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1.
Int J Biol Sci ; 20(10): 3923-3941, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39113695

RESUMO

About 20% of breast cancer patients are positive for HER2. The efficacy of current treatments is limited by primary and secondary resistance to trastuzumab. tRNA-derived fragments (tRFs) have shown crucial regulatory roles in various cancers. This study aimed to evaluate the role of tRF-27 in regulating the resistance of HER2-positive breast cancer against trastuzumab. tRF-27 was highly expressed in trastuzumab-resistant cells, and its expression level could predict the resistance to trastuzumab. High expression of tRF-27 promoted the growth and proliferation of trastuzumab-exposed cells. RNA-pulldown assay and mass spectrometry were performed to identify Ras GTPase-activating protein-binding proteins 1 and 2 (G3BPs) (two proteins targeted by tRF-27); RNA-immunoprecipitation (RIP) to confirm their bindings; co-immunoprecipitation (co-IP) and RNA-pulldown assay to determine the binding domains between G3BPs and tRF-27.tRF-27 bound to the nuclear transport factor 2 like domain(NTF2 domain) of G3BPs through a specific sequence. tRF-27 relied on G3BPs and NTF2 domain to increase trastuzumab tolerance. tRF-27 competed with lysosomal associated membrane protein 1(LAMP1) for NTF2 domain, thereby inhibiting lysosomal localization of G3BPs and tuberous sclerosis complex (TSC). Overexpression of tRF-27 inhibited phosphorylation of TSCs and promoted the activation of mechanistic target of rapamycin complex 1(MTORC1) to enhance cell proliferation and entice the resistance of HER2-positive breast cancer against trastuzumab.


Assuntos
Neoplasias da Mama , Alvo Mecanístico do Complexo 1 de Rapamicina , Trastuzumab , Humanos , Trastuzumab/farmacologia , Trastuzumab/uso terapêutico , Neoplasias da Mama/metabolismo , Neoplasias da Mama/tratamento farmacológico , Feminino , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos , Receptor ErbB-2/metabolismo , Animais , Proteínas de Ligação a Poli-ADP-Ribose/metabolismo , RNA de Transferência/metabolismo , Camundongos , RNA Helicases/metabolismo , Camundongos Nus , Proteínas com Motivo de Reconhecimento de RNA/metabolismo
2.
MedComm (2020) ; 5(7): e624, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38903538

RESUMO

The use of trastuzumab emtansine (T-DM1) has revealed significant efficacy in HER2-positive metastatic breast cancer (MBC). However, optimal therapeutic strategies following T-DM1 failure remain a subject of debate in clinical practice. In this multicenter, retrospective, real-world study, we sought to examine the effectiveness and safety of tyrosine kinase inhibitors (TKIs) as a therapeutic strategy in HER2-positive MBC who developed T-DM1 resistance. Between September 2018 and December 2022, 66 patients were enrolled. The median progression-free survival of TKIs-based therapy was 10.1 months (95% CI, 4.7-15.6). Objective response rate and clinical benefit rate were 18.2 and 66.7%, respectively. TKIs-based therapy demonstrated better effectiveness in patients who had previously derived benefit from T-DM1 and featured acquired resistance to trastuzumab. The most common adverse events were diarrhea (36, 54.5%), hand-foot syndrome (31, 47.0%), and leucopenia (30, 45.5%). In conclusion, TKIs-based therapy showed promising effectiveness and safety in HER2-positive MBC patients after T-DM1 failure.

3.
Cancer Pathog Ther ; 2(1): 31-37, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38328709

RESUMO

Background: Human epidermal growth factor receptor 2 (HER2)-targeted agents have significantly improved the outcomes of patients with HER2-positive breast cancer; however, a large proportion of patients still develop resistance to trastuzumab. In this study, we investigated the efficacy and safety of inetetamab, another anti-HER2 antibody, combined with pyrotinib and oral vinorelbine in patients with HER2-positive advanced breast cancer so as to provide new ideas for the treatment. Methods: In this prospective, single-arm, phase 2 trial, patients with HER2-positive advanced breast cancer with disease progression after trastuzumab were recruited. Patients received a combination of inetetamab (loading dose of 8 mg/kg and subsequent doses of 6 mg/kg intravenously once every 3 weeks), pyrotinib (400 mg orally once daily), and vinorelbine (60 mg/m2 orally once weekly) until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS). The secondary endpoints included objective response rate (ORR), overall survival (OS), disease control rate (DCR), and safety. Results: Between February 13, 2022 and December 25, 2022, 30 patients were screened and enrolled in this study. The median age of the patients at enrollment was 54 years, 12 patients (40.0 %) had hormone-receptor-positive disease and 23 patients (76.7 %) had visceral metastasis. The median PFS was 8.63 months (95 % confidence interval [CI] 4.15-13.12 months). The median OS was not reached. The ORR was 53.3 % (16/30) and the DCR was 96.7 % (29/30). The most common Grade III/IV adverse events were leukopenia (n = 5, 16.7 %), neutropenia (n = 4, 13.3 %), and diarrhea (n = 3, 10 %). No treatment-related serious adverse events or deaths occurred. Conclusions: The combination regimen of inetetamab, pyrotinib, and oral vinorelbine showed encouraging efficacy and favorable safety in patients with HER2-positive advanced breast cancer and could be considered as an alternative treatment option for the patients. Trial registration: No.NCT05823623; https://www.clinicaltrials.gov/.

4.
Biosens Bioelectron ; 242: 115748, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37847984

RESUMO

Granzyme B (GrB) is a serine protease released by natural killer cells and cytotoxic T lymphocytes during immune responses, which not only plays a role in tumor diagnosis but also provides valuable guidance during tumor treatment. In this work, we have designed a charge-switching peptide to fabricate an electrochemical biosensor for quantitative analysis of GrB. Specifically, the designed zwitterionic peptide is in an electrically neutral state before activation, and a door lock structure (proline) is constructed by utilizing the selectivity of carboxypeptidase A (CPA) to the carboxy-terminus of the peptide chain. The door lock is opened when the target is present, allowing CPA to hydrolyze the peptide. At this time, the peptide will convert from neutral to positive, triggering the assembly of a positively charged peptide layer on the electrode surface, resulting in a signal change. Studies have shown that the biosensor has good analytical performance, with a detection range of 0.01 pM-8 pM and a detection limit as low as 3.5 fM. Moreover, the developed biosensor has been effectively applied to the analysis of clinical samples, demonstrating its ability to monitor tumor progression and treatment with clinical applications.


Assuntos
Técnicas Biossensoriais , Neoplasias , Humanos , Técnicas Biossensoriais/métodos , Granzimas , Peptídeos/química , Técnicas Eletroquímicas/métodos , Limite de Detecção
5.
Artigo em Inglês | MEDLINE | ID: mdl-37769245

RESUMO

PURPOSE: To describe a rare case of Epstein-Barr virus (EBV)-positive primary vitreoretinal lymphoma (PVRL) in an immunosuppressed patient. METHODS: Observational case report. RESULTS: A 64-year-old man under immunosuppressive therapy for rheumatic arthritis was referred for 2-month of blurred vision and decreased visual acuity in the right eye. Only mutton-fat keratic precipitates and mild vitreous opacity were found in the right eye without (sub-)retinal or sub-retinal pigment epithelial lesions. Vitreous biopsy and systemic workup suggested the diagnosis of PVRL of diffuse large B cell lymphoma (DLBCL) subform. Neoplastic cells stained positive for EBV antigens, EBV-encoded small RNA and Epstein-Barr nuclear antigen 2, consistent with EBV-positive DLBCL. Intravitreal methotrexate was effective in improving ocular symptoms. CONCLUSION: Our case provided evidence on the association of EBV infection with PVRL.

6.
Ecotoxicol Environ Saf ; 256: 114840, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37001191

RESUMO

Harmful cyanobacterial blooms have caused numerous biosecurity incidents owing to the production of hazardous secondary metabolites such as microcystin. Additionally, cyanobacteria also release many other components that have not been explored. We identified compounds of a toxic mixture exudated from a dominant, blooming species, Microcystis aeruginosa, and found that phytosphingosine (PHS) was one of the bioactive components. Since PHS exhibited toxicity and is deemed a hazardous substance by the European Chemicals Agency, we hypothesized that PHS is a potentially toxic compound in M. aeruginosa exudates. However, the mechanisms of PHS ecotoxicity remain unclear. We assessed the cytotoxicity of PHS using an in vitro cell model in eight human cell lines and observed that the nasopharyngeal carcinoma cell line CNE2 was the most sensitive. We exposed CNE2 cells to 0-25 µmol/L PHS for 24 hr to explore its toxicity and mechanism. PHS exposure resulted in abnormal nuclear morphology, micronuclei, and DNA damage. Moreover, PHS significantly inhibited cell proliferation and arrested cell cycle at S phase. The results of Western blot suggested that PHS increased the expression of DNA damage-related proteins (ATM, p-P53 and P21) and decreased the expression of S phase-related proteins (CDK2, CyclinA2 and CyclinE1), indicating the toxicological mechanism of PHS on CNE2 cells. These data provide evidence that PHS has genetic toxicity and inhibits cell proliferation by damaging DNA. Our study provides evidence that PHS inhibits cell proliferation by damaging DNA. While additional work is required, we propose that PHS been considered as a potentially toxic component in MaE in addition to other well-characterized secondary compounds.


Assuntos
Cianobactérias , Microcystis , Humanos , Microcistinas/toxicidade , Proliferação de Células , Linhagem Celular
7.
Cancers (Basel) ; 15(3)2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36765853

RESUMO

Tamoxifen resistance remains a challenge in hormone receptor-positive (HR+) breast cancer. Recent evidence suggests that transfer ribonucleic acid (tRNA)-derived fragments play pivotal roles in the occurrence and development of various tumors. However, the relationship between tRNA-derived fragments and tamoxifen resistance remains unclear. In this study, we found that the expression of tRF-16-K8J7K1B was upregulated in tamoxifen-resistant cells in comparison with tamoxifen-sensitive cells. Higher levels of tRF-16-K8J7K1B were associated with shorter disease-free survival in HR+ breast cancer. Overexpression of tRF-16-K8J7K1B promotes tamoxifen resistance. Moreover, extracellular tRF-16-K8J7K1B could be packaged into exosomes and could disseminate tamoxifen resistance to recipient cells. Mechanistically, exosomal tRF-16-K8J7K1B downregulates the expression of apoptosis-related proteins, such as caspase 3 and poly (ADP-ribose) polymerase, by targeting tumor necrosis factor-related apoptosis-inducing ligand in receptor cells, thereby reducing drug-induced cell apoptosis. Therapeutically, the inhibition of exosomal tRF-16-K8J7K1B increases the sensitivity of breast cancer cells to tamoxifen in vivo. These data demonstrate that exosomal tRF-16-K8J7K1B may be a novel therapeutic target to overcome tamoxifen resistance in HR+ breast cancer.

8.
Toxicology ; 482: 153370, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36334778

RESUMO

Cyanobacterial blooms, usually dominated by Microcystis aeruginosa, pose a serious threat to global freshwater ecosystems owing to their production and release of various harmful secondary metabolites. Detection of the chemicals in M. aeruginosa exudates using metabolomics technology revealed that phytosphingosine (PHS) was one of the most abundant compounds. However, its specific toxicological mechanism remained unclear. CNE-2 cells were selected to illustrate the cytotoxic mechanism of PHS, and it was determined to cause excessive production of reactive oxygen species and subsequently damage the mitochondrial structure. Mitochondrial membrane rupture led to matrix mitochondrial membrane potential disintegration, which induced Ca2+ overload and interrupted ATP synthesis. Furthermore, rupture of the mitochondrial membrane induced the opening of the permeability transition pore, which caused the release of proapoptotic factors into the cytoplasm and the expression of apoptosis-related proteins Bax, Bcl-2, cytochrome-c and cleaved caspase-3 in CNE-2 cells. These events, in turn, activated the mitochondrially mediated intrinsic apoptotic pathway. A mitochondrial repair mechanism, namely, PINK1/Parkin-mediated mitophagy, was then blocked, which further promoted apoptosis. Our findings suggest that more attention should be paid to the ecotoxicity of PHS, which is already listed as a contaminant of emerging concern.


Assuntos
Ecossistema , Esfingosina , Apoptose , Citocromos c
9.
J Immunother Cancer ; 10(11)2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36450378

RESUMO

The mechanism(s) of immune checkpoint inhibitor (ICI)-induced myasthenia gravis (MG), an immune-related adverse event (irAE) that is fatal and limits subsequent ICI use, remain unexplored. Here, through comparative genomic analysis, we identified a pathogenic p.S467C germline variant in SLC22A5 in a thymoma case with ICI-induced MG, which was found to be associated with fatty acid oxidation through its regulation on L-carnitine levels. Remarkably, ICI rechallenge with L-carnitine pretreatment led to durable response without MG-related symptoms. Thus, we provide the first clinical evidence of genetic test-directed irAE management, which integrates individualized ICI treatment into the evolving paradigm of cancer management.


Assuntos
Miastenia Gravis , Timoma , Neoplasias do Timo , Humanos , Inibidores de Checkpoint Imunológico/efeitos adversos , Miastenia Gravis/induzido quimicamente , Timoma/tratamento farmacológico , Carnitina , Membro 5 da Família 22 de Carreadores de Soluto
10.
Front Oncol ; 12: 985734, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36313724

RESUMO

Background: With increased survival in breast cancer, resulting from advances in treatment, patients incur the possibility of subsequent primary malignancies, especially lung cancer. The aim of this study was to assess the frequency of CT-detected pulmonary ground-glass nodules and lung cancer following breast cancer diagnosis, the associations between breast cancer and lung cancer, the pathological features of double primary cancer, and the status of epidermal growth factor receptor (EGFR) mutations in second primary lung cancer. Methods: Clinical data from more than 9000 individuals who were diagnosed with primary breast cancer at Jiangsu Province Hospital (Jiangsu, China) between January 2008 and December 2021 were retrospectively analyzed. Results: Of the 9179 patients, 6512 underwent diagnostic CT, 55 (0.8%) were diagnosed with a second primary lung cancer, which accounted for approximately 18.4% of the pulmonary ground-glass nodules (GGNs) detected. The incidence was higher than in the general female population (standardized incidence ratio 1.4 [95% confidence interval (CI): 1.25-1.55]). Patients who experienced a second primary lung cancer exhibited a significantly higher rate of EGFR mutation (78.5%) than those with lung adenocarcinoma alone, with most exhibiting low-grade malignancy, older age, estrogen receptor negativity, low Ki67, and no lymph node metastasis. Conclusions: Breast cancer patients, especially those with low-grade malignancy, were at high risk for developing primary lung cancer. For isolated GGN in patients with high-risk factors, clinicians should insist on close follow-up. Furthermore, EGFR may play an important role in primary lung adenocarcinomas and breast cancer.

11.
Cancers (Basel) ; 14(17)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36077621

RESUMO

Treatment options for human epidermal growth factor receptor (HER2)-negative breast cancer patients are limited in comparison to the HER2-positive patients, particularly for metastatic breast cancer patients. Apatinib is a small-molecule tyrosine kinase inhibitor that targets the vascular endothelial growth factor receptor 2 (VEGFR-2). Here, we reported the apatinib-based therapy data in HER2-negative metastatic breast cancer. Apatinib was taken at a dose of 250 mg orally once per day and combined with standard chemotherapy regimens. The PFS and OS of 128 patients were 4.7 months and 15.3 months, respectively. The objective response rate (ORR) and the disease control rate (DCR) were 22.7% and 80.5%, respectively. Patients with breast cancer susceptibility gene (BRCA) mutations were found to have a longer PFS and OS. Moreover, combination immunotherapy or paclitaxel-platinum regimens shared an improved response to other regimens. Most of the adverse effects (hypertension, anaemia, and hand-foot syndrome) were grade 1 to 2. Metastatic breast cancer patients could benefit from apatinib therapy at a low dosage, and the adverse effects are mild in real-world clinical practice. Furthermore, BRCA may be a putative biomarker for apatinib in HER2-negative breast cancer. Immunotherapy or paclitaxel-platinum regimens may be recommended to combine with apatinib therapy.

12.
Org Lett ; 24(22): 3993-3997, 2022 06 10.
Artigo em Inglês | MEDLINE | ID: mdl-35616425

RESUMO

The Wnt/ß-catenin signaling pathway is an evolutionarily conserved signaling cascade involved in a broad range of biological roles. Dysregulation of the Wnt/ß-catenin pathway is implicated in congenital malformations and various kinds of cancers. We discovered a novel Wnt/ß-catenin inhibitor, talaverrucin A (1), featuring an unprecedented 6/6/6/5/5/5/6 fused ring system, from an Antarctica sponge-derived fungus Talaromyces sp. HDN151403. Talaverrucin A exhibits inhibitory activity on the Wnt/ß-catenin pathway in both zebrafish embryos in vivo and cultured mammalian cells in vitro, providing a naturally inspired small molecule therapeutic lead to target the Wnt/ß-catenin pathway.


Assuntos
Talaromyces , Via de Sinalização Wnt , Animais , Regiões Antárticas , Mamíferos/metabolismo , Talaromyces/metabolismo , Peixe-Zebra , beta Catenina/metabolismo
13.
Front Oncol ; 12: 859157, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35574394

RESUMO

Background: Hemangioblastoma (HB) is a rare and highly vascularized tumor that originates from the central nervous system as well as other part of the body. They can appear sporadically or as part of von Hippel-Lindau (VHL) disease, a rare hereditary cancer syndrome. Although surgery can cure the majority of HBs, the disease shows a treatment-refractory challenge upon recurrence. HBs express a high amount of vascular endothelial growth factor (VEGF) which is responsible for angiogenesis and subsequently tumor progression. Anti-angiogenic treatment like bevacizumab has showed effect on HB, so we hypothesized that anlotinib could trigger HB regression via its inhibitory effect on VEGF. Case Presentation: We will share our experience in treating a 62-year-old woman with multiple recurrent lumbar and sacral cord HBs. She was treated with anlotinib (8mg qd d1-14, q3w) for three months and her follow up radiological examination demonstrated marked tumor regression which was evaluated as having partial response pursuant to RECIST 1.1 system. She is currently still receiving treatment of anlotinib orally and the lesions continuously reduced. Conclusion: We have reported that anlotinib can cause significant radiographic response in a patient with multiple recurrent lumbar and sacral cord HBs for the first time. This might enable a novel therapeutic approach for patients with multiple recurrent HB or those with multiple lesions such as in VHL disease which are difficult to resect surgically.

14.
J Nat Prod ; 85(4): 987-996, 2022 04 22.
Artigo em Inglês | MEDLINE | ID: mdl-35380848

RESUMO

Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive neoplastic diseases of the pancreas with fatal proliferation and metastasis and no medicine available for treatment. From an Antarctica sponge-derived fungus, Aspergillus insulicola HDN151418, four new nitrobenzoyl sesquiterpenoids, namely, insulicolides D-G (1-4), were isolated. Compounds 3 and 4 exhibited selective inhibition against human PDAC cell lines. Further studies indicated that compound 4 could significantly suppress cell proliferation to induce apoptosis and blocked migration and invasion of PDAC cells. Compound 4 could also avoid resistance and improved the therapeutic effect of the chemotherapy drug gemcitabine. A preliminary mechanism study showed that compound 4 can significantly inhibit the expression of EGFR and XIAP in PDAC cells. Altogether, 4 is a potential lead compound for anti-PDAC drug research.


Assuntos
Antineoplásicos , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Sesquiterpenos , Regiões Antárticas , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose , Aspergillus , Carcinoma Ductal Pancreático/tratamento farmacológico , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Linhagem Celular Tumoral , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/patologia , Sesquiterpenos/farmacologia , Sesquiterpenos/uso terapêutico , Neoplasias Pancreáticas
15.
Cell Death Discov ; 8(1): 196, 2022 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-35413945

RESUMO

As a key regulator of the DNA translesion synthesis (TLS) pathway, RAD18 is error-prone and contributes to the accumulation of DNA mutations. Our previous study showed that it plays an essential role in the progression of multiple tumors. However, the mechanism through which RAD18 influences triple-negative breast cancer (TNBC), especially the interaction between tumor cells and the tumor microenvironment, remains elusive. In this study, we showed that RAD18 expression is markedly higher in patients with high T stage TNBC and inversely correlated with prognosis. High expression of RAD18 facilitated a highly stem-cell phenotype through the Hippo/YAP pathway, which supports the proliferation of TNBC. In addition, the cytokine byproduct TGF-ß activates macrophages to have an M2-like tumor-associated macrophage (TAM) phenotype. Reciprocally, TGF-ß from TAMs activated RAD18 in TNBC to enhance tumor stemness, forming a positive feedback loop. Inhibition of YAP or TGF-ß breaks this loop and suppresses cancer stemness and proliferation In nude mice, RAD18 promoted subcutaneous transplanted tumor growth and M2-type TAM recruitment. Collectively, the RAD18-YAP-TGF-ß loop is essential for the promotion of the stemness phenotype by TNBC and could be a potential therapeutic target for TNBC.

16.
Ther Adv Med Oncol ; 14: 17588359221085232, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35356262

RESUMO

Background: Tyrosine kinase inhibitors (TKIs) are effective for treating human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer. However, therapies subsequent to TKI progression remain controversial, and effective treatments for TKI resistance are urgently needed. We evaluate the practice of exchange of TKIs, which involves treatment with a different TKI following prior TKI failure. Specifically, this study investigated the efficacy of pyrotinib-based therapy in lapatinib-resistant HER2-positive metastatic breast cancer (NCT04899128). Methods: This real-world study included 76 patients diagnosed with HER2-positive metastatic breast cancer who received pyrotinib-based therapy after lapatinib progression at four Chinese institutions between August 2018 and March 2020. Progression-free survival (PFS), overall survival (OS), objective response rate (ORR), clinical benefit rate (CBR), and toxicity profiles were reported. Results: All patients received pyrotinib-based therapy in two or later line therapy. The median PFS was 8.0 months (95% CI 5.1-10.9). OS has not reached. The ORR and CBR were 17.1% and 60.5%, respectively. The median PFS was 7.1 months (95% CI 5.633-8.567) and intracranial ORR was 42.9% in patients who had brain metastasis (n = 14). Patients who benefited from lapatinib ⩾ 6.0 months prior exhibited a longer PFS (10.6 versus 6.0 months, p = 0.034, stratified hazard ratio (HR) 0.534, 95% CI 0.293-0.975). The most common adverse effects were diarrhea (n = 34, 44.7%) and hand-foot syndrome (n = 10, 13.2%). Conclusion: Pyrotinib-based therapy has the potential to improve survival in patients with lapatinib-resistant HER2-positive metastatic breast cancer, including those with brain metastases. Pyrotinib could provide a clinically significant increase in PFS for patients who benefited from prior lapatinib.

17.
Mutat Res Rev Mutat Res ; 788: 108396, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34893161

RESUMO

Enzymatic methylation catalyzed by methyltransferases has a significant impact on many human biochemical reactions. As the second most ubiquitous cofactor in humans, S-adenosyl-l-methionine (SAM or AdoMet) serves as a methyl donor for SAM-dependent methyltransferases (MTases), which transfer a methyl group to a nucleophilic acceptor such as O, As, N, S, or C as the byproduct. SAM-dependent methyltransferases can be grouped into different types based on the substrates. Here we systematically reviewed eight types of methyltransferases associated with human diseases. Catechol O-methyltransferase (COMT), As(III) S-adenosylmethionine methyltransferase (AS3MT), indolethylamine N-methyltransferase (INMT), phenylethanolamine N-methyltransferase (PNMT), histamine N-methyltransferase (HNMT), nicotinamide N-methyltransferase (NNMT), thiopurine S-methyltransferase (TPMT) and DNA methyltansferase (DNMT) are classic SAM-dependent MTases. Correlations between genotypes and disease susceptibility can be partially explained by genetic polymorphisms. The physiological function, substrate specificity, genetic variants and disease susceptibility associated with these eight SAM-dependent methyltransferases are discussed in this review.


Assuntos
Erros Inatos do Metabolismo/genética , Metiltransferases/genética , Polimorfismo de Nucleotídeo Único , S-Adenosilmetionina/metabolismo , Animais , Humanos , Erros Inatos do Metabolismo/metabolismo , Metiltransferases/química , Metiltransferases/metabolismo
18.
Front Cell Dev Biol ; 9: 731062, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34790660

RESUMO

Breast cancer (BC) develops from breast tissue and is the most common aggressive malignant tumor in women worldwide. Although advanced treatment strategies have been applied and reduced current mortality rates, BC control remains unsatisfactory. It is essential to elucidate the underlying molecular mechanisms to assist clinical options. Exosomes are a type of extracellular vesicles and mediate cellular communications by delivering various biomolecules (oncogenes, oncomiRs, proteins, and even pharmacological compounds). These bioactive molecules can be transferred to change the transcriptome of target cells and influence tumor-related signaling pathways. Extensive studies have implicated exosomes in BC biology, including therapeutic resistance and the surrounding microenvironment. This review focuses on discussing the functions of exosomes in tumor treatment resistance, invasion and metastasis of BC. Moreover, we will also summarize multiple interactions between exosomes and the BC tumor microenvironment. Finally, we propose promising clinical applications of exosomes in BC.

19.
Cancer Med ; 10(23): 8662-8672, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34643330

RESUMO

BACKGROUND: With life span extending, breast cancer (BC) survivors may face the possibility of developing second primary cancer (SPC) and considerably shorten survivorship. However, little is known about multiple primary cancer (MPC) patients with nonmetastatic breast cancer as a first primary malignancy (BCFPM). METHODS: Here, we retrospectively analyzed data on cancer survivors with BCFPM diagnosed between 2010 and 2015 from the Surveillance, Epidemiology, and End Results (SEER) database. The prognostic factors for breast cancer-specific survival (BCSS) were ascertained by the stepwise regression analysis and a competing risk model, and were integrated to the establishment of prognostic nomogram, of which the accuracy was measured by the calibration curve and the concordance index (C-index). RESULTS: In total, 8616 patients were identified with 4.6% of 3-year breast cancer- specific death (BCSD) and 8.6% of 5-year BCSD. The most common SPC among BCFPM patients were female BC and lung cancer. Besides, the median latency time between BC and SPC was 22 months. At a ratio of 7:3, all patients were randomly categorized into a training cohort (n = 6032) and a validation cohort (n = 2584). By a proportional subdistribution hazards regression analysis, the following factors were considered to own independent prognostic abilities of BCSS: subtypes, grade, T classification, N classification, radiation, and sites of SPC. The nomogram could accurately predict 3-year and 5-year breast cancer-associated survival of BCFPM patients with high internal and external validated C-index, 0.715 (95% CI, 0.691-0.739), and 0.683 (95% CI, 0.642-0.724), respectively. CONCLUSIONS: BC survivors remained a high risk of developing SPC and considerably shortened survival time. In this study, a favorable nomogram was constructed to as a prediction model for 3-year and 5-year BCSS of BCFPM patients, largely intending to prolong the life of these patients by assisting clinicians to make individualized follow-up plans.


Assuntos
Neoplasias da Mama/patologia , Segunda Neoplasia Primária/epidemiologia , Adulto , China/epidemiologia , Feminino , Humanos , Pessoa de Meia-Idade , Nomogramas , Prognóstico , Estudos Retrospectivos , Análise de Sobrevida
20.
Ann Transl Med ; 9(15): 1229, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34532366

RESUMO

BACKGROUND: Poly (ADP-ribose) polymerase (PARP) inhibitors, which are among the most important breakthroughs in precision medicine, have played a crucial role in cancer treatment. Understanding the toxicity profiles of the different PARP inhibitors will improve strategic treatment in clinical practice. METHODS: PubMed, Cochrane Library, and Web of Science were systematically searched to include related studies published in English between January 2009 and February 2020. Only prospective, phase II and III randomized controlled trials were included. The following treatment groups were analyzed: niraparib, talazoparib, olaparib, rucaparib, conventional therapy (chemotherapy), one PARP inhibitor with one angiogenesis inhibitor, and placebo. Baseline data and adverse event data were extracted from the Bayesian random-effects network meta-analysis. RESULTS: Fourteen phase II and III randomized controlled trials (4,336 patients) were included. When considering grade 3-5 adverse events, olaparib may be a better choice (probability =57%), followed by conventional therapy (50%), talazoparib (45%), rucaparib (75%), niraparib (77%), and a PARP inhibitor with one angiogenesis inhibitor (94%). Niraparib and rucaparib had higher risks for hematological and gastrointestinal toxicities, respectively. Talazoparib was safer for gastrointestinal function. Constipation and neutropenia were less observed in olaparib, but the risks for anorexia increased. The combination of PARP inhibitor and angiogenesis inhibitor increased the risk of general, metabolic, and gastrointestinal disorders. CONCLUSIONS: This network meta-analysis suggested that the toxicity spectrum of each PARP inhibitor is different. Olaparib had the best safety profile among all PARP inhibitors because of its mild toxicity and narrow spectrum. This study may guide clinicians and support further research.

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