Project description:Overall, NSCLC has a poor 5-year survival and new therapeutic approaches are urgently needed. ERBB-addicted NSCLC that have become resistant to ERBB inhibitors are often refractory to additional therapeutic interventions. The sphingosine-1-phosphate receptor modulator fingolimod (FTY720), approved for the treatment of multiple sclerosis, synergized with the NSCLC therapeutic pemetrexed to kill NSCLC and ovarian cancer cells. This occurred in lung cancer cells expressing mutated K-RAS, mutated ERBB1, or in NSCLC cells resistant to afatinib (an ERBB1/2/4 inhibitor). This drug combination appeared to use overlapping and distinct mechanisms of killing in different cell lines. Activation of AMP-dependent kinase (AMPK) and reduced expression and inactivation of mTOR were associated with increased autophagosome and autolysosome formation. Downregulation of Beclin1 considerably reduced formation of autophagosomes and protected the cells from drug combination-induced killing without significantly altering autolysosome formation. Autophagy protein 5 (ATG5) knock down afforded greater protection against the combination of pemetrexed with fingolimod. Treatment of cells with the mTOR inhibitor everolimus markedly enhanced the lethality of pemetrexed plus fingolimod combination. Our data suggest that the combination of fingolimod with the established NSCLC/ovarian cancer drug pemetrexed should be explored as a new therapy.
Project description:PurposePrevious retrospective studies suggest that anaplastic lymphoma kinase (ALK) mutation-positive (ALK+) non-small cell lung cancer (NSCLC) patients are sensitive to pemetrexed. To determine its efficacy, we retrospectively evaluated clinical outcomes of pemetrexed-based chemotherapy in patients with ALK+ NSCLC.Materials and methodsWe identified 126 patients with advanced, ALK+ NSCLC who received first-line cytotoxic chemotherapy. We compared response, progression-free survival (PFS), and overall survival (OS) rates according to chemotherapy regimens. Furthermore, we evaluated intracranial time to tumor progression (TTP) and proportion of ALK+ cells as prognostic factors.ResultsForty-eight patients received pemetrexed-based chemotherapy, while 78 received other regimens as first-line treatment. The pemetrexed-based chemotherapy group showed superior overall response (44.7% vs. 14.3%, p<0.001) and disease control (85.1% vs. 62.3%, p=0.008) rates. The pemetrexed-based chemotherapy group also exhibited longer PFS (6.6 months vs. 3.8 months, p<0.001); OS rates were not significantly different. The lack of exposure to second-generation ALK inhibitors and intracranial metastasis on initial diagnosis were independent negative prognostic factors of OS. Intracranial TTP was similar between the treatment groups (32.7 months vs. 35.7 months, p=0.733). Patients who harbored a greater number of ALK+ tumor cells (≥70%) showed prolonged OS on univariate analysis (not reached vs. 44.8 months, p=0.041), but not on multivariate analysis (hazard ratio: 0.19, 95% confidence interval: 0.03-1.42; p=0.106).ConclusionPemetrexed-based regimens may prolong PFS in patients with ALK+ NSCLC as a first-line treatment, but are not associated with prolonged OS. Exposure to second-generation ALK inhibitors may improve OS rates in patients with ALK+ NSCLC.
Project description:In many cancers, including non-small cell lung cancer (NSCLC), tumor angiogenesis pathways have been identified as important therapeutic targets. Angiogenesis is essential in the process of primary tumor growth, proliferation and metastasis. One of the best characterized group of protein factors for angiogenesis include the members of the vascular endothelial growth factor (VEGF) family, consisting of VEGF-(A-D), and placenta growth factor (PIGF). Targeting tumor angiogenesis has been approached through two primary methods, monoclonal antibodies that block VEGF-vascular endothelial growth factor receptor (VEGFR) binding or small molecule tyrosine kinase inhibitors (TKIs) that inhibit the downstream VEGFR mediated signaling. Many TKIs inhibit multiple pro-angiogenic and pro-proliferative pathways such as the mitogen activated protein (MAP) kinase pathway. Bevacizumab and ramucirumab, monoclonal antibodies targeting VEGF and the VEGFR, respectively, have each led to improvements in overall survival (OS) for NSCLC when added to standard first and second line chemotherapy, respectively. Small incremental gains seen with both bevacizumab and ramucirumab may be further improved upon by incorporating novel agents and treatment strategies, and many additional trials are ongoing.
Project description:Inhibition of thymidylate synthase (TS) results in a transient "flare" in DNA thymidine salvage pathway activity measurable with FLT ([18F]thymidine)-positron emission tomography (PET). Here we characterize this imaging strategy for potential clinical translation in non-small cell lung cancer (NSCLC). Since pemetrexed acts by inhibiting TS, we defined the kinetics of increases in thymidine salvage pathway mediated by TS inhibition following treatment with pemetrexed in vitro. Next, using a mouse model of NSCLC, we validated the kinetics of the pemetrexed-mediated "flare" in thymidine salvage pathway activity in vivo using FLT-PET imaging. Finally, we translated our findings into a proof-of-principle clinical trial of FLT-PET in a human NSCLC patient. In NSCLC cells in vitro, we identified a burst in pemetrexed-mediated thymidine salvage pathway activity, assessed by 3H-thymidine assays, thymidine kinase 1 (TK1) expression, and equilibrative nucleoside transporter 1 (ENT1) mobilization to the cell membrane, that peaked at 2hrs. This 2hr time-point was also optimal for FLT-PET imaging of pemetrexed-mediated TS inhibition in murine xenograft tumors and was demonstrated to be feasible in a NSCLC patient. FLT-PET imaging of pemetrexed-induced TS inhibition is optimal at 2hrs from therapy start; this timing is feasible in human clinical trials.
Project description:BackgroundNon-small cell lung cancer (NSCLC) is the leading cause of cancer-related death worldwide. Pemetrexed, a multi-target folate antagonist, has demonstrated efficacy in NSCLC histological subtypes characterized by low thymidylate synthase (TS) expression. Among many other potential targets, histone deacetylase inhibitors (HDACi) modulate TS expression, potentially sensitizing to the cytotoxic action of anti-cancer drugs that target the folate pathway, such as pemetrexed. Since high levels of TS have been linked to clinical resistance to pemetrexed in NSCLC, herein we investigated the molecular and functional effects of combined pemetrexed and ITF2357, a pan-HDACi currently in clinical trials as an anti-cancer agent.ResultsIn NSCLC cell lines, HDAC inhibition by ITF2357 induced histone and tubulin acetylation and downregulated TS expression at the mRNA and protein level. In combination experiments in vitro ITF2357 and pemetrexed demonstrated sequence-dependent synergistic growth-inhibitory effects, with the sequence pemetrexed followed by ITF2357 inducing a strikingly synergistic reduction in cell viability and induction of both apoptosis and autophagy in all cell line models tested, encompassing both adenocarcinoma and squamous cell carcinoma. Conversely, simultaneous administration of both drugs achieved frankly antagonistic effects, while the sequence of ITF2357 followed by pemetrexed had additive to slightly synergistic growth-inhibitory effects only in certain cell lines. Similarly, highly synergistic growth inhibition was also observed in patient-derived lung cancer stem cells (LCSC) exposed to pemetrexed followed by ITF2357. In terms of molecular mechanisms of interaction, the synergistic growth-inhibitory effects observed were only partially related to TS modulation by ITF2357, as genetic silencing of TS expression potentiated growth inhibition by either pemetrexed or ITF2357 and, to a lesser extent, by their sequential combination. Genetic and pharmacological approaches provided an interesting link between the autophagic and apoptotic pathways, and showed that sequential pemetrexed/ITF2357 causes a toxic form of autophagy with consequent activation of a caspase-dependent apoptotic program. In vivo experiments in NSCLC xenografts confirmed that sequential pemetrexed/ITF2357 is feasible and results in increased inhibition of tumor growth and increased mice survival.ConclusionsOverall, these data provide a strong rationale for the clinical development of sequential schedules employing pemetrexed followed by HDACi in NSCLC.
Project description:Cisplatin‑pemetrexed is a frequently adopted first‑line treatment for patients with advanced non‑small cell lung cancer (NSCLC) ineligible for biological therapy, notwithstanding its limited efficacy. In the present study, the RAL cell line, an epidermal growth factor receptor (EGFR)‑wild‑type, p53‑ and KRAS‑mutated model of NSCLC, was used to investigate novel biomarkers of resistance to this treatment. Cells were analyzed 96 h (96 h‑post wo) and 21 days (21 d‑post wo) after the combined treatment washout. Following an initial moderate sensitivity to the treatment, the cell growth proliferative capability had fully recovered. Gene expression analysis of the resistant surviving cells revealed a significant upregulation of CDKN1A expression in the cells at 96 h post‑wo and, although to a lesser extent, in the cells at 21 d post‑wo, accompanied by an enrichment of acetylated histone H3 in its promoter region. CDKN1A was also upregulated at the protein level, being mainly detected in the cytoplasm of the cells at 96 h‑post wo. A marked increase in the number of apoptotic cells, together with a significant G1 phase block, were observed at 96 h post‑wo in the cells in which CDKN1A was knocked down, suggesting its involvement in the modulation of the response of RAL cells to the drug combination. On the whole, these data suggest that CDKN1A plays a role in the response to the cisplatin‑pemetrexed combination in advanced KRAS‑mutated NSCLC, thus suggesting that it may be used as a promising predictive marker.
Project description:The cytotoxic mechanisms of thymidylate synthase inhibitors, such as the multitarget antifolate pemetrexed, are not yet fully understood. Emerging evidence indicates that combining pemetrexed with histone deacetylase inhibitors (HDACi) may enhance therapeutic efficacy in non-small cell lung cancer (NSCLC). To explore this further, A549 NSCLC cells were treated with various combinations of pemetrexed and the HDACi MS275 (Entinostat), and subsequently assessed for cell viability, cell cycle changes, and genotoxic markers. Proteomic alterations were analyzed using label-free shotgun and targeted LC–MS/MS. MS275 enhanced the sensitivity of A549 cells to pemetrexed, but only when administered following prior treatment with pemetrexed. Both HeLa (p53 negative) and A549 (p53 positive) showed robust activation of γH2AX upon treatment with this combination. Importantly, CRISPR/Cas9 knockout of the uracil-DNA glycosylase UNG did not affect γH2AX activation or sensitivity to pemetrexed. Proteomic analysis revealed that MS275 altered the expression of known pemetrexed targets, as well as several proteins involved in pyrimidine metabolism and DNA repair, which could potentiate pemetrexed cytotoxicity. Contrary to the conventional model of antifolate toxicity, which implicates futile cycles of uracil incorporation and excision in DNA, we propose that ribonucleotide incorporation in nuclear and mitochondrial DNA significantly contributes to the cytotoxicity of antifolates like pemetrexed, and likely also of fluorinated pyrimidine analogs. HDAC inhibition apparently exacerbates cytotoxicity of these agents by inhibiting error-free repair of misincorporated ribonucleotides in DNA. The potential of HDACis to modulate pyrimidine metabolism and DNA damage responses offers novel strategies for improving NSCLC outcomes.
Project description:BackgroundA previous study showed a survival benefit with maintenance therapy with pemetrexed in patients with advanced non-small cell lung cancer (NSCLC). However, it remains unclear whether continuation maintenance therapy with pemetrexed is beneficial in Japanese patients. Here, we present our phase II study that assessed the efficacy and safety of cisplatin plus pemetrexed as induction chemotherapy, followed by maintenance therapy with pemetrexed in advanced NSCLC patients in Japan.MethodsChemotherapy-naïve patients received 500 mg/m(2) pemetrexed and 75 mg/m(2) cisplatin on day one every three weeks for four cycles. In patients who responded to therapy or achieved stable disease, pemetrexed was continued until disease progression. The primary endpoint of this study was the progression-free survival rate at six months (PFS-6).ResultsOf the 35 patients initially enrolled in the study, 18 (51%) received maintenance chemotherapy with pemetrexed. The median PFS was 6.7 months, and the PFS-6 was 60% (95% confidence interval [CI], 42-76%). Median overall survival (OS) was 15.5 months (95% CI, 8.3-22.7 months). The median PFS and OS in patients who received maintenance chemotherapy with pemetrexed were 9.5 months and 25.3 months, respectively. The most frequently noted severe toxicity during induction chemotherapy was neutropenia, which occurred in seven patients. Two patients discontinued maintenance therapy owing to prolonged grade 2 edema in one patient and grade 3 neutropenia in another.ConclusionContinuation maintenance chemotherapy with pemetrexed is associated with a survival benefit in patients who have completed induction chemotherapy for non-squamous NSCLC.
Project description:Pemetrexed is currently mainly considered for the treatment of advanced nonsquamous non-small-cell lung cancer (NSCLC) negative for gene mutations/rearrangements (wild-type disease (WTD)). This narrative review aimed to highlight the role of pemetrexed in the treatment of onco-driven nonsquamous advanced NSCLC by reviewing published clinical studies. For epidermal growth factor receptor (EGFR) mutations, patient survival following first-line pemetrexed-platinum was longer than for WTD. Later-line pemetrexed-based treatment after tyrosine kinase inhibitor (TKI) failure provided greater benefits than non-pemetrexed regimens. First- and later-line pemetrexed-based therapy also provided survival benefits in patients with anaplastic lymphoma kinase (ALK) or ROS proto-oncogene 1 (ROS1) rearrangements. In patients with rearranged during transfection (RET) proto-oncogene rearrangements, survival with pemetrexed was similar to that in ALK- and ROS1-positive patients and longer than that in patients with Kirsten rat sarcoma (KRAS) virus proto-oncogene mutations or WTD, although the available studies were limited. For Erb-b2 receptor tyrosine kinase 2 (ERRB2) mutations, first-line pemetrexed showed outcomes similar to those for EGFR and KRAS alterations. Data on pemetrexed in patients with KRAS mutations or MNNG HOS-transforming (MET) expression were limited. Pemetrexed could be an option for first- and second-line treatment for TKI failure in nonsquamous advanced NSCLC with select targetable driver mutations.
Project description:BackgroundAnaplastic lymphoma kinase (ALK)-positive non-small-cell lung cancer (NSCLC) is highly responsive to crizotinib. To determine whether ALK-positive NSCLC is also sensitive to pemetrexed, we retrospectively evaluated progression-free survival (PFS) of ALK-positive versus ALK-negative patients who had been treated with pemetrexed-based chemotherapy for advanced NSCLC.Patients and methodsWe identified 121 patients with advanced, ALK-positive NSCLC in the USA, Australia, and Italy. For comparison, we evaluated 266 patients with advanced, ALK-negative, epidermal growth factor receptor (EGFR)-wild-type NSCLC, including 79 with KRAS mutations and 187 with wild-type KRAS (WT/WT/WT). We determined PFS on different pemetrexed regimens.ResultsAmong 70 ALK-positive patients treated with a platinum/pemetrexed regimen, the median PFS (mPFS) was 7.3 months (95% confidence interval (CI) 5.5-9.5). The mPFS of 51 ALK-positive patients treated with single-agent pemetrexed or nonplatinum/pemetrexed combinations was 5.5 months (2.8-9.0). For ALK-negative patients, PFS on all pemetrexed-based regimens was similar to that of ALK-positive patients, except in the specific setting of first-line platinum/pemetrexed where the mPFS was only 4.2 and 5.4 months in KRAS and WT/WT/WT patients, respectively. However, among patients with a never/light-smoking history (0-10 pack-year smoking history) treated with first-line platinum/pemetrexed, there was no difference in PFS between ALK-positive and ALK-negative patients.ConclusionsPFS on pemetrexed or nonplatinum/pemetrexed combinations was similar in ALK-positive and ALK-negative patients. PFS on first-line platinum/pemetrexed may be prolonged in never/light-smoking patients regardless of ALK status.