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MBio Feb 2024The accessory protein ORF6 of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a key interferon (IFN) antagonist that strongly suppresses the...
The accessory protein ORF6 of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a key interferon (IFN) antagonist that strongly suppresses the production of primary IFN as well as the expression of IFN-stimulated genes. However, how host cells respond to ORF6 remains largely unknown. Our research of ORF6-binding proteins by pulldown revealed that E3 ligase components such as Cullin 4B (CUL4B), DDB1, and RBX1 are potential ORF6-interacting proteins. Further study found that the substrate recognition receptor PRPF19 interacts with CUL4B, DDB1, and RBX1 to form a CRL4B-based E3 ligase, which catalyzes ORF6 ubiquitination and subsequent degradation. Overexpression of PRPF19 promotes ORF6 degradation, releasing ORF6-mediated IFN inhibition, which inhibits SARS-CoV-2 replication. Moreover, we found that activation of CUL4B by the neddylation inducer etoposide alleviates lung lesions in a SARS-CoV-2 mouse infection model. Therefore, targeting ORF6 for degradation may be an effective therapeutic strategy against SARS-CoV-2 infection.IMPORTANCEThe cellular biological function of the ubiquitin-proteasome pathway as an important modulator for the regulation of many fundamental cellular processes has been greatly appreciated. The critical role of the ubiquitin-proteasome pathway in viral pathogenesis has become increasingly apparent. It is a powerful tool that host cells use to defend against viral infection. Some cellular proteins can function as restriction factors to limit viral infection by ubiquitin-dependent degradation. In this research, we identificated of CUL4B-DDB1-PRPF19 E3 Ubiquitin Ligase Complex can mediate proteasomal degradation of ORF6, leading to inhibition of viral replication. Moreover, the CUL4B activator etoposide alleviates disease development in a mouse infection model, suggesting that this agent or its derivatives may be used to treat infections caused by SARS-CoV-2. We believe that these results will be extremely useful for the scientific and clinic communities in their search for cues and preventive measures to combat the COVID-19 pandemic.
Topics: Animals; Humans; Mice; Carrier Proteins; COVID-19; Cullin Proteins; DNA Repair Enzymes; Etoposide; Nuclear Proteins; Pandemics; Proteasome Endopeptidase Complex; RNA Splicing Factors; SARS-CoV-2; Ubiquitin; Ubiquitin-Protein Ligases; Ubiquitination
PubMed: 38265236
DOI: 10.1128/mbio.03071-23 -
Cell Death & Disease Jan 2024DNA topoisomerase II (TOP2) is an enzyme that performs a critical function in manipulating DNA topology during replication, transcription, and chromosomal compaction by...
DNA topoisomerase II (TOP2) is an enzyme that performs a critical function in manipulating DNA topology during replication, transcription, and chromosomal compaction by forming a vital intermediate known as the TOP2-DNA cleavage complex (TOP2cc). Although the TOP2cc is often transient, stabilization can be achieved by TOP2 poisons, a family of anti-cancer chemotherapeutic agents targeting TOP2, such as etoposide (VP-16), and then induce double-strand breaks (DSBs) in cellular DNA. TOP2cc first needs to be proteolyzed before it can be processed by TDP2 for the removal of these protein adducts and to produce clean DNA ends necessary for proper repair. However, the mechanism by which TOP2βcc is proteolyzed has not been thoroughly studied. In this study, we report that after exposure to VP-16, MDM2, a RING-type E3 ubiquitin ligase, attaches to TOP2β and initiates polyubiquitination and proteasomal degradation. Mechanistically, during exposure to VP-16, TOP2β binds to DNA to form TOP2βcc, which promotes MDM2 binding and subsequent TOP2β ubiquitination and degradation, and results in a decrease in TOP2βcc levels. Biologically, MDM2 inactivation abrogates TOP2β degradation, stabilizes TOP2βcc, and subsequently increases the number of TOP2β-concealed DSBs, resulting in the rapid death of cancer cells via the apoptotic process. Furthermore, we demonstrate the combination activity of VP-16 and RG7112, an MDM2 inhibitor, in the xenograft tumor model and in situ lung cancer mouse model. Taken together, the results of our research reveal an underlying mechanism by which MDM2 promotes cancer cell survival in the presence of TOP2 poisons by activating proteolysis of TOP2βcc in a p53-independent manner, and provides a rationale for the combination of MDM2 inhibitors with TOP2 poisons for cancer therapy.
Topics: Animals; Humans; Mice; Disease Models, Animal; DNA; DNA Topoisomerases, Type II; DNA-Binding Proteins; Etoposide; Phosphoric Diester Hydrolases; Proteolysis; Proto-Oncogene Proteins c-mdm2; Tumor Suppressor Protein p53
PubMed: 38263255
DOI: 10.1038/s41419-024-06474-3 -
Antioxidants (Basel, Switzerland) Dec 2023Podophyllotoxin (PTOX) is naturally produced by the plant Podophyllum species. Some of its derivatives are anticancer drugs, which are produced mainly by using chemical...
Podophyllotoxin (PTOX) is naturally produced by the plant Podophyllum species. Some of its derivatives are anticancer drugs, which are produced mainly by using chemical semi-synthesis methods. Recombinant bacteria have great potential in large-scale production of the derivatives of PTOX. In addition to introducing the correct enzymes, the transportation of PTOX into the cells is an important factor, which limits its modification in the bacteria. Here, we improved the cellular uptake of PTOX into with the help of the zero-valent sulfur transporter YedE1E2 in the presence of cetyltrimethylammonium bromide (CTAB). CTAB promoted the uptake of PTOX, but induced the production of reactive oxygen species. A protein complex (YedE1E2) of YedE1 and YedE2 enabled cells to resist CTAB by reducing reactive oxygen species, and YedE1E2 was a hypothetical transporter. Further investigation showed that YedE1E2 facilitated the uptake of extracellular zero-valent sulfur across the cytoplasmic membrane and the formation of glutathione persulfide (GSSH) inside the cells. The increased GSSH minimized oxidative stress. Our results indicate that YedE1E2 is a zero-valent sulfur transporter and it also facilitates CTAB-assisted uptake of PTOX by recombinant bacteria.
PubMed: 38247452
DOI: 10.3390/antiox13010027 -
Annals of Hematology May 2024Indolent lymphoma, including chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and follicular lymphoma (FL), can undergo histological transformation into...
Venetoclax plus dose-adjusted R-EPOCH (VR-DA-EPOCH) or G-EPOCH bridging to subsequent cellular therapy for the patients with transformed lymphoma a single center clinical experience.
Indolent lymphoma, including chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) and follicular lymphoma (FL), can undergo histological transformation into an aggressive subtype, typically diffuse large B-cell lymphoma (DLBCL). The prognosis of transformed lymphoma is poor. In this study, we reported the efficacy and toxicity of a combination of venetoclax, dose-adjusted rituximab or obinutuzumab, etoposide, prednisone, vincristine, doxorubicin, and cyclophosphamide (VR-DA-EPOCH or VG-DA-EPOCH) in 11 patients with biopsy-proven histology transformation into DLBCL, including 8 patients with RT and 3 with transformed FL (tFL). The study was conducted between October 2019 and March 2023 at our single center. The median age of participants at enrolment was 53 years. Six patients (85.7%, 6/7) achieved complete remission (CR) at the end of treatment. The best overall response rate (ORR) and CR rate were both 72.7%, respectively. Two patients received autologous hemopoietic stem cell transplant (ASCT) while two patients received ASCT concurrently with CAR-T therapy for consolidation. With a median follow-up of 13.5 (range, 2.4-29.8) months after enrollment, the median event-free survival, progression-free survival, and overall survival were 9.4, 11.5, and 17.5 months, respectively. Hematologic toxicities of grade ≥3 consisted of neutropenia (90.9%, 10/11), thrombocytopenia (63.6%, 7/11), and febrile neutropenia (54.5%, 6/11). In conclusion, VR-DA-EPOCH or VG-DA-EPOCH was a promising strategy to achieve an early remission, bridging to cellular therapy within this population.
Topics: Humans; Middle Aged; Prednisone; Vincristine; Etoposide; Antibodies, Monoclonal, Murine-Derived; Cyclophosphamide; Rituximab; Lymphoma, Non-Hodgkin; Doxorubicin; Lymphoma, Large B-Cell, Diffuse; Antineoplastic Combined Chemotherapy Protocols; Virtual Reality; Sulfonamides; Bridged Bicyclo Compounds, Heterocyclic
PubMed: 38246951
DOI: 10.1007/s00277-024-05618-x -
Scientific Reports Jan 2024Impaired spermatogenesis and male infertility are common consequences of chemotherapy drugs used in patients with testicular cancer. The present study investigated the...
Therapeutic effect of sodium alginate on bleomycin, etoposide and cisplatin (BEP)-induced reproductive toxicity by inhibiting nitro-oxidative stress, inflammation and apoptosis.
Impaired spermatogenesis and male infertility are common consequences of chemotherapy drugs used in patients with testicular cancer. The present study investigated the effects of sodium alginate (NaAL) on testicular toxicity caused by bleomycin, etoposide, and cisplatin (BEP). Rats in group 1 received normal saline, while groups 2 and 3 were treated with 25 and 50 mg/kg of NaAL, respectively. Group 4 was treated with a 21-day cycle of BEP (0.5 mg/kg bleomycin, 5 mg/kg etoposide, and 1 mg/kg cisplatin), and groups 5 and 6 received BEP regimen plus 25 and 50 mg/kg of NaAL, respectively. Then, sperm parameters, testosterone levels, testicular histopathology and stereological parameters, testicular levels of malondialdehyde (MDA), nitric oxide (NO), and total antioxidant capacity (TAC), and the expression of apoptosis-associated genes including Bcl2, Bax, Caspase3, p53, and TNF-α were evaluated. Our findings revealed that NaAL improved sperm parameters, testosterone levels, histopathology, and stereology parameters in BEP-administrated rats. NaAL also improved testis antioxidant status by enhancing TAC and ameliorating MDA and NO. Further, modifications to the expression of Bcl2, Bax, Caspase3, p53, and TNF-α suggested that NaAL alleviated BEP-induced apoptosis and inflammation. Collectively, NaAL protects rats' testes against BEP-evoked toxicity damage through the modulation of nitro-oxidative stress, apoptosis, and inflammation.
Topics: Humans; Male; Rats; Animals; Cisplatin; Etoposide; Testicular Neoplasms; Bleomycin; Antioxidants; Alginates; Tumor Necrosis Factor-alpha; Tumor Suppressor Protein p53; bcl-2-Associated X Protein; Antineoplastic Combined Chemotherapy Protocols; Semen; Testosterone; Oxidative Stress; Apoptosis; Inflammation
PubMed: 38238398
DOI: 10.1038/s41598-024-52010-w -
Blood Advances Apr 2024MYC-aberrant non-Hodgkin lymphoma (NHL) is associated with poor outcomes with conventional chemotherapy. Ixazomib is an orally bioavailable proteasome inhibitor that...
MYC-aberrant non-Hodgkin lymphoma (NHL) is associated with poor outcomes with conventional chemotherapy. Ixazomib is an orally bioavailable proteasome inhibitor that targets drivers of MYC expression and has demonstrated preclinical activity in aggressive MYC-aberrant NHL. We conducted a phase 1/2 study evaluating the safety and efficacy of DA-EPOCH-R with adjunctive ixazomib in aggressive MYC-aberrant NHL. For induction, patients received 6 cycles of DA-EPOCH-R with ixazomib administered twice per 21-day cycle; responders continued weekly ixazomib maintenance for up to 1 year. Primary objectives were to determine the maximum tolerated dose in phase 1 and efficacy of DA-EPOCH-R with ixazomib as measured by 12-month progression-free survival (PFS) rate in phase 2. Thirty-six patients were evaluable for response. Median age was 63 years (range, 31-77) and 44% had double-hit lymphoma (DHL)/triple-hit lymphoma (THL). In phase 1, 3 mg of ixazomib was established as recommended phase 2 dose. Twenty-nine (76.3%) patients completed 6 cycles of DA-EPOCH-R and 25 (65.8%) underwent dose escalations. The ORR after induction was 97% (95% confidence interval, 81-100) with a CR rate of 69%. At median follow-up of 18.8 months, the 12-month PFS and overall survival (OS) rates were 78% and 86%, respectively. For DHL/THL vs dual expressor lymphomas (DEL), 12-month PFS rates were 53% vs 95% and 12-month OS rates were 65% vs 100%, respectively. Grade ≥3 toxicities were predominantly hematologic. Twenty-seven (75%) of patients experienced neuropathy, nearly all low-grade. DA-EPOCH-R induction with adjunctive ixazomib is feasible and appears effective in patients with DEL. This trial was registered at www.clinicaltrials.gov as #NCT02481310.
Topics: Humans; Middle Aged; Treatment Outcome; Rituximab; Cyclophosphamide; Prednisone; Vincristine; Etoposide; Doxorubicin; Lymphoma, Non-Hodgkin; Boron Compounds; Glycine
PubMed: 38237077
DOI: 10.1182/bloodadvances.2023011369 -
Lung Cancer (Amsterdam, Netherlands) Feb 2024Trilaciclib is a transient cyclin-dependent kinase 4/6 inhibitor that decreases the incidence of chemotherapy-induced myelosuppression in extensive-stage small cell lung... (Randomized Controlled Trial)
Randomized Controlled Trial
Myeloprotection with trilaciclib in Chinese patients with extensive-stage small cell lung cancer receiving chemotherapy: Results from a randomized, double-blind, placebo-controlled phase III study (TRACES).
INTRODUCTION
Trilaciclib is a transient cyclin-dependent kinase 4/6 inhibitor that decreases the incidence of chemotherapy-induced myelosuppression in extensive-stage small cell lung cancer (ES-SCLC). TRACES study was designed to assess the safety, efficacy and pharmacokinetics (PK) of trilaciclib before chemotherapy in Chinese patients with ES-SCLC.
METHODS
The study included an open-label safety run-in part (Part 1) and double-blinded, placebo-controlled part (Part 2) where patients received trilaciclib or placebo before chemotherapy. Treatment-naïve or previously treated ES-SCLC patients received intravenous trilaciclib (240 mg/m) or placebo before etoposide/carboplatin or topotecan, respectively. Primary endpoints were PK, safety and duration of severe neutropenia (DSN) in Cycle 1 in Part 1 and Part 2. Exploratory endpoints included the effect of trilaciclib on other myeloprotection endpoints, safety and antitumor efficacy.
RESULTS
Overall, 95 Chinese patients were enrolled, of which 12 and 83 patients were in Part 1 and Part 2, respectively. In Part 1, trilaciclib was well tolerated. Non-compartmental analysis results revealed no substantial differences in the main exposure parameters. In Part 2, 41 patients received trilaciclib, and 42 received placebo. Patients in trilaciclib arm vs placebo arm had a clinically and statistically significant decrease in DSN (mean [SD]) in Cycle 1 (0 [1.7] vs 2 [3.0] days; P = 0.0003), with improvements in additional neutrophil, red blood cell, and platelet measures. After a median follow-up of 14.1 months, the median overall survival was 12.0 months in trilaciclib arm and 8.8 months in placebo arm (HR, 0.69; 95 % CI: 0.40-1.22). Median progression-free survival was 4.8 months and 4.3 months, respectively (HR, 0.86; 95 % CI: 0.53-1.39). Trilaciclib had a well-tolerated safety profile.
CONCLUSIONS
Trilaciclib in the Chinese population demonstrated a similar PK and safety profile as seen in other global trials. There was significant reduction of DSN in Cycle 1, thereby substantiating the myeloprotective effects of trilaciclib in Chinese ES-SCLC patients.
Topics: Humans; Small Cell Lung Carcinoma; Lung Neoplasms; Carboplatin; Etoposide; Neutropenia; China; Antineoplastic Combined Chemotherapy Protocols; Double-Blind Method; Pyrimidines; Pyrroles
PubMed: 38224653
DOI: 10.1016/j.lungcan.2023.107455 -
Nucleic Acids Research Apr 2024RNA-binding proteins emerge as effectors of the DNA damage response (DDR). The multifunctional non-POU domain-containing octamer-binding protein NONO/p54nrb marks...
RNA-binding proteins emerge as effectors of the DNA damage response (DDR). The multifunctional non-POU domain-containing octamer-binding protein NONO/p54nrb marks nuclear paraspeckles in unperturbed cells, but also undergoes re-localization to the nucleolus upon induction of DNA double-strand breaks (DSBs). However, NONO nucleolar re-localization is poorly understood. Here we show that the topoisomerase II inhibitor etoposide stimulates the production of RNA polymerase II-dependent, DNA damage-inducible antisense intergenic non-coding RNA (asincRNA) in human cancer cells. Such transcripts originate from distinct nucleolar intergenic spacer regions and form DNA-RNA hybrids to tether NONO to the nucleolus in an RNA recognition motif 1 domain-dependent manner. NONO occupancy at protein-coding gene promoters is reduced by etoposide, which attenuates pre-mRNA synthesis, enhances NONO binding to pre-mRNA transcripts and is accompanied by nucleolar detention of a subset of such transcripts. The depletion or mutation of NONO interferes with detention and prolongs DSB signalling. Together, we describe a nucleolar DDR pathway that shields NONO and aberrant transcripts from DSBs to promote DNA repair.
Topics: Humans; DNA Breaks, Double-Stranded; DNA-Binding Proteins; Etoposide; RNA Precursors; Transcription Factors; DNA; RNA-Binding Proteins
PubMed: 38224452
DOI: 10.1093/nar/gkae022 -
International Journal of Molecular... Dec 2023Four copper(II) complexes, -, derived from 1-(isoquinolin-3-yl)heteroalkyl-2-one ligands - were synthesized and characterized using an elemental analysis, IR...
Four copper(II) complexes, -, derived from 1-(isoquinolin-3-yl)heteroalkyl-2-one ligands - were synthesized and characterized using an elemental analysis, IR spectroscopic data as well as single crystal X-ray diffraction data for complex . The stability of complexes - under conditions mimicking the physiological environment was estimated using UV-Vis spectrophotometry. The antiproliferative activity of both ligands - and copper(II) compounds - were evaluated using an MTT assay on four human cancer cell lines, A375 (melanoma), HepG2 (hepatoma), LS-180 (colon cancer) and T98G (glioblastoma), and a non-cancerous cell line, CCD-1059Sk (human normal skin fibroblasts). Complexes - showed greater potency against HepG2, LS180 and T98G cancer cell lines than (IC = 5.04-14.89 μg/mL vs. IC = 43.21->100 μg/mL), while free ligands - remained inactive in all cell lines. The prominent copper(II) compound appeared to be more selective towards cancer cells compared with normal cells than compounds , and . The treatment of HepG2 and T98G cells with complex resulted in sub-G1 and G2/M cell cycle arrest, respectively, which was accompanied by DNA degradation. Moreover, the non-cytotoxic doses of synergistically enhanced the cytotoxic effects of chemotherapeutic drugs, including , and , in HepG2 and T98G cells. The antimicrobial activities of ligands - and their copper(II) complexes - were evaluated using different types of Gram-positive bacteria, Gram-negative bacteria and yeast species. No correlation was found between the results of the antiproliferative and antimicrobial experiments. The antioxidant activities of all compounds were determined using the DPPH and ABTS radical scavenging methods. Antiradical tests revealed that among the investigated compounds, copper(II) complex possessed the strongest antioxidant properties. Finally, the ADME technique was used to determine the physicochemical and drug-likeness properties of the obtained complexes.
Topics: Humans; Etoposide; Antioxidants; Copper; Anti-Infective Agents; Carcinoma, Hepatocellular
PubMed: 38203181
DOI: 10.3390/ijms25010008 -
RSC Advances Jan 2024Two different synthetic approaches to novel heterocyclic hybrid compounds of 4-azapodophyllotoxin were investigated. The obtained products were characterized by infrared...
Two different synthetic approaches to novel heterocyclic hybrid compounds of 4-azapodophyllotoxin were investigated. The obtained products were characterized by infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution mass spectrometry. MTT protocol was then performed to examine the cytotoxic activity of these products against KB, HepG2, A549, MCF7, and Hek-293 cell lines. The cytotoxic assessment indicated that all products displayed moderate to high cytotoxicity against all tested cancer cell lines. The most active compound 13k containing the 2-methoxypyridin-4-yl group exhibited selective cytotoxicity against KB, A549, and HepG2 cell lines with the IC values ranging from 0.23 to 0.27 μM, which were between 5- to 10-fold more potent than the positive control ellipticine. Compounds 13a (HetAr = thiophen-3-yl) and 13d (HetAr = 5-bromofuran-2-yl) displayed high cytotoxic selectivity for A549 and HepG2 cancer cell lines when compared to the other cancer cell lines and low toxicity to the normal Hek-293 cell line. Molecular docking study was conducted to evaluate the interaction of new synthesized compounds with the colchicine-binding-site of tubulin. Besides that, physicochemical and pharmacokinetic properties of the most active compounds 13h,k were predicted.
PubMed: 38192320
DOI: 10.1039/d3ra07396c