cancer: The SPRUCE Trial

BACKGROUND

This randomized, double-blinded, phase II trial evaluated the efficacy of carboplatin and pemetrexed plus either apatorsen, an antisense oligonucleotide targeting heat shock protein (Hsp) 27 mRNA, or placebo in patients with previously untreated metastatic nonsquamous non-small cell lung cancer (NSCLC).

METHODS

Patients were randomized 1:1 to Arm A (carboplatin/pemetrexed plus apatorsen) or Arm B (carboplatin/pemetrexed plus placebo). Treatment was administered in 21-day cycles, with restaging every two cycles, until progression or intolerable toxicity. Serum Hsp27 levels were analyzed at baseline and during treatment. The primary endpoint was progression-free survival (PFS); secondary endpoints included overall survival (OS), objective response rate, and toxicity.

RESULTS

The trial enrolled 155 patients (median age 66 years; 44% Eastern Cooperative Oncology Group performance status 0). Toxicities were similar in the 2 treatment arms; cytopenias, nausea, vomiting, and fatigue were the most frequent treatment-related adverse events. Median PFS and OS were 6.0 and 10.8 months, respectively, for Arm A, and 4.9 and 11.8 months for Arm B (differences not statistically significant). Overall response rates were 27% for Arm A and 32% for Arm B. Sixteen patients (12%) had high serum levels of Hsp27 at baseline. In this small group, patients who received apatorsen had median PFS of 10.8 months, and those who received placebo had median PFS 4.8 months.

CONCLUSION

The addition of apatorsen to carboplatin and pemetrexed was well tolerated but did not improve outcomes in patients with metastatic nonsquamous NSCLC cancer in the first-line setting.

IMPLICATIONS FOR PRACTICE

This randomized, double-blinded, phase II trial evaluated the efficacy of carboplatin and pemetrexed plus either apatorsen, an antisense oligonucleotide targeting heat shock protein 27 mRNA, or placebo in patients with previously untreated metastatic nonsquamous non-small cell lung cancer (NSCLC). The addition of apatorsen to carboplatin and pemetrexed was well tolerated but did not improve outcomes in patients with metastatic nonsquamous NSCLC cancer in the first-line setting.

Gene expression profiling of homologous recombination repair pathway indicates susceptibility for olaparib treatment in malignant pleural mesothelioma in vitro

BACKGROUND

Malignant pleural mesothelioma (MPM) is a tumour arising from pleural cavities with poor prognosis. Multimodality treatment with pemetrexed combined with cisplatin shows unsatisfying response-rates of 40%. The reasons for the rather poor efficacy of chemotherapeutic treatment are largely unknown. However, it is conceivable that DNA repair mechanisms lead to an impaired therapy response. We hypothesize a major role of homologous recombination (HR) for genome stability and survival of this tumour. Therefore, we analysed genes compiled under the term "BRCAness". An inhibition of this pathway with olaparib might abrogate this effect and induce apoptosis.

METHODS

We investigated the response of three MPM cell lines and lung fibroblasts serving as a control to treatment with pemetrexed, cisplatin and olaparib. Furthermore, we aimed to find possible correlations between response and gene expression patterns associated with BRCAness phenotype. Therefore, 91 clinical MPM samples were digitally screened for gene expression patterns of HR members.

RESULTS

A BRCAness-dependent increase of apoptosis and senescence during olaparib-based treatment of BRCA-associated-protein 1 (BAP1)-mutated cell lines was observed. The gene expression pattern identified could be found in approx. 10% of patient samples. Against this background, patients could be grouped according to their defects in the HR system. Gene expression levels of Aurora Kinase A (AURKA), RAD50 as well as DNA damage-binding protein 2 (DDB2) could be identified as prognostic markers in MPM.

CONCLUSIONS

Defects in HR compiled under the term BRCAness are a common event in MPM. The present data can lead to a better understanding of the underlaying cellular mechanisms and leave the door wide open for new therapeutic approaches for this severe disease with infaust prognosis. Response to Poly (ADP-ribose)-Polymerase (PARP)-Inhibition could be demonstrated in the BAP1-mutated NCI-H2452 cells, especially when combined with cisplatin. Thus, this combination therapy might be effective for up to 2/3 of patients, promising to enhance patients' clinical management and outcome.

Pemetrexed-loaded nanoparticles targeted to malignant pleural mesothelioma cells: an in vitro study

PURPOSE

Malignant pleural mesothelioma (MPM) is an aggressive tumor characterized by poor prognosis. Its incidence is steadily increasing due to widespread asbestos exposure. There is still no effective therapy for MPM. Pemetrexed (Pe) is one of the few chemotherapeutic agents approved for advanced-stage disease, although the objective response to the drug is limited. The use of gold nanoparticles (GNPs) as a drug delivery system promises several advantages, including specific targeting of malignant cells, with increased intracellular drug accumulation and reduced systemic toxicity, and, in the case of MPM, direct treatment administration into the pleural space. This study aims at exploring CD146 as a potential MPM cell-specific target for engineered Pe-loaded GNPs and to assess their effectiveness in inhibiting MPM cell line growth.

METHODS

MPM cell lines and primary cultures obtained by pleural effusions from MPM patients were assayed for CD146 expression by flow cytometry. Internalization by MPM cell lines of fluorescent dye-marked GNPs decorated with a monoclonal anti CD146 coated GNPs (GNP-HC) was proven by confocal microscopy. The effects of anti CD146 coated GNPs loaded with Pe (GNP-HCPe) on MPM cell lines were evaluated by cell cycle (flow cytometry), viability (MTT test), clonogenic capacity (soft agar assay), ROS production (electric paramagnetic resonance), motility (wound healing assay), and apoptosis (flow cytometry).

RESULTS

GNP-HC were selectively uptaken by MPM cells within 1 hour. MPM cell lines were blocked in the S cell cycle phase in the presence of GNP-HCPe. Both cell viability and motility were significantly affected by nanoparticle treatment compared to Pe. Apoptotic rate and ROS production were significantly higher in the presence of nanoparticles. Clonogenic capacity was completely inhibited following nanoparticle internalization.

CONCLUSION

GNP-HCPe treatment displays in vitro antineoplastic action and is more effective than Pe alone in inhibiting MPM cell line malignant phenotype. The innovative use of specifically targeted GNPs opens the perspective of local intrapleural administration to avoid normal cell toxicity and enhance chemotherapy efficacy.

Evaluation of pemetrexed and etoposide as therapeutic regimens for human papillomavirus-positive oral and oropharyngeal cancer

Although human papillomavirus (HPV) positive oral and oropharyngeal cancers have distinct epidemiologic and molecular characteristics compared to HPV-negative cancers, all patients with oral and oropharyngeal cancers received same standard regimen regardless of HPV status. For these reasons, specific regimens for patients with HPV-positive oral and oropharyngeal cancer are needed. Differentially expressed genes (DEG) between HPV-positive and HPV-negative oropharyngeal cancers were re-analyzed and categorized from public database. Then, druggable targets to HPV-positive oral and oropharyngeal cancer were identified and were validated with E6/E7, which is oncogene of HPV, transfected oral and oropharyngeal cancer cell lines and HPV infected cell lines. In DEG analysis, HPV-positive oral and oropharyngeal cancer showed distinct disease entity from HPV-negative cancers. Unlike HPV-negative oral and oropharyngeal cancer, thymidylate synthase (TS) and topoisomerase II (Topo II) were overexpressed in HPV-positive cancers. Transfection of Lenti-virus containing E6/ E7 to HPV-negative oral and oropharyngeal cancer cells induced upregulation of TS and Topo II in those cells. Although cisplatin, which is standard regimen in head and neck cancers, showed more effectiveness in HPV-negative cells, 5-FU and pemetrexed, which are TS inhibitors, or etoposide, which is Topo II inhibitors, worked more effectively in HPV-positive cells. In addition, cisplatin/etoposide and cisplatin/pemetrexed combination regimens showed synergic effects in HPV-positive cells. Pemetrexed or etoposide alone, or in combination with other chemotherapeutic agents such as cisplatin, can be used as novel substitutes in a regimen of concurrent chemoradiotherapy or a palliative regimen for HPV-positive oral and oropharyngeal cancer patients. However, a well-designed clinical trial is needed.

Loss of Uracil DNA Glycosylase Selectively Resensitizes p53-Mutant and -Deficient Cells to 5-FdU

Thymidylate synthase (TS) inhibitors including fluoropyrimidines [e.g., 5-Fluorouracil (5-FU) and 5-Fluorodeoxyuridine (5-FdU, floxuridine)] and antifolates (e.g., pemetrexed) are widely used against solid tumors. Previously, we reported that shRNA-mediated knockdown (KD) of uracil DNA glycosylase (UDG) sensitized cancer cells to 5-FdU. Because p53 has also been shown as a critical determinant of the sensitivity to TS inhibitors, we further interrogated 5-FdU cytotoxicity after UDG depletion with regard to p53 status. By analyzing a panel of human cancer cells with known p53 status, it was determined that p53-mutated or -deficient cells are highly resistant to 5-FdU. UDG depletion resensitizes 5-FdU in p53-mutant and -deficient cells, whereas p53 wild-type (WT) cells are not affected under similar conditions. Utilizing paired HCT116 p53 WT and p53 knockout (KO) cells, it was shown that loss of p53 improves cell survival after 5-FdU, and UDG depletion only significantly sensitizes p53 KO cells. This sensitization can also be recapitulated by UDG depletion in cells with p53 KD by shRNAs. In addition, sensitization is also observed with pemetrexed in p53 KO cells, but not with 5-FU, most likely due to RNA incorporation. Importantly, in p53 WT cells, the apoptosis pathway induced by 5-FdU is activated independent of UDG status. However, in p53 KO cells, apoptosis is compromised in UDG-expressing cells, but dramatically elevated in UDG-depleted cells. Collectively, these results provide evidence that loss of UDG catalyzes significant cell death signals only in cancer cells mutant or deficient in p53.Implications: This study reveals that UDG depletion restores sensitivity to TS inhibitors and has chemotherapeutic potential in the context of mutant or deficient p53. Mol Cancer Res; 16(2); 212-21. ©2017 AACR.

Phase I Trial of Cediranib in Combination with Cisplatin and Pemetrexed in Chemonaive Patients with Unresectable Malignant Pleural Mesothelioma (SWOG S0905)

INTRODUCTION

In malignant pleural mesothelioma, targeting angiogenesis with cediranib, a vascular endothelial growth factor receptor and platelet-derived growth factor receptor inhibitor, may have therapeutic potential.

METHODS

S0905 phase I combined cediranib (two dose cohorts [30 mg and 20 mg daily]) with cisplatin-pemetrexed for six cycles followed by maintenance cediranib in unresectable chemonaive patients with malignant pleural mesothelioma of any histologic subtype. The primary end point established the maximum tolerated dose in combination with cisplatin-pemetrexed in a dose deescalation scheme.

RESULTS

A total of 20 patients were enrolled (seven to the 30-mg cohort and 13 to the 20-mag cohort). In the cediranib 30-mg cohort, two of the initial six patients reported dose-limiting toxicities and the dose was deemed too toxic to continue. In the next cohort, two patients experienced dose-limiting toxicities, and thus, the maximum tolerated dose of cediranib was established as 20 mg. During the six cycles of cisplatin-pemetrexed-cediranib, 20 mg, there were grade 3 toxicities (neutropenia and gastrointestinal) and grade 4 thrombocytopenia. No patients had any significant episodes of bleeding. According to the Response Evaluation Criteria in Solid Tumors (n = 17 evaluable patients), the median progression-free survival was 12.8 months (95% confidence interval [CI]: 6.9-17.2); according to the Modified Response Evaluation Criteria in Solid Tumors (n = 19 evaluable patients), the median progression-free survival was 8.6 months (95% CI: 6.1-10.9). For all patients, the disease control rate at 6 weeks was 90% and median overall survival time was 16.2 months (95% CI: 10.5-28.7).

CONCLUSIONS

Cediranib combined with cisplatin-pemetrexed has a reasonable toxicity profile and preliminary promising efficacy. The phase II S0905 trial will evaluate the efficacy of the triplet regimen compared with the current standard of care, cisplatin-pemetrexed.

Metformin synergistic pemetrexed suppresses non-small-cell lung cancer cell proliferation and invasion in vitro

The aim of this study was to investigate whether metformin in combination with pemetrexed has an effect on the treatment of non-small-cell lung cancer (NSCLC) models and to explore the related molecular mechanism. The half maximal inhibitory concentration (IC50) and combination index (CI) of metformin and pemetrexed were detected by the CCK8 assay to assess the antiproliferative and therapeutic effects of the two-drug combination. Flow cytometry (FCM) and invasion assays were used to estimate the variation in apoptosis rate and invasion ability of the differently treated NSCLC cell lines. Apoptotic markers were detected by western blotting to validate the data related to the antiproliferation and proapoptosis effects. Metformin monotherapy inhibited the growth of NSCLC cell lines and reduced the invasion ability to different degrees compared with the control groups (P < 0.05). Metformin in combination with pemetrexed produced a synergistic effect (CI < 0.90) compared with the two drugs in monotherapy in the three tested NSCLC cell lines. Metformin in combination with pemetrexed significantly increased the cell numbers of HCC827 cells at S phase (P < 0.001), and the combination therapy had no influence on the A549 and H1975 cell lines. We found that combining metformin with pemetrexed induced more cell apoptosis than metformin or pemetrexed used alone (P < 0.05), which was validated by the apoptotic markers. These results demonstrate that the combination of metformin and pemetrexed has a synergistic effect on the treatment of NSCLC cell lines by inducing apoptosis or blocking the cell cycle. Our data indicate that the combination of metformin and pemetrexed could have beneficial antitumor effects on NSCLC cells in vitro.

Synthesis and evaluation of 5-(arylthio)-9H-pyrimido[4,5-b]indole-2,4-diamines as receptor tyrosine kinase and thymidylate synthase inhibitors and as antitumor agents

In an effort to optimize the structural requirements for combined cytostatic and cytotoxic effects in single agents, a series of 5-(arylthio)-9H-pyrimido[4,5-b]indole-2,4-diamines 3-7 were synthesized and evaluated as inhibitors of receptor tyrosine kinases (RTKs) as well as thymidylate synthase (TS). The synthesis of these compounds involved the nucleophilic displacement of the common intermediate 5-bromo/5-chloro-9H-pyrimido[4,5-b]indole-2,4-diamine with appropriate aryl thiols. A novel four step synthetic scheme to the common intermediate was developed which is more efficient relative to the previously reported six-step sequence. Biological evaluation of these compounds indicated dual activity in RTKs and human TS (hTS). In the VEGFR-2 assay, compound 5 was equipotent to the standard compound semaxanib and was better than standard TS inhibitor pemetrexed, in the hTS assay. Compounds 3, 6 and 7 were nanomolar inhibitors of hTS and were several fold better than pemetrexed.

One-Component Supramolecular Filament Hydrogels as Theranostic Label-Free Magnetic Resonance Imaging Agents

Gadolinium (Gd)-based compounds and materials are the most commonly used magnetic resonance imaging (MRI) contrast agents in the clinic; however, safety concerns associated with their toxicities in the free ionic form have promoted the development of new generations of metal-free contrast agents. Here we report a supramolecular strategy to convert an FDA-approved anticancer drug, Pemetrexed (Pem), to a molecular hydrogelator with inherent chemical exchange saturation transfer (CEST) MRI signals. The rationally designed drug-peptide conjugate can spontaneously associate into filamentous assemblies under physiological conditions and consequently form theranostic supramolecular hydrogels for injectable delivery. We demonstrated that the local delivery and distribution of Pem-peptide nanofiber hydrogels can be directly assessed using CEST MRI in a mouse glioma model. Our work lays out the foundation for the development of drug-constructed theranostic supramolecular materials with an inherent CEST MRI signal that enables noninvasive monitoring of their in vivo distribution and drug release.

[The relationship between the effects of MTA on mRNA expression of four iconic proteins in cells of fetal rat skull and cell culture environment]

PURPOSE

To discuss the influence of MTA on mRNA expression of Cbfa1, ALP, Col-Ⅰand BGP which are 4 kinds of iconic protein in cells of fetal rats skull, and explore its influence on cell culture environment and association of changes of calcium, phosphorus.

METHODS

Cells were obtained by 2 kinds of mixed enzymatic digestion for 3 steps from gestation fetal rat calvarial bone. The expression of Cbfa1mRNA, ALPmRNA, Col-1mRNA, BGP mRNA and extracellular calcium were detected. Phosphorus (P) and calcium concentration of fetal rat skull cells co-cultured with MTA for 3 weeks at different stages of cell differentiation was assessed atomic absorption spectrophotometry. The data was statistically analyzed using SPSS10.0 software package.

RESULTS

At the 4th day, P3- content decreased significantly (P<0.05), while ALPmRNA in MTA group increased most greatly and was 40 times of the control group. At the 14th to 18th day, the Ca2+ and P3- content reduced significantly (P<0.05), and then the BGPmRNA in MTA group rised most greatly which was about 7.71 times of the control group. Then Cbfalpha l mRNA in MTA group increased most strongly later which was about 7.38 times of the control group. Col Ⅰ mRNA increased minimally in all time points.

CONCLUSIONS

The change of P3- content may be the initiating factor when MTA promoted differentiation of fetal rats skull cells in vitro, and Ca2+ could greatly accelerate the process of mineralization when accumulated to a certain extent. At the same time, the expression of ALPmRNA, BGPmRNA, Col Ⅰ mRNA and Cbfalpha lmRNA were regulated accordingly, which is the key to explain osteogenetic mechanism of MTA.