ABSTRACT
Intrinsic and acquired drug resistance and induction of secondary malignancies limit successful chemotherapy. Because mutagenic translesion synthesis (TLS) contributes to chemoresistance as well as treatment-induced mutations, targeting TLS is an attractive avenue for improving chemotherapeutics. However, development of small molecules with high specificity and in vivo efficacy for mutagenic TLS has been challenging. Here, we report the discovery of a small-molecule inhibitor, JH-RE-06, that disrupts mutagenic TLS by preventing recruitment of mutagenic POL ζ. Remarkably, JH-RE-06 targets a nearly featureless surface of REV1 that interacts with the REV7 subunit of POL ζ. Binding of JH-RE-06 induces REV1 dimerization, which blocks the REV1-REV7 interaction and POL ζ recruitment. JH-RE-06 inhibits mutagenic TLS and enhances cisplatin-induced toxicity in cultured human and mouse cell lines. Co-administration of JH-RE-06 with cisplatin suppresses the growth of xenograft human melanomas in mice, establishing a framework for developing TLS inhibitors as a novel class of chemotherapy adjuvants.
Subject(s)
Antineoplastic Agents/therapeutic use , Cisplatin/therapeutic use , Mutagenesis/drug effects , Neoplasms/drug therapy , Quinolines/therapeutic use , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cell Survival/drug effects , Cisplatin/adverse effects , Cisplatin/pharmacology , DNA Damage/drug effects , DNA-Directed DNA Polymerase , Female , Gene Knockdown Techniques , Humans , Mad2 Proteins/metabolism , Mice , Mice, Nude , Mice, Transgenic , Neoplasms/metabolism , Neoplasms/pathology , Nucleotidyltransferases/antagonists & inhibitors , Nucleotidyltransferases/chemistry , Nucleotidyltransferases/genetics , Nucleotidyltransferases/metabolism , Quinolines/chemistry , Quinolines/pharmacology , Transfection , Tumor Burden/drug effects , Xenograft Model Antitumor AssaysABSTRACT
Many types of human cancers suppress the expression of argininosuccinate synthase 1 (ASS1), a rate-limiting enzyme for arginine production. Although dependency on exogenous arginine can be harnessed by arginine-deprivation therapies, the impact of ASS1 suppression on the quality of the tumor proteome is unknown. We therefore interrogated proteomes of cancer patients for arginine codon reassignments (substitutants) and surprisingly identified a strong enrichment for cysteine (R>C) in lung tumors specifically. Most R>C events did not coincide with genetically encoded R>C mutations but were likely products of tRNA misalignments. The expression of R>C substitutants was highly associated with oncogenic kelch-like epichlorohydrin (ECH)-associated protein 1 (KEAP1)-pathway mutations and suppressed by intact-KEAP1 in KEAP1-mutated cancer cells. Finally, functional interrogation indicated a key role for R>C substitutants in cell survival to cisplatin, suggesting that regulatory codon reassignments endow cancer cells with more resilience to stress. Thus, we present a mechanism for enriching lung cancer proteomes with cysteines that may affect therapeutic decisions.
Subject(s)
Arginine , Cysteine , Kelch-Like ECH-Associated Protein 1 , Lung Neoplasms , Proteome , Humans , Cysteine/metabolism , Lung Neoplasms/genetics , Lung Neoplasms/metabolism , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Kelch-Like ECH-Associated Protein 1/metabolism , Kelch-Like ECH-Associated Protein 1/genetics , Proteome/metabolism , Arginine/metabolism , Mutation , Argininosuccinate Synthase/metabolism , Argininosuccinate Synthase/genetics , Cisplatin/pharmacology , Cell Line, Tumor , Proteomics/methods , Gene Expression Regulation, Neoplastic , Cell Survival/drug effects , RNA, Transfer/metabolism , RNA, Transfer/geneticsABSTRACT
Many chemotherapeutic drugs kill only a fraction of cancer cells, limiting their efficacy. We used live-cell imaging to investigate the role of p53 dynamics in fractional killing of colon cancer cells in response to chemotherapy. We found that both surviving and dying cells reach similar levels of p53, indicating that cell death is not determined by a fixed p53 threshold. Instead, a cell's probability of death depends on the time and levels of p53. Cells must reach a threshold level of p53 to execute apoptosis, and this threshold increases with time. The increase in p53 apoptotic threshold is due to drug-dependent induction of anti-apoptotic genes, predominantly in the inhibitors of apoptosis (IAP) family. Our study underlines the importance of measuring the dynamics of key players in response to chemotherapy to determine mechanisms of resistance and optimize the timing of combination therapy.
Subject(s)
Antineoplastic Agents/pharmacology , Cisplatin/pharmacology , Drug Resistance, Neoplasm , Tumor Suppressor Protein p53/metabolism , Apoptosis/drug effects , Cell Line, Tumor , Humans , Inhibitor of Apoptosis Proteins , Up-RegulationABSTRACT
Effector T cells and fibroblasts are major components in the tumor microenvironment. The means through which these cellular interactions affect chemoresistance is unclear. Here, we show that fibroblasts diminish nuclear accumulation of platinum in ovarian cancer cells, resulting in resistance to platinum-based chemotherapy. We demonstrate that glutathione and cysteine released by fibroblasts contribute to this resistance. CD8(+) T cells abolish the resistance by altering glutathione and cystine metabolism in fibroblasts. CD8(+) T-cell-derived interferon (IFN)γ controls fibroblast glutathione and cysteine through upregulation of gamma-glutamyltransferases and transcriptional repression of system xc(-) cystine and glutamate antiporter via the JAK/STAT1 pathway. The presence of stromal fibroblasts and CD8(+) T cells is negatively and positively associated with ovarian cancer patient survival, respectively. Thus, our work uncovers a mode of action for effector T cells: they abrogate stromal-mediated chemoresistance. Capitalizing upon the interplay between chemotherapy and immunotherapy holds high potential for cancer treatment.
Subject(s)
CD8-Positive T-Lymphocytes/metabolism , Drug Resistance, Neoplasm , Ovarian Neoplasms/drug therapy , Animals , Antineoplastic Agents/therapeutic use , Cell Culture Techniques , Cell Line, Tumor , Cisplatin/therapeutic use , Female , Fibroblasts/metabolism , Glutathione/metabolism , Humans , Interferon-gamma/metabolism , Mice , Mice, Inbred NOD , Mice, NudeABSTRACT
Subsets of long-lived, tumor-initiating stem cells often escape cancer therapies. However, sources and mechanisms that generate tumor heterogeneity and drug-resistant cell population are still unfolding. Here, we devise a functional reporter system to lineage trace and/or genetic ablate signaling in TGF-ß-activated squamous cell carcinoma stem cells (SCC-SCs). Dissecting TGF-ß's impact on malignant progression, we demonstrate that TGF-ß concentrating near tumor-vasculature generates heterogeneity in TGF-ß signaling at tumor-stroma interface and bestows slower-cycling properties to neighboring SCC-SCs. While non-responding progenies proliferate faster and accelerate tumor growth, TGF-ß-responding progenies invade, aberrantly differentiate, and affect gene expression. Intriguingly, TGF-ß-responding SCC-SCs show increased protection against anti-cancer drugs, but slower-cycling alone does not confer survival. Rather, TGF-ß transcriptionally activates p21, which stabilizes NRF2, thereby markedly enhancing glutathione metabolism and diminishing effectiveness of anti-cancer therapeutics. Together, these findings establish a surprising non-genetic paradigm for TGF-ß signaling in fueling heterogeneity in SCC-SCs, tumor characteristics, and drug resistance.
Subject(s)
Carcinoma, Squamous Cell/metabolism , Drug Resistance, Neoplasm , Signal Transduction , Skin Neoplasms/metabolism , Transforming Growth Factor beta/metabolism , 9,10-Dimethyl-1,2-benzanthracene , Animals , Carcinoma, Squamous Cell/drug therapy , Cisplatin/therapeutic use , Female , Gene Expression Profiling , Glutathione/metabolism , Head and Neck Neoplasms/drug therapy , Head and Neck Neoplasms/metabolism , Heterografts , Humans , Mice , Mice, Nude , NF-E2-Related Factor 2 , Neoplasm Transplantation , Neoplastic Stem Cells/metabolism , Skin Neoplasms/drug therapy , Tetradecanoylphorbol AcetateABSTRACT
Mutations in BRCA1 or BRCA2 (BRCA) is synthetic lethal with poly(ADP-ribose) polymerase inhibitors (PARPi). Lethality is thought to derive from DNA double-stranded breaks (DSBs) necessitating BRCA function in homologous recombination (HR) and/or fork protection (FP). Here, we report instead that toxicity derives from replication gaps. BRCA1- or FANCJ-deficient cells, with common repair defects but distinct PARPi responses, reveal gaps as a distinguishing factor. We further uncouple HR, FP, and fork speed from PARPi response. Instead, gaps characterize BRCA-deficient cells, are diminished upon resistance, restored upon resensitization, and, when exposed, augment PARPi toxicity. Unchallenged BRCA1-deficient cells have elevated poly(ADP-ribose) and chromatin-associated PARP1, but aberrantly low XRCC1 consistent with defects in backup Okazaki fragment processing (OFP). 53BP1 loss resuscitates OFP by restoring XRCC1-LIG3 that suppresses the sensitivity of BRCA1-deficient cells to drugs targeting OFP or generating gaps. We highlight gaps as a determinant of PARPi toxicity changing the paradigm for synthetic lethal interactions.
Subject(s)
BRCA1 Protein/genetics , DNA Replication/drug effects , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Animals , Cell Line , Cisplatin/pharmacology , DNA/genetics , DNA/metabolism , DNA, Single-Stranded/genetics , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Fanconi Anemia Complementation Group Proteins/genetics , Homologous Recombination/drug effects , Humans , Mice, Inbred NOD , RNA Helicases/genetics , Rad51 Recombinase/genetics , Replication Protein A/genetics , Tumor Suppressor p53-Binding Protein 1/geneticsABSTRACT
Chemotherapy with cisplatin becomes limiting due to toxicity and secondary malignancies. In principle, therapeutics could be improved by targeting translesion synthesis (TLS) polymerases (Pols) that promote replication through intrastrand cross-links, the major cisplatin-induced DNA adduct. However, to specifically target malignancies with minimal adverse effects on normal cells, a good understanding of TLS mechanisms in normal versus cancer cells is paramount. We show that in normal cells, TLS through cisplatin intrastrand cross-links is promoted by Polη- or Polι-dependent pathways, both of which require Rev1 as a scaffolding component. In contrast, cancer cells require Rev1-Polζ. Our findings that a recently identified Rev1 inhibitor, JH-RE-06, purported to specifically disrupt Rev1 interaction with Polζ to block TLS through cisplatin adducts in cancer cells, abrogates Rev1's ability to function with Y family Pols as well, implying that by inactivating Rev1-dependent TLS in normal cells, this inhibitor will exacerbate the toxicity and tumorigenicity of chemotherapeutics with cisplatin.
Subject(s)
Cisplatin , DNA Damage , Cisplatin/pharmacology , DNA Repair , DNA Replication , DNA-Directed DNA Polymerase/metabolism , Nuclear Proteins/metabolism , Nucleotidyltransferases/genetics , Nucleotidyltransferases/metabolismABSTRACT
BACKGROUND: No treatment has surpassed platinum-based chemotherapy in improving overall survival in patients with previously untreated locally advanced or metastatic urothelial carcinoma. METHODS: We conducted a phase 3, global, open-label, randomized trial to compare the efficacy and safety of enfortumab vedotin and pembrolizumab with the efficacy and safety of platinum-based chemotherapy in patients with previously untreated locally advanced or metastatic urothelial carcinoma. Patients were randomly assigned in a 1:1 ratio to receive 3-week cycles of enfortumab vedotin (at a dose of 1.25 mg per kilogram of body weight intravenously on days 1 and 8) and pembrolizumab (at a dose of 200 mg intravenously on day 1) (enfortumab vedotin-pembrolizumab group) or gemcitabine and either cisplatin or carboplatin (determined on the basis of eligibility to receive cisplatin) (chemotherapy group). The primary end points were progression-free survival as assessed by blinded independent central review and overall survival. RESULTS: A total of 886 patients underwent randomization: 442 to the enfortumab vedotin-pembrolizumab group and 444 to the chemotherapy group. As of August 8, 2023, the median duration of follow-up for survival was 17.2 months. Progression-free survival was longer in the enfortumab vedotin-pembrolizumab group than in the chemotherapy group (median, 12.5 months vs. 6.3 months; hazard ratio for disease progression or death, 0.45; 95% confidence interval [CI], 0.38 to 0.54; P<0.001), as was overall survival (median, 31.5 months vs. 16.1 months; hazard ratio for death, 0.47; 95% CI, 0.38 to 0.58; P<0.001). The median number of cycles was 12 (range, 1 to 46) in the enfortumab vedotin-pembrolizumab group and 6 (range, 1 to 6) in the chemotherapy group. Treatment-related adverse events of grade 3 or higher occurred in 55.9% of the patients in the enfortumab vedotin-pembrolizumab group and in 69.5% of those in the chemotherapy group. CONCLUSIONS: Treatment with enfortumab vedotin and pembrolizumab resulted in significantly better outcomes than chemotherapy in patients with untreated locally advanced or metastatic urothelial carcinoma, with a safety profile consistent with that in previous reports. (Funded by Astellas Pharma US and others; EV-302 ClinicalTrials.gov number, NCT04223856.).
Subject(s)
Antibodies, Monoclonal , Antineoplastic Agents , Carcinoma, Transitional Cell , Urologic Neoplasms , Humans , Antibodies, Monoclonal/administration & dosage , Antibodies, Monoclonal/adverse effects , Antibodies, Monoclonal/therapeutic use , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Carcinoma, Transitional Cell/drug therapy , Carcinoma, Transitional Cell/pathology , Carcinoma, Transitional Cell/secondary , Cisplatin/administration & dosage , Cisplatin/adverse effects , Cisplatin/therapeutic use , Urinary Bladder Neoplasms , Gemcitabine/administration & dosage , Gemcitabine/adverse effects , Gemcitabine/therapeutic use , Carboplatin/administration & dosage , Carboplatin/adverse effects , Carboplatin/therapeutic use , Antineoplastic Agents/administration & dosage , Antineoplastic Agents/adverse effects , Antineoplastic Agents/therapeutic use , Survival Analysis , Urologic Neoplasms/drug therapy , Urologic Neoplasms/pathology , Urologic Neoplasms/secondaryABSTRACT
Progress in defining genomic fitness landscapes in cancer, especially those defined by copy number alterations (CNAs), has been impeded by lack of time-series single-cell sampling of polyclonal populations and temporal statistical models1-7. Here we generated 42,000 genomes from multi-year time-series single-cell whole-genome sequencing of breast epithelium and primary triple-negative breast cancer (TNBC) patient-derived xenografts (PDXs), revealing the nature of CNA-defined clonal fitness dynamics induced by TP53 mutation and cisplatin chemotherapy. Using a new Wright-Fisher population genetics model8,9 to infer clonal fitness, we found that TP53 mutation alters the fitness landscape, reproducibly distributing fitness over a larger number of clones associated with distinct CNAs. Furthermore, in TNBC PDX models with mutated TP53, inferred fitness coefficients from CNA-based genotypes accurately forecast experimentally enforced clonal competition dynamics. Drug treatment in three long-term serially passaged TNBC PDXs resulted in cisplatin-resistant clones emerging from low-fitness phylogenetic lineages in the untreated setting. Conversely, high-fitness clones from treatment-naive controls were eradicated, signalling an inversion of the fitness landscape. Finally, upon release of drug, selection pressure dynamics were reversed, indicating a fitness cost of treatment resistance. Together, our findings define clonal fitness linked to both CNA and therapeutic resistance in polyclonal tumours.
Subject(s)
DNA Copy Number Variations , Drug Resistance, Neoplasm , Triple Negative Breast Neoplasms/genetics , Animals , Cell Line, Tumor , Cisplatin/pharmacology , Clone Cells/pathology , Female , Genetic Fitness , Humans , Mice , Models, Statistical , Neoplasm Transplantation , Tumor Suppressor Protein p53/genetics , Whole Genome SequencingABSTRACT
Protein ubiquitination at sites of DNA double-strand breaks (DSBs) by RNF168 recruits BRCA1 and 53BP11,2, which are mediators of the homologous recombination and non-homologous end joining DSB repair pathways, respectively3. Non-homologous end joining relies on 53BP1 binding directly to ubiquitinated lysine 15 on H2A-type histones (H2AK15ub)4,5 (which is an RNF168-dependent modification6), but how RNF168 promotes BRCA1 recruitment and function remains unclear. Here we identify a tandem BRCT-domain-associated ubiquitin-dependent recruitment motif (BUDR) in BRCA1-associated RING domain protein 1 (BARD1) (the obligate partner protein of BRCA1) that, by engaging H2AK15ub, recruits BRCA1 to DSBs. Disruption of the BUDR of BARD1 compromises homologous recombination and renders cells hypersensitive to PARP inhibition and cisplatin. We further show that BARD1 binds nucleosomes through multivalent interactions: coordinated binding of H2AK15ub and unmethylated H4 lysine 20 by its adjacent BUDR and ankyrin repeat domains, respectively, provides high-affinity recognition of DNA lesions in replicated chromatin and promotes the homologous recombination activities of the BRCA1-BARD1 complex. Finally, our genetic epistasis experiments confirm that the need for BARD1 chromatin-binding activities can be entirely relieved upon deletion of RNF168 or 53BP1. Thus, our results demonstrate that by sensing DNA-damage-dependent and post-replication histone post-translation modification states, BRCA1-BARD1 complexes coordinate the antagonization of the 53BP1 pathway with promotion of homologous recombination, establishing a simple paradigm for the governance of the choice of DSB repair pathway.
Subject(s)
Homologous Recombination , Lysine/chemistry , Lysine/metabolism , Tumor Suppressor Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Ubiquitination , Adult , Amino Acid Motifs , BRCA1 Protein/chemistry , BRCA1 Protein/metabolism , Chromatin/metabolism , Cisplatin/pharmacology , DNA Breaks, Double-Stranded , DNA Damage/drug effects , Female , HCT116 Cells , HEK293 Cells , Histones/chemistry , Histones/metabolism , Humans , Male , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Protein Domains , Recombinational DNA Repair , Tumor Suppressor Proteins/chemistry , Tumor Suppressor p53-Binding Protein 1/deficiency , Tumor Suppressor p53-Binding Protein 1/metabolism , Ubiquitin/metabolism , Ubiquitin-Protein Ligases/chemistry , Ubiquitin-Protein Ligases/deficiencyABSTRACT
Programmed death ligand 1 (PD-L1, also called B7-H1) is an immune checkpoint protein that inhibits immune function through its binding of the programmed cell death protein 1 (PD-1) receptor. Clinically approved antibodies block extracellular PD-1 and PD-L1 binding, yet the role of intracellular PD-L1 in cancer remains poorly understood. Here, we discovered that intracellular PD-L1 acts as an RNA binding protein that regulates the mRNA stability of NBS1, BRCA1, and other DNA damage-related genes. Through competition with the RNA exosome, intracellular PD-L1 protects targeted RNAs from degradation, thereby increasing cellular resistance to DNA damage. RNA immunoprecipitation and RNA-seq experiments demonstrated that PD-L1 regulates RNA stability genome-wide. Furthermore, we developed a PD-L1 antibody, H1A, which abrogates the interaction of PD-L1 with CMTM6, thereby promoting PD-L1 degradation. Intracellular PD-L1 may be a potential therapeutic target to enhance the efficacy of radiotherapy and chemotherapy in cancer through the inhibition of DNA damage response and repair.
Subject(s)
B7-H1 Antigen/genetics , DNA Repair , DNA, Neoplasm/genetics , Exosome Multienzyme Ribonuclease Complex/genetics , Gene Expression Regulation, Neoplastic , Programmed Cell Death 1 Receptor/genetics , Animals , Antineoplastic Agents/pharmacology , B7-H1 Antigen/antagonists & inhibitors , B7-H1 Antigen/metabolism , BRCA1 Protein/genetics , BRCA1 Protein/metabolism , Cell Cycle Proteins/genetics , Cell Cycle Proteins/metabolism , Cell Line, Tumor , Cisplatin/pharmacology , DNA Damage , DNA, Neoplasm/metabolism , Exosome Multienzyme Ribonuclease Complex/metabolism , Gamma Rays/therapeutic use , HCT116 Cells , HeLa Cells , Humans , MARVEL Domain-Containing Proteins , Membrane Proteins/genetics , Membrane Proteins/metabolism , Mice , Myelin Proteins , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , Programmed Cell Death 1 Receptor/antagonists & inhibitors , Programmed Cell Death 1 Receptor/metabolism , Proteolysis/drug effects , Proteolysis/radiation effects , RNA Stability/drug effects , RNA Stability/radiation effects , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: No new agent has improved overall survival in patients with unresectable or metastatic urothelial carcinoma when added to first-line cisplatin-based chemotherapy. METHODS: In this phase 3, multinational, open-label trial, we randomly assigned patients with previously untreated unresectable or metastatic urothelial carcinoma either to receive intravenous nivolumab (at a dose of 360 mg) plus gemcitabine-cisplatin (nivolumab combination) every 3 weeks for up to six cycles, followed by nivolumab (at a dose of 480 mg) every 4 weeks for a maximum of 2 years, or to receive gemcitabine-cisplatin alone every 3 weeks for up to six cycles. The primary outcomes were overall and progression-free survival. The objective response and safety were exploratory outcomes. RESULTS: A total of 608 patients underwent randomization (304 to each group). At a median follow-up of 33.6 months, overall survival was longer with nivolumab-combination therapy than with gemcitabine-cisplatin alone (hazard ratio for death, 0.78; 95% confidence interval [CI], 0.63 to 0.96; P = 0.02); the median survival was 21.7 months (95% CI, 18.6 to 26.4) as compared with 18.9 months (95% CI, 14.7 to 22.4), respectively. Progression-free survival was also longer with nivolumab-combination therapy than with gemcitabine-cisplatin alone (hazard ratio for progression or death, 0.72; 95% CI, 0.59 to 0.88; P = 0.001). The median progression-free survival was 7.9 months and 7.6 months, respectively. At 12 months, progression-free survival was 34.2% and 21.8%, respectively. The overall objective response was 57.6% (complete response, 21.7%) with nivolumab-combination therapy and 43.1% (complete response, 11.8%) with gemcitabine-cisplatin alone. The median duration of complete response was 37.1 months with nivolumab-combination therapy and 13.2 months with gemcitabine-cisplatin alone. Grade 3 or higher adverse events occurred in 61.8% and 51.7% of the patients, respectively. CONCLUSIONS: Combination therapy with nivolumab plus gemcitabine-cisplatin resulted in significantly better outcomes in patients with previously untreated advanced urothelial carcinoma than gemcitabine-cisplatin alone. (Funded by Bristol Myers Squibb and Ono Pharmaceutical; CheckMate 901 ClinicalTrials.gov number, NCT03036098.).
Subject(s)
Antineoplastic Combined Chemotherapy Protocols , Carcinoma, Transitional Cell , Cisplatin , Gemcitabine , Nivolumab , Urinary Bladder Neoplasms , Humans , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Transitional Cell/drug therapy , Carcinoma, Transitional Cell/pathology , Cisplatin/administration & dosage , Cisplatin/adverse effects , Gemcitabine/administration & dosage , Gemcitabine/adverse effects , Nivolumab/administration & dosage , Nivolumab/adverse effects , Urinary Bladder Neoplasms/drug therapy , Urinary Bladder Neoplasms/pathology , Administration, IntravenousABSTRACT
BACKGROUND: Among patients with resectable early-stage non-small-cell lung cancer (NSCLC), a perioperative approach that includes both neoadjuvant and adjuvant immune checkpoint inhibition may provide benefit beyond either approach alone. METHODS: We conducted a randomized, double-blind, phase 3 trial to evaluate perioperative pembrolizumab in patients with early-stage NSCLC. Participants with resectable stage II, IIIA, or IIIB (N2 stage) NSCLC were assigned in a 1:1 ratio to receive neoadjuvant pembrolizumab (200 mg) or placebo once every 3 weeks, each of which was given with cisplatin-based chemotherapy for 4 cycles, followed by surgery and adjuvant pembrolizumab (200 mg) or placebo once every 3 weeks for up to 13 cycles. The dual primary end points were event-free survival (the time from randomization to the first occurrence of local progression that precluded the planned surgery, unresectable tumor, progression or recurrence, or death) and overall survival. Secondary end points included major pathological response, pathological complete response, and safety. RESULTS: A total of 397 participants were assigned to the pembrolizumab group, and 400 to the placebo group. At the prespecified first interim analysis, the median follow-up was 25.2 months. Event-free survival at 24 months was 62.4% in the pembrolizumab group and 40.6% in the placebo group (hazard ratio for progression, recurrence, or death, 0.58; 95% confidence interval [CI], 0.46 to 0.72; P<0.001). The estimated 24-month overall survival was 80.9% in the pembrolizumab group and 77.6% in the placebo group (P = 0.02, which did not meet the significance criterion). A major pathological response occurred in 30.2% of the participants in the pembrolizumab group and in 11.0% of those in the placebo group (difference, 19.2 percentage points; 95% CI, 13.9 to 24.7; P<0.0001; threshold, P = 0.0001), and a pathological complete response occurred in 18.1% and 4.0%, respectively (difference, 14.2 percentage points; 95% CI, 10.1 to 18.7; P<0.0001; threshold, P = 0.0001). Across all treatment phases, 44.9% of the participants in the pembrolizumab group and 37.3% of those in the placebo group had treatment-related adverse events of grade 3 or higher, including 1.0% and 0.8%, respectively, who had grade 5 events. CONCLUSIONS: Among patients with resectable, early-stage NSCLC, neoadjuvant pembrolizumab plus chemotherapy followed by resection and adjuvant pembrolizumab significantly improved event-free survival, major pathological response, and pathological complete response as compared with neoadjuvant chemotherapy alone followed by surgery. Overall survival did not differ significantly between the groups in this analysis. (Funded by Merck Sharp and Dohme; KEYNOTE-671 ClinicalTrials.gov number, NCT03425643.).
Subject(s)
Antibodies, Monoclonal, Humanized , Antineoplastic Combined Chemotherapy Protocols , Carcinoma, Non-Small-Cell Lung , Cisplatin , Lung Neoplasms , Humans , Adjuvants, Immunologic/administration & dosage , Adjuvants, Immunologic/adverse effects , Adjuvants, Immunologic/therapeutic use , Antibodies, Monoclonal, Humanized/administration & dosage , Antibodies, Monoclonal, Humanized/adverse effects , Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Non-Small-Cell Lung/drug therapy , Carcinoma, Non-Small-Cell Lung/pathology , Carcinoma, Non-Small-Cell Lung/surgery , Lung Neoplasms/drug therapy , Lung Neoplasms/pathology , Lung Neoplasms/surgery , Cisplatin/administration & dosage , Cisplatin/adverse effects , Cisplatin/therapeutic use , Combined Modality TherapyABSTRACT
Wnt signaling pathways are transmitted via 10 homologous frizzled receptors (FZD1-10) in humans. Reagents broadly inhibiting Wnt signaling pathways reduce growth and metastasis of many tumors, but their therapeutic development has been hampered by the side effect. Inhibitors targeting specific Wnt-FZD pair(s) enriched in cancer cells may reduce side effect, but the therapeutic effect of narrow-spectrum Wnt-FZD inhibitors remains to be established in vivo. Here, we developed a fragment of C. difficile toxin B (TcdBFBD), which recognizes and inhibits a subclass of FZDs, FZD1/2/7, and examined whether targeting this FZD subgroup may offer therapeutic benefits for treating breast cancer models in mice. Utilizing 2 basal-like and 1 luminal-like breast cancer models, we found that TcdBFBD reduces tumor-initiating cells and attenuates growth of basal-like mammary tumor organoids and xenografted tumors, without damaging Wnt-sensitive tissues such as bones in vivo. Furthermore, FZD1/2/7-positive cells are enriched in chemotherapy-resistant cells in both basal-like and luminal mammary tumors treated with cisplatin, and TcdBFBD synergizes strongly with cisplatin in inhibiting both tumor types. These data demonstrate the therapeutic value of narrow-spectrum Wnt signaling inhibitor in treating breast cancers.
Subject(s)
Bacterial Toxins , Breast Neoplasms , Clostridioides difficile , Mammary Neoplasms, Animal , Humans , Animals , Mice , Female , Wnt Signaling Pathway , Breast Neoplasms/metabolism , Bacterial Toxins/metabolism , Clostridioides difficile/metabolism , CisplatinABSTRACT
Chemotherapy-induced peripheral neuropathy (CIPN) is a persistent and irreversible side effect of antineoplastic agents. Patients with CIPN usually show chronic pain and sensory deficits with glove-and-stocking distribution. However, whether spinal neuronal microRNA (miR)-124 is involved in cisplatin-induced peripheral neuropathy remains to be studied. In this study, miR-124 was significantly reduced in the spinal dorsal horn in CIPN mice. Overexpression of neuronal miR-124 induced by injecting adeno-associated virus with neuron-specific promoter into the spinal cord of mice prevented the development of mechanical allodynia, sensory deficits, and the loss of intraepidermal nerve fibers induced by cisplatin. Meanwhile, cisplatin-induced M1 microglia activation and the release of proinflammatory cytokines were significantly inhibited by overexpression of neuronal miR-124. Furthermore, electroacupuncture (EA) treatment upregulated miR-124 expression in the spinal dorsal horn of CIPN mice. Interestingly, downregulation of spinal neuronal miR-124 significantly inhibited the regulatory effect of EA on CIPN and microglia activity as well as spinal neuroinflammation induced by cisplatin. These results demonstrate that spinal neuronal miR-124 is involved in the prevention and treatment of EA on cisplatin-induced peripheral neuropathy in mice. Our findings suggest that spinal neuronal miR-124 might be a potential target for EA effect, and we provide, to our knowledge, a new experimental basis for EA prevention of CIPN.
Subject(s)
Antineoplastic Agents , Electroacupuncture , MicroRNAs , Peripheral Nervous System Diseases , Humans , Mice , Animals , Cisplatin/toxicity , Microglia , Paclitaxel/adverse effects , Antineoplastic Agents/toxicity , Peripheral Nervous System Diseases/chemically induced , Peripheral Nervous System Diseases/genetics , Peripheral Nervous System Diseases/prevention & control , Neurons/metabolism , MicroRNAs/genetics , MicroRNAs/metabolismABSTRACT
Acetaldehyde is a highly reactive, DNA-damaging metabolite that is produced upon alcohol consumption1. Impaired detoxification of acetaldehyde is common in the Asian population, and is associated with alcohol-related cancers1,2. Cells are protected against acetaldehyde-induced damage by DNA crosslink repair, which when impaired causes Fanconi anaemia (FA), a disease resulting in failure to produce blood cells and a predisposition to cancer3,4. The combined inactivation of acetaldehyde detoxification and the FA pathway induces mutation, accelerates malignancies and causes the rapid attrition of blood stem cells5-7. However, the nature of the DNA damage induced by acetaldehyde and how this is repaired remains a key question. Here we generate acetaldehyde-induced DNA interstrand crosslinks and determine their repair mechanism in Xenopus egg extracts. We find that two replication-coupled pathways repair these lesions. The first is the FA pathway, which operates using excision-analogous to the mechanism used to repair the interstrand crosslinks caused by the chemotherapeutic agent cisplatin. However, the repair of acetaldehyde-induced crosslinks results in increased mutation frequency and an altered mutational spectrum compared with the repair of cisplatin-induced crosslinks. The second repair mechanism requires replication fork convergence, but does not involve DNA incisions-instead the acetaldehyde crosslink itself is broken. The Y-family DNA polymerase REV1 completes repair of the crosslink, culminating in a distinct mutational spectrum. These results define the repair pathways of DNA interstrand crosslinks caused by an endogenous and alcohol-derived metabolite, and identify an excision-independent mechanism.
Subject(s)
Acetaldehyde/chemistry , Cross-Linking Reagents/chemistry , DNA Damage , DNA Repair , DNA Replication/physiology , DNA/chemistry , Ethanol/chemistry , Fanconi Anemia/metabolism , Animals , Cisplatin/chemistry , Cisplatin/pharmacology , DNA Damage/drug effects , DNA Replication/drug effects , DNA-Directed DNA Polymerase/metabolism , Ethanol/pharmacology , Mutagenesis/drug effects , Nucleotidyltransferases/metabolism , Point Mutation/drug effects , Point Mutation/genetics , Xenopus , Xenopus Proteins/metabolismABSTRACT
Replication stress converts the stalled forks into reversed forks, which is an important protection mechanism to prevent fork degradation and collapse into poisonous DNA double-strand breaks (DSBs). Paradoxically, the mechanism also acts in cancer cells to contribute to chemoresistance against various DNA-damaging agents. PARP1 binds to and is activated by stalled forks to facilitate fork reversal. Aprataxin and polynucleotide kinase/phosphatase-like factor (APLF) binds to PARP1 through the poly(ADP-ribose) zinc finger (PBZ) domain and is known to be involved in non-homologous end joining (NHEJ). Here, we identify a novel function of APLF involved in interstrand DNA crosslink (ICL) repair and fork protection. We demonstrate that PARP1 activity facilitates the APLF recruitment to stalled forks, enabling the FANCD2 recruitment to stalled forks. The depletion of APLF sensitizes cells to cisplatin, impairs ICL repair, reduces the FANCD2 recruitment to stalled forks, and results in nascent DNA degradation by MRE11 nucleases. Additionally, cisplatin-resistant cancer cells show high levels of APLF and homologous recombination-related gene expression. The depletion of APLF sensitizes cells to cisplatin and results in fork instability. Our results reveal the novel function of APLF to facilitate ICL repair and fork protection, thereby contributing to cisplatin-resistant phenotypes of cancer cells.
Subject(s)
Cisplatin , DNA Repair , DNA Replication , DNA-(Apurinic or Apyrimidinic Site) Lyase , Drug Resistance, Neoplasm , Poly (ADP-Ribose) Polymerase-1 , Humans , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cisplatin/pharmacology , DNA/metabolism , DNA/genetics , DNA Breaks, Double-Stranded , DNA Damage , DNA Replication/drug effects , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Drug Resistance, Neoplasm/genetics , Fanconi Anemia Complementation Group D2 Protein/metabolism , Fanconi Anemia Complementation Group D2 Protein/genetics , Poly (ADP-Ribose) Polymerase-1/metabolism , Poly (ADP-Ribose) Polymerase-1/genetics , Poly-ADP-Ribose Binding ProteinsABSTRACT
BRCA2 tumor suppressor protein ensures genome integrity by mediating DNA repair via homologous recombination (HR). This function is executed in part by its canonical DNA binding domain located at the C-terminus (BRCA2CTD), the only folded domain of the protein. Most germline pathogenic missense variants are located in this highly conserved region which binds to single-stranded DNA (ssDNA) and to the acidic protein DSS1. These interactions are essential for the HR function of BRCA2. Here, we report that the variant R2645G, identified in breast cancer and located at the DSS1 interface, unexpectedly increases the ssDNA binding activity of BRCA2CTDin vitro. Human cells expressing this variant display a hyper-recombination phenotype, chromosomal instability in the form of chromatid gaps when exposed to DNA damage, and increased PARP inhibitor sensitivity. In mouse embryonic stem cells (mES), this variant alters viability and confers sensitivity to cisplatin and Mitomycin C. These results suggest that BRCA2 interaction with ssDNA needs to be tightly regulated to limit HR and prevent chromosomal instability and we propose that this control mechanism involves DSS1. Given that several missense variants located within this region have been identified in breast cancer patients, these findings might have clinical implications for carriers.
Subject(s)
BRCA2 Protein , DNA, Single-Stranded , Protein Binding , Humans , BRCA2 Protein/genetics , BRCA2 Protein/metabolism , Animals , Mice , DNA, Single-Stranded/metabolism , DNA, Single-Stranded/genetics , Chromosomal Instability , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Cisplatin/pharmacology , DNA Damage , Mutation, Missense , Female , Poly(ADP-ribose) Polymerase Inhibitors/pharmacology , Mouse Embryonic Stem Cells/metabolism , Cell Line, Tumor , Mitomycin/pharmacology , DNA-Binding Proteins/metabolism , DNA-Binding Proteins/genetics , Proteasome Endopeptidase ComplexABSTRACT
Hearing loss is a major disability in everyday life and therapeutic interventions to protect hearing would benefit a large portion of the world population. Here we found that mice devoid of the protein kinase suppressor of RAS 1 (KSR1) in their tissues (germline KO mice) exhibit resistance to both cisplatin- and noise-induced permanent hearing loss compared with their wild-type KSR1 littermates. KSR1 is a scaffold protein that brings in proximity the mitogen-activated protein kinase (MAPK) proteins BRAF, MEK1/2 and ERK1/2 and assists in their activation through a phosphorylation cascade induced by both cisplatin and noise insults in the cochlear cells. KSR1, BRAF, MEK1/2, and ERK1/2 are all ubiquitously expressed in the cochlea. Deleting the KSR1 protein tempered down the MAPK phosphorylation cascade in the cochlear cells following both cisplatin and noise insults and conferred hearing protection of up to 30â dB SPL in three tested frequencies in male and female mice. Treatment with dabrafenib, an FDA-approved oral BRAF inhibitor, protected male and female KSR1 wild-type mice from both cisplatin- and noise-induced hearing loss. Dabrafenib treatment did not enhance the protection of KO KSR1 mice, providing evidence dabrafenib works primarily through the MAPK pathway. Thus, either elimination of the KSR1 gene expression or drug inhibition of the MAPK cellular pathway in mice resulted in profound protection from both cisplatin- and noise-induced hearing loss. Inhibition of the MAPK pathway, a cellular pathway that responds to damage in the cochlear cells, can prove a valuable strategy to protect and treat hearing loss.
Subject(s)
Cisplatin , Hearing Loss, Noise-Induced , MAP Kinase Signaling System , Mice, Knockout , Protein Kinases , Animals , Cisplatin/toxicity , Mice , Female , Hearing Loss, Noise-Induced/metabolism , Hearing Loss, Noise-Induced/genetics , Male , MAP Kinase Signaling System/drug effects , MAP Kinase Signaling System/physiology , Protein Kinases/metabolism , Protein Kinases/genetics , Mice, Inbred C57BLABSTRACT
BACKGROUND: Neoadjuvant therapy is the standard treatment for patients with locally advanced oesophageal squamous cell carcinoma (OSCC). However, the prognosis remains poor and more intensive neoadjuvant treatment might be needed to improve patient outcomes. We therefore aimed to compare the efficacy and safety of neoadjuvant doublet chemotherapy, triplet chemotherapy, and doublet chemotherapy plus radiotherapy in patients with previously untreated locally advanced OSCC. METHODS: In this randomised, open-label, phase 3 trial, patients aged 20-75 years with previously untreated locally advanced OSCC and an Eastern Cooperative Oncology Group performance status of 0 or 1 were recruited from 44 centres across Japan. Patients were randomly assigned (1:1:1) centrally via a web-based system to receive neoadjuvant doublet chemotherapy (two courses of fluorouracil [800 mg/m2 per day intravenously on days 1-5] and cisplatin [80 mg/m2 per day on day 1] separated by an interval of 3 weeks [NeoCF]), triplet chemotherapy (three courses of fluorouracil [750 mg/m2 per day on days 1-5], cisplatin [70 mg/m2 per day on day 1], and docetaxel [70 mg/m2 per day on day 1] repeated every 3 weeks [NeoCF+D]), or doublet chemotherapy (two courses of fluorouracil [1000 mg/m2 per day on days 1-4] and cisplatin [75 mg/m2 per day on day 1] separated by an interval of 4 weeks) plus 41·4 Gy radiotherapy [NeoCF+RT]) followed by oesophagectomy with regional lymph node dissection. Randomisation was stratified by T stage and institution. Participants, investigators, and those assessing outcomes were not masked to group assignment. The primary endpoint was overall survival, analysed by intention to treat. Analysis of safety included all patients who received at least one course of chemotherapy, and analysis of surgical complications included those who also underwent surgery. This study is registered with the Japan Registry of Clinical Trials, jRCTs031180202, and the trial is complete. FINDINGS: A total of 601 patients (529 male individuals and 72 female individuals) were randomly assigned between Dec 5, 2012, and July 20, 2018, with 199 patients in the NeoCF group, 202 patients in the NeoCF+D group, and 200 patients in the NeoCF+RT group. Compared with the NeoCF group, during a median follow-up period of 50·7 months (IQR 23·8-70·7), the 3-year overall survival rate was significantly higher in the NeoCF+D group (72·1% [95% CI 65·4-77·8] vs 62·6% [55·5-68·9]; hazard ratio [HR] 0·68, 95% CI 0·50-0·92; p=0·006) but not in the NeoCF+RT group (68·3% [61·3-74·3]; HR 0·84, 0·63-1·12; p=0·12). Grade 3 or higher febrile neutropenia occurred in two (1%) of 193 patients in the NeoCF group, 32 (16%) of 196 patients in the NeoCF+D group, and nine (5%) of 191 patients in the NeoCF+RT group. Treatment-related adverse events leading to termination of neoadjuvant therapy were more common in the NeoCF+D group (18 [9%] of 202 participants) than in the NeoCF+RT group (12 [6%] of 200) and NeoCF group (eight [4%] of 199). There were three (2%) treatment-related deaths during neoadjuvant therapy in the NeoCF group, four (2%) deaths in the NeoCF+D group, and two (1%) deaths in the NeoCF+RT group. Grade 2 or higher postoperative pneumonia, anastomotic leak, and recurrent laryngeal nerve paralysis were reported in 19 (10%), 19 (10%), and 28 (15%) of 185 patients, respectively, in the NeoCF group; 18 (10%), 16 (9%), and 19 (10%) of 183 patients, respectively, in the NeoCF+D group; and 23 (13%), 23 (13%), and 17 (10%) of 178 patients, respectively, in the NeoCF+RT group. The in-hospital deaths following surgery included three deaths in the NeoCF group, two deaths in the NeoCF+D group, and one in the NeoCF+RT group. INTERPRETATION: Neoadjuvant triplet chemotherapy followed by oesophagectomy resulted in a statistically significant overall survival benefit compared with doublet chemotherapy and might be the new standard of care for locally advanced OSCC who are in good condition in Japan. Neoadjuvant doublet chemotherapy plus radiotherapy did not show significant improvement of survival compared with doublet chemotherapy. FUNDING: Japan Agency for Medical Research and Development and National Cancer Center Research and Development Fund.