RESUMO
BACKGROUND: This study aimed to evaluate the feasibility of applying carbon nanoparticles (CNs) to visualize clip-marked metastatic nodes in combination with indocyanine green (ICG) and methylene blue (MB) as sentinel lymph node (SLN) tracers for targeted axillary dissection (TAD) after neoadjuvant therapy (NAT). METHODS: This feasibility trial enrolled 40 patients with node-positive breast cancer, and 38 patients completed NAT and surgery were included in the final analysis. Before NAT or surgery, clip-marked nodes were localized with CNs by ultrasonography. After NAT, the clip-marked nodes were removed under the guidance of carbon-tattooing and confirmed by radiography. SLNs were mapped with ICG and MB. Axillary lymph node dissection (ALND) was performed for all patients after TAD. RESULTS: The clip-marked nodes were retrieved in all patients. The SLN identification rate was 100%. 29 of 38 clipped-nodes were SLNs. The false-negative rate was 6.25% (2/32,95% CI:1.09% ~ 22.22%) for TAD nodes and 9.38% (3/32,95% CI 3.24%-24.22%) for SLNs, and 18.75% for clipped-nodes (6/32, 95% CI:7.86% ~ 37.04%). No adverse events were reported during clip placement, CNs localization, or the TAD procedure. CONCLUSIONS: The TAD procedure with CNs to locate and visualize clipped nodes as well as SLN tracing with ICG and MB has good accessibility in China, and this technique could be easily mastered by experienced surgeons. The modified TAD technique has also demonstrated good predictive ability for residual axillary lesions after NAT, and is worth of further evaluation.
Assuntos
Neoplasias da Mama , Nanopartículas , Humanos , Feminino , Biópsia de Linfonodo Sentinela/métodos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/cirurgia , Verde de Indocianina , Estudos Prospectivos , Azul de Metileno , Terapia Neoadjuvante/métodos , Estadiamento de Neoplasias , Linfonodos/patologia , Excisão de Linfonodo/métodos , Instrumentos Cirúrgicos , Axila/patologiaRESUMO
S-nitrosoglutathione reductase 1 (GSNOR1) is the key enzyme that regulates cellular homeostasis of S-nitrosylation. Although extensively studied in Arabidopsis, the roles of GSNOR1 in tetraploid Nicotiana species have not been investigated previously. To study the function of NtGSNOR1, we knocked out two NtGSNOR1 genes simultaneously in Nicotiana tabacum using clustered regularly interspaced short palindromic repeats (CRISPR)/caspase 9 (Cas9) technology. To our surprise, spontaneous cell death occurred on the leaves of the CRISPR/Cas9 lines but not on those of the wild-type (WT) plants, suggesting that NtGSNOR1 negatively regulates cell death. The natural cell death on the CRISPR/Cas9 lines could be a result from interactions between overaccumulated nitric oxide (NO) and hydrogen peroxide (H2O2). This spontaneous cell death phenotype was not affected by knocking out two Enhanced disease susceptibility 1 genes (NtEDS11a/1b) and thus was independent of the salicylic acid (SA) pathway. Unexpectedly, we found that the NtGSNOR1a/1b knockout plants displayed a significantly (p < 0.001) enhanced resistance to paraquat-induced cell death compared to WT plants, suggesting that NtGSNOR1 functions as a positive regulator of the paraquat-induced cell death. The increased resistance to the paraquat-induced cell death of the NtGSNOR1a/1b knockout plants was correlated with the reduced level of H2O2 accumulation. Interestingly, whereas the N gene-mediated resistance to Tobacco mosaic virus (TMV) was significantly enhanced (p < 0.001), the resistance to Pseudomonas syringae pv. tomato DC3000 was significantly reduced (p < 0.01) in the NtGSNOR1a/1b knockout lines. In summary, our results indicate that NtGSNOR1 functions as both positive and negative regulator of cell death under different conditions and displays distinct effects on resistance against viral and bacterial pathogens.